[Triptolide reduces neuronal damage in cerebral ischemia-reperfusion rats by promoting microglial M2 polarization].

Objective To investigate the effects of triptolide (TP) on microglial M1/M2 polarization after cerebral ischemia-reperfusion (I/R) injury in rats and the underlying molecular mechanism. Methods A rat model of middle cerebral artery occlusion (MCAO) was established. TP was administered to rats at doses of 0.1 and 0.2 mg/kg, with a sham surgery group as the control group. Longa scoring was performed to grade neurological deficits in rats; HE staining was used to observe the morphology of neurons in ischemic brain tissues; neuron-specific nuclear protein (NeuN) immunofluorescence staining was used to measure the number of neurons; and Western blot analysis was used to measure the expression levels of ionised calcium-binding adaptor molecule-1 (Iba1), inducible nitric oxide synthase (iNOS), arginase 1 (Arg1), Toll-like receptor 4 (TLR4), nuclear factor κB (NF-κB), NeuN and caspase-3 in ischemic-brain tissues. The protein levels of interleukin 1ß (IL-1ß) and IL-10 were measured by ELISA. Immunofluorescence double labelling was performed to detect the expression of Arg1 and TLR4 in microglia. Results Compared with the model group, the neurological score of the TP treatment group was significantly reduced and the neuronal damage was significantly alleviated. IL-1ß levels decreased while IL-10 levels increased. The expression levels of iNOS, TLR4, NF-κB and caspase-3 decreased, while the expression levels of Arg1 and NeuN increased. Conclusion TP treatment ameliorates cerebral I/R injury in rats, which may be attributed to the promotion of microglial M2 polarization, thereby reducing the release of inflammatory factors and inhibiting apoptosis.

Icariin ameliorates the cuprizone-induced demyelination associated with antioxidation and anti-inflammation.

The treatment of immunomodulation in multiple sclerosis (MS) can alleviate the severity and relapses. However, it cannot improve the neurological disability of patients due to a lack of myelin protection and regeneration. Therefore, remyelinating therapies may be one of the feasible strategies that can prevent axonal degeneration and restore neurological disability. Natural product icariin (ICA) is a flavonol compound extracted from epimedium flavonoids, which has neuroprotective effects in several models of neurological diseases. Here, we attempt to explore whether ICA has the potential to treat demyelination and its possible mechanisms of action using lipopolysaccharide-treated BV2 microglia, primary microglia, bone marrow-derived macrophages, and cuprizone-induced demyelination model. The indicators of oxidative stress and inflammatory response were evaluated using commercial kits. The results showed that ICA significantly reduced the levels of oxidative intermediates nitric oxide, hydrogen peroxide, malondialdehyde, and inflammatory cytokines TNF-α, IL-1ß, and increased the levels of antioxidants superoxide dismutase, catalase, glutathione peroxidase, and anti-inflammatory cytokines IL-10 and TGF-ß in vitro cell experiments. In vivo demyelination model, ICA significantly alleviated the behavioral abnormalities and enhanced the integrated optical density/mm2 of Black Gold II and myelin basic protein myelin staining, accompanied by the inhibition of oxidative stress/inflammatory response. Immunohistochemical staining showed that ICA significantly induced the expression of nuclear factor erythroid derived 2/heme oxygenase-1 (Nrf2/HO-1) and inhibited the expression of toll-like receptor 4/ nuclear factor kappa B (TLR4/NF-κB), which are two key signaling pathways in antioxidant and anti-inflammatory processes. Our results strongly suggest that ICA may be used as a potential agent to treat demyelination via regulating Nrf2/HO-1-mediated antioxidative stress and TLR4/NF-κB-mediated inflammatory responses.

Triptolide promotes nerve repair after cerebral ischemia reperfusion injury by regulating the NogoA/NgR/ROCK pathway.

Activation of the NogoA/NgR/ROCK pathway limits nerve repair after brain ischemia-reperfusion (I/R) injury. Triptolide displays anti-inflammatory, anti-oxidant, and immunosuppressive effects and is derived from the traditional Chinese medicine Tripterygium wilfordii Hook F. This agent can also penetrate the blood-brain barrier, where it has a neuroprotective effect and ameliorates cerebral I/R injury via an as yet unknown mechanism(s). Here, an animal model of middle cerebral artery occlusion and reperfusion (MCAO/R) was employed to assess triptolide's therapeutic impact on brain I/R injury and the possible mechanism of action. The results indicate that triptolide treatment can decrease cerebral infarction and nerve injury after cerebral I/R injury. Importantly, in vivo and in vitro experiments revealed that treatment with triptolide decreased NogoA, NgR, p75NTR and ROCK2 expression, and upregulated the expression of GAP43 and PSD-95, thus suggesting improved synaptic function. These results indicate that triptolide can promote nerve repair following brain I/R injury by inhibiting NogoA/NgR/ROCK signalling.

[Eriodictyol improves cognitive function in 5×FAD mice of Alzheimer's disease by inhibiting the microglia NLRP3 inflammasome signaling pathway].

Objective To investigate the therapeutic effects of eriodictyol on transgenic mice with five familial Alzheimer's disease (5×FAD) and the modulation of NOD-like receptor-pyrin domain containing 3 (NLRP3) inflammasome in microglia. Methods The 8-month-old 5×FAD mice were randomly divided into AD model group and eriodictyol-treated AD group. Same-aged wild-type C57BL/6J mice were randomly divided into wild-type (WT) control group and eriodictyol-treated WT group. Morris water maze and Y-maze experiments were performed to assess the cognitive function of each group of mice. Immunofluorescence histochemical staining was performed to detect the expression of NLRP3, caspase-1 and interleukin 18 (IL-18) in mouse brain tissue, and Western blot was performed to detect the protein levels of NLRP3, apoptosis-associated speckle-like protein containing a CARD (ASC), caspase-1, IL-18, IL-1ß and ion calcium-binding adaptor molecule 1 (Iba-1) in mouse brain tissue. Results Compared with the WT group and the eriodictyol-treated WT group, cognitive function was significantly impaired in the AD group mice, and the expression of NLRP3, caspase-1, IL-18, ASC, IL-1ß and Iba1 were increased in microglia of mouse brain tissue. After eriodictyol treatment, learning memory and cognitive function were improved, and the expression of NLRP3, ASC, caspase-1, IL-1ß, IL-18 and Iba1 were all down-regulated in the eriodictyol-treated AD group mice compared with the AD group mice. Conclusion Eriodictyol may improve cognitive function in animal models of AD by inhibiting the activation of the NLRP3 signaling pathway in microglia.

Astragaloside IV inhibits experimental autoimmune encephalomyelitis by modulating the polarization of both microglia/macrophages and astrocytes.

Astragaloside IV (AST IV), a major saponin component and active ingredient isolated from Astragalus membranaceus, has been well known to exhibit neuroprotective effects on diverse models of neurological diseases. Accumulating evidence suggests that dynamic balance of microglia/macrophages and astrocytes plays a vital role in neuroprotection and remyelination. However, dysregulation of microglia/macrophages and astrocytes orchestrate the pathogenesis of nervous system disorders. Therefore, we hypothesized that switching the transformation of microglia/macrophages and astrocytes into the neuroprotective M2 and A2 phenotypes, respectively, could be a potential target for therapeutic intervention. In the present study, we evaluate the efficacy of AST IV intervention on the effects of microglia/macrophages and astrocytes in an experimental autoimmune encephalomyelitis (EAE) model. AST IV improved paralysis and pathology of EAE by inhibiting the neurotoxic M1 microglia/macrophage phenotype, promoting M2 phenotype, shifting astrocytes towards a neuroprotective A2 phenotype, and protecting neurons from apoptosis through inhibition of TLR4/Myd88/NF-kB signalling pathway. Our study showed that AST IV could be a potential and promising drug for multiple sclerosis treatment.

[Knock-down of ROCK2 gene improves cognitive function and reduces neuronal apoptosis in AD mice by promoting mitochondrial fusion and inhibiting its division].

Objective To explore the effect of knocking down Rho-associated coiled-coil kinase (ROCK2) gene on the cognitive function of amyloid precursor protein/presenilin-1 (APP/PS1) double transgenic mice and its mechanism. Methods APP/PS1 double transgenic mice were randomly divided into AD model group (AD group), ROCK2 gene knock-down group (shROCK2 group), ROCK2 gene knock-down control group (shNCgroup), and wild-type C57BL/6 mice of the same age served as the wild-type control (WT group). Morris water maze and Y maze were employed to test the cognitive function of mice. Neuron morphology was detected by Nissl staining. Immunofluorescence histochemical staining was used to detect the expression of phosphorylated dynamin-related protein 1 (p-Drp1) and mitochondrial fusion 1 (Mfn1). Western blot analysis was used to detect the expression ROCK2, cleaved-caspase-3 (c-caspase-3), B-cell lymphoma 2 (Bcl2), Bcl2-related protein X (BAX), p-Drp1, mitochondrial fission 1 (Fis1), optic atrophy 1 (OPA1), Mfn1 and Mfn2. Results Compared with AD group mice, the expression of ROCK2 in shROCK2 group mice was significantly reduced; the cognitive function was significantly improved with the number of neurons in the hippocampal CA3 and DG areas increasing, and nissl bodies were deeply stained; the expression of c-caspase-3 and BAX was decreased, while the expression of Bcl2 was increased; the expression of mitochondrial division related proteins p-Drp1 and Fis1 were decreased, while the expression of mitochondrial fusion-related proteins OPA1, Mfn1 and Mfn2 were increased. Conclusion Knock-down of ROCK2 gene can significantly improve the cognitive function and inhibit the apoptosis of nerve cells of APP/PS1 mice. The mechanism may be related to promoting mitochondrial fusion and inhibiting its division.

Fasudil alleviates cerebral ischemia­reperfusion injury by inhibiting inflammation and improving neurotrophic factor expression in rats.

The Rho kinase inhibitor fasudil exerts neuroprotective effects. We previously showed that fasudil can regulate M1/M2 microglia polarization and inhibit neuroinflammation. Here, the therapeutic effect of fasudil on cerebral ischemia­reperfusion (I/R) injury was investigated using the middle cerebral artery occlusion and reperfusion (MCAO/R) model in Sprague­Dawley rats. The effect of fasudil on the phenotype of microglia and neurotrophic factors in the I/R brain and its potential molecular mechanism was also explored. It was found that fasudil ameliorated neurological deficits, neuronal apoptosis, and inflammatory response in rats with cerebral I/R injury. Fasudil also promoted the polarization of microglia into the M2 phenotype, in turn promoting the secretion of neurotrophic factors. Furthermore, fasudil significantly inhibited the expression of TLR4 and NF­κB. These findings suggest that fasudil could inhibit the neuroinflammatory response and reduce brain injury after I/R injury by regulating the shift of microglia from an inflammatory M1 phenotype to an anti­inflammatory M2 phenotype, which may be related to the regulation of the TLR4/ NF­κB signal pathway.

[Acupuncture ameliorates neurological function by suppressing microglia polarization and inflammatory response after cerebral ischemia in rats].

OBJECTIVE: To observe the effect of acupuncture on microglia polarization and inflammatory reaction in rats with cerebral ischemia-reperfusion injury (CIRI), so as to explore its mechanisms underlying improvement of CIRI. METHODS: Thirty male SD rats were randomly divided into sham operation, model, and acupuncture groups, with 10 rats in each group. The CIRI model was established by occlusion of the middle cerebral artery (MCAO) for 1 h, followed by reperfusion. After modeling, rats in the acupuncture group received manual acupuncture stimulation of "Dazhui" (GV14), "Baihui"(GV20), "Shuigou" (GV26), bilateral "Zusanli" (ST36) and "Fengchi" (GB20) by twirling the needles rapidly for 10 s/acupoint every 10 min, with the needles retained for 20 min. The treatment was conducted once daily for successive 7 days. The neurological function was evaluated according to Longa's method. The state of CIRI was observed after Nissl staining, and the expression levels of Iba-1, iNOS, Arg1, BDNF, GDNF and NeuN in the ischemic cortex tissue were detected by immunofluorescence staining. The contents of TNF-α, IL-6 and IL-10 in the ischemic tissue were assayed by ELISA. The protein expression levels of BDNF, GDNF, TLR4, MyD88 and NF-κB in the ischemic tissues were detected by Western blot. RESULTS: The neurological deficit score on the 24 h and 7th day was considerably higher in the model group than in the sham operation group (P<0.01), and evidently lower on the 7th day in the acupuncture group than in the model group (P<0.01). The number of NeuN positive cells，the area of immunofluorescence dual labelling of Arg1, BDNF and GDNF positive staining, IL-10 content, BDNF and GDNF protein expressions were significantly decreased (P<0.01), and the immunofluorescence dual labelling area of Iba-1 and iNOS, TNF-α and IL-6 contents, the pretein expression levels of TLR4, MyD88 and NF-κB considerably increased (P<0.01) in the model group relevant to the sham operation group. In contrast to the model group, the acupuncture group had a significant increase in the number of NeuN positive cells, the immunofluorescence dual labelling area of Arg1, BDNF and GDNF positive staining, IL-10 content, and BDNF and GDNF protein expressions (P<0.05, P<0.01), and an evident decrease in Iba-1 and iNOS positive staining, contents of TNF-α and IL-6, and the protein expression levels of TLR4, MyD88 and NF-κB (P<0.01, P<0.05). Nissl staining showed a marked reduction in the number of neurons, the nucleus pyknosis and nissl bodies and loose arrangement of the neuronal cells in the model group, which was relatively milder in the acupuncture group. CONCLUSION: Acupuncture intervention can improve neurological function in CIRI rats, which may be related to its effects in regulating the polarization of microglia, reducing inflammatory reaction and increasing the secretion of neurotrophic factors in the brain, inhibiting TLR4/MyD88/NF-κB signaling pathway.

[Astragaloside IV inhibits oxidative stress-mediated apoptosis of human SY5Y cells by activating Nrf-2/HO-1 signaling pathway].

Objective To investigate the protective effect and mechanism of astragaloside IV (AST4) on H2O2-induced oxidative stress injury and apoptosis of SY5Y cells. Methods Human SY5Y cells were cultured in vitro and induced by H2O2 to establish oxidative stress model, which was divided into PBS group, H2O2 group and AST4 group. Cell viability was determined by MTT assay. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL). The supernatant was used to determine the activity of malondialdehyde (MAD), superoxide dismutase (SOD) and glutathione (GSH) in each group. Immunofluorescence cytochemistry was used to detect the nuclear factor E2-related factor (Nrf-2) and cleaved caspase-3 (c-caspase-3). B-lymphoblastoma-2 (Bcl2), Bcl2-associated X protein (BAX), c-caspase-3, Nrf-2 in cells and nuclei and heme oxygenase-1 (HO-1) were determined by Western blot analysis. Results AST4 had a protective effect on viability of SY5Y cells under oxidative stress damage, reduced the content of MAD, and increased the content of GSH and SOD. AST4 increased Bcl2 and decreased BAX, thus Bc12/BAX ratio was significantly increased compared with that in H2O2 group. Meanwhile, AST4 inhibited the expression of c-caspase-3. AST4 promoted nuclear translocation of Nrf-2 and increased the expression of the downstream antioxidant protein HO-1. Conclusion AST4 can promote Nrf-2 nuclear translocation, increase HO-1 expression, regulate oxidation/antioxidant balance, improve antioxidant level, protect cells from oxidative damage and reduce apoptosis by activating Nrf-2/HO-1 signaling pathway.

[Fasudil reduces apoptosis of SH-SY5Y cells induced by H2O2 and promotes synaptic plasticity by inhibiting neurite outgrowth inhibitor A and its receptor (NogoA/NgR) signaling pathway].

Objective To investigate the effect of Fasudil on H2O2-induced apoptosis and synaptic plasticity in human neuroblastoma SY5Y cells and its mechanism. Methods The cells were divided into three groups: PBS control group, H2O2 model group (250 µmol/L H2O2 treatment) and Fasudil intervention group (250 µmol/L H2O2 combined with 15 µg/mL Fasudil treatment). MTT assay was applied to detect cell activity and TUNEL was performed to detect cell apoptosis respectively. Immunofluorescence cytochemical staining was used to determine the expression of neurite outgrowth inhibitor A (NogoA), Nogo receptor (NgR) and synaptophysin (Syn). Western blotting was then conducted to detect the expression of NogoA, NgR, p75 neurotrophin receptor (p75NTR), leucine-rich repeat Ig domain-containing Nogo-interacting protein 1 (LINGO-1), Syn and postsynaptic density protein-95 (PSD-95). Results Compared with the PBS group, the H2O2 group showed decreased cell viability and increased apoptosis rate while Fasudil treatment significantly increased the cell viability and reduced the apoptosis rate. Compared with the H2O2 model group, Fasudil intervention increased expressions of Syn and PSD-95. Compared with the PBS group, the expression of NogoA and its receptor complex NgR/p75NTR/LINGO-1 grew significantly in the H2O2 group, suggesting Fasudil treatment could inhibit the expression of NogoA and its receptor complex NgR/p75NTR/LINGO-1. Conclusion Fasudil may inhibit the activation of the NogoA/NgR signaling pathway, therefore reducing the apoptosis induced by H2O2 in SH-SY5Y cells and enhancing the plasticity of the synapses.

[Lycium barbarum polysaccharide promotes M2 polarization of BV2 microglia induced by LPS via inhibiting the TLR4/NF-κB signaling pathway].

Objective To investigate the effect of Lycium barbarum polysaccharide (LBP) on the polarization of BV2 microglia from M1 to M2 induced by lipopolysaccharide (LPS) and its mechanism. Methods The BV2 microglia were divided into control group, LPS group, and LBP treatment group (0.6, 0.9, 1.2) g/L. MTT assay was used to observe the cell viability of BV2 cells, and Griess assay was used to detect the release of NO. The levels of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were detected by ELISA. The expressions of Toll-like receptor 4 (TLR4), nuclear factor kappa B (NF-κB), inducible nitric oxide synthase (iNOS), and arginase-1 (Arg1) were detected by immunofluorescence cytochemistry. Western blot was used to evaluate the protein levels of ionized calcium-binding adaptor molecule-1 (Iba-1), TLR4, NF-κB, iNOS, and Arg1. Results There was no significant difference of the cell survival rate after treatment with different doses of LBP. Compared to those in the control group, in LPS group the BV2 microglia were activated with amoeba-like shape and increased release of NO, the expressions of Iba-1, TLR4, NF-κB, iNOS, TNF-α, IL-1ß, and IL-6 were significantly increased, while the expressions of Arg1 and IL-10 was significantly decreased. In LBP group, Iba-1, TLR4, NF-κB, iNOS, TNF-α, IL-1ß, and IL-6 were dramatically decreased and negatively correlated with the dose, while Arg1 and IL-10 were increased and positively correlated with the dose. Conclusion LBP inhibits activation of BV2 microglia induced by LPS and promots the M2 polarization, which may be realized through inhibiting TLR4/NF-κB signaling pathway.

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 enhances the phagocytosis of myelin debris and the expression of neurotrophic factors in cuprizone-induced demyelinating mice.

Multiple sclerosis (MS) is mainly associated with the neuroinflammation and demyelination in the central nervous system (CNS), in which the failure of remyelination results in persistent neurological dysfunction. Fasudil, a typical Rho kinase inhibitor, has been exhibited beneficial effects on several models of neurodegenerative disorders. In this study, we showed that Fasudil promoted the uptake of myelin debris by microglia via cell experiments and through a cuprizone (CPZ)-induced demyelinating model. In vitro, microglia with phagocytic debris exhibited enhanced expression of brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF), and the conditioned medium promoted the maturation of oligodendrocyte precursor cells (OPCs). Meanwhile, Fasudil upregulated TREM2/DAP12 pathway, which positively regulated the phagocytosis of myelin debris by microglia. Similarly, in vivo, Fasudil intervention enhanced the clearance of myelin debris, upregulated the expression of BDNF and GDNF on microglia, and promoted the formation of Oligo2+/PDGFRα+ OPCs and the maturation of MBP + oligodendrocytes in the brain. Our results showed that Fasudil targeted the phagocytic function of microglia, effectively clearing myelin debris produced during pathological process possibly by upregulating TREM2/DAP12 pathway, accompanied by increased expression of BDNF and GDNF. However, the precise mechanism underlying the effects of Fasudil in promoting phagocytic effects and neurotrophic factors remains to be elucidated.

Fasudil reduces ß-amyloid levels and neuronal apoptosis in APP/PS1 transgenic mice via inhibition of the Nogo-A/NgR/RhoA signaling axis.

Recent studies have shown that Nogo-A and the Nogo-A receptor affect ß-amyloid metabolism and the downstream Rho GTP enzyme signaling pathway, which may affect the levels of ß-amyloid and tau. Nogo-A may play a key role in the pathogenesis of Alzheimer's disease. However, the underlying molecular mechanisms of Fasudil treatment in Alzheimer's disease are not yet clear. Our results have found that Fasudil treatment for two months substantially ameliorated behavioral deficits, diminished ß-amyloid plaque and tau protein pathology, and alleviated neuronal apoptosis in APP/PS1 transgenic mice. More importantly, two well-established markers for synaptic function, growth-associated protein 43 and synaptophysin, were upregulated after Fasudil treatment. Finally, the levels of Nogo-A, Nogo-A receptor complex NgR/p75NTR/LINGO-1 and the downstream Rho/Rho kinase signaling pathway were significantly reduced. These findings suggest that Fasudil exerts its neuroprotective function in Alzheimer's disease by inhibiting the Nogo-A/NgR1/RhoA signaling pathway.

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.

[Dihydrotanshinone I (DHTS1) attenuates cuprizone-induced demyelination via regulating microglia polarization].

Objective To evaluate whether dihydrotanshinone I (DHTS1) attenuates cuprizone-induced demyelination. Methods DHTS1 was dissolved in 5 g/L sodium carboxymethyl cellulose (CMC-Na). The cuprizone model was induced via feeding with the diet containing 2 g/L cuprizone. We administrated DHTS1 to the cuprizone-exposed mice. The mice were randomly divided into CMC-Na normal group, CMC-Na combined with cuprizone group and DHTS1 combined with cuprizone group. Myelin degeneration was checked by Luxol fast blue (LFB) staining and the immunohistochemical staining of myelin basic protein (MBP) and myelin proteolipid (PLP). Cell apoptosis was measured by TUNEL. Microglia polarization was evaluated by Iba-1, CD86 and CD163 immunohistochemical staining in vivo. The SIM-A9 cells cultured were divided into CMC-Na group, DHTS1 group, CMC-Na combined with LPS group and DHTS1 combined with LPS group. The expression of CD16/32, tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS) was analyzed by flow cytometry in vitro. Results Compared with CMC-Na combined with cuprizone group, DHTS1 treatment significantly attenuated myelin loss and cell apoptosis, reduced the area of Iba-1+ amoebic microglia and the number of CD86+ cells, while increased the number of CD163+ cells in the corpus callosum area of the brain. In addition, compared with CMC-Na combined with LPS group, DHTS1 obviously decreased the percentages of CD16/32+, iNOS+, TNF-α+ microglia. Conclusion DHTS1 can suppress cuprizone-induced demyelination and cell apoptosis through regulating the microglia polarization and mitigating inflammatory reaction in the central nerve system.

MicroRNA-153-3p sensitizes melanoma cells to dacarbazine by suppressing ATG5-mediated autophagy and apoptosis.

BACKGROUND: Dacarbazine is one of the most commonly used chemotherapeutic agents for the treatment of melanoma; however, only 5-10% of patients benefit from this treatment. MicroRNA-153-3p (miR-153-3p) has a tumor-suppressive effect in melanoma. In the present study, we found that miR-153-3p was downregulated in melanoma cell lines (A357 and M14). METHODS: The target relationship between miR-153-3p and Autophagy-related gene 5 (ATG5) was confirmed by Dual-Luciferase Reporter Assay. Cell Counting Kit-8, flow cytometry, immunofluorescence, and Western blot were used to examine cell viability, apoptosis, and autophagy, respectively. RESULTS: miR-153-3p overexpression decreased the half-maximal inhibitory concentration value of dacarbazine, while increasing the apoptotic rate in both A357 and M14 cells. Moreover, miR-153-3p enhanced dacarbazine-induced autophagy in melanoma cells. Our bioinformatics study revealed that ATG5 is one of the potential targets of miR-153-3p. The overexpression of ATG5 decreased dacarbazine sensitivity and promoted proliferation, as well as inhibited apoptosis and autophagy in melanoma cells. miR-153-3p exhibited suppressive effects via directly binding and downregulating ATG5 expression, which subsequently increased sensitivity to dacarbazine and inhibited proliferation, and enhanced apoptosis and autophagy in melanoma cells. CONCLUSIONS: The results of the present study showed that miR-153-3p sensitizes melanoma cells to dacarbazine by suppressing ATG5-mediated autophagy and apoptosis, and provided a basis to explore the functions of miRNAs on drug resistance in the treatment of melanoma.

Astragaloside IV protects neurons from microglia-mediated cell damage through promoting microglia polarization.

Astragaloside IV (AST-IV) is a major active ingredient of astragalus, with a neuroprotective effect. The current study is aimed to investigate the impact of AST-IV on the M1/M2 microglial activation in response to lipopolysaccharide (LPS) stimulation, how AST-IV attenuated microglia-mediated neuronal damage, and the molecular mechanisms underlying AST-IV's protection of neurons against microglia-mediated neuronal damage. Our results showed that AST-IV partially protected microglia from death evoked by LPS and downregulated the release of pro-inflammatory (M1) mediators including interleukin (IL)-1ß, IL-6, tumour necrosis factor α (TNF-α) and nitric oxide, as well as the expression of Toll-like receptors 4 (TLR4), MyD88, and nuclear factor κB (NF-κB) of these cells. In contrast, AST-IV elevated the production of anti-inflammatory cytokine IL-10 and expression of arginase 1, an M2 marker of microglia, whose conditioned medium promoted PC12 neurons survival. These results indicate that AST-IV exerts an anti-inflammatory effect on microglia, possibly through inhibiting TLR4/NF-κB signalling pathways, and protects neurons from microglia-mediated cell death through conversion of microglia from inflammatory M1 to an anti-inflammatory M2 phenotype.

Mdivi-1, a mitochondrial fission inhibitor, modulates T helper cells and suppresses the development of experimental autoimmune encephalomyelitis.

BACKGROUND: Unrestrained activation of Th1 and Th17 cells is associated with the pathogenesis of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). While inactivation of dynamin-related protein 1 (Drp1), a GTPase that regulates mitochondrial fission, can reduce EAE severity by protecting myelin from demyelination, its effect on immune responses in EAE has not yet been studied. METHODS: We investigated the effect of Mdivi-1, a small molecule inhibitor of Drp1, on EAE. Clinical scores, inflammation, demyelination and Drp1 activation in the central nervous system (CNS), and T cell responses in both CNS and periphery were determined. RESULTS: Mdivi-1 effectively suppressed EAE severity by reducing demyelination and cellular infiltration in the CNS. Mdivi-1 treatment decreased the phosphorylation of Drp1 (ser616) on CD4+ T cells, reduced the numbers of Th1 and Th17 cells, and increased Foxp3+ regulatory T cells in the CNS. Moreover, Mdivi-1 treatment effectively inhibited IFN-γ+, IL-17+, and GM-CSF+ CD4+ T cells, while it induced CD4+ Foxp3+ regulatory T cells in splenocytes by flow cytometry. CONCLUSIONS: Together, our results demonstrate that Mdivi-1 has therapeutic potential in EAE by modulating the balance between Th1/Th17 and regulatory T cells.

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.