The interplay between adipokines and pancreatic beta cells, often referred to as the adipo-insular axis, plays a crucial role in regulating metabolic homeostasis. Adipokines are signaling molecules secreted by adipocytes that have profound effects on several physiological processes. Adipokines such as adiponectin, leptin, resistin, and visfatin influence the function of pancreatic beta cells. The reciprocal communication between adipocytes and beta cells is remarkable. Insulin secreted by beta cells affects adipose tissue metabolism, influencing lipid storage and lipolysis. Conversely, adipokines released from adipocytes can influence beta cell function and survival. Chronic obesity and insulin resistance can lead to the release of excess fatty acids and inflammatory molecules from the adipose tissue, contributing to beta cell dysfunction and apoptosis, which are key factors in developing type 2 diabetes. Understanding the complex interplay of the adipo-insular axis provides insights into the mechanisms underlying metabolic regulation and pathogenesis of metabolic disorders. By elucidating the molecular mediators involved in this interaction, new therapeutic targets and strategies may emerge to reduce the risk and progression of diseases, such as type 2 diabetes and its associated complications. This review summarizes the interactions between adipokines and pancreatic beta cells, and their roles in the pathogenesis of diabetes and metabolic diseases.
Junctional proteins in cerebrovascular endothelial cells are essential for maintaining the barrier function of the blood-brain barrier (BBB), thus protecting the brain from the infiltration of pathogens. The present study showed that the potential therapeutic natural compound auraptene (AUR) enhances junction assembly in cerebrovascular endothelial cells by inducing antioxidant enzymes and the mitochondrial unfolded protein response (mtUPR). Treatment of mouse cerebrovascular endothelial cells with AUR enhanced the expression of junctional proteins, such as occludin, zonula occludens-1 (ZO-1) and vascular endothelial cadherin (VE-cadherin), by increasing the levels of mRNA encoding antioxidant enzymes. AUR treatment also resulted in the depolarization of mitochondrial membrane potential and activation of mtUPR. The ability of AUR to protect against ischemic conditions was further assessed using cells deprived of oxygen and glucose. Pretreatment of these cells with AUR protected against damage to junctional proteins, including occludin, claudin-5, ZO-1 and VE-cadherin, accompanied by a stress resilience response regulated by levels of ATF5, LONP1 and HSP60 mRNAs. Collectively, these results indicate that AUR promotes resilience against oxidative stress and improves junction assembly, suggesting that AUR may help maintain intact barriers in cerebrovascular endothelial cells.
Post-translational modifications (PTMs) provide an integrated regulatory layer that couples nutrient and hormonal signals to whole-body energy homeostasis across metabolic organs. PTMs modulate protein activity, localization, stability, and metabolic networks in a tissue- and state-specific manner. Through network remodeling, PTMs integrate receptor signaling with chromatin and organelle function and align transcriptional control with mitochondrial function, proteostasis, and membrane trafficking. PTM crosstalk connects kinase cascades, nutrient-sensing pathways, and ubiquitin-family modifiers to orchestrate gluconeogenesis, lipolysis, glucose uptake, thermogenesis, and insulin secretion in response to nutrient cues. The metabolic state regulates PTM enzymes through changes in cofactors, redox tone, and compartmentalization, and PTM-dependent changes in transcription and signaling feedback to metabolic tone. In obesity and diabetes, dysregulated post translational modification networks disrupt insulin receptor signaling, disturb organelle quality control, and impair beta cell function, which promotes insulin resistance and beta cell failure. Consequently, PTMs organize metabolic information flow and modulate tissue responses to overnutrition and metabolic stress. A systems-level understanding of PTMs clarifies mechanisms of whole-body energy homeostasis and supports the discovery of new therapeutic targets in metabolic disease.