Single-cell brain atlas of Parkinson's disease mouse model.

Parkinson's disease (PD) is a neurodegenerative disease, leading to the impairment of movement execution. PD pathogenesis has been largely investigated, either limited to bulk transcriptomic levels or at certain cell types, which failed to capture the cellular heterogeneity and intrinsic interplays among distinct cell types. Here, we report the application of single-nucleus RNA-seq on midbrain, striatum, and cerebellum of the α-syn-A53T mouse, a well-established PD mouse model, and matched controls, generating the first single cell transcriptomic atlas for the PD model mouse brain composed of 46,174 individual cells. Additionally, we comprehensively depicte the dysfunctions in PD pathology, covering the elevation of NF-κB activity, the alteration of ion channel components, the perturbation of protein homeostasis network, and the dysregulation of glutamatergic signaling. Notably, we identify a variety of cell types closely associated with PD risk genes. Taken together, our study provides valuable resources to systematically dissect the molecular mechanism of PD pathogenesis at the single-cell resolution, which facilitates the development of novel approaches for diagnosis and therapies against PD.

Wnt-3a alleviates neuroinflammation after ischemic stroke by modulating the responses of microglia/macrophages and astrocytes.

Neuroinflammation crucially influences functional recovery after ischemic stroke. Wnt-3a, a novel Wnt protein that specifically promotes Wnt/ß-catenin signaling pathway, has been shown to regulate apoptosis and cell proliferation, but how it affects ischemic stroke-induced toxic brain inflammation remains unknown. Using a transient middle cerebral artery occlusion (tMCAO) mouse model in this study, we found that intranasal Wnt-3a-treated tMCAO mice had apparently reduced infarct volume and decreased brain water content after being allowed to recover for 72 h, as well as better neurologic outcomes on days 3, 7, and 14. Mice received Wnt-3a had significantly fewer tMCAO-induced peri-infarct TUNEL-positive cells compared with those received vehicle. Further, Wnt-3a-delivered tMCAO mice had notably fewer peri-infarct CD68-positive cells and lower ionized calcium-binding adapter molecule (Iba)-1 protein level. Wnt-3a significantly downregulated the expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α, and upregulated the expression of arginase 1 (Arg1) and CD206. Finally, Wnt-3a obviously decreased the number of tMCAO-induced peri-infarct glial fibrillary acidic protein (GFAP)/C3-positive cells, increased the number of GFAP/S100A10-positive cells, attenuated the protein levels of GFAP and interleukin 15 (IL15), and elevated IL33 protein level. Our findings suggest that intranasal Wnt-3a could ameliorate toxic responses of microglia/macrophages and astrocytes in ischemic brain injury, supporting that Wnt-3a might be potentially appropriate for ischemic stroke treatment functioning as an immunomodulatory agent.

Effects of prebiotic galacto-oligosaccharide on postoperative cognitive dysfunction and neuroinflammation through targeting of the gut-brain axis.

BACKGROUND: Surgery-induced neuroinflammation plays an important role in postoperative cognitive dysfunction (POCD). Gut microbiota is a key regulator of neurological inflammation. Nurturing with prebiotics is an effective microbiota manipulation that can regulate host immunity and cognition. The aim of the present study was to test whether administration of the prebiotic Bimuno® (galactooligosaccharide (B-GOS) mixture) could ameliorate POCD and attenuate surgery-induced neuroinflammation through the microbiota-brain-axis. METHODS: Adult rats undergoing abdominal surgery under isoflurane anesthesia were fed with water or prebiotic B-GOS supplementation (15 g/L) for 3 weeks. Novel objective recognition task was employed for testing cognitive changes on postoperative day three. Expression of microglial marker Iba-1 in the hippocampus was assessed by immunohistochemical staining. Expression levels of phenotypic gene markers of activated microglia (M1: iNOS, CD68, CD32; M2: Ym1, CD206, and SOCS3) in hippocampus were determined by quantitative polymerase chain reaction (qPCR). Inflammatory cytokines in the hippocampus were assessed using enzyme-linked immunosorbent assay (ELISA). Feces were collected for microbial community analysis. RESULTS: Rats exhibited an impairment in novel objective recognition 3 days after surgery compared with control rats (P < .01). In the hippocampus, expressions of Iba-1 and M1 markers of surgical rats were significantly upregulated. Similarly, expressions of SOCS3 and CD206 in the hippocampus were upregulated. Additionally, increasing levels of IL-6 and IL-4 were evident in the hippocampus. Administration of B-GOS significantly alleviated cognitive decline induced by surgery (P < .01). B-GOS-fed rats showed a significantly downregulated activation of microglia and expressions of M1-related genes and SOCS3 and IL-6. While there was no significant difference in expressions of CD206 and Ym1 and IL-4 between the surgical and B-GOS groups. Analysis of gut microbiome found that administration of B-GOS induced a significant change beta diversity of the gut microbiome and proliferation of Bifidobacterium and other potentially anti-inflammatory microbes. CONCLUSIONS: Administration of B-GOS has a beneficial effect on regulating neuroinflammatory and cognitive impairment in a rat model of abdominal surgery and was associated with the manipulation of gut microbiota.

Resolving neuroinflammation, the therapeutic potential of the anti-malaria drug family of artemisinin.

Artemisinin (Qinghaosu) and its semi-synthetic derivatives have been demonstrated to alleviate neuroinflammatory response in the central nerve system (CNS). In this review, we summarized that artemisinins are capable to treat neuroinflammtion-related CNS diseases in both direct (via regulating inflammatory process in the CNS, exerting anti-oxidative stress and neuroprotective effect, and preventing Aß accumulation) and indirect (via maintaining BBB integrity, suppressing systemic inflammation and alleviating intestinal inflammtion) manner. However, the precise mechanism of their anti-neuroinflammatory effects and potential neurotoxicity, which hindered further progress in these aspects, remains unclear. We suggest that further understanding of the PK/PD properties and structure-action relationship of atemisinin and its derivatives will facilitate the development of new therapeutics with better curative effects and safety.

[Inhibitory effects of vina-ginsenoside R7 on activation of rat C6 astrocytes induced by LPS and TNF-α combination].

To investigate the inhibitory effect and mechanism of vina-ginsenoside R7 (R7) on the activation of rat C6 astrocytes cells induced by LPS/TNF-α, cells in logarithmic growth phase were cultured in DMEM medium without FBS for 24 h. After dissociated using 0.25% EDTA-trypsin, the cells were seeded into respective plates at the density of 1.5×106 cells per mL and cultured overnight. The cells were divided into the following groups： control group (no treatment), model group (treated with LPS 1 µg•mL⁻¹ and TNF-α 10 µg•L⁻¹ treated for 24 h), R7 groups (pre-treated with 6.25, 12.5, 25, 50, and 75 µmol•L⁻¹ R7, 4 µmol•L⁻¹ L-NMMA for 2 h and then stimulated with LPS 1 mg•L⁻¹ and TNF-α 10 µg•L⁻¹ for 24 h). Cell viability was analyzed by CCK-8 kit. Secretion of nitric oxide (NO) in the medium was measured by Greiss method. Concentrations of interleukin-6 (IL-6) and tumor necrosis factor (TNF-α) were assayed by ELISA kits. Gene expressions of inflammatory factors were examined by quantitative-PCR analysis. Activation of NF-κB was detected by dual luciferase reporter gene assay kit. The results showed that R7 could significantly inhibit the secretion of NO from C6 cells in a dose-effect manner, with an IC50 of 34 µmol•L⁻¹. And it could reduce cell proliferation induced by LPS/TNF-α stimulation. Furthermore, R7 at 50 µmol•L⁻¹ significantly down-regulated gene expressions of iNOS (P<0.001), TNF-α (P<0.001), IL-1ß(P<0.05), and COX-2 (P<0.001), but could not change gene expression of IL-6. However, R7 reduced the secretion of TNF-α (P<0.001) and IL-6 (P<0.001). Further studies disclosed that, different concentrations of R7 (25, 50, 100 µmol•L⁻¹) could significantly inhibit the transcription activity of NF-κB(P<0.05, P<0.01, and P<0.001). In conclusion, R7 could inhibit inflammatory responses in C6 cells induced by LPS/TNF-α probably by inhibiting the transcription activity of NF-κB, which indicates its possible therapeutic effect in neurological diseases related to neuroinflammation.

Inhibitory effects of vina-ginsenoside R7 on activation of rat C6 astrocytes induced by LPS and TNF-α combination / 中国中药杂志

To investigate the inhibitory effect and mechanism of vina-ginsenoside R7 (R7) on the activation of rat C6 astrocytes cells induced by LPS/TNF-α, cells in logarithmic growth phase were cultured in DMEM medium without FBS for 24 h. After dissociated using 0.25% EDTA-trypsin, the cells were seeded into respective plates at the density of 1.5×10⁶ cells per mL and cultured overnight. The cells were divided into the following groups： control group (no treatment), model group (treated with LPS 1 μg•mL⁻¹ and TNF-α 10 μg•L⁻¹ treated for 24 h), R7 groups (pre-treated with 6.25, 12.5, 25, 50, and 75 μmol•L⁻¹ R7, 4 μmol•L⁻¹ L-NMMA for 2 h and then stimulated with LPS 1 mg•L⁻¹ and TNF-α 10 μg•L⁻¹ for 24 h). Cell viability was analyzed by CCK-8 kit. Secretion of nitric oxide (NO) in the medium was measured by Greiss method. Concentrations of interleukin-6 (IL-6) and tumor necrosis factor (TNF-α) were assayed by ELISA kits. Gene expressions of inflammatory factors were examined by quantitative-PCR analysis. Activation of NF-κB was detected by dual luciferase reporter gene assay kit. The results showed that R7 could significantly inhibit the secretion of NO from C6 cells in a dose-effect manner, with an IC₅₀ of 34 μmol•L⁻¹. And it could reduce cell proliferation induced by LPS/TNF-α stimulation. Furthermore, R7 at 50 μmol•L⁻¹ significantly down-regulated gene expressions of iNOS (P<0.001), TNF-α (P<0.001), IL-1β(P<0.05), and COX-2 (P<0.001), but could not change gene expression of IL-6. However, R7 reduced the secretion of TNF-α (P<0.001) and IL-6 (P<0.001). Further studies disclosed that, different concentrations of R7 (25, 50, 100 μmol•L⁻¹) could significantly inhibit the transcription activity of NF-κB(P<0.05, P<0.01, and P<0.001). In conclusion, R7 could inhibit inflammatory responses in C6 cells induced by LPS/TNF-α probably by inhibiting the transcription activity of NF-κB, which indicates its possible therapeutic effect in neurological diseases related to neuroinflammation.