Corrigendum: Effects of Yulin Tong Bu formula on modulating gut microbiota and fecal metabolite interactions in mice with polycystic ovary syndrome.

[This corrects the article DOI: 10.3389/fendo.2023.1122709.].

Glycyrrhizin ameliorates impaired glucose metabolism and ovarian dysfunction in a polycystic ovary syndrome mouse model.

The aim of this study was to determine the impact of glycyrrhizin, an inhibitor of high mobility group box 1, on glucose metabolic disorders and ovarian dysfunction in mice with polycystic ovary syndrome. We generated a polycystic ovary syndrome mouse model by using dehydroepiandrosterone plus high-fat diet. Glycyrrhizin (100 mg/kg) was intraperitoneally injected into the polycystic ovary syndrome mice and the effects on body weight, glucose tolerance, insulin sensitivity, estrous cycle, hormone profiles, ovarian pathology, glucolipid metabolism, and some molecular mechanisms were investigated. Increased number of cystic follicles, hormonal disorders, impaired glucose tolerance, and decreased insulin sensitivity in the polycystic ovary syndrome mice were reverted by glycyrrhizin. The increased high mobility group box 1 levels in the serum and ovarian tissues of the polycystic ovary syndrome mice were also reduced by glycyrrhizin. Furthermore, increased expressions of toll-like receptor 9, myeloid differentiation factor 88, and nuclear factor kappa B as well as reduced expressions of insulin receptor, phosphorylated protein kinase B, and glucose transporter type 4 were restored by glycyrrhizin in the polycystic ovary syndrome mice. Glycyrrhizin could suppress the polycystic ovary syndrome-induced upregulation of high mobility group box 1, several inflammatory marker genes, and the toll-like receptor 9/myeloid differentiation factor 88/nuclear factor kappa B pathways, while inhibiting the insulin receptor/phosphorylated protein kinase B/glucose transporter type 4 pathways. Hence, glycyrrhizin is a promising therapeutic agent against polycystic ovary syndrome.

Effects of Yulin Tong Bu formula on modulating gut microbiota and fecal metabolite interactions in mice with polycystic ovary syndrome.

Background: Polycystic ovarian syndrome (PCOS) is a common endocrine disorder characterized by hyperandrogenism, ovarian dysfunction and polycystic ovarian morphology. Gut microbiota dysbiosis and metabolite are associated with PCOS clinical parameters. Yulin Tong Bu formula (YLTB), a traditional Chinese medicine formula, has been recently indicated to be capable of ameliorating polycystic ovary symptoms and correcting abnormal glucose metabolism. However, the therapeutic mechanism of YLTB on PCOS has not been fully elucidated. Methods: A pseudo sterile mouse model was established during this four-day acclimatization phase by giving the animals an antibiotic cocktail to remove the gut microbiota. Here, the therapeutic effects of YLTB on PCOS were investigated using dehydroepiandrosterone plus high-fat diet-induced PCOS mice model. Female prepuberal mice were randomly divided into three groups; namely, the control group, PCOS group and YLTB (38.68 g·kg-1·day-1) group. To test whether this effect is associated with the gut microbiota, we performed 16S rRNA sequencing studies to analyze the fecal microbiota of mice. The relationships among metabolites, gut microbiota, and PCOS phenotypes were further explored by using Spearman correlation analysis. Then, the effect of metabolite ferulic acid was then validated in PCOS mice. Results: Our results showed that YLTB treatment ameliorated PCOS features (ovarian dysfunction, delayed glucose clearance, decreased insulin sensitivity, deregulation of glucolipid metabolism and hormones, etc.) and significantly attenuated PCOS gut microbiota dysbiosis. Spearman correlation analysis showed that metabolites such as ferulic acid and folic acid are negatively correlated with PCOS clinical parameters. The effect of ferulic acid was similar to that of YLTB. In addition, the bacterial species such as Bacteroides dorei and Bacteroides fragilis were found to be positively related to PCOS clinical parameters, using the association study analysis. Conclusion: These results suggest that YLTB treatment systematically regulates the interaction between the gut microbiota and the associated metabolites to ameliorate PCOS, providing a solid theoretical basis for further validation of YLTB effect on human PCOS trials.

Apoptosis in response to heat stress is positively associated with heat-shock protein 90 expression in chicken myocardial cells in vitro.

To determine heat-shock protein (Hsp)90 expression is connected with cellular apoptotic response to heat stress and its mechanism, chicken (Gallus gallus) primary myocardial cells were treated with the Hsp90 promoter, aspirin, and its inhibitor, geldanamycin (GA), before heat stress. Cellular viability, heat-stressed apoptosis and reactive oxygen species level under different treatments were measured, and the expression of key proteins of the signaling pathway related to Hsp90 and their colocalization with Hsp90 were detected. The results showed that aspirin treatment increased the expression of protein kinase B (Akt), the signal transducer and activator of transcription (STAT)-3 and p-IKKα/ß and the colocalization of Akt and STAT-3 with Hsp90 during heat stress, which was accompanied by improved viability and low apoptosis. GA significantly inhibited Akt expression and p-IKKα/ß level, but not STAT-3 quantity, while the colocalization of Akt and STAT-3 with Hsp90 was weakened, followed by lower cell viability and higher apoptosis. Aspirin after GA treatment partially improved the stress response and apoptosis rate of tested cells caused by the recovery of Akt expression and colocalization, rather than the level of STAT-3 (including its co-localization with Hsp90) and p-IKKα/ß. Therefore, Hsp90 expression has a positive effect on cellular capacity to resist heat-stressed injury and apoptosis. Moreover, inhibition of Hsp90 before stress partially attenuated its positive effects.

Prostaglandin I2 Attenuates Prostaglandin E2-Stimulated Expression of Interferon γ in a ß-Amyloid Protein- and NF-κB-Dependent Mechanism.

Cyclooxygenase-2 (COX-2) has been recently identified as being involved in the pathogenesis of Alzheimer's disease (AD). However, the role of an important COX-2 metabolic product, prostaglandin (PG) I2, in AD development remains unknown. Using mouse-derived astrocytes as well as APP/PS1 transgenic mice as model systems, we firstly elucidated the mechanisms of interferon γ (IFNγ) regulation by PGE2 and PGI2. Specifically, PGE2 accumulation in astrocytes activated the ERK1/2 and NF-κB signaling pathways by phosphorylation, which resulted in IFNγ expression. In contrast, the administration of PGI2 attenuated the effects of PGE2 on stimulating the production of IFNγ via inhibiting the translocation of NF-κB from the cytosol to the nucleus. Due to these observations, we further studied these prostaglandins and found that both PGE2 and PGI2 increased Aß1-42 levels. In detail, PGE2 induced IFNγ expression in an Aß1-42-dependent manner, whereas PGI2-induced Aß1-42 production did not alleviate cells from IFNγ inhibition by PGI2 treatment. More importantly, our data also revealed that not only Aß1-42 oligomer but also fibrillar have the ability to induce the expression of IFNγ via stimulation of NF-κB nuclear translocation in astrocytes of APP/PS1 mice. The production of IFNγ finally accelerated the deposition of Aß1-42 in ß-amyloid plaques.

[Effects of hypoxia on the proliferation of human bone marrow mesenchymal stem cells].

OBJECTIVE: To study the effect of hypoxia on the proliferation of human bone marrow mesenchymal stem cells (hBMSCs). METHODS: The method of density gradient centrifugation was employed to isolate and culture hBMSCs. And flow cytometry (FCM) was employed to detect the cell surface marker. After establishing the experimental model of CoCl2-chemical hypoxia, MTT method and flow cytometry were applied to evaluate the proliferation and the proliferation index of hBMSCs at different time points with various CoCl2 concentrations. RESULTS: The proliferations of hBMSCs was inhibited within the first 12 hours under chemical hypoxia condition. Compared with the normal group, the hBMSCs of each CoCl2 group were remarkably proliferated 1, 2, 4 days after chemical hypoxia with CoCl2, but 300 µmol/L CoCl2 group showed no significant difference (P > 0.05). 100 µmol/L CoCl2 group (0.139 ± 0.003, 0.178 ± 0.005, 0.224 ± 0.005) and 150 µmol/L CoCl2 group (0.202 ± 0.020, 0.224 ± 0.019, 0.263 ± 0.004) proliferation was significantly higher than that of the control group (0.134 ± 0.005, 0.167 ± 0.004, 0.206 ± 0.005). Compared with the normal group, the hBMSCs were remarkably proliferated 24 hours after chemical hypoxia with CoCl2 concentration of 150 µmol/L (all P < 0.05). At Day 6, the 100, 150 µmol/L CoCl2 group (0.258 ± 0.020, 0.264 ± 0.008) cells was still higher than that of normal group (0.248 ± 0.004), but the advantage gradually diminished (P < 0.05). At Day 7, the proliferative effects of hypoxia disappeared. CONCLUSION: CoCl2-induced chemical hypoxia may promote the proliferation of hBMSCs.

[Effects of peptidoglycan on proliferation and cell cycle of human bone marrow-derived mesenchymal stem cells].

This study was aimed to explore the effects of peptidoglycan (PGN) on proliferation and cell cycle of human bone marrow mesenchymal stem cells (MSCs). MSCs were isolated from human bone marrow by density gradient centrifugation. The purity of MSCs with the spindle fibroblastic morphology was identified by microphotography and the phenotypes were detected by flow cytometry (FCM). MSCs incubated with different doses of PGN (1, 10, 20 µg/ml) were used as test groups, and those incubated without PGN were regarded as control group. The isolated and cultured MSCs were inoculated into 96-well plates according to a certain concentration. Cell cycle was measured by flow cytometry after incubated with PGN for 72 hours. The results showed that the cell proliferation index was significantly increased in dose and time dependent manners after MSCs was incubated with PGN. Its effects on the proliferation of MSCs were highest in 10 µg/ml group. Compared with the control group, PGN could significantly decrease proportion of MSCs in G0/G1 phase and increase them in S and G2/M phases (p < 0.05). It is concluded that PGN can promote more MSCs to enter the DNA synthesis phase and proliferate many much MSCs in dose and time dependent manners.

[Expression of Toll-like receptors in human bone marrow mesenchymal stem cells].

The aim of this study was to explore the characteristics of Toll-like receptor expression in mesenchymal stem cells derived from bone marrow of healthy donor (BM-MSCs). BM-MSCs were isolated from bone marrow of healthy donor by Ficoll method. Expressions of CD34, CD45, HLA-DR, CD44 and CD71 in BM-MSCs were detected by flow cytometry. CD71 in BM-MSCs was assayed by immunocytochemistry. The adipocyte and osteoblast induction of BM-MSCs were detected by alizarin red stain and oil red stain respectively. TLR 1 - 10 mRNA levels in BM-MSCs were evaluated by semiquantitative RT-PCR. The results showed that expressions of CD34, CD45 and HLA-DR in BM-MSC were negative while the expressions of CD44 and CD71 were positive. CD71 in BM-MSCs was positive. After induced by osteoblast and adipocyte inductor, BM-MSCs were positive for alizarin red staining and oil red staining respectively. All of TLR 1 - 10 mRNA were found in BM-MSCs with high expression levels of TLR2, TLR3, TLR4, TLR7, TLR8, TLR9 and low expression levels of TLR1, TLR5, TLR6, TLR10. In conclusion, different levels of TLR 1 - 10 mRNA were expressed in BM-MSCs of healthy donor.