#epigenome

Using cannabis may cause changes in the human body's epigenome, a study of over 1,000 adults suggests. The epigenome functions like a set of switches, activating or deactivating genes to change how our bodies function. "We observed associations between cumulative marijuana use and multiple epigenetic markers across time," explained epidemiologist Lifang Hou from Northwestern University when the research was published in 2023.

Abstract

“The science of the biological effects of the stresses of poverty is in its early stages. Still, it has presented us with multiple mechanisms through which such effects could happen, and many of these admit an inheritable component. If a pregnant woman, for example, is exposed to the stresses of poverty, her fetus and that fetus’ gametes can both be affected, extending the effects of poverty to at least her grandchildren. And it could go further.

Studies of mice and fruit flies have shown that epigenetic traits similar to the ones Meaney proposed can be passed down, and last for dozens of generations. The effects of things like diet and prenatal parental stress have been observed to be inherited, not just through histone modifications, but also through DNA methylation and non-coding RNAs.7 In one 2014 study, the offspring of a mouse trained to fear a particular smell were observed to also fear that smell, even with no previous exposure to it. The effect lasted for two generations.8 In humans, inheritable effects of stress have been observed through at least three generations from parents who survived mass starvation (Dutch Hunger Winter),9 a fluctuating food supply (the Överkalix cohort)10 and the Holocaust. The effects of early paternal smoking and paternal betel quid chewing have been observed to be transmitted to children in a sex-specific manner, supporting biological epigenetic transmission in humans.11 According to a 2014 survey of the field, “the few human observational studies to date suggest (male line) transgenerational effects exist that cannot easily be attributed to cultural and/or genetic inheritance.”10.

This science challenges us to re-evaluate a cornerstone of American mythology, and of our social policies for the poor: the bootstrap. The story of the self-made, inspirational individual transcending his or her circumstances by sweat and hard work. A pillar of the framework of meritocracy, where rewards are supposedly justly distributed to those who deserve them most.

Teachers are all around us

The world is our home

We learn best experientially 

We say no to prisons

It is a space to meditate and reflect; to practice silence and awe

To detach from expectations

22/2/18

I am having such a productive day today and honestly so proud of myself, I’m also thinking about doing a couple of these for maths as well so message me if you are interested! I’m also feeling quite good in myself and it’s nice after having a couple of lows :)

So you guys were big fans on my Chemistry A-Level notes so I have done the same for my Biology as well :) Here you go:

EPIGENETICS: https://docs.google.com/document/d/1zc8JR6IhYKJnRPP0OEVanapHQWrlV8Y_eeaXwzi-4lQ/edit?usp=sharing

Abstract

Epigenetics can be explored at different levels and can be divided into two major areas: epigenetics of nuclear-encoded DNA and epigenetics of mitochondrial-encoded DNA. In epigenetics of nuclear-encoded DNA, the main roles are played by DNA methylation, changes in histone structure and several types of non-coding RNAs. Mitochondrial epigenetics seems to be similar in the aspect of DNA methylation and to some extent in the role of non-coding RNAs but differs significantly in changes in components coiling DNA. Nuclear DNA is coiled around histones, but mitochondrial DNA, together with associated proteins, is located in mitochondrial pseudocompartments called nucleoids. It has been shown that mitochondrial epigenetic mechanisms influence cell fate, transcription regulation, cell division, cell cycle, physiological homeostasis, bioenergetics and even pathologies, but not all of these mechanisms have been explored in stem cells. The main issue is that most of these mechanisms have only recently been discovered in mitochondria, while improvements in methodology, especially next-generation sequencing, have enabled in-depth studies. Because studies exploring mitochondria from other aspects show that mitochondria are crucial for the normal behavior of stem cells, it is suggested that precise mitochondrial epigenetics in stem cells should be studied more intensively.

KeywordsMitochondria Mitochondrial DNA Epigenetics Stem cell References

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Abstract

Background

Age-associated epigenetic changes are implicated in aging. Notably, age-associated DNA methylation changes comprise a so-called aging “clock”, a robust biomarker of aging. However, while genetic, dietary and drug interventions can extend lifespan, their impact on the epigenome is uncharacterised. To fill this knowledge gap, we defined age-associated DNA methylation changes at the whole-genome, single-nucleotide level in mouse liver and tested the impact of longevity-promoting interventions, specifically the Ames dwarf Prop1 df/df mutation, calorie restriction and rapamycin.

Results

In wild-type mice fed an unsupplemented ad libitum diet, age-associated hypomethylation was enriched at super-enhancers in highly expressed genes critical for liver function. Genes harbouring hypomethylated enhancers were enriched for genes that change expression with age. Hypermethylation was enriched at CpG islands marked with bivalent activating and repressing histone modifications and resembled hypermethylation in liver cancer. Age-associated methylation changes are suppressed in Ames dwarf and calorie restricted mice and more selectively and less specifically in rapamycin treated mice.

Conclusions