scholarly journals The Roles of IL-22 and Its Receptor in the Regulation of Inflammatory Responses in the Brain

2022 ◽  
Vol 23 (2) ◽  
pp. 757
Author(s):  
Dahae Lee ◽  
Hyejung Jo ◽  
Cheolhyeon Go ◽  
Yoojin Jang ◽  
Naghyung Chu ◽  
...  

Interleukin (IL)-22 is a potent mediator of inflammatory responses. The IL-22 receptor consists of the IL-22Rα and IL-10Rβ subunits. Previous studies have shown that IL-22Rα expression is restricted to non-hematopoietic cells in the skin, pancreas, intestine, liver, lung, and kidney. Although IL-22 is involved in the development of inflammatory responses, there have been no reports of its role in brain inflammation. Here, we used RT-PCR, Western blotting, flow cytometry, immunohistochemical, and microarray analyses to examine the role of IL-22 and expression of IL-22Rα in the brain, using the microglial cell line, hippocampal neuronal cell line, and inflamed mouse brain tissue. Treatment of BV2 and HT22 cells with recombinant IL-22 increased the expression levels of the pro-inflammatory cytokines IL-6 and TNF-α, as well as cyclooxygenase (COX)-2 and prostaglandin E2. We also found that the JNK and STAT3 signaling pathways play an important role in IL-22-mediated increases in inflammatory mediators. Microarray analyses revealed upregulated expression of inflammation-related genes in IL-22-treated HT22 cells. Finally, we found that IL-22Rα is spontaneously expressed in the brain and is upregulated in inflamed mouse brain. Overall, our results demonstrate that interaction of IL-22 with IL-22Rα plays a role in the development of inflammatory responses in the brain.

Endocrinology ◽  
2007 ◽  
Vol 148 (7) ◽  
pp. 3371-3382 ◽  
Author(s):  
Toni R. Pak ◽  
Wilson C. J. Chung ◽  
Laura R. Hinds ◽  
Robert J. Handa

Arginine vasopressin (AVP) is a neuropeptide involved in the regulation of fluid balance, stress, circadian rhythms, and social behaviors. In the brain, AVP is tightly regulated by gonadal steroid hormones in discrete regions with gonadectomy abolishing and testosterone replacement restoring normal AVP expression in adult males. Previous studies demonstrated that 17β-estradiol, a primary metabolite of testosterone, is responsible for restoring most of the AVP expression in the brain after castration. However, 5α-dihydrotestosterone (DHT) has also been shown to play a role in the regulation of AVP expression, thus implicating the involvement of both androgen and estrogen receptors (ER). Furthermore, DHT, through its conversion to 5α-androstane-3β,17β-diol, has been shown to modulate estrogen response element-mediated promoter activity through an ER pathway. The present study addressed two central hypotheses: 1) that androgens directly modulate AVP promoter activity and 2) the effect is mediated by an estrogen or androgen receptor pathway. To that end, we overexpressed androgen receptor, ERβ, and ERβ splice variants in a neuronal cell line and measured AVP promoter activity using a firefly luciferase reporter assay. Our results demonstrate that DHT and its metabolite 5α-androstane-3β,17β-diol stimulate AVP promoter activity through ERβ in a neuronal cell line.


Antioxidants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Mei-Hua Jin ◽  
Jia-Bin Yu ◽  
Hu-Nan Sun ◽  
Ying-Hua Jin ◽  
Gui-Nan Shen ◽  
...  

Excessive alcohol intake can significantly reduce cognitive function and cause irreversible learning and memory disorders. The brain is particularly vulnerable to alcohol-induced ROS damage; the hippocampus is one of the most sensitive areas of the brain for alcohol neurotoxicity. In the present study, we observed significant increasing of intracellular ROS accumulations in Peroxiredoxin II (Prx II) knockdown HT22 cells, which were induced by alcohol treatments. We also found that the level of ROS in mitochondrial was also increased, resulting in a decrease in the mitochondrial membrane potential. The phosphorylation of GSK3β (Ser9) and anti-apoptotic protein Bcl2 expression levels were significantly downregulated in Prx II knockdown HT22 cells, which suggests that Prx II knockdown HT22 cells were more susceptible to alcohol-induced apoptosis. Scavenging the alcohol-induced ROS with NAC significantly decreased the intracellular ROS levels, as well as the phosphorylation level of GSK3β in Prx II knockdown HT22 cells. Moreover, NAC treatment also dramatically restored the mitochondrial membrane potential and the cellular apoptosis in Prx II knockdown HT22 cells. Our findings suggest that Prx II plays a crucial role in alcohol-induced neuronal cell apoptosis by regulating the cellular ROS levels, especially through regulating the ROS-dependent mitochondrial membrane potential. Consequently, Prx II may be a therapeutic target molecule for alcohol-induced neuronal cell death, which is closely related to ROS-dependent mitochondria dysfunction.


Marine Drugs ◽  
2019 ◽  
Vol 17 (2) ◽  
pp. 79 ◽  
Author(s):  
Beika Zhu ◽  
Yang Zhang ◽  
Karl Herrup

Cell cycle reentry is a unified mechanism shared by several neurodegenerative diseases, including Alzheimer’s disease (AD) and Ataxia Telangiectasia (A-T). This phenotype is often related to neuroinflammation in the central nervous system. To mimic brain inflammation in vitro, we adopted the previously established method of using conditioned medium collected from activated THP-1 cells and applied it to both differentiated HT22 cells and primary neurons. Unscheduled cell cycle events were observed in both systems, indicating the potential of this approach as an in vitro model of neurodegenerative disease. We used this assay to measure the neuroprotective effects of New Zealand green-lipped mussel extract, PCSO-524®, to protect post-mitotic cells from cell cycle reentry. We found that, both in vitro and in an animal model, PCSO-524® displayed promising neuroprotective effects, and thus has potential to postpone or prevent the onset of neurodegenerative disease.


2019 ◽  
Author(s):  
Johan Winnubst ◽  
Erhan Bas ◽  
Tiago A. Ferreira ◽  
Zhuhao Wu ◽  
Michael N. Economo ◽  
...  

SummaryNeuronal cell types are the nodes of neural circuits that determine the flow of information within the brain. Neuronal morphology, especially the shape of the axonal arbor, provides an essential descriptor of cell type and reveals how individual neurons route their output across the brain. Despite the importance of morphology, few projection neurons in the mouse brain have been reconstructed in their entirety. Here we present a robust and efficient platform for imaging and reconstructing complete neuronal morphologies, including axonal arbors that span substantial portions of the brain. We used this platform to reconstruct more than 1,000 projection neurons in the motor cortex, thalamus, subiculum, and hypothalamus. Together, the reconstructed neurons comprise more than 75 meters of axonal length and are available in a searchable online database. Axonal shapes revealed previously unknown subtypes of projection neurons and suggest organizational principles of long-range connectivity.


2021 ◽  
Author(s):  
Jinhua Zhang ◽  
Wei Han ◽  
changqing xie ◽  
mingxing Gao ◽  
Xugang Wang ◽  
...  

Abstract Background: Japanese Encephalitis (JE) is a zoonotic natural epidemic disease caused by Japanese Encephalitis Virus (JEV) infection. Currently, there is no specific medicine for Japanese encephalitis. At present, autophagy regulating drugs have played an important role in the treatment of tumors, heart diseases and other diseases. We hope that by studying the effects of autophagy-regulating drugs on JEV infection and host response in mice, will provide effective clinical trials for autophagy-regulating drugs in the treatment of Japanese encephalitis and other viral infectious diseases. Methods: After establishing appropriate animal model. We observed the neurological symptoms of the mice and counted their survival rate. We compared the degree of viral infection in the brain of mice infected with JE virus. We compared the extent of neuroinflammatory responses in the brain of mice and explored the signaling processes involved in neuroinflammation.Results: We found autophagy inhibitors wortmannin (Wort) and chloroquine (CQ) alleviate degree of viral infection in the brain of JEV-infected mice. Autophagy inhibitors reduced the neuroinflammation in Mouse Model of Japanese encephalitis. We speculated that autophagy inhibitors may attenuate the activation of the PI3K/AKT/NF-kB pathway, thereby reducing the brain inflammation in mice, thereby protecting mice from JEV-induced death. This result is not significant enough, the specific mechanism still needs further study.Conclusions: Our study suggests that autophagy inhibitors wortmannin and chloroquine could reduce the degree of viral infection and inflammatory response in the brain of JEV infected mice, providing a clinical basis for the treatment of Japanese encephalitis.


2021 ◽  
Author(s):  
Sruti Rayaprolu ◽  
Sara Bitarafan ◽  
Ranjita Betarbet ◽  
Sydney N Sunna ◽  
Lihong Cheng ◽  
...  

Isolation and proteomic profiling of brain cell types, particularly neurons, pose several technical challenges which limit our ability to resolve distinct cellular phenotypes in neurological diseases. Therefore, we generated a novel mouse line that enables cell type-specific expression of a biotin ligase, TurboID, via Cre-lox strategy for in vivo proximity-dependent biotinylation of proteins. Using adenoviral-based and transgenic approaches, we show striking protein biotinylation in neuronal cell bodies and axons throughout the mouse brain. We quantified more than 2,000 neuron-derived proteins following enrichment that mapped to numerous subcellular compartments. Synaptic, transmembrane transporters, ion channel subunits, and disease-relevant druggable targets were among the most significantly enriched proteins. Remarkably, we resolved brain region-specific proteomic profiles of Camk2a neurons with distinct functional molecular signatures and disease associations that may underlie regional neuronal vulnerability. Leveraging the neuronal specificity of this in vivo biotinylation strategy, we used an antibody-based approach to uncover regionally unique patterns of neuron-derived signaling phospho-proteins and cytokines, particularly in the cortex and cerebellum. Our work provides a proteomic framework to investigate cell type-specific mechanisms driving physiological and pathological states of the brain as well as complex tissues beyond the brain.


2019 ◽  
Vol 116 (47) ◽  
pp. 23760-23771 ◽  
Author(s):  
Manish Sharma ◽  
Uri Nimrod Ramírez-Jarquín ◽  
Oscar Rivera ◽  
Melissa Kazantzis ◽  
Mehdi Eshraghi ◽  
...  

Elimination of dysfunctional mitochondria via mitophagy is essential for cell survival and neuronal functions. But, how impaired mitophagy participates in tissue-specific vulnerability in the brain remains unclear. Here, we find that striatal-enriched protein, Rhes, is a critical regulator of mitophagy and striatal vulnerability in brain. In vivo interactome and density fractionation reveal that Rhes coimmunoprecipitates and cosediments with mitochondrial and lysosomal proteins. Live-cell imaging of cultured striatal neuronal cell line shows Rhes surrounds globular mitochondria, recruits lysosomes, and ultimately degrades mitochondria. In the presence of 3-nitropropionic acid (3-NP), an inhibitor of succinate dehydrogenase, Rhes disrupts mitochondrial membrane potential (ΔΨm) and promotes excessive mitophagy and cell death. Ultrastructural analysis reveals that systemic injection of 3-NP in mice promotes globular mitochondria, accumulation of mitophagosomes, and striatal lesion only in the wild-type (WT), but not in the Rhes knockout (KO), striatum, suggesting that Rhes is critical for mitophagy and neuronal death in vivo. Mechanistically, Rhes requires Nix (BNIP3L), a known receptor of mitophagy, to disrupt ΔΨm and promote mitophagy and cell death. Rhes interacts with Nix via SUMO E3-ligase domain, and Nix depletion totally abrogates Rhes-mediated mitophagy and cell death in the cultured striatal neuronal cell line. Finally, we find that Rhes, which travels from cell to cell via tunneling nanotube (TNT)-like cellular protrusions, interacts with dysfunctional mitochondria in the neighboring cell in a Nix-dependent manner. Collectively, Rhes is a major regulator of mitophagy via Nix, which may determine striatal vulnerability in the brain.


2020 ◽  
Vol 16 ◽  
Author(s):  
Karrington Craig ◽  
Paula Avila ◽  
Dennis A. Brown

Background: Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system characterized by demyelination of neurons and neurodegeneration. Current MS therapies ameliorate inflammatory damage but are unable to address the degenerative aspects of the disease. Objective: In this report, we evaluate the ability of amide-based dithiolethiones (DTTs) to suppress neuroinflammation in microglia and increase anti-oxidant capacity neuron-like cells. Methods: A series of amide-containing DTTs were designed, synthesized, and assayed for ability to suppress proneuroinflammatory cytokines IL-12p40 and IL-23p19 induced by LPS in the BV2 microglial cell line. Lead analog 2c was identified and further characterized. Results: Structure-activity data revealed tolerance towards a variety of amides. Morpholine analog 2c dose-dependently reduced various other inflammatory cytokines and mediators, including TNF, IL-6, IL-1β, NOS2, and COX2. Additionally, 2c elevated cellular levels of glutathione in SH-SH5Y neuronal cell line. Furthermore, mechanistic studies showed 2c increased the expression of anti-inflammatory Nrf2 and HMOX proteins. Conclusion: The combination of anti-neuroinflammatory and anti-oxidant activities of amide-based DTTs suggest they are promising agents for the treatment of both demyelination and neurodegeneration in MS.


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