Expression Of RhoA Research Articles

Plexin-B2 Mediates Orthodontic Tension-Induced Osteogenesis via the RhoA/F-Actin/YAP Pathway.

This study aims to investigate the role of Plexin-B2 in tension-induced osteogenesis of periodontal ligament stem cells (PDLSCs) and its biomechanical mechanism. In vitro, cyclic tension simulated orthodontic forces to assess Plexin-B2 expression in PDLSCs. We then knocked out Plexin-B2 using lentivirus to explore its role in tension-induced osteogenesis. Invivo, we used nickel-titanium springs to establish orthodontic tooth movement (OTM) models in mice. Local periodontal Plexin-B2 expression was knocked down using adeno-associated viruses (AAVs) to study its influence on new bone formation under mechanical tension in OTM models. Molecular mechanisms were elucidated by manipulating Plexin-B2 and RhoA expression, assessing related proteins, and observing F-actin and Yes-associated protein (YAP) through immunofluorescence. Plexin-B2 expression in PDLSCs increased under cyclic tension. Decrease of Plexin-B2 reduced the expression of osteogenic protein in PDLSCs and negatively affected new bone formation during OTM. RhoA expression and phosphorylation of ROCK2/LIMK2/Cofilin decreased in Plexin-B2 knockout PDLSCs but were reversed by RhoA overexpression. The level of F-actin decreased in Plexin-B2 knockout PDLSCs but increased after RhoA rescue. Nuclear YAP was reduced in Plexin-B2 knockout PDLSCs but increased after RhoA overexpression. Plexin-B2 is involved in tension-induced osteogenesis. Mechanistically, the RhoA signaling pathway, the F-actin arrangement, and the nuclear translocation of YAP are involved in the mechanotransduction of Plexin-B2.

Reduced microvascular flow-mediated dilation in Syrian hamsters lacking d-sarcoglycan is caused by increased oxidative stress.

d-sarcoglycan mutation reduces mechanotransduction and induces dilated cardiomyopathy with aging. We hypothesized that in young hamsters with d-sarcoglycan mutation, which do not show cardiomyopathy, flow mechanotransduction might be affected in resistance arteries as the control of local blood flow. Flow-mediated-dilation (FMD) was measured in isolated mesenteric resistance arteries, using 3-months old hamsters carrying a mutation in the d-sarcoglycan gene (CH-147) and their control littermates. The FMD was significantly reduced in the CHF-147 group. Nevertheless, passive arterial diameter, vascular structure and endothelium-independent dilation to sodium nitroprusside were not modified. Contraction induced by KCl was not modified, whereas contraction due to phenylephrine was increased. The basal NO production and total eNOS expression levels were not altered. Nevertheless, eNOS phosphorylation, FAKs and RhoA expression were reduced in CH-147. In contrast, p47phox, COX2, iNOS and reactive oxygen species levels were higher in the endothelium of CHF-147 hamsters. Reducing ROS levels using the superoxide dismutase analog Tempol significantly restored the flow-mediated dilation (FMD) levels in CHF-147 hamsters. However, treatment with the COX-2 inhibitor NS-398 showed a non-significant improvement in FMD.

A DNA base-specific sequence interposed between CRX and NRL contributes to RHODOPSIN expression

Gene expression emerges from DNA sequences through the interaction of transcription factors (TFs) with DNA cis-regulatory sequences. In eukaryotes, TFs bind to transcription factor binding sites (TFBSs) with differential affinities, enabling cell-specific gene expression. In this view, DNA enables TF binding along a continuum ranging from low to high affinity depending on its sequence composition; however, it is not known whether evolution has entailed a further level of entanglement between DNA-protein interaction. Here we found that the composition and length (22 bp) of the DNA sequence interposed between the CRX and NRL retinal TFs in the proximal promoter of RHODOPSIN (RHO) largely controls the expression levels of RHO. Mutagenesis of CRX-NRL DNA linking sequences (here termed “DNA-linker”) results in uncorrelated gene expression variation. In contrast, mutual exchange of naturally occurring divergent human and mouse Rho cis-regulatory elements conferred similar yet species-specific Rho expression levels. Two orthogonal DNA-binding proteins targeted to the DNA-linker either activate or repress the expression of Rho depending on the DNA-linker orientation relative to the CRX and NRL binding sites. These results argue that, in this instance, DNA itself contributes to CRX and NRL activities through a code based on specific base sequences of a defined length, ultimately determining optimal RHO expression levels.

CAMP/PKA-mediated in vitro angiogenesis: A novel interplay between PKA, RhoA/ROCK, and VEGFR2 signalling

Abstract Background and Aims Others and we have previously demonstrated that cAMP/PKA signalling stabilise endothelial cell (EC) barrier function via modulating the activities of Rho GTPases, mainly RhoA and Rac1. In the present study we analysed whether cAMP/PKA also modulates EC angiogenesis capacity and whether Rho GTPases are involved in this function. Methods The study was carried out on cultured human umbilical vein ECs (HUVECs). RhoA and Rac1 activities were genetically manipulated by lentiviral-mediated over expression of dominant negative (DN) and constitutive active (CA) forms of RhoA and Rac1. Pharmacologically, specific activation and inhibition of PKA was achieved by using cAMP analogue N6-Benzoyl-cAMP (5 mM) and PKI (1 µM), respectively. Pharmacologically, Rac1 was inhibited using NSC 23766 (10 µM) and RhoA was activated using Rho activator I (Cytoskeleton Inc.). In vitro angiogenesis was analysed by 3-D spheroid assay and matrigel tube formation assay. Results Pharmacologically, specific activation of PKA induced EC migration (Wound healing assay), tube formation, and 3-D spheroids and potentiated the VEGF-induced in vitro angiogenesis. These pro-angiogenesis activities were abrogated by highly specific cell-permeable peptide inhibitor (PKI) of PKA. Activation of cAMP/PKA-signalling resulted in an increased VEGFR2 and Akt phosphorylation, increased Rac1 activity, and a strong inhibition of RhoA/Rock pathway. Pharmacological activation of RhoA but not inhibition of Rac1 abrogated PKA-induced VEGFR2 phosphorylation, tube formation and 3-D spheroids. Lentiviral mediated over-expression of constitutive active form of RhoA but not Rac1 abrogated PKA-induced VEGFR2 and Akt phosphorylation and angiogenesis. Moreover, pharmacological inhibition of Akt also abrogated PKA-mediated VEGFR2 phosphorylation and angiogenesis. Likewise, over expression of either dominant negative RhoA or pharmacological inhibitors of Rho kinase (ROCK) promoted basal and potentiated PKA-mediated VEGFR2 and Akt phosphorylation and angiogenesis. Conclusion We describe for the first time a novel interplay between PKA, RhoA/ROCK, Akt, and VEGFR2 signalling and angiogenesis. Inhibition of RhoA/ROCK plays an important role in mediating PKA-induced angiogenesis and activation of RhoA/ROCK signalling may offer an important target to intervene therapeutic angiogenesis.

Effects of mesenchymal stromal cells and human recombinant Nerve Growth Factor delivered by bioengineered human corneal lenticule on an innovative model of diabetic retinopathy.

Diabetic retinopathy (DR) is a microvascular complication of diabetes in which neurodegeneration has been recently identified as a driving force. In the last years, mesenchymal stromal cells (MSCs) and neurotrophins like Nerve Growth Factor (NGF), have garnered significant attention as innovative therapeutic approaches targeting DR-associated neurodegeneration. However, delivering neurotrophic factors directly in the eye remains a challenge. Hence, this study evaluated the effects of MSCs from human amniotic fluids (hAFSCs) and recombinant human NGF (rhNGF) delivered by human corneal lenticule (hCL) on a high glucose (HG) induced ex vivo model simulating the molecular mechanisms driving DR. Porcine neuroretinal explants exposed to HG (25 mM for four days) were used to mimic DR ex vivo. hCLs collected from donors undergoing refractive surgery were decellularized using 0.1% sodium dodecyl sulfate and then bioengineered with hAFSCs, microparticles loaded with rhNGF (rhNGF-PLGA-MPs), or both simultaneously. Immunofluorescence (IF) and scanning electron microscopy (SEM) analyses were performed to confirm the hCLs bioengineering process. To assess the effects of hAFSCs and rhNGF, bioengineered hCLs were co-cultured with HG-treated neuroretinal explants and following four days RT-PCR and cytokine array experiments for inflammatory, oxidative, apoptotic, angiogenic and retinal cells markers were performed. Data revealed that HG-treated neuroretinal explants exhibit a characteristic DR-phenotype, including increased level of NF-kB, NOS2, NRF2 GFAP, VEGFA, Bax/Bcl2 ratio and decreased expression of TUBB3 and Rho. Then, the feasibility to bioengineer decellularized hCLs with hAFSCs and rhNGF was demonstrated. Interestingly, co-culturing hAFSCs- and rhNGF- bioengineered hCLs with HG-treated neuroretinal explants for four days significantly reduced the expression of inflammatory, oxidative, apoptotic, angiogenic and increased retinal markers. Overall, we found for the first time that hAFSCs and rhNGF were able to modulate the molecular mechanisms involved in DR and that bioengineered hCLs represents a promising ocular drug delivery system of hAFSCs and rhNGF for eye diseases treatment. In addition, results demonstrated that porcine neuroretinal explants treated with HG is a useful model to reproduce ex vivo the DR pathophysiology.

3D spheroids versus 2D-cultured human adipose stem cells to generate smooth muscle cells in an internal anal sphincter-targeting cryoinjured mouse model

BackgroundThe efficacy of cell implantation via 3D-spheroids to treat basal tone in fecal incontinence remains unclear. To address this, in this study, we aimed to identify cell differentiation and assess the development of a contractile phenotype corresponding to smooth muscle cells (SMCs) following implantation of 3D-spheroid and 2D-cultured human adipose stem cells (hASCs) in an in vivo internal anal sphincter (IAS)-targeted mouse model.MethodsWe developed an IAS-targeted in vivo model via rapid freezing (at − 196 °C) of the dorsal layers of the region of interest (ROI) of the IAS ring posterior quarter, between the submucosal and muscular layers, following submucosal dissection (n = 60 rats). After implantation of tetramethylindocarbocyanine perchlorate (Dil)-stained 3D and 2D-cells into randomly allocated cryoinjured rats, the entire sphincter ring or only the cryoinjured ROI was harvested. Expression of SMC markers, RhoA/ROCKII and its downstream molecules, and fibrosis markers was analyzed. Dil, α-smooth muscle actin (α-SMA), and RhoA signals were used for cell tracking.ResultsIn vitro, 3D-spheroids exhibited higher levels of SMC markers and RhoA/ROCKII-downstream molecules than 2D-hASCs. The IAS-targeted cryoinjured model exhibited substantial loss of SMC layers of the squamous epithelium lining of the anal canal, as well as reduced expression of SMC markers and RhoA-related downstream molecules. In vivo, 3D-spheroid implantation induced SMC markers and contractile molecules weakly at 1 week. At 2 weeks, the mRNA expression of aSma, Sm22a, Smoothelin, RhoA, Mypt1, Mlc20, Cpi17, and Pp1cd increased, whereas that of fibrosis markers reduced significantly in the 3D-spheroid implanted group compared to those in the sham, non-implanted, and 2D-hASC implanted groups. Protein levels of RhoA, p-MYPT1, and p-MLC20 were higher in the 3D-spheroid-implanted group than in the other groups. At 2 weeks, in the implanted groups, the cryoinjured tissues (which exhibited Dil, α-SMA, and RhoA signals) were restored, while they remained defective in the sham and non-implanted groups.ConclusionsThese findings demonstrate that, compared to 2D-cultured hASCs, 3D-spheroids more effectively induce a contractile phenotype that is initially weak but subsequently improves, inducing expression of RhoA/ROCKII-downstream molecules and SMC differentiation associated with IAS basal tone.

Complex sporulation-specific expression of transcription termination factor Rho highlights its involvement in Bacillus subtilis cell differentiation

Termination factor Rho, responsible for the main factor-dependent pathway of transcription termination and the major inhibitor of antisense transcription, is an emerging regulator of various physiological processes in microorganisms. In Gram-positive bacterium Bacillus subtilis, Rho is involved in the control of cell adaptation to starvation and, in particular, in the control of sporulation, a complex differentiation program leading to formation of a highly resistant dormant spore. While the initiation of sporulation requires a decrease in Rho protein levels during the transition to stationary phase, the mechanisms regulating the expression of rho gene throughout the cell cycle remain largely unknown. Here we show that a drop in the activity of the vegetative SigA-dependent rho promoter causes the inhibition of rho expression in stationary phase. However, after the initiation of sporulation, rho gene is specifically reactivated in two compartments of the sporulating cell using distinct mechanisms. In the mother cell, rho expression occurs by read-through transcription initiated at the SigH-dependent promoter of the distal spo0F gene. In the forespore, rho gene is transcribed from the intrinsic promoter recognized by the alternative sigma factor SigF. These regulatory elements ensure the activity of Rho during sporulation, which appears important for the proper formation of spores. We provide experimental evidence that disruption of the spatiotemporal expression of rho during sporulation affects the resistance properties of spores, their morphology, and the ability to return to vegetative growth under favorable growth conditions.

Anti-fibrogenic effect of umbilical cord-derived mesenchymal stem cell-conditioned media in human esophageal fibroblasts.

Esophageal fibrosis can develop due to caustic or radiation injuries. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) are known to mitigate fibrosis in various organs. However, the potential effects of UC-MSCs on human esophageal fibrosis remain underexplored. This study investigated the anti-fibrogenic properties and mechanisms of UC-MSC-derived conditioned media (UC-MSC-CM) on human esophageal fibroblasts (HEFs). HEFs were treated with TGF-β1 and then cultured with UC-MSC-CM, and the expression levels of extracellular matrix (ECM) components, RhoA, myocardin related transcription factor A (MRTF-A), serum response factor (SRF), Yes-associated protein (YAP), and transcriptional coactivator with PDZ-binding motif (TAZ) were measured. UC-MSC-CM suppressed TGF-β1-induced fibrogenic activation in HEFs, as evidenced by the downregulation of ECM. UC-MSC-CM diminished the expression of RhoA, MRTF-A, and SRF triggered by TGF-β1. In TGF-β1-stimulated HEFs, UC-MSC-CM decreased the nuclear localization of MRTF-A and YAP. Additionally, UC-MSC-CM diminished the TGF-β1-induced nuclear expressions of YAP and TAZ, while concurrently enhancing the cytoplasmic presence of phosphorylated YAP. Furthermore, UC-MSC-CM reduced TGF-β1-induced phosphorylation of Smad2. These findings suggest that UC-MSC-CM may inhibit TGF-β1-induced fibrogenic activation in HEFs by targeting the Rho-mediated MRTF/SRF and YAP/TAZ pathways, as well as the Smad2 pathway. This indicates its potential as a stem cell therapy for esophageal fibrosis.

Chungtaejeon (CTJ) inhibits adhesion and migration of VSMC through cytoskeletal remodeling pathway

IntroductionVascular remodeling is crucial for the progression of vascular disease such as atherosclerosis. We utilize the in vitro experimental model of atherosclerosis to elucidate the activity of Chungtaejeon (CTJ), a Korean fermented tea on adhesion and migration of human aortic vascular smooth muscle cells (HASMC). Materials and methodsVarious in vitro assays such as cell viability, cell adhesion, Western blot, immunofluorescence, were carried out on HASMC to explore pathway associated with cytoskeletal remodeling during the progression of atherosclerosis. ResultsIn result, CTJ significantly inhibited adhesion of HASMC as revealed by collagen assay. Similarly, CTJ inhibited the β1-integrin protein expression as well as FAK phosphorylation. Treatment of CTJ also inhibited stress fiber formation. Likewise, adherence of cells on collagen optimally increased the expression of both RhoA and Cdc42, however, treatment of CTJ dose dependently decreased their expression. The lysophosphatidic acid stimulation of HASMC rapidly increased the level of phosphorylated forms of MLC20 within 15 min, followed by an extended level of MLC20 phosphorylation. The treatment of CTJ at a dose of 50, 100 and 250 μg/ml remarkably reduced the diphosphorylated form while decreased the level of monophosphorylated form of MLC20. ConclusionsOur results suggests that, with further validation CTJ could be a promising herbal resource for prevention of atherosclerosis.

The role of the RHOA/ROCK pathway in the regulation of myometrial stages throughout pregnancy

BackgroundControlling uterine contractile activity is essential to regulate the duration of pregnancy. During most of the pregnancy, the uterus does not contract (i.e., myometrial quiescence). The myometrium recovers its contractile phenotype at around 36 weeks (i.e., myometrial activation) through several mechanisms. The RHOA/ROCK pathway plays a vital role in facilitating muscular contractions by calcium sensitization in humans. Yet, the role of this pathway during different myometrial stages, including quiescence, has not been elucidated. Objectivewe aimed to study the role of the RHOA/ROCK pathway in the regulation of the different myometrial stages throughout pregnancy. Specifically, we hypothesized that the inhibition of the components of the RHOA/ROCK pathway play an important role in maintaining uterine quiescence. Study designMyometrial samples were obtained from pregnant individuals who underwent cesarean section. Pregnant individuals who delivered preterm without labor (myometrial quiescence), preterm with labor (nonphysiological myometrial stimulation), term not in labor (activation), and term in labor (physiological myometrial stimulation) were included. The mRNA and protein expression of RHOA, ROCK I, ROCK II, RND1-3, and ROCK activity through pMYTP1 were evaluated. ResultsWe found that the human myometrium constitutively expressed RHOA/ROCK pathway components throughout pregnancy. No changes in the components of the RHOA/ROCK pathway were found during quiescence. Moreover, the RHOA protein and ROCK activity increased in the myometrium during labor, supporting the hypothesis that this pathway participates in maintaining the contractile activity of the myometrium. This study provides insight into the role of the RHOA/ROCK pathway in controlling myometrial contractile activity during pregnancy.

A comparative anticancer analysis of iron oxide nanoparticles of Hippophae rhamnoides and Cichorium intybus found in the Karakoram Range of Gilgit Baltistan against liver cancer targeting the RhoA gene

Objective The current research work focused on the evaluation of of H. rhamnoides and C. intybus Fe2O3 NPs against liver cancer cell line (HepG2) by performing antiproliferative assay targeting the RhoA gene and apoptotic pathway genes and proteins. Methods Fe2O3 NPs were synthesized using extracts of H. rhamnoides and C. intybus and characterized by UV–Vis spectroscopy, FTIR, SEM/EDS and XRD. MTT assay was used to study cytotoxicity against the HepG2 cells. Real-time qPCR and ELISA were used for the gene and protein analysis. Results An absorbance peak at 300 nm for H. rhamnoides and 289 nm for C. intybus nanoparticles were observed by UV–Vis analysis. The FTIR bands of H. rhamnoide Fe2O3 NPs suggested the presence of aldehydes, alcohols and polyols whereas bands of C. intybus Fe2O3 NPs suggested the presence of carboxyl groups, hydroxyl groups, alkynes and amines. The size of Fe2O3 NPs was found to be 27 ± 5nm for H. rhamnoides and 84 ± 4nm for C. intybus. The IC50 value of 41.69 µM for H. rhmnoides and 71.04 µM for C. intybus Fe2O3 NPs compared to plant extract (78.10 and 96.03 µM for H. rhamnoides and C. intybus, respectively) were found against HepG2 cells. The gene expression and protein levels of RhoA were decreased whereas those of bax, caspase 3, caspase 8 and caspase 9 were found increased. Conclusion Nanoparticles and extract of H. rhamnoides were found more effective as compared to C. intybus, which was evident by the results of cytotoxicity and analysis of studied genes and proteins.

Shengmai Powder regulates alveolar macrophage PPAR-γ and improves the chronic inflammatory state of chronic obstructive pulmonary disease.

This study examines the therapeutic effects of Shengmai Powder (SMP) on both in vitro and in vivo models of chronic obstructive pulmonary disease (COPD) and the underlying mechanisms. Cigarette smoke and cigarette extracts were used to create in vitro and in vivo models of COPD. ELISA was used to measure the levels of pro-inflammatory factors (IL-6, TNF-α, and IL-1β) in mouse lung tissue and alveolar macrophages. Flow cytometry assessed the phagocytic capacity of alveolar macrophage. Western blotting was used to analyze the expression of RhoA, PPARγ, IκBα, p-IκBα, P65, and p-P65 in alveolar. The results show that SMP reversed the increased levels of pro-inflammatory factors (IL-6, TNF-α, and IL-1β) in mouse lung tissue and alveolar macrophages induced by cigarette smoke and cigarette extract. SMP also restored the decreased fluorescence intensity and RhoA levels in alveolar macrophages caused by cigarette extract. Additionally, SMP increased PPARγ expression and decreased IκBα and P65 phosphorylation in alveolar macrophages exposed to cigarette extract. Also, the effects of SMP were reversed by PPARγ inhibitors. The study concluded that SMP regulates alveolar macrophage phagocytic function through the PPAR-γ/NF-κB pathway, thereby improving the chronic inflammatory state of COPD.

Targeting RhoA expression with formononetin and salvianolic acid B to mitigate pancreatic cancer-associated endothelial cells changes

Ethnopharmacological relevanceAccording to the theory of Qi and blood in Traditional Chinese Medicine (TCM), the combination of Qi-reinforcing herbs and blood-activating herbs has a synergistic effect in improving blood stasis syndrome, especially in tumor treatment. The classic “Radix Astragali - Salvia miltiorrhiza” duo exemplifies this principle, renowned for invigorating Qi and activating blood flow, employed widely in tumor therapies. Our prior research underscores the potent inhibition of pancreatic tumor xenografts by the combination of Formononetin (from Radix Astragali) and Salvianolic acid B (from Salvia miltiorrhiza) in vitro. However, it remains unclear whether this combination can inhibit the abnormal vascularization of pancreatic tumors to achieve its anti-cancer effect. Aim of the studyAbnormal vasculature, known to facilitate tumor growth and metastasis. Strategies to normalize tumor-associated blood vessels provide a promising avenue for anti-tumor therapy. This study aimed to unravel the therapeutic potential of Formononetin combined with Salvianolic acid B (FcS) in modulating pancreatic cancer's impact on endothelial cells, illuminate the underlying mechanisms that govern this therapeutic interaction, thereby advancing strategies to normalize tumor vasculature and combat cancer progression. Materials and methodsA co-culture system involving Human Umbilical Vein Endothelial Cells (HUVECs) and PANC-1 cells was established to investigate the potential of targeting abnormal vasculature as a novel anti-tumor therapeutic strategy. We systematically compared HUVEC proliferation, migration, invasion, and lumenogenesis in both mono- and co-culture conditions with PANC-1 (H-P). Subsequently, FcS treatment of the H-P system was evaluated for its anti-angiogenic properties. Molecular docking was utilized to predict the interactions between Formononetin and Salvianolic acid B with RhoA, and the post-treatment expression of RhoA in HUVECs was assessed. Furthermore, we utilized shRhoA lentivirus to elucidate the role of RhoA in FcS-mediated effects on HUVECs. In vivo, a zebrafish xenograft tumor model was employed to assess FcS's anti-tumor potential, focusing on cancer cell proliferation, migration, apoptosis, and vascular development. ResultsFcS treatment demonstrated a significant, dose-dependent inhibition of PANC-1-induced alterations in HUVECs, including proliferation, migration, invasion, and tube formation capabilities. Molecular docking analyses indicated potential interactions between FcS and RhoA. Further, FcS treatment was found to downregulate RhoA expression and modulated the PI3K/AKT signaling pathway in PANC-1-induced HUVECs. Notably, the phenotypic inhibitory effects of FcS on HUVECs were attenuated by RhoA knockdown. In vivo zebrafish studies validated FcS's anti-tumor activity, inhibiting cancer cell proliferation, metastasis, and vascular sprouting, while promoting tumor cell apoptosis. ConclusionsThis study underscores the promising potential of FcS in countering pancreatic cancer-induced endothelial alterations. FcS exhibits pronounced anti-abnormal vasculature effects, potentially achieved through downregulation of RhoA and inhibition of the PI3K/Akt signaling pathway, thereby presenting a novel therapeutic avenue for pancreatic cancer management.

Unveiling the role of RhoA and ferroptosis in vascular permeability: Implications for osteoarthritis.

Abnormal angiogenesis and increased vascular permeability of subchondral bone are key mechanisms related to osteoarthritis (OA). However, the precise mechanisms responsible for heightened vascular permeability in OA remain unclear. The present study used proteomics to identify protein expression in damaged subchondral bone compared with normal subchondral bone. The results suggest that Ras homolog family member A (RhoA) may be associated with the vascular permeability of subchondral bone and ferroptosis in OA. The results of analysis of clinical samples indicated a significant increase in expression of RhoA in the subchondral bone of OA. This were consistent with the proteomics findings. We found through western blotting, RT‑PCR, and immunofluorescence that RhoA significantly increased the permeability of endothelial cells (ECs) by inhibiting inter‑EC adhesion proteins (zona occludens‑1, connexin 43 and Vascular endothelial‑Cadherin) and actin filaments. Furthermore, RhoA induced ferroptosis core proteins (glutathione peroxidase 4, solute carrier family 7 member 11 and acyl‑CoA synthase long‑chain family member 4, ACSL4) by influencing lipid peroxidation and mitochondrial function, leading to ferroptosis of ECs. This suggested an association between RhoA, ferroptosis and vascular permeability. Ferroptosis significantly increased permeability of ECs by inhibiting inter‑EC adhesion proteins. RhoA increased vascular permeability by inducing ferroptosis of ECs. In vivo, inhibition of RhoA and ferroptosis significantly mitigated progression of OA by alleviating cartilage degeneration and subchondral bone remodeling in mice with destabilization of the medial meniscus. In conclusion, the present findings indicated that RhoA enhanced vascular permeability in OA by inducing ferroptosis. This may serve as a novel strategy for the early prevention and treatment of OA.

Electroacupuncture improves retinal function in myopia Guinea pigs probably via inhibition of the RhoA/ROCK2 signaling pathway

ObjectiveTo investigate the effect of electroacupuncture (EA) on retinal function in guinea pigs with negative lens-induced myopia (LIM) by inhibiting the RhoA/ROCK2 signaling pathway. MethodsGuinea pigs were randomly divided into normal control (NC) group, LIM group, EA group, SHAM acupoint (SHAM) group, and electro-acupuncture + ROCK pathway inhibitor Y27632 (EA + Y27632) group. The refraction, axial length, retinal blood flow density, choroidal vascular index, retinal physiological function, the contents of total antioxidant capacity (T-AOC), catalase (CAT), glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) of each group were determined. The changes in retinal tissue structure were observed by hematoxylin and eosin (H&E) staining, and the expression of the RhoA/ROCK2 signaling pathway-related molecules in the retina was measured by real-time quantitative polymerase chain reaction (qPCR) and Western blot. ResultsMyopic refraction, AL, and MDA content in the LIM and SHAM groups were significantly increased, retinal blood flow density and CVI, SOD, GSH, CAT, T-AOC content were decreased. After EA intervention, myopic refraction, AL, and MDA content decreased, retinal blood flow density and CVI, SOD, GSH, CAT, T-AOC content were increased. H&E staining showed that the thickness of the guinea pig retina, the thickness of the inner and outer layers of the nucleus, and the number of cells were significantly increased after EA intervention. qPCR and western blot analyses showed that the expression of RhoA、ROCK2、MLC、CollagenⅠ、MMP-2、TIMP-2 and α-SMA were elevated in the LIM and SHAM group than those in the NC group. Compared with the LIM group, the expression of EA group was significantly decreased. ConclusionsElectroacupuncture can improve retinal function by improving retinal blood flow, reducing retinal oxidative damage, inhibiting RhoA/ROCK2 signaling pathway and controlling extracellular matrix remodeling, thus delaying the occurrence and development of myopia.

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

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. 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. 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. Heraclenin facilitates the osteogenic differentiation of human BMSCs through the activation of the RhoA/ROCK pathway.

Mechano-growth factor regulates periodontal ligament stem cell proliferation and differentiation through Fyn–RhoA-YAP signaling

BackgroundMechano-growth factor (MGF), which is a growth factor produced specifically in response to mechanical stimuli, with potential of tissue repair and regeneration. Our previous research has shown that MGF plays a crucial role in repair of damaged periodontal ligaments by promoting differentiation of periodontal ligament stem cells (PDLSCs). However, the molecular mechanism is not fully understood. This study aimed to investigated the regulatory effect of MGF on differentiation of PDLSCs and its molecular mechanism. MethodsInitially, we investigated how MGF impacts cell growth and differentiation, and the relationship with the activation of Fyn-p-YAPY357 and LATS1-p-YAPS127. Then, inhibitors were used to interfere Fyn phosphorylation to verify the role of Fyn-p-YAP Y357 signal after MGF stimulation; moreover, siRNA was used to downregulate YAP expression to clarify the function of YAP in PDLSCs proliferation and differentiation. Finally, after C3 was used to inhibit the RhoA expression, we explored the role of RhoA in the Fyn-p-YAP Y357 signaling pathway in PDLSCs proliferation and differentiation. ResultsOur study revealed that MGF plays a regulatory role in promoting PDLSCs proliferation and fibrogenic differentiation by inducing Fyn-YAPY357 phosphorylation but not LATS1-YAP S127 phosphorylation. Moreover, the results indicated that Fyn could not activate YAP directly but rather activated YAP through RhoA in response to MGF stimulation. ConclusionThe research findings indicated that the Fyn-RhoA-p-YAPY357 pathway is significant in facilitating the proliferation and fibrogenic differentiation of PDLSCs by MGF. Providing new ideas for the study of MGF in promoting periodontal regenerative repair.

RhoA/ROCK-TAZ Axis regulates bone formation within calvarial trans-sutural distraction osteogenesis

BackgroundCraniofacial skeletal deformities can be addressed by applying tensile force to sutures to prompt sutural bone formation. The intricate process of mechanical modulation in craniofacial sutures involves complex biomechanical signal transduction. The small GTPase Ras homolog gene family member A (RhoA) functions as a key mechanotransduction protein, orchestrating the dynamic assembly of the cytoskeleton by activating the Rho-associated coiled-coil containing protein kinase (ROCK). Transcriptional coactivator with PDZ-binding motif (TAZ) serves as a crucial mediator in the regulation of genes and the orchestration of biological functions within the mechanotransduction signaling pathway. However, the role of RhoA/ROCK-TAZ in trans-sutural distraction osteogenesis has not been reported. MethodsWe utilized pre-osteoblast-specific RhoA deletion mice to establish an in vivo calvarial trans-sutural distraction model and an in vitro mechanical stretch model for pre-osteoblasts isolated from neonatal mice. Micro-CT and histological staining were utilized to detect the formation of new bone in the sagittal suture of the skull as well as the activation of RhoA, Osterix and TAZ. The activation of ROCK-limk-cofilin and the nuclear translocation of TAZ in pre-osteoblasts under mechanical tension were detected through Western blot, qRT-PCR, and immunofluorescence. ResultsThe osteogenic differentiation of pre-osteoblasts was facilitated by mechanical tension through the activation of RhoA and Rho-associated kinase (ROCK), while ablation of RhoA impaired osteogenesis by inhibiting pre-osteoblast differentiation after suture expansion. Furthermore, inhibiting RhoA expression could block tensile-stimulated nuclear translocation of TAZ by preventing F-actin assembly through ROCK-LIM-domain kinase (LIMK)-cofilin pathway. In addition, the TAZ agonist TM-25659 could attenuate impaired osteogenesis caused by ablation of RhoA in pre-osteoblasts by increasing TAZ nuclear accumulation. ConclusionsThis study demonstrates that mechanical stretching promotes the osteogenic differentiation of pre-osteoblasts in trans-sutural distraction osteogenesis, and this process is mediated by the RhoA/ROCK-TAZ signaling axis. Overall, our results may provide an insight for potential treatment strategies for craniosynostosis patients through trans-sutural distraction osteogenesis.

MiR-129–2-3p binds SEMA4C to regulate HCC development and inhibit the EMT

BackgroundAmong primary liver cancers, HCC is the most prevalent. Small noncoding RNAs called miRNAs control the expression of downstream target genes to take part in a variety of physiological and pathological processes, including those related to cancer. MethodsmiR-129–2–3p and SEMA4C expression levels were assessed using RT-qPCR. The CCK-8, invasion, and wound healing assays were used to confirm the capacity of HCC cells for proliferation, invasion and migration respectively. Serum SEMA4C levels were detected via ELISA. The RIP and dual-luciferase reporter assays were used to confirm the existence of intergenic binding sites. Cell apoptosis assay and cell cycle assay were performed to detect the apoptosis rate and cycle distribution of cells, and WB was performed to detect the protein expression of SEMA4C, RhoA, ROCK1, E-cadherin, N-cadherin, and vimentin. Furthermore, cancer-inhibiting role of miR-129–2–3p were further confirmed by animal tests. ResultsmiR-129–2–3p expression was reduced in HCC tissues and cells. Overexpression of miR-129–2–3p decreased the proliferation, invasion, migration, and EMT in HCC cells, whereas inhibition of miR-129–2–3p had the opposite effects. Our research also showed that SEMA4C was increased in HCC tissues, serum and cells, and that SEMA4C knockdown prevented HCC cell invasion, migration, proliferation, and EMT. Overexpression of SEMA4C reversed the inhibitory effect of miR-129–2–3p on HCC. ConclusionsOverall, we discovered that through binding to SEMA4C, miR-129–2–3p regulates HCC cell proliferation, invasion, migration, and EMT.

Paeoniflorin regulates RhoA/ROCK1 and Nrf2 pathways in PDLIM1-dependent or independent manners in oxidative stressed melanocytes.

The adhesive properties of vitiligo melanocytes have decreased under oxidative stress., cytoskeleton proteins can control cell adhesion. Paeoniflorin (PF) was proved to resist hydrogen peroxide (H2O2)-induced oxidative stress in melanocytes via nuclear factorE2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. This study was to investigate whether PF exerts anti-oxidative effect through influencing cytoskeleton markers or potential signaling pathway. Human Oxidative Stress Plus array was used to identify the differentially expressed genes between H2O2 + PF group and H2O2 only group, in PIG1 and PIG3V melanocyte cell lines respectively. Western blotting was used to verify the PCR array results and to test the protein expression levels of cytoskeleton markers including Ras homolog family member A (RhoA), Rho-associated kinase 1 (ROCK1) and antioxidative marker Nrf2. Small interfering RNA was used to knock down PDZ and LIM domain 1 (PDLIM1). PF increased the expressions of PDLIM1, RhoA and ROCK1 in H2O2-induced PIG1, in contrast, decreased the expressions of PDLIM1 and ROCK1 in H2O2-induced PIG3V. Knockdown of PDLIM1 increased the expressions of RhoA and Nrf2 in PF-pretreated H2O2-induced PIG1, and ROCK1 and Nrf2 in PF-pretreated H2O2-induced PIG3V. PF regulates RhoA/ROCK1 and Nrf2 pathways in PDLIM1-dependent or independent manners in H2O2-induced melanocytes. In PIG1, PF promotes PDLIM1 to inhibit RhoA/ROCK1 pathway or activates Nrf2/HO-1 pathway, separately. In PIG3V, PF directly downregulates ROCK1 in PDLIM1-independent manner or upregulates Nrf2 dependent of PDLIM1.