1
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Pinho RM, Garas LC, Huang BC, Weimer BC, Maga EA. Malnourishment affects gene expression along the length of the small intestine. Front Nutr 2022; 9:894640. [PMID: 36118759 PMCID: PMC9478944 DOI: 10.3389/fnut.2022.894640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
Malnourishment is a risk factor for childhood mortality, jeopardizing the health of children by aggravating pneumonia/acute respiratory infections and diarrheal diseases. Malnourishment causes morphophysiological changes resulting in stunting and wasting that have long-lasting consequences such as cognitive deficit and metabolic dysfunction. Using a pig model of malnutrition, the interplay between the phenotypic data displayed by the malnourished animals, the gene expression pattern along the intestinal tract, microbiota composition of the intestinal contents, and hepatic metabolite concentrations from the same animals were correlated using a multi-omics approach. Samples from the duodenum, jejunum, and ileum of malnourished (protein and calorie-restricted diet) and full-fed (no dietary restrictions) piglets were subjected to RNA-seq. Gene co-expression analysis and phenotypic correlations were made with WGCNA, while the integration of transcriptome with microbiota composition and the hepatic metabolite profile was done using mixOmics. Malnourishment caused changes in tissue gene expression that influenced energetic balance, cell proliferation, nutrient absorption, and response to stress. Repression of antioxidant genes, including glutathione peroxidase, in coordination with induction of metal ion transporters corresponded to the hepatic metabolite changes. These data indicate oxidative stress in the intestine of malnourished animals. Furthermore, several of the phenotypes displayed by these animals could be explained by changes in gene expression.
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Affiliation(s)
- Raquel M. Pinho
- Department of Animal Science, University of California, Davis, Davis, CA, United States
- *Correspondence: Raquel M. Pinho
| | - Lydia C. Garas
- Department of Animal Science, University of California, Davis, Davis, CA, United States
| | - B. Carol Huang
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Bart C. Weimer
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Elizabeth A. Maga
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
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2
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Sarvestani SK, Signs S, Hu B, Yeu Y, Feng H, Ni Y, Hill DR, Fisher RC, Ferrandon S, DeHaan RK, Stiene J, Cruise M, Hwang TH, Shen X, Spence JR, Huang EH. Induced organoids derived from patients with ulcerative colitis recapitulate colitic reactivity. Nat Commun 2021; 12:262. [PMID: 33431859 PMCID: PMC7801686 DOI: 10.1038/s41467-020-20351-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/30/2020] [Indexed: 02/08/2023] Open
Abstract
The pathogenesis of ulcerative colitis (UC), a major type of inflammatory bowel disease, remains unknown. No model exists that adequately recapitulates the complexity of clinical UC. Here, we take advantage of induced pluripotent stem cells (iPSCs) to develop an induced human UC-derived organoid (iHUCO) model and compared it with the induced human normal organoid model (iHNO). Notably, iHUCOs recapitulated histological and functional features of primary colitic tissues, including the absence of acidic mucus secretion and aberrant adherens junctions in the epithelial barrier both in vitro and in vivo. We demonstrate that the CXCL8/CXCR1 axis was overexpressed in iHUCO but not in iHNO. As proof-of-principle, we show that inhibition of CXCL8 receptor by the small-molecule non-competitive inhibitor repertaxin attenuated the progression of UC phenotypes in vitro and in vivo. This patient-derived organoid model, containing both epithelial and stromal compartments, will generate new insights into the underlying pathogenesis of UC while offering opportunities to tailor interventions to the individual patient.
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Affiliation(s)
- Samaneh K Sarvestani
- Department of Cancer Biology, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Steven Signs
- Department of Cancer Biology, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Bo Hu
- Department of Quantitative Health Sciences, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Yunku Yeu
- Department of Quantitative Health Sciences, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Hao Feng
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Ying Ni
- Department of Quantitative Health Sciences, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - David R Hill
- Department of Internal Medicine, Gastroenterology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Robert C Fisher
- Department of Cancer Biology, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Sylvain Ferrandon
- Department of Cancer Biology, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Reece K DeHaan
- Department of Colorectal Surgery, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Jennifer Stiene
- Department of Cancer Biology, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Michael Cruise
- Department of Pathology, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Tae Hyun Hwang
- Department of Quantitative Health Sciences, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Xiling Shen
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
| | - Jason R Spence
- Department of Internal Medicine, Gastroenterology, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Emina H Huang
- Department of Cancer Biology, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA.
- Department of Colorectal Surgery, Cleveland Clinic, Cleveland, OH, 44195, USA.
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3
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Deletion of SOCS2 Reduces Post-Colitis Fibrosis via Alteration of the TGFβ Pathway. Int J Mol Sci 2020; 21:ijms21093073. [PMID: 32349250 PMCID: PMC7246483 DOI: 10.3390/ijms21093073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 03/31/2020] [Accepted: 04/05/2020] [Indexed: 12/31/2022] Open
Abstract
Inflammatory bowel disease (IBD) is an immunologically mediated chronic intestinal disorder. Growth hormone (GH) administration enhances mucosal repair and decreases intestinal fibrosis in patients with IBD. In the present study, we investigated the effect of cellular sensitivity to GH via suppressor of cytokine signaling 2 (SOCS2) deletion on colitis and recovery. To induce colitis, wild type and SOCS2 knockout (SOCS2−/−) mice were treated with 3% dextran sodium sulphate (DSS), followed by a recovery period. SOCS2−/− mice showed higher disease activity during colitis with increased mRNA expression of the pro-inflammatory cytokines nitric oxide synthase 2 (NOS2) and interleukin 1 β (IL1-β). At recovery time point, SOCS2−/− showed better recovery with less fibrosis measured by levels of α-SMA and collagen deposition. Protein and mRNA expressions of transforming growth factor beta β1 (TGF-β1) receptors were significantly lower in SOCS2−/− mice compared to wild-type littermates. Using an in vivo bromodeoxyuridine (BrdU) proliferation assay, SOCS2−/− mice showed higher intestinal epithelial proliferation compared to wild-type mice. Our results demonstrated that deletion of the SOCS2 protein results in higher growth hormone sensitivity associated with higher pro-inflammatory signaling; however, it resulted in less tissue damage with less fibrotic lesions and higher epithelial proliferation, which are markers of GH-protective effects in IBD. This suggests a pleiotropic effect of SOCS2 and multiple cellular targets. Further study is required to study role of SOCS2 in regulation of TGFβ-mothers against the decapentaplegic homolog (Smad) pathway.
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Schmiedlin-Ren P, Reingold LJ, Broxson CS, Rittershaus AC, Brudi JS, Adler J, Owens SR, Zimmermann EM. Anti-TNFα alters the natural history of experimental Crohn's disease in rats when begun early, but not late, in disease. Am J Physiol Gastrointest Liver Physiol 2016; 311:G688-G698. [PMID: 27562059 PMCID: PMC5142192 DOI: 10.1152/ajpgi.00216.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 08/16/2016] [Indexed: 02/06/2023]
Abstract
Anti-TNFα therapy decreases inflammation in Crohn's disease (CD). However, its ability to decrease fibrosis and alter the natural history of CD is not established. Anti-TNF-α prevents inflammation and fibrosis in the peptidoglycan-polysaccharide (PG-PS) model of CD. Here we studied anti-TNF-α in a treatment paradigm. PG-PS or human serum albumin (HSA; control) was injected into bowel wall of anesthetized Lewis rats at laparotomy. Mouse anti-mouse TNF-α or vehicle treatment was begun day (d)1, d7, or d14 postlaparotomy. Rats were euthanized d21-23. Gross abdominal and histologic findings were scored. Cecal levels of relevant mRNAs were measured by quantitative real-time PCR. There was a stepwise loss of responsiveness when anti-TNFα was begun on d7 and d14 compared with d1 that was seen in the percent decrease in the median gross abdominal score and histologic inflammation score in PG-PS-injected rats [as %decrease; gross abdominal score: d1 = 75% (P = 0.003), d7 = 57% (P = 0.18), d14 = no change (P = 0.99); histologic inflammation: d1 = 57% (P = 0.006), d7 = 50% (P = 0.019), d14 = no change (P = 0.99)]. This was also reflected in changes in IL-1β, IL-6, TNF-α, IGF-I, TGF-β1, procollagen I, and procollagen III mRNAs that were decreased or trended downward in PG-PS-injected animals given anti-TNF-α beginning d1 or d7 compared with vehicle-treated rats; there was no effect if anti-TNF-α was begun d14. This change in responsiveness to anti-TNFα therapy was coincident with a major shift in the cytokine milieu observed on d14 in the PG-PS injected rats (vehicle treated). Our data are consistent with the clinical observation that improved outcomes occur when anti-TNF-α therapy is initiated early in the course of CD.
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Affiliation(s)
- Phyllissa Schmiedlin-Ren
- 1Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan;
| | - Laura J. Reingold
- 1Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan;
| | - Christopher S. Broxson
- 4Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, University of Florida Health System, Gainesville, Florida
| | - Ahren C. Rittershaus
- 2Department of Pathology, University of Michigan Health System, Ann Arbor, Michigan;
| | - Josh S. Brudi
- 1Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan;
| | - Jeremy Adler
- 3Division of Gastroenterology, Department of Pediatrics and Communicable Diseases, University of Michigan Health System, Ann Arbor, Michigan; and
| | - Scott R. Owens
- 2Department of Pathology, University of Michigan Health System, Ann Arbor, Michigan;
| | - Ellen M. Zimmermann
- 1Division of Gastroenterology, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan; ,4Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, University of Florida Health System, Gainesville, Florida
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5
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Moxibustion Inhibits the ERK Signaling Pathway and Intestinal Fibrosis in Rats with Crohn's Disease. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:198282. [PMID: 23970928 PMCID: PMC3736408 DOI: 10.1155/2013/198282] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 07/02/2013] [Indexed: 12/12/2022]
Abstract
Intestinal fibrosis is the main pathological process in Crohn's disease (CD); acupuncture and moxibustion can inhibit the process of fibrosis in CD rats, but the regulatory mechanism remains unknown. The present study observed the effect of moxibustion on the extracellular signal-regulated kinase (ERK) signaling pathway in the CD rat. The result shows that the phosphorylation of the Ras, Raf-1, MEK-1, and ERK-1/2 proteins and the expression of the corresponding mRNAs in the colon tissue of CD rat were significantly higher than the normal control group. Both treatments with mild moxibustion and with herb-separated moxibustion significantly reduced the expression of the Ras, Raf-1, MEK-1, and ERK-1/2 proteins and Ras and Raf-1 mRNA. MEK-1 and ERK-1/2 mRNA expression in each treatment group showed a downward trend, and the ERK-1/2 mRNA levels were significantly lower in the mild moxibustion group. It indicates that Ras, Raf-1, MEK-1, and ERK-1/2 are involved in the process of intestinal fibrosis in CD rats. Moxibustion can downregulate the abnormal expression of colonic Ras, Raf-1, MEK-1, and ERK-1/2 protein and mRNA levels in CD intestinal fibrosis in rats. Moxibustion may play a role in the treatment of CD intestinal fibrosis by regulating ERK signaling pathway.
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6
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Veraldi KL, Feghali-Bostwick CA. Insulin-like growth factor binding proteins-3 and -5: central mediators of fibrosis and promising new therapeutic targets. Open Rheumatol J 2012; 6:140-5. [PMID: 22802912 PMCID: PMC3395973 DOI: 10.2174/1874312901206010140] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2012] [Revised: 03/27/2012] [Accepted: 04/04/2012] [Indexed: 12/22/2022] Open
Abstract
Fibrosis involves an orchestrated cascade of events including activation of fibroblasts, increased production and deposition of extracellular matrix components, and differentiation of fibroblasts into myofibroblasts. Epithelial-mesenchymal cross-talk plays an important role in this process, and current hypotheses of organ fibrosis liken it to an aberrant wound healing response in which epithelial-mesenchymal transition (EMT) and cellular senescence may also contribute to disease pathogenesis. The fibrotic response is associated with altered expression of growth factors and cytokines, including increased levels of transforming growth factor-β1 (TGF-β1) and the more recent observation that increased levels of several insulin-like growth factor binding proteins (IGFBPs) are associated with a number of fibrotic conditions. IGFBPs have been implicated in virtually every cell type and process associated with the fibrotic response, making the IGFBPs attractive targets for the development of novel anti-fibrotic therapies. In this review, the current state of knowledge regarding the classical IGFBP family in organ fibrosis will be summarized and the clinical implications considered.
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Affiliation(s)
- Kristen L Veraldi
- The Division of Pulmonary, Allergy, and Critical Care Medicine, and Pittsburgh Scleroderma Center, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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7
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Murali SG, Brinkman AS, Solverson P, Pun W, Pintar JE, Ney DM. Exogenous GLP-2 and IGF-I induce a differential intestinal response in IGF binding protein-3 and -5 double knockout mice. Am J Physiol Gastrointest Liver Physiol 2012; 302:G794-804. [PMID: 22281475 PMCID: PMC3355561 DOI: 10.1152/ajpgi.00372.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glucagon-like peptide-2 (GLP-2) action is dependent on intestinal expression of IGF-I, and IGF-I action is modulated by IGF binding proteins (IGFBP). Our objective was to evaluate whether the intestinal response to GLP-2 or IGF-I is dependent on expression of IGFBP-3 and -5. Male, adult mice in six treatment groups, three wild-type (WT) and three double IGFBP-3/-5 knockout (KO), received twice daily intraperitoneal injections of GLP-2 (0.5 μg/g body wt), IGF-I (4 μg/g body wt), or PBS (vehicle) for 7 days. IGFBP-3/-5 KO mice showed a phenotype of lower plasma IGF-I concentration, but greater body weight and relative mass of visceral organs, compared with WT mice (P < 0.001). WT mice showed jejunal growth with either IGF-I or GLP-2 treatment. In KO mice, IGF-I did not stimulate jejunal growth, crypt mitosis, sucrase activity, and IGF-I receptor (IGF-IR) expression, suggesting that the intestinotrophic actions of IGF-I are dependent on expression of IGFBP-3 and -5. In KO mice, GLP-2 induced significant increases in jejunal mucosal cellularity, crypt mitosis, villus height, and crypt depth that was associated with increased expression of the ErbB ligand epiregulin and decreased expression of IGF-I and IGF-IR. This suggests that in KO mice, GLP-2 action in jejunal mucosa is independent of the IGF-I system and linked with ErbB ligands. In summary, the intestinotrophic actions of IGF-I, but not GLP-2, in mucosa are dependent on IGFBP-3 and -5. These findings support the role of multiple downstream mediators for the mucosal growth induced by GLP-2.
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Affiliation(s)
| | - Adam S. Brinkman
- Departments of 1Nutritional Sciences and ,2Surgery, School of Medicine and Public Health, University
of Wisconsin-Madison, Madison, Wisconsin;
| | | | - Wing Pun
- Departments of 1Nutritional Sciences and
| | - John E. Pintar
- 3Department of Neuroscience and Cell Biology, Robert Wood
Johnson Medical School, University of Medicine and Dentistry of New Jersey,
Piscataway, New Jersey
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8
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Garcia P, Schmiedlin-Ren P, Mathias JS, Tang H, Christman GM, Zimmermann EM. Resveratrol causes cell cycle arrest, decreased collagen synthesis, and apoptosis in rat intestinal smooth muscle cells. Am J Physiol Gastrointest Liver Physiol 2012; 302:G326-35. [PMID: 22052016 PMCID: PMC3287405 DOI: 10.1152/ajpgi.00083.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
One of the most difficult and treatment-resistant complications of Crohn's disease is the development of fibrotic intestinal strictures due to mesenchymal cell hyperplasia and collagen deposition. Resveratrol, a phytoalexin found in berries, peanuts, grapes, and red wine, has been shown to inhibit fibrosis in vasculature, heart, lung, kidney, liver, and esophagus in animal models. Resveratrol has also been shown to inhibit oxidation, inflammation, and cell proliferation and to decrease collagen synthesis in several cell types or animal models. The aim of this study was to determine whether resveratrol has antifibrotic effects on intestinal smooth muscle cells. Responses to resveratrol by cultured smooth muscle cells isolated from colons of untreated Lewis rats were examined; this rat strain is used in a model of Crohn's disease with prominent intestinal fibrosis. A relative decrease in cell numbers following treatment with 50 and 100 μM resveratrol was evident at 24 h (P ≤ 0.005). This effect was largely due to cell cycle arrest, with an increase in the percent of cells in S phase from 8 to 25-35% (P < 0.05). Cell viability was unchanged until 2-3 days of treatment when there was a 1.2- to 5.0-fold increase in the percent of apoptotic cells, depending on the assay (P < 0.05). Expression of collagen type I protein was decreased following treatment with resveratrol for 24 h (to 44 and 25% of control levels with 50 and 100 μM resveratrol, respectively; P < 0.05). Expression of procollagen types I and III mRNA was also decreased with resveratrol treatment. Resveratrol (50 μM) diminished the proliferative response to TGF-β₁ (P = 0.02) as well as IGF-I-stimulated collagen production (P = 0.02). Thus resveratrol decreases intestinal smooth muscle cell numbers through its effects on cell cycle arrest and apoptosis and also decreases collagen synthesis by the cells. These effects could be useful in preventing the smooth muscle cell hyperplasia and collagen deposition that characterize stricture formation in Crohn's disease.
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Affiliation(s)
- Patricia Garcia
- 1Division of Gastroenterology, Department of Internal Medicine and
| | | | - Jason S. Mathias
- 1Division of Gastroenterology, Department of Internal Medicine and
| | - Huaijing Tang
- 2Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan
| | - Gregory M. Christman
- 2Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan
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von der Thüsen JH, Borensztajn KS, Moimas S, van Heiningen S, Teeling P, van Berkel TJC, Biessen EAL. IGF-1 has plaque-stabilizing effects in atherosclerosis by altering vascular smooth muscle cell phenotype. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:924-34. [PMID: 21281823 DOI: 10.1016/j.ajpath.2010.10.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Revised: 09/30/2010] [Accepted: 10/19/2010] [Indexed: 01/17/2023]
Abstract
Insulin-like growth factor-1 (IGF-1) signaling is important for the maintenance of plaque stability in atherosclerosis due to its effects on vascular smooth muscle cell (vSMC) phenotype. To investigate this hypothesis, we studied the effects of the highly inflammatory milieu of the atherosclerotic plaque on IGF-1 signaling and stability-related phenotypic parameters of murine vSMCs in vitro, and the effects of IGF-1 supplementation on plaque phenotype in an atherosclerotic mouse model. M1-polarized, macrophage-conditioned medium inhibited IGF-1 signaling by ablating IGF-1 and increasing IGF-binding protein 3, increased vSMC apoptosis, and decreased proliferation. Expression of α-actin and col3a1 genes was strongly attenuated by macrophage-conditioned medium, whereas expression of matrix-degrading enzymes was increased. Importantly, all of these effects could be corrected by supplementation with IGF-1. In vivo, treatment with the stable IGF-1 analog Long R3 IGF-1 in apolipoprotein E knockout mice reduced stenosis and core size, and doubled cap/core ratio in early atherosclerosis. In advanced plaques, Long R3 IGF-1 increased the vSMC content of the plaque by more than twofold and significantly reduced the rate of intraplaque hemorrhage. We believe that IGF-1 in atherosclerotic plaques may have a role in preventing plaque instability, not only by modulating smooth muscle cell turnover, but also by altering smooth muscle cell phenotype.
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Affiliation(s)
- Jan H von der Thüsen
- Department of Histopathology, Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom.
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10
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Flynn RS, Mahavadi S, Murthy KS, Kellum JM, Kuemmerle JF. Insulin-like growth factor-binding protein-5 stimulates growth of human intestinal muscle cells by activation of G{alpha}i3. Am J Physiol Gastrointest Liver Physiol 2009; 297:G1232-8. [PMID: 19808657 PMCID: PMC2850095 DOI: 10.1152/ajpgi.00323.2009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In human intestinal smooth muscle cells, endogenous insulin-like growth factor-I (IGF-I) regulates growth and IGF-binding protein-5 (IGFBP-5) expression. The effects of IGF-I are facilitated by IGFBP-5. We previously showed that IGFBP-5 acts independently of IGF-I in human intestinal muscle to stimulate proliferation and upregulate IGF-I production by activation of Erk1/2 and p38 MAPK. Thus a positive feedback loop exists between IGF-I and IGFBP-5, whereby both stimulate muscle growth and production of the other factor. In Crohn's disease, IGF-I and IGFBP-5 expression are increased and contribute to stricture formation through this effect on muscle growth. To determine the signaling pathways coupling IGFBP-5 to MAPK activation and growth, smooth muscle cells were isolated from muscularis propria of human intestine and placed into primary culture. Erk1/2 and p38 MAPK activation and type I collagen production were measured by immunoblot. Proliferation was measured by [(3)H]thymidine incorporation. Activation of specific G proteins was measured by ELISA. AG1024, an IGF-I receptor tyrosine kinase inhibitor, was used to isolate the IGF-I-independent effects of IGFBP-5. IGFBP-5-induced phosphorylation of Erk1/2 and p38 MAPK and proliferation were abolished by pertussis toxin, implying the participation of Gi. IGFBP-5 specifically activated Gi3 but not other G proteins. Transfection of an inhibitory Galphai minigene specifically inhibited MAPK activation, proliferation, and both collagen-I and IGF-I production. Our results indicate that endogenous IGFBP-5 activates Gi3 and regulates smooth muscle growth, IGF-I production, and collagen production via the alpha-subunit of Gi3, independently of IGF-I, in normal human intestinal muscle cells.
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Affiliation(s)
| | | | | | - John M. Kellum
- 3Surgery, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
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11
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Hazelgrove KB, Flynn RS, Qiao LY, Grider JR, Kuemmerle JF. Endogenous IGF-I and alpha v beta3 integrin ligands regulate increased smooth muscle growth in TNBS-induced colitis. Am J Physiol Gastrointest Liver Physiol 2009; 296:G1230-7. [PMID: 19359426 PMCID: PMC2697946 DOI: 10.1152/ajpgi.90508.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Endogenous insulin-like growth factor-I (IGF-I) regulates intestinal smooth muscle growth by concomitantly stimulating proliferation and inhibiting apoptosis. IGF-I-stimulated growth is augmented by the alpha(v)beta(3) integrin ligands vitronectin and fibronectin. IGF-I expression in smooth muscle is increased in both TNBS-induced colitis and Crohn's disease. We hypothesized that intestinal inflammation increased vitronectin and fibronectin expression by smooth muscle and, along with IGF-I upregulation, increased intestinal muscle growth. Intestinal smooth muscle cells were examined 7 days following the induction of TNBS-induced colitis. Although alpha(v)beta(3) integrin expression was not altered by TNBS-induced colitis, vitronectin and fibronectin levels were increased by 80 +/- 10% and 90 +/- 15%, above control levels, respectively. Basal IGF-I receptor phosphorylation in inflamed muscle from TNBS-treated rats was increased by 86 +/- 8% over vehicle-treated controls. Basal ERK1/2, p70S6 kinase, and GSK-3beta phosphorylation in muscle cells of TNBS-treated rats were also increased by 140-180%. TNBS treatment increased basal muscle cell proliferation by 130 +/- 15% and decreased apoptosis by 20 +/- 2% compared with that in vehicle-treated controls. The changes in proliferation and apoptosis were reversed by an IGF-I receptor tyrosine kinase inhibitor or an alpha(v)beta(3) integrin antagonist. The results suggest that smooth muscle hyperplasia in TNBS-induced colitis partly results from the upregulation of endogenous IGF-I and ligands of alpha(v)beta(3) integrin that mediate increased smooth muscle cell proliferation and decreased apoptosis. This paper has identified one mechanism regulating smooth muscle hyperplasia, a feature of stricture formation that occurs in the chronically inflamed intestine of TNBS-induced colitis and potentially Crohn's disease.
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Affiliation(s)
- Krystina B. Hazelgrove
- Departments of Medicine and Physiology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - Robert S. Flynn
- Departments of Medicine and Physiology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - Li-Ya Qiao
- Departments of Medicine and Physiology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - John R. Grider
- Departments of Medicine and Physiology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - John F. Kuemmerle
- Departments of Medicine and Physiology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
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12
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Pereira-Fantini PM, Thomas SL, Taylor RG, Nagy E, Sourial M, Fuller PJ, Bines JE. Colostrum supplementation restores insulin-like growth factor -1 levels and alters muscle morphology following massive small bowel resection. JPEN J Parenter Enteral Nutr 2008; 32:266-75. [PMID: 18443138 DOI: 10.1177/0148607108316197] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Colostrum protein concentrate (CPC) contains a high level of insulin-like growth factor-1 (IGF-1). IGF-1 and IGF binding protein (IGFBPs) may play an important role during the postresection adaptation response. As smooth muscle is an important site for IGF-1 action in the intestine, this study aims to (1) investigate the effect of CPC supplementation on circulating levels and tissue expression of IGF-1, IGF-1 receptor, and IGFBPs following massive small bowel resection (MSBR), and (2) characterize the effect of CPC on the muscular adaptation response following MSBR. METHODS Four-week-old piglets underwent either a 75% MSBR or sham operation. Piglets received either a polymeric infant formula (PIF) diet or PIF supplemented with CPC for 8 weeks. Serum was analyzed by enzyme-linked immunosorbent assay, and ileal tissue assessed by molecular and histological analysis. RESULTS There was no difference in IGF-1 or IGFBPs mRNA among groups. CPC treatment resulted in significant increases in circulating levels of IGF-1 and IGFBPs and a concurrent increase in muscle width and the number of muscle cells, but did not alter muscle cell size. CONCLUSIONS Strategies aimed at increasing muscular adaptation may decrease Gl transit and allow greater mucosal contact time for absorption. We have shown that CPC supplementation following resection results in increased levels of circulating IGF-1, IGFBP-2, and IGFBP-3 and muscular hypertrophy. Our results suggest that IGF-1 and its mediators may play a role in the muscular adaptation response and warrant further exploration as a treatment option for short bowel syndrome.
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Affiliation(s)
- Prue M Pereira-Fantini
- Intestinal Failure and Clinical Nutrition Group, Murdoch Childrens Research Institute, Atlantic Philanthropy Building, Flemington Road, Parkville 3052, Victoria, Australia.
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13
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Simmons JG, Ling Y, Wilkins H, Fuller CR, D’Ercole AJ, Fagin J, Lund PK. Cell-specific effects of insulin receptor substrate-1 deficiency on normal and IGF-I-mediated colon growth. Am J Physiol Gastrointest Liver Physiol 2007; 293:G995-1003. [PMID: 17823215 PMCID: PMC2267759 DOI: 10.1152/ajpgi.00537.2006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Insulin-like growth factor I (IGF-I) potently stimulates intestinal growth. Insulin receptor substrate-1 (IRS-1) mediates proliferative and antiapoptotic actions of IGF-I in cell lines, but its in vivo relevance in intestine is not defined. This study tested the hypothesis that there is cell type-specific dependence on IRS-1 as a mediator of IGF-I action. Length, mass, crypt cell proliferation, and apoptosis were measured in small intestine and colon of IRS-1-null mice and wild-type (WT) littermates and in colon of IRS-1-null or WT mice expressing IGF-I transgenes. Expression of IGF-I receptor and signaling intermediates was examined in intestine of WT and IRS-1-null mice, cultured intestinal epithelial cells, and myofibroblasts. Absolute IRS-1 deficiency reduced mucosal mass in jejunum and colon, but effects were more pronounced in colon. Muscularis mass was decreased in both segments. In IGF-I transgenics, IRS-1 deficiency significantly attenuated IGF-I-stimulated growth of colonic mucosa and abolished antiapoptotic but not mitogenic effects of IGF-I transgene on crypt cells. IGF-I-induced muscularis growth was unaffected by IRS-1 deficiency. In intestinal epithelial cells, IRS-1 was expressed at higher levels than IRS-2 and was preferentially activated by IGF-I. In contrast, IGF-I activated both IRS-1 and IRS-2 in intestinal myofibroblasts and IRS-2 activation was upregulated in IRS-1-null myofibroblasts. We conclude that the intestinal epithelium but not the muscularis requires IRS-1 for normal trophic actions of IGF-I and that IRS-1 is required for antiapoptotic but not mitogenic effects of IGF-I in the intestinal crypts in vivo.
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Affiliation(s)
- J. G. Simmons
- Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Y. Ling
- Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - H. Wilkins
- Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - C. R. Fuller
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - A. J. D’Ercole
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - James Fagin
- Department of Medicine, University of Cincinnati, Cincinnati, Ohio
| | - P. K. Lund
- Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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14
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Murali SG, Liu X, Nelson DW, Hull AK, Grahn M, Clayton MK, Pintar JE, Ney DM. Intestinotrophic effects of exogenous IGF-I are not diminished in IGF binding protein-5 knockout mice. Am J Physiol Regul Integr Comp Physiol 2007; 292:R2144-50. [PMID: 17332154 DOI: 10.1152/ajpregu.00903.2006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
IGF binding protein-5 (IGFBP-5) modulates the availability of IGF-I to its receptor and potentiates the intestinotrophic action of IGF-I. Our aim was to test the hypothesis that stimulation of intestinal growth due to coinfusion of IGF-I with total parenteral nutrition (TPN) solution is dependent on increased expression of IGFBP-5 through conducting our studies in IGFBP-5 knockout (KO) mice. IGFBP-5 KO, heterozygote (HT) and wild type (WT) male and female mice were maintained with TPN or TPN plus coinfusion of IGF-I [recombinant human (rh)IGF-I; 2.5 mg x kg(-1) x day(-1)] for 5 days. The concentration of IGF-I in serum was 73% greater (P < 0.0001) in mice given TPN + IGF-I infusion compared with TPN alone. IGF-I attenuated the 2-3 g loss of body weight associated with TPN in WT mice, whereas KO and HT mice did not show improvement in body weight with IGF-I treatment. KO and HT mice had significantly greater levels of circulating IGF-I binding proteins (IGFBPs) compared with WT mice. Intestinal growth due to IGF-I was observed in all groups treated with IGF-I based on greater concentrations of protein and DNA in small intestine and colon and significantly greater crypt depth and muscularis thickness in jejunum. Jejunal expression of IGFBP-5 mRNA was greater in WT mice, whereas IGFBP-3 mRNA was greater in KO mice treated with IGF-I. In summary, the absence of the IGFBP-5 gene did not block the ability of IGF-I to stimulate intestinal growth, possibly because greater jejunal expression of IGFBP-3 compensates for the absence of IGFBP-5.
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Affiliation(s)
- Sangita G Murali
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsinn 53706, USA
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15
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Sorrentino D, Avellini C, Beltrami CA, Pasqual E, Zearo E. Selective effect of infliximab on the inflammatory component of a colonic stricture in Crohn's disease. Int J Colorectal Dis 2006; 21:276-81. [PMID: 15951989 DOI: 10.1007/s00384-005-0739-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/04/2005] [Indexed: 02/04/2023]
Abstract
Although infliximab has been shown to improve the clinical course of Crohn's disease, its effect on intestinal strictures is controversial. We describe the case of a woman with steroid-resistant colonic Crohn's disease presenting with intermittent obstruction because of a tight stricture in the splenic flexure. Compared with uninvolved areas, biopsies showed intense edema and inflammatory cell infiltration and immunohistochemistry revealed an excess of TNF-alpha. Her symptoms responded promptly (CDAI went from 444 to 168) to an infliximab infusion (10 mg kg(-1) BW), which also had a dramatic effect on the stricture, now presenting radiologically as a moderate residual, apparently fibrotic, narrowing of the lumen. Endoscopy and histology confirmed the resolution of inflammation and TNF-alpha virtually disappeared. The patient refused additional infusions and after a few months the disease recurred with features identical to the pre-treatment phase. She then opted for surgery. Histology of the resected strictured colon revealed edema, inflammation, and fibrosis, with TNF-alpha back to pre-treatment levels. This case indicates that, in the colon, infliximab specifically relieves the TNF-alpha-mediated inflammatory component of the stricture while having no effect on fibrosis and suggests that the response to infliximab treatment may depend on the nature of the, stricture itself.
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Affiliation(s)
- Dario Sorrentino
- G.I. Unit, Internal Medicine of the Department of Clinical and Experimental Pathology, University of Udine School of Medicine, Udine, Italy.
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16
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Fruchtman S, Simmons JG, Michaylira CZ, Miller ME, Greenhalgh CJ, Ney DM, Lund PK. Suppressor of cytokine signaling-2 modulates the fibrogenic actions of GH and IGF-I in intestinal mesenchymal cells. Am J Physiol Gastrointest Liver Physiol 2005; 289:G342-50. [PMID: 15831713 DOI: 10.1152/ajpgi.00413.2004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Growth hormone (GH) and IGF-I play important roles in wound healing during intestinal injury and inflammation, but there is also indirect evidence that locally expressed IGF-I may act to induce excessive collagen deposition, which can lead to intestinal fibrosis. Factors that dictate the balance between normal wound healing and excessive healing responses are unknown. Using RNase protection assay and in situ hybridization, we determined whether GH and/or IGF-I increase type I collagen deposition in the intestine of rats fed by total parenteral nutrition (TPN), a feeding modality used for many patients following intestinal surgery and resection. We also used an in vitro model system to confirm our in vivo effects and to directly evaluate the relative potency of GH and IGF-I on DNA synthesis and collagen deposition in intestinal myofibroblasts. Both GH and IGF-I stimulated collagen production in vivo and in vitro, and IGF-I, but not GH, stimulated DNA synthesis in vitro. In collagen production, GH was less potent than IGF-I. Suppressors of cytokine signaling (SOC) are cytokine-inducible proteins that negatively feedback to inhibit the actions of cytokines and we recently found that GH selectively upregulates SOC-2 in the intestine of TPN-fed rats. We examined whether SOC-2 may be responsible for the difference in magnitude of action of GH and IGF-I on collagen accumulation. GH, but not IGF-I, induced SOC-2 in isolated myofibroblasts, and overexpression of SOC-2 led to a suppression of GH- and IGF-I-induced collagen accumulation. SOC-2 null mice infused with IGF-I showed greater collagen gene expression compared with wild-type (WT) mice. Myofibroblasts isolated from SOC-2 null mice showed increased IGF-I-stimulated DNA synthesis compared with WT cells. Taken together, these findings suggest that SOC-2 induced by GH may play an important role in suppressing collagen accumulation and mesenchymal cell proliferation induced by GH or GH-induced IGF-I, providing a mechanism for the differing potencies of GH and IGF-I on intestinal mesenchyme and collagen synthesis.
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Affiliation(s)
- Shira Fruchtman
- Dept. of Cell and Molecular Physiology, CB#7545, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599-7545, USA
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17
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El Yafi F, Winkler R, Delvenne P, Boussif N, Belaiche J, Louis E. Altered expression of type I insulin-like growth factor receptor in Crohn's disease. Clin Exp Immunol 2005; 139:526-33. [PMID: 15730399 PMCID: PMC1809313 DOI: 10.1111/j.1365-2249.2004.02724.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The fibrotic and antiapoptotic effects of insulin-like growth factors (IGF) are mediated by type I IGF receptor (IGF-1R). IGFs could play a role in intestinal stricturing and in the maintenance of inflammation in Crohn's disease (CD). We aimed to describe IGF-1R expression in CD intestinal lesions, to compare it to other intestinal inflammatory diseases and to correlate it with fibrosis and apoptosis. IGF-1R expression and apoptosis (active caspase-3) were studied by immunohistochemistry. Surgical intestinal specimens [17 CD, nine controls, six diverticulitis and four ulcerative colitis (UC)] were used. IGF-1R was expressed transmurally mainly by inflammatory cells (IC) and smooth muscle cells, both in diseased intestine and controls. IGF-1R positive IC were increased in the mucosa and the submucosa of CD (P < 0.007), and in involved areas compared to uninvolved areas (P = 0.03). In UC, the number of IGF-1R positive IC was only increased in the mucosa, and was not different from controls in the submucosa. In diverticulitis, the number of IGF-1R positive IC did not differ from controls. In CD submucosa, IGF-1R expression in IC was inversely correlated with apoptosis in uninvolved areas (P = 0.01). Expression of IGF-1R in submucosal fibroblast-like cells, subserosal adipocytes and hypertrophic nervous plexi was specific for CD. We have shown a transmural altered expression of IGF-1R in CD. This may suggest a role for IGF-1R in the maintenance of chronic inflammation and stricture formation in CD.
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Affiliation(s)
- F El Yafi
- Department of Gastroenterology, CHU of Liège, Liège, Belgium
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18
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Hyun TS, Li L, Oravecz-Wilson KI, Bradley SV, Provot MM, Munaco AJ, Mizukami IF, Sun H, Ross TS. Hip1-related mutant mice grow and develop normally but have accelerated spinal abnormalities and dwarfism in the absence of HIP1. Mol Cell Biol 2004; 24:4329-40. [PMID: 15121852 PMCID: PMC400480 DOI: 10.1128/mcb.24.10.4329-4340.2004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In mice and humans, there are two known members of the Huntingtin interacting protein 1 (HIP1) family, HIP1 and HIP1-related (HIP1r). Based on structural and functional data, these proteins participate in the clathrin trafficking network. The inactivation of Hip1 in mice leads to spinal, hematopoietic, and testicular defects. To investigate the biological function of HIP1r, we generated a Hip1r mutant allele in mice. Hip1r homozygous mutant mice are viable and fertile without obvious morphological abnormalities. In addition, embryonic fibroblasts derived from these mice do not have gross abnormalities in survival, proliferation, or clathrin trafficking pathways. Altogether, this demonstrates that HIP1r is not necessary for normal development of the embryo or for normal adulthood and suggests that HIP1 or other functionally related members of the clathrin trafficking network can compensate for HIP1r absence. To test the latter, we generated mice deficient in both HIP1 and HIP1r. These mice have accelerated development of abnormalities seen in Hip1 -deficient mice, including kypholordosis and growth defects. The severity of the Hip1r/Hip1 double-knockout phenotype compared to the Hip1 knockout indicates that HIP1r partially compensates for HIP1 function in the absence of HIP1 expression, providing strong evidence that HIP1 and HIP1r have overlapping roles in vivo.
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Affiliation(s)
- Teresa S Hyun
- Department of Internal Medicine, and Graduate Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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19
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Xin X, Hou YT, Li L, Schmiedlin-Ren P, Christman GM, Cheng HL, Bitar KN, Zimmermann EM. IGF-I increases IGFBP-5 and collagen alpha1(I) mRNAs by the MAPK pathway in rat intestinal smooth muscle cells. Am J Physiol Gastrointest Liver Physiol 2004; 286:G777-83. [PMID: 15068962 DOI: 10.1152/ajpgi.00293.2003] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
IGF-I is a potent fibrogenic growth factor that stimulates proliferation of intestinal smooth muscle cells and increases synthesis of collagen and IGF-I-binding proteins by the cells. These processes contribute to intestinal fibrosis that develops in patients with Crohn's disease and in Lewis-strain rats with experimental Crohn's disease. The aim of this study was to determine which early docking proteins are associated with IGF-I receptor signal transduction and which transduction pathway is involved in IGF-I-mediated gene regulation in intestinal smooth muscle cells. Primary cultures of smooth muscle cells isolated from the muscularis externa of the distal colon of Lewis rats were treated with IGF-I (100 ng/ml). Immunoprecipitation studies demonstrated that IGF-I stimulation resulted in tyrosine phosphorylation of IRS-1, IRS-2, and Shc. Coimmunoprecipitation demonstrated a close association between the IGF-I receptor and these three early docking proteins. Concurrent treatment with the MAPK inhibitor PD98059 (10 microM) resulted in an inhibition of the IGF-I-mediated increase in IGFBP-5 and collagen alpha(1)(I) mRNAs, while concurrent treatment with the phosphatidylinositol 3-kinase (PI3-K) inhibitor wortmannin (100 nM) had no effect. In additional experiments, cells were transiently transfected with adenoviral vectors dominantly expressing inactive mutant Akt or constitutively expressing wild-type Akt. In both cases, the IGF-I-mediated increase in collagen I protein did not differ from that observed in control cultures that had been transfected with an adenoviral vector carrying the LacZ reporter gene. These results suggest that the MAPK pathway is key to IGF-I-mediated gene regulation in intestinal smooth muscle cells, whereas data do not suggest a role for the Akt-dependent pathway in our system.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Adaptor Proteins, Vesicular Transport/metabolism
- Animals
- Cells, Cultured
- Collagen Type I/genetics
- Collagen Type I/metabolism
- Crohn Disease/metabolism
- Crohn Disease/pathology
- Dose-Response Relationship, Drug
- Enzyme Inhibitors/pharmacology
- Female
- Flavonoids/pharmacology
- Insulin Receptor Substrate Proteins
- Insulin-Like Growth Factor Binding Protein 5/genetics
- Insulin-Like Growth Factor Binding Protein 5/metabolism
- Insulin-Like Growth Factor I/administration & dosage
- Insulin-Like Growth Factor I/pharmacology
- Insulin-Like Growth Factor I/physiology
- Intestinal Mucosa/metabolism
- Intestines/drug effects
- Intracellular Signaling Peptides and Proteins
- Mitogen-Activated Protein Kinases/antagonists & inhibitors
- Mitogen-Activated Protein Kinases/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Phosphoproteins/metabolism
- Phosphorylation/drug effects
- RNA, Messenger/antagonists & inhibitors
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred Lew
- Receptor, IGF Type 1/metabolism
- Shc Signaling Adaptor Proteins
- Src Homology 2 Domain-Containing, Transforming Protein 1
- Time Factors
- Tyrosine/metabolism
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Affiliation(s)
- Xiping Xin
- Univ. of Michigan Medical School, Rm. 6520 MSRB I, 1150 West Medical Center Dr., Ann Arbor, MI 48109-0682, USA
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20
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Williams KL, Fuller CR, Fagin J, Lund PK. Mesenchymal IGF-I overexpression: paracrine effects in the intestine, distinct from endocrine actions. Am J Physiol Gastrointest Liver Physiol 2002; 283:G875-85. [PMID: 12223347 DOI: 10.1152/ajpgi.00089.2002] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Local IGF-I expression is frequently increased in intestinal mesenchyme during adaptive growth of intestinal epithelium, but paracrine growth effects of IGF-I in vivo are not defined. We tested whether overexpression of IGF-I in intestinal mesenchyme increases epithelial growth and if effects are distinct from known effects of circulating IGF-I. SMP8-IGF-I-transgenic (TG) mice overexpress IGF-I driven by an alpha-smooth muscle actin promoter. Mucosal and muscularis growth were assessed in the jejunum, ileum, and colon of SMP8-IGF-I-TG mice and wild-type littermates. Abundance of the SMP8-IGF-I transgene and IGF binding protein (IGFBP)-3 and -5 mRNAs was determined. Mucosal growth was increased in SMP8-IGF-I-TG ileum but not jejunum or colon; muscularis growth was increased throughout the bowel. IGFBP-5 mRNA was increased in SMP8-IGF-I-TG jejunum and ileum and was specifically upregulated in ileal lamina propria. Overexpression of IGF-I in intestinal mesenchymal cells has preferential paracrine effects on the ileal mucosal epithelium and autocrine effects on the muscularis throughout the bowel. Locally expressed IGF-I has distinct actions on IGFBP expression compared with circulating IGF-I.
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Affiliation(s)
- Kristen L Williams
- Department of Cell and Molecular Physiology, University of North Carolina, Chapel Hill, North Carolina 27599-7080, USA.
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21
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Simmons JG, Pucilowska JB, Keku TO, Lund PK. IGF-I and TGF-beta1 have distinct effects on phenotype and proliferation of intestinal fibroblasts. Am J Physiol Gastrointest Liver Physiol 2002; 283:G809-18. [PMID: 12181198 DOI: 10.1152/ajpgi.00057.2002] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Insulin-like growth factor I (IGF-I) and transforming growth factor-beta1 (TGF-beta1) are upregulated in myofibroblasts at sites of fibrosis in experimental enterocolitis and in Crohn's disease (CD). We compared the sites of expression of IGF-I and TGF-beta1 in a rat peptidoglycan-polysaccharide (PG-PS) model of chronic granulomatous enterocolitis and fibrosis. We used the human colonic CCD-18Co fibroblast/myofibroblast cell line to test the hypothesis that TGF-beta1 and IGF-I interact to regulate proliferation, collagen synthesis, and activated phenotype typified by expression of alpha-smooth muscle actin and organization into stress fibers. IGF-I potently stimulated while TGF-beta1 inhibited basal DNA synthesis. TGF-beta1 and IGF-I each had similar but not additive effects to induce type I collagen. TGF-beta1 but not IGF-I potently stimulated expression of alpha-smooth muscle actin and stress fiber formation. IGF-I in combination with TGF-beta1 attenuated stress fiber formation without reducing alpha-smooth muscle actin expression. Stress fibers were not a prerequisite for increased collagen synthesis. TGF-beta1 upregulated IGF-I mRNA, which led us to examine the effects of IGF-I in cells previously activated by TGF-beta1 pretreatment. IGF-I potently stimulated proliferation of TGF-beta1-activated myofibroblasts without reversing activated fibrogenic phenotype. We conclude that TGF-beta1 and IGF-I both stimulate type I collagen synthesis but have differential effects on activated phenotype and proliferation. We propose that during intestinal inflammation, regulation of activated phenotype and proliferation may require sequential actions of TGF-beta1 and IGF-I, but they may act in concert to increase collagen deposition.
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Affiliation(s)
- James G Simmons
- Department of Cell and Molecular Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7545, USA.
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22
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Shoubridge CA, Steeb CB, Read LC. IGFBP mRNA expression in small intestine of rat during postnatal development. Am J Physiol Gastrointest Liver Physiol 2001; 281:G1378-84. [PMID: 11705742 DOI: 10.1152/ajpgi.2001.281.6.g1378] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In contrast to the adult gut, the immature intestine is refractory to subcutaneously infused insulin-like growth factor I (IGF-I). IGF binding protein (IGFBP) mRNA expression was characterized in intestinal tissues from 6-, 19-, and 90-day-old rats to determine if changes in local expression could account for this age-related change in IGF-I potency. For all age groups, IGFBP-3 to -6, but not IGFBP-1 or -2, were detected by Northern blot analysis. IGFBP-3, -4, and -5 were more intensely expressed in the 6-day-old rat intestine compared with weanling or adult tissue. In contrast, IGFBP-6 expression peaked at the time of weaning. In situ hybridization showed IGFBP-3 to -6 expression was confined to cells of the lamina propria and submucosa and also in the muscularis layer for IGFBP-5. Furthermore, the pattern of IGFBP-5 localization in the intestine changed with development. The findings indicate that the expression of IGFBP-3 to -6 is higher in the immature intestine compared with the adult intestine, suggesting locally produced IGFBPs may inhibit systemically derived IGF-I action in the intestine. Therefore, changes to local IGFBP expression may contribute to the varying response of the rat intestine to IGF-I peptides during postnatal development.
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Affiliation(s)
- C A Shoubridge
- Child Health Research Institute and Cooperative Research Centre for Tissue Growth and Repair, North Adelaide, South Australia 5006, Australia.
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23
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Zimmermann EM, Li L, Hou YT, Mohapatra NK, Pucilowska JB. Insulin-like growth factor I and insulin-like growth factor binding protein 5 in Crohn's disease. Am J Physiol Gastrointest Liver Physiol 2001; 280:G1022-9. [PMID: 11292612 DOI: 10.1152/ajpgi.2001.280.5.g1022] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Insulin-like growth factor (IGF)-I and its binding protein IGF binding protein 5 (IGFBP-5) were highly expressed in inflamed and fibrotic intestine in experimental Crohn's disease. IGF-I induced proliferation and increased collagen synthesis by smooth muscle cells and fibroblasts/myofibroblasts in vitro. Here we studied IGF-I and IGFBP-5 in Crohn's disease tissue. Tissue was collected from patients undergoing intestinal resection for Crohn's disease. IGF-I and IGFBP-5 mRNAs were quantitated by RNase protection assay and Northern blot analysis, respectively. In situ hybridization was performed to localize mRNA expression, and Western immunoblot was performed to quantitate protein expression. IGF-I and IGFBP-5 mRNAs were increased in inflamed/fibrotic intestine compared with normal-appearing intestine. IGF-I mRNA was expressed in multiple cell types in the lamina propria and fibroblast-like cells of the submucosa and muscularis externa. IGFBP-5 mRNA was highly expressed in smooth muscle of the muscularis mucosae and muscularis externa as well as fibroblast-like cells throughout the bowel wall. Tissue IGFBP-5 protein correlated with collagen type I (r = 0.82). These findings are consistent with a mechanism whereby IGF-I acts on smooth muscle and fibroblasts/myofibroblasts to increase collagen synthesis and cellular proliferation; its effects may be modulated by locally expressed IGFBP-5.
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Affiliation(s)
- E M Zimmermann
- University of Michigan, Department of Internal Medicine, 4410 Kresge III, Ann Arbor, MI 48109-0589.
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24
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Pucilowska JB, McNaughton KK, Mohapatra NK, Hoyt EC, Zimmermann EM, Sartor RB, Lund PK. IGF-I and procollagen alpha1(I) are coexpressed in a subset of mesenchymal cells in active Crohn's disease. Am J Physiol Gastrointest Liver Physiol 2000; 279:G1307-22. [PMID: 11093955 DOI: 10.1152/ajpgi.2000.279.6.g1307] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This study tested the hypothesis that insulin-like growth factor I (IGF-I) expression is increased at sites of fibrosis in diseased intestine of patients with Crohn's disease (CD). IGF-I mRNA was quantified by RNase protection assay in uninvolved and involved intestine of 13 CD patients (10 ileum, 3 colon) and 7 ulcerative colitis (UC) patients (colon). In situ hybridization histochemistry compared the localization of IGF-I and procollagen alpha1(I) mRNAs. Masson's trichrome staining and immunohistochemistry for IGF-I precursor, alpha-smooth muscle actin (A), vimentin (V), desmin (D), and c-kit were used to examine the mesenchymal cell subtypes that express IGF-I and collagen in uninvolved and involved ileum and colon of CD patients and "normal" ileum and colon from noninflammatory controls. IGF-I mRNA was elevated in involved ileum and colon of patients with CD but not in involved colon of patients with UC. IGF-I and procollagen alpha1(I) mRNA showed overlapping distribution within fibrotic submucosa and muscularis propria of involved CD ileum and colon. In involved CD intestine, increased IGF-I precursor expression localized to mesenchymal cells in regions of tissue disorganization and fibrosis in muscularis mucosa, submucosa, and muscularis propria. In these regions, there were increased numbers of V(+) cells relative to normal or uninvolved intestine. Increased IGF-I expression was localized to cells with a phenotype typical of fibroblasts (V(+)/A(-)/D(-)), myofibroblasts (V(+)/A(+)/D(+)), and, to a lesser extent, cells with normal enteric smooth muscle phenotype (V(-)/A(+)/D(+)). We conclude that increased IGF-I expression in multiple mesenchymal cell subtypes and increased numbers of cells with fibroblast/myofibroblast phenotype are involved in fibrosis associated with CD.
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Affiliation(s)
- J B Pucilowska
- Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7545, USA.
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Kuemmerle JF, Teng B. Regulation of IGFBP-4 levels in human intestinal muscle by an IGF-I-activated, confluence-dependent protease. Am J Physiol Gastrointest Liver Physiol 2000; 279:G975-82. [PMID: 11052994 DOI: 10.1152/ajpgi.2000.279.5.g975] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Human intestinal smooth muscle cells in culture produce insulin-like growth factor-I (IGF-I), IGF binding protein-3 (IGFBP-3), IGFBP-4, and IGFBP-5, which can modulate the effects of IGF-I on growth. This study examined the role of IGFBP-4 on IGF-I-induced growth and the mechanisms regulating IGFBP-4 levels. IGFBP-4 inhibited IGF-I-induced [(3)H]thymidine incorporation. IGFBP-4 mRNA levels were not altered by IGF-I. IGF-I caused a concentration-dependent activation of an endogenous IGFBP-4 protease, resulting in time-dependent degradation of intact IGFBP-4 into inactive fragments. Protease activity was measured in a cell-free assay using smooth muscle cell conditioned medium containing the IGFBP-4 protease. The protease was inhibited by EDTA and benzamidine. Protease activity was highest in proliferating cells and lowest in postconfluent cells. The role of endogenous IGF-I in regulating IGFBP-4 degradation was confirmed by the ability of an IGF-I antagonist to inhibit IGF-I-activated IGFBP-4 proteolysis in intact cells. We conclude that in human intestinal smooth muscle cells levels of secreted IGFBP-4 are determined by the confluence-dependent production of a cation-dependent serine protease that is activated by endogenous IGF-I.
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Affiliation(s)
- J F Kuemmerle
- Department of Medicine, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23298, USA.
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Pucilowska JB, Williams KL, Lund PK. Fibrogenesis. IV. Fibrosis and inflammatory bowel disease: cellular mediators and animal models. Am J Physiol Gastrointest Liver Physiol 2000; 279:G653-9. [PMID: 11005750 DOI: 10.1152/ajpgi.2000.279.4.g653] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The cellular mediators of intestinal fibrosis and the relationship between fibrosis and normal repair are not understood. Identification of the types of intestinal mesenchymal cells that produce collagen during normal healing and fibrosis is vital for elucidating the answers to these questions. Acute injury may cause normal mesenchymal cells to convert to a fibrogenic phenotype that is not maintained during normal healing but may lead to fibrosis when inappropriately sustained. Proliferation of normal or fibrogenic mesenchymal cells may lead to muscularis overgrowth associated with fibrosis. The presence of increased numbers of vimentin-positive cells within fibrotic, hypertrophied muscularis in Crohn's disease suggests that changes in mesenchymal cell phenotype and number may indeed be associated with fibrosis. Fibrosis is induced in rats by peptidoglycan polysaccharides or trinitrobenzene sulfonic acid-ethanol administration, but inducing fibrosis in mice has been technically challenging. The development of current mouse models of colitis, such as dextran sodium sulfate or trinitrobenzene sulfonic acid-ethanol administration, into models of fibrosis will allow us to use genetic manipulation to study molecular mediators of fibrosis.
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Affiliation(s)
- J B Pucilowska
- Department of Cell and Molecular Physiology and Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7545, USA
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Kuemmerle JF. Endogenous IGF-I regulates IGF binding protein production in human intestinal smooth muscle cells. Am J Physiol Gastrointest Liver Physiol 2000; 278:G710-7. [PMID: 10801263 DOI: 10.1152/ajpgi.2000.278.5.g710] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Human intestinal smooth muscle in culture produces insulin-like growth factor (IGF)-I and IGF binding protein (IGFBP)-3, IGFBP-4, and IGFBP-5, which modulate the effects of IGF-I. This study examined the regulation of IGFBP production by endogenous IGF-I. R3-IGF-I, an agonist unaffected by IGFBPs, elicited concentration-dependent increase in growth, measured by [(3)H]thymidine incorporation, and production of IGFBP-3, IGFBP-4, and IGFBP-5, measured by Western blot. Antagonists of the IGF-I receptor, IGF-I Analog or monoclonal antibody 1H7, elicited concentration-dependent inhibition of growth and decrease in IGFBP-3, IGFBP-4, and IGFBP-5 production, implying that endogenous IGF-I stimulated growth and IGFBP production. R3-IGF-I-induced increase in IGFBP-3, IGFBP-4, and IGFBP-5 production was partially inhibited by a mitogen-activated protein (MAP) kinase or a phosphatidylinositol-3-kinase (PI 3-kinase) inhibitor and abolished by the combination. We conclude that endogenous IGF-I stimulates growth and IGFBP-3, IGFBP-4, and IGFBP-5 production in human intestinal smooth muscle cells. Regulation of IGFBP production by IGF-I is mediated by activation of distinct MAP kinase and PI 3-kinase pathways, the same pathways through which IGF-I stimulates growth.
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Affiliation(s)
- J F Kuemmerle
- Departments of Medicine and Physiology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23298-0711, USA.
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