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Jagirdar RM, Pitaraki E, Rouka E, Papazoglou ED, Bartosova M, Zebekakis P, Schmitt CP, Zarogiannis SG, Liakopoulos V. Differential effects of biocompatible peritoneal dialysis fluids on human mesothelial and endothelial cells in 2D and 3D phenotypes. Artif Organs 2024; 48:484-494. [PMID: 38151979 DOI: 10.1111/aor.14703] [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: 09/07/2023] [Revised: 11/30/2023] [Accepted: 12/12/2023] [Indexed: 12/29/2023]
Abstract
INTRODUCTION Peritoneal dialysis (PD) is a life maintaining treatment in patients with end-stage renal disease. Its chronic application leads to peritoneal mesothelial layer denudation and fibrotic transformation along with vascular activation of inflammatory pathways. The impact of different PD fluids (PDF) on mesothelial and endothelial cell function and repair mechanisms are not comprehensively described. MATERIALS AND METHODS Mesothelial (MeT-5A) and endothelial cells (EA.hy926) were cultured in 1:1 ratio with cell medium and different PDF (icodextrin-based, amino acid-based, and glucose-based). Cell adhesion, cell migration, and cell proliferation in 2D and spheroid formation and collagen gel contraction assays in 3D cell cultures were performed. RESULTS Cell proliferation and cell-mediated gel contraction were both significantly decreased in all conditions. 3D spheroid formation was significantly reduced with icodextrin and amino acid PDF, but unchanged with glucose PDF. Adhesion was significantly increased by amino acid PDF in mesothelial cells and decreased by icodextrin and amino acid PDF in endothelial cells. Migration capacity was significantly decreased in mesothelial cells by all three PDF, while endothelial cells remained unaffected. CONCLUSIONS In 3D phenotypes the effects of PDF are more uniform in both mesothelial and endothelial cells, mitigating spheroid formation and gel contraction. On the contrary, effects on 2D phenotypes are more uniform in the icodextrin and amino acid PDF as opposed to glucose ones and affect mesothelial cells more variably. 2D and 3D comparative assessments of PDF effects on the main peritoneal membrane cell barriers, the mesothelial and endothelial, could provide useful translational information for PD studies.
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Affiliation(s)
- Rajesh M Jagirdar
- 2nd Department of Nephrology, AHEPA Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Eleanna Pitaraki
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Erasmia Rouka
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Eleftherios D Papazoglou
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Maria Bartosova
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Pantelis Zebekakis
- First Department of Internal Medicine, AHEPA Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Claus Peter Schmitt
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Sotirios G Zarogiannis
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Vassilios Liakopoulos
- 2nd Department of Nephrology, AHEPA Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Tanriverdi HI, Günşar C, Neşe N, Yılmaz Ö, Şencan A. Could increased expression of aquaporin-1 be an etiological cause in childhood noncommunicating hydroceles that do not regress spontaneously? J Pediatr Urol 2021; 17:706.e1-706.e4. [PMID: 34391691 DOI: 10.1016/j.jpurol.2021.07.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND Aquaporins are membrane water channel proteins that are expressed in the epithelium and endothelium. Their primary function is to control the flow of water in the membranes of the cells. OBJECTIVE In this study, we investigated whether there is increased expression of aquaporin-1 in the tunica vaginalis of hydrocele patients in childhood that do not regress spontaneously an whether it has an effect on the etiology of hydrocele. STUDY DESIGN Boys who were diagnosed with hydrocele and scheduled for surgery were included and formed the hydrocele group. Boys in the same age range who underwent surgery for inguinal hernia or undescended testicles were included as a control group. Aquaporin-1 expression was evaluated by immunohistochemical examination of capillaries in tissue samples taken from the tunica vaginalis during the operation. Aquaporin-1-positive vessels were counted by selecting 5 unrelated areas with the highest vascular density, and the average number of vessels was calculated for each case. RESULTS A total of 48 male patients were included in the study. Of these, 27 constituted the hydrocele group (mean age 3.51 ± 2.59 years), and 21 constituted the control group (inguinal hernia, n = 17; undescended testicle, n = 4) (mean age 3.95 ± 3.80 years). The mean ages of both groups were statistically similar (p = 0.32). The mean numbers of aquaporin-1-positive vessels at the capillaries in the tunica vaginalis of the patients were 20.74 ± 7.10 in hydrocele group and 17.23 ± 4.07 in the control group. The expression of aquaporin-1 in the hydrocele group was significantly higher (p = 0.037). DISCUSSION It was shown that aquaporin-1 expression was higher in adult cases with hydrocele. Also an increase in aquaporin-1 expression was detected in tunica vaginalis of children with hydrocele in our study. CONCLUSION It was thought that aquaporin-1 overexpression may play a role in non-communicating hydroceles in children.
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Affiliation(s)
| | - Cüneyt Günşar
- Manisa Celal Bayar University Medical School, Department of Pediatric Surgery, Manisa, Turkey.
| | - Nalan Neşe
- Manisa Celal Bayar University Medical School, Department of Pathology, Manisa, Turkey.
| | - Ömer Yılmaz
- Manisa Celal Bayar University Medical School, Department of Pediatric Surgery, Manisa, Turkey.
| | - Aydın Şencan
- Manisa Celal Bayar University Medical School, Department of Pediatric Surgery, Manisa, Turkey.
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3
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van Gelder MK, Ligabue G, Giovanella S, Bianchini E, Simonis F, Hazenbrink DHM, Joles JA, Bajo Rubio MA, Selgas R, Cappelli G, Gerritsen KGF. In vitro efficacy and safety of a system for sorbent-assisted peritoneal dialysis. Am J Physiol Renal Physiol 2020; 319:F162-F170. [PMID: 32475132 DOI: 10.1152/ajprenal.00079.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A system for sorbent-assisted peritoneal dialysis (SAPD) was designed to continuously recirculate dialysate via a tidal mode using a single lumen peritoneal catheter with regeneration of spent dialysate by means of sorbent technology. We hypothesize that SAPD treatment will maintain a high plasma-to-dialysate concentration gradient and increase the mass transfer area coefficient of solutes. Thereby, the SAPD system may enhance clearance while reducing the number of exchanges. Application is envisaged at night as a bedside device (12 kg, nighttime system). A wearable system (2.0 kg, daytime system) may further enhance clearance during the day. Urea, creatinine, and phosphate removal were studied with the daytime and nighttime system (n = 3 per system) by recirculating 2 liters of spent peritoneal dialysate via a tidal mode (mean flow rate: 50 and 100 mL/min, respectively) for 8 h in vitro. Time-averaged plasma clearance over 24 h was modeled assuming one 2 liter exchange/day, an increase in mass transfer area coefficient, and 0.9 liters ultrafiltration/day. Urea, creatinine, and phosphate removal was 33.2 ± 4.1, 5.3 ± 0.5, and 6.2 ± 1.8 mmol, respectively, with the daytime system and 204 ± 28, 10.3 ± 2.4, and 11.4 ± 2.1 mmol, respectively, with the nighttime system. Time-averaged plasma clearances of urea, creatinine and phosphate were 9.6 ± 1.1, 9.6 ± 1.7, and 7.0 ± 0.9 mL/min, respectively, with the nighttime system and 10.8 ± 1.1, 13.4 ± 1.8, and 9.7 ± 1.6 mL/min, respectively, with the daytime and nighttime system. SAPD treatment may improve removal of uremic toxins compared with conventional peritoneal dialysis, provided that peritoneal mass transport will increase.
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Affiliation(s)
- Maaike K van Gelder
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Giulia Ligabue
- Division of Nephrology, Surgical, Medical, Dental, Morphology Sciences, Transplant, Oncology and Regenerative Medicine Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Silvia Giovanella
- Division of Nephrology, Surgical, Medical, Dental, Morphology Sciences, Transplant, Oncology and Regenerative Medicine Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Elena Bianchini
- Division of Nephrology, Surgical, Medical, Dental, Morphology Sciences, Transplant, Oncology and Regenerative Medicine Department, University of Modena and Reggio Emilia, Modena, Italy
| | | | - Diënty H M Hazenbrink
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jaap A Joles
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maria A Bajo Rubio
- Nephrology Service, Hospital Universitario La Paz, Institute for Health Research, Instituto Reina Sofía de Investigación en Nefrología, the Spanish Renal Research Network, Madrid, Spain
| | - Rafael Selgas
- Nephrology Service, Hospital Universitario La Paz, Institute for Health Research, Instituto Reina Sofía de Investigación en Nefrología, the Spanish Renal Research Network, Madrid, Spain
| | - Gianni Cappelli
- Division of Nephrology, Surgical, Medical, Dental, Morphology Sciences, Transplant, Oncology and Regenerative Medicine Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Karin G F Gerritsen
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
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Roumeliotis S, Dounousi E, Salmas M, Eleftheriadis T, Liakopoulos V. Unfavorable Effects of Peritoneal Dialysis Solutions on the Peritoneal Membrane: The Role of Oxidative Stress. Biomolecules 2020; 10:biom10050768. [PMID: 32423139 PMCID: PMC7277773 DOI: 10.3390/biom10050768] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/08/2020] [Accepted: 05/12/2020] [Indexed: 02/07/2023] Open
Abstract
One of the main limitations to successful long-term use of peritoneal dialysis (PD) as a renal replacement therapy is the harmful effects of PD solutions to the structure and function of the peritoneal membrane (PM). In PD, the PM serves as a semipermeable membrane that, due to exposure to PD solutions, undergoes structural alterations, including peritoneal fibrosis, vasculopathy, and neoangiogenesis. In recent decades, oxidative stress (OS) has emerged as a novel risk factor for mortality and cardiovascular disease in PD patients. Moreover, it has become evident that OS plays a pivotal role in the pathogenesis and development of the chronic, progressive injury of the PM. In this review, we aimed to present several aspects of OS in PD patients, including the pathophysiologic effects on the PM, clinical implications, and possible therapeutic antioxidant strategies that might protect the integrity of PM during PD therapy.
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Affiliation(s)
- Stefanos Roumeliotis
- Division of Nephrology and Hypertension, 1st Department of Internal Medicine, School of Medicine, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece;
| | - Evangelia Dounousi
- Department of Nephrology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece;
| | - Marios Salmas
- Department of Anatomy, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | | | - Vassilios Liakopoulos
- Division of Nephrology and Hypertension, 1st Department of Internal Medicine, School of Medicine, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece;
- Correspondence: ; Tel.: +30-2310-994-694
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AQP1-Containing Exosomes in Peritoneal Dialysis Effluent As Biomarker of Dialysis Efficiency. Cells 2019; 8:cells8040330. [PMID: 30970608 PMCID: PMC6523141 DOI: 10.3390/cells8040330] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/29/2019] [Accepted: 04/06/2019] [Indexed: 11/24/2022] Open
Abstract
The water channel Aquaporin 1 (AQP1) plays a fundamental role in water ultrafiltration during peritoneal dialysis (PD) and its reduced expression or function may be responsible for ultrafiltration failure (UFF). In humans, AQP1 is expressed in the endothelium of the peritoneal capillaries but its expression in mesothelial cells (MC) and its functional role in PD is still being debated. Here, we studied a cohort of 30 patients using PD in order to determine the presence of AQP1 in peritoneal biopsies, AQP1 release in the PD effluent through exosomes and the correlation of AQP1 abundance with the efficiency of peritoneal ultrafiltration. The experiments using immunofluorescence showed a strong expression of AQP1 in MCs. Immunoblotting analysis on vesicles isolated from PD effluents showed a consistent presence of AQP1, mesothelin and Alix and the absence of the CD31. Thus, this suggests that they have an exclusive mesothelial origin. The immunoTEM analysis showed a homogeneous population of nanovesicles and confirmed the immunoblotting results. Interestingly, the quantitative analysis by ELISA showed a positive correlation between AQP1 in the PD effluent and ultrafiltration (UF), free water transport (FWT) and Na-sieving. This evidence opens the discussion on the functional role of mesothelial AQP1 during PD and suggests that it may represent a potential non-invasive biomarker of peritoneal barrier integrity, with predictive potential of UFF in PD patients.
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6
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Bartosova M, Schmitt CP. Biocompatible Peritoneal Dialysis: The Target Is Still Way Off. Front Physiol 2019; 9:1853. [PMID: 30700974 PMCID: PMC6343681 DOI: 10.3389/fphys.2018.01853] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/07/2018] [Indexed: 01/01/2023] Open
Abstract
Peritoneal dialysis (PD) is a cost-effective, home-based therapy for patients with end-stage renal disease achieving similar outcome as compared to hemodialysis. Still, a minority of patients only receive PD. To a significant extend, this discrepancy is explained by major limitations regarding PD efficiency and sustainability. Due to highly unphysiological composition of PD fluids, the peritoneal membrane undergoes rapid morphological and long-term functional alterations, which limit the treatment and contribute to adverse patient outcome. This review is focused on the peritoneal membrane ultrastructure and its transformation in patients with kidney disease and chronic PD, underlying molecular mechanisms, and potential systemic sequelae. Current knowledge on the impact of conventional and second-generation PD fluids is described; novel strategies and innovative PD fluid types are discussed.
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Affiliation(s)
| | - Claus Peter Schmitt
- Center for Pediatric and Adolescent Medicine Heidelberg, University of Heidelberg, Heidelberg, Germany
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Zhai Y, Xu H, Shen Q, Schaefer F, Schmitt CP, Chen J, Liu H, Liu J, Liu J. pH-mediated upregulation of AQP1 gene expression through the Spi-B transcription factor. BMC Mol Biol 2018; 19:4. [PMID: 29554889 PMCID: PMC5859780 DOI: 10.1186/s12867-018-0104-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 03/06/2018] [Indexed: 11/21/2022] Open
Abstract
Background Bicarbonate-based peritoneal dialysis (PD) fluids enhance the migratory capacity and damage-repair ability of human peritoneal mesothelial cells by upregulating AQP1. However, little is known about the underlying molecular mechanisms. Results Here we used HEK-293T cells to investigate the effect of pH on AQP1 gene transcription levels. We found that AQP1 mRNA levels increases with pH. Transfection of HEK-293T cells with luciferase reporter vectors containing different regions of the AQP1 promoter identified an upstream region in the AQP1 gene between − 2200 and – 2300 bp as an enhancer required for pH-mediated regulation of AQP1 expression. Site-directed mutagenesis of this specific promoter region revealed a critical region between − 2257 and − 2251 bp, and gene knock-down experiments and ChIP assays suggested that the Spi-B transcription factor SPIB is involved in pH-mediated regulation of AQP1 expression. Conclusions We identified an upstream region in the AQP1 gene and the transcription factor SPIB that are critically involved in pH-mediated regulation of AQP1 expression. These findings provide the basis for further studies on the pH- and buffer-dependent effects of PD fluids on peritoneal membrane integrity and function. Electronic supplementary material The online version of this article (10.1186/s12867-018-0104-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yihui Zhai
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, No. 399 Wanyuan Road, Shanghai, 201102, China.,Shanghai Kidney Development and Pediatric Kidney Disease Research Center, Shanghai, China
| | - Hong Xu
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, No. 399 Wanyuan Road, Shanghai, 201102, China. .,Shanghai Kidney Development and Pediatric Kidney Disease Research Center, Shanghai, China.
| | - Qian Shen
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, No. 399 Wanyuan Road, Shanghai, 201102, China.,Shanghai Kidney Development and Pediatric Kidney Disease Research Center, Shanghai, China
| | - Franz Schaefer
- Division of Pediatric Nephrology, Center for Pediatric and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Claus P Schmitt
- Division of Pediatric Nephrology, Center for Pediatric and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Jing Chen
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, No. 399 Wanyuan Road, Shanghai, 201102, China.,Shanghai Kidney Development and Pediatric Kidney Disease Research Center, Shanghai, China
| | - Haimei Liu
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, No. 399 Wanyuan Road, Shanghai, 201102, China.,Shanghai Kidney Development and Pediatric Kidney Disease Research Center, Shanghai, China
| | - Jialu Liu
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, No. 399 Wanyuan Road, Shanghai, 201102, China.,Shanghai Kidney Development and Pediatric Kidney Disease Research Center, Shanghai, China
| | - Jiaojiao Liu
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, No. 399 Wanyuan Road, Shanghai, 201102, China.,Shanghai Kidney Development and Pediatric Kidney Disease Research Center, Shanghai, China
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Eich G, Bartosova M, Tischer C, Wlodkowski TT, Schaefer B, Pichl S, Kraewer N, Ranchin B, Vondrak K, Liebau MC, Hackert T, Schmitt CP. Bicarbonate buffered peritoneal dialysis fluid upregulates angiopoietin-1 and promotes vessel maturation. PLoS One 2017; 12:e0189903. [PMID: 29253861 PMCID: PMC5734783 DOI: 10.1371/journal.pone.0189903] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 12/04/2017] [Indexed: 11/28/2022] Open
Abstract
Background Ultrafiltration decline is a progressive issue for patients on chronic peritoneal dialysis (PD) and can be caused by peritoneal angiogenesis induced by PD fluids. A recent pediatric trial suggests better preservation of ultrafiltration with bicarbonate versus lactate buffered fluid; underlying molecular mechanisms are unknown. Methods Angiogenic cytokine profile, tube formation capacity and Receptor Tyrosine Kinase translocation were assessed in primary human umbilical vein endothelial cells following incubation with bicarbonate (BPDF) and lactate buffered (LPDF), pH neutral PD fluid with low glucose degradation product content and lactate buffered, acidic PD fluid with high glucose degradation product content (CPDF). Peritoneal biopsies from age-, PD-vintage- and dialytic glucose exposure matched, peritonitis-free children on chronic PD underwent automated histomorphometry and immunohistochemistry. Results In endothelial cells angiopoietin-1 mRNA and protein abundance increased 200% upon incubation with BPDF, but decreased by 70% with LPDF as compared to medium control; angiopoietin-2 remained unchanged. Angiopoietin-1/Angiopoietin-2 protein ratio was 15 and 3-fold increased with BPDF compared to LPDF and medium. Time-lapse microscopy with automated network analysis demonstrated less endothelial cell tube formation with BPDF compared to LPDF and CPDF incubation. Receptor Tyrosine Kinase translocated to the cell membrane in BPDF but not in LPDF or CPDF incubated endothelial cells. In children dialyzed with BPDF peritoneal vessels were larger and angiopoietin-1 abundance in CD31 positive endothelium higher compared to children treated with LPDF. Conclusion Bicarbonate buffered PD fluid promotes vessel maturation via upregulation of angiopoietin-1 in vitro and in children on dialysis. Our findings suggest a molecular mechanism for the observed superior preservation of ultrafiltration capacity with bicarbonate buffered PD fluid with low glucose degradation product content.
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Affiliation(s)
- Gwendolyn Eich
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Maria Bartosova
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | | | - Tanja Tamara Wlodkowski
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Betti Schaefer
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Sebastian Pichl
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Nicole Kraewer
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Bruno Ranchin
- Service de Néphrologie Pédiatrique, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, France
| | - Karel Vondrak
- Department of Pediatrics, University Hospital Motol, Prague, Czech Republic
| | - Max Christoph Liebau
- Pediatric Nephrology, Department of Pediatrics and Center for Molecular Medicine, University Hospital of Cologne, Cologne, Germany
| | - Thilo Hackert
- Department of Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Claus Peter Schmitt
- Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
- * E-mail:
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Kitterer D, Biegger D, Segerer S, Braun N, Alscher MD, Latus J. Alteration of membrane complement regulators is associated with transporter status in patients on peritoneal dialysis. PLoS One 2017; 12:e0177487. [PMID: 28542228 PMCID: PMC5438122 DOI: 10.1371/journal.pone.0177487] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/27/2017] [Indexed: 01/05/2023] Open
Abstract
Introduction A growing body of evidence from animal models and cell culture studies indicate an important role of a local regulatory complement system (CS) in peritoneal injury during peritoneal dialysis (PD). We investigated the expression of the local regulatory CS (reflected by CD46,CD55,CD59) in the peritoneal tissue of patients with different membrane function characteristics. Patients and methods Biopsies from the parietal peritoneum were taken from 24 patients on PD, 22 uremic patients prior to PD. PD patients were grouped according to the dialysate-to-plasma ratio of creatinine (D/P Cre) and ratio of dialysate glucose at 4 hours versus dialysate glucose at time zero (D/D0 glucose) into low or low-average peritoneal transport status (L/LA) and high-average or high-transport status (HA/H) groups. CD46, CD55, and CD59 RNA expression were analyzed by real-time polymerase chain reaction (RT-PCR). Further localization of membrane complement regulators (CRegs) and semiquantitatively analysis was done by immunohistochemistry (IHC). Results CD46 and CD59 expression were similar in all groups. CD55 expression was significantly decreased in the HA/H group compared to the L/LA group and to uremic controls (p < 0.05 and p = 0.05, respectively). No statistically significant differences in CD46, CD55, and CD55 expression were detected when considering the history of peritonitis. There was no statistically significant correlation between PD duration and the expressions of CD46, CD55, and CD59. IHC revealed strong CD46, CD55, and CD59 expression in mesothelial cells. CD55 and CD59 were additionally detected in the vasculature. Using IHC, CD46 was lower in PD patients compared to uremic controls (p>0.05), but there was no difference between the L/LA compared to the H/HA group. Moreover IHC confirmed decreased expression of CD55 in the HA/H group compared to the L/LA group and uremic controls (p<0.0001 and p = 0.0001, respectively). Conclusion CD55 expression is decreased in patients with fast transporter membrane function, whereas peritonitis and PD duration do not appear to alter CReg expression.
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Affiliation(s)
- Daniel Kitterer
- Department of Internal Medicine, Division of Nephrology, Robert-Bosch-Hospital, Stuttgart, Germany
- * E-mail:
| | - Dagmar Biegger
- Dr. Margarete Fischer–Bosch Institute of Clinical Pharmacology, University of Tuebingen, Stuttgart, Germany
| | - Stephan Segerer
- Division of Nephrology, Dialysis & Transplantation, Kantonsspital Aarau, Aarau, Switzerland
| | - Niko Braun
- Nephrology Center Stuttgart, Stuttgart, Germany
| | - M. Dominik Alscher
- Department of Internal Medicine, Division of Nephrology, Robert-Bosch-Hospital, Stuttgart, Germany
| | - Joerg Latus
- Department of Internal Medicine, Division of Nephrology, Robert-Bosch-Hospital, Stuttgart, Germany
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Zhang W, Freichel M, van der Hoeven F, Nawroth PP, Katus H, Kälble F, Zitron E, Schwenger V. Novel Endothelial Cell-Specific AQP1 Knockout Mice Confirm the Crucial Role of Endothelial AQP1 in Ultrafiltration during Peritoneal Dialysis. PLoS One 2016; 11:e0145513. [PMID: 26760974 PMCID: PMC4711985 DOI: 10.1371/journal.pone.0145513] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/05/2015] [Indexed: 11/25/2022] Open
Abstract
The water channel aquaporin-1 (AQP1) mediates about 50% ultrafiltration during a 2-hour hypertonic dwell in global AQP1 knockout (AQP1-/-) mice. Although AQP1 is widely expressed in various cell types including mesothelial cells, the ultrafiltration has been assumed to be mediated via endothelial AQP1 of the peritoneum. The partial embryonic lethality and reduced body weight in AQP1-/- mice may reflect potential confounding phenotypic effects evoked by ubiquitous AQP1 deletion, which may interfere with functional analysis of endothelial AQP1. Using a Cre/loxP approach, we generated and characterised endothelial cell- and time-specific AQP1 knockout (AQP1fl/fl; Cdh5-Cre+) mice. Compared to controls, AQP1fl/fl; Cdh5-Cre+ mice showed no difference in an initial clinical and biological analysis at baseline, including body weight and survival. During a 1-hour 3.86% mini-peritoneal equilibration test (mini-PET), AQP1fl/fl; Cdh5-Cre+ mice exhibited strongly decreased indices for AQP1-related transcellular water transport (43.0% in net ultrafiltration, 93.0% in sodium sieving and 57.9% in free water transport) compared to controls. The transport rates for small solutes of urea and glucose were not significantly altered. Our data provide the first direct experimental evidence for the functional relevance of endothelial AQP1 to the fluid transport in peritoneal dialysis and thereby further validate essential predictions of the three-pore model of peritoneal transport.
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Affiliation(s)
- Wei Zhang
- Department of Nephrology, University of Heidelberg, Heidelberg, Germany
- * E-mail:
| | - Marc Freichel
- Institute of Pharmacology, University of Heidelberg, Heidelberg, Germany
| | | | - Peter Paul Nawroth
- Department of Endocrinology and Metabolism, University of Heidelberg, Heidelberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Hugo Katus
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Florian Kälble
- Department of Nephrology, University of Heidelberg, Heidelberg, Germany
| | - Edgar Zitron
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Vedat Schwenger
- Department of Nephrology, University of Heidelberg, Heidelberg, Germany
- Department of Nephrology, Klinikum Stuttgart, Stuttgart, Germany
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Salis A, Ninham BW. Models and mechanisms of Hofmeister effects in electrolyte solutions, and colloid and protein systems revisited. Chem Soc Rev 2014; 43:7358-77. [PMID: 25099516 DOI: 10.1039/c4cs00144c] [Citation(s) in RCA: 365] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Specific effects of electrolytes have posed a challenge since the 1880's. The pioneering work was that of Franz Hofmeister who studied specific salt induced protein precipitation. These effects are the rule rather the exception and are ubiquitous in chemistry and biology. Conventional electrostatic theories (Debye-Hückel, DLVO, etc.) cannot explain such effects. Over the past decades it has been recognised that additional quantum mechanical dispersion forces with associated hydration effects acting on ions are missing from theory. In parallel Collins has proposed a phenomenological set of rules (the law of matching water affinities, LMWA) which explain and bring to order the order of ion-ion and ion-surface site interactions at a qualitative level. The two approaches appear to conflict. Although the need for inclusion of quantum dispersion forces in one form or another is not questioned, the modelling has often been misleading and inappropriate. It does not properly describe the chemical nature (kosmotropic/chaotropic or hard/soft) of the interacting species. The success of the LMWA rules lies in the fact that they do. Here we point to the way that the two apparently opposing approaches might be reconciled. Notwithstanding, there are more challenges, which deal with the effect of dissolved gas and its connection to 'hydrophobic' interactions, the problem of water at different temperatures and 'water structure' in the presence of solutes. They take us to another dimension that requires the rebuilding of theoretical foundations.
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Affiliation(s)
- Andrea Salis
- Department of Chemical and Geological Science, University of Cagliari, Italy and CSGI.
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Optimizing peritoneal dialysis prescription for volume control: the importance of varying dwell time and dwell volume. Pediatr Nephrol 2014; 29:1321-7. [PMID: 23903692 DOI: 10.1007/s00467-013-2573-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 07/01/2013] [Accepted: 07/09/2013] [Indexed: 01/24/2023]
Abstract
Not only adequate uremic toxin removal but also volume control is essential in peritoneal dialysis (PD) to improve patient outcome. Modification of dwell time impacts on both ultrafiltration (UF) and purification. A short dwell favors UF but preferentially removes small solutes such as urea. A long dwell favors uremic toxin removal but also peritoneal fluid reabsorption due to the time-dependent loss of the crystalloid osmotic gradient. In particular, the long daytime dwell in automated PD may result in significant water and sodium reabsorption, and in such cases icodextrin should be considered. Increasing dwell volume favors the removal of solutes such as sodium due to the increased volume of diffusion and the recruitment of peritoneal surface area. A very large fill volume with too high an intraperitoneal pressure (IPP) may, however, result in back-filtration and thus reduced UF and sodium clearance. Based on these principles and the individual transport and pressure kinetics obtained from peritoneal equilibration tests and IPP measurements, we suggest combining short dwells with a low fill volume to favor UF with long dwells and a large fill volume to favor solute removal. Results from a recent randomized cross-over trial and earlier observational data in children support this concept: the absolute UF and UF relative to the administered glucose increased and solute removal and blood pressure improved.
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Büchel J, Bartosova M, Eich G, Wittenberger T, Klein-Hitpass L, Steppan S, Hackert T, Schaefer F, Passlick-Deetjen J, Schmitt CP. Interference of peritoneal dialysis fluids with cell cycle mechanisms. Perit Dial Int 2014; 35:259-74. [PMID: 25082841 DOI: 10.3747/pdi.2013.00010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 01/28/2014] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Peritoneal dialysis fluids (PDF) differ with respect to osmotic and buffer compound, and pH and glucose degradation products (GDP) content. The impact on peritoneal membrane integrity is still insufficiently described. We assessed global genomic effects of PDF in primary human peritoneal mesothelial cells (PMC) by whole genome analyses, quantitative real-time polymerase chain reaction (RT-PCR) and functional measurements. METHODS PMC isolated from omentum of non-uremic patients were incubated with conventional single chamber PDF (CPDF), lactate- (LPDF), bicarbonate- (BPDF) and bicarbonate/lactate-buffered double-chamber PDF (BLPDF), icodextrin (IPDF) and amino acid PDF (APDF), diluted 1:1 with medium. Affymetrix GeneChip U133Plus2.0 (Affymetrix, CA, USA) and quantitative RT-PCR were applied; cell viability was assessed by proliferation assays. RESULTS The number of differentially expressed genes compared to medium was 464 with APDF, 208 with CPDF, 169 with IPDF, 71 with LPDF, 45 with BPDF and 42 with BLPDF. Out of these genes 74%, 73%, 79%, 72%, 47% and 57% were downregulated. Gene Ontology (GO) term annotations mainly revealed associations with cell cycle (p = 10(-35)), cell division, mitosis, and DNA replication. One hundred and eighteen out of 249 probe sets detecting genes involved in cell cycle/division were suppressed, with APDF-treated PMC being affected the most regarding absolute number and degree, followed by CPDF and IPDF. Bicarbonate-containing PDF and BLPDF-treated PMC were affected the least. Quantitative RT-PCR measurements confirmed microarray findings for key cell cycle genes (CDK1/CCNB1/CCNE2/AURKA/KIF11/KIF14). Suppression was lowest for BPDF and BLPDF, they upregulated CCNE2 and SMC4. All PDF upregulated 3 out of 4 assessed cell cycle repressors (p53/BAX/p21). Cell viability scores confirmed gene expression results, being 79% of medium for LPDF, 101% for BLPDF, 51% for CPDF and 23% for IPDF. Amino acid-containing PDF (84%) incubated cells were as viable as BPDF (86%). CONCLUSION In conclusion, PD solutions substantially differ with regard to their gene regulating profile and impact on vital functions of PMC, i.e. on cells known to be essential for peritoneal membrane homeostasis.
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Affiliation(s)
- Janine Büchel
- Fresenius Medical Care Deutschland GmbH, Bad Homburg, Germany
| | - Maria Bartosova
- University Hospital for Pediatrics & Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Gwendolyn Eich
- University Hospital for Pediatrics & Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | | | - Ludger Klein-Hitpass
- University of Duisburg-Essen, Faculty of Medicine, Institute of Cell Biology, Essen, Germany
| | - Sonja Steppan
- Fresenius Medical Care Deutschland GmbH, Bad Homburg, Germany
| | - Thilo Hackert
- Department of Surgery, University of Heidelberg, Heidelberg, Germany
| | - Franz Schaefer
- University Hospital for Pediatrics & Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | | | - Claus P Schmitt
- University Hospital for Pediatrics & Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
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Cugia F, Monduzzi M, Ninham BW, Salis A. Interplay of ion specificity, pH and buffers: insights from electrophoretic mobility and pH measurements of lysozyme solutions. RSC Adv 2013. [DOI: 10.1039/c3ra00063j] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Schmitt CP, Nau B, Gemulla G, Bonzel KE, Hölttä T, Testa S, Fischbach M, John U, Kemper MJ, Sander A, Arbeiter K, Schaefer F. Effect of the dialysis fluid buffer on peritoneal membrane function in children. Clin J Am Soc Nephrol 2012; 8:108-15. [PMID: 23124784 DOI: 10.2215/cjn.00690112] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Double-chamber peritoneal dialysis fluids exert less toxicity by their neutral pH and reduced glucose degradation product content. The role of the buffer compound (lactate and bicarbonate) has not been defined in humans. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A multicenter randomized controlled trial in 37 children on automated peritoneal dialysis was performed. After a 2-month run-in period with conventional peritoneal dialysis fluids, patients were randomized to neutral-pH, low-glucose degradation product peritoneal dialysis fluids with 35 mM lactate or 34 mM bicarbonate content. Clinical and biochemical monitoring was performed monthly, and peritoneal equilibration tests and 24-hour clearance studies were performed at 0, 3, 6, and 10 months. RESULTS No statistically significant difference in capillary blood pH, serum bicarbonate, or oral buffer supplementation emerged during the study. At baseline, peritoneal solute equilibration and clearance rates were similar. During the study, 4-hour dialysis to plasma ratio of creatinine tended to increase, and 24-hour dialytic creatinine and phosphate clearance increased with lactate peritoneal dialysis fluid but not with bicarbonate peritoneal dialysis fluid. Daily net ultrafiltration, which was similar at baseline (lactate fluid=5.4±2.6 ml/g glucose exposure, bicarbonate fluid=4.9±1.9 ml/g glucose exposure), decreased to 4.6±1.0 ml/g glucose exposure in the lactate peritoneal dialysis fluid group, whereas it increased to 5.1±1.7 ml/g glucose exposure in the bicarbonate content peritoneal dialysis fluid group (P=0.006 for interaction). CONCLUSIONS When using biocompatible peritoneal dialysis fluids, equally good acidosis control is achieved with lactate and bicarbonate buffers. Improved long-term preservation of peritoneal membrane function may, however, be achieved with bicarbonate-based peritoneal dialysis fluids.
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