Differences in metabonomic profiles of abdominal subcutaneous adipose tissue in women with polycystic ovary syndrome

Figure 1. Identified metabolic profile in NC and PCOS. (A, B) PCA revealed a distinct metabolic profile in the PCOS group compared with the NC group. The X-axis and Y-axis represent the first and second principal components, respectively. (C, D) Statistical validation with perripening analysis of the corresponding OPLS–DA model of the NC and PCOS groups. (E, F) Perripening tests were obtained from LC–MS data of the NC and PCOS groups. The intercept values of the regression line and the Y-axis are R2 and Q2.

Figure 2. Differentially expressed metabolites in PCOS. (A) The volcano map of all metabolites expressed in NC and PCOS groups. (B) Hierarchical clustering analysis was used to assess significantly regulated metabolites between NC and PCOS groups. Increased and decreased metabolites are depicted by red and blue, respectively. (C) Super chemical class metabolite sets of the differential metabolites. (D) Main chemical class metabolite sets of the differential metabolites. (E) Enriched diseases clustering analysis. (F) Enriched metabolic pathway clustering analysis.

Figure 3. ROC analysis of representative differentially expressed metabolites. The AUC of (A) DL-tryptophan, (B) L-lysine, (C) L-histidine, (D) L-tyrosine, (E) L-phenylalanine, and (F) isoleucine.

Figure 4. The growth function of representative metabolites in granulosa cells. (A–F) CCK-8 assays were used to detect cell viability of KGN cells at different times using the same concentration of metabolites (10, 20, 50, or 100 μM). (G). Relative cell growth after treatment with DHEA (10−4 M) and L-phenylalanine (20 μM) was detected by the CCK-8 assay. (H). Relative cell growth after treatment with DHEA (10−4 M) and isoleucine (20 μM) was detected by the CCK-8 assay. *p < 0.05, ****p < 0.0001.

Figure 5. Analysis of the cell apoptosis of KGN cells transfected with DHEA (10−4 M) and isoleucine (20 μM) or L-phenylalanine (20 μM). The early and late apoptosis rates of KGN cells were compared using PI and FITC. ***p < 0.001; ns, non-significant.

Figure 6. The possible mechanism of isoleucine in granulosa cells. (A) Network and function analysis of differential metabolites using the IPA database. The yellow nodes represent the upregulated metabolites. The blue nodes represent the downregulated metabolites. CP represents the signaling pathway related to the changed metabolites. (B) Relative ATP level of KGN cells transfected with DHEA (10−4 M) and isoleucine (20 μM). Cell serum was collected for ELISA analysis of (C) T0, (D) P4, and (E) E2. *p < 0.05, **p < 0.01, ****p < 0.0001.

Figure 7. GC–MS/MS-targeted amino acid metabolism analysis. (A) Histogram showing the concentration of isoleucine in the NC group and PCOS group. *p < 0.05.