Tropisetron attenuates high glucose-induced oxidative stress and inflammation in ARPE-19 cells in vitro via regulating SIRT1/ROCK1 signaling.

Diabetic retinopathy (DR) is the leading cause of acquired blindness in diabetic patients. Tropisetron (TRO) exerts potent therapeutic effects against diabetic tissues. The present study aimed to investigate the effects of TRO on retinal injury under diabetic condition. Human retinal pigment epithelial cell line ARPE-19 was treated with high glucose (HG) for 48 h to mimic hyperglycemia-induced retinal damage and subsequently treated with multiple concentrations of TRO for therapeutic intervention. Cell viability and lactate dehydrogenase (LDH) release were detected to assess cell damage. The production of inflammatory cytokines and oxidative stress-related factors was evaluated by corresponding commercial kits. Cell apoptosis was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. The expression of inflammation-, apoptosis-, and SIRT1/ROCK1-related proteins was examined using western blot analysis. Additionally, ARPE-19 cells were transfected with over-express ROCK1 (Ov-ROCK1) or pretreatment with SIRT1 inhibitor EX527 to perform the rescue experiments. TRO alleviated cell damage in HG-induced ARPE-19 cells through elevating cell viability and reducing LDH release. HG-caused excessive production of TNF-α, IL-1ß and IL-6, ROS, malondialdehyde and decreased superoxide dismutase activity were partly inhibited by TRO treatment. HG-induced cell apoptosis, accompanied with the upregulation of proapoptotic proteins and the downregulation of antiapoptotic proteins, was hindered by TRO treatment. HG led to the loss of SIRT1 and an elevation of ROCK1 in ARPE-19 cells, which was reversed following TRO treatment. Furthermore, pretreatment with EX527 or transfected with Ov-ROCK1 partially abolished the protective role of TRO against inflammation, oxidative stress and cell apoptosis in HG-challenged ARPE-19 cells. TRO exerted a protective role against HG-caused ARPE-19 cells inflammation, oxidative stress and cell apoptosis by regulating SIRT1/ROCK1 axis, suggesting that TRO might be therapeutic agent for alleviating retinal pigment epithelial cell damage in DR.

Force-mediated recruitment and reprogramming of healthy endothelial cells drive vascular lesion growth.

Force-driven cellular interactions are crucial for cancer cell invasion but remain underexplored in vascular abnormalities. Cerebral cavernous malformations (CCM), a vascular abnormality characterized by leaky vessels, involves CCM mutant cells recruiting wild-type endothelial cells to form and expand mosaic lesions. The mechanisms behind this recruitment remain poorly understood. Here, we use an in-vitro model of angiogenic invasion with traction force microscopy to reveal that hyper-angiogenic Ccm2-silenced endothelial cells enhance angiogenic invasion of neighboring wild-type cells through force and extracellular matrix-guided mechanisms. We demonstrate that mechanically hyperactive CCM2-silenced tips guide wild-type cells by transmitting pulling forces and by creating paths in the matrix, in a ROCKs-dependent manner. This is associated with reinforcement of ß1 integrin and actin cytoskeleton in wild-type cells. Further, wild-type cells are reprogrammed into stalk cells and activate matrisome and DNA replication programs, thereby initiating proliferation. Our findings reveal how CCM2 mutants hijack wild-type cell functions to fuel lesion growth, providing insight into the etiology of vascular malformations. By integrating biophysical and molecular techniques, we offer tools for studying cell mechanics in tissue heterogeneity and disease progression.

ROCK inhibitor enhances mitochondrial transfer via tunneling nanotubes in retinal pigment epithelium.

Rationale: Tunnel nanotube (TNT)-mediated mitochondrial transport is crucial for the development and maintenance of multicellular organisms. Despite numerous studies highlighting the significance of this process in both physiological and pathological contexts, knowledge of the underlying mechanisms is still limited. This research focused on the role of the ROCK inhibitor Y-27632 in modulating TNT formation and mitochondrial transport in retinal pigment epithelial (RPE) cells. Methods: Two types of ARPE19 cells (a retinal pigment epithelial cell line) with distinct mitochondrial fluorescently labeled, were co-cultured and treated with ROCK inhibitor Y-27632. The formation of nanotubes and transport of mitochondria were assessed through cytoskeletal staining and live cell imaging. Mitochondrial dysfunction was induced by light damage to establish a model, while mitochondrial function was evaluated through measurement of oxygen consumption rate. The effects of Y-27632 on cytoskeletal and mitochondrial dynamics were further elucidated through detailed analysis. Results: Y-27632 treatment led to an increase in nanotube formation and enhanced mitochondrial transfer among ARPE19 cells, even following exposure to light-induced damage. Our analysis of cytoskeletal and mitochondrial distribution changes suggests that Y-27632 promotes nanotube-mediated mitochondrial transport by influencing cytoskeletal remodeling and mitochondrial movement. Conclusions: These results suggest that Y-27632 has the ability to enhance mitochondrial transfer via tunneling nanotubes in retinal pigment epithelium, and similarly predict that ROCK inhibitor can fulfill its therapeutic potential through promoting mitochondrial transport in the retinal pigment epithelium in the future.

Anti-astmatic effect of ROCK inhibitor, GSK429286 A, in experimentally induced allergic airway inflammation.

BACKGROUND: Allergic asthma is a chronic inflammatory disease characterized by airway hyperresponsiveness, inflammation and remodeling. ROCK inhibitors have now been shown to have the potential to alleviate these symptoms, although the specific effects of a new ROCK inhibitor, GSK429286 A, remain underexplored. OBJECTIVE: The aim of this study was to evaluate the therapeutic effects of a novel ROCK inhibitor, GSK429286 A, which exhibits a high affinity for both ROCK1 and ROCK2 isoforms, on allergic asthma in a guinea pig model, focusing on its effects on airway hyperresponsiveness, inflammation, and remodeling. METHODS: To induce allergic asthma, guinea pigs were sensitized with ovalbumin for 28 days, and in the middle of sensitization they were treated with different doses of the RoCK inhibitor, GSK429286 A. The study evaluated the effect of the administered doses on the reduction of airway hyperresponsiveness, by measuring specific airway resistance (sRaw), and the number of coughs after citric acid inhalation. We also monitored the anti-inflammatory effect by measuring levels of inflammatory cytokines, IL-2, IL-4, IL-5, IL-13, and remodeling markers, such as collagen deposition, and goblet cell hyperplasia. In addition, we monitored the possible anti-remodeling effect of GSK429286 A by histopathological examination. RESULTS: The ROCK inhibitor, GSK429286 A, showed an effect on suppressing airway hyperresponsiveness by reducing sRaw and the number of coughs in treated guinea pigs compared to controls. Our investigated drug suppressed the release of key mediators of inflammation, including IL-2, IL-4, and IL-5, thus demonstrating the effect of this ROCK inhibitor on the suppression of inflammation in the airways. Finally, GSK429286 A reduced markers of airway remodeling such as collagen deposition and goblet cell hyperplasia. CONCLUSION: GSK429286 A, an inhibitor of the ROCK pathway, exhibits significant anti-inflammatory and antiremodeling effects in a guinea pig model of allergic asthma. Indeed, we demonstrate its effect on suppressing airway hyperreactivity and reducing cough frequency. These findings suggest that GSK429286 A may be a promising therapeutic agent for allergic asthma, although further studies are needed to investigate its long-term efficacy, underlying mechanisms, and optimal dosing strategy.

Synthesis and in vitro evaluation of benzo[b]thiophene-3-carboxylic acid 1,1-dioxide derivatives as anticancer agents targeting the RhoA/ROCK pathway.

Rho family GTPases regulate cellular processes and promote tumour growth and metastasis; thus, RhoA is a potential target for tumour metastasis inhibition. However, limited progress has been made in the development of RhoA targeting anticancer drugs. Here, we synthesised benzo[b]thiophene-3-carboxylic acid 1,1-dioxide derivatives based on a covalent inhibitor of RhoA (DC-Rhoin), reported in our previous studies. The observed structure-activity relationship (contributed by carboxamide in C-3 and 1-methyl-1H-pyrazol in C-5) enhanced the anti-proliferative activity of the derivatives. Compound b19 significantly inhibited the proliferation, migration, and invasion of MDA-MB-231 cells and promoted their apoptosis. The suppression of myosin light chain phosphorylation and the formation of stress fibres confirmed the inhibitory activity of b19 via the RhoA/ROCK pathway. b19 exhibited a different binding pattern from DC-Rhoin, as observed in molecular docking analysis. This study provides a reference for the development of anticancer agents targeting the RhoA/ROCK pathway.

Arpin deficiency increases actomyosin contractility and vascular permeability.

Arpin was discovered as an inhibitor of the Arp2/3 complex localized at the lamellipodial tip of fibroblasts, where it regulated migration steering. Recently, we showed that arpin stabilizes the epithelial barrier in an Arp2/3-dependent manner. However, the expression and functions of arpin in endothelial cells (EC) have not yet been described. Arpin mRNA and protein are expressed in EC and downregulated by pro-inflammatory cytokines. Arpin depletion in Human Umbilical Vein Endothelial Cells causes the formation of actomyosin stress fibers leading to increased permeability in an Arp2/3-independent manner. Instead, inhibitors of ROCK1 and ZIPK, kinases involved in the generation of stress fibers, normalize the loss-of-arpin effects on actin filaments and permeability. Arpin-deficient mice are viable but show a characteristic vascular phenotype in the lung including edema, microhemorrhage, and vascular congestion, increased F-actin levels, and vascular permeability. Our data show that, apart from being an Arp2/3 inhibitor, arpin is also a regulator of actomyosin contractility and endothelial barrier integrity.

Evaluation of Rho kinase inhibitor effects on neuroprotection and neuroinflammation in an ex-vivo retinal explant model.

BACKGROUND: Glaucoma is a leading cause of blindness, affecting retinal ganglion cells (RGCs) and their axons. By 2040, it is likely to affect 110 million people. Neuroinflammation, specifically through the release of proinflammatory cytokines by M1 microglial cells, plays a crucial role in glaucoma progression. Indeed, in post-mortem human studies, pre-clinical models, and ex-vivo models, RGC degeneration has been consistently shown to be linked to inflammation in response to cell death and tissue damage. Recently, Rho kinase inhibitors (ROCKis) have emerged as potential therapies for neuroinflammatory and neurodegenerative diseases. This study aimed to investigate the potential effects of three ROCKis (Y-27632, Y-33075, and H-1152) on retinal ganglion cell (RGC) loss and retinal neuroinflammation using an ex-vivo retinal explant model. METHODS: Rat retinal explants underwent optic nerve axotomy and were treated with Y-27632, Y-33075, or H-1152. The neuroprotective effects on RGCs were evaluated using immunofluorescence and Brn3a-specific markers. Reactive glia and microglial activation were studied by GFAP, CD68, and Iba1 staining. Flow cytometry was used to quantify day ex-vivo 4 (DEV 4) microglial proliferation and M1 activation by measuring the number of CD11b+, CD68+, and CD11b+/CD68+ cells after treatment with control solvent or Y-33075. The modulation of gene expression was measured by RNA-seq analysis on control and Y-33075-treated explants and glial and pro-inflammatory cytokine gene expression was validated by RT-qPCR. RESULTS: Y-27632 and H-1152 did not significantly protect RGCs. By contrast, at DEV 4, 50 µM Y-33075 significantly increased RGC survival. Immunohistology showed a reduced number of Iba1+/CD68+ cells and limited astrogliosis with Y-33075 treatment. Flow cytometry confirmed lower CD11b+, CD68+, and CD11b+/CD68+ cell numbers in the Y-33075 group. RNA-seq showed Y-33075 inhibited the expression of M1 microglial markers (Tnfα, Il-1ß, Nos2) and glial markers (Gfap, Itgam, Cd68) and to reduce apoptosis, ferroptosis, inflammasome formation, complement activation, TLR pathway activation, and P2rx7 and Gpr84 gene expression. Conversely, Y-33075 upregulated RGC-specific markers, neurofilament formation, and neurotransmitter regulator expression, consistent with its neuroprotective effects. CONCLUSION: Y-33075 demonstrates marked neuroprotective and anti-inflammatory effects, surpassing the other tested ROCKis (Y-27632 and H-1152) in preventing RGC death and reducing microglial inflammatory responses. These findings highlight its potential as a therapeutic option for glaucoma.

CircPWWP2A promotes renal interstitial fibrosis through modulating miR-182/ROCK1 axis.

Renal fibrosis is a long-term and progressively worsening condition that impacts kidney function during aging and in the context of chronic kidney disease (CKD). CKD and renal fibrosis affect approximately 10% of the global population and are prevalent in about half of individuals over the age of 70. Despite ongoing research, the mechanisms underlying renal fibrosis are still not well understood, and there is currently a lack of effective treatments available. In the present study, we demonstrated a significant increase of circPWWP2A in renal tubular cells both in vivo and in vitro models of renal fibrosis. Suppressing circPWWP2A has the potential to reduce mitochondrial dysfunction and the production of mitochondrial reactive oxygen species (mtROS), ultimately leading to the inhibition of renal fibrosis. Whereas, supplementation of circPWWP2A led to more serve mitochondrial dysfunction, mtROS production and renal fibrosis. Mechanistically, we found the expression of circPWWP2A was negatively correlated with the expression of miR-182. And we further confirmed miR-182 was the direct target of circPWWP2A by dual-luciferase reporter assay and RIP assay. Then, we found miR-182 suppressed the expression of ROCK1 in both in vitro and in vivo models of renal fibrosis. Luciferase microRNA target reporter assay further indicated ROCK1 as a direct target of miR-182. Knockdown of ROCK1 inhibits renal fibrosis and mitochondrial dysfunction, suggesting ROCK1 not only served as an injurious role in mitochondrial homeostasis but also a pro-fibrotic factor in CKD. Taking together, our findings suggest that circPWWP2A may promote renal interstitial fibrosis by modulating miR-182/ROCK1-mediated mitochondrial dysfunction.

[Effects of inhibition of Rho/ROCK pathway on proliferation and migration of airway smooth muscle cells and related mechanisms]. / 抑制Rho/ROCKé€šè·¯å¯¹æ°”é“å¹³æ»‘è‚Œç»†èƒžå¢žæ®–ä¸Žè¿ç§»çš„å½±å“åŠç›¸å ³æœºåˆ¶.

OBJECTIVES: To investigate the effects and molecular mechanisms of inhibition of the Ras homolog gene (Rho)/Rho-associated coiled-coil forming protein kinase (ROCK) pathway on the proliferation and migration of airway smooth muscle cells involving myocardin (MYOCD). METHODS: Human airway smooth muscle cells were infected with the adenoviral vector Ad-ZsGreen-shRNA-hROCK1 in vitro. The cells were randomly divided into four groups: ROCK1 gene silencing control (shNC) group, shNC + arachidonic acid (AA, Rho/ROCK pathway activator) group, ROCK1 gene silencing (shROCK1) group, and shROCK1 + AA group (n=3 each). Quantitative real-time polymerase chain reaction and Western blot were used to detect the expression levels of ROCK1 and MYOCD mRNA and protein. ELISA was employed to measure the levels of globular actin and filamentous actin, while immunofluorescent staining and scratch assays were utilized to assess cell proliferation and migration. RESULTS: Compared to the shNC + AA group, the shROCK1 + AA group exhibited decreased levels of ROCK1 and MYOCD mRNA and protein expression, reduced expression levels of globular actin and filamentous actin, and diminished cell proliferation and migration capabilities (P<0.05). CONCLUSIONS: Inhibition of the Rho/ROCK pathway suppresses the proliferation and migration of airway smooth muscle cells, which may be associated with the downregulation of MYOCD.

Non-Muscle Myosin II A: Friend or Foe in Cancer?

Non-muscle myosin IIA (NM IIA) is a motor protein that belongs to the myosin II family. The myosin heavy chain 9 (MYH9) gene encodes the heavy chain of NM IIA. NM IIA is a hexamer and contains three pairs of peptides, which include the dimer of heavy chains, essential light chains, and regulatory light chains. NM IIA is a part of the actomyosin complex that generates mechanical force and tension to carry out essential cellular functions, including adhesion, cytokinesis, migration, and the maintenance of cell shape and polarity. These functions are regulated via light and heavy chain phosphorylation at different amino acid residues. Apart from physiological functions, NM IIA is also linked to the development of cancer and genetic and neurological disorders. MYH9 gene mutations result in the development of several autosomal dominant disorders, such as May-Hegglin anomaly (MHA) and Epstein syndrome (EPS). Multiple studies have reported NM IIA as a tumor suppressor in melanoma and head and neck squamous cell carcinoma; however, studies also indicate that NM IIA is a critical player in promoting tumorigenesis, chemoradiotherapy resistance, and stemness. The ROCK-NM IIA pathway regulates cellular movement and shape via the control of cytoskeletal dynamics. In addition, the ROCK-NM IIA pathway is dysregulated in various solid tumors and leukemia. Currently, there are very few compounds targeting NM IIA, and most of these compounds are still being studied in preclinical models. This review provides comprehensive evidence highlighting the dual role of NM IIA in multiple cancer types and summarizes the signaling networks involved in tumorigenesis. Furthermore, we also discuss the role of NM IIA as a potential therapeutic target with a focus on the ROCK-NM IIA pathway.

MiRNA expression profiling reveals a potential role of microRNA-148b-3p in cerebral vasospasm in subarachnoid hemorrhage.

Cerebral vasospasm (CVS) is an important contributor to delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage (aSAH), leading to high morbidity and long-term disability. While several microRNAs (miRNAs) have been implicated in vasospasm, the underlying mechanisms for CVS remain poorly understood. Our study aims to identify miRNAs that may contribute to the development of CVS. Whole-blood samples were obtained during or outside of vasospasm from aSAH patients whose maximal vasospasm was moderate or severe. MiRNAs were isolated from serial whole-blood samples, and miRNA sequencing was performed. Differentially expressed miRNAs were identified and the expression levels in patients' samples were verified using real-time qPCR. The biological functions of identified miRNA were evaluated in human brain endothelial cells (HBECs). MiRNA profiling revealed significant upregulation of miR-148b-3p in patients during CVS. We demonstrated that miR-148b-3p directly targeted and decreased the expression of ROCK1, affecting cell proliferation, migration, and invasion of HBECs through the ROCK-LIMK-Cofilin pathway. We propose that the upregulation of miRNA-148b-3p plays a role in the development of CVS by regulating actin cytoskeletal dynamics in HBECs, which is crucial for vascular function. Our study highlights miR-148b-3p as a potential diagnostic marker as well as therapeutic target for CVS following aSAH.

The RhoGAP ARHGAP32 interacts with desmoplakin, and is required for desmosomal organization and assembly.

Desmosomes play a crucial role in maintaining tissue barrier integrity, particularly in mechanically stressed tissues. The assembly of desmosomes is regulated by the cytoskeleton and its regulators, and desmosomes also function as a central hub for regulating F-actin. However, the specific mechanisms underlying the crosstalk between desmosomes and F-actin remain unclear. Here, we identified that ARHGAP32, a Rho GTPase-activating protein, is located in desmosomes through its interaction with desmoplakin (DSP) via its GAB2-interacting domain (GAB2-ID). We confirmed that ARHGAP32 is required for desmosomal organization, maturation and length regulation. Notably, loss of ARHGAP32 increased formation of F-actin stress fibers and phosphorylation of the regulatory myosin light chain Myl9 at T18/S19. Inhibition of ROCK activity in ARHGAP32-knockout (KO) cells effectively restored desmosomal organization and the integrity of epithelial cell sheets. Moreover, loss of DSP impaired desmosomal ARHGAP32 location and led to decreased actomyosin contractility. ARHGAP32 with a deletion of the GAB2-ID domain showed enhanced association with RhoA in the cytosol and failed to rescue the desmosomal organization in ARHGAP32-KO cells. Collectively, our study unveils that ARHGAP32 associates with and regulates desmosomes by interacting with DSP. This interaction potentially facilitates the crosstalk between desmosomes and F-actin.

Signal flow in the NMDA receptor-dependent phosphoproteome regulates postsynaptic plasticity for aversive learning.

Structural plasticity of dendritic spines in the nucleus accumbens (NAc) is crucial for learning from aversive experiences. Activation of NMDA receptors (NMDARs) stimulates Ca2+-dependent signaling that leads to changes in the actin cytoskeleton, mediated by the Rho family of GTPases, resulting in postsynaptic remodeling essential for learning. We investigated how phosphorylation events downstream of NMDAR activation drive the changes in synaptic morphology that underlie aversive learning. Large-scale phosphoproteomic analyses of protein kinase targets in mouse striatal/accumbal slices revealed that NMDAR activation resulted in the phosphorylation of 194 proteins, including RhoA regulators such as ARHGEF2 and ARHGAP21. Phosphorylation of ARHGEF2 by the Ca2+-dependent protein kinase CaMKII enhanced its RhoGEF activity, thereby activating RhoA and its downstream effector Rho-associated kinase (ROCK/Rho-kinase). Further phosphoproteomic analysis identified 221 ROCK targets, including the postsynaptic scaffolding protein SHANK3, which is crucial for its interaction with NMDARs and other postsynaptic scaffolding proteins. ROCK-mediated phosphorylation of SHANK3 in the NAc was essential for spine growth and aversive learning. These findings demonstrate that NMDAR activation initiates a phosphorylation cascade crucial for learning and memory.

MYO3B promotes cancer progression in endometrial cancer by mediating the calcium ion-RhoA/ROCK1 signaling pathway.

PURPOSE: This study aimed to investigate the effect of MYO3B on endometrial cancer (EC) proliferation and invasion. METHODS: The expression of MYO3B in EC tissues and cells was analyzed using TCGA database, immunohistochemical staining, real-time PCR, and western blot (WB). Cell proliferation was detected by CCK8, Annexin V-APC/PI flow cytometry was used to detect apoptosis, intracellular calcium ion (Ca2+) was detected by flow cytometry with Fluo-4 AM fluorescent probe, cell migration by scratch assay, and cell invasion by Transwell assay, and the expression of proteins related to Ca2+ homeostasis and RhoA/ROCK1 signaling pathway was detected by WB and immunofluorescence staining. RESULTS: The expression of MYO3B was an influential factor in EC recurrence, and the expression of MYO3B was significantly up-regulated in EC tissues and cells, but down-regulated in KLE cells, and MYO3B knockdown inhibited the proliferation, migration, and invasion ability of EC cells and promoted apoptosis, suggesting that MYO3B plays a tumor-promoting role in EC. Furthermore, MYO3B knockdown decreased Ca2+ concentration in EC cells and the RhoA/ROCK1 signaling pathway was inhibited, and the effect of MYO3B knockdown on RhoA/ROCK1 signaling was reversed by treatment with the Calmodulin agonist CALP-2, and the effects of MYO3B knockdown on cell proliferation, migration, and invasion were reversed after treatment with the RhoA agonist U-46,619. CONCLUSION: MYO3B promotes the proliferation and migration of endometrial cancer cells via Ca2+-RhoA/ROCK1 signaling pathway. High expression of MYO3B may be a biomarker for EC metastasis.

Exogenous S1P via S1P receptor 2 induces CTGF expression through Src-RhoA-ROCK-YAP pathway in hepatic stellate cells.

BACKGROUND: Hepatic fibrosis, a prevalent chronic liver condition, involves excessive extracellular matrix production associated with aberrant wound healing. Hepatic stellate cells (HSCs) play a pivotal role in liver fibrosis, activated by inflammatory factors such as sphingosine 1-phosphate (S1P). Despite S1P's involvement in fibrosis, its specific role and downstream pathway in HSCs remain controversial. METHODS: In this study, we investigated the regulatory role of S1P/S1P receptor (S1PR) in Hippo-YAP activation in both LX-2 cell lines and primary HSCs. Real-time PCR, western blot, pharmacological inhibitors, siRNAs, and Rho activity assays were adopted to address the molecular mechanisms of S1P mediated YAP activation. RESULTS: Serum and exogenous S1P significantly increased the expression of YAP target genes in HSCs. Pharmacologic inhibitors and siRNA-mediated knockdowns of S1P receptors showed S1P receptor 2 (S1PR2) as the primary mediator for S1P-induced CTGF expression in HSCs. Results using siRNA-mediated knockdown, Verteporfin, and Phospho-Tag immunoblots showed that S1P-S1PR2 signaling effectively suppressed the Hippo kinases cascade, thereby activating YAP. Furthermore, S1P increased RhoA activities in cells and ROCK inhibitors effectively blocked CTGF induction. Cytoskeletal-perturbing reagents were shown to greatly modulate CTGF induction, suggesting the important role of actin cytoskeleton in S1P-induced YAP activation. Exogeneous S1P treatment was enough to increase the expression of COL1A1 and α-SMA, that were blocked by YAP specific inhibitor. CONCLUSIONS: Our data demonstrate that S1P/S1PR2-Src-RhoA-ROCK axis leads to Hippo-YAP activation, resulting in the up-regulation of CTGF, COL1A1 and α-SMA expression in HSCs. Therefore, S1PR2 may represent a potential therapeutic target for hepatic fibrosis.

IL-13 and IL-17A activate ß1 integrin through an NF-kB/Rho kinase/PIP5K1γ pathway to enhance force transmission in airway smooth muscle.

Integrin activation resulting in enhanced adhesion to the extracellular matrix plays a key role in fundamental cellular processes. Although integrin activation has been extensively studied in circulating cells such as leukocytes and platelets, much less is known about the regulation and functional impact of integrin activation in adherent cells such as smooth muscle. Here, we show that two different asthmagenic cytokines, IL-13 and IL-17A, activate type I and IL-17 cytokine receptor families, respectively, to enhance adhesion of airway smooth muscle. These cytokines also induce activation of ß1 integrins detected by the conformation-specific antibody HUTS-4. Moreover, HUTS-4 binding is increased in the smooth muscle of patients with asthma compared to nonsmokers without lung disease, suggesting a disease-relevant role for integrin activation in smooth muscle. Indeed, integrin activation induced by the ß1-activating antibody TS2/16, the divalent cation manganese, or the synthetic peptide ß1-CHAMP that forces an extended-open integrin conformation dramatically enhances force transmission in smooth muscle cells and airway rings even in the absence of cytokines. We demonstrate that cytokine-induced activation of ß1 integrins is regulated by a common pathway of NF-κB-mediated induction of RhoA and its effector Rho kinase, which in turn stimulates PIP5K1γ-mediated synthesis of PIP2 at focal adhesions, resulting in ß1 integrin activation. Taken together, these data identify a pathway by which type I and IL-17 cytokine receptor family stimulation induces functionally relevant ß1 integrin activation in adherent smooth muscle and help to explain the exaggerated force transmission that characterizes chronic airway diseases such as asthma.

Discovery of novel pyrazolo[1,5-a]pyrimidine derivatives as selective ROCK2 inhibitors with anti-breast cancer migration and invasion activities.

Rho-associated coiled-coil kinase (ROCK) is involved in multiple cellular activities regulating the actin cytoskeleton, such as cell morphology, adhesion, and migration. The inhibition of ROCK is a feasible strategy to suppress breast cancer metastasis. Herein, based on Belumosudil, a series of pyrazolo[1,5-a]pyrimidine derivatives as selective ROCK2 inhibitors were designed and synthesized. Through systematic investigation of SARs, the piperazine analog 7u was identified with optimum ROCK2 inhibitory activity (IC50 = 36.8 nM) and excellent selectivity over the isoform protein ROCK1 (>250-fold). Intriguingly, upon treatment with 7u, the arrangement of the MDA-MB-231 cytoskeleton was affected accompanied by the alteration of morphology. Furthermore, cell scratch and transwell assays indicated that 7u inhibited MDA-MB-231 cell migration and invasion in a dose-dependent manner. Ultimately, the binding model of 7u with ROCK2 well accounted for the superior activities of 7u as a promising ROCK2 inhibitor with the potential application in breast cancer metastasis treatment.

ROCK2 increases drug resistance in acute myeloid leukemia via metabolic reprogramming and MAPK/PI3K/AKT signaling.

Rho-associated coiled-coil kinase 2 (ROCK2) is classified as a member of the serine/threonine protein kinase family and has been identified as a key driver of the development of various forms of cancer. The cause of ROCK2's impact on acute myeloid leukemia (AML) is still unknown. We found that ROCK2 expression was higher in AML patients, leading to lower complete response rates and worse overall survival. Additionally, ROCK2 expression was elevated in the doxorubicin-resistant leukemia cell line HL-60/ADM when compared to their individual parent cells. Moreover, the suppression or inhibition of ROCK2 leads to enhanced drug sensitivity in both AML cell lines and primary AML specimens, along with a notable decrease in downstream signaling pathways. Furthermore, the suppression of ROCK2 caused disruption of cellular energy production pathways by directly affecting the functionality of proteins within the mitochondrial electron transport chain. Finally, we discovered that TRIM26, a specific E3 ligase, is capable of ubiquitylating ROCK2, and the upregulation of TRIM26 within HL-60/ADM cells resulted in heightened sensitivity to the drug and reduced resistance. Thus, our study presents a new strategy for overcoming drug resistance in AML through targeting ROCK2/AKT/MAPK signaling pathway.

Prenatal exposure to dibutyl phthalate contributes to erectile dysfunction in offspring male rats by activating the RhoA/ROCK signalling pathway.

Prenatal exposure to dibutyl phthalate (DBP) has been reported to cause erectile dysfunction (ED) in adult offspring rats. However, its underlying mechanisms are not fully understood. Previously, we found that DBP activates the RhoA/ROCK pathway in the male reproductive system. This study investigated how prenatal exposure to DBP activates the RhoA/ROCK signalling pathway, leading to ED in male rat offspring. Pregnant rats were stratified into DBP-exposed and NC groups, with the exposed group receiving 750 milligrams per kilogram per day (mg/kg/day) of DBP through gavage from days 14-18 of gestation. DBP exposure activated the RhoA/ROCK pathway in the penile corpus cavernosum (CC) of descendants, causing smooth muscle cell contraction, fibrosis, and apoptosis, all of which contribute to ED. In vitro experiments confirmed that DBP induces apoptosis and RhoA/ROCK pathway activation in CC smooth muscle cells. Treatment of DBP-exposed offspring with the ROCK inhibitor Y-27632 for 8 weeks significantly improved smooth muscle cell condition, erectile function, and reduced fibrosis. Thus, prenatal DBP exposure induces ED in offspring through RhoA/ROCK pathway activation, and the ROCK inhibitor Y-27632 shows potential as an effective treatment for DBP-induced ED.

Hypoxia-induced LAMB2-enriched extracellular vesicles promote peritoneal metastasis in gastric cancer via the ROCK1-CAV1-Rab11 axis.

Peritoneal metastasis is one of the most common risk factors contributing to the poor prognosis of gastric cancer. We previously reported that extracellular vesicles from gastric cancer cells could facilitate peritoneal metastasis. However, their impact on gastric cancer-induced peritoneal metastasis under hypoxic conditions remains unclear. This study aims to elucidate how hypoxia-resistant gastric cancer cell-derived extracellular vesicles affect the peritoneal metastasis of normoxic gastric cancer cells. Proteomic analysis revealed elevated levels of Caveolin1 and Laminin ß2 in hypoxia-resistant gastric cancer cells and their corresponding extracellular vesicles. Importantly, Caveolin1 was found to play a central role in mediating Laminin ß2 sorting into extracellular vesicles derived from hypoxia-resistant gastric cancer cells, and subsequently, extracellular vesicle-associated Laminin ß2 promoted peritoneal metastasis in normoxic gastric cancer cells by activating the AKT pathway. Further investigation confirmed that Caveolin1 activation by Rho-related Coiled-coil kinase 1-mediated phosphorylation of Y14 residue is a key factor facilitating Laminin ß2 sorting into extracellular vesicles. Moreover, Y14 phosphorylated- Caveolin1 enhanced Laminin ß2 sorting by activating Rab11. Finally, our study demonstrated that a combined assessment of plasma extracellular vesicle-associated Caveolin1 and extracellular vesicle-associated Laminin ß2 could provide an accurate predictive tool for peritoneal metastasis occurrence in gastric cancer.