Inflammation Research最新文献

Background: Sepsis represents a significant global health and hygiene challenge. Excessive activation of macrophages in sepsis can result in certain patients displaying characteristics akin to those observed in Macrophage Activation Syndrome (MAS). MAS represents a grave immune system disorder characterized by persistent and severe inflammation within the body. In the context of sepsis, MAS presents atypically, leading some researchers to refer to it as Macrophage Activation-Like Syndrome (MALS). However, there are currently no effective treatment measures for this situation. The purpose of this article is to explore potential treatment methods for sepsis-associated MALS.

Objective: The objective of this review is to synthesize the specific pathophysiological mechanisms and treatment strategies of MAS to investigate potential therapeutic approaches for sepsis-associated MALS.

Method: We searched major databases (including PubMed, Web of Science, and Google Scholar etc.) for literature encompassing macrophage activation syndrome and sepsis up to Mar 2024 and combined with studies found in the reference lists of the included studies.

Conclusion: We have synthesized the underlying pathophysiological mechanism of MALS in sepsis, and then summarized the diagnostic criteria and the effects of various treatment modalities utilized in patients with MAS or MALS. In both scenarios, heterogeneous treatment responses resulting from identical treatment approaches were observed. The determination of whether the patient is genuinely experiencing MALS significantly impacts the ultimate outcomes of therapeutic efficacy. In order to tackle this concern, additional clinical trials and research endeavors are imperative.

Background: AC-186 (4-[4-4-Difluoro-1-(2-fluorophenyl) cyclohexyl] phenol) is a neuroprotective non-steroidal selective oestrogen receptor modulator. This study investigated whether inhibition of neuroinflammation contributed to neuroprotective activity of this compound.

Methods: BV-2 microglia were treated with AC-186 (0.65-5 μM) prior to stimulation with LPS (100 ng/mL). Levels of pro-inflammatory mediators and proteins were then evaluated.

Results: Treatment of LPS-activated BV-2 microglia with AC-186 resulted in significant (p < 0.05) reduction in TNFα, IL-6, NO, PGE₂, iNOS and COX-2. Further investigations showed that AC-186 decreased LPS-induced elevated levels of phospho-p65, phospho-IκBα and acetyl-p65 proteins, while blocking DNA binding and luciferase activity of NF-κB. AC-186 induced significant (p < 0.05) increase in protein expression of ERβ, while enhancing ERE luciferase activity in BV-2 cells. Effects of the compound on oestrogen signalling in the microglia was confirmed in knockdown experiments which revealed a loss of anti-inflammatory activity following transfection with ERβ siRNA. In vitro neuroprotective activity of AC-186 was demonstrated by inhibition of activated microglia-mediated damage to HT-22 neurons.

Conclusions: This study established that AC-186 produces NF-κB-mediated anti-inflammatory activity, which is proposed as a contributory mechanism involved in its neuroprotective actions. It is suggested that the anti-inflammatory activity of this compound is linked to its agonist effect on ERβ.

Background: Vascularization after rib fracture is a crucial physiological process that is essential for the repair and healing of the rib. Studies have shown that CD90 plays a critical role in regulating rib fracture healing, but the underlying mechanism of its role has not been fully elucidated.

Methods: CD90 adenovirus knockout mice were used to construct a rib injury model. The bone healing was observed by micro-CT. CD31/EMCN immunofluorescence staining was performed on bone tissue to observe the density of H-shaped and L-shaped blood vessels at the site of bone injury. CD31 and EMCN dual-stained single cells from the rib fracture sites were detected by flow cytometry. The periosteal stem cells transfected with CD90 or Notch1 overexpression and silencing vector were co-cultured with osteoblast MC3T3-E1 in osteogenic induction medium. Moreover, bone microvascular endothelial cells were extracted from the rib injury and co-cultured with the periosteal stem cells transfected with CD90. CCK-8 was used to detect cell viability, RT-qPCR and Western blot were used to detect Notch1, Notch2, Notch3, Notch4, CD31, HIF-1α, CD90, RUNX2, OCN and OPN expression. Alkaline phosphatase (ALP) staining and alizarin red staining were used to observe mineralized nodules. Immunofluorescence staining was used to detect the expression of Dll4, Notch, and CD90 in each group of cells. The angiogenesis experiment was conducted to observe cellular vascular formation.

Results: Compared with the Adsh-NC group, the bone healing in the Adsh-CD90 group was significantly impaired, with a marked reduction in the number and volume of blood vessels at the rib fracture site, as evidenced by CD31/EMCN immunofluorescence staining, which showed a reduction in the number of H type vessels at the site of bone injury. It was found that CD90 depletion can inhibit the signaling of Dll4/Notch in the rib fracture site. Furthermore, we found that overexpression of Notch1 reverses the impairment of tubule formation in bone microvascular endothelial cells caused by CD90 suppression.r.Dll4 protein reverses the inhibitory effect of CD90 deletion on periosteal stem cells and MC3T3-E1 cell viability and osteogenesis. In the end, we found that overexpression of Notch1 and CD90 can promote angiogenesis of bone microvascular endothelial cells and Notch pathway activation.

Conclusion: CD90 can affect vascular formation in mouse rib fractures, and CD90 may be regulated by Dll4/Notch.

Background: The role of complement in cancer remains controversial. Whether immune cells and inflammatory factors mediate the pathway from complement to cancer has not been fully elucidated.

Methods: We conducted bidirectional Mendelian randomization (MR) analysis to explore the causal association between complement components and cancer. Meta-analysis was conducted to enhance the robustness of the results. We further explored the mediation roles of immune cells and inflammatory factors in these associations.

Results: Our study identified causal associations between 11 complement components and 12 types of cancer. Furthermore, we identified five immune cells as potential mediators: BAFF-R on IgD + CD38- naive B cell mediated 7.434% of the increased risk for liver cancer from C3; CD4 on CD39 + activated CD4 regulatory T cell mediated 12.384% of the increased risk for biliary tract cancer from CD93; CD25 +  + CD45RA + CD4 not regulatory T cell and Basophil %CD33dim HLA DR- CD66b- mediated 7.721% and 7.986% of the increased risk of colorectal cancer from MASP1, respectively; CD45RA on resting CD4 regulatory T cell mediated 11.444% of the increased risk of skin cancer from MASP1.

Conclusion: This study revealed the causal relationships between complement components and certain cancers, with five immune cells as potential mediators.

Introduction: Pentoxifylline (PTX) affects most blood components and the blood vessels, potentially modulating various conditions. Due to its impact on markers linked to COVID-19 severity, research has explored PTX for acute COVID-19. Following the widespread administration of COVID-19 vaccinations, there has been a notable and consistently growing increase in research focusing on long COVID. Consequently, our examination of relevant acute COVID-19 data shall additionally be contextualized into long COVID research.

Methods: Various Databases were searched until July 2024 for all primary clinical studies on Pentoxifylline (PTX) in COVID-19.

Results: Studies were on acute infection with SARS-CoV-2 where PTX was an adjuvant to standard therapy for ethical and practical reasons under the circumstance. PTX generally reduced hospitalization duration and improved some inflammatory markers, but its impact on mortality was inconsistent. Adverse events were minimal. Meta-analysis revealed a significant reduction in hospitalization duration.

Conclusion: This systematic review and meta-analysis suggest that adding pentoxifylline (PTX) to standard COVID-19 therapy may significantly reduce hospitalization duration and improve some inflammatory markers. However, its impact on mortality rates is inconclusive. Adverse events are minimal. PTX can be favorable as an add-on in managing acute COVID-19 and could reduce the risk of long COVID, as well as assist in managing many of its most common symptoms.

Psoriasis (Ps) is a chronic inflammatory disorder marked by skin plaque formation, driven by immune dysregulation and genetic factors. Despite the available treatments, incidence of Ps is increasing in the dermatology patients. Novel strategies are crucial due to current treatment limitations. The interleukin 17 (IL-17) pathway is pivotal in Ps pathogenesis, however the expression of its putative target gene placenta expressed transcript 1 (Plet1) remains unstudied in Ps. Considering the potential anti-inflammatory properties of N-Acetylglucosamine (GlcNAc), our study explored its role in modulating Plet1 expression in an imiquimod (IMQ)-induced Ps mouse model. Our data demonstarted a significant reduction of inflammation and Psoriasis Area and Severity Index (PASI) scores, downregulation of growth factors (GFs), IL-17 A, and MAPK expression after GlcNAc treatment. In addition, GlcNAc treatment reduced neutrophils, monocyte-dendritic cells (Mo-DC) and conventional T cells (Tcons) while increasing monocyte-macrophages (Mo-Macs) and regulatory T cells (Tregs). GlcNAc treatment also downregulated Plet1 overexpression in psoriatic mouse skin and in vitro, reduced proliferation and apoptosis in IL-17 A stimulated human dermal fibroblasts (HDF), along with IL-17 A and TGF-β mRNA expression. Together, these data suggest that, GlcNAc interferes with downstream mechanisms in IL-17 pathway and downregulating Plet1 expression, presenting a promising strategy for Ps treatment.

Background: G proteins are a class of important signal transducers in mammalians. G proteins can corpoarated with G proteincoupled receptors (GPCRs) and transmit signals from extracellular stimuli into intracellular response, which will regulate a series of biological functions. G-proteins are heterotrimeric proteins composed of Gα, Gβ, and Gγ subunits. Based on structural and functional similarity of their α-subunits, G proteins are typically grouped into four classes (Gi, Gs, Gq/11, and G12/13). The Gq/11 subfamily consists of Gq, G11, G14, and G15/16 proteins. Gαq is the α-subunit of Gq protein and encoded by GNAQ. Our previous studies revealed that Gαq play an important role in regulating T cell survival and T cell differentiation. Inflammasomes are multiprotein complexes that play a critical role in modulating innate inflammatory response. NLRP3 inflammasome is currently the most extensively studied inflammasome.

Methods: We found that Gαq suppressed NLRP3 inflammasome activation in macrophage, Gαq also suppressed NLRP3 inflammasome activation in a LPS-induced sepsis mouse model. Gαq can locate to mitochondria and Gαq was required for the maintenance of mitochondrial homeostasis. Gαq regulated NLRP3 inflammasome activation by modulating mitochondrial reactive oxygen species (mtROS).

Results: We found that Gαq suppressed NLRP3 inflammasome activation in macrophage, Gαq also suppressed NLRP3 inflammasome activation in a LPS-induced sepsis mouse model. Gαq can locate to mitochondria and Gαq was required for the maintenance of mitochondrial homeostasis. Gαq regulated NLRP3 inflammasome activation by modulating mitochondrial reactive oxygen species (mtROS).

Conclusion: Our results indicate that Gαq regulates NLRP3 inflammasome activation by modulating mitochondrial ROS production. Our research provides new mechanistic insight into the activation of NLRP3 inflammasome. As it has been proved that NLRP3 inflammasome plays an important role in the pathogenesis many diseases such as Alzheimer's disease, cancer, and inflammatory bowel disease, Gαq might become a novel drug target for these diseases in future.

Background: Crohn's disease and chronic obstructive pulmonary disease (COPD) are chronic inflammatory diseases that affect the gut and lung respectively and can occur comorbidly.

Methods: Using the SHIP-1^-/- model of Crohn's-like ileitis and chronic lung inflammation, the two diseases were co-investigated.

Results: Contrary to prior literature, Crohn's-like ileitis was not fully penetrant in SHIP-1^-/- mice, and housing in a specific pathogen-free facility was completely protective. Indeed, ileal tissue from SHIP-1^-/- mice without overt ileitis was similar to control ilea. However, SHIP-1^-/- mice with ileitis exhibited increased granulocytes in ileal tissue together with T cell lymphopenia and they lacked low abundance Bifidobacteria, suggesting this bacterium protects against ileitis. Lung disease, as defined by inflammation in lung washes, emphysema, and lung consolidation, was present in SHIP-1^-/- mice regardless of ileitis phenotype; however, there was a shift in the nature of lung inflammation in animals with ileitis, with increased G-CSF and neutrophils, in addition to type 2 cytokines and eosinophils. Deficiency of G-CSF, which protects against lung disease, protected against the development of ileitis in SHIP-1^-/- mice.

Conclusions: These studies have defined environmental, immune, and inflammatory factors that predispose to ileitis, and have identified that comorbid lung disease correlates with a granulocyte signature.

Background: One mechanism by which antiphospholipid syndrome (APS) IgG contribute to thrombotic events in patients with APS is through the potentiation of neutrophil extracellular traps (NETs) release. However, the exact mechanism by which APS IgG induces NETs formation and thrombosis has not been fully elucidated.

Methods: We conducted untargeted metabolomics on serum samples from thrombotic APS patients to identify metabolic changes. The effect of 5-oxoETE on NETs formation and oxidative stress was evaluated in vitro by treating neutrophils with various concentrations of 5-oxoETE. The involvement of the PLC/PKC/ERK signaling pathway in 5-oxoETE-induced NETs formation was examined using pharmacological inhibitors. In vivo, we assessed the effects of inhibiting 5-oxoETE synthesis or blocking its receptor (OXE-R) on NETs formation and thrombosis in APS mouse models.

Results: Serum metabolomics revealed significantly elevated levels of 5-oxoETE in APS patients. In vitro experiments demonstrated that 5-oxoETE, via OXE-R activation of the PLC/PKC/ERK signaling pathway, increased NETs formation and oxidative stress in a dose-dependent manner. In vivo, inhibiting 5-oxoETE synthesis or OXE-R reduced NETs formation and attenuated venous thrombosis in APS mice models.

Conclusion: This study identifies 5-oxoETE as a critical mediator of NET formation and thrombosis in APS. Targeting 5-oxoETE or OXE-R may offer a promising therapeutic approach for thrombotic APS and other NET-associated autoimmune diseases.

Importance: Studies have reported an association among systemic immune inflammation index (SII), all-cause and cause-specific mortality, but the results are inconsistent.

Objective: To comprehensively explore the association between Systemic Immune Inflammation (SII) and the risk of all-cause mortality, cardiovascular disease (CVD), and cancer mortality.

Evidence review: A meta-analysis was conducted by reviewing existing literature. The search encompassed prominent databases including PubMed, Embase, Cochrane, and the Web of Science, with the cutoff date set at March 1, 2024. Furthermore, subgroup analyses and dose-response assessments were undertaken to provide a nuanced exploration of mortality risk factors.

Findings: A total of 33 articles were included (427,819 participants). In the study, SII was associated with an increased risk of all-cause mortality (HR = 1.45, 95%CI [1.36,1.54], P < 0.05). SII increased the risk of CVD mortality (HR = 1.44, 95%CI [1.29,1.60], P < 0.05). The Linear independence shows that for every 100 units increase in SII, the risk of all-cause and CVD death increases by 5% and 6%. SII was not associated with a statistically significant risk of cancer death (HR = 1.09, 95%CI [0.96,1.23], P < 0.05).

Conclusions and relevance: Meta-analysis showed that SII was associated with all-cause mortality and CVD mortality. More data and basic research are needed to confirm the association.