Dyslipidemia in rheumatoid arthritis: the possible mechanisms.

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease, of which the leading cause of death is cardiovascular disease (CVD). The levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c) in RA decrease especially under hyperinflammatory conditions. It is conflictive with the increased risk of CVD in RA, which is called "lipid paradox". The systemic inflammation may explain this apparent contradiction. The increased systemic proinflammatory cytokines in RA mainly include interleukin-6(IL-6)、interleukin-1(IL-1)and tumor necrosis factor alpha(TNF-α). The inflammation of RA cause changes in the subcomponents and structure of HDL particles, leading to a weakened anti-atherosclerosis function and promoting LDL oxidation and plaque formation. Dysfunctional HDL can further worsen the abnormalities of LDL metabolism, increasing the risk of cardiovascular disease. However, the specific mechanisms underlying lipid changes in RA and increased CVD risk remain unclear. Therefore, this article comprehensively integrates the latest existing literature to describe the unique lipid profile of RA, explore the mechanisms of lipid changes, and investigate the impact of lipid changes on cardiovascular disease.

Sodium tanshinone IIA sulfonate attenuates sepsis-associated brain injury via inhibiting NOD-like receptor 3/caspase-1/gasdermin D-mediated pyroptosis.

BACKGROUND: Sodium tanshinone IIA sulfonate (STS) has been reported to protect organ function in sepsis. However, the attenuation of sepsis-associated brain injury and its underlying mechanisms by STS has not been established. METHODS: C57BL/6 mice were used to establish the cecal ligation perforation (CLP) model, and STS was injected intraperitoneally 30 min before the surgery. The BV2 cells were stimulated by lipopolysaccharide after being pre-treated with STS for 4 h. The STS protective effects against brain injury and in vivo anti-neuroinflammatory effects were investigated using the 48-hour survival rate and body weight changes, brain water content, histopathological staining, immunohistochemistry, ELISA, RT-qPCR, and transmission electron microscopy. The pro-inflammatory cytokines of BV2 cells were detected by ELISA and RT-qPCR. At last, the levels of NOD-like receptor 3 (NLRP3) inflammasome activation and pyroptosis in brain tissues of the CLP model and BV2 cells were detected using western blotting. RESULTS: STS increased the survival rate, decreased brain water content, and improved brain pathological damage in the CLP models. STS increased the expressions of tight junction proteins ZO-1 and Claudin5 while reducing the expressions of tumor necrosis factor α (TNF-α), interleukin-1ß(IL-1ß), and interleukin-18 (IL-18) in the brain tissues of the CLP models. Meanwhile, STS inhibited microglial activation and M1-type polarization in vitro and in vivo. The NLRP3/caspase-1/ gasdermin D (GSDMD)-mediated pyroptosis was activated in the brain tissues of the CLP models and lipopolysaccharide (LPS)-treated BV2 cells, which was significantly inhibited by STS. CONCLUSIONS: The activation of NLRP3/caspase-1/GSDMD-mediated pyroptosis and subsequent secretion of proinflammatory cytokines may be the underlying mechanisms of STS against sepsis-associated brain injury and neuroinflammatory response.

Interaction of gut microbiota with the tumor microenvironment: A new strategy for antitumor treatment and traditional Chinese medicine in colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies worldwide and the second leading cause of cancer-related death. In recent years, the relationship between gut microbiota and CRC has attracted increasing attention from researchers. Studies reported that changes in the composition of gut microbiota, such as increase in the number of Fusobacterium nucleatum and Helicobacter hepaticus, impair the immune surveillance by affecting the intestinal mucosal immunity and increase the risk of tumor initiation and progression. The tumor microenvironment is the soil for tumor survival. Close contacts between gut microbiota and the tumor microenvironment may directly affect the progression of tumors and efficacy of antitumor drugs, thus influencing the prognosis of patients with CRC. Recently, many studies have shown that traditional Chinese medicine can safely and effectively improve the efficacy of antitumor drugs, potentially through remodeling of the tumor microenvironment by regulated gut microbiota. This article describes the effect of gut microbiota on the tumor microenvironment and possible mechanisms concerning the initiation and progression of CRC, and summarizes the potential role of traditional Chinese medicine.

A diagnostic challenge of mysterious bone pain caused by tumor-induced osteomalacia with multiple tumors: a case report.

Background: Tumor-induced osteomalacia (TIO) is a rare, tumor-induced, metabolic bone disorder, the exact incidence of which is unknown. The most common cause of TIO is hypersecretion of tumor-derived fibroblast growth factor 23 (FGF23). Surgical resection can cure TIO in most cases, while for patients with TIO who are ineligible for surgery, biologic antibodies targeting FGF23 can be used as treatment. However, the diagnosis of TIO is more difficult than its treatment as the initial presentation can be misleading or nonspecific; thus, diagnosing TIO remains a clinical challenge. Case Description: Herein, we present a case of TIO originating from the nasal cavity neoplasm in which the patient also had a rare, thymic-derived, tumorous lesion. A diagnosis of osteoporosis was subsequently made, and a disorder of phosphorus metabolism was discovered. After determining that the patient was exhibiting signs of TIO, we used gallium-68 dotatate positron emission tomography/computed tomography (68Ga-DOTATATE PET/CT) to locate the tumor position. Conclusions: This case report emphasizes the importance of electrolyte testing, which is potentially helpful for quickly identifying the presence of disorders of phosphorus metabolism in suspected patients. Subsequently, appropriate imaging techniques (e.g., 68Ga-DOTATATE PET/CT) should be used to identify potential TIO lesions. Most patients with TIO can be treated successfully following diagnosis. Keywords: Tumor-induced osteomalacia (TIO); gallium-68 dotatate positron emission tomography/computed tomography (68Ga-DOTATATE PET/CT); phosphaturic mesenchymal tumor (PMTs); weakness; case report.

Wutou decoction attenuates the synovial inflammation of collagen-induced arthritis rats via regulating macrophage M1/M2 type polarization.

ETHNOPHARMACOLOGICAL RELEVANCE: Thousands of years of clinical practice in the treatment of joint-related diseases support the efficacy and safety of Wutou decoction (WTD). Nevertheless, the lack of pharmacological evidence and unclear mechanisms make it difficult for WTD to become a recognized complementary therapy for the treatment of rheumatoid arthritis (RA). AIM OF THE STUDY: This study aimed to investigate the effect of WTD against synovial inflammation in RA and whether this effect depends on the regulation of macrophage polarization. MATERIALS AND METHODS: Sprague-Dawley rats were used to establish the collagen-induced arthritis (CIA) model. WTD with low and high doses was administered for 45 days. RAW264.7 cells were stimulated by lipopolysaccharide (LPS) or interleukin (IL)-4 to polarize M1 and M2 macrophages, which were pre-treated with WTD extract for 4 h. The anti-arthritic and anti-inflammatory effects of WTD were studied using arthritis score, histopathological staining, immunostaining, and enzyme-linked immunosorbent assay (ELISA). The polarization state of RAW264.7 cells and related pro/anti-inflammatory cytokines was detected by ELISA, reverse transcription quantitative polymerase chain reaction and western blotting. Western blotting and immunofluorescence were used to investigate the effect of WTD on nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and peroxisome proliferator-activated receptors γ (PPARγ) activation both in vivo and in vitro. RESULTS: WTD significantly reduced the arthritis score and the pathological damage of the knee joint and decreased the expression of tumor necrosis factor alpha (TNF-α), IL-6 in serum, TNF-α, IL-1ß, monocyte chemoattractant protein-1 (MCP-1), and matrix metalloproteinase-3 (MMP3) in the knee synovium. WTD inhibited M1 type polarization and promoted M2 type polarization, both in vitro and in vivo, and reduced the expression of pro-inflammatory cytokines while increasing the expression of anti-inflammatory cytokines. Experiments showed that WTD inhibited the phosphorylation of NF-κB and downstream p38 in the synovium of CIA rats and LPS-induced M1 type polarized RAW264.7 cells. In addition, PPARγ expression in the synovium of CIA rats was mainly located in the cytoplasm, and WTD treatment increased the nuclear translocation of PPARγ, which was further verified in RAW264.7 cells. CONCLUSIONS: NF-κB and PPARγ regulating M1 and M2 macrophage polarization and subsequent secretion of pro-inflammatory and anti-inflammatory cytokines are the underlying mechanisms of WTD that ameliorate RA synovial inflammation.

Reactive Oxygen Species in Autoimmune Cells: Function, Differentiation, and Metabolism.

Accumulated reactive oxygen species (ROS) directly contribute to biomacromolecule damage and influence various inflammatory responses. Reactive oxygen species act as mediator between innate and adaptive immune cells, thereby influencing the antigen-presenting process that results in T cell activation. Evidence from patients with chronic granulomatous disease and mouse models support the function of ROS in preventing abnormal autoimmunity; for example, by supporting maintenance of macrophage efferocytosis and T helper 1/T helper 2 and T helper 17/ regulatory T cell balance. The failure of many anti-oxidation treatments indicates that ROS cannot be considered entirely harmful. Indeed, enhancement of ROS may sometimes be required. In a mouse model of rheumatoid arthritis (RA), absence of NOX2-derived ROS led to higher prevalence and more severe symptoms. In patients with RA, naïve CD4+ T cells exhibit inhibited glycolysis and enhanced pentose phosphate pathway (PPP) activity, leading to ROS exhaustion. In this "reductive" state, CD4+ T cell immune homeostasis is disrupted, triggering joint destruction, together with oxidative stress in the synovium.

Effect of tumor necrosis factor inhibitors on interstitial lung disease in rheumatoid arthritis: angel or demon?

Objectives: This study evaluated the correlation between tumor necrosis factor alpha inhibitor (TNF-I) and interstitial lung disease (ILD) in rheumatoid arthritis (RA). We aimed to raise awareness and consummate therapy by summarizing the characteristics of the adverse events of ILD. Methods: A comprehensive search of the PubMed, Embase, Ovid, Cochrane, China National Knowledge Infrastructure, and Wanfang databases was performed from inception to November 2018. Statistical analysis of demographic characteristics, clinical features, and relative risks was performed using Microsoft Excel 2007 and SPSS version 20.0. Results: A total of 7 eligible articles and another 28 case reports were enrolled. The 7 cohort studies demonstrated the tendency that ILD cases might not benefit from TNF-I therapy. TNF-I might be associated with ILD adverse events. The case reports further confirmed these findings, as most (87.5%) of the cases showed that TNF-1 was harmful to patients with ILD and even resulted in a 35% mortality rate. Further investigation revealed that ILD adverse events tended to appear in female patients with a long RA history (p<0.05). The subgroup analysis suggested that early detection and precise treatment are key factors in determining survival or death when an ILD adverse event occurs. A large proportion of ILD adverse events (48.6%) appeared at 2.38±1.03 weeks after the infusion of infliximab. Conclusion: A fresh look at the evidence highlights that TNF-I might be associated with ILD adverse events in RA, which can induce more severe pulmonary symptoms and even result in death. Therefore, more attention should be paid to effective prevention, early diagnosis, and precise management. Notably, further prospective cohort studies are warranted to better interpret the association or causality between TNF-I and ILD.