title: Imbalance of Wnt/Dkk negative feedback promotes persistent activation of pancreatic stellate cells in chronic pancreatitis.
abstract: The role of persistent activation of pancreatic stellate cells (PSCs) in the fibrosis associated with chronic pancreatitis (CP) is increasingly being recognized. Recent studies have shown that Wnt signaling is involved in the development of fibrosis in multiple organs, however, the role of specific Wnts in pancreatic fibrosis remains unknown. We investigated the role of Wnt signaling during PSC activation in CP and the effect of β-catenin inhibition and Dickkopf-related protein 1 (Dkk1) restoration on the phenotype of PSCs. CP was induced in mice by repetitive caerulein injection and mouse PSCs were isolated and activated in vitro. The expression of Wnts, β-catenin, secreted frizzled-related proteins (sFRPs) and Dkks was analyzed by quantitative RT-PCR and western blotting. The canonical Wnt signaling pathway was examined by immunofluorescence and western blot detection of nuclear β-catenin expression. The effect of recombinant mouse Dkk-1 (rmDkk-1) on cell proliferation and apoptosis was assessed by flow cytometry, immunofluorescence, immunocytochemistry and Cell Counting Kit-8 (CCK-8) analysis. The expression of β-catenin, collagen1α1, TGFβRII, PDGFRβ and α-SMA in PSCs treated with different concentrations of rmDkk-1 or siRNA against β-catenin was determined by quantitative RT-PCR and western blotting. Wnt2 was the only Wnt whose expression was significantly upregulated in response to PSC activation, and Wnt2 and β-catenin protein levels were significantly increased in the pancreas of CP mice, whereas Dkk-1 expression was evidently decreased. Nuclear β-catenin levels were markedly increased in activated PSCs, and rmDkk-1 suppressed the nuclear translocation of β-catenin and the proliferation and extracellular matrix production of PSCs through the downregulation of PDGFRβ and TGFβRII. Upregulation of Dkk-1 expression increased apoptosis in cultured PSCs. These results indicate that Wnt signaling may mediate the profibrotic effect of PSC activation, and Wnt2/Dkk-1 could be potential therapeutic targets for CP.
authors.affiliation: Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Wan
authors.affiliation: Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Yu
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Shen
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Ni
authors.affiliation: Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Guojian
authors.initials: G
authors.lastname: Yin
authors.affiliation: Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Xing
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Congying
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Wenqin
authors.initials: W
authors.lastname: Xiao
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Xu
authors.affiliation: Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China; Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Xingpeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China; Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Guoyong
authors.initials: G
authors.lastname: Hu
mesh_terms: D000818:Animals; D001483:Base Sequence; D049109:Cell Proliferation; D002478:Cells, Cultured; D002908:Chronic Disease; D017931:DNA Primers; D020868:Gene Silencing; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D058954:Pancreatic Stellate Cells / Q000378:metabolism / Q000473:pathology*; D010195:Pancreatitis / Q000378:metabolism / Q000473:pathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051153:Wnt Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000235:genetics
chemical_list: D017931:DNA Primers; C501127:Dkk1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D051153:Wnt Proteins; D051176:beta Catenin
references.citation: Gut. 2011 Jun;60(6):820-8
references.pmid: 21193457
references.citation: EMBO J. 2012 Jan 18;31(2):429-42
references.pmid: 22085926
references.citation: Am J Physiol Renal Physiol. 2002 Mar;282(3):F431-41
references.pmid: 11832423
references.citation: Cold Spring Harb Perspect Biol. 2012 Aug 01;4(8):a008078
references.pmid: 22723493
references.citation: Dig Dis Sci. 2000 Apr;45(4):665-74
references.pmid: 10759232
references.citation: Carcinogenesis. 2011 May;32(5):741-7
references.pmid: 21304055
references.citation: Am J Pathol. 2003 May;162(5):1495-502
references.pmid: 12707032
references.citation: Annu Rev Cell Dev Biol. 2004;20:781-810
references.pmid: 15473860
references.citation: Genome Biol. 2002;3(1):REVIEWS3001
references.pmid: 11806834
references.citation: Gastroenterology. 2005 Mar;128(3):728-41
references.pmid: 15765408
references.citation: J Am Soc Nephrol. 2009 Apr;20(4):765-76
references.pmid: 19297557
references.citation: Clin Cancer Res. 2004 Jan 15;10(2):615-25
references.pmid: 14760084
references.citation: J Mol Med (Berl). 2005 Oct;83(10):795-805
references.pmid: 15976918
references.citation: PLoS One. 2008 May 14;3(5):e2142
references.pmid: 18478089
references.citation: Cardiovasc Pathol. 2013 Jan-Feb;22(1):54-7
references.pmid: 22475572
references.citation: Mol Cancer. 2004 Oct 06;3:26
references.pmid: 15469605
references.citation: IUBMB Life. 2012 Sep;64(9):724-31
references.pmid: 22807036
references.citation: J Invest Dermatol. 2008 Apr;128(4):871-81
references.pmid: 17943183
references.citation: Gut. 2006 Jan;55(1):79-89
references.pmid: 16043492
references.citation: Oncogene. 2004 Nov 4;23(52):8520-6
references.pmid: 15378020
references.citation: Lab Invest. 2004 Dec;84(12):1610-8
references.pmid: 15502860
references.citation: Gastroenterology. 2011 Oct;141(4):1486-97, 1497.e1-14
references.pmid: 21704588
references.citation: J Clin Invest. 2007 Jan;117(1):50-9
references.pmid: 17200706
references.citation: Lab Invest. 2003 Mar;83(3):429-34
references.pmid: 12649343
references.citation: Nat Rev Mol Cell Biol. 2012 Dec;13(12):767-79
references.pmid: 23151663
references.citation: Cold Spring Harb Perspect Biol. 2013 Mar 01;5(3):a015081
references.pmid: 23085770
references.citation: Cell. 2012 Jun 8;149(6):1192-205
references.pmid: 22682243
references.citation: Nat Genet. 2004 Apr;36(4):417-22
references.pmid: 15034581
references.citation: Methods. 2001 Dec;25(4):402-8
references.pmid: 11846609
references.citation: J Gastroenterol Hepatol. 2008 Mar;23 Suppl 1:S119-21
references.pmid: 18336654
references.citation: FEBS Lett. 2007 Jun 26;581(16):2954-8
references.pmid: 17544413
references.citation: Oncogene. 2006 Dec 4;25(57):7469-81
references.pmid: 17143291
references.citation: Cold Spring Harb Perspect Biol. 2012 May 01;4(5):
references.pmid: 22550229
references.citation: Am J Physiol Gastrointest Liver Physiol. 2008 Jan;294(1):G39-49
references.pmid: 18006602
references.citation: Oncogene. 2006 Jul 6;25(29):4116-21
references.pmid: 16491118
references.citation: Gut. 2012 Feb;61(2):172-8
references.pmid: 22115911
references.citation: Protein Sci. 2011 Nov;20(11):1802-13
references.pmid: 21805521
references.citation: PLoS One. 2012;7(2):e31807
references.pmid: 22359633
references.citation: Pancreatology. 2012 Mar-Apr;12(2):91-9
references.pmid: 22487517
references.citation: J Hepatol. 2006 Sep;45(3):401-9
references.pmid: 16780995
references.citation: Gut. 1998 Jul;43(1):128-33
references.pmid: 9771417