Protective effects of budesonide on LPS‑induced podocyte injury by modulating macrophage M1/M2 polarization: Evidence from in vitro and in silico studies

Lactobacillus plantarum 45 activates SHP2 through inhibition of oxidative stress to regulate osteoblast and osteoclast differentiation

BACKGROUND

The purpose of this study is to observe LP45 (Lactobacillus plantarum 45) to investigate the mechanism by which LP45 attenuates oxidative stress-induced damage and regulates the osteoblast-osteoclast balance.

MATERIALS AND METHODS

The oxidative stress level and osteoblast- and osteoclast-related proteins were detected by immunofluorescence staining, Western blotting, ROS fluorescent probe and ELISA. Osteoblast cell proliferation capacity was determined by the CCK-8 assay. X-ray observation and HE staining were used to detect the effect of LP45 on osteoporosis.

RESULTS

The expression level of SHP2 and Src was significantly increased, and the expression levels of NOX4, P22, P47, IL-1β, NLRP3, IRF3, RANK, β-catenin and INF-β were inhibited in LP45 group and LPS + LP45 group as compared to those in LPS group. Compared with that in LPS group, the concentration of SOD was increased and the concentration of MDA was decreased in LPS + LP45 group. The protein expressions of OPG, RANKL, RUNX3, RANK and β-catenin in LP45 group and LPS + LP45 group increased. The protein expressions of NF-κB, CREB and AP-1 in LP45 group and LPS + LP45 group decreased significantly. The results were also confirmed by immunofluorescence staining and ROS fluorescent probe. X-ray observation and HE staining showed that LP45 could inhibit the progression of osteoporosis.

CONCLUSION

LP45 can exert its antioxidant effect by inhibiting the production of oxidative stress to activate the SHP2 signaling pathway, thus promoting osteoblast differentiation and repressing osteoclast formation to maintain bone homeostasis and improve bone metabolism.

Desmosterol-driven atypical macrophage polarization regulates podocyte dynamics in diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN) stands as a leading diabetes complication, with macrophages intricately involved in its evolution. While glucose metabolism's impact on macrophage activity is well-established, cholesterol metabolism's contributions remain less explored. Our study seeks to elucidate this association.

METHODS AND RESULTS

Methods and Results: Gene expression analysis of monocytes from the blood of both normal and diabetic patients was conducted using public databases, showing that cholesterol metabolism pathways, especially Bloch and Kandutsch-Russell, were more altered in diabetic monocytes/macrophages than glucose-responsive pathways. When bone marrow-derived macrophages (BMDMs) were subjected to desmosterol, they exhibited an unconventional polarization. These BMDMs displayed heightened levels of both M1-related pro-inflammatory cytokines and M2-linked anti-inflammatory factors. Further, in co-culture, desmosterol-conditioned BMDMs paralleled M2 macrophages in augmenting Ki-67 + podocyte populations while mimicking M1 macrophages in elevating TUNEL + apoptotic podocytes. Comparable outcomes on podocytes were obtained using conditioned media from the respective BMDMs.

CONCLUSIONS

Our data underscores the pivotal role of cholesterol metabolism, particularly via desmosterol, in steering macrophages toward an unconventional polarization marked by both inflammatory and regulatory traits. Such unique macrophage behavior concurrently impacts podocyte proliferation and apoptosis, shedding fresh light on DN pathogenesis and hinting at potential therapeutic interventions.