Effect of ripasudil after trabeculectomy with mitomycin C: a multicentre, randomised, prospective clinical study.

BACKGROUND: To investigate if there are improvements in trabeculectomy outcomes supporting filtration bleb formation caused by Rho-associated protein kinase (ROCK) inhibitors. METHODS: This prospective, multicentre, randomised, open-label clinical study examined open-angle glaucoma patients who underwent trabeculectomy or trabeculectomy combined with cataract surgery followed by 3-month postoperative ripasudil treatments. After randomly allocating patients to ripasudil-ROCK inhibitor (ripasudil) or without ripasudil (non-ripasudil) groups. Mean intraocular pressure (IOP) changes, success rate, and number of eyedrops were compared for both groups. RESULTS: A total of 17 and 15 subjects dropped out in the ripasudil group and non-ripasudil group, respectively. At baseline, the mean IOP was 16.8±5.0 mm Hg in the ripasudil group (38 patients) and 16.2±4.4 in the non-ripasudil group (52 patients). The IOP decreased to 11.4±3.2 mm Hg, 10.9±3.9 mm Hg and 10.6±3.5 mm Hg at 12, 24 and 36 months in the ripasudil group, while it decreased to 11.2±4.1 mm Hg, 10.5±3.1 mm Hg and 10.9±3.2 mm Hg at 12, 24 and 36 months in the non-ripasudil group, respectively. There was a significant decrease in the number of IOP-lowering medications after trabeculectomy in the ripasudil group versus the non-ripasudil group at 24 (p=0.010) and 36 months (p=0.016). There was no statistically significant difference between the groups for the 3-year cumulative probability of success. CONCLUSION: Although ripasudil application did not increase the primary trabeculectomy success rate, it did reduce IOP-lowering medications after trabeculectomy with mitomycin C.

Hypericin-mediated photodynamic therapy inhibits metastasis and EMT of colorectal cancer cells by regulating RhoA-ROCK1 signaling pathway.

Colorectal cancer (CRC) is significantly contributed to global cancer mortality rates. Treating CRC is particularly challenging due to metastasis and drug resistance. There is a pressing need for new treatment strategies against metastatic CRC. Photodynamic therapy (PDT) offers a well-established, minimally invasive treatment option for cancer with limited side effects. Hypericin (HYP), a potent photosensitizer for PDT, has been documented to induce cytotoxicity and apoptosis in various types of cancers. However, there are few reports on the inhibitory effects of HYP-mediated PDT on the metastatic ability of CRC cells. Here, we evaluate the inhibitory effects of HYP-mediated PDT against metastatic CRC cells and define its underlying mechanisms. Wound-healing and Transwell assays show that HYP-mediated PDT suppresses migration and invasion of CRC cells. F-actin visualization assays indicate HYP-mediated PDT decreases F-actin formation in CRC cells. TEM assays reveal HYP-mediated PDT disrupts pseudopodia formation of CRC cells. Mechanistically, immunofluorescence and western blotting results show that HYP-mediated PDT upregulates E-cadherin and downregulates N-cadherin and Vimentin. HYP-mediated PDT also suppresses key EMT regulators, including Snail, MMP9, ZEB1 and α-SMA. Additionally, the expressions of RhoA and ROCK1 are downregulated by HYP-mediated PDT. Together, these findings suggest that HYP-mediated PDT inhibits the migration and invasion of HCT116 and SW620 cells by modulating EMT and RhoA-ROCK1 signaling pathway. Thus, HYP-mediated PDT presents a potential therapeutic option for CRC.

Connecting GSK-3ß Inhibitory Activity with IKK-ß or ROCK-1 Inhibition to Target Tau Aggregation and Neuroinflammation in Alzheimer's Disease-Discovery, In Vitro and In Cellulo Activity of Thiazole-Based Inhibitors.

GSK-3ß, IKK-ß, and ROCK-1 kinases are implicated in the pathomechanism of Alzheimer's disease due to their involvement in the misfolding and accumulation of amyloid ß (Aß) and tau proteins, as well as inflammatory processes. Among these kinases, GSK-3ß plays the most crucial role. In this study, we present compound 62, a novel, remarkably potent, competitive GSK-3ß inhibitor (IC50 = 8 nM, Ki = 2 nM) that also exhibits additional ROCK-1 inhibitory activity (IC50 = 2.3 µM) and demonstrates anti-inflammatory and neuroprotective properties. Compound 62 effectively suppresses the production of nitric oxide (NO) and pro-inflammatory cytokines in the lipopolysaccharide-induced model of inflammation in the microglial BV-2 cell line. Furthermore, it shows neuroprotective effects in an okadaic-acid-induced tau hyperphosphorylation cell model of neurodegeneration. The compound also demonstrates the potential for further development, characterized by its chemical and metabolic stability in mouse microsomes and fair solubility.

Protective effects of Y-27632 against cisplatin-induced ototoxicity: A zebrafish model Y-27632 and cisplatin-induced ototoxicity.

Cisplatin is an effective chemotherapy agent against various solid malignancies; however, it is associated with irreversible bilateral sensorineural hearing loss, emphasizing the need for drug development to prevent this complication, with the current options being very limited. Rho-associated coiled-coil-containing protein kinase (ROCK) is a serine-threonine protein kinase involved in various cellular processes, including apoptosis regulation. In this study, we used a transgenic zebrafish model (Brn3C: EGFP) in which hair cells within neuromasts are observed in green under fluorescent microscopy without the need for staining. Zebrafish larvae were exposed to cisplatin alone or in combination with various concentrations of Y-27632, a potent ROCK inhibitor. Hair cell counts, apoptosis assessments using the terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assay, FM1-43FX labeling assay and behavioral analyses (startle response and rheotaxis) were performed to evaluate the protective effects of Y-27632 against cisplatin-induced ototoxicity. Cisplatin treatment reduced the number of hair cells in neuromasts, induced apoptosis, and impaired zebrafish larval behaviors. Y-27632 demonstrated a dose-dependent protective effect against cisplatin-induced hair cell loss and apoptosis. These findings suggest that Y-27632, as a ROCK inhibitor, mitigates cisplatin-induced hair cell loss and associated ototoxicity in zebrafish.

The Application of Rho Kinase Inhibitors in the Management of Glaucoma.

Glaucoma is a chronic neurodegenerative disease that poses a significant threat of irreversible blindness worldwide. Current treatments for glaucoma focus on reducing intraocular pressure (IOP), which is the only modifiable risk factor. Traditional anti-glaucomatous agents, including carbonic anhydrase inhibitors, beta-blockers, alpha-2 agonists, and prostaglandin analogs, work by either improving uveoscleral outflow or reducing aqueous humor production. Rho kinase (ROCK) inhibitors represent a novel class of anti-glaucomatous drugs that have emerged from bench to bedside in the past decade, offering multifunctional characteristics. Unlike conventional medications, ROCK inhibitors directly target the trabecular meshwork outflow pathway. This review aims to discuss the mechanism of ROCK inhibitors in reducing IOP, providing neuroprotection, and preventing fibrosis. We also highlight recent studies and clinical trials evaluating the efficacy and safety of ROCK inhibitors, compare them with other clinical anti-glaucomatous medications, and outline future prospects for ROCK inhibitors in glaucoma treatment.

The ROCK inhibitor netarsudil in the treatment of corneal endothelial decompensation caused by corneal endotheliitis: A case report and literature review.

Proper hydration and the clarity of the cornea are maintained through the crucial function of the corneal endothelium. Inflammation of the corneal endothelium, known as endotheliitis, can disrupt endothelial function, resulting in alterations to vision. Corneal endotheliitis is characterised by corneal oedema, the presence of keratic precipitates, inflammation within the anterior chamber, and occasionally, limbal injection, neovascularisation, and the concurrent or overlapping presence of uveitis. The aetiology of this condition is diverse, predominantly viral, but it may also be drug-induced, result from bacterial or fungal infections, be associated with systemic diseases and procedures, or remain idiopathic with no identifiable cause. To date, no standardised protocol for the treatment of this ocular disease exists, and in severe cases, corneal transplantation may be required. A 31-year-old male was transferred to our hospital for the management of corneal endothelial decompensation resulting from corneal endotheliitis. Hormonal therapy and antiviral medications proved ineffective, rendering the patient a candidate for corneal transplantation. As a final measure, treatment with the ROCK inhibitor netarsudil was initiated. The patient demonstrated significant improvement in symptoms, and the inflammation was successfully managed after nine months. In this study, a novel approach employing ROCK inhibitor therapy was utilised for the treatment of corneal endotheliitis, leading to marked recovery during patient follow-up. This case report represents the inaugural application of the ROCK inhibitor netarsudil in managing corneal endothelial decompensation attributed to corneal endotheliitis. These findings suggest that this method warrants consideration as a potential novel treatment option for similar conditions.

Fasudil attenuates oxidative stress-induced partial epithelial-mesenchymal transition of tubular epithelial cells in hyperuricemic nephropathy via activating Nrf2.

Anti-partial epithelial-mesenchymal transition (pEMT) treatment of renal tubular epithelial cells (TECs) represents a promising therapeutic approach. Hyperuricemia nephropathy (HN) arises as a consequence of hyperuricemia (HUA)-induced tubulointerstitial fibrosis (TIF). Studies have suggested that the Ras homolog member A (RhoA)/Rho-associated kinase (ROCK) pathway is a crucial signaling transduction system in renal fibrosis. Fasudil, a RhoA/ROCK inhibitor, has exhibited the potential to prevent fibrosis progress. However, its impact on the pEMT of TECs in HN remains unclear. Here, an HN rat model and an uric acid (UA)-stimulated human kidney 2 (HK2) cell model were established and treated with Fasudil to explore its effects. Furthermore, the underlying mechanism of action involved in the attenuation of pEMT in TECs by Fasudil during HN was probed by using multiple molecular approaches. The HN rat model exhibited significant renal dysfunction and histopathological damage, whereas in vitro and in vivo experiments further confirmed the pEMT status accompanied by RhoA/ROCK pathway activation and oxidative stress in tubular cells exposed to UA. Notably, Fasudil ameliorated these pathological changes, and this was consistent with the trend of ROCK silencing in vitro. Mechanistically, we identified the Neh2 domain of nuclear factor erythroid 2-related factor 2 (Nrf2) as a target of Fasudil for the first time. Fasudil targets Nrf2 activation and antagonizes oxidative stress to attenuate the pEMT of TECs in HN. Our findings suggest that Fasudil attenuates oxidative stress-induced pEMT of TECs in HN by targeting Nrf2 activation. Thus, Fasudil is a potential therapeutic agent for the treatment of HN.

A novel strategy to facilitate uniform epithelial cell maturation using liquid-liquid interfaces.

Epithelial tissue forms and maintains a critical barrier function in the body. A novel culture design aimed at promoting uniform maturation of epithelial cells using liquid materials is described. Culturing Madin-Darby canine kidney (MDCK) cells at the liquid-liquid interface yielded reduced migration and stimulated active cell growth. Similar to solid-liquid interfaces, cells cultured on a fibronectin-coated liquid-liquid interface exhibited active migration and growth, ultimately reaching a confluent state. These cells exhibited reduced stress fiber formation and adopted a cobblestone-like shape, which led to their even distribution in the culture vessel. To inhibit stress fiber formation and apoptosis, the exposure of cells on liquid-liquid interfaces to Y27632, a specific inhibitor of the Rho-associated protein kinase (ROCK), facilitated tight junction formation (frequency of ZO-2-positive cells, FZ = 0.73). In Y27632-exposed cells on the liquid-liquid interface, the value obtained by subtracting the standard deviation of the ratio of nucleus densities in each region that compartmentalized a culture vessel from 1, denoted as HLN, was 0.93 ± 0.01, indicated even cell distribution in the culture vessel at t = 72 h. The behavior of epithelial cells on liquid-liquid interfaces contributes to the promotion of their uniform maturation.

Rho-associated kinase regulates Langerhans cell morphology and responsiveness to tissue damage.

Skin damage requires efficient immune cell responses to restore organ function. Epidermal-resident immune cells known as Langerhans cells use dendritic protrusions to surveil the skin microenvironment, which contains keratinocytes and peripheral axons. The mechanisms governing Langerhans cell dendrite dynamics and responses to tissue damage are poorly understood. Using skin explants from adult zebrafish, we show that Langerhans cells maintain normal surveillance following axonal degeneration and use their dendrites to engulf small axonal debris. By contrast, a ramified-to-rounded shape transition accommodates the engulfment of larger keratinocyte debris. We find that Langerhans cell dendrites are populated with actin and sensitive to a broad-spectrum actin inhibitor. We show that Rho-associated kinase (ROCK) inhibition leads to elongated dendrites, perturbed clearance of large debris, and reduced Langerhans cell migration to epidermal wounds. Our work describes the dynamics of Langerhans cells and involvement of the ROCK pathway in immune cell responses.

Isolation and Culture of Primary Human Mammary Epithelial Cells.

The mammary gland is a fundamental structure of the breast and plays an essential role in reproduction. Human mammary epithelial cells (HMECs), which are the origin cells of breast cancer and other breast-related inflammatory diseases, have garnered considerable attention. However, isolating and culturing primary HMECs in vitro for research purposes has been challenging due to their highly differentiated, keratinized nature and their short lifespan. Therefore, developing a simple and efficient method to isolate and culture HMECs is of great scientific value for the study of breast biology and breast-related diseases. In this study, we successfully isolated primary HMECs from small amounts of mammary tissue by digestion with a mixture of enzymes combined with an initial culture in 5% fetal bovine serum-DMEM containing the Rho-associated kinase (ROCK) inhibitor Y-27632, followed by culture expansion in serum-free keratinocyte medium. This approach selectively promotes the growth of epithelial cells, resulting in an optimized cell yield. The simplicity and convenience of this method make it suitable for both laboratory and clinical research, which should provide valuable insights into these important areas of study.

Rho kinase inhibitor Y-27632 downregulates IL-1ß expression in mice with experimental autoimmune myocarditis.

Autoimmune myocarditis is the limited or diffuse inflammation of the myocardium due to dysfunctional cellular and humoral immunity mechanisms. We constructed mouse models of experimental autoimmune myocarditis (EAM) using peptide MyHC-α614-629. On the day after secondary immunization, the mice were intraperitoneally injected with Rho kinase (ROCK) inhibitor Y-27632. On day 21, the cardiac tissues were harvested and weighed. The hearts of EAM mice were significantly enlarged and whitened. Furthermore, body weight (BW) slowly increased during the treatment period, the heart weight (HW) and the ratio of HW/eventual BW were increased, and inflammatory infiltration and fibrosis were aggravated in the myocardial tissue. Y-27632 treatment improved the aforementioned phenotypic and pathological features of EAM mice. Mechanistic analysis revealed a significant increase in Notch1, Hes1, Jag2, Dil1, Toll-like receptor (Tlr) 2, and interleukin (IL)-1ß expression in the myocardial tissue of EAM mice. Notably, IL-1ß expression was correlated with that of Notch1 and Tlr2. Following Y-27632 treatment, the expression of key target genes of the Notch signaling pathway (Notch1, Hes1, Dil1, and Jag2) and Tlr2 were obviously decreased. Y-27632 treatment also decreased the number of monocytes in the spleen of EAM mice. Thus, ROCK inhibitor Y-27632 exerted a protective effect in EAM mice by downregulating IL-1ß expression. This study aimed to provide a reference point for the future treatment of myocarditis in clinical settings.

Exploration of the Mechanisms Underlying Yu's Enema Formula in Treating Ulcerative Colitis by Blocking the RhoA/ROCK Pathway based on Network Pharmacology, High-performance Liquid Chromatography Analysis, and Experimental Verification.

BACKGROUND: The traditional Chinese medicine formula, Yu's Enema Formula (YEF), has demonstrated potential in the treatment of Ulcerative Colitis (UC). OBJECTIVE: This study aimed to unveil the anti-UC mechanisms of YEF. METHODS: Utilizing public databases, we obtained YEF and UC-related targets. GO and KEGG analyses were conducted via clusterProfiler and Reactome. The STRING database facilitated the construction of the PPI network, and hub targets were selected using cytoHubba. We used R software for differential expression and correlation analyses, and molecular docking was performed with PyMOL and AutoDock. HPLC analysis identified the compounds in YEF. For in vivo validation, a UC rat model was employed. RESULTS AND DISCUSSION: 495 YEF-UC overlapping targets were identified. GO and KEGG analyses indicated enrichment in exogenous stimuli response, peptide response, positive MAPK cascade regulation, interleukin- related signaling, and the TLR4 cascade. Hub targets included CTNNB1, JUN, MAPK1, MAPK3, SRC, STAT3, TLR4, TP53, and RELA, which were often interconnected. Molecular docking revealed quercetin's strong binding affinity with CTNNB1, MAPK1, MAPK3, SRC, STAT3, TLR4, and TP53, consistent with HPLC analysis. In vivo experiments suggested that YEF has the potential to alleviate UC symptoms and protect the intestinal mucosal barrier by inhibiting the RhoA/ROCK pathway. CONCLUSION: YEF may safeguard the intestinal mucosal barrier in UC by targeting CTNNB1, MAPK1, MAPK3, SRC, STAT3, TLR4, and TP53, while blocking the RhoA/ROCK pathway.

ROCK1 inhibition improves wound healing in diabetes via RIPK4/AMPK pathway.

Refractory wounds are a severe complication of diabetes mellitus that often leads to amputation because of the lack of effective treatments and therapeutic targets. The pathogenesis of refractory wounds is complex, involving many types of cells. Rho-associated protein kinase-1 (ROCK1) phosphorylates a series of substrates that trigger downstream signaling pathways, affecting multiple cellular processes, including cell migration, communication, and proliferation. The present study investigated the role of ROCK1 in diabetic wound healing and molecular mechanisms. Our results showed that ROCK1 expression significantly increased in wound granulation tissues in diabetic patients, streptozotocin (STZ)-induced diabetic mice, and db/db diabetic mice. Wound healing and blood perfusion were dose-dependently improved by the ROCK1 inhibitor fasudil in diabetic mice. In endothelial cells, fasudil and ROCK1 siRNA significantly elevated the phosphorylation of adenosine monophosphate-activated protein kinase at Thr172 (pThr172-AMPKα), the activity of endothelial nitric oxide synthase (eNOS), and suppressed the levels of mitochondrial reactive oxygen species (mtROS) and nitrotyrosine formation. Experiments using integrated bioinformatics analysis and coimmunoprecipitation established that ROCK1 inhibited pThr172-AMPKα by binding to receptor-interacting serine/threonine kinase 4 (RIPK4). These results suggest that fasudil accelerated wound repair and improved angiogenesis at least partially through the ROCK1/RIPK4/AMPK pathway. Fasudil may be a potential treatment for refractory wounds in diabetic patients.

Rho-kinase inhibitor alleviates CD4+T cell mediated corneal graft rejection by modulating its STAT3 and STAT5 activation.

Penetrating keratoplasty remains the most common treatment to restore vision for corneal diseases. Immune rejection after corneal transplantation is one of the major causes of graft failure. In recent years, Rho-associated protein kinase (ROCK) inhibitors have been found to be associated with the activation of the STATs pathway and are widely studied in autoimmune diseases. Therefore, it may be possible that the ROCK inhibitors also participate in the local and systemic immune regulation in corneal transplantation through activation of the STATs pathway and affect the CD4+ T cell differentiation. This study aimed to explore the role of ROCK-STATs pathway in the occurrence of immune rejection in corneal transplantation by applying Y27632, a ROCK inhibitor, to the recipient mice and peripheral CD4+ T cells. We found that Y27632 significantly up-regulated the phosphorylation level of STAT5 in both spleen and lymph nodes, down-regulated the phosphorylation level of STAT3 in the CD4+ T cells in the spleen. It also increased the proportion of CD4+CD25+Foxp3+Helios+ Tregs while decreased CD4+IL17A+ -Th17 cells. Moreover, Y27632 also reduced the proportion of dendritic cells in both spleen and lymph nodes, as well as the expression level of CD86 on their surfaces in the spleen, while the proportion of macrophages was not affected. The expression levels of ROCK1, ROCK2, CD11c and IL-17A mRNA were also found to be low in the graft tissue while the expression of Helios was upregulated. Rho-kinase inhibitor can modulate the balance of Tregs/Th17 by regulating the phosphorylation levels of both STAT3 and STAT5, thereby inhibiting the occurrence of immune rejection in allogeneic corneal transplantation.

"Keep on ROCKIn": Repurposed ROCK inhibitors to boost corneal endothelial regeneration.

The global shortage of corneal endothelial graft tissue necessitates the exploration of alternative therapeutic strategies. Rho-associated protein kinase inhibitors (ROCKi), recognized for their regenerative potential in cardiology, oncology, and neurology, have shown promise in corneal endothelial regeneration. This study investigates the repurposing potential of additional ROCKi compounds. Through screening a self-assembled library of ROCKi on B4G12 corneal endothelial cells, we evaluated their dose-dependent effects on proliferation, migration, and toxicity using live-cell imaging. Nine ROCKi candidates significantly enhanced B4G12 proliferation compared to the basal growth rate. These candidates were further assessed for their potential to accelerate wound closure as another indicator for tissue regeneration capacity, with most demonstrating notable efficacy. To assess the potential impact of candidate ROCKi on key corneal endothelial cell markers related to cell proliferation, leaky tight junctions and ion efflux capacity, we analyzed the protein expression of cyclin E1, CDK2, p16, ZO-1 and Na+/K+-ATPase, respectively. Immunocytochemistry and western blot analysis confirmed the preservation of corneal endothelial markers post-treatment with ROCKi hits. However, notable cytoplasm enlargement and nuclear fragmentation were detected after the treatment with SR-3677 and Thiazovivin, indicating possible cellular stress. In compared parameters, Chroman-1 at a concentration of 10 nM outperformed other ROCKi, requiring significantly 1000-fold lower effective concentration than established ROCKi Y-27632 and Fasudil. Altogether, this study underscores the potential of repurposing ROCKi for treating corneal endothelial dysfunctions, offering a viable alternative to conventional grafting methods, and highlights Chroman-1 as a promising candidate structure for hit-to-lead development.

Targeting ROCK2 improves macromolecular permeability in a 3D fibrotic pancreatic cancer microenvironment model.

Pancreatic cancer is characterized by a densely fibrotic stroma. The fibrotic stroma hinders the intratumoral penetration of nanomedicine and diminishes therapeutic efficacy. Fibrosis is characterized by an abnormal organization of extracellular matrix (ECM) components, namely the abnormal deposition and/or orientation of collagen and fibronectin. Abnormal ECM organization is chiefly driven by pathological signaling in pancreatic stellate cells (PSCs), the main cell type involved in fibrogenesis. However, whether targeting signaling pathways involved in abnormal ECM organization improves the intratumoral penetration of nanomedicines is unknown. Here, we show that targeting transforming growth factor-ß (TGFß)/Rho-associated kinase (ROCK) 1/2 signaling in PSCs normalizes ECM organization and concomitantly improves macromolecular permeability of the fibrotic stroma. Using a 3-dimensional cell culture model of the fibrotic pancreatic cancer microenvironment, we found that pharmacological inhibition of TGFß or ROCK1/2 improves the permeation of various macromolecules. By using an isoform-specific pharmacological inhibitor and siRNAs, we show that targeting ROCK2, but not ROCK1, alone is sufficient to normalize ECM organization and improve macromolecular permeability. Moreover, we found that ROCK2 inhibition/knockdown attenuates Yes-associated protein (YAP) nuclear localization in fibroblasts co-cultured with pancreatic cancer cells in 3D. Finally, pharmacological inhibition or siRNA-mediated knockdown of YAP normalized ECM organization and improved macromolecular permeability. Our results together suggest that the TGFß/ROCK2/YAP signaling axis may be therapeutically targeted to normalize ECM organization and improve macromolecular permeability to augment therapeutic efficacy of nanomedicines in pancreatic cancer.

Rho Kinase Inhibitors: Strategies in Glaucoma Treatment in Older Adults.

Glaucoma is a leading cause of irreversible blindness which preferentially affects older individuals. No medications or therapies which are currently in our arsenal actually treat glaucoma itself. We know that intraocular pressure (IOP) is currently the only modifiable risk factor for glaucoma. The primary treatments for glaucoma include medications, laser therapies, and surgical therapies. The Rho kinase inhibitors are the newest class of medications currently on the market and in development for topical IOP-lowering therapy. Studies have shown their ability to lower eye pressure individually and in combination with other medications. Their ability to potentially provide neuroprotective effects for disease modification also gives this class exciting potential for glaucoma treatment.

Heraclenin promotes the osteogenic differentiation of bone marrow stromal cells by activating the RhoA/ROCK pathway.

BACKGROUND: Osteoporosis is a devastating skeletal disease, the pathogenesis of which is related to abnormal bone metabolism, featured by the imbalance between osteoblastic bone formation and osteoclastic bone resorption. Stem cell-based therapies have been demonstrated to improve osteoporosis treatment. Previously, the linear furanocoumarin heraclenin was reported to enhance osteoblast differentiation and mineralization in mouse mesenchymal stem cells (MSCs), suggesting its potential for osteogenic differentiation and bone regeneration. Our study was designed to confirm the promotive role of heraclenin on osteogenic differentiation of human bone MSCs (BMSCs) and explore the underlying mechanisms. METHODS: Human BMSCs were treated for 24, 48, and 72h with heraclenin (5, 10, 20, 40, and 80 µM), and cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. To further evaluate the cytotoxicity of heraclenin, cell suspension obtained from BMSCs treated with heraclenin (5, 10, and 20 µM) for 72h was subjected to a MUSE™ cell analyzer for cell viability and count assay. BMSCs were incubated in osteogenic induction medium for 7 days. Then, osteogenic differentiation and mineralization of BMSCs were assessed through alkaline phosphatase (ALP) and Alizarin Red S staining. The expression of osteogenesis markers including ALP, osteocalcin (OCN), osterix (OSX), and runt-related transcription factor 2 (RUNX2) was detected via reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. The effects of heraclenin on the RhoA/ROCK pathway were estimated through western blotting. Y-27632, the ROCK inhibitor, was used to confirm the role of the RhoA/ROCK pathway in heraclenin-mediated osteogenic differentiation of BMSCs. RESULTS: Heraclenin (5-80 µM) was non-toxic on human BMSCs. Heraclenin treatment (5-20 µM) dose-dependently enhanced ALP activity and calcium deposition. Furthermore, heraclenin promoted ALP, OCN, OSX, and RUNX2 mRNA and protein expression. Mechanically, heraclenin treatment increased RhoA and ROCK1 mRNA expression, stimulated the translocation of ROCK from the cytosolic to the membrane fraction, and elevated the protein levels of phosphorylated cofilin (p-cofilin) and active RhoA. Additionally, treatment with Y-27632 overturned the promotion of heraclenin on ALP activity, calcium deposition, the expression of osteogenesis markers, and the RhoA/ROCK signaling pathway. CONCLUSION: Heraclenin facilitates the osteogenic differentiation of human BMSCs through the activation of the RhoA/ROCK pathway.

Inhibition of RhoA/ROCK signalling pathway activity improves neural damage and cognitive deficits in the fluorosis model.

Excessive fluoride intake poses health risks to humans and animals. Many studies have indicated that fluoride exposure can damage the cytoskeleton and synapses, which has negative effects on the intellectual development of humans and animals. Our previous study suggested that the RhoA/ROCK signalling pathway is activated by NaF exposure in HT-22 cells and plays a vital role in cytoskeletal assembly and synaptogenesis. However, the mechanism underlying RhoA/ROCK-mediated cytoskeletal injury induced by fluoride remains unclear. In this study, Neuro-2A cells and ICR mice were used to investigate the effects of RhoA/ROCK activation inhibition on NaF-induced synaptic dysfunction and cognitive impairment. We detected the expression of GAP, RhoA, ROCK1/2, and (p)-MLC in vivo and in vitro model. The results showed that NaF exposure activated the RhoA/ROCK/MLC signalling pathway. We measured the effects of RhoA/ROCK inhibition on synaptic injury and intellectual impairment induced by NaF exposure. In vitro, Y-27632 suppressed activated RhoA/ROCK, attenuated morphological and ultrastructural damage, and decreased the survival rate and synapse-functional protein expression caused by NaF. In vivo, the results showed that the RhoA/ROCK/MLC pathway was inhibited by fasudil and improved pathological damage in the hippocampus, cognitive impairment, and decreased expression of neurofunctional proteins induced by NaF. Overall, these results suggest that fasudil and Y-27632 can reverse neurotoxicity caused by fluoride exposure. Furthermore, inhibition of RhoA/ROCK may be a future treatment for CNS injury, and more detailed studies on other neurodegenerative disease models are required to confirm its effectiveness.