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miRNA-34a inhibits cell adhesion by targeting CD44 in human renal epithelial cells: implications for renal stone disease. Urolithiasis 2019; 48:109-116. [PMID: 31506763 DOI: 10.1007/s00240-019-01155-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 09/02/2019] [Indexed: 02/06/2023]
Abstract
Nephrolithiasis is a very common disease in which cell-crystal adhesion is an essential mechanism for kidney stone formation. This study has explored the anti-adhesion function of the microRNA, miR-34a, by targeting CD44, a cell surface receptor, in human renal epithelial (HK-2) cells. The expression of CD44 was monitored by qPCR and western blot. A luciferase assay validated the target of miR-34a in CD44 3' UTR. Immunofluorescence staining under confocal microscopy was used to detect the cell-crystal adhesion effects in vitro. Pizzolato staining was performed to examine the adhesion role of miR-34a in vivo. In HK-2 cells, miR-34a was down-regulated and CD44 was up-regulated when exposed to calcium oxalate monohydrate crystals. Moreover, miR-34a negatively regulated the expression of CD44. According to the luciferase report assay, miR-34a direct targeted a binding site in the CD44 3'UTR. In vitro experiments, miR-34a overexpression inhibited CD44 expression and cell-crystals adhesion; whereas CD44 overexpression showed reversed results. Furthermore, miR-34a suppressed cell-crystals adhesion and stone formation in vivo. These findings indicate that miR-34a targets CD44 in HK-2 cells and inhibits cell-crystal adhesion both in vitro and in vivo. Based on these results, miR-34a may be a potential therapeutic target for renal stone disease.
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Tzou DT, Taguchi K, Chi T, Stoller ML. Animal models of urinary stone disease. Int J Surg 2016; 36:596-606. [PMID: 27840313 DOI: 10.1016/j.ijsu.2016.11.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 11/04/2016] [Accepted: 11/07/2016] [Indexed: 01/29/2023]
Abstract
The etiology of stone disease remains unknown despite the major technological advances in the treatment of urinary calculi. Clinically, urologists have relied on 24-h urine collections for the last 30-40 years to help direct medical therapy in hopes of reducing stone recurrence; yet little progress has been made in preventing stone disease. As such, there is an urgent need to develop reliable animal models to study the pathogenesis of stone formation and to assess novel interventions. A variety of vertebrate and invertebrate models have been used to help understand stone pathogenesis. Genetic knockout and exogenous induction models are described. Surrogates for an endpoint of stone formation have been urinary crystals on histologic examination and/or urinalyses. Other models are able to actually develop true stones. It is through these animal models that real breakthroughs in the management of urinary stone disease will become a reality.
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Affiliation(s)
- David T Tzou
- Department of Urology, University of California, San Francisco, 400 Parnassus Avenue, Suite Box 0738, San Francisco, CA 94143, USA.
| | - Kazumi Taguchi
- Department of Urology, University of California, San Francisco, 400 Parnassus Avenue, Suite Box 0738, San Francisco, CA 94143, USA; Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, Japan.
| | - Thomas Chi
- Department of Urology, University of California, San Francisco, 400 Parnassus Avenue, Suite Box 0738, San Francisco, CA 94143, USA.
| | - Marshall L Stoller
- Department of Urology, University of California, San Francisco, 400 Parnassus Avenue, Suite Box 0738, San Francisco, CA 94143, USA.
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Kanlaya R, Fong-ngern K, Thongboonkerd V. Cellular adaptive response of distal renal tubular cells to high-oxalate environment highlights surface alpha-enolase as the enhancer of calcium oxalate monohydrate crystal adhesion. J Proteomics 2013; 80:55-65. [DOI: 10.1016/j.jprot.2013.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 12/07/2012] [Accepted: 01/07/2013] [Indexed: 01/14/2023]
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Inhibition of calcium oxalate crystal deposition on kidneys of urolithiatic rats by Hibiscus sabdariffa L. extract. ACTA ACUST UNITED AC 2011; 40:211-8. [DOI: 10.1007/s00240-011-0433-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 10/15/2011] [Indexed: 10/15/2022]
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Ilbey YO, Ozbek E, Simsek A, Cekmen M, Somay A, Tasci AI. Effects of pomegranate juice on hyperoxaluria-induced oxidative stress in the rat kidneys. Ren Fail 2010; 31:522-31. [PMID: 19839830 DOI: 10.1080/08860220902963871] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
To evaluate the role of the inducible nitric oxide synthase (iNOS), selective nuclear factor-kB (NF-kB), and p38-mitogene-activated protein kinase (p38-MAPK) on hyperoxaluria-induced oxidative stress and stone formation in rat kidneys. The rats were divided into five groups: group 1, control group; group 2: ethylene glycol (EG) group; group 3: EG + pomegranate juice (PJ)-low group; group 4: EG + PJ-middle group; group 5: EG + PJ-high group. Rats were sacrificed on 7, 15, and 45 days. The iNOS expression, p65-NF-kB and p38-MAPK activity, and oxidative stress markers were evaluated in the kidney. Crystal depositions were evident on day 7, and mild and severe crystallization were observed on day 15 and 45 in EG group, respectively. There was limited or no crystal formation in rats in both middle- and high-dose PJ groups when compared to low-dose PJ group. Crystal depositions, iNOS, p38-MAPK and p65-NF-kB activity, and oxidative stress markers were found to be decreased by middle- and high-dose PJ treatment. PJ was found to have inhibitory effects on renal tubular cell injury and oxidative stress caused by oxalate crystals by reducing ROS, iNOS, p38-MAPK, and NF-kB expression.
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Affiliation(s)
- Yusuf Ozlem Ilbey
- Department of Urology, Bezm-i Alem Valide Sultan Vakif Gureba Research and Education Hospital, Istanbul, Turkey.
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Effects of Lactobacillus casei and Bifidobacterium breve on urinary oxalate excretion in nephrolithiasis patients. ACTA ACUST UNITED AC 2009; 37:95-100. [PMID: 19214493 DOI: 10.1007/s00240-009-0177-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 01/12/2009] [Indexed: 12/12/2022]
Abstract
It had been suggested that lactic acid bacteria (LAB) may degrade oxalate in the intestinal lumen, reducing urinary oxalate excretion. We aimed to evaluate the effect of a LAB mixture containing Lactobacillus casei (LC) and Bifidobacterium breve (BB) (LC + BB) upon urinary oxalate reduction in stone-forming (SF) patients without hyperoxaluria under conditions of an oxalate-rich diet. After an oxalate restriction period (7 days washout), 14 SF patients consumed an oxalate-rich diet during 4 weeks (200 mg/day) and a lyophilized LC + BB preparation was given t.i.d. after meals during the last 2 weeks. Twenty-four-hour urine samples were collected for determination of oxalate, calcium, magnesium, citrate, sodium, potassium and creatinine at baseline, after 2 weeks (DIET) and 4 weeks (DIET + LC + BB). The mean urinary oxalate excretion was significantly higher after DIET versus baseline (27 +/- 8 vs. 35 +/- 11 mg/24 h), but the mean decrease was not significant between DIET + LC + BB and DIET periods (35 +/- 11 vs. 33 +/- 10 mg/24 h). Seven out of 14 patients presented a reduction in oxaluria after LC + BB versus DIET, being the reduction higher than 25% in 4, and up to 50% in 2 of them. The latter two patients were those who had presented the greatest increase in oxaluria in response to dietary oxalate. In conclusion, this mixture of L. casei and B. breve was shown to possess a variable lowering effect upon urinary oxalate excretion that may be dependent on dietary oxalate intake.
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Huang HS, Ma MC, Chen J. Low-vitamin E diet exacerbates calcium oxalate crystal formation via enhanced oxidative stress in rat hyperoxaluric kidney. Am J Physiol Renal Physiol 2008; 296:F34-45. [PMID: 18799548 DOI: 10.1152/ajprenal.90309.2008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Vitamin E was previously reported to reduce calcium oxalate (CaOx) crystal formation. This study explored whether vitamin E deficiency affects intrarenal oxidative stress and accelerates crystal deposition in hyperoxaluria. The control (C) group of rats received a standard diet and drinking water, while the experimental groups received 0.75% ethylene glycol (EG) in drinking water for 42 days. Of the latter, one group received a standard diet (EG group), one received a low-vitamin E (LE) diet (EG+LE group), and the last received an LE diet with vitamin E supplement (4 mg) (EG+LE+E group). The C+LE and C+LE+E groups were the specific controls for the last two experimental groups, respectively. In a separate experiment, EG and EG+LE rats were studied on days 3-42 to examine the temporal relationship between oxidative change and crystal formation. Urinary biochemistry and activity/levels of antioxidative and oxidative enzymes in glomeruli and tubulointerstitial specimens (TIS) were examined. In EG rats, CaOx crystal accumulation was associated with low antioxidative enzyme activity in TIS and with increased oxidative enzyme expression in glomeruli. In the EG+LE group, marked changes in antioxidative and oxidative enzyme levels were seen and correlated with massive CaOx deposition and tubular damage. The increased oxidative stress seen with EG+LE treatment was largely reversed by vitamin E supplementation. A temporal study showed that decrease in antioxidative defense and increased free radical formation in the EG+LE group occurred before crystal deposition. This study shows that low vitamin E disrupts the redox balance and causes cell death, thereby favoring crystal formation.
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Affiliation(s)
- Ho-Shiang Huang
- Dept. of Urology, National Taiwan Univ. Hospital, Yun-Lin Branch #582, Section 2, Yun-Lin Road, Douliou City, Taiwan
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Mo L, Liaw L, Evan AP, Sommer AJ, Lieske JC, Wu XR. Renal calcinosis and stone formation in mice lacking osteopontin, Tamm-Horsfall protein, or both. Am J Physiol Renal Physiol 2007; 293:F1935-43. [PMID: 17898038 DOI: 10.1152/ajprenal.00383.2007] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although often supersaturated with mineral salts such as calcium phosphate and calcium oxalate, normal urine possesses an innate ability to keep them from forming harmful crystals. This inhibitory activity has been attributed to the presence of urinary macromolecules, although controversies abound regarding their role, or lack thereof, in preventing renal mineralization. Here, we show that 10% of the mice lacking osteopontin (OPN) and 14.3% of the mice lacking Tamm-Horsfall protein (THP) spontaneously form interstitial deposits of calcium phosphate within the renal papillae, events never seen in wild-type mice. Lack of both proteins causes renal crystallization in 39.3% of the double-null mice. Urinalysis revealed elevated concentrations of urine phosphorus and brushite (calcium phosphate) supersaturation in THP-null and OPN/THP-double null mice, suggesting that impaired phosphorus handling may be linked to interstitial papillary calcinosis in THP- but not in OPN-null mice. In contrast, experimentally induced hyperoxaluria provokes widespread intratubular calcium oxalate crystallization and stone formation in OPN/THP-double null mice, while completely sparing the wild-type controls. Whole urine from OPN-, THP-, or double-null mice all possessed a dramatically reduced ability to inhibit the adhesion of calcium oxalate monohydrate crystals to renal epithelial cells. These data establish OPN and THP as powerful and functionally synergistic inhibitors of calcium phosphate and calcium oxalate crystallization in vivo and suggest that defects in either molecule may contribute to renal calcinosis and stone formation, an exceedingly common condition that afflicts up to 12% males and 5% females.
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Affiliation(s)
- Lan Mo
- Dept. of Urology, New York Univ. School of Medicine, Veterans Affairs Medical Center in Manhattan, 423 E23 St., Rm. 18064S, New York, NY 10010, USA.
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Touhami M, Laroubi A, Elhabazi K, Loubna F, Zrara I, Eljahiri Y, Oussama A, Grases F, Chait A. Lemon juice has protective activity in a rat urolithiasis model. BMC Urol 2007; 7:18. [PMID: 17919315 PMCID: PMC2194764 DOI: 10.1186/1471-2490-7-18] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Accepted: 10/05/2007] [Indexed: 11/25/2022] Open
Abstract
Background The use of herbal medicines (medicinal plants or phytotherapy) has recently gained popularity in Europe and the United States. Nevertheless the exact mechanism of the preventive effects of these products is still far to be clearly established, being its knowledge necessary to successfully apply these therapies to avoid stone formation. Methods The effect of oral lemon juice administration on calcium oxalate urolithiasis was studied in male Wistar rats. Rats were rendered nephrolithic by providing drinking water containing 0.75% ethylene glycol [v/v] (EG) and 2% ammonium chloride [w/v] (AC) for 10 days. In addition to EG/AC treatment, three groups of rats were also gavage-administered solutions containing 100%, 75% or 50% lemon juice [v/v] (6 μl solution/g body weight). Positive control rats were treated with EG/AC but not lemon juice. Negative control rats were provided with normal drinking water, and were administered normal water by gavage. Each group contained 6 rats. After 10 days, serum samples were collected for analysis, the left kidney was removed and assessed for calcium levels using flame spectroscopy, and the right kidney was sectioned for histopathological analysis using light microscopy. Results Analysis showed that the rats treated with EG/AC alone had higher amounts of calcium in the kidneys compared to negative control rats. This EG/AC-induced increase in kidney calcium levels was inhibited by the administration of lemon juice. Histology showed that rats treated with EG/AC alone had large deposits of calcium oxalate crystals in all parts of the kidney, and that such deposits were not present in rats also treated with either 100% or 75% lemon juice. Conclusion These data suggest that lemon juice has a protective activity against urolithiasis.
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Affiliation(s)
- Mohammed Touhami
- Laboratory of Animal Physiology, Ecophysiology Unit, Department of Biology, Faculty of Sciences Semlalia, University Cadi Ayyad, PO Box 2390, Marrakech, 40000, Morocco.
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Verkoelen CF. Crystal Retention in Renal Stone Disease: A Crucial Role for the Glycosaminoglycan Hyaluronan? J Am Soc Nephrol 2006; 17:1673-87. [PMID: 16707562 DOI: 10.1681/asn.2006010088] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The mechanisms that are involved in renal stone disease are not entirely clear. In this article, the various concepts that have been proposed during the past century are reviewed briefly and integrated into current insights. Much attention is dedicated to hyaluronan (HA), an extremely large glycosaminoglycan that may play a central role in renal stone disease. The precipitation of poorly soluble calcium salts (crystal formation) in the kidney is the inevitable consequence of producing concentrated urine. HA is a major constituent of the extracellular matrix in the renal medullary interstitium and the pericellular matrix of mitogen/stress-activated renal tubular cells. HA is an excellent crystal-binding molecule because of its size, negative ionic charge, and ability to form hydrated gel-like matrices. Crystal binding to HA leads to crystal retention in the renal tubules (nephrocalcinosis) and to the formation of calcified plaques in the renal interstitium (Randall's plaques). It remains to be determined whether one or both forms of renal crystal retention are involved in the development of kidney stones (nephrolithiasis).
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Evan AP, Coe FL, Lingeman JE, Worcester E. Insights on the pathology of kidney stone formation. ACTA ACUST UNITED AC 2005; 33:383-9. [PMID: 16078085 DOI: 10.1007/s00240-005-0488-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Accepted: 06/08/2005] [Indexed: 10/25/2022]
Abstract
The purpose of these studies was to test the hypothesis that Randall's plaque develops in unique anatomical sites of the kidney and that its formation is conditioned by specific stone-forming pathophysiologies. To test this hypothesis, we performed intraoperative mapping studies with biopsies of papilla from the kidneys of 15 idiopathic calcium oxalate (CaOx) stone formers, four intestinal bypass for obesity patients and ten brushite stone formers, and obtained papillary specimens from four non-stone formers after nephrectomy. Both light and electron microscopic examination of tissue changes along with infrared and electron diffraction analyses of mineral composition were performed. Distinct patterns of mineral deposition and papillary pathology were discovered in each of the three different stone forming groups. CaOx stone formers had predictable sites of interstitial apatite crystals beginning at the thin loops of Henle and spreading to the urothelium. These plaque areas are termed Randall's plaque and are thought to serve as sites for stone attachment. The papilla and medullary tubules appeared normal. The intestinal bypass patients only had intraluminal sites of crystalline material in the medullary collecting ducts. The brushite stone formers had the most severe form of cortical and medullary changes with sites of Randall's plaque, and yellowish intraluminal deposits in medullary collecting ducts. All deposits were determined to be apatite. The metabolic and surgical pathologic finding in three distinct groups of stone formers clearly shows that "the histology of the renal papilla from a stone former is particular to the clinical setting". It is observations like these that we believe will provide the insights to allow the stone community to generate better clinical treatments for kidney stone disease, as we understand the pathogenesis of stone formation for each type of stone former.
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Affiliation(s)
- Andrew P Evan
- Department of Anatomy and Cell Biology, Indiana University, School of Medicine, Indianapolis, IN, USA.
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Dal Moro F, Mancini M, Tavolini IM, De Marco V, Bassi P. Cellular and molecular gateways to urolithiasis: a new insight. Urol Int 2005; 74:193-7. [PMID: 15812202 DOI: 10.1159/000083547] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2003] [Accepted: 05/12/2004] [Indexed: 11/19/2022]
Abstract
Urolithiasis is a relevant clinical problem in everyday practice with a subsequent burden for the health system. Urolithiasis is classically explained as the derangement in the process of biomineralization involving the equilibrium between promoters and inhibitors of crystallization: a deficit of one or several inhibitors or an excess of one or several promoters plays a pivotal role in the stone formation. The revolutionary introduction of the molecular biology in medicine has given a new insight in urolithiasis too. Genetic factors have also been postulated to play an important role. A review of the current knowledge on urolithiasis based upon a molecular and genetic approach is reported.
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Affiliation(s)
- Fabrizio Dal Moro
- Department of Urology, Padova Medical School, University of Padova, Padova, Italy
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Tungsanga K, Sriboonlue P, Futrakul P, Yachantha C, Tosukhowong P. Renal tubular cell damage and oxidative stress in renal stone patients and the effect of potassium citrate treatment. ACTA ACUST UNITED AC 2004; 33:65-9. [PMID: 15565439 DOI: 10.1007/s00240-004-0444-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Accepted: 07/16/2004] [Indexed: 11/30/2022]
Abstract
Our objective was to evaluate the oxidative stress and renal tubular cell damage in patients who have renal stones compared to normal subjects. The patients were re-evaluated after 1-months supplementation with potassium citrate. We recruited 30 patients (11 males and 19 females) diagnosed with kidney stones and scheduled for surgical stone removal the following month, and 30 healthy non-stone formers (14 males and 16 females). Two 24-h urine samples and one heparinized blood sample were collected from each subject. Plasma was separated from the erythrocytes and assayed for creatinine, potassium, sodium, calcium, magnesium, phosphate, malondialdehyde (MDA, a lipid peroxidation product) (P-MDA), protein thiol as an indicator of protein oxidation, and vitamin E. Erythrocytes were analysed for MDA (E-MDA), reduced glutathione (GSH) and cellular glutathione peroxidase (cGPx) activity. The urine was analyzed for pH, creatinine, potassium, sodium, calcium, magnesium, phosphate, oxalate, citrate, MDA (U-MDA), total protein (U-protein) and N-acetyl-beta-glucosaminidase (NAG) activity. For the stone patients, urine and blood samples were re-evaluated after supplementation with potassium citrate (60 mEq/day) for 1 month. Renal stone patients had higher plasma creatinine and lower plasma potassium, urinary pH, potassium, magnesium, phosphate and citrate than the controls. The patients had higher P-MDA, E-MDA, U-MDA, U-protein and NAG activity, but lower GSH, cGPx activity, protein thiol and vitamin E, when compared with controls. After potassium citrate supplementation, P-MDA and E-MDA decreased while plasma vitamin E, urinary NAG activity and citrate increased. Renal stone disease is associated with high oxidative stress and damage to renal tubular cells. These abnormalities are coincident with an increase in blood lipid peroxidation products and a decrease in antioxidant status. Although supplementation with potassium citrate improved urinary citrate levels and oxidative stress, it neither reduced urinary lipid peroxidation products nor remedied the damage to renal tubular cells, probably due to the existence of kidney stones.
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Affiliation(s)
- Kriang Tungsanga
- Department of Internal Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
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Ferraz RRN, Tiselius HG, Heilberg IP, Heiberg IP. Fat malabsorption induced by gastrointestinal lipase inhibitor leads to an increase in urinary oxalate excretion. Kidney Int 2004; 66:676-82. [PMID: 15253722 DOI: 10.1111/j.1523-1755.2004.00790.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Unabsorbed fat and bile acids may react with calcium in the intestinal lumen, limiting the amount of free calcium binding with oxalate and thereby raising intestinal oxalate absorption leading to hyperoxaluria. The aim of the present study was to determine whether orlistat (Xenical), a gastrointestinal lipase inhibitor, might increase urinary oxalate in an experimental rat model. METHODS Thirty-nine male adult Wistar rats were fed a standard diet alone (controls) or supplemented with either 2% sodium oxalate (NaOx) or 3.2 mL of soy oil, or with both (NaOx + soy oil) for 4 weeks (diet period). Orlistat (16 mg/day) was added to the diet from the 5th to the 8th week (diet + orlistat period). Urinary oxalate (uOx), calcium (uCa), magnesium (uMg), and citrate (uCit) were determined and the ion-activity product of calcium oxalate [AP (CaOx) index(rat)] was estimated. RESULTS Compared to baseline uOx significantly increased after diet + orlistat in controls (0.64 +/- 0.1 mg/24 hours vs. 0.56 +/-0.1 mg/24 hours), soy oil (0.80 +/- 0.3 mg/24 hours vs. 0.49 +/-0.2 mg/24 hours), and NaOx (2.48 +/- 0.8 mg/24 hours vs. 0.57 +/- 0.2 mg/24 hours), but the most marked increase occurred in NaOx + soy oil (3.87 +/- 0.7 mg/24 hours vs. 0.47 +/- 0.1 mg/24 hours). All groups except controls presented a significant reduction in uCa and uMg. Orlistat induced a significant increase in AP (CaOx) index(rat) compared, respectively, to baseline and to the diet period in NaOx (4.52 +/- 2.34 mg/24 hours vs. 0.94 +/- 0.86 and 1.53 +/- 0.93 mg/24 hours) and NaOx + soy oil (6.49 +/- 4.03 mg/24 hours vs. 0.54 +/- 0.17 and 1.76 +/- 1.32 mg/24 hours). CONCLUSION These data suggest that the use of lipase inhibitors, especially under a diet rich in oxalate alone or associated with fat, leads to a significant and marked increase in urinary oxalate and a slight reduction in uCa and uMg that, taken together, resulted in an increase in AP (CaOx) index(rat), elevating the risk of stone formation.
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Verkoelen CF, Van Der Boom BG, Romijn JC. Identification of hyaluronan as a crystal-binding molecule at the surface of migrating and proliferating MDCK cells. Kidney Int 2000; 58:1045-54. [PMID: 10972669 DOI: 10.1046/j.1523-1755.2000.00262.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The adherence of calcium oxalate crystals to the renal tubule epithelium is considered a critical event in the pathophysiology of calcium nephrolithiasis. Calcium oxalate monohydrate (COM) crystals cannot adhere to the surface of a functional Madin-Darby canine kidney (MDCK) monolayer, but they bind avidly to the surface of proliferating and migrating cells. METHODS To identify crystal-binding molecules (CBMs) at the surface of crystal-attracting cells, we applied metabolic labeling protocols in combination with differential enzymatic digestion and gel filtration, which was compared with [14C]COM crystal binding and confirmed by confocal microscopy. RESULTS The indication that hyaluronan [hyaluronic acid (HA)] might act as a CBM in subconfluent cultures came from studies with glycosaminoglycan (GAG)-degrading enzymes. Subsequently, metabolic-labeling studies revealed that hyaluronidase cleaved significantly more radiolabeled glycoconjugates from crystal-attracting cells than from cells without affinity for crystals. During wound repair, crystal binding could be prevented by pretreating the healing cultures with hyaluronate lyase, an enzyme that specifically hydrolyzes HA. Binding to immobilized HA provided evidence that COM crystals physically can become associated with this polysaccharide. Finally, confocal microscopy demonstrated that fluorescently labeled HA binding protein (HABP) adhered to the surface of proliferating cells in subconfluent cultures as well as to cells involved in closing a wound, but not to cells in confluent monolayers. CONCLUSIONS These results identify HA as binding molecule for COM crystals at the surface of migrating and proliferating MDCK cells.
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Affiliation(s)
- C F Verkoelen
- Erasmus Urological Stone Treatment and Research Rotterdam (Eurostarr), and Department Urology, Erasmus University Rotterdam, The Netherlands.
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Patzer L, van't Hoff W, Shah V, Hallson P, Kasidas GP, Samuell C, de Bruyn R, Barratt TM, Dillon MJ. Urinary supersaturation of calcium oxalate and phosphate in patients with X-linked hypophosphatemic rickets and in healthy schoolchildren. J Pediatr 1999; 135:611-7. [PMID: 10547250 DOI: 10.1016/s0022-3476(99)70060-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
UNLABELLED Nephrocalcinosis (NC) is a complication of the treatment of X-linked hypophosphatemic rickets (XLHR). Some studies have found that treated patients have enteric hyperoxaluria caused by phosphate therapy and have implicated calcium oxalate, whereas others have found only calcium phosphate in renal biopsy tissue. AIM AND METHODS We aimed to study the urinary supersaturation of calcium oxalate and calcium phosphate and to determine whether these measures are risk factors for NC. We collected 24-hour urine samples from 20 patients (12 girls) with XLHR, mean +/- SD age 8.2 +/- 4.7 years, and from 79 age-matched members of a healthy control group prospectively. RESULTS The median 24-hour urine excretions of oxalate, phosphate, and citrate (mmol/1.73 m(2) per day) were significantly increased in patients compared with the control group (oxalate 0.38 vs 0.28, P =. 0012; phosphate 63.1 vs 25.8, P <.0001; citrate 4.18 vs 2.7, P =. 0002). However, no significant differences were seen in the calcium oxalate or calcium phosphate between patients and the control group. No significant differences were seen in 24-hour urine calcium or magnesium excretion between patients and the control group; however, 8 patients had hypercalciuria. A significant higher urine volume in patients compared with the normal group (826 mL/m(2) 24-hour vs 597 mL/m(2) 24-hour; P <.005) was found. Twelve patients had NC at the time of investigation, and although the oxalate excretion was significantly higher in these patients, no significant difference was seen in the relative supersaturation of calcium oxalate monohydrate (CaC(2)O(4).H(2)O) compared with the 8 without NC. CONCLUSIONS Although 24-hour urine oxalate and phosphate excretion are increased in treated patients with XLHR, there is no increase in the supersaturation of either calcium oxalate or phosphate. Determination of the supersaturation of calcium oxalate or calcium phosphate does not predict the development of NC in XLHR.
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Affiliation(s)
- L Patzer
- Nephro-Urology Unit, Institute of Child Health, University College of London Medical School, United Kingdom
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Grases F, Costa-Bauzá A, García-Ferragut L. Biopathological crystallization: a general view about the mechanisms of renal stone formation. Adv Colloid Interface Sci 1998; 74:169-94. [PMID: 9561720 DOI: 10.1016/s0001-8686(97)00041-9] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A general classification of most common renal calculi (calcium oxalate, phosphate and uric acid stones) based on their formation mechanism is presented. The main etiological factors that enable their development are discussed considering present knowledge of calcium oxalate, insoluble urinary phosphates and uric acid crystallization and the fine structure of respective renal stones. Considering the formation mechanisms of the discussed calculi, common aspects permit us to distinguish two general mechanisms of calculi formation: development of calculi attached to papillary epithelium and development of calculi in cavities without any attachment to urothelium.
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Affiliation(s)
- F Grases
- Laboratory of Urolithiasis Research, University of Illes Balears, Palma de Mallorca, Spain
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18
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Abstract
Calcific kidney stones in both humans and mildly hyperoxaluric rats are located on renal papillary surfaces and consist of an organic matrix and crystals of calcium oxalate and/or calcium phosphate. The matrix is intimately associated with the crystals and contains substances that can promote as well as inhibit calcification. Osteopontin, Tamm-Horsfall protein, bikunin, and prothrombin fragment 1 have been identified in matrices of both human and rat stones. Hyperoxaluria can provoke calcium oxalate nephrolithiasis in both humans and rats. Kidney-stone-forming rats are hypomagnesuric and hypocitraturic during nephrolithiasis. Human stone formers may have the same disorders. Males of both species are prone to develop calcium oxalate nephrolithiasis, whereas females tend to form calcium phosphate stones. Oxalate metabolism is considered to be almost identical between rats and humans. Thus, there are many similarities between experimental nephrolithiasis induced in rats and human kidney-stone formation, and a rat model of calcium oxalate nephrolithiasis can be used to investigate the mechanisms involved in human kidney stone formation.
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Affiliation(s)
- S R Khan
- Department of Pathology, College of Medicine, University of Florida, Gainesville 32610-0275, USA
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Baker PW, Rofe AM, Bais R. Idiopathic calcium oxalate urolithiasis and endogenous oxalate production. Crit Rev Clin Lab Sci 1996; 33:39-82. [PMID: 8833627 DOI: 10.3109/10408369609101486] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Despite the great effort that has gone into investigating urolithiasis, this condition still persists as one of the major ailments of the urinary tract. Calcium oxalate urolithiasis is the most common form, accounting for some 60 to 80% of total stones. This review examines the elements (i.e., urine volume and pH and urinary excretion of calcium, oxalate, citrate, urate, magnesium, pyrophosphate, and glycosaminoglycans) that give rise to idiopathic calcium oxalate urolithiasis. Treatment strategies for idiopathic calcium oxalate urolithiasis, including lithotripsy, also are discussed. Urinary oxalate excretion is a major risk factor for calcium oxalate urolithiasis, with 85 to 95% of the urinary load derived endogenously. The factors controlling endogenous oxalate production are reviewed, including pathways for the diversion of glyoxylate from oxalate production. The use of beta-aminothiols and other substances to reduce endogenous oxalate production in subjects with idiopathic calcium oxalate urolithiasis is also discussed. A review of current methodologies for the determination of urinary oxalate is also included.
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Affiliation(s)
- P W Baker
- Institute of Medical and Veterinary Science, Adelaide, South Australia
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22
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McKee MD, Nanci A, Khan SR. Ultrastructural immunodetection of osteopontin and osteocalcin as major matrix components of renal calculi. J Bone Miner Res 1995; 10:1913-29. [PMID: 8619372 DOI: 10.1002/jbmr.5650101211] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The organic matrix of renal calculi has long been considered to influence the crystal growth that occurs in these pathological mineral deposits. Recent advances in characterizing individual organic moieties from mineralized tissues in general and the combined use of antibodies raised against these molecules with different immunocytochemical approaches have allowed their precise distribution to be visualized in a variety of normal and pathological mineralized tissues. The present ultrastructural study reports on the epithelial expression and extracellular localization of several noncollagenous proteins in rat and human kidney stones using high-resolution colloidal-gold immunocytochemistry. To this end, we have examined in an ethylene glycol-induced calcium oxalate model of urolithiasis in the rat, and in human kidney stones, the distribution of certain noncollagenous and plasma proteins known to accumulate in bone and other mineralized tissues that include osteopontin, osteocalcin, bone sialoprotein, albumin, and alpha 2HS-glycoprotein. Of these proteins, osteopontin (uropontin) and osteocalcin (or osteocalcin-related gene/protein) were prominent constituents of the calcium oxalate-associated crystal "ghosts" found in the nuclei, lamellae, and striations of the organic matrix of lumenal renal calculi in the rat and of small crystal ghosts found within epithelial cells. Immunocytochemical labeling for both proteins of the content of secretory granules in tubular epithelial cells from treated rats, together with labeling of a similarly textured organic material in the tubular lumen, provides evidence for cosecretion of osteopontin and osteocalcin by epithelial cells, their transit through the urinary filtrate, and ultimately their incorporation into growing renal calculi. In normal rat kidney, osteopontin was localized to the Golgi apparatus of thin loop of Henle cells. In human calcium oxalate monohydrate stones, osteopontin was similarly detected in the lamellae and striations of the organic matrix. Based on these data, it is proposed that during urolithiasis, secretion of osteopontin (uropontin) and osteocalcin (or osteocalcin-related gene/protein), and the subsequent incorporation of these proteins into kidney stone matrix, may influence the nucleation, growth processes, aggregation, and/or tubular adhesion of renal calculi in mammalian kidneys.
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Affiliation(s)
- M D McKee
- Department of Stomatology, Faculty of Dentistry, Université de Montréal, QC, Canada
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Khan SR. Calcium oxalate crystal interaction with renal tubular epithelium, mechanism of crystal adhesion and its impact on stone development. UROLOGICAL RESEARCH 1995; 23:71-9. [PMID: 7676537 DOI: 10.1007/bf00307936] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The interaction between renal epithelial cells and calcium oxalate (CaOx) crystals and/or oxalate ions plays a critical role in the formation of urinary stones. Epithelial cells respond to hyperoxaluria and the presence of CaOx crystals in the kidneys by increased enzymuria and internalization of the crystals. Crystal cell interaction results in movement of crystals from the luminal to the basolateral side between the cells and the basement membrane. Once beneath the epithelium, crystals adhere to the basement membrane and become anchored inside the kidneys. Crystals anchored to basement membrane of the peripheral collecting duct aggregate with other crystals and move through an eroding epithelium to the papillary surface, furnishing an encrustation platform or a nidus for future development of a kidney stone. Thus interaction between renal epithelial cells and CaOx crystals and/or oxalate ions is an essential element in the development of urinary stone disease.
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De Bruijn WC, Ketelaars GA, Boevé ER, Sorber CW, Cao LC, Schröder FH. Electron energy-loss spectroscopical and image analysis of experimentally induced rat microliths. II. J Urol 1993; 149:900-5. [PMID: 8455271 DOI: 10.1016/s0022-5347(17)36255-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Following a microlith-inducing diet of ethylene glycol plus ammonium chloride, intraluminal and intracellular crystals are observed in aldehyde-fixed rat proximal and distal tubule cells by light and electron microscopy. Qualitative, in-situ analysis with electron-probe X-ray microanalysis (EPMA) of these intraluminal and intracellular crystals shows the presence of calcium, a trace of magnesium, some chlorine and the virtual absence of phosphorus and sulphur. Electron energy-loss spectroscopical element (EELS) analysis and electron-spectroscopic imaging (ESI) confirm, at both sites, the presence of calcium. Selected area electron diffraction (a) confirmed the crystallinity of both the intracellular and intraluminal crystals; (b) produced identical diffractograms from intracellular crystals in proximal tubule cells and deliberately internalized exogenous COM-crystals in cultured LLC-PK1 cells and (c) produced mean dhkl-values, identical to the dhkl-values from calcium oxalate monohydrate (14-771) in the ASTM index, from 4 different intracellular crystals in proximal-tubule cells.
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Alon U, Donaldson DL, Hellerstein S, Warady BA, Harris DJ. Metabolic and histologic investigation of the nature of nephrocalcinosis in children with hypophosphatemic rickets and in the Hyp mouse. J Pediatr 1992; 120:899-905. [PMID: 1317418 DOI: 10.1016/s0022-3476(05)81957-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To investigate the biochemical nature of nephrocalcinosis in children with hypophosphatemic rickets treated with orally administered phosphate and vitamin D, we studied five such patients, aged 3.7 to 12.3 years, during treatment and again 3 days after it had been discontinued. Treatment was associated with significant increases in mean serum phosphate concentration and urine phosphate/creatinine ratio, from 0.71 to 1.03 mmol/L and from 3.61 to 9.42 mmol/mmol, respectively. Significant correlation was found between urine phosphate/creatinine and oxalate/creatinine ratios (r = 0.670; p less than 0.01); however, the mean urine oxalate/creatinine ratio of 65.0 mumol/mmol while patients were taking phosphate orally was not significantly different from the ratio of 59.0 mumol/mmol when treatment was discontinued. Kidney biopsy specimens from three of the patients showed that the renal calcifications were located mainly intratubularly and were composed exclusively of calcium phosphate. In a further investigation of the nature of phosphate-induced nephrocalcinosis, six 6-week-old male Hyp mice, the murine analog of the human disease, received oral phosphate therapy with drinking water for 48 days; six others served as control animals. Mice in the experimental group excreted more phosphate (p less than 0.001) and less calcium (p less than 0.01) than control mice did, and medullary nephrocalcinosis, with a high kidney calcium content, developed (p less than 0.001). Histologic sections showed that the renal calcifications were located intratubularly and were composed of calcium phosphate. We conclude that, both in children with hypophosphatemic rickets and in the Hyp mouse, the development of nephrocalcinosis is associated with high oral phosphate intake and subsequent deposition of calcium phosphate precipitates in the kidney.
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Affiliation(s)
- U Alon
- Division of Pediatric Nephrology, Children's Mercy Hospital, University of Missouri, Kansas City 64108
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