title: Role of the Janus kinase (JAK)/signal transducters and activators of transcription (STAT) cascade in advanced glycation end-product-induced cellular mitogenesis in NRK-49F cells.
abstract: Advanced glycation end product (AGE) is important in the pathogenesis of diabetic nephropathy, which is characterized by cellular hypertrophy/hyperplasia leading to renal fibrosis. However, the signal transduction pathways of AGE remain poorly understood. The Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway has been associated with cellular proliferation in some extra-renal cells. Because interstitial fibroblast proliferation might be important in renal fibrosis, we studied the role of the JAK/STAT pathway in NRK-49F (normal rat kidney fibroblast) cells cultured in AGE/BSA and non-glycated BSA. We showed that AGE dose-dependently (10-200 microgram/ml) increased cellular mitogenesis in NRK-49F cells at 5 and 7 days. However, cellular mitogenesis was unaffected by the simultaneous presence of BSA. Regarding the JAK/STAT pathway, AGE (100 microgram/ml) induced tyrosine phosphorylation of JAK2 (but not JAK1, JAK3 or TYK2) at 15-60 min; it also induced the tyrosine phosphorylation of STAT1 and STAT3 at 1-2 h and 0.5-4 h respectively. Being a transcription factor, AGE also increased the DNA-binding activities of STAT1 and STAT3 AG-490 (a specific JAK2 inhibitor) (5 microM) inhibited tyrosine phosphorylation of JAK2 and the DNA-binding activities of STAT1 and STAT3. The same results were obtained by using specific 'decoy' oligodeoxynucleotides (ODNs) that prevented STAT1 and STAT3 from binding to DNA. Meanwhile, the STAT1 or STAT3 decoy ODN and AG-490 were effective in reversing AGE-induced cellular mitogenesis. We concluded that the JAK2-STAT1/STAT3 signal transduction pathway is necessary for AGE-induced cellular mitogenesis in NRK-49F cells.
authors.affiliation: Department of Biochemistry, Kaohsiung Medical College, Kaohsiung, Taiwan, R.O.C.
authors.forename: J S
authors.initials: JS
authors.lastname: Huang
authors.forename: J Y
authors.initials: JY
authors.lastname: Guh
authors.forename: W C
authors.initials: WC
authors.lastname: Hung
authors.forename: M L
authors.initials: ML
authors.lastname: Yang
authors.forename: Y H
authors.initials: YH
authors.lastname: Lai
authors.forename: H C
authors.initials: HC
authors.lastname: Chen
authors.forename: L Y
authors.initials: LY
authors.lastname: Chuang
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts; D017127:Glycation End Products, Advanced / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D053616:Janus Kinase 3; D007668:Kidney; D008934:Mitogens / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009838:Oligodeoxyribonucleotides / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D019000:Phosphotyrosine / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D051381:Rats; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects*; D015534:Trans-Activators / Q000378:metabolism*; D020032:Tyrphostins / Q000494:pharmacology
chemical_list: D004268:DNA-Binding Proteins; D017127:Glycation End Products, Advanced; C507936:Jak3 protein, rat; D008934:Mitogens; D009838:Oligodeoxyribonucleotides; D011518:Proto-Oncogene Proteins; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; C494081:Stat1 protein, rat; C494088:Stat3 protein, rat; D015534:Trans-Activators; D020032:Tyrphostins; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; D019000:Phosphotyrosine; D012710:Serum Albumin, Bovine; D004247:DNA; D011505:Protein-Tyrosine Kinases; C507906:Jak1 protein, rat; C507927:Jak2 protein, rat; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D053616:Janus Kinase 3