The ins and outs of microglial cells in brain health and disease.

Microglia are the brain's resident macrophages that play pivotal roles in immune surveillance and maintaining homeostasis of the Central Nervous System (CNS). Microglia are functionally implicated in various cerebrovascular diseases, including stroke, aneurysm, and tumorigenesis as they regulate neuroinflammatory responses and tissue repair processes. Here, we review the manifold functions of microglia in the brain under physiological and pathological conditions, primarily focusing on the implication of microglia in glioma propagation and progression. We further review the current status of therapies targeting microglial cells, including their re-education, depletion, and re-population approaches as therapeutic options to improve patient outcomes for various neurological and neuroinflammatory disorders, including cancer.

Central Retinal Artery Occlusion in Rhino-Orbital-Cerebral Mucormycosis: An Inflammatory-Prothrombotic State.

PURPOSE: The aim was to evaluate patient profiles of rhino-orbital-cerebral mucormycosis (ROCM) cases with central retinal artery occlusion (CRAO) postcoronavirus disease 2019. DESIGN: A nonrandomized retrospective case-control study. METHODS: The ROCM cases presenting with CRAO were compared with a control ROCM group without CRAO at a tertiary care center. Demography, systemic status, clinical features, histopathology, imaging, and blood profile were assessed for any specific risk factors. RESULTS: A total of 12 patients were seen in the CRAO group and 16 in the non-CRAO group. The male-to-female ratio was 3:1 with a mean age of 49.5 years. In the CRAO group, 75% had diabetes mellitus with mean hemoglobin A1c of 9.03%, and 66.7% had received steroid treatment. All cases were histopathologically confirmed positive for mucor. There was a significant difference in mean D-dimer and serum ferritin between the 2 groups, with higher level in the CRAO group. All patients with CRAO had light perception-negative vision, with total ophthalmoplegia and proptosis seen in 66.7% of cases. Four patients had orbital apex involvement, 5 had cavernous sinus involvement, and 8 had intracranial involvement in the CRAO group. CONCLUSIONS: Inflammatory markers D-dimer and serum ferritin were significantly associated with CRAO, suggestive of hyperinflammatory and hypercoagulable state. A high index of suspicion should be maintained in cases with elevated markers and prophylactic anticoagulants can be started to prevent CRAO in a subset of patients.

A unique cerebellar pattern of microglia activation in a mouse model of encephalopathy of prematurity.

Preterm infants often show pathologies of the cerebellum, which are associated with impaired motor performance, lower IQ and poor language skills at school ages. Using a mouse model of inflammation-induced encephalopathy of prematurity driven by systemic administration of pro-inflammatory IL-1ß, we sought to uncover causes of cerebellar damage. In this model, IL-1ß is administered between postnatal day (P) 1 to day 5, a timing equivalent to the last trimester for brain development in humans. Structural MRI analysis revealed that systemic IL-1ß treatment induced specific reductions in gray and white matter volumes of the mouse cerebellar lobules I and II (5% false discovery rate [FDR]) from P15 onwards. Preceding these MRI-detectable cerebellar volume changes, we observed damage to oligodendroglia, with reduced proliferation of OLIG2+ cells at P10 and reduced levels of the myelin proteins myelin basic protein (MBP) and myelin-associated glycoprotein (MAG) at P10 and P15. Increased density of IBA1+ cerebellar microglia were observed both at P5 and P45, with evidence for increased microglial proliferation at P5 and P10. Comparison of the transcriptome of microglia isolated from P5 cerebellums and cerebrums revealed significant enrichment of pro-inflammatory markers in microglia from both regions, but cerebellar microglia displayed a unique type I interferon signaling dysregulation. Collectively, these data suggest that perinatal inflammation driven by systemic IL-1ß leads to specific cerebellar volume deficits, which likely reflect oligodendrocyte pathology downstream of microglial activation. Further studies are now required to confirm the potential of protective strategies aimed at preventing sustained type I interferon signaling driven by cerebellar microglia as an important therapeutic target.

Tylvalosin demonstrates anti-parasitic activity and protects mice from acute toxoplasmosis.

AIMS: Toxoplasmosis, caused by Toxoplasma gondii (Tg), is one of the most prevalent zoonotic diseases worldwide. Currently, safe and efficient therapeutic options for this disease are still being developed, and are urgently needed. Tylvalosin (Tyl), a broad-spectrum third-generation macrolide, exhibits anti-bacterial, anti-viral, and anti-inflammatory properties. The present study aims to explore the anti-parasitic and immunomodulation activities of Tyl against Tg, and the underlying mechanism. MAIN METHODS: Adhesion, invasion, replication, proliferation, plaque, reversibility, immunofluorescence assays and transmission electron microscopy were utilized to determine the anti-Toxoplasma effect of Tyl. With acute toxoplasmosis model and rabies virus-induced brain inflammation model, the anti-toxoplasmosis and immunomodulation activities of Tyl were assessed by colorimetric assay, histopathological and Oil red O staining, and real-time quantitative PCR. The involved molecular mechanisms were investigated by western blotting and immunohistochemical staining. KEY FINDINGS: Tyl (5 and 10 µg/ml) can inhibit Tg propagation, and damage its ultrastructure irreversibly. The combination of Tyl and Pyrimethamine (Pyr) exhibits a better synergistic effect. Tyl (50 and 100 mg/kg) treatment intraperitoneally can delay mice death and improve survival rate, accompanying the reduced histopathological score and parasite load in the indicated tissues, espically for ileum, liver, spleen, lung and brain. Furthermore, Tg can modulate host phospho-p38 MAPK (pp38), subtilisin/kexin-isozyme-1 (SKI-1)-sterol regulatory element binding protein-1 (SREBP-1) (SKI-1-SREBP-1) pathway and peroxisome proliferators-activated receptor δ (PPARδ), while Tyl is able to reverse these signal pathways close to normal levels. SIGNIFICANCE: Our findings indicate that Tyl exhibits anti-Toxoplasma activity and protects mice from acute toxoplasmosis.

The blood-brain barrier in systemic infection and inflammation.

The vascular blood-brain barrier is a highly regulated interface between the blood and brain. Its primary function is to protect central neurons while signaling the presence of systemic inflammation and infection to the brain to enable a protective sickness behavior response. With increasing degrees and duration of systemic inflammation, the vascular blood-brain barrier becomes more permeable to solutes, undergoes an increase in lymphocyte trafficking, and is infiltrated by innate immune cells; endothelial cell damage may occasionally occur. Perturbation of neuronal function results in the clinical features of encephalopathy. Here, the molecular and cellular anatomy of the vascular blood-brain barrier is reviewed, first in a healthy context and second in a systemic inflammatory context. Distinct from the molecular and cellular mediators of the blood-brain barrier's response to inflammation, several moderators influence the direction and magnitude at genetic, system, cellular and molecular levels. These include sex, genetic background, age, pre-existing brain pathology, systemic comorbidity, and gut dysbiosis. Further progress is required to define and measure mediators and moderators of the blood-brain barrier's response to systemic inflammation in order to explain the heterogeneity observed in animal and human studies.

Microglia and Perivascular Macrophages Act as Antigen Presenting Cells to Promote CD8 T Cell Infiltration of the Brain.

CD8 T cell infiltration of the central nervous system (CNS) is necessary for host protection but contributes to neuropathology. Antigen presenting cells (APCs) situated at CNS borders are thought to mediate T cell entry into the parenchyma during neuroinflammation. The identity of the CNS-resident APC that presents antigen via major histocompatibility complex (MHC) class I to CD8 T cells is unknown. Herein, we characterize MHC class I expression in the naïve and virally infected brain and identify microglia and macrophages (CNS-myeloid cells) as APCs that upregulate H-2Kb and H-2Db upon infection. Conditional ablation of H-2Kb and H-2Db from CNS-myeloid cells allowed us to determine that antigen presentation via H-2Db, but not H-2Kb, was required for CNS immune infiltration during Theiler's murine encephalomyelitis virus (TMEV) infection and drives brain atrophy as a consequence of infection. These results demonstrate that CNS-myeloid cells are key APCs mediating CD8 T cell brain infiltration.

Phosphorylated TAR DNA-binding protein-43: Aggregation and antibody-based inhibition.

TAR DNA-binding protein-43 (TDP-43) pathology, including fibrillar aggregates and mutations, develops in amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD) and limbic-predominant age-related TDP-43 encephalopathy (LATE). Hyperphosphorylation and aggregation of TDP-43 contribute to pathology and are viable therapeutic targets for ALS. In vivo inhibition of TDP-43 aggregation was evaluated using anti-TDP-43 antibodies with promising outcomes. However, the exact mechanism of antibody-based inhibition targeting TDP-43 is not well understood but may lead to the identification of viable immunotherapies. Herein, the mechanism of in vitro aggregation of phosphorylated TDP-43 was explored, and the anti-TDP-43 antibodies tested for their inhibitor efficacies. Specifically, the aggregation of phosphorylated full-length TDP-43 protein (pS410) was monitored by transmission electron microscopy (TEM), turbidity absorbance, and thioflavin (ThT) spectroscopy. The protein aggregates were insoluble, ThT-positive and characterized with heterogeneous morphologies (fibers, amorphous structures). Antibodies specific to epitopes 178-393 and 256-269, within the RRM2-CTD domain, reduced the formation of ß-sheets and insoluble aggregates, at low antibody loading (antibody: protein ratio = 1 µg/mL: 45 µg/mL). Inhibition outcomes were highly dependent on the type and loading of antibodies, indicating dual functionality of such inhibitors, as aggregation inhibitors or aggregation promoters. Anti-SOD1 and anti-tau antibodies were not effective inhibitors against TDP-43 aggregation, indicating selective inhibition.

NOD1 in the interplay between microbiota and gastrointestinal immune adaptations.

Nucleotide-binding oligomerization domain 1 (NOD1), a pattern recognition receptor (PRR) that detects bacterial peptidoglycan fragments and other danger signals, has been linked to inflammatory pathologies. NOD1, which is expressed by immune and non-immune cells, is activated after recognizing microbe-associated molecular patterns (MAMPs). This recognition triggers host defense responses and both immune memory and tolerance can also be achieved during these processes. Since the gut microbiota is currently considered a master regulator of human physiology central in health and disease and the intestine metabolizes a wide range of nutrients, drugs and hormones, it is a fact that dysbiosis can alter tissues and organs homeostasis. These systemic alterations occur in response to gastrointestinal immune adaptations that are not yet fully understood. Even if previous evidence confirms the connection between the microbiota, the immune system and metabolic disorders, much remains to be discovered about the contribution of NOD1 to low-grade inflammatory pathologies such as obesity, diabetes and cardiovascular diseases. This review compiles the most recent findings in this area, while providing a dynamic and practical framework with future approaches for research and clinical applications on targeting NOD1. This knowledge can help to rate the consequences of the disease and to stratify the patients for therapeutic interventions.

Infectious disease-associated encephalopathies.

Infectious diseases may affect brain function and cause encephalopathy even when the pathogen does not directly infect the central nervous system, known as infectious disease-associated encephalopathy. The systemic inflammatory process may result in neuroinflammation, with glial cell activation and increased levels of cytokines, reduced neurotrophic factors, blood-brain barrier dysfunction, neurotransmitter metabolism imbalances, and neurotoxicity, and behavioral and cognitive impairments often occur in the late course. Even though infectious disease-associated encephalopathies may cause devastating neurologic and cognitive deficits, the concept of infectious disease-associated encephalopathies is still under-investigated; knowledge of the underlying mechanisms, which may be distinct from those of encephalopathies of non-infectious cause, is still limited. In this review, we focus on the pathophysiology of encephalopathies associated with peripheral (sepsis, malaria, influenza, and COVID-19), emerging therapeutic strategies, and the role of neuroinflammation.

Encephalopathies Associated With Severe COVID-19 Present Neurovascular Unit Alterations Without Evidence for Strong Neuroinflammation.

OBJECTIVE: Coronavirus disease (COVID-19) has been associated with a large variety of neurologic disorders. However, the mechanisms underlying these neurologic complications remain elusive. In this study, we aimed at determining whether neurologic symptoms were caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) direct infection or by either systemic or local proinflammatory mediators. METHODS: In this cross-sectional study, we checked for SARS-CoV-2 RNA by quantitative reverse transcription PCR, SARS-CoV-2-specific antibodies, and 49 cytokines/chemokines/growth factors (by Luminex) in the CSF +/- sera of a cohort of 22 COVID-19 patients with neurologic presentation and 55 neurologic control patients (inflammatory neurologic disorder [IND], noninflammatory neurologic disorder, and MS). RESULTS: We detected anti-SARS-CoV-2 immunoglobulin G in patients with severe COVID-19 with signs of intrathecal synthesis for some of them. Of the 4 categories of tested patients, the CSF of IND exhibited the highest level of cytokines, chemokines, and growth factors. By contrast, patients with COVID-19 did not present overall upregulation of inflammatory mediators in the CSF. However, patients with severe COVID-19 (intensive care unit patients) exhibited higher concentrations of CCL2, CXCL8, and vascular endothelium growth factor A (VEGF-A) in the CSF than patients with a milder form of COVID-19. In addition, we could show that intrathecal CXCL8 synthesis was linked to an elevated albumin ratio and correlated with the increase of peripheral inflammation (serum hepatocyte growth factor [HGF] and CXCL10). CONCLUSIONS: Our results do not indicate active replication of SARS-CoV-2 in the CSF or signs of massive inflammation in the CSF compartment but highlight a specific impairment of the neurovascular unit linked to intrathecal production of CXCL8.

Altered distributions and functions of natural killer T cells and γδ T cells in neonates with neonatal encephalopathy, in school-age children at follow-up, and in children with cerebral palsy.

We enumerated conventional and innate lymphocyte populations in neonates with neonatal encephalopathy (NE), school-age children post-NE, children with cerebral palsy and age-matched controls. Using flow cytometry, we demonstrate alterations in circulating T, B and natural killer cell numbers. Invariant natural killer T cell and Vδ2+ γδ T cell numbers and frequencies were strikingly higher in neonates with NE, children post-NE and children with cerebral palsy compared to age-matched controls, whereas mucosal-associated invariant T cells and Vδ1 T cells were depleted from children with cerebral palsy. Upon stimulation ex vivo, T cells, natural killer cells and Vδ2 T cells from neonates with NE more readily produced inflammatory cytokines than their counterparts from healthy neonates, suggesting that they were previously primed or activated. Thus, innate and conventional lymphocytes are numerically and functionally altered in neonates with NE and these changes may persist into school-age.

Rhinocerebral mucormycosis secondary to severe acute pancreatitis and diabetic ketoacidosis: a case report.

INTRODUCTION: Rhinocerebral mucormycosis is a rare and severe form of opportunistic fungal infection that can develop rapidly and cause significant mortality, particularly among diabetic patients suffering from ketoacidosis. Diagnosing rhinocerebral mucormycosis during the early stages of infection is challenging. CASE PRESENTATION: We describe a case of rhinocerebral mucormycosis secondary to severe acute pancreatitis in a patient suffering from diabetic ketoacidosis. In this case, the condition was not diagnosed during the optimal treatment window. we therefore provide a thorough overview of related clinical findings and histopathological characteristics, and we discuss potential differential diagnoses. CONCLUSIONS: In summary, we described a case of rhinocerebral mucormycosis secondary to severe acute pancreatitis in a patient suffering from diabetic ketoacidosis, with the optimal treatment window for this condition having been missed. This report suggests that a definitive mucormycosis diagnosis can be made based upon tissue biopsy that reveals the presence of characteristic hyphae. Early diagnosis and treatment are essential in order to improve patient prognosis.

Altered inflammasome activation in neonatal encephalopathy persists in childhood.

Neonatal encephalopathy (NE) is characterized by altered neurological function in term infants and inflammation plays an important pathophysiological role. Inflammatory cytokines interleukin (IL)-1ß, IL-1ra and IL-18 are activated by the nucleotide-binding and oligomerization domain (NOD)-, leucine-rich repeat domain (LRR)- and NOD-like receptor protein 3 (NLRP3) inflammasome; furthermore, we aimed to examine the role of the inflammasome multiprotein complex involved in proinflammatory responses from the newborn period to childhood in NE. Cytokine concentrations were measured by multiplex enzyme-linked immunosorbent assay (ELISA) in neonates and children with NE in the absence or presence of lipopolysaccharide (LPS) endotoxin. We then investigated expression of the NLRP3 inflammasome genes, NLRP3, IL-1ß and ASC by polymerase chain reaction (PCR). Serum samples from 40 NE patients at days 1 and 3 of the first week of life and in 37 patients at age 4-7 years were analysed. An increase in serum IL-1ra and IL-18 in neonates with NE on days 1 and 3 was observed compared to neonatal controls. IL-1ra in NE was decreased to normal levels at school age, whereas serum IL-18 in NE was even higher at school age compared to school age controls and NE in the first week of life. Percentage of LPS response was higher in newborns compared to school-age NE. NLRP3 and IL-1ß gene expression were up-regulated in the presence of LPS in NE neonates and NLRP3 gene expression remained up-regulated at school age in NE patients compared to controls. Increased inflammasome activation in the first day of life in NE persists in childhood, and may increase the window for therapeutic intervention.

Human Herpesvirus-6 and -7 in the Brain Microenvironment of Persons with Neurological Pathology and Healthy People.

During persistent human beta-herpesvirus (HHV) infection, clinical manifestations may not appear. However, the lifelong influence of HHV is often associated with pathological changes in the central nervous system. Herein, we evaluated possible associations between immunoexpression of HHV-6, -7, and cellular immune response across different brain regions. The study aimed to explore HHV-6, -7 infection within the cortical lobes in cases of unspecified encephalopathy (UEP) and nonpathological conditions. We confirmed the presence of viral DNA by nPCR and viral antigens by immunohistochemistry. Overall, we have shown a significant increase (p < 0.001) of HHV antigen expression, especially HHV-7 in the temporal gray matter. Although HHV-infected neurons were found notably in the case of HHV-7, our observations suggest that higher (p < 0.001) cell tropism is associated with glial and endothelial cells in both UEP group and controls. HHV-6, predominantly detected in oligodendrocytes (p < 0.001), and HHV-7, predominantly detected in both astrocytes and oligodendrocytes (p < 0.001), exhibit varying effects on neural homeostasis. This indicates a high number (p < 0.001) of activated microglia observed in the temporal lobe in the UEP group. The question remains of whether human HHV contributes to neurological diseases or are markers for some aspect of the disease process.

Understanding the heart-brain axis response in COVID-19 patients: A suggestive perspective for therapeutic development.

In-depth characterization of heart-brain communication in critically ill patients with severe acute respiratory failure is attracting significant interest in the COronaVIrus Disease 19 (COVID-19) pandemic era during intensive care unit (ICU) stay and after ICU or hospital discharge. Emerging research has provided new insights into pathogenic role of the deregulation of the heart-brain axis (HBA), a bidirectional flow of information, in leading to severe multiorgan disease syndrome (MODS) in patients with confirmed infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Noteworthy, HBA dysfunction may worsen the outcome of the COVID-19 patients. In this review, we discuss the critical role HBA plays in both promoting and limiting MODS in COVID-19. We also highlight the role of HBA as new target for novel therapeutic strategies in COVID-19 in order to open new translational frontiers of care. This is a translational perspective from the Italian Society of Cardiovascular Researches.

Intravenous methadone causes acute toxic and delayed inflammatory encephalopathy with persistent neurocognitive impairments.

BACKGROUND: The mu-opioid agonist methadone is administered orally and used in opioid detoxification and in the treatment of moderate-to-severe pain. Acute oral methadone-use and -abuse have been associated with inflammatory and toxic central nervous system (CNS) damage in some cases and cognitive deficits can develop in long-term methadone users. In contrast, reports of intravenous methadone adverse effects are rare. CASE PRESENTATION: Here, we report a patient who developed acute bilateral hearing loss, ataxia and paraparesis subsequently to intravenous methadone-abuse. While the patient gradually recovered from these deficits, widespread magnetic resonance imaging changes progressed and delayed-onset encephalopathy with signs of cortical dysfunction persisted. This was associated with changes in the composition of monocyte and natural killer cell subsets in the cerebrospinal fluid. CONCLUSION: This case suggests a potential bi-phasic primary toxic and secondary inflammatory CNS damage induced by intravenous methadone.

Clinical, cerebrospinal fluid, and neuroimaging findings in COVID-19 encephalopathy: a case series.

OBJECTIVE: To describe the clinical, neurological, neuroimaging, and cerebrospinal fluid (CSF) findings associated with encephalopathy in patients admitted to a COVID-19 tertiary reference center. METHODS: We retrospectively reviewed records of consecutive patients with COVID-19 evaluated by a consulting neurology team from March 30, 2020 through May 15, 2020. RESULTS: Fifty-five patients with confirmed SARS-CoV-2 were included, 43 of whom showed encephalopathy, and were further divided into mild, moderate, and severe encephalopathy groups. Nineteen patients (44%) had undergone mechanical ventilation and received intravenous sedatives. Eleven (26%) patients were on dialysis. Laboratory markers of COVID-19 severity were very common in encephalopathy patients, but did not correlate with the severity of encephalopathy. Thirty-nine patients underwent neuroimaging studies, which showed mostly non-specific changes. One patient showed lesions possibly related to CNS demyelination. Four had suffered an acute stroke. SARS-CoV-2 was detected by RT-PCR in only one of 21 CSF samples. Two CSF samples showed elevated white blood cell count and all were negative for oligoclonal bands. In our case series, the severity of encephalopathy correlated with higher probability of death during hospitalization (OR = 5.5 for each increment in the degree of encephalopathy, from absent (0) to mild (1), moderate (2), or severe (3), p < 0.001). CONCLUSION: In our consecutive series with 43 encephalopathy cases, neuroimaging and CSF analysis did not support the role of direct viral CNS invasion or CNS inflammation as the cause of encephalopathy.

Intracranial Mass Lesions in Human Immunodeficiency Virus Patients in the Philippines: A Retrospective Cohort Study.

BACKGROUND: Central nervous system involvement is commonly seen in patients with human immunodeficiency virus (HIV) infection, with up to 2%-10% of patients presenting with intracranial mass lesions. The management of these lesions depends largely on their etiology and their relative frequency in the local population. METHODS: We performed a retrospective chart review of patients with HIV and evidence of intracranial mass lesions on cranial magnetic resonance imaging or computed tomography from 2007 to 2018. Demographic data, clinical features, etiology, surgical management, and outcomes were collected. RESULTS: The prevalence of intracranial mass lesions in our cohort was 2.2% (45/2032). Patients were predominantly male (98%), with a mean age at diagnosis of 28 years. The most common clinical manifestations were headache (75%), focal weakness (49%), and seizures (32%). The most common diagnoses were toxoplasmic encephalitis (51%) and tuberculosis (24%). Biopsy or excision was performed in 10% of cases, leading to a definitive diagnosis in 60% of these cases. A favorable outcome was observed in 58% of all patients at 46 months median follow-up, with adequate disease-specific treatment. CONCLUSIONS: The prevalence of intracranial mass lesions in Filipino patients with HIV is 2.2%. The most common etiology was toxoplasmic encephalitis followed by tuberculosis. These findings are substantially different from other findings reported in the literature and should be considered in formulating guidelines for the Filipino population.

Ion channels and transporters in microglial function in physiology and brain diseases.

Microglial cells interact with all components of the central nervous system (CNS) and are increasingly recognized to play essential roles during brain development, homeostasis and disease pathologies. Functions of microglia include maintaining tissue integrity, clearing cellular debris and dead neurons through the process of phagocytosis, and providing tissue repair by releasing anti-inflammatory cytokines and neurotrophic factors. Changes of microglial ionic homeostasis (Na+, Ca2+, K+, H+, Cl-) are important for microglial activation, including proliferation, migration, cytokine release and reactive oxygen species production, etc. These are mediated by ion channels and ion transporters in microglial cells. Here, we review the current knowledge about the role of major microglial ion channels and transporters, including several types of Ca2+ channels (store-operated Ca2+ entry (SOCE) channels, transient receptor potential (TRP) channels and voltage-gated Ca2+ channels (VGCCs)) and Na+ channels (voltage-gated Na+ channels (Nav) and acid-sensing ion channels (ASICs)), K+ channels (inward rectifier K+ channels (Kir), voltage-gated K+ channels (KV) and calcium-activated K+ channels (KCa)), proton channels (voltage-gated proton channel (Hv1)), and Cl- channels (volume (or swelling)-regulated Cl- channels (VRCCs) and chloride intracellular channels (CLICs)). In addition, ion transporter proteins such as Na+/Ca2+ exchanger (NCX), Na+-K+-Cl- cotransporter (NKCC1), and Na+/H+ exchanger (NHE1) are also involved in microglial function in physiology and brain diseases. We discussed microglial activation and neuroinflammation in relation to the ion channel/transporter stimulation under brain disease conditions and therapeutic aspects of targeting microglial ion channels/transporters for neurodegenerative disease, ischemic stroke, traumatic brain injury and neuropathic pain.