Different sites of actions make different responses to thiazolidinediones between mouse and rat models of fatty liver

Metformin versus metformin plus pioglitazone on gonadal and metabolic profiles in normal-weight women with polycystic ovary syndrome: a single-center, open-labeled prospective randomized controlled trial

OBJECTIVE

To investigate the effects of metformin (MET) monotherapy and pioglitazone plus MET (PIOMET) therapy on gonadal and metabolic profiles in normal-weight women with polycystic ovary syndrome (PCOS).

METHODS

Sixty normal-weight women with PCOS were recruited between January and September 2022 at the Shengjing Hospital of China Medical University. They were randomly assigned to the MET or PIOMET groups for 12 weeks of MET monotherapy or PIOMET therapy. Anthropometric measurements, menstrual cycle changes, gonadal profiles, and the oral glucose insulin-releasing test (OGIRT) were performed at baseline and after the 12-week treatment.

RESULTS

Thirty-six participants completed the trial. MET and PIOMET therapies improved menstrual cycles after the 4- and 12-week treatments; however, there was no statistical difference between the two groups. PIOMET therapy improved luteinizing hormone (LH), luteinizing hormone/follicle stimulating hormone (LH/FSH) ratio, and free androgen index (FAI) levels after the 4-week treatment, whereas MET monotherapy only improved total testosterone (TT) levels compared to baseline (P < 0.05). Both MET and PIOMET therapies improved TT and anti-Mullerian hormone (AMH) levels after the 12-week treatment (P < 0.05). In addition, only PIOMET therapy significantly improved sex hormone-binding globulin (SHBG), FAI, and androstenedione (AND) levels than the baseline (P < 0.05). PIOMET therapy improved SHBG and AMH levels more effectively than MET monotherapy (P < 0.05). Furthermore, PIOMET treatment was more effective in improving blood glucose levels at 120 and 180 min of OGIRT compared to MET monotherapy (P < 0.05).

CONCLUSIONS

In normal-weight women with PCOS, PIOMET treatment may have more benefits in improving SHBG, AMH, and postprandial glucose levels than MET monotherapy, and did not affect weight. However, the study findings need to be confirmed in PCOS study populations with larger sample sizes.

The anti-fibrotic efficacy of adelmidrol depends on hepatic PPARγ levels

Adelmidrol, an anti-inflammatory small-molecule compound, can treat inflammatory diseases like arthritis and colitis in a PPARγ-dependent manner. Effective anti-inflammatory therapy is beneficial in delaying the progression of liver fibrosis. This study aimed to investigate the effect and underlying mechanisms of adelmidrol on hepatic fibrosis induced by CCl4 and CDAA-HFD. In the CCl4 model, adelmidrol (10 mg/kg) significantly reduced the incidence of liver cirrhosis from 76.5% to 38.9%, with a reduction of ALT, AST, and extracellular matrix deposition. RNA-seq revealed adelmidrol markedly inhibited the activation of hepatic scar-associated Trem2+ macrophages and PDGFRα+ stellate cells. Adelmidrol exhibited a limited anti-fibrotic effect in CDAA-HFD-induced fibrosis. Further, inconsistencies were observed in the expression trends in liver PPARγ in both models. CCl4 injury led to the continuous decrease in hepatic PPARγ levels, adelmidrol treatment up-regulated hepatic PPARγ expression and down-regulated the expression of pro-inflammatory factor NF-κB and pro-fibrotic factor TGF-β1. Adelmidrol also inhibited the activation of macrophages and HSCs in a PPARγ-dependent manner in vitro. GW9662, a specific PPARγ antagonist, counteracted the anti-fibrotic effect of adelmidrol. In CDAA-HFD-induced model, hepatic PPARγ expression gradually increased with the progress of modeling. Adelmidrol enhanced steatosis in hepatocytes by the activation of the PPARγ/CD36 pathway in the CDAA-HFD model and FFA-treated HepG2, showing a limited anti-fibrotic effect. GW9662 reversed the pro-steatotic effect of adelmidrol and improved fibrosis. The anti-fibrotic outcomes of adelmidrol were related to hepatic PPARγ levels, which depends on the synergistic effect of PPARγ agonism caused by adelmidrol on hepatocytes, macrophages, and HSCs in different pathological states.

Role of Seipin in Human Diseases and Experimental Animal Models

Seipin, a protein encoded by the Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) gene, is famous for its key role in the biogenesis of lipid droplets and type 2 congenital generalised lipodystrophy (CGL2). BSCL2 gene mutations result in genetic diseases including CGL2, progressive encephalopathy with or without lipodystrophy (also called Celia’s encephalopathy), and BSCL2-associated motor neuron diseases. Abnormal expression of seipin has also been found in hepatic steatosis, neurodegenerative diseases, glioblastoma stroke, cardiac hypertrophy, and other diseases. In the current study, we comprehensively summarise phenotypes, underlying mechanisms, and treatment of human diseases caused by BSCL2 gene mutations, paralleled by animal studies including systemic or specific Bscl2 gene knockout, or Bscl2 gene overexpression. In various animal models representing diseases that are not related to Bscl2 mutations, differential expression patterns and functional roles of seipin are also described. Furthermore, we highlight the potential therapeutic approaches by targeting seipin or its upstream and downstream signalling pathways. Taken together, restoring adipose tissue function and targeting seipin-related pathways are effective strategies for CGL2 treatment. Meanwhile, seipin-related pathways are also considered to have potential therapeutic value in diseases that are not caused by BSCL2 gene mutations.