Fasudil ameliorates cognitive deficits, oxidative stress and neuronal apoptosis via inhibiting ROCK/MAPK and activating Nrf2 signalling pathways in APP/PS1 mice.

Alzheimer's disease (AD) is a severe neurodegenerative disorder of the central nervous system (CNS) characterized by neuron loss and dementia. Previous abundant evidence demonstrates that the first critical step in the course of AD is the state of oxidative stress and the neuronal loss is closely related to the interaction of several signalling pathways. The neuroprotective efficacy of Rho-associated protein kinase (ROCK) inhibitor in the treatment of AD has been reported, but its exact mechanism has not been well elucidated. The purpose of this study is to investigate the therapeutic effects of Fasudil on amyloid precursor protein/presenilin-1 (APP/PS1) mice and to discover the potential underlying mechanism. Sixteen 8-month-old APP/PS1 mice were divided into model and Fasudil treatment groups and 8 wild-type mice were used as a normal control group. After the behavioural test, all mice were sacrificed for immunofluorescence and other biochemical tests. The results showed that the administration of Fasudil improved learning and memory ability, elevated the concentration of antioxidative substances and decreased lipid peroxides, as well as inhibited neuronal apoptosis by increasing the expression of B-cell lymphoma-2 (Bcl-2) (p < 0.05), reducing Bcl-2 Associated X (Bax) (p < 0.05) and cleaved caspase-3 (p < 0.05) of APP/PS1 mice. Moreover, Fasudil treatment also ameliorated the phosphorylation of p38 (p < 0.01), c-Jun N-terminal kinase (JNK) (p < 0.001) and extracellular regulated protein kinases (ERK) (p < 0.001), and accelerated the nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) (p < 0.01) expression and its antioxidative downstream molecules (p < 0.05, p < 0.05, and p < 0.05, respectively). Data from the present study demonstrate that Fasudil significantly restored cognitive function, restrained oxidative stress and reduced neuronal apoptosis in the hippocampus, probably by inhibiting ROCK/MAPK and activating Nrf2 signalling pathways in APP/PS1 mice.

Fasudil inhibits the activation of microglia and astrocytes of transgenic Alzheimer's disease mice via the downregulation of TLR4/Myd88/NF-κB pathway.

Emerging evidence suggests an association of Alzheimer's Disease (AD) with microglial and astrocytic dysregulation. Recent studies have proposed that activated microglia can transform astrocytes to a neurotoxic A1 phenotype, which has been shown to be involved in the promotion of neuronal damage in several neurodegenerative diseases, including AD. In the present study, we observed an obvious microglial activation and A1-specific astrocyte response in the brain tissue of APP/PS1 Tg mice. Fasudil treatment improved the cognitive deficits of APP/PS1 Tg mice, inhibited microglial activation and promoted their transformation to an anti-inflammatory phenotype, and further shifted astrocytes from an A1 to an A2 phenotype. Our experiments suggest Fasudil exerted these functions by inhibing the expression of TLR4, MyD88, and NF-κB, which are key mediators of inflammation. Using in vitro experiments, we further validated in vivo findings. Our cell experiments indicated that Fasudil induces a shift of inflammatory microglia towards an anti-inflammatory phenotype. LPS-induced microglia-conditioned medium promotes A1 astrocytic polarization, but Fasudil treatment resulted in a direct transformation of A1 astrocytes to A2. To summarize, our results show that Fasudil inhibits the neurotoxic activation of microglia and shifts astrocytes towards a neuroprotective A2 phenotype, representing a promising candidate for AD treatment.

Therapeutic effect of Rho kinase inhibitor FSD-C10 in a mouse model of Alzheimer's disease.

Fasudil, a Rho kinase (ROCK) inhibitor, effectively inhibits disease severity in a mouse model of Alzheimer's disease (AD). However, given its significant limitations, including a relatively narrow safety window and poor oral bioavailability, Fasudil is not suitable for long-term use. Thus, screening for ROCK inhibitor(s) that are more efficient, safer, can be used orally and suitable for long-term use in the treatment of neurodegenerative disorders is required. The main purpose of the present study is to explore whether FSD-C10, a novel ROCK inhibitor, has therapeutic potential in amyloid precursor protein/presenilin-1 transgenic (APP/PS1 Tg) mice, and to determine possible mechanisms of its action. The results showed that FSD-C10 effectively improved learning and memory impairment, accompanied by reduced expression of amyloid-ß 1-42 (Aß1-42), Tau protein phosphorylation (P-tau) and ß-site APP-cleaving enzyme in the hippocampus and cortex area of brain. In addition, FSD-C10 administration boosted the expression of synapse-associated proteins, such as postynaptic density protein 95, synaptophsin, α-amino 3-hydroxy-5-methyl-4-isoxa-zolep-propionate receptor and neurotrophic factors, e,g., brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor. Taken together, our results demonstrate that FSD-C10 has therapeutic potential in the AD mouse model, possibly through inhibiting the formation of Aß1-42 and P-tau, and promoting the generation of synapse-associated proteins and neurotrophic factors.

Fasudil in Combination With Bone Marrow Stromal Cells (BMSCs) Attenuates Alzheimer's Disease-Related Changes Through the Regulation of the Peripheral Immune System.

Alzheimer's disease (AD) is a chronic progressive neurodegenerative disease. Its mechanism is still not clear. Majority of research focused on the central nervous system (CNS) changes, while few studies emphasize on peripheral immune system modulation. Our study aimed to investigate the regulation of the peripheral immune system and its relationship to the severity of the disease after treatment in an AD model of APPswe/PSEN1dE9 transgenic (APP/PS1 Tg) mice. APP/PS1 Tg mice (8 months old) were treated with the ROCK-II inhibitor 1-(5-isoquinolinesulfonyl)-homo-piperazine (Fasudil) (intraperitoneal (i.p.) injections, 25 mg/kg/day), bone marrow stromal cells (BMSCs; caudal vein injections, 1 × 106 BMSCs /time/mouse), Fasudil combined with BMSCs, or saline (i.p., control) for 2 months. Morris water maze (MWM) test was used to evaluate learning and memory. The mononuclear cells (MNCs) of spleens of APP/PS1 Tg mice were analyzed using flow cytometry for CD4+ T-cells, macrophages, and the pro-inflammatory and anti-inflammatory molecules of the macrophages. Immunohistochemical staining was used to examine the expression of ROCK-II in the spleens of APP/PS1 Tg mice. The MWM test showed improved spatial learning ability in APP/PS1 Tg mice treated with Fasudil or BMSCs alone or in combination, compared to untreated APP/PS1 Tg mice. Fasudil combined with BMSCs intervention significantly promoted the proliferation of CD4+/CD25+ and CD4+/ IL-10 lymphocytes, induced the release of cytokine factors, and regulated the balance of the immune system to work functionally. It also shifted M1 (MHC-II, CD86) to M2 (IL-10, CD206) phenotype of macrophages of CD11b and significantly enhanced the anti-inflammatory and phagocytic abilities (CD16/32) of macrophages of CD11b. Immunohistochemical staining showed significantly decreased expression of ROCK-II in mice treated with combination of Fasudil with BMSCs as compared to saline control. Fasudil in combination of BMSCs improved cognition of APP/PS1 Tg mice through the regulation of the peripheral immune system, including reduction of ROCK-II expression and increased proportion of anti-inflammatory M2 mononuclear phenotype and phagocytic macrophages in the spleen of the peripheral immune system. The latter was achieved through the communication between brain and spleen to improve the immunoregulation of CNS and AD disease conditions.

Multitarget Therapeutic Effect of Fasudil in APP/PS1transgenic Mice.

INTRODUCTION: Therapeutic strategies targeting Alzheimer's disease-related molecule ß- amyloid (Aß), Tau protein and ß-site amyloid precursor protein cleaving enzyme (BACE) have been recently explored. However, the treatment effect for single target is not ideal. Based on multiaspect roles of Rho kinase inhibitor Fasudil on neuroprotection, neurorepair and immunomodulation, we observed therapeutic potential of Fasudil and explored possible mechanisms in amyloid precursor protein/ presenilin-1 transgenic (APP/PS1 Tg) mice, an animal model of Alzheimer's disease. METHODS: APP/PS1 Tg mice were treated with Fasudil (25 mg/kg/day) for 2 months by intraperitoneal injection. Mouse behavior tests were recorded every day. The expression of Aß deposition, Tau protein phosphorylation, BACE and postsynaptic density 95 (PSD-95) in hippocampus was assayed. The levels in the brain of Toll-like receptors (TLRs)-nuclear factor kappa B/p65（NF-κB/p65)- myeloid differentiation primary response gene 88 (MyD88) inflammatory cytokine axis were measured. RESULTS: Fasudil treatment ameliorated learning and memory deficits, accompanied by reduced Aß deposition, Tau protein phosphorylation, and BACE expression, as well as increased PSD-95 expression in hippocampus. Fasudil intervention also inhibited TLR-2/4, p-NF-κB/p65, MyD88, interleukin-1beta, interleukin-6 and tumor necrosis factor-α for TLRs-NF-κB-MyD88 inflammatory cytokine axis and the induction of interleukin-10. CONCLUSION: Fasudil exhibited multitarget therapeutic effect in APP/PS1 Tg mice. The study provides preclinical evidence that Fasudil treatment ameliorated memory deficits in APP/PS1 Tg mice, accompanied by the reduction of Aß deposition and Tau protein phosphorylation, the decrease of BACE and the increase of PSD-95, as well as inhibition of TLRs-NF-κB-MyD88 inflammatory cytokine axis. However, these results still need to be repeated and confirmed before clinical application.

[Fasudil improves cognition of APP/PS1 transgenic mice via inhibiting the activation of microglia and shifting microglia phenotypes from M1 to M2].

Objective To examine the regulatory effects of Rho kinase inhibitor fasudil on cognition and microglia polarization in APP/PS1 transgenic (APP/PS1 Tg) mice, a widely used model of Alzheimer's disease (AD). Methods Male APP/PS1 Tg mice at 8 months of age were randomly divided into two groups: Fasudil (25 mg/kg) and saline, i.p., once daily for 2 months; age- and gender-matched wild type (WT) mice without treatment were used as the controls. The Morris water maze (MWM) test was applied to examine spatial cognition of mice. Aß1-42 deposition, the microglia surface marker CD11b, and the M1 and M2 microglia surface markers [iNOS, arginase 1 (ARG1) and CD206] in the hippocampus and cerebral cortex were analyzed by immunohistochemistry and Western blotting. Results Compared with WT controls, APP/PS1 Tg mice (10 months old at the time of testing) treated with saline displayed increases in the latency to target, mean distance to target, latency 1st entrance to SW quadrant during the MWM test; they also showed increased latency and mean distance entering to the target in the MWM test, indicating their impaired cognition, which was reversed by fasudil. In addition, fasudil decreased the expressions of Aß1-42 and iNOS and increased ARG1/CD206 in the hippocampus and cerebral cortex. further, the microglia marker CD11b had an overlap with the M1 marker iNOS or the M2 markers ARG1/CD206 in the cerebral cortex of the AD mice following fasudil treatment. Conclusion Fasudil reverses spatial cognitive dysfunction in APP/PS1 Tg mice via facilitating the transformation of Aß1-42-activated microglia from the M1 to M2 phenotype.