Production Of Pro-inflammatory Factors Research Articles

Targeting S100A9-TLR2 axis controls macrophage NLRP3 inflammasome activation in fatty liver ischemia reperfusion injury

Abstract Liver ischemia reperfusion (IR) injury significantly impacts clinical outcomes by increasing the risk of hepatic dysfunction after liver surgery. Fatty livers are more susceptible to IR stress. Recent studies have demonstrated that S100A9 plays a crucial role in both IR injury and the progression of liver steatosis. Nevertheless, the precise mechanisms underlying these effects remain unclear. In our study, transcriptome analysis of fatty livers subjected to IR insult in mice identified S100A9 as an important mediator. Employing loss-of-function approaches, we investigated the immune regulatory function of S100A9 and its downstream signaling in fatty liver IR injury. As expected, S100A9 emerged as one of the most significantly upregulated genes during the reperfusion stage in fatty livers. Genetic knockdown of S100A9 markedly ameliorated liver pathological damage, evidenced by reduced macrophage/neutrophil infiltration as well as the decreased expression of proinflammatory factors. Transcriptome/functional studies revealed that S100A9 triggered liver inflammatory response via regulating Toll-like receptor 2 (TLR2)/Activating transcription factor 4 (ATF4) signaling. Additionally, TLR2 expression was notably increased in macrophages from ischemic fatty livers. In vitro, recombinant S100A9-stimulated macrophages exhibited the elevated production of proinflammatory factors and TLR2/ATF4 pathway activation. Intriguingly, S100A9 facilitated ATF4 nuclear translocation and enhanced NEK7/NLRP3 inflammasome activation in macrophages. In conclusion, our study identified S100A9 as a key regulator responsible for macrophage NLRP3 inflammasome activation and subsequent inflammatory injury in fatty liver IR process. Targeting TLR2/ATF4 signaling may offer a novel therapeutic strategy for mitigating S100A9-mediated liver injury.

In-vitro scientific validation of anti-inflammatory activity of Punica granatum L. on Leukemia monocytic cell line

Background: The induction of the inflammatory cascade results in the production of a number of inflammatory mediators, including prostaglandin E2 (PGE2), nitric oxide (NO), and proinflammatory cytokines like TNF-, IL-, and IL-6. This study examined the cytotoxicity and anti-inflammatory properties of a methanolic crude extract of Punica granatum L. peel (PPM) on monocytic leukaemia cell line (THP-1). Materials and methods: The PPM along with Quercetin as reference was used to assess the cytotoxic effect on THP-1 cells and describe its effect on pro-inflammatory cytokines such as COX-2, TNF-α, IL-6 against cancer cell line by flow cytometry. Results: The percentage of viable cells significantly decreased which correlates to non-toxicity whereas quercetin was found to be highly toxic, the IC50 could not be calculated because of drug precipitation. There was a significant decrease in the expressions of inflammatory cytokines upon pre-treatment of the cells with PPM prior to LPS stimulation. Conclusion: Our findings indicate that no cytotoxicity was observed after the treatment of THP-1 cells with PPM (25-400 µg/ml), but at higher concentration (400µg/ml), the cell viability decreased to 84% and attenuated the expression level of inflammatory cytokines. The inhibitory effect of the extract on pro-inflammatory factors production may provide a theoretical source on upcoming treatment of inflammation. Keywords: Punica granatum L; Monocytic leukaemia cell line; cytotoxicity; anti-inflammation.

Involvement of the Kinin B1 Receptor in Increased Permeability of Cerebral Microvessels in Rats Subjected to Autoimmune Encephalomyelitis.

Kinins are vasoactive peptides that are involved in various cellular mechanisms, including the inflammatory response. Kinins, released in vessel walls, exacerbate inflammation by modulating the production and release of pro-inflammatory factors via two types of G protein-related receptors-B1 and B2 receptors. B1 R is overexpressed during the inflammation that accompanies numerous neurological disorders, including multiple sclerosis (MS), in which loss of BBB integrity is an early pathomechanism of the disease. In this work, we apply pharmacological inhibition of the kinin B1 receptor with DALBK to investigate its effect on blood-brain barrier (BBB) permeability during the course of EAE, an animal model of MS. Functional, ultrastructural and molecular analyses were performed. The expression of selected BBB-associated proteins such as occludin and claudin-5 was assessed, as well as the astrocytic marker GFAP. We show that administration of a specific antagonist attenuates neurological symptoms in EAE rats and recovers the downregulation of TJ proteins and BBB leakage observed during the course of the disease, as well as significantly reducing the disease-specific activation of astroglia. The results show that B1 R-mediated signaling is involved in inducing molecular changes at the level of cerebral microvessels, leading to increased permeability of the BBB following neuroinflammation in EAE.

Targeting mast cell activation alleviates anti-MHC I antibody and LPS-induced TRALI in mice by pharmacologically blocking the TLR3 and MAPK pathway

Transfusion-related lung injury (TRALI) poses a significant risk following blood transfusion and remains the primary cause of transfusion-related morbidity and mortality, primarily driven by the activation of immune cells through anti-major histocompatibility complex class I (anti-MHC I) antibody. However, it remains to be defined how immune microenvironmental cue contributes to TRALI. Here, we uncover that activated mast cells within the immune microenvironment promote lung inflammation and injury in antibody-mediated TRALI, both in vitro and in vivo. This was demonstrated by co-culturing lipopolysaccharide (LPS)-pretreated mast cell line with anti-MHC I antibody and establishing a “two-hit” TRALI mouse model through intratracheal injection of LPS followed by tail-vein injection of anti-MHC I antibody. Importantly, mast cell-deficient KitW-sh/W-sh mice exhibited markedly reduced lung inflammation and injury responses in antibody-mediated TRALI compared with wild-type mice. Mechanistically, activation of toll-like receptor 3 (TLR3)/mitogen-activated protein kinase (MAPK) signaling pathway in mast cells contributes to the enhanced production of proinflammatory factors. These excessive proinflammatory factors produced by activated mast cells contribute to lung inflammation and injury in antibody-mediated TRALI. Pharmacologically targeting the TLR3/MAPK pathway to inhibit mast cell activation normalizes the proinflammatory microenvironment and alleviates lung inflammation and injury in the preclinical TRALI mouse model. Overall, we find that activation of mast cells via the TLR3/MAPK pathway contributes to lung inflammation and injury in antibody-mediated TRALI, providing novel insights into its underlying mechanisms. Furthermore, targeting activated mast cells and the associated pathway offers potential therapeutic strategies for antibody-mediated TRALI.

Surface Chemistry Induced IgG Unfolding and Modulation of Immune Responses.

Immunoglobulin G (IgG) comprises a significant portion of the protein corona that forms on biomaterial surfaces and holds a pivotal role in modulating host immune responses. To shed light on the important relationship between biomaterial surface functionality, IgG adsorption, and innate immune responses, we prepared, using plasma deposition, four surface coatings with specific chemistries, wettability, and charge. We found that nitrogen-containing coatings such as these deposited from allylamine (AM) and 2-methyl-2-oxazoline (POX) cause the greatest IgG unfolding, while hydrophilic acrylic acid (AC) surfaces allowed for the retention of the protein structure. Structural changes in IgG significantly modulated macrophage attachment, migration, polarization, and the expression of pro- and anti-inflammatory cytokines. Unfolded IgG on the POX and AM surfaces enhanced macrophage attachment, migration, extracellular trap release, and pro-inflammatory factors production such as IL-6 and TNF-α. Retention of IgG structure on the AC surface downregulated inflammatory responses. The findings of this study demonstrate that the retention of protein structure is an essential factor that must be taken into consideration when designing biomaterial surfaces. Our study indicates that using hydrophilic surface coatings could be a promising strategy for designing immune-modulatory biomaterials for clinical applications.

PEG-SeNPs as therapeutic agents inhibiting apoptosis and inflammation of cells infected with H1N1 influenza A virus

The rapid variation of influenza challenges vaccines and treatments, which makes an urgent task to develop the high-efficiency and low-toxicity new anti-influenza virus drugs. Selenium is one of the essential trace elements for the human body that possesses a good antiviral activity. In this study, we assessed anti-influenza A virus (H1N1) activity of polyethylene glycol (PEG)-modified gray selenium nanoparticles (PEG-SeNPs) on Madin-Darby Canine Kidney (MDCK) cells in vitro. CCK-8 assay showed that PEG-SeNPs had a protective effect on H1N1-infected MDCK cells. Moreover, PEG-SeNPs significantly reduced the mRNA level of H1N1. TUNEL-DAPI test showed that DNA damage reached a high level but effectively prevented after PEG-SeNPs treatment. Meanwhile, JC-1, Annexin V-FITC and cell cycle assay demonstrated the apoptosis induced by H1N1 was reduced greatly when treated with PEG-SeNPs. Furthermore, the downregulation of p-ATM, p-ATR and P53 protein, along with the upregualation of AKT protein indicated that PEG-SeNPs could inhibit H1N1-induced cell apoptosis through reactive oxygen species (ROS)-mediated related signaling pathways. Finally, Cytokine detection demonstrated PEG-SeNPs inhibited the production of pro-inflammatory factors after infection, including IL-1β, IL-5, IL-6, and TNF-α. To sum up, PEG-SeNPs might become a new potential anti-H1N1 influenza virus drug due to its antiviral and anti-inflammatory activity.

Oat anthranilamides regulates high-fat diet-induced intestinal inflammation by the TLR4/NF-κb signalling pathway and gut microbiota

Oat anthranilamides have demonstrated antioxidant and anti-inflammatory effects; however, the precise mechanism of action remains unclear. This study investigated the impact of oat anthranilamide B (AVN B) on high-fat diet (HFD)-induced intestinal inflammation in mice and its underlying mechanisms. The results indicated that AVN B supplementation mitigated weight gain and reduced inflammatory and oxidative stress markers in serum, liver, and intestines. It improved intestinal barrier dysfunction by upregulating the expression levels of Occludin and MUC2 while simultaneously reducing intestinal inflammation by inhibiting the TLR4/NF-κB signalling pathway. Additionally, AVN B treatment improved gut microbiota composition. It increased the abundance of beneficial flora and the production of short-chain fatty acids (SCFAs), especially propionate and butyrate, associated with reduced production of pro-inflammatory factors and enhanced intestinal protection. The findings provide scientific evidence for the potential of AVN B as an anti-inflammatory agent.

Yiqi Huoxue Tongluo formula-containing serum attenuates high glucose-induced injury in microglia via MAPK pathways: Network pharmacology-based analysis and biological validation

IntroductionThe Yiqi Huoxue Tongluo formula (YQHX), containing Astragalus mongholicus Bunge, Angelica sinensis (Oliv.) Diels, Rehmannia glutinosa Libosch., Pueraria lobata (Willd.) Ohwi, Corydalis yanhusuo W.T.Wang, Spatholobus suberectus Dunn, Clematis chinensis Osbeck, is a proprietary formula of the First Affiliated Hospital of Anhui University of Chinese Medicine, and can attenuate diabetic neuropathy pain (DNP). This study aimed to explore the mechanisms underlying YQHX-mediated DNP alleviation. Additionally, the effects of YQHX on BV2 microglia injured by high glucose via the mitogen-activated protein kinase (MAPK) signaling pathways were investigated. MethodsLiquid chromatography tandem mass spectroscopy (LC-MS/MS) was performed to identify the chemical compounds in YQHX. The potential mechanism of YQHX for treating DNP was explored through network pharmacology analysis. The established glucose-induced BV2 cell injury model was treated with varying concentrations of YQHX-containing serum. The effects of YQHX-containing serum and MAPK pathway inhibitors on microglial cells were assessed by Cell Counting Kit-8 and enzyme-linked immunosorbent assays. The messenger RNA (mRNA) and protein levels of microglial marker OX42 were measured. Additionally, phosphorylated-p38, -c-Jun-terminal kinase, and -extracellular signal-regulated kinase and downstream nuclear factor-κB/p65 and phosphorylated-activating transcription factor 2 (ATF2) proteins were detected by western blotting. ResultsIn total, 503 chemical components were identified in YQHX by LC-MS/MS analysis. Network pharmacology results showed 203 active ingredients and 363 overlapping targets, respectively, as potential therapeutic candidates for YQHX-mediated DNP treatment. Additionally, the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis yielded a total of 105 signal pathways. Notably, YQHX considerably improved the cell viability of BV2 cells (P < 0.01), remarkably reduced the production of proinflammatory factors (P < 0.01), significantly increased the production of anti-inflammatory factors (P < 0.01), and markedly inhibited the mRNA and protein levels of OX42 (P < 0.01). Furthermore, YQHX treatment inhibited MAPK activation and ATF2 expression. ConclusionsYQHX may protect against high-glucose-induced BV2 microglial cell injury by inhibiting the activation of MAPKs and downstream ATF2, thus, reducing microglial activation and proinflammatory cytokine release. These results provide a foundational theoretical basis for exploring the further mechanism of YQHX in treating DNP, and they provide a novel target for the application of traditional Chinese medicine.

Anabolic deficits and divergent unfolded protein response underlie skeletal and cardiac muscle growth impairments in the Yoshida hepatoma tumor model of cancer cachexia.

Cancer cachexia manifests as whole body wasting, however, the precise mechanisms governing the alterations in skeletal muscle and cardiac anabolism have yet to be fully elucidated. In this study, we explored changes in anabolic processes in both skeletal and cardiac muscles in the Yoshida AH-130 ascites hepatoma model of cancer cachexia. AH-130 tumor-bearing rats experienced significant losses in body weight, skeletal muscle, and heart mass. Skeletal and cardiac muscle loss was associated with decreased ribosomal (r)RNA, and hypophosphorylation of the eukaryotic factor 4E binding protein 1. Endoplasmic reticulum stress was evident by higher activating transcription factor mRNA in skeletal muscle and growth arrest and DNA damage-inducible protein (GADD)34 mRNA in both skeletal and cardiac muscles. Tumors provoked an increase in tissue expression of interferon-γ in the heart, while an increase in interleukin-1β mRNA was apparent in both skeletal and cardiac muscles. We conclude that compromised skeletal muscle and heart mass in the Yoshida AH-130 ascites hepatoma model involves a marked reduction translational capacity and efficiency. Furthermore, our observations suggest that endoplasmic reticulum stress and tissue production of pro-inflammatory factors may play a role in the development of skeletal and cardiac muscle wasting.

In vitro and in vivo effects of pectin‐type polysaccharides isolated from crabapples (Malus prunifolia) on inflammatory colitis models

SummaryThe aim of this study was to investigate the anti‐inflammatory effects of polysaccharides extracted from crabapples (Malus prunifolia; MP) in vitro and in vivo. Crabapples were subjected to hot water extraction to obtain MP‐HW, which was further separated into low (MP‐L) and high molecular weight (MW) (crude polysaccharide; MP‐CP) fractions by ethanol precipitation. Based on MW distribution, general composition, component sugars, and Fourier transform infrared spectroscopy, MP‐CP was identified as a pectin‐type polysaccharide rich in galacturonic acid with an MW of 106.2 kDa. MP‐CP inhibited the production and mRNA expression of proinflammatory factors in an IL‐1β‐treated intestinal epithelial cell model. In addition, MP‐CP significantly alleviated the body weight, disease activity index score, colon length, and spleen weight in mice with dextran sulfate sodium (DSS)‐induced colitis. The MP‐CP‐treated group showed effective regulation of the expression of pro‐ and anti‐inflammatory factors and immunoglobulin A than the DSS‐treated group. Haematoxylin and eosin and Alcian blue staining revealed that MP‐CP alleviated inflammatory manifestations and mucin expression in the intestinal lumen. Collectively, pectin‐type polysaccharides isolated from crabapples may be used as a new functional food and pharmaceutical agent for the prevention and treatment of inflammatory colitis.

Mulberroside A mitigates intervertebral disc degeneration by inhibiting MAPK and modulating Ppar-γ/NF-κB pathways

BackgroundIntervertebral disc degeneration (IVDD) is a common spine disease with inflammation as its main pathogenesis. Mulberroside A (MA), isolated from herbal medicine, possesses anti-inflammatory characteristics in many diseases. Whereas, there is little exploration of the therapeutic potential of MA on IVDD. This study aimed at the therapeutic potential of MA on IVDD in vivo and in vitro and the mechanism involved.MethodsIn vitro, western blotting, RT-qPCR, and immunofluorescence analysis were implemented to explore the bioactivity of MA on interleukin-1 beta (IL-1β)-induced inflammation nucleus pulposus cells (NPCs) isolated from Sprague-Dawley male rats. In vivo, X-ray and MRI were applied to measure the morphological changes, and histological staining and immunohistochemistry were employed to investigate the histological changes of intervertebral disc sections on puncture-induced IVDD rat models.ResultsIn vitro, MA up-regulated the expression level of anabolic-related proteins (Aggrecan and Collagen II) and decreased catabolic-related proteins (Mmp2, Mmp3, Mmp9, and Mmp13) in IL-1β-induced NPCs. Furthermore, MA inhibits the production of pro-inflammatory factors (Inos, Cox-2, and Il-6) stimulated by IL-1β. Mechanistically, MA inhibited the signal transduction of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) pathways in IL-1β-induced NPCs. Moreover, MA might bind to Ppar-γ and then suppress the NF-kB pathway. In vivo experiment illustrated that MA mitigates the IVDD progression in puncture-induced IVDD model. X-ray and MRI images showed MA restore the disc height and T2-weighted signal intensity after puncturing. H&E and Safranin O/Fast Green also showed MA also alleviated morphological changes caused by acupuncture. In addition, MA reversed the expression level of Mmp13, Aggrecan, Collagen II, and Ppar-γ induced in IVDD models.ConclusionsMA inhibited degenerative phenotypes in NPCs and alleviated IVDD progression via inhibiting the MAPK and NF-κB pathways; besides, MA suppressed the NF-κB pathway was attributed to activating Ppar-γ, those supported that MA or Ppar-γ might be a potential drug or target for IVDD.

Cocaine-derived hippuric acid activates mtDNA-STING signaling in alcoholic liver disease: Implications for alcohol and cocaine co-abuse

The simultaneous abuse of alcohol-cocaine is known to cause stronger and more unpredictable cellular damage in the liver, heart, and brain. However, the mechanistic crosstalk between cocaine and alcohol in liver injury remains unclear. The findings revealed cocaine-induced liver injury and inflammation in both marmosets and mice. Of note, co-administration of cocaine and ethanol in mice causes more severe liver damage than individual treatment. The metabolomic analysis confirmed that hippuric acid (HA) is the most abundant metabolite in marmoset serum after cocaine consumption and that is formed in primary marmoset hepatocytes. HA, a metabolite of cocaine, increases mitochondrial DNA leakage and subsequently increases the production of proinflammatory factors via STING signaling in Kupffer cells (KCs). In addition, conditioned media of cocaine-treated KC induced hepatocellular necrosis via alcohol-induced TNFR1. Finally, disruption of STING signaling in vivo ameliorated co-administration of alcohol- and cocaine-induced liver damage and inflammation. These findings postulate intervention of HA-STING-TNFR1 axis as a novel strategy for treatment of alcohol- and cocaine-induced excessive liver damage.Graphical

The pivotal role of dysregulated autophagy in the progression of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is a clinicopathologic syndrome characterized by excessive fat deposition in hepatocytes and a major cause of end-stage liver disease. Autophagy is a metabolic pathway responsible for degrading cytoplasmic products and damaged organelles, playing a pivotal role in maintaining the homeostasis and functionality of hepatocytes. Recent studies have shown that pharmacological intervention to activate or restore autophagy provides benefits for liver function recovery by promoting the clearance of lipid droplets (LDs) in hepatocytes, decreasing the production of pro-inflammatory factors, and inhibiting activated hepatic stellate cells (HSCs), thus improving liver fibrosis and slowing down the progression of NAFLD. This article summarizes the physiological process of autophagy, elucidates the close relationship between NAFLD and autophagy, and discusses the effects of drugs on autophagy and signaling pathways from the perspectives of hepatocytes, kupffer cells (KCs), and HSCs to provide assistance in the clinical management of NAFLD.

SHP-1 mediates cigarette smoke extract-induced epithelial-mesenchymal transformation and inflammation in 16HBE cells.

Src-homology region 2 domain-containing phosphatase 1 (SHP-1) is considered an anti-inflammatory factor, but its role in chronic obstructive pulmonary disease (COPD) remains unknown. Herein, overexpression of SHP-1 was utilized to explore the functions of SHP-1 in COPD models established by stimulating 16HBE cells with cigarette smoke extracts (CSE) in vitro. SHP-1 was downregulated in both COPD patients and CES-treated 16HBE cells. SHP-1 overexpression reinforced cell viability and significantly prevented CSE-induced cell apoptosis in 16HBE cells. Furthermore, SHP-1 overexpression greatly reversed the CSE-induced migration, epithelial-mesenchymal transition (EMT), and pro-inflammatory factor production in 16HBE cells. In addition, CSE activated the P65 and PI3K/AKT pathways in 16HBE cells, which was also reversed by SHP-1 overexpression. Our findings indicated that SHP-1 alleviated CSE-induced EMT and inflammation in 16HBE cells, suggesting that SHP-1 regulated the development of COPD, and these functions may be linked to the inhibition of the PI3K/AKT pathway.

Effect of rhamnogalacturonan-I-rich polysaccharides isolated from crabapple hydrolysates on IL-1β-induced inflammation in intestinal epithelial cells

This study aimed to investigate the structural characteristics and intracellular mechanisms of polysaccharides (MP-PE-I) purified from a crabapple (Malus prunifolia) enzymatic hydrolysate (MP-PE). Activity-guided fractionation revealed that MP-PE-I was the active moiety and significantly reduced the production and gene expression of pro-inflammatory factors in interleukin (IL)-1β-treated intestinal epithelial cells (Caco-2). Moreover, MP-PE-I downregulated the phosphorylation and nuclear localization of proteins involved in the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways, as evidenced by immunoblotting and immunofluorescence analysis. In antagonistic studies with specific inhibitors of the MAPK and NF-κB pathways, IL-6 inhibition was significantly regulated by p38; IL-8 by IκBα, JNK, and p38; and monocyte chemoattractant protein-1 (MCP-1) by JNK, p38, and ERK. Additionally, MP-PE-I significantly decreased the mRNA and protein expression of IL-1 receptor type 1. Chemical and structural characteristic analyses showed that MP-PE-I is a polysaccharide rich in rhamnogalacturonan (RG)-I and plays a crucial role in intestinal immunomodulation. To our knowledge, this is the first study to demonstrate the intestinal immunomodulatory activity, intracellular mechanisms, and structural characteristics of RG-I-rich polysaccharides isolated from crabapples.

Beta-Blockers as an Immunologic and Autonomic Manipulator in Critically Ill Patients: A Review of the Recent Literature.

The autonomic nervous system plays a key role in maintaining body hemostasis through both the sympathetic and parasympathetic nervous systems. Sympathetic overstimulation as a reflex to multiple pathologies, such as septic shock, brain injury, cardiogenic shock, and cardiac arrest, could be harmful and lead to autonomic and immunologic dysfunction. The continuous stimulation of the beta receptors on immune cells has an inhibitory effect on these cells and may lead to immunologic dysfunction through enhancing the production of anti-inflammatory cytokines, such as interleukin-10 (IL-10), and inhibiting the production of pro-inflammatory factors, such as interleukin-1B IL-1B and tissue necrotizing factor-alpha (TNF-alpha). Sympathetic overstimulation-induced autonomic dysfunction may also happen due to adrenergic receptor insensitivity or downregulation. Administering anti-adrenergic medication, such as beta-blockers, is a promising treatment to compensate against the undesired effects of adrenergic surge. Despite many misconceptions about beta-blockers, beta-blockers have shown a promising effect in decreasing mortality in patients with critical illness. In this review, we summarize the recently published articles that have discussed using beta-blockers as a promising treatment to decrease mortality in critically ill patients, such as patients with septic shock, traumatic brain injury, cardiogenic shock, acute decompensated heart failure, and electrical storm. We also discuss the potential pathophysiology of beta-blockers in various types of critical illness. More clinical trials are encouraged to evaluate the safety and effectiveness of beta-blockers in improving mortality among critically ill patients.

Microglial purinergic signaling in Alzheimer's disease.

Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disease. The prevalent features of AD pathogenesis are the appearance of β-amyloid (Aβ) plaques and neurofibrillary tangles, which cause microglial activation, synaptic deficiency, and neuronal loss. Microglia accompanies AD pathological processes and is also linked to cognitive deficits. Purinergic signaling has been shown to play a complex and tight interplay with the chemotaxis, phagocytosis, and production of pro-inflammatory factors in microglia, which is an important mechanism for regulating microglia activation. Here, we review recent evidence for interactions between AD, microglia, and purinergic signaling and find that the purinergic P2 receptors pertinently expressed on microglia are the ionotropic receptors P2X4 and P2X7, and the subtypes of P2YRs expressed by microglia are metabotropic receptors P2Y2, P2Y6, P2Y12, and P2Y13. The adenosine P1 receptors expressed in microglia include A1R, A2AR, and A2BR. Among them, the activation of P2X4, P2X7, and adenosine A1, A2A receptors expressed in microglia can aggravate the pathological process of AD, whereas P2Y2, P2Y6, P2Y12, and P2Y13 receptors expressed by microglia can induce neuroprotective effects. However, A1R activation also has a strong neuroprotective effect and has a significant anti-inflammatory effect in chronic neuroinflammation. These receptors regulate a variety of pathophysiological processes in AD, including APP processing, Aβ production, tau phosphorylation, neuroinflammation, synaptic dysfunction, and mitochondrial dysfunction. This review also provides key pharmacological advances in purinergic signaling receptors.

Polydatin attenuates diabetic renal inflammatory fibrosis via the inhibition of STING pathway

Diabetic nephropathy (DN) is a complication of diabetes and is mainly characterized by renal fibrosis, which could be attributed to chronic kidney inflammation. Stimulator of interferon genes (STING), a linker between immunity and metabolism, could ameliorate various metabolic and inflammatory diseases. However, the regulatory role of STING in DN remains largely unexplored. In this study, knockdown of STING decreased extracellular matrix (ECM), pro-inflammatory, and fibrotic factors in high glucose (HG)-induced glomerular mesangial cells (GMCs), whereas overexpression of STING triggered the inflammatory fibrosis process, suggesting that STING was a potential target for DN. Polydatin (PD) is a glucoside of resveratrol and has been reported to ameliorate DN by inhibiting inflammatory responses. Nevertheless, whether PD improved DN via STING remains unclear. Here, transcriptomic profiling implied that the STING/NF-κB pathway might be an important target for PD. We further found that PD decreased the protein expression of STING, and subsequently suppressed the activation of downstream targets including TBK1 phosphorylation and NF-κB nuclear translocation, and eventually inhibited the production of ECM, pro-inflammatory and fibrotic factors in HG-induced GMCs. Notably, results of molecular docking, molecular dynamic simulations, surface plasmon resonance, cellular thermal shift assay and Co-immunoprecipitation assay indicated that PD directly bound to STING and restored the declined proteasome-mediated degradation of STING induced by HG. In diabetic mice, PD also inhibited the STING pathway and improved the pathological changes of renal inflammatory fibrosis. Our study elucidated the regulatory role of STING in DN, and the novel mechanism of PD treating DN via inhibiting STING expression.

A Dose-Response Study on Functional and Transcriptomic Effects of FSH on Ex Vivo Mouse Folliculogenesis.

Follicle-stimulating hormone (FSH) binds to its membrane receptor (FSHR) in granulosa cells to activate various signal transduction pathways and drive the gonadotropin-dependent phase of folliculogenesis. Both FSH insufficiency (due to genetic or nongenetic factors) and FSH excess (as encountered with ovarian stimulation in assisted reproductive technology [ART]) can cause poor female reproductive outcomes, but the underlying molecular mechanisms remain elusive. Herein, we conducted single-follicle and single-oocyte RNA sequencing analysis along with other approaches in an ex vivo mouse folliculogenesis and oogenesis system to investigate the effects of different concentrations of FSH on key follicular events. Our study revealed that a minimum FSH threshold is required for follicle maturation into the high estradiol-secreting preovulatory stage, and such threshold is moderately variable among individual follicles between 5 and 10 mIU/mL. FSH at 5, 10, 20, and 30 mIU/mL induced distinct expression patterns of follicle maturation-related genes, follicular transcriptomics, and follicular cAMP levels. RNA sequencing analysis identified FSH-stimulated activation of G proteins and downstream canonical and novel signaling pathways that may critically regulate follicle maturation, including the cAMP/PKA/CREB, PI3K/AKT/FOXO1, and glycolysis pathways. High FSH at 20 and 30 mIU/mL resulted in noncanonical FSH responses, including premature luteinization, high production of androgen and proinflammatory factors, and reduced expression of energy metabolism-related genes in oocytes. Together, this study improves our understanding of gonadotropin-dependent folliculogenesis and provides crucial insights into how high doses of FSH used in ART may impact follicular health, oocyte quality, pregnancy outcome, and systemic health.

RND3 modulates microglial polarization and alleviates neuroinflammation in Parkinson's disease by suppressing NLRP3 inflammasome activation

Neuroinflammation mediated by microglia plays an important role in the etiology of Parkinson's disease (PD). Rho family GTPase 3 (RND3) exerts anti-inflammatory effects and may act as a potential new inducer of neuroprotective phenotypes in microglia. However, whether RND3 can be used to regulate microglia activation or reduce neuroinflammation in PD remains elusive. The study investigated the microglia modulating effects and potential anti-inflammatory effects of RND3 in vivo and in vitro, using animal models of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD and cell models of BV-2 cells stimulated by LPS plus IFN-γ with or without RND3-overexpression. The results showed that RND3 was highly expressed in the MPTP-induced PD mouse model and BV-2 cells treated with LPS and IFN-γ. In vivo experiments confirmed that RND3 overexpression could modulate microglia phenotype and ameliorate MPTP-induced neuroinflammation through inhibiting activation of the NLRP3 inflammasome in substantia nigra pars compacta (SNpc). In vitro study showed that RND3 overexpression could attenuate the production of pro-inflammatory factors in BV2 cells stimulated by LPS and IFN-γ. Mechanistically, RND3 reduced the activation of the NLRP3 inflammasome upon LPS and IFN-γ stimulation. Taken together, these findings suggest that RND3 modulates microglial polarization and alleviates neuroinflammation in Parkinson's disease by suppressing NLRP3 inflammasome activation.