Objectives: The pathogenesis of Graves’ disease (GD) remains unclear. In terms of environmental factors, GD development may be associated with chronic inflammation caused by alteration of the intestinal flora. This study explored the association of intestinal flora alteration with the development of GD among the Han population in southwest China. Design and methods: Fifteen GD patients at the Affiliated Hospital of Zunyi Medical College between March 2016 and March 2017 were randomly enrolled. Additionally, 15 sex- and age-matched healthy volunteers were selected as the control group during the same period. Fresh stool samples were collected, and bacterial 16S RNA was extracted and amplified for gene sequencing with the Illumina MiSeq platform. The sequencing results were subjected to operational taxonomic unit-based classification, classification verification, alpha diversity analysis, taxonomic composition analysis and partial least squares-discriminant analysis (PLS-DA). Results: The diversity indices for the GD group were lower than those for the control group. The GD group showed significantly higher abundances of Firmicutes, Proteobacteria and Actinobacillus and a higher Firmicutes/Bacteroidetes ratio than the control group. PLS-DA suggested the satisfactory classification of the flora between the GD group and the control group. The abundances of the genera Oribacterium, Mogibacterium, Lactobacillus, Aggregatibacter and Mogibacterium were significantly higher in the GD group than in the control group (P < 0.05). Conclusions: The intestinal flora of GD patients was significantly different from that of the healthy population. Thus, alteration of intestinal flora may be associated with the development of GD.

Role of the JAK2/STAT3 signaling pathway in the pathogenesis of type 2 diabetes mellitus with macrovascular complications Role of the JAK2/STAT3 signaling pathway in the pathogenesis of type 2 diabetes mellitus with macrovascular complications

Immune dysfunction caused by environmental factors plays an important role in the development of Graves’ disease (GD), and environmental factors are closely related to the intestinal flora. Our previous study showed significant changes in the intestinal flora in GD patients compared with healthy volunteers. This study analyzed the relationships between changes in the intestinal flora, thyroid function and relevant thyroid antibodies in GD patients before and after methimazole treatment. The subjects were divided into the UGD group (18 newly diagnosed GD patients), the TGD group (10 GD patients with normal or approximately normal thyroid function after methimazole treatment) and the NC group (11 healthy volunteers). Their fresh stool samples were sent for 16S rRNA gene amplification and Illumina platform sequencing. The correlations of the relative abundance of Bifidobacterium with the levels of TRAb, TgAb and TPOAb in the NC group and the UGD group were analyzed. A total of 1,562,445 high-quality sequences were obtained. In the UGD group, the abundances of Bifidobacterium and Collinsella were higher than that in the NC group; Bacteroides abundance in the TGD group was higher than that in the NC group, while Prevotella and Dialister abundances were lower than that in the NC group; Prevotella and Collinsella abundances in the UGD group were higher than that in the TGD group. The predominant abundance distribution of Bifidobacteriaceae in the UGD group at the family level was superior to that in the NC group. The abundance of Bifidobacterium was positively correlated with the levels of TRAb, TgAb, and TPOAb. The biological diversity of the intestinal flora was reduced in GD patients. After methimazole treatment, the composition of the intestinal flora was significantly altered. The change in Bifidobacterium abundance was positively correlated with TRAb, TgAb and TPOAb, suggesting that it might be related to the immune mechanism of GD. The results of this study may deepen our understanding of the pathogenesis of GD and provide a new idea for the treatment of GD.

Objectives: Although it has been shown that exposure to environmental endocrine disruptors (EDCs) has been implicated as a potential risk factor for metabolic disease, information on adverse effect of chronic low-dose exposure to nonylphenol (NP), on the development and progress of type 2 diabetes mellitus (T2DM) is scarce. NP, as an EDC, is a ubiquitous degradation product of nonylphenol polyethoxylate (NPE) that is primarily used in cleaning and industrial processes. Method: Eighty Sprague-Dawley rats were assigned into 8 groups (n = 10 per group): rats fed a normal-diet (ND) as the control (C-ND); rats fed a normal diet and were gavaged with NP at a dose level of 0.02 μg/kg/day (NP-L-ND), 0.2 μg/kg/day (NP-M-ND) or 2 μg/kg/day (NP-H-ND), respectively; rats fed a high-sucrose/high-fat diet (HSHFD) as the HSHFD control (C-HSHFD); rats fed a HSHFD and were gavaged with NP at a dose level of 0.02 μg/kg/day (NP-L-HSHFD), 0.2 μg/kg/day (NP-M-HSHFD) or 2 μg/kg/day (NP-H-HSHFD), respectively. Result: On day 180, the rats in the groups treated with NP-M-HSHFD and NP-H-HSHFD showed significant increases in body weight (p < 0.05) in comparison with the C-ND group. Fast blood glucose (FBG) level in the NP-M-HSHFD and NP-H-HSHFD groups was higher than that in the C-ND group (F = 96.17, p < 0.001). The fast serum insulin (FINS) level of rats was lower in both the NP-M-HSHFD and NP-H-HSHFD groups compared with the C-ND group (F = 145.56, p < 0.001). Serum leptin (LEP) level in both the NP-M-HSHFD and NP-H-HSHFD groups was lower when compared with the C-ND group (F = 34.62, p < 0.001). The effect of NP at the dose level of 0.2 μg/kg/day on FBG, serum FINS and LEP levels in rats was greatest among the treatment groups (p < 0.05). Oral glucose tolerance test showed increased area under the curve (AUC) in treatment groups at week 12 (p < 0.05). A decrease of pancreatic islet numbers and size was exhibited in the pancreatic tissue of NP-M-HSHFD and NP-H-HSHFD treated rats compared with C-ND treated rats. Co-exposure to NP and HSHFD causes inflammatory changes histologically. Conclusion: Chronic low-dose exposure to NP might induce impaired glucose tolerance, which further lead to insulin resistance, and pancreatic β cell insulin secretion deficiency, ultimately increase the risk of T2DM. Moreover, additive toxic effects of NP and HSHFD on pancreatic beta-cell function and glucose metabolism have been identified in rats as well.

1,25‑Dihydroxyvitamin D3 (1,25‑(OH)2D3) has an anti‑inflammatory effect on human monocytes incubated with sera from patients with type 2 diabetes/diabetic nephropathy; however, the detailed mechanism behind the effect remains to be explored. The current study further validated the effects of 1,25‑(OH)2D3 and lipopolysaccharide (LPS) + human recombinant interleukin (IL)‑15 on the expression of the vitamin D receptor (VDR) and phosphorylated signal transducer and activator of transcription 5 (p‑STAT5) in human monocytes and explored the possible interaction between VDR and p‑STAT5. Synchronized THP‑1 cells were divided into pre‑intervened groups, namely the control, LPS + IL‑15 and 1,25‑(OH)2D3, groups, according to their differing treatments. The expression of STAT5 and p‑STAT5 was evaluated by western blot analysis; the concentration of IL‑6 in the supernatant was determined using an enzyme‑linked immunosorbent assay; the expression of cytoskeletal proteins was observed using immunofluorescence and laser confocal microscopy; and the possible intranuclear interaction between VDR and p‑STAT5 was investigated using immunofluorescence, immuno‑coprecipitation and western blot analysis. LPS + IL‑15 upregulated p‑STAT5 expression and the IL‑6 level (P<0.05), with cytoskeletal rearrangement. These effects were partially prevented through pretreatment with 1,25‑(OH)2D3. The LPS + IL‑15 group and the 1,25‑(OH)2D3 group exhibited an interaction between p‑STAT5 and VDR in the nucleus, with the latter group showing a significant increase compared with the former (P<0.05). The immuno‑coprecipitation results provided evidence of the interaction between VDR and p‑STAT5, which suggests the existence of STAT5‑VDR crosstalk in THP‑1 monocytes. Cytoskeletal rearrangement, VDR and p‑STAT5 potentially have interactions in THP‑1 monocytes. The anti‑inflammatory effect of 1,25‑(OH)2D3 may be associated with crosstalk between STAT5 and VDR, which further induces cytoskeletal rearrangement.

Chemerin is an adipocytokine that participates in glycolipid metabolism; however, its association with type 2 diabetes (T2DM) with lower extremity macroangiopathy (T2DM-V) has rarely been reported. This study explored the association of chemerin and inflammatory factors with body fat parameters, glucolipid metabolism, and insulin resistance (IR) in T2DM and T2DM-V. Patients were classified into normal glucose regulation (NGR), T2DM, and T2DM-V groups. Serum chemerin, glucolipid metabolic parameters, transforming growth factor (TGF)-β, interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1 and fasting insulin levels were measured along with HOMA-IR, body mass index (BMI), and waist-to-stature ratio (WSR). Serum chemerin, TGF-β, IL-6 and MCP-1 levels were significantly higher in T2DM groups than in NGR group, and BMI, WSR, fasting plasma glucose (FPG), 2hPG, glycated hemoglobin (HbA1c), triglycerides (TG) and HOMA-IR were higher in T2DM-V subgroups with moderate or severe lower extremity macroangiopathy than in NGR group, simple T2DM group, and T2DM-V subgroup with mild macroangiopathy. FPG, 2hPG, HbA1c, TG and HOMA-IR were higher in T2DM-V subgroup with severe macroangiopathy than in T2DM-V with moderate macroangiopathy (p < 0.05). In all groups, serum chemerin levels were positively correlated with BMI, WSR, FPG, 2hPG, HbA1c, fasting insulin, aspartate transaminase, TG, TGF-β, IL-6 and HOMA-IR (p < 0.05) and negatively correlated with high-density lipoprotein cholesterol [HDL-c] (p < 0.05). Multiple stepwise regression analysis showed that 2hPG, HbA1c, and HDL-c were independent predictors of serum chemerin levels (β = -0.768, -0.122, -0.115, and 3.261, respectively; p < 0.01). Collectively, chemerin, factors associated with obesity, pathological and physiological changes in glucolipid metabolism, and inflammatory factors may promote the development of T2DM macroangiopathy.