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Li HL, Verhoeven A, Elferink RO. The role of soluble adenylyl cyclase in sensing and regulating intracellular pH. Pflugers Arch 2024; 476:457-465. [PMID: 38581526 PMCID: PMC11006738 DOI: 10.1007/s00424-024-02952-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/08/2024]
Abstract
Soluble adenylyl cyclase (sAC) differs from transmembrane adenylyl cyclases (tmAC) in many aspects. In particular, the activity of sAC is not regulated by G-proteins but by the prevailing bicarbonate concentrations inside cells. Therefore, sAC serves as an exquisite intracellular pH sensor, with the capacity to translate pH changes into the regulation of localization and/or activity of cellular proteins involved in pH homeostasis. In this review, we provide an overview of literature describing the regulation of sAC activity by bicarbonate, pinpointing the importance of compartmentalization of intracellular cAMP signaling cascades. In addition, examples of processes involving proton and bicarbonate transport in different cell types, in which sAC plays an important regulatory role, were described in detail.
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Affiliation(s)
- Hang Lam Li
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, Meibergdreef 69-71, 1105BK, Amsterdam, the Netherlands
| | - Arthur Verhoeven
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, Meibergdreef 69-71, 1105BK, Amsterdam, the Netherlands
| | - Ronald Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, Meibergdreef 69-71, 1105BK, Amsterdam, the Netherlands.
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2
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Li HL, Go S, Chang JC, Verhoeven A, Elferink RO. Soluble adenylyl cyclase, the cell-autonomous member of the family. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166936. [PMID: 37951509 DOI: 10.1016/j.bbadis.2023.166936] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/12/2023] [Accepted: 10/24/2023] [Indexed: 11/14/2023]
Abstract
Soluble adenylyl cyclase (sAC) is the evolutionarily most ancient of a set of 10 adenylyl cyclases (Adcys). While Adcy1 to Adcy9 are cAMP-producing enzymes that are activated by G-protein coupled receptors (GPCRs), Adcy10 (sAC) is an intracellular adenylyl cyclase. sAC plays a pivotal role in numerous cellular processes, ranging from basic physiological functions to complex signaling cascades. As a distinct member of the adenylyl cyclase family, sAC is not activated by GPCRs and stands apart due to its unique characteristics, regulation, and localization within cells. This minireview aims to honour Ulli Brandt, the outgoing Executive Editor of our journal, Biochimica Biophysica Acta (BBA), and longstanding Executive Editor of the BBA section Bioenergetics. We will therefore focus this review on bioenergetic aspects of sAC and, in addition, review some important recent general developments in the field of research on sAC.
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Affiliation(s)
- Hang Lam Li
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands
| | - Simei Go
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands
| | - Jung-Chin Chang
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands
| | - Arthur Verhoeven
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands
| | - Ronald Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands.
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3
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Small Hepatitis B Virus Surface Antigen Promotes Hepatic Gluconeogenesis via Enhancing Glucagon/cAMP/Protein Kinase A/CREB Signaling. J Virol 2022; 96:e0102022. [PMID: 36394315 PMCID: PMC9749458 DOI: 10.1128/jvi.01020-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Hepatitis B virus (HBV) is a major risk factor for serious liver diseases. The liver plays a unique role in controlling carbohydrate metabolism to maintain the glucose level within the normal range. Chronic HBV infection has been reported to associate with a high prevalence of diabetes. However, the detailed molecular mechanism underlying the potential association remains largely unknown. Here, we report that liver-targeted delivery of small HBV surface antigen (SHBs), the most abundant viral protein of HBV, could elevate blood glucose levels and impair glucose and insulin tolerance in mice by promoting hepatic gluconeogenesis. Hepatocytes with SHB expression also exhibited increased glucose production and expression of gluconeogenic genes glucose-6-phosphatase (G6pc) and phosphoenolpyruvate carboxykinase (PEPCK) in response to glucagon stimulation. Mechanistically, SHBs increased cellular levels of cyclic AMP (cAMP) and consequently activated protein kinase A (PKA) and its downstream effector cAMP-responsive element binding protein (CREB). SHBs-induced activation of CREB enhanced transcripts of gluconeogenic genes, thus promoting hepatic gluconeogenesis. The elevated cAMP level resulted from increased transcription activity and expression of adenylyl cyclase 1 (AC1) by SHBs through a binary E-box factor binding site (BEF). Taken together, we unveiled a novel pathogenic role and mechanism of SHBs in hepatic gluconeogenesis, and these results might highlight a potential target for preventive and therapeutic intervention in the development and progression of HBV-associated diabetes. IMPORTANCE Chronic HBV infection causes progressive liver damage and is found to be a risk factor for diabetes. However, the mechanism in the regulation of glucose metabolism by HBV remains to be established. In the current study, we demonstrate for the first time that the small hepatitis B virus surface antigen (SHBs) of HBV elevates AC1 transcription and expression to activate cAMP/PKA/CREB signaling and subsequently induces the expression of gluconeogenic genes and promotes hepatic gluconeogenesis both in vivo and in vitro. This study provides a direct link between HBV infection and diabetes and implicates that SHBs may represent a potential target for the treatment of HBV-induced metabolic disorders.
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4
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Norcia LF, Watanabe EM, Hamamoto Filho PT, Hasimoto CN, Pelafsky L, de Oliveira WK, Sassaki LY. Polycystic Liver Disease: Pathophysiology, Diagnosis and Treatment. Hepat Med 2022; 14:135-161. [PMID: 36200122 PMCID: PMC9528914 DOI: 10.2147/hmer.s377530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/07/2022] [Indexed: 11/25/2022] Open
Abstract
Polycystic liver disease (PLD) is a clinical condition characterized by the presence of more than 10 cysts in the liver. It is a rare disease Of genetic etiology that presents as an isolated disease or assoc\iated with polycystic kidney disease. Ductal plate malformation, ciliary dysfunction, and changes in cell signaling are the main factors involved in its pathogenesis. Most patients with PLD are asymptomatic, but in 2–5% of cases the disease has disabling symptoms and a significant reduction in quality of life. The diagnosis is based on family history of hepatic and/or renal polycystic disease, clinical manifestations, patient age, and polycystic liver phenotype shown on imaging examinations. PLD treatment has evolved considerably in the last decades. Somatostatin analogues hold promise in controlling disease progression, but liver transplantation remains a unique curative treatment modality.
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Affiliation(s)
- Luiz Fernando Norcia
- Department of Surgery, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
- Correspondence: Luiz Fernando Norcia, Department of Surgery, São Paulo State University (UNESP), Medical School, 783 Pedro Delmanto Street, Botucatu, São Paulo, 18610-303, Brazil, Tel +55 19982840542, Email
| | - Erika Mayumi Watanabe
- Department of Radiology, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Pedro Tadao Hamamoto Filho
- Department of Neurology, Psychology and Psychiatry, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Claudia Nishida Hasimoto
- Department of Surgery, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Leonardo Pelafsky
- Department of Surgery, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Walmar Kerche de Oliveira
- Department of Surgery, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Ligia Yukie Sassaki
- Department of Internal Medicine, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
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Masyuk TV, Masyuk AI, LaRusso NF. Polycystic Liver Disease: Advances in Understanding and Treatment. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2021; 17:251-269. [PMID: 34724412 DOI: 10.1146/annurev-pathol-042320-121247] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Polycystic liver disease (PLD) is a group of genetic disorders characterized by progressive development of cholangiocyte-derived fluid-filled hepatic cysts. PLD is the most common manifestation of autosomal dominant and autosomal recessive polycystic kidney diseases and rarely occurs as autosomal dominant PLD. The mechanisms of PLD are a sequence of the primary (mutations in PLD-causative genes), secondary (initiation of cyst formation), and tertiary (progression of hepatic cystogenesis) interconnected molecular and cellular events in cholangiocytes. Nonsurgical, surgical, and limited pharmacological treatment options are currently available for clinical management of PLD. Substantial evidence suggests that pharmacological targeting of the signaling pathways and intracellular processes involved in the progression of hepatic cystogenesis is beneficial for PLD. Many of these targets have been evaluated in preclinical and clinical trials. In this review, we discuss the genetic, molecular, and cellular mechanisms of PLD and clinical and preclinical treatment strategies. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 17 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Tatyana V Masyuk
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota 55905, USA;
| | - Anatoliy I Masyuk
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota 55905, USA;
| | - Nicholas F LaRusso
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota 55905, USA;
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Salmerón C, Harter TS, Kwan GT, Roa JN, Blair SD, Rummer JL, Shiels HA, Goss GG, Wilson RW, Tresguerres M. Molecular and biochemical characterization of the bicarbonate-sensing soluble adenylyl cyclase from a bony fish, the rainbow trout Oncorhynchus mykiss. Interface Focus 2021; 11:20200026. [PMID: 33633829 DOI: 10.1098/rsfs.2020.0026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2020] [Indexed: 12/14/2022] Open
Abstract
Soluble adenylyl cyclase (sAC) is a HC O 3 - -stimulated enzyme that produces the ubiquitous signalling molecule cAMP, and deemed an evolutionarily conserved acid-base sensor. However, its presence is not yet confirmed in bony fishes, the most abundant and diverse of vertebrates. Here, we identified sAC genes in various cartilaginous, ray-finned and lobe-finned fish species. Next, we focused on rainbow trout sAC (rtsAC) and identified 20 potential alternative spliced mRNAs coding for protein isoforms ranging in size from 28 to 186 kDa. Biochemical and kinetic analyses on purified recombinant rtsAC protein determined stimulation by HC O 3 - at physiologically relevant levels for fish internal fluids (EC50 ∼ 7 mM). rtsAC activity was sensitive to KH7, LRE1, and DIDS (established inhibitors of sAC from other organisms), and insensitive to forskolin and 2,5-dideoxyadenosine (modulators of transmembrane adenylyl cyclases). Western blot and immunocytochemistry revealed high rtsAC expression in gill ion-transporting cells, hepatocytes, red blood cells, myocytes and cardiomyocytes. Analyses in the cell line RTgill-W1 suggested that some of the longer rtsAC isoforms may be preferentially localized in the nucleus, the Golgi apparatus and podosomes. These results indicate that sAC is poised to mediate multiple acid-base homeostatic responses in bony fishes, and provide cues about potential novel functions in mammals.
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Affiliation(s)
- Cristina Salmerón
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.,Department of Pharmacology, University of California San Diego, San Diego, CA, USA
| | - Till S Harter
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Garfield T Kwan
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Jinae N Roa
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Salvatore D Blair
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Department of Biology, Winthrop University, Rock Hill, SC, USA
| | - Jodie L Rummer
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| | - Holly A Shiels
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Greg G Goss
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Rod W Wilson
- Department of Biosciences, University of Exeter, Exeter, UK
| | - Martin Tresguerres
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
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7
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Kar P, Millo T, Saha S, Mahtab S, Agarwal S, Goswami R. Osteogenic Mechanisms of Basal Ganglia Calcification and its ex vivo Model in the Hypoparathyroid Milieu. Endocrinology 2021; 162:6128830. [PMID: 33539507 DOI: 10.1210/endocr/bqab024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Indexed: 01/10/2023]
Abstract
CONTEXT Basal-ganglia calcification (BGC) is common (70%) in patients with chronic hypoparathyroidism. Interestingly, cortical gray matter is spared from calcification. The mechanism of BGC, role of hyperphosphatemia, and modulation of osteogenic molecules by parathyroid hormone (PTH) in its pathogenesis is not clear. OBJECTIVE We assessed the expression of a large repertoire of molecules with proosteogenic or antiosteogenic effects, including neuroprogenitor cells in caudate, dentate, and cortical gray matter from normal autopsy tissues. The effect of high phosphate and PTH was assessed in an ex vivo model of BGC using striatum tissue culture of the Sprague-Dawley rat. METHODS The messenger RNA and protein expression of 39 molecules involved in multiple osteogenic pathways were assessed in 25 autopsy tissues using reverse-transcriptase polymerase chain reaction, Western blot, and immunofluorescence. The striatal culture was maintained in a hypoparathyroid milieu for 24 days with and without (a) high phosphate (10-mm β-glycerophosphate) and (b) PTH(1-34) (50 ng/mL Dulbecco's modified Eagle's medium-F12 media) for their effect on striatal calcification and osteogenic molecules. RESULTS Procalcification molecules (osteonectin, β-catenin, klotho, FZD4, NT5E, LRP5, WNT3A, collagen-1α, and SOX2-positive neuroprogenitor stem cells) had significantly higher expression in the caudate than gray matter. Caudate nuclei also had higher expression of antiosteogenic molecules (osteopontin, carbonic anhydrase-II [CA-II], MGP, sclerostin, ISG15, ENPP1, and USP18). In an ex vivo model, striatum culture showed an increased propensity for calcified nodules with mineral deposition similar to that of bone tissue on Fourier-transformed infrared spectroscopy, alizarin, and von Kossa stain. Mineralization in striatal culture was enhanced by high phosphate and decreased by exogenous PTH through increased expression of CA-II. CONCLUSION This study provides a conceptual advance on the molecular mechanisms of BGC and the possibility of PTH therapy to prevent this complication in a hypoparathyroid milieu.
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Affiliation(s)
- Parmita Kar
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, Delhi, India
| | - Tabin Millo
- Department of Forensic Medicine and Toxicology, New Delhi, Delhi, India
| | - Soma Saha
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, Delhi, India
| | - Samrina Mahtab
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, Delhi, India
| | - Shipra Agarwal
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, Delhi, India
| | - Ravinder Goswami
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, Delhi, India
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Mariotti V, Fiorotto R, Cadamuro M, Fabris L, Strazzabosco M. New insights on the role of vascular endothelial growth factor in biliary pathophysiology. JHEP Rep 2021; 3:100251. [PMID: 34151244 PMCID: PMC8189933 DOI: 10.1016/j.jhepr.2021.100251] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/06/2021] [Accepted: 01/12/2021] [Indexed: 02/06/2023] Open
Abstract
The family of vascular endothelial growth factors (VEGFs) includes 5 members (VEGF-A to -D, and placenta growth factor), which regulate several critical biological processes. VEGF-A exerts a variety of biological effects through high-affinity binding to tyrosine kinase receptors (VEGFR-1, -2 and -3), co-receptors and accessory proteins. In addition to its fundamental function in angiogenesis and endothelial cell biology, VEGF/VEGFR signalling also plays a role in other cell types including epithelial cells. This review provides an overview of VEGF signalling in biliary epithelial cell biology in both normal and pathologic conditions. VEGF/VEGFR-2 signalling stimulates bile duct proliferation in an autocrine and paracrine fashion. VEGF/VEGFR-1/VEGFR-2 and angiopoietins are involved at different stages of biliary development. In certain conditions, cholangiocytes maintain the ability to secrete VEGF-A, and to express a functional VEGFR-2 receptor. For example, in polycystic liver disease, VEGF secreted by cystic cells stimulates cyst growth and vascular remodelling through a PKA/RAS/ERK/HIF1α-dependent mechanism, unveiling a new level of complexity in VEFG/VEGFR-2 regulation in epithelial cells. VEGF/VEGFR-2 signalling is also reactivated during the liver repair process. In this context, pro-angiogenic factors mediate the interactions between epithelial, mesenchymal and inflammatory cells. This process takes place during the wound healing response, however, in chronic biliary diseases, it may lead to pathological neo-angiogenesis, a condition strictly linked with fibrosis progression, the development of cirrhosis and related complications, and cholangiocarcinoma. Novel observations indicate that in cholangiocarcinoma, VEGF is a determinant of lymphangiogenesis and of the immune response to the tumour. Better insights into the role of VEGF signalling in biliary pathophysiology might help in the search for effective therapeutic strategies.
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Key Words
- ADPKD, adult dominant polycystic kidney disease
- Anti-Angiogenic therapy
- BA, biliary atresia
- BDL, bile duct ligation
- CCA, cholangiocarcinoma
- CCl4, carbon tetrachloride
- CLDs, chronic liver diseases
- Cholangiocytes
- Cholangiopathies
- DP, ductal plate
- DPM, ductal plate malformation
- DRCs, ductular reactive cells
- Development
- HIF-1α, hypoxia-inducible factor type 1α
- HSCs, hepatic stellate cells
- IHBD, intrahepatic bile ducts
- IL-, interleukin-
- LECs, lymphatic endothelial cells
- LSECs, liver sinusoidal endothelial cells
- Liver repair
- MMPs, matrix metalloproteinases
- PBP, peribiliary plexus
- PC, polycystin
- PDGF, platelet-derived growth factor
- PIGF, placental growth factor
- PLD, polycystic liver diseases
- Polycystic liver diseases
- SASP, senescence-associated secretory phenotype
- TGF, transforming growth factor
- VEGF, vascular endothelial growth factors
- VEGF-A
- VEGF/VEGFR-2 signalling
- VEGFR-1/2, vascular endothelial growth factor receptor 1/2
- mTOR, mammalian target of rapamycin
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Affiliation(s)
- Valeria Mariotti
- Section of Digestive Diseases, Liver Center, Yale University, New Haven, CT, USA
| | - Romina Fiorotto
- Section of Digestive Diseases, Liver Center, Yale University, New Haven, CT, USA
| | - Massimiliano Cadamuro
- Department of Molecular Medicine, University of Padua, School of Medicine, Padua, Italy
| | - Luca Fabris
- Section of Digestive Diseases, Liver Center, Yale University, New Haven, CT, USA.,Department of Molecular Medicine, University of Padua, School of Medicine, Padua, Italy
| | - Mario Strazzabosco
- Section of Digestive Diseases, Liver Center, Yale University, New Haven, CT, USA
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Wu N, Baiocchi L, Zhou T, Kennedy L, Ceci L, Meng F, Sato K, Wu C, Ekser B, Kyritsi K, Kundu D, Chen L, Meadows V, Franchitto A, Alvaro D, Onori P, Gaudio E, Lenci I, Francis H, Glaser S, Alpinis G. Functional Role of the Secretin/Secretin Receptor Signaling During Cholestatic Liver Injury. Hepatology 2020; 72:2219-2227. [PMID: 32737904 PMCID: PMC8957864 DOI: 10.1002/hep.31484] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/02/2020] [Indexed: 12/19/2022]
Abstract
The gastrointestinal peptide, secretin (Sct) is an important homeostatic regulator of pancreatic and liver secretory function. With regard to the liver, discoveries have been made, in the last decades, indicating a key role for the secretin/secretin receptor axis during normal or cholestatic conditions. Since large cholangiocytes are the only cells to express secretin receptor in the liver, research on secretin also expanded our knowledge on biliary epithelia. In this review we examined in detail the role of the secretin/secretin receptor axis, not only on biliary secretion, but also on cholangiocyte proliferation and senescence, as well as in prompting fibrotic processes involving biliary epithelia. Relevant data on human chronic cholestatic liver diseases, such as primary biliary cholangitis or primary sclerosing cholangitis, and obtained in animal models mimicking the diseases or in correlative studies on human are also reported. The aim of this review is to provide an update on the progress regarding the interactions between secretin and the biliary epithelia in normal and pathological conditions, underlining the aspects that suggests modulation of secretin pathway as a possible therapeutic approach for chronic cholestatic human liver disease.
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Affiliation(s)
- Nan Wu
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN
| | - Leonardo Baiocchi
- Liver Unit, Department of Medicine, University of Rome “Tor Vergata”, Rome, Italy
| | - Tianhao Zhou
- Department of Medical Physiology, Texas A&M University, Bryan, TX
| | - Lindsey Kennedy
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN
| | - Ludovica Ceci
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN
| | - Fanyin Meng
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN,Richard L. Roudebush VA Medical Center, Indianapolis, IN
| | - Keisaku Sato
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN
| | - Chaodong Wu
- Department of Nutrition, Texas A&M University, College Station, TX
| | - Burcin Ekser
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN
| | - Konstantina Kyritsi
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN
| | - Debjyoti Kundu
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN
| | - Lixian Chen
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN
| | - Vik Meadows
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN
| | | | - Domenico Alvaro
- Department of Internal Medicine and Medical Specialties and Sapienza University of Rome, Rome, Italy
| | - Paolo Onori
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, Sapienza University of Rome, Rome, Italy
| | - Eugenio Gaudio
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, Sapienza University of Rome, Rome, Italy
| | - Ilaria Lenci
- Liver Unit, Department of Medicine, University of Rome “Tor Vergata”, Rome, Italy
| | - Heather Francis
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN,Richard L. Roudebush VA Medical Center, Indianapolis, IN
| | - Shannon Glaser
- Department of Medical Physiology, Texas A&M University, Bryan, TX
| | - Gianfranco Alpinis
- Hepatology and Gastroenterology, Medicine, Indiana University, Indianapolis, IN,Richard L. Roudebush VA Medical Center, Indianapolis, IN
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Mariotti V, Cadamuro M, Spirli C, Fiorotto R, Strazzabosco M, Fabris L. Animal models of cholestasis: An update on inflammatory cholangiopathies. Biochim Biophys Acta Mol Basis Dis 2018; 1865:954-964. [PMID: 30398152 DOI: 10.1016/j.bbadis.2018.07.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 12/21/2022]
Abstract
Cholestasis is a frequent clinical condition initiating or complicating chronic liver diseases, particularly cholangiopathies, where the biliary epithelium is the primary target of the pathogenetic sequence. Until a few decades ago, understanding of cholestasis relied mostly on the experimental model of bile duct ligation in rodents. However, a simple model of biliary obstruction cannot reproduce the complex mechanisms and networks leading to cholestasis in cholangiopathies. These networks are underpinned by an intricate dysregulation of pro-inflammatory and pro-fibrotic signals involving besides cholangiocytes, multiple cell elements of both innate and adaptive immunity. Therefore, in the last years, a wide range of animal models of biliary injury have been developed, mostly in mice, following three main approaches, chemical induction, immunization and genetic manipulation. In this review, we will give an update of the animal models of the two main cholangiopathies, primary sclerosing cholangitis and primary biliary cholangitis, which have provided us with the most relevant insights into the pathogenesis of these still controversial diseases.
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Affiliation(s)
- Valeria Mariotti
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | | | - Carlo Spirli
- Section of Digestive Disease, Liver Center, Yale University, Yale, USA
| | - Romina Fiorotto
- Section of Digestive Disease, Liver Center, Yale University, Yale, USA
| | | | - Luca Fabris
- Department of Molecular Medicine, University of Padua, Padua, Italy; Section of Digestive Disease, Liver Center, Yale University, Yale, USA.
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11
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Oliva-Vilarnau N, Hankeova S, Vorrink SU, Mkrtchian S, Andersson ER, Lauschke VM. Calcium Signaling in Liver Injury and Regeneration. Front Med (Lausanne) 2018; 5:192. [PMID: 30023358 PMCID: PMC6039545 DOI: 10.3389/fmed.2018.00192] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/11/2018] [Indexed: 12/12/2022] Open
Abstract
The liver fulfills central roles in metabolic control and detoxification and, as such, is continuously exposed to a plethora of insults. Importantly, the liver has a unique ability to regenerate and can completely recoup from most acute, non-iterative insults. However, multiple conditions, including viral hepatitis, non-alcoholic fatty liver disease (NAFLD), long-term alcohol abuse and chronic use of certain medications, can cause persistent injury in which the regenerative capacity eventually becomes dysfunctional, resulting in hepatic scaring and cirrhosis. Calcium is a versatile secondary messenger that regulates multiple hepatic functions, including lipid and carbohydrate metabolism, as well as bile secretion and choleresis. Accordingly, dysregulation of calcium signaling is a hallmark of both acute and chronic liver diseases. In addition, recent research implicates calcium transients as essential components of liver regeneration. In this review, we provide a comprehensive overview of the role of calcium signaling in liver health and disease and discuss the importance of calcium in the orchestration of the ensuing regenerative response. Furthermore, we highlight similarities and differences in spatiotemporal calcium regulation between liver insults of different etiologies. Finally, we discuss intracellular calcium control as an emerging therapeutic target for liver injury and summarize recent clinical findings of calcium modulation for the treatment of ischemic-reperfusion injury, cholestasis and NAFLD.
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Affiliation(s)
- Nuria Oliva-Vilarnau
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Simona Hankeova
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden.,Faculty of Science, Institute of Experimental Biology, Masaryk University, Brno, Czechia
| | - Sabine U Vorrink
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Souren Mkrtchian
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Emma R Andersson
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden.,Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Volker M Lauschke
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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12
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Wiggins SV, Steegborn C, Levin LR, Buck J. Pharmacological modulation of the CO 2/HCO 3-/pH-, calcium-, and ATP-sensing soluble adenylyl cyclase. Pharmacol Ther 2018; 190:173-186. [PMID: 29807057 DOI: 10.1016/j.pharmthera.2018.05.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cyclic AMP (cAMP), the prototypical second messenger, has been implicated in a wide variety of (often opposing) physiological processes. It simultaneously mediates multiple, diverse processes, often within a single cell, by acting locally within independently-regulated and spatially-restricted microdomains. Within each microdomain, the level of cAMP will be dependent upon the balance between its synthesis by adenylyl cyclases and its degradation by phosphodiesterases (PDEs). In mammalian cells, there are many PDE isoforms and two types of adenylyl cyclases; the G protein regulated transmembrane adenylyl cyclases (tmACs) and the CO2/HCO3-/pH-, calcium-, and ATP-sensing soluble adenylyl cyclase (sAC). Discriminating the roles of individual cyclic nucleotide microdomains requires pharmacological modulators selective for the various PDEs and/or adenylyl cyclases. Such tools present an opportunity to develop therapeutics specifically targeted to individual cAMP dependent pathways. The pharmacological modulators of tmACs have recently been reviewed, and in this review, we describe the current status of pharmacological tools available for studying sAC.
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Affiliation(s)
- Shakarr V Wiggins
- Graduate Program in Neuroscience, Weill Cornell Medicine, New York, NY 10065, United States
| | - Clemens Steegborn
- Department of Biochemistry, University of Bayreuth, 95440 Bayreuth, Germany
| | - Lonny R Levin
- Department of Pharmacology, Weill Cornell Medicine, New York, NY 10065, United States.
| | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medicine, New York, NY 10065, United States
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13
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Chang JC, Go S, Verhoeven AJ, Beuers U, Oude Elferink RP. Role of the bicarbonate-responsive soluble adenylyl cyclase in cholangiocyte apoptosis in primary biliary cholangitis; a new hypothesis. Biochim Biophys Acta Mol Basis Dis 2018; 1864:1232-1239. [DOI: 10.1016/j.bbadis.2017.09.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/19/2017] [Accepted: 09/20/2017] [Indexed: 02/08/2023]
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14
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Dessauer CW, Watts VJ, Ostrom RS, Conti M, Dove S, Seifert R. International Union of Basic and Clinical Pharmacology. CI. Structures and Small Molecule Modulators of Mammalian Adenylyl Cyclases. Pharmacol Rev 2017; 69:93-139. [PMID: 28255005 PMCID: PMC5394921 DOI: 10.1124/pr.116.013078] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Adenylyl cyclases (ACs) generate the second messenger cAMP from ATP. Mammalian cells express nine transmembrane AC (mAC) isoforms (AC1-9) and a soluble AC (sAC, also referred to as AC10). This review will largely focus on mACs. mACs are activated by the G-protein Gαs and regulated by multiple mechanisms. mACs are differentially expressed in tissues and regulate numerous and diverse cell functions. mACs localize in distinct membrane compartments and form signaling complexes. sAC is activated by bicarbonate with physiologic roles first described in testis. Crystal structures of the catalytic core of a hybrid mAC and sAC are available. These structures provide detailed insights into the catalytic mechanism and constitute the basis for the development of isoform-selective activators and inhibitors. Although potent competitive and noncompetitive mAC inhibitors are available, it is challenging to obtain compounds with high isoform selectivity due to the conservation of the catalytic core. Accordingly, caution must be exerted with the interpretation of intact-cell studies. The development of isoform-selective activators, the plant diterpene forskolin being the starting compound, has been equally challenging. There is no known endogenous ligand for the forskolin binding site. Recently, development of selective sAC inhibitors was reported. An emerging field is the association of AC gene polymorphisms with human diseases. For example, mutations in the AC5 gene (ADCY5) cause hyperkinetic extrapyramidal motor disorders. Overall, in contrast to the guanylyl cyclase field, our understanding of the (patho)physiology of AC isoforms and the development of clinically useful drugs targeting ACs is still in its infancy.
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Affiliation(s)
- Carmen W Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Val J Watts
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Rennolds S Ostrom
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Marco Conti
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Stefan Dove
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Roland Seifert
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
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15
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Spirli C, Mariotti V, Villani A, Fabris L, Fiorotto R, Strazzabosco M. Adenylyl cyclase 5 links changes in calcium homeostasis to cAMP-dependent cyst growth in polycystic liver disease. J Hepatol 2017; 66:571-580. [PMID: 27826057 PMCID: PMC5316496 DOI: 10.1016/j.jhep.2016.10.032] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 10/17/2016] [Accepted: 10/23/2016] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS Genetic defects in polycystin-1 or -2 (PC1 or PC2) cause polycystic liver disease associated with autosomal dominant polycystic kidney disease (PLD-ADPKD). Progressive cyst growth is sustained by a cAMP-dependent Ras/ERK/HIFα pathway, leading to increased vascular endothelial growth factor A (VEGF-A) signaling. In PC2-defective cholangiocytes, cAMP production in response to [Ca2+]ER depletion is increased, while store-operated Ca2+ entry (SOCE), intracellular and endoplasmic reticulum [Ca2+]ER levels are reduced. We investigated whether the adenylyl cyclases, AC5 and AC6, which can be inhibited by Ca2+, are activated by the ER chaperone STIM1. This would result in cAMP/PKA-dependent Ras/ERK/HIFα pathway activation in PC2-defective cells, in response to [Ca2+]ER depletion. METHODS PC2/AC6 double conditional knockout (KO) mice were generated (Pkd2/AC6 KO) and compared to Pkd2 KO mice. The AC5 inhibitor SQ22,536 or AC5 siRNA were used in isolated cholangiocytes while the inhibitor was used in biliary organoid and animals; liver tissues were harvested for histochemical analysis. RESULTS When comparing Pkd2/AC6 KO to Pkd2 KO mice, no decrease in liver cyst size was found, and cellular cAMP after [Ca2+]ER depletion only decreased by 12%. Conversely, in PC2-defective cells, inhibition of AC5 significantly reduced cAMP production, pERK1/2 expression and VEGF-A secretion. AC5 inhibitors significantly reduced growth of biliary organoids derived from Pkd2 KO and Pkd2/AC6 KO mice. In vivo treatment with SQ22,536 significantly reduced liver cystic area and cell proliferation in PC2-defective mice. After [Ca2+]ER depletion in PC2-defective cells, STIM1 interacts with AC5 but not with Orai1, the Ca2+ channel that mediates SOCE. CONCLUSION [Ca2+]ER depletion in PC2-defective cells activates AC5 and results in stimulation of cAMP/ERK1-2 signaling, VEGF production and cyst growth. This mechanism may represent a novel therapeutic target. LAY SUMMARY Polycystic liver diseases are characterized by progressive cyst growth until their complications mandate surgery or liver transplantation. In this manuscript, we demonstrate that inhibiting cell proliferation, which is induced by increased levels of cAMP, may represent a novel therapeutic target to slow the progression of the disease.
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Affiliation(s)
- Carlo Spirli
- Section of Digestive Diseases, Yale University, New Haven, Connecticut, USA
| | - Valeria Mariotti
- Section of Digestive Diseases, Yale University, New Haven, Connecticut, USA,Section of Digestive Diseases, International Center for Digestive Health, Department of Medicine and Surgery, University of Milan-Bicocca, Milan, Italy
| | - Ambra Villani
- Section of Digestive Diseases, Yale University, New Haven, Connecticut, USA
| | - Luca Fabris
- Department of Molecular Medicine, University of Padua, Italy
| | - Romina Fiorotto
- Section of Digestive Diseases, Yale University, New Haven, Connecticut, USA
| | - Mario Strazzabosco
- Section of Digestive Diseases, Yale University, New Haven, CT, USA; Section of Digestive Diseases, International Center for Digestive Health, Department of Medicine and Surgery, University of Milan-Bicocca, Milan, Italy.
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16
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Chang JC, Beuers U, Oude Elferink RP. The Emerging Role of Soluble Adenylyl Cyclase in Primary Biliary Cholangitis. Dig Dis 2017; 35:217-223. [PMID: 28249274 PMCID: PMC5516404 DOI: 10.1159/000450914] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Primary biliary cholangitis (PBC; previously referred to as primary biliary cirrhosis) is a chronic fibrosing cholangiopathy with the signature of an autoimmune disease and features of intrahepatic cholestasis. Immunosuppressing treatments are largely unsuccessful. Responsiveness to ursodeoxycholic acid and reduced expression of anion exchanger 2 (AE2) on canalicular membranes and small bile ducts underline the importance of bicarbonate transportation in its disease mechanism. Soluble adenylyl cyclase (sAC; ADCY10) is an evolutionarily conserved bicarbonate sensor that regulates apoptosis, barrier function and TNF signaling. Key Messages: The biliary epithelium defends against the toxic bile by bicarbonate secretion and by maintaining a tight barrier. Passive diffusion of weak acid conjugates (e.g. bile salts and other toxins) across plasma membrane is pH-dependent. Reduced AE2 expression results in both reduced bicarbonate secretion and accumulation of bicarbonate in the cells. Increased intracellular bicarbonate leads to increased sAC activity, which regulates bile salt-induced apoptosis. Reduced bicarbonate secretion causes more bile salts to enter cells, which further increase sAC activity by releasing intracellular Ca2+ store. In vitro studies demonstrate that inhibition of sAC not only corrects sensitization to bile salt-induced apoptosis as a result of AE2 down-regulation but also prevents bile salt-induced apoptosis altogether. Targeting sAC is also likely to slow down disease progression by strengthening the barrier function of biliary epithelia and by reducing oxidative stress as a result of chronic inflammation. CONCLUSIONS sAC is a potential therapeutic target for PBC. More in vitro and in vivo studies are needed to understand how sAC regulates bile salt-induced apoptosis and to establish its therapeutic value in PBC and other cholestatic cholangiopathies.
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Affiliation(s)
| | | | - Ronald P.J. Oude Elferink
- *Ronald P.J. Oude Elferink, Tytgat Institute for Liver and Intestinal Research, Academic Medical Center S1-162, Meibergdreef 69-71, NL-1105 BK Amsterdam (The Netherlands), E-Mail
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17
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Hall C, Sato K, Wu N, Zhou T, Kyritsi K, Meng F, Glaser S, Alpini G. Regulators of Cholangiocyte Proliferation. Gene Expr 2017; 17:155-171. [PMID: 27412505 PMCID: PMC5494439 DOI: 10.3727/105221616x692568] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cholangiocytes, a small population of cells within the normal liver, have been the focus of a significant amount of research over the past two decades because of their involvement in cholangiopathies such as primary sclerosing cholangitis and primary biliary cholangitis. This article summarizes landmark studies in the field of cholangiocyte physiology and aims to provide an updated review of biliary pathogenesis. The historical approach of rodent extrahepatic bile duct ligation and the relatively recent utilization of transgenic mice have led to significant discoveries in cholangiocyte pathophysiology. Cholangiocyte physiology is a complex system based on heterogeneity within the biliary tree and a number of signaling pathways that serve to regulate bile composition. Studies have expanded the list of neuropeptides, neurotransmitters, and hormones that have been shown to be key regulators of proliferation and biliary damage. The peptide histamine and hormones, such as melatonin and angiotensin, angiotensin, as well as numerous sex hormones, have been implicated in cholangiocyte proliferation during cholestasis. Numerous pathways promote cholangiocyte proliferation during cholestasis, and there is growing evidence to suggest that cholangiocyte proliferation may promote hepatic fibrosis. These pathways may represent significant therapeutic potential for a subset of cholestatic liver diseases that currently lack effective therapies.
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Affiliation(s)
- Chad Hall
- *Research, Central Texas Veterans Health Care System, Temple, TX, USA
- †Baylor Scott & White Digestive Disease Research Center, Temple, TX, USA
- ‡Department of Surgery, Baylor Scott & White and Texas A&M Health Science Center, Temple, TX, USA
| | - Keisaku Sato
- §Operational Funds, Baylor Scott & White, Temple, TX, USA
| | - Nan Wu
- §Operational Funds, Baylor Scott & White, Temple, TX, USA
| | - Tianhao Zhou
- §Operational Funds, Baylor Scott & White, Temple, TX, USA
| | | | - Fanyin Meng
- *Research, Central Texas Veterans Health Care System, Temple, TX, USA
- §Operational Funds, Baylor Scott & White, Temple, TX, USA
- ¶Department of Medicine, Baylor Scott & White and Texas A&M Health Science Center, Temple, TX, USA
| | - Shannon Glaser
- *Research, Central Texas Veterans Health Care System, Temple, TX, USA
- §Operational Funds, Baylor Scott & White, Temple, TX, USA
- ¶Department of Medicine, Baylor Scott & White and Texas A&M Health Science Center, Temple, TX, USA
| | - Gianfranco Alpini
- ‡Department of Surgery, Baylor Scott & White and Texas A&M Health Science Center, Temple, TX, USA
- §Operational Funds, Baylor Scott & White, Temple, TX, USA
- ¶Department of Medicine, Baylor Scott & White and Texas A&M Health Science Center, Temple, TX, USA
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18
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Roa JN, Tresguerres M. Bicarbonate-sensing soluble adenylyl cyclase is present in the cell cytoplasm and nucleus of multiple shark tissues. Physiol Rep 2017; 5:5/2/e13090. [PMID: 28108644 PMCID: PMC5269408 DOI: 10.14814/phy2.13090] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 12/31/2022] Open
Abstract
The enzyme soluble adenylyl cyclase (sAC) is directly stimulated by bicarbonate (HCO3−) to produce the signaling molecule cyclic adenosine monophosphate (cAMP). Because sAC and sAC‐related enzymes are found throughout phyla from cyanobacteria to mammals and they regulate cell physiology in response to internal and external changes in pH, CO2, and HCO3−, sAC is deemed an evolutionarily conserved acid‐base sensor. Previously, sAC has been reported in dogfish shark and round ray gill cells, where they sense and counteract blood alkalosis by regulating the activity of V‐type H+‐ ATPase. Here, we report the presence of sAC protein in gill, rectal gland, cornea, intestine, white muscle, and heart of leopard shark Triakis semifasciata. Co‐expression of sAC with transmembrane adenylyl cyclases supports the presence of cAMP signaling microdomains. Furthermore, immunohistochemistry on tissue sections, and western blots and cAMP‐activity assays on nucleus‐enriched fractions demonstrate the presence of sAC protein in and around nuclei. These results suggest that sAC modulates multiple physiological processes in shark cells, including nuclear functions.
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Affiliation(s)
- Jinae N Roa
- Marine Biology Research Division, Scripps Institution of Oceanography University of California San Diego, 9500 Gilman Drive La Jolla, California, 92093, USA
| | - Martin Tresguerres
- Marine Biology Research Division, Scripps Institution of Oceanography University of California San Diego, 9500 Gilman Drive La Jolla, California, 92093, USA
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19
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Chang J, Go S, de Waart DR, Munoz‐Garrido P, Beuers U, Paulusma CC, Oude Elferink R. Soluble Adenylyl Cyclase Regulates Bile Salt-Induced Apoptosis in Human Cholangiocytes. Hepatology 2016; 64:522-34. [PMID: 26991014 PMCID: PMC5111777 DOI: 10.1002/hep.28550] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 03/14/2016] [Indexed: 12/20/2022]
Abstract
UNLABELLED Anion exchanger 2 (AE2), the principal bicarbonate secretor in the human biliary tree, is down-regulated in primary biliary cholangitis. AE2 creates a "bicarbonate umbrella" that protects cholangiocytes from the proapoptotic effects of bile salts by maintaining them deprotonated. We observed that knockdown of AE2 sensitized immortalized H69 human cholangiocytes to not only bile salt-induced apoptosis (BSIA) but also etoposide-induced apoptosis. Because the toxicity of etoposide is pH-independent, there could be a more general mechanism for sensitization of AE2-depleted cholangiocytes to apoptotic stimuli. We found that AE2 deficiency led to intracellular bicarbonate accumulation and increased expression and activity of soluble adenylyl cyclase (sAC), an evolutionarily conserved bicarbonate sensor. Thus, we hypothesized that sAC regulates BSIA. H69 cholangiocytes and primary mouse cholangiocytes were used as models. The sAC-specific inhibitor KH7 not only reversed sensitization to BSIA in AE2-depleted H69 cholangiocytes but even completely prevented BSIA. sAC knockdown by tetracycline-inducible short hairpin RNA also prevented BSIA. In addition, sAC inhibition reversed BSIA membrane blebbing, nuclear condensation, and DNA fragmentation. Furthermore, sAC inhibition also prevented BSIA in primary mouse cholangiocytes. Mechanistically, sAC inhibition prevented Bax phosphorylation at Thr167 and mitochondrial translocation of Bax and cytochrome c release but not c-Jun N-terminal kinase activation during BSIA. Finally, BSIA in H69 cholangiocytes was inhibited by intracellular Ca(2+) chelation, aggravated by thapsigargin, and unaffected by removal of extracellular calcium. CONCLUSIONS BSIA is regulated by sAC, depends on intracellular Ca(2+) stores, and is mediated by the intrinsic apoptotic pathway; down-regulation of AE2 in primary biliary cholangitis sensitizes cholangiocytes to apoptotic insults by activating sAC, which may play a crucial role in disease pathogenesis. (Hepatology 2016;64:522-534).
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Affiliation(s)
- Jung‐Chin Chang
- Tytgat Institute for Liver and Intestinal Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Simei Go
- Tytgat Institute for Liver and Intestinal Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Dirk R. de Waart
- Tytgat Institute for Liver and Intestinal Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Patricia Munoz‐Garrido
- Tytgat Institute for Liver and Intestinal Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands,Department of Liver and Gastrointestinal Diseases, Biodonostia Health Research Institute, Donostia University HospitalUniversity of the Basque Country (UPV/EHU)San SebastiánSpain,National Institute for the Study of Liver and Gastrointestinal Diseases (CIBERehd, Instituto de Salud Carlos III)MadridSpain
| | - Ulrich Beuers
- Tytgat Institute for Liver and Intestinal Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Coen C. Paulusma
- Tytgat Institute for Liver and Intestinal Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Ronald Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
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20
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Roa JN, Tresguerres M. Soluble adenylyl cyclase is an acid-base sensor in epithelial base-secreting cells. Am J Physiol Cell Physiol 2016; 311:C340-9. [PMID: 27335168 DOI: 10.1152/ajpcell.00089.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/16/2016] [Indexed: 12/20/2022]
Abstract
Blood acid-base regulation by specialized epithelia, such as gills and kidney, requires the ability to sense blood acid-base status. Here, we developed primary cultures of ray (Urolophus halleri) gill cells to study mechanisms for acid-base sensing without the interference of whole animal hormonal regulation. Ray gills have abundant base-secreting cells, identified by their noticeable expression of vacuolar-type H(+)-ATPase (VHA), and also express the evolutionarily conserved acid-base sensor soluble adenylyl cyclase (sAC). Exposure of cultured cells to extracellular alkalosis (pH 8.0, 40 mM HCO3 (-)) triggered VHA translocation to the cell membrane, similar to previous reports in live animals experiencing blood alkalosis. VHA translocation was dependent on sAC, as it was blocked by the sAC-specific inhibitor KH7. Ray gill base-secreting cells also express transmembrane adenylyl cyclases (tmACs); however, tmAC inhibition by 2',5'-dideoxyadenosine did not prevent alkalosis-dependent VHA translocation, and tmAC activation by forskolin reduced the abundance of VHA at the cell membrane. This study demonstrates that sAC is a necessary and sufficient sensor of extracellular alkalosis in ray gill base-secreting cells. In addition, this study indicates that different sources of cAMP differentially modulate cell biology.
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Affiliation(s)
- Jinae N Roa
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California
| | - Martin Tresguerres
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California
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21
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Abstract
Research related to primary sclerosing cholangitis (PSC) has since 1980 been a major activity at the Oslo University Hospital Rikshospitalet. The purpose of this publication is to describe the development of this research, the impact of this research on the clinical handling of the patients, and finally to describe what we believe are the most urgent, remaining problems to be solved. During the early years, our research dealt primarily with clinical aspects of the disease. The concomitant inflammatory bowel disease (IBD) seen in most patients with PSC was a major interest and we also started looking into genetic associations of PSC. Prognosis, malignancy development and treatment with special emphasis on transplantation have later been dealt with. These activities has had impact on several aspects of PSC management; when and how to diagnose PSC and variant forms of PSC, how to handle IBD in PSC and how to deal with the increased rate of malignancy? The problems remaining to be solved are many. What is the role of the gut and the gut microbiota in the development of PSC? Do the PSC patients have an underlying disturbance in the bile homeostasis? And how does the characteristic type of fibrosis in PSC develop? The genetic studies have supported a role for the adaptive immune system in the disease development, but how should this be dealt with? Importantly, the development of malignancy in PSC is still not understood, and we lack appropriate medical treatment for our patients.
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Affiliation(s)
- Erik Schrumpf
- Norwegian PSC research center, Department of Transplantation Medicine, Division of Cancer Medicine, Surgery and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway
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22
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Affiliation(s)
- Lonny R. Levin
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065; ,
| | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065; ,
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Afroze S, Meng F, Jensen K, McDaniel K, Rahal K, Onori P, Gaudio E, Alpini G, Glaser SS. The physiological roles of secretin and its receptor. ANNALS OF TRANSLATIONAL MEDICINE 2014; 1:29. [PMID: 25332973 DOI: 10.3978/j.issn.2305-5839.2012.12.01] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 12/13/2012] [Indexed: 12/19/2022]
Abstract
Secretin is secreted by S cells in the small intestine and affects the function of a number of organ systems. Secretin receptors (SR) are expressed in the basolateral domain of several cell types. In addition to regulating the secretion of a number of epithelia (e.g., in the pancreas and biliary epithelium in the liver), secretin exerts trophic effects in several cell types. In this article, we will provide a comprehensive review on the multiple roles of secretin and SR signaling in the regulation of epithelial functions in various organ systems with particular emphasis in the liver. We will discuss the role of secretin and its receptor in health and biliary disease pathogenesis. Finally, we propose future areas of research for the further evaluation of the secretin/secretin receptor axis in liver pathophysiology.
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Affiliation(s)
- Syeda Afroze
- 1 Department of Medicine, Division Gastroenterology, 2 Research, Central Texas Veterans Health Care System, 3 Scott & White Digestive Disease Research Center, Scott & White, and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA ; 4 Experimental Medicine, University of L'Aquila, L'Aquila, Italy ; 5 Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University Sapienza, Rome, Italy
| | - Fanyin Meng
- 1 Department of Medicine, Division Gastroenterology, 2 Research, Central Texas Veterans Health Care System, 3 Scott & White Digestive Disease Research Center, Scott & White, and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA ; 4 Experimental Medicine, University of L'Aquila, L'Aquila, Italy ; 5 Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University Sapienza, Rome, Italy
| | - Kendal Jensen
- 1 Department of Medicine, Division Gastroenterology, 2 Research, Central Texas Veterans Health Care System, 3 Scott & White Digestive Disease Research Center, Scott & White, and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA ; 4 Experimental Medicine, University of L'Aquila, L'Aquila, Italy ; 5 Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University Sapienza, Rome, Italy
| | - Kelly McDaniel
- 1 Department of Medicine, Division Gastroenterology, 2 Research, Central Texas Veterans Health Care System, 3 Scott & White Digestive Disease Research Center, Scott & White, and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA ; 4 Experimental Medicine, University of L'Aquila, L'Aquila, Italy ; 5 Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University Sapienza, Rome, Italy
| | - Kinan Rahal
- 1 Department of Medicine, Division Gastroenterology, 2 Research, Central Texas Veterans Health Care System, 3 Scott & White Digestive Disease Research Center, Scott & White, and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA ; 4 Experimental Medicine, University of L'Aquila, L'Aquila, Italy ; 5 Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University Sapienza, Rome, Italy
| | - Paolo Onori
- 1 Department of Medicine, Division Gastroenterology, 2 Research, Central Texas Veterans Health Care System, 3 Scott & White Digestive Disease Research Center, Scott & White, and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA ; 4 Experimental Medicine, University of L'Aquila, L'Aquila, Italy ; 5 Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University Sapienza, Rome, Italy
| | - Eugenio Gaudio
- 1 Department of Medicine, Division Gastroenterology, 2 Research, Central Texas Veterans Health Care System, 3 Scott & White Digestive Disease Research Center, Scott & White, and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA ; 4 Experimental Medicine, University of L'Aquila, L'Aquila, Italy ; 5 Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University Sapienza, Rome, Italy
| | - Gianfranco Alpini
- 1 Department of Medicine, Division Gastroenterology, 2 Research, Central Texas Veterans Health Care System, 3 Scott & White Digestive Disease Research Center, Scott & White, and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA ; 4 Experimental Medicine, University of L'Aquila, L'Aquila, Italy ; 5 Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University Sapienza, Rome, Italy
| | - Shannon S Glaser
- 1 Department of Medicine, Division Gastroenterology, 2 Research, Central Texas Veterans Health Care System, 3 Scott & White Digestive Disease Research Center, Scott & White, and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA ; 4 Experimental Medicine, University of L'Aquila, L'Aquila, Italy ; 5 Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University Sapienza, Rome, Italy
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Abstract
Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterized by selective destruction of intrahepatic cholangiocytes. Mechanisms underlying the development and progression of the disease are still controversial and largely undefined. Evidence suggests that PBC results from an articulated immunologic response against an immunodominant mitochondrial autoantigen, the E2 component of the pyruvate dehydrogenase complex (PDC-E2); characteristics of the disease are also the presence of disease-specific antimitochondrial autoantibodies (AMAs) and autoreactive CD4 and CD8 T cells. Recent evidence suggests that cholangiocytes show specific immunobiological features that are responsible for the selective targeting of those cells by the immune system. The immune reaction in PBC selectively targets small sized, intrahepatic bile ducts; although a specific reason for that has not been defined yet, it has been established that the biliary epithelium displays a unique heterogeneity, for which the physiological and pathophysiological features of small and large cholangiocytes significantly differ. In this review article, the authors provide a critical overview of the current evidence on the role of cholangiocytes in the immune-mediated destruction of the biliary tree that characterizes PBC.
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Affiliation(s)
- Ana Lleo
- Liver Unit and Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Rozzano (MI), Italy
| | - Luca Maroni
- Clinic of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy
| | - Shannon Glaser
- Research, Central Texas Veterans Health Care System, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas,Scott & White Digestive Disease Research Center, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas,Department of Medicine, Division Gastroenterology, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas
| | - Gianfranco Alpini
- Research, Central Texas Veterans Health Care System, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas,Scott & White Digestive Disease Research Center, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas,Department of Medicine, Division Gastroenterology, S and W and Texas A and M System Health Science Center, College of Medicine, Temple, Texas
| | - Marco Marzioni
- Clinic of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy
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25
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Tresguerres M. sAC from aquatic organisms as a model to study the evolution of acid/base sensing. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2629-35. [PMID: 24971688 DOI: 10.1016/j.bbadis.2014.06.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 06/17/2014] [Indexed: 12/26/2022]
Abstract
Soluble adenylyl cyclase (sAC) is poised to play multiple physiological roles as an acid/base (A/B) sensor in aquatic organisms. Many of these roles are probably similar to those in mammals; a striking example is the evolutionary conservation of a mechanism involving sAC, carbonic anhydrase and vacuolar H⁺-ATPase that acts as a sensor system and regulator of extracellular A/B in shark gills and mammalian epididymis and kidney. Additionally, the aquatic environment presents unique A/B and physiological challenges; therefore, sACs from aquatic organisms have likely evolved distinct kinetic properties as well as distinct physiological roles. sACs from aquatic organisms offer an excellent opportunity for studying the evolution of A/B sensing at both the molecular and whole organism levels. Moreover, this information could help understand and predict organismal responses to environmental stress based on mechanistic models.This article is part of a Special Issue entitled "The Role of Soluble Adenylyl Cyclase in Health and Disease," guest edited by J. Buck and L. R. Levin.
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Affiliation(s)
- Martin Tresguerres
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
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26
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Schmitz B, Brand SM, Brand E. Aldosterone signaling and soluble adenylyl cyclase-a nexus for the kidney and vascular endothelium. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2601-9. [PMID: 24907563 DOI: 10.1016/j.bbadis.2014.05.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/23/2014] [Accepted: 05/28/2014] [Indexed: 12/14/2022]
Abstract
The steroid hormone aldosterone regulates the reabsorption of water and ions in the kidney and plays a central role in blood pressure regulation and homeostasis. In recent years, the vascular endothelium has been established as an important aldosterone target organ with major implications in renal and cardiovascular health and disease. Different lines of evidence suggest that the calcium- and bicarbonate-activated soluble adenylyl cyclase (sAC) is a novel mediator of aldosterone signaling in both the kidney and vascular endothelium. This review summarizes our current understanding of the molecular mechanisms of sAC gene expression regulation in the kidney and vascular endothelium and outlines the potential clinical implications of sAC in chronic kidney disease and cardiovascular disease. This review is part of a special issue entitled: The role of soluble adenylyl cyclase in health and disease. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.
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Affiliation(s)
- Boris Schmitz
- Institute of Sports Medicine, Molecular Genetics of Cardiovascular Disease, University Hospital Muenster, Horstmarer Landweg 39, 48149 Muenster, Germany; Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany
| | - Stefan-Martin Brand
- Institute of Sports Medicine, Molecular Genetics of Cardiovascular Disease, University Hospital Muenster, Horstmarer Landweg 39, 48149 Muenster, Germany
| | - Eva Brand
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany.
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27
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Sabbatini ME, Gorelick F, Glaser S. Adenylyl cyclases in the digestive system. Cell Signal 2014; 26:1173-81. [PMID: 24521753 DOI: 10.1016/j.cellsig.2014.01.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 01/31/2014] [Indexed: 02/08/2023]
Abstract
Adenylyl cyclases (ACs) are a group of widely distributed enzymes whose functions are very diverse. There are nine known transmembrane AC isoforms activated by Gαs. Each has its own pattern of expression in the digestive system and differential regulation of function by Ca(2+) and other intracellular signals. In addition to the transmembrane isoforms, one AC is soluble and exhibits distinct regulation. In this review, the basic structure, regulation and physiological roles of ACs in the digestive system are discussed.
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Affiliation(s)
| | - Fred Gorelick
- Department of Cell Biology and Medicine, Yale University, United States; VA CT, United States
| | - Shannon Glaser
- Department of Internal Medicine, Scott & White-Digestive Disease Research Center, Texas A&M Health Science Center, Central Texas Veterans Health Care System, United States
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28
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Tabibian JH, Masyuk AI, Masyuk TV, O'Hara SP, LaRusso NF. Physiology of cholangiocytes. Compr Physiol 2013; 3:541-65. [PMID: 23720296 DOI: 10.1002/cphy.c120019] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cholangiocytes are epithelial cells that line the intra- and extrahepatic ducts of the biliary tree. The main physiologic function of cholangiocytes is modification of hepatocyte-derived bile, an intricate process regulated by hormones, peptides, nucleotides, neurotransmitters, and other molecules through intracellular signaling pathways and cascades. The mechanisms and regulation of bile modification are reviewed herein.
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29
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Bitterman JL, Ramos-Espiritu L, Diaz A, Levin LR, Buck J. Pharmacological distinction between soluble and transmembrane adenylyl cyclases. J Pharmacol Exp Ther 2013; 347:589-98. [PMID: 24091307 DOI: 10.1124/jpet.113.208496] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The second messenger cAMP is involved in a number of cellular signaling pathways. In mammals, cAMP is produced by either the hormonally responsive, G protein-regulated transmembrane adenylyl cyclases (tmACs) or by the bicarbonate- and calcium-regulated soluble adenylyl cyclase (sAC). To develop tools to differentiate tmAC and sAC signaling, we determined the specificity and potency of commercially available adenylyl cyclase inhibitors. In cellular systems, two inhibitors, KH7 and catechol estrogens, proved specific for sAC, and 2',5'-dideoxyadenosine proved specific for tmACs. These tools provide a means to define the specific contributions of the different families of adenylyl cyclases in cells and tissues, which will further our understanding of cell signaling.
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Affiliation(s)
- Jacob L Bitterman
- Department of Pharmacology, Weill Cornell Medical College, New York, New York
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30
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Han Y, Glaser S, Meng F, Francis H, Marzioni M, McDaniel K, Alvaro D, Venter J, Carpino G, Onori P, Gaudio E, Alpini G, Franchitto A. Recent advances in the morphological and functional heterogeneity of the biliary epithelium. Exp Biol Med (Maywood) 2013; 238:549-65. [PMID: 23856906 DOI: 10.1177/1535370213489926] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This review focuses on the recent advances related to the heterogeneity of different-sized bile ducts with regard to the morphological and phenotypical characteristics, and the differential secretory, apoptotic and proliferative responses of small and large cholangiocytes to gastrointestinal hormones/peptides, neuropeptides and toxins. We describe several in vivo and in vitro models used for evaluating biliary heterogeneity. Subsequently, we discuss the heterogeneous proliferative and apoptotic responses of small and large cholangiocytes to liver injury and the mechanisms regulating the differentiation of small into large (more differentiated) cholangiocytes. Following a discussion on the heterogeneity of stem/progenitor cells in the biliary epithelium, we outline the heterogeneity of bile ducts in human cholangiopathies. After a summary section, we discuss the future perspectives that will further advance the field of the functional heterogeneity of the biliary epithelium.
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Affiliation(s)
- Yuyan Han
- Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, TX, USA
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31
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Mancinelli R, Franchitto A, Glaser S, Meng F, Onori P, DeMorrow S, Francis H, Venter J, Carpino G, Baker K, Han Y, Ueno Y, Gaudio E, Alpini G. GABA induces the differentiation of small into large cholangiocytes by activation of Ca(2+) /CaMK I-dependent adenylyl cyclase 8. Hepatology 2013; 58:251-63. [PMID: 23389926 PMCID: PMC3733050 DOI: 10.1002/hep.26308] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 01/11/2013] [Accepted: 01/31/2013] [Indexed: 01/30/2023]
Abstract
UNLABELLED Large, but not small, cholangiocytes (1) secrete bicarbonate by interaction with secretin receptors (SRs) through activation of cystic fibrosis transmembrane regulator (CFTR), Cl(-) /HCO3 (-) (apex) anion exchanger 2 (Cl(-) /HCO3 (-) AE2), and adenylyl cyclase (AC)8 (proteins regulating large biliary functions) and (2) proliferate in response to bile duct ligation (BDL) by activation of cyclic adenosine monophosphate (cAMP) signaling. Small, mitotically dormant cholangiocytes are activated during damage of large cholangiocytes by activation of D-myo-inositol 1,4,5-trisphosphate/Ca(2+) /calmodulin-dependent protein kinase (CaMK) I. gamma-Aminobutyric acid (GABA) affects cell functions by modulation of Ca(2+) -dependent signaling and AC. We hypothesized that GABA induces the differentiation of small into large cholangiocytes by the activation of Ca(2+) /CaMK I-dependent AC8. In vivo, BDL mice were treated with GABA in the absence or presence of 1,2-bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid, tetraacetoxymethyl ester (BAPTA/AM) or N-(6-aminohexyl)-5-chloro-1-naphtalenesulfonamide (W7) before evaluating apoptosis and intrahepatic bile ductal mass (IBDM) of small and large cholangiocytes. In vitro, control- or CaMK I-silenced small cholangiocytes were treated with GABA for 3 days before evaluating apoptosis, proliferation, ultrastructural features, and the expression of CFTR, Cl(-) /HCO3 (-) AE2, AC8, and secretin-stimulated cAMP levels. In vivo administration of GABA induces the apoptosis of large, but not small, cholangiocytes and decreases large IBDM, but increased de novo small IBDM. GABA stimulation of small IBDM was blocked by BAPTA/AM and W7. Subsequent to GABA in vitro treatment, small cholangiocytes de novo proliferate and acquire ultrastructural and functional phenotypes of large cholangiocytes and respond to secretin. GABA-induced changes were prevented by BAPTA/AM, W7, and stable knockdown of the CaMK I gene. CONCLUSION GABA damages large, but not small, cholangiocytes that differentiate into large cholangiocytes. The differentiation of small into large cholangiocytes may be important in the replenishment of the biliary epithelium during damage of large, senescent cholangiocytes.
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Affiliation(s)
- Romina Mancinelli
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University “Sapienza”, Rome, Italy
| | - Antonio Franchitto
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University “Sapienza”, Rome, Italy,Eleonora Lorillard Spencer Cenci Foundation, Rome, Italy
| | - Shannon Glaser
- Research, Central Texas Veterans Health Care System, Scott & White, Temple, TX 76504,Scott & White Digestive Disease Research Center, Scott & White, Temple, TX 76504,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Scott & White, Temple, TX 76504
| | - Fanyin Meng
- Research, Central Texas Veterans Health Care System, Scott & White, Temple, TX 76504,Scott & White Digestive Disease Research Center, Scott & White, Temple, TX 76504,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Scott & White, Temple, TX 76504,Division of Research and Education, Scott & White, Temple, TX 76504
| | - Paolo Onori
- Experimental Medicine, University of L’Aquila, L’Aquila, Italy
| | - Sharon DeMorrow
- Scott & White Digestive Disease Research Center, Scott & White, Temple, TX 76504,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Scott & White, Temple, TX 76504
| | - Heather Francis
- Research, Central Texas Veterans Health Care System, Scott & White, Temple, TX 76504,Scott & White Digestive Disease Research Center, Scott & White, Temple, TX 76504,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Scott & White, Temple, TX 76504,Division of Research and Education, Scott & White, Temple, TX 76504
| | - Julie Venter
- Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Scott & White, Temple, TX 76504
| | | | - Kimberley Baker
- Research, Central Texas Veterans Health Care System, Scott & White, Temple, TX 76504,Scott & White Digestive Disease Research Center, Scott & White, Temple, TX 76504
| | - Yuyan Han
- Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Scott & White, Temple, TX 76504
| | - Yoshiyuki Ueno
- Department Gastroenterology, Yamagata University Faculty of Medicine, Yamagata, Japan,CREST, Yamagata Japan
| | - Eugenio Gaudio
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University “Sapienza”, Rome, Italy,Address Correspondence to Eugenio Gaudio, M.D., Professor, Dean of the First Faculty of Medicine, Dept. Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University “Sapienza”, Rome, Italy, Via Alfonso Borelli 50, 00161, Rome, Italy, Phone: 01139-0649918060, Fax: 01139-0649918062, Or Gianfranco Alpini, Ph. D., VA Research Scientist Recipient, Professor, Medicine, Director, Scott & White Digestive Diseases Research Center, Dr. Nicholas C. Hightower Centennial Chair of Gastroenterology, Central Texas Veterans Health Care System, Texas A & M Health Science Center College of Medicine, Olin E. Teague Medical Center, 1901 South 1 Street, Bldg. 205, 1R60, Temple, TX, 76504, Phone: 254-743-2625 and 254-743-1044 Fax: 743-0378 or 743-0555, or
| | - Gianfranco Alpini
- Research, Central Texas Veterans Health Care System, Scott & White, Temple, TX 76504,Scott & White Digestive Disease Research Center, Scott & White, Temple, TX 76504,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Scott & White, Temple, TX 76504,Address Correspondence to Eugenio Gaudio, M.D., Professor, Dean of the First Faculty of Medicine, Dept. Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, University “Sapienza”, Rome, Italy, Via Alfonso Borelli 50, 00161, Rome, Italy, Phone: 01139-0649918060, Fax: 01139-0649918062, Or Gianfranco Alpini, Ph. D., VA Research Scientist Recipient, Professor, Medicine, Director, Scott & White Digestive Diseases Research Center, Dr. Nicholas C. Hightower Centennial Chair of Gastroenterology, Central Texas Veterans Health Care System, Texas A & M Health Science Center College of Medicine, Olin E. Teague Medical Center, 1901 South 1 Street, Bldg. 205, 1R60, Temple, TX, 76504, Phone: 254-743-2625 and 254-743-1044 Fax: 743-0378 or 743-0555, or
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32
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Soluble adenylyl cyclase activity is necessary for retinal ganglion cell survival and axon growth. J Neurosci 2012; 32:7734-44. [PMID: 22649251 DOI: 10.1523/jneurosci.5288-11.2012] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
cAMP is a critical second messenger mediating activity-dependent neuronal survival and neurite growth. We investigated the expression and function of the soluble adenylyl cyclase (sAC, ADCY10) in CNS retinal ganglion cells (RGCs). We found sAC protein expressed in multiple RGC compartments including the nucleus, cytoplasm and axons. sAC activation increased cAMP above the level seen with transmembrane adenylate cyclase (tmAC) activation. Electrical activity and bicarbonate, both physiologic sAC activators, significantly increased survival and axon growth, whereas pharmacologic or siRNA-mediated sAC inhibition dramatically decreased RGC survival and axon growth in vitro, and survival in vivo. Conversely, RGC survival and axon growth were unaltered in RGCs from AC1/AC8 double knock-out mice or after specifically inhibiting tmACs. These data identify a novel sAC-mediated cAMP signaling pathway regulating RGC survival and axon growth, and suggest new neuroprotective or regenerative strategies based on sAC modulation.
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33
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Kolodecik TR, Shugrue CA, Thrower EC, Levin LR, Buck J, Gorelick FS. Activation of soluble adenylyl cyclase protects against secretagogue stimulated zymogen activation in rat pancreaic acinar cells. PLoS One 2012; 7:e41320. [PMID: 22844459 PMCID: PMC3402497 DOI: 10.1371/journal.pone.0041320] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 06/20/2012] [Indexed: 01/11/2023] Open
Abstract
An early feature of acute pancreatitis is activation of zymogens, such as trypsinogen, within the pancreatic acinar cell. Supraphysiologic concentrations of the hormone cholecystokinin (CCK; 100 nM), or its orthologue cerulein (CER), induce zymogen activation and elevate levels of cAMP in pancreatic acinar cells. The two classes of adenylyl cyclase, trans-membrane (tmAC) and soluble (sAC), are activated by distinct mechanisms, localize to specific subcellular domains, and can produce locally high concentrations of cAMP. We hypothesized that sAC activity might selectively modulate acinar cell zymogen activation. sAC was identified in acinar cells by PCR and immunoblot. It localized to the apical region of the cell under resting conditions and redistributed intracellularly after treatment with supraphysiologic concentrations of cerulein. In cerulein-treated cells, pre-incubation with a trans-membrane adenylyl cyclase inhibitor did not affect zymogen activation or amylase secretion. However, treatment with a sAC inhibitor (KH7), or inhibition of a downstream target of cAMP, protein kinase A (PKA), significantly enhanced secretagogue-stimulated zymogen activation and amylase secretion. Activation of sAC with bicarbonate significantly inhibited secretagogue-stimulated zymogen activation; this response was decreased by inhibition of sAC or PKA. Bicarbonate also enhanced secretagogue-stimulated cAMP accumulation; this effect was inhibited by KH7. Bicarbonate treatment reduced secretagogue-stimulated acinar cell vacuolization, an early marker of pancreatitis. These data suggest that activation of sAC in the pancreatic acinar cell has a protective effect and reduces the pathologic activation of proteases during pancreatitis.
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Affiliation(s)
- Thomas R. Kolodecik
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Veterans Administration Connecticut Healthcare, West Haven, Connecticut, United States of America
| | - Christine A. Shugrue
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Veterans Administration Connecticut Healthcare, West Haven, Connecticut, United States of America
| | - Edwin C. Thrower
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Veterans Administration Connecticut Healthcare, West Haven, Connecticut, United States of America
| | - Lonny R. Levin
- Department of Pharmacology, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Jochen Buck
- Department of Pharmacology, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Fred S. Gorelick
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Veterans Administration Connecticut Healthcare, West Haven, Connecticut, United States of America
- * E-mail:
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34
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Abstract
PURPOSE OF REVIEW To critically review most recent experimental evidence for the protective action of biliary HCO(3)(-) secretion against bile acid-induced bile duct damage and development of fibrosing cholangiopathy in humans and experimental animals. RECENT FINDINGS Studies in human cholangiocytes in vitro indicate that a biliary HCO(3)(-) umbrella protects against bile acid-induced cholangiocyte damage and apoptosis in humans. The Cl(-)/HCO(3)(-) exchanger, AE2, and an intact biliary glycocalyx appear crucial for its stability. Related studies with experimental animal models in vivo have to be interpreted with caution as humans and mice differ not only with regard to bile salt pool, but also their expression patterns of transport proteins and signalling molecules. SUMMARY Adequate biliary HCO(3)(-) secretion may protect against bile salt-induced cholangiopathies. Future therapeutic strategies in biliary diseases will aim at stabilizing the biliary HCO(3)(-) umbrella.
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Spirli C, Locatelli L, Fiorotto R, Morell CM, Fabris L, Pozzan T, Strazzabosco M. Altered store operated calcium entry increases cyclic 3',5'-adenosine monophosphate production and extracellular signal-regulated kinases 1 and 2 phosphorylation in polycystin-2-defective cholangiocytes. Hepatology 2012; 55:856-68. [PMID: 21987453 PMCID: PMC3272110 DOI: 10.1002/hep.24723] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
UNLABELLED Mutations in polycystins (PC1 or PC2/TRPP2) cause progressive polycystic liver disease (PLD). In PC2-defective mice, cyclic 3',5'-adenosine monophosphate/ protein kinase A (cAMP/PKA)-dependent activation of extracellular signal-regulated kinase/ mammalian target of rapamycin (ERK-mTOR) signaling stimulates cyst growth. We investigated the mechanisms connecting PC2 dysfunction to altered Ca(2+) and cAMP production and inappropriate ERK signaling in PC2-defective cholangiocytes. Cystic cholangiocytes were isolated from PC2 conditional-KO (knockout) mice (Pkd2(flox/-) :pCxCreER™; hence, called Pkd2KO) and compared to cholangiocytes from wild-type mice (WT). Our results showed that, compared to WT cells, in PC2-defective cholangiocytes (Pkd2KO), cytoplasmic and ER-Ca(2+) (measured with Fura-2 and Mag-Fluo4) levels are decreased and store-operated Ca(2+) entry (SOCE) is inhibited, whereas the expression of Ca(2+) -sensor stromal interaction molecule 1 (STIM1) and store-operated Ca(2+) channels (e.g., the Orai1 channel) are unchanged. In Pkd2KO cells, ER-Ca(2+) depletion increases cAMP and PKA-dependent ERK1/2 activation and both are inhibited by STIM1 inhibitors or by silencing of adenylyl cyclase type 6 (AC6). CONCLUSION These data suggest that PC2 plays a key role in SOCE activation and inhibits the STIM-dependent activation of AC6 by ER Ca(2+) depletion. In PC2-defective cells, the interaction of STIM-1 with Orai channels is uncoupled, whereas coupling to AC6 is maximized. The resulting overproduction of cAMP, in turn, potently activates the PKA/ERK pathway. PLD, because of PC2 deficiency, represents the first example of human disease linked to the inappropriate activation of store-operated cAMP production.
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Affiliation(s)
- Carlo Spirli
- Dept. of Internal Medicine; Liver Center and Digestive Diseases Section; Yale University; New Haven; USA
- CeLiveR; Ospedali Riuniti di Bergamo; Bergamo, Italy
| | - Luigi Locatelli
- Dept. of Internal Medicine; Liver Center and Digestive Diseases Section; Yale University; New Haven; USA
- CeLiveR; Ospedali Riuniti di Bergamo; Bergamo, Italy
- Dept. of Clinical Medicine and Prevention University of Milan-Bicocca, Monza, Italy
| | - Romina Fiorotto
- Dept. of Internal Medicine; Liver Center and Digestive Diseases Section; Yale University; New Haven; USA
- CeLiveR; Ospedali Riuniti di Bergamo; Bergamo, Italy
| | - Carola M. Morell
- Dept. of Internal Medicine; Liver Center and Digestive Diseases Section; Yale University; New Haven; USA
- Dept. of Clinical Medicine and Prevention University of Milan-Bicocca, Monza, Italy
| | - Luca Fabris
- CeLiveR; Ospedali Riuniti di Bergamo; Bergamo, Italy
- Department of Gastroenterological Sciences, University of Padova, Padova, Italy
| | - Tullio Pozzan
- Consiglio Nazionale delle Ricerche, Neuroscience Institute, Dept. of Biomedical Sciences, University of Padova and Venetian Institute of Molecular Medicine, Padova, Italy
| | - Mario Strazzabosco
- Dept. of Internal Medicine; Liver Center and Digestive Diseases Section; Yale University; New Haven; USA
- CeLiveR; Ospedali Riuniti di Bergamo; Bergamo, Italy
- Dept. of Clinical Medicine and Prevention University of Milan-Bicocca, Monza, Italy
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36
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Francis HL, DeMorrow S, Franchitto A, Venter JK, Mancinelli RA, White MA, Meng F, Ueno Y, Carpino G, Renzi A, Baker KK, Shine HE, Francis TC, Gaudio E, Alpini GD, Onori P. Histamine stimulates the proliferation of small and large cholangiocytes by activation of both IP3/Ca2+ and cAMP-dependent signaling mechanisms. J Transl Med 2012; 92:282-94. [PMID: 22064319 PMCID: PMC3293651 DOI: 10.1038/labinvest.2011.158] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Although large cholangiocytes exert their functions by activation of cyclic adenosine 3',5'-monophosphate (cAMP), Ca(2+)-dependent signaling regulates the function of small cholangiocytes. Histamine interacts with four receptors, H1-H4HRs. H1HR acts by Gαq activating IP(3)/Ca(2+), whereas H2HR activates Gα(s) stimulating cAMP. We hypothesize that histamine increases biliary growth by activating H1HR on small and H2HR on large cholangiocytes. The expression of H1-H4HRs was evaluated in liver sections, isolated and cultured (normal rat intrahepatic cholangiocyte culture (NRIC)) cholangiocytes. In vivo, normal rats were treated with histamine or H1-H4HR agonists for 1 week. We evaluated: (1) intrahepatic bile duct mass (IBDM); (2) the effects of histamine, H1HR or H2HR agonists on NRIC proliferation, IP(3) and cAMP levels and PKCα and protein kinase A (PKA) phosphorylation; and (3) PKCα silencing on H1HR-stimulated NRIC proliferation. Small and large cholangiocytes express H1-H4HRs. Histamine and the H1HR agonist increased small IBDM, whereas histamine and the H2HR agonist increased large IBDM. H1HR agonists stimulated IP(3) levels, as well as PKCα phosphorylation and NRIC proliferation, whereas H2HR agonists increased cAMP levels, as well as PKA phosphorylation and NRIC proliferation. The H1HR agonist did not increase proliferation in PKCα siRNA-transfected NRICs. The activation of differential signaling mechanisms targeting small and large cholangiocytes is important for repopulation of the biliary epithelium during pathologies affecting different-sized bile ducts.
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Affiliation(s)
- Heather L Francis
- Department of Internal Medicine, Scott and White Digestive Disease Research Center, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA,Division of Gastroenterology, Department of Medicine, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA,Division of Research and Education, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA
| | - Sharon DeMorrow
- Department of Internal Medicine, Scott and White Digestive Disease Research Center, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA,Division of Gastroenterology, Department of Medicine, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA
| | - Antonio Franchitto
- Department of Anatomical, Histological, Forensic Internal Medicine and Orthopedics Sciences, ‘La Sapienza’, Rome, Italy,Eleonora Lonillard Spencer Cenci Foundation, Rome, Italy
| | - Julie K Venter
- Division of Gastroenterology, Department of Medicine, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA
| | - Romina A Mancinelli
- Department of Anatomical, Histological, Forensic Internal Medicine and Orthopedics Sciences, ‘La Sapienza’, Rome, Italy
| | - Mellanie A White
- Division of Gastroenterology, Department of Medicine, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA
| | - Fanyin Meng
- Division of Gastroenterology, Department of Medicine, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA,Division of Research and Education, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA
| | - Yoshiyuki Ueno
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Guido Carpino
- Department Health Science, University of Rome‘Foro Italico’, Italy
| | - Anastasia Renzi
- Department of Internal Medicine, Scott and White Digestive Disease Research Center, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA,Department of Anatomical, Histological, Forensic Internal Medicine and Orthopedics Sciences, ‘La Sapienza’, Rome, Italy
| | - Kimberly K Baker
- Division of Research and Education, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA
| | - Hannah E Shine
- Division of Research and Education, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA
| | - Taylor C Francis
- Division of Research and Education, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA
| | - Eugenio Gaudio
- Department of Anatomical, Histological, Forensic Internal Medicine and Orthopedics Sciences, ‘La Sapienza’, Rome, Italy
| | - Gianfranco D Alpini
- Department of Internal Medicine, Scott and White Digestive Disease Research Center, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA,Division of Gastroenterology, Department of Medicine, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA,Division Research, Central Texas Veterans Health Care System, Scott and White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, TX, USA
| | - Paolo Onori
- Department of Experimental Medicine, State University of L’Aquila, L’Aquila, Italy
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Abstract
Polycystic liver diseases (PLD) are inherited disorders of the biliary epithelium, caused by genetic defects in proteins associated with intracellular organelles, mainly the endoplasmic reticulum and the cilium. PLD are characterized by the formation and progressive enlargement of multiple cysts scattered throughout the liver parenchyma, and include different entities, classified based on their pathology, inheritance pattern, involvement of the kidney and clinical features. PLD should be considered as congenital diseases of cholangiocyte signaling. Here, we will review the changes in signaling pathways involved in liver cyst formation and progression, and their impact on cholangiocyte physiology. Each pathway represents a potential target for therapies aimed at reducing disease progression.
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Affiliation(s)
- Mario Strazzabosco
- Liver Center and Section of Digestive Diseases, Department of Internal Medicine, School of Medicine, Yale University, New Haven, Connecticut 06520, USA.
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38
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Munshi MK, Priester S, Gaudio E, Yang F, Alpini G, Mancinelli R, Wise C, Meng F, Franchitto A, Onori P, Glaser SS. Regulation of biliary proliferation by neuroendocrine factors: implications for the pathogenesis of cholestatic liver diseases. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:472-84. [PMID: 21281779 DOI: 10.1016/j.ajpath.2010.09.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2010] [Revised: 08/23/2010] [Accepted: 09/02/2010] [Indexed: 12/15/2022]
Abstract
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.
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Tresguerres M, Levin LR, Buck J. Intracellular cAMP signaling by soluble adenylyl cyclase. Kidney Int 2011; 79:1277-88. [PMID: 21490586 DOI: 10.1038/ki.2011.95] [Citation(s) in RCA: 156] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Soluble adenylyl cyclase (sAC) is a recently identified source of the ubiquitous second messenger cyclic adenosine 3',5' monophosphate (cAMP). sAC is distinct from the more widely studied source of cAMP, the transmembrane adenylyl cyclases (tmACs); its activity is uniquely regulated by bicarbonate anions, and it is distributed throughout the cytoplasm and in cellular organelles. Due to its unique localization and regulation, sAC has various functions in a variety of physiological systems that are distinct from tmACs. In this review, we detail the known functions of sAC, and we reassess commonly held views of cAMP signaling inside cells.
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Affiliation(s)
- Martin Tresguerres
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
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40
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Alpini G, Franchitto A, DeMorrow S, Onori P, Gaudio E, Wise C, Francis H, Venter J, Kopriva S, Mancinelli R, Carpino G, Stagnitti F, Ueno Y, Han Y, Meng F, Glaser S. Activation of alpha(1) -adrenergic receptors stimulate the growth of small mouse cholangiocytes via calcium-dependent activation of nuclear factor of activated T cells 2 and specificity protein 1. Hepatology 2011; 53:628-39. [PMID: 21274883 PMCID: PMC3522188 DOI: 10.1002/hep.24041] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2010] [Accepted: 10/01/2010] [Indexed: 01/08/2023]
Abstract
UNLABELLED Small cholangiocytes proliferate via activation of calcium (Ca(2+) )-dependent signaling in response to pathological conditions that trigger the damage of large cyclic adenosine monophosphate-dependent cholangiocytes. Although our previous studies suggest that small cholangiocyte proliferation is regulated by the activation of Ca(2+) -dependent signaling, the intracellular mechanisms regulating small cholangiocyte proliferation are undefined. Therefore, we sought to address the role and mechanisms of action by which phenylephrine, an α(1) -adrenergic agonist stimulating intracellular D-myo-inositol-1,4,5-triphosphate (IP(3) )/Ca(2+) levels, regulates small cholangiocyte proliferation. Small and large bile ducts and cholangiocytes expressed all AR receptor subtypes. Small (but not large) cholangiocytes respond to phenylephrine with increased proliferation via the activation of IP(3) /Ca(2+) -dependent signaling. Phenylephrine stimulated the production of intracellular IP(3) . The Ca(2+) -dependent transcription factors, nuclear factor of activated T cells 2 (NFAT2) and NFAT4, were predominantly expressed by small bile ducts and small cholangiocytes. Phenylephrine stimulated the Ca(2+) -dependent DNA-binding activities of NFAT2, NFAT4, and Sp1 (but not Sp3) and the nuclear translocation of NFAT2 and NFAT4 in small cholangiocytes. To determine the relative roles of NFAT2, NFAT4, or Sp1, we knocked down the expression of these transcription factors with small hairpin RNA. We observed an inhibition of phenylephrine-induced proliferation in small cholangiocytes lacking the expression of NFAT2 or Sp1. Phenylephrine stimulated small cholangiocyte proliferation is regulated by Ca(2+) -dependent activation of NFAT2 and Sp1. CONCLUSION Selective stimulation of Ca(2+) -dependent small cholangiocyte proliferation may be key to promote the repopulation of the biliary epithelium when large bile ducts are damaged during cholestasis or by toxins.
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Affiliation(s)
| | | | - Sharon DeMorrow
- Scott & White Digestive Disease Research Center, Temple, Texas 76504
,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas 76504
| | - Paolo Onori
- Dept. of Experimental Medicine, University of L’Aquila, L’Aquila, Italy
| | - Eugenio Gaudio
- Dept. Human Anatomy, University of Rome “La Sapienza”, Rome, Italy
| | - Candace Wise
- Scott & White Digestive Disease Research Center, Temple, Texas 76504
,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas 76504
| | - Heather Francis
- Scott & White Digestive Disease Research Center, Temple, Texas 76504
,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas 76504
,Division of Research and Education at Scott & White, Temple, Texas 76504
| | - Julie Venter
- Scott & White Digestive Disease Research Center, Temple, Texas 76504
,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas 76504
| | - Shelley Kopriva
- Scott & White Digestive Disease Research Center, Temple, Texas 76504
,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas 76504
| | - Romina Mancinelli
- Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas 76504
,Dept. Human Anatomy, University of Rome “La Sapienza”, Rome, Italy
| | - Guido Carpino
- Dept. of Health Science, “Foro Italico” University of Rome, Italy
| | - Franco Stagnitti
- Dept. Surgery, University of Rome “La Sapienza”, Rome, Polo Pontino, Italy
| | - Yoshiyuki Ueno
- Division of Gastroenterology, Tohoku University School of Medicine, Sendai, Japan
| | - Yuyan Han
- Scott & White Digestive Disease Research Center, Temple, Texas 76504
,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas 76504
| | - Fanyin Meng
- Scott & White Digestive Disease Research Center, Temple, Texas 76504
,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas 76504
,Division of Research and Education at Scott & White, Temple, Texas 76504
| | - Shannon Glaser
- Scott & White Digestive Disease Research Center, Temple, Texas 76504
,Department of Medicine, Division Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas 76504
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41
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42
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Hirschfield GM, Heathcote EJ, Gershwin ME. Pathogenesis of cholestatic liver disease and therapeutic approaches. Gastroenterology 2010; 139:1481-96. [PMID: 20849855 DOI: 10.1053/j.gastro.2010.09.004] [Citation(s) in RCA: 190] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 09/01/2010] [Accepted: 09/07/2010] [Indexed: 12/11/2022]
Abstract
Cholestatic liver disorders are caused by genetic defects, mechanical aberrations, toxins, or dysregulations in the immune system that damage the bile ducts and cause accumulation of bile and liver tissue damage. They have common clinical manifestations and pathogenic features that include the responses of cholangiocytes and hepatocytes to injury. We review the features of bile acid transport, tissue repair and regulation, apoptosis, vascular supply, immune regulation, and cholangiocytes that are associated with cholestatic liver disorders. We now have a greater understanding of the physiology of cholangiocytes at the cellular and molecular levels, as well as genetic factors, repair pathways, and autoimmunity mechanisms involved in the pathogenesis of disease. These discoveries will hopefully lead to new therapeutic approaches for patients with cholestatic liver disease.
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43
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Glaser S, Onori P, Gaudio E, Ueno Y, Pannarale L, Franchitto A, Francis H, Mancinelli R, Carpino G, Venter J, White M, Kopriva S, Vetuschi A, Sferra R, Alpini G. Taurocholic acid prevents biliary damage induced by hepatic artery ligation in cholestatic rats. Dig Liver Dis 2010; 42:709-17. [PMID: 20303838 PMCID: PMC2891101 DOI: 10.1016/j.dld.2010.02.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 02/05/2010] [Accepted: 02/11/2010] [Indexed: 12/11/2022]
Abstract
BACKGROUND Ischemic injury by hepatic artery ligation (HAL) during obstructive cholestasis induced by bile duct ligation (BDL) results in bile duct damage, which can be prevented by administration of VEGF-A. The potential regulation of VEGF and VEGF receptor expression and secretion by bile acids in BDL with HAL is unknown. AIMS We evaluated whether taurocholic acid (TC) can prevent HAL-induced cholangiocyte damage via the alteration of VEGFR-2 and/or VEGF-A expression. METHODS Utilizing BDL, BDL+TC, BDL+HAL, BDL+HAL+TC, and BDL+HAL+wortmannin+TC treated rats, we evaluated cholangiocyte apoptosis, proliferation, and secretion as well VEGF-A and VEGFR-2 expression by immunohistochemistry. In vitro, we evaluated the effects of TC on cholangiocyte secretion of VEGF-A and the dependence of TC-induced proliferation on the activity of VEGFR-2. RESULTS In BDL rats with HAL, chronic feeding of TC prevented HAL-induced loss of bile ducts and HAL-induced decreased cholangiocyte secretion. TC also prevented HAL-inhibited VEGF-A and VEGFR-2 expression in liver sections and HAL-induced circulating VEGF-A levels, which were blocked by wortmannin administration. In vitro, TC stimulated increased VEGF-A secretion by cholangiocytes, which was blocked by wortmannin and stimulated cholangiocyte proliferation that was blocked by VEGFR-2 kinase inhibitor. CONCLUSION TC prevented HAL-induced biliary damage by upregulation of VEGF-A expression.
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Affiliation(s)
- Shannon Glaser
- Scott & White Digestive Disease Research Center, Scott & White, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504,Department of Medicine, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504
| | - Paolo Onori
- Experimental Medicine, University of L'Aquila, L'Aquila, Italy
| | - Eugenio Gaudio
- Department of Human Anatomy, University of Rome “La Sapienza”, Rome, Italy
| | - Yoshiyuki Ueno
- Division of Gastroenterology, Tohoku University School of Med, Aobaku, Sendai, Japan
| | - Luigi Pannarale
- Department of Human Anatomy, University of Rome “La Sapienza”, Rome, Italy
| | - Antonio Franchitto
- Department of Human Anatomy, University of Rome “La Sapienza”, Rome, Italy
| | - Heather Francis
- Scott & White Digestive Disease Research Center, Scott & White, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504,Department of Medicine, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504,Division of Research and Education, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504
| | - Romina Mancinelli
- Department of Human Anatomy, University of Rome “La Sapienza”, Rome, Italy
| | | | - Julie Venter
- Scott & White Digestive Disease Research Center, Scott & White, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504,Department of Medicine, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504
| | - Mellanie White
- Scott & White Digestive Disease Research Center, Scott & White, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504,Department of Medicine, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504
| | - Shelley Kopriva
- Scott & White Digestive Disease Research Center, Scott & White, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504,Department of Medicine, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504
| | | | - Roberta Sferra
- Experimental Medicine, University of L'Aquila, L'Aquila, Italy
| | - Gianfranco Alpini
- Central Texas Veterans Health Care System, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, Scott & White Digestive Disease Research Center, Scott & White, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504,Department of Medicine, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX 76504
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44
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Tresguerres M, Buck J, Levin LR. Physiological carbon dioxide, bicarbonate, and pH sensing. Pflugers Arch 2010; 460:953-64. [PMID: 20683624 DOI: 10.1007/s00424-010-0865-6] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 07/16/2010] [Accepted: 07/18/2010] [Indexed: 12/20/2022]
Abstract
In biological systems, carbon dioxide exists in equilibrium with bicarbonate and protons. The individual components of this equilibrium (i.e., CO₂, HCO₃⁻, and H(+)), which must be sensed to be able to maintain cellular and organismal pH, also function as signals to modulate multiple physiological functions. Yet, the molecular sensors for CO₂/HCO₃⁻/pH remained unknown until recently. Here, we review recent progress in delineating molecular and cellular mechanisms for sensing CO₂, HCO₃⁻, and pH.
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Affiliation(s)
- Martin Tresguerres
- Department of Pharmacology, Weill Cornell Medical College, Cornell University, New York, USA
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45
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Glaser S, Onori P, Wise C, Yang F, Marzioni M, Alvaro D, Franchitto A, Mancinelli R, Alpini G, Munshi MK, Gaudio E. Recent advances in the regulation of cholangiocyte proliferation and function during extrahepatic cholestasis. Dig Liver Dis 2010; 42:245-52. [PMID: 20153989 PMCID: PMC2836402 DOI: 10.1016/j.dld.2010.01.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 01/08/2010] [Indexed: 12/11/2022]
Abstract
Bile duct epithelial cells (i.e., cholangiocytes), which line the intrahepatic biliary epithelium, are the target cells in a number of human cholestatic liver diseases (termed cholangiopathies). Cholangiocyte proliferation and death is present in virtually all human cholangiopathies. A number of recent studies have provided insights into the key mechanisms that regulate the proliferation and function of cholangiocytes during the pathogenesis of cholestatic liver diseases. In our review, we have summarised the most important of these recent studies over the past 3 years with a focus on those performed in the animal model of extrahepatic bile duct ligation. In the first part of the review, we provide relevant background on the biliary ductal system. We then proceed with a general discussion of the factors regulating biliary proliferation performed in the cholestatic animal model of bile duct ligation. Further characterisation of the factors that regulate cholangiocyte proliferation and function will help in elucidating the mechanisms regulating the pathogenesis of biliary tract diseases in humans and in devising new treatment approaches for these devastating diseases.
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Affiliation(s)
- S.S. Glaser
- Digestive Disease Research Center, Scott & White, TX, United States, Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX, United States,* Corresponding author at: Digestive Disease Research Center, Texas A&M Health Science Center, 702 SW H.K. Dodgen Loop, Temple, TX 76504, United States. Tel.: +1 254 742 7058; fax: +1 254 724 5944. ** Corresponding author at: Department of Human Anatomy, University of Rome “La Sapienza”, Via Alfonso Borelli 50 00161 Rome, Rome 00161, Italy. Tel.: +39 06 4991 8060; fax: +39 06 4991 8062
| | - P. Onori
- Department of Experimental Medicine, University of L'Aquila, L'Aquila, Italy
| | - C. Wise
- Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX, United States
| | - F. Yang
- Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX, United States, Shengjing Hospital, China Medical University, Shenyang City, Liaoning Province, China
| | - M. Marzioni
- Department of Gastroenterology, Universita' Politecnica delle Marche, Ancona, Italy
| | - D. Alvaro
- Gastroenterology, University of Rome “La Sapienza”, Rome, Italy
| | - A. Franchitto
- Department of Human Anatomy, University of Rome “La Sapienza”, Rome, Italy
| | - R. Mancinelli
- Department of Human Anatomy, University of Rome “La Sapienza”, Rome, Italy
| | - G. Alpini
- Digestive Disease Research Center, Scott & White, TX, United States, Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX, United States, Central Texas Veterans Health Care System, Temple, TX, United States
| | - Md. K. Munshi
- Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, Temple, TX, United States
| | - E. Gaudio
- Department of Human Anatomy, University of Rome “La Sapienza”, Rome, Italy,* Corresponding author at: Digestive Disease Research Center, Texas A&M Health Science Center, 702 SW H.K. Dodgen Loop, Temple, TX 76504, United States. Tel.: +1 254 742 7058; fax: +1 254 724 5944. ** Corresponding author at: Department of Human Anatomy, University of Rome “La Sapienza”, Via Alfonso Borelli 50 00161 Rome, Rome 00161, Italy. Tel.: +39 06 4991 8060; fax: +39 06 4991 8062
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46
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Mancinelli R, Franchitto A, Gaudio E, Onori P, Glaser S, Francis H, Venter J, Demorrow S, Carpino G, Kopriva S, White M, Fava G, Alvaro D, Alpini G. After damage of large bile ducts by gamma-aminobutyric acid, small ducts replenish the biliary tree by amplification of calcium-dependent signaling and de novo acquisition of large cholangiocyte phenotypes. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 176:1790-800. [PMID: 20185575 DOI: 10.2353/ajpath.2010.090677] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Large cholangiocytes secrete bicarbonate in response to secretin and proliferate after bile duct ligation by activation of cyclic adenosine 3', 5'-monophosphate signaling. The Ca(2+)-dependent adenylyl cyclase 8 (AC8, expressed by large cholangiocytes) regulates secretin-induced choleresis. Ca(2+)-dependent protein kinase C (PKC) regulates small cholangiocyte function. Because gamma-aminobutyric acid (GABA) affects cell functions by activation of both Ca(2+) 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: GABA(A), GABA(B), and GABA(C) 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 Ca(2+-)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 PKCbetaII; and (iii) de novo expressed secretin receptor, cystic fibrosis transmembrane regulator, Cl(-)/HCO(3)(-) anion exchanger 2 and AC8, and responded to secretin. Therefore, in pathologies of large ducts, small ducts replenish the biliary epithelium by amplification of Ca(2+)-dependent signaling and acquisition of large cholangiocyte phenotypes.
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Affiliation(s)
- Romina Mancinelli
- Texas A & M Health Science Center, Medical Research Building, Temple, TX 76504, USA
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Choi LJ, Jenikova G, Hanson E, Spehlmann ME, Boehling NS, Kirstein SL, Bundey RA, Smith JR, Insel PA, Eckmann L. Coordinate down-regulation of adenylyl cyclase isoforms and the stimulatory G protein (G(s)) in intestinal epithelial cell differentiation. J Biol Chem 2010; 285:12504-11. [PMID: 20157112 DOI: 10.1074/jbc.m109.059741] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The intestinal epithelium is dynamic, with proliferation of undifferentiated crypt cells balanced by terminal differentiation and cell death at the colon surface or small intestinal villus tips. Cyclic AMP, induced by agonists such as prostaglandin E(2) and vasoactive intestinal polypeptide, promotes proliferation and ion secretion and suppresses apoptosis in intestinal epithelial cells. Here, we show that cell differentiation in a model intestinal epithelium leads to attenuation of cAMP production in response to G protein-coupled receptor and receptor-independent agonists. Concomitantly, key components of the cAMP cascade, the alpha subunit of the stimulatory G protein, G(s), and adenylyl cyclase (AC) isoforms 3, 4, 6, and 7 are down-regulated. By contrast, AC1, AC2, AC8, and AC9, and the receptors for prostaglandin E(2) and vasoactive intestinal polypeptide, are not expressed or not affected by differentiation. We confirmed key findings in normal murine colon epithelium, in which the major AC isoforms and G(s)alpha are markedly down-regulated in differentiated surface cells. Suppression of AC isoforms and G(s)alpha is functionally important, because their constitutive expression completely reverses differentiation-induced cAMP attenuation. Thus, down-regulation of AC isoforms and G(s)alpha is an integral part of the intestinal epithelial differentiation program, perhaps serving to release cells from cAMP-promoted anti-apoptosis as a prerequisite for cell death upon terminal differentiation.
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Affiliation(s)
- Lillian J Choi
- Department of Medicine, University of California, San Diego, La Jolla, California 92093, USA
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