scholarly journals NADPH-Oxidase, Rho-Kinase and Autophagy Mediate the (Pro)renin-Induced Pro-Inflammatory Microglial Response and Enhancement of Dopaminergic Neuron Death

Antioxidants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1340
Author(s):  
Andrea Lopez-Lopez ◽  
Begoña Villar-Cheda ◽  
Aloia Quijano ◽  
Pablo Garrido-Gil ◽  
María Garcia-Garrote ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Kinase Inhibitor ◽  
Inflammatory Responses ◽  
Rho Kinase ◽  
Renin Angiotensin System ◽  
Microglial Cells ◽  
Nigrostriatal System ◽  
Neuron Death ◽  
Pre Treatment ◽  
Microglial Response

Dysregulation of the tissue renin–angiotensin system (RAS) is involved in tissue oxidative and inflammatory responses. Among RAS components, renin, its precursor (pro)renin and its specific receptor (PRR) have been less investigated, particularly in the brain. We previously showed the presence of PRR in neurons and glial cells in the nigrostriatal system of rodents and primates, including humans. Now, we used rat and mouse models and cultures of BV2 and primary microglial cells to study the role of PRR in microglial pro-inflammatory responses. PRR was upregulated in the nigral region, particularly in microglia during the neuroinflammatory response. In the presence of the angiotensin type-1 receptor blocker losartan, to exclude angiotensin-related effects, treatment of microglial cells with (pro)renin induces the expression of microglial pro-inflammatory markers, which is mediated by upregulation of NADPH-oxidase and Rho-kinase activities, downregulation of autophagy and upregulation of inflammasome activity. Conditioned medium from (pro)renin-treated microglia increased dopaminergic cell death relative to medium from non-treated microglia. However, these effects were blocked by pre-treatment of microglia with the Rho-kinase inhibitor fasudil. Activation of microglial PRR enhances the microglial pro-inflammatory response and deleterious effects of microglia on dopaminergic cells, and microglial NADPH-oxidase, Rho-Kinase and autophagy are involved in this process.

scholarly journals The absence of sympathoexcitation during the development of hypertension in Cyp1a1 Ren-2 transgenic rats

2019 ◽  
pp. 329-334
Author(s):  
J. Zicha ◽  
J. Hojná ◽  
L. Kopkan ◽  
L. Červenka ◽  
I. Vaněčková
Keyword(s):  
Blood Pressure ◽  
Kinase Inhibitor ◽  
Rho Kinase ◽  
Renin Angiotensin System ◽  
Ang Ii ◽  
Transgenic Rats ◽  
Calcium Sensitization ◽  
Sympathetic Vasoconstriction ◽  
Rho Kinase Inhibitor ◽  
Dependent Form

The insertion of mouse renin gene (Ren-2) into the genome of normotensive rats causes a spontaneous rise of blood pressure (BP), leading to an angiotensin II (Ang II)-dependent form of hypertension in transgenic (mRen-2)27 rats (TGR). However, enhanced sympathetic BP component was demonstrated in heterozygous TGR aged 20 weeks. In the present study we used another model, i.e. Cyp1a1-Ren-2 transgenic rats (iTGR) in which hypertension can be induced by natural xenobiotic indole-3 carbinol (I3C) added to the diet. We investigated whether the development of high blood pressure (BP) in 5-month-old iTGR animals fed I3C diet for 10 days is solely due to enhanced Ang II-dependent vasoconstriction or whether enhanced sympathetic vasoconstriction also participates in BP maintenance in this form of hypertension. Using acute sequential blockade of renin-angiotensin system (RAS), sympathetic nervous system (SNS) and NO synthase (NOS) we have demonstrated that the observed gradual increase of BP in iTGR fed I3C diet was entirely due to the augmentation of Ang II-dependent BP component without significant changes of sympathetic BP component. Thus, the hypertension in iTGR resembles to that of homozygous TGR in which high BP was entirely dependent on Ang II-dependent vasoconstriction. Moreover, our measurements of acute BP response to Rho kinase inhibitor fasudil in animals subjected to a combined blockade of RAS, SNS and NOS indicated the attenuation of basal calcium sensitization in both iTGR and homozygous TGR.

scholarly journals The Chemically-Modified Tetracycline COL-3 and Its Parent Compound Doxycycline Prevent Microglial Inflammatory Responses by Reducing Glucose-Mediated Oxidative Stress

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2163 ◽  
Author(s):  
Nilson Carlos Ferreira Junior ◽  
Maurício dos Santos Pereira ◽  
Nour Francis ◽  
Paola Ramirez ◽  
Paula Martorell ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Inflammatory Responses ◽  
Parent Compound ◽  
Antioxidant Properties ◽  
Microglial Cells ◽  
Activated Microglia ◽  
Tnf Α ◽  
Immunosuppressive Action ◽  
Anti Inflammatory

We used mouse microglial cells in culture activated by lipopolysaccharide (LPS) or α-synuclein amyloid aggregates (αSa) to study the anti-inflammatory effects of COL-3, a tetracycline derivative without antimicrobial activity. Under LPS or αSa stimulation, COL-3 (10, 20 µM) efficiently repressed the induction of the microglial activation marker protein Iba-1 and the stimulated-release of the pro-inflammatory cytokine TNF-α. COL-3′s inhibitory effects on TNF-α were reproduced by the tetracycline antibiotic doxycycline (DOX; 50 µM), the glucocorticoid dexamethasone, and apocynin (APO), an inhibitor of the superoxide-producing enzyme NADPH oxidase. This last observation suggested that COL-3 and DOX might also operate themselves by restraining oxidative stress-mediated signaling events. Quantitative measurement of intracellular reactive oxygen species (ROS) levels revealed that COL-3 and DOX were indeed as effective as APO in reducing oxidative stress and TNF-α release in activated microglia. ROS inhibition with COL-3 or DOX occurred together with a reduction of microglial glucose accumulation and NADPH synthesis. This suggested that COL-3 and DOX might reduce microglial oxidative burst activity by limiting the glucose-dependent synthesis of NADPH, the requisite substrate for NADPH oxidase. Coherent with this possibility, the glycolysis inhibitor 2-deoxy-D-glucose reproduced the immunosuppressive action of COL-3 and DOX in activated microglia. Overall, we propose that COL-3 and its parent compound DOX exert anti-inflammatory effects in microglial cells by inhibiting glucose-dependent ROS production. These effects might be strengthened by the intrinsic antioxidant properties of DOX and COL-3 in a self-reinforcing manner.

scholarly journals Rho-kinase inhibitor hydroxyfasudil protects against HIV-1 Tat-induced dysfunction of tight junction and neprilysin/Aβ transfer receptor expression in mouse brain microvessels

2021 ◽  
Vol 476 (5) ◽  
pp. 2159-2170
Author(s):  
Qiangtang Chen ◽  
Yu Wu ◽  
Yachun Yu ◽  
Junxiang Wei ◽  
Wen Huang
Keyword(s):  
Tight Junction ◽  
Signaling Pathway ◽  
Mouse Brain ◽  
Kinase Inhibitor ◽  
Rho Kinase ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Brain Microvessels ◽  
Rho Kinase Inhibitor ◽  
Hiv 1

AbstractHIV-1 transactivator protein (Tat) induces tight junction (TJ) dysfunction and amyloid-beta (Aβ) clearance dysfunction, contributing to the development and progression of HIV-1-associated neurocognitive disorder (HAND). The Rho/ROCK signaling pathway has protective effects on neurodegenerative disease. However, the underlying mechanisms of whether Rho/ROCK protects against HIV-1 Tat-caused dysfunction of TJ and neprilysin (NEP)/Aβ transfer receptor expression have not been elucidated. C57BL/6 mice were administered sterile saline (i.p., 100 μL) or Rho-kinase inhibitor hydroxyfasudil (HF) (i.p., 10 mg/kg) or HIV-1 Tat (i.v., 100 μg/kg) or HF 30 min before being exposed to HIV-1 Tat once a day for seven consecutive days. Evans Blue (EB) leakage was detected via spectrophotometer and brain slides in mouse brains. The protein and mRNA levels of zonula occludens-1 (ZO-1), occludin, NEP, receptor for advanced glycation end products (RAGE), and low-density lipoprotein receptor-related protein 1 (LRP1) in mouse brain microvessels were, respectively, analyzed by Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) analyses. Exposure of the mice to HIV-1 Tat increased the amount of EB leakage, EB fluorescence intensity, blood–brain barrier (BBB) permeability, as well as the RAGE protein and mRNA levels, and decreased the protein and mRNA levels of ZO-1, occludin, NEP, and LRP1 in mouse brain microvessels. However, these effects were weakened by Rho-kinase inhibitor HF. Taken together, these results provide information that the Rho/ROCK signaling pathway is involved in HIV-1 Tat-induced dysfunction of TJ and NEP/Aβ transfer receptor expression in the C57BL/6 mouse brain. These findings shed some light on potentiality of inhibiting Rho/Rock signaling pathway in handling HAND.

Rho kinase inhibitor for primary open-angle glaucoma and ocular hypertension

2020 ◽  
Author(s):  
Josefine Clement Freiberg ◽  
Alexander von Spreckelsen ◽  
Naira Khachatryan ◽  
Miriam Kolko ◽  
Augusto Azuara-Blanco ◽  
...  
Keyword(s):  
Ocular Hypertension ◽  
Primary Open Angle Glaucoma ◽  
Kinase Inhibitor ◽  
Open Angle Glaucoma ◽  
Rho Kinase ◽  
Open Angle ◽  
Rho Kinase Inhibitor

scholarly journals CD36 deficiency ameliorates drug-induced acute liver injury in mice

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Chen Zhang ◽  
Xiao Shi ◽  
Zhongping Su ◽  
Chao Hu ◽  
Xianmin Mu ◽  
...  
Keyword(s):  
Liver Injury ◽  
Western Blot ◽  
Kinase Inhibitor ◽  
Inflammatory Responses ◽  
Acute Liver Injury ◽  
Protein Adducts ◽  
Sterile Inflammation ◽  
Inflammatory Factor ◽  
Cd36 Deficiency ◽  
Significant Difference

Abstract Background Acetaminophen (APAP) overdose causes hepatotoxicity and even acute liver failure. Recent studies indicate that sterile inflammation and innate immune cells may play important roles in damage-induced hepatocytes regeneration and liver repair. The scavenger receptor CD36 has its crucial functions in sterile inflammation. However, the roles of CD36 in APAP induced acute liver injury remain unclear and warrant further investigation. Methods WT C57BL/6 J and CD36−/− mice were intraperitoneally injected with APAP (300 mg/kg) after fasting for 16 h. Liver injury was evaluated by serum alanine aminotransferase (ALT) level and liver tissue hematoxylin and eosin (H&E) staining. Liver inflammatory factor expression was determined by real-time polymerase chain reaction (PCR). The protein adducts forming from the metabolite of APAP and the metabolism enzyme cytochrome P450 2E1 (CYP2E1) levels were measured by Western blot. Liver infiltrating macrophages and neutrophils were characterized by flow cytometry. RNA sequencing and Western blot were used to evaluate the effect of damage-associated molecular patterns (DAMP) molecule high mobility group B1 (HMGB1) on WT and CD36−/− macrophages. Moreover, PP2, a Src kinase inhibitor, blocking CD36 signaling, was applied in APAP model. Results The expression of CD36 was increased in the liver of mice after APAP treatment. Compared with WT mice, APAP treated CD36−/− mice show less liver injury. There was no significant difference in APAP protein adducts and CYP2E1 expression between these two strains. However, reduced pro-inflammatory factor mRNA expression and serum IL-1β level were observed in APAP treated CD36−/− mice as well as infiltrating macrophages and neutrophils. Moreover, CD36 deficiency impaired the activation of c-Jun N-terminal kinase (JNK) caused by APAP. Interestingly, the lack of CD36 reduced the activation of extracellular regulated protein kinases (Erk) and v-akt murine thymoma viral oncogene homolog (Akt) induced by HMGB1. RNA transcription sequencing data indicated that HMGB1 has a different effect on WT and CD36−/− macrophages. Furthermore, treatment with PP2 attenuated APAP induced mouse liver injury. Conclusion Our data demonstrated that CD36 deficiency ameliorated APAP-induced acute liver injury and inflammatory responses by decreasing JNK activation. CD36 might serve as a new target to reduce acute liver injury.

scholarly journals Manifestation of lipopolysaccharide-induced tolerance in neuro-glial primary cultures of the rat afferent somatosensory system

2021 ◽  
Vol 70 (4) ◽  
pp. 429-444
Author(s):  
Franz Nürnberger ◽  
Stephan Leisengang ◽  
Daniela Ott ◽  
Jolanta Murgott ◽  
Rüdiger Gerstberger ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Nuclear Translocation ◽  
Mrna Level ◽  
Primary Cultures ◽  
Somatosensory System ◽  
Cellular Level ◽  
Microglial Cells ◽  
Substantia Gelatinosa ◽  
Tnf Α ◽  
Pre Treatment

Abstract Objective Bacterial lipopolysaccharide (LPS) may contribute to the manifestation of inflammatory pain within structures of the afferent somatosensory system. LPS can induce a state of refractoriness to its own effects termed LPS tolerance. We employed primary neuro-glial cultures from rat dorsal root ganglia (DRG) and the superficial dorsal horn (SDH) of the spinal cord, mainly including the substantia gelatinosa to establish and characterize a model of LPS tolerance within these structures. Methods Tolerance was induced by pre-treatment of both cultures with 1 µg/ml LPS for 18 h, followed by a short-term stimulation with a higher LPS dose (10 µg/ml for 2 h). Cultures treated with solvent were used as controls. Cells from DRG or SDH were investigated by means of RT-PCR (expression of inflammatory genes) and immunocytochemistry (translocation of inflammatory transcription factors into nuclei of cells from both cultures). Supernatants from both cultures were assayed for tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) by highly sensitive bioassays. Results At the mRNA-level, pre-treatment with 1 µg/ml LPS caused reduced expression of TNF-α and enhanced IL-10/TNF-α expression ratios in both cultures upon subsequent stimulation with 10 µg/ml LPS, i.e. LPS tolerance. SDH cultures further showed reduced release of TNF-α into the supernatants and attenuated TNF-α immunoreactivity in microglial cells. In the state of LPS tolerance macrophages from DRG and microglial cells from SDH showed reduced LPS-induced nuclear translocation of the inflammatory transcription factors NFκB and NF-IL6. Nuclear immunoreactivity of the IL-6-activated transcription factor STAT3 was further reduced in neurons from DRG and astrocytes from SDH in LPS tolerant cultures. Conclusion A state of LPS tolerance can be induced in primary cultures from the afferent somatosensory system, which is characterized by a down-regulation of pro-inflammatory mediators. Thus, this model can be applied to study the effects of LPS tolerance at the cellular level, for example possible modifications of neuronal reactivity patterns upon inflammatory stimulation.

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