Canagliflozin Delays Aging of HUVECs Induced by Palmitic Acid via the ROS/p38/JNK Pathway

Regulation of ENPP5, a senescence-associated secretory phenotype factor, prevents skin aging

Aging negatively affects the appearance and texture of the skin owing to the accumulation of senescent fibroblasts within the dermis. Senescent cells undergo abnormal remodeling of collagen and the extracellular matrix through an inflammatory histolytic senescence-associated secretory phenotype (SASP). Therefore, suppression of SASP in senescent cells is essential for the development of effective skin anti-aging therapies. Ectonucleotide pyrophosphatase/phosphodiesterase family member 5 (ENPP5), an extracellular signaling molecule, has been implicated in vascular aging and apoptosis; however, its role in SASP remains unclear. Therefore, this study aimed to investigate the role of ENPP5 in SASP and skin aging using molecular techniques. We investigated the effects of siRNA-mediated ENPP5 knockdown, human recombinant ENPP5 (rENPP5) treatment, and lentiviral overexpression of ENPP5 on SASP and aging in human skin fibroblasts. Additionally, we investigated the effect of siRNA-mediated ENPP5 knockdown on the skin of C57BL/6 mice. We found that ENPP5 was significantly expressed in replication-aged and otherwise DNA-damaged human skin fibroblasts and that treatment with human rENPP5 and lentiviral overexpression of ENPP5 promoted SASP and senescence. By contrast, siRNA-mediated knockdown of ENPP5 suppressed SASP and the expression of skin aging-related factors. Additionally, ENPP5 knockdown in mouse skin ameliorated the age-related reduction of subcutaneous adipose tissue, the panniculus carnosus muscle layer, and thinning of collagen fibers. Conclusively, these findings suggest that age-related changes may be prevented through the regulation of ENPP5 expression to suppress SASP in aging cells, contributing to the development of anti-aging treatments for the skin.

Modulation of fracture healing by senescence-associated secretory phenotype (SASP): a narrative review of the current literature

The senescence-associated secretory phenotype (SASP) is a generic term for the secretion of cytokines, such as pro-inflammatory factors and proteases. It is a crucial feature of senescent cells. SASP factors induce tissue remodeling and immune cell recruitment. Previous studies have focused on the beneficial role of SASP during embryonic development, wound healing, tissue healing in general, immunoregulation properties, and cancer. However, some recent studies have identified several negative effects of SASP on fracture healing. Senolytics is a drug that selectively eliminates senescent cells. Senolytics can inhibit the function of senescent cells and SASP, which has been found to have positive effects on a variety of aging-related diseases. At the same time, recent data suggest that removing senescent cells may promote fracture healing. Here, we reviewed the latest research progress about SASP and illustrated the inflammatory response and the influence of SASP on fracture healing. This review aims to understand the role of SASP in fracture healing, aiming to provide an important clinical prevention and treatment strategy for fracture. Clinical trials of some senolytics agents are underway and are expected to clarify the effectiveness of their targeted therapy in the clinic in the future. Meanwhile, the adverse effects of this treatment method still need further study.

Antibacterial Activity and Mechanism of Canagliflozin against Methicillin-Resistant Staphylococcus aureus

Diabetic foot infection (DFI) is a common complication in diabetes patients, with foot infections being the leading cause of amputations. Staphylococcus aureus is frequently found in diabetic foot infections, of which methicillin-resistant Staphylococcus aureus (MRSA) has become a major clinical and epidemiological challenge. Since MRSA strains are resistant to most β-lactam antibiotics, and also partially resistant to other antibiotics, treatment is difficult and costly. The emergence of drug-resistant bacteria often arises from overuse or misuse of antibiotics. Clinically, canagliflozin is commonly used for the treatment of type 2 diabetes. On this basis, we investigated the antibacterial activity and mechanism of canagliflozin against MRSA, with the aim to discover novel functions of canagliflozin and provide new insights for the treatment of MRSA. Using the microbroth dilution method to determine the half maximal inhibitory concentration of drugs, we found that canagliflozin not only can inhibit the growth of methicillin-sensitive Staphylococcus aureus (MSSA) but also exhibits antibacterial activity against MRSA. The IC50 values, at approximately 56.01 μM and 57.60 μM, were almost the same. At 12 h, canagliflozin showed a significant antibacterial effect against MRSA at and above 30 μM. In addition, its combined use with penicillin achieved better antibacterial effects, which were increased by about three times. Additive antibacterial activity (FICI = 0.69) was found between penicillin and canagliflozin, which was better than that of doxycycline and canagliflozin (FICI = 0.95). Canagliflozin also affected bacterial metabolic markers, such as glucose, ATP, and lactic acid. The results of crystal violet staining indicate that canagliflozin disrupted the formation of bacterial biofilm. Our electron microscopy results showed that canagliflozin distorted the bacterial cell wall. The results of RT-PCR suggest that canagliflozin down-regulated the expressions of biofilm-related gene (clfA, cna, agrC, mgrA, hld) and methicillin-resistance gene (mecA), which was related to MRSA. Molecular docking also indicated that canagliflozin affected some interesting targets of MRSA, such as the sarA, crtM and fnbA proteins. In conclusion, canagliflozin exhibits antibacterial activity against MRSA by affecting bacterial metabolism, inhibiting its biofilm formation, distorting the bacterial cell wall, and altering the gene expression of biofilm formation and its virulence. Our study reveals the antibacterial activity of canagliflozin against MRSA, providing a new reference for treating diabetic foot infections.