Fig 2: Putative roles of YULINK in PDGF- or MCT-induced PAH pathological aberrations. During PAH-related pathogenesis induced by PDGF or MCT, an increase in YULINK expression occurs. YULINK coordinates with GLUT1 to facilitate glucose uptake, accompanied by an upregulation of HK-2, promoting enhanced glycolysis in PASMCs. This increased YULINK expression also contributes to uncontrolled cell migration and proliferation through the PDGFR-PI3K-AKT signaling pathways. While numerous reports have highlighted the role of this pathway in glucose metabolism and the Warburg effect, whether the triggered PI3K-AKT signaling regulates PAH-related processes requires further investigation. Suppression of YULINK through gene knockdown or the use of an inhibitor LY294002 to suppress PI3K activation has the potential to reverse these pathological abnormalities associated with PAH. In this graph, the black arrows represent the signaling transduction pathways, and the red arrows denote the enhancements in response to PAH pathogenesis. The dotted lines summarize findings from other published literature, not experiments conducted in this manuscript

Fig 3: YULINK regulated cell migration and proliferation in PASMCs via PI3K-AKT signaling. A PASMCs and PAH-PASMCs with or without YULINK KD were treated with or without 20 ng/ml PDGF for 24 h for protein extraction. Cell lysates were subjected to western blot analysis for the indicated proteins. β-Actin served as an internal control. The numbers labeled below the respective blot lanes indicate the relative fold normalized with the internal control. B Representative images (magnification 200×) together with the bar graphs indicate the cell migration analysis of PASMCs, PASMCs with or without YULINK OE treated with LY294002 (10 µM), and PAH-PASMCs treated with LY294002. C A 5-day cell proliferation assay in the cells under the indicated treatments. *p < 0.05 compared to control PASMCs. #p < 0.05 between compared groups

Fig 4: Enhanced YULINK expression in MCT-induced PAH rats and human PAH specimen. A Pulmonary artery tissues were derived from normal and MCT-induced PAH rats for IHC staining. The brown color in the photomicrograph indicates the expression of YULINK expression. B Tissue sample from the right pulmonary artery of a clinical patient with severe PAH was subjected to IHC staining to assess YULINK expression. A normal pulmonary artery tissue was used as a control for comparison. Scale bar in 1–3: 100 µM, and 4: 200 µM

Fig 5: YULINK interacted with GLUT1 and participated in PDGF-triggered glucose uptake and glycolysis. The bar graphs illustrate A glucose uptake and B pyruvate production in PASMCs with YULINK KD or OE treated with or without PDGF (20 ng/ml) for 24 h. The values represent the mean of three independent experiments ± standard deviation. *p < 0.05 compared to scramble control without PDGF. #p < 0.05 between compared groups. C Western blot analysis indicates the expression of GLUT1 and HK-2 in normal PASMCs, PASMCs with YULINK KD, and PASMCs with YULINK OE treated with or without PDGF for 24 h. The numbers labeled below the respective blot lanes indicate the relative fold normalized with the internal control. D Representative images from immunofluorescence analysis indicate the expression of YULINK (green) and GLUT1 (red), and DAPI (blue) indicates nuclear staining. Magnification 200×. E Whole-cell lysates and F membrane fractions derived from PASMCs or PAH-PASMCs with or without 20 ng/ml PDGF treatment and PAH-PASMCs were subjected to Western blot analysis for YULINK expression. β-Actin and Na/K ATPase served as internal controls. G Membrane protein lysates obtained from PASMCs subjected to indicated treatments were used for immunoprecipitation with YULINK antibody-conjugated beads. The proteins pulled down were subsequently analyzed via Western blot to assess the expression of YULINK and GLUT1. While Input serves as positive control, Isotype IgG serves as negative control