| First Author | Chen CH | Year | 2019 |
| Journal | Biochim Biophys Acta Gen Subj | Volume | 1863 |
| Issue | 6 | Pages | 1059-1069 |
| PubMed ID | 30905621 | Mgi Jnum | J:275503 |
| Mgi Id | MGI:6303690 | Doi | 10.1016/j.bbagen.2019.03.014 |
| Citation | Chen CH, et al. (2019) O-GlcNAcylation disrupts STRA6-retinol signals in kidneys of diabetes. Biochim Biophys Acta Gen Subj 1863(6):1059-1069 |
| abstractText | BACKGROUND: O-GlcNAcylation is an important mechanism of diabetic complication. Retinoid homeostasis regulates cell-physiological functions through STRA6-retinol signaling. Therefore, we investigated whether O-GlcNAcylation disrupted STRA6-retinol signals in diabetes. METHODS: Immunoprecipitation and proximity ligation assay were used to investigate O-GlcNAcylation of STRA6-retinol signals in kidneys of db/db and ob/ob mice. Western blot and immunohistochemistry were done for STRA6/CRBP1/LRAT/RALDH1/RARs pathway, GFAT, OGT, TGFbeta1 and collagen 1 level. HPLC and ELISA for retinol, retinal, and retinoic acid concentrations were performed in vivo and vitro. RBP4 binding with STRA6 was measured in vitro. To verify whether O-GlcNAcylation disrupted STRA6-retinol signals, treatment of TMG and OSMI-1, transfection of OGA and OGT, and OGT siRNA were performed in HK-2 cells. RESULTS: STRA6 and RALDH1 were highly O-GlcNAc-modified in glomeruli and tubules of db/db and ob/ob mice. RBP4, p-Try, p-JAK2, and p-STAT5 on STRA6 immunoprecipitate were reduced. Cellular retinol signals (CRBP1, LRAT, ADH, retinol, retinal, RA, RARalpha, RARgamma and RXRalpha) remarkably decreased in kidneys of db/db, ob/ob mice and HG-cultured cells. TMG and OGT transfection induced O-GlcNAcylation of STRA6 and RALDH1, repressed RBP4-bound STRA6, and retinol signals in NG-cultured cells. OSMI-1, OGA transfection, and OGT silence reversed O-GlcNAc-modification of STRA6 and RALDH1, and rescued the decrease of retinol signals, and reversed the increase of TGFbeta1 and collagen 1 in HG-treated cells. CONCLUSIONS: O-GlcNAcylation significantly modified STRA6 and RALDH1, suppressed RBP4 binding activity, and disrupted retinol signals in the kidney of diabetes. GENERAL SIGNIFICANCE: This study first indicates that STRA6-retinol signals were directly disrupted by O-GlcNAcylation in diabetic kidney. |
