Fatty acid oxidation regulates cellular senescence by modulating the autophagy-SIRT1 axis

Renal Fibrosis: SIRT1 Still of Value

Chronic kidney disease (CKD) is a major global health concern. Renal fibrosis, a prevalent outcome regardless of the initial cause, ultimately leads to end-stage renal disease. Glomerulosclerosis and renal interstitial fibrosis are the primary pathological features. Preventing and slowing renal fibrosis are considered effective strategies for delaying CKD progression. However, effective treatments are lacking. Sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase belonging to class III histone deacetylases, is implicated in the physiological regulation and protection of the kidney and is susceptible to a diverse array of pathological influences, as demonstrated in previous studies. Interestingly, controversial conclusions have emerged as research has progressed. This review provides a comprehensive summary of the current understanding and advancements in the field; specifically, the biological roles and mechanisms of SIRT1 in regulating renal fibrosis progression. These include aspects such as lipid metabolism, epithelial-mesenchymal transition, oxidative stress, aging, inflammation, and autophagy. This manuscript explores the potential of SIRT1 as a therapeutic target for renal fibrosis and offers new perspectives on treatment approaches and prognostic assessments.

Modulation of atherosclerosis-related signaling pathways by Chinese herbal extracts: Recent evidence and perspectives

Atherosclerotic cardiovascular disease remains a preeminent cause of morbidity and mortality globally. The onset of atherosclerosis underpins the emergence of ischemic cardiovascular diseases, including coronary heart disease (CHD). Its pathogenesis entails multiple factors such as inflammation, oxidative stress, apoptosis, vascular endothelial damage, foam cell formation, and platelet activation. Furthermore, it triggers the activation of diverse signaling pathways including Phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), NF-E2-related factor 2/antioxidant response element (Nrf2/ARE), the Notch signaling pathway, peroxisome proliferator-activated receptor (PPAR), nucleotide oligo-structural domain-like receptor thermoprotein structural domain-associated protein 3 (NLRP3), silencing information regulator 2-associated enzyme 1 (Sirt1), nuclear transcription factor-κB (NF-κB), Circular RNA (Circ RNA), MicroRNA (mi RNA), Transforming growth factor-β (TGF-β), and Janus kinase-signal transducer and activator of transcription (JAK/STAT). Over recent decades, therapeutic approaches for atherosclerosis have been dominated by the utilization of high-intensity statins to reduce lipid levels, despite significant adverse effects. Consequently, there is a growing interest in the development of safer and more efficacious drugs and therapeutic modalities. Traditional Chinese medicine (TCM) offers a vital strategy for the prevention and treatment of cardiovascular diseases. Numerous studies have detailed the mechanisms through which TCM active ingredients modulate signaling molecules and influence the atherosclerotic process. This article reviews the signaling pathways implicated in the pathogenesis of atherosclerosis and the advancements in research on TCM extracts for prevention and treatment, drawing on original articles from various databases including Google Scholar, Medline, CNKI, Scopus, and Pubmed. The objective is to furnish a reference for the clinical management of cardiovascular diseases.

Targeting Senescent Cells as Therapy for CKD

Senescent cells accumulate in the kidney with aging, after acute and chronic injuries, and are present in increased numbers in deteriorating kidney transplants. Senescent cells have undergone permanent cell cycle arrest and release many proinflammatory cytokines/chemokines and profibrotic factors: the senescence-associated secretory phenotype. Recent work from several groups including our own has shown that senescent cells play a causative role in progression of kidney disease. Experimental evidence also indicates that targeting senescent cells has potential to alter the renal regenerative response, reducing progressive fibrosis and improving functional recovery after injury. Research and clinical interest is focused on understanding how accumulating chronic senescent cells link acute injury to progressive fibrosis, dysfunction, and mortality in human CKD. In this review, we outline current protocols for the identification of how senescent cells are identified in vitro and in vivo . We discuss the proposed mechanisms of actions of first-generation senolytic and senomorphic agents, such as ABT-263 (navitoclax) which targets the BCL2 family of survival factors, and senomorphic agents such as metformin which targets aspects of the senescence-associated secretory phenotype. We also review that emerging technologies, such as nanocarriers, are now being developed to have safer delivery systems for senolytics, greater specificity, fewer off-target effects, and less toxicity. Other methods of senescent cell elimination being developed target various immune evasion tactics displayed by these cells. By understanding the role of senescence in kidney homeostasis and disease, developing new, targeted compounds and the tools to allow their efficacy to be charted noninvasively, it should become possible for senolytic treatments to move from the bench to bedside.

The Roles of Caloric Restriction Mimetics in Central Nervous System Demyelination and Remyelination

The dysfunction of myelinating glial cells, the oligodendrocytes, within the central nervous system (CNS) can result in the disruption of myelin, the lipid-rich multi-layered membrane structure that surrounds most vertebrate axons. This leads to axonal degeneration and motor/cognitive impairments. In response to demyelination in the CNS, the formation of new myelin sheaths occurs through the homeostatic process of remyelination, facilitated by the differentiation of newly formed oligodendrocytes. Apart from oligodendrocytes, the two other main glial cell types of the CNS, microglia and astrocytes, play a pivotal role in remyelination. Following a demyelination insult, microglia can phagocytose myelin debris, thus permitting remyelination, while the developing neuroinflammation in the demyelinated region triggers the activation of astrocytes. Modulating the profile of glial cells can enhance the likelihood of successful remyelination. In this context, recent studies have implicated autophagy as a pivotal pathway in glial cells, playing a significant role in both their maturation and the maintenance of myelin. In this Review, we examine the role of substances capable of modulating the autophagic machinery within the myelinating glial cells of the CNS. Such substances, called caloric restriction mimetics, have been shown to decelerate the aging process by mitigating age-related ailments, with their mechanisms of action intricately linked to the induction of autophagic processes.