Exploring Telomere Dynamics in Aging Male Rat Tissues: Can Tissue-Specific Differences Contribute to Age-Associated Pathologies?

Association of Telomere Length in T Lymphocytes, B Lymphocytes, NK Cells and Monocytes with Different Forms of Age-Related Macular Degeneration

BACKGROUND

Age plays a primary role in the development of age-related macular degeneration (AMD). Telomere length (TL) is one of the most relevant biomarkers of aging. In our study, we aimed to determine the association of TL with T lymphocytes, B lymphocytes, NK cells or monocytes with different forms of AMD.

METHODS

Our study included 62 patients with AMD: geographic atrophy (GA), neovascular AMD (NVAMD) with and without macular atrophy and 22 healthy controls. Each leukocyte subtype was isolated from peripheral blood by immunomagnetic separation, and the DNA was purified. The TL in the genomic DNA was determined using qPCR by amplifying the telomere region with specific oligonucleotide primers and normalizing to the control gene. Statistical analysis was performed using R version 4.5.1.

RESULTS

We observed a statistically significant increase in TL in the T cells between the control and NVAMD groups but not for the GA group. The B cells and monocytes showed a significant decrease in TL in all AMD groups. The TL in the NK cells did not decrease in any of the AMD groups.

CONCLUSIONS

The TL in the monocytes had the strongest association with AMD. It reflects a person's "telomeric status" and may become a diagnostic hallmark of these degenerative processes.

The Effect of Royal Jelly on Telomere Length and Some Biochemical Parameters in Wistar Albino Rats with Liver Damage Caused by Carbon Tetrachloride

Royal jelly (RJ) is a natural bee product that has been used for therapeutic purposes since ancient times. The therapeutic properties of this product, which has rich biological content, are still being investigated with new approaches. In this study, the effect of RJ on telomere length, some antioxidant parameters, and lipid profile was examined. This study will contribute to the literature as it is the first to evaluate the effect of RJ on the length of telomeres in damaged liver tissues. In the study, the levels of serum triglyceride, total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDL-C), aspartate transaminase (AST), alanine transaminase (ALT), telomerase, 8'-hydroxy-2'-deoxyguanosine (8-OHdG), and paraoxonase-1 (PON1) were investigated with enzyme-linked immunosorbent assay method and telomere lengths were investigated by real-time quantitative polymerase chain reaction. The increased TC, LDL-C levels, and AST and ALT activities in the serum after carbon tetrachloride (CCl4) administration approached the control level after RJ administration. PON1 activity decreased in groups with CCl4. PON1 activity increased after RJ administration. The level of 8-OHdG, which increased groups with CCl4, decreased after RJ administration. According to the results of telomere length analysis in liver tissues, telomere lengths in damaged tissues were significantly shortened with CCl4 application and increased with RJ application. Based on the findings of the study, it was concluded that RJ may have therapeutic effects on telomere lengths and some biochemistry parameters.

Diagnostic and Therapeutic Roles of Extracellular Vesicles in Aging-Related Diseases

Aging shows a decline in overall physical function, and cellular senescence is the powerful catalyst leading to aging. Considering that aging will be accompanied with the emergence of various aging-related diseases, research on new antiaging drugs is still valuable. Extracellular vesicles (EVs), as tools for intercellular communication, are important components of the senescence-associated secretory phenotype (SASP), and they can play pathological roles in the process of cellular senescence. In addition, EVs are similar to their original cells in functions. Therefore, EVs derived from pathological tissues or body fluids may be closely related to the progression of diseases and become potential biomarkers, while those from healthy cells may have therapeutic effects. Moreover, EVs are satisfactory drug carriers. At present, numerous studies have supported the idea that engineered EVs could improve drug targeting ability and utilization efficiency. Here, we summarize the characteristics of EVs and cellular senescence and focus on the diagnostic and therapeutic potential of EVs in various aging-related diseases, including Alzheimer disease, osteoporosis, cardiovascular disease, diabetes mellitus and its complications, and skin aging.

A multi-tissue view on telomere dynamics and postnatal growth

Trade-offs between growth and self-maintenance are common in nature, such that early-life effects on growth can generate lasting consequences on survival and longevity. Telomeres-putative biomarkers of self-maintenance-may link early growth with these later phenotypic effects, but evidence for growth-telomere trade-offs is mixed. Null or even positive relationships between growth and telomeres may be driven by heterogeneity in resource availability or invariable allocation towards telomere maintenance within a population. We used nestling tree swallows (Tachycineta bicolor) to assess the directionality and timing of relationships between growth and telomere length in several tissues. We focused on two important phases of growth: first, the peak of postnatal growth occurring around 6 days old when nestlings grow by ~33% in a single day, and subsequently, the later phase of growth occurring as body mass plateaus near adult size at 12 days old. We quantified telomere attrition in blood during postnatal growth, as well as telomere length in the blood, brain, adrenals, and liver at 12 days old. Growth was unrelated to telomere length in the liver and telomere dynamics in blood. However, brain telomere length was positively correlated with peak growth, and adrenal telomere length was positively related to later growth, particularly for chicks that had experienced a temporary stressor. These observations suggest that variation in resource availability may mask trade-offs, generating positive correlations between growth and telomere length at the population level. They also provide insights into complex relationships between growth and self-maintenance that can be revealed by looking in multiple tissues.

[Gerontological aspects of eye diseases]

The global rate of aging is rapidly rising due to the increase in life expectancy, and the number of age-related diseases - including eye diseases - is increasing. The most common eye conditions affecting people over 50 years old are age-related macular degeneration, cataract, glaucoma and diabetic retinopathy. Timely and effective treatment of age-related eye diseases requires a deeper understanding of the cellular mechanisms of aging.