Protective effect of sterubin against neurochemical and behavioral impairments in rotenone-induced Parkinson's disease

This study was conducted to evaluate how sterubin affects rotenone-induced Parkinson's disease (PD) in rats. A total of 24 rats were distributed into 4 equal groups: normal saline control and rotenone control were administered saline or rotenone (ROT), respectively, orally; sterubin 10 received ROT + sterubin 10 mg/kg po; and sterubin alone was administered to the test group (10 mg/kg). Rats of the normal saline and sterubin alone groups received sunflower oil injection (sc) daily, 1 h after receiving the treatments cited above, while rats of the other groups received rotenone injection (0.5 mg/kg, sc). The treatment was continued over the course of 28 days daily. On the 29th day, catalepsy and akinesia were assessed. The rats were then euthanized, and the brain was extracted for estimation of endogenous antioxidants (MDA: malondialdehyde, GSH: reduced glutathione, CAT: catalase, SOD: superoxide dismutase), nitrative (nitrite) stress markers, neuroinflammatory cytokines, and neurotransmitter levels and their metabolites (3,4-dihydroxyphenylacetic acid (DOPAC), dopamine (DA), norepinephrine (NE), serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), and homovanillic acid (HVA)). Akinesia and catatonia caused by ROT reduced the levels of endogenous antioxidants (GSH, CAT, and SOD), elevated the MDA level, and altered the levels of nitrites, neurotransmitters, and their metabolites. Sterubin restored the neurobehavioral deficits, oxidative stress, and metabolites of altered neurotransmitters caused by ROT. Results demonstrated the anti-Parkinson's activities of sterubin in ROT-treated rats.

La alteración hipotalámica en la obesidad: neuroinflamación y disfunción metabólica / The hypotalamic disturbances during obesity: neuroinflammation and metabolic dysfunction

Resumen La obesidad es considerada actualmente como un problema de salud pública global y se caracteriza por la hipertrofia e hiperplasia del tejido adiposo debido a la ingesta hipercalórica y la falta de actividad física, disfunción metabólica, inflamación sistémica crónica de bajo grado y gradualmente neuroinflamación hipotalámica. El tejido adiposo actúa como un órgano endocrino secretando adipocinas y citocinas que actúan como reguladores del metabolismo. Sin embargo, la presencia de niveles elevados de ácidos grasos libres y de moléculas inflamatorias derivadas de los adipocitos, pueden alterar la respuesta inmunitaria sistémica, generando inflamación crónica, comprometiendo la integridad de la barrera hematoencefálica y estimulando la respuesta de la glía, especialmente en regiones específicas del hipotálamo, centro de regulación de la homeostasis energética. Las células gliales hipotalámicas son importantes en la transmisión de señales inflamatorias relacionadas con la dieta, pueden modular la actividad neuronal, responder a las señales inmunológicas periféricas e iniciar una respuesta inflamatoria local y gliosis. Esta revisión se enfoca en la descripción general de la disfunción metabólica asociada a la obesidad y su participación en la alteración de la regulación hipotalámica, provocando neuroinflamación y modificaciones en la conducta alimentaria.

Abstract Nowadays, obesity is considered a worldwide rising health problem and is characterized by adipose tissue hypertrophy and hyperplasia due to hypercaloric intake and lack of physical activity, promoting the development of metabolic dysfunction, low-grade systemic chronic inflammation, and gradually hypothalamic neuroinflammation. Adipose tissue acts as an endocrine organ secreting adipokines and cytokines around peripheral organs, functioning as a master metabolism regulator. However, high levels of adipocyte-derived free fatty acids and inflammatory molecules promote impairments in systemic immune response, generate chronic inflammation, disrupt the blood-brain barrier, and stimulate glia, specifically in some hypothalamic regions, the master regulators of energetic homeostasis. Hypothalamic glial cells are essential in diet-related inflammatory signals transmission and can modulate neuronal activity, also respond to peripheral inflammatory signals and begin local inflammatory response and gliosis. This review aims to analyze obesity-related metabolic dysfunction and how it participates in the hypothalamic regulation impairments due to neuroinflammation and impairment in food intake behavior.

Activation of the complement C3/C3aR pathway in the prefrontal cortex mediates methamphetamine addiction in rats / 中国药理学与毒理学杂志

OBJECTIVE To investigate the role of the complement C3/C3aR signaling pathway in the prefrontal cortex and colon neuroglia cell interactions during meth-amphetamine(METH)addiction,to observe the effects of TLR4 inhibitors as well as complement C3 elimination on METH reward and relapse behavior,and to explore the neuroinflammatory mechanisms of complement C3 acti-vation in METH addiction.METHODS ①A 14 d and 28 d rat METH addiction model was established to observe the effects of TLR4 antagonist ibudilast 3 mg·kg-1 and 10 mg·kg-1 on self-administration,reward motivation,relapse,and natural reward behavior in METH-trained 14 d rats and the effects of 0.02 mg·kg-1 complement C3 antago-nist on self-administration behavior in METH-trained 28 d rats.② Differences in the expression of TLR4,NF-κB,GRP94,C3,cathepsin L,CD68,and GFAP in the pre-frontal cortex of each group were examined using West-ern blotting.③ In addition,the expression of ATF6 in the prefrontal cortex of each group and the effects on neuro-nal and microglia/macrophage INOS,CD206 GRP94,and complement C3/C3aR.RESULTS ① Endoplasmic reticulum stress occurred in neurons and microglia after METH exposure depending on GRP94 and unfolded pro-tein responses to the ATF6 pathway.In addition,it acti-vates the TLR4-NF-κB pathway.② Microglia with high complement C3/C3aR expression in the prefrontal cortex were recruited to synaptic pruning and phagocytic responses around neurons with high GRP94,comple-ment C3/C3aR expression and these effects were blocked by complement C3 antagonists.③ In the rec-tum,GRP94 functions as a molecular chaperone for com-plement C3 and cathepsin L.Crosstalk occurs between enteric neurons high in GRP94,complement C3,and macrophages high in C3aR,located in the submucosa,lamina propria,and muscular,respectively,and all of these effects are blocked by complement C3 antago-nists.④ Treatment with the TLR4 antagonist ibudilast inhibits self-administration,reward motivation,and cue-or METH-priming in METH-trained 14 d rats,but fails to affect natural reward behavior.Ibudilast treatment attenu-ates the TLR4-NF-κB inflammatory pathway and comple-ments C3/C3aR pathway in the prefrontal cortex.CON-CLUSION Activation of the complement C3/C3aR signal-ing pathway by TLR4-NF-κB inflammatory signaling in the prefrontal cortex mediates the METH addiction pro-cess,providing an experimental basis for the clinical treatment of METH addiction,and targeting TLR4/NF-κB inflammatory signaling and complement C3/C3aR may be a new way to intervene in METH addiction.

Synergistic effects of lipopolysaccharide and rote-none on dopamine neuronal damage in rats / 中国药理学与毒理学杂志

OBJECTIVE The etiology of Parkinson disease(PD)is still unknown.Until now,oxidative stress and neuroinflammation play a crucial role in the patho-genesis of PD.However,the specific synergistic role of oxidative stress and neuroinflammation in the occurrence and development of PD remains unclear.METHODS The changes in motor behavior,dopamine(DA)neurons quantification and their mitochondrial respiratory chain,glial cells activation and secreted cytokines,Nrf2 signal-ing pathway,and redox balance in the brain of rats were evaluated.RESULTS Lipopolysaccharide(LPS)-induced neuroinflammation and rotenone(ROT)-induced oxidative stress synergistically aggravated motor dysfunc-tion,DA neuron damage,activation of glial cells,and release of related mediators,activation of Nrf2 signaling and destruction of oxidative balance.In addition,further studies indicated that after ROT-induced oxidative stress caused direct damage to DA neurons,LPS-induced inflammatory effects had stronger promoting neurotoxic effects on the above aspects.CONCLUSION Neuroinflammation and oxidative stress synergistically aggravated DA neuronal loss.Furtherly,oxidative stress followed by neuroinflammation caused more DA neuro-nal loss than neuroinflammation followed by oxidative stress.

Tetrahydroxy stilbene glycoside ameliorates neuroin-flammation for Alzheimer's disease via cGAS-STING / 中国药理学与毒理学杂志

OBJECTIVE Alzheimer's disease(AD)is the most common neurodegenerative disease worldwide.Neuroinflammation is a potential target for the patients with AD.It is attributed to activated microglia and the release of various inflammatory mediators from infec-tion,ischemia and toxin accumulation.Accumulating evi-dence has indicated that the cGAS-STING pathway driven neuroinflammation in neurological disease.TSG is a main natural active ingredient that derived from polyg-onum multiflorum.Previous research from our group found that TSG has beneficial effects of anti-aging,anti-inflammatory action and improving memory function in APP/PS1 transgenic AD mice.Here,we investigated the effects of TSG on cognitive impairment and neuroinflam-mation in APP/PS1-AD mice and explore the underly-ing mechanism by which TSG ameliorates memory func-tion in the cGAS-STING-mediated inflammatory response.METHODS The Morris water mace test and the novel object recognition test were performed to test the effects of TSG on spatial learning and cognitive and memory abil-ity in APP/PS1 double transgenic AD mice model.In addi-tion,real-time quantitative PCR,Western blotting,ELISA analysis,and flow cytometry to examine gene and pro-tein expression of cGAS-STING related pro-inflammatory cytokines and chemokines.Statistical analyses were ana-lyzed using the SPSS 25.0 package by analysis of vari-ance(ANOVA).Neuman-Keuls or Tukey's multiple-com-parisons test were conducted as ANOVA justified post hoc comparisons between group means.RESULTS We demonstrated that AD transgenic mice exhibited cognitive deficits accompanied by the elevated serum and brain inflammation.The expressions of serum inflammatory cytokines and the activation of microglia in cerebral cor-tex and hippocampus were suppressed after TSG treat-ment,which was probably attributable to the decrease of cyclic GMP-AMP synthase(cGAS)and stimulator of interferon genes(STING)triggered immune response.Additionally,the data showed that TSG treatment reduced the expression level of inflammatory cytokines(IL-1β,TNF-α,IFN-β,IFN-α)in microglial cells BV2 primed with LPS and IFN-γ.CONCLUSION TSG implicated the health benefits in preventing cognitive disorders by inhib-iting neuroinflammation via cGAS-STING signalling path-way in AD.

Genetic inhibition of MLKL exerts protective effects against cognitive impairment and neuroinflammation in a cerebral small vessel disease model / 中国药理学与毒理学杂志

OBJECTIVE To identify the role of mixed lineage kinase domain like protein(MLKL)in cerebral small vessel disease(CSVD)and explore the underlying mechanism.METHODS Transient bilateral common carotid artery occlusion(tBCCAO)was used to establish a mouse model of CSVD.Immunofluorescence staining and Western blotting were used to observe the expres-sions of RIPK3/MLKL signaling molecules in brain tissues at 7,14 and 28 d after tBCCAO.Open field test,rotarod test,Y-maze and novel object recognition test were used to observe the effect of MLKL knockout on cognitive func-tion after tBCCAO.Blood-brain barrier(BBB)disruption was observed by sodium fluorescein permeability test and the expressions of tight junction proteins.Immunoflu-orescence staining and Western blotting were used to detect the expression of microglia marker Iba-1,astro-cyte marker GFAP,and NLRP3/Caspase-1 signaling mol-ecules in the hippocampus of CSVD mice.ELISA was used to detect the level of inflammatory factors(TNF-α,IL-1β,IL-18)in hippocampus.RESULTS The expres-sions of RIPK3/MLKL signaling molecules increased in cortex and hippocampus after tBCCAO,especially on day 14.The expression of pMLKL mainly increased in neurons,glia cells and endothelial cells in CSVD mice.MLKL knockout improved the cognitive functions such as motor learning,spatial learning and working memory,and object recognition ability in CSVD mice.MLKL knock-out alleviated the leakage of sodium fluorescein and attenuated the down-regulation of tight junction proteins at 1 d and 14 d after tBCCAO.At 14 d after tBCCAO,MLKL knock out inhibited the activations of microglia and astrocytes,attenuated the expressions of NLRP3/cas-pase-1 molecules,and decreased the levels of inflamma-tory factors in the hippocampus of mice.CONCLUSION Genetic inhibition of MLKL exerts protective effects against cognitive impairment by ameliorating BBB dam-age and neuroinflammation in a mouse cerebral small vessel disease model.

Pharmacological inhibition of STING signaling attenu-ates MPTP-induced neuroinflammation and neurode-generation in experimental models of Parkinson's disease / 中国药理学与毒理学杂志

OBJECTIVE To investigate the effects of pharmacological inhibition of STING by C-176,a STING selective inhibitor,in experimental model of Parkinson's disease.METHODS The acute and sub-acute mice mod-els of Parkinson's disease(PD)were established by in-traperitoneal injection of 1-methyl-4-(2′-methylphenyl)-1,2,3,6-tetrahydrophine(MPTP).The selective STING inhibitor C-176 was administered by intraperitoneal injec-tion.The potential neuroprotective effects of C-176 were evaluated by behavioral test,tyrosine hydroxylase(TH)immunostaining,Nissl staining,Western blotting,qPCR and immunofluorescence.For in vitro study,the effects of C-176 on LPS/MPP+-induced inflammatory responses in BV2 microglial cells were determined by real time RT-PCR and Western blotting analysis.RESULTS Our study revealed that C-176 significantly inhibited STING signaling activation,ameliorated MPTP-induced dopami-nergic neurotoxicity,motor deficit and associated neuroin-flammation.Furthermore,pharmacological inhibition of STING in BV2 microglia treated with LPS/MPP+ exhibited decreased inflammatory responses.More importantly,C176 also reduced NLRP3 inflammasome activation both in vitro and in vivo.CONCLUSION The results of our study suggest that pharmacologic inhibition of STING protects against neuroinflammation that may act at least in part through suppressing NLRP3 inflammasome acti-vation and thus ameliorated dopaminergic neurodegener-ation.STING signaling may holds great promise for the development of new treatment strategy for PD as an effective therapeutic target.

Traditional Chinese medicine polysaccharides in the treatment of Parkinson's disease and its mechanism / 中国药理学与毒理学杂志

Parkinson's disease(PD)is a degenera-tive disease of the central nervous system characterized by the loss of dopamine(DA)neurons in the dense sub-stantia nigra and the depletion of DA neurons.Clinically,the treatment of PD is mainly supplementing dopamine deficiency or using DA receptor agonists,but these drugs can only alleviate the symptoms of PD patients,but cannot prevent neuronal loss and delay disease progres-sion.Natural bioactive polysaccharides have the advan-tages of multi-target,low toxicity and synergistic effect,and have great potential in the prevention and treatment of PD.Numerous studies have shown that polysaccha-rides can be involved in neuronal protection and preven-tion of neurodegenerative diseases through mechanisms such as oxidative stress,reducing neuroinflammation,and inhibiting anti-apoptosis.①Anti-oxidative stress.Oxi-dative stress is caused by increased reactive oxygen spe-cies(ROS)products and weakened antioxidant capacity,resulting in destruction of lipids,proteins,and DNA.Oxi-dative stress-induced mitochondrial dysfunction is thought to be an important cause of DA neuronal loss in PD mice.Polysaccharides reduce the damage of DA neurons in the substantia nigra by increasing the activity of antioxidant enzymes and inhibiting the formation of reactive oxygen species.② Reduce neuroinflammation.Neuroinflamma-tory response is the main causative factor of neurodegener-ation,microglia are innate immune cells present in the central nervous system,and their continuous activation is a key link in central nervous system neuroinflammation.Polysaccharides can regulate the expression of inflamma-somes,reduce the levels of pro-inflammatory cytokines and cytotoxic factors,inhibit the excessive activation of microglia,reduce PD neuroinflammatory damage,and then exert neuroprotective effects.③ Inhibiting apopto-sis.Apoptosis(APO)is the process of cell death caused by the activation of cell death procedures by various fac-tors.During the pathogenesis of PD,due to changes in the internal and external environment of DA neurons,some apoptosis-related genes cause DA neuronal death by regulating cell death signaling pathways.Polysaccha-rides can reduce the Bax/Bcl2 ratio,weaken the activa-tion of caspase-related proteins,improve the viability of PC12 cells,reduce apoptosis,and protect the activity of dopamine neurons.In summary,traditional Chinese med-icine polysaccharides can effectively treat and improve PD,and its mechanism of action involves anti-oxidative stress,reducing neuroinflammation and apoptosis.There-fore,traditional Chinese medicine polysaccharides have great development potential in the field of medicine and health.

Artesunate reduces neuronal apoptosis and inflammatory response in model rats with ischemic stroke in vivo, and promotes microglia polarization in vitro / 中华行为医学与脑科学杂志

Objective:To investigate the effects of artesunate ( ART ) on neuronal apoptosis, inflammatory response after stroke in rats and microglia polarization.Methods:(1)Animal experiment: twenty-seven male SD rats of SPF grade were divided into sham operation group, model group and ART treatment group according to the random number table method, with 9 rats in each group.Rats in the model group and ART treatment group were used to establish a stroke model by middle cerebral artery occlusion (MCAO). And rats in the ART treatment group were intraperitoneally injected with ART (25 mg/kg) once a day for three days before modeling, while the rats in sham operation group and the model group were injected with the same amount of solvent.And 24 h after the modeling, TTC staining was used to evaluate the volume of cerebral infarction, Western blot was used to detect the expression of Bcl2 in the infarct area, penumbra and hippocampus, TUNEL method was used to detect neuronal apoptosis, and tissue immunofluorescence was used to observe the expression of tumor necrosis factor-α(TNF-α) in the penumbra region of cerebral cortex.(2)Cell experiments: microglia BV2 were cultured and divided into control group, oxygen-glucose deprivation/reoxygenation group, oxygen-glucose deprivation/reoxygenation + 0.05 μmol/L ART group, oxygen-glucose deprivation/reoxygenation + 0.1 μmol/L ART group and oxygen-glucose deprivation/reoxygenation + 0.5 μmol/L ART group.The levels of inflammatory factors interleukin-6(IL-6), interleukin-1β(IL-1β) and TNF-α were detected by qRT-PCR, the expressions of M2 type microglia marker protein CD206 and ARG1 were detected by Western blot, the BV2 cell medium after treatment in each of the above groups was collected as conditioned medium to culture HT22 hippocampal neuron cells and cell activity was measured by CCK8 method.GraphPad Prism 7 software was used for data analysis.One-way ANOVA was used for comparison of differences among multiple groups, and LSD was used for further two-by-two comparisons.Results:(1)Animal experiment results: TTC staining results showed that the percentage of cerebral infarction volume in the ART treatment group was smaller than that in the model group ((23.09±8.51)%, (39.63±5.71)%, t=33.93, P<0.01). The results of TUNEL staining showed that the number of apoptotic cells in the model group and ART treatment group was higher than that in the sham operation group ((638.90±177.82)cells/mm 2, (72.75±13.21) cells/mm 2, (16.16±2.73) cells/mm 2, both P<0.05), and the number of apoptotic cells in the ART treatment group was lower than that in the model group ( P<0.05). Western blot results showed that the levels of Bcl2 protein in penumbra and infarct area of the model group were both lower than those in sham group(both P<0.05). The levels of Bcl2 protein in penumbra, the hippocampus and infarcted area of the ART treatment group were significantly lower than those of the model group(all P<0.05). The results of tissue immunofluorescence showed that the fluorescence intensities of TNF-α in the model group and ART treatment group were higher than those in the sham group (all P<0.05), while the fluorescence intensity of TNF-α in the ART treatment group was lower than that in the model group ( P<0.05). (2)Cell experiment: qRT-PCR results showed that compared with the control group, the mRNA levels of IL-6, IL-1β and TNF-α (all P<0.05) in oxygen-glucose deprivation/reoxygenation group were significantly higher than those of the control group.And the mRNA levels of IL-1β, IL-6 and TNF-α in oxygen-glucose deprivation/reoxygenation + 0.05 μmol/L ART group, oxygen-glucose deprivation/reoxygenation + 0.1 μmol/L ART group and oxygen-glucose deprivation/reoxygenation + 0.5 μmol/L ART group were significantly lower than those of the oxygen-glucose deprivation/reoxygenation group (all P<0.05). Western blot results showed that compared with the control group, the expression of CD206 ((0.85±0.04), (1.07±0.07), P<0.05) was significantly down-regulated in the oxygen-glucose deprivation/reoxygenation group.The CD206 and ARG in oxygen-glucose deprivation/reoxygenation + 0.1 μmol/L ART group((1.22±0.06), (1.35±0.08)) and oxygen-glucose deprivation/reoxygenation + 0.5 μmol/L ART group((1.24±0.14), (1.14±0.07)) were significantly higer than those of oxygen-glucose deprivation/reoxygenation group((0.85±0.04), (0.85±0.05))(all P<0.05). The results of CCK8 showed that compared with the control group, the cell viability in the oxygen-glucose deprivation/reoxygenation group was significantly decreased( P<0.05). The cell viability of the oxygen-glucose deprivation/reoxygenation + 0.05 μmol/L ART group, the oxygen-glucose deprivation/reoxygenation + 0.1 μmol/L ART group, the oxygen-glucose deprivation/reoxygenation + 0.5 μmol/L ART group were all higher than those of oxygen-glucose deprivation/reoxygenation group(all P<0.05). Conclusion:ART reduces neuronal apoptosis after stroke, decreases the neuroinflammatory response after stroke, and promotes oxygen-glucose deprivation/reoxygenation-activated microglia BV2 polarization to the M2 type.

Improvement effects and mechanism of total flavonoids of Bidens pilosa on lipopolysaccharide-induced neuroin-flammation in mice / 中国药房

OBJECTIVE To investigate the effect and mechanism of total flavonoids of Bidens pilosa L. （TFB） on lipopolysaccharide （LPS）-induced neuroinflammation in mice. METHODS Fifty C57BL/6 mice were randomly divided into normal control group， LPS group and TFB low-dose， medium-dose and high-dose groups， with 10 mice in each group. TFB low-dose， medium-dose and high-dose groups were given TFB solution intragastrically at 60， 120 and 240 mg/kg， and the normal control group and LPS group were given corresponding volume of normal saline， once a day， for consecutive 21 d. From the 15th day of administration， except for the normal control group， other groups were given LPS （400 μg/kg） intraperitoneally for 7 consecutive days to establish neuroinflammatory model. Brain tissues were taken under anesthesia 4 h after the final administration. The morphological changes of neuronal cells in mice were observed； the contents of nitric oxide （NO）， tumor necrosis factor α （TNF- α）， interleukin-1β （IL-1β）， IL-6 and IL-10 were measured， and the expressions of inflammatory pathway-related proteins [inducible NO synthase （iNOS）， cyclooxygenase-2 （COX-2）， myeloid differentiation factor 88 （Myd88） and protein kinase C （PKC）] were measured in the brain tissues of mice. RESULTS Compared with the normal control group， the neuronal arrangement in the hippocampal region of the brain tissue of mice in the LPS group was sparsely disorganized， with a large number of neuronal fixations and shrunken nuclei； the contents of TNF-α， IL-1β， IL-6 and NO in the brain tissue were significantly increased， the contents of IL-10 were significantly decreased， and the relative expressions of iNOS， COX-2， Myd88 and PKC proteins were significantly increased （P＜0.05）. Compared with the LPS group， the neuronal pathological changes in the brain tissue of mice in the TFB low-dose， medium-dose and high-dose groups were 202014810） significantly improved， and the changes of the above indices in the brain tissue were significantly reversed （P＜0.05） CONCLUSIONS TFB has an inhibitory effect on E-mail：pangxjun@163.com neuroinflammation， and its mechanism of action may be related to down-regulation of the expressions of inflammatory pathway-related proteins iNOS， COX-2， Myd88 and PKC， and reduction of inflammatory factors release.

Mechanism of Dendrobium huoshanense Polysaccharide Against Neuroinflammation in Parkinson's Disease Model： Based on NLRP3 Inflammasome / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of Dendrobium huoshanense polysaccharide （DHP） against inflammatory damage of neurons in Parkinson's disease （PD） model. MethodSH-SY5Y cells were randomized into blank group， model group， and DHP group. The survival rate of cells was measured by thiazole blue（MTT） assay， and the levels of lactate dehydrogenase （LDH）， reactive oxygen species （ROS）， malondialdehyde （MDA）， and superoxide dismutase （SOD） were measured by colorimetric analysis. BV-2 microglia were classified into blank group， model group， DHP group， and MCC950 group （positive control group）， and enzyme-linked immunosorbent assay （ELISA） was applied to detect the levels of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-18 （IL-18）. The expression of NOD-like receptor protein 3 （NLRP3）， adaptor protein apoptosis-associated dot protein （ASC）， cysteine aspartic protease-1 （Caspase-1）， and IL-1β was measured by Western blot. A total of 50 C57BL/6 mice were randomized into blank group， model group， DHP low-dose （100 mg·kg-1） group， DHP equivalent-dose （350 mg·kg-1） group， and MCC950 group （positive control group）， 10 mice in each group. The motor balance and coordination of C57BL/6 mice were observed by beam walking test， tail suspension test and rotarod test. The levels of Iba-1 and tyrosine hydroxylase （TH） were detected by immunofluorescence staining. The damage of dopaminergic neurons in the substantia nigra was detected by FJB staining. The levels of inflammatory factors such as IL-1β， IL-18， and TNF-α in mouse midbrain tissues were detected by ELISA and the protein levels of NLRP3， ASC， Caspase-1， and IL-1β protein were measured by Western blot. ResultCompared with the blank group， the SH-SY5Y model group showed decreased cell survival， increased levels of LDH， ROS， and MDA （P<0.05）， and decreased levels of SOD （P<0.05）. Compared with the model group， the DHP group demonstrated increased cell survival， decreased levels of LDH， ROS， and MDA （P<0.01）， and increased level of SOD （P<0.01）. Compared with the blank group， BV-2 model group had high levels of IL-1β， IL-18， and TNF-α （P<0.05） and high protein expression of NLRP3， Caspase-1， IL-1β， and ASC （P<0.05）. Compared with the model group， DHP and MCC950 groups demonstrated low levels of IL-1β， IL-18， and TNF-α （P<0.01） and low protein expression of NLRP3， Caspase-1， IL-1β， and ASC （P<0.01）. Compared with the blank group， the C57BL/6 model group displayed long time to pass the balance wood （P<0.05）， short time spent on the rod in the rotarod test （P<0.05）， high levels of IL-1β， IL-18， and TNF-α （P<0.05） and expression of Iba-1 in the midbrain substantia nigra （P<0.05）， low TH expression （P<0.05）， more positive neurons in the FJB staining （P<0.05）， and high expression of NLRP3， Caspase-1， ASC， and IL-1β proteins （P < 0.05）. Compared with the model group， the mice in the DHP and MCC950 groups had short time to pass the balance beam （P<0.01）， long time spent on the rod （P<0.01）， low levels of IL-1β， IL-18， and TNF-α （P<0.01）， low Iba-1 expression in midbrain substantia nigra （P<0.01）， high TH expression （P<0.01）， and small number of positive neurons in the midbrain substantia nigra （P<0.01）. The expression of NLRP3， ASC， and IL-1β proteins was lower in the MCC950 group （P<0.01）， and the expression of NLRP3， ASC， Caspase-1 and IL-1β proteins was lower in the DHP equivalent-dose group （P<0.01） than in the model group. ConclusionDHP has anti-oxidative stress effect. It regulates the expression of NLRP3 inflammasome and inhibits the overactivation of microglia， thereby alleviating the neuroinflammatory injury in PD and exerting the neuroprotective effect.

Discovery of novel phosphodiesterase-1 inhibitors for curing vascular dementia: Suppression of neuroinflammation by blocking NF-κB transcription regulation and activating cAMP/CREB axis

Vascular dementia (VaD) is the second commonest type of dementia which lacks of efficient treatments currently. Neuroinflammation as a prominent pathological feature of VaD, is highly involved in the development of VaD. In order to verify the therapeutic potential of PDE1 inhibitors against VaD, the anti-neuroinflammation, memory and cognitive improvement were evaluated in vitro and in vivo by a potent and selective PDE1 inhibitor 4a. Also, the mechanism of 4a in ameliorating neuroinflammation and VaD was systematically explored. Furthermore, to optimize the drug-like properties of 4a, especially for metabolic stability, 15 derivatives were designed and synthesized. As a result, candidate 5f, with a potent IC50 value of 4.5 nmol/L against PDE1C, high selectivity over PDEs, and remarkable metabolic stability, efficiently ameliorated neuron degeneration, cognition and memory impairment in VaD mice model by suppressing NF-κB transcription regulation and activating cAMP/CREB axis. These results further identified PDE1 inhibition could serve as a new therapeutic strategy for treatment of VaD.

Novel Microglia-based Therapeutic Approaches to Neurodegenerative Disorders / 神经科学通报·英文版

As prominent immune cells in the central nervous system, microglia constantly monitor the environment and provide neuronal protection, which are important functions for maintaining brain homeostasis. In the diseased brain, microglia are crucial mediators of neuroinflammation that regulates a broad spectrum of cellular responses. In this review, we summarize current knowledge on the multifunctional contributions of microglia to homeostasis and their involvement in neurodegeneration. We further provide a comprehensive overview of therapeutic interventions targeting microglia in neurodegenerative diseases. Notably, we propose microglial depletion and subsequent repopulation as promising replacement therapy. Although microglial replacement therapy is still in its infancy, it will likely be a trend in the development of treatments for neurodegenerative diseases due to its versatility and selectivity.

Interactions Between Astrocytes and Oligodendroglia in Myelin Development and Related Brain Diseases / 神经科学通报·英文版

Astrocytes (ASTs) and oligodendroglial lineage cells (OLGs) are major macroglial cells in the central nervous system. ASTs communicate with each other through connexin (Cx) and Cx-based network structures, both of which allow for quick transport of nutrients and signals. Moreover, ASTs interact with OLGs through connexin (Cx)-mediated networks to modulate various physiological processes in the brain. In this article, following a brief description of the infrastructural basis of the glial networks and exocrine factors by which ASTs and OLGs may crosstalk, we focus on recapitulating how the interactions between these two types of glial cells modulate myelination, and how the AST-OLG interactions are involved in protecting the integrity of the blood-brain barrier (BBB) and regulating synaptogenesis and neural activity. Recent studies further suggest that AST-OLG interactions are associated with myelin-related diseases, such as multiple sclerosis. A better understanding of the regulatory mechanisms underlying AST-OLG interactions may inspire the development of novel therapeutic strategies for related brain diseases.

Association of Glial Activation and α-Synuclein Pathology in Parkinson's Disease / 神经科学通报·英文版

The accumulation of pathological α-synuclein (α-syn) in the central nervous system and the progressive loss of dopaminergic neurons in the substantia nigra pars compacta are the neuropathological features of Parkinson's disease (PD). Recently, the findings of prion-like transmission of α-syn pathology have expanded our understanding of the region-specific distribution of α-syn in PD patients. Accumulating evidence suggests that α-syn aggregates are released from neurons and endocytosed by glial cells, which contributes to the clearance of α-syn. However, the activation of glial cells by α-syn species produces pro-inflammatory factors that decrease the uptake of α-syn aggregates by glial cells and promote the transmission of α-syn between neurons, which promotes the spread of α-syn pathology. In this article, we provide an overview of current knowledge on the role of glia and α-syn pathology in PD pathogenesis, highlighting the relationships between glial responses and the spread of α-syn pathology.

miR-34b-3p Inhibition of eIF4E Causes Post-stroke Depression in Adult Mice / 神经科学通报·英文版

Post-stroke depression (PSD) is a serious and common complication of stroke, which seriously affects the rehabilitation of stroke patients. To date, the pathogenesis of PSD is unclear and effective treatments remain unavailable. Here, we established a mouse model of PSD through photothrombosis-induced focal ischemia. By using a combination of brain imaging, transcriptome sequencing, and bioinformatics analysis, we found that the hippocampus of PSD mice had a significantly lower metabolic level than other brain regions. RNA sequencing revealed a significant reduction of miR34b-3p, which was expressed in hippocampal neurons and inhibited the translation of eukaryotic translation initiation factor 4E (eIF4E). Furthermore, silencing eIF4E inactivated microglia, inhibited neuroinflammation, and abolished the depression-like behaviors in PSD mice. Together, our data demonstrated that insufficient miR34b-3p after stroke cannot inhibit eIF4E translation, which causes PSD by the activation of microglia in the hippocampus. Therefore, miR34b-3p and eIF4E may serve as potential therapeutic targets for the treatment of PSD.

Effects of scutellarin on neuroinflammation in rats with traumatic brain injury by regulating cGAS/STING signaling pathway / 中国药房

OBJECTIVE To investigate the improvement effects and mechanism of scutellarin （Scu） on neuroinflammation in rats with traumatic brain injury （TBI）. METHODS The modified Feeney method was applied to construct TBI rat model. The rats were randomly grouped into TBI group，Scu low-dose group （40 mg/kg），Scu high-dose group （80 mg/kg），cyclic guanylate- adenylate synthase （cGAS） inhibitor group （cGAS inhibitor RU.521，450 μg/kg），with 24 rats in each group. Other 24 rats were included in the sham operation group. The modified neurological deficit score （mNSS） method was applied to assess the neurological function of rats； the brain water content of rats was measured by dry/wet specific gravity method； hematoxylin-eosin and TdT-mediated dUTP nick-end labeling staining were applied to observe the pathological changes and apoptosis of brain tissue in rats； the levels of interferon-β （IFN-β），CXC chemokine ligand-10 （CXCL10），tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in rat brain tissue were detected by enzyme-linked immunosorbent assay； Western blot method was applied to detect the expression of cGAS/interferon gene stimulating protein （STING） signal pathway-related proteins in brain tissue of rats. RESULTS Compared with the sham operation group，the mNSS，brain water content，apoptosis rate，the contents of IFN-β，CXCL10，TNF-α and IL-6，and the relative expressions of cGAS and STING proteins in TBI group increased significantly （P＜0.05）； there were edema，bleeding and pathological damage to neurons in the brain tissue. Compared with TBI group，the above indicators and pathological changes of rats in administration groups were improved significantly （P＜0.05），and the effect of Scu was in a dose- dependent manner （P＜0.05）； however，there was no statistically obvious difference in the above indicators between the Scu high- dose group and the cGAS inhibitor group （P＞0.05）. CONCLUSIONS Scu may alleviate neuroinflammation，reduce brain tissue damage and apoptosis，and promote the recovery of neural function in TBI rats by inhibiting the activation of cGAS/STING signaling pathway.

Effect of Erjing Pills on alleviating neuroinflammation of AD rats based on TLR4/NF-κB/NLRP3 pathway and its mechanism / 中国中药杂志

This paper aimed to study the effect of Erjing Pills on the improvement of neuroinflammation of rats with Alzheimer's di-sease(AD) induced by the combination of D-galactose and Aβ_(25-35) and its mechanism. SD rats were randomly divided into a sham group, a model control group, a positive drug group(donepezil, 1 mg·kg~(-1)), an Erjing Pills high-dose group(9.0 g·kg~(-1)), and an Erjing Pills low-dose group(4.5 g·kg~(-1)), with 14 rats each group. To establish the rat model of AD, Erjing Pills were intragastrically administrated to rats for 5 weeks after 2 weeks of D-galactose injection. D-galactose was intraperitoneally injected into rats for 3 weeks, and then Aβ_(25-35) was injected into the bilateral hippocampus. The new object recognition test was used to evaluate the learning and memory ability of rats after 4 weeks of intragastric administration. Tissues were acquired 24 h after the last administration. The immunofluorescence method was used to detect the activation of microglia in the brain tissue of rats. The positive expressions of Aβ_(1-42) and phosphory protein Tau~(404)(p-Tau~(404)) in the CA1 area of the hippocampus were detected by immunohistochemistry. The levels of inflammatory factors interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), and interleukin-6(IL-6) in the brain tissue were determined by enzyme-linked immunosorbent assay(ELISA). Toll-like receptor 4(TLR4)/nuclear factor kappa B(NF-κB)/nucleotide-binding oligomerization domain-like receptors 3(NLRP3) pathway-associated proteins in the brain tissue were determined by Western blot. The results showed that as compared with the sham group, the new object recognition index of rats in the model control group decreased significantly, the deposition of Aβ_(1-42) and p-Tau~(404) positive protein in the hippocampus increased significantly, and the levels of microglia activation increased significantly in the dentate gyrus. The levels of IL-1β, TNF-α, and IL-6 in the hippocampus of the model control group increased significantly, and the expression levels of TLR4, p-NF-κB p65/NF-κB p65, p-IκBα/IκBα, and NLRP3 proteins in the hippocampus increased significantly. Compared with the model control group, the Erjing Pill groups enhanced the new object recognition index of rats, decreased the deposition of Aβ_(1-42) and the expression of p-Tau~(404) positive protein in the hippocampus, inhibited the activation of microglia in the dentate gyrus, reduced the levels of inflammatory factors IL-1β, TNF-α, and IL-6 in the hippocampus, and down-regulated the expression levels of TLR4, p-NF-κB P65/NF-κB P65, p-IκBα/IκBα, and NLRP3 proteins in the hippocampus. In conclusion, Erjing Pills can improve the learning and memory ability of the rat model of AD presumably by improving the activation of microglia, reducing the expression levels of neuroinflammatory factors IL-1β, TNF-α, and IL-6, inhibiting the TLR4/NF-κB/NLRP3 neuroinflammation pathway, and decreasing hippocampal deposition of Aβ and expression of p-Tau, thereby restoring the hippocampal morphological structure.

Anti-depression targets and mechanism study of Kaixin San / 中国中药杂志

This study identified the anti-depression targets of Kaixin San(KXS) in the brain tissue with "target fishing" strategy, and explored the target-associated pharmacological signaling pathways to reveal the anti-depression molecular mechanism of KXS. The Balb/c mouse model of depression was established by chronic unpredictable mild stress(CUMS) and the anti-depression effect of KXS was evaluated by forced swimming test and sucrose preference test. KXS active components were bonded to the benzophenone-modified magnetic nanoparticles by photocrosslinking reaction for capturing target proteins from cortex, thalamus and hippocampus of depressive mice. The target proteins were identified by liquid chromatography-mass spectrometry/mass spectrometry(LC-MS/MS). The enrichment analysis on signaling pathways was performed by Cytoscape. The potential biological functions of targets were verified by immunohistochemistry and Western blot assay. The results showed that KXS significantly improved the behavioral indexes. There were 64, 91, and 44 potential targets of KXS identified in cortex, thalamus, and hippocampus, respectively, according to the target identification experiment. The functions of these targets were mainly associated with vasopressin-regulated water reabsorption, salmonella infection, thyroid hormone synthesis, and other signaling pathways. Besides, the results of immunohistochemistry and Western blot showed that KXS up-regulated the expressions of argipressine(AVP) in the cortex, heat shock protein 60(HSP60), cytochrome C oxidase 4(COX4), and thyrotropin-releasing hormone(TRH) in the thalamus, and down-regulated the expressions of tumor necrosis factor-α(TNF-α) and nuclear factor kappa B(NF-κB) p65 in the thalamus. Therefore, KXS may exert anti-depression effect through regulating vasopressin signaling pathway in the cortex and inflammation, energy metabolism, and thyroid hormone signaling pathways in the thalamus, and the effect of KXS on hippocampus is not significant.

Role of NLRP3 inflammasome in diabetic neuropathy and prevention and treatment with traditional Chinese medicine / 中国中药杂志

As one of the most frequent complications of diabetes, diabetic neuropathy often involves peripheral and central nervous systems. Neuroinflammation is the key pathogenic factor of secondary nerve injury in diabetes. NOD-like receptor pyrin domain-containing 3(NLRP3) inflammasome is a group of subcellular multiprotein complexes, including NLRP3, apoptosis associated speck-like protein(ASC), and pro-cysteinyl aspartate specific proteinase 1(pro-caspase-1). NLRP3 inflammasome is an inducer of innate immune responses. Its activation stimulates the inflammatory cascade reaction, promotes the release of inflammatory mediators, triggers cell death and uncontrolled autophagy, activates glial cells, facilitates peripheral immune cell infiltration, and initiates amyoid β(Aβ)-tau cascade reactions. As a result, it contributes to the central nerve, somatic nerve, autonomic nerve, and retinal nerve cell damage secondary to diabetes. Therefore, due to its key role in the neuroinflammation responses of the body, NLRP3 inflammasome may provide new targets for the treatment of diabetic neuropathy. With multi-target and low-toxicity advantages, traditional Chinese medicine plays a vital role in the treatment of diabetic neuropathy. Accumulating evidence has shown that traditional Chinese medicine exerts curative effects on diabetic neuropathy possibly through regulating NLRP3 inflammasome. Although the role of NLRP3 inflammasome in diabetes and related complications has been investigated in the literature, systematical studies on drugs and mechanism analysis for secondary neuropathy are still lacking. In this article, the role of NLRP3 inflammasome in diabetic neuropathy was explored, and the research progress on traditional Chinese medicine in the treatment of diabetic neuropathy through NLRP3 inflammasome was reviewed.