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Feng H, Zhu X, Tang Y, Fu S, Kong B, Liu X. Astragaloside IV ameliorates diabetic nephropathy in db/db mice by inhibiting NLRP3 inflammasome‑mediated inflammation. Int J Mol Med 2021; 48:164. [PMID: 34278447 PMCID: PMC8262660 DOI: 10.3892/ijmm.2021.4996] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 05/31/2021] [Indexed: 12/21/2022] Open
Abstract
Diabetic nephropathy (DN) is a primary cause of end‑stage renal disease. Despite the beneficial effects of astragaloside IV (AS)‑IV on renal disease, the underlying mechanism of its protective effects against DN has not been fully determined. The aims of the present study were to assess the effects of AS‑IV against DN in db/db mice and to explore the mechanism of AS‑IV involving the NLR family pyrin domain containing 3 (NLRP3), caspase‑1 and interleukin (IL)‑1β pathways. The 8‑week‑old db/db mice received 40 mg/kg AS‑IV once a day for 12 weeks via intragastric administration. Cultured mouse podocytes were used to further confirm the underlying mechanism in vitro. AS‑IV effectively reduced weight gain, hyperglycemia and the serum triacylglycerol concentration in db/db mice. AS‑IV also reduced urinary albumin excretion, urinary albumin‑to‑creatinine ratio and creatinine clearance rate, as well as improved renal structural changes, accompanied by the upregulation of the podocyte markers podocin and synaptopodin. AS‑IV significantly inhibited the expression levels of NLRP3, caspase‑1 and IL‑1β in the renal cortex, and reduced the serum levels of tumor necrosis factor (TNF)‑α and monocyte chemoattractant protein‑1. In high glucose‑induced podocytes, AS‑IV significantly improved the expression levels of NLRP3, pro‑caspase‑1 and caspase‑1, and inhibited the cell viability decrease in a dose‑dependent manner, while NLRP3 overexpression eliminated the effect of AS‑IV on podocyte injury and the inhibition of the NLRP3 and caspase‑1 pathways. The data obtained from in vivo and in vitro experiments demonstrated that AS‑IV ameliorated renal functions and podocyte injury and delayed the development of DN in db/db mice via anti‑NLRP3 inflammasome‑mediated inflammation.
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Affiliation(s)
- Hui Feng
- School of Chinese Medicine, School of Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, P.R. China
- Department of Laboratory of Diabetes, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, P.R. China
| | - Xiaoyun Zhu
- Department of Laboratory of Diabetes, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, P.R. China
| | - Yang Tang
- School of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, P.R. China
| | - Shouqiang Fu
- School of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, P.R. China
| | - Bingtan Kong
- Department of Laboratory of Diabetes, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, P.R. China
| | - Ximing Liu
- Department of Laboratory of Diabetes, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, P.R. China
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Racetin A, Filipović N, Lozić M, Ogata M, Gudelj Ensor L, Kelam N, Kovačević P, Watanabe K, Katsuyama Y, Saraga-Babić M, Glavina Durdov M, Vukojević K. A Homozygous Dab1 -/- Is a Potential Novel Cause of Autosomal Recessive Congenital Anomalies of the Mice Kidney and Urinary Tract. Biomolecules 2021; 11:biom11040609. [PMID: 33924028 PMCID: PMC8073787 DOI: 10.3390/biom11040609] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 01/09/2023] Open
Abstract
This study aimed to explore morphology changes in the kidneys of Dab1−/− (yotari) mice, as well as expression patterns of reelin, NOTCH2, LC3B, and cleaved caspase3 (CASP3) proteins, as potential determinants of normal kidney formation and function. We assumed that Dab1 functional inactivation may cause disorder in a wide spectrum of congenital anomalies of the kidney and urinary tract (CAKUT). Animals were sacrificed at postnatal days P4, P11, and P14. Paraffin-embedded kidney tissues were sectioned and analyzed by immunohistochemistry using specific antibodies. Kidney specimens were examined by bright-field, fluorescence, and electron microscopy. Data were analyzed by two-way ANOVA and t-tests. We noticed that yotari kidneys were smaller in size with a reduced diameter of nephron segments and thinner cortex. TEM microphotographs revealed foot process effacement in the glomeruli (G) of yotari mice, whereas aberrations in the structure of proximal convoluted tubules (PCT) and distal convoluted tubules (DCT) were not observed. A significant increase in reelin expression, NOTCH2, LC3B and cleaved CASP3 proteins was observed in the glomeruli of yotari mice. Renal hypoplasia in conjunction with foot process effacement and elevation in the expression of examined proteins in the glomeruli revealed CAKUT phenotype and loss of functional kidney tissue of yotari.
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Affiliation(s)
- Anita Racetin
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
- Department of Medical Genetics, School of Medicine, University of Mostar, 88000 Mostar, Bosnia and Herzegovina;
| | - Natalija Filipović
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | - Mirela Lozić
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | - Masaki Ogata
- Division of Anatomy, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi 981-8558, Japan;
| | - Larissa Gudelj Ensor
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | - Nela Kelam
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | - Petra Kovačević
- Department of Medical Genetics, School of Medicine, University of Mostar, 88000 Mostar, Bosnia and Herzegovina;
| | - Koichiro Watanabe
- Department of Anatomy, Shiga University of Medical Science, Ötsu 520-2192, Japan; (K.W.); (Y.K.)
| | - Yu Katsuyama
- Department of Anatomy, Shiga University of Medical Science, Ötsu 520-2192, Japan; (K.W.); (Y.K.)
| | - Mirna Saraga-Babić
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | | | - Katarina Vukojević
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
- Department of Medical Genetics, School of Medicine, University of Mostar, 88000 Mostar, Bosnia and Herzegovina;
- Correspondence: ; Tel.: +385-21-557-807; Fax: +385-1-557-811
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Zeng X, Ma S, Kruger JM, Wang R, Tan X, Qian C. High-resolution MRI of kidney microstructures at 7.05 T with an endo-colonic Wireless Amplified NMR detector. J Magn Reson 2019; 303:121-127. [PMID: 31051387 PMCID: PMC6590910 DOI: 10.1016/j.jmr.2019.04.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/19/2019] [Accepted: 04/21/2019] [Indexed: 05/06/2023]
Abstract
To map the hemodynamic responses of kidney microstructures at 7.05 T with improved sensitivity, a Wireless Amplified NMR Detector (WAND) with cylindrical symmetry was fabricated as an endoluminal detector that can convert externally provided wireless signal at 600.71 MHz into amplified MR signals at 300.33 MHz. When this detector was inserted inside colonic lumens to sensitively observe adjacent kidneys, it could clearly identify kidney microstructures in the renal cortex and renal medullary. Owing to the higher achievable spatial resolution, differential hemodynamic responses of kidney microstructures under different breathing conditions could be individually quantified to estimate the underlying correlation between oxygen bearing capability and local levels of oxygen unsaturation. The WAND's ability to map Blood Oxygen Level Dependent (BOLD) signal responses in heterogeneous microstructures will pave way for early-stage diagnosis of kidney diseases, without the use of contrast agents for reduced tissue retention and toxicity.
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Affiliation(s)
- Xianchun Zeng
- Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China; Department of Radiology, Michigan State University, East Lansing, MI, USA
| | - Shuangtao Ma
- Department of Medicine, Michigan State University, East Lansing, MI, USA
| | - John M Kruger
- Veterinary Medical Center, Michigan State University, East Lansing, MI, USA
| | - Rongpin Wang
- Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Xiaobo Tan
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA
| | - Chunqi Qian
- Department of Radiology, Michigan State University, East Lansing, MI, USA.
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Roda E, Barni S, Milzani A, Dalle-Donne I, Colombo G, Coccini T. Single Silver Nanoparticle Instillation Induced Early and Persisting Moderate Cortical Damage in Rat Kidneys. Int J Mol Sci 2017; 18:ijms18102115. [PMID: 28994738 PMCID: PMC5666797 DOI: 10.3390/ijms18102115] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 09/25/2017] [Accepted: 09/28/2017] [Indexed: 12/19/2022] Open
Abstract
The potential toxic effects of silver nanoparticles (AgNPs), administered by a single intratracheal instillation (i.t), was assessed in a rat model using commercial physico-chemical characterized nanosilver. Histopathological changes, overall toxic response and oxidative stress (kidney and plasma protein carbonylation), paralleled by ultrastructural observations (TEM), were evaluated to examine renal responses 7 and 28 days after i.t. application of a low AgNP dose (50 µg/rat), compared to an equivalent dose of ionic silver (7 µg AgNO3/rat). The AgNPs caused moderate renal histopathological and ultrastructural alteration, in a region-specific manner, being the cortex the most affected area. Notably, the bulk AgNO3, caused similar adverse effects with a slightly more marked extent, also triggering apoptotic phenomena. Specifically, 7 days after exposure to both AgNPs and AgNO3, dilatation of the intercapillary and peripheral Bowman’s space was observed, together with glomerular shrinkage. At day 28, these effects still persisted after both treatments, accompanied by an additional injury involving the vascular component of the mesangium, with interstitial micro-hemorrhages. Neither AgNPs nor AgNO3 induced oxidative stress effects in kidneys and plasma, at either time point. The AgNP-induced moderate renal effects indicate that, despite their benefits, novel AgNPs employed in consumer products need exhaustive investigation to ensure public health safety.
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Affiliation(s)
- Elisa Roda
- Laboratory of Clinical & Experimental Toxicology and Poison Control Centre and National Toxicology Information Centre, Toxicology Unit, ICS Maugeri SpA-Benefit Corporation, IRCCS Pavia, via Maugeri 10, 27100 Pavia, Italy.
- Department of Biology and Biotechnology "L. Spallanzani", Laboratory of Cell Biology and Neurobiology, University of Pavia, via Ferrata 9, 27100 Pavia, Italy.
| | - Sergio Barni
- Department of Biology and Biotechnology "L. Spallanzani", Laboratory of Cell Biology and Neurobiology, University of Pavia, via Ferrata 9, 27100 Pavia, Italy.
| | - Aldo Milzani
- Department of Biosciences, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy.
| | - Isabella Dalle-Donne
- Department of Biosciences, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy.
| | - Graziano Colombo
- Department of Biosciences, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy.
| | - Teresa Coccini
- Laboratory of Clinical & Experimental Toxicology and Poison Control Centre and National Toxicology Information Centre, Toxicology Unit, ICS Maugeri SpA-Benefit Corporation, IRCCS Pavia, via Maugeri 10, 27100 Pavia, Italy.
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Chen JY, Jian DY, Lien CC, Lin YT, Ting CH, Chen LK, Hsu TC, Huang HM, Wu YT, Kuan TT, Chao YW, Wu LY, Huang SW, Juan CC. Adipocytes play an etiological role in the podocytopathy of high-fat diet-fed rats. J Endocrinol 2016; 231:109-120. [PMID: 27539963 DOI: 10.1530/joe-16-0064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 08/18/2016] [Indexed: 12/14/2022]
Abstract
Obesity is a risk factor that promotes progressive kidney disease. Studies have shown that an adipocytokine imbalance contributes to impaired renal function in humans and animals, but the underlying interplay between adipocytokines and renal injury remains to be elucidated. We aimed to investigate the mechanisms linking obesity to chronic kidney disease. We assessed renal function in high-fat (HF) diet-fed and normal diet-fed rats, and the effects of preadipocyte- and adipocyte-conditioned medium on cultured podocytes. HF diet-fed and normal diet-fed Sprague Dawley rats were used to analyze the changes in plasma BUN, creatinine, urine protein and renal histology. Additionally, podocytes were incubated with preadipocyte- or adipocyte-conditioned medium to investigate the effects on podocyte morphology and protein expression. In the HF diet group, 24 h urinary protein excretion (357.5 ± 64.2 mg/day vs 115.9 ± 12.4 mg/day, P < 0.05) and the urine protein/creatinine ratio were significantly higher (1.76 ± 0.22 vs 1.09 ± 0.15, P < 0.05), increased kidney weight (3.54 ± 0.04 g vs 3.38 ± 0.04 g, P < 0.05) and the glomerular volume and podocyte effacement increased by electron microscopy. Increased renal expression of desmin and decreased renal expression of CD2AP and nephrin were also seen in the HF diet group (P < 0.05). Furthermore, we found that adipocyte-conditioned medium-treated podocytes showed increased desmin expression and decreased CD2AP and nephrin expression compared with that in preadipocyte-conditioned medium-treated controls (P < 0.05). These findings show that adipocyte-derived factor(s) can modulate renal function. Adipocyte-derived factors play an important role in obesity-related podocytopathy.
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MESH Headings
- 3T3-L1 Cells
- Adipocytes, White/metabolism
- Adipocytes, White/pathology
- Adiposity
- Animals
- Biomarkers/blood
- Biomarkers/metabolism
- Biomarkers/urine
- Cell Line
- Culture Media, Conditioned
- Diet, High-Fat/adverse effects
- Disease Models, Animal
- Disease Progression
- Gene Expression Regulation
- Insulin Resistance
- Intra-Abdominal Fat/metabolism
- Intra-Abdominal Fat/pathology
- Kidney Cortex/metabolism
- Kidney Cortex/pathology
- Kidney Cortex/physiopathology
- Kidney Cortex/ultrastructure
- Male
- Mice
- Microscopy, Electron, Transmission
- Obesity/etiology
- Obesity/physiopathology
- Organ Size
- Podocytes/metabolism
- Podocytes/pathology
- Podocytes/ultrastructure
- Rats, Sprague-Dawley
- Renal Insufficiency, Chronic/diagnostic imaging
- Renal Insufficiency, Chronic/metabolism
- Renal Insufficiency, Chronic/pathology
- Renal Insufficiency, Chronic/physiopathology
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Affiliation(s)
- Jinn-Yang Chen
- Division of NephrologyDepartment of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Faculty of MedicineNational Yang-Ming University, Taipei, Taiwan
| | - Deng-Yuan Jian
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
- Division of NephrologyWen-Lin Hemodialysis Unit, Taipei, Taiwan
| | - Chih-Chan Lien
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
| | - Yu-Ting Lin
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
| | - Ching-Heng Ting
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
| | - Luen-Kui Chen
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
| | - Ting-Chia Hsu
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
| | - Hsuan-Min Huang
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
| | - Yu-Ting Wu
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
| | - Tse-Ting Kuan
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
| | - Yu-Wen Chao
- Department of Medical Research and EducationTaipei Veterans General Hospital, Taipei, Taiwan
- Section of NephrologyDepartment of Internal Medicine, Heping Branch, Taipei City Hospital, Taipei, Taiwan
| | - Liang-Yi Wu
- Department of Bioscience TechnologyCollege of Science, Chung Yuan Christian University, Chung Li District, Taoyuan City, Taiwan
| | - Seng-Wong Huang
- Faculty of MedicineNational Yang-Ming University, Taipei, Taiwan
| | - Chi-Chang Juan
- Institute of PhysiologyNational Yang-Ming University, Taipei, Taiwan
- Department of Medical Research and EducationTaipei Veterans General Hospital, Taipei, Taiwan
- Department of Education and ResearchTaipei City Hospital, Taipei, Taiwan
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Kumar D, Singla SK, Puri V, Puri S. The restrained expression of NF-kB in renal tissue ameliorates folic acid induced acute kidney injury in mice. PLoS One 2015; 10:e115947. [PMID: 25559736 PMCID: PMC4283964 DOI: 10.1371/journal.pone.0115947] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 11/27/2014] [Indexed: 01/13/2023] Open
Abstract
The Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) represent family of structurally-related eukaryotic transcription factors which regulate diverse array of cellular processes including immunological responses, inflammation, apoptosis, growth & development. Increased expression of NF-kB has often been seen in many diverse diseases, suggesting the importance of genomic deregulation to disease pathophysiology. In the present study we focused on acute kidney injury (AKI), which remains one of the major risk factor showing a high rate of mortality and morbidity. The pathology associated with it, however, remains incompletely known though inflammation has been reported to be one of the major risk factor in the disease pathophysiology. The role of NF-kB thus seemed pertinent. In the present study we show that high dose of folic acid (FA) induced acute kidney injury (AKI) characterized by elevation in levels of blood urea nitrogen & serum creatinine together with extensive tubular necrosis, loss of brush border and marked reduction in mitochondria. One of the salient observations of this study was a coupled increase in the expression of renal, relA, NF-kB2, and p53 genes and proteins during folic acid induced AKI (FA AKI). Treatment of mice with NF-kB inhibitor, pyrrolidine dithio-carbamate ammonium (PDTC) lowered the expression of these transcription factors and ameliorated the aberrant renal function by decreasing serum creatinine levels. In conclusion, our results suggested that NF-kB plays a pivotal role in maintaining renal function that also involved regulating p53 levels during FA AKI.
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Affiliation(s)
- Dev Kumar
- Department of Biochemistry, Panjab University, Chandigarh, India
| | | | - Veena Puri
- Centre for Systems Biology & Bioinformatics, Panjab University, Chandigarh, India
| | - Sanjeev Puri
- Biotechnology Branch, University Institute of Engineering & Technology, Panjab University, Chandigarh, India
- Centre for Stem Cell & Tissue Engineering, Panjab University, Chandigarh, India
- * E-mail:
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Milosavljevic Z, Zelen I, Sazdanovic M. Autonomic innervation of the periglomerular arteries. Anal Quant Cytopathol Histpathol 2014; 36:161-166. [PMID: 25141492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVE To explore spatial and volume relations of the calcitonine gene-related peptide (CGRP)-positive and tyrosine hydroxylase (TH)-positive nerve fibers in the wall of cortical blood vessels. STUDY DESIGN Kidney specimens from 10 rats were processed for confocal microscopy. Nerve fibers were stained with anti-CGRP and anti-TH antibodies and image stacks were collected. Three-dimensional reconstruction and quantification of labeled fibers were performed to reveal their distribution and spatial relations. RESULTS CGRP- and TH-immunoreactive nerve fibers were distributed throughout the kidney cortex. TH-positive fibers were dominant in the small periglomerular arteries (up to 4.6-fold). Examined nerves were finely intertwined in the wall of small blood vessels of the kidney and ran in the same nerve bundle but without co-localization. Extensive, web-like branching and varicosities of the TH nerves were observed. Sensory fibers prevailed in the wall of the larger arteries "embedded" into tubules near the medullary rays, and their endings can be verified in the muscularis layer of the interlobular arteries. CONCLUSION Characteristics of the investigated fibers emphasize their role in the regulation of kidney blood vessel diameter and their influence on hypertension onset.
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Rashedy AH, Solimany AA, Ismail AK, Wahdan MH, Saban KA. Histopathological and functional effects of antimony on the renal cortex of growing albino rat. Int J Clin Exp Pathol 2013; 6:1467-80. [PMID: 23923065 PMCID: PMC3726962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 07/09/2013] [Indexed: 06/02/2023]
Abstract
Contamination of the environment with antimony compounds may affect human health through the persistent exposure to small doses over a long period. Sixty growing male albino rats, weighing 43-57 grams, utilized in this study. The animals were divided into 3 groups; each of 20 rats: animals of group I served as control, animals of group II received 6 mg/kg body weight antimony trisulfide daily for 8 weeks with drinking water, and those of group III received the same dose by the same route for 12 weeks. The Malpighian renal corpuscles showed distortion, destruction and congestion of glomerular tuft, vacuoles in the glomeruli, peritubular haemorrhage, obliteration of Bowman's space, and thickening with irregularity of Bowman's membrane. The proximal convoluted tubules demonstrated patchy loss of their brush border, thickening of the basement membrane with loss of its basal infoldings, disarrangement of the mitochondria, pleomorphic vacuoles in the cytoplasm, apical destruction of the cells, apical migration of the nuclei, and absence of microvilli. On the other hand, peri-tubular hemorrhage, apical vacuolation, small atrophic nuclei, swelling of mitochondria, obliteration of the lumina, destruction of cells, and presence of tissue debris in the lumina, were observed in the distal convoluted tubules. The present work demonstrated the hazardous effect of antimony on the renal function as evidenced by the significant increase of the level of blood urea, serum creatinine, and serum sodium and potassium. In conclusion, this study proposed that continuous oral administration of antimony for 8 and 12 weeks has hazardous toxic effect on the structure and function of the kidney in growing albino rat. Based on the results of the present study, it is recommended to avoid the use of any drinking water contaminated with antimony compounds and forbidden its use in infants and children foods.
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Affiliation(s)
- Ahmed H Rashedy
- Department of Pathology, College of Medicine, Taif UniversityKSA
| | - Adnan A Solimany
- Department of Pediatric, College of Medicine, Taif UniversityKSA
| | - Ayman K Ismail
- Departments of Forensic Medicine and Toxicology, College of Medicine, Taif UniversityKSA
- Departments of Forensic Medicine and Toxicology, Suez Canal UniversityEgypt
| | | | - Khalid A Saban
- Department of Nuclear Medicine, College of Medicine, Taif UniversityKSA
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Rice WL, Van Hoek AN, Păunescu TG, Huynh C, Goetze B, Singh B, Scipioni L, Stern LA, Brown D. High resolution helium ion scanning microscopy of the rat kidney. PLoS One 2013; 8:e57051. [PMID: 23505418 PMCID: PMC3591388 DOI: 10.1371/journal.pone.0057051] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 01/17/2013] [Indexed: 01/11/2023] Open
Abstract
Helium ion scanning microscopy is a novel imaging technology with the potential to provide sub-nanometer resolution images of uncoated biological tissues. So far, however, it has been used mainly in materials science applications. Here, we took advantage of helium ion microscopy to explore the epithelium of the rat kidney with unsurpassed image quality and detail. In addition, we evaluated different tissue preparation methods for their ability to preserve tissue architecture. We found that high contrast, high resolution imaging of the renal tubule surface is possible with a relatively simple processing procedure that consists of transcardial perfusion with aldehyde fixatives, vibratome tissue sectioning, tissue dehydration with graded methanol solutions and careful critical point drying. Coupled with the helium ion system, fine details such as membrane texture and membranous nanoprojections on the glomerular podocytes were visualized, and pores within the filtration slit diaphragm could be seen in much greater detail than in previous scanning EM studies. In the collecting duct, the extensive and striking apical microplicae of the intercalated cells were imaged without the shrunken or distorted appearance that is typical with conventional sample processing and scanning electron microscopy. Membrane depressions visible on principal cells suggest possible endo- or exocytotic events, and central cilia on these cells were imaged with remarkable preservation and clarity. We also demonstrate the use of colloidal gold probes for highlighting specific cell-surface proteins and find that 15 nm gold labels are practical and easily distinguishable, indicating that external labels of various sizes can be used to detect multiple targets in the same tissue. We conclude that this technology represents a technical breakthrough in imaging the topographical ultrastructure of animal tissues. Its use in future studies should allow the study of fine cellular details and provide significant advances in our understanding of cell surface structures and membrane organization.
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Affiliation(s)
- William L. Rice
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Alfred N. Van Hoek
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Teodor G. Păunescu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Chuong Huynh
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Bernhard Goetze
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Bipin Singh
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Larry Scipioni
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Lewis A. Stern
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Dennis Brown
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
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Sasser JM, Moningka NC, Tsarova T, Baylis C. Nebivolol does not protect against 5/6 ablation/infarction induced chronic kidney disease in rats - comparison with angiotensin II receptor blockade. Life Sci 2012; 91:54-63. [PMID: 22727796 DOI: 10.1016/j.lfs.2012.06.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 05/24/2012] [Accepted: 05/31/2012] [Indexed: 01/31/2023]
Abstract
AIMS Nitric oxide (NO) deficiency contributes to chronic kidney disease progression. Nebivolol, a beta adrenergic receptor antagonist, may enhance endogenous NO. Here, we investigated whether Nebivolol attenuates hypertension and renal injury after 5/6 ablation/infarction (A/I). Efficacy was compared to the AT1 receptor antagonist Olmesartan. MAIN METHODS Kidney disease and hypertension were induced by right kidney ablation and ~2/3 infarction of the left kidney. Rats were treated orally with vehicle (placebo), Nebivolol (5mg/kg b.i.d.), or Olmesartan (2.5mg/kg/day) for 6 weeks after A/I. KEY FINDINGS With placebo, glomerular sclerosis and tubulointersititial fibrosis developed with increased blood pressure and proteinuria, and a fall in NO(x) excretion. Olmesartan prevented these changes, but Nebivolol had no effect on these measures but lowered heart rate. Neither treatment reduced systemic oxidative stress (urinary hydrogen peroxide and TBARS). Compared to controls, renal cortex abundance of nNOSα decreased and nNOSβ increased in rats after 5/6 A/I, with no changes in eNOS. Neither treatment restored nNOSα; however, both reduced nNOSβ. Activity of DDAH was decreased by 5/6 A/I but restored by both treatments despite no increase in DDAH protein abundance. Kidney cortex abundance of manganese SOD fell after 5/6 A/I and was restored by treatment with Olmesartan but not Nebivolol. Extracellular and copper/zinc SOD abundances were not changed. SIGNIFICANCE In conclusion, Nebivolol showed no benefit after 6 weeks in rapidly progressing, ANG II-dependent 5/6 A/I model of chronic kidney disease. This contrasts to the protection seen with 6 month treatment of Nebivolol in the slowly progressing 5/6 ablation model.
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Affiliation(s)
- Jennifer M Sasser
- Departments of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA.
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12
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Abdelhalim MAK, Jarrar BM. The appearance of renal cells cytoplasmic degeneration and nuclear destruction might be an indication of GNPs toxicity. Lipids Health Dis 2011; 10:147. [PMID: 21859444 PMCID: PMC3175180 DOI: 10.1186/1476-511x-10-147] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 08/22/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Advances in nanotechnology have identified promising candidates for many biological and biomedical applications. Since the properties of nanoparticles (NPs) differ from that of their bulk materials, they are being increasingly exploited for medical uses and other industrial applications. The histological and the histochemical alterations in the renal tissues due to gold nanoparticles (GNPs) have not well documented and have not yet been identified. The aim of the present study was to investigate the particle-size effect of GNPs on the renal tissue in an attempt to address their potential toxicity. METHODS A total of 70 healthy male Wistar-Kyoto rats were exposed to GNPs received 50 or 100 μl of GNPs infusion of size (10, 20 and 50 nm for 3 or 7 days) to investigate particle-size effect of GNPs on the renal tissue. Animals were randomly divided into groups, 6 GNPs-treated rats groups and one control group. Groups 1, 2 and 3 received infusion of 50 μl GNPs of size 10 nm (3 or 7 days), size 20 nm (3 or 7 days) and 50 nm (3 or 7 days), respectively; while groups 4, 5 and 6 received infusion of 100 μl GNPs of size 10 nm, size 20 nm and 50 nm, respectively. RESULTS The histological alterations were mainly seen in the cortex and the proximal renal convoluted tubules were more affected than the distal ones. In comparison with respective control rats, exposure to GNPs doses has produced the following renal tubular alterations: cloudy swelling and renal tubular necrosis. Interstitial alterations included: intertubular blood capillaries dilatation, intertubular hemorrhage and inflammatory cell infiltrations. The glomeruli showed moderate congestion with no hypercelluraity and mesangial proliferation or basement membrane thickening. CONCLUSIONS The induced histological alterations might be an indication of injured renal tubules due to GNPs toxicity that become unable to deal with the accumulated residues resulting from metabolic and structural disturbances caused by these NPs. These alterations were size-dependent with smaller ones induced more effects and related with time exposure of GNPs. The produced histological alterations may suggest that GNPs interact with proteins and enzymes of the renal tissue interfering with the antioxidant defense mechanism and leading to reactive oxygen species (ROS) generation which in turn may induce stress in the renal cells to undergo atrophy and necrosis. More histomorphologcal investigations are needed to address the potential threat of GNPs as a therapeutic and diagnostic tool.
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Affiliation(s)
- Mohamed Anwar K Abdelhalim
- Department of Physics and Astronomy, College of Science, King Saud, University, P.O. Box 2455, Riyadh-11451, Saudi Arabia
| | - Bashir M Jarrar
- College of Applied Medical Sciences, Al-Jouf University, Saudi Arabia
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Vandeputte DF, Verbueken AH, Jacob WA, Van Grieken RE. Laser microprobe mass analysis (LAMMA) to study lead intoxication at the subcellular level. Acta Pharmacol Toxicol (Copenh) 2009; 59 Suppl 7:617-9. [PMID: 3776638 DOI: 10.1111/j.1600-0773.1986.tb02840.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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14
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Gao MJ, Liu M, Li B, Li ML, Bian LX, Yu GN. [Protective effect of calcium dobesilate against early diabetic nephropathy of rat kidney]. Yao Xue Xue Bao 2009; 44:126-133. [PMID: 19408680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The aim of this study is to study the effect of calcium dobesilate on streptozotocin (STZ)-induced early diabetic nephrophathy (DN) in rats. All male Wistar rats were randomly divided into six groups: normal group; DN blank group; calcium dobesilate 75, 150, and 300 mg x kg(-1) groups and perindopril 0.4 mg x kg(-1) group. Blood glucose and the 24 h urinary albumin were measured dynamically during the experiment, after 8 weeks administration, the level of glycosylated hemoglobin (HbA1c) was determined, the expressions of plasminogen activator inhibitor-1 (PAI-1) and matrix metalloprotein-9 (MMP-9) in cortex of kidney were examined with immunohistochemical staining. The endothelin (ET) in plasma and kidney cortex was measured with radioimmunoassay, renal pathomorphism was observed with light and electron microscopes. Calcium dobesilate could decrease the 24 h urinary albumin and ET in plasma and kidney cortex, down-regulate the expression of PAI-1, and up-regulate MMP-9 in kidney. These findings suggested that calcium dobesilate could protect blood vessel endothelium, inhibit kidney fibrous degeneration, ameliorate renal pathological damage, and protect kidney function in many ways.
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Affiliation(s)
- Mei-Juan Gao
- Department of Endocrinology, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China
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15
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Spicer ST, Tran GT, Killingsworth MC, Carter N, Power DA, Paizis K, Boyd R, Hodgkinson SJ, Hall BM. Induction of passive Heymann nephritis in complement component 6-deficient PVG rats. J Immunol 2007; 179:172-8. [PMID: 17579035 DOI: 10.4049/jimmunol.179.1.172] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Passive Heymann nephritis (PHN), a model of human membranous nephritis, is induced in susceptible rat strains by injection of heterologous antisera to rat renal tubular Ag extract. PHN is currently considered the archetypal complement-dependent form of nephritis, with the proteinuria resulting from sublytic glomerular epithelial cell injury induced by the complement membrane attack complex (MAC) of C5b-9. This study examined whether C6 and MAC are essential to the development of proteinuria in PHN by comparing the effect of injection of anti-Fx1A antisera into PVG rats deficient in C6 (PVG/C6(-)) and normal PVG rats (PVG/c). PVG/c and PVG/C6(-) rats developed similar levels of proteinuria at 3, 7, 14, and 28 days following injection of antisera. Isolated whole glomeruli showed similar deposition of rat Ig and C3 staining in PVG/c and PVG/C6(-) rats. C9 deposition was abundant in PVG/c but was not detected in PVG/C6(-) glomeruli, indicating C5b-9/MAC had not formed in PVG/C6(-) rats. There was also no difference in the glomerular cellular infiltrate of T cells and macrophages nor the size of glomerular basement membrane deposits measured on electron micrographs. To examine whether T cells effect injury, rats were depleted of CD8+ T cells which did not affect proteinuria in the early heterologous phase but prevented the increase in proteinuria associated with the later autologous phase. These studies showed proteinuria in PHN occurs without MAC and that other mechanisms, such as immune complex size, early complement components, CD4+ and CD8+ T cells, disrupt glomerular integrity and lead to proteinuria.
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Affiliation(s)
- S Timothy Spicer
- Department of Medicine, University of New South Wales and Liverpool Hospital, Liverpool BC 1871, New South Wales, Australia.
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16
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Tarry-Adkins JL, Joles JA, Chen JH, Martin-Gronert MS, van der Giezen DM, Goldschmeding R, Hales CN, Ozanne SE. Protein restriction in lactation confers nephroprotective effects in the male rat and is associated with increased antioxidant expression. Am J Physiol Regul Integr Comp Physiol 2007; 293:R1259-66. [PMID: 17581837 DOI: 10.1152/ajpregu.00231.2007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Telomere shortening has been implicated in the aging process and various age-associated disorders, including renal disease. Moreover, oxidative stress has been identified as an initiator of accelerated telomere shortening. We have shown previously that maternal protein restriction during lactation leads to reduced renal telomere shortening, reduced albuminuria, and increased longevity in rats. Here we address the hypothesis that maternal protein restriction during lactation is nephroprotective and associated with increased expression of antioxidative enzymes and decreased age-dependent renal telomere shortening. Newborn rats were suckled by a dam fed either a control (20% protein) or low-protein (8% protein) diet. All animals were weaned onto standard chow. Offspring that had been suckled by protein-restricted mothers had reduced albuminuria, N-acetyl-glucosaminidase, and urinary aldosterone excretion. These animals also did not show significant age-dependent renal telomere shortening and hence had significantly longer telomeres at 12 mo of age. This lack of renal telomere shortening was associated with increased levels of the antioxidant enzymes manganese superoxide dismutase, glutathione peroxidase, and glutathione reductase. These findings suggest that beneficial effects of slow growth during lactation are associated with increased antioxidant capacity and prevention of age-dependent telomere shortening in the kidney.
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Affiliation(s)
- Jane L Tarry-Adkins
- Department of Clinical Biochemistry, University of Cambridge, Addenbrookes Hospital, Hills Road, Cambridge, UK.
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17
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Terryn S, Jouret F, Vandenabeele F, Smolders I, Moreels M, Devuyst O, Steels P, Van Kerkhove E. A primary culture of mouse proximal tubular cells, established on collagen-coated membranes. Am J Physiol Renal Physiol 2007; 293:F476-85. [PMID: 17475898 DOI: 10.1152/ajprenal.00363.2006] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A simple method is described to establish primary cultures of kidney proximal tubule cells (PTC) on membranes. The permeable membranes represent a unique culture surface, allowing a high degree of differentiation since both apical and basolateral membranes are accessible for medium. Proximal tubule (PT) segments from collagenase-digested mouse renal cortices were grown for 7 days, by which time cells were organized as a confluent monolayer. Electron microscopic evaluation revealed structurally polarized epithelial cells with numerous microvilli, basolateral invaginations, and apical tight junctions. Immunoblotting for markers of distinct parts of the nephron demonstrated that these primary cultures only expressed PT-specific proteins. Moreover immunodetection of distinct components of the receptor-mediated endocytic pathway and uptake of FITC-albumin indicated that these cells expressed a functional endocytotic apparatus. In addition, primary cultures possessed the PT brush-border enzymes, alkaline phosphatase, and gamma-glutamyl-transferase, and a phloridzin-sensitive sodium-dependent glucose transport at their apical side. Electrophysiological measurements show that the primary cultured cells have a low transepithelial resistance and high short-circuit current that was completely carried by Na(+) similar to a leaky epithelium like proximal tubule cells. This novel method established well-differentiated PTC cultures.
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Affiliation(s)
- Sara Terryn
- Laboratory of Cell Physiology, Hasselt University, Agoralaan, Gebouw D, B-3590 Diepenbeek, Belgium.
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18
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Medeiros FJ, Aguila MB, Mandarim-de-Lacerda CA. Renal cortex remodeling in streptozotocin-induced diabetic spontaneously hypertensive rats treated with olive oil, palm oil and fish oil from Menhaden. Prostaglandins Leukot Essent Fatty Acids 2006; 75:357-65. [PMID: 16919431 DOI: 10.1016/j.plefa.2006.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Revised: 06/08/2006] [Accepted: 06/22/2006] [Indexed: 01/31/2023]
Abstract
We studied the effects of edible oils intake on the renal cortical structure of streptozotocin-induced diabetic (Db) and non-diabetic spontaneously hypertensive rats (SHR). Male SHR divided into 5 groups were studied during 6 weeks: one non-diabetic SHR group and four diabetic SHR groups (three groups received by gavage olive, palm or fish oil). Kidneys were analyzed by light microscopy and stereology. Oils intake did not change the plasma glucose levels. The blood pressure (BP) was lower in SHR-Db than in SHR, but SHR-Db-fish oil showed the lowest BP. Creatinine clearance was different between diabetic SHR and non-diabetic SHR, but not between treated SHR-Db and untreated SHR-Db. The renal cortex showed scars surrounding obsolete glomeruli with inflammatory infiltrate mainly in untreated SHR-Db. The olive oil, palm oil and mainly fish oil intake retard the usual loss of glomeruli and attenuate the renal cortex adverse remodeling of Db and non-Db SHR.
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Affiliation(s)
- Fernanda J Medeiros
- Laboratory of Morphometry and Cardiovascular Morphology, State University of Rio de Janeiro (UERJ), Rio de Janeiro RJ 20551-030, Brazil
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19
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Kinsey GR, McHowat J, Beckett CS, Schnellmann RG. Identification of calcium-independent phospholipase A2gamma in mitochondria and its role in mitochondrial oxidative stress. Am J Physiol Renal Physiol 2006; 292:F853-60. [PMID: 17047165 DOI: 10.1152/ajprenal.00318.2006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Oxidant-induced lipid peroxidation and cell death mediate pathologies associated with ischemia-reperfusion and inflammation. Our previous work in rabbit renal proximal tubular cells (RPTC) demonstrated that inhibition of Ca(2+)-independent phospholipase A(2) (iPLA(2)) potentiates oxidant-induced lipid peroxidation and necrosis, implicating iPLA(2) in phospholipid repair. This study was conducted to identify a RPTC mitochondrial PLA(2) and determine the role of PLA(2) in oxidant-induced mitochondrial dysfunction. iPLA(2) activity was detected in Percoll-purified rabbit renal cortex mitochondria (RCM) and in isolated mitochondrial inner membrane fractions from rabbit and human RCM. Immunoblot analysis and inhibitor sensitivity profiles revealed that iPLA(2)gamma is the RCM iPLA(2) activity. RCM iPLA(2) activity was enhanced in the presence of ATP and was blocked by the PKCepsilon V1-2 inhibitor. Oxidant-induced mitochondrial lipid peroxidation and swelling were accelerated by pretreatment with R-BEL, but not S-BEL. Furthermore, oxidant treatment of isolated RCM resulted in decreased iPLA(2)gamma activity. These results reveal that RCM iPLA(2) is iPLA(2)gamma, RCM iPLA(2)gamma is regulated by phosphorylation by PKCepsilon, iPLA(2)gamma protects RCM from oxidant-induced lipid peroxidation and dysfunction, and that a strategy to preserve or enhance iPLA(2)gamma activity may be of therapeutic benefit.
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Affiliation(s)
- Gilbert R Kinsey
- Dept. of Pharmaceutical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
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20
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Yabuki A, Tanaka S, Matsumoto M, Suzuki S. Morphometric study of gender differences with regard to age-related changes in the C57BL/6 mouse kidney. Exp Anim 2006; 55:399-404. [PMID: 16880688 DOI: 10.1538/expanim.55.399] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
To investigate gender differences with regard to age-related changes in the mouse kidney, kidneys from male and female C57BL/6Cr mice were morphometrically examined at 2, 4, 12, 27 and 33 months of age. Gender differences were clearly observed in age-related changes in renal corpuscle diameter, in addition to semiquantitative scores of glomerular damage and interstitial fibrosis. A greater relative increase in renal corpuscle diameter was observed in females compared to males, and scores indicating glomerular damage and interstitial fibrosis were more severe in males than in females.
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Affiliation(s)
- Akira Yabuki
- Laboratory of Veterinary Anatomy, Department of Veterinary Medicine, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan
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21
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García N, Martínez-Abundis E, Pavón N, Chávez E. Sodium inhibits permeability transition by decreasing potassium matrix content in rat kidney mitochondria. Comp Biochem Physiol B Biochem Mol Biol 2006; 144:442-50. [PMID: 16762575 DOI: 10.1016/j.cbpb.2006.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2005] [Revised: 04/18/2006] [Accepted: 04/18/2006] [Indexed: 01/19/2023]
Abstract
Inner membrane mitochondria undergo a permeability increase elicited after the opening of a nonspecific pore due to supraphysiological matrix Ca2+ load, and the presence of an inducer. Multiple inducers have been used to promote the transition in permeability; among them are carboxyatractyloside (CAT) and reactive oxygen-derived species. In contrast, inhibitors such as ADP and cyclosporin A have been commonly used. In this work, we show that the opening or closure of the nonspecific pore depends on the cationic composition of the incubation medium. It was found that when mitochondria were incubated in either 125 mM KCl or 125 mM LiCl, ADP was essential to maintain selective membrane permeability. Interestingly, the nucleotide was not required when the medium contained 125 mM NaCl. Furthermore, it was established that CAT promotes membrane leakage in K(+)- or Li(+)-incubated mitochondria, while it failed to do so in Na(+)-incubated mitochondria. Evidence is also presented on the ability of Na+ to induce resistance in mitochondria against membrane damage by oxidative stress. Mitochondrial Ca2+ discharge, swelling, and transmembrane electric gradient were analyzed to establish permeability transition. It is concluded that the protection provided by Na+ was accomplished by inducing matrix K+ depletion, which, in turn, diminished the free fraction of matrix Ca2+.
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Affiliation(s)
- Noemí García
- Departamento de Bioquímica, Instituto Nacional de Cardiología, Ignacio Chávez, Juan Badiano No. 1, Col. Sección XVI, Tlalpan, DF, México, Mexico
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Abstract
Several vectorial transport routes in mammalian cells involve clathrin and associated proteins. In kidney epithelia urine production requires numerous transport processes. However, only little is known about the distribution of clathrin and its associated proteins in this organ in situ. We now report on the presence and distribution of clathrin and its accessory proteins AP1, AP2, Eps15, Epsin, CALM and Clint/EpsinR in the epithelia of the rat kidney cortex using immunoblotting, immunofluorescence and immuno-electron microscopy. Our data show that all investigated proteins are ubiquitously present in rat kidney cortex epithelia, however, with distinct distribution patterns. In the renal corpuscle, podocytes showed the most conspicuous labelling. Clathrin, AP2 and CALM were highly expressed in foot processes, while AP1 was primarily localized in the cell body. In the proximal tubule all proteins were present in dots along the plasma membrane and most conspicuous below the brush border. However, clathrin and AP2 co-localized in vesicle subtypes distinct from those containing clathrin and AP1. In the distal tubule and in the cortical collecting duct all proteins were found in the apex of the cells; however, AP1 and Clint/EpsinR showed additional staining in perinuclear dots. The occurrence and distribution of the investigated proteins in kidney epithelia are discussed with respect to their possible involvement in the functions of the specific nephron segment.
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Affiliation(s)
- Sabine Hasse
- Department of Cell Biology, OE 4130, Center of Anatomy, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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Yabuki A, Taharaguchi S, Ichii O, Kojima M, Nishi Y, Mifune H, Kamimura R, Matsumoto M, Suzuki S. Immunohistochemical localization of ghrelin in rodent kidneys. Histochem Cell Biol 2006; 126:231-8. [PMID: 16514547 DOI: 10.1007/s00418-006-0165-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2006] [Indexed: 12/27/2022]
Abstract
Ghrelin is a novel peptide hormone, originally identified in the rat and human stomach that plays various important roles. In the present study, we report the intra-renal localization of ghrelin in laboratory rodents. Kidneys from 3 month-old mice, rats and hamsters of both sexes were analyzed by immunohistochemistry. Positive signals were clearly observed in the epithelium of the distal tubules, whereas other segments of the nephron or interstitial cells, including juxtaglomerular cells, showed negative reactions. Pre-embedding immunoelectron microscopy revealed positive signals exclusively on the basolateral membrane in the distal tubular cells and in the collecting ducts. In addition, prepro-ghrelin gene expression was assessed by RT-PCR, and the expected 329-bp prepro-ghrelin mRNA was clearly detected in the kidney. On Western blot analysis, although a specific band for ghrelin (3 kDa) was not detected in the kidney, the expected band for prepro-ghrelin (13 kDa) was clearly detected in both the stomach and the kidney. This paper clarified the intra-renal localization of ghrelin.
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Affiliation(s)
- Akira Yabuki
- Laboratory of Veterinary Anatomy, Department of Veterinary Medicine, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, 890-0065 Kagoshima, Japan.
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Sabolic I, Herak-Kramberger CM, Antolovic R, Breton S, Brown D. Loss of basolateral invaginations in proximal tubules of cadmium-intoxicated rats is independent of microtubules and clathrin. Toxicology 2005; 218:149-63. [PMID: 16288946 DOI: 10.1016/j.tox.2005.10.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2005] [Revised: 10/11/2005] [Accepted: 10/11/2005] [Indexed: 11/22/2022]
Abstract
Experimental cadmium (Cd) nephrotoxicity after treating rats with CdCl(2) (2mg Cd/kg b.m./day) for 2 weeks (subchronic nephrotoxicity) or with Cd-metallothionein (CdMT, a single dose of 0.4 mg Cd/kg b.m.) for a few hours (acute nephrotoxicity) is characterized by significant damage to cortical proximal tubules (PT) that results in reabsorptive and secretory defects. Most of the damage, studied so far, has been reported at the PT cell apical domain. This includes the loss of apical transporters and brush-border microvilli, and is considered to be the main cause of the kidney malfunction seen in this condition. However, in some studies the loss of basolateral (BL) invaginations and the activity of Na/K-ATPase in PT cells was also observed, but this "basolateral" aspect of intracellular Cd toxicity has been poorly investigated. In this report we induced subchronic and acute Cd nephrotoxicity in rats, and we studied the expression and intracellular distribution of microtubules and clathrin, and the abundance of Na/K-ATPase associated with BL invaginations in renal cortical tubules. Methods used were immunofluorescence microscopy, transmission and immunogold microscopy and immunoblotting of tissue homogenates and isolated total cell membranes. In both experimental models, in the cortical PT we demonstrated: (a) significantly damaged morphology of the cells, (b) fragmentation and depolymerization of microtubules, (c) loss of clathrin in the subapical domain and its relocation into vesicles scattered throughout the cytoplasm and (d) loss of BL invaginations and the associated Na/K-ATPase immunostaining. A similar loss of microtubules and redistribution of clathrin in the cortical PT was observed in rats treated with microtubule depolymerizing agent colchicine, but without any detectable loss of BL invaginations. We conclude that the loss of BL invaginations and the associated Na/K-ATPase in the cortical PT of Cd-intoxicated rats may contribute to the loss of PT function that characterizes Cd nephrotoxicity. This loss is accompanied by, but it is not dependent on perturbation of microtubule organization and loss of membrane-associated clathrin.
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Affiliation(s)
- Ivan Sabolic
- Unit of Molecular Toxicology, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, P.O. Box 291, HR-10001 Zagreb, Croatia.
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Li JM, Che CT, Lau CBS, Leung PS, Cheng CHK. Inhibition of intestinal and renal Na+-glucose cotransporter by naringenin. Int J Biochem Cell Biol 2005; 38:985-95. [PMID: 16289850 DOI: 10.1016/j.biocel.2005.10.002] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Revised: 10/03/2005] [Accepted: 10/03/2005] [Indexed: 12/20/2022]
Abstract
Reduction in glucose uptake constitutes a possible means of controlling diabetic hyperglycemia. Using purified intestinal brush border membrane vesicles and everted intestinal sleeves, we have demonstrated that naringenin, a flavonoid present in citrus fruits and juices, significantly inhibited glucose uptake in the intestine. In addition, naringenin also elicited inhibitory actions towards glucose uptake in renal brush border membrane vesicles. Naringin, a glycoside of naringenin, was totally inactive in these aspects. Naringenin exhibited moderate inhibitory action on glucose uptake in rabbit intestinal brush border membrane vesicles, and showed strong inhibitory action in rat everted intestinal sleeves. The IC(50) values were 205.9 and 2.4 micromol/l, respectively. Lineweaver-Burk analysis demonstrated that naringenin inhibited glucose uptake in rat everted intestinal sleeves in a competitive manner with a K(i) value of 1.1 micromol/l. Glucose uptake activities in both the intestinal and renal brush border membrane vesicles of diabetic rats were significantly higher than in normal rats. Naringenin (500 microM) reduced glucose uptake by more than 60% in both the intestinal and renal brush border membrane vesicles of diabetic rats to a level similar to that of the normal rats. The IC(50) values of naringenin in the renal brush border membrane vesicles of normal and diabetic rats were 323.9 and 166.1 micromol/l, respectively. These results suggest that inhibition of intestinal glucose uptake and renal glucose reabsorption explains, in part at least, the in vivo antihyperglycemic action of naringenin and its derivatives. The possible application of these natural compounds in controlling hyperglycemia warrants further investigations.
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Affiliation(s)
- Jian Mei Li
- School of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
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Basivireddy J, Jacob M, Balasubramanian KA. Indomethacin induces free radical-mediated changes in renal brush border membranes. Arch Toxicol 2005; 79:441-50. [PMID: 15889237 DOI: 10.1007/s00204-005-0658-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2004] [Accepted: 03/16/2005] [Indexed: 01/22/2023]
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) are used extensively in clinical medicine. One disadvantage of their use, however, is the occurrence of adverse effects in the kidneys. The side effects produced in this organ have been classically attributed to the inhibitory effect of these drugs on the activity of cyclooxygenase, a key enzyme in prostaglandin synthesis. Our earlier work with indomethacin, a commonly used NSAID, has shown that oxidative stress and mitochondrial dysfunction occur in the kidney in response to the drug. In view of this, this study looked into the effect of indomethacin on brush border membranes (BBM) from the kidney, as these biomembranes are prime targets of oxygen free radicals. Rats, fasted overnight, were dosed with indomethacin (20 mg/kg) by gavage and sacrificed 24 h later. BBM were isolated from the kidneys by polyethylene glycol precipitation. It was found that there was an increase in levels of products of peroxidation and a fall in the level of alpha-tocopherol in the BBM from indomethacin-dosed rats. These BBM also exhibited impaired glucose transport. The lipid composition of the membranes was also found to be altered. Alterations in lipids were associated with up-regulation of phospholipase A2. Pretreatment with L-arginine, a nitric oxide donor, protected against these effects of indomethacin. Thus, this study suggests that indomethacin induces impairment in structure and function of BBM in the kidney, with these effects possibly mediated by free radicals and activation of phospholipases. We postulate that such alterations may be important in the pathogenesis of NSAID-induced nephropathy.
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Affiliation(s)
- J Basivireddy
- Department of Gastrointestinal Sciences, The Wellcome Trust Research Laboratory, Christian Medical College and Hospital, Vellore 632004, India
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Stern ST, Bruno MK, Hennig GE, Horton RA, Roberts JC, Cohen SD. Contribution of acetaminophen-cysteine to acetaminophen nephrotoxicity in CD-1 mice: I. Enhancement of acetaminophen nephrotoxicity by acetaminophen-cysteine. Toxicol Appl Pharmacol 2005; 202:151-9. [PMID: 15629190 DOI: 10.1016/j.taap.2004.06.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Accepted: 06/07/2004] [Indexed: 11/19/2022]
Abstract
Acetaminophen (APAP) nephrotoxicity has been observed both in humans and research animals. Recent studies suggest a contributory role for glutathione (GSH)-derived conjugates of APAP in the development of nephrotoxicity. Inhibitors of either gamma-glutamyl transpeptidase (gamma-GT) or the probenecid-sensitive organic anion transporter ameliorate APAP-induced nephrotoxicity but not hepatotoxicity in mice and inhibition of gamma-GT similarly protected rats from APAP nephrotoxicity. Protection against APAP nephrotoxicity by disruption of these GSH conjugate transport and metabolism pathways suggests that GSH conjugates are involved. APAP-induced renal injury may involve the acetaminophen-glutathione (APAP-GSH) conjugate or a metabolite derived from APAP-GSH. Acetaminophen-cysteine (APAP-CYS) is a likely candidate for involvement in APAP nephrotoxicity because it is both a product of the gamma-GT pathway and a probable substrate for the organic anion transporter. The present experiments demonstrated that APAP-CYS treatment alone depleted renal but not hepatic glutathione (GSH) in a dose-responsive manner. This depletion of renal GSH may predispose the kidney to APAP nephrotoxicity by diminishing GSH-mediated detoxification mechanisms. Indeed, pretreatment of male CD-1 mice with APAP-CYS before challenge with a threshold toxic dose of APAP resulted in significant enhancement of APAP-induced nephrotoxicity. This was evidenced by histopathology and plasma blood urea nitrogen (BUN) levels at 24 h after APAP challenge. APAP alone was minimally nephrotoxic and APAP-CYS alone produced no detectable injury. By contrast, APAP-CYS pretreatment did not alter the liver injury induced by APAP challenge. These data are consistent with there being a selective, contributory role for APAP-GSH-derived metabolites in APAP-induced renal injury that may involve renal-selective GSH depletion.
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Affiliation(s)
- Stephan T Stern
- Toxicology Program, Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06268, USA
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28
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Abstract
Diabetic nephropathy is characterized by an early period of renal growth with glomerular and tubular cell hypertrophy, but this is followed by progressive glomerulosclerosis and tubulointerstitial fibrosis, associated with loss of renal tissue. We studied whether apoptotic cell death occurs in human diabetic nephropathy. Percutaneous renal biopsy samples were obtained from five patients with diabetic nephropathy who were receiving insulin and/or angiotensin-converting enzyme inhibitor therapy. Apoptosis was determined by the presence of DNA fragmentation, detected by in situ TUNEL staining, and by characteristic features on electron microscopy, such as chromatin condensation. Apoptosis was present in all five biopsy specimens, either in epithelial cells of the proximal or distal tubules, or in endothelial cells or interstitial cells. No apoptosis was detected in cells of the glomeruli. The present study provides evidence for apoptosis in human diabetic kidney, and suggests a role for apoptosis in the gradual loss of renal mass.
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Affiliation(s)
- Dinender Kumar
- Cardiovascular Research Centre, Department of Medicine, University of Wisconsin, Madison, WI, USA
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Seki T, Ishimoto T, Sakurai T, Yasuda Y, Taniguchi K, Doi M, Sato M, Roman RJ, Miyata N. Increased Excretion of Urinary 20-HETE in Rats With Cyclosporine-Induced Nephrotoxicity. J Pharmacol Sci 2005; 97:132-7. [PMID: 15655287 DOI: 10.1254/jphs.fp0040574] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The present study examined the contribution of 20-hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE) in cyclosporine A (CsA)-induced renal nephrotoxicity. Treatment of rats with CsA (50 mg/kg) for 9 days induced renal damage as indicated by marked increase in urine flow (from 9.0 +/- 0.3 ml/day to 46.6 +/- 7.1 ml/day) and a 3 - 5-fold rise in blood urea nitrogen (BUN) levels. The urinary excretion of 20-HETE increased from 164 +/- 5 ng/day (N = 5) to 2432 +/- 290 ng/day (N = 5, P<0.01) after 9 days of CsA treatment. The increase in the urinary excretion of 20-HETE in the CsA treated rats was highly correlated with the increase in BUN levels (r = 0.819, P<0.001) and urine volume (r = 0.832, P<0.001). Immunohistochemical examination of kidney revealed that expression of cytochrome P450 4A (CYP4A) protein was markedly enhanced in the proximal tubules of CsA-treated rats. These results indicate that CsA-induced nephrotoxicity in rats is associated with a marked elevation in the renal production of 20-HETE and that 20-HETE may contribute to the pathophysiological condition of CsA-induced nephrotoxicity.
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Affiliation(s)
- Takayuki Seki
- Medicinal Research Laboratories, Taisho Pharmaceutical Co., Ltd., Saitama-city, Japan
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30
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Abstract
Claudins are integral membrane proteins of the tight junction that determine the magnitude and selectivity of paracellular permeability in epithelial tissues. The mammalian renal tubule exhibits considerable heterogeneity in the permeability properties of its different segments. To determine the nephron segment localization of claudin-7 and -8, immunofluorescence staining of mouse kidney sections was performed using isoform-specific antibodies. Claudin-8 was found to be expressed primarily at the tight junction along the entire aldosterone-sensitive distal nephron and in the late segments of the thin descending limbs of long-looped nephrons. This pattern of expression is consistent with the putative role of claudin-8 as a paracellular cation barrier. By contrast, claudin-7 was found in the same nephron segments as claudin-8, but it was expressed primarily at the basolateral membrane.
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Affiliation(s)
- Wing Y Li
- Univ. of Southern California Keck School of Medicine, Div. of Nephrology, 2025 Zonal Ave, RMR 406, Los Angeles, CA 90033, USA
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31
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Shao Y, Connors BA, Evan AP, Willis LR, Lifshitz DA, Lingeman JE. Morphological changes induced in the pig kidney by extracorporeal shock wave lithotripsy: nephron injury. ACTA ACUST UNITED AC 2004; 275:979-89. [PMID: 14533172 DOI: 10.1002/ar.a.10115] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
While shock wave lithotripsy (SWL) is known to cause significant damage to the kidney, little is known about the initial injury to cells along the nephron. In this study, one kidney in each of six juvenile pigs (6-7 weeks old) was treated with 1,000 shock waves (at 24 kV) directed at a lower pole calyx with an unmodified HM-3 lithotripter. Three pigs were utilized as sham-controls. Kidneys were fixed by vascular perfusion immediately after SWL or sham-SWL. Three of the treated kidneys were used to quantitate lesion size. Cortical and medullary samples for light (LM) and transmission electron microscopy (TEM) were taken from the focal zone for the shock waves (F2), the contralateral kidney, and the kidneys of sham-SWL pigs. Because preservation of the tissue occurred within minutes of SWL, the initial injury caused by the shock waves could be separated from secondary changes. No tissue damage was observed in contralateral sham-SWL kidneys, but treated kidneys showed signs of injury, with a lesion of 0.2% +/- 0.1% of renal volume. Intraparenchymal hemorrhage and injury to tubules was found at F2 in both the cortex and medulla of SWL-treated kidneys. Tubular injury was always associated with intraparenchymal bleeding, and the range of tissue injury included total destruction of tubules, focal cellular fragmentation, necrosis, cell vacuolization, and membrane blebbing. The initial injury caused by SWL was cellular fragmentation and necrosis. Cellular vacuolization, membrane blebbing, and disorganization of apical brush borders appear to be secondary changes related to hypoxia.
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Affiliation(s)
- Youzhi Shao
- Department of Histology, Jinzhou Medical College, Jinzhou, Liaoning Province, People's Republic of China
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Asar M, Kayisli UA, Izgüt-Uysal VN, Akkoyunlu G. Immunohistochemical and ultrastructural changes in the renal cortex of cadmium-treated rats. Biol Trace Elem Res 2004; 97:249-63. [PMID: 14997025 DOI: 10.1385/bter:97:3:249] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2003] [Revised: 05/13/2003] [Accepted: 06/19/2003] [Indexed: 11/11/2022]
Abstract
The aim of this study was to determine the cadmium-induced immunohistochemical and morphological changes in the renal cortex of adult male rats exposed to high doses of cadmium for 30 d. Animals used as controls received a standard diet and water ad libitum. The animals used for this study received 15 ppm CdCl2 in their drinking water for 1 mo. The mean arterial pressure (MAP), the mean blood Cd level, and the mean tissue Cd content were significantly higher when compared to controls (p < 0.01). Immunohistochemical studies demonstrated a weak labeling to type IV collagen and laminin, but a strong labeling to fibronectin in the renal cortex of the Cd-treated animals when compared to controls. The ultrastructural alterations found in Cd-treated rats were a diminution in the amount of filtration slits, increased fusion of foot processes in epithelial cells of the glomeruli, increase of lysosomal structures and pinocytic vesicles as well as large mitochondria in proximal tubule cells, and degenerated cells in distal tubules. Additionally, the glomerular basement membrane was slightly thickened. In conclusion, cadmium toxicity results in alterations in the renal extracellular matrix and tubular or glomerular cells, which could play an important role in renal dysfunction.
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Affiliation(s)
- Mevlüt Asar
- Department of Histology and Embryology, Faculty of Medicine, University of Akdeniz, Antalya, Turkey
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Limaye PV, Sivakami S. Evaluation of the fluidity and functionality of the renal cortical brush border membrane in experimental diabetes in rats. Int J Biochem Cell Biol 2003; 35:1163-9. [PMID: 12757753 DOI: 10.1016/s1357-2725(03)00047-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The present study was aimed at addressing the effect of hyperglycemia on the renal cortical brush border membrane. The fluidity and the functionality of the renal cortical brush border membrane have been evaluated after 6 weeks of streptozotocin-induced diabetes in rats. Lipid peroxidation and protein oxidation were first performed to confirm a state of oxidative stress. The fluidity of the brush border membrane of diabetic rats decreased significantly by 15.76%. There was an increase in the amount of early (19.39%) and advanced (42.23%) glycation end-products suggesting the accumulation of significant amount of non-enzymic glycation products at 6 weeks of diabetes. Although, the activities of both gamma-glutamyl transpeptidase and alkaline phosphatase of the brush border membrane decreased, that of the latter decreased to a significant extent with an increase in K(m) (81%) and no change in the V(max). A study of the activities of glutathione-dependent antioxidant enzymes in the renal cortical homogenates showed that the activities of glutathione peroxidase and glyoxalase II were altered significantly. Our study seems to suggest that increased free radical generation accompanied by non-enzymic glycation may be responsible for oxidative stress and an increased rigidity of the diabetic brush border membrane. Alkaline phosphatase may thus serve as a potentially useful marker of free radical induced damage to the renal cortical brush border membrane. The results also suggest that enhanced susceptibility to oxidative stress during early stages may be an important factor in the development of secondary complications of diabetes.
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Affiliation(s)
- Pallavi V Limaye
- Department of Life Sciences, University of Mumbai, Santacruz (E), India
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Abstract
Aprotinin (Ap), a basic polypeptide with a molecular weight of 6500, is filtered at the glomerular membrane without steric restriction and is completely absorbed by the proximal tubule cells. Here Ap is broken down to amino acids, but no breakdown products enter the peritubular circulation during the first 20 min following an intravenous injection. These properties have recently been exploited for measurement of local glomerular filtration rate, based on the assumption that the proximal tubular uptake site is located at the level of the filtering glomerulus. To evaluate that assumption we have now made serial autoradiographs of the rat kidney 20 min after intravenous injection of 2-750 microg of 125I-Aprotinin. With all doses the percent 125I-containing proximal tubular transections were about 50 in the outer and middle cortex and 35 in the inner third. We interpret these numbers to mean that all filtered Ap is taken up in the first two thirds of the proximal convoluted tubular length and does not reach the pars recta. Since the proximal tubule on average is located more superficial than its glomerulus, measurement of local Ap uptake will tend to overestimate glomerular filtration rate in outer layers of the cortex. Quantitative estimate of this "displacement" will be presented in a companion article.
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Affiliation(s)
- Dadash Baran
- Department of Physiology, University of Bergen, Cionas Liesvei 91, Norway.
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35
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Brzóska MM, Kamiński M, Supernak-Bobko D, Zwierz K, Moniuszko-Jakoniuk J. Changes in the structure and function of the kidney of rats chronically exposed to cadmium. I. Biochemical and histopathological studies. Arch Toxicol 2003; 77:344-52. [PMID: 12799774 DOI: 10.1007/s00204-003-0451-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2002] [Accepted: 01/09/2003] [Indexed: 10/20/2022]
Abstract
The aim of this study was to assess the effects of chronic exposure to cadmium (Cd) on the structure and function of kidneys, as well as to establish the body burden of Cd at which the changes occur. For this purpose we have created an experimental model using rats intoxicated with Cd administered in drinking water at the concentration of 5 or 50 mg Cd/l for 6, 12 and 24 weeks. The degree of kidney damage was evaluated biochemically and histopathologically. Sensitive biomarkers of Cd-induced proximal tubular injury such as urinary total N-acetyl-beta- d-glucosaminidase (NAG-T) and its isoenzyme B (NAG-B), and alkaline phosphatase (ALP) were used. Cd content in the kidney increased with the level and duration of exposure leading to dose- and time-dependent structural and functional renal failure. In rats exposed to 5 mg Cd/l, first symptoms of injury of the main tubules of long and short nephrons (structural damage to epithelial cells, increased urinary activities of NAG-T and NAG-B) were noted after 12 weeks of the experiment. The damage occurred at a low kidney Cd concentration amounting to 4.08+/-0.33 micro g/g wet weight (mean +/-SE) and a urinary concentration of 4.31+/-0.28 micro g/g creatinine. On exposure to 50 mg Cd/l, damage to the main tubules (blurred structure of tubular epithelium, atrophy of brush border, partial fragmentation of cells with release of nuclei into tubular lumen as well as increased urinary activities of NAG-T, NAG-B and ALP) was already evident after 6 weeks with the kidney Cd concentration of 24.09+/-1.72 micro g/g wet weight. In rats exposed to 50 mg Cd/l, a lack of regular contour of glomeruli was noted after 12 weeks, whereas after 24 weeks thickening of capillary vessels and widening of filtering space were evident. After 24 weeks of exposure to Cd, increased urea concentration in the serum with simultaneous decrease in its level in the urine, indicating decreased clearance of urea, and increased excretion of total protein were observed, but endogenous creatinine clearance remained unaffected. At the lower exposure, symptoms of structural, but not functional, damage to the glomeruli were also evident after 24 weeks of the experiment. Our results provide evidence that chronic exposure to Cd dose-dependently damages (structurally and functionally) the whole kidney. The injury affects the main resorptive part (proximal convoluted tubules and straight tubules) and the filtering part (glomeruli) of the nephron. But the target site for Cd action is the main tubule. We hypothesize that the threshold for Cd effects on the kidney is less than 4.08+/-0.33 micro g/g wet kidney weight and greater than 2.40+/-0.15 micro g/g (at this Cd concentration no symptoms of kidney damage were noted), and it may be close to the latter value. A very important finding of this study is that Cd acts on the whole kidney, especially on the main tubules, even at relatively low accumulation in this organ. It confirms the hypothesis that humans environmentally exposed to Cd, especially smokers, are at risk of tubular dysfunction.
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Affiliation(s)
- Małgorzata M Brzóska
- Department of Toxicology, Medical University of Białystok, Mickiewicza 2c str., 15-222, Białystok, Poland.
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Christensen BM, Wang W, Frøkiaer J, Nielsen S. Axial heterogeneity in basolateral AQP2 localization in rat kidney: effect of vasopressin. Am J Physiol Renal Physiol 2003; 284:F701-17. [PMID: 12453871 DOI: 10.1152/ajprenal.00234.2002] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of the present study was to examine whether there is axial heterogeneity in the basolateral plasma membrane (BLM) localization of AQP2 and whether altered vasopressin action or medullary tonicity affects the BLM localization of AQP2. Immunocytochemistry and immunoelectron microscopy revealed AQP2 labeling of the BLM in connecting tubule (CNT) cells and inner medullary collecting duct (IMCD) principal cells in normal rats and vasopressin-deficient Brattleboro rats. In contrast there was little basolateral AQP2 labeling in cortical (CCD) and outer medullary collecting duct principal cells. Short-term desamino-Cys(1), (D)-Arg(8) vasopressin (dDAVP) treatment (2 h) of Brattleboro rats caused no increase in AQP2 labeling of the BLM. In contrast, long-term dDAVP treatment (6 days) of Brattleboro rats caused an increased BLM labeling in CNT, CCD, and IMCD. Treatment of normal rats with V(2)-receptor antagonist for 60 min caused retrieval of AQP2 from the apical plasma membrane. Moreover, AQP2 labeling of the BLM was unchanged in CNT and IMCD but increased in CCD. In conclusion, there is an axial heterogeneity in the subcellular localization of AQP2 with prominent AQP2 labeling of the BLM in CNT and IMCD. There was no increase in AQP2 labeling of the BLM in response to short-term dDAVP. Moreover, acute V(2)-receptor antagonist treatment did not cause retrieval of AQP2 from the BLM. In contrast, long-term dDAVP treatment caused a major increase in AQP2 expression in the BLM in CCD.
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Fenoglio C, Boicelli CA, Ottone M, Addario C, Chiari P, Viale M. Protective effect of procaine hydrochloride on cisplatin-induced alterations in rat kidney. Anticancer Drugs 2002; 13:1043-54. [PMID: 12439338 DOI: 10.1097/00001813-200211000-00008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Efforts have been made to reduce the undesirable side effects of cisplatin, mainly nephro- and neurotoxicity, but their reduction is usually accompanied by a concomitant inhibition of antitumor activity. The local anesthetic procaine hydrochloride (P.HCl) improves the therapeutic index of cisplatin not only by the reduction of its nephro- and hemotoxicity, but also by an increase of its antitumor activity. We therefore investigated the effects of a combined treatment of cisplatin and P.HCl on rat kidneys and compared this to kidneys from rats treated with a toxic dose of cisplatin or P.HCl alone. Treatment with a saline solution was used as control. Dehydrogenase activities [succinate dehydrogenase (SDH) and NADPH diaphorase reaction demonstrating nitric oxide synthase (NOS/NADPHd)] and phosphatase activities [K -nitrophenyl phosphatase (K pNPPase), alkaline phosphatase (AlPase) and acid phosphatase (AcPase)] were studied on cryostatic sections of kidneys from controls and treated rats. Evidence of heavy morphological damage and altered AlPase and AcPase activities induced by cisplatin were observed in the S3 segment of the proximal tubules. In addition, SDH and K pNPPase activities showed some changes in the distal tubule cells. The NOS/NADPHd activity in macula densa was drastically reduced. Combined treatment of cisplatin and P.HCl greatly attenuated morphological alterations of the rat kidney and reduced the changes in enzyme activities, except for NOS/NADPHd activity, compared to the cisplatin-treated group of animals. The study indicates that, in cisplatin-induced nephrotoxicity, a significant role is played by enzyme activities, in particular K pNPPase and NOS/NADPHd, and that P.HCl can mitigate the nephrotoxicity of cisplatin, possibly by influencing some enzyme activities involved in important renal metabolic pathways.
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Affiliation(s)
- Carla Fenoglio
- Dipartimento di Biologia Animale, Università di Pavia, 27100 Pavia, Italy.
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Hosoyamada Y, Kudo H, Ichimura K, Kurihara H, Sakai T. Fibroblasts and antigen-presenting cells in the renal interstitium of streptozotocin-induced diabetic rats on a high cholesterol diet. Arch Histol Cytol 2002; 65:307-15. [PMID: 12501888 DOI: 10.1679/aohc.65.307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The cortical peritubular interstitium of the normal kidney contains both fibroblasts and antigen-presenting dendritic cells. Characteristics of these interstitial cells were analyzed in an overnutrition model by electron microscopy after the cold-dehydration technique and immunohistochemistry for antigen-presenting cells. In control rats, fibroblasts and dendritic cells were clearly identified by electron microscopy on the basis of their distinct ultrastructures. Fibroblasts possessed slender cell processes, and contained an abundance of actin filament bundles occasionally anchoring to surrounding structures, whereas dendritic cells possessed irregularly-shaped cell processes with a clear cytoplasm and a paucity of actin filament bundles. In the experimental kidney from diabetic rats given a high cholesterol diet, the peritubular interstitium contained fibroblasts and vacuolated cells, and the extracellular matrices such as collagen bundles were distinctly increased compared with the control rat kidney. Immunohistochemical staining with OX6 and ED1 revealed that the peritubular interstitium in the control rat kidney contained dendritic cells, while that in the experimental rats was occupied by macrophages. The present study provides the first evidence indicating that overnutrition may dramatically affect the immune cells in nonlymphoid tissue.
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Affiliation(s)
- Yasue Hosoyamada
- Department of Nutrition, Chiba College of Health Science, Chiba, Japan
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39
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Crljen V, Volinia S, Banfic H. Hepatocyte growth factor activates phosphoinositide 3-kinase C2 beta in renal brush-border plasma membranes. Biochem J 2002; 365:791-9. [PMID: 11931646 PMCID: PMC1222704 DOI: 10.1042/bj20020316] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2002] [Revised: 03/27/2002] [Accepted: 04/03/2002] [Indexed: 01/29/2023]
Abstract
Upon stimulation of renal cortical slices with hepatocyte growth factor (HGF), inositol lipid metabolism was studied in basal-lateral plasma membranes (BLM) and brush-border plasma membranes (BBM). Whereas in BLM rapid increases in 1,2-diacylglycerol, PtdIns(3,4,5)P(3) and PtdIns(3,4)P(2) were observed, suggesting that in BLM HGF activates both phospholipase C (PLC) and phosphoinositide 3-kinase (PI3K), in BBM only HGF-induced transient accumulation of PtdIns3P was seen, which was temporarily delayed from signalling events in BLM and could be blocked by the PtdIns-specific-PLC inhibitor ET-18-OCH(3) and the calpain inhibitor calpeptin, suggesting that 3-kinase activation in BBM lies downstream of PLC activation in BLM and is a calpain-mediated event. Moreover, the increase in immunoprecipitable PI3K-C2 beta activity, which is sensitive to wortmannin (10 nM) and shows strong preference for PtdIns over PtdIns4P as a substrate, was observed only in BBM upon stimulation of renal cortical slices with HGF and could be mimicked by the Ca(2+) ionophore A23187 and blocked by the cell-penetrant Ca(2+) chelator BAPTA-AM [1,2-bis-(2-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid tetrakis(acetoxymethyl ester)]. On Western blots PI3K-C2 beta revealed a single immunoreactive band of 180 kDa in BLM and BBM, while after stimulation with HGF a gel shift of 18 kDa was noticed only in BBM, suggesting that the observed enzyme activation is achieved by proteolysis. When BBM were subjected to short-term (15 min) exposure to mu-calpain, a similar gel shift together with an increase in PI3K-C2 beta activity was observed, when compared with the BBM harvested after HGF stimulation. The above-mentioned gel shift and increase in PI3K-C2 beta activity could be prevented by the calpain inhibitor calpeptin. The data presented in this report show that in renal cells there is a spatial separation of the inositol lipid signalling system between BLM and BBM, and that HGF causes activation of PLC and PI3K primarily in BLM, which leads to calpain-mediated activation of PI3K-C2 beta in BBM with a concomitant increase in PtdIns3P.
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Affiliation(s)
- Vladiana Crljen
- Department of Physiology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 3, 10000 Zagreb, Croatia
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40
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Iino N, Gejyo F, Arakawa M, Ushiki T. The three-dimensional structure of the neonatal mouse kidney as revealed by scanning electron microscopy after KOH treatment. Ital J Anat Embryol 2002; 106:415-21. [PMID: 11729984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
The shape and arrangement of the developing nephrons were studied three-dimensionally by scanning electron microscopy (SEM) of the neonatal mouse kidney. The specimens were treated with the KOH digestion method in order to remove extracellular connective tissue components, thus enabling the direct observation of the developing nephrons at various stages. At the subcapsular region of the renal cortex, the ureteric ducts were observed as branched tubules with terminal swellings or ampullae. Newly formed blood vessels were often associated with terminals of these ureteric ducts. The cup-shaped renal corpuscles had aggregations of mesangial cells with blood vessels in the groove. At the vascular pole of mature nephrons, extraglomerular mesangial cells were observed as a cellular sheet, which was continuous with the smooth muscle layer of afferent and efferent blood vessels. The present study also demonstrated the shape of the immature podocytes in relation to the endothelial morphology of glomerular capillaries.
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Affiliation(s)
- N Iino
- Department of Anatomy and Histology, Faculty of Medicine, Niigata University, Japan.
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41
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Wielert-Badt S, Hinterdorfer P, Gruber HJ, Lin JT, Badt D, Wimmer B, Schindler H, Kinne RKH. Single molecule recognition of protein binding epitopes in brush border membranes by force microscopy. Biophys J 2002; 82:2767-74. [PMID: 11964262 PMCID: PMC1302064 DOI: 10.1016/s0006-3495(02)75617-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sidedness and accessibility of protein epitopes in intact brush border membrane vesicles were analyzed by detecting single molecule interaction forces using molecular recognition force microscopy in aqueous physiological solutions. Frequent antibody-antigen recognition events were observed with a force microscopy tip carrying an antibody directed against the periplasmically located gamma-glutamyltrans- peptidase, suggesting a right side out orientation of the vesicles. Phlorizin attached to the tips bound to NA+/D-glucose cotransporter molecules present in the vesicles. The recognition was sodium dependent and inhibited by free phlorizin and D-glucose, and revealed an apparent K(D) of 0.2 microM. Binding events were also observed with an antibody directed against the epitope aa603-aa630 close to the C terminus of the transporter. In the presence of phlorizin the probability of antibody binding was reduced but the most probable unbinding force f(u) = 100 pN remained unchanged. In the presence of D-glucose and sodium, however, both the binding probability and the most probable binding force (f(u) = 50 pN) were lower than in its absence. These studies demonstrate that molecular recognition force microscopy is a versatile tool to probe orientation and conformational changes of epitopes of membrane components during binding and trans-membrane transport.
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Affiliation(s)
- Susanne Wielert-Badt
- Max-Planck-Institute for Molecular Physiology, Department of Epithelial Cell Physiology, 44227 Dortmund, Germany
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42
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Abstract
We used immunoelectron microscopy to examine whether glomerular podocytes have the endocytotic function of macromolecular proteins in the early stage of diabetic nephropathy. Diabetes was induced by injecting streptozocin 60 mg kg wt(-1) into rats. Creatinine clearance but not urinary protein excretion was increased after four weeks of diabetes. The kidneys were morphologically studied 1 h after goat serum injection. In conventional electron microscopy, lysosomes were conspicuous in the podocytes of diabetic rats. Immunoelectron microscopy revealed that endogenous rat IgG and exogenous goat IgG were present in the lysosomes of podocytes from diabetic rats. The results indicated that the podocytes had an increased capacity for endocytosis in the early stage of diabetic nephropathy without increased urinary protein excretion.
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43
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Bardakhch'ian EA, Kharlanova NG, Lomov IM, Tkacheva TI, Saiamov SR. [Ultrastructure of renal cortex in suckling rabbits with experimental cholera]. Arkh Patol 2001; 63:30-4. [PMID: 11810923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Development of experimental cholera in suckling rabbits is associated with appearance of alterations in glomerular filtration and tubular reabsorption of renal cortex. Ultrastructural changes of nephrons appear in the adhesion period and progress 24 hours later. In this case, particular vulnerability of the kidneys is associated with insufficient development of principal stages both in the cavity and membrane digestion in the gut, therefore, the kidney plays a role of one of the components of the protein-splitting system in the organism.
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44
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Abstract
The morphological basis of diabetic nephropathy has been studied using light and electron microscopy. Kidneys of streptozotocin-induced diabetic rats were examined on the light microscope at 4 weeks and 8 months after induction of diabetes mellitus. In addition, the 8-month diabetic kidneys were examined with the electron microscope. Renal hypertrophy was evidenced by the increase in the weight of kidneys of diabetic rats. Whilst the diabetic kidneys were approximately twice as large after 4 weeks they were only 30% larger compared to age-matched controls after 8 months of induction of diabetes. After 4 weeks, light microscopy revealed dilated tubules within the cortex of the diabetic kidneys. Light microscopy showed a significant amount of destruction of the distal convoluted tubules while electron microscopy revealed a spectrum of damage that included basement membrane thickening, loss of podocytic foot processes, disruption of tubular basal infoldings and their related mitochondria and fibrosis of the tubules 8 months after induction of diabetes. It is concluded that renal hypertrophy persists after a prolonged occurrence of diabetes but the extensive damage and loss of renal tissue including the loss of the foot processes of podocytes might be partly responsible for the clinical presentation of diabetic nephropathy.
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Affiliation(s)
- E N Obineche
- Department of Internal Medicine, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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45
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Vázquez CM, Mate A, Angeles de la Hermosa M, Planas JM, Ruíz-Gutiérrez V. Abnormalities in lipid composition of brush-border membranes isolated from renal cortex of spontaneously hypertensive rats. Am J Hypertens 2001; 14:578-84. [PMID: 11411739 DOI: 10.1016/s0895-7061(00)01325-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The lipid composition and fluidity in brush-border membrane vesicles (BBMV) isolated from renal cortex of spontaneously hypertensive rats (SHR) and their normotensive control, Wistar Kyoto (WKY) rats have been studied. The activity of Na+-dependent D-glucose transport has been also determined. A significant increase in total phospholipids and free cholesterol were observed in renal BBMVs from SHR, which led to a decrease in the ratio of phospholipid-to-free cholesterol in these hypertensive rats. A reduction in the content of phosphatidylcholine and an increase in the percentage of sphingomyelin were observed in SHR. As a consequence, a diminished ratio of phosphatidylcholine-to-sphingomyelin was present in kidneys from SHR. The content of phosphatidylserine and phosphatidylinositol was reduced in SHR. However, the levels of phosphatidylethanolamine, cardiolipin, and lysophosphatidylethanolamine were increased in hypertensive animals. An increase in the level of saturated fatty acids, together with a decrease in the level of unsaturated fatty acids was responsible for the lower ratio of unsaturated-to-saturated fatty acids found in kidneys from SHR. The ratio of linoleic-to-arachidonic acid was increased in SHR when compared to WKY rats, as a result of the observed decrease in the content of arachidonic acid in hypertensive rats. Studies of diphenylhexatriene fluorescence polarization indicated no changes in the fluidity between BBMVs from both experimental rats, which did not correlate to the observed changes in the lipid composition of these membranes. These modifications in brush-border membrane lipid composition were accompanied by changes in the Na+-dependent D-glucose transport through renal BBMVs from SHR.
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Affiliation(s)
- C M Vázquez
- Departamento de Fisiología y Biología Animal, Facultad de Farmacia, Universidad de Sevilla, Spain.
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46
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Hager H, Kwon TH, Vinnikova AK, Masilamani S, Brooks HL, Frøkiaer J, Knepper MA, Nielsen S. Immunocytochemical and immunoelectron microscopic localization of α-, β-, and γ-ENaC in rat kidney. Am J Physiol Renal Physiol 2001; 280:F1093-106. [PMID: 11352848 DOI: 10.1152/ajprenal.2001.280.6.f1093] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Epithelial sodium channel (ENaC) subunit (α, β, and γ) mRNA and protein have been localized to the principal cells of the connecting tubule (CNT), cortical collecting duct (CCD), and outer medullary collecting duct (OMCD) in rat kidney. However, the subcellular localization of ENaC subunits in the principal cells of these cells is undefined. The cellular and subcellular localization of ENaC subunits in rat kidney was therefore examined. Immunocytochemistry demonstrated the presence of all three subunits in principal cells of the CNT, CCD, OMCD, and IMCD. In cortex and outer medulla, confocal microscopy demonstrated a difference in the subcellular localization of subunits. α-ENaC was localized mainly in a zone in the apical domains, whereas β- and γ-ENaC were found throughout the cytoplasm. Immunoelectron microscopy confirmed the presence of ENaC subunits in both the apical plasma membrane and intracellular vesicles. In contrast to the labeling pattern seen in cortex, α-ENaC labeling in IMCD cells was distributed throughout the cytoplasm. In the urothelium covering pelvis, ureters, and bladder, immunoperoxidase and confocal microscopy revealed differences the presence of all ENaC subunits. As seen in CCD, α-ENaC was present in a narrow zone near the apical plasma membrane, whereas β- and γ-ENaC were dispersed throughout the cytoplasm. In conclusion, all three subunits of ENaC are expressed throughout the collecting duct (CD), including the IMCD as well as in the urothelium. The intracellular vesicular pool in CD principal cells suggests ENaC trafficking as a potential mechanism for the regulation of Na+ reabsorption.
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Affiliation(s)
- H Hager
- Department of Cell Biology, Institute of Anatomy, University of Aarhus, DK-8000 Aarhus C., Denmark
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47
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Kakkis ED, Schuchman E, He X, Wan Q, Kania S, Wiemelt S, Hasson CW, O'Malley T, Weil MA, Aguirre GA, Brown DE, Haskins ME. Enzyme replacement therapy in feline mucopolysaccharidosis I. Mol Genet Metab 2001; 72:199-208. [PMID: 11243725 DOI: 10.1006/mgme.2000.3140] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Enzyme replacement therapy (ERT) has long been considered an approach to treating lysosomal storage disorders caused by deficiency of lysosomal enzymes. ERT is currently used to treat Gaucher disease and is being developed for several lysosomal storage disorders now that recombinant sources of the enzymes have become available. We have continued development of ERT for mucopolysaccharidosis I (MPS I) using the feline model. Recombinant alpha-L-iduronidase was administered intravenously at low dose (approximately 0.1 mg/kg or 25,000 units/kg) to four cats and high dose (0.5 mg/kg or 125,000 units/kg) to two cats on a weekly basis for 3- or 6-month terms. Clinical examinations showed distinct clearing of corneal clouding in one cat although clinical effects in the others were not evident. Biochemical studies of the cats showed that the enzyme was distributed to a variety of tissues although the liver and spleen contained the highest enzyme activities. Glycosaminoglycan storage was decreased in liver and spleen, and the histologic appearance improved in liver, spleen, and renal cortex. Enzyme was not consistently detected in cerebral cortex, brainstem, or cerebellum and the histologic appearance and ganglioside profiles did not improve. A variety of other tissues showed low variable uptake of enzyme and no distinct improvement. IgG antibodies to alpha-L-iduronidase were observed in five cats with higher titers noted when higher doses were administered. Mild complement activation occurred in three cats. Enzyme replacement therapy was effective in reversing storage in some tissues at the biochemical and histologic level in MPS I cats but an improved tissue distribution and prevention of a significant immune response could make the therapy more effective.
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Affiliation(s)
- E D Kakkis
- Department of Pediatrics, Division of Medical Genetics, Harbor-UCLA Medical Center, Torrance, California 90502, USA.
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48
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Anastassiadou M, Danoun S, Crane L, Baziard-Mouysset G, Payard M, Caignard DH, Rettori MC, Renard P. Synthesis and pharmacological evaluation of imidazoline sites I1 and I2 selective ligands. Bioorg Med Chem 2001; 9:585-92. [PMID: 11310592 DOI: 10.1016/s0968-0896(00)00280-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several series of 2-aryl or heterocyclic-imidazoline compounds have been prepared and evaluated in vitro as imidazoline sites (I1 and I2) and alpha-adrenergic (alpha1 and alpha2) receptor ligands. Their pKi values indicate that linkage of the imidazoline moiety at the 2-position with an aromatic substituent dramatically decreases alpha-adrenergic affinity. I1 sites are more accessible by phenyl imidazolines substituted by a methyl or a methoxy group at the ortho or meta position. Indeed, 2-(2'-methoxyphenyl)-imidazoline (17) is one of the best I1 ligands ever reported (pKi = 8.53 and I1/I2 > 3388). On the other hand, I2 selectivity increases in the presence of a methyl group in the para position. The original compound, 2-(3'-fluoro-4'-tolyl)-imidazoline (31) is a new potent ligand for the I2 sites with high selectivity (pKi = 8.53 and I2/I1 > 3388).
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Affiliation(s)
- M Anastassiadou
- Laboratoire de Chimie Pharmaceutique, Université Paul Sabatier, Faculté de Pharmacie 35, Toulouse, France
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49
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Ito O, Omata K, Ito S, Hoagland KM, Roman RJ. Effects of converting enzyme inhibitors on renal P-450 metabolism of arachidonic acid. Am J Physiol Regul Integr Comp Physiol 2001; 280:R822-30. [PMID: 11171663 DOI: 10.1152/ajpregu.2001.280.3.r822] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of blockade of the renin-angiotensin system on the renal metabolism of arachidonic acid (AA) were examined. Male Sprague-Dawley rats were treated with vehicle, captopril (25 mg x kg(-1) x day(-1)), enalapril (10 mg x kg(-1) x day(-1)), or candesartan (1 mg x kg(-1) x day(-1)) for 1 wk. The production of 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) by renal cortical microsomes increased in rats treated with captopril by 59 and 24% and by 90 and 58% in rats treated with enalapril. Captopril and enalapril increased 20-HETE production in the outer medulla by 100 and 143%, respectively. In contrast, blockade of ANG II type 1 receptors with candesartan had no effect on the renal metabolism of AA. Captopril and enalapril increased cytochrome P-450 (CYP450) reductase protein levels in the renal cortex and outer medulla and the expression of CYP450 4A protein in the outer medulla. The effects of captopril on the renal metabolism of AA were prevented by the bradykinin-receptor antagonist, HOE-140, or the nitric oxide (NO) synthase inhibitor, N(G)-nitro-L-arginine methyl ester. These results suggest that angiotensin-converting enzyme inhibitors may increase the formation of 20-HETE and EETs secondary to increases in the intrarenal levels of kinins and NO.
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Affiliation(s)
- O Ito
- Department of Nephrology, Endocrinology, and Hypertension, Tohoku University Graduate School of Medicine, Sendai 980 - 8574, Japan
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50
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Abstract
The purpose of this study was to compare the intensity of the immunogold labeling of H(2)O(2)-treated and heated epoxy sections. Renal swine tissue with glomerular immune complex deposits with reactivity against IgG was embedded in epoxy resin. Immunogold labeling with anti-IgG was performed on sections from these blocks. Some of these sections were treated by H(2)O(2), others were heated in a citrate solution, while some were not treated at all. Some epoxy sections, which had been exposed to both H(2)O(2) and heat, were also exposed to the same immunolabeling. The heated epoxy sections obtained an yield of specific immunogold labeling, which was twice as large as the labeling of the H(2)O(2)-treated sections. The yield of immunolabeling of the sections that had been exposed to both H(2)O(2) and heat was not significantly different from the sections that were only exposed to heat. The non-treated sections were very weakly labeled with anti-IgG. We believe that both H(2)O(2) and heat have the ability to break some chemical bonds between the epoxy resin and the antigens, but heating in citrate buffer has a larger potential in this respect than H(2)O(2). We interpret the results from the combined treatment with H(2)O(2) and heat in the following way; the bonds that are broken by H(2)O(2) will also be broken by heating in citrate solution. The practical significance of these results is that heating in citrate buffer is a more convenient method for enhancing the immunolabeling of epoxy sections than treatment with H(2)O(2).
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Affiliation(s)
- S H Brorson
- Department of Pathology, Ullevål Hospital, Kirkeveien 166, 0407 Oslo, Norway.
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