Punicalagin inhibits neuroinflammation in LPS-activated rat primary microglia

2014 ◽  
Vol 58 (9) ◽  
pp. 1843-1851 ◽  
Author(s):  
Olumayokun A. Olajide ◽  
Asit Kumar ◽  
Ravikanth Velagapudi ◽  
Uchechukwu P. Okorji ◽  
Bernd L. Fiebich
Keyword(s):  
Primary Microglia

scholarly journals GPR110 ligands reduce chronic optic tract gliosis and visual deficit following repetitive mild traumatic brain injury in mice

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Huazhen Chen ◽  
Karl Kevala ◽  
Elma Aflaki ◽  
Juan Marugan ◽  
Hee-Yong Kim
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Mild Traumatic Brain Injury ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Optic Tract ◽  
Primary Microglia ◽  
Visual Dysfunction ◽  
The Brain

Abstract Background Repetitive mild traumatic brain injury (mTBI) can result in chronic visual dysfunction. G-protein receptor 110 (GPR110, ADGRF1) is the target receptor of N-docosahexaenoylethanolamine (synaptamide) mediating the anti-neuroinflammatory function of synaptamide. In this study, we evaluated the effect of an endogenous and a synthetic ligand of GPR110, synaptamide and (4Z,7Z,10Z,13Z,16Z,19Z)-N-(2-hydroxy-2-methylpropyl) docosa-4,7,10,13,16,19-hexaenamide (dimethylsynaptamide, A8), on the mTBI-induced long-term optic tract histopathology and visual dysfunction using Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA), a clinically relevant model of mTBI. Methods The brain injury in wild-type (WT) and GPR110 knockout (KO) mice was induced by CHIMERA applied daily for 3 days, and GPR110 ligands were intraperitoneally injected immediately following each impact. The expression of GPR110 and proinflammatory mediator tumor necrosis factor (TNF) in the brain was measured by using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) in an acute phase. Chronic inflammatory responses in the optic tract and visual dysfunction were assessed by immunostaining for Iba-1 and GFAP and visual evoked potential (VEP), respectively. The effect of GPR110 ligands in vitro was evaluated by the cyclic adenosine monophosphate (cAMP) production in primary microglia isolated from adult WT or KO mouse brains. Results CHIMERA injury acutely upregulated the GPR110 and TNF gene level in mouse brain. Repetitive CHIMERA (rCHIMERA) increased the GFAP and Iba-1 immunostaining of glia cells and silver staining of degenerating axons in the optic tract with significant reduction of N1 amplitude of visual evoked potential at up to 3.5 months after injury. Both GPR110 ligands dose- and GPR110-dependently increased cAMP in cultured primary microglia with A8, a ligand with improved stability, being more effective than synaptamide. Intraperitoneal injection of A8 at 1 mg/kg or synaptamide at 5 mg/kg significantly reduced the acute expression of TNF mRNA in the brain and ameliorated chronic optic tract microgliosis, astrogliosis, and axonal degeneration as well as visual deficit caused by injury in WT but not in GPR110 KO mice. Conclusion Our data demonstrate that ligand-induced activation of the GPR110/cAMP system upregulated after injury ameliorates the long-term optic tract histopathology and visual impairment caused by rCHIMERA. Based on the anti-inflammatory nature of GPR110 activation, we suggest that GPR110 ligands may have therapeutic potential for chronic visual dysfunction associated with mTBI.

scholarly journals Microglia and Astrocyte Activation by Toll-Like Receptor Ligands: Modulation by PPAR-γAgonists

PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-15 ◽  
Author(s):  
Catherine Gurley ◽  
Jessica Nichols ◽  
Shuliang Liu ◽  
Nirmal K. Phulwani ◽  
Nilufer Esen ◽  
...  
Keyword(s):  
Tissue Damage ◽  
Critical Role ◽  
Host Immunity ◽  
Toll Like Receptor ◽  
Primary Microglia ◽  
Tissue Destruction ◽  
Receptor Ligands ◽  
Astrocyte Activation ◽  
Comprehensive Survey ◽  
Ccl2 Production

Microglia and astrocytes express numerous members of the Toll-like receptor (TLR) family that are pivotal for recognizing conserved microbial motifs expressed by a wide array of pathogens. Despite the critical role for TLRs in pathogen recognition, when dysregulated these pathways can also exacerbate CNS tissue destruction. Therefore, a critical balance must be achieved to elicit sufficient immunity to combat CNS infectious insults and down-regulate these responses to avoid pathological tissue damage. We performed a comprehensive survey on the efficacy of various PPAR-γagonists to modulate proinflammatory mediator release from primary microglia and astrocytes in response to numerous TLR ligands relevant to CNS infectious diseases. The results demonstrated differential abilities of select PPAR-γagonists to modulate glial activation. For example, 15d-PGJ2and pioglitazone were both effective at reducing IL-12 p40 release by TLR ligand-activated glia, whereas CXCL2 expression was either augmented or inhibited by 15d-PGJ2, effects that were dependent on the TLR ligand examined. Pioglitazone and troglitazone demonstrated opposing actions on microglial CCL2 production that were TLR ligand-dependent. Collectively, this information may be exploited to modulate the host immune response during CNS infections to maximize host immunity while minimizing inappropriate bystander tissue damage that is often characteristic of such diseases.

Rapid isolation and culture of primary microglia from adult mouse spinal cord

2009 ◽  
Vol 183 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Ping K. Yip ◽  
Timothy K.Y. Kaan ◽  
Daniel Fenesan ◽  
Marzia Malcangio
Keyword(s):  
Spinal Cord ◽  
Adult Mouse ◽  
Primary Microglia ◽  
Mouse Spinal Cord ◽  
Rapid Isolation

scholarly journals Priming of Hypothalamic Ghrelin Signaling and Microglia Activation Exacerbate Feeding in Rats’ Offspring Following Maternal Overnutrition

Nutrients ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1241 ◽  
Author(s):  
Roger Maldonado-Ruiz ◽  
Marcela Cárdenas-Tueme ◽  
Larisa Montalvo-Martínez ◽  
Roman Vidaltamayo ◽  
Lourdes Garza-Ocañas ◽  
...  
Keyword(s):  
Food Intake ◽  
Palmitic Acid ◽  
Cell Activation ◽  
Programming Model ◽  
Microglia Activation ◽  
Tnf Alpha ◽  
Primary Microglia ◽  
Female Wistar Rats ◽  
C6 Ceramide ◽  
Maternal Overnutrition

Maternal overnutrition during pregnancy leads to metabolic alterations, including obesity, hyperphagia, and inflammation in the offspring. Nutritional priming of central inflammation and its role in ghrelin sensitivity during fed and fasted states have not been analyzed. The current study aims to identify the effect of maternal programming on microglia activation and ghrelin-induced activation of hypothalamic neurons leading to food intake response. We employed a nutritional programming model exposing female Wistar rats to a cafeteria diet (CAF) from pre-pregnancy to weaning. Food intake in male offspring was determined daily after fasting and subcutaneous injection of ghrelin. Hypothalamic ghrelin sensitivity and microglia activation was evaluated using immunodetection for Iba-1 and c-Fos markers, and Western blot for TBK1 signaling. Release of TNF-alpha, IL-6, and IL-1β after stimulation with palmitic, oleic, linoleic acid, or C6 ceramide in primary microglia culture were quantified using ELISA. We found that programmed offspring by CAF diet exhibits overfeeding after fasting and peripheral ghrelin administration, which correlates with an increase in the hypothalamic Iba-1 microglia marker and c-Fos cell activation. Additionally, in contrast to oleic, linoleic, or C6 ceramide stimulation in primary microglia culture, stimulation with palmitic acid for 24 h promotes TNF-alpha, IL-6, and IL-1β release and TBK1 activation. Notably, intracerebroventricular (i.c.v.) palmitic acid or LPS inoculation for five days promotes daily increase in food intake and food consumption after ghrelin administration. Finally, we found that i.c.v. palmitic acid substantially activates hypothalamic Iba-1 microglia marker and c-Fos. Together, our results suggest that maternal nutritional programing primes ghrelin sensitivity and microglia activation, which potentially might mirror hypothalamic administration of the saturated palmitic acid.

scholarly journals Progesterone Attenuates Stress-Induced NLRP3 Inflammasome Activation and Enhances Autophagy Following Ischemic Brain Injury

2020 ◽  
Vol 21 (11) ◽  
pp. 3740 ◽  
Author(s):  
Claudia Espinosa-Garcia ◽  
Fahim Atif ◽  
Seema Yousuf ◽  
Iqbal Sayeed ◽  
Gretchen N. Neigh ◽  
...  
Keyword(s):  
Brain Injury ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Global Ischemia ◽  
Inflammasome Activation ◽  
Ischemic Brain Injury ◽  
Primary Microglia ◽  
Ischemic Brain ◽  
Nlrp3 Inflammasome Activation ◽  
The Impact

NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome inhibition and autophagy induction attenuate inflammation and improve outcome in rodent models of cerebral ischemia. However, the impact of chronic stress on NLRP3 inflammasome and autophagic response to ischemia remains unknown. Progesterone (PROG), a neuroprotective steroid, shows promise in reducing excessive inflammation associated with poor outcome in ischemic brain injury patients with comorbid conditions, including elevated stress. Stress primes microglia, mainly by the release of alarmins such as high-mobility group box-1 (HMGB1). HMGB1 activates the NLRP3 inflammasome, resulting in pro-inflammatory interleukin (IL)-1β production. In experiment 1, adult male Sprague-Dawley rats were exposed to social defeat stress for 8 days and then subjected to global ischemia by the 4-vessel occlusion model, a clinically relevant brain injury associated with cardiac arrest. PROG was administered 2 and 6 h after occlusion and then daily for 7 days. Animals were killed at 7 or 14 days post-ischemia. Here, we show that stress and global ischemia exert a synergistic effect in HMGB1 release, resulting in exacerbation of NLRP3 inflammasome activation and autophagy impairment in the hippocampus of ischemic animals. In experiment 2, an in vitro inflammasome assay, primary microglia isolated from neonatal brain tissue, were primed with lipopolysaccharide (LPS) and stimulated with adenosine triphosphate (ATP), displaying impaired autophagy and increased IL-1β production. In experiment 3, hippocampal microglia isolated from stressed and unstressed animals, were stimulated ex vivo with LPS, exhibiting similar changes than primary microglia. Treatment with PROG reduced HMGB1 release and NLRP3 inflammasome activation, and enhanced autophagy in stressed and unstressed ischemic animals. Pre-treatment with an autophagy inhibitor blocked Progesterone’s (PROG’s) beneficial effects in microglia. Our data suggest that modulation of microglial priming is one of the molecular mechanisms by which PROG ameliorates ischemic brain injury under stressful conditions.

scholarly journals Noncanonical function of an autophagy protein prevents spontaneous Alzheimer’s disease

2020 ◽  
Vol 6 (33) ◽  
pp. eabb9036
Author(s):  
Bradlee L. Heckmann ◽  
Brett J. W. Teubner ◽  
Emilio Boada-Romero ◽  
Bart Tummers ◽  
Clifford Guy ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Human Disease ◽  
Memory Impairment ◽  
Memory Loss ◽  
Tau Hyperphosphorylation ◽  
Primary Microglia ◽  
Amyloid Aβ ◽  
Β Amyloid ◽  
Old Mice

Noncanonical functions of autophagy proteins have been implicated in neurodegenerative conditions, including Alzheimer’s disease (AD). The WD domain of the autophagy protein Atg16L is dispensable for canonical autophagy but required for its noncanonical functions. Two-year-old mice lacking this domain presented with robust β-amyloid (Aβ) pathology, tau hyperphosphorylation, reactive microgliosis, pervasive neurodegeneration, and severe behavioral and memory deficiencies, consistent with human disease. Mechanistically, we found this WD domain was required for the recycling of Aβ receptors in primary microglia. Pharmacologic suppression of neuroinflammation reversed established memory impairment and markers of disease pathology in this novel AD model. Therefore, loss of the Atg16L WD domain drives spontaneous AD in mice, and inhibition of neuroinflammation is a potential therapeutic approach for treating neurodegeneration and memory loss. A decline in expression of ATG16L in the brains of human patients with AD suggests the possibility that a similar mechanism may contribute in human disease.

Resistance of mouse primary microglia and astrocytes to acrylonitrile-induced oxidative stress

2017 ◽  
Vol 63 ◽  
pp. 120-125
Author(s):  
Samuel Caito ◽  
Marion Park ◽  
Michael Aschner
Keyword(s):  
Oxidative Stress ◽  
Primary Microglia
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