While increased intracellular calcium (Ca2+) has been identified as a key effect of nanoparticles on endothelial cells, the mechanism has not been fully elucidated or examined under shear stress. Here, we show the effect of several types of 20 nm particles on Ca2+ in the presence of shear stress in human umbilical vein endothelial cells (HUVECs), human coronary artery endothelial cells (HCAECs), and human cardiac microvascular endothelial cells (HMVEC-Cs). Intracellular Ca2+ levels increased by nearly three-fold in these cell types upon exposure to 100 μg mL-1 20 nm Au particles, which was not seen in response to larger or smaller particles. An antagonist to the calcium channel - transient receptor potential vanilloid-type 4 (TRPV4) - drastically reduced the amount of calcium by 9.3-fold in HUVECs exposed to 0.6 Pa shear stress and 100 μg mL-1 20 nm gold particles, a trend upheld in both HCAECs and HMVEC-Cs. Cell alignment in the direction of fluid flow is a well-known phenomenon in endothelial cells, and interestingly, cells in the presence of 20 nm particles with fluid flow had a higher alignment index than cells in the fluid flow alone. When compared with previous works, these results indicated that 20 nm particles may be inducing endothelial permeability by activating the TRPV4 channel in vitro. The potential of nanoparticle delivery technologies hinges on an improved understanding of this effect toward improved delivery with limited toxicity.

Traumatic brain injury (TBI) is one of the primary causes of long-term brain disabilities among military personnel and civilians, regardless of gender. A plethora of secondary events are triggered by a primary brain insult, increasing the complexity of TBI. One of the most affected brain regions is the hippocampus, where neurogenesis occurs throughout life due to the presence of neural stem cells (NSC). Preclinical models have been extensively used to better understand TBI and develop effective treatments. Among these, rapid stretch injury has been used to mimic the effect of mechanical stress produced by a TBI on neurons and glia in vitro. In this study, we aimed to determine the impact of rapid stretch on the viability, proliferation, and differentiation of NSC isolated from rat hippocampus (Hipp-NSC) and to determine the role of the stretch-activated ion channel Piezo-1 in modulating their response to mechanical stress. We found that while rapid stretch (30 and 50 PSI) reduced Hipp-NSC viability (measured as a function of LDH release), it did not change their proliferation and differentiation potentials. Interestingly, rapid stretch in the presence of a selective Piezo-1 inhibitor, GsMTx4, or Piezo1 targeting siRNA, directed Hipp-NSC differentiation toward a neurogenic lineage. Additionally, we found that inhibiting Piezo1 with the addition of a rapid stretch injury increased the expression of miRNAs known to regulate neurogenesis. This work uses a novel approach for studying the effect of mechanical stress on NSC in vitro and points to the critical role the stretch-activated ion channel Piezo-1 has in modulating the impact of TBI on hippocampal neurogenesis.

In vivo, epithelial cells maintain structural integrity under dynamic mechanical perturbations. To study this, we treated various epithelial cell lines with long-term cyclic stretch (CS). Surprisingly, cells transitioned from cuboidal to columnar shape (columnarization) in MDCK cells, while others only elongated. This change correlated with actin accumulation at the top and stress fiber realignment at the bottom. Blocking mechanical stimulation via FAK inhibition or reducing vinculin partially prevented columnarization; however, disrupting tight junctions or cellular contractility substantially blocked it. The MK4 cells, derived from MDCK cells with weaker cell-cell junctions, showed less columnarization under CS, whereas overexpressing Caveolin-1 (Cav1) in MK4 cells enhanced junctions and promoted columnar formation. Atomic force microscopy studies revealed increased apical junctional stiffness in both CS-treated MDCK and Cav1-overexpressing MK4 cells. This, combined with a mathematical model, elucidated the physical characteristics and changes in cell tension post-stretch, revealing the mechanobiological foundation of epithelial cell columnarization.

Ion channels play a crucial role in various physiological processes, yet their functions in the reproductive system remain underexplored. This study investigates the expression and the localization of ASIC2, ASIC4, and PIEZO2 ion channels in the reproductive tracts of prepubertal bitches. Western blotting on samples from eight prepubertal bitches confirmed the presence of these ion channels in ovarian, uterine, and uterine tubes tissues, and validated antibody specificity. Immunohistochemistry revealed that all primordial follicles expressed these ion channels, while only some developing follicles showed immunolabeling. These findings suggest ion channels' potential involvement in oocyte differentiation and maturation. The localization of these channels in uterine tubes, uterine lining, and glandular epithelium suggests a role in tissue maintenance, oocyte transport, and embryo implantation. Additionally, their expression in the tunica media of reproductive vasculature points to a potential role in vascular regulation. Future studies are needed to elucidate the specific mechanisms underlying the role of these channels in reproductive physiology.

Pulmonary hypertension (PH) is a life-threatening and progressive yet incurable disease. The hallmarks of PH comprise (1) sustained contraction and (2) excessive proliferation of pulmonary arterial smooth muscle cells (PASMCs). A major stimulus to which PASMCs are exposed during PH development is altered mechanical stress, originating from increased blood pressure, changes in blood flow velocity, and a progressive stiffening of pulmonary arteries. Mechanosensitive ion channels, including Piezo1 (Piezo-type mechanosensitive ion channel component-1), perceive such mechanical stimuli and translate them into a variety of cellular responses, including contractility or proliferation. Thus, the objective of the present study was to elucidate the specific role of Piezo1 in PASMCs for PH development and progression.

The cell-type specific function of Piezo1 in PH was assessed in (1) PASMCs and lung tissues from patients with PH and (2) 2 mouse strains characterized by smooth muscle cell-specific, conditional Piezo1 knockout. Taking advantage of these strains, the smooth muscle cell-specific role of Piezo1 in PH development and progression was assessed in isolated, perfused, and ventilated mouse lungs, wire myography, and proliferation assays. Finally, in vivo function of smooth muscle cell-specific Piezo1 knockout was evaluated upon induction of chronic hypoxia-induced PH in these mice with insights into pulmonary vascular cell senescence.

Compared with healthy controls, PASMCs from patients with PH featured an elevated Piezo1 expression and increased proliferative phenotype. Smooth muscle cell-specific Piezo1 deletion, as confirmed via quantitative real-time polymerase chain reaction and patch clamp recordings, prevented the hypoxia-induced increase in PASMC proliferation in mice. Moreover, Piezo1 knockout reduced hypoxic pulmonary vasoconstriction in isolated, perfused, and ventilated mouse lungs, endothelial-denuded pulmonary arteries, and hemodynamic measurements in vivo. Consequently, Piezo1-deficient mice were considerably protected against chronic hypoxia-induced PH development with ameliorated right heart hypertrophy and improved hemodynamic function. In addition, distal pulmonary capillaries were preserved in the Piezo1-knockout mice, associated with a lower number of senescent endothelial cells.

This study provides evidence that Piezo1 expressed in PASMCs is critically involved in the pathogenesis of PH by controlling pulmonary vascular tone, arterial remodeling, and associated lung capillary rarefaction due to endothelial cell senescence.

Pancreatic stellate cells (PSCs) are primarily responsible for producing the stiff tumor tissue in pancreatic ductal adenocarcinoma (PDAC). Thereby, PSCs generate a stiffness gradient between the healthy pancreas and the tumor. This gradient induces durotaxis, a form of directional cell migration driven by differential stiffness. However, the molecular sensors behind durotaxis are still unclear. To investigate the role of mechanosensitive ion channels in PSC durotaxis, we established a two-dimensional stiffness gradient mimicking PDAC. Using pharmacological and genetic methods, we investigated the contribution of the ion channels Piezo1, TRPC1 and TRPV4 in PSC durotaxis. We found that PSC migration towards a stiffer substrate is diminished by altering Piezo1 activity. Moreover, disrupting TRPC1 along with TRPV4 abolishes PSC durotaxis even when Piezo1 is functional. Our results demonstrate that optimal PSC durotaxis requires an intermediary level of ion channel activity, which we simulated via a numerically discretized mathematical model. These findings suggest that mechanosensitive Piezo1 channels detect the differential stiffness microenvironment. The resulting intracellular signals are amplified by TRPV4 and TRPC1 channels to guide efficient PSC durotaxis.

There is currently no cure for HIV because of the presence of latent viral reservoirs in people with HIV (PWH) on antiretroviral therapy (ART). Latency-reversing agents (LRAs) that can effectively reactivate and destroy latent HIV are being developed as a possible cure for HIV. Here, we identify Yoda1, a Piezo1 agonist, as a novel LRA. Yoda1 reactivated latent HIV in vitro ACH2 cells and ex vivo PBMCs from an HIV patient on ART. Yoda1 induced infectious virus production and HIV gene expression via Piezo1 activation and calcium signaling. Transcriptomic and proteomic analyses revealed a unique latent HIV reactivation pathway involving T cell activation, upregulation of TCR/CD3 and HLA genes, as well as modulation of host and viral transcription and translation that favors viral gene expression. These findings suggest further testing and development of Yoda1 as an effective LRA to reactivate latent HIV and destroy latent reservoirs for the cure of HIV.

Non-surgical and safe prostate cancer (PCa) therapies are in demand. Soluble tumor necrosis factor (TNF-α) related apoptosis inducing ligand (TRAIL), a cancer-specific drug, shows preclinical efficacy but has a short circulation half-life. This research has shown that physiological fluid shear stress activates mechanosensitive ion channels (MSCs), such as Piezo1, enhancing TRAIL-mediated apoptosis in cancer cells. Herein, noninvasive, focal ultrasound (FUS) is implemented to augment the pro-apoptotic effects of TRAIL. Using thermally safe FUS parameters, it is observed that TRAIL sensitivity increases with higher FUS pressure in PCa cells, mediated by Piezo1. This is confirmed by examining the effects of calcium chelation, MSC inhibitors, and PIEZO knockdown. In vivo, a multi-dose study with 10 min FUS exposure shows that 0 and 4-h intervals between TRAIL and FUS significantly reduce tumor burden, with an increase in apoptosis evident by enhanced cleaved-caspase 3 expression. This mechanotherapy offers a clinically translatable approach by utilizing widely available FUS technology, applicable to treat additional cancer types.

Copper is an essential micronutrient in all kingdoms of life, requiring a meticulous balance between acquisition and toxic overload. While copper import in eukaryotes has been investigated extensively, few prokaryotic copper importers have been identified, leading to the notion that cytoplasmic copper uptake is unnecessary in prokaryotes. Here we report that mechanosensitive channels are key players in prokaryotic copper import. Deletion of the gene encoding the E. coli small mechanosensitive channel, Ec MscS, leads to significantly reduced copper influx. Conversely, overexpression of Ec MscS leads to increased copper influx, elevated intracellular copper content, and renders cells hypersensitive to copper. Furthermore, specific channel blockers and competing permeating ions inhibit Ec MscS copper conductance, lowering intracellular copper accumulation and alleviating copper hypersensitivity. These findings extend beyond E. coli , as other prokaryotic small mechanosensitive channels of bacterial and archaeal origin also facilitate copper influx. Taken together, these results uncover a previously unknown moonlighting function for mechanosensitive channels as a pathway for prokaryotic copper uptake.

Sickle cell disease (SCD), an inherited blood disorder caused by a mutation in the β-globin gene, is characterized by sickle erythrocytes that are prone to hemolysis, causing anemia and vaso-occlusion crises. In sickle erythrocytes, hemoglobin aggregation is followed by altered cation permeability and subsequent dehydration. Interventions to restore cation permeability can decrease hemolysis and ameliorate the symptoms associated with SCD. PIEZO1 is a non-selective mechanosensitive cation channel that regulates erythrocyte volume. Gain-of-function (GOF) mutations in PIEZO1 cause hemolytic anemia by increasing cation permeability, leading to erythrocyte dehydration in humans and mice. Although PIEZO1 plays a key role in erythrocyte homeostasis, its role in SCD remains unknown. Here, we demonstrate that the function of the PIEZO1 channel is upregulated in sickle erythrocytes of humans and mice, and this enhancement can be restored through a dietary intervention. We found that PIEZO1 function in sickle erythrocytes resembles that of the GOF mutation causing hemolytic anemia. A diet enriched in the ω -3 fatty acid eicosapentaenoic (EPA) acid decreases PIEZO1 function in sickle erythrocytes and hemolysis in a mouse model of SCD. Furthermore, EPA decreases hemolysis and reduces inflammatory markers. We propose that PIEZO1 contributes to the increase in nonselective cationic conductance (i.e., Psickle), which leads to dehydration downstream of hemoglobin polymerization. Our results suggest that reducing PIEZO1 function is a promising therapeutic approach to reestablishing normal cation permeability in SCD.

The mechanical properties of the tumor microenvironment (TME) undergo significant changes during tumor growth, primarily driven by alterations in extracellular (ECM) stiffness and tumor viscoelasticity. These mechanical changes not only promote tumor progression but also hinder therapeutic efficacy by impairing drug delivery and activating mechanotransduction pathways that regulate crucial cellular processes such as migration, proliferation, and resistance to therapy. In this review, we examine the mechanisms through which tumor cells sense and transmit mechanical signals to maintain homeostasis in the biomechanically altered TME. We explore current computational modelling strategies for mechanotransduction pathways, highlighting the need for developing models that incorporate additional components of the mechanosignaling machinery. Furthermore, we review available methods for measuring the mechanical properties of tumors in clinical settings and strategies aiming at restoring the TME and blocking deregulated mechanotransduction pathways. Finally, we propose that proper characterization and a deeper understanding of the mechanical landscape of the TME, both at the tissue and cellular levels, are essential for developing therapeutic strategies that account for the influence of mechanical forces on treatment efficacy.

B cell responses to membrane-presented antigens appear to be strongly favored over soluble antigens in vivo suggesting that vaccines that mimic membrane-presented antigens may be highly efficacious. We recently demonstrated that human B cell responses to membrane-associated but not to soluble antigens in vitro depended on the expression and activity of the plasma membrane mechanosensitive ion channel, Piezo1. Here, we provide evidence that the efficacy of the current human papillomavirus virus-like particle (HPV VLP) vaccines may be due in part to their inherent ability to mimic Piezo1-dependent membrane presentation of antigens to B cells. We compared HPV-specific human B cell responses to HPV VLPs versus soluble HPV pentameric capsomeres and showed that although both induced calcium responses, only HPV VLP-induced responses were blocked by Piezo1 inhibitors. The kinetics of internalization of HPV-VLP and capsomeres into HPV-specific B cells were similar and neither required Piezo1 function as shown by small interfering RNA (siRNA)-mediated knockdown of Piezo. However, trafficking of HPV-VLPs into intracellular major histocompatibility complex (MHC) class II, lysosomal associated membrane protein 1 (LAMP1)+ antigen-processing compartments was Piezo1-dependent, whereas trafficking of capsomeres was not. In addition, a time course of intracellular trafficking suggested that colocalization of HPV-VLP with MHC classII was more stable over time as compared to capsomeres. Taken together these findings suggest that the ability of HPV-VLP vaccines to mimic Piezo1-dependent membrane antigen presentation may be exploited in the design of highly effective human vaccines.

Mesenchymal stem cells obtained from desquamated endometrium (eMSCs) are considered as reliable and promising objects for stem cell-based therapy. eMSCs aggregated into three-dimensional (3D) spheroids demonstrate greater efficiency compared to monolayer 2D eMSCs. However, molecular processes and specific mechanisms regulating the effectiveness of spheroids remain unknown. Regulation of a number of physiological reactions in MSCs is associated with the functioning of Ca2+-permeable mechanosensitive Piezo1 channels. In our previous study, we showed that selective Piezo1 activation by its selective agonist Yoda1 controls the migratory activity of 2D eMSCs. Here, we aimed to determine the effect of Yoda1 on eMSC spheroid formation and spreading. PIEZO1 mRNA expression was lower in spheroids compared to 2D culture. Spheroids formed with Yoda1 or spread in the presence of Yoda1 demonstrated lower spreading rates compared to control (Yoda1-free) spheroids. The spreading rates of control spheroids depended on the substrate stiffness, whereas spheroids formed with Yoda1 had similar spreading rates regardless of the surface properties. Our results demonstrate several Piezo1-dependent reactions of eMSC spheroids that could be modulated by selective Piezo1 activation.

Sensation begins at the periphery, where distinct transducer proteins, activated by specific physical stimuli, initiate biological events to convert the stimulus into electrical activity. These evoked pulse trains encode various properties of the stimulus and travel to higher centers, enabling perception of the physical environment. Transduction is an essential process in all of the five senses described by Aristotle. A substantial amount of information is already available on how G-protein coupled receptor proteins transduce exposure to light, odors, and tastants. Functional studies have revealed the presence of mechanosensitive (MS) ion channels, which act as force transducers, in a wide range of organisms from archaea to mammals. However, the molecular basis of mechanosensitivity is incompletely understood. Recently, the structure of a few MS channels and the molecular mechanisms linking mechanical force to channel gating have been partially revealed. This article reviews recent developments focusing on the molecular basis of mechanosensitivity and emerging methods to investigate MS channels.

Mammalian transmembrane channel-like proteins 1 and 2 (TMC1 and TMC2) have emerged as very promising candidate mechanotransduction channels in hair cells. However, controversy persists because the heterogeneously expressed TMC1/2 in cultured cells lack evidence of mechanical gating, primarily due to their absence from the plasma membrane. By employing domain swapping with OSCA1.1 and subsequent point mutations, we successfully identified membrane-localized mouse TMC1/2 mutants, demonstrating that they are mechanically gated in heterologous cells. Further, whole-genome CRISPRi screening enabled wild-type human TMC1/2 localization in the plasma membrane, where they responded robustly to poking stimuli. In addition, wild-type human TMC1/2 showed stretch-activated currents and clear single-channel current activities. Deafness-related TMC1 mutations altered the reversal potential of TMC1, indicating that TMC1/2 are pore-forming mechanotransduction channels. In summary, our study provides evidence that human TMC1/2 are pore-forming, mechanically activated ion channels, supporting their roles as mechanotransduction channels in hair cells.

The mechanically activated ion channel PIEZO1 is critical to numerous physiological processes, and is activated by diverse mechanical cues. The channel is gated by membrane tension and has been found to be mobile in the plasma membrane. We employed single-particle tracking (SPT) of endogenous, tdTomato-tagged PIEZO1 using total internal reflection fluorescence microscopy in live cells. Application of SPT unveiled a surprising heterogeneity of diffusing PIEZO1 subpopulations, which we labeled "mobile" and "immobile." We sorted these trajectories into the two aforementioned categories using trajectory spread. To evaluate the effects of the plasma membrane composition on PIEZO1 diffusion, we manipulated membrane composition by depleting or supplementing cholesterol, or by adding margaric acid to stiffen the membrane. To examine effects of channel activation on PIEZO1 mobility, we treated cells with Yoda1, a PIEZO1 agonist, and GsMTx-4, a channel inhibitor. We collected thousands of trajectories for each condition, and found that cholesterol removal and Yoda1 incubation increased the channel's propensity for mobility. Conversely, we found that GsMTx-4 incubation and cholesterol supplementation resulted in a lower chance of mobile trajectories, whereas margaric acid incubation did not have a significant effect on PIEZO1 mobility. The mobile trajectories were analyzed further by fitting the time-averaged mean-squared displacement as a function of lag time to a power law model, revealing that mobile PIEZO1 puncta exhibit anomalous subdiffusion. These studies illuminate the fundamental properties governing PIEZO1 diffusion in the plasma membrane and set the stage to determine how cellular processes and interactions may influence channel activity and mobility.

Dysfunction of the enteric nervous system (ENS) is linked to a myriad of gastrointestinal (GI) disorders. Piezo1 is a mechanosensitive ion channel found throughout the GI tract, but its role in the ENS is largely unknown. We hypothesize that Piezo1 plays an important role in the growth and development of the ENS.

Enteric neural crest-derived progenitor cells (ENPC) were isolated from adult mouse intestine and propagated in culture as neurospheres. ENPC-derived neurons were then subject to in vitro stretch in the presence or absence of Piezo1 antagonist (GsMTx4). Transcriptomes of stretched and unstretched ENPC-derived cells were compared using bulk RNA sequencing. Enteric neurons were also cultured under static conditions in the presence of Piezo1 agonist (Yoda1) or antagonist. Neuronal phenotype, migration, and recovery from injury were compared between groups.

Though stretch did not cause upregulation of Piezo1 expression in enteric neurons, both stretch and Piezo1 activation produced similar alterations in neuronal morphology. Compared to control, neurite length was significantly shorter when stretched and in the presence of Piezo1 activation. Piezo1 inhibition prevented a significant reduction in neurite length in stretched neurons. Piezo1 inhibition also led to significantly increased neuronal migration, whereas Piezo1 activation resulted in significantly decreased neuronal migration and slower neuronal recovery from injury.

Mechanotransduction plays an important role in regulating normal GI function. Our results suggest that the Piezo1 mechanoreceptor may play an important role in the ENS as its activation leads to decreased neuronal growth and migration. Piezo1 could be an important target for diseases of ENS dysfunction and development.

Basement membranes are extracellular matrix sheets separating tissue layers and providing mechanical support, and Collagen IV (Col4) is their most abundant protein. Although basement membranes are repaired after damage, little is known about repair, including whether and how damage is detected, what cells repair the damage, and how repair is controlled to avoid fibrosis. Using the intestinal basement membrane of adult Drosophila as a model, we show that after basement membrane damage, there is a sharp increase in enteroblasts transiently expressing Col4, or "matrix mender" cells. Enteroblast-derived Col4 is specifically required for matrix repair. The increase in matrix mender cells requires the mechanosensitive ion channel Piezo, expressed in intestinal stem cells. Matrix menders are induced by the loss of matrix stiffness, as specifically inhibiting Col4 crosslinking is sufficient for Piezo-dependent induction of matrix mender cells. Our data suggest that epithelial stem cells control basement membrane integrity by monitoring stiffness.

A sharp increase in intramedullary pressure after spinal cord injury (SCI) can aggravate secondary injury and lead to severe neurological deficits. Unfortunately, effective treatment options are currently lacking. The mechanosensitive ion channel Piezo1 plays an important role in the pathological process of SCI by transducing mechanical stress. The Piezo1 inhibitor GsMTx4 has been shown to have neuroprotective effects and may hold therapeutic potential for SCI. Given that single drug treatment strategy has limited effect on functional recovery after SCI, we explored the efficacy of combining GsMTx4 with exercise training in treating SCI in rats and investigated the underlying mechanisms. We used the T10 SCI rat model, administered GsMTx4 immediately after injury, and performed 4 weeks of body weight supported treadmill training starting (BWSTT) 2 weeks post injury. Subsequently, HE and LFB staining were used to observe the morphology of spinal cord tissue, WB was used to detect autophagy and apoptosis-related proteins, biochemical detection of calcium ion concentration and CTSD activity, IHC detection of LAMP1 expression, immunofluorescence labeling of NeuN and ChAT-positive motor neurons, as well as MBP and GFAP, and BBB scores were used to evaluate rat motor function. We found that the combined treatment of GsMTx4 drug and exercise training was more effective than single treatment alone. The combined treatment reduced calcium ion concentration, improved lysosomal function, enhanced autophagic flux, reduced cell apoptosis, and significantly improved the motor function of rats. This combined treatment regimen may pave the way for developing more comprehensive treatment strategies for SCI in the future.

During morphogenesis, epithelial sheets undergo sequential folding to form three-dimensional organ structures. The resulting folds are often irreversible, ensuring that morphogenesis progresses in one direction. However, the mechanism establishing folding irreversibility remains unclear. Here, we report a mechanical property of epithelia that determines folding irreversibility. Using a mechanical assay, we demonstrate that long-term, high-curvature folding induces plastic, irreversible deformations, while short-term or low-curvature folding results in an elastic, shape-restoring response. This elastic-plastic transition occurs in a switch-like manner, with critical thresholds in folding curvature and duration. The transition is induced by F-actin accumulating into a bracket-like structure across the fold, triggered by cells sensing deformations via mechanosensitive signaling pathways, including TRPC 3/6-mediated calcium influx and ligand-independent EGFR activation. These results demonstrate that cells control epithelial folding irreversibility by detecting folding characteristics and adaptively switching between elastic and plastic responses, providing mechanical insight into the directionality of morphogenesis.

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.

Mechanotransduction is the process whereby cells convert mechanical signals into electrochemical responses, where mechanosensitive proteins mediate this interaction. To characterize these critical proteins, numerous techniques have been developed that apply forces and measure the subsequent cellular responses. While these approaches have given insight into specific aspects of many such proteins, subsequent validation and cross-comparison between techniques remain difficult given significant variations in reported activation thresholds and responses for the same protein across different studies. Accurately determining mechanosensitivity responses for various proteins, however, is essential for understanding mechanotransduction and potential physiological implications, including therapeutics. This critical review provides an assessment of current and emerging approaches used for mechanosensitive ion channel and G-Coupled Receptors (GPCRs) stimulation and measurement, with a specific focus on the ability to quantitatively measure mechanosensitive responses.

In recent years, the Piezo1 channel has attracted great attention. Piezo1's research has made remarkable advance in many aspects. However, the overall trends and knowledge structures have not been systematically investigated from a worldwide viewpoint. Therefore, it is important to fill this knowledge gap and utilize a proper tool to show the research status, hotspots, and frontiers in the Piezo1 channel. In order to better investigate the hotspots and frontiers of the Piezo1 channel research, we retrieved relevant literature from Web of Science Core Collection (WoSCC) and applied CiteSpace to perform a bibliometric analysis. Our findings might serve as a reference for future research in this area.

Stem cells perceive and respond to biochemical and physical signals to maintain homeostasis. Yet, it remains unclear how stem cells sense mechanical signals from their niche in vivo. In this work, we investigated the roles of PIEZO mechanosensitive channels in the intestinal stem cell (ISC) niche. We used mouse genetics and single-cell RNA sequencing analysis to assess the requirement for PIEZO channels in ISC maintenance. In vivo measurement of basement membrane stiffness showed that ISCs reside in a more rigid microenvironment at the bottom of the crypt. Three-dimensional and two-dimensional organoid systems combined with bioengineered substrates and a stretching device revealed that PIEZO channels sense extracellular mechanical stimuli to modulate ISC function. This study delineates the mechanistic cascade of PIEZO activation that coordinates ISC fate decision and maintenance.

T cell-based immunotherapy has recently emerged as a promising strategy to treat cancer, requiring the activation of antigen-directed cytotoxicity to eliminate cancer cells. Mechanical signaling, although often overshadowed by its biochemical counterpart, plays a crucial role in T cell anticancer responses, from activation to cytolytic killing. Rapid advancements in the fields of chemistry, biomaterials, and micro/nanoengineering offer an interdisciplinary approach to incorporating mechano- and immunomodulatory ligands, including but not limited to synthetic peptides, small molecules, cytokines, and artificial antigens, onto the biomaterial-based platforms to modulate mechanotransducive processes in T cells. The surface engineering of these immunomodulatory ligands with optimization of ligand density, geometrical arrangement, and mobility has been proven to better mimic the natural ligation between immunoreceptors and ligands to directly enhance or inhibit mechanotransduction pathways in T cells, through triggering upstream mechanosensitive channels, adhesion molecules, cytoskeletal components, or downstream mechanoimmunological regulators. Despite its tremendous potential, current research on this new biomaterial surface engineering approach for mechanomodulatory T cell activation and effector functions remains in a nascent stage. This review highlights the recent progress in this new direction, focusing on achievements in mechanomodulatory ligand-based surface engineering strategies and underlying principles, and outlooks the further research in the rapidly evolving field of T cell mechanotransduction engineering for efficient immunotherapy.

EPHB4 (ephrin receptor B4) and the RASA1 (p120 Ras GTPase-activating protein) are necessary for the development of lymphatic vessel (LV) valves. However, precisely how EPHB4 and RASA1 regulate LV valve development is unknown. In this study, we examine the mechanisms by which EPHB4 and RASA1 regulate the development of LV valves.

We used LV-specific inducible EPHB4-deficient mice and EPHB4 knockin mice that express a form of EPHB4 that is unable to bind RASA1 yet retains protein tyrosine kinase activity (EPHB4 2YP) to study the role of EPHB4 and RASA1 in LV valve development in the embryo and LV valve maintenance in adults. We also used human dermal lymphatic endothelial cells in vitro to study the role of EPHB4 and RASA1 as regulators of LV valve specification induced by oscillatory shear stress, considered the trigger for LV valve specification in vivo.

LV valve specification, continued valve development postspecification, and LV valve maintenance were blocked upon induced loss of EPHB4 in LV. LV valve specification and maintenance were also impaired in EPHB4 2YP mice. Defects in LV valve development were reversed by inhibition of the Ras-MAPK (mitogen-activated protein kinase) signaling pathway. In human dermal lymphatic endothelial cells, loss of expression of EPHB4 or its ephrin b2 ligand, loss of expression of RASA1, and inhibition of physical interaction between EPHB4 and RASA1 resulted in dysregulated oscillatory shear stress-induced Ras-MAPK activation and impaired expression of LV specification markers that could be rescued by Ras-MAPK pathway inhibition. The same results were observed when human dermal lymphatic endothelial cells were stimulated with the Yoda1 agonist of the PIEZO1 oscillatory shear stress sensor. Although Yoda1 increased the number of LV valves when administered to wild-type embryos, it did not increase LV valve number when administered to EPHB4 2YP embryos.

EPHB4 is necessary for LV valve specification, continued valve development postspecification, and valve maintenance. LV valve specification requires physical interaction between EPHB4 and RASA1 to limit activation of the Ras-MAPK pathway in lymphatic endothelial cells. Specifically, EPHB4-RASA1 physical interaction is necessary to dampen Ras-MAPK activation induced through the PIEZO1 oscillatory shear stress sensor. These findings reveal the mechanism by which EPHB4 and RASA1 regulate the development of LV valves.

Mechanical force is an essential physical element that contributes to the formation and function of life. The discovery of the evolutionarily conserved PIEZO family, including PIEZO1 and PIEZO2 in mammals, as bona fide mechanically activated cation channels has transformed our understanding of how mechanical forces are sensed and transduced into biological activities. In this Review, I discuss recent structure-function studies that have illustrated how PIEZO1 and PIEZO2 adopt their unique structural design and curvature-based gating dynamics, enabling their function as dedicated mechanotransduction channels with high mechanosensitivity and selective cation conductivity. I also discuss our current understanding of the physiological and pathophysiological roles mediated by PIEZO channels, including PIEZO1-dependent regulation of development and functional homeostasis and PIEZO2-dominated mechanosensation of touch, tactile pain, proprioception and interoception of mechanical states of internal organs. Despite the remarkable progress in PIEZO research, this Review also highlights outstanding questions in the field.

The occurrence and development of central nervous system (CNS) diseases is a multi-factor and multi-gene pathological process, and their diagnosis and treatment have always posed a serious challenge in the medical field. Therefore, exploring the relevant factors in the pathogenesis of CNS and improving the diagnosis and treatment rates has become an urgent problem. Piezo1 is a recently discovered mechanosensitive ion channel that opens in response to mechanical stimuli. A number of previous studies have shown that the Piezo channel family plays a crucial role in CNS physiology and pathology, especially in diseases related to CNS development and mechanical stimulation. This article comprehensively describes the biological properties of Piezo1, focuses on the potential association between Piezo1 and CNS disorders, and explores the pharmacological roles of Piezo1 agonists and inhibitors in treating CNS disorders.

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.

Preeclampsia (PE) is a prevalent obstetric complication affecting approximately 3-5% of pregnancies worldwide and is a major cause of maternal and perinatal morbidity and mortality. Preeclampsia is considered a disease of the endothelial system that can progress to eclampsia, characterized by seizures. Early diagnosis and appropriate management are crucial to improving maternal and fetal outcomes, as preeclampsia can lead to severe complications such as placental abruption, fetal growth restriction, and stroke. The pathophysiology of PE is complex, involving a combination of genetic, acquired, and immunological factors. A central feature of the condition is inadequate placentation and impaired uteroplacental perfusion, leading to local hypoxia, endothelial dysfunction, vasoconstriction, and immunological dysregulation. Recent evidence suggests that dysregulation of ion transporters may play a significant role in the adaptation of uterine circulation during placentation. These transporters are essential for maintaining maternal-fetal homeostasis, influencing processes such as nutrient exchange, hormone synthesis, trophoblast cell migration, and the function of smooth muscle cells in blood vessels. In preeclampsia, adverse conditions like hypoxia and oxidative stress result in the downregulation of ion, solute, and water transporters, impairing their function. This review focuses on membrane transporters involved in PE, discussing functional alterations and their physiological implications. The goal of this investigation is to enhance understanding of how dysregulation of ion and small molecule transporters contributes to the development and progression of preeclampsia, underscoring the importance of exploring these signaling pathways for potential therapeutic interventions.

Force sensing is a fundamental ability that allows cells and organisms to interact with their physical environment. The eye is constantly subjected to mechanical forces such as blinking and eye movements. Furthermore, elevated intraocular pressure (IOP) can cause mechanical strain at the optic nerve head, resulting in retinal ganglion cell death (RGC) in glaucoma. How mechanical stimuli are sensed and affect cellular physiology in the eye is unclear. Recent studies have shown that mechanosensitive ion channels are expressed in many ocular tissues relevant to glaucoma and may influence IOP regulation and RGC survival. Furthermore, variants in mechanosensitive ion channel genes may be associated with risk for primary open angle glaucoma. These findings suggest that mechanosensitive channels may be important mechanosensors mediating cellular responses to pressure signals in the eye. In this review, we focus on mechanosensitive ion channels from three major channel families-PIEZO, two-pore potassium and transient receptor potential channels. We review the key properties of these channels, their effects on cell function and physiology, and discuss their possible roles in glaucoma pathophysiology.

The human immune system is capable of defending against, monitoring, and self-stabilizing various immune cells. Differentiation, proliferation, and development of these cells are regulated by biochemical signals. Moreover, biophysical signals, such as mechanical forces, have been found to affect immune cell function, thus introducing a new area of immunological research. Piezo1, a mechanically sensitive ion channel, was awarded the Nobel Prize for Physiology and Medicine in 2021. This channel is present on the surface of many cells, and when stimulated by mechanical force, it controls calcium (Ca2+) inside the cells, leading to changes in downstream signals and thus regulating cell functions. Piezo1 is also expressed in various innate and adaptive immune cells and plays a major role in the immune function. In this review, we will explore the physiological functions and regulatory mechanisms of Piezo1 and its impact on innate and adaptive immunity. This may offer new insights into diagnostics and therapeutics for the prevention and treatment of diseases and surgical infections.

Pain is a common symptom of many clinical diseases; it adversely affects patients' physical and mental health, reduces their quality of life, and heavily burdens patients and society. Pain treatment is one of the most difficult problems today. There is an urgent need to explore the potential factors involved in the pathogenesis of pain to improve its diagnosis and treatment rate. Piezo1/2, a newly identified mechanosensitive ion channel opens in response to mechanical stimuli and plays a critical role in regulating pain-related diseases. Inhibition or downregulation of Piezo1/2 alleviates disease-induced pain. Therefore, in this study, we comprehensively discussed the biology of this gene, focusing on its potential relevance in pain-related diseases, and explored the pharmacological effects of drugs using this gene for the treatment of pain.

Cystic fibrosis (CF) is a genetic disease caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Despite reports of CFTR expression on endothelial cells, pulmonary vascular perturbations, and perfusion deficits in CF patients, the mechanism of pulmonary vascular disease in CF remains unclear. Here, our pilot study of 40 CF patients reveals a loss of small pulmonary blood vessels in patients with severe lung disease. Using a vessel-on-a-chip model, we establish a shear-stress-dependent mechanism of endothelial barrier failure in CF involving TRPV4, a mechanosensitive channel. Furthermore, we demonstrate that CFTR deficiency downregulates the function of PIEZO1, another mechanosensitive channel involved in angiogenesis and wound repair, and exacerbates loss of small pulmonary blood vessel. We also show that CFTR directly interacts with PIEZO1 and enhances its function. Our study identifies key cellular targets to mitigate loss of small pulmonary blood vessels in CF.

Mechanical force is the basis of cardiovascular development, homeostasis, and diseases. The perception and response of mechanical force by the cardiovascular system are crucial. However, the molecular mechanisms mediating mechanotransduction in the cardiovascular system are not yet understood. PIEZO1, a novel transmembrane mechanosensitive cation channel known for its regulation of touch sensation, has been found to be widely expressed in the mammalian cardiovascular system. In this review, we elucidate the role and mechanism of PIEZO1 as a mechanical sensor in cardiovascular development, homeostasis, and disease processes, including embryo survival, angiogenesis, cardiac development repair, vascular inflammation, lymphangiogenesis, blood pressure regulation, cardiac hypertrophy, cardiac fibrosis, ventricular remodeling, and heart failure. We further summarize chemical molecules targeting PIEZO1 for potential translational applications. Finally, we address the controversies surrounding emergent concepts and challenges in future applications.

The rising incidences of atherosclerosis have necessitated efforts to identify novel targets for therapeutic interventions. In the present study, we observed increased expression of the mechanosensitive calcium channel Piezo1 transcript in mouse and human atherosclerotic plaques, correlating with infiltration of PIEZO1-expressing macrophages. In vitro administration of Yoda1, a specific agonist for PIEZO1, led to increased foam cell apoptosis and enhanced phagocytosis by macrophages. Mechanistically, PIEZO1 activation resulted in intracellular F-actin rearrangement, elevated mitochondrial ROS levels and induction of mitochondrial fragmentation upon PIEZO1 activation, as well as increased expression of anti-inflammatory genes. In vivo, ApoE-/- mice treated with Yoda1 exhibited regression of atherosclerosis, enhanced stability of advanced lesions, reduced plaque size and necrotic core, increased collagen content, and reduced expression levels of inflammatory markers. Our findings propose PIEZO1 as a novel and potential therapeutic target in atherosclerosis.

The molecular mechanisms behind orthodontic tooth movements (OTM) were investigated by clarifying the role of chemical messengers released by cells.

Using the Cochrane library, Google scholar, and PubMed databases, a literature search was conducted, and studies published from 1984 to 2024 were considered.

Both bone growth and remodeling may occur when a tooth is subjected to mechanical stress. These chemicals have a significant effect on the stimulation and regulation of osteoblasts, osteoclasts, and osteocytes during alveolar bone remodeling. This regulation can take place in pathological conditions, such as periodontal diseases, or during OTM alone. This comprehensive review outlines key molecular mechanisms underlying OTM and explores various clinical assumptions associated with specific molecules and their functional domains during this process. Furthermore, clinical applications of certain molecules such as relaxin, prostaglandin E (PGE), and interleukin-1β (IL-1β) in accelerating OTM have been reported. Our findings underscore the existing gap between OTM clinical applications and basic research investigations.

A comprehensive understanding of orthodontic treatment is enriched by insights into biological systems. We reported the activation of osteoblasts, osteoclast precursor cells, osteoclasts, and osteocytes in response to mechanical stress, leading to targeted cellular and molecular interventions and facilitating rapid and regulated alveolar bone remodeling during tooth movement. Despite the shortcomings of clinical studies in accelerating OTM, this review highlights the crucial role of biological agents in this process and advocates for prioritizing high-quality human studies in future research to gain further insights from clinical trials.

Transient receptor potential (TRP) channels are broadly implicated in the developmental programs of most tissues. Amongst these tissues, skeletal muscle and adipose are noteworthy for being essential in establishing systemic metabolic balance. TRP channels respond to environmental stimuli by supplying intracellular calcium that instigates enzymatic cascades of developmental consequence and often impinge on mitochondrial function and biogenesis. Critically, aminoglycoside antibiotics (AGAs) have been shown to block the capacity of TRP channels to conduct calcium entry into the cell in response to a wide range of developmental stimuli of a biophysical nature, including mechanical, electromagnetic, thermal, and chemical. Paradoxically, in vitro paradigms commonly used to understand organismal muscle and adipose development may have been led astray by the conventional use of streptomycin, an AGA, to help prevent bacterial contamination. Accordingly, streptomycin has been shown to disrupt both in vitro and in vivo myogenesis, as well as the phenotypic switch of white adipose into beige thermogenic status. In vivo, streptomycin has been shown to disrupt TRP-mediated calcium-dependent exercise adaptations of importance to systemic metabolism. Alternatively, streptomycin has also been used to curb detrimental levels of calcium leakage into dystrophic skeletal muscle through aberrantly gated TRPC1 channels that have been shown to be involved in the etiology of X-linked muscular dystrophies. TRP channels susceptible to AGA antagonism are critically involved in modulating the development of muscle and adipose tissues that, if administered to behaving animals, may translate to systemwide metabolic disruption. Regenerative medicine and clinical communities need to be made aware of this caveat of AGA usage and seek viable alternatives, to prevent contamination or infection in in vitro and in vivo paradigms, respectively.

Mechanosensitive Piezo channels regulate cell division, cell extrusion, and cell death. However, systems-level functions of Piezo in regulating organogenesis remain poorly understood. Here, we demonstrate that Piezo controls epithelial cell topology to ensure precise organ growth by integrating live-imaging experiments with pharmacological and genetic perturbations and computational modeling. Notably, the knockout or knockdown of Piezo increases bilateral asymmetry in wing size. Piezo's multifaceted functions can be deconstructed as either autonomous or non-autonomous based on a comparison between tissue-compartment-level perturbations or between genetic perturbation populations at the whole-tissue level. A computational model that posits cell proliferation and apoptosis regulation through modulation of the cutoff tension required for Piezo channel activation explains key cell and tissue phenotypes arising from perturbations of Piezo expression levels. Our findings demonstrate that Piezo promotes robustness in regulating epithelial topology and is necessary for precise organ size control.

The gastrointestinal (GI) tract is an organ actively involved in mechanical processes, where it detects forces via a mechanosensation mechanism. Mechanosensation relies on specialized cells termed mechanoreceptors, which convert mechanical forces into electrochemical signals via mechanosensors. The mechanosensitive Piezo1 and Piezo2 are widely expressed in various mechanosensitive cells that respond to GI mechanical forces by altering transmembrane ionic currents, such as epithelial cells, enterochromaffin cells, and intrinsic and extrinsic enteric neurons. This review highlights recent research advances on mechanosensitive Piezo channels in GI physiology and pathology. Specifically, the latest insights on the role of Piezo channels in the intestinal barrier, GI motility, and intestinal mechanosensation are summarized. Additionally, an overview of Piezo channels in the pathogenesis of GI disorders, including irritable bowel syndrome, inflammatory bowel disease, and GI cancers, is provided. Overall, the presence of mechanosensitive Piezo channels offers a promising new perspective for the treatment of various GI disorders.