Piezo1 specific deletion in macrophage protects the progression of liver fibrosis in mice.

Background and Aims: Liver fibrosis is the common pathological pathway of chronic liver diseases and its mechanisms of which have not been fully declared. Macrophages play essential roles in progression of liver fibrosis partially by sensing abnormal mechanical signals. The aim of the study is to investigate the functions of macrophage Piezo1, a mechano-sensitive ion channel, in liver fibrosis. Approach and Results: Immunofluorescence in human and murine fibrotic liver samples revealed that expression of macrophage Piezo1 was increased. Myeloid-specific Piezo1 knockout (Piezo1ΔLysM) attenuated liver fibrosis by decreased collagen deposition and epithelial-mesenchymal transition (EMT). In Piezo1ΔLysM mice, less inflammation during development of liver fibrosis was observed by lessened macrophage infiltration, decreased M1 polarization and expression of inflammatory cytokines. RNA-seq data showed macrophage Piezo1 regulated transcription of cathepsin S (CTSS). Piezo1ΔLysM inhibited expression and activity of CTSS in vitro and in vivo and regulated T cell activity. Furthermore, inhibition of CTSS reversed macrophage inflammatory response driven by Piezo1 activation and LPS. Macrophage Piezo1 activation promoted CTSS secretion due to increased activity of Ca2+-dependent calpain protease induced by Ca2+ influx to cleave lysosome-associated membrane protein-1 (LAMP1). Pharmacological inhibition of calpain activity partially blocked Piezo1 mediated CTSS secretion. Conclusions: Macrophage Piezo1 deficiency limits the progression of liver fibrosis by inhibited inflammatory response and decreased secretion of CTSS. These findings suggest that targeting Piezo1 channel may be a potential strategy for treating hepatic fibrosis.

A real-world analysis of tyrosine receptor kinase inhibitor-related toxicities in cancer treatment.

Background: This study analyzed real-world data from 2004 to 2023 to evaluate the toxicity profile of tyrosine receptor kinase (TRK) inhibitor therapy. Method: A retrospective analysis of US FDA Adverse Event Reporting System data was conducted to identify adverse events in patients receiving TRK inhibitor therapy. Result: Entrectinib demonstrated toxicities primarily in the cardiovascular and nervous systems, followed by the renal and urinary system. Common adverse effects included dizziness, renal impairment, constipation, heart failure and taste disorders. Larotrectinib induced adverse events mainly in the hepatobiliary and nervous systems, with peripheral neuropathy, myalgia, renal impairment and increased alanine aminotransferase commonly reported. Conclusion: Careful monitoring and supportive care strategies are essential for managing adverse events associated with TRK inhibitor therapy.

Myeloid Piezo1 Deletion Protects Renal Fibrosis by Restraining Macrophage Infiltration and Activation.

BACKGROUND: Macrophages play important roles in renal fibrosis, partially by sensing mechanical forces, including shear stress and increased stiffness. The mechanically activated cationic channel Piezo1 drives vascular formation and blood pressure regulation to inflammatory responses, or cancer, but its role in macrophages in fibrotic kidney is elusive. Here, we hypothesized that Piezo1 in macrophages may have functions in renal fibrosis. METHODS: We established a genetically engineered mouse model with Piezo1 specific knockout in myeloid cells and challenged with unilateral ureteric obstruction operation and folic acid treatment to induce the renal fibrosis, aiming to investigate the function of the mechanical-sensitive protein Piezo1 in macrophages in renal fibrosis and its underlying mechanisms. RESULTS: Myeloid Piezo1 was indispensable for renal fibrosis generation. Piezo1 gene deletion in the myeloid lineage was protective in mice with renal fibrosis. Further analyses revealed that macrophage accumulation in the injured kidney depended on the Piezo1-regulated C-C motif chemokine ligand 2, C-C motif chemokine receptor 2 pathway, and Notch signaling cascade. Moreover, Piezo1 deletion restrained macrophage inflammation and consequently suppressed kidney fibrosis and epithelial-mesenchymal transition. In vitro assays showed that Piezo1 deficiency blocked lipopolysaccharide and Piezo1 activation-induced inflammatory responses in bone marrow-derived macrophages. Mechanistically, Piezo1 regulated inflammation through the Ca2+-dependent intracellular cysteine protease, as the pharmacological inhibition of calpain blocked the proinflammatory role of Piezo1. CONCLUSIONS: This study characterized the important function of Piezo1 in renal fibrosis. Targeting the Piezo1 channels by genetic or pharmacological manipulations may be a promising strategy for the treatment of renal fibrosis.

Inhibition of chemically and mechanically activated Piezo1 channels as a mechanism for ameliorating atherosclerosis with salvianolic acid B.

BACKGROUND AND PURPOSE: Salvianolic acid B (SalB) is effective for treating cardiovascular diseases. However, the molecular mechanisms underlying its therapeutic effects remain unclear. Mechanosensitive Piezo1 channels play important roles in vascular biology, although their pharmacological properties are poorly defined. Here, we aimed to identify novel Piezo1 inhibitors and gain insights into their mechanisms of action. EXPERIMENTAL APPROACH: Intracellular Ca2+ ions were measured in HUVECs, murine liver endothelial cells (MLECs), THP-1 and RAW264.7 cell lines and bone marrow-derived macrophages (BMDMs). Isometric tensions in mouse thoracic aorta were recorded. Shear-stress assays with HUVECs were conducted. Patch-clamp recordings with mechanical stimulation were performed with HUVECs in whole-cell mode. Foam cell formation was induced by treating BMDMs with oxidised LDL (oxLDL). Atherosclerotic plaque assays were performed with Ldlr-/- and Piezo1 genetically depleted mice on a high-fat diet. KEY RESULTS: Salvianolic acid B inhibited Yoda1-induced Ca2+ influx in HUVECs and MLECs. Similar results were observed in macrophage cell lines and BMDMs. Furthermore, we demonstrated that salvianolic acid B inhibited Yoda1- and mechanically activated currents. Salvianolic acid B suppressed Yoda1-induced aortic ring relaxation and inhibited HUVECs alignment in the direction of shear stress. Additionally, Yoda1 enhanced the formation of foam cells, which was reversed by salvianolic acid B. Salvianolic acid B also inhibited formation of atherosclerotic plaques and was insensitive to Piezo1 genetic depletion. CONCLUSION AND IMPLICATIONS: Our study provides novel mechanistic insights into the inhibitory role of salvianolic acid B against Piezo1 channels and improves our understanding of salvianolic acid B in preventing atherosclerotic lesions.

Dingxin Recipe IV attenuates atherosclerosis by regulating lipid metabolism through LXR-α/SREBP1 pathway and modulating the gut microbiota in ApoE-/- mice fed with HFD.

ETHNOPHARMACOLOGICAL RELEVANCE: Dingxin Recipe (DXR) is a traditional Chinese medicine formula that has been reported to be effective and safe treatment for cardiovascular diseases, such as arrhythmias, coronary heart disease. Dingxin Recipe IV (DXR IV) was further improved from the DXR according to the traditional use. However, the mechanism of DXR IV in atherosclerosis is unclear. AIM OF THE STUDY: This study aimed to illustrate whether DXR IV improve atherosclerosis through modulating the lipid metabolism and gut microbiota in atherosclerosis mice. MATERIALS AND METHODS: 40 male ApoE-/- mice were fed on HFD for 12 weeks and were then treated with DXR IV (1.8, 0.9, or 0.45 g/kg/d) for another 12 weeks. The decroation of DXR IV contains four traditional Chinese medicines: the dried rhizome of Coptis chinensis Franch. (15.09%), the root of Salvia miltiorrhiza Bunge (28.30%), the seed of Ziziphus jujuba Mill. (37.74%) and the fruiting body of Ganoderma lucidum (Leyss.ex Fr.) Karst. (18.87%). 8 male c57BL/6 mice fed a normal diet served as control group. The atherosclerotic plaque was quantified by oil-red O staining and masson trichrome staining. Mice feces were collected. The gut micobiota were detected by 16S rRNA gene sequencing and fecal metabolites were analyzed by 1H NMR spectroscopy. The effect of DXR IV on blood lipids (TG, TC, LDL-C, HDL-C) was investigated. The lipid metabolism related genes were determined by RT-qPCR and western blotting respectively. RESULTS: DXR IV exerted the anti-atherosclerosis effect by inhibiting the excessive cholesterol deposition in aorta and regulating the level of TG, TC, LDL-C and HDL-C. The composition of gut microbiota was changed. Interestingly, the relative abundance of Muribaculaceae and Ruminococcaceae increased after DXR IV administration, whereas the abundance of Erysipelotrichaceae decreased, which have been beneficial to lipid metabolism. Nine potential metabolic biomarkers, including acetate, butyrate, propionate, alanine, succinate, valerate, xylose, choline, glutamate, were identified, which were related to fatty acid metabolism. Further, the pathway of fatty acid was detected by the RT-qPCR and western blotting. Compared with model group, the level of LXR-α and SREBP1 decreased significantly in DXR IV group while LXR-ß, SREBP2 showed no statistical significance. It indicated that DXR IV modulated lipid metabolism by LXR-α/SREBP1 but not LXRß and SREBP2. CONCLUSIONS: DXR IV exhibits potential anti-atherosclerosis effect, which is closely related to lipid metabolism and the gut microbiota. This study may provide novel insights into the mechanism of DXR IV on atherosclerosis and a basis for promising clinical usage.