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  • Author: Yan Zhao x
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Open access

Hong-Fa Yan, Zhao-Yu Liu, Zhi-Ang Guan and Chuang Guo

Objective

The mechanisms underlying obesity and anti-obesity processes have garnered remarkable attention as potential therapeutic targets for obesity-associated metabolic syndromes. Our prior work has shown the healing efficacy of iron reduction therapies for hepatic steatosis in a rodent model of diabetes and obesity. In this study, we investigated how iron depletion by deferoxamine (DFO) affected adipocyte dysfunction in the epididymal adipose tissues of ob/ob mice.

Methods

Male ob/ob mice were assigned to either a vehicle-treated or DFO-treated group. DFO (100 mg/kg body weight) was injected intraperitoneally for 15 days.

Results

We confirmed that iron deposits were statistically increased in the epididymal fat pad of 26-week-old ob/ob mice compared with wild-type (WT) mice. DFO significantly improved vital parameters of adipose tissue biology by reducing reactive oxygen species and inflammatory marker (TNFα, IL-2, IL-6, and Hepcidin) secretion, by increasing the levels of antioxidant enzymes, hypoxia-inducible factor-1α (HIF-1α) and HIF-1α-targeted proteins, and by altering adipocytic iron-, glucose- and lipid-associated metabolism proteins. Meanwhile, hypertrophic adipocytes were decreased in size, and insulin signaling pathway-related proteins were also activated after 15 days of DFO treatment.

Conclusions

These findings suggest that dysfunctional iron homeostasis contributes to the pathophysiology of obesity and insulin resistance in adipose tissues of ob/ob mice. Further investigation is required to develop safe iron chelators as effective treatment strategies against obesity, with potential for rapid clinical application.

Open access

Xiujuan Su, Yan Zhao, Zhijuan Cao, Yingying Yang, Tony Duan and Jing Hua

Background

The effect of isolated maternal hypothyroxinaemia (IMH) on pregnancy complications and neonatal outcomes in human beings is still controversial.

Methods

This was a retrospective cohort study based on the electronic medical register system. The records of women with a singleton pregnancy who sought antenatal examination between January 2014 and December 2015 at Shanghai First Maternity and Infant Hospital were extracted from the electronic medical records system. Thyroid-stimulating hormone (TSH), free thyroxine (fT4) and anti-thyroperoxidase autoantibody (TPO-Ab) was measured before 20 gestational weeks, and a multiple logistic regression model was used to estimate the odds ratios of pregnancy complications and neonatal outcomes between euthyroid women and those with isolated hypothyroxinaemia.

Results

A total of 8173 women were included in this study, of whom 342 (4.18%) were diagnosed with IMH. Regression analysis showed that IMH diagnosed in the second trimester (13–20 weeks) was associated with an increased risk of hypertensive disorders of pregnancy (OR = 2.66, 95% CI: 1.38–5.10) and placenta abruption (OR = 3.64, 95% CI: 1.07–12.41), but not with preterm delivery (OR = 1.09, 95% CI: 0.50–2.40), small or large gestational age of infant (OR = 0.91, 95% CI: 0.39–2.12; OR = 1.16, 95% CI: 0.72–1.86), macrosomia (OR = 1.71, 95% CI: 0.95–3.07), gestational diabetes mellitus (OR = 1.36, 95% CI: 0.86–2.15) and placenta previa (OR = 1.62, 95% CI: 0.39–7.37).

Conclusion

IMH could be a risk factor for hypertensive disorders of pregnancy.

Open access

Jia Li, Yan Zhao, Caoxin Huang, Zheng Chen, Xiulin Shi, Long Li, Zhong Chen and Xuejun Li

Objective

Exercise benefits people with nonalcoholic fatty liver disease (NAFLD). The aim of this study was to identify a panel of biomarkers and to provide the possible mechanism for the effect of exercise on NAFLD patients via an untargeted mass spectrometry-based serum metabolomics study.

Methods

NAFLD patients were classified randomly into a control group (n = 74) and a 6-month vigorous exercise (n = 68) group. Differences in serum metabolic profiles were analyzed using untargeted ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) technology. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to validate the differences between these two groups, and altered metabolites were obtained by ANOVA (fold change >2, P < 0.05) and identified with the online database Metlin and an in-house database.

Results

Metabolic profiling and multiple statistical analyses of the serum samples indicated significant differences between the NAFLD patients in the control and the 6-month vigorous exercise groups. Finally, 36 metabolites were identified between the control vs exercise groups. These metabolites were mainly associated with glycerophospholipid- and sphingolipid-related pathways.

Conclusion

Our study demonstrates that glycerophospholipid and sphingolipid alterations may contribute to the mechanism underlying the effect of exercise on NAFLD patients. A LC-MS-based metabolomics approach has a potential value for screening exercise-induced biomarkers.

Open access

Min Li, Ying Chen, Jingjing Jiang, Yan Lu, Zhiyi Song, Shengjie Zhang, Chao Sun, Hao Ying, Xiaofang Fan, Yuping Song, Jialin Yang and Lin Zhao

Objective

Recent studies have shown that neuregulin 4 (Nrg4), a member of the epidermal growth factor (EGF) family of extracellular ligands, plays an important role in the prevention of obesity, insulin resistance and nonalcoholic fatty liver disease (NAFLD). Considering that thyroid hormone (TH) has profound effects on whole-body energy metabolism, we speculate that circulating Nrg4 levels might be altered in patients with hyperthyroidism.

Design and methods

A total of 129 hyperthyroid patients and 100 healthy subjects were recruited. Of them, 39 hyperthyroid patients received thionamide treatment for 3 months until euthyroidism. Serum Nrg4 levels were determined using the ELISA method. To further confirm the relationship between TH and Nrg4, C57BL/6 mice were treated with T3 and quantitative real-time PCR was performed to detect Nrg4 gene expression.

Results

Serum Nrg4 levels were significantly elevated in hyperthyroid patients as compared with normal controls (3.84 ± 1.63 vs 2.21 ± 1.04 ng/mL, P < 0.001). After achieving euthyroidism by thionamide treatment, serum Nrg4 levels dropped markedly from 3.57 ± 1.26 to 1.94 ± 0.72 ng/ml (P < 0.001). After adjustment for potential confounders, serum Nrg4 levels were independently associated with hyperthyroidism. The upregulation of Nrg4 expression in the livers and white adipose tissues by T3 was further confirmed by animal and cell culture experiments.

Conclusions

Serum Nrg4 levels were increased in patients with hyperthyroidism. The liver and white adipose tissue might be primary sources contributing to elevated serum Nrg4 concentrations.

Open access

Chenghao Piao, Xiaojie Wang, Shiqiao Peng, Xinyu Guo, Hui Zhao, Li He, Yan Zeng, Fan Zhang, Kewen Zhu and Yiwei Wang

Objective

Gestational diabetes mellitus (GDM) is characterized by glucose intolerance during gestation. It is associated with a series of maternal and foetal complications. Interleukin (IL)-34 is a recently discovered pro-inflammatory cytokine that functions as a ligand for colony-stimulating factor-1 receptor (CSF-1R). The contribution of IL-34 in the development of multiple chronic inflammatory diseases and autoimmune diseases has been recently discovered. The aim of this study was to evaluate whether IL-34 participates in the pathogenesis of GDM.

Method

A total of 120 women were enrolled in this study, which included 60 GDM patients and age- and sex-matched healthy pregnant women. The expression of IL-34 in serum, cord blood and placental tissues was analysed by ELISA and Western blot assays. The association between IL-34 levels and clinical features was also studied. We additionally evaluated the effect of recombinant mouse IL-34 (rmIL-34) on apoptosis and pancreatic β cell function.

Results

We found that IL-34 expression is highly increased in serum, cord blood and placental tissues in patients with GDM. In addition, there was a positive association between serum IL-34 and insulin resistance and glucose concentrations. Our data also revealed that IL-34 contributes to the apoptosis of pancreatic β cells in GDM caused by CSF-1R. Furthermore, functional studies found that IL-34 inhibited pancreatic β cell function and cell viability, while CSF-1R inhibitor blocked this effect.

Conclusion

IL-34 plays a crucial role in the development of GDM by targeting CSF-1R, insulin production and β cell function.