Polystyrene nanoplastics cause reproductive toxicity in zebrafish: PPAR mediated lipid metabolism disorder

The ubiquitous presence of micro-and nanoplastics (MNPs) in the environment and everyday products has attracted attention due to their hazardous risks. However, the effects of MNPs on reproduction and the underlying mechanisms remain unclear. The present study investigated the impact of polystyrene (PS) nanoplastics of 80, 200 and 500 nm diameters on zebrafish reproduction at an environmentally relevant concentration of 0.5 mg/L. Exposure to PS delayed spermatogenesis and caused aberrant follicular growth, resulting in dysgenesis in F0 adults and impacting F1 embryo development. Notably, the reproductive toxicity exhibited size-dependency, with the 500 nm PS being the most detrimental. Combined analyses of transcriptomics and metabolomics in ovary tissue revealed that treatment with 500 nm PS affected the peroxisome proliferator-activated receptor (PPAR) signaling pathway, dysregulated lipid transport, binding and activity processes, and led to dysgenesis in zebrafish. Specifically, the ovulatory dysfunction induced by PS exposure resembled clinical manifestations of polycystic ovary syndrome (PCOS) and can be attributed to lipid metabolism disorder involving glycerophospholipid, sphingolipid, arachidonic acid, and alpha-linolenic acid. Collectively, our results provide new evidence revealing the molecular mechanisms of PS-induced reproductive toxicity, highlighting that MNPs may pose a risk to female reproductive health.

Integrated metabolomics and network analysis reveal changes in lipid metabolisms of tripterygium glycosides tablets in rats with collagen-induced arthritis

Tripterygium glycosides tablets (TGT) are the commonly used preparation for rheumatoid arthritis (RA). However, the changes in TGT on RA are still unclear at the metabolic level. This study aimed to reveal the biological processes of TGT in collagen-induced arthritis (CIA) rats through integrated metabolomics and network analysis. First, the CIA model in rats was established, and the CIA rats were given three doses of TGT. Then, the endogenous metabolites in the serum from normal rats, CIA rats, and CIA rats treated with varying doses of TGT were detected by UHPLC-QTOF-MS/MS. Next, univariate and multivariate statistical analyses were performed to find the differential metabolites. Finally, differential metabolites, metabolic pathways, and hub genes were analyzed integrally to reveal the biological processes of TGT in CIA rats. The paw diameter, arthritis score, immunoglobulin G (IgG) concentration, CT image, and histological assay showed that TGT had evident therapeutic effects on CIA rats. Untargeted metabolomics revealed that TGT could ameliorate the down-regulation of lipid levels in CIA rats. Four key differential metabolites were found including LysoP(18:0), LysoPA(20:4), LysoPA(18:2), and PS(O-20:0/17:1). The glycerophospholipid metabolic pathway was perturbed in treating CIA with TGT. A total of 24 genes, including PLD1, LPCAT4, AGPAT1, and PLA2G4A, were found to be the hub genes of TGT in CIA rats. In conclusion, the integrated analysis provided a novel and holistic perspective on the biological processes of TGT in CIA rats, which could give helpful guidance for further TGT on RA. Future studies based on human samples are necessary.

Differences in lipid metabolism between anagliptin and sitagliptin in patients with type 2 diabetes on statin therapy: a secondary analysis of the REASON trial

Background

Anagliptin, a dipeptidyl peptidase-4 inhibitor, is reported to reduce the level of low-density lipoprotein cholesterol (LDL-C). The underlying mechanism of this effect and effect on lipid metabolism however remains uncertain.

Aim and methods

We therefore evaluate the effects of anagliptin on lipid metabolism-related markers compared with those of sitagliptin. The study was a secondary analysis using data obtained from the Randomized Evaluation of Anagliptin versus Sitagliptin On low-density lipoproteiN cholesterol in diabetes (REASON) trial. This trial in patients with type 2 diabetes at a high risk of cardiovascular events and on statin therapy showed that anagliptin reduced LDL-C levels to a greater extent than sitagliptin. Cholesterol absorption (campesterol and sitosterol) and synthesis (lathosterol) markers were measured at baseline and 52 weeks in the study cohort (n = 353).

Results

There was no significant difference in the changes of campesterol or sitosterol between the two treatment groups (p = 0.85 and 0.55, respectively). Lathosterol concentration was increased significantly at 52 weeks with sitagliptin treatment (baseline, 1.2 ± 0.7 μg/mL vs. 52 weeks, 1.4 ± 1.0 μg/mL, p = 0.02), whereas it did not change in the anagliptin group (baseline, 1.3 ± 0.8 μg/mL vs. 52 weeks, 1.3 ± 0.7 μg/mL, p = 0.99). The difference in absolute change between the two groups showed a borderline significance (p = 0.06).

Conclusion

These findings suggest that anagliptin reduces LDL-C level by suppressing excess cholesterol synthesis, even in combination with statin therapy.

Trial registration ClinicalTrials.gov number NCT02330406. https://clinicaltrials.gov/ct2/show/NCT02330406; registered January 5, 2015.