An antioxidant suppressed lung cellular senescence and enhanced pulmonary function in aged mice

Ex vivo Anti-Senescence Activity of N-Acetylcysteine in Visceral Adipose Tissue of Obese Volunteers

INTRODUCTION

Excessive visceral adiposity is known to drive the onset of metabolic derangements, mostly involving oxidative stress, prolonged inflammation, and cellular senescence. N-acetylcysteine (NAC) is a synthetic form of l-cysteine with potential antioxidant, anti-inflammatory, and anti-senescence properties. This ex-vivo study aimed to determine the effect of NAC on some markers of senescence including β-galactosidase activity and p16, p53, p21, IL-6, and TNF-α gene expressions in visceral adipose tissue in obese adults.

METHODS

This ex-vivo experimental study involved 10 obese participants who were candidates for bariatric surgery. Duplicate biopsies from the abdominal visceral adipose tissue were obtained from the omentum. The biopsies were treated with or without NAC (5 and 10 mm). To evaluate adipose tissue senescence, beta-galactosidase (β-gal) activity and the expression of P16, P21, P53, IL-6, and TNF-α were determined. ANOVA test was employed to analyze the varying markers of cellular senescence and inflammation between treatment groups.

RESULTS

The NAC at concentrations of 5 mm and 10 mm resulted in a noteworthy reduction β-gal activity compared to the control group (p < 0.001). Additionally, the expression of P16, P21, and IL-6 was significantly reduced following treatment with NAC (5 mm) and NAC (10 mm) compared to the control group (All p < 0.001).

DISCUSSION/CONCLUSION

Taken together, these data suggest the senotherapeutic effect of NAC, as it effectively reduces the activity of SA-β-gal and the expression of IL-6, P16, and P21 genes in the visceral adipose tissue of obese individuals.

Epigenetic regulation of aging: implications for interventions of aging and diseases

Aging is accompanied by the decline of organismal functions and a series of prominent hallmarks, including genetic and epigenetic alterations. These aging-associated epigenetic changes include DNA methylation, histone modification, chromatin remodeling, non-coding RNA (ncRNA) regulation, and RNA modification, all of which participate in the regulation of the aging process, and hence contribute to aging-related diseases. Therefore, understanding the epigenetic mechanisms in aging will provide new avenues to develop strategies to delay aging. Indeed, aging interventions based on manipulating epigenetic mechanisms have led to the alleviation of aging or the extension of the lifespan in animal models. Small molecule-based therapies and reprogramming strategies that enable epigenetic rejuvenation have been developed for ameliorating or reversing aging-related conditions. In addition, adopting health-promoting activities, such as caloric restriction, exercise, and calibrating circadian rhythm, has been demonstrated to delay aging. Furthermore, various clinical trials for aging intervention are ongoing, providing more evidence of the safety and efficacy of these therapies. Here, we review recent work on the epigenetic regulation of aging and outline the advances in intervention strategies for aging and age-associated diseases. A better understanding of the critical roles of epigenetics in the aging process will lead to more clinical advances in the prevention of human aging and therapy of aging-related diseases.

Circular RNA expression profiles in human bronchial epithelial cells treated with beryllium sulfate

Circular RNAs (circRNAs), is a novel type of endogenous non-coding RNAs (ncRNAs) participated in the pathogenesis of many diseases. Beryllium is one of the carcinogenesis elements. However, the mechanism and function of circRNAs in human bronchial epithelial cells (16HBE) induced by beryllium sulfate (BeSO₄) was rarely reported. Therefore, the high-throughput RNA sequencing analysis was performed to detect the circRNA profiles between control groups and BeSO₄-induced groups. Furthermore, circRNA-miRNA-mRNA network, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and PPI network analysis were used for bioinformatics analysis. CircRNA sequencing analysis revealed that 36 circRNAs were up-regulated and 35 circRNAs were down-regulated in the BeSO₄-exposed groups. The selected circRNAs were verified by real-time fluorescent quantitative PCR (qRT-PCR). Hsa_circ_0004214 and hsa_circ_0003586 were validated to be up-regulated, hsa_circ_0047958, hsa_circ_0001944, and hsa_circ_0008982 were down-regulated. The circRNA-miRNA-mRNA network annotated the key signaling pathway including cellular senescence, TNF signaling pathway, NF-kappa B signaling pathway, HIF-1 signaling pathway, and Hippo signaling pathway. The PPI network indicated the most circRNAs might participate in the BeSO₄ toxicity by acting as a sponge for the miR-663b through JAK-STAT signaling pathway. In summary, our study suggests that circRNAs may play roles in the mechanism of beryllium toxicity.

Cellular senescence promotes cancer metastasis by enhancing soluble E-cadherin production

Cellular senescence acts as a potent tumor-suppression mechanism in mammals; however, it also promotes tumor progression in a non-cell-autonomous manner. We provided insights into the mechanism underlying senescence-dependent metastatic cancer development. The elimination of senescent cells suppressed the lung metastasis of melanoma cells. Using an antibody array screening of humoral factor(s) that depend on cellular senescence, we identified soluble E-cadherin (seCad) as a potential mediator of the senescence-induced melanoma metastasis. seCad enhanced the invasive activity of melanoma cells both in vitro and in vivo, and gene expression profiling revealed that seCad induced genes associated with poor prognosis in patients with melanoma. An analysis of sera from patients revealed that serum seCad is associated with distant metastasis. Our data suggest that senescent cells promote metastatic lung cancer through seCad, and that seCad may be a potential diagnostic marker as well as a therapeutic target for metastatic lung cancer.