Resveratrol inhibits the progression of premature senescence partially by regulating v-rel avian reticuloendotheliosis viral oncogene homolog A (RELA) and sirtuin 1 (SIRT1)

Cellular senescence in acute kidney injury: Target and opportunity

Acute kidney injury (AKI) is a common clinical disease with a high incidence and mortality rate. It typically arises from hemodynamic alterations, sepsis, contrast agents, and toxic drugs, instigating a series of events that culminate in tissue and renal damage. This sequence of processes often leads to acute renal impairment, prompting the initiation of a repair response. Cellular senescence is an irreversible arrest of the cell cycle. Studies have shown that renal cellular senescence is closely associated with AKI through several mechanisms, including the promotion of oxidative stress and inflammatory response, telomere shortening, and the down-regulation of klotho expression. Exploring the role of cellular senescence in AKI provides innovative therapeutic ideas for both the prevention and treatment of AKI. Furthermore, it has been observed that targeted removal of senescent cells in vivo can efficiently postpone senescence, resulting in an enhanced prognosis for diseases associated with senescence. This article explores the effects of common anti-senescence drugs senolytics and senostatic and lifestyle interventions on renal diseases, and mentions the rapid development of mesenchymal stem cells (MSCs). These studies have taken senescence-related research to a new level. Overall, this article comprehensively summarizes the studies on cellular senescence in AKI, aiming is to elucidate the relationship between cellular senescence and AKI, and explore treatment strategies to improve the prognosis of AKI.

Diet and Aging: The Role of Polyphenol-Rich Diets in Slow Down the Shortening of Telomeres: A Review

The ends of human chromosomes are defended by DNA-protein complexes named telomeres, which inhibit the chromosomes from fusing with each other and from being known as a double-strand break by DNA reparation proteins. Telomere length is a marker of biological aging, and disfunction of telomeres is related to age-related syndromes. Telomere attrition has been shown to be accelerated by oxidative stress and inflammation. Telomere length has been proven to be positively linked with nutritional status in human and animal scientific research as several nutrients influence it through mechanisms that imitate their function in cellular roles including oxidative stress and inflammation. Data reported in this article support the idea that following a low-in-fat and rich-plant polyphenols food diet seems to be able to slow down the shortening of telomeres.

The Ethanolic Extract of Lycium ruthenicum Ameliorates Age-Related Physiological Damage in Mice

Aging and age-related diseases are important study topics due to their associations with progressive physiological damage to genes, cells, tissues, and the entire organism, which ultimately affects the functional efficiency of organs. Lycium ruthenicum Murr. is a functional food that is known for its high contents of anthocyanins and spermidines, both of which have been demonstrated to have positive effects on anti-aging activity and anti-oxidation. In this study, we used HPLC-MS to analyze the constituents of L. ruthenicum Murr. Extract (LRM) and investigated their potential mechanism for exerting antioxidative effects in D-galactose (D-Gal) aging model mice. LRM (25 mg/kg, 50 mg/kg, and 100 mg/kg) improved cognitive function in D-Gal-treated mice, as shown by reduced escape latencies and increased platform crossings in behavioral tests. We measured the contents of lipid peroxidation (LPO) and malondialdehyde (MDA) and the enzyme activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in mice serum and brain after 6 weeks of D-Gal treatment. LRM decreased the contents of LPO and MDA and increased the enzyme activities of SOD and GSH-Px, indicating the protection effect of LRM against D-Gal-induced oxidative stress. Additionally, LRM can inhibit oxidative stress in cells by reducing intracellular ROS levels and restoring mitochondrial membrane potential, thereby inhibiting paraquat (PQ)-induced cellular senescence and delaying cell aging. Therefore, LRM has the potential to be a healthcare product for the treatment of age-related diseases.

Walnut Kernel Oil and Defatted Extracts Enhance Mesenchymal Stem Cell Stemness and Delay Senescence

Decreased stemness and increased cellular senescence impair the ability of mesenchymal stem cells (MSCs) to renew themselves, change into different cell types, and contribute to regenerative medicine. There is an urgent need to discover new compounds that can boost MSCs' stemness and delay senescence. Therefore, this study aimed to investigate the impact of walnut kernel oil (WKO) and defatted (WKD) extracts on bone marrow (BM)-MSC stemness and senescence. Premature senescence and inflammation were induced in BM-MSCs using H2O2 and LPS, respectively. Phytochemical constituents of WKO and WKD extracts were detected by HPLC. The stemness (proliferation and migration), senescence-related markers (p53, p21, SIRT1, and AMPK), oxidative stress/antioxidant markers, inflammatory cytokines, and cell cycle of BM-MSCs were measured by MTT assay, qPCR, ELISA, and flow cytometry. WKO and WKD extracts improved rat BM-MSC stemness, as evidenced by (1) increased cell viability, (2) decreased apoptosis (low levels of Bax and caspase3 and high levels of Bcl2), (3) upregulated MMP9 and downregulated TIMP1 expression, and (4) cell cycle arrest in the G0/G1 phase and declined cell number in the S and G2/M phases. Additionally, WKO and WKD extracts reduced rat BM-MSC senescence, as indicated by (1) decreased p53 and p21 expression, (2) upregulated expression and levels of SIRT1 and AMPK, (3) reduced levels of ROS and improved antioxidant activity (higher activity of CAT, SOD, and GPx and upregulated expression of NrF2 and HO-1), and (4) declined levels of TNFα, IL1β, and NF-κB. When compared to the WKO extract, the WKD extract had a greater impact on the induction of stemness and reduction of senescence of BM-MSCs due to its stronger antioxidant activity, which could be attributed to its higher levels of flavonoids and phenolic compounds, as detected by HPLC analysis. WKO and WKD extracts enhance rat BM-MSC stemness and protect them from senescence, suggesting their potential use as enhancers to increase MSCs' therapeutic efficacy.

Resveratrol plays an anti-fibrotic and anti-autophagy role by stimulating miR-192-5p expression in urethral fibrosis

BACKGROUND

Resveratrol (RSV) exerts anti-fibrotic effects on various fibrotic diseases. Whereas the biological role of RSV on urethral fibrosis remains to be elucidated. This study aimed to determine the mechanisms by which RSV affects urethral fibrosis and autophagy.

METHODS

Sprague‒Dawley rats and primary fibroblasts were treated with transforming growth factor-β1 (TGFβ1) to generate in vivo and in vitro fibrosis models. Then, those were treated with RSV, and autophagy and fibrosis-related indicators were tested.

RESULTS

Firstly, we found that RSV reversed the upregulation of indicators related to TGFβ1-induced fibrosis (TGFβ1, α-smooth muscle actin, collagen type I, and collagen type III), autophagy (TFEB and LC3), and TGFβR1/Smad4 pathway, as well as the downregulation of p62 and miR-192-5p expression both in vivo and in vitro. Overexpression of miR-192-5p suppressed the upregulation of fibrosis-related markers expression, as well as TFEB and LC3 expression, induced by TGFβ1, while the expression trend of p62 was the opposite. Inhibiting miR-192-5p reversed the effects of RSV on the model group cells. It was also shown that RSV combined with sh-Smad4 inhibited autophagy more effectively than RSV alone.

CONCLUSION

These results suggest that RSV inhibits urinary fibrosis and autophagy via the miR-192-5p/TGFβR1/Smad4 pathway. RAV may be a potential drug for alleviating urethral fibrosis.

Sirtuins, resveratrol and the intertwining cellular pathways connecting them

Sirtuins are a family of NAD+-dependent deacylases with numerous physiological and pathological implications, which lately became an attractive therapeutic target. Sirtuin-activating compounds (STACs) could be useful in disease prevention and treatment. Despite its bioavailability issues, resveratrol exerts a myriad of beneficial effects, known as the "resveratrol paradox". Modulation of sirtuins' expression and activity may, in fact, underlie many of resveratrol revered actions; however, the cellular pathways affected by modulating the activity of each sirtuin isoform, in different physio-pathological conditions, are not fully known. The purpose of this review was to summarize recent reports concerning the effects of resveratrol on the activity of sirtuins in different experimental settings, focusing on in vitro and in vivo preclinical studies. Most reports concern SIRT1, however recent studies dive into the effects initiated via other isoforms. Numerous cellular signaling pathways were reported to be modulated by resveratrol in a sirtuin-dependent manner (increased phosphorylation of MAPKs, AKT, AMPK, RhoA, BDNF, decreased activation of NLRP3 inflammasome, NF-κB, STAT3, upregulation of SIRT1/SREBP1c pathway, reduced β-amyloid via SIRT1-NF-κB-BACE1 signaling and counteracting mitochondrial damage by deacetylating PGC-1α). Thus, resveratrol may be the ideal candidate in the search for STACs as a tool for preventing and treating inflammatory and neurodegenerative diseases.

Polystyrene microplastics mediate inflammatory responses in the chicken thymus by Nrf2/NF-κB pathway and trigger autophagy and apoptosis

Microplastics (MPs) are now a hot environmental contaminant. However, researchers paid little attention to their effects on immune organs such as the thymus. Here, we exposed chickens to a concentration gradient of polystyrene microplastics (PS-MPs) and then followed the decrease in the thymus index. HE staining showed cellular infiltration in the thymus. The assay kit corroborated that PS-MPs impelled oxidative stress in the thymus: increased MDA levels, downregulated antioxidants such as SOD, CAT, and GSH, and significantly undermined total antioxidant capacity. Western blotting and qRT-PCR results showed that Nrf2/NF-κB, Bcl-2/Bax, and AKT signaling pathways were activated in the thymus after exposure to PS-MPs. It stimulated the increased expression of downstream such as IL-1β, caspase-3, and Beclin1, triggering thymus inflammation, apoptosis, and autophagy. This study provides new insights into the field of microplastic immunotoxicity and highlights potential environmental hazards in poultry farming.

Antisenescence ZIF-8/Resveratrol Nanoformulation with Potential for Enhancement of Bone Fracture Healing in the Elderly

Accumulation of senescent cells in the elderly impairs bone homeostasis. It is important to alleviate cell senescence and scavenge excessive oxidative stress for enhanced bone fracture healing in elderly patients. In this study, resveratrol (RSV), an antioxidant drug, was encapsulated in a biocompatible zeolitic imidazolate framework-8 (ZIF-8) nanoparticle to protect it from oxidation and improve its bioavailability. Cells responsible for bone healing, including osteoblasts, bone marrow-derived mesenchymal stem cells (BMSCs), macrophages, and endothelial cells, were used to evaluate the regulatory role of the nanoformulation in the alleviation of cellular senescence and promotion of cell functions. It was proved that the nanoformulation sustainably released RSV with well-preserved bioactivity and improved bioavailability. Cell experiments confirmed that ZIF-8/RSV was capable of alleviating the senescence of cells [human osteoblasts (HOBs), BMSCs, H₂O₂-induced senescent vascular endothelial cells (HUVECs)] and scavenging excessive intracellular reactive oxygen species (ROS). Excitingly, the ZIF-8/RSV improved the osteogenic ability of senescent osteoblasts and promoted macrophage M2 polarization. In addition, the ZIF-8/RSV also enhanced the angiogenic function of senescent HUVECs. More importantly, the ZIF-8/RSV nanoformulation outperformed the REV alone, indicating the critical role of encapsulation using ZIF-8. These findings suggest that the ZIF-8/RSV nanoformulation exhibits potential for bone fracture treatment in elderly patients.

Enhancers of mesenchymal stem cell stemness and therapeutic potency

Mesenchymal stem cells (MSCs) are multipotent stromal cells that can differentiate into a range of cell types, including osteoblasts, chondrocytes, myocytes, and adipocytes. Multiple preclinical investigations and clinical trials employed enhanced MSCs-dependent therapies in treatment of inflammatory and degenerative diseases. They have demonstrated considerable and prospective therapeutic potentials even though the large-scale use remains a problem. Several strategies have been used to improve the therapeutic potency of MSCs in cellular therapy. Treatment of MSCs utilizing pharmaceutical compounds, cytokines, growth factors, hormones, and vitamins have shown potential outcomes in boosting MSCs' stemness. In this study, we reviewed the current advances in enhancing techniques that attempt to promote MSCs' therapeutic effectiveness in cellular therapy and stemness in vivo with potential mechanisms and applications.

The Molecular Mechanism of Polyphenols in the Regulation of Ageing Hallmarks

Ageing is a complex process characterized mainly by a decline in the function of cells, tissues, and organs, resulting in an increased risk of mortality. This process involves several changes, described as hallmarks of ageing, which include genomic instability, telomere attrition, epigenetic changes, loss of proteostasis, dysregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell depletion, and altered intracellular communication. The determining role that environmental factors such as diet and lifestyle play on health, life expectancy, and susceptibility to diseases, including cancer and neurodegenerative diseases, is wellestablished. In view of the growing interest in the beneficial effects of phytochemicals in the prevention of chronic diseases, several studies have been conducted, and they strongly suggest that the intake of dietary polyphenols may bring numerous benefits due to their antioxidant and anti-inflammatory properties, and their intake has been associated with impaired ageing in humans. Polyphenol intake has been shown to be effective in ameliorating several age-related phenotypes, including oxidative stress, inflammatory processes, impaired proteostasis, and cellular senescence, among other features, which contribute to an increased risk of ageing-associated diseases. This review aims to address, in a general way, the main findings described in the literature about the benefits of polyphenols in each of the hallmarks of ageing, as well as the main regulatory mechanisms responsible for the observed antiageing effects.

Aging of mesenchymal stem cell: machinery, markers, and strategies of fighting

Human mesenchymal stem cells (MSCs) are primary multipotent cells capable of differentiating into osteocytes, chondrocytes, and adipocytes when stimulated under appropriate conditions. The role of MSCs in tissue homeostasis, aging-related diseases, and cellular therapy is clinically suggested. As aging is a universal problem that has large socioeconomic effects, an improved understanding of the concepts of aging can direct public policies that reduce its adverse impacts on the healthcare system and humanity. Several studies of aging have been carried out over several years to understand the phenomenon and different factors affecting human aging. A reduced ability of adult stem cell populations to reproduce and regenerate is one of the main  contributors to the human aging process. In this context, MSCs senescence is a major challenge in front of cellular therapy advancement. Many factors, ranging from genetic and metabolic pathways to extrinsic factors through various cellular signaling pathways, are involved in regulating the mechanism of MSC senescence. To better understand and reverse cellular senescence, this review highlights the underlying mechanisms and signs of MSC cellular senescence, and discusses the strategies to combat aging and cellular senescence.

Stress-induced premature senescence is associated with a prolonged QT interval and recapitulates features of cardiac aging

Rationale: Aging in the heart is a gradual process, involving continuous changes in cardiovascular cells, including cardiomyocytes (CMs), namely cellular senescence. These changes finally lead to adverse organ remodeling and resulting in heart failure. This study exploits CMs from human induced pluripotent stem cells (iCMs) as a tool to model and characterize mechanisms involved in aging. Methods and Results: Human somatic cells were reprogrammed into human induced pluripotent stem cells and subsequently differentiated in iCMs. A senescent-like phenotype (SenCMs) was induced by short exposure (3 hours) to doxorubicin (Dox) at the sub-lethal concentration of 0.2 µM. Dox treatment induced expression of cyclin-dependent kinase inhibitors p21 and p16, and increased positivity to senescence-associated beta-galactosidase when compared to untreated iCMs. SenCMs showed increased oxidative stress, alteration in mitochondrial morphology and depolarized mitochondrial membrane potential, which resulted in decreased ATP production. Functionally, when compared to iCMs, SenCMs showed, prolonged multicellular QTc and single cell APD, with increased APD variability and delayed afterdepolarizations (DADs) incidence, two well-known arrhythmogenic indexes. These effects were largely ascribable to augmented late sodium current (I_NaL) and reduced delayed rectifier potassium current (Ikr). Moreover sarcoplasmic reticulum (SR) Ca²⁺ content was reduced because of downregulated SERCA2 and increased RyR2-mediated Ca²⁺ leak. Electrical and intracellular Ca²⁺ alterations were mostly justified by increased CaMKII activity in SenCMs. Finally, SenCMs phenotype was furtherly confirmed by analyzing physiological aging in CMs isolated from old mice in comparison to young ones. Conclusions: Overall, we showed that SenCMs recapitulate the phenotype of aged primary CMs in terms of senescence markers, electrical and Ca²⁺ handling properties and metabolic features. Thus, Dox-induced SenCMs can be considered a novel in vitro platform to study aging mechanisms and to envision cardiac specific anti-aging approach in humans.