Berberine (BBR), a small molecule protoberberine isoquinoline alkaloid, is easy to cross the blood-brain barrier and is a potential drug for neurodegenerative diseases. Here, we explored the role and molecular mechanism of BBR in Alzheimer's disease (AD) progression. Weighted gene co-expression network analysis (WGCNA) was conducted to determine AD pathology-associated gene modules and differentially expressed genes (DEGs) were also identified. GO and KEGG analyses were performed for gene function and signaling pathway annotation. Cell counting kit-8 (CCK8) assay was applied to analyze cell viability. Immunofluorescence (IF) staining assay was conducted to measure the levels of polarization markers. The production of inflammatory cytokines was analyzed by enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) level and mitochondrial membrane potential (MMP) were detected using a ROS detection kit and a MMP Detection Kit (JC-1), respectively. AD pathology-associated DEGs were applied for GO function annotation and KEGG enrichment analysis, and the results uncovered that AD pathology was related to immune and inflammation. Lipopolysaccharide (LPS) exposure induced the M1 phenotype of microglia, and BBR suppressed LPS-induced M1 polarization and induced microglia toward M2 polarization. Through co-culture of microglia and neuronal cells, we found that BBR exerted a neuro-protective role by attenuating the injury of LPS-induced HMC3 on SH-SY5Y cells. Mechanically, BBR switched the M1/M2 phenotypes of microglia by activating PI3K-AKT signaling. In summary, BBR protected neuronal cells from activated microglia-mediated neuro-inflammation by switching the M1/M2 polarization in LPS-induced microglia via activating PI3K-AKT signaling. Key words Alzheimer's Disease, Berberine, Microglia polarization, Neuroinflammation, PI3K-AKT signaling.
- MeSH
- Alzheimerova nemoc * metabolismus farmakoterapie patologie MeSH
- berberin * farmakologie terapeutické užití MeSH
- fosfatidylinositol-3-kinasy * metabolismus MeSH
- lidé MeSH
- mikroglie * účinky léků metabolismus MeSH
- myši MeSH
- neuroprotektivní látky * farmakologie MeSH
- polarita buněk účinky léků MeSH
- protoonkogenní proteiny c-akt * metabolismus MeSH
- signální transdukce * účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Tick-borne encephalitis virus (TBEV) is a neurotropic orthoflavivirus responsible for severe infections of the central nervous system. Although neurons are predominantly targeted, specific involvement of microglia in pathogenesis of TBE is not yet fully understood. In this study, the susceptibility of human microglia to TBEV is investigated, focusing on productive infection and different immune responses of different viral strains. We investigated primary human microglia and two immortalized microglial cell lines exposed to three TBEV strains (Hypr, Neudörfl and 280), each differing in virulence. Our results show that all microglia cultures tested support long-term productive infections, regardless of the viral strain. In particular, immune response varied significantly with the viral strain, as shown by the differential secretion of cytokines and chemokines such as IP-10, MCP-1, IL-8 and IL-6, quantified using a Luminex 48-plex assay. The most virulent strain triggered the highest cytokine induction. Electron tomography revealed substantial ultrastructural changes in the infected microglia, despite the absence of cytopathic effects. These findings underscore the susceptibility of human microglia to TBEV and reveal strain-dependent variations in viral replication and immune responses, highlighting the complex role of microglia in TBEV-induced neuropathology and contribute to a deeper understanding of TBE pathogenesis and neuroinflammation.
- MeSH
- buněčné linie MeSH
- cytokiny * metabolismus MeSH
- klíšťová encefalitida * virologie patologie imunologie MeSH
- kultivované buňky MeSH
- lidé MeSH
- mikroglie * virologie imunologie patologie MeSH
- neurozánětlivé nemoci virologie patologie imunologie MeSH
- replikace viru MeSH
- viry klíšťové encefalitidy * patogenita fyziologie imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- alkoholismus * imunologie komplikace patofyziologie MeSH
- enterocyty patologie MeSH
- lidé MeSH
- mikroglie patologie MeSH
- neurotransmiterové látky MeSH
- osa mozek-střevo * fyziologie imunologie MeSH
- poruchy nervového systému vyvolané alkoholem MeSH
- střevní mikroflóra imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Netrin-1 (NTN-1) plays a vital role in the progress of nervous system development and inflammatory diseases. However, the role and underlying mechanism of NTN-1 in inflammatory pain (IP) are unclear. BV2 microglia were treated with LPS to mimic the cell status under IP. Adeno-associated virus carrying the NTN-1 gene (AAV-NTN-1) was used to overexpress NTN-1. Complete Freund's Adjuvant (CFA)-induced mouse was recruited as an in vivo model. MTT and commercial kits were utilized to evaluate cell viability and cell death of BV2 cells. The mRNA expressions and secretions of cytokines were measured using the ELISA method. Also, the pyroptosis and activation of BV2 cells were investigated based on western blotting. To verify the role of Rac1/NF-kappaB signaling, isochamaejasmin (ISO) and AAV-Rac1 were presented. The results showed that NTN-1 expression was decreased in LPS-treated BV2 microglia and spinal cord tissues of CFA-injected mice. Overexpressing NTN-1 dramatically reversed cell viability and decreased cell death rate of BV2 microglia under lipopolysaccharide (LPS) stimulation, while the level of pyroptosis was inhibited. Besides, AAV-NTN-1 rescued the activation of microglia and inflammatory injury induced by LPS, decreasing IBA-1 expression, as well as iNOS, IL-1beta and IL-6 secretions. Meanwhile AAV-NTN-1 promoted the anti-inflammation response, including increases in Arg-1, IL-4 and IL-10 levels. In addition, the LPS-induced activation of Rac1/NF-kappaB signaling was depressed by NTN-1 overexpression. The same results were verified in a CFA-induced mouse model. In conclusion, NTN-1 alleviated IP by suppressing pyroptosis and promoting M2 type activation of microglia via inhibiting Rac1/NF-?B signaling, suggesting the protective role of NTN-1 in IP. Keywords: Netrin-1, Inflammatory pain, Pyroptosis, Microglia M2 activation, Rac1/NF-kappaB.
- MeSH
- bolest metabolismus MeSH
- buněčné linie MeSH
- lipopolysacharidy MeSH
- mikroglie * metabolismus MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- netrin-1 * metabolismus MeSH
- neuropeptidy * MeSH
- NF-kappa B * metabolismus MeSH
- pyroptóza * fyziologie účinky léků MeSH
- rac1 protein vázající GTP * metabolismus MeSH
- signální transdukce * MeSH
- zánět * metabolismus patologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Microglial cells mediate diverse homeostatic, inflammatory, and immune processes during normal development and in response to cytotoxic challenges. During these functional activities, microglial cells undergo distinct numerical and morphological changes in different tissue volumes in both rodent and human brains. However, it remains unclear how these cytostructural changes in microglia correlate with region-specific neurochemical functions. To better understand these relationships, neuroscientists need accurate, reproducible, and efficient methods for quantifying microglial cell number and morphologies in histological sections. To address this deficit, we developed a novel deep learning (DL)-based classification, stereology approach that links the appearance of Iba1 immunostained microglial cells at low magnification (20×) with the total number of cells in the same brain region based on unbiased stereology counts as ground truth. Once DL models are trained, total microglial cell numbers in specific regions of interest can be estimated and treatment groups predicted in a high-throughput manner (<1 min) using only low-power images from test cases, without the need for time and labor-intensive stereology counts or morphology ratings in test cases. Results for this DL-based automatic stereology approach on two datasets (total 39 mouse brains) showed >90% accuracy, 100% percent repeatability (Test-Retest) and 60× greater efficiency than manual stereology (<1 min vs. ∼ 60 min) using the same tissue sections. Ongoing and future work includes use of this DL-based approach to establish clear neurodegeneration profiles in age-related human neurological diseases and related animal models.
Článek přináší výběr zajímavých základních výzkumů zejména významu mikroglie u chronické bolesti, nových doporučení k optimalizaci a urychlení vývoje „přesné“ léčby chronické bolesti, IASP doporučení pro rok integrativní medicíny, kterým byl rok 2023. Pozoruhodnou publikací je rovněž alkoholem indukovaná mechanická alodynie, kdy chronická konzumace alkoholu může způsobit, že lidé jsou citlivější na bolest prostřednictvím dvou různých molekulárních mechanismů. Posledním neméně zajímavým tématem je uvedení nasálního naloxonu na americký trh ve verzi volně prodejného léku. Zpracovány jsou pouze zahraniční a relevantní zdroje.
The article presents a selection of interesting basic research, particularly the importance of microglia in chronic pain, new recommendations to optimize and accelerate the development of "precision" treatments for chronic pain, IASP recommendations for the year of integrative medicine, which was 2023. Also of note is alcohol-induced mechanical allodynia, where chronic alcohol consumption can make people more sensitive to pain through two different molecular mechanisms. A final no less interesting topic is the introduction of nasal naloxone to the ame-ric market as an over-the-counter drug. Only international and relevant sources are discussed.
- MeSH
- astrocyty MeSH
- blokátory kalciových kanálů terapeutické užití MeSH
- chronická bolest * terapie MeSH
- lidé MeSH
- mikroglie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Stroke is a devastating cerebrovascular pathology with high morbidity and mortality. Inflammation plays a central role in the pathophysiology of stroke. Vagus nerve stimulation (VNS) is a promising immunomodulatory method that has shown positive effects in stroke treatment, including neuroprotection, anti-apoptosis, anti-inflammation, antioxidation, reduced infarct volume, improved neurological scores, and promotion of M2 microglial polarization. In this review, we summarize the current knowledge about the vagus nerve's immunomodulatory effects through the cholinergic anti-inflammatory pathway (CAP) and provide a comprehensive assessment of the available experimental literature focusing on the use of VNS in stroke treatment.
The fungal pathogen Candida albicans is linked to chronic brain diseases such as Alzheimer's disease (AD), but the molecular basis of brain anti-Candida immunity remains unknown. We show that C. albicans enters the mouse brain from the blood and induces two neuroimmune sensing mechanisms involving secreted aspartic proteinases (Saps) and candidalysin. Saps disrupt tight junction proteins of the blood-brain barrier (BBB) to permit fungal brain invasion. Saps also hydrolyze amyloid precursor protein (APP) into amyloid β (Aβ)-like peptides that bind to Toll-like receptor 4 (TLR4) and promote fungal killing in vitro while candidalysin engages the integrin CD11b (Mac-1) on microglia. Recognition of Aβ-like peptides and candidalysin promotes fungal clearance from the brain, and disruption of candidalysin recognition through CD11b markedly prolongs C. albicans cerebral mycosis. Thus, C. albicans is cleared from the brain through innate immune mechanisms involving Saps, Aβ, candidalysin, and CD11b.
- MeSH
- Alzheimerova nemoc metabolismus mikrobiologie MeSH
- amyloidní beta-protein metabolismus MeSH
- antigeny CD11b * metabolismus MeSH
- Candida albicans metabolismus MeSH
- fungální proteiny metabolismus MeSH
- mikroglie * metabolismus mikrobiologie MeSH
- mykózy * genetika metabolismus MeSH
- myši MeSH
- toll-like receptor 4 * metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
The activity of the immune system is controlled by circadian clocks present in different immune cells. The brain-resident subtype of immune cells, microglia, exhibits a wide range of functional phenotypes depending on the signaling molecules in their microenvironment. The exact role of microglia in the hypothalamic suprachiasmatic nuclei (SCN), the central circadian clock, has not been known. Therefore, the aim of this study was to determine (1) whether microenvironment-induced changes in microglial polarization affect circadian clocks in these cells and (2) whether the presence of microglia contributes to SCN clock function. Microglial and SCN clocks were monitored using PER2-driven bioluminescence rhythms at the tissue and single-cell levels. We found that polarization of resting microglia to a pro-inflammatory (M1) or anti-inflammatory (M2) state significantly altered the period and amplitude of their molecular circadian clock; importantly, the parameters changed plastically with the repolarization of microglia. This effect was reflected in specific modulations of the expression profiles of individual clock genes in the polarized microglia. Depletion of microglia significantly reduced the amplitude of the SCN clock, and co-cultivation of the SCN explants with M2-polarized microglia specifically improved the amplitude of the SCN clock. These results demonstrate that the presence of M2-polarized microglia has beneficial effects on SCN clock function. Our results provide new insight into the mutual interaction between immune and circadian systems in the brain.
- MeSH
- cirkadiánní hodiny * genetika MeSH
- cirkadiánní rytmus fyziologie MeSH
- mikroglie MeSH
- mozek MeSH
- myši MeSH
- nucleus suprachiasmaticus metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Siponimod (Mayzent®), a sphingosine 1-phosphate receptor (S1PR) modulator which prevents lymphocyte egress from lymphoid tissues, is approved for the treatment of relapsing-remitting and active secondary progressive multiple sclerosis. It can cross the blood-brain barrier (BBB) and selectively binds to S1PR1 and S1PR5 expressed by several cell populations of the central nervous system (CNS) including microglia. In multiple sclerosis, microglia are a key CNS cell population moving back and forth in a continuum of beneficial and deleterious states. On the one hand, they can contribute to neurorepair by clearing myelin debris, which is a prerequisite for remyelination and neuroprotection. On the other hand, they also participate in autoimmune inflammation and axonal degeneration by producing pro-inflammatory cytokines and molecules. In this study, we demonstrate that siponimod can modulate the microglial reaction to lipopolysaccharide-induced pro-inflammatory activation.
- MeSH
- azetidiny * farmakologie metabolismus MeSH
- benzylové sloučeniny farmakologie MeSH
- lidé MeSH
- mikroglie metabolismus MeSH
- roztroušená skleróza * metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
