Upregulation Of Proinflammatory Genes Research Articles

Transcriptional and phenotypical alterations associated with a gradual benzo[a]pyrene-induced transition of human bronchial epithelial cells into mesenchymal-like cells

The role of benzo[a]pyrene (BaP), a prominent genotoxic carcinogen and aryl hydrocarbon receptor (AhR) ligand, in tumor progression remains poorly characterized. We investigated the impact of BaP on the process of epithelial-mesenchymal transition (EMT) in normal human bronchial epithelial HBEC-12KT cells. Early morphological changes after 2-week exposure were accompanied with induction of SERPINB2, IL1, CDKN1A/p21 (linked with cell cycle delay) and chemokine CXCL5. After 8-week exposure, induction of cell migration and EMT-related pattern of markers/regulators led to induction of further pro-inflammatory cytokines or non-canonical Wnt pathway ligand WNT5A. This trend of up-regulation of pro-inflammatory genes and non-canonical Wnt pathway constituents was observed also in the BaP-transformed HBEC-12KT-B1 cells. In general, transcriptional effects of BaP differed from those of TGFβ1, a prototypical EMT inducer, or a model non-genotoxic AhR ligand, TCDD. Carcinogenic polycyclic aromatic hydrocarbons could thus induce a unique set of molecular changes linked with EMT and cancer progression.

NF-κB as an Inducible Regulator of Inflammation in the Central Nervous System.

The NF-κB (nuclear factor K-light-chain-enhancer of activated B cells) transcription factor family is critical for modulating the immune proinflammatory response throughout the body. During the resting state, inactive NF-κB is sequestered by IκB in the cytoplasm. The proteasomal degradation of IκB activates NF-κB, mediating its translocation into the nucleus to act as a nuclear transcription factor in the upregulation of proinflammatory genes. Stimuli that initiate NF-κB activation are diverse but are canonically attributed to proinflammatory cytokines and chemokines. Downstream effects of NF-κB are cell type-specific and, in the majority of cases, result in the activation of pro-inflammatory cascades. Acting as the primary immune responders of the central nervous system, microglia exhibit upregulation of NF-κB upon activation in response to pathological conditions. Under such circumstances, microglial crosstalk with other cell types in the central nervous system can induce cell death, further exacerbating the disease pathology. In this review, we will emphasize the role of NF-κB in triggering neuroinflammation mediated by microglia.

AgNPs-induced oxidative stress and inflammation confer an increased susceptibility to aquatic reovirus infection

Silver nanoparticles (AgNPs) are increasingly utilized in diverse fields due to their superior physical properties and antimicrobial effects. However, the continuous release of AgNPs into aquatic environments may pose potential hazards to aquatic animals and cause toxicological effects. Nevertheless, there is a lack of research regarding whether chronic exposure to AgNPs induces immunotoxicity that affects the susceptibility of aquatic animals to pathogens, and its precise mechanism of action remains largely unknown. Herein, by deploying AgNP stress and an aquatic reovirus (grass carp reovirus, GCRV) infection as a model system, we illustrated that exposure to AgNPs resulted in chronic oxidative stress and inflammatory effects in grass carp, which included the deposition of silver particles in tissues, impaired activity of antioxidant enzymes, overt tissue damage, imbalances of gut microbiota composition, and induction of inflammatory responses. Additionally, AgNPs exposure in conjunction with GCRV infection led to a noteworthy rise in viral loads and upregulation of pro-inflammatory genes, as compared to the control group. This work suggests that chronic stress by AgNPs may enhance susceptibility to aquatic virus infection through oxidative stress and inflammatory effects, providing fresh insights to elucidate the disease development in aquatic animals caused by heavy metal pollution.

Expression network analysis of bovine skin infested with Rhipicephalus australis identifies pro-inflammatory genes contributing to tick susceptibility

The skin is the primary feeding site of ticks that infest livestock animals such as cattle. The highly specialised functions of skin at the molecular level may be a factor contributing to variation in susceptibility to tick infestation; but these remain to be well defined. The aim of this study was to investigate the bovine skin transcriptomic profiles of tick-naïve and tick-infested cattle and to uncover the gene expression networks that influence contrasting phenotypes of host resistance to ticks. RNA-Seq data was obtained from skin of Brangus cattle with high (n = 5) and low (n = 6) host resistance at 0 and 12 weeks following artificial tick challenge with Rhipicephalus australis larvae. No differentially expressed genes were detected pre-infestation between high and low resistance groups, but at 12-weeks there were 229 differentially expressed genes (DEGs; FDR < 0.05), of which 212 were the target of at least 1866 transcription factors (TFs) expressed in skin. Regulatory impact factor (RIF) analysis identified 158 significant TFs (P < 0.05) of which GRHL3, and DTX1 were also DEGs in the experiment. Gene term enrichment showed the significant TFs and DEGs were enriched in processes related to immune response and biological pathways related to host response to infectious diseases. Interferon Type 1-stimulated genes, including MX2, ISG15, MX1, OAS2 were upregulated in low host resistance steers after repeated tick challenge, suggesting dysregulated wound healing and chronic inflammatory skin processes contributing to host susceptibility to ticks. The present study provides an assessment of the bovine skin transcriptome before and after repeated tick challenge and shows that the up-regulation of pro-inflammatory genes is a prominent feature in the skin of tick-susceptible animals. In addition, the identification of transcription factors with high regulatory impact provides insights into the potentially meaningful gene–gene interactions involved in the variation of phenotypes of bovine host resistance to ticks.

Genetic changes from type I interferons and JAK inhibitors: clues to drivers of juvenile dermatomyositis.

To better understand the pathogenesis of juvenile dermatomyositis (JDM), we examined the effect of the cytokines type I interferons (IFN I) and JAK inhibitor drugs (JAKi) on gene expression in bioengineered pediatric skeletal muscle. Myoblasts from 3 healthy pediatric donors were used to create three-dimensional skeletal muscle units termed myobundles. Myobundles were treated with IFN I, either IFNα or IFNβ. A subset of IFNβ-exposed myobundles was treated with JAKi tofacitinib or baricitinib. RNA sequencing analysis was performed on all myobundles. Seventy-six myobundles were analyzed. Principal component analysis showed donor-specific clusters of gene expression across IFNα and IFNβ-exposed myobundles in a dose-dependent manner. Both cytokines upregulated interferon response and proinflammatory genes; however, IFNβ led to more significant upregulation. Key downregulated pathways involved oxidative phosphorylation, fatty acid metabolism and myogenesis genes. Addition of tofacitinib or baricitinib moderated the gene expression induced by IFNβ, with partial reversal of upregulated inflammatory and downregulated myogenesis pathways. Baricitinib altered genetic profiles more than tofacitinib. IFNβ leads to more pro-inflammatory gene upregulation than IFNα, correlating to greater decrease in contractile protein gene expression and reduced contractile force. JAK inhibitors, baricitinib more so than tofacitinib, partially reverse IFN I-induced genetic changes. Increased IFN I exposure in healthy bioengineered skeletal muscle leads to IFN-inducible gene expression, inflammatory pathway enrichment, and myogenesis gene downregulation, consistent with what is observed in JDM.

Macrophage Responses Against Acellularized Dermal Matrix from Human Versus Porcine Predicts the In-vivo Fibrosis

Background: Due to the possible difference in the manufacturer’s processes, in-vitro and in-vivo tests might be beneficial for the selection of an Acellularized Dermal Matrix (ADM). Methods: ADMs from human and porcine were replaced the mouse skins and tested macrophage reactions using RAW264.7 cells. Results: In comparison with porcine ADM, human ADM induced higher reaction and fibrosis on mouse histology at 2 wk (but became similar between groups at 14 wk post-operation) and induced higher upregulation of pro-inflammatory genes at 24 h post-macrophage stimulation. Conclusion: Macrophage responses were proposed to use for the prediction of in-vivo ADM responses which might be beneficial for the ADM selection.

Dietary alpha-lipoic acid boosts growth, immune-antioxidant traits, behavior, and transcriptomes of antioxidant, apoptosis, and immune-related genes to combat cold stress in Nile tilapia (Oreochromis niloticus)

AbstractWater temperature is a major environmental factor affecting fish activity, physiology, behavior, and growth. Alpha lipoic acid (ALA) has garnered much attention lately as an aqua feed supplement because of its antioxidant effects. Thus, this study aimed to assess the effect of dietary ALA on performance, hematological and immunological indices, behavior and oxidative stress, apoptosis, and genetic inflammation in Oreochromis niloticus following 60 days of cold stress. Two hundred forty fish were divided into four groups (15 fish/replicate, N = 60 fish/group). The control (CNT) and ALA groups were reared at 25 °C and fed a basal diet without any supplementation or a basal diet containing 600 mg ALA/kg diet, respectively. The cold water-stressed group (CWS) and ALA + CWS groups were reared at 18 °C and fed basal and basal diets containing ALA, respectively. The results revealed that dietary ALA supplementation significantly improved feed utilization and growth in fish. ALA also mitigated CWS-induced microcytic hypochromic anemia and hyperlipidemia. Moreover, ALA supplementation considerably enhanced the antioxidant status and boosted intestinal α amylase, lipase, protease, and serum acetylcholinesterase activity of CWS-exposed fish. Besides, ALA supplementation significantly reversed CWS-induced upregulation of proinflammatory genes, pro-apoptotic genes, heat shock protein, and proliferating cell nuclear antigen or downregulation of superoxide dismutase and catalase gene expressions in liver and spleen tissues. Furthermore, ALA supplementation reduced CWS-induced histopathological alterations in fish liver, spleen, and intestine. We can conclude that ALA (600 mg/kg diet) could be recommended as an aqua feed supplement to boost growth, antioxidant capacity, and immunity and attenuate inflammatory and apoptotic reactions of fish reared under CWS-induced.

Fucoxanthin Abrogates Ionizing Radiation-Induced Inflammatory Responses by Modulating Sirtuin 1 in Macrophages.

Ionizing radiation (IR) triggers an overproduction of reactive oxygen species (ROS), disrupting the normal function of both immune and metabolic systems, leading to inflammation and metabolic disturbances. To address the pressing requirement for protection against IR, fucoxanthin (FX), a naturally occurring compound extracted from algae, was utilized as an efficient radioprotective agent in macrophages. In this study, we cultured murine RAW 264.7 macrophages and treated them with FX, along with agents influencing the activity of sirtuin 1 (SIRT1) and estrogen receptor α (ERα), to investigate their impact on IR-induced cellular responses. FX significantly attenuated IR-induced upregulation of pro-inflammatory genes (Il1b, Tnf, and Ccl2) and inhibited macrophage polarization toward the pro-inflammatory M1 phenotype. Additionally, FX regulated IR-induced metabolic genes mediating glycolysis and mitochondrial biogenesis. The ability of FX to mitigate IR-induced inflammation and glycolysis was ascribed to the expression and activity of SIRT1 and ERα in macrophages. This study not only uncovers the underlying mechanisms of FX's radioprotective properties but also highlights its potential as a protective agent against the detrimental effects of IR, thus offering new opportunities for enhancing radiation protection in the future.

Reproductive Immunology and Embryo Acceptance

Pregnancy is a test of the fundamental laws of transplantation immunology - the coexistence of genetically disparate tissues without host immune rejection. Advances over recent decades show that implantation and placental development depend on an active state of maternal immune tolerance, and breakdown of tolerance is a key contributor to infertility and recurrent pregnancy loss. Tolerance in pregnancy depends on regulatory T (Treg) cells, which are critical to inhibit effector immunity, constrain inflammation, and support maternal vascular adaptations that allow placental access to maternal nutrient supply. Treg cell defects are implicated in disorders of embryo implantation and placental development, but the origins of Treg cell dysfunction are unknown. In recent studies, we have comprehensively analysed the phenotypes and transcriptional profile of peripheral blood Treg cells in individuals with early pregnancy failure (recurrent miscarriage and recurrent implantation failure). Compared to fertile women, women with early pregnancy failure have fewer total Treg cells and altered Treg cell phenotypes, accompanied by lower Treg:Th1 and Treg:Th17 ratios. RNAseq demonstrates an aberrant Treg cell gene expression profile in early pregnancy failure, with upregulation of pro-inflammatory genes including CSF2, IL4, IL17A, IL21, and IFNG. Our data indicate that Treg cell defects in women with early pregnancy failure can arise due to loss of lineage fidelity associated with impaired FOXP3 regulation. Factors including metabolic function, luteal phase progesterone, and male partner seminal fluid components are all implicated in causing Treg cell deficit. Treg cells may be a useful target for therapeutic interventions to improve uterine receptivity, but this will depend on developing diagnostic tests that are informative. Moreover, safe, and effective interventions to modulate these cells are in their infancy, and personalized approaches matched to specific diagnostic criteria will be needed.

BET Protein Inhibitor JQ1 Ameliorates Experimental Peritoneal Damage by Inhibition of Inflammation and Oxidative Stress.

Peritoneal dialysis (PD) is a current replacement therapy for end-stage kidney diseases (ESKDs). However, long-term exposure to PD fluids may lead to damage of the peritoneal membrane (PM) through mechanisms involving the activation of the inflammatory response and mesothelial-to-mesenchymal transition (MMT), leading to filtration failure. Peritoneal damage depends on a complex interaction among external stimuli, intrinsic properties of the PM, and subsequent activities of the local innate-adaptive immune system. Epigenetic drugs targeting bromodomain and extra-terminal domain (BET) proteins have shown beneficial effects on different experimental preclinical diseases, mainly by inhibiting proliferative and inflammatory responses. However the effect of BET inhibition on peritoneal damage has not been studied. To this aim, we have evaluated the effects of treatment with the BET inhibitor JQ1 in a mouse model of peritoneal damage induced by chlorhexidine gluconate (CHX). We found that JQ1 ameliorated the CHX-induced PM thickness and inflammatory cell infiltration. Moreover, JQ1 decreased gene overexpression of proinflammatory and profibrotic markers, together with an inhibition of the nuclear factor-κB (NF-κB) pathway. Additionally, JQ1 blocked the activation of nuclear factor erythroid 2-related factor 2 (NRF2) and restored changes in the mRNA expression levels of NADPH oxidases (NOX1 and NOX4) and NRF2/target antioxidant response genes. To corroborate the in vivo findings, we evaluated the effects of the BET inhibitor JQ1 on PD patients' effluent-derived primary mesothelial cells and on the MeT-5A cell line. JQ1 inhibited tumor necrosis factor-α (TNF-α)-induced proinflammatory gene upregulation and restored MMT phenotype changes, together with the downmodulation of oxidative stress. Taken together, these results suggest that BET inhibitors may be a potential therapeutic option to ameliorate peritoneal damage.

Mid-old cells are a potential target for anti-aging interventions in the elderly

The biological process of aging is thought to result in part from accumulation of senescent cells in organs. However, the present study identified a subset of fibroblasts and smooth muscle cells which are the major constituents of organ stroma neither proliferative nor senescent in tissues of the elderly, which we termed “mid-old status” cells. Upregulation of pro-inflammatory genes (IL1B and SAA1) and downregulation of anti-inflammatory genes (SLIT2 and CXCL12) were detected in mid-old cells. In the stroma, SAA1 promotes development of the inflammatory microenvironment via upregulation of MMP9, which decreases the stability of epithelial cells present on the basement membrane, decreasing epithelial cell function. Remarkably, the microenvironmental change and the functional decline of mid-old cells could be reversed by a young cell-originated protein, SLIT2. Our data identify functional reversion of mid-old cells as a potential method to prevent or ameliorate aspects of aging-related tissue dysfunction.

Transcriptomic analyses reveal proinflammatory activation of human brain microvascular endothelial cells by aging-associated peptide medin and reversal by nanoliposomes

Medin is a common vascular amyloidogenic peptide recently implicated in Alzheimer’s disease (AD) and vascular dementia and its pathology remains unknown. We aim to identify changes in transcriptomic profiles and pathways in human brain microvascular endothelial cells (HBMVECs) exposed to medin, compare that to exposure to β-amyloid (Aβ) and evaluate protection by monosialoganglioside-containing nanoliposomes (NL). HBMVECs were exposed for 20 h to medin (5 µM) without or with Aβ(1-42) (2 µM) or NL (300 µg/mL), and RNA-seq with signaling pathway analyses were performed. Separately, reverse transcription polymerase chain reaction of select identified genes was done in HBMVECs treated with medin (5 µM) without or with NFκB inhibitor RO106-9920 (10 µM) or NL (300 µg/mL). Medin caused upregulation of pro-inflammatory genes that was not aggravated by Aβ42 co-treatment but reversed by NL. Pathway analysis on differentially expressed genes revealed multiple pro-inflammatory signaling pathways, such as the tumor necrosis factor (TNF) and the nuclear factor-κB (NFkB) signaling pathways, were affected specifically by medin treatment. RO106-9920 and NL reduced medin-induced pro-inflammatory activation. Medin induced endothelial cell pro-inflammatory signaling in part via NFκB that was reversed by NL. This could have potential implications in the pathogenesis and treatment of vascular aging, AD and vascular dementia.

Single cell transcriptomics reveals cell type specific features of developmentally regulated responses to lipopolysaccharide between birth and 5 years.

Human perinatal life is characterized by a period of extraordinary change during which newborns encounter abundant environmental stimuli and exposure to potential pathogens. To meet such challenges, the neonatal immune system is equipped with unique functional characteristics that adapt to changing conditions as development progresses across the early years of life, but the molecular characteristics of such adaptations remain poorly understood. The application of single cell genomics to birth cohorts provides an opportunity to investigate changes in gene expression programs elicited downstream of innate immune activation across early life at unprecedented resolution. In this study, we performed single cell RNA-sequencing of mononuclear cells collected from matched birth cord blood and 5-year peripheral blood samples following stimulation (18hrs) with two well-characterized innate stimuli; lipopolysaccharide (LPS) and Polyinosinic:polycytidylic acid (Poly(I:C)). We found that the transcriptional response to LPS was constrained at birth and predominantly partitioned into classical proinflammatory gene upregulation primarily by monocytes and Interferon (IFN)-signaling gene upregulation by lymphocytes. Moreover, these responses featured substantial cell-to-cell communication which appeared markedly strengthened between birth and 5 years. In contrast, stimulation with Poly(I:C) induced a robust IFN-signalling response across all cell types identified at birth and 5 years. Analysis of gene regulatory networks revealed IRF1 and STAT1 were key drivers of the LPS-induced IFN-signaling response in lymphocytes with a potential developmental role for IRF7 regulation. Additionally, we observed distinct activation trajectory endpoints for monocytes derived from LPS-treated cord and 5-year blood, which was not apparent among Poly(I:C)-induced monocytes. Taken together, our findings provide new insight into the gene regulatory landscape of immune cell function between birth and 5 years and point to regulatory mechanisms relevant to future investigation of infection susceptibility in early life.

PI3K-AKT activation resculpts integrin signaling to drive filamentous tau-induced proinflammatory astrogliosis

BackgroundMicrotubule-binding protein tau is a misfolding-prone protein associated with tauopathies. As tau undergoes cell-to-cell transmission, extracellular tau aggregates convert astrocytes into a pro-inflammatory state via integrin activation, causing them to release unknown neurotoxic factors.ResultsHere, we combine transcriptomics with isotope labeling-based quantitative mass spectrometry analysis of mouse primary astrocyte secretome to establish PI3K-AKT as a critical differentiator between pathogenic and physiological integrin activation; simultaneous activation of PI3K-AKT and focal adhesion kinase (FAK) in tau fibril-treated astrocytes changes the output of integrin signaling, causing pro-inflammatory gene upregulation, trans-Golgi network restructuring, and altered secretory flow. Furthermore, NCAM1, as a proximal signaling component in tau-stimulated integrin and PI3K-AKT activation, facilitates the secretion of complement C3 as a main neurotoxic factor. Significantly, tau fibrils-associated astrogliosis and C3 secretion can be mitigated by FAK or PI3K inhibitors.ConclusionsThese findings reveal an unexpected function for PI3K-AKT in tauopathy-associated reactive astrogliosis, which may be a promising target for anti-inflammation-based Alzheimer’s therapy.

Dietary n-3/n-6 polyunsaturated fatty acid ratio modulates growth performance in spotted seabass (Lateolabrax maculatus) through regulating lipid metabolism, hepatic antioxidant capacity and intestinal health.

An 8-week feeding experiment was carried out to explore the effects of dietary n-3/n-6 polyunsaturated fatty acid (PUFA) ratio on growth performance, lipid metabolism, hepatic antioxidant status, and gut flora of spotted seabass (Lateolabrax maculatus). Six experimental diets were formulated to contain different levels of two purified oil sources including docosahexaenoic and eicosapentaenoic acids enriched oil (n-3) and linoleic acid-enriched oil (n-6) leading to n-3/n-6 PUFA ratios of 0.04, 0.35, 0.66, 1.35, 2.45 and 16.17. Each diet was fed to triplicate groups of juvenile L.maculatus (11.06±0.20g, 30 fish/tank). Final body weight (FBW), weight gain (WG), specific growth rates (SGR), protein efficiency ratio (PER) and feed utilization efficiency increased as n-3/n-6 PUFA ratio increased up to a certain level, and then decreased thereafter. Fish fed the diet with n-3/n-6 PUFA ratio of 0.66 exhibited the highest FBW, WG, SGR and PER and the lowest feed conversion ratio. Lower n-3/n-6 PUFA ratios induced up-regulated expression of lipid synthesis-related genes (fas, acc2 and srebp-1c) and down-regulated expression of lipolysis related genes (atgl, pparα, cpt-1 and aox). Higher expression of lipolysis-related genes (atgl, pparα and cpt-1) was recorded at moderate n-3/n-6 PUFA ratios (0.66 to 1.35). Moreover, inappropriate n-3/n-6 PUFA ratios triggered up-regulation of pro-inflammatory genes (il-6 and tnf-α) and down-regulation of anti-inflammatory genes (il-4 and il-10) in the intestine. The diet with n-3/n-6 PUFA ratio of 0.66 inhibited intestine inflammation, improved intestinal flora richness, increased the abundance of beneficial bacteria such as Lactobacillus, Alloprevotella and Ruminococcus, and reduced the abundance of harmful bacteria including Escherichia-Shigella and Enterococcus. In summary, it could be suggested that a dietary n-3/n-6 PUFA ratio of 0.66 can improve growth performance and feed utilization in L.maculatus, as is deemed to be mediated through regulation of lipid metabolism and intestinal flora.

Transcriptome analysis of multiple tissues reveals the potential mechanism of death under acute heat stress in chicken

BackgroundAcute heat stress could induce high mortality and cause huge economic losses in the poultry industry. Although many studies have revealed heat stress-induced injuries of multiple tissues, the main target tissue and molecular mechanism of death under acute heat stress was largely unknown. This study systematically compared the transcriptome data of five main visceral tissues in chickens to reveal the response of multiple tissues to acute heat stress and determine the main target tissue of acute heat stress, further revealing the injuries of main target tissue and their potential mechanism by combing pathological section and qRT-PCR technologies.ResultsThe transcriptome data of five visceral tissues revealed that acute heat stress broadly caused inflammatory response and damaged tissues metabolic homeostasis. Among the five tested visceral tissues, the number of differentially expressed genes in the lung was the highest, and their fold changes were the greatest, indicating that the lung was the main target tissue of acute heat stress. The results of pathological section revealed severe inflammation, emphysema and pulmonary hemorrhage in the lung under acute heat stress. Our study found that some pro-inflammatory genes, including CNTFR, FURIN, CCR6, LIFR and IL20RA, were significantly up-regulated both in the heat-stress and heat-death groups, and their fold changes in the heat-death group were significantly greater than that in the heat-stress group. We also found an anti-inflammatory gene, AvBD9, exhibiting an extremely high expression in the heat-stress group but a low expression in the heat-death group.ConclusionsOur study found that acute heat stress caused multiple tissue injuries broadly and the lung was the main target tissue of acute heat stress in chicken. Acute heat stress caused a severe inflammatory response, emphysema, and pulmonary haemorrhage, The severe inflammatory response in the heat-death group was related to the up-regulation of pro-inflammatory genes and down-regulation of anti-inflammatory genes.

Neat1 lncRNA organizes the inflammatory gene expressions in the dorsal root ganglion in neuropathic pain caused by nerve injury.

Primary sensory neurons regulate inflammatory processes in innervated regions through neuro-immune communication. However, how their immune-modulating functions are regulated in concert remains largely unknown. Here, we show that Neat1 long non-coding RNA (lncRNA) organizes the proinflammatory gene expressions in the dorsal root ganglion (DRG) in chronic intractable neuropathic pain in rats. Neat1 was abundantly expressed in the DRG and was upregulated after peripheral nerve injury. Neat1 overexpression in primary sensory neurons caused mechanical and thermal hypersensitivity, whereas its knockdown alleviated neuropathic pain. Bioinformatics analysis of comprehensive transcriptome changes indicated the inflammatory response was the most relevant function of genes upregulated through Neat1. Consistent with this, upregulation of proinflammatory genes in the DRG following nerve injury was suppressed by Neat1 knockdown. Expression changes of these proinflammatory genes were regulated through Neat1-mRNA interaction-dependent and -independent mechanisms. Notably, Neat1 increased proinflammatory genes by stabilizing its interacting mRNAs in neuropathic pain. Finally, Neat1 in primary sensory neurons contributed to spinal inflammatory processes that mediated peripheral neuropathic pain. These findings demonstrate that Neat1 lncRNA is a key regulator of neuro-immune communication in neuropathic pain.

CCN2 Activates RIPK3, NLRP3 Inflammasome, and NRF2/Oxidative Pathways Linked to Kidney Inflammation.

Inflammation is a key characteristic of both acute and chronic kidney diseases. Preclinical data suggest the involvement of the NLRP3/Inflammasome, receptor-interacting protein kinase-3 (RIPK3), and NRF2/oxidative pathways in the regulation of kidney inflammation. Cellular communication network factor 2 (CCN2, also called CTGF in the past) is an established fibrotic biomarker and a well-known mediator of kidney damage. CCN2 was shown to be involved in kidney damage through the regulation of proinflammatory and profibrotic responses. However, to date, the potential role of the NLRP3/RIPK3/NRF2 pathways in CCN2 actions has not been evaluated. In experimental acute kidney injury induced with folic acid in mice, CCN2 deficiency diminished renal inflammatory cell infiltration (monocytes/macrophages and T lymphocytes) as well as the upregulation of proinflammatory genes and the activation of NLRP3/Inflammasome-related components and specific cytokine products, such as IL-1β. Moreover, the NRF2/oxidative pathway was deregulated. Systemic administration of CCN2 to C57BL/6 mice induced kidney immune cell infiltration and activated the NLRP3 pathway. RIPK3 deficiency diminished the CCN2-induced renal upregulation of proinflammatory mediators and prevented NLRP3 modulation. These data suggest that CCN2 plays a fundamental role in sterile inflammation and acute kidney injury by modulating the RIKP3/NLRP3/NRF2 inflammatory pathways.

Sulfur metabolic response in macrophage limits excessive inflammatory response by creating a negative feedback loop

The excessive inflammatory response of macrophages plays a vital role in the pathogenesis of various diseases. The dynamic metabolic alterations in macrophages, including amino acid metabolism, are known to orchestrate their inflammatory phenotype. To explore a new metabolic pathway that regulates the inflammatory response, we examined metabolome changes in mouse peritoneal macrophages (PMs) in response to lipopolysaccharide (LPS) and found a coordinated increase of cysteine and its related metabolites, suggesting an enhanced demand for cysteine during the inflammatory response. Because Slc7a11, which encodes a cystine transporter xCT, was remarkably upregulated upon the pro-inflammatory challenge and found to serve as a major channel of cysteine supply, we examined the inflammatory behavior of Slc7a11 knockout PMs (xCT-KO PMs) to clarify an impact of the increased cysteine demand on inflammation. The xCT-KO PMs exhibited a prolonged upregulation of pro-inflammatory genes, which was recapitulated by cystine depletion in the culture media of wild-type PMs, suggesting that cysteine facilitates the resolution of inflammation. Detailed analysis of the sulfur metabolome revealed that supersulfides, such as cysteine persulfide, were increased in PMs in response to LPS, which was abolished in xCT-KO PMs. Supplementation of N-acetylcysteine tetrasulfide (NAC-S2), a supersulfide donor, attenuated the pro-inflammatory gene expression in xCT-KO PMs. Thus, activated macrophages increase cystine uptake via xCT and produce supersulfides, creating a negative feedback loop to limit excessive inflammation. Our study highlights the finely tuned regulation of macrophage inflammatory response by sulfur metabolism.

Sphingosine 1-Phosphate Activates S1PR3 to Induce a Proinflammatory Phenotype in Human Myometrial Cells.

One of the common mechanisms responsible for obstetric complications, affecting millions of women every year, is abnormal uterine contractility. Despite the critical importance of this process for women's health, the mechanisms of uterine contraction regulation remain poorly understood. The initiation of uterine smooth muscle (myometrial) contraction is an inflammatory process, accompanied by upregulation of proinflammatory genes and cytokine release. In this study, we show that sphingolipid metabolism is activated during human labor and that sphingosine 1-phosphate (S1P), the main bioactive sphingolipid, may modify the myometrial proinflammatory phenotype. Our data in both primary and immortalized human myometrial cells show that exogenous S1P induces a proinflammatory gene signature and upregulates the expression of known inflammatory markers of parturition, such as IL8 and COX2. Using expression of IL8 as a readout for S1P activity in myometrial cells, we established that these S1P effects are mediated through the activation of S1P receptor 3 (S1PR3) and downstream activation of ERK1/2 pathways. Inhibition of S1PR3 in human myometrial cells attenuates upregulation of IL8, COX2, and JUNB both at the mRNA and protein levels. Furthermore, activation of S1PR3 with a receptor-specific agonist recapitulated the effects seen after treatment with exogenous S1P. Collectively, these results suggest a signaling pathway activated by S1P in human myometrium during parturition and propose new targets for development of novel therapeutics to alter uterine contractility during management of preterm labor or labor dystocia.