Piezo1 senses pressure overload and initiates cardiac hypertrophy

Piezo1 deletion mitigates diabetic cardiomyopathy by maintaining mitochondrial dynamics via ERK/Drp1 pathway

OBJECTIVE

Increasing evidence highlights the critical role of Piezo1 in cardiovascular diseases, with its expression upregulated in diabetic heart. However, the involvement of Piezo1 in the pathogenesis of diabetic cardiomyopathy (DCM) remains unclear. This study aims to elucidate the regulatory role of Piezo1 in mitochondrial dynamics within the context of DCM and to investigate the underlying mechanisms.

METHODS

We constructed cardiac-specific knockout of Piezo1 (Piezo1∆Myh6) mice. Type 1 diabetes was induced using streptozotocin (STZ) injection while type 2 diabetes was established through a high-fat diet combined with STZ. Echocardiography assessed left ventricular function, histological evaluations used HE and Masson staining to examine cardiac pathology in Piezo1fl/fl controls, Piezo1∆Myh6 controls, Piezo1fl/fl diabetic and Piezo1∆Myh6 diabetic mice. Mitochondrial function including oxygen species level, mitochondrial morphology, and respiration rate were also assessed.

RESULTS

Our findings revealed that Piezo1 expression was upregulated in the myocardium of diabetic mice and in high-glucose-treated cells. Cardiac-specific knockout of Piezo1 improved cardiac dysfunction and ameliorated cardiac fibrosis in diabetic mice. Moreover, Piezo1 deficiency also attenuated mitochondrial impairment. Piezo1fl/fl diabetic mice exhibited increased calpain activity and excessive mitochondrial fission mediated by Drp1 and obvious reduced fusion; however, Piezo1 deficiency restored calpain levels and mitochondrial dysfunction. These observations were also corroborated in H9C2 cells and neonatal mouse cardiomyocytes. Cardiac-specific knockout of Piezo1 increased phosphorylation of Drp1 and ERK1/2 in vivo and in vitro. Piezo1 knockout or treatment with inhibitor improved mitochondrial function.

CONCLUSIONS

This study provides the first evidence that Piezo1 is elevated in DCM through the modulation of mitochondrial dynamics, which is reversed by Piezo1 deficiency. Thus, Piezo1 inhibition may provide a promising therapeutic strategy for the treatment of DCM.

The role of Piezo1 in bone marrow stem cells in response to elevated intraosseous pressure on regulating osteogenesis and angiogenesis of steroid-induced osteonecrosis of the femoral head

Objectives

Steroid-induced osteonecrosis of the femoral head (SONFH) remains a significant global health issue, with an unclear pathogenesis. Elevated intraosseous pressure is considered a key initiating factor in SONFH development. Impaired osteogenesis and angiogenesis are believed to be critical in SONFH progression. Piezo1, a mechanosensitive cation channel, may sense changes in intraosseous pressure. In this study, we set out to explore the role of Piezo1 in SONFH and how to target Piezo1 to treat SONFH.

Methods

Femoral head tissue specimens were collected from patients with ONFH and femoral neck fracture. Histological staining, Western blotting, and RT-PCR analysis were conducted to investigate the relationship between elevated intraosseous pressure and SONFH in rat models. Immunofluorescence staining of femoral head tissues was performed to study the spatiotemporal relationship between elevated intraosseous pressure and angiogenesis, osteogenesis, and development of SONFH.

Results

In the early stages of SONFH, elevated intraosseous pressure increased angiogenesis and osteogenesis. However, as the pressure continued to rise, both processes were inhibited. Furthermore, Elevated intraosseous pressure activated the Piezo1 signaling pathway in bone marrow stem cells. Piezo1 activation led to increased intracellular calcium influx, thus enhancing osteogenesis and angiogenesis through CAM-NFAT1 signaling pathway.

Conclusion

In the early stages of SONFH, Piezo1 in BMSCs senses increased intraosseous pressure, promoting angiogenesis and osteogenesis. Targeting Piezo1 to promote the osteogenic and angiogenic potential of stem cells, which could curb further increases in pressure, contribute to early treatment of SONFH.

The translational potential of this article

Currently, many mechanisms of the impact of elevated intraosseous pressure on osteonecrosis of the femoral head are still in the basic theoretical research stage, and we hope to translate them into clinical applications as soon as possible. We discovered that targeting Piezo1 curb further increases in intraosseous pressure, alleviating the damaging effects of glucocorticoids on stem cells and blood vessels, which exerting great significance in treatment of early stage SONFH.

The mechanisms of exercise improving cardiovascular function by stimulating Piezo1 and TRP ion channels: a systemic review

Mechanosensitive ion channels are widely distributed in the heart, lung, bladder and other tissues, and plays an important role in exercise-induced cardiovascular function promotion. By reviewing the PubMed databases, the results were summarized using the terms "Exercise/Sport", "Piezo1", "Transient receptor potential (TRP)" and "Cardiovascular" as the keywords, 124-related papers screened were sorted and reviewed. The results showed that: (1) Piezo1 and TRP channels play an important role in regulating blood pressure and the development of cardiovascular diseases such as atherosclerosis, myocardial infarction, and cardiac fibrosis; (2) Exercise promotes cardiac health, inhibits the development of pathological heart to heart failure, regulating the changes in the characterization of Piezo1 and TRP channels; (3) Piezo1 activates downstream signaling pathways with very broad pathways, such as AKT/eNOS, NF-κB, p38MAPK and HIPPO-YAP signaling pathways. Piezo1 and Irisin regulate nuclear localization of YAP and are hypothesized to act synergistically to regulate tissue mechanical properties of the cardiovascular system and (4) The cardioprotective effects of exercise through the TRP family are mostly accomplished through Ca2+ and involve many signaling pathways. TRP channels exert their important cardioprotective effects by reducing the TRPC3-Nox2 complex and mediating Irisin-induced Ca2+ influx through TRPV4. It is proposed that exercise stimulates the mechanosensitive cation channel Piezo1 and TRP channels, which exerts cardioprotective effects. The activation of Piezo1 and TRP channels and their downstream targets to exert cardioprotective function by exercise may provide a theoretical basis for the prevention of cardiovascular diseases and the rehabilitation of clinical patients.

Mechanical network motifs as targets for mechanomedicine

The identification and analysis of network motifs has been widely used in the functional analysis of signaling components, disease discovery and other fields. The positive feedback loop (PFL) is a simple but important network motif. The formation of a PFL is regulated by mechanical cues such as substrate stiffness, fiber stretching and cell compression in the cell microenvironment. Here, we propose a new term, 'mechanical PFL', and analyze the mechanisms of mechanical PFLs at molecular, subcellular and cellular scales. More and more therapies are being targeted against mechanosignaling pathways at the experimental and preclinical stages, and exploring mechanical PFLs as potential mechanomedicine targets could be a new direction for disease treatment.

Piezo ion channels: long-sought-after mechanosensors mediating hypertension and hypertensive nephropathy

Recent advances in mechanobiology and the discovery of mechanosensitive ion channels have opened a new era of research on hypertension and related diseases. Piezo1 and Piezo2, first reported in 2010, are regarded as bona fide mechanochannels that mediate various biological and pathophysiological phenomena in multiple tissues and organs. For example, Piezo channels have pivotal roles in blood pressure control, triggering shear stress-induced nitric oxide synthesis and vasodilation, regulating baroreflex in the carotid sinus and aorta, and releasing renin from renal juxtaglomerular cells. Herein, we provide an overview of recent literature on the roles of Piezo channels in the pathogenesis of hypertension and related kidney damage, including our experimental data on the involvement of Piezo1 in podocyte injury and that of Piezo2 in renin expression and renal fibrosis in animal models of hypertensive nephropathy. The mechanosensitive ion channels Piezo1 and Piezo2 play various roles in the pathogenesis of systemic hypertension by acting on vascular endothelial cells, baroreceptors in the carotid artery and aorta, and the juxtaglomerular apparatus. Piezo channels also contribute to hypertensive nephropathy by acting on mesangial cells, podocytes, and perivascular mesenchymal cells.

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.

Strain sensor on a chip for quantifying the magnitudes of tensile stress on cells

During cardiac development, mechanotransduction from the in vivo microenvironment modulates cardiomyocyte growth in terms of the number, area, and arrangement heterogeneity. However, the response of cells to different degrees of mechanical stimuli is unclear. Organ-on-a-chip, as a platform for investigating mechanical stress stimuli in cellular mimicry of the in vivo microenvironment, is limited by the lack of ability to accurately quantify externally induced stimuli. However, previous technology lacks the integration of external stimuli and feedback sensors in microfluidic platforms to obtain and apply precise amounts of external stimuli. Here, we designed a cell stretching platform with an in-situ sensor. The in-situ liquid metal sensors can accurately measure the mechanical stimulation caused by the deformation of the vacuum cavity exerted on cells. The platform was applied to human cardiomyocytes (AC16) under cyclic strain (5%, 10%, 15%, 20 and 25%), and we found that cyclic strain promoted cell growth induced the arrangement of cells on the membrane to gradually unify, and stabilized the cells at 15% amplitude, which was even more effective after 3 days of culture. The platform's precise control and measurement of mechanical forces can be used to establish more accurate in vitro microenvironmental models for disease modeling and therapeutic research.

Liraglutide ameliorates TAC-induced cardiac hypertrophy and heart failure by upregulating expression level of ANP expression

Recent studies have underscored the cardioprotective properties of liraglutide. This research explores its impact on cardiac hypertrophy and heart failure following transverse aortic constriction (TAC). We found that liraglutide administration markedly ameliorated cardiac hypertrophy, fibrosis, and function. These benefits correlated with increased ANP expression and reduced activity in the calcineurin A/NFATc3 signaling pathway. Moreover, liraglutide mitigated ER stress and cardiomyocyte apoptosis, and enhanced autophagy. Notably, the positive effects of liraglutide diminished when co-administered with A71915, an ANP inhibitor, suggesting that ANP upregulation is critical to its cardioprotective mechanism.

Mechanosensitive Piezo1 channel in physiology and pathophysiology of the central nervous system

Since the discovery of the mechanosensitive Piezo1 channel in 2010, there has been a significant amount of research conducted to explore its regulatory role in the physiology and pathology of various organ systems. Recently, a growing body of compelling evidence has emerged linking the activity of the mechanosensitive Piezo1 channel to health and disease of the central nervous system. However, the exact mechanisms underlying these associations remain inadequately comprehended. This review systematically summarizes the current research on the mechanosensitive Piezo1 channel and its implications for central nervous system mechanobiology, retrospects the results demonstrating the regulatory role of the mechanosensitive Piezo1 channel on various cell types within the central nervous system, including neural stem cells, neurons, oligodendrocytes, microglia, astrocytes, and brain endothelial cells. Furthermore, the review discusses the current understanding of the involvement of the Piezo1 channel in central nervous system disorders, such as Alzheimer's disease, multiple sclerosis, glaucoma, stroke, and glioma.

The Role of the Piezo1 Mechanosensitive Channel in Heart Failure

Mechanotransduction (MT) is inseparable from the pathobiology of heart failure (HF). However, the effects of mechanical forces on HF remain unclear. This review briefly describes how Piezo1 functions in HF-affected cells, including endothelial cells (ECs), cardiac fibroblasts (CFs), cardiomyocytes (CMs), and immune cells. Piezo1 is a mechanosensitive ion channel that has been extensively studied in recent years. Piezo1 responds to different mechanical forces and converts them into intracellular signals. The pathways that modulate the Piezo1 switch have also been briefly described. Experimental drugs that specifically activate Piezo1-like proteins, such as Yoda1, Jedi1, and Jedi2, are available for clinical studies to treat Piezo1-related diseases. The only mechanosensitive ion-channel-specific inhibitor available is GsMTx4, which can turn off Piezo1 by modulating the local membrane tension. Ultrasound waves can modulate Piezo1 switching in vitro with the assistance of microbubbles. This review provides new possible targets for heart failure therapy by exploring the cellular functions of Piezo1 that are involved in the progression of the disease. Modulation of Piezo1 activity may, therefore, effectively delay the progression of heart failure.