Direct Correlation among Telomere Length, Cellular Aging, and Rejuvenation Effects of Honey Child Powder

Purpose: Telomere length (TL) is an indicator of age;however, hormonal influences complicate individual aging. It remains unclear whether TL shortening is a direct factor in both individual and cellular aging. Therefore, we examined the direct relationship between TL and cellular senescence at the cellular level. Methods: Telomerase activity, TL, and gene expression were measured in cultured human lung-, fetal-, and skin-derived fibroblasts, human skin keratinocytes, and telomerase reverse transcriptase (TERT) gene-immortalized cells using detection kits, Cawthon’s method, and reverse transcription-quantitative polymerase chain reaction, respectively. Novel substances that elongate telomeres were screened to confirm cell rejuvenation effects. Results: Long-term cell culture of TIG-1-20 normal human fibroblasts resulted in TL shortening, decreased division rate, and senescence progression, whereas in OUMS-36T-2 cells, TL elongation via TERT gene transfer increased the division rate, reduced endoplasmic reticulum stress, and upregulated genes associated with young individuals, indicating that cellular rejuvenation occurs via TL elongation. In addition, a honey child powder (HCP) extract was found through screening, and the HCP extract strongly suppressed the menin gene, resulting in increased telomerase activity and extended cell lifespan. Upon addition of the HCP extract to skin fibroblasts, gene expression of moisturizing components, including collagen, hyaluronic acid, and elastin, increased, and exhibited a rejuvenating effect with an increase in elastin amount. Conclusions: TL elongation or shortening is involved in cell proliferation rate and cellular aging, and TL elongation rejuvenates cells. In addition, HCP extract has a rejuvenating effect on cells and is expected to be a rejuvenating compound.

The effect of cellular aging on the dynamics of spiral waves

Cellular aging can result in deterioration of electrical coupling, the extension of the action potential duration, and lower excitability of the cell. Those factors are introduced into the Greenberg–Hastings cellular automaton model and the effects of the cellular aging on the dynamics of spiral waves are studied. The numerical results show that a 50% reduction of the coupling strength of aging cells has a little influence on spiral waves. If the coupling strength of aging cells equals zero, the ability for the medium to maintain spiral waves will be reduced by approximately 50% when the aging cell ratio increases from 0 to 0.5, where the reduction of cell excitability plays a major role in inducing disappearance of spiral waves. When the relevant parameters are properly chosen, the cellular aging can lead to the meandering of spiral waves,the emergence of the binary spiral waves, and even the disappearance of spiral waves via the stopping rotation or shrinkage of wave. Physical mechanisms of the above phenomena are analyzed briefly.

Epigenetics recording varied environment and complex cell events represents the origin of cellular aging

Although a relationship between epigenetics and aging phenotypic changes has been established,a theoretical explanation of the intrinsic connection between the epigenetics and aging is lacking.In this essay,we propose that epigenetic recording of varied cell environment and complex history could be an origin of cellular aging.Through epigenetic modifications,the environment and historical events can induce the chromatin template into an activated or repressive accessible structure,thereby shaping the DNA template into a spectrum of chromatin states.The inner nature of diversity and conflicts born by the cell environment and its historical events are hence recorded into the chromatin template.This could result in a dissipated spectrum of the chromatin state and chaos in overall gene expression.An unavoidable degradation of epigenome entropy,similar to Shannon entropy,would be consequently induced.The resultant disorder in epigenome,characterized by corrosion of epigenome entropy as reflected in chromatin template,can be stably memorized and propagated through cell division.Furthermore,the hysteretic nature of epigenetics responding to the emerging environment could exacerbate the degradation of epigenome entropy.As well as stochastic errors,we propose that outside entropy(or chaos) derived from the varied environment and complex cell history,gradually input and imprinted into the chromatin via epigenetic modifications,would lead inevitably to cellular aging,the extent of which could be aggravated by hysteresis of epigenetics without error erasing and correction.

How to Predict AGEs Accumulation Slowdown Effect of a Cosmetic Ingredient? Two Steps <i>In-Vitro</i>System for Evaluating the Anti-AGE Impact of a New Blend

Advanced Glycation End-Products (AGEs), play a crucial part in advancing the process of cellular skin aging and its link to chronological age was re-assessed. AGEs accumulation alters cell structure and function of most types of skin cells, affecting skin’s mechanical and physiological properties, following the molecular transformations. Slowdown AGEs accumulation rate in skin, although a potent anti-aging strategy, is difficult and tricky. The lack of working methods for In-Vitro and In-Vitro measuring AGEs level complicates the evaluation and prediction of active ingredients’ ability to affect cellular AGEs accumulation. A two-step In-Vitro systematic screening method is proposed and three different cosmetic active ingredients were selected for its demonstration, using BSA-Glucose and Collagen-Glucose predicting models. Candidates’ effects on AGEs accumulation were evaluated as standalone, and when formulated in a blend. Additionally, the potency of non-invasive auto-fluorescence in-vivo measurement to detect AGEs levels among subjects of different ages was demonstrated. The results are presented in this work and the potential contribution of the proposed system to assist the desired inhibition of AGEs accumulation in skin is discussed.