Curcumin alleviates acute kidney injury in a dry‐heat environment by reducing oxidative stress and inflammation in a rat model

Curcumin exhibits anti‐inflammatory and antioxidant activities. We investigated the protective effects of curcumin in a renal injury rat model under dry‐heat conditions. We divided Sprague‐Dawley rats into four groups: dry‐heat 0‐ (normal temperature control group), 50‐, 100‐, and 150‐minute groups. Each group was divided into five subgroups (n = 10): normal saline (NS), sodium carboxymethylcellulose (CMCNa), and curcumin pretreated low, medium, and high‐dose (50, 100, and 200 mg/kg, respectively) groups. Compared to the normal temperature group, serum creatinine, blood urea nitrogen, urinary kidney injury molecule‐1, and neutrophil gelatinase‐associated load changes in lipoprotein (NGAL) levels were significantly increased in the dry‐heat environment group (P < .05); inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) expression and malondialdehyde (MDA) and related inflammatory factor levels were increased in the kidney tissue. Superoxide dismutase (SOD) and catalase (CAT) levels were decreased. However, following all curcumin pretreatment, the serum levels of kidney injury indicators and NGAL were decreased in the urine compared to those in the NS and CMCNa groups (P < .05), whereas renal SOD and CAT activities were increased and MDA was decreased (P < .05). Renal tissues of the 150‐minute group showed obvious pathological changes. Compared to the NS group, pathological changes in the renal tissues of the 100‐ and 200‐mg/kg curcumin groups were significantly reduced. Furthermore, iNOS and COX‐2 expression and inflammatory factor levels were decreased after curcumin treatment. Curcumin exerted renoprotective effects that were likely mediated by its antioxidant and anti‐inflammatory effects in a dry‐heat environment rat model.     

Thiopurine S-Methyltransferase Gene Polymorphisms in a Healthy Slovak Population and Pediatric Patients with Inflammatory Bowel Disease

Thiopurine methyltransferase (TPMT) is a key component in thiopurine metabolism. There is an insufficient evidence about the distribution of the genotype frequencies of TPMT variants and frequencies of TPMT alleles associated with intermediate and deficient activity in a healthy Slovak population and pediatric patients with inflammatory bowel disease (IBD). TPMT variant alleles (*1,*2, *3A, *3B, and *3C) were determined in 114 children treated for IBD and in 281 healthy volunteers. Mutant alleles were present in 9/114 (7.89%) in the IBD patients and in 23/281 (8.19%) of probands. The distribution of the most frequent variants of TPMT gene was similar in a healthy population and patients with IBD.     

Lysoglycerophospholipids in chronic inflammatory disorders: The PLA2/LPC and ATX/LPA axes

Lysophosphatidylcholine (LPC) and lysophosphatidic acid (LPA), the most prominent lysoglycerophospholipids, are emerging as a novel class of inflammatory lipids, joining thromboxanes, leukotrienes and prostaglandins with which they share metabolic pathways and regulatory mechanisms. Enzymes that participate in LPC and LPA metabolism, such as the phospholipase A₂ superfamily (PLA₂) and autotaxin (ATX, ENPP2), play central roles in regulating LPC and LPA levels and consequently their actions. LPC/LPA biosynthetic pathways will be briefly presented and LPC/LPA signaling properties and their possible functions in the regulation of the immune system and chronic inflammation will be reviewed. Furthermore, implications of exacerbated LPC and/or LPA signaling in the context of chronic inflammatory diseases, namely rheumatoid arthritis, multiple sclerosis, pulmonary fibrosis and hepatitis, will be discussed. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.     

Tanshinone IIA inhibits the adipogenesis and inflammatory response in ox-LDL-challenged human monocyte-derived macrophages via regulating miR-130b/WNT5A

Atherosclerosis is a kind of chronic cardiovascular disease, characterized by oxidized low-density lipoprotein (ox-LDL) accumulation in macrophage. Tanshinone IIA (Tan), a lipophilic pharmacologically activate compound from Salvia miltiorrhiza Bunge, has been indicated to exert cardioprotective roles. Nevertheless, the biological role of Tan and regulatory mechanism in atherosclerosis are not fully established. In present study, atherosclerosis model was established in THP-1-derived macrophages by treatment of ox-LDL. The adipogenesis was measured by Nile red staining. The expressions of inflammatory factors, microRNA-130b (miR-130b) and WNT5A were measured by quantitative real-time polymerase chain reaction or Western blot. The target association between miR-130b and WNT5A was explored via luciferase activity and RNA immunoprecipitation assay. The results showed that exposure of Tan inhibited ox-LDL-induced adipogenesis and expressions of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-alpha in THP-1-derived macrophages. miR-130b expression was decreased in THP-1-derived macrophages treated by ox-LDL and its overexpression attenuated adipogenesis as well as inflammatory response. miR-130b knockdown reversed the regulatory effect of Tan on adipogenesis and inflammatory response in THP-1-derived macrophages stimulated by ox-LDL. In addition, WNT5A acted as a functional target of miR-130b and inhibited by Tan and miR-130b. As a conclusion, Tan decreased the adipogenesis and inflammatory response by mediating miR-130b and WNT5A, providing a novel theoretical foundation for treatment of atherosclerosis.     

Retracted: Upregulated microRNA-31 inhibits oxidative stress-induced neuronal injury through the JAK/STAT3 pathway by binding to PKD1 in mice with ischemic stroke

Ischemic stroke (IS), which is characterized by high morbidity, disability, and mortality, is recognized as a major cerebrovascular disease. MicroRNA-31 (miR-31) was reported to participate in the progression of brain disease. The present study was conducted in order to investigate the effect of miR-31 on oxidative stress-induced neuronal injury in IS mice with the involvement of protein kinase D1 (PKD1) and the JAK/STAT3 pathway. C57BL/6J mice were used to establish the middle cerebral artery occlusion (MCAO) model. Astrocytes were transfected with miR-31 mimic, miR-31 inhibitor, si-PKD1, or JAK-STAT3 pathway inhibitor. Following the establishment of an oxygen–glucose deprivation (OGD) model, the astrocytes were cocultured with neuronal OGD. Lower miR-31, higher PKD1 expressions, and activated JAK/STAT3 pathway were found in both the MCAO and OGD models. miR-31 could negatively target PKD1. In an MCAO model, overexpressing miR-31 and silencing PKD1 reduced neuronal injury, cerebral infarct volume, neuron loss, and oxidative stress injury, inhibited the activation of JAK/STAT3 pathway and the expressions of PKD1, interleukin (IL)-1β, IL-6, tumor necrosis factor-α, malondialdehyde, 4-HNE, 8-HOdG, caspase-3, and Bax, but increased the superoxide dismutase content. In the OGD model, overexpression of miR-31 and silencing of PKD1 attenuated oxidative stress-induced neuronal injury, and diminished the lactate dehydrogenase leakage and reactive oxygen species level, accompanied by elevated neuronal viability. These results indicate that miR-31 alleviates inflammatory response as well as an oxidative stress-induced neuronal injury in IS mice by downregulating PKD1 and JAK/STAT3 pathway.     

Association of the macrophage migration inhibitory factor gene − 173G/C polymorphism with inflammatory bowel disease: A meta-analysis of 4296 subjects

A variety of epidemiologic studies have focused on the association between macrophage migration inhibitory factor (MIF) gene − 173G/C polymorphism and inflammatory bowel disease (IBD). However, results in different studies have been inconsistent. In order to derive a more precise estimation of the associations, we performed this meta-analysis and systematic searches of electronic databases PubMed and Web of Science (up to April 30, 2013). Based on our search criteria, a total of seven eligible studies concerning the MIF − 173G/C polymorphism and IBD risk were included in the final meta-analysis, comprising 2162 IBD cases and 2134 controls. Significant association was found between MIF − 173G/C polymorphism and the risk of IBD when all studies were pooled into the meta-analysis (for C allele vs. G allele: OR = 1.25, 95% CI = 1.12–1.41, p = 0.000; for C/C vs. G/G: OR = 1.71, 95% CI = 1.23–2.39, p = 0.002; for C/C + G/C vs. G/G: OR = 1.24, 95% CI = 1.09–1.42, p = 0.002; for C/C vs. G/C + G/G: OR = 1.67, 95% CI = 1.20–2.33, p = 0.002). Heterogeneity and publication bias did not exist in the overall comparisons. The present meta-analysis suggests an association between the MIF − 173G/C polymorphism and IBD risk. However, due to few studies and the selection bias existed in some studies, the results should be interpreted with caution.