Alzheimer's disease (AD) is the most common cause of dementia and is a growing public health challenge. Neuroinflammation has been proposed as a prominent pathological feature of AD and has traditionally been attributed to the innate immune system. However, emerging evidence highlights the involvement of adaptive immunity, particularly T and B lymphocytes, in the neuroinflammatory processes of AD. It remains unclear how adaptive immune responses, originally intended to protect the body, contribute to chronic inflammation and neuronal dysfunction in AD. Here, we review the roles of adaptive immunity, cellular composition, and niches and their contribution to AD development and progression. Notably, we synthesize the crosstalk between adaptive immunity and the innate immune system of the central nervous system (CNS), which is mainly mediated by glial cells and myeloid cells, and their interrelationships with amyloid-β (Aβ)/Tau pathology. We hypothesized that the alterations observed in innate immunity in AD mirror age-related immune alterations, whereas the dysregulation of adaptive immunity contributes more accurately to disease-specific immune responses. Targeting adaptive immunity in the context of neuroinflammation may provide new insights into potential therapeutic strategies designed to modulate immune responses, thereby facilitating the diagnosis, intervention, and treatment of AD.
Alzheimer Disease/metabolism* ; Humans ; Adaptive Immunity/physiology* ; Immunity, Innate/immunology* ; Animals ; Neuroinflammatory Diseases/immunology* ; Inflammation/immunology* ; Amyloid beta-Peptides/metabolism*

This study investigated the mechanism of Chaishao Kaiyu Decoction in improving hippocampal neuroinflammation in depressed rats based on complement component 3(C3)/C3 receptor(C3aR). A total of 60 SD rats were randomly divided into a blank group, a model group, high, medium, and low dose groups of Chaishao Kaiyu Decoction, and a positive drug group, with 10 rats in each group. Except for the blank group, chronic unpredictable mild stress(CUMS) was used to construct depression models in other groups. Sucrose preference, open-field experiment, forced swimming, and water maze were used to detect the changes in depression-like behavior in each group. Enzyme-linked immunosorbent assay(ELISA) was used to detect the serum inflammatory factor level in rats, and hematoxylin-eosin(HE) staining and Nissl staining were employed to observe the pathological damage of hippocampal neurons. Golgi-Cox staining was used to observe the dendritic spine damage of hippocampal neurons, and immunofluorescence and Western blot were utilized to detect the expression of microglial marker Iba-1 and C3/C3aR protein in the hippocampus of rats. The behavioral results showed that compared with the model group, Chaishao Kaiyu Decoction could significantly strengthen the sugar water preference, increase the distance and number of voluntary activities, shorten the immobility time in forced swimming and the successful incubation period of positioning navigation, and prolong the stay time of space exploration in the target quadrant. ELISA results showed that the content of inflammatory factors in the hippocampus of depressed rats was significantly higher than that of the blank group, and the content of inflammatory factors decreased significantly after the intervention of Chaishao Kaiyu Decoction. In addition, Chaishao Kaiyu Decoction could relieve pathological damage such as cell swelling and loose arrangement of hippocampus tissue. In the Western blot experiment, the expression levels of C3 and C3aR proteins in the model group were higher than those in the blank group, while the expression of C3 and C3aR in Chaishao Kaiyu Decoction could be down-regulated. Immunofluorescence results showed that compared with the model group, the fluorescence intensity of microglia marker Iba-1 decreased significantly after the intervention of Chaishao Kaiyu Decoction and positive drugs. The antidepressant effect of Chaishao Kaiyu Decoction may be related to the down-regulation of C3/C3aR signaling pathway-related proteins, thus alleviating hippocampal inflammation.
Animals ; Hippocampus/metabolism* ; Rats, Sprague-Dawley ; Drugs, Chinese Herbal/administration & dosage* ; Rats ; Male ; Depression/metabolism* ; Complement C3/metabolism* ; Receptors, Complement/metabolism* ; Humans ; Neuroinflammatory Diseases/genetics*

This study aims to investigate the effect of Congrong San(CRS) on endoplasmic reticulum stress-induced neuroinflammation in the rat model of Aβ_(1-42)-induced Alzheimer's disease(AD). Sixty male Sprague-Dawley rats(2 months old) were randomized into blank(CON), model(MOD), low-dose Congrong San(L-CRS), medium-dose Congrong San(M-CRS), high-dose Congrong San(H-CRS), and memantine hydrochloride(MJG) groups. The Morris water maze test was carried out to examine the learning and memory abilities of rats in each group. Hematoxylin-eosin staining and Nissl staining were employed to observe the morphology and number of CA1 neurons in the hippocampus of rats in each group. The morphology and structure of the endoplasmic reticulum in the hippocampus were observed by transmission electron microscopy. The immunofluorescence assay was employed to detect the expression of 78 kDa glucose-regulated protein(GRP78) in the hippocampus. Western blot was employed to determine the expression of apoptosis-associated speck-like protein containing a CARD(ASC), cysteinyl aspartate-specific proteinase(caspase-1), interleukin-18(IL-18), interleukin-1β(IL-1β), GRP78, and pathway proteins including protein kinase RNA-like endoplasmic reticulum kinase(PERK), phosphorylated PERK(p-PERK), C/EBP homologous protein(CHOP), and NOD-like receptor pyrin domain-containing protein 3(NLRP3) in the rat hippocampus. Compared with the MOD group, the M-CRS and H-CRS groups showed improved learning and memory abilities, reduced neuron losses in the hippocampus, alleviated endoplasmic reticulum stress, inhibited PERK-CHOP-NLRP3 pathway, and lowered levels of IL-1β, IL-6, and tumor necrosis factor-alpha(TNF-α). The results suggest that CRS can alleviate cognitive impairment and hippocampal neuron damage and reduce neuroinflammation in AD rats by alleviating endoplasmic reticulum stress to inhibit the activation of NLRP3 inflammasomes.
Animals ; Endoplasmic Reticulum Stress/drug effects* ; Male ; Alzheimer Disease/psychology* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Rats, Sprague-Dawley ; Rats ; Inflammasomes/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Cognitive Dysfunction/metabolism* ; Disease Models, Animal ; Hippocampus/drug effects* ; Humans ; Neuroinflammatory Diseases/drug therapy*

This study aims to explore the effects and mechanisms of 4'-O-methylbavachalcone(MeBavaC), an active compound from Psoraleae Fructus, in regulating white matter neuroinflammation to improve vascular cognitive impairment. Male Sprague-Dawley(SD) rats were randomly divided into four groups: sham group, model group, high-dose MeBavaC group(14 mg·kg~(-1)), and low-dose MeBavaC group(7 mg·kg~(-1)). The rat model of chronic cerebral hypoperfusion(CCH) was established using bilateral common carotid artery occlusion. The Morris water maze test was performed to evaluate the learning and memory abilities of the rats. Luxol fast blue staining, Nissl staining, immunofluorescence, immunohistochemistry, and transmission electron microscopy were utilized to observe the morphology and ultrastructure of the white matter myelin sheaths, axon integrity, the morphology and number of hippocampal neurons, and the loss and activation of glial cells in the white matter. Transcriptome analysis was performed to explore the potential mechanisms of white matter injury induced by CCH. Western blot and quantitative real-time polymerase chain reaction(qRT-PCR) assays were conducted to measure the expression levels of NOD-like receptor protein 3(NLRP3), absent in melanoma 2(AIM2), gasdermin D(GSDMD), cysteinyl aspartate-specific proteinase-1(caspase-1), interleukin-18(IL-18), interleukin-1β(IL-1β), erythropoietin(EPO), nuclear factor erythroid 2-related factor 2(Nrf2), and heme oxygenase-1(HO-1) in the white matter of rats. The results showed that compared with the model group, MeBavaC significantly improved the learning and memory abilities of rats with CCH, improved the damage of white matter myelin sheath, maintained axonal integrity, reduced the loss of hippocampal neurons and oligodendrocytes in the white matter, inhibited the activation of microglia and the proliferation of astrocytes in the white matter, and suppressed the NLRP3/AIM2/caspase-1/GSDMD pathway. The expression levels of inflammatory cytokines IL-1β and IL-18 were significantly reduced, while EPO expression and the expression of Nrf2/HO-1 antioxidant pathway were notably elevated. In conclusion, MeBavaC can alleviate cognitive impairment in rats with CCH and suppress neuroinflammation in cerebral white matter. The mechanism of action may involve activation of EPO activity, promotion of endogenous antioxidant pathways, and inhibition of neuroinflammation in the white matter. This study suggests that MeBavaC exhibits antioxidant and anti-neuroinflammatory effects, showing potential application in improving cognitive dysfunction.
Animals ; Male ; Rats, Sprague-Dawley ; NF-E2-Related Factor 2/immunology* ; Rats ; Chalcones/administration & dosage* ; Cognitive Dysfunction/metabolism* ; Signal Transduction/drug effects* ; Neuroinflammatory Diseases/drug therapy* ; Heme Oxygenase-1/metabolism* ; Humans ; Heme Oxygenase (Decyclizing)/genetics*

Objective To investigate the effects and underlying mechanisms of human placental chorionic plate-derived mesenchymal stem cells (hpcMSCs) on cognitive dysfunction, neuroinflammation, neuronal damage and synaptic plasticity in a mouse model of stroke. Methods A mouse model of middle cerebral artery occlusion (MCAO) was adopted. The mice were randomly divided into three groups: sham operation group, MCAO group and hpcMSCs treatment group, with seven mice in each group. The hpcMSCs treatment group received hpcMSCs transplantation on the 1st, 3rd and 10th day after MCAO. One month after MCAO, the cognitive ability of the mice was evaluated by Morris water maze and Y maze behavioral tests; the morphological changes and synaptic functions of hippocampal neurons were analyzed by HE staining, Nissl staining, Golgi staining and immunofluorescence staining techniques; the density and activation status of microglia was analyzed by Fluorescent labeling method; the levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and IL-6 in brain tissue were analyzed by ELISA; the expressions of phosphorylated-mitogen-activated protein kinase kinase 1 (p-MEK1), phosphorylated-extracellular regulated protein kinase (p-ERK) and phosphorylated-cAMP-response element binding protein (p-CREB) and other proteins related to neuroprotection in the signal pathways were detected by Western blotting; and electrophysiological detection was performed using hippocampal slices in vitro. Results Compared with the MCAO group, mice in the hpcMSCs treatment group showed significant improvements, including improved cognitive ability, alleviated neuroinflammation (demonstrated by reduced microglial activation and decreased levels of inflammatory factors TNF-α, IL-1β and IL-6), and increased neuronal density with normalized morphology of neurons in the hippocampal CA1 region. The treatment group also demonstrated a significantly increased number of Nissl-positive cells and density of dendritic spines of hippocampal neurons, along with restored frequency of miniature excitatory postsynaptic potential (mEPSP). Moreover, hpcMSCs treatment significantly increased the expression levels of p-MEK1, p-ERK and p-CREB in the hippocampus. Conclusion Transplantation of hpcMSCs ameliorates cognitive dysfunction and hippocampal neuronal injury in stroke mice through the reduction of neuroinflammation, restoration of hippocampal neuronal function, promotion of synaptic plasticity and activation of the MEK/ERK/CREB signaling pathway. These findings suggest a new potential therapeutic approach for post-stroke neural repair.
Animals ; Hippocampus/physiopathology* ; Mice ; Cognitive Dysfunction/etiology* ; Mesenchymal Stem Cell Transplantation ; Male ; Neurons/metabolism* ; Stroke/metabolism* ; Humans ; Neuroinflammatory Diseases/therapy* ; Female ; Cyclic AMP Response Element-Binding Protein/metabolism* ; Disease Models, Animal ; Mesenchymal Stem Cells/cytology* ; Mice, Inbred C57BL

Objective To explore the effects of Shuanglu Tongnao Formula on neuroinflammation in ischemic stroke (IS) rats via the P2X purinoceptor 7 receptor (P2X7R)/NLR family pyrin domain-containing 3 (NLRP3) pathway. Methods The rats were divided into five groups: the IS group, control group, Shuanglu Tongnao Formula group, P2X7R inhibitor brilliant blue G (BBG) group, and Shuanglu Tongnao Formula combined with P2X7R activator adenosine triphosphate (ATP) group, with 18 rats in each group. Except for the control group, rats in all other groups were used to construct an IS model using the suture method. After successful modeling, the drug was given once a day for 2 weeks. Neurological function scores and cerebral infarction volume ratios were measured in rats. Pathological examination of the ischemic penumbra brain tissue was performed. Immunofluorescence staining was used to quantify the proportions of microglia co-expressing both inducible nitric oxide synthase (iNOS) and ionized calcium-binding adapter molecule 1 (Iba1), as well as arginase 1 (Arg1) and Iba1, in the ischemic penumbra brain tissue. ELISA was used to detect tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta (TGF-β), interleukin 6 (IL-6) and IL-10 in the ischemic penumbra brain tissue. Western blotting was used to measure P2X7R, NLRP3, and IL-1β proteins in the ischemic penumbra brain tissue. Results Compared with the control group, the IS group showed disordered neuronal arrangement, nuclear condensation, and obvious infiltration of inflammatory cells in the ischemic penumbra; significantly elevated neurological function scores, cerebral infarction volume ratios, proportions of microglia co-expressing iNOS and Iba1, and levels of TNF-α, IL-6, and P2X7R, NLRP3, IL-1β proteins; along with reduced proportions of microglia co-expressing Arg1 and Iba1 and levels of TGF-β and IL-10. Compared with the IS group, the Zhuang medicine Shuanglu Tongnao Formula and BBG groups demonstrated alleviated brain tissue damage; reduced neurological function scores, cerebral infarction volume ratios, proportions of microglia co-expressing iNOS and Iba1, and levels of TNF-α, IL-6, and P2X7R, NLRP3, IL-1β proteins; along with increased proportions of microglia co-expressing Arg1 and Iba1 and levels of TGF-β and IL-10. ATP reversed the effects of Zhuang medicine Shuanglu Tongnao Formula on microglial polarization and neuroinflammation in IS rats. Conclusion Zhuang medicine Shuanglu Tongnao Formula may promote the transformation of microglia from M1 type to M2 type by inhibiting the P2X7R/NLRP3 pathway, thereby improving neuroinflammation in IS rats.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Receptors, Purinergic P2X7/metabolism* ; Male ; Drugs, Chinese Herbal/pharmacology* ; Rats ; Ischemic Stroke/pathology* ; Rats, Sprague-Dawley ; Disease Models, Animal ; Signal Transduction/drug effects* ; Neuroinflammatory Diseases/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Nitric Oxide Synthase Type II/metabolism* ; Interleukin-10/metabolism* ; Brain Ischemia/drug therapy* ; Microglia/metabolism*

Neuroinflammatory responses play an important role in the pathogenesis of various diseases, particularly those affecting the central nervous system. Inhibition of neuroinflammation is a crucial therapeutic strategy for the management of central nervous system disorders. The intestinal microbial-gut-brain axis serves as a key regulatory pathway that modulates neuroinflammatory processes. Intestinal flora metabolites such as short-chain fatty acids, indoles and their derivatives, lipopolysaccharides, trimethylamine oxide, and secondary bile acids exert direct or indirect effects on neuroinflammation. Studies have shown that electroacupuncture (EA) modulates the composition of the intestinal microbiota and its metabolites, while also suppressing neuroinflammation by targeting the TLR4/NF- κ B, NLRP3/caspase-1, and microglial cell M2-type transformation pathways. This review discusses the mechanisms by which EA regulates neuroinflammation via intestinal microbiota and its metabolites, providing information and a foundation for further investigation of the precise therapeutic mechanisms of EA in neurological disorders.
Humans ; Gastrointestinal Microbiome ; Electroacupuncture ; Neuroinflammatory Diseases/metabolism* ; Animals

OBJECTIVE: To illustrate the role of dehydrocorydaline (DHC) in chronic constriction injury (CCI)-induced neuropathic pain and the underlying mechanism. METHODS: C57BL/6J mice were randomly divided into 3 groups by using a random number table, including sham group (sham operation), CCI group [intrathecal injection of 10% dimethyl sulfoxide (DMSO)], and CCI+DHC group (intrathecal injection of DHC), 8 mice in each group. A CCI mouse model was conducted to induce neuropathic pain through ligating the right common sciatic nerve. On day 14 after CCI modeling or sham operation, mice were intrathecal injected with 5 µL of 10% DMSO or 10 mg/kg DHC (5 µL) into the 5th to 6th lumbar intervertebral space (L5-L6). Pregnant ICR mice were sacrificed for isolating primary spinal neurons on day 14 of embryo development for in vitro experiment. Pain behaviors were evaluated by measuring the paw withdrawal mechanical threshold (PWMT) of mice. Immunofluorescence was used to observe the activation of astrocytes and microglia in mouse spinal cord. Protein expressions of inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), phosphorylation of N-methyl-D-aspartate receptor subunit 2B (p-NR2B), and NR2B in the spinal cord or primary spinal neurons were detected by Western blot. RESULTS: In CCI-induced neuropathic pain model, mice presented significantly decreased PWMT, activation of glial cells, overexpressions of iNOS, TNF-α, IL-6, and higher p-NR2B/NR2B ratio in the spinal cord (P<0.05 or P<0.01), which were all reversed by a single intrathecal injection of DHC (P<0.05 or P<0.01). The p-NR2B/NR2B ratio in primary spinal neurons were also inhibited after DHC treatment (P<0.05). CONCLUSION An intrathecal injection of DHC relieved CCI-induced neuropathic pain in mice by inhibiting the neuroinflammation and neuron hyperactivity.
Animals ; Neuralgia/etiology* ; Mice, Inbred C57BL ; Analgesics/pharmacology* ; Neuroinflammatory Diseases/pathology* ; Constriction ; Male ; Receptors, N-Methyl-D-Aspartate/metabolism* ; Nitric Oxide Synthase Type II/metabolism* ; Mice, Inbred ICR ; Microglia/pathology* ; Spinal Cord/drug effects* ; Female ; Mice ; Tumor Necrosis Factor-alpha/metabolism* ; Disease Models, Animal ; Constriction, Pathologic/complications* ; Interleukin-6/metabolism* ; Astrocytes/metabolism* ; Chronic Disease ; Neurons/metabolism*

Epilepsy affects over 50 million people worldwide. Drug-resistant epilepsy (DRE) accounts for up to a third of these cases, and neuro-inflammation is thought to play a role in such cases. Despite being a long-debated issue in the field of DRE, the mechanisms underlying neuroinflammation have yet to be fully elucidated. The pro-inflammatory microenvironment within the brain tissue of people with DRE has been probed using single-cell multimodal transcriptomics. Evidence suggests that inflammatory cells and pro-inflammatory cytokines in the nervous system can lead to extensive biochemical changes, such as connexin hemichannel excitability and disruption of neurotransmitter homeostasis. The presence of inflammation may give rise to neuronal network abnormalities that suppress endogenous antiepileptic systems. We focus on the role of neuroinflammation and brain network anomalies in DRE from multiple perspectives to identify critical points for clinical application. We hope to provide an insightful overview to advance the quest for better DRE treatments.
Humans ; Drug Resistant Epilepsy/metabolism* ; Neuroinflammatory Diseases/immunology* ; Animals ; Brain/pathology* ; Nerve Net/pathology*

The nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome plays a crucial role in the prognosis of subarachnoid hemorrhage (SAH). WNK1 kinase negatively regulates NLRP3 in various inflammatory conditions, but its role in early brain injury (EBI) after SAH remains unclear. In this study, we used an in vivo SAH model in rats/mice and AAV-WNK1 intraventricular injection to investigate its neuroprotective mechanisms. WNK1 expression was significantly reduced in SAH patient blood and SAH model brain tissue, correlating negatively with microglial activation. AAV-WNK1 alleviated brain edema, neuronal necrosis, behavioral deficits, and inflammation by inhibiting NLRP3 inflammasome activation. In hemin-stimulated BV-2 cells, WNK1 overexpression reduced NLRP3 activation and inflammatory cytokines. Chloride counteracted WNK1's inhibitory effects, and WNK1 suppressed P2X7R-induced NLRP3 activation. Mechanistically, WNK1 functioned via the OXSR1/STK39 pathway. These findings highlight WNK1 as a key regulator of intracellular chloride balance and neuroinflammation, presenting a potential therapeutic target for SAH treatment.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Subarachnoid Hemorrhage/complications* ; Inflammasomes/metabolism* ; Rats ; Mice ; Neuroinflammatory Diseases/metabolism* ; WNK Lysine-Deficient Protein Kinase 1/genetics* ; Male ; Humans ; Chlorides/metabolism* ; Mice, Inbred C57BL ; Rats, Sprague-Dawley ; Brain Injuries/metabolism* ; Microglia/metabolism* ; Protein Serine-Threonine Kinases