Lithospermic acid improves liver fibrosis through Piezo1-mediated oxidative stress and inflammation.

BACKGROUND: Hepatic fibrosis is becoming an increasingly serious public health issue worldwide. Although liver transplantation is the only and definitive treatment for end-stage liver fibrosis, traditional Chinese medicine offers certain benefits in the treatment of advanced hepatic fibrosis. PURPOSE: This study aims to explore the protective effect of lithospermic acid (LA), an extraction from Salvia miltiorrhiza (the roots of S. miltiorrhiza Bunge, known as Danshen in Chinese), on liver fibrosis and investigate its potential mechanisms. METHODS AND RESULTS: Mice were treated with carbon tetrachloride (CCl4) via intraperitoneal injection for 4 weeks. LA was orally administered or colchicine (COL) was injected intraperitoneally for 3 weeks starting one week after the initial CCl4 injection. After the LA treatment, we observed a decrease in the fibrosis index and an improvement in liver function. Molecular docking results revealed that Piezo1 may be a potential pharmacological target of LA. The further experimental results showed that LA inhibited Piezo1 activation and expression in macrophages. Mechanistically, both Piezo1/Notch-mediated inflammation and oxidative stress regulated by the Piezo1/Ca2+ pathway were alleviated in fibrotic livers following LA treatment. Moreover, less oxidative stress and Notch activation were observed in the deficiency of macrophage Piezo1 (Piezo1ΔLysM) mice. In addition, Piezo1ΔLysM partially counteracted the pharmacological effects of LA on liver fibrosis. CONCLUSION: In conclusion, our present study corroborated LA limits the progression of liver fibrosis by regulating Piezo1-mediated oxidative stress and inflammation. These results indicate that LA could be a potential medication for hepatic fibrosis treatment.

Guizhitongluo Tablet inhibits atherosclerosis and foam cell formation through regulating Piezo1/NLRP3 mediated macrophage pyroptosis.

BACKGROUND: Atherosclerosis (AS) is the main pathological basis for the development of cardiovascular diseases. Vascular inflammation is an important factor in the formation of AS, and macrophage pyroptosis plays a key role in AS due to its unique inflammatory response. Guizhitongluo Tablet (GZTLT) has shown clinically effective in treating patients with AS, but its mechanism is elusive. PURPOSE: This study was to determine the effects of GZTLT on atherosclerotic vascular inflammation and pyroptosis and to understand its underlying mechanism. MATERIALS AND METHODS: The active constituents of GZTLT were analysed by means of UPLC-HRMS. In vivo experiments were performed using ApoE-/- mice fed a high fat diet for 8 weeks, followed by treatment with varying concentrations of GZTLT orally by gavage and GsMTx4 (GS) intraperitoneally and followed for another 8 weeks. Oil red O, Haematoxylin-eosin (HE) and Masson staining were employed to examine the lipid content, plaque size, and collagen fibre content of the mouse aorta. Immunofluorescence staining was utilised to identify macrophage infiltration, as well as the expression of Piezo1 and NLRP3 proteins in aortic plaques. The levels of aortic inflammatory factors were determined using RT-PCR and ELISA. In vitro, foam cell formation in bone marrow-derived macrophages (BMDMs) was observed using Oil Red O staining. Intracellular Ca2+ measurements were performed to detect the calcium influx in BMDMs, and the expression of NLRP3 and its related proteins were detected by Western blot. RESULTS: The UPLC-HRMS analysis revealed 31 major components of GZTLT. Our data showed that GZTLT inhibited aortic plaque formation in mice and increased plaque collagen fibre content to stabilise plaques. In addition, GZTLT could restrain the expression of serum lipid levels and suppress macrophage foam cell formation. Further studies found that GZTLT inhibited macrophage infiltration in aortic plaques and suppressed the expression of inflammatory factors. It is noteworthy that GZTLT can restrain Piezo1 expression and reduce Ca2+ influx in BMDMs. Additionally, we found that GZTLT could regulate NLRP3 activation and pyroptosis by inhibiting Piezo1. CONCLUSION: The present study suggests that GZTLT inhibits vascular inflammation and macrophage pyroptosis through the Piezo1/NLRP3 signaling pathway, thereby delaying AS development. Our finding provides a potential target for AS treatment and drug discovery.

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 dual-targeting peptide facilitates targeting anti-inflammation to attenuate atherosclerosis in ApoE-/- mice.

We report a peptidic dual-targeting drug delivery platform (integrins targeting and self-assembly instructed by matrix metalloproteinases) towards inflamed endothelial cells, which improved the anti-inflammatory ability of the loaded drug (i.e., puerarin) in vitro and thus improved the antiatherogenic effect of the loaded drug (i.e., puerarin) in vivo.

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.

Piezo1 impairs hepatocellular tumor growth via deregulation of the MAPK-mediated YAP signaling pathway.

Accumulating evidence has revealed the mechanosensitive ion channel protein Piezo1 is contributing to tumorigenesis. However, its role in hepatocellular carcinoma (HCC) remains unexplored. In this study, we demonstrated that Piezo1 was expressed in the HepG2 cell line and depletion of Piezo1 impaired proliferation and migration, as well as increased apoptosis in these cells. Using a Piezo1-specific activator, Yoda1, we identified that calcium entry induced by Yoda1 resulted in phosphorylation of JNK, p38, and ERK, thereby activating the mitogen-activated protein kinase (MAPK) pathway, in a dose- and time-dependent manner. More strikingly, Piezo1 activation integrated with YAP signaling to control the nuclear translocation of YAP and regulation of its target genes. JNK, p38, and ERK (MAPK signaling) regulated Yoda1-induced YAP activation. Consistent with the association of calpain with Piezo1, we also found that calpain activity was decreased by siRNA-mediated knockdown of Piezo1. In addition, the growth of HCC tumors was inhibited in Piezo1 haploinsufficient mice. Together, our findings establish that the Piezo1/MAPK/YAP signaling cascade is essential for HepG2 cell function. These results highlight the importance of Piezo1 in HCC and the potential utility of Piezo1 as a biomarker and therapeutic target.

ß-Galactosidase instructed supramolecular hydrogelation for selective identification and removal of senescent cells.

The identification and removal of senescent cells is very important to improve human health and prolong life. In this study, we introduced a novel strategy of ß-galactosidase (ß-Gal) instructed peptide self-assembly to selectively form nanofibers and hydrogels in senescent cells. We demonstrated that the in situ formed nanofibers could alleviate endothelial cell senescence by reducing p53, p21, and p16INK4a expression levels. We also demonstrated that our strategy could selectively remove senescent endothelial cells by inducing cell apoptosis, with an increase in the BAX/BCL-2 ratio and caspase-3 expression. Our study reports the first example of enzyme-instructed self-assembly (EISA) by a sugar hydrolase, which may lead to the development of supramolecular nanomaterials for the diagnosis and treatment of many diseases, such as cancer, and for other applications, such as wound healing and senescence.