Longevity Daily: 27th August, 2020

Everyday our team of researchers in Oxford are inundated with scientific, and medical research articles that have the potential to improve health, wellbeing, and longevity. In this blog we highlight a few of them that caught our attention today.

1. How much of what you are is due to your genes (nature), and how much is due to your life and environment (nurture)?
   • Why is this important: We often wonder how much of our intelligence, or our neuroticism, or extrovertedness, or disease risks, are a result of our inherited genes, and how much of it is due to our upbringing, and lifestyle. In order to figure out the impact of nature vs. nurture on a given trait scientists study genetically identical twins. Twins offer a ready-made test of nature and nurture and their paired roles influencing complex traits.
   • What did the researchers do: In this seminal and comprehensive study researchers from the Netherlands, Sweden, Australia, and US reviewed all the data from almost every twin study conducted during the past 50 years, amounting to a total of 2,748 twin studies. This meta-analysis explored 17,804 traits, including depression and cigarette use. They studied these traits in over 14.5 Million pairs of twins in 39 countries. Traits that were linked with non-identical twins are thought to have more influence from the environment, and vice versa.
   • Key takeaway(s): The researchers found that neurological, heart, personality, ophthalmological, cognitive, and ear-nose-and-throat disorders are mostly influenced by your genetic inheritance. But there can be large variances, for example your genes largely (~70%) influence your depression, while your environment has a major impact (~60%) on your eating disorder. The researchers found that for most traits the ratio is closer to about half & half, i.e. 50% dependent on your genes, and 50% on your environment.
     
     
2. What genes are involved in the development of our brain, and how do they affect the health and longevity of our brain?
   • Why is this important: Many of us imagine that our brain is our most important organ. The cerebral cortex region of the brain is considered to be headquarters of the brain. The cerebral cortex is responsible for all higher thought processes including speech, imagination, and decision making. But we still know very little about the genes involved in creation, maintenance, and repair of the cortex. Or how these genes impact the structure of the cortex which in turn impacts our traits and behaviors.
   • What did the researchers do: In this large meta-analysis study a massive team of researchers from all over the world studied the brain data of over 51,665 people. The researchers looked at the structure of their brain using MRI scans, and then combined that with their genomic data.
   • Key takeaway(s): The researchers found that over 241 genomic regions influenced the size of our cortex, while a mostly different set of more than 14 genomic regions were involved in its thickness. Additionally, the researchers found that people with larger cortex surface area were more likely to have better cognitive function, and achieve higher education. Unfortunately, these people were also more likely to get Parkinson’s disease. Finally, the researchers highlight that the larger the cortex surface area the less likely you are to suffer from insomnia, depression, neuroticism, and attention deficit disorders.
     
     
3. Reducing levels of senescence in hypothalamic stem cells protects against physiological decline caused by aging
   • Why is this important: Various aspects of physiological degeneration are controlled by the hypothalamus, a region of the brain which connects the neuroendocrine system to physiological function. Manipulation of the underlying causes of hypothalamus aging, such as reducing hypothalamic neural stem cell (htNSC) senescence, could help us improve physiological health into old age.
   • What did the researchers do: In this paper, researchers investigated what triggers the senescence of htNSC in mice.
   • Key takeaway(s): It was found that the depletion of a long non-coding RNA, Hnscr, drives the cellular senescence of the htNSCs, from a young age where it is highly expressed, to middle-age where Hnscr levels were found to be notably decreased. Treatment of these middle-aged mice with theaflavin 3-gallate reduced the senescence of htNSCs, improving the age-related pathology. This study highlights Hnscr as an important mediator of the aging process, whilst highlighting theaflavin 3-gallate as a potential therapeutic compound.

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