Limbic system

Part 2 of Rejuvenation therapy and sulforaphane

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A rejuvenation therapy and sulforaphane focused on the study’s clinical biomarkers and not its biological age measurements. This Part 2 curation of the study highlights its epigenetic clocks because:

“While clinical biomarkers have obvious advantages (being indicative of organ dysfunction or disease), they are neither sufficiently mechanistic nor proximal to fundamental mechanisms of aging to serve as indicators of them. It has long been recognized that epigenetic changes are one of several primary hallmarks of aging.

DNA methylation (DNAm) epigenetic clocks capture aspects of biological age. The discrepancy between DNAm age and chronological age (term as ‘epigenetic age acceleration’) is predictive of all-cause mortality. Pathologies and conditions that are associated with epigenetic age acceleration includes, but are not limited to, cognitive and physical functioning, centenarian status, Down syndrome, HIV infection, obesity, and early menopause.

The [new] human-rat clocks apply to both species. The two human-rat pan-tissue clocks are distinct, by way of measurement parameters. One estimates absolute age (in units of years), while the other estimates relative age, which is the ratio of chronological age to maximum lifespan; with values between 0 and 1. This ratio allows alignment and biologically meaningful comparison between species with very different lifespan (rat and human), which is not afforded by mere measurement of absolute age.

Relative age estimation was made using the formula: Relative age = Age / maxLifespan where the maximum lifespan for rats and humans were set to 3.8 years and 122.5 years, respectively.”

From Supplementary Table 3, old control and old treatment subjects were males 109 weeks old, 55% of their maximum lifespan (109 / 197.6). Young control subjects were males 30 weeks old, 15% of their maximum lifespan.

The money charts for this study’s human aging applications – measured by the new human-rat relative biological age clock – were buried in Supplementary Figure 12, bar plots M through P:

“Human-rat clock measure of relative age defined as age/maximum species lifespan. Each bar-plot reports the mean value and one standard error.”

From Supplementary Table 8, the percentages of rejuvenation for the above bar plots, calculated as “(100 * (1 – Old Treated / Old Control)” were:

  • “Blood 70.6%
  • Liver 79.4%
  • Heart 61.6%
  • Hypothalamus 20.9%”

Let’s return to clinical biomarkers for comparison purposes. The current study measured pro-inflammatory cytokine IL-6 blood plasma levels at every time point, but didn’t publish numbers. Bar plots and narrative were:

“Inflammation is an important response that helps protect the body, but excess inflammation especially in terms of duration of this response can have very detrimental effects instead. This occurs when inflammation fails to subside and persists indefinitely; a condition referred to as chronic inflammation, which for reasons not well-understood, increases with age and is associated with a multitude of conditions and pathologies.

The levels of two of the most reliable and common biomarkers of chronic inflammation, interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α), are found to be considerably higher in old rats, and these were very rapidly diminished, within days by plasma fraction treatment, to comparable levels with those of young rats. This was especially stark with IL-6.

In time, the levels of these inflammatory factors began to rise gradually, but they were once again very effectively reduced following the second administration of the plasma fraction on the 95th day.”

Let’s compare the above IL-6 graphic with IL-6 concentration improvements of our 2018 model clinical trial, Effects of long-term consumption of broccoli sprouts on inflammatory markers in overweight subjects, calculated as (100 * (1 – Day _ mean / Day 0 mean):

Mean pg/ml | % improvement | Period | Broccoli sprout consumption

  • 4.594 | 0% | Day 0 | “One week before the beginning of the intervention period, subjects were asked to avoid the consumption of Brassica vegetables (broccoli, radish, cauliflower, Brussel sprouts, mustards, among others) and their derived products.”
  • 1.748 | 62.0% | Day 0 to 70 | Subjects ate 30 g raw broccoli sprouts every day, and stopped eating them after Day 70.
  • 0.896 | 80.5% | Day 0 to 90 | “After the intervention period, a follow-up recovery period for all subjects continued for another 90 days with no ingestion of broccoli sprouts.”
  • 2.170 | 52.8% | Day 0 to 160 | Subjects had not eaten broccoli sprouts after Day 70.

Results between the studies were similar in that:

  1. IL-6 levels improved during early treatments through rat Day 8 and human Day 70, respectively.
  2. IL-6 levels continued decreasing shortly after treatments for 7 days (through rat Day 15) and 20 days (through human Day 90), respectively.
  3. IL-6 levels rose after rat Day 15 and human Day 90, respectively, but were still significantly below Day 0 values at rat Day 95 and human Day 160.

The current study measured Nrf2 but didn’t publish numbers. Bar plots and narrative were:

“The reduction of these inflammation markers is consistent with the profile of the nuclear factor erythroid 2-like 2 protein (Nrf2), which plays a major role in resolving inflammation, in part by inhibiting the expression of IL-6 and TNF-α. Nrf2 also induces the expression of antioxidants that neutralizes ROS [reactive oxygen species], which is also a significant feature in inflammation.”

A PubMed search on “nrf2 sulforaphane human” didn’t turn up relevant 2020 human in vivo studies. I disregarded reviews, cancer studies, disproven hypotheses, and other compounds listed in the below graphic.

I won’t repeat the entire Nrf2 section from the Part 1 curation, just one graphic and paragraph:

It [sulforaphane] is not only a potent Nrf2 inducer but also highly bioavailable [around 80%], so that modest practical doses can produce significant clinical responses. Other Nrf2 activators [shown in the above image] not only lack potency but also lack the bioavailability to be considered as significant intracellular Nrf2 activators.”

As noted in Reviewing clinical trials of broccoli sprouts and their compounds, there are no sulforaphane clinical trials that also use epigenetic clocks. Broccoli sprouts and their compounds’ effects on human aging is an area that hasn’t drawn attention and funding.

What effects may broccoli sprout compounds have on human aging? With this new human-rat relative biological age clock, researchers can get reliable answers from rat studies, with human clinical trials needed only to confirm those findings!

As rejuvenation research continues, what could people do easily, cheaply, and today for our long-term selves? Don’t know about the hypothalamus, but our blood, liver, and heart biological ages may decrease as we reduce inflammation and oxidative stress by eating broccoli sprouts.

I’m at a similar percentage of species maximum lifespan as were the study’s treated subjects. It’s my choice as to what my healthspan will be.

There isn’t evidence today to definitively say that changing my inflammatory phenotype with broccoli sprouts has had / will have rejuvenation effects on biological ages of my cells, organs, and body. But if eating broccoli sprouts every day not only reduces chronic inflammation and oxidative stress as expected, but also makes me younger, I could probably learn to live with that. 🙂

Continued with Part 3 of Rejuvenation therapy and sulforaphane.

An environmental signaling paradigm of aging

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To follow up A rejuvenation therapy and sulforaphane, the study’s lead laboratory researcher – Dr. Harold Katcher – provided evidence for an environmental signaling paradigm of aging in this 2015 paper:

“The age-phenotype of a cell or organ depends on its environment and not its history.

Organ dysfunction is not the cause of aging, but is the result of its milieu. Therefore, the aged milieu is the cause. Though it has been thought that the aging immune system is the cause of aging, it can seen to be the result of aging.

The systemic milieu of an organism sets the age-phenotype of its cells, tissues and organs. Cells and organs secrete factors into blood, which are determined by the age-phenotype and repair-states of those cells and organs. The presence and concentrations of these blood-borne factors determine the age-phenotype of cells and organs.

Here we must be a bit more speculative. Changes in concentrations of factors present in blood, rather than their presence or absence, determines age-phenotype.

Interactions between disparate levels of the body’s hierarchy establish a consensus age-phenotype for cells and organs, and this largely occurs via the bloodstream. There appear to be positive factors that promote youthful age-phenotypes and negative factors that promote the aged phenotypes.

We readily consider development as a ‘program’, and it seems clear that we must consider post-adult development as ‘programmed’ as well. But if there is a program it is neither in genes nor chromatin, but in interaction of complex, interconnected systems spanning hierarchical levels.

If these aforementioned principles are correct, it should be easy to verify. If so, whole organism rejuvenation might require little more than:

  • Changing concentrations of all age-determining molecules of the bloodstream and various stem cell niche environments to youthful levels;
  • For a time sufficient to cause rejuvenation at the cellular level.

Once cells start secreting factors appropriate to their new, younger age-phenotypes, cognate changes should propagate through hierarchical levels.

The analogy to workings of a mechanical clock is not very exact. ‘Gears’ represent individual aging clocks, both cellular and organic (shown at different levels within the mechanism) which interact, ultimately resulting in organismic age, i.e. ‘body clock’, represented by the ‘hour hand’ (no minute hand is shown).

In mammals, readout of the clock corresponds to age-related composition of blood plasma. In this model, moving the hour hand backwards should result in a turning back of composite clocks as well – a result obtained when induction to pluripotence is used to reset cellular clocks.

Apart from being slowed down or sped up, the body clock can also be reset. Organisms, organs, and their cells can be reset to different age-phenotypes depending on their environment.

We know that old transplanted tissues and organs can regain function and live for the entire life of the younger host at least in rodents. We must suppose that age-phenotype changes must have taken place at the cellular level to allow this.

Rejuvenation cannot be explained on the basis that aging represents accumulation of irreparable cellular damage.

None of these principles are rigorously established as such, but all are supported by experimental evidence.”

http://www.eurekaselect.com/130538/article “Towards an Evidence-based Model of Aging”

Here are some of his responses to comments on the blog post that first curated his current research:

“We’ve (scientists), spent the past 70 years trying to definitively prove the commonsense ‘wear and tear’ theories and have not succeeded. So I tried something different, looking at results of experiments.

This is not based on ‘theory’ (say mitochondrial aging or ‘wear and tear’) but on experimental evidence. Theory comes in explaining our results, not achieving them. There is a theory becoming clear, one very different from the commonsense view of ‘wear and tear’ aging.

We haven’t examined immune response. All that we know for sure is that chronic inflammation of aging stopped. I can definitively say that chronic inflammation due to aging can be reversed with factors present in young blood.

There are amazing things that Big Pharma won’t touch as there’s not enough profit in them (they can’t be patented). So I guess we’re somewhat the same, but we know what to do and have proven it – for us, it’s not money. However, money allows you to do things.

Being 75 myself puts a time-frame around the project. We plan to propose its use for diseases of aging – eventually, everyone will use it. It will end up changing humanity. As people already seem to have too much free time to begin with, what will people do with those extra years they will be given?”

Sections 3 “Aging Manifestations that Have Hitherto Been Proposed as the Causes of Aging are the Consequences of Aging” and 10 “Several Factors ‘Conspire’ to Promote Inflammation in Old Mammalian Bodies, Inflammation Leads to Several Diseases of Aging and Perhaps to Aging Itself” were especially informative.

The former section discussed cells that were capable of making repairs but didn’t make repairs, with aging being the consequence of this behavior. The latter reviewed topics such as senescence, IL-6, NF-κB, and C-reactive protein in terms of feedback loops.

See Reevaluate findings in another paradigm for comparisons of Section 6 with another view of hypothalamic aging.

A rejuvenation therapy and sulforaphane

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The founder of the epigenetic clock methodology with the coauthor of Aging as an unintended consequence released a 2020 rodent study “Reversing age: dual species measurement of epigenetic age with a single clock” at https://www.biorxiv.org/content/10.1101/2020.05.07.082917v1.full.pdf:

“We employed six clocks to investigate the rejuvenation effects of a plasma fraction treatment in different rat tissues. Two of these epigenetic clocks apply to both humans and rats.

The treatment more than halved the epigenetic ages of blood, heart, and liver tissue. A less pronounced, but statistically significant, rejuvenation effect could be observed in the hypothalamus.

The treatment was accompanied by progressive improvement in the function of these organs as ascertained through numerous biochemical/physiological biomarkers and behavioral responses to assess cognitive functions. Cellular senescence, which is not associated with epigenetic aging, was also considerably reduced in vital organs.

Plasma fraction treatment consists of two series of intravenous injections of plasma fraction. Rats were injected four times on alternate days for 8 days. A second identical series of injections were administered 95 days later. In its entirety, the experiment lasted 155 days.

Overall, this study demonstrates that a plasma-derived treatment markedly reverses aging according to epigenetic clocks and benchmark biomarkers of aging.”

The study hasn’t been peer reviewed, so can’t be viewed yet as conclusive. Given that researchers’ single-most valuable asset is their reputations, though, will the findings have major revisions?

I was alerted to the study by Josh Mitteldorf’s blog post Age Reduction Breakthrough, who did his usual excellent curation:

“Most of the explosion in aging research (and virtually all the venture capital startups) are looking to treat aging at the cellular level. Their paradigm is that aging is an accumulation of molecular damage, and they see their job as engineering of appropriate repair mechanisms.

The truth, as Katcher [the lead lab researcher] understands it, is that, to a large extent, aging is coordinated system-wide via signal molecules in the blood. The problem is that there are thousands of constituents represented in tiny concentrations in blood plasma, but conveying messages that cells read. Which of these are responsible for aging?

The two-species clock[s] was [were] a significant innovation, a first bridge for translating results from an animal model into their probable equivalent in humans. Besides the methylation clock[s], the paper presents evidence of rejuvenation by many other measures. For example:

  • IL-6, a marker of inflammation, was restored to low youthful levels;
  • Glutathione (GSH), superoxide dismutase (SOD), and other antioxidants were restored to higher youthful levels;
  • In tests of cognitive function (Barnes maze), treated rats scored better than old rats, but not as well as young rats.;
  • Blood triglycerides were brought down to youthful levels;
  • HDL cholesterol rose to youthful levels; and
  • Blood glucose fell toward youthful levels.

These results bring together three threads that have been gaining credibility over the last decade. Mutually reinforcing, the three have a strength that none of them could offer separately.

  1. The root cause of aging is epigenetic progression = changes in gene expression over a lifetime.
  2. Methylation patterns in nuclear DNA are not merely a marker of aging, but its primary source. Thus aging can be reversed by reprogramming DNA methylation.
  3. Information about the body’s age state is transmitted system-wide via signal molecules in the blood. Locally, tissues respond to these signals and adopt a young or an old cellular phenotype as they are directed.”

Several of these aging measurements are also positively affected by sulforaphane. Using Sulforaphane: Its “Coming of Age” as a Clinically Relevant Nutraceutical in the Prevention and Treatment of Chronic Disease as a reference:

1. “Chronic inflammation”

“Antioxidants in general and glutathione in particular can be depleted rapidly under conditions of oxidative stress, and this can signal inflammatory pathways associated with NF-κB. SFN [sulforaphane] has been shown to inhibit NF-κB in endothelial cells.

Two key inflammatory cytokines were measured at four time points in forty healthy overweight people [our model clinical trial, Effects of long-term consumption of broccoli sprouts on inflammatory markers in overweight subjects]. The levels of both interleukin-6 (Il-6) and C-reactive protein (CRP) declined over the 70 days during which the sprouts were ingested. These biomarkers were measured again at day 90, wherein it was found that Il-6 continued to decline, whereas CRP climbed again. When the final measurement was taken at day 160, CRP, although climbing, had not returned to its baseline value. Il-6 remained significantly below the baseline level at day 160.”

OMCL2019-2716870.010

2. “Oxidative stress”

“As a mediator for amplification of the mammalian defence system against various stressors, Nrf2 [nuclear factor erythroid 2-related factor 2] sits at the interface between our prior understanding of oxidative stress and the endogenous mechanisms cells use to deal with it. Diseases known to be underpinned by oxidative stress are proving to be more responsive to amplification of cellular defences via Nrf2 activation than by administration of direct-acting antioxidant supplements.

SFN, with absolute bioavailability of around 80%, [is] capable of increasing several endogenous antioxidant compounds via the transcription factor, Nrf2.

Nrf2 is ubiquitously expressed with the highest concentrations (in descending order) in the kidney, muscle, lung, heart, liver, and brain. Nrf2 was shown to prevent endothelial cells from exhibiting a proinflammatory state. Nrf2 is required for protection against glucose-induced oxidative stress and cardiomyopathy in the heart.

Well in excess of 500 genes have been identified as being activated by SFN via the Nrf2/ARE [Antioxidant Response Element] pathway, and it is likely that this underestimates the number as others are being discovered. Of the available SFN clinical trials associated with genes induced via Nrf2 activation, many demonstrate a linear dose-response. More recently, it has become apparent that SFN can behave hormetically with different effects responsive to different doses.

It [sulforaphane] is not only a potent Nrf2 inducer but also highly bioavailable so that modest practical doses can produce significant clinical responses. Other Nrf2 activators [shown in the above image] not only lack potency but also lack the bioavailability to be considered as significant intracellular Nrf2 activators.”

The study’s most relentlessly questioned, scrutinized, and criticized findings may be the two new epigenetic clocks that apply to both humans and rats. The researchers invited other researchers to validate these clocks because:

“If validated, this would be a step change in aging research. Although conservation of aging mechanism could be equally deduced from the existence of multiple individual clocks for other mammals (mouse, dog), the single formula of the human-rat clock that is equally applicable to both species effectively demonstrates this fact.”

The commonalities of this study with efforts to change my inflammatory phenotype with broccoli sprouts were summarized in the Discussion section:

“Apart from rejuvenating the vital organs of the treated rats, plasma fraction also impacted two fundamental physiological processes that underlie a great number of pathologies, namely oxidative stress and inflammation. Within a week of treatment, the markers of chronic inflammation (IL-6 and TNF-α) were significantly reduced and remained low throughout the entire experiment.

Likewise, markers of oxidative stress in brain, heart, lung and liver, which were very much higher in control old rats, were at the end of the experimental period, indistinguishable between plasma fraction-treated old rats and young ones. Concomitant with this drastic reduction in oxidative stress was the augmented levels of antioxidants (GSH, Catalase and SOD) in these tissues, indicating that modulating the levels of ROS [reactive oxygen species] to that of youthful rats is at least one way by which plasma fraction suppresses oxidative stress. It remains to be ascertained whether the rate of ROS generation is also reduced.

The levels of Nrf2, a transcription factor that impacts on oxidative stress, as well as inflammation, were raised by plasma fraction treatment of old rats to those of the young ones, indicating yet another level by which this treatment modulates these two critical processes. Collectively, these results show that plasma fraction treatment impacts not only the overt performances of organs, but also the underlying physiological processes that are pivotal for optimal organ function and health.”

Great stuff, huh? Are you ready to change your phenotype?

Continued with Part 2 of Rejuvenation therapy and sulforaphane.

We believe what we need to believe

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While getting ready for bed tonight, I mused about how my younger brother had such an idealized postmortem view of our father. As he expressed six years ago in an obituary for our high school Literature teacher:

“I’ll remember my favorite teacher and how much he’s meant to my life. My father and Martin Obrentz were the two people who made me care about the things that make me the person I am today.”

Believe what you need to believe, David. But like I said five years ago in Reflections on my four-year anniversary of spine surgery:

“I don’t remember that my three siblings ever received a paddling or belting, although they were spanked. Even before he retired, 17 years before he died, the Miami-Dade County public school system stopped him and the rest of their employees from spanking, whipping, beating, and paddling children.”

It’s extremely important for a child to have a witness to their adverse childhood experiences. Otherwise, it’s crazy-making when these experiences aren’t acknowledged as truths by anyone else.

Especially by those who saw but disavow what they saw.

It didn’t really drum into my conscious awareness until tonight that I had such a witness. It wasn’t my mother, of course, since she directed most of my being whipped with a belt, and beaten with a paddle that had holes in it to produce welts. She has denied and deflected my childhood experiences of her ever since then.

It wasn’t my siblings, regrettably for all of us. It wasn’t our Miami neighbors.

When I was twenty, I ran across a guy 300 miles north in Gainesville, Florida, named David Eisenberg, if I remember correctly. A couple of weeks after we met, he asked if my father was Fred Rice, Dean of Boys, West Miami Junior High School. He said he had been beaten by my father several times!

Those weren’t early childhood memories like mine. Those were experiences of a young man during grades 7-9 that he remembered more than a decade later.

I was shocked. It came at a time when I wasn’t ready to face facts about my life, though. I needed fantasies, beliefs to smother what I felt.

I don’t expect that the impacts of my childhood experiences will ever go away. After three years of Primal Therapy that ended a decade ago, at least mine don’t completely control my life anymore.

Dr. Arthur Janov put self-narratives of several patients’ experiences into his May 2016 book Beyond Belief which I partially curated in February 2017. It was partial because I couldn’t read much past Frank’s horrendous story in pages 89 – 105, “The Myth of a Happy Childhood.”

Aging as an unintended consequence

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The coauthors of 2018’s The epigenetic clock theory of aging reviewed progress that’s been made todate in understanding epigenetic clock mechanisms.

1. Proven DNA methylation features of epigenetic clocks:

  1. “Methylation of cytosines is undoubtedly a binary event.
  2. The increase in epigenetic age is contributed by changes of methylation profiles in a very small percent of cells in a population.
  3. The clock ticks extremely fast in early post-natal years and much slower after puberty.
  4. Clock CpGs have specific locations in the genome.
  5. It applies to prenatal biological samples and embryonic stem cells.

While consistency with all the five attributes does not guarantee veracity of a model, inconsistency with any one will signal the unlikely validity of a hypothesis.”

2. Regarding what epigenetic clocks don’t measure:

“The effects of

  • Telomere maintenance,
  • Cellular senescence,
  • DNA damage signaling,
  • Terminal differentiation and
  • Cellular proliferation

have all been tested and found to be unrelated to epigenetic ageing.”

3. Regarding cyclical features:

“Both the epigenetic and circadian clocks are present in all cells of the body, but their ticking rates are regulated. Both these clocks lose synchronicity when cells are isolated from tissues and grown in vitro.

These similarities compel one to ponder potential links between them.”

This was among the points that Linear thinking about biological age clocks missed.

4. The reviewers discussed 3 of the 5 treatment elements in Reversal of aging and immunosenescent trends:

“It is not known at this stage whether the rejuvenating effect is mediated through the regeneration of the thymus or a direct effect of the treatment modality on the body. Also, it is not known if the effect is mediated by all three compounds or one or two of them.

What we know at this stage does not allow the formation of general principles regarding the impact of hormones on epigenetic age, but their involvement in development and maintenance of the body argue that they do indeed have a very significant impact on the epigenetic clock.”

Not sure why they omitted 3000 IU vitamin D and 50 mg zinc, especially since:

“It is not known if the effect is mediated by all three [five] compounds or one or two of them.”

5. They touched on the specialty of Aging as a disease researchers with:

“Muscle stem cells isolated from mice were epigenetically much younger independently of the ages of the tissue / animal from which they were derived.

The proliferation and differentiation of muscle stem cells cease upon physical maturation. These activities are initiated in adult muscles only in response to injury.“

6. The reviewers agreed with those researchers in the Conclusion:

“Epigenetic ageing begins from very early moments after the embryonic stem cell stage and continues uninterrupted through the entire lifespan. The significance of this is profound as the question of why we age has been attributed to many different things, most commonly to ‘wear-and-tear.’

The ticking of the epigenetic clock from the embryonic state challenges this perspective and supports the notion that ageing is an unintended consequence of processes that are necessary for

  • The development of the organism and
  • Tissue homeostasis thereafter.”


https://journals.sagepub.com/doi/10.1177/1535370220918329 “Current perspectives on the cellular and molecular features of epigenetic ageing” (not freely available)

Broccoli sprouts oppose effects of advanced glycation end products (AGEs)

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This 2020 Australian/UK review subject was AGEs:

“AGEs are formed during cooking and food processing or produced endogenously as a consequence of metabolism. Deleterious effects of AGEs are underpinned by their ability to trigger mechanisms well known to elicit metabolic dysfunction, including activation of inflammatory pathways, oxidative stress and impaired mitochondrial oxidative metabolism. They have been widely implicated in complications of diabetes affecting cardiovascular health, the nervous system, eyes and kidneys.

Reactive carbonyl groups are constantly being produced via normal metabolism and when production overrides detoxification, AGEs accumulate. AGE formation may take several days or weeks to complete in the body.

Factors affecting AGE content of food depends on composition of protein, fat, and sugar and types of processing and cooking methods employed, predominantly on temperature and duration of preparation. Circulating free-AGEs concentrations are a good marker for dietary AGE intake while plasma protein-bound AGEs better represent endogenously produced AGEs.

Receptor for Advanced glycation end products (RAGE) signals via transcription factor NF-kB increasing gene expression of inflammatory mediators and production of ROS (reactive oxygen species).”

https://onlinelibrary.wiley.com/doi/abs/10.1002/mnfr.201900934 “The Role of Dietary Advanced Glycation End Products (AGEs) in Metabolic Dysfunction” (not freely available)

Let’s use the Australian 2019 Sulforaphane: Its “Coming of Age” as a Clinically Relevant Nutraceutical in the Prevention and Treatment of Chronic Disease as a reference for how sulforaphane may counter effects of AGEs:

1. “Activation of inflammatory pathways”

“Antioxidants in general and glutathione in particular can be depleted rapidly under conditions of oxidative stress, and this can signal inflammatory pathways associated with NF-κB. SFN [sulforaphane] has been shown to inhibit NF-κB in endothelial cells.

Two key inflammatory cytokines were measured at four time points in forty healthy overweight people [our model clinical trial, Effects of long-term consumption of broccoli sprouts on inflammatory markers in overweight subjects]. Levels of both interleukin-6 (Il-6) and C-reactive protein (CRP) declined over the 70 days during which sprouts were ingested. These biomarkers were measured again at day 90, wherein it was found that Il-6 continued to decline, whereas CRP climbed again. When the final measurement was taken at day 160, CRP, although climbing, had not returned to its baseline value. Il-6 remained significantly below the baseline level at day 160.”

OMCL2019-2716870.010

2. “When production overrides detoxification”

“SFN significantly activates Nrf2 and as such has the potential to modulate the expression of genes associated with redox balance, inflammation, detoxification, and antimicrobial capacity, all key components of the upstream cellular defence processes.

Toxins presented to Phase 1 enzymes produce intermediate compounds which are sometimes more toxic to cells than the initial toxin. It is therefore important that Phase 2 is sufficiently active that intermediate products cannot accumulate in the cellular environment.

As a monofunctional inducer, SFN has been described as an ideal detoxifier, as its effect on Phase 1 is minimal compared with its significant activity on Phase 2.”

3. “Oxidative stress”

“As a mediator for amplification of the mammalian defence system against various stressors, Nrf2 sits at the interface between our prior understanding of oxidative stress and endogenous mechanisms cells use to deal with it. Diseases known to be underpinned by oxidative stress are proving to be more responsive to amplification of cellular defences via Nrf2 activation than by administration of direct-acting antioxidant supplements.

SFN, with absolute bioavailability of around 80%, is capable of increasing several endogenous antioxidant compounds via transcription factor Nrf2.”

4. “Complications of diabetes affecting cardiovascular health, the nervous system, eyes and kidneys”

“Nrf2 is ubiquitously expressed with highest concentrations (in descending order) in the kidney, muscle, lung, heart, liver, and brain. Nrf2 was shown to prevent endothelial cells from exhibiting a proinflammatory state. Nrf2 is required for protection against glucose-induced oxidative stress and cardiomyopathy in the heart.

Well in excess of 500 genes have been identified as being activated by SFN via the Nrf2/ARE [Antioxidant Response Element] pathway, and it is likely that this underestimates the number as others are being discovered. Of available SFN clinical trials associated with genes induced via Nrf2 activation, many demonstrate a linear dose-response. More recently, it has become apparent that SFN can behave hormetically with different effects responsive to different doses.

It [sulforaphane] is not only a potent Nrf2 inducer but also highly bioavailable so that modest practical doses can produce significant clinical responses. Other Nrf2 activators [shown in the above image] not only lack potency but also lack the bioavailability to be considered as significant intracellular Nrf2 activators.”

As mentioned in Changing an inflammatory phenotype with broccoli sprouts, per the above bolded part of section 3, I stopped taking N-acetyl-cysteine, the precursor to our endogenous antioxidant glutathione. I stopped taking curcumin last year due to no noticeable effects, probably because of its poor bioavailability. I may soon stop taking more vitamin E than the RDA, and β-carotene.

I changed my diet last summer to reduce AGEs, with mild effects. I expect stronger effects from also daily eating 60 grams of 3-day-old broccoli sprouts that yield 27 mg of sulforaphane after microwaving.

Forcing people to learn helplessness

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Learned helplessness is a proven animal model. Its reliably-created phenotype is often the result of applying chronic unpredictable stress.

As we’re finding out worldwide, forcing humans to learn helplessness works in much the same way, with governments imposing what amounts to martial law. Never mind that related phenotypes and symptoms include:

  • “Social defeat
  • Social avoidance behavior
  • Irritable bowel syndrome
  • Depression
  • Anxiety
  • Anhedonia
  • Increased hypothalamic-pituitary-adrenal (HPA)-axis sensitivity
  • Visceral hypersensitivity” [1]

Helplessness is both a learned behavior and a cumulative set of experiences. Animal models demonstrate that these phenotypes usually continue on throughout the subjects’ entire lifespans.

Will the problems caused in humans by humans be treated by removing the causes? Or will the responses be approaches such as drugs to treat the symptoms?

A major difference between our current situation and the situation depicted below is that during communism, most people didn’t really trust or believe what the authorities, newspapers, television, and radio said:

Image from Prague’s Memorial to the Victims of Communism

[1] 2014 GABAB(1) receptor subunit isoforms differentially regulate stress resilience curated in If research provides evidence for the causes of stress-related disorders, why only focus on treating the symptoms?

Flatten the Panic Curve April 13-17, 2020

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To better understand our internal origins of panic, here’s Dr. Arthur Janov’s interpretation of a 2013 Iowa study Fear and panic in humans with bilateral amygdala damage (not freely available):

“Justin Feinstein did a study with those who had a damaged amygdala, the hub of the emotional system. They did not have normal fear responses. But if oxygen supplies were lowered and carbon dioxide supplies were increased, mimicking suffocation (increasing acidity of the blood) there were panic attacks.

Where in the world did those attacks come from? Certainly not from the usual emotional structures.

They believe it includes the brainstem! Because the lowering of oxygen supplies and adding carbon dioxide provoked the lower structures to sense the danger and reacted appropriately.

Very much like what happens to a fetus when the mother smokes during pregnancy and produces those same effects.”

Since those of us who chronically experience panic aren’t going into therapy over this weekend, what else can we do?

1. Stop looking at the John Hopkins Panic map.

2. Search out realistic news such as: “Change in [New York state] ICU admissions is actually a negative number for the first time since we started this intense journey.”

3. Stop clicking sensational headline links.

4. Question your information, and investigate multiple views. Trust has been lost:

  • Dr. Scott Jensen, a Minnesota physician for 35 years and state senator, on the inappropriate CDC / WHO guidelines for reporting COVID-19 deaths:

    “It’s ridiculous. The determination of cause of death is a big deal. The idea that we’re going to allow people to massage and game the numbers is a real issue because we’re going to undermine trust.

    I would never put down influenza as the cause of death. Yet that’s what we’re being asked to do here.”

  • The same day, Dr. Fauci arrogantly grouped physicians in with conspiracy theorists if they didn’t conform to these bordering-on-fraudulent CDC / WHO guidelines:

    “Every time we have a crisis of any sort, there’s always this popping-up of conspiracy theories. I think the deaths that we’re seeing are coronavirus deaths, and the other deaths are not being counted as coronavirus deaths.”

    Telling people to trust him – a bureaucrat who hasn’t been in active practice for over three decades – because he had far superior medical judgment than did practicing doctors who for years continuously see patients?

  • Consider the evidence.
  • Don’t accept lies you feel uneasy about. Trust your internal BS detector.

Which herd will you choose to belong to?

https://nypost.com/video/bison-stampede-terrorizes-family-trapped-in-car/

or

The epigenetics of perinatal stress

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This 2019 McGill review discussed long-lasting effects of perinatal stress:

“Epigenetic processes are involved in embedding the impact of early-life experience in the genome and mediating between social environments and later behavioral phenotypes. Since these phenotypes are apparent a long time after early experience, changes in gene expression programming must be stable.

Although loss of methylation in a promoter is necessary for expression, it is not sufficient. Demethylation removes a barrier for expression, but expression might be realized at the right time or context when needed factors or signals are present.

DNA methylation anticipates future transcriptional response to triggers. Comparing steady-state expression with DNA methylation does not capture the full meaning and scope of regulatory roles of differential methylation.

A model for epigenetic programming by early life stress:

  1. Perinatal stress perceived by the brain triggers release of glucocorticoids (GC) from the adrenal in the mother prenatally or the newborn postnatally.
  2. GC activate nuclear glucocorticoid receptors across the body, which epigenetically program (demethylate) genes that are targets of GR in brain and white blood cells (WBC).
  3. Demethylation events are insufficient for activation of these genes. A brain specific factor (TF) is required for expression and will activate low expression of the gene in the brain but not in blood.
  4. During adulthood a stressful event transiently triggers a very high level of expression of the GR regulated gene specifically in the brain.

Horizontal arrow, transcription; circles, CpG sites; CH3 in circles, methylated sites; empty circles, unmethylated CpG sites; horizon[t]al curved lines, mRNA.”

Review points discussed:

  • “Epigenetic marks are laid down and maintained by enzymes that either add or remove epigenetic modifications and are therefore potentially reversible in contrast to genetic changes.
  • Response to early life stress and maternal behavior is also not limited to the brain and involves at least the immune system as well.
  • The placenta is also impacted by maternal social experience and early life stress.
  • Most studies are limited to peripheral tissues such as saliva and white blood cells, and relevance to brain physiology and pathology is uncertain.
  • Low absolute differences in methylation seen in most human behavioral EWAS raise questions about their biological significance.

  • Although post-mortem studies examine epigenetic programming in physiologically relevant tissues, they represent only a final and single stage that does not capture dynamic evolution of environments and epigenetic programming in living humans.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6952743/ “The epigenetics of perinatal stress”

Other reviewers try to ignore times when we were all fetuses and newborns. For example, in the same journal issue was a Boston review of PTSD that didn’t mention anything about earliest times of human lives! Those reviewers speculated around this obvious gap on their way to being paid by NIH.

Why would researchers ignore perinatal stress events that prime humans for later-life PTSD? Stress generally has a greater impact on fetuses and newborns than on infants, and a greater impact on infants than on adults.

Clearing out the 2019 queue of interesting papers

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I’m clearing out the below queue of 27 studies and reviews I’ve partially read this year but haven’t taken the time to curate. I have a pesky full-time job that demands my presence elsewhere during the day. :-\

Should I add any of these back in? Let’s be ready for the next decade!

Early life

https://link.springer.com/article/10.1007/s12035-018-1328-x “Early Behavioral Alterations and Increased Expression of Endogenous Retroviruses Are Inherited Across Generations in Mice Prenatally Exposed to Valproic Acid” (not freely available)

https://www.sciencedirect.com/science/article/pii/S0166432818309392 “Consolidation of an aversive taste memory requires two rounds of transcriptional and epigenetic regulation in the insular cortex” (not freely available)

https://www.nature.com/articles/s41380-018-0265-4 “Intergenerational transmission of depression: clinical observations and molecular mechanisms” (not freely available)

mother

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6454089/ “Epigenomics and Transcriptomics in the Prediction and Diagnosis of Childhood Asthma: Are We There Yet?”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6628997/ “Placental epigenetic clocks: estimating gestational age using placental DNA methylation levels”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6770436/ “Mismatched Prenatal and Postnatal Maternal Depressive Symptoms and Child Behaviours: A Sex-Dependent Role for NR3C1 DNA Methylation in the Wirral Child Health and Development Study”

https://www.sciencedirect.com/science/article/pii/S0889159119306440 “Environmental influences on placental programming and offspring outcomes following maternal immune activation”

https://academic.oup.com/mutage/article-abstract/34/4/315/5581970 “5-Hydroxymethylcytosine in cord blood and associations of DNA methylation with sex in newborns” (not freely available)

https://physoc.onlinelibrary.wiley.com/doi/full/10.1113/JP278270 “Paternal diet impairs F1 and F2 offspring vascular function through sperm and seminal plasma specific mechanisms in mice”

https://onlinelibrary.wiley.com/doi/full/10.1111/nmo.13751 “Sex differences in the epigenetic regulation of chronic visceral pain following unpredictable early life stress” (not freely available)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6811979/ “Genome-wide DNA methylation data from adult brain following prenatal immune activation and dietary intervention”

https://link.springer.com/article/10.1007/s00702-019-02048-2 “miRNAs in depression vulnerability and resilience: novel targets for preventive strategies”

Later life

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6543991/ “Effect of Flywheel Resistance Training on Balance Performance in Older Adults. A Randomized Controlled Trial”

https://www.mdpi.com/2411-5142/4/3/61/htm “Eccentric Overload Flywheel Training in Older Adults”

https://www.nature.com/articles/s41577-019-0151-6 “Epigenetic regulation of the innate immune response to infection” (not freely available)

https://link.springer.com/chapter/10.1007/978-981-13-6123-4_1 “Hair Cell Regeneration” (not freely available)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422915/ “Histone Modifications as an Intersection Between Diet and Longevity”

https://www.sciencedirect.com/science/article/abs/pii/S0306453019300733 “Serotonin transporter gene methylation predicts long-term cortisol concentrations in hair” (not freely available)

https://www.sciencedirect.com/science/article/abs/pii/S0047637419300338 “Frailty biomarkers in humans and rodents: Current approaches and future advances” (not freely available)

https://onlinelibrary.wiley.com/doi/full/10.1111/pcn.12901 “Neural mechanisms underlying adaptive and maladaptive consequences of stress: Roles of dopaminergic and inflammatory responses”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6627480/ “In Search of Panacea—Review of Recent Studies Concerning Nature-Derived Anticancer Agents”

https://www.sciencedirect.com/science/article/abs/pii/S0028390819303363 “Reversal of oxycodone conditioned place preference by oxytocin: Promoting global DNA methylation in the hippocampus” (not freely available)

https://www.futuremedicine.com/doi/10.2217/epi-2019-0102 “Different epigenetic clocks reflect distinct pathophysiological features of multiple sclerosis”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6834159/ “The Beige Adipocyte as a Therapy for Metabolic Diseases”

https://www.sciencedirect.com/science/article/abs/pii/S8756328219304077 “Bone adaptation: safety factors and load predictability in shaping skeletal form” (not freely available)

https://www.nature.com/articles/s41380-019-0549-3 “Successful treatment of post-traumatic stress disorder reverses DNA methylation marks” (not freely available)

https://www.sciencedirect.com/science/article/abs/pii/S0166223619301821 “Editing the Epigenome to Tackle Brain Disorders” (not freely available)

Using oxytocin receptor gene methylation to pursue an agenda

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A pair of 2019 Virginia studies involved human mother/infant subjects:

“We show that OXTRm [oxytocin receptor gene DNA methylation] in infancy and its change is predicted by maternal engagement and reflective of behavioral temperament.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6795517 “Epigenetic dynamics in infancy and the impact of maternal engagement”

“Infants with higher OXTRm show enhanced responses to anger and fear and attenuated responses to happiness in right inferior frontal cortex, a region implicated in emotion processing through action-perception coupling.

Infant fNIRS [functional near-infrared spectroscopy] is limited to measuring responses from cerebral cortex. It is unknown whether OXTR is expressed in the cerebral cortex during prenatal and early postnatal human brain development.”

https://www.sciencedirect.com/science/article/pii/S187892931830207X “Epigenetic modification of the oxytocin receptor gene is associated with emotion processing in the infant brain”

Both studies had weak disclosures of limitations on their findings’ relevance and significance. The largest non-disclosed contrary finding was from the 2015 Early-life epigenetic regulation of the oxytocin receptor gene:

These results suggest that:

  • Blood Oxtr DNA methylation may reflect early experience of maternal care, and
  • Oxtr methylation across tissues is highly concordant for specific CpGs, but
  • Inferences across tissues are not supported for individual variation in Oxtr methylation.

That rat study found that blood OXTR methylation of 25 CpG sites couldn’t accurately predict the same 25 CpG sites’ OXTR methylation in each subject’s hippocampus, hypothalamus, and striatum (which includes the nucleus accumbens) brain areas. Without significant effects in these limbic system structures, there couldn’t be any associated behavioral effects.

But CpG site associations and correlations were deemed good in the two current studies because they cited:

“Recent work in prairie voles has found that both brain- and blood-derived OXTRm levels at these sites are negatively associated with gene expression in the brain and highly correlated with each other.”

https://www.sciencedirect.com/science/article/pii/S0306453018306103 “Early nurture epigenetically tunes the oxytocin receptor”

The 2018 prairie vole study – which included several of the same researchers as the two current studies – found four nucleus accumbens CpG sites that had high correlations to humans. Discarding one of these CpG sites allowed their statistics package to make a four-decimal place finding:

“The methylation state of the blood was also associated with the level of transcription in the brain at three of the four CpG sites..whole blood was capable of explaining 94.92% of the variance in Oxtr DNA methylation and 18.20% of the variance in Oxtr expression.”

Few limitations on the prairie vole study findings were disclosed. Like the two current studies, there wasn’t a limitation section that placed research findings into suitable contexts. So readers didn’t know researcher viewpoints on items such as:

  • What additional information showed that 3 of the 30+ million human CpGs accurately predicted specific brain OXTR methylation and expression from saliva OXTR methylation?
  • What additional information demonstrated how “measuring responses from cerebral cortex” although “it is unknown whether OXTR is expressed in the cerebral cortex” provided detailed and dependable estimates of limbic system CpG site OXTR methylation and expression?
  • Was the above 25-CpG study evidence considered?

Further contrast these three studies with a typical, four-point, 285-word limitation section of a study like Prenatal stress heightened adult chronic pain. The word “limit” appeared 6 times in that pain study, 3 times in the current fNIRS study, and 0 times in the current maternal engagement and cited prairie vole studies.

Frank interpretations of one’s own study findings to acknowledge limitations is one way researchers can address items upfront that will be questioned anyway. Such analyses also indicate a goal to advance science.

Prenatal stress heightened adult chronic pain

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This 2019 McGill rodent study found:

“Prenatal stress exacerbates pain after injury. Analysis of mRNA expression of genes related to epigenetic regulation and stress responses in the frontal cortex and hippocampus, brain structures implicated in chronic pain, showed distinct sex and region-specific patterns of dysregulation.

In general, mRNA expression was most frequently altered in the male hippocampus and effects of prenatal stress were more prevalent than effects of nerve injury. Recent studies investigating chronic pain-related pathology in the hippocampus in humans and in rodent models demonstrate functional abnormalities in the hippocampus, changes in associated behavior, and decreases in adult hippocampal neurogenesis.

The change in expression of epigenetic- and stress-related genes is not a consequence of nerve injury but rather precedes nerve injury, consistent with the hypothesis that it might play a causal role in modulating the phenotypic response to nerve injury. These findings demonstrate the impact of prenatal stress on behavioral sensitivity to a painful injury.

Decreased frontal mRNA expression of BDNF and BDNF IV in male offspring following neuropathic pain or prenatal stress respectively. Relative mRNA expression of other stress-related genes (GR17, FKBP5) and epigenetic-related genes (DNMTs, TETs, HDACs, MBDs, MeCP2) in male offspring.

A drastic decrease in expression of HDAC1 was observed in all groups compared to sham-control animals. CCI: chronic constriction injury.”

The study’s design was similar to the PRS (prenatal restraint stress) model, except that the PRS procedure covered gestational days 11 to 21 (birth):

“Prenatal stress was induced on Embryonic days 13 to 17 by restraining the pregnant dams in transparent cylinder with 5 mm water, under bright light exposure, 3 times per day for 45 min.”

None of the French, Italian, and Swiss PRS studies were cited.

The limitation section included:

  1. “Although our study shows significant changes in expression of epigenetic enzymes, it didn’t examine the impact of these changes on genes that are epigenetically regulated by this machinery or their involvement in intensifying pain responses.
  2. The current study is limited by the focus on changes in gene expression which do not necessarily correlate with changes in protein expression.
  3. Another limitation of this study is the inability to distinguish the direct effects of stress in utero vs. changes in the dam’s maternal behavior due to stress during pregnancy; cross-fostering studies are needed to address this issue.
  4. Functional experiments that involve up and down regulation of epigenetic enzymes in specific brain regions are required to establish a causal role for these processes in chronic pain.”

What do you think about possible human applicability of this study’s “effects of prenatal stress were more prevalent than effects of nerve injury” finding?

Are there any professional therapeutic frameworks that instruct trainees to recognize that if a person’s mother was stressed while pregnant, their prenatal experiences could cause more prevalent biological and behavioral effects than a recent injury?

https://www.sciencedirect.com/science/article/pii/S0166432819315219 “Prenatal maternal stress is associated with increased sensitivity to neuropathic pain and sex-specific changes in supraspinal mRNA expression of epigenetic- and stress-related genes in adulthood” (not freely available)

An epigenetic clock review by committee

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This 2019 worldwide review of epigenetic clocks was a semi-anonymous mishmash of opinions, facts, hypotheses, unwarranted extrapolations, and beliefs. Diversity of viewpoints among the 21 coauthors wasn’t evident.

1. Citations of coauthors’ works seemed excessive, and they apologized for omissions. However:

  • Challenge 5 was titled “Single-cell analysis of aging changes and disease” and
  • Table 1 “Major biological and analytic issues with epigenetic DNA methylation clocks” had single-cell analysis as the Proposed solution to five Significant issues.

Yet studies such as High-Resolution Single-Cell DNA Methylation Measurements Reveal Epigenetically Distinct Hematopoietic Stem Cell Subpopulations were unmentioned.

2. Some coauthors semi-anonymously expressed faith that using current flawed methodologies in the future – only more thoroughly, with newer equipment, etc. – would yield better results. If all 21 coauthors were asked their viewpoints of Proposed solutions to the top three Significant issues of epigenetic clocks, what would they emphasize when quoted?

3. Techniques were praised:

“Given the precision with which DNA methylation clock age can be estimated and evolving measures of biological, phenotype-, and disease-related age (e.g., PhenoAge, GrimAge)..”

Exactly why these techniques have at times produced inexplicable results wasn’t examined, though. Two examples:

  • In Reversal of aging and immunosenescent trends, Levine PhenoAge methodology estimated that the 51-65 year old subjects’ biological ages at the beginning of the study averaged 17.5 years less than their chronological age. Comparing that to Horvath average biological age of 3.95 years less raised the question: exactly why did PhenoAge show such a large difference?
  • The paper mentioned GrimAge methodology findings about “smoking-related changes.” But it didn’t explain why GrimAge methylation findings most closely associated with smoking history also accurately predicted future disease risk with non-smokers.

Eluding explanations for these types of findings didn’t help build confidence in methodologies.

4. A more readable approach to review by committee could have coauthors – in at least one section – answer discussion questions, as Reversing epigenetic T cell exhaustion did with 18 experts.

https://genomebiology.biomedcentral.com/articles/10.1186/s13059-019-1824-y “DNA methylation aging clocks: challenges and recommendations”

A review of fetal adverse events

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This 2019 Australian review subject was fetal adversities:

“Adversity during the perinatal period is a significant risk factor for the development of neurodevelopmental disorders long after the causative event. Despite stemming from a variety of causes, perinatal compromise appears to have similar effects on the developing brain, thereby resulting in behavioural disorders of a similar nature.

These behavioural disorders occur in a sex‐dependent manner, with males affected more by externalizing behaviours such as attention deficit hyperactivity disorder (ADHD) and females by internalizing behaviours such as anxiety. The term ‘perinatal compromise’ serves as an umbrella term for intrauterine growth restriction, maternal immune activation, prenatal stress, early life stress, premature birth, placental dysfunction, and perinatal hypoxia.

The above conditions are associated with imbalanced excitatory-inhibitory pathways resulting from reduced GABAergic signalling. Methylation of the GAD1/GAD67 gene, which encodes the key glutamate‐to‐GABA synthesizing enzyme Glutamate Decarboxylase 1, resulting in increased levels of glutamate is one epigenetic mechanism that may account for a tendency towards excitation in disorders such as ADHD.

The posterior cerebellum’s role in higher executive functioning is becoming well established due to its connections with the prefrontal cortex, association cortices, and limbic system. It is now suggested that disruptions to cerebellar development, which can occur due to late gestation compromises such as preterm birth, can have a major impact on the region of the brain to which it projects.

Activation of the maternal hypothalamic-pituitary adrenal (HPA) axis and placental protection. Psychological stress is perceived by the maternal HPA axis, which stimulates cortisol release from the maternal adrenal gland.

High levels of maternal cortisol are normally prevented from reaching the fetus by the 11β-hydroxysteroid dehydrogenase 2 (HSD11B2) enzyme, which converts cortisol to the much less active cortisone. Under conditions of high maternal stress, this protective mechanism can be overwhelmed, with the gene encoding the enzyme becoming methylated, which reduces its expression allowing cortisol to cross the placenta and reach the fetus.”

The reviewers extrapolated many animal study findings to humans, although most of their own work was with guinea pigs. The “suggest” and “may” qualifiers were used often – 22 and 37 times, respectively. More frequent use of the “appears,” “hypothesize,” “propose,” and “possible” terms was justified.

As a result, many reviewed items such as the above graphic and caption should be viewed as hypothetical for humans rather than reflecting solid evidence from quality human studies.

The reviewers focused on the prenatal (before birth) period more than the perinatal (last trimester of pregnancy to one month after birth) period. There were fewer mentions of birth and early infancy adversities.

https://onlinelibrary.wiley.com/doi/abs/10.1111/jne.12814 “Perinatal compromise contributes to programming of GABAergic and Glutamatergic systems leading to long-term effects on offspring behaviour” (not freely available)

Organismal aging and cellular senescence

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I’ll curate this 2019 German review through its figures:

“With the discovery of beneficial aspects of cellular senescence and evidence of senescence being not limited to replicative cellular states, a redefinition of our comprehension of aging and senescence appears scientifically overdue.

Figure 1. Current determinants and relevant open questions, marking the processes of aging and senescence as discussed in the text. Aspects represented in green are considered as broadly accepted or scientifically consolidated. Novel aspects that are yet unproven, or are under debate, are highlighted in red.

SASP = senescence-associated secretory phenotype. AASP = putative aging-associated secretory phenotype as suggested in the text.

Figure 2. Theories on the causality and purpose of aging. Graphically summarized are four contrasting concepts crystallized from current evidence addressing the inductive driving force of aging. Apart from a stochastic deleteriome, there are arguments for a pseudo-programmed, programmed or at least partially programmed nature of aging.

Figure 3. Comparative representation of the aging and senescence processes highlighting different levels of interaction and putative sites of interventions.

(1) As discussed in the text, causative mechanisms of aging are still not well understood, however, multiple factors including genetic, epigenetic and stress-related effects seem to have an orchestrated role in the progression of aging. Senescence on the other hand, is seen as a programmed response to different kinds of stressors, which proceed in defined stages. Whether, in analogy, aging also follows a defined program or sequential stages is not known.

(2) Senescence involves autocrine and paracrine factors, which are responsible for a ‘seno-infection’ or bystander effect in neighboring cells. There is currently no direct evidence for a similar factor composition propagating the aging process via a kind of ‘gero-infection’.

(3) Accumulation of senescent cells has been described as a hallmark of aging; however, whether they are a causative factor or a consequence of tissue and organismal aging is still unknown. As discussed in the text, it appears possible that aging and senescence mutually influence each other through positive feedback at this level, leading to accelerated tissue damage and aging.

(4,5) Clearance of senescent or aging cells might constitute putative targets for interventional approaches aimed to reduce or reverse the impact of aging and improve cell and tissue homeostasis by inducing a ‘rejuvenation’ process.

Figure 4. Pathological and beneficial functions of aging and senescence, according to current knowledge. In red are represented pathological consequences and in green beneficial functions of aging and senescence.

The impact of aging has mainly been described at the organismal level, since a complete cellular functional profile has not yet been established. Accordingly, whether beneficial consequences of the aging process exist at the cellular level is unclear.”

The assertion of Figure 3 (2) that:

“There is currently no direct evidence for a similar factor composition propagating the aging process via a kind of ‘gero-infection.”

was shown to be false in Reevaluate findings in another paradigm:

“It was demonstrated that increased aging occurred as a result of lack of gonadotropin-releasing hormone and that increased lifespan resulted from its provision during aging.

In this manner:

  1. Aging of hypothalamic microglia leads to
  2. Aging of the hypothalamus, which leads to
  3. Aging elsewhere in the body.

So here we have a multi-level interaction:

  1. Activation of NF-κB leads to
  2. Cellular aging, leading to
  3. A diminished production of GnRH, which then
  4. Acts (through cells with a receptor for it, or indirectly as a result of changes to GnRH-receptor-possessing cells) to decrease lifespan.

So the age state of hypothalamic cells, at least with respect to NF-κB activation, is communicated to other cells via reduced output of GnRH.”

The reviewers’ position on Figure 2 was:

“In our view, recent evidence that

  • Senescence is based on an unterminated developmental growth program and the finding that
  • The concept of post-mitotic senescence requires the activation of expansion, or ‘growth’ factors as a second hit,

favor the assumption that aging underlies a grating of genetic determination similarly to what is summarized above under the pseudo-programmed causative approach.”

Their position on Figure 4’s beneficial effects of aging began with the sentence:

“If we assume that aging already starts before birth, it can be considered simply a developmental stage, required to complete the evolutionary program associated with species-intrinsic biological functions such as reproduction, survival, and selection.”

Cited studies included:

https://www.mdpi.com/2073-4409/8/11/1446 “Dissecting Aging and Senescence-Current Concepts and Open Lessons”