Gene Therapy-Mediated Partial Reprogramming Extends Lifespan and Reverses Age-Related Changes in Aged Mice.

Aging is a complex progression of changes best characterized as the chronic dysregulation of cellular processes leading to deteriorated tissue and organ function. Although aging cannot currently be prevented, its impact on life- and healthspan in the elderly can potentially be minimized by interventions that aim to return these cellular processes to optimal function. Recent studies have demonstrated that partial reprogramming using the Yamanaka factors (or a subset; , and can reverse age-related changes and .

The Information Theory of Aging.

Information storage and retrieval is essential for all life. In biology, information is primarily stored in two distinct ways: the genome, comprising nucleic acids, acts as a foundational blueprint and the epigenome, consisting of chemical modifications to DNA and histone proteins, regulates gene expression patterns and endows cells with specific identities and functions. Unlike the stable, digital nature of genetic information, epigenetic information is stored in a digital-analog format, susceptible to alterations induced by diverse environmental signals and cellular damage.

The Role of Epigenetics in Accelerated Aging: A Reconsideration of Later-Life Visual Loss After Early Optic Neuropathy.

Background: In 2005, we reported 3 patients with bilateral optic nerve damage early in life. These patients had stable vision for decades but then experienced significant bilateral vision loss with no obvious cause. Our hypothesis, novel at that time, was that the late decline of vision was due to age-related attrition of retinal ganglion cells superimposed on a reduced neuronal population due to the earlier injury.

Loss of epigenetic information as a cause of mammalian aging.

All living things experience an increase in entropy, manifested as a loss of genetic and epigenetic information. In yeast, epigenetic information is lost over time due to the relocalization of chromatin-modifying proteins to DNA breaks, causing cells to lose their identity, a hallmark of yeast aging. Using a system called "ICE" (inducible changes to the epigenome), we find that the act of faithful DNA repair advances aging at physiological, cognitive, and molecular levels, including erosion of the epigenetic landscape, cellular exdifferentiation, senescence, and advancement of the DNA methylation clock, which can be reversed by OSK-mediated rejuvenation.

The 2022 International Society for Stem Cell Research (ISSCR) Annual Meeting: Celebrating 20 Years of Achievements.

Last June, the stem cell community came together to celebrate the 20th anniversary of the International Society for Stem Cell Research (ISSCR), one of the leading organizations in the field. The hybrid event mixed a varied program filled with plenary talks, concurrent track sessions, poster presentations, exhibit booths, and plenty of opportunities to enhance stem cell research through bonding between academia and industry. This report highlights the Plenary sessions, with the main topics discussed by each speaker.

Reprogramming to recover youthful epigenetic information and restore vision.

Ageing is a degenerative process that leads to tissue dysfunction and death. A proposed cause of ageing is the accumulation of epigenetic noise that disrupts gene expression patterns, leading to decreases in tissue function and regenerative capacity. Changes to DNA methylation patterns over time form the basis of ageing clocks, but whether older individuals retain the information needed to restore these patterns-and, if so, whether this could improve tissue function-is not known.

Molecular and Cellular Characterization of SIRT1 Allosteric Activators.

SIRT1 is an NAD-dependent lysine deacetylase that promotes healthy aging and longevity in diverse organisms. Small molecule allosteric activators of SIRT1 such as resveratrol and SRT2104 directly bind to the N-terminus of SIRT1 and lower the K for the protein substrate. In rodents, sirtuin-activating compounds (STACs) protect from age-related diseases and extend life span.

Assays for NAD-Dependent Reactions and NAD Metabolites.

Nicotinamide adenine dinucleotide (NAD) is an essential redox cofactor and signaling molecule that controls the activity of enzymes involved in metabolism, DNA repair, and cellular survival, such as the PARPs, CD38, and the sirtuins. Here, we describe three methods for measuring the activity of these enzymes: the etheno-NAD assay measures NAD hydrolase activity using an NAD analog to produce a fluorescent product that is measured in real time; the PNC1 assay converts a native product of NAD hydrolysis, nicotinamide, into a quantitative fluorescent readout; and liquid chromatography tandem mass spectrometry (LC-MS/MS) is used to characterize the entire NAD metabolome in a sample. These methods will enable new insights into the roles that NAD and the enzymes that utilize it play in health and disease.

Impairment of an Endothelial NAD-HS Signaling Network Is a Reversible Cause of Vascular Aging.

A decline in capillary density and blood flow with age is a major cause of mortality and morbidity. Understanding why this occurs is key to future gains in human health. NAD precursors reverse aspects of aging, in part, by activating sirtuin deacylases (SIRT1-SIRT7) that mediate the benefits of exercise and dietary restriction (DR).

[Research progresses in animal cryptochromes].

Animal cryptochromes are widely known to regulate circadian clock and can be divided into two types. Type I cryptochromes receive light to initiate the degradation of transcriptional inhibitors, whereas type II cryptochromes directly act as light-irresponsive transcriptional inhibitors. Recent studies reveal that animal cryptochromes also have functions in immune response and carbohydrate metabolism, and are required in light-induced chemical magnetoreception in animals like Drosophila.