title: Arecoline-induced pro-fibrotic proteins in LLC-PK1 cells are dependent on c-Jun N-terminal kinase.
abstract: Areca nut (AN) chewing is associated with chronic kidney disease (CKD). However, the molecular mechanisms of AN-induced CKD are not known. Thus, we studied the effects of arecoline, a major alkaloid of AN, on proximal tubule (LLC-PK1) cells in terms of cytotoxicity, fibrosis, transforming growth factor-β (TGF-β) and c-Jun N-terminal kinase (JNK). We found that arecoline dose (0.1-0.5mM) and time (24-72h)-dependently induced cytotoxicity without causing cell death. Arecoline (0.25 mM) also time-dependently (24-72h) increased fibronectin and plasminogen activator inhibitor-1 (PAI1) protein expressions. Arecoline (0.25 mM) time-dependently (24-72h) increased TGF-β gene transcriptional activity and supernatant levels of active TGF-β1. Moreover, arecoline (0.25 mM) activated JNK while SP600125 (a JNK inhibitor) attenuated arecoline-induced TGF-β gene transcriptional activity. SP600125, but not SB431542 (a TGF-β receptor type I kinase inhibitor), attenuated arecoline-induced fibronectin and PAI1 protein expressions. Finally, tubulointerstitial fibrosis occurred and renal cortical expressions of fibronectin and PAI1 proteins increased in arecoline-fed mice at 24 weeks. We concluded that arecoline induced tubulointerstitial fibrosis in mice while arecoline-induced TGF-β and pro-fibrotic proteins (fibronectin, PAI1) are dependent on JNK in LLC-PK1 cells.
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Sheng-Hsuan
authors.initials: SH
authors.lastname: Lin
authors.affiliation: Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Shean-Jaw
authors.initials: SJ
authors.lastname: Chiou
authors.affiliation: Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Wan-Ting
authors.initials: WT
authors.lastname: Ho
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chao-Tang
authors.initials: CT
authors.lastname: Chuang
authors.affiliation: Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: chuangly@gmail.com.
authors.forename: Lea-Yea
authors.initials: LY
authors.lastname: Chuang
authors.affiliation: Department of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: guhjy@kmu.edu.tw.
authors.forename: Jinn-Yuh
authors.initials: JY
authors.lastname: Guh
mesh_terms: D000818:Animals; D001115:Arecoline / Q000633:toxicity*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005353:Fibronectins / Q000096:biosynthesis; D005355:Fibrosis / Q000139:chemically induced* / Q000201:enzymology*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000201:enzymology*; D018374:LLC-PK1 Cells; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis; D013552:Swine
chemical_list: D005353:Fibronectins; D017395:Plasminogen Activator Inhibitor 1; D001115:Arecoline; D048031:JNK Mitogen-Activated Protein Kinases
keywords: Arecoline; JNK; Proximal tubule; Renal fibrosis; TGF-β