Total extract of Abelmoschus manihot L. alleviates uric acid-induced renal tubular epithelial injury via inhibition of caspase-8/caspase-3/NLRP3/GSDME signaling.

Purpose: The incidence of uric acid (UA)-induced kidney injury is increasing owing to the high incidence of hyperuricemia in recent years. The flower of Abelmoschus manihot (Linneus) Medik is a traditional Chinese medicinal herb widely used in the treatment of some kidney diseases. In our previous study, we reported that the total extract of A. manihot L. flower (TEA) attenuated adriamycin-induced renal tubular cell injury. In this study, we aimed to evaluate the role of TEA in UA-induced tubular cell injury. Methods: Normal rat proximal epithelial NRK-52E cells were incubated with UA to mimic hyperuricemia conditions. The role of TEA in the renal tubular cells was also assessed. The cellular morphology was observed using phase-contrast microscopy, and cell viability was analyzed using the Cell Counting kit-8. Living and dead cells were stained using a Calcein-AM/PI double stain kit. The release of lactate dehydrogenase (LDH) was analyzed by LDH cytotoxicity Assay Kit. The expression of target proteins was analyzed using western blot analysis. Results: UA triggered NRK-52E cell injury, as evidenced by morphological changes, detachment of cells from the bottom, cell swelling, large bubbles blowing from cell membrane and loss of cell viability. UA increased release of LDH. UA induced the expression of p-ERK1/2 and the subsequent activation of caspase-8, caspase-3, and NLRP3 inflammasomes. Pyroptosis was elicited by UA after gasdermin E N-terminal (GSDME-NT) was cleaved from gasdermin E (GSDME). Z-DEVD-FMK, a caspase-3 inhibitor, suppressed the expression of both NLRP3 and GSDME-NT, but not that of caspase-8. INF39, an NLRP3 inhibitor, altered the expression of GSDME-NT expression, but not that caspase-3 and caspase-8. TEA alleviated UA-induced cell injury by suppressing ERK1/2/caspase-8/caspase-3/NLRP3/GSDME signaling. Conclusion: GSDME-mediated pyroptosis was involved in UA-induced renal tubular cell injury. This is the first study to report that TEA protects renal tubular epithelial cells against UA by inhibiting the ERK/1/2/caspase-8/caspase-3/NLRP3/GSDME pathway.

16-Channel Organic Electrochemical Transistor Array for In Vitro Conduction Mapping of Cardiac Action Potential.

16-Channel organic electrochemical transistor arrays (OECTs) are developed for mapping the propagation and studying the characteristics of action potentials of primary cardiomyocytes. The physiological activities of a rat cardiomyocyte monolayer during a long-term culturing is revealed by this biocompatible, low-cost, and high transconductance organic electronic device. OECT has great potential to be used in cardiac and neuronal drug screening.

[Protective effects of luteolin on neurons against oxygen-glucose deprivation/reperfusion injury via improving Na+/K+ -ATPase activity].

OBJECTIVE: Luteolin, a flavone, has considerable neuroprotective effects by its anti-oxidative mechanism. However, it is still unclear whether luteolin can protect neurons against oxygen-glucose deprivation/reperfusion (OGD/R) induced injury. METHOD: After 2 hours oxygen-glucose deprivation and 24 hours reperfusion treatment in primary cultured hippocampal neurons, the neuron viability, survival rate and apoptosis rate were evaluated by MTT assay, lactate dehydrogenase (LDH) leakage assay and Hoechst staining, respectively. The activity of Na+/K+ -ATPase was examined in cultured neurons or in the hippocampus of SD rats treated by 10 minutes global cerebral ischemia and followed 24 hours reperfusion. RESULT: Treatment by OGD/R markedly reduced neuronal viability, increased LDH leakage rate and increased apoptosis rate. Application of luteolin (10-100 micromol x L(-1)) during OGD inhibited OGD/R induced neuron injury and apoptosis in a dose-dependent manner. Compared to the control group or OGP/R-treated neurons, the activity of Na+/K+ -ATPase was significantly suppressed in global ischemia/reperfusion group or OGD/R-treated neurons. Application of luteolin during ischemia or OGD preserved the Na+/K+ -ATPase activity. Furthermore, inhibition of Na+/K+ -ATPase with ouabain attenuated the protective effect afforded by luteolin. CONCLUSION: The data provide the evidence that luteolin has neuroprotective effect against OGD/R induced injury and the protective effect may be associated with its ability to improve Na+/K+ -ATPase activity after OGD/R.