Escin ameliorates inflammation via inhibiting mechanical stretch and chemically induced Piezo1 activation in vascular endothelial cells

Roles of Piezo1 in chronic inflammatory diseases and prospects for drug treatment (Review)

The human body is chronically stimulated by various mechanical forces and the body cells can sense harmful stimuli through mechanotransduction to induce chronic inflammation. Piezo type mechanosensitive ion channel component 1 (Piezo1), a novel transmembrane mechanosensitive cation channel, is widely expressed in inflammatory cells, such as neutrophils, macrophages and endothelial cells, as well as in non‑inflammatory cells, such as osteoblasts, osteoclasts and periodontal cells. A growing number of studies have demonstrated that Piezo1 senses changes in environmental mechanical forces, regulates cellular functions and influences the development and regression of chronic inflammation. The present study summarized the roles of Piezo1 and its possible mechanisms in some common chronic inflammatory diseases and evaluated the potential application of drugs that modulate its activity, so as to prove that Piezo1 is likely to become a new target for the treatment of inflammatory diseases.15.

The anti-inflammatory effects of saponins from natural herbs

Inflammation is a protective mechanism that also starts the healing process. However, inflammatory reaction may cause severe tissue damage. The increased influx of phagocytic leukocytes may produce excessive amount of reactive oxygen species, which leads to additional cell injury. Inflammatory response activates the leukocytes and thus induces tissue damage and prolongs inflammation. The inflammation-induced activation of the complement system may also contribute to cell injury. Non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids are chief agents for treating inflammation associated with the diseases. However, the unwanted side effects of NSAIDs (e.g., gastrointestinal disturbances, skin reactions, adverse renal effects, cardiovascular side effects) and glucocorticoids (e.g., suppression of immune system, Cushing's syndrome, osteoporosis, hyperglycemia) limit their use in patients. Natural herbs are important sources of anti-inflammatory drugs. The ingredients extracted from natural herbs display anti-inflammatory effects to work through multiple pathways with lower risk of adverse reaction. At present, the main anti-inflammatory natural agents include saponins, flavonoids, alkaloids, polysaccharides, and so on. The present article will review the anti-inflammatory effects of saponins including escin, ginsenosides, glycyrrhizin, astragaloside, Panax notoginseng saponins, saikosaponin, platycodin, timosaponin, ophiopogonin D, dioscin, senegenin.

The Peptide PROTAC Modality: A New Strategy for Drug Discovery

In recent years, proteolysis targeting chimera (PROTAC) technology has made significant progress in the field of drug development. Traditional drugs mainly focus on inhibiting or activating specific proteins, while PROTAC technology provides new ideas for treating various diseases by inducing the degradation of target proteins. Especially for peptide PROTACs, due to their unique structural and functional characteristics, they have become a hot research topic. This review provides a detailed description of the key components, mechanisms, and design principles of peptide PROTACs, elaborates on their applications in skin-related diseases, oncology, and other potential therapeutic fields, analyzes their advantages and challenges, and looks forward to their future development prospects. The development of peptide PROTAC technology not only opens up new paths for drug research and development, but also provides new ideas for solving the resistance and safety issues faced by traditional small-molecule drugs. Compared with small-molecule PROTACs, peptide PROTACs have advantages such as multitargeting, biodegradability, low toxicity, and flexibility in structural design. With the deepening of research and the continuous maturity of technology, peptide PROTACs are expected to become one of the important strategies for future drug discovery, providing new hope for the treatment of more intractable diseases. Peptide PROTACs are ushering in a new era of precision medicine.

Piezo1-specific Deletion in Macrophage Protects the Progression of Chronic Inflammatory Bowel Disease in Mice

BACKGROUND & AIMS

Piezo1, a recently identified mechanically activated nonselective cation channel protein, demonstrates sensitivity to various mechanical stimuli, such as matrix stiffness and shear stress. Although accumulating evidence implicates Piezo1 channels in numerous physiologic and pathophysiologic processes, its involvement in dextran sulfate sodium (DSS)-induced acute and chronic inflammatory bowel disease (IBD) remains incompletely understood. This study aimed to investigate the effect of Piezo1 channels in macrophage polarization and its associated functions in IBD.

METHODS

DSS-induced inflammatory bowel disease model was established in Piezo1td/Tdt or Piezo1fl/fl and Piezo1△LysM male mice. Additionally, bone marrow-derived macrophages from Piezo1fl/fl and Piezo1△LysM male mice were isolated to elucidate the downstream targets of Piezo1 and the associated underlying molecular mechanisms.

RESULTS

Our findings revealed that Piezo1 deficiency in macrophages could protect mice from DSS-induced chronic IBD, as evidenced by improved colon length and the preservation of colon structure. The mitigation of inflammation during chronic IBD progression was observed with Piezo1 deficiency in macrophages, characterized by reduced macrophage accumulation, M1 macrophage polarization, T helper 1 infiltration, and decreased inflammatory cytokine secretion. Further investigations unveiled that Piezo1-deficient macrophages inhibit the expression and activity of Nod-like receptor protein 3 and nuclear factor kappa B in colon tissues and bone marrow-derived macrophages while regulating the nuclear translocation of p65. Conversely, macrophage Piezo1 activation enhanced inflammatory cytokine secretion by activating Nod-like receptor protein 3/nuclear factor kappa B pathways.

CONCLUSIONS

Myeloid Piezo1 mediates colonic immune response, and disrupting Piezo1 inhibits the progression of chronic IBD. This study provides hitherto undocumented evidence of the pivotal role of macrophage Piezo1 channels in regulating the progression of chronic IBD. Targeting macrophage Piezo1 may offer a promising therapeutic strategy against chronic IBD.

Pharmacology of PIEZO1 channels

PIEZO1 is a eukaryotic membrane protein that assembles as trimers to form calcium-permeable, non-selective cation channels with exquisite capabilities for mechanical force sensing and transduction of force into effect in diverse cell types that include blood cells, endothelial cells, epithelial cells, fibroblasts and stem cells and diverse systems that include bone, lymphatics and muscle. The channel has wide-ranging roles and is considered as a target for novel therapeutics in ailments spanning cancers and cardiovascular, dental, gastrointestinal, hepatobiliary, infectious, musculoskeletal, nervous system, ocular, pregnancy, renal, respiratory and urological disorders. The identification of PIEZO1 modulators is in its infancy but useful experimental tools emerged for activating, and to a lesser extent inhibiting, the channels. Elementary structure-activity relationships are known for the Yoda series of small molecule agonists, which show the potential for diverse physicochemical and pharmacological properties. Intriguing effects of Yoda1 include the stimulated removal of excess cerebrospinal fluid. Despite PIEZO1's broad expression, opportunities are suggested for selective positive or negative modulation without intolerable adverse effects. Here we provide a focused, non-systematic, narrative review of progress with this pharmacology and discuss potential future directions for research in the area.

Endothelial KDM5B Regulated by Piezo1 Contributes to Disturbed Flow Induced Atherosclerotic Plaque Formation

Epigenetic modifications play an important role in disturbed flow (d-flow) induced atherosclerotic plaque formation. By analysing a scRNA-seq dataset of the left carotid artery (LCA) under d-flow conditions, we found that Jarid1b (KDM5B) was upregulated primarily in a subcluster of endothelial cells in response to d-flow stimulation. We therefore investigated the mechanism of KDM5B expression and the role of KDM5B in endothelial cell. Intriguingly, activation of Piezo1, a major endothelial mechanosensor, was found to promote KDM5B expression, which was reversed by Piezo1 inhibition in HUVECs. Downstream of Piezo1, ETS1 expression and c-JUN phosphorylation were enhanced by d-flow or Piezo1 activation, leading to an increase in KDM5B expression. Furthermore, knockdown of either KDM5B or Piezo1 was found to prevent d-flow induced H3K4me3 demethylation, which was supported by the pharmacological inhibition of Piezo1 in HUVECs. RNA sequencing on shKdm5b HUVECs implied that KDM5B is associated with endothelial inflammation and atherosclerosis. Using partial carotid ligation surgery on Kdm5bf/f Cdh5cre mice with mAAV-PCSK9D377Y infected, we showed that endothelial KDM5B deficiency reduced atherosclerotic lesions in hypercholesterolemic mice. Our findings indicate that endothelial KDM5B expression induced by d-flow via the Piezo1 pathway promotes atherosclerotic plaque formation, providing targets for the prevention or therapeutic intervention of atherosclerosis.

Kaempferol regulating macrophage foaming and atherosclerosis through Piezo1-mediated MAPK/NF-κB and Nrf2/HO-1 signaling pathway

INTRODUCTION

Antioxidants represented by kaempferol have been shown to be effective against atherosclerosis (AS). However, the underlying mechanisms still remain unclear.

OBJECTIVES

The aim of this research was to reveal the mechanism of kaempferol regarding the treatment of AS and accumulation of foam cell.

METHODS

We explored the contribution of kaempferol to the levels of inflammatory factors, scavenger receptor CD36, mitochondrial membrane potential, ROS, MAPK/NF-κB, Nrf2/HO-1, Ca2+ and Piezo1 levels in RAW264.7 macrophages exposed to ox-LDL. In addition, to explore whether kaempferol inhibits ox-LDL-induced foamy macrophage through Piezo1, we extracted macrophages from Piezo1 macrophage-specific knockout (Piezo1ΔLysM) mice. For further validation, ApoE-/- and Piezo1 macrophage-specific knockout mice (Piezo1ΔLysM/ ApoE-/-) were generated.

RESULTS

The results showed that kaempferol notably suppressed inflammatory response, CD36 expression, mitochondrial membrane potential elevation, ROS production, MAPK/NF-κB expression, Ca2+ influx, and increased Nrf2/HO-1 levels in RAW264.7. In addition, depletion of macrophage Piezo1 also effectively reduced lipid droplet deposition, inflammatory factor expression, oxidative damage, MAPK/NF-κB, Ca2+ influx, and increased Nrf2/HO-1 expression in mouse BMDMs, and the results were still consistent after kaempferol treatment. In vivo studies have shown that kaempferol significantly reduces atherosclerotic plaque formation. However, the beneficial effect of kaempferol was attenuated in Piezo1 depletion mice.

CONCLUSIONS

These results collectively provide compelling evidence that kaempferol regulates CD36-mediated mitochondrial ROS production by inhibiting the Piezo1 channels and Ca2+ influx, and then regulates the downstream pathways of NF-κB/MAPK and HO-1/Nrf2, inhibiting to the formation of foam cells. In conclusion, this study revealed a potential mechanism by which the natural antioxidant kaempferol prevents foamy macrophage.

A Novel Piezo1 Agonist Promoting Mesenchymal Stem Cell Proliferation and Osteogenesis to Attenuate Disuse Osteoporosis

Disuse osteoporosis (OP) is a state of bone loss due to lack of mechanical stimuli, probably induced by prolonged bed rest, neurological diseases, as well as microgravity. Currently the precise treatment strategies of disuse OP remain largely unexplored. Piezo1, a mechanosensitive calcium (Ca2+) ion channel, is a key force sensor mediating mechanotransduction and it is demonstrated to regulate bone homeostasis and osteogenesis in response to mechanical forces. Using structure-based drug design, a novel small-molecule Piezo1 agonist, MCB-22-174, which can effectively activate Piezo1 and initiate Ca2+ influx, is developed and is more potent than the canonical Piezo1 agonist, Yoda1. Moreover, MCB-22-174 is found as a safe Piezo1 agonist without any signs of serious toxicity. Mechanistically, Piezo1 activation promotes the proliferation of bone marrow mesenchymal stem cells by activating the Ca2+-related extracellular signal-related kinases and calcium-calmodulin (CaM)-dependent protein kinase II (CaMKII) pathway. Importantly, MCB-22-174 could effectively promote osteogenesis and attenuate disuse OP in vivo. Overall, the findings provide a promising therapeutic strategy for disuse OP by chemical activation of Piezo1.

Quercetin ameliorates atherosclerosis by inhibiting inflammation of vascular endothelial cells via Piezo1 channels

BACKGROUND

Natural antioxidants, exemplified by quercetin (Qu), have been shown to exert a protective effect against atherosclerosis (AS). However, the precise pharmacological mechanisms of Qu also remain elusive.

PURPOSE

Here, we aimed to uncover the anti-atherosclerotic mechanisms of Qu.

METHODS/STUDY DESIGNS

The inflammatory cytokine expression, activity of NLRP3 inflammasome and NF-κB, as well as mechanically activated currents and intracellular calcium levels were measured in endothelial cells (ECs). In addition, to explore whether Qu inhibited atherosclerotic plaque formation via Piezo1 channels, Ldlr-/- and Piezo1 endothelial-specific knockout mice (Piezo1△EC) were established.

RESULTS

Our findings revealed that Qu significantly inhibited Yoda1-evoked calcium response in human umbilical vein endothelial cells (HUVECs), underscoring its role as a selective modulator of Piezo1 channels. Additionally, Qu effectively reduced mechanically activated currents in HUVECs. Moreover, Qu exhibited a substantial inhibitory effect on inflammatory cytokine expression and reduced the activity of NF-κB/NLRP3 in ECs exposed to ox-LDL or mechanical stretch, and these effects remained unaffected after Piezo1 genetic depletion. Furthermore, our study demonstrated that Qu substantially reduced the formation of atherosclerotic plaques, and this effect remained consistent even after Piezo1 genetic depletion.

CONCLUSION

These results collectively provide compelling evidence that Qu ameliorates atherosclerosis by inhibiting the inflammatory response in ECs by targeting Piezo1 channels. In addition, Qu modulated atherosclerosis via inhibiting Piezo1 mediated NFκB/IL-1β and NLRP3/caspase1/ IL-1β axis to suppress the inflammation. Overall, this study reveals the potential mechanisms by which natural antioxidants, such as Qu, protect against atherosclerosis.

Role of STIM1 in stretch-induced signaling in human airway smooth muscle

Alteration in the normal mechanical forces of breathing can contribute to changes in contractility and remodeling characteristic of airway diseases, but the mechanisms that mediate these effects in airway cells are still under investigation. Airway smooth muscle (ASM) cells contribute to both contractility and extracellular matrix (ECM) remodeling. In this study, we explored ASM mechanisms activated by mechanical stretch, focusing on mechanosensitive piezo channels and the key Ca2+ regulatory protein stromal interaction molecule 1 (STIM1). Expression of Ca2+ regulatory proteins, including STIM1, Orai1, and caveolin-1, mechanosensitive ion channels Piezo-1 and Piezo-2, and NLRP3 inflammasomes were upregulated by 10% static stretch superimposed on 5% cyclic stretch. These effects were blunted by STIM1 siRNA. Histamine-induced [Ca2+]i responses and inflammasome activation were similarly blunted by STIM1 knockdown. These data show that the effects of mechanical stretch in human ASM cells are mediated through STIM1, which activates multiple pathways, including Piezo channels and the inflammasome, leading to potential downstream changes in contractility and ECM remodeling.NEW & NOTEWORTHY Mechanical forces on the airway can contribute to altered contractility and remodeling in airway diseases, but the mechanisms are not clearly understood. Using human airway smooth muscle cells exposed to cyclic forces with static stretch to mimic breathing and static pressure, we found that the effects of stretch are mediated through STIM1, resulting in the activation of multiple pathways, including Piezo channels and the inflammasome, with potential downstream influences on contractility and remodeling.

Piezo1 and its inhibitors: Overview and perspectives

The cation channel Piezo1, a crucial mechanotransducer found in various organs and tissues, has gained considerable attention as a therapeutic target in recent years. Following this trend, several Piezo1 inhibitors have been discovered and studied for potential pharmacological properties. This review provides an overview of the structural and functional importance of Piezo1, as well as discussing the biological activities of Piezo1 inhibitors based on their mechanism of action. The compounds addressed include the toxin GsMTx4, Aβ peptides, certain fatty acids, ruthenium red and gadolinium, Dooku1, as well as the natural products tubeimoside I, salvianolic acid B, jatrorrhzine, and escin. The findings revealed that misexpression of Piezo1 can be associated with a number of chronic diseases, including hypertension, cancer, and hemolytic anemia. Consequently, inhibiting Piezo1 and the subsequent calcium influx can have beneficial effects on various pathological processes, as shown by many in vitro and in vivo studies. However, the development of Piezo1 inhibitors is still in its beginnings, with many opportunities and challenges remaining to be explored.

Progress in Research on the Mechanisms and Interventions of Phlebitis from the Perspective of Vascular Endothelial Cell and Signaling Pathway

Background

Phlebitis is a common complication of intravenous administration and greatly affects clinical outcomes, patient satisfaction, and health-care expenditure. Numerous studies have revealed venous injuries only through visual and histopathological examination. Although sporadic studies have explored the cellular and molecular biological mechanisms of phlebitis and the outcomes of pharmacological interventions, an updated review over the last decade is not available.

Methods

Progress in research on the mechanisms and interventions of phlebitis was summarized from the perspective of endothelial cells and signaling pathways by retrieving the PubMed, Web of Science Core Collection, MEDLINE, Embase, and CNKI.

Results

Phlebitis involves multiple signaling pathways (eg, nuclear factor kappa B, Wnt/β-catenin, focal adhesion kinase/protein kinase B, Toll-like receptor, protein kinase C beta/NADPH oxidase, PI3K/AKT/TNF, and JAK2/STAT3), upregulation of E-selectin, GBP5/NLRP3 inflammasome axis, cell apoptosis, intracellular ROS generation, SOD reduction, stimulation of angiogenesis, and induction of autophagy-associated cell death. Preventive and curative interventions included α-solanine, baicalein, escin, intermedin, Y15, micro-ribonucleic acid-223, sotrastaurin, cimetidine, aescin, resveratrol, α-chaconine, Chahuang ointment, QingLuoTongMai, Mailuo Shutong, and N-acetylcysteine. Laboratory models included vascular endothelial cells, real-time cell-monitoring analysis, network pharmacology analysis and experimental verification in vivo, animal models of phlebitis (rat, rabbit, and mouse), rabbit models with peripherally inserted central catheters (PICC) catheterization, models of PICC/central venous catheter indwelling with combined drugs in human umbilical vein endothelial cells, and compatibility with endothelial cells. Factors affecting vascular endothelial cell injury include difference in the same class of drugs, concentration and exposure time of precipitant, and infusion strategy.

Conclusion

Phlebitis is accompanied by endothelial dysfunction and may involve multiple molecular and cellular mechanisms. These findings improve our understanding of the molecular targets of interventions and help identify effective candidates for the prophylaxis and treatment of phlebitis. Vascular health and risk management should be considered when initiating intravenous administration.