Does aging do something to time so it seems like as you get older that time goes by faster? Remember as a little kid when summer seemed to last forever and car rides could be agonizingly long? I’ve heard two theories on this.
One is that the brain’s baseline of activity slows down with aging while the speed of the world’s activities (like the length of a day) remains the same so time seems to be faster. The other is that we experience time in relation to how much time we’ve lived. So when you’re young a day is a much longer fraction of your entire life’s experiences.
Whatever is going on with our brains and time, it’s clear that time affects individual cells and often not in great ways. More time often equals more mutations. Older cells also tend to not function as well. Of course, the topic of stem cell anti aging approaches is big both in the legit science world and amongst stem cell clinics. As to the latter, there’s a lot of hooey.
On the research side, there are huge efforts on the stem cell anti-aging front including a Saudi one committing $1B USD a year to it. Altos Labs has a major emphasis on regeneration and anti-aging as well.
Let’s start our recommended reads with the topic of time and cells. But first, see the image of a young guy above from decades ago. Who do you think this could be? It’s not me. See the answer at the bottom of the post.
Aging, mutations, and stem cells
- Substantial somatic genomic variation and selection for BCOR mutations in human induced pluripotent stem cells, Nat Gen. Many somatic cells like skin in particular but also blood cells tend to accumulate mutations as we age. The reprogramming process may sometimes only work efficiently in cells that already have certain mutations. This paper highlights the importance of carefully screening iPS cells, especially those intended for clinical use, for potential mutations.
- Global Chromatin Accessibility Profiling Analysis Reveals a Chronic Activation State in Aged Muscle Stem Cells, iScience.
- Limbal epithelial stem cell sheets from young donors have better regenerative potential, Scientific Reports.
Additional recommended reads
- Thy1 marks a distinct population of slow-cycling stem cells in the mouse epidermis, Nat. Comm.
- From Gene-Edited Embryos to Covid: China Faces Regulatory and Ethical Challenges, The Hastings Center.
- Transcriptional regulation and chromatin architecture maintenance are decoupled functions at the Sox2 locus, G&D.
- Lymphatics and fibroblasts support intestinal stem cells in homeostasis and injury, Cell Stem Cell.
- Modeling congenital heart disease: lessons from mice, hPSC-based models, and organoids, G&D.
The photo above is of Professor Irv Weissman of Stanford when he was a young man first doing science. Photo courtesy of Irv Weissman found on the Stanford website. You can read my mini-interview of a sort from 11 years ago with Irv on science mentoring.