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Xuan Z, Gurevich L, Christiansen JDC, Zachar V, Pennisi CP. Stable hydrogel adhesion to polydimethylsiloxane enables cyclic mechanical stimulation of 3D-bioprinted smooth muscle constructs. Biotechnol Bioeng 2023; 120:3396-3408. [PMID: 37526327 DOI: 10.1002/bit.28516] [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: 03/30/2023] [Revised: 07/05/2023] [Accepted: 07/11/2023] [Indexed: 08/02/2023]
Abstract
During normal urination, smooth muscle cells (SMCs) in the lower urinary tract (LUT) are exposed to mechanical signals that have a critical impact on tissue structure and function. Nevertheless, the mechanisms underlying the maintenance of the contractile phenotype of SMCs remain poorly understood. This is due, in part, to a lack of studies that have examined the effects of mechanical loading using three-dimensional (3D) models. In this study, surface modifications of polydimethylsiloxane (PDMS) membrane were evaluated to investigate the effects of cyclic mechanical stimulation on SMC maturation in 3D constructs. Commercially available cell stretching plates were modified with amino or methacrylate groups to promote adhesion of 3D constructs fabricated by bioprinting. After 6 days of stimulation, the effects of mechanical stimulation on the expression of contractile markers at the mRNA and protein levels were analyzed. Methacrylate-modified surfaces supported stable adhesion of the 3D constructs to the membrane and facilitated cyclic mechanical stimulation, which significantly increased the expression of contractile markers at the mRNA and protein levels. These effects were found to be mediated by activation of the p38 MAPK pathway, as inhibition of this pathway abolished the effects of stimulation in a dose-dependent manner. These results provide valuable insights into the role of mechanical signaling in maintaining the contractile phenotype of bladder SMCs, which has important implications for the development of future treatments for LUT diseases.
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Affiliation(s)
- Zongzhe Xuan
- Regenerative Medicine Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Leonid Gurevich
- Department of Materials and Production, Aalborg University, Aalborg, Denmark
| | | | - Vladimir Zachar
- Regenerative Medicine Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Cristian Pablo Pennisi
- Regenerative Medicine Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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Chua AWC, Guo D, Tan JC, Lim FTW, Ong CT, Masilamani J, Lim TKH, Hwang WYK, Lim IJ, Chen J, Phan TT, Fan X. Intraperitoneally Delivered Umbilical Cord Lining Mesenchymal Stromal Cells Improve Survival and Kidney Function in Murine Lupus via Myeloid Pathway Targeting. Int J Mol Sci 2022; 24:ijms24010365. [PMID: 36613807 PMCID: PMC9820333 DOI: 10.3390/ijms24010365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/16/2022] [Accepted: 12/16/2022] [Indexed: 12/28/2022] Open
Abstract
To determine the therapeutic efficacy of human umbilical cord lining mesenchymal stromal cells (CL-MSCs) (US Patent number 9,737,568) in lupus-prone MRL/lpr (Faslpr) mice and elucidate its working mechanisms. A total of 4 doses of (20-25) × 106 cells/kg of CL-MSCs was given to 16-week-old female Faslpr mice by intraperitoneal injection. Three subsequent doses were given on 17 weeks, 18 weeks, and 22 weeks, respectively. Six-week-old Faslpr mice were used as disease pre-onset controls. Mice were monitored for 10 weeks. Mouse kidney function was evaluated by examining complement component 3 (C3) deposition, urinary albumin-to-creatinine ratio (ACR), and lupus nephritis (LN) activity and chronicity. Working mechanisms were elucidated by flow cytometry, Luminex/ELISA (detection of anti-dsDNA and isotype antibodies), and RNA sequencing. CL-MSCs improved mice survival and kidney function by reducing LN activity and chronicity and lymphocyte infiltration over 10 weeks. CL-MSCs also reduced urinary ACR, renal complement C3 deposition, anti-dsDNA, and isotype antibodies that include IgA, IgG1, IgG2a, IgG2b, and IgM. Immune and cytokine profiling demonstrated that CL-MSCs dampened inflammation by suppressing splenic neutrophils and monocytes/macrophages, reducing plasma IL-6, IL-12, and CXCL1 and stabilizing plasma interferon-γ and TNF-α. RNA sequencing further showed that CL-MSCs mediated immunomodulation via concerted action of pro-proinflammatory cytokine-induced chemokines and production of nitric oxide in macrophages. CL-MSCs may provide a novel myeloid (neutrophils and monocytes/macrophages)-targeting therapy for SLE.
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Affiliation(s)
- Alvin Wen Choong Chua
- Department of Plastic, Reconstructive and Aesthetic Surgery, Singapore General Hospital, Singapore 169856, Singapore
| | - Dianyang Guo
- Department of Clinical Translational Research, Singapore General Hospital, Singapore 169608, Singapore
| | - Jia Chi Tan
- Single-Cell Computational Immunology, Singapore Immunology Network, Singapore 138668, Singapore
| | - Frances Ting Wei Lim
- Department of Clinical Translational Research, Singapore General Hospital, Singapore 169608, Singapore
| | - Chee Tian Ong
- CellResearch Corporation Pte Ltd., Singapore 048943, Singapore
| | | | - Tony Kiat Hon Lim
- Department of Anatomical Pathology, Singapore General Hospital, Singapore 169856, Singapore
| | - William Ying Khee Hwang
- Department of Hematology, Singapore General Hospital, Singapore 169856, Singapore
- National Cancer Centre Singapore, Singapore 169610, Singapore
| | - Ivor Jiun Lim
- CellResearch Corporation Pte Ltd., Singapore 048943, Singapore
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Jinmiao Chen
- Single-Cell Computational Immunology, Singapore Immunology Network, Singapore 138668, Singapore
| | - Toan Thang Phan
- CellResearch Corporation Pte Ltd., Singapore 048943, Singapore
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Correspondence: (T.T.P.); (X.F.); Tel.: +65-6444-9968 (T.T.P.); +65-9101-6288 (X.F.); Fax: +65-6220-3321 (T.T.P.); +65-6221-5142 (X.F.)
| | - Xiubo Fan
- Department of Clinical Translational Research, Singapore General Hospital, Singapore 169608, Singapore
- SingHealth Duke-NUS Medicine Academic Clinical Programme, Duke-NUS Medical School, Singapore 169857, Singapore
- Correspondence: (T.T.P.); (X.F.); Tel.: +65-6444-9968 (T.T.P.); +65-9101-6288 (X.F.); Fax: +65-6220-3321 (T.T.P.); +65-6221-5142 (X.F.)
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3
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Wiafe B, Kadam R, Metcalfe PD. Intraperitoneal administration of mesenchymal stem cells is effective at mitigating detrusor deterioration after pBOO. Am J Physiol Renal Physiol 2020; 318:F549-F556. [PMID: 31904287 DOI: 10.1152/ajprenal.00486.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Partial bladder outlet obstruction (pBOO) results in bladder fibrosis that is initiated by an inflammatory cascade and the decompensation after smooth muscle hypertrophy. We have been using an animal model to develop the hypothesis that mesenchymal stem cells (MSCs) are able to mitigate this cytokine cascade and prevent bladder deterioration. We hypothesized that intraperitoneal administration of MSCs can produce the same effects as intravenously administered cells but may require higher dosing. Intraperitoneal treatment will provide insights into the mechanisms of action and may offer advantages over intravenous administration, as it will permit allow higher doses and potentially reduce systemic exposure. Rats underwent a surgical induction of pBOO and instillation of either 1 × 106 or 5 × 106 commercially acquired MSCs into the peritoneum. RT-PCR, immunohistochemistry, and urodynamics were used to compare treatment groups with controls. pBOO resulted in a marked, statistically significant, upregulation of inflammatory markers in the bladder, including transforming growth factor-β, hypoxia-inducible factor-1α, hypoxia-inducible factor-3α, mammalian target of rapamycin, and collagen types I and III. Moderate but inconsistent levels of downregulation were seen with 1 × 106 MSCs, but excellent and reliable downregulation was seen with 5 × 106 MSCs (P < 0.05). Immunohistochemistry confirmed that protein levels were affected in accordance with mRNA upregulation. Urodynamics demonstrated MSC treatment resulted in whole organ physiological benefits, as they prevented elevations in detrusor pressure. In conclusion, intraperitoneal administration of MSCs resulted in a similar effect as intravenous administration; however, this required a higher dose. This has significant implications for determining the mechanism of action and potential clinical application for human therapy.
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Affiliation(s)
- Bridget Wiafe
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Rutuja Kadam
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Peter D Metcalfe
- Division of Urology and Pediatric Surgery, University of Alberta, Edmonton, Alberta, Canada
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Hashemi Gheinani A, Burkhard FC, Rehrauer H, Aquino Fournier C, Monastyrskaya K. MicroRNA MiR-199a-5p regulates smooth muscle cell proliferation and morphology by targeting WNT2 signaling pathway. J Biol Chem 2015; 290:7067-86. [PMID: 25596533 DOI: 10.1074/jbc.m114.618694] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
MicroRNA miR-199a-5p impairs tight junction formation, leading to increased urothelial permeability in bladder pain syndrome. Now, using transcriptome analysis in urothelial TEU-2 cells, we implicate it in the regulation of cell cycle, cytoskeleton remodeling, TGF, and WNT signaling pathways. MiR-199a-5p is highly expressed in the smooth muscle layer of the bladder, and we altered its levels in bladder smooth muscle cells (SMCs) to validate the pathway analysis. Inhibition of miR-199a-5p with antimiR increased SMC proliferation, reduced cell size, and up-regulated miR-199a-5p targets, including WNT2. Overexpression of WNT2 protein or treating SMCs with recombinant WNT2 closely mimicked the miR-199a-5p inhibition, whereas down-regulation of WNT2 in antimiR-expressing SMCs with shRNA restored cell phenotype and proliferation rates. Overexpression of miR-199a-5p in the bladder SMCs significantly increased cell size and up-regulated SM22, SM α-actin, and SM myosin heavy chain mRNA and protein levels. These changes as well as increased expression of ACTG2, TGFB1I1, and CDKN1A were mediated by up-regulation of the smooth muscle-specific transcriptional activator myocardin at mRNA and protein levels. Myocardin-related transcription factor A downstream targets Id3 and MYL9 were also induced. Up-regulation of myocardin was accompanied by down-regulation of WNT-dependent inhibitory Krüppel-like transcription factor 4 in miR-199a-5p-overexpressing cells. In contrast, Krüppel-like transcription factor 4 was induced in antimiR-expressing cells following the activation of WNT2 signaling, leading to repression of myocardin-dependent genes. MiR-199a-5p plays a critical role in the WNT2-mediated regulation of proliferative and differentiation processes in the smooth muscle and may behave as a key modulator of smooth muscle hypertrophy, which is relevant for organ remodeling.
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Affiliation(s)
- Ali Hashemi Gheinani
- From the Urology Research Laboratory, Department Clinical Research, University of Bern, 3010 Bern, Switzerland
| | - Fiona C Burkhard
- Department of Urology, University Hospital, 3010 Bern, Switzerland, and
| | | | | | - Katia Monastyrskaya
- From the Urology Research Laboratory, Department Clinical Research, University of Bern, 3010 Bern, Switzerland,
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Wang Z, Cheng Z, Cristofaro V, Li J, Xiao X, Gomez P, Ge R, Gong E, Strle K, Sullivan MP, Adam RM, White MF, Olumi AF. Inhibition of TNF-α improves the bladder dysfunction that is associated with type 2 diabetes. Diabetes 2012; 61:2134-45. [PMID: 22688336 PMCID: PMC3402324 DOI: 10.2337/db11-1763] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Diabetic bladder dysfunction (DBD) is common and affects 80% of diabetic patients. However, the molecular mechanisms underlying DBD remain elusive because of a lack of appropriate animal models. We demonstrate DBD in a mouse model that harbors hepatic-specific insulin receptor substrate 1 and 2 deletions (double knockout [DKO]), which develops type 2 diabetes. Bladders of DKO animals exhibited detrusor overactivity at an early stage: increased frequency of nonvoiding contractions during bladder filling, decreased voided volume, and dispersed urine spot patterns. In contrast, older animals with diabetes exhibited detrusor hypoactivity, findings consistent with clinical features of diabetes in humans. The tumor necrosis factor (TNF) superfamily genes were upregulated in DKO bladders. In particular, TNF-α was upregulated in serum and in bladder smooth muscle tissue. TNF-α augmented the contraction of primary cultured bladder smooth muscle cells through upregulating Rho kinase activity and phosphorylating myosin light chain. Systemic treatment of DKO animals with soluble TNF receptor 1 (TNFRI) prevented upregulation of Rho A signaling and reversed the bladder dysfunction, without affecting hyperglycemia. TNFRI combined with the antidiabetic agent, metformin, improved DBD beyond that achieved with metformin alone, suggesting that therapies targeting TNF-α may have utility in reversing the secondary urologic complications of type 2 diabetes.
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Affiliation(s)
- Zongwei Wang
- Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Zhiyong Cheng
- Division of Endocrinology, Howard Hughes Medical Institute, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts
| | - Vivian Cristofaro
- Urology Research, Veterans Administration Boston Healthcare System, Harvard Medical School, Boston, Massachusetts
| | - Jijun Li
- Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Department of Integrative Medicine, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xingyuan Xiao
- Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Department of Urology, Wuhan Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Pablo Gomez
- Urology Research Center, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts
| | - Rongbin Ge
- Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Edward Gong
- Urology Research Center, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts
| | - Klemen Strle
- Department of Medicine, Division of Allergy/Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Maryrose P. Sullivan
- Urology Research, Veterans Administration Boston Healthcare System, Harvard Medical School, Boston, Massachusetts
| | - Rosalyn M. Adam
- Urology Research Center, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts
| | - Morris F. White
- Division of Endocrinology, Howard Hughes Medical Institute, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts
| | - Aria F. Olumi
- Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Corresponding author: Aria F. Olumi,
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6
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Chen C, Krishnan R, Zhou E, Ramachandran A, Tambe D, Rajendran K, Adam RM, Deng L, Fredberg JJ. Fluidization and resolidification of the human bladder smooth muscle cell in response to transient stretch. PLoS One 2010; 5:e12035. [PMID: 20700509 PMCID: PMC2917357 DOI: 10.1371/journal.pone.0012035] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Accepted: 07/14/2010] [Indexed: 11/22/2022] Open
Abstract
Background Cells resident in certain hollow organs are subjected routinely to large transient stretches, including every adherent cell resident in lungs, heart, great vessels, gut, and bladder. We have shown recently that in response to a transient stretch the adherent eukaryotic cell promptly fluidizes and then gradually resolidifies, but mechanism is not yet understood. Principal Findings In the isolated human bladder smooth muscle cell, here we applied a 10% transient stretch while measuring cell traction forces, elastic modulus, F-actin imaging and the F-actin/G-actin ratio. Immediately after a transient stretch, F-actin levels and cell stiffness were lower by about 50%, and traction forces were lower by about 70%, both indicative of prompt fluidization. Within 5min, F-actin levels recovered completely, cell stiffness recovered by about 90%, and traction forces recovered by about 60%, all indicative of resolidification. The extent of the fluidization response was uninfluenced by a variety of signaling inhibitors, and, surprisingly, was localized to the unstretch phase of the stretch-unstretch maneuver in a manner suggestive of cytoskeletal catch bonds. When we applied an “unstretch-restretch” (transient compression), rather than a “stretch-unstretch” (transient stretch), the cell did not fluidize and the actin network did not depolymerize. Conclusions Taken together, these results implicate extremely rapid actin disassembly in the fluidization response, and slow actin reassembly in the resolidification response. In the bladder smooth muscle cell, the fluidization response to transient stretch occurs not through signaling pathways, but rather through release of increased tensile forces that drive acute disassociation of actin.
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Affiliation(s)
- Cheng Chen
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, China
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Ramaswamy Krishnan
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Enhua Zhou
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Aruna Ramachandran
- Urological Diseases Research Center, Department of Urology, Children's Hospital Boston and Department of Surgery, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Dhananjay Tambe
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Kavitha Rajendran
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Rosalyn M. Adam
- Urological Diseases Research Center, Department of Urology, Children's Hospital Boston and Department of Surgery, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Linhong Deng
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, China
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
- * E-mail:
| | - Jeffrey J. Fredberg
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
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Ramachandran A, Ranpura SA, Gong EM, Mulone M, Cannon GM, Adam RM. An Akt- and Fra-1-dependent pathway mediates platelet-derived growth factor-induced expression of thrombomodulin, a novel regulator of smooth muscle cell migration. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:119-31. [PMID: 20472895 PMCID: PMC2893656 DOI: 10.2353/ajpath.2010.090772] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/09/2010] [Indexed: 11/20/2022]
Abstract
Overdistension of hollow organs evokes pathological changes characterized by smooth muscle remodeling. Mechanical stimuli induce smooth muscle cell (SMC) growth through acute activation of signaling cascades and by increased expression of soluble mitogens. Physical forces have also been implicated in ligand-independent activation of receptor tyrosine kinases, including the platelet-derived growth factor (PDGF) receptor, although the extent to which this occurs in intact tissue is unknown. Previously, we implicated Akt and activator protein-1 (AP-1) as mediators of growth and gene expression in SMC exposed to cyclic stretch or PDGF. Here we show that bladder wall distension leads to PDGFR activation and identify thrombomodulin (TM) as an Akt and AP-1 target in SMC. We demonstrate that TM, also induced by bladder stretch injury, is regulated at the transcriptional level by the AP-1 components c-jun and Fra1. Mutation of an AP-1 motif at -2010/-2004 abolished both AP-1 binding and PDGF responsiveness of the TM promoter. Fra1 silencing diminished PDGF-induced TM expression and SMC cell cycle transit. In contrast, TM knockdown did not affect cell growth but attenuated PDGF-stimulated SMC migration. Taken together, these results reveal new facets of TM regulation in SMC and provide the first demonstration of a role for endogenous TM in PDGF-induced cell migration. Moreover, TM induction on bladder injury suggests that it may be a biomarker for pathological smooth muscle remodeling.
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Affiliation(s)
- Aruna Ramachandran
- Urological Diseases Research Center, John F. Enders Research Laboratories, Room 1077, Children's Hospital Boston, 300 Longwood Ave., Boston, MA 02115, USA
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Aitken KJ, Tolg C, Panchal T, Leslie B, Yu J, Elkelini M, Sabha N, Tse DJ, Lorenzo AJ, Hassouna M, Bägli DJ. Mammalian target of rapamycin (mTOR) induces proliferation and de-differentiation responses to three coordinate pathophysiologic stimuli (mechanical strain, hypoxia, and extracellular matrix remodeling) in rat bladder smooth muscle. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 176:304-19. [PMID: 20019183 DOI: 10.2353/ajpath.2010.080834] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Maladaptive bladder muscle overgrowth and de-differentiation in human bladder obstructive conditions is instigated by coordinate responses to three stimuli: mechanical strain, tissue hypoxia, and extracellular matrix remodeling.( 1,2) Pathway analysis of genes induced by obstructive models of injury in bladder smooth muscle cells (BSMCs) identified a mammalian target of rapamycin (mTOR)-specific inhibitor as a potential pharmacological inhibitor. Strain-induced mTOR-specific S6K activation segregated differently from ERK1/2 activation in intact bladder ex vivo. Though rapamycin's antiproliferative effects in vascular smooth muscle cells are well known, its effects on BSMCs were previously unknown. Rapamycin significantly inhibited proliferation of BSMCs in response to mechanical strain, hypoxia, and denatured collagen. Rapamycin inhibited S6K at mTOR-sensitive phosphorylation sites in response to strain and hypoxia. Rapamycin also supported smooth muscle actin expression in response to strain or hypoxia-induced de-differentiation. Importantly, strain plus hypoxia synergistically augmented mTOR-dependent S6K activation, Mmp7 expression and proliferation. Forced expression of wild-type and constitutively active S6K resulted in loss of smooth muscle actin expression. Decreased smooth muscle actin, increased Mmp7 levels and mTOR pathway activation during in vivo partial bladder obstruction paralleled our in vitro studies. These results point to a coordinate role for mTOR in BSMCs responses to the three stimuli and a potential new therapeutic target for myopathic bladder disease.
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Affiliation(s)
- Karen J Aitken
- Developmental & Stem Cell Biology, The Hospital For Sick Children Research Institute, Toronto, ON M5G 1X8, Canada
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9
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The effect of enzymatically degradable poly(ethylene glycol) hydrogels on smooth muscle cell phenotype. Biomaterials 2008; 29:314-26. [DOI: 10.1016/j.biomaterials.2007.09.036] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 09/23/2007] [Indexed: 11/17/2022]
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10
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Estrada CR, Adam RM, Eaton SH, Bägli DJ, Freeman MR. Inhibition of EGFR signaling abrogates smooth muscle proliferation resulting from sustained distension of the urinary bladder. J Transl Med 2006; 86:1293-302. [PMID: 17043666 DOI: 10.1038/labinvest.3700483] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Urinary bladder outlet obstruction results in sustained stretch of the detrusor muscle and can lead to pathological smooth muscle hyperplasia and hypertrophy. The epidermal growth factor receptor (EGFR) is a cognate receptor for mitogens implicated in bladder hyperplasia/hypertrophy. Here, we investigated the potential for modulation of this pathway by pharmacologic targeting with a clinically available EGFR antagonist using an organ culture model of bladder stretch injury as a test system. Urinary bladders from adult female rats were distended in vivo with medium containing the EGFR inhibitor ZD1839 (gefitinib, Iressa). The bladders were excised and incubated in ex vivo organ culture for 4-24 h. EGFR phosphorylation, DNA proliferation, and the extent of apoptosis in the cultured tissues were assessed. To verify that the smooth muscle cells (SMC) are a target of the EGFR inhibitor, primary culture human and rat bladder SMC were subjected to cyclic mechanical stretch in vitro in the presence of ZD1839. Levels of phosphorylated EGFR were significantly increased in the detrusor muscle with 12 h of stretch in the organ cultures. This activation coincided with a subsequent 23-fold increase in DNA synthesis and a 30-fold decrease in apoptosis in the muscle compartment at 24 h. In the presence of ZD1839, DNA synthesis was reduced to basal levels without an increase in the rate of apoptosis under ex vivo conditions. Mechanical stretch of bladder SMC in vitro resulted in a significant increase in DNA synthesis, which was completely abrogated by treatment with ZD1839 but not by AG825, an inhibitor of the related receptor, ErbB2. Our results indicate that the EGFR pathway is a physiologically relevant signaling mechanism in hypertrophic bladder disease resulting from mechanical distension and may be amenable to pharmacologic intervention.
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Affiliation(s)
- Carlos R Estrada
- Urological Diseases Research Center, Department of Urology, Children's Hospital Boston, Boston, MA 02115, USA
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11
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Barros M, Martinelli R, Rocha H. Experimental supratrigonal cystectomy: evaluation of long-term complications. Int Braz J Urol 2006; 32:350-4. [PMID: 16813683 DOI: 10.1590/s1677-55382006000300017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2006] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The present study aims at assessing the occurrence of pyelonephritis and long-term complications in rats submitted to surgical reduction of bladder capacity. MATERIALS AND METHODS Sprague-Dawley rats were submitted to supratrigonal cystectomy (animals) or sham operation ( animals) and sacrificed 2, 4 and 6 months after the surgical procedure. The arterial blood pressure and serum creatinine levels were assessed before the surgery and at the time of the sacrifice. After the sacrifice a careful inspection of the urinary apparatus was performed to the characterization of the hydronephrosis and for the detection of the presence of calculi. With sterile technique, the urine was aspirated from the bladder and the kidneys removed and sent to a microbiologic study. RESULTS Pyelonephritis was frequent in animals submitted to supratrigonal cystectomy. The most frequent and isolated microorganisms were Staphylococcus sp. and E. coli. The presence of urinary calculi was correlated significantly to the presence of urinary tract infection (p < 0.003). Arterial hypertension was frequent amongst animals submitted to supratrigonal cystectomy. Serum creatinine was high in 72.4% of the animals in the group submitted to supratrigonal cystectomy. The presence of calculi and pyelonephritis were frequent in rats presenting renal insufficiency and in hypertensive rats. CONCLUSIONS The long-term course of urinary infection in rats submitted to supratrigonal cystectomy was characterized by a high incidence of renal insufficiency and arterial hypertension that seem to be related to dysfunction and bladder obstruction induced by an extensive surgical procedure and the presence of urolithiasis and pyelonephritis.
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Affiliation(s)
- Milton Barros
- Section of Urology, School of Medicine, Federal University of Bahia, Salvador, Bahia, Brazil.
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