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Muacevic A, Adler JR, Shukla TS, Gutlapalli SD, Farhat H, Muthiah K, Pallipamu N, Hamid P. A Review on Major Pathways Leading to Peritoneal Fibrosis in Patients Receiving Continuous Peritoneal Dialysis. Cureus 2022; 14:e31799. [PMID: 36579194 PMCID: PMC9788797 DOI: 10.7759/cureus.31799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022] Open
Abstract
Peritoneal fibrosis (PF) is the most important complication of peritoneal dialysis (PD) that may arise among patients receiving continuous ambulatory peritoneal dialysis (CAPD). PF is a complex process, and many factors contribute to the formation of fibrosis. PD solutions with high glucose content, chronic inflammation, inflammatory cytokines, angiogenesis, and mesothelial to mesenchymal transition (MMT) are factors contributing to the fibrosis of the peritoneum. These factors, as well as stress-induced fibrosis, are going to be discussed further in this article. Although most experimental models are promising in preventing or delaying PD-related fibrosis, most of these recommended treatment options require further research. The lack of sufficient data from real PD patients and many inconclusive data make clinicians depend on conservative treatment. New therapeutics are indeed required for the management of patients undergoing PD to prevent the dreaded complication that may arise from continuous PD. Newer PD solutions are needed to improve survival and minimize the complication associated with PD. Recently, newer PD solutions have been shown to improve patient survival and peritoneal viability and reduce this complication that may arise as a result of continuous PD.
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Strippoli R, Sandoval P, Moreno-Vicente R, Rossi L, Battistelli C, Terri M, Pascual-Antón L, Loureiro M, Matteini F, Calvo E, Jiménez-Heffernan JA, Gómez MJ, Jiménez-Jiménez V, Sánchez-Cabo F, Vázquez J, Tripodi M, López-Cabrera M, Del Pozo MÁ. Caveolin1 and YAP drive mechanically induced mesothelial to mesenchymal transition and fibrosis. Cell Death Dis 2020; 11:647. [PMID: 32811813 PMCID: PMC7435273 DOI: 10.1038/s41419-020-02822-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 12/27/2022]
Abstract
Despite their emerging relevance to fully understand disease pathogenesis, we have as yet a poor understanding as to how biomechanical signals are integrated with specific biochemical pathways to determine cell behaviour. Mesothelial-to-mesenchymal transition (MMT) markers colocalized with TGF-β1-dependent signaling and yes-associated protein (YAP) activation across biopsies from different pathologies exhibiting peritoneal fibrosis, supporting mechanotransduction as a central driving component of these class of fibrotic lesions and its crosstalk with specific signaling pathways. Transcriptome and proteome profiling of the response of mesothelial cells (MCs) to linear cyclic stretch revealed molecular changes compatible with bona fide MMT, which (i) overlapped with established YAP target gene subsets, and were largely dependent on endogenous TGF-β1 signaling. Importantly, TGF-β1 blockade blunts the transcriptional upregulation of these gene signatures, but not the mechanical activation and nuclear translocation of YAP per se. We studied the role therein of caveolin-1 (CAV1), a plasma membrane mechanotransducer. Exposure of CAV1-deficient MCs to cyclic stretch led to a robust upregulation of MMT-related gene programs, which was blunted upon TGF-β1 inhibition. Conversely, CAV1 depletion enhanced both TGF-β1 and TGFBRI expression, whereas its re-expression blunted mechanical stretching-induced MMT. CAV1 genetic deficiency exacerbated MMT and adhesion formation in an experimental murine model of peritoneal ischaemic buttons. Taken together, these results support that CAV1-YAP/TAZ fine-tune the fibrotic response through the modulation of MMT, onto which TGF-β1-dependent signaling coordinately converges. Our findings reveal a cooperation between biomechanical and biochemical signals in the triggering of MMT, representing a novel potential opportunity to intervene mechanically induced disorders coursing with peritoneal fibrosis, such as post-surgical adhesions.
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Affiliation(s)
- Raffaele Strippoli
- Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy. .,National Institute for Infectious Diseases L. Spallanzani, IRCCS, Via Portuense, 292, 00149, Rome, Italy. .,Mechanoadaptation & Caveolae Biology Lab, Cell and Developmental Biology Area, Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029, Madrid, Spain.
| | - Pilar Sandoval
- Programa de Homeostasis de Tejidos y Organos, Centro de Biología Molecular "Severo Ochoa"-CSIC, 28049, Madrid, Spain
| | - Roberto Moreno-Vicente
- Mechanoadaptation & Caveolae Biology Lab, Cell and Developmental Biology Area, Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029, Madrid, Spain
| | - Lucia Rossi
- Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Cecilia Battistelli
- Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Michela Terri
- Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy.,National Institute for Infectious Diseases L. Spallanzani, IRCCS, Via Portuense, 292, 00149, Rome, Italy
| | - Lucía Pascual-Antón
- Programa de Homeostasis de Tejidos y Organos, Centro de Biología Molecular "Severo Ochoa"-CSIC, 28049, Madrid, Spain
| | - Marta Loureiro
- Cardiovascular Proteomics laboratory, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) and CIBER Cardiovascular Diseases (CIBERCV), Instituto de Salud Carlos III, 28029, Madrid, Spain
| | - Francesca Matteini
- Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Enrique Calvo
- Cardiovascular Proteomics laboratory, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) and CIBER Cardiovascular Diseases (CIBERCV), Instituto de Salud Carlos III, 28029, Madrid, Spain
| | - José Antonio Jiménez-Heffernan
- Departamento de Anatomía Patológica, Hospital Universitario La Princesa, Instituto de Investigación Sanitaria Princesa (IP), 28006, Madrid, Spain
| | - Manuel José Gómez
- Bioinformatics Unit, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029, Madrid, Spain
| | - Victor Jiménez-Jiménez
- Mechanoadaptation & Caveolae Biology Lab, Cell and Developmental Biology Area, Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029, Madrid, Spain
| | - Fátima Sánchez-Cabo
- Bioinformatics Unit, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029, Madrid, Spain
| | - Jesús Vázquez
- Cardiovascular Proteomics laboratory, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) and CIBER Cardiovascular Diseases (CIBERCV), Instituto de Salud Carlos III, 28029, Madrid, Spain
| | - Marco Tripodi
- Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy.,National Institute for Infectious Diseases L. Spallanzani, IRCCS, Via Portuense, 292, 00149, Rome, Italy
| | - Manuel López-Cabrera
- Programa de Homeostasis de Tejidos y Organos, Centro de Biología Molecular "Severo Ochoa"-CSIC, 28049, Madrid, Spain.
| | - Miguel Ángel Del Pozo
- Mechanoadaptation & Caveolae Biology Lab, Cell and Developmental Biology Area, Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029, Madrid, Spain.
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Paniagua R, de Jesús Ventura M, Rodríguez E, Sil J, Galindo T, Hurtado ME, Alcántara G, Chimalpopoca A, González I, Sanjurjo A, Barrón L, Amato D, Mujais S. Impact of Fill Volume on Peritoneal Clearances and Cytokine Appearance in Peritoneal Dialysis. Perit Dial Int 2020. [DOI: 10.1177/089686080402400206] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background Current adequacy guidelines for peritoneal dialysis encourage the use of large fill volumes for the attainment of small solute clearance targets. These guidelines have influenced clinical practice in a significant way, and adoption of higher fill volumes has become common in North America. Several studies, however, have challenged the relevance of increasing small solute clearance; this practice may result in untoward consequences in patients. Objective The present study was designed to explore the relationship between dialysate volume and the clearance of different sized molecules, fluid dynamics, and appearance of peritoneal cytokines. Methods Thirteen adult prevalent patients on continuous ambulatory peritoneal dialysis were studied. Three different dialysate volumes (2.0, 2.5, and 3.0 L) were infused on consecutive days in a random order. Several measurements of peritoneal fluid dynamics (intraperitoneal pressure, net ultrafiltration, fluid absorption), solute clearances (urea, creatinine, β2-microglobulin, albumin, IgG, and transferrin), and appearance of interleukin-6 and tumor necrosis factor alpha (TNFα) were assessed. Results Increase in dialysate fill volume (from 2 to 2.5 to 3 L) was examined in relationship to body surface area (BSA). The dialysate volume/BSA (DV/BSA) ratio increased from 1262 to 1566 to 1871 mL/m2 on 2.0, 2.5, and 3.0 L dialysate volumes, respectively. In parallel, diastolic blood pressure increased from 82.7 ± 8.8 to 87.0 ± 9.5 to 92 ± 8.3 mmHg ( p < 0.05). Net ultrafiltration rate also increased, from 0.46 ± 0.48 to 0.72 ± 0.42 to 0.97 ± 0.49 mL/minute ( p < 0.01), despite a concomitant increase in fluid absorption, from 1.05 ± 0.34 to 1.21 ± 0.40 to 1.56 ± 0.22 mL/min ( p < 0.01). Urea peritoneal clearance increased from 8.27 ± 0.68 to 9.92 ± 1.6 to 12.98 ± 4.03 mL/min ( p < 0.01); creatinine peritoneal clearance increased from 6.69 ± 1.01 to 7.64 ± 1.12 to 8.69 ± 1.76 mL/min ( p < 0.01). Clearance of the other measured molecules did not change. Appearance of interleukin-6 increased 17% and 43% ( p < 0.01), and TNFα appearance increased 14% and 50% ( p < 0.01) when dialysate volumes of 2.5 and 3.0 L were used, compared with 2.0 L. Conclusions These results show that, with higher values of DV/BSA ratio, small solute peritoneal clearance is increased, but clearances of large molecules remain unchanged. With the use of higher volumes, fluid absorption rate and the appearance of proinflammatory cytokines in the dialysate are increased.
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Affiliation(s)
- Ramón Paniagua
- Unidad de Investigación Médica en Enfermedades Nefrológicas, Hospital de Especialidades Centro Médico Nacional Siglo XXI, México
| | - María de Jesús Ventura
- Unidad de Investigación Médica en Enfermedades Nefrológicas, Hospital de Especialidades Centro Médico Nacional Siglo XXI, México
| | - Ernesto Rodríguez
- Unidad de Investigación Médica en Enfermedades Nefrológicas, Hospital de Especialidades Centro Médico Nacional Siglo XXI, México
| | - Juana Sil
- Hospital General Regional Gabriel Mancera IMSS, México
| | | | | | | | | | | | | | | | - Dante Amato
- Unidad de Investigación Médica en Enfermedades Nefrológicas, Hospital de Especialidades Centro Médico Nacional Siglo XXI, México
| | - Salim Mujais
- Baxter Healthcare Corporation, Deerfield, Illinois, USA
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Shimizu M, Ishibashi Y, Taki F, Shimizu H, Hirahara I, Kaname S, Fujita T. EndothelinB Receptor Blocker Inhibits High Glucose-Induced Synthesis of Fibronectin in Human Peritoneal Mesothelial Cells. Perit Dial Int 2020. [DOI: 10.1177/089686080602600318] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background Long-term peritoneal dialysis using glucose-based dialysates is associated with peritoneal fibrosis. The object of this study was to investigate the hypothesis that endothelin (ET)-1, which is known to play an important role in various fibrotic diseases, may also be involved in peritoneal fibrosis using human peritoneal mesothelial cells (HPMC). Methods HPMC were cultured with 4% d- or l-glucose, or loaded with 10 nmol/L ET-1. In some experiments, the ETA receptor antagonist BQ-123, the ETB receptor antagonist BQ-788, and antioxidants 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPOL) and diphenyleneiodium chloride (DPI) were used. mRNA expression of ET-1, ETA receptor, ETB receptor, and fibronectin (FN) was analyzed by real-time polymerase chain reaction (real-time PCR). The protein levels for FN and ET-1 were measured by ELISA. CM-H2DCFDA-sensitive reactive oxygen species (ROS) were evaluated by flow cytometry. Results d-Glucose significantly induced mRNA expression of ET-1 and the ETB receptor but not the ETA receptor. FN production under high glucose conditions was inhibited by BQ-788. ET-1 directly stimulated HPMC to increase mRNA expression of FN and CM-H2DCFDA-sensitive ROS production. BQ-788, TEMPOL, and DPI inhibited mRNA expression of FN induced by ET-1. Conclusion The present study suggests that high-glucose-induced FN synthesis is mediated by the ET-1/ETB receptor pathway and, therefore, an ETB receptor antagonist may be useful in preventing FN production in HPMC.
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Affiliation(s)
- Miyuki Shimizu
- Division of Total Renal Care Medicine, Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo
- Terumo Corporation R&D Center, Kanagawa, Japan
| | - Yoshitaka Ishibashi
- Division of Total Renal Care Medicine, Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo
| | - Fumika Taki
- Division of Total Renal Care Medicine, Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo
| | - Hideki Shimizu
- Division of Total Renal Care Medicine, Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo
| | - Ichiro Hirahara
- Division of Total Renal Care Medicine, Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo
- Terumo Corporation R&D Center, Kanagawa, Japan
| | - Shinya Kaname
- Division of Total Renal Care Medicine, Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo
| | - Toshiro Fujita
- Division of Total Renal Care Medicine, Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo
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Busnadiego O, Loureiro-Álvarez J, Sandoval P, Lagares D, Dotor J, Pérez-Lozano ML, López-Armada MJ, Lamas S, López-Cabrera M, Rodríguez-Pascual F. A pathogenetic role for endothelin-1 in peritoneal dialysis-associated fibrosis. J Am Soc Nephrol 2014; 26:173-82. [PMID: 25012164 DOI: 10.1681/asn.2013070799] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In patients undergoing peritoneal dialysis (PD), chronic exposure to nonphysiologic PD fluids elicits low-grade peritoneal inflammation, leading to fibrosis and angiogenesis. Phenotype conversion of mesothelial cells into myofibroblasts, the so-called mesothelial-to-mesenchymal transition (MMT), significantly contributes to the peritoneal dysfunction related to PD. A number of factors have been described to induce MMT in vitro and in vivo, of which TGF-β1 is probably the most important. The vasoconstrictor peptide endothelin-1 (ET-1) is a transcriptional target of TGF-β1 and mediates excessive scarring and fibrosis in several tissues. This work studied the contribution of ET-1 to the development of peritoneal damage and failure in a mouse model of PD. ET-1 and its receptors were expressed in the peritoneal membrane and upregulated on PD fluid exposure. Administration of an ET receptor antagonist, either bosentan or macitentan, markedly attenuated PD-induced MMT, fibrosis, angiogenesis, and peritoneal functional decline. Adenovirus-mediated overexpression of ET-1 induced MMT in human mesothelial cells in vitro and promoted the early cellular events associated with peritoneal dysfunction in vivo. Notably, TGF-β1-blocking peptides prevented these actions of ET-1. Furthermore, a positive reciprocal relationship was observed between ET-1 expression and TGF-β1 expression in human mesothelial cells. These results strongly support a role for an ET-1/TGF-β1 axis as an inducer of MMT and subsequent peritoneal damage and fibrosis, and they highlight ET-1 as a potential therapeutic target in the treatment of PD-associated dysfunction.
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Affiliation(s)
- Oscar Busnadiego
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jesús Loureiro-Álvarez
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; Laboratorio de Envejecimiento e Inflamación, Instituto de Investigación Biomédica, A Coruña, A Coruña, Spain; and
| | - Pilar Sandoval
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - David Lagares
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - María Luisa Pérez-Lozano
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - María J López-Armada
- Laboratorio de Envejecimiento e Inflamación, Instituto de Investigación Biomédica, A Coruña, A Coruña, Spain; and
| | - Santiago Lamas
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Manuel López-Cabrera
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Fernando Rodríguez-Pascual
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain;
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Kovačević P, Dragić S, Rajkovača Z, Veljković S, Kovačević T. Serum levels of nitric oxide and endothelin-1 in patients treated with continuous ambulatory peritoneal dialysis. Ren Fail 2013; 36:437-40. [DOI: 10.3109/0886022x.2013.867812] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Chennasamudram SP, Noor T, Vasylyeva TL. COMPARISON OF SEVELAMER AND CALCIUM CARBONATE ON ENDOTHELIAL FUNCTION AND INFLAMMATION IN PATIENTS ON PERITONEAL DIALYSIS. J Ren Care 2013; 39:82-9. [DOI: 10.1111/j.1755-6686.2013.12009.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sudha P. Chennasamudram
- Department of Pediatrics, School of Medicine; Texas Tech University Health Sciences Center; Amarillo; Texas; USA
| | - Tanjila Noor
- Department of Pediatrics, School of Medicine; Texas Tech University Health Sciences Center; Amarillo; Texas; USA
| | - Tetyana L. Vasylyeva
- Department of Pediatrics, School of Medicine; Texas Tech University Health Sciences Center; Amarillo; Texas; USA
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Kourti P, Zarogiannis SG, Liakopoulos V, Karioti A, Eleftheriadis T, Hatzoglou C, Gourgoulianis K, Molyvdas PA, Stefanidis I. Endothelin-1 acutely reduces the permeability of visceral sheep peritoneum in vitro through both endothelin-A and endothelin-B receptors. Artif Organs 2013; 37:308-12. [PMID: 23369074 DOI: 10.1111/j.1525-1594.2012.01565.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mesothelium is an important part of the peritoneal barrier for water and ion transport, essential for effective peritoneal dialysis (PD). Peritoneal fibrosis has been associated with PD treatment failure. Endothelin-1 (ET-1) is a potent vasoactive peptide, involved in pathologic fibrotic processes. Its action is mediated mainly by endothelin type A (ETA ) and type B (ETB ) receptors. The aim of this study was to investigate, by Ussing chamber experiments, the effect of ET-1 on the transmesothelial electrical resistance (RTM ) of the isolated visceral sheep peritoneum. Intact sheets of visceral peritoneum were obtained from 40 adult sheep and mounted in Ussing-type chambers. ET-1 (10(-7) M), BQ-123 (ETA receptor antagonist; 10(-6) M), BQ-788 (ETB receptor antagonist; 10(-6) M), and their combinations were added on the apical and the basolateral side of the peritoneum. RTM was measured before and serially after addition of the substances, and changes were registered as percentage (ΔRTM %). RTM increased within 1 min after addition of ET-1 apically (ΔRTM 65.03 ± 15.87%; P < 0.05) or basolaterally (ΔRTM 85.5 ± 20.86%; P < 0.05). BQ-123 and BQ-788 and their combination significantly reduced (P < 0.05) the effect of ET-1 to a similar degree in all cases. These results clearly indicate that ET-1 reduces ionic permeability of the visceral sheep peritoneum in vitro. Additionally, it is obvious that this inhibitory effect is mediated through both ETA and ETB receptors.
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Affiliation(s)
- Panagiota Kourti
- Department of Nephrology, Medical School, University of Thessaly, Larissa, Greece
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9
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Kalk P, Rückert M, Godes M, von Websky K, Relle K, Neumayer HH, Hocher B, Morgera S. Does endothelin B receptor deficiency ameliorate the induction of peritoneal fibrosis in experimental peritoneal dialysis? Nephrol Dial Transplant 2009; 25:1474-8. [PMID: 19945955 DOI: 10.1093/ndt/gfp652] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Peritoneal fibrosis is a serious complication of peritoneal dialysis (PD); however, the mechanisms are poorly understood. The endothelin system exhibits potent pro-fibrotic properties and is known to be stimulated in peritoneal fibrosis. Thus, our study aimed at elucidating the impact of the endothelin B (ETB) receptor on peritoneal membrane thickening by means of an ETB-deficient rat model (ETB(-)(/)(-)) in experimental PD. METHODS Wild-type (WT) and ETB(-/-) rats were randomly allocated to four groups (each group n = 10): (i) WT Sham, (ii) WT PD, (iii) ETB(-/-) Sham and (iv) ETB(-/-) PD. All animals underwent surgical implantation of a port for intraperitoneal administration and 1 week of habituation to the procedure by administration of 2 ml of saline once daily. Afterwards, all animals were switched to 12 weeks of 15 ml of saline (Sham groups) or commercially available PD fluid containing 3.86% glucose (PD groups) administered twice daily. Afterwards, animals were sacrificed, and samples from visceral as well as parietal peritoneum were obtained. The samples were stained with Sirius-Red, and at 10 different sites per sample, peritoneal membrane thickness was measured using computer-aided histomorphometry devices. RESULTS Mean peritoneal membrane thickness was increased by PD in both WT and ETB(-/-) rats versus respective Sham controls (WT Sham: 22.3 +/- 0.7 microm/ETB Sham: 22.3 +/- 0.9 microm versus WT PD: 26.5 +/- 1.5 microm/ETB PD: 28.7 +/- 1.2 microm; P < 0.05, respectively). However, no difference in peritoneal membrane thickness was detected between WT PD and ETB(-/-) PD groups. CONCLUSION Our study demonstrates that PD increases peritoneal membrane thickness in a rat model, but deficiency of the ETB receptor has no detectable impact on this process.
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Affiliation(s)
- Philipp Kalk
- Department of Pharmacology and Toxicology, Center for Cardiovascular Research, Charite, Berlin, Germany
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Morgera S, Schlenstedt J, Hambach P, Giessing M, Deger S, Hocher B, Neumayer HH. Combined ETA/ETB receptor blockade of human peritoneal mesothelial cells inhibits collagen I RNA synthesis. Kidney Int 2003; 64:2033-40. [PMID: 14633125 DOI: 10.1046/j.1523-1755.2003.00320.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Peritoneal fibrosis is a serious complication of peritoneal dialysis; however, the mechanisms are poorly understood. We studied osmolarity and physical stress-induced effects on collagen I RNA synthesis in human peritoneal mesothelial cells (HPMCs) and focused on endothelin as a possible mediator. METHODS HPMCs were grown in a medium containing either d-glucose or glycerol to analyze the impact of osmolarity on mesothelial endothelin-1 (ET-1) release and on collagen I RNA synthesis [reverse transcription-polymerase chain reaction (RT-PCR)]. A cellular model of nonlaminar fluid shear stress and cellular stretch was used to analyze the effects of physical forces. To neutralize the endothelin effects, a combined ETA/ETB receptor antagonist (LU 302 872) was chosen. RESULTS Glucose, but not glycerol, increased mesothelial ET-1 release in a concentration and time-dependent manner (P < 0.05 vs. controls). Collagen I RNA synthesis was significantly higher in glucose-challenged cell cultures (P < 0.05 vs. controls). The glucose-mediated collagen I RNA synthesis was completely inhibited by adding the combined ETA/ETB receptor antagonist to the medium. Fluid shear stress, but not cellular stretch, led to a significant increase in the mesothelial ET-1 release (P < 0.005 vs. controls) and collagen I RNA synthesis (P < 0.05 vs. controls). LU 302 872 completely inhibited these effects. CONCLUSION We found that glucose and fluid shear stress are potent stimuli for ET-1 release and collagen I RNA synthesis in a model cellular system. Although our system is highly artificial, our findings raise the hypothesis that similar effects may occur in the peritoneal membranes of peritoneal dialysis patients and suggest that endothelin might be involved.
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Affiliation(s)
- Stanislao Morgera
- Department of Nephrology, Charité, Humboldt University of Berlin, Berlin, Germany.
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