Rho-kinase inhibitor, fasudil, prevents neuronal apoptosis via the Akt activation and PTEN inactivation in the ischemic penumbra of rat brain

The ROCK Inhibitor Fasudil and Sertraline Share Morphological and Molecular Effects in the Hippocampus of Chronically Stressed Rats: Exploring Common Antidepressant Pathways by Network Pharmacology

Despite the widespread use of selective serotonin reuptake inhibitors like sertraline, the intricate molecular mechanisms underlying major depression and the therapeutic efficacy of these treatments remain not fully elucidated. Building on our preliminary findings, this study investigates the antidepressant effects of fasudil, a Rho-associated protein kinase (ROCK) inhibitor typically utilized as a vasodilator and antispasmodic, and compares its effects with those of sertraline using a chronic restraint stress model in rats. Specifically, we examined the effects of chronic administration on dendritic spine density, key molecular survival pathways, and miRNA levels in the hippocampus. Adult male Sprague-Dawley rats were administered sertraline, fasudil (10 mg/kg/day), or saline over 14 days, with a subset experiencing daily restraint stress. Our findings demonstrate that both sertraline and fasudil effectively prevented stress-induced reductions in dendritic spine density and miR-138 levels in the rat hippocampus. Additionally, by employing a network pharmacology approach, we explored the converging molecular pathways influenced by both drugs, facilitating the identification of novel molecular targets and pathways implicated in the pathophysiology of depression and its treatment. Pharmacoinformatic analysis revealed common signaling cascades and critical proteins that may potentially underlie the observed pharmacological effects, contributing to a paradigm shift in understanding depression by integrating drug repurposing and network pharmacology, offering valuable insights into the underlying mechanisms of depression and the antidepressant effect from a new network-based paradigm rather than focusing solely on a single protein target.

Fasudil protects spiral ganglion neurons and hair cells against cisplatin-induced apoptosis by inhibiting reactive oxygen species accumulation and regulating the ROCK/PTEN/AKT signaling pathway

Cisplatin causes hearing loss in at least 60% of chemotherapy patients, leading to impairments in the patient's life quality. Spiral ganglion neurons (SGNs) and hair cells (HCs) are the main cell types affected by cisplatin accumulation in the inner ear. Fasudil is an FDA-approved drug and has been reported to exert neuroprotective effects in previous research. However, whether fasudil possesses protective effects in cisplatin-induced SGN and HC damage and the potential mechanisms remain unknown. In this study, we investigated whether fasudil has a protective effect on cisplatin-induced damage to inner ear SGNs and HCs. We first observed the effect of different concentrations of fasudil on cisplatin-induced cell loss of SGNs and HCs. We also studied the effects of fasudil on cisplatin-induced apoptosis of SGNs and HCs and detected the mitochondrial reactive oxygen species (ROS) level. Furthermore, we investigated the mechanisms of fasudil in protecting the SGNs and HCs from cisplatin- induced cells apoptosis. We found that fasudil treatment significantly ameliorated SGNs and HCs loss and attenuated cell apoptosis after cisplatin exposure. Moreover, fasudil attenuated the cisplatin-induced ROS generation in SGN- and HC-explants culture. Further mechanistic studies revealed that fasudil regulated the ROCK/PTEN/AKT signaling pathway in SGN- and HC-explants after cisplatin exposure. This study indicates that fasudil might be a novel therapeutic target for preventing cisplatin-induced SGNs and HCs damage.

Involvement of RhoA/ROCK Signaling Pathway in Methamphetamine-Induced Blood-Brain Barrier Disruption

Methamphetamine (METH) is a powerful addictive psychostimulant that gives rise to severe abusers worldwide. While many studies have reported on the neurotoxicity of METH, blood-brain barrier (BBB) dysfunction has recently attracted attention as an essential target in METH-induced pathological changes in the brain. However, its mechanism has not been fully understood. We found that METH increased paracellular permeability and decreased vascular integrity through FITC-dextran and trans-endothelial electrical resistance (TEER) assay in primary human brain endothelial cells (HBMECs). Also, redistribution of tight junction proteins (zonula occluden-1 and claudin-5) and reorganization of F-actin cytoskeleton were observed in METH-exposed HBMECs. To determine the mechanism of METH-induced BBB disruption, the RhoA/ROCK signaling pathway was examined in METH-treated HBMECs. METH-activated RhoA, followed by an increase in the phosphorylation of downstream effectors, myosin light chain (MLC) and cofilin, occurs in HBMECs. Pretreatment with ROCK inhibitors Y-27632 and fasudil reduced the METH-induced increase in phosphorylation of MLC and cofilin, preventing METH-induced redistribution of junction proteins and F-actin cytoskeletal reorganization. Moreover, METH-induced BBB leakage was alleviated by ROCK inhibitors in vitro and in vivo. Taken together, these results suggest that METH induces BBB dysfunction by activating the RhoA/ROCK signaling pathway, which results in the redistribution of junction proteins via F-actin cytoskeletal reorganization.

LncRNA NEAT1, an Important Biomarker Involved in the Pathological and Physiological Processes of Parkinson's Disease

Parkinson's disease (PD) is a complex progressive neurodegenerative disorder and the pathogenesis and treatment methods are unknown. This aim is to investigate the effects of long non coding RNA NEAT1 (LncRNA NEAT1) on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD). Immunoprecipitation and western blot were used to search for the effects of LncRNA NEAT1 on PD. Tyrosine hydroxylase (TH) and brain derived neurotrophic factor (BDNF) were evaluated in substantia nigra (SN) region of the brain by immunohistochemical staining. Compared with the control group, the relative expression level of LncRNA NEAT1 in the MPTP group was significantly increased. LncRNA NEAT1 is negatively correlated with miR-376b-3p. LncRNA NEAT1 significantly increased oxidative stress, neuroinflammation along with enhanced neurotrophic potential via NLR family Pyrin domain protein 3 (NLRP3) pathway. In conclusion, these results indicated that LncRNA NEAT1 participated in the pathophysiological of PD and its mechanism via the miR-376b-3p/NLRP3 signaling pathway.

Role of Rho-associated kinases and their inhibitor fasudil in neurodegenerative diseases

Neurodegenerative diseases (NDDs) are prevalent in the elderly. The pathogenesis of NDDs is complex, and currently, there is no cure available. With the increase in aging population, over 20 million people are affected by common NDDs alone (Alzheimer's disease and Parkinson's disease). Therefore, NDDs have profound negative impacts on patients, their families, and society, making them a major global health concern. Rho-associated kinases (ROCKs) belong to the serine/threonine protein kinases family, which modulate diverse cellular processes (e.g., apoptosis). ROCKs may elevate the risk of various NDDs (including Huntington's disease, Parkinson's disease, and Alzheimer's disease) by disrupting synaptic plasticity and promoting inflammatory responses. Therefore, ROCK inhibitors have been regarded as ideal therapies for NDDs in recent years. Fasudil, one of the classic ROCK inhibitor, is a potential drug for treating NDDs, as it repairs nerve damage and promotes axonal regeneration. Thus, the current review summarizes the relationship between ROCKs and NDDs and the mechanism by which fasudil inhibits ROCKs to provide new ideas for the treatment of NDDs.

Fasudil alleviates alcohol-induced cognitive deficits and hippocampal morphology injury partly by altering the assembly of the actin cytoskeleton and microtubules

Alcohol-Related Brain Damage (ARBD) manifests predominantly as cognitive impairment and brain atrophy with the hippocampus showing particular vulnerability. Fasudil, a Rho kinase (ROCK) inhibitor, has established neuroprotective properties; however, its impact on alcohol-induced cognitive dysfunction and hippocampal structural damage remains unelucidated. This study probes Fasudil's neuroprotective potential and identifies its mechanism of action in an in vivo context. Male C57BL/6 J mice were exposed to 30% (v/v, 6.0 g/kg) ethanol by intragastric administration for four weeks. Concurrently, these mice received a co-treatment with Fasudil through intraperitoneal injections at a dosage of 10 mg/kg/day. Fasudil was found to mitigate alcohol-induced spatial and recognition memory deficits, which were quantified using Y maze, Morris water maze, and novel object recognition tests. Concurrently, Fasudil attenuated hippocampal structural damage prompted by chronic alcohol exposure. Notably, Fasudil moderated alcohol-induced disassembly of the actin cytoskeleton and microtubules-mechanisms central to the maintenance of hippocampal synaptic integrity. Collectively, our findings indicate that Fasudil partially reverses alcohol-induced cognitive and morphological detriments by modulating cytoskeletal dynamics, offering insights into potential therapeutic strategies for ARBD.

Recent advances on signaling pathways and their inhibitors in spinal cord injury

Spinal cord injury (SCI) is a serious and disabling central nervous system injury. Its complex pathological mechanism can lead to sensory and motor dysfunction. It has been reported that signaling pathway plays a key role in the pathological process and neuronal recovery mechanism of SCI. Such as PI3K/Akt, MAPK, NF-κB, and Wnt/β-catenin signaling pathways. According to reports, various stimuli and cytokines activate these signaling pathways related to SCI pathology, thereby participating in the regulation of pathological processes such as inflammation response, cell apoptosis, oxidative stress, and glial scar formation after injury. Activation or inhibition of relevant pathways can delay inflammatory response, reduce neuronal apoptosis, prevent glial scar formation, improve the microenvironment after SCI, and promote neural function recovery. Based on the role of signaling pathways in SCI, they may be potential targets for the treatment of SCI. Therefore, understanding the signaling pathway and its inhibitors may be beneficial to the development of SCI therapeutic targets and new drugs. This paper mainly summarizes the pathophysiological process of SCI, the signaling pathways involved in SCI pathogenesis, and the potential role of specific inhibitors/activators in its treatment. In addition, this review also discusses the deficiencies and defects of signaling pathways in SCI research. It is hoped that this study can provide reference for future research on signaling pathways in the pathogenesis of SCI and provide theoretical basis for SCI biotherapy.

Redox Regulation of PTEN by Reactive Oxygen Species: Its Role in Physiological Processes

Phosphatase and tensin homolog (PTEN) is a tumor suppressor due to its ability to regulate cell survival, growth, and proliferation by downregulating the PI3K/AKT signaling pathway. In addition, PTEN plays an essential role in other physiological events associated with cell growth demands, such as ischemia-reperfusion, nerve injury, and immune responsiveness. Therefore, recently, PTEN inhibition has emerged as a potential therapeutic intervention in these situations. Increasing evidence demonstrates that reactive oxygen species (ROS), especially hydrogen peroxide (H2O2), are produced and required for the signaling in many important cellular processes under such physiological conditions. ROS have been shown to oxidize PTEN at the cysteine residue of its active site, consequently inhibiting its function. Herein, we provide an overview of studies that highlight the role of the oxidative inhibition of PTEN in physiological processes.

Sex-Specific Acute Cerebrovascular Responses to Photothrombotic Stroke in Mice

Mechanisms underlying cerebrovascular stroke outcomes are poorly understood, and the effects of biological sex on cerebrovascular regulation post-stroke have yet to be fully comprehended. Here, we explore the overlapping roles of gonadal sex hormones and rho-kinase (ROCK), two important modulators of cerebrovascular tone, on the acute cerebrovascular response to photothrombotic (PT) focal ischemia in mice. Male mice were gonadectomized and female mice were ovariectomized to remove gonadal hormones, whereas control ("intact") animals received a sham surgery prior to stroke induction. Intact wild-type (WT) males showed a delayed drop in cerebral blood flow (CBF) compared with intact WT females, whereby maximal CBF drop was observed 48 h following stroke. Gonadectomy in males did not alter this response. However, ovariectomy in WT females produced a "male-like" phenotype. Intact Rock2+/- males also showed the same phenotypic response, which was not altered by gonadectomy. Alternatively, intact Rock2+/- females showed a significant difference in CBF values compared with intact WT females, displaying higher CBF values immediately post-stroke and showing a maximal CBF drop 48 h post-stroke. This pattern was not altered by ovariectomy. Altogether, these data illustrate sex differences in acute CBF responses to PT stroke, which seem to involve gonadal female sex hormones and ROCK2. Overall, this study provides a framework for exploring sex differences in acute CBF responses to focal ischemic stroke in mice.

A multi-laboratory preclinical trial in rodents to assess treatment candidates for acute ischemic stroke

Human diseases may be modeled in animals to allow preclinical assessment of putative new clinical interventions. Recent, highly publicized failures of large clinical trials called into question the rigor, design, and value of preclinical assessment. We established the Stroke Preclinical Assessment Network (SPAN) to design and implement a randomized, controlled, blinded, multi-laboratory trial for the rigorous assessment of candidate stroke treatments combined with intravascular thrombectomy. Efficacy and futility boundaries in a multi-arm multi-stage statistical design aimed to exclude from further study highly effective or futile interventions after each of four sequential stages. Six independent research laboratories performed a standard focal cerebral ischemic insult in five animal models that included equal numbers of males and females: young mice, young rats, aging mice, mice with diet-induced obesity, and spontaneously hypertensive rats. The laboratories adhered to a common protocol and efficiently enrolled 2615 animals with full data completion and comprehensive animal tracking. SPAN successfully implemented treatment masking, randomization, prerandomization inclusion and exclusion criteria, and blinded assessment of outcomes. The SPAN design and infrastructure provide an effective approach that could be used in similar preclinical, multi-laboratory studies in other disease areas and should help improve reproducibility in translational science.

Therapeutic Effect of a Hydrogel-based Neural Stem Cell Delivery Sheet for Mild Traumatic Brain Injury

OBJECTIVE

There are no effective clinically applicable treatments for neuronal dysfunction after mild traumatic brain injury (TBI). Here, we evaluated the therapeutic effect of a new delivery method of mouse neural stem cell (mNSC) spheroids using a hydrogel, in terms of improvement in damaged cortical lesions and cognitive impairment after mild TBI.

METHODS

mNSCs were isolated from the subventricular zone and subgranular zone by a hydrogel-based culture system. GFP-transduced mNSCs were generated into spheroids and wrapped into a sheet for transplantation. Male C57BL/6J mice were randomly divided into four groups: sham operation, TBI, TBI with mNSC spheroids, and TBI with mNSC spheroid sheet transplantation covering the damaged cortex. Histopathological and immunohistochemical features and cognitive function were evaluated 7, 14, and 28 days after transplantation following TBI.

RESULTS

Hydrogel-based culture systems and mNSC isolation were successfully established from the adult mice. Essential transcription factors for NSCs, such as SOX2, PAX6, Olig2, nestin, and doublecortin (DCX), were highly expressed in the mNSCs. A transplanted hydrogel-based mNSC spheroid sheet showed good engraftment and survival ability, differentiated into TUJ1-positive neurons, promoted angiogenesis, and reduced neuronal degeneration. Also, TBI mice treated with mNSC spheroid sheet transplantation exhibited a significantly increased preference for a new object, suggesting improved cognitive function compared to the mNSC spheroids or no treatment groups.

CONCLUSION

Transplantation with a hydrogel-based mNSC spheroid sheet showed engraftment, migration, and stability of delivered cells in a hostile microenvironment after TBI, resulting in improved cognitive function via reconstruction of the damaged cortex.

STATEMENT OF SIGNIFICANCE

This study presents the therapeutic effect of a new delivery method of mouse neural stem cells spheroids using a hydrogel, in terms of improvement in damaged cortical lesions and cognitive impairment after traumatic brain injury. Collagen/fibrin hydrogel allowed long-term survival and migratory ability of NSCs spheroids. Furthermore, transplanted hydrogel-based mNSCs spheroids sheet showed good engraftment, migration, and stability of delivered cells in a hostile microenvironment, resulting in reconstruction of the damaged cortex and improved cognitive function after TBI. Therefore, we suggest that a hydrogel-based mNSCs spheroids sheet could help to improve cognitive impairment after TBI.

Novel Dual AChE and ROCK2 Inhibitor Induces Neurogenesis via PTEN/AKT Pathway in Alzheimer's Disease Model

Alzheimer's disease (AD) is a progressive and complex neurodegenerative disease. Acetylcholinesterase inhibitors (AChEIs) are a major class of drugs used in AD therapy. ROCK2, another promising target for AD, has been associated with the induction of neurogenesis via PTEN/AKT. This study aimed to characterize the therapeutic potential of a novel donepezil-tacrine hybrid compound (TA8Amino) to inhibit AChE and ROCK2 protein, leading to the induction of neurogenesis in SH-SY5Y cells. Experiments were carried out with undifferentiated and neuron-differentiated SH-SY5Y cells submitted to treatments with AChEIs (TA8Amino, donepezil, and tacrine) for 24 h or 7 days. TA8Amino was capable of inhibiting AChE at non-cytotoxic concentrations after 24 h. Following neuronal differentiation for 7 days, TA8Amino and donepezil increased the percentage of neurodifferentiated cells and the length of neurites, as confirmed by β-III-tubulin and MAP2 protein expression. TA8Amino was found to participate in the activation of PTEN/AKT signaling. In silico analysis showed that TA8Amino can stably bind to the active site of ROCK2, and in vitro experiments in SH-SY5Y cells demonstrate that TA8Amino significantly reduced the expression of ROCK2 protein, contrasting with donepezil and tacrine. Therefore, these results provide important information on the mechanism underlying the action of TA8Amino with regard to multi-target activities.

Tight junctions: from molecules to gastrointestinal diseases

Intestinal epithelium functions as a tissue barrier to prevent interaction between the internal compartment and the external milieu. Intestinal barrier function also determines epithelial polarity for the absorption of nutrients and the secretion of waste products. These vital functions require strong integrity of tight junction proteins. In fact, intestinal tight junctions that seal the paracellular space can restrict mucosal-to-serosal transport of hostile luminal contents. Tight junctions can form both an absolute barrier and a paracellular ion channel. Although defective tight junctions potentially lead to compromised intestinal barrier and the development and progression of gastrointestinal (GI) diseases, no FDA-approved therapies that recover the epithelial tight junction barrier are currently available in clinical practice. Here, we discuss the impacts and regulatory mechanisms of tight junction disruption in the gut and related diseases. We also provide an overview of potential therapeutic targets to restore the epithelial tight junction barrier in the GI tract.

USP20 mitigates ischemic stroke in mice by suppressing neuroinflammation and neuron death via regulating PTEN signal

Ischemic stroke is a leading cause of death worldwide. The lack of effective pharmacotherapies for ischemic stroke is mainly attributed to the incomplete understanding of its pathogenesis. Deubiquitinase ubiquitin-specific protease 20 (USP20) plays an important role in regulating multiple cellular processes. However, its effects on cerebral ischemic stroke still remain unknown. In the present study, we found that USP20 expression was markedly increased in the early phase of ischemic stroke in mice with middle cerebral artery occlusion (MCAO) operation, and were then considerably decreased in mice with ischemia reperfusion (I/R) injury. Double immunofluorescence staining showed USP20 abundance in both microglial cells and neurons. We then found that promoting USP20 expression remarkably ameliorated MCAO-induced ischemic brain injury, along with significantly reduced infarct volume, neurological scores and brain water contents. In addition, cognitive impairments in MCAO-operated mice were considerably alleviated by USP20 over-expression. Furthermore, USP20 over-expression dramatically restrained microglial activation, inflammatory response and neuronal death in mice with ischemic stroke. Moreover, our results indicated that phosphatase and tensin homolog (PTEN) expression was highly decreased in the infarct areas of MCAO-treated mice, while being greatly rescued by USP20 over-expression. All these effects mediated by USP20 during cerebral I/R injury were confirmed in the cultured primary microglial cells and cortical neurons stimulated by oxygen-glucose deprivation and reoxygenation (OGD/R). Mechanistically, we found that USP20 directly interacted with PTEN. Notably, suppressing PTEN with its specific inhibitor dramatically abolished the function of USP20 to ameliorate neuroinflammation and neuron death induced by OGD/R. Collectively, our results illustrated that USP20 could effectively mitigate the severity of cerebral ischemic stroke and improve behavior deficits in MCAO-operated mice, and identified the USP20/PTEN axis as a promising therapeutic target for ischemic stroke treatment.

Rho/ROCK Pathway and Noncoding RNAs: Implications in Ischemic Stroke and Spinal Cord Injury

Ischemic strokes (IS) and spinal cord injuries (SCI) are major causes of disability. RhoA is a small GTPase protein that activates a downstream effector, ROCK. The up-regulation of the RhoA/ROCK pathway contributes to neuronal apoptosis, neuroinflammation, blood-brain barrier dysfunction, astrogliosis, and axon growth inhibition in IS and SCI. Noncoding RNAs (ncRNAs), such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), were previously considered to be non-functional. However, they have attracted much attention because they play an essential role in regulating gene expression in physiological and pathological conditions. There is growing evidence that ROCK inhibitors, such as fasudil and VX-210, can reduce injury in IS and SCI in animal models and clinical trials. Recently, it has been reported that miRNAs are decreased in IS and SCI, while lncRNAs are increased. Inhibiting the Rho/ROCK pathway with miRNAs alleviates apoptosis, neuroinflammation, oxidative stress, and axon growth inhibition in IS and SCI. Further studies are required to explore the significance of ncRNAs in IS and SCI and to establish new strategies for preventing and treating these devastating diseases.

An adherent drug depot for retinal ganglion cell protection and regeneration in rat traumatic optic neuropathy models

Traumatic optic neuropathy (TON) describes an injury to the optic nerve following either blunt or penetrating trauma, and remains an important cause of vision loss. No generalized treatment of TON has been established so far to restore the injured optic nerve. We developed an adherent drug-encapsulated bi-layered depot (DBP) as a dual drug vehicle for local treatment to protect the residual retinal ganglion cells (RGCs) and regenerate axons following optic nerve damage. The inner layer of the depot was prepared by co-electrospinning poly(d,l-lactide-co-glycolide acid) (PLGA: 75 : 25) and collagen (COL) with the hydrophobic corticosteroid triamcinolone acetonide (TA) loaded. The outer layer was made of PLGA and the hydrophilic neuroprotective agent Fasudil (FA). The DBP showed suitable morphology, hydrophilicity and mechanical properties, and slowly released TA and FA in vitro by undergoing time-dependent degradation and swelling. All depots showed good biocompatibility with L929 mouse fibroblasts, and DBP was helpful in maintaining the morphology of RGCs in vitro. In addition, direct implantation of DBP at the injured optic nerve in a rat model mitigated inflammation and the death of RGCs, and increased the expression of nerve growth-related protein GAP-43. Therefore, DBP maybe a promising local therapy against TON in future.

The neuroprotective effect of Rho-kinase Inhibition in 1-methyl-4-phenylpyridinium (MPP+)-induced cellular model of neurodegeneration

Introduction: The 1-methyl 4-phenyl 1,2,3,6-tetrahydropiridium (MPTP) induced model of neurodegeneration in Parkinson's disease (PD) is one of the most commonly used experimental models. This neurotoxic agent , or rather its metabolite MPP+, leads to inhibition of mitochondrial complex I, an increase in free radicals' production and ATP depletion, all resulting in cellular demise and death. Rho-kinase is an enzyme involved with numerous cellregulatory mechanisms, such as cytoskeleton organization, axonogenesis, vesicular transport regulation and apoptosis regulation, which are all important for cell survival. Aim: Our aim was to investigate the effects of Rho-kinase inhibition on the MPP+ induced model of neurodegeneration and the role of Akt and adenosine monophosphate-activated protein kinase (AMPK) signaling pathways in this process. Material and methods: The experiments were performed on the human neuroblastoma SHSY5Y cell line. The MTT test was used to measure the viability of the cells after the MPP+ and/ or Rho-kinase inhibitor, fasudil, treatments. Changes in activation levels, or expression of pAMPK, pAkt, AMPK and Akt, were measured using the immunoblotting method, and the protein levels were quantified by densitometry. Results: The MPP+ caused a dose-dependent decrease in cellular viability, compared to the control group (untreated cells), while fasudil treatment, prior to MPP+ exposure, improved cell viability in a dose dependant manner, compared to MPP+ treatment. Analysis of activation status of target proteins showed an increase in Akt activation after the fasudil treatment, while the AMPK activation was not significantly changed. Conclusion: Inhibition of Rho-kinase using fasudil causes a decrease in MPP+ induced cell death, which is possibly mediated by an activation of the Akt/PI3K signaling pathway.

A Rho kinase inhibitor (Fasudil) suppresses TGF-β mediated autophagy in urethra fibroblasts to attenuate traumatic urethral stricture (TUS) through re-activating Akt/mTOR pathway: An in vitro study

AIMS

Transforming growth factor-β (TGF-β) mediated super-activation of urethra fibroblasts contributes to the progression of traumatic urethral stricture (TUS), and the Rho-associated kinase inhibitors, Fasudil, might be a novel therapeutic agent for TUS, but the underlying mechanisms had not been studied.

MATERIALS AND METHODS

The primary urethral fibroblasts (PUFs) were isolated from rabbit urethral scar tissues and cultured in vitro, and the PUFs were subsequently treated with TGF-β (10 μg/L) to simulate the realistic conditions of TUS pathogenesis. Next, the PUFs were exposed to Fasudil (50 μM) and autophagy inhibitor 3-methyladenine (3-MA) treatment. Genes expression was examined by Western Blot and immunofluorescence staining, and cellular functions were determined by MTT assay and Transwell assay.

KEY FINDINGS

TGF-β promoted cell proliferation, migration, autophagy, and secretion of extracellular matrix (ECM), including collagen I and collagen III, which were reversed by co-treating cells with both Fasudil and 3-MA. In addition, TGF-β treatment decreased the expression levels of phosphorylated Akt (p-Akt) and mTOR (p-mTOR) to inactivate the Akt/mTOR pathway in the PUFs, which could be re-activated by Fasudil. Then, the fibroblasts were treated with the Pan-Akt inhibitor (GDC-0068), and we surprisingly found that GDC-0068 abrogated the inhibiting effects of Fasudil on cell autophagy and proliferation in the PUFs treated with TGF-β.

SIGNIFICANCE

Fasudil regulated Akt/mTOR pathway mediated autophagy to hamper TGF-β-mediated super-activation in PUFs, which supported that Fasudil might be an ideal candidate therapeutic agent for TUS treatment for clinical utilization.

Fasudil attenuates glial cell-mediated neuroinflammation via ERK1/2 and AKT signaling pathways after optic nerve crush

To investigate the functional role of fasudil in optic nerve crush (ONC), and further explore its possible molecular mechanism. After ONC injury, the rats were injected intraperitoneally either with fasudil or normal saline once a day until euthanized. RGCs survival was assessed by retrograde labeling with FluoroGold. Retinal glial cells activation and population changes (GFAP, iba-1) were measured by immunofluorescence. The expressions of cleaved caspase 3 and 9, p-ERK1/2 and p-AKT were detected by western blot. The levels of the pro-inflammatory cytokines were determined using real-time polymerase chain reaction. Fasudil treatment inhibited RGCs apoptosis and reduced RGCs loss demonstrated by the decreased apoptosis-associated proteins expression and the increased fluorogold labeling of RGCs after ONC, respectively. In addition, the ONC + fasudil group compared had a significantly lower expression of GFAP and iba1 compared with the ONC group. The levels of pro-inflammatory cytokines were significantly reduced in the ONC + fasudil group than in the ONC group. Furthermore, the phosphorylation levels of ERK1/2 and AKT (p-ERK1/2 and p-AKT) were obviously elevated by the fasudil treatment. Our study demonstrated that fasudil attenuated glial cell-mediated neuroinflammation by up-regulating the ERK1/2 and AKT signaling pathways in rats ONC models. We conclude that fasudil may be a novel treatment for traumatic optic neuropathy.

Rho kinase inhibitor fasudil reduces l-DOPA-induced dyskinesia in a rat model of Parkinson's disease

BACKGROUND AND PURPOSE

Rho kinase (ROCK) activation is involved in neuroinflammatory processes leading to progression of neurodegenerative diseases such as Parkinson's disease. Furthermore, ROCK plays a major role in angiogenesis. Neuroinflammation and angiogenesis are mechanisms involved in developing l-DOPA-induced dyskinesias (LID). However, it is not known whether ROCK plays a role in LID and whether ROCK inhibitors may be useful against LID.

EXPERIMENTAL APPROACH

In rats, we performed short- and long-term dopaminergic lesions using 6-hydroxydopamine and developed a LID model. Effects of dopaminergic lesions and LID on the RhoA/ROCK levels were studied by western blot, real-time PCR analyses and ROCK activity assays in the substantia nigra and striatum. The effects of the ROCK inhibitor fasudil on LID were particularly investigated.

KEY RESULTS

Short-term 6-hydroxydopamine lesions increased nigrostriatal RhoA/ROCK expression, apparently related to the active neuroinflammatory process. However, long-term dopaminergic denervation (completed and stabilized lesions) led to a decrease in RhoA/ROCK levels. Rats with LID showed a significant increase of RhoA and ROCK expression. The development of LID was reduced by the ROCK inhibitor fasudil (10 and 40 mg·kg^-1 ), without interfering with the therapeutic effect of l-DOPA. Interestingly, treatment of 40 mg·kg^-1 of fasudil also induced a significant reduction of dyskinesia in rats with previously established LID.

CONCLUSION AND IMPLICATIONS

The present results suggest that ROCK is involved in the pathophysiology of LID and that ROCK inhibitors such as fasudil may be a novel target for preventing or treating LID. Furthermore, previous studies have revealed neuroprotective effects of ROCK inhibitors.

CDK5 Targeting as a Therapy for Recovering Neurovascular Unit Integrity in Alzheimer's Disease

The neurovascular unit (NVU) is responsible for synchronizing the energetic demand, vasodynamic changes, and neurochemical and electrical function of the brain through a closed and interdependent interaction of cell components conforming to brain tissue. In this review, we will focus on cyclin-dependent kinase 5 (CDK5) as a molecular pivot, which plays a crucial role in the healthy function of neurons, astrocytes, and the endothelium and is implicated in the cross-talk of cellular adhesion signaling, ion transmission, and cytoskeletal remodeling, thus allowing the individual and interconnected homeostasis of cerebral parenchyma. Then, we discuss how CDK5 overactivation affects the integrity of the NVU in Alzheimer's disease (AD) and cognitive impairment; we emphasize how CDK5 is involved in the excitotoxicity spreading of glutamate and Ca2+ imbalance under acute and chronic injury. Additionally, we present pharmacological and gene therapy strategies for producing partial depletion of CDK5 activity on neurons, astrocytes, or endothelium to recover neuroplasticity and neurotransmission, suggesting that the NVU should be the targeted tissue unit in protective strategies. Finally, we conclude that CDK5 could be effective due to its intervention on astrocytes by its end feet on the endothelium and neurons, acting as an intermediary cell between systemic and central communication in the brain. This review provides integrated guidance regarding the pathogenesis of and potential repair strategies for AD.

Wnt Pathway: An Emerging Player in Vascular and Traumatic Mediated Brain Injuries

The Wnt pathway, which comprises the canonical and non-canonical pathways, is an evolutionarily conserved mechanism that regulates crucial biological aspects throughout the development and adulthood. Emergence and patterning of the nervous and vascular systems are intimately coordinated, a process in which Wnt pathway plays particularly important roles. In the brain, Wnt ligands activate a cell-specific surface receptor complex to induce intracellular signaling cascades regulating neurogenesis, synaptogenesis, neuronal plasticity, synaptic plasticity, angiogenesis, vascular stabilization, and inflammation. The Wnt pathway is tightly regulated in the adult brain to maintain neurovascular functions. Historically, research in neuroscience has emphasized essentially on investigating the pathway in neurodegenerative disorders. Nonetheless, emerging findings have demonstrated that the pathway is deregulated in vascular- and traumatic-mediated brain injuries. These findings are suggesting that the pathway constitutes a promising target for the development of novel therapeutic protective and restorative interventions. Yet, targeting a complex multifunctional signal transduction pathway remains a major challenge. The review aims to summarize the current knowledge regarding the implication of Wnt pathway in the pathobiology of ischemic and hemorrhagic stroke, as well as traumatic brain injury (TBI). Furthermore, the review will present the strategies used so far to manipulate the pathway for therapeutic purposes as to highlight potential future directions.

Pharmacological Effects of Fasudil on Flap Survival in a Rodent Model

BACKGROUND

Necrosis of the perforator flap is a critical problem. Fasudil, an inhibitor of Rho-associated coiled-coil containing kinase, has antiapoptosis activity and attenuates oxidative stress in many diseases. We characterized the effects of fasudil through intraperitoneal injection on perforator flap survival and identified its possible mechanism.

METHODS AND MATERIALS

Rats were divided into a control group (without surgery), a flap group (only surgery), and a fasudil group (surgery plus fasudil). Perforator flaps were made on the backs of the rats. The expression of vascular endothelial growth factor, the protein kinase B (PKB/Akt), endothelial nitric oxide synthase, Bax, Bcl-2, Beclin-1, P62, and LC3 II/LC3 I was determined by Western blot at day 3 after surgery. Nitric oxide (NO) components, superoxide dismutase, and malondialdehyde were also measured at day 3. The survival rate and laser Doppler perfusion imaging were performed at day 7 after surgery.

RESULT

The group with fasudil treatment exhibited the higher survival rates and angiogenesis levels. Fasudil also induced the activation of Akt/eNOS/NO pathway detected by the Western blot and NO expression kit. Furthermore, Western blot results showed fasudil-attenuated apoptosis through a raised Bcl-2/Bax rate and enhanced autophagy levels through raised beclin-1, decreased p62, and the elevated rate of LC3 II/LC3 I. Finally, fasudil increased superoxide dismutase and decreased malondialdehyde.

CONCLUSIONS

In conclusion, fasudil treatment decreased necrosis of perforator flaps possibly by affecting the Akt/eNOS/NO pathway, attenuating apoptosis and activating autophagy.

A Dual Role of ATM in Ischemic Preconditioning and Ischemic Injury

The ataxia-telangiectasia mutated (ATM) protein is regarded as the linchpin of cellular defenses to stress. Deletion of ATM results in strong oxidative stress and degenerative diseases in the nervous system. However, the role of ATM in neuronal ischemic preconditioning and lethal ischemic injury is still largely unknown. In this study, mice cortical neurons preconditioned with sublethal exposure to oxygen glucose deprivation (OGD) exhibited ATM/glucose-6-phosphate dehydrogenase pathway activation. Additionally, pharmacological inhibition of ATM prior to the preconditioning reversed neuroprotection provided by preconditioning in vitro and in vivo. Meanwhile, we found that ATM/P53 pro-apoptosis pathway was driven by lethal OGD injury, and pharmacological inhibition of ATM during fatal oxygen-glucose deprivation/reperfusion injury promoted neuronal survival. More importantly, inhibition of ATM activity after cerebral ischemia protected against cerebral ischemic-reperfusion damage in mice. In conclusion, our data show the dual role of ATM in neuronal ischemic preconditioning and lethal ischemic injury, involving in the protection of ischemic preconditioning, but promoting neuronal death in lethal ischemic injury. Thus, the present study provides new opportunity for the treatment of ischemic stroke.

RhoA-ROCK Signaling as a Therapeutic Target in Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. TBIs, which range in severity from mild to severe, occur when a traumatic event, such as a fall, a traffic accident, or a blow, causes the brain to move rapidly within the skull, resulting in damage. Long-term consequences of TBI can include motor and cognitive deficits and emotional disturbances that result in a reduced quality of life and work productivity. Recovery from TBI can be challenging due to a lack of effective treatment options for repairing TBI-induced neural damage and alleviating functional impairments. Central nervous system (CNS) injury and disease are known to induce the activation of the small GTPase RhoA and its downstream effector Rho kinase (ROCK). Activation of this signaling pathway promotes cell death and the retraction and loss of neural processes and synapses, which mediate information flow and storage in the brain. Thus, inhibiting RhoA-ROCK signaling has emerged as a promising approach for treating CNS disorders. In this review, we discuss targeting the RhoA-ROCK pathway as a therapeutic strategy for treating TBI and summarize the recent advances in the development of RhoA-ROCK inhibitors.

Dysregulation of Rac or Rho elicits death of motor neurons and activation of these GTPases is altered in the G93A mutant hSOD1 mouse model of amyotrophic lateral sclerosis

Rho GTPases play a central role in neuronal survival; however, the antagonistic relationship between Rac and Rho in the regulation of motor neuron survival remains poorly defined. In the current study, we demonstrate that treatment with NSC23766, a selective inhibitor of the Rac-specific guanine nucleotide exchange factors, Tiam1 and Trio, is sufficient to induce the death of embryonic stem cell (ESC)-derived motor neurons. The mode of cell death is primarily apoptotic and is characterized by caspase-3 activation, de-phosphorylation of ERK5 and AKT, and nuclear translocation of the BH3-only protein Bad. As opposed to the inhibition of Rac, motor neuron cell death is also induced by constitutive activation of Rho, via a mechanism that depends on Rho kinase (ROCK) activity. Investigation of Rac and Rho in the G93A mutant, human Cu, Zn-superoxide dismutase (hSOD1) mouse model of amyotrophic lateral sclerosis (ALS), revealed that active Rac1-GTP is markedly decreased in spinal cord motor neurons of transgenic mice at disease onset and end-stage, when compared to age-matched wild type (WT) littermates. Furthermore, although there is no significant change in active RhoA-GTP, total RhoB displays a striking redistribution from motor neuron nuclei in WT mouse spinal cord to motor neuron axons in end-stage G93A mutant hSOD1 mice. Collectively, these data suggest that the intricate balance between pro-survival Rac signaling and pro-apoptotic Rho/ROCK signaling is critical for motor neuron survival and therefore, disruption in the balance of their activities and/or localization may contribute to the death of motor neurons in ALS.

An Update on the Association of Protein Kinases with Cardiovascular Diseases

Background:

Protein kinases are the enzymes involved in phosphorylation of different proteins which leads to functional changes in those proteins. They belong to serine-threonine kinases family and are classified into the AGC (Protein kinase A/ Protein kinase G/ Protein kinase C) families of protein and Rho-associated kinase protein (ROCK). The AGC family of kinases are involved in G-protein stimuli, muscle contraction, platelet biology and lipid signaling. On the other hand, ROCK regulates actin cytoskeleton which is involved in the development of stress fibres. Inflammation is the main signal in all ROCK-mediated disease. It triggers the cascade of a reaction involving various proinflammatory cytokine molecules.

Methods:

Two ROCK isoforms are found in mammals and invertebrates. The first isoforms are present mainly in the kidney, lung, spleen, liver, and testis. The second one is mainly distributed in the brain and heart.

Results:

ROCK proteins are ubiquitously present in all tissues and are involved in many ailments that include hypertension, stroke, atherosclerosis, pulmonary hypertension, vasospasm, ischemia-reperfusion injury and heart failure. Several ROCK inhibitors have shown positive results in the treatment of various disease including cardiovascular diseases.

Conclusion:

ROCK inhibitors, fasudil and Y27632, have been reported for significant efficiency in dropping vascular smooth muscle cell hyper-contraction, vascular inflammatory cell recruitment, cardiac remodelling and endothelial dysfunction which highlight ROCK role in cardiovascular diseases.

Therapeutic potentials of the Rho kinase inhibitor Fasudil in experimental autoimmune encephalomyelitis and the related mechanisms

Multiple sclerosis (MS), Parkinson's disease (PD), Alzheimer's disease (AD), and other neurodegenerative diseases of central nervous system (CNS) disorders are serious human health problems. Rho-kinase (ROCK) is emerging as a potentially important therapeutic target relevant to inflammatory neurodegeneration diseases. This is supported by studies showing the beneficial effects of fasudil, a ROCK inhibitor, in inflammatory neurodegeneration diseases. MS is an autoimmune disease resulting from inflammation and demyelination in the white matter of the CNS. It has been postulated that activation of Rho/ROCK causes neuropathological changes accompanied with related clinical symptoms, which are improved by treatment with ROCK inhibitors. Therefore, inhibition of abnormal activation of the Rho/ROCK signaling pathway appears to be a new mechanism for treating CNS diseases. In this review, we extensively discussed the role of ROCK inhibitors, summarized the efficacy of fasudil in the MS conventional animal model of experimental autoimmune encephalomyelitis (EAE), both in vivo and in vitro, and highlighted the mechanism involved. Overall, the findings collected in this review support the role of the ROCK signaling pathway in neurodegenerative diseases. Hence, ROCK inhibitors such as fasudil can be novel, and efficacious treatment for inflammatory neurodegenerative diseases.

Fasudil alleviates brain damage in rats after carbon monoxide poisoning through regulating neurite outgrowth inhibitor/oligodendrocytemyelin glycoprotein signalling pathway

Carbon monoxide (CO) poisoning can lead to many serious neurological symptoms. Currently, there are no effective therapies for CO poisoning. In this study, rats exposed to CO received hyperbaric oxygen therapy, and those in the Fasudil group were given additional Fasudil injection once daily. We found that the escape latency in CO poisoning group (CO group) was significantly prolonged, the T₁ /T_total was obviously decreased, and the mean escape time and the active escape latency were notably extended compared with those in normal control group (NC group, P < 0.05). After administration of Fasudil, the escape latency was significantly shortened, T₁ /T_total was gradually increased as compared with CO group (>1 week, P < 0.05). Ultrastructural damage of neurons and blood-brain barrier of rats was serious in CO group, while the structural and functional integrity of neuron and mitochondria maintained relatively well in Fasudil group. Moreover, we also noted that the expressions of neurite outgrowth inhibitor (Nogo), oligodendrocyte-myelin glycoprotein (OMgp) and Rock in brain tissue were significantly increased in CO group, and the elevated levels of the three proteins were still observed at 2 months after CO poisoning. Fasudil markedly reduced their expressions compared with those of CO group (P < 0.05). In summary, the activation of Nogo-OMgp/Rho signalling pathway is associated with brain injury in rats with CO poisoning. Fasudil can efficiently down-regulate the expressions of Nogo, OMgp and Rock proteins, paving a way for the treatment of acute brain damage after CO poisoning.

Ferulic acid ameliorates cerebral infarction by activating Akt/mTOR/4E‑BP1/Bcl‑2 anti‑apoptotic signaling in the penumbral cortex following permanent cerebral ischemia in rats

The aim of the present study was to determine the effects of ferulic acid (FerA) administered immediately following the onset of permanent middle cerebral artery occlusion (MCAo) and then 7 days of ischemia, and also to explore the involvement of protein kinase B (Akt)‑induced signaling in the penumbral cortex. Immediately following the onset of MCAo, FerA was intravenously administered to rats at a dose of 60 mg/kg (FerA‑60 mg), 80 mg/kg (FerA‑80 mg), or 100 mg/kg (FerA‑100 mg). FerA‑80 mg and FerA‑100 mg effectively ameliorated cerebral infarction and neurological deficits 7 days following permanent cerebral ischemia. FerA‑80 mg and FerA‑100 mg significantly upregulated the expression of phospho‑Akt (p‑Akt), phospho‑mammalian target of rapamycin (p‑mTOR), and eukaryotic initiation factor 4E (eIF4E)‑binding protein 1 (4E‑BP1), and the phospho‑4E‑BP1 (p‑4E‑BP1)/4E‑BP1 and mitochondrial Bcl‑2/Bax ratios, and markedly downregulated the levels of cytochrome c‑, cleaved caspase‑3‑, and terminal deoxynucleotidyl transferase‑mediated dUTP‑biotin nick‑end labeling‑immunoreactive cells in the penumbral cortex at 7 days post‑ischemia. LY294002, a selective inhibitor of phosphoinositide 3‑kinase/Akt signaling, was administered 30 min prior to ischemia, which abrogated the upregulating effects of FerA‑100 mg on the expression of p‑Akt, p‑mTOR, 4E‑BP1, p‑4E‑BP1 and eIF4E, the mitochondrial Bcl‑2/Bax ratio and the ameliorating effect of FerA‑100 mg on cerebral infarction. FerA administered at doses of 80 and 100 mg/kg exerted beneficial effects against cerebral ischemia by activating Akt‑induced signaling. The effects of FerA at doses of 80 and 100 mg/kg on mitochondrial B‑cell lymphoma-2 (Bcl‑2)‑associated X protein‑related apoptosis were attributed to the activation of Akt/mTOR/4E‑BP1/Bcl‑2 anti‑apoptotic signaling, and eventually contributed to suppression of the cytochrome c/caspase‑3 activation pathway in the penumbral cortex 7 days following permanent cerebral ischemia.

Combination of drug and stem cells neurotherapy: Potential interventions in neurotrauma and traumatic brain injury

Traumatic brain injury (TBI) has been recognized as one of the major public health issues that leads to devastating neurological disability. As a consequence of primary and secondary injury phases, neuronal loss following brain trauma leads to pathophysiological alterations on the molecular and cellular levels that severely impact the neuropsycho-behavioral and motor outcomes. Thus, to mitigate the neuropathological sequelae post-TBI such as cerebral edema, inflammation and neural degeneration, several neurotherapeutic options have been investigated including drug intervention, stem cell use and combinational therapies. These treatments aim to ameliorate cellular degeneration, motor decline, cognitive and behavioral deficits. Recently, the use of neural stem cells (NSCs) coupled with selective drug therapy has emerged as an alternative treatment option for neural regeneration and behavioral rehabilitation post-neural injury. Given their neuroprotective abilities, NSC-based neurotherapy has been widely investigated and well-reported in numerous disease models, notably in trauma studies. In this review, we will elaborate on current updates in cell replacement therapy in the area of neurotrauma. In addition, we will discuss novel combination drug therapy treatments that have been investigated in conjunction with stem cells to overcome the limitations associated with stem cell transplantation. Understanding the regenerative capacities of stem cell and drug combination therapy will help improve functional recovery and brain repair post-TBI. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".

FSD-C10 Shows Therapeutic Effects in Suppressing oxidized low-density lipoprotein (ox-LDL)-Induced Human Brain Microvascular Endothelial Cells Apoptosis via Rho-Associated Coiled-Coil Kinase (ROCK)/Mitogen-Activated Protein Kinase (MAPK) Signaling

BACKGROUND ox-LDL-induced injury of brain microvascular endothelial cells (BMECs) is strongly associated with cerebral vascular diseases such as cerebral arterial atherosclerosis. ROCK inhibitor was proved to be anti-apoptotic and has been used in treating cerebral vascular diseases. Research on the neuroprotective effects of a novel ROCK inhibitor, FSD-C10, is still limited. The present study investigated the anti-apoptotic effect and underlying molecular mechanism of FSD-C10 in ox-LDL-mediated apoptosis of BMECs. MATERIAL AND METHODS ox-LDL and/or FSD-C10 were used to incubate immortalized human BMECs. MTT assay was used to assess cell viability. Cell apoptosis was evaluated by TUNEL assay. A colorimetric method was used to assess ROCK activity. Western blot analysis was used to examine the expression and phosphorylation levels of proteins. RESULTS ox-LDL incubation reduced the viability of BMECs by inducing cell apoptosis in a concentration-dependent manner. ROCK activity was also elevated by ox-LDL incubation in BMECs in a concentration-dependent manner. Expression level of Bcl2 was reduced while expression levels of Bax and active caspase3 were increased by ox-LDL treatment in a concentration-dependent manner. ox-LDL also increased the phosphorylation levels of p38, JNK, and ERK1/2 in a concentration-dependent manner. FSD-C10 treatment increased the cell viability by reducing apoptosis of BMECs exposed to ox-LDL. Moreover, FSD-C10 was found to suppress the phosphorylation levels of p38, JNK, and ERK1/2 and the expression levels of Bax and active caspase3 in ox-LDL treated BMECs. CONCLUSIONS FSD-C10 increases cell viability in ox-LDL-treated BMECs by reducing cell apoptosis. ROCK/MAPKs-mediated apoptosis appears to be the underlying molecular mechanism.

Role of phosphatase and tensin homolog in hypoxic pulmonary vasoconstriction

Aims

Hypoxic pulmonary vasoconstriction (HPV) redistributes blood flow from poorly ventilated to better aerated areas in the lung, thereby optimizing ventilation-perfusion ratio (V/Q). Pulmonary artery smooth muscle cell (PASMC) contraction in response to hypoxia is triggered by Ca2+ influx via transient receptor potential canonical 6 (TRPC6) cation channels that have translocated to caveolae in the plasma membrane. Since phosphatase and tensin homolog (PTEN) was suggested to regulate TRPC6 in endothelial cells, we aimed to define its role in the hypoxic response of PASMCs and as a putative mediator of HPV.

Methods and results

In isolated perfused mouse lungs, smooth muscle specific PTEN deficiency attenuated pulmonary vasoconstriction in response to hypoxia but not to angiotensin II (Ang II). Analogously, siRNA-mediated knock down of PTEN in human PASMC inhibited the hypoxia-induced increase in cytosolic Ca2+ concentration ([Ca2+]i). Co-immunoprecipitation and proximity ligation assays revealed increased interaction of PTEN with TRPC6 in human PASMC and murine lungs in response to hypoxia. In hypoxic PASMC, both PTEN and TRPC6 translocated to caveolae, and this response was blocked by pharmacological inhibition of Rho-associated protein kinase (ROCK) which in parallel prevented PTEN-TRPC6 interaction, hypoxia-induced [Ca2+]i increase, and HPV in PASMC and murine lungs, respectively.

Conclusion

Our data indicate a novel interplay between ROCK and [Ca2+]i signalling in HPV via PTEN, in that ROCK mediates interaction of PTEN and TRPC6 which then conjointly translocate to caveolae allowing for Ca2+ influx into and subsequent contraction of PASMC.

Treatment with low dose fasudil for acute ischemic stroke in chronic hypertension

We investigated the effect of Rho kinase inhibition on changes in cerebral blood flow (CBF), brain injury and vascular function after ischemic stroke in spontaneously hypertensive rats (SHR). Changes in core MCA and collateral perfusion were measured by a validated laser Doppler method. Animals underwent 2 h tMCAO and 2 h reperfusion. Fasudil (0.1 mg/kg, i.v.) or vehicle was given at 30 min ischemia (n = 9/group; mean (SD)). Brain injury was determined by 2,3,5-triphenyltetrazolium chloride staining. To determine the effect of fasudil on vascular function, fasudil was given 10 min before reperfusion and parenchymal arterioles studied isolated (n = 6/group; mean(SD)). Collateral perfusion was low in vehicle-treated SHR (-8(32)%) that changed minimally with fasudil (6(24)%, p > 0.05, effect size: 0.47;95% CI-0.49-1.39). Reperfusion CBF was below baseline in vehicle (-27(26)%) and fasudil (-32(25)%, p > 0.05, effect size: 0.19; 95% CI-0.74-1.11) groups, suggesting incomplete reperfusion in both groups. Fasudil had little effect on brain injury volume (28(13)% vs. 36(7)% in vehicle, p > 0.05, effect size: 0.75; 95% CI-0.24-1.66). In isolated parenchymal arterioles, myogenic tone was similar between groups (37(6)% vs. 38(10)% in vehicle, p > 0.05, effect size: 0.09; 95% CI-1.05-1.21). There were no differences with fasudil treatment vs. vehicle in perfusion, brain injury and vascular function that may be related to the low dose that had minimal blood pressure lowering effect.

Stem cells and combination therapy for the treatment of traumatic brain injury

TBI is a nondegenerative, noncongenital insult to the brain from an external mechanical force; for instance a violent blow in a car accident. It is a complex injury with a broad spectrum of symptoms and has become a major cause of death and disability in addition to being a burden on public health and societies worldwide. As such, finding a therapy for TBI has become a major health concern for many countries, which has led to the emergence of many monotherapies that have shown promising effects in animal models of TBI, but have not yet proven any significant efficacy in clinical trials. In this paper, we will review existing and novel TBI treatment options. We will first shed light on the complex pathophysiology and molecular mechanisms of this disorder, understanding of which is a necessity for launching any treatment option. We will then review most of the currently available treatments for TBI including the recent approaches in the field of stem cell therapy as an optimal solution to treat TBI. Therapy using endogenous stem cells will be reviewed, followed by therapies utilizing exogenous stem cells from embryonic, induced pluripotent, mesenchymal, and neural origin. Combination therapy is also discussed as an emergent novel approach to treat TBI. Two approaches are highlighted, an approach concerning growth factors and another using ROCK inhibitors. These approaches are highlighted with regard to their benefits in minimizing the outcomes of TBI. Finally, we focus on the consequent improvements in motor and cognitive functions after stem cell therapy. Overall, this review will cover existing treatment options and recent advancements in TBI therapy, with a focus on the potential application of these strategies as a solution to improve the functional outcomes of TBI.

The ROCK Inhibitor Fasudil Prevents Chronic Restraint Stress-Induced Depressive-Like Behaviors and Dendritic Spine Loss in Rat Hippocampus

BACKGROUND

Dendritic arbor simplification and dendritic spine loss in the hippocampus, a limbic structure implicated in mood disorders, are assumed to contribute to symptoms of depression. These morphological changes imply modifications in dendritic cytoskeleton. Rho GTPases are regulators of actin dynamics through their effector Rho kinase. We have reported that chronic stress promotes depressive-like behaviors in rats along with dendritic spine loss in apical dendrites of hippocampal pyramidal neurons, changes associated with Rho kinase activation. The present study proposes that the Rho kinase inhibitor Fasudil may prevent the stress-induced behavior and dendritic spine loss.

METHODS

Adult male Sprague-Dawley rats were injected with saline or Fasudil (i.p., 10 mg/kg) starting 4 days prior to and maintained during the restraint stress procedure (2.5 h/d for 14 days). Nonstressed control animals were injected with saline or Fasudil for 18 days. At 24 hours after treatment, forced swimming test, Golgi-staining, and immuno-western blot were performed.

RESULTS

Fasudil prevented stress-induced immobility observed in the forced swimming test. On the other hand, Fasudil-treated control animals showed behavioral patterns similar to those of saline-treated controls. Furthermore, we observed that stress induced an increase in the phosphorylation of MYPT1 in the hippocampus, an exclusive target of Rho kinase. This change was accompanied by dendritic spine loss of apical dendrites of pyramidal hippocampal neurons. Interestingly, increased pMYPT1 levels and spine loss were both prevented by Fasudil administration.

CONCLUSION

Our findings suggest that Fasudil may prevent the development of abnormal behavior and spine loss induced by chronic stress by blocking Rho kinase activity.

Two PTP receptors mediate CSPG inhibition by convergent and divergent signaling pathways in neurons

Receptor protein tyrosine phosphatase σ (PTPσ) and its subfamily member LAR act as transmembrane receptors that mediate growth inhibition of chondroitin sulfate proteoglycans (CSPGs). Inhibition of either receptor increases axon growth into and beyond scar tissues after CNS injury. However, it is unclear why neurons express two similar CSPG receptors, nor whether they use the same or different intracellular pathways. We have now studied the signaling pathways of these two receptors using N2A cells and primary neurons derived from knockout mice. We demonstrate that both receptors share certain signaling pathways (RhoA, Akt and Erk), but also use distinct signals to mediate CSPG actions. Activation of PTPσ by CSPGs selectively inactivated CRMP2, APC, S6 kinase and CREB. By contrast LAR activation inactivated PKCζ, cofilin and LKB1. For the first time, we propose a model of the signaling pathways downstream of these two CSPG receptors. We also demonstrate that deleting both receptors exhibits additive enhancement of axon growth in adult neuronal cultures in vitro. Our findings elucidate the novel downstream pathways of CSPGs and suggest potential synergy of blocking their two PTP receptors.

Effective PI3K modulators for improved therapy against malignant tumors and for neuroprotection of brain damage after tumor therapy (Review)

Due to the key role in various cellular processes including cell proliferation and cell survival on many cell types, dysregulation of the PI3K/AKT pathway represents a crucial step of the pathogenesis in many diseases. Furthermore, the tumor suppressor PTEN negatively regulates the PI3K/AKT pathway through its lipid phosphatase activity, which is recognized as one of the most frequently deleted and/or mutated genes in human cancer. Given the pervasive involvement of this pathway, the development of the molecules that modulate this PI3K/AKT signaling has been initiated in studies which focus on the extensive effective drug discovery. Consequently, the PI3K/AKT pathway appears to be an attractive pharmacological target both for cancer therapy and for neurological protection necessary after the therapy. A better understanding of the molecular relations could reveal new targets for treatment development. We review recent studies on the features of PI3K/AKT and PTEN, and their pleiotropic functions relevant to the signaling pathways involved in cancer progress and in neuronal damage by the therapy.

Renoprotective Effects of Atorvastatin in Diabetic Mice: Downregulation of RhoA and Upregulation of Akt/GSK3

Potential benefits of statins in the treatment of chronic kidney disease beyond lipid-lowering effects have been described. However, molecular mechanisms involved in renoprotective actions of statins have not been fully elucidated. We questioned whether statins influence development of diabetic nephropathy through reactive oxygen species, RhoA and Akt/GSK3 pathway, known to be important in renal pathology. Diabetic mice (db/db) and their control counterparts (db/+) were treated with atorvastatin (10 mg/Kg/day, p.o., for 2 weeks). Diabetes-associated renal injury was characterized by albuminuria (albumin:creatinine ratio, db/+: 3.2 ± 0.6 vs. db/db: 12.5 ± 3.1*; *P<0.05), increased glomerular/mesangial surface area, and kidney hypertrophy. Renal injury was attenuated in atorvastatin-treated db/db mice. Increased ROS generation in the renal cortex of db/db mice was also inhibited by atorvastatin. ERK1/2 phosphorylation was increased in the renal cortex of db/db mice. Increased renal expression of Nox4 and proliferating cell nuclear antigen, observed in db/db mice, were abrogated by statin treatment. Atorvastatin also upregulated Akt/GSK3β phosphorylation in the renal cortex of db/db mice. Our findings suggest that atorvastatin attenuates diabetes-associated renal injury by reducing ROS generation, RhoA activity and normalizing Akt/GSK3β signaling pathways. The present study provides some new insights into molecular mechanisms whereby statins may protect against renal injury in diabetes.

Improving Reperfusion Therapies in the Era of Mechanical Thrombectomy

Recent positive clinical trials using mechanical thrombectomy proved that endovascular recanalization is an effective treatment for patients with acute stroke secondary to large vessel occlusions. The trials offer definite evidence that in acute ischemia recanalization is a powerful predictor of good outcome. However, even in the era of rapid and effective recanalization using endovascular approaches, the percentage of patients with good outcomes varies between 33 and 71 %. In addition, the number of patients who are eligible for endovascular thrombectomy is small and usually based on having salvageable tissue on imaging. There is therefore room for improvement to both enhance the effectiveness of current practice and expand treatment to a larger subset of stroke patients. In this review, we highlight some of the most promising approaches to improve endovascular therapy by combining with strategies to enhance collateral perfusion and vascular protection.

Caspase-3 dependent nitrergic neuronal apoptosis following cavernous nerve injury is mediated via RhoA and ROCK activation in major pelvic ganglion

Axonal injury due to prostatectomy leads to Wallerian degeneration of the cavernous nerve (CN) and erectile dysfunction (ED). Return of potency is dependent on axonal regeneration and reinnervation of the penis. Following CN injury (CNI), RhoA and Rho-associated protein kinase (ROCK) increase in penile endothelial and smooth muscle cells. Previous studies indicate that nerve regeneration is hampered by activation of RhoA/ROCK pathway. We evaluated the role of RhoA/ROCK pathway in CN regulation following CNI using a validated rat model. CNI upregulated gene and protein expression of RhoA/ROCK and caspase-3 mediated apoptosis in the major pelvic ganglion (MPG). ROCK inhibitor (ROCK-I) prevented upregulation of RhoA/ROCK pathway as well as activation of caspase-3 in the MPG. Following CNI, there was decrease in the dimer to monomer ratio of neuronal nitric oxide synthase (nNOS) protein and lowered NOS activity in the MPG, which were prevented by ROCK-I. CNI lowered intracavernous pressure and impaired non-adrenergic non-cholinergic-mediated relaxation in the penis, consistent with ED. ROCK-I maintained the intracavernous pressure and non-adrenergic non-cholinergic-mediated relaxation in the penis following CNI. These results suggest that activation of RhoA/ROCK pathway mediates caspase-3 dependent apoptosis of nitrergic neurons in the MPG following CNI and that ROCK-I can prevent post-prostatectomy ED.

Effects of Rho Kinase Inhibitors on Grafts of Dopaminergic Cell Precursors in a Rat Model of Parkinson's Disease

In models of Parkinson's disease (PD), Rho kinase (ROCK) inhibitors have antiapoptotic and axon-stabilizing effects on damaged neurons, decrease the neuroinflammatory response, and protect against dopaminergic neuron death and axonal retraction. ROCK inhibitors have also shown protective effects against apoptosis induced by handling and dissociation of several types of stem cells. However, the effect of ROCK inhibitors on dopaminergic cell grafts has not been investigated. In the present study, treatment of dopaminergic cell suspension with ROCK inhibitors yielded significant decreases in the number of surviving dopaminergic neurons, in the density of graft-derived dopaminergic fibers, and in graft vascularization. Dopaminergic neuron death also markedly increased in primary mesencephalic cultures when the cell suspension was treated with ROCK inhibitors before plating, which suggests that decreased angiogenesis is not the only factor leading to cell death in grafts. Interestingly, treatment of the host 6-hydroxydopamine-lesioned rats with ROCK inhibitors induced a slight, nonsignificant increase in the number of surviving neurons, as well as marked increases in the density of graft-derived dopaminergic fibers and the size of the striatal reinnervated area. The study findings discourage treatment of cell suspensions before grafting. However, treatment of the host induces a marked increase in graft-derived striatal reinnervation. Because ROCK inhibitors have also exerted neuroprotective effects in several models of PD, treatment of the host with ROCK inhibitors, currently used against vascular diseases in clinical practice, before and after grafting may be a useful adjuvant to cell therapy in PD.

SIGNIFICANCE

Cell-replacement therapy is one promising therapy for Parkinson's disease (PD). However, many questions must be addressed before widespread application. Rho kinase (ROCK) inhibitors have been used in a variety of applications associated with stem cell research and may be an excellent strategy for improving survival of grafted neurons and graft-derived dopaminergic innervation. The present results discourage the treatment of suspensions of dopaminergic precursors with ROCK inhibitors in the pregrafting period. However, treatment of the host (patients with PD) with ROCK inhibitors, currently used against vascular diseases, may be a useful adjuvant to cell therapy in PD.