Inflammation最新文献

Necrotizing enterocolitis (NEC) stands as the most prevalent and severe gastrointestinal ailment affecting premature newborns, particularly those with extremely low birth weights. Intestinal barrier dysfunction emerges as a crucial factor in NEC's pathogenesis. REGγ predominantly manifests in the intestinal epithelium and has shown to regulate experimental colitis. However, the potential correlation between REGγ and NEC remains ambiguous. This study reveals that REGγ is notably overexpressed in both human and murine NEC samples. REGγ-deficient mice displayed improvements in intestinal mucosal inflammation and reduced NEC severity. Additionally, REGγ deficiency notably lowered the expression of phosphorylated transcription factor p65 and inflammatory factors in intestinal epithelial cells of NEC-afflicted mice. REGγ exacerbates the local inflammation by triggering the degradation of IκBɛ, a negative regulator of NFκB. Clinically, REGγ and p65 expression levels exhibit a positive correlation in NEC specimens. Moreover, pre-treatment of mice with a p65 inhibitor effectively suppressed the expression of inflammatory mediators and alleviated REGγ-mediated NEC development. These findings underscore that abnormal upregulation of REGγ triggers NEC development by enhancing NF-κB activity and exacerbating epithelial barrier dysfunction. Thus, novel therapeutic approaches targeting REGγ inhibition may offer enhanced treatment for NEC.

Background: Emerging data suggest a complex pathophysiology of chronic subdural hematoma (CSDH) to which an inflammatory response might contribute. The complement system is activated in acute traumatic setting, although its role in CSDH is unknown. To investigate the complement system in CSDH pathophysiology, we analyzed blood and hematoma fluid biomarkers, as well as immunohistochemistry of the CSDH membrane and dura.

Materials and methods: We simultaneously collected CSDH fluid and peripheral blood from 20 CSDH patients at the time of surgery. Biopsies of the dura mater and the CSDH capsule were obtained and analyzed by immunohistochemistry for C5b-C9 or C5a deposition. Biomarkers of inflammation and complement activation were analyzed by a 21-multiplex assay, including Adiponectin, Clusterin, Complement factor C9 and CRP. Complement factor C5a was analyzed separately by a commercial R-plex electrochemiluminescence assay.

Results: Ten biomarkers differed significantly between peripheral blood and paired CSDH of which two were significantly increased in CSDH fluid (Clusterin and Cystatin C). Eight of the significantly altered biomarkers were significantly decreased in CSDH fluid, including C5a, Complement 9 and Adiponectin. There was no immunoreactivity for C5a or the C5b-C9 membrane attack complex in the dura or CSDH membrane.

Conclusions: In CSDH levels of the complement inhibitor Clusterin were increased, whereas levels of C5a and C9 were decreased. Membrane attack complex C5b-C9 was not detected in the membrane or dura surrounding the CSDH. Inhibition of complement could lead to reduced clearance of debris in the CSDH as well as secondary inflammatory reactions.

Inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4) acts as a mediator of inflammation and extracellular matrix stabilization. The current study intended to delve into the impact of ITIH4 on locomotor performance, nerve injury, neuroinflammation, systemic inflammation, and the downstream pathway in spinal cord injury (SCI) mice. Overexpression lentivirus of ITIH4 (LV-ITIH4) and negative control lentivirus (LV-NC) were intravenously injected into adult C57BL/6 mice on 7 days before SCI surgery. All mice were euthanized on day 28 after SCI surgery, and their blood samples and spinal cord tissues were collected. Decreased relative gene expression and protein levels of ITIH4 were observed in SCI mice. LV-ITIH4 improved the locomotor performance compared to LV-NC in SCI mice. In spinal cord of SCI mice, LV-ITIH4 reduced apoptosis and increased survival of neurons compared to LV-NC. By comparison with LV-NC, LV-ITIH4 also reduced relative gene expressions of interleukin (IL)-6 and tumor necrosis factor-α in spinal cord of SCI mice. Moreover, LV-ITIH4 reduced microglia M1 polarization compared with LV-NC in spinal cord of SCI mice. In the serum, LV-ITIH4 decreased the protein levels of IL-6 and IL-1β compared to LV-NC in SCI mice. LV-ITIH4 also inhibited the nuclear factor kappa-B (NF-κB) pathway compared to LV-NC in spinal cord of SCI mice. ITIH4 enhances locomotor performance in SCI mice, and it inhibits nerve injury, neuroinflammation, systemic inflammation, and the NF-κB pathway in SCI mice.

Multiple sclerosis (MS) is a complex, chronic inflammatory disease of the central nervous system, where immune dysregulation plays a critical role. We sought to explore the modulation of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNFɑ) and TNF-like weak inducer of apoptosis (TWEAK), along with their respective autoantibodies, TNAb and TWAb, and to decipher potential associations between these and clinical characteristics which could assist personalized therapy in MS. We also assessed the complementarity to leading candidate biomarkers in MS patient monitoring, namely, glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL). Serum levels of these cytokines and their autoantibodies were measured in 150 MS patients and 186 healthy controls (HC) by ELISA. We found that sTWEAK levels were significantly higher, while sTNFɑ levels were lower in MS patients compared to HC. Additionally, we detected TWAb in 10% of MS patients, a prevalence significantly higher than in HC (4%) and TNAb in only one patient. TWAb-positive patients were significantly younger, had lower EDSS scores, a shorter disease duration, and predominantly presented with the relapsing-remitting form of MS. Together, these results provide new actors to be considered in the development of a biomarker profiling panel to be used in MS patient management. Further research is warranted to elucidate the clinical significance of these autoantibodies and their role in MS neuroinflammatory modulation.

Mitochondrial dysfunction, which can be caused by metabolic stressors such as oxidized low-density lipoprotein (oxLDL), sensitizes the endothelium to pathological changes. The transcription factor interferon regulatory factor 1 (IRF-1) is a master regulator of inflammation, previously shown to promote oxLDL-induced inflammatory pyroptosis in human aortic endothelial cells (HAEC). However, a presumed role for IRF-1 in regulating the intrinsic apoptotic pathway in response to metabolic stress has not been demonstrated. Here targeted deletion of IRF-1 by siRNA in HAEC aggravated oxLDL-induced, mitochondria-mediated intrinsic apoptosis, as evidenced by increased Caspase-3 and Caspase-9 activation, and chromosomal DNA breakage. The increased apoptosis was concomitant with accumulation of mitochondrial ROS, decrease in intracellular ATP production and respiratory oxygen consumption, and abnormal mitochondrial structure. RNA profiling of endothelial cells isolated from wild type and Irf1 knockout mice, followed by quantitative PCR, luciferase activity assay and chromatin immunoprecipitation (ChIP), revealed that IRF-1 directly regulated the expression of transmembrane protein 70 (TMEM70), an ancillary factor required for the assembly of ATP synthase and conversion of an electrochemical gradient to ATP synthesis. Mirroring the effect of IRF1 knockdown, depletion of TMEM70 in HAEC resulted in impaired mitochondrial function and enhanced cell apoptosis. In contrast, overexpression of TMEM70 rescued ATP biosynthesis and suppressed apoptosis in oxLDL-treated, IRF-1-deficient HAEC. These results reveal a novel homeostatic role for IRF-1 in the regulation of mitochondrial function and associated stress-induced apoptosis.

The pathogenesis of sepsis-induced Acute lung injury (ALI) progresses rapidly, and no effective treatment drugs are known, resulting in a high mortality rate. NLR family pyrin domain containing 3 (NLRP3) inflammasome activation plays an important role in the pathological progression of ALI, and often coincide with the inflammatory activation and polarization of macrophages. NLR family CARD domain-containing protein 3 (NOD3) was reported protecting against sepsis-induced pulmonary pathological injury and inhibiting the inflammatory response in lung tissue. NOD3 can also inhibit NLRP3 inflammasome activation by competitively inhibiting the binding of pro-caspase-1 to apoptosis-related ASC or reducing NLRP3/cryopyrin-induced ASC speckle formation. In this study, we aimed to explore whether NOD3 decrease sepsis-induced lung injury by interfering with NLRP3 inflammasome activation and regulating alveolar macrophages (AMs) polarization. To investigate whether NOD3 reduce sepsis-induced ALI by inhibiting the activation of NLRP3 inflammasome to regulate the polarization of AMs. Sepsis-induced WT (C57BL/6) and NLRC3^-/--C57BL/6 mice ALI models were established by intraperitoneal injection of lipopolysaccharide (LPS). In vitro experiments, AMs and bone marrow-derived macrophages (BMDMs) were isolated from WT and NLRC3^-/- mice. Using in vivo and in vitro experiments, we found that NOD3 knockout promoted the sepsis-induced inflammatory response in lung tissue. In addition, NOD3 knockout promoted the activation of the TRAF6-NF-κB signaling pathway and the NLRP3 inflammasome in AMs, enhanced the M1-type polarization of AMs and decreased the M2-type polarization of AMs in sepsis-induced lung injury model mice. NOD3 interfered with NLRP3 inflammasome activation by inhibiting NLRP3 inflammasome assembly or negatively regulating the TRAF6-NF-κB signaling pathway, and regulating the polarization of AMs, thereby alleviating sepsis-induced lung injury.

Sepsis is defined as a dysregulated host response to infection that leads to multiorgan failure. Innate immune memory, i.e., "trained immunity", can result in stronger immune responses and provide protection against various infections. Many biological agents, including β-glucan, can induce trained immunity, but these stimuli may cause uncontrolled inflammation. Oroxylin A (OA) is an active flavonoid compound that is derived from Scutellaria baicalensis. OA is an agonist for inducing trained immunity in vivo and in vitro, and β-glucan was used as a positive control. The protective effects of OA-induced trained immunity were evaluated in mouse models that were established by either lipopolysaccharide (LPS) administration or caecal ligation and puncture (CLP). The expression of inflammatory factors and signaling pathway components involved in trained immunity was evaluated in vitro using qRT‒PCR, western blotting (WB) and enzyme-linked immunosorbent assay (ELISA). Flow cytometry and confocal microscopy were used to examine reactive oxygen species (ROS) levels and phagocytosis in trained macrophages. A PCR array was used to screen genes that were differentially expressed in trained macrophages. Here, we revealed that OA alleviated sepsis via trained immunity. OA-treated macrophages displayed increased glycolysis and mTOR phosphorylation, and mTOR inhibitors suppressed OA-induced trained immunity by effectively reprogramming macrophages. The PCR array revealed key genes in the mTOR signaling pathway in OA-treated macrophages. Furthermore, OA targeted the Dectin-1-syk axis to promote LC3-associated phagocytosis (LAP) by trained macrophages, thereby enhancing the ability of these macrophages to protect against infection. This ability could be transferred to a new host via the adoptive transfer of peritoneal macrophages. This study is the first to provide new insights into the potential of OA-induced trained immunity to be used as a strategy to protect mice against sepsis by promoting LAP by macrophages.

Hemorrhagic shock/resuscitation (HS/R) can lead to acute kidney injury, mainly manifested as oxidative stress and inflammatory injury in the renal tubular epithelial cells, as well as abnormal autophagy and apoptosis. Sulforaphane (SFN), an agonist of the nuclear factor-erythroid factor 2-related factor 2 (Nrf2) signaling pathway, is involved in multiple biological activities, such as anti-inflammatory, antioxidant, autophagy, and apoptosis regulation. This study investigated the effect of SFN on acute kidney injury after HS/R in mice. Hemorrhagic shock was induced in mice by controlling the arterial blood pressure at a range of 35-45 mmHg for 90 min within arterial blood withdrawal. Fluid resuscitation was carried out by reintroducing withdrawn blood and 0.9% NaCl. We found that SFN suppressed the elevation of urea nitrogen and serum creatinine levels in the blood induced by HS/R. SFN mitigated pathological alterations including swollen renal tubules and renal casts in kidney tissue of HS/R mice. Inflammation levels and oxidative stress were significantly downregulated in mouse kidney tissue after SFN administration. In addition, the kidney tissue of HS/R mice showed high levels of autophagosomes as observed by electron microscopy. However, SFN can further enhance the formation of autophagosomes in the HS/R + SFN group. SFN also increased autophagy-related proteins Beclin1 expression and suppressed P62 expression, while increasing the ratio of microtubule-associated protein 1 light chain 3 (LC3)-II and LC3-I (LC3-II/LC3-I). SFN also effectively decreased cleaved caspase-3 level and enhanced the ratio of anti-apoptotic protein B cell lymphoma 2 and Bcl2-associated X protein (Bcl2/Bax). Collectively, SFN effectively inhibited inflammation and oxidative stress, enhanced autophagy, thereby reducing HS/R-induced kidney injury and apoptosis levels in mouse kidneys.

Lung immune cells such as lymphocytes and macrophages can induce an inflammatory response due to the activation of mineralocorticoid receptor (MR), which is manifested by the infiltration of inflammatory cells and the secretion of inflammatory cytokines and subsequent apoptosis, pyroptosis and necrosis of intrinsic lung cells and immune cells. Macrophages are immune cells that are abundant in the lung and act as the first line of defense against pathogens but are also aggravating factors of infection. The activation of the renin-angiotensin-aldosterone system (RAAS), especially aldosterone-stimulated MR activation, can induce macrophage and CD8⁺ T cell aggregation and the secretion of cytokines such as tumor necrosis factor-α (TNF-α) and interferon-gamma (IFN-γ). Increased IFN-γ secretion can induce macrophage pyroptosis and the release of interleukin 1-β (IL-1β), aggravating lung injury. In this study, lung injury in C57BL/6 mice was induced by subcutaneous micro-osmotic pump infusion of aldosterone. After 12 weeks of administration, the kidney, heart, blood vessels and lungs all showed obvious inflammatory injury, which manifested as rapid accumulation of macrophages. The overexpression of IFN-γ in the lungs of aldosterone-treated mice and the stimulation of MH-S and RAW264.7 alveolar macrophages (AMs) with aldosterone in vitro showed that IFN-γ induced pyroptosis of macrophages via the activation of the inflammasome, and the MR blocker esaxerenone effectively inhibited this effect and alleviated lung injury. In addition, IFN-γ secreted by CD8⁺ T cells is associated with macrophage pyroptosis. In conclusion, the inhibition of macrophage pyroptosis can effectively alleviate lung injury.

In vitro induced T regulatory cells (iTregs) are promising for addressing inflammation-driven diseases. However, current protocols for the generation and expansion of iTregs fail to induce extensive demethylation of the Treg-specific demethylated region (TSDR) within the FOXP3 gene, recognized as the master regulator for regulatory T cells (Tregs). This deficiency results in the rapid loss of Foxp3 expression and an unstable regulatory phenotype. Nevertheless, inhibition of STAT6 signaling effectively stabilizes Foxp3 expression in iTregs. Thus, this study aimed to develop a protocol combining epigenetic editing with STAT6 deficiency to improve iTregs' ability to maintain stable suppressive function and a functional phenotype. Our findings demonstrate that the combination of STAT6 deficiency (STAT6-/-) with targeted demethylation of the TSDR using a CRISPR-TET1 tool leads to extensive demethylation of FOXP3-TSDR. Demethylation in STAT6-/- iTregs was associated with enhanced expression of Foxp3 and suppressive markers such as CTLA-4, PD-1, IL-10, and TGF-β. Furthermore, the edited STAT6-/- iTregs exhibited an increased capacity to suppress CD8+ and CD4+ lymphocytes and could more efficiently impair Th1-signature gene expression compared to conventional iTregs. In conclusion, the deactivation of STAT6 and TSDR-targeted demethylation via CRISPR-TET1 is sufficient to induce iTregs with heightened stability and increased suppressive capacity, offering potential applications against inflammatory and autoimmune diseases.