Here are the most popular of the 65 posts I’ve made so far in 2018, starting from the earliest:
The principal way science advances is through the principle Einstein expressed as:
“No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”
Members of the scientific community and of the public should be satisfied that the scientific process is working well when hypotheses are discarded due to nonconfirming evidence. Researchers should strive to develop evidence that rejects paradigms, and be lauded for their efforts.
The opposite took place with this 2018 commentary on two studies where the evidence didn’t confirm current biases. I curated one of these studies in DNA methylation and childhood adversity.
The commentators’ dismissive tone was set in the opening paragraph:
“Is early exposure to adversity associated with a genetic or an epigenetic signature? At first glance, two articles in this issue -..and the other from Marzi et al., who measured genome-wide DNA methylation in a prospective twin cohort assessed at age 18 – appear to say that it is not.”
The two commentators, one of whom was a coauthor of Manufacturing PTSD evidence with machine learning, went on to protect their territory. Never mind the two studies’ advancement of science that didn’t coincide with the commentators’ vested interests.
My main concern with the study was that although the children had been studied at ages 5, 7, 10, 12, and 18, the parents had never been similarly evaluated! The researchers passed up an opportunity to develop the parents as a F0 generation for understanding possible human transgenerational inherited epigenetic causes and effects.
The study focused on the children’s intergenerational epigenetic effects. However, animal studies have often demonstrated transgenerational effects that skip over the F1 generation children!
- Transgenerational pathological traits induced by prenatal immune activation found a F2 grandchild and F3 great-grandchild phenotype of impaired sociability, abnormal fear expression and behavioral despair – effects that weren’t present in the F1 children;
- A self-referencing study of transgenerational epigenetic inheritance found histone modifications in the F3 generation that weren’t found in the F1 and F2 generations; and
- A study not cited in – but completely appropriate for – The lack of oxygen’s epigenetic effects on a fetus found heart disease effects in the F1 generation that were different from the heart disease effects found in the F2 and F3 generations.
https://ajp.psychiatryonline.org/doi/pdf/10.1176/appi.ajp.2018.18020156 “Considering the Genetic and Epigenetic Signature of Early Adversity Within a Biopsychosocial Framework” (not freely available)
This 2018 Michigan review subject was cancer evolution:
“Based on the fact that cancer typically represents a complex adaptive system, where there is no linear relationship between lower-level agents (such as each individual gene mutation) and emergent properties (such as cancer phenotypes), we call for a new strategy based on the evolutionary mechanism of aneuploidy [abnormal number of chromosomes] in cancer, rather than continuous analysis of various individual molecular mechanisms.
Cancer evolution can be understood by the dynamic interaction among four key components:
- Internal and external stress;
- Elevated genetic and non-genetic variations (either necessary for cellular adaptation or resulting from cellular damages under stress);
- Genome-based macro-cellular evolution (genome replacement, emergent as new systems); and
- Multiple levels of system constraint which prevent/slow down cancer evolution (from tissue/organ organization to the immune system interaction).
Since the sources of stress are unlimited and unavoidable (as they are required by all living systems), there are large numbers of gene mutations / epigenetic events / chromosomal aberrations, such as aneuploidy, that can be linked to stress-mediated genomic variants. Furthermore, as environmental constraints are constantly changing, even identical instances of aneuploidy will have completely different outcomes in the context of cancer evolution, as the results of each independent run of evolution will most likely differ.
Most current research efforts are focusing on molecular profiles based on an average population, and outliers are eliminated or ignored, either by the methods used or statistical tools. The traditional view of biological research is to identify patterns from “noise,” without the realization that the so-called “noise” in fact is heterogeneity, which represents a key feature of cancer evolution by functioning as the evolutionary potential.
Understanding the molecular mechanism (both cause and effect) of aneuploidy is far from enough. A better strategy is to monitor the evolutionary process by measuring evolutionary potential. For example, the overall degree of CIN [chromosome instability] is more predictive than individual gene mutation profile.”
Although I read many abstracts of cancer research papers every week, I usually don’t curate them. I curated this paper because the reviewers emphasized several themes of this blog, including:
- Further examples of how stress may shape one’s life.
- How researchers miss information when they ignore or process away variation:
“Studies have demonstrated the importance of outliers in cancer evolution, as cancer is an evolutionary game of outliers. While this phenomenon can provide a potential advantage for cellular adaptation, it can also, paradoxically, generate non-specific system stress, which can further produce more genetic and non-genetic variants which favor the disease condition.”
Epigenetics researchers may benefit from evolutionary viewpoints that incorporate the interactions of stress and “genetic and non-genetic variants.”
Since epigenetic changes require inheritance in order to persist, it would be a step forward to see researchers start “measuring evolutionary potential” of these inheritance processes.
https://molecularcytogenetics.biomedcentral.com/articles/10.1186/s13039-018-0376-2 “Understanding aneuploidy in cancer through the lens of system inheritance, fuzzy inheritance and emergence of new genome systems”
This 2018 French review subject was mechanisms of autoimmunity:
“Autoimmune diseases (AIDs) encompass more than 80 distinct chronic disorders characterized by inflammatory reactions that can either be systemic or organ specific. In all cases, the disease development is the consequence of the effects of environmental factors in predisposed individuals.
Most of the genes identified by genome-wide association studies (GWAS) on AIDs are related to immunity. However, functional immune parameters that are commonly dysregulated in AIDs do not necessarily stem from these genetic variants. Rather than performing even larger GWAS, understanding complex traits, such as human diseases, may require meticulous analysis or cell-specific gene networks and take into account not only core genes but also seemingly irrelevant genes that may overall have an impact on the disease.
Treg cell defects have been considered a primary cause of AIDs. However, one could ask whether the Treg cell dysfunction exists before the onset of the disease or is provoked by the inflammatory event induced by the triggering components. The defect of Treg cells generally coexists with the inflammatory processes, suggesting several hypotheses:
- The inflammation might develop because of a poor regulation of the immune system,
- The Treg cells could become inefficient because of the inflammatory environment, or
- A common factor concomitantly leads to both effects.
It is likely that autoimmunity results from a chronic imbalance involving both environmental and intrinsic factors. It is now clear that polygenic explanations did not fulfill expectations and that more efforts are needed to understand how the interplay of environmental clues may have a phenotypic impact.”
https://nyaspubs.onlinelibrary.wiley.com/doi/full/10.1111/nyas.13560 “Pathophysiological mechanisms of autoimmunity” (not freely available) Thanks to Dr. Julien Verdier for providing a copy.
My 400th blog post curates a 2018 US/UK paper by two of the coauthors of Using an epigenetic clock to distinguish cellular aging from senescence. The authors reviewed the current state of epigenetic clock research, and proposed a new theory of aging:
“The proposed epigenetic clock theory of ageing views biological ageing as an unintended consequence of both developmental programmes and maintenance programmes, the molecular footprints of which give rise to DNAm [DNA methylation] age estimators.
It is best to interpret epigenetic age estimates as a higher-order property of a large number of CpGs much in the same way that the temperature of a gas is a higher-order property that reflects the average kinetic energy of the underlying molecules. This interpretation does not imply that DNAm age simply measures entropy across the entire genome.
To date, the most effective in vitro intervention against epigenetic ageing is achieved through expression of Yamanaka factors, which convert somatic cells into pluripotent stem cells, thereby completely resetting the epigenetic clock. In vivo, haematopoietic stem cell therapy resets the epigenetic age of blood of the recipient to that of the donor.
Future epidemiological studies should consider other sources of DNA (for example, buccal cells), because more powerful estimates of organismal age can be obtained by evaluating multiple tissues. Other types of epigenetic modifications such as adenine methylation or histone modifications may lend themselves for developing epigenetic age estimators.”
- The cerebellum ages more slowly than other body and brain areas
- Using an epigenetic clock with older adults
- Using an epigenetic clock with children
- The degree of epigenetic DNA methylation may be used as a proxy to measure biological age
The challenge is: do you want your quality of life to be under or over this curve?
What are you doing to reverse epigenetic processes and realize what you want? Do you have ideas and/or behaviors that interfere with taking constructive actions to change your phenotype?
If you aren’t doing anything, are you honest with yourself about the personal roots of beliefs in fate/feelings of helplessness? Do beliefs in technological or divine interventions provide justifications for inactions?
https://www.nature.com/articles/s41576-018-0004-3 “DNA methylation-based biomarkers and the epigenetic clock theory of ageing” (not freely available)
This 2018 Chinese paper reviewed the associations among long non-coding RNA and four neurodegenerative diseases:
“lncRNAs are widely implicated in various physiological and pathological processes, such as epigenetic regulation, cell cycle regulation, cell differentiation regulation, cancer, and neurodegenerative diseases, through their interactions with chromatin, protein, and other RNAs. Numerous studies have suggested that lncRNAs are closely linked with the occurrence and development of a variety of diseases, especially neurodegenerative diseases, of which the etiologies are complicated and the underlying mechanisms remain elusive.
We focus on how lncRNA dysfunctions are involved in the pathogenesis of Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis.”
Table 1 showed specific lncRNAs that acted as “bodyguards” in inherited Huntington’s disease, “culprits” in Alzheimer’s disease, and as both in Parkinson’s disease. The table didn’t include lncRNAs associated with amyotrophic lateral sclerosis although the review text mentioned several.
https://www.sciencedirect.com/science/article/pii/S2162253117303104 “Long Non-coding RNAs, Novel Culprits, or Bodyguards in Neurodegenerative Diseases”
Let’s start by observing that people structure their lives around beliefs. As time goes on, what actions would a person have taken to ward off non-confirming evidence?
One response may be that they would engage in ever-increasing efforts to develop new beliefs that justified how they spent their precious life’s time so far.
Such was my take on the embedded beliefs in https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5684598/pdf/PSYCHIATRY2017-5491812.pdf “Epigenetic and Neural Circuitry Landscape of Psychotherapeutic Interventions”:
“Animal models have shown the benefits of continued environmental enrichment (EE) on psychopathological phenotypes, which carries exciting translational value.
This paper posits that psychotherapy serves as a positive environmental input (something akin to EE).”
The author conveyed his belief that wonderful interventions were going to happen in the future. However, when scrutinized, most human studies have demonstrated null effects of psychotherapeutic interventions on causes. Without sound evidence that treatments affect causes, his belief seemed driven by something else.
The author cited the findings of research like A problematic study of oxytocin receptor gene methylation, childhood abuse, and psychiatric symptoms as supporting external interventions to tamp down symptoms of patients’ presenting problems. Did any of the paper’s 300+ cited references concern treatments where patients instead therapeutically addressed their problems’ root causes?
For an analogous religious example, a person’s belief caused him to spend years of his life trying to convince men to act so that they could get their own planet after death, and trying to convince women to latch onto men who had this belief. A new and apparently newsworthy belief developed from his underlying causes:
“The founder and CEO of neuroscience company Kernel wants “to expand the bounds of human intelligence”. He is planning to do this with neuroprosthetics; brain augmentations that can improve mental function and treat disorders. Put simply, Kernel hopes to place a chip in your brain.
He was raised as a Mormon in Utah and it was while carrying out two years of missionary work in Ecuador that he was struck by what he describes as an “overwhelming desire to improve the lives of others.”
He suffered from chronic depression from the ages of 24 to 34, and has seen his father and stepfather face huge mental health struggles.”
https://www.theguardian.com/small-business-network/2017/dec/14/humans-20-meet-the-entrepreneur-who-wants-to-put-a-chip-in-your-brain “Humans 2.0: meet the entrepreneur who wants to put a chip in your brain”
The article stated that the subject had given up Mormonism. There was nothing to suggest, though, that he had therapeutically addressed any underlying causes for his misdirected thoughts, feelings, and behavior. So he developed other beliefs instead.
What can people do to keep their lives from being wasted on beliefs? As mentioned in What was not, is not, and will never be:
“The problem is that spending our time and efforts on these ideas, beliefs, and behaviors won’t ameliorate their motivating causes. Our efforts only push us further away from our truths, with real consequences: a wasted life.”
The goal of the therapeutic approach advocated by Dr. Arthur Janov’s Primal Therapy is to remove the force of the presenting problems’ motivating causes. Success in reaching this goal is realized when patients become better able to live their own lives.
This post has somehow become a target for spammers, and I’ve disabled comments. Readers can comment on other posts and indicate that they want their comment to apply here, and I’ll re-enable comments.