Scott and White Digestive Disease Research Center

College Station, TX, United States

Scott and White Digestive Disease Research Center

College Station, TX, United States

Time filter

Source Type

Kim K.-H.,University of Illinois at Chicago | Chen C.-C.,University of Illinois at Chicago | Alpini G.,Scott and White Digestive Disease Research Center | Alpini G.,Texas A&M University | Lau L.F.,University of Illinois at Chicago
Journal of Clinical Investigation | Year: 2015

Liver cholestatic diseases, which stem from diverse etiologies, result in liver toxicity and fibrosis and may progress to cirrhosis and liver failure. We show that CCN1 (also known as CYR61), a matricellular protein that dampens and resolves liver fibrosis, also mediates cholangiocyte proliferation and ductular reaction, which are repair responses to cholestatic injury. In cholangiocytes, CCN1 activated NF-κB through integrin αvβ5vβ3, leading to Jag1 expression, JAG1/NOTCH signaling, and cholangiocyte proliferation. CCN1 also induced Jag1 expression in hepatic stellate cells, whereupon they interacted with hepatic progenitor cells to promote their differentiation into cholangiocytes. Administration of CCN1 protein or soluble JAG1 induced cholangiocyte proliferation in mice, which was blocked by inhibitors of NF-κB or NOTCH signaling. Knock-in mice expressing a CCN1 mutant that is unable to bind αvβ5vβ3 were impaired in ductular reaction, leading to massive hepatic necrosis and mortality after bile duct ligation (BDL), whereas treatment of these mice with soluble JAG1 rescued ductular reaction and reduced hepatic necrosis and mortality. Blockade of integrin αvβ5vβ3, NF-κB, or NOTCH signaling in WT mice also resulted in defective ductular reaction after BDL. These findings demonstrate that CCN1 induces cholangiocyte proliferation and ductular reaction and identify CCN1/αvβ5/NF-κB/JAG1 as a critical axis for biliary injury repair. © 2015, American Society for Clinical Investigation. All rights reserved.


Sato K.,Texas A&M University | Meng F.,Texas A&M University | Meng F.,Scott and White Digestive Disease Research Center | Meng F.,Academic Research Integration | And 4 more authors.
Journal of Hepatology | Year: 2016

Exosomes are small (∼100 nm) membrane-bound extracellular vesicles released by various types of cells into biological fluids. They contain proteins, mRNAs and miRNAs as cargo. Different cell types can take up exosomes by endocytosis and the cargo contained within them can be transferred horizontally to these recipient cells. Exosomal proteins and miRNAs can be functional and regulate physiological cell events modifying the microenvironment in target cells, a key event of liver pathology. Exosome-mediated cell-cell communication can alter tumor growth, cell migration, antiviral infection and hepatocyte regeneration, indicating that exosomes have great potential for development as diagnostic or therapeutic tools. Analyses of circulating total or exosomal miRNAs have identified a large number of candidate miRNAs that are regulated in liver diseases, and the diagnostic testing using single or multiple miRNAs shows good sensitivity and specificity. Some candidate miRNAs have been identified to play an important role in various liver disorders. This review summarizes recent findings on the role of extracellular vesicles in liver diseases and their diagnostic and therapeutic potential, mainly focusing on exosomes but also includes microvesicles in liver pathology. © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.


Mancinelli R.,Scott and White Digestive Disease Research Center | Mancinelli R.,Texas A&M University | Mancinelli R.,University of Rome La Sapienza | Franchitto A.,University of Rome La Sapienza | And 20 more authors.
American Journal of Pathology | Year: 2010

Large cholangiocytes secrete bicarbonate in response to secretin and proliferate after bile duct ligation by activation of cyclic adenosine 3′, 5′-monophosphate signaling. The Ca2+-dependent adenylyl cyclase 8 (AC8, expressed by large cholangiocytes) regulates secretin-induced choleresis. Ca2+-dependent protein kinase C (PKC) regulates small cholangiocyte function. Because γ-aminobutyric acid (GABA) affects cell functions by activation of both Ca2+ signaling and inhibition of AC, we sought to develop an in vivo model characterized by large cholangiocyte damage and proliferation of small ducts. Bile duct ligation rats were treated with GABA for one week, and we evaluated: GABAA, GABAB, and GABAC receptor expression; intrahepatic bile duct mass (IBDM) and the percentage of apoptotic cholangiocytes; secretin-stimulated choleresis; and extracellular signal-regulated kinase1/2 (ERK1/2) phosphorylation and activation of Ca2+-dependent PKC isoforms and AC8 expression. We found that both small and large cholangiocytes expressed GABA receptors. GABA: (i) induced apoptosis of large cholangiocytes and reduced large IBDM; (ii) decreased secretin-stimulated choleresis; and (iii) reduced ERK1/2 phosphorylation and AC8 expression in large cholangiocytes. Small cholangiocytes: (i) proliferated leading to increased IBDM; (ii) displayed activation of PKCβII; and (iii) de novo expressed secretin receptor, cystic fibrosis transmembrane regulator, Cl-/HCO3- anion exchanger 2 and AC8, and responded to secretin. Therefore, in pathologies of large ducts, small ducts replenish the biliary epithelium by amplification of Ca2+-dependent signaling and acquisition of large cholangiocyte phenotypes. Copyright © American Society for Investigative Pathology.


Munshi Md.K.,Texas A&M University | Priester S.,Scott and White Digestive Disease Research Center | Gaudio E.,University of Rome La Sapienza | Yang F.,Shenyang University | And 10 more authors.
American Journal of Pathology | Year: 2011

The proliferation of cholangiocytes occurs during the progression of cholestatic liver diseases and is critical for the maintenance and/or restoration of biliary mass during bile duct damage. The ability of cholangiocytes to proliferate is important in many different human pathologic conditions. Recent studies have brought to light the concept that proliferating cholangiocytes serve as a unique neuroendocrine compartment in the liver. During extrahepatic cholestasis and other pathologic conditions that trigger ductular reaction, proliferating cholangiocytes acquire a neuroendocrine phenotype. Cholangiocytes have the capacity to secrete and respond to a variety of hormones, neuropeptides, and neurotransmitters, regulating their surrounding cell functions and proliferative activity. In this review, we discuss the regulation of cholangiocyte growth by neuroendocrine factors in animal models of cholestasis and liver injury, which includes a discussion of the acquisition of neuroendocrine phenotypes by proliferating cholangiocytes and how this relates to cholangiopathies. We also review what is currently known about the neuroendocrine phenotypes of cholangiocytes in human cholestatic liver diseases (ie, cholangiopathies) that are characterized by ductular reaction. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.


Glaser S.,Scott and White Digestive Disease Research Center | Glaser S.,Central Texas Veterans Health Care System | Wang M.,Rush University Medical Center | Ueno Y.,Tohoku University | And 7 more authors.
American Journal of Physiology - Gastrointestinal and Liver Physiology | Year: 2010

Biliary epithelial cells (BEC) are morphologically and functionally heterogeneous. To investigate the molecular mechanism for their diversities, we test the hypothesis that large and small BEC have disparity in their target gene response to their transcriptional regulator, the biliary cell-enriched hepatocyte nuclear factor HNF6. The expression of the major HNF (HNF6, OC2, HNF1b, HNF1a, HNF4a, C/EBPb, and Foxa2) and representative biliary transport target genes that are HNF dependent were compared between SV40-transformed BEC derived from large (SV40LG) and small (SV40SM) ducts, before and after treatment with recombinant adenoviral vectors expressing HNF6 (AdHNF6) or control LacZ cDNA (AdLacZ). Large and small BEC were isolated from mouse liver treated with growth hormone, a known transcriptional activator of HNF6, and the effects on selected target genes were examined. Constitutive Foxa2, HNF1a, and HNF4a gene expression were 2.3-, 12.4-, and 2.6-fold, respectively, higher in SV40SM cells. This was associated with 2.7- and 4-fold higher baseline expression of HNF1a- and HNF4a-regulated ntcp and oatp1 genes, respectively. Following AdHNF6 infection, HNF6 gene expression was 1.4-fold higher (P = 0.02) in AdHNF6 SV40SM relative to AdHNF6 SV40LG cells, with a corresponding higher Foxa2 (4-fold), HNF1a (15-fold), and HNF4a (6-fold) gene expression in AdHNF6-SV40SM over AdHNF6-SV40LG. The net effects were upregulation of HNF6 target gene glucokinase and of Foxa2, HNF1a, and HNF4a target genes oatp1, ntcp, and mrp2 over AdLacZ control in both cells, but with higher levels in AdH6-SV40SM over AdH6-SV40LG of glucokinase, oatp1, ntcp, and mrp2 (by 1.8-, 3.4-, 2.4-, and 2.5-fold, respectively). In vivo, growth hormone-mediated increase in HNF6 expression was associated with similar higher upregulation of glucokinase and mrp2 in cholangiocytes from small vs. large BEC. Small and large BEC have a distinct profile of hepatocyte transcription factor and cognate target gene expression, as well as differential strength of response to transcriptional regulation, thus providing a potential molecular basis for their divergent function.


Cardinale V.,University of Rome La Sapienza | Renzi A.,University of Rome La Sapienza | Carpino G.,Foro Italico University of Rome | Torrice A.,University of Rome La Sapienza | And 17 more authors.
American Journal of Pathology | Year: 2015

Cholangiocarcinomas (CCAs) comprise a mucin-secreting form, intrahepatic or perihilar, and a mixed form located peripherally. We characterized cancer stem cells (CSCs) in CCA subtypes and evaluated their cancerogenic potential. CSC markers were investigated in 25 human CCAs in primary cultures and established cell lines. Tumorigenic potential was evaluated in vitro or in xenografted mice after s.c. or intrahepatic injection in normal and cirrhotic (carbon tetrachloride-induced) mice. CSCs comprised more than 30% of the tumor mass. Although the CSC profile was similar between mucin-intrahepatic and mucin-perihilar subtypes, CD13+ CSCs characterized mixed-intrahepatic, whereas LGR5+ characterized mucin-CCA subtypes. Many neoplastic cells expressed epithelial-mesenchymal transition markers and coexpressed mesenchymal and epithelial markers. In primary cultures, epithelial-mesenchymal transition markers, mesenchymal markers (vimentin, CD90), and CD13 largely predominated over epithelial markers (CD133, EpCAM, and LGR5). In vitro, CSCs expressing epithelial markers formed a higher number of spheroids than CD13+ or CD90+ CSCs. In s.c. tumor xenografts, tumors dominated by stromal markers were formed primarily by CD90+ and CD13+ cells. By contrast, in intrahepatic xenografts in cirrhotic livers, tumors were dominated by epithelial traits reproducing the original human CCAs. In conclusion, CSCs were rich in human CCAs, implicating CCAs as stem cell-based diseases. CSC subpopulations generate different types of cancers depending on the microenvironment. Remarkably, CSCs reproduce the original human CCAs when injected into cirrhotic livers. © 2015 American Society for Investigative Pathology.


Torrice A.,University of Rome La Sapienza | Cardinale V.,University of Rome La Sapienza | Gatto M.,University of Rome La Sapienza | Semeraro R.,University of Rome La Sapienza | And 5 more authors.
Digestive and Liver Disease | Year: 2010

Background: Polycystin-1 and -2 (PC-1 and PC-2) are critical components of primary cilia, which act as mechanosensors and drive cell response to injury. PC-1 activation involves the cleavage/processing of PC-1 cytoplasmic tail, driven by regulated intramembrane proteolysis or ubiquitine/proteasome, translocation in the nucleus and activation of transcription factors. Mutations of PC-1 or PC-2 occur in polycystic liver where cholangiocyte proliferation is enhanced. Aim: We evaluated the involvement of PC-1 and PC-2 in modulating cholangiocyte proliferation. Methods: We investigated rat cholangiocytes induced to proliferate by 17β-oestradiol. Proliferation was evaluated by PCNA immunoblotting or [ 3H]-thymidine incorporation into DNA. PC-1 silencing was performed by siRNA, while inhibition of regulated intramembrane proteolysis or proteasome by γ-secretase inhibitor, leupeptin or MG115. Results: Cholangiocyte proliferation was associated with decreased PC-1 and PC-2 expression, which was inversely correlated with enhanced PCNA. The selective silencing of PC-1 induced activation of cholangiocyte proliferation in association with decreased PC-1 expression. Two different regulated intramembrane proteolysis inhibitors, γ-secretase-inhibitor and leupeptin, and the proteasome inhibitor, MG115, abolished the 17β-oestradiol proliferative effect. Conclusions: PC-1 and PC-2 play a major role as modulators of cholangiocyte proliferation suggesting that primary cilia may act as sensors of cell injury driving, when activated, a proliferative cholangiocyte response to trigger the reparative processes. © 2009 Editrice Gastroenterologica Italiana S.r.l.


Meng F.,Central Texas Veterans Health Care System | Meng F.,Scott and White Digestive Disease Research Center | Meng F.,Texas A&M University | Onori P.,University of Rome La Sapienza | And 12 more authors.
American Journal of Pathology | Year: 2014

Histamine is formed by the conversion of l-histidine into histamine by histidine decarboxylase (HDC). We have previously shown that inhibition of HDC blocks cholangiocyte proliferation and silencing of HDC decreases vascular endothelial growth factor (VEGF) expression. We hypothesized that increased HDC expression during cholestatic liver injury is mediated by the down-regulation of the specific miRNA miR-125b, a post-transcriptional regulator. Mice were subjected to sham surgery or bile duct ligation (BDL), which induces large cholangiocyte proliferation, and subsequently treated with either saline or α-methyl-dl-histidine (an HDC inhibitor) for 7 days. Liver blocks, serum, and large cholangiocytes were obtained, and intrahepatic bile duct mass, cholangiocyte proliferation (proliferating cellular nuclear antigen expression), and expression of both HDC and VEGF were measured. miRNA profiling was performed in isolated cholangiocytes. In vitro, miR-125b was overexpressed (or inhibited) or HDC was silenced before measuring HDC and VEGF-A/C expression and cholangiocyte proliferation. After BDL plus α-methyl-dl-histidine, expression of intrahepatic bile duct mass, proliferating cellular nuclear antigen, VEGF-A/C, and HDC and levels of histamine all decreased compared with those of BDL alone. miR-125b was significantly down-regulated after BDL. In vitro, overexpression of miR-125b and knockdown of HDC both decreased HDC and VEGF expression and cholangiocyte proliferation. Manipulation of miR-125b-regulated HDC/VEGF expression may, thus, be a therapeutic approach for the treatment of aberrant cholangiocyte growth in biliary disorders. Copyright © 2014 American Society for Investigative Pathology.


PubMed | University of Rome La Sapienza, Japan Science and Technology Agency, Scott and White Digestive Disease Research Center and Texas A&M University
Type: Journal Article | Journal: The American journal of pathology | Year: 2014

Histamine is formed by the conversion of l-histidine into histamine by histidine decarboxylase (HDC). We have previously shown that inhibition of HDC blocks cholangiocyte proliferation and silencing of HDC decreases vascular endothelial growth factor (VEGF) expression. We hypothesized that increased HDC expression during cholestatic liver injury is mediated by the down-regulation of the specific miRNA miR-125b, a post-transcriptional regulator. Mice were subjected to sham surgery or bile duct ligation (BDL), which induces large cholangiocyte proliferation, and subsequently treated with either saline or -methyl-dl-histidine (an HDC inhibitor) for 7 days. Liver blocks, serum, and large cholangiocytes were obtained, and intrahepatic bile duct mass, cholangiocyte proliferation (proliferating cellular nuclear antigen expression), and expression of both HDC and VEGF were measured. miRNA profiling was performed in isolated cholangiocytes. Invitro, miR-125b was overexpressed (or inhibited) or HDC was silenced before measuring HDC and VEGF-A/C expression and cholangiocyte proliferation. After BDL plus -methyl-dl-histidine, expression of intrahepatic bile duct mass, proliferating cellular nuclear antigen, VEGF-A/C, and HDC and levels of histamine all decreased compared with those of BDL alone. miR-125b was significantly down-regulated after BDL. Invitro, overexpression of miR-125b and knockdown of HDC both decreased HDC and VEGF expression and cholangiocyte proliferation. Manipulation of miR-125b-regulated HDC/VEGF expression may, thus, be a therapeutic approach for the treatment of aberrant cholangiocyte growth in biliary disorders.


PubMed | Japan Science and Technology Agency, Scott and White Digestive Disease Research Center, Digestive Disease Research Center and Texas A&M University
Type: Journal Article | Journal: Laboratory investigation; a journal of technical methods and pathology | Year: 2014

Cholangiopathies are characterized by dysregulation of the balance between biliary growth and loss. We have shown that histamine (HA) stimulates biliary growth via autocrine mechanisms. To evaluate the paracrine effects of mast cell (MC) stabilization on biliary proliferation, sham or BDL rats were treated by IP-implanted osmotic pumps filled with saline or cromolyn sodium (24mg/kg BW/day (inhibits MC histamine release)) for 1 week. Serum, liver blocks and cholangiocytes were collected. Histidine decarboxylase (HDC) expression was measured using real-time PCR in cholangiocytes. Intrahepatic bile duct mass (IBDM) was evaluated by IHC for CK-19. MC number was determined using toluidine blue staining and correlated to IBDM. Proliferation was evaluated by PCNA expression in liver sections and purified cholangiocytes. We assessed apoptosis using real-time PCR and IHC for BAX. Expression of MC stem factor receptor, c-kit, and the proteases chymase and tryptase were measured by real-time PCR. HA levels were measured in serum by EIA. In vitro, MCs and cholangiocytes were treated with 0.1% BSA (basal) or cromolyn (25M) for up to 48h prior to assessing HDC expression, HA levels and chymase and tryptase expression. Supernatants from MCs treated with or without cromolyn were added to cholangiocytes before measuring (i) proliferation by MTT assays, (ii) HDC gene expression by real-time PCR and (iii) HA release by EIA. In vivo, cromolyn treatment decreased BDL-induced: (i) IBDM, MC number, and biliary proliferation; (ii) HDC and MC marker expression; and (iii) HA levels. Cromolyn treatment increased cholangiocyte apoptosis. In vitro, cromolyn decreased HA release and chymase and tryptase expression in MCs but not in cholangiocytes. Cromolyn-treated MC supernatants decreased biliary proliferation and HA release. These studies provide evidence that MC histamine is key to biliary proliferation and may be a therapeutic target for the treatment of cholangiopathies.

Loading Scott and White Digestive Disease Research Center collaborators
Loading Scott and White Digestive Disease Research Center collaborators