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Brodeur AC, Roberts-Pilgrim AM, Thompson KL, Franklin CL, Phillips CL. Transforming growth factor-β1/Smad3-independent epithelial-mesenchymal transition in type I collagen glomerulopathy. Int J Nephrol Renovasc Dis 2017; 10:251-259. [PMID: 28919801 PMCID: PMC5587152 DOI: 10.2147/ijnrd.s141393] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The glomerulofibrotic Col1a2-deficient mouse model demonstrates glomerular homotrimeric type I collagen deposition in mesangial and subendothelial spaces. In this report, we investigate the role of transforming growth factor β1 (TGF-β1) in myofibroblast activation and epithelial-mesenchymal transition (EMT) in this glomerulopathy. Immunohistochemical analyses of glomerular α-sma, desmin, vimentin, and proliferating cell nuclear antigen demonstrated parietal epithelial cell proliferation and EMT in late stages of the glomerulopathy in the Col1a2-deficient mice. Glomerular TGF-β1 RNA and protein were not elevated in 1- and 3-month-old mice as determined by quantitative reverse transcriptase-polymerase chain reaction and protein immunoassay analyses. To investigate further whether TGF-β1 plays a role in the glomerulopathy outside of the 1- and 3-month time periods, the Col1a2-deficient mice were bred with Smad3 knockout mice. If the glomerular fibrosis in the Col1a2-deficient mice is mediated by the TGF-β1/Smad3 transcription pathway, it was hypothesized that the resultant Col1a2-deficient/Smad3-deficient mice would exhibit attenuated glomerular homotrimer deposition. However, the Col1a2-deficient/Smad3-deficient kidneys were similarly affected as compared to age-matched Col1a2-deficient kidneys, suggesting that homotrimeric type I collagen deposition in the Col1a2-deficient mouse is independent of TGF-β1/Smad3 signaling. Deposition of homotrimeric type I collagen appears to be the initiating event in this glomerulopathy, providing evidence that EMT and myofibroblast activation occur following initiation, consistent with a secondary wound-healing response independent of TGF-β1.
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Affiliation(s)
- Amanda C Brodeur
- Department of Biomedical Sciences, Missouri State University, Springfield, MO, USA.,Department of Child Health, University of Missouri, Columbia, MO, USA.,Department of Biochemistry, University of Missouri, Columbia, MO, USA
| | | | - Kimberlee L Thompson
- Department of Biomedical Sciences, Missouri State University, Springfield, MO, USA
| | - Craig L Franklin
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, USA
| | - Charlotte L Phillips
- Department of Child Health, University of Missouri, Columbia, MO, USA.,Department of Biochemistry, University of Missouri, Columbia, MO, USA
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Mirigian LS, Makareeva E, Mertz EL, Omari S, Roberts-Pilgrim AM, Oestreich AK, Phillips CL, Leikin S. Osteoblast Malfunction Caused by Cell Stress Response to Procollagen Misfolding in α2(I)-G610C Mouse Model of Osteogenesis Imperfecta. J Bone Miner Res 2016; 31:1608-1616. [PMID: 26925839 PMCID: PMC5061462 DOI: 10.1002/jbmr.2824] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 02/22/2016] [Accepted: 02/26/2016] [Indexed: 12/26/2022]
Abstract
Glycine (Gly) substitutions in collagen Gly-X-Y repeats disrupt folding of type I procollagen triple helix and cause severe bone fragility and malformations (osteogenesis imperfecta [OI]). However, these mutations do not elicit the expected endoplasmic reticulum (ER) stress response, in contrast to other protein-folding diseases. Thus, it has remained unclear whether cell stress and osteoblast malfunction contribute to the bone pathology caused by Gly substitutions. Here we used a mouse with a Gly610 to cysteine (Cys) substitution in the procollagen α2(I) chain to show that misfolded procollagen accumulation in the ER leads to an unusual form of cell stress, which is neither a conventional unfolded protein response (UPR) nor ER overload. Despite pronounced ER dilation, there is no upregulation of binding immunoglobulin protein (BIP) expected in the UPR and no activation of NF-κB signaling expected in the ER overload. Altered expression of ER chaperones αB crystalline and HSP47, phosphorylation of EIF2α, activation of autophagy, upregulation of general stress response protein CHOP, and osteoblast malfunction reveal some other adaptive response to the ER disruption. We show how this response alters differentiation and function of osteoblasts in culture and in vivo. We demonstrate that bone matrix deposition by cultured osteoblasts is rescued by activation of misfolded procollagen autophagy, suggesting a new therapeutic strategy for OI. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Lynn S Mirigian
- Section on Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892.,Department of Cell Biology, University of Texas Medical Branch, Galveston, TX 77555
| | - Elena Makareeva
- Section on Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
| | - Edward L Mertz
- Section on Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
| | - Shakib Omari
- Section on Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
| | - Anna M Roberts-Pilgrim
- Section on Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
| | - Arin K Oestreich
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211
| | | | - Sergey Leikin
- Section on Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
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Roberts-Pilgrim AM, Makareeva E, Myles MH, Besch-Williford CL, Brodeur AC, Walker AL, Leikin S, Franklin CL, Phillips CL. Deficient degradation of homotrimeric type I collagen, α1(I)3 glomerulopathy in oim mice. Mol Genet Metab 2011; 104:373-82. [PMID: 21855382 PMCID: PMC3205245 DOI: 10.1016/j.ymgme.2011.07.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 07/27/2011] [Accepted: 07/27/2011] [Indexed: 01/15/2023]
Abstract
Col1a2-deficient (oim) mice synthesize homotrimeric type I collagen due to nonfunctional proα2(I) collagen chains. Our previous studies revealed a postnatal, progressive type I collagen glomerulopathy in this mouse model, but the mechanism of the sclerotic collagen accumulation within the renal mesangium remains unclear. The recent demonstration of the resistance of homotrimeric type I collagen to cleavage by matrix metalloproteinases (MMPs), led us to investigate the role of MMP-resistance in the glomerulosclerosis of Col1a2-deficient mice. We measured the pre- and post-translational expression of type I collagen and MMPs in glomeruli from heterozygous and homozygous animals. Both the heterotrimeric and homotrimeric isotypes of type I collagen were equally present in whole kidneys of heterozygous mice by immunohistochemistry and biochemical analysis, but the sclerotic glomerular collagen was at least 95-98% homotrimeric, suggesting homotrimeric type I collagen is the pathogenic isotype of type I collagen in glomerular disease. Although steady-state MMP and Col1a1 mRNA levels increased with the disease progression, we found these changes to be a secondary response to the deficient clearance of MMP-resistant homotrimers. Increased renal MMP expression was not sufficient to prevent homotrimeric type I collagen accumulation.
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Affiliation(s)
- Anna M. Roberts-Pilgrim
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA. , , and ,
| | - Elena Makareeva
- NICHD, National Institutes of Health, Bethesda, MD 20892, USA. ,
| | - Matthew H. Myles
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri 65211, USA. , ,
| | | | - Amanda C. Brodeur
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA. , , and ,
- Department of Child Health, University of Missouri, Columbia, Missouri 65212, USA. ,
| | - Andrew L. Walker
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA. , , and ,
| | - Sergey Leikin
- NICHD, National Institutes of Health, Bethesda, MD 20892, USA. ,
| | - Craig L. Franklin
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri 65211, USA. , ,
| | - Charlotte L. Phillips
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA. , , and ,
- Department of Child Health, University of Missouri, Columbia, Missouri 65212, USA. ,
- Correspondence and Reprint Requests: Charlotte L. Phillips, Ph.D., Associate Professor, Departments of Biochemistry and Child Health, University of Missouri, 117 Schweitzer Hall, Columbia, MO 65211 USA, Phone: 1-573-882-5122, Fax: 1-573-882-5635,
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