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Stepanova N, Tolstanova G, Akulenko I, Nepomnyashchyi V, Savchenko S, Zholos A, Kolesnyk M. Pilot testing for long-term impact of glycerol-induced acute kidney injury on oxalate homeostasis in rats. UKRAINIAN JOURNAL OF NEPHROLOGY AND DIALYSIS 2022:15-24. [DOI: 10.31450/ukrjnd.2(74).2022.03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2023]
Abstract
Abstract. There is a general lack of research on the long-term effects of acute kidney injury (AKI) on oxalate-degrading bacteria (ODB) and their total oxalate-degrading activity (ODA) in fecal microbiota. In the present pilot study, we separately evaluated the changes in the ODB number and their total ODA in fecal microbiota at 3-time points after glycerol-induced AKI. In addition, we assessed the interactions between AKI-induced renal histopathological changes and ODB, total fecal ODA, and plasma and urine oxalate concentrations in rats.
Methods. The male Wistar rats (200-300 g, n = 20) on oxalate-free diet were randomly divided into 2 groups. After 24-h of water deprivation, experimental group 1 (n = 10) received an intramuscular injection of 50% glycerol (10 ml/kg of body weight), and group 2 (n = 10) served as a control. The numbers of ODB (incubated in a highly selective Oxalate Medium and determined using the culture method), total fecal ODA and urinary oxalate (UOx) excretion were measured after injection on days 8, 22 and 70. The method of redoximetric titration with a KMnO4 solution was adopted to evaluate total ODA in fecal microbiota. Renal injury was assessed by histopathology examination, serum creatinine plasma oxalic acid (POx) concentration and daily proteinuria levels after removing the animals from the experiment on day 70.
Results. After glycerol injection on days 8 and 22, no differences were found in the numbers of ODB, their total fecal ODA, and UOx excretion level between the experimental and control groups. However, after AKI initiation on day 70, the numbers of ODB, total fecal ODA, and daily UOx excretion were significantly lower in the experimental group as compared with the control group. In addition, in 10 weeks following AKI, the number of ODB had a direct correlation with UOx excretion and an inverse correlation with POx and serum creatinine concentrations and daily proteinuria. Total ODA in fecal microbiota was directly associated with the percentage of renal interstitial fibrosis and the average glomerular volumes in the experimental rats.
Conclusions: AKI had long-term negative effects on the quantitative and qualitative characteristics of ODB in fecal microbiota in rats. Moreover, the results of our study confirmed an increasing trend in total fecal ODA according to the aggravation of renal interstitial fibrosis and glomerular volume in rats’ kidneys. Further studies are warranted to gain more insight into the mechanism of oxalate homeostasis impairment in AKI.
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Østergaard MV, Sembach FE, Skytte JL, Roostalu U, Secher T, Overgaard A, Fink LN, Vrang N, Jelsing J, Hecksher-Sørensen J. Automated Image Analyses of Glomerular Hypertrophy in a Mouse Model of Diabetic Nephropathy. ACTA ACUST UNITED AC 2020; 1:469-479. [DOI: 10.34067/kid.0001272019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 04/24/2020] [Indexed: 01/17/2023]
Abstract
BackgroundGlomerular hypertrophy is a hallmark of kidney injury in metabolically induced renal diseases such as obesity-associated glomerulopathies and diabetic nephropathy (DN).MethodsUsing light sheet fluorescent microscopy (LSFM) and 3D image analysis, we tested algorithms for automated and unbiased quantification of total glomerular numbers and individual glomerular volume in the uninephrectomized (UNx) db/db mouse model of DN.ResultsAt 6 weeks after surgery, db/db and UNx db/db mice showed increased urine albumin-to-creatinine ratio (ACR) compared with db/+ control mice. Before euthanasia, glomeruli were labeled in vivo by injecting tomato lectin. Whole-kidney LSFM 3D image analysis revealed that mean glomerular volume was significantly increased in UNx db/db mice compared with db/+ mice. Moreover, analysis of individual glomerular volume showed a shift in volume distribution toward larger glomeruli and thereby demonstrated additive effects of diabetes and UNx on induction of glomerular hypertrophy. The automatized quantification showed no significant differences in glomerular numbers among db/+, db/db, and UNx db/db mice. These data correlated with glomerular numbers as quantified by subsequent stereologic quantification.ConclusionsOverall, LSFM coupled with automated 3D histomorphometric analysis was demonstrated to be advantageous for unbiased assessment of glomerular volume and numbers in mouse whole-kidney samples. Furthermore, we showed that injection of fluorescently labeled lectin and albumin can be used as markers of nephron segments in the mouse kidneys, thus enabling functional assessment of kidney physiology, pathology, and pharmacology in preclinical rodent models of kidney disease.
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Baldelomar EJ, Charlton JR, deRonde KA, Bennett KM. In vivo measurements of kidney glomerular number and size in healthy and Os /+ mice using MRI. Am J Physiol Renal Physiol 2019; 317:F865-F873. [PMID: 31339774 DOI: 10.1152/ajprenal.00078.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The development of chronic kidney disease (CKD) is associated with the loss of functional nephrons. However, there are no methods to directly measure nephron number in living subjects. Thus, there are no methods to track the early stages of progressive CKD before changes in total renal function. In this work, we used cationic ferritin-enhanced magnetic resonance imaging (CFE-MRI) to enable measurements of glomerular number (Nglom) and apparent glomerular volume (aVglom) in vivo in healthy wild-type (WT) mice (n = 4) and mice with oligosyndactylism (Os/+; n = 4), a model of congenital renal hypoplasia leading to nephron reduction. We validated in vivo measurements of Nglom and aVglom by high-resolution ex vivo MRI. CFE-MRI measured a mean Nglom of 12,220 ± 2,028 and 6,848 ± 1,676 (means ± SD) for WT and Os/+ mouse kidneys in vivo, respectively. Nglom measured in all mice in vivo using CFE-MRI varied by an average 15% from Nglom measured ex vivo in the same kidney (α = 0.05, P = 0.67). To confirm that CFE-MRI can also be used to track nephron endowment longitudinally, a WT mouse was imaged three times by CFE-MRI over 2 wk. Values of Nglom measured in vivo in the same kidney varied within ~3%. Values of aVglom calculated from CFE-MRI in vivo were significantly different (~15% on average, P < 0.01) from those measured ex vivo, warranting further investigation. This is the first report of direct measurements of Nglom and aVglom in healthy and diseased mice in vivo.
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Affiliation(s)
- Edwin J Baldelomar
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri.,Department of Physics, University of Hawai'i at Mānoa, Honolulu, Hawaii
| | - Jennifer R Charlton
- University of Virginia Children's Hospital, Department of Pediatrics, Charlottesville, Virginia
| | - Kimberly A deRonde
- University of Virginia Children's Hospital, Department of Pediatrics, Charlottesville, Virginia
| | - Kevin M Bennett
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri.,Department of Biology, University of Hawai'i at Mānoa, Honolulu, Hawaii
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Romoli S, Angelotti ML, Antonelli G, Kumar Vr S, Mulay SR, Desai J, Anguiano Gomez L, Thomasova D, Eulberg D, Klussmann S, Melica ME, Conte C, Lombardi D, Lasagni L, Anders HJ, Romagnani P. CXCL12 blockade preferentially regenerates lost podocytes in cortical nephrons by targeting an intrinsic podocyte-progenitor feedback mechanism. Kidney Int 2018; 94:1111-1126. [PMID: 30385042 PMCID: PMC6251974 DOI: 10.1016/j.kint.2018.08.013] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 08/01/2018] [Accepted: 08/09/2018] [Indexed: 01/10/2023]
Abstract
Insufficient podocyte regeneration after injury is a central pathomechanism of glomerulosclerosis and chronic kidney disease. Podocytes constitutively secrete the chemokine CXCL12, which is known to regulate homing and activation of stem cells; hence we hypothesized a similar effect of CXCL12 on podocyte progenitors. CXCL12 blockade increased podocyte numbers and attenuated proteinuria in mice with Adriamycin-induced nephropathy. Similar studies in lineage-tracing mice revealed enhanced de novo podocyte formation from parietal epithelial cells in the setting of CXCL12 blockade. Super-resolution microscopy documented full integration of these progenitor-derived podocytes into the glomerular filtration barrier, interdigitating with tertiary foot processes of neighboring podocytes. Quantitative 3D analysis revealed that conventional 2D analysis underestimated the numbers of progenitor-derived podocytes. The 3D analysis also demonstrated differences between juxtamedullary and cortical nephrons in both progenitor endowment and Adriamycin-induced podocyte loss, with more robust podocyte regeneration in cortical nephrons with CXCL12 blockade. Finally, we found that delayed CXCL12 inhibition still had protective effects. In vitro studies found that CXCL12 inhibition uncoupled Notch signaling in podocyte progenitors. These data suggest that CXCL12-driven podocyte-progenitor feedback maintains progenitor quiescence during homeostasis, but also limits their intrinsic capacity to regenerate lost podocytes, especially in cortical nephrons. CXCL12 inhibition could be an innovative therapeutic strategy in glomerular disorders.
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Affiliation(s)
- Simone Romoli
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | - Maria Lucia Angelotti
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Giulia Antonelli
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Santhosh Kumar Vr
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | - Shrikant R Mulay
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | - Jyaysi Desai
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | | | - Dana Thomasova
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | | | | | - Maria Elena Melica
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Carolina Conte
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Duccio Lombardi
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Laura Lasagni
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Hans-Joachim Anders
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany.
| | - Paola Romagnani
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy.
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Zhang J, Cong J, Yang J, Thomsen JS, Andreasen A, Chang SJ, Wang KY, Gu L, Zhai XY. Morphologic and morphometric study on microvasculature of developing mouse kidneys. Am J Physiol Renal Physiol 2018; 315:F852-F860. [DOI: 10.1152/ajprenal.00615.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A proper morphogenesis of the renal microvasculature is crucial not only for fulfilling the renal function but also to slow down the progression of chronic kidney disease in adulthood. However, the current description of the developing microvasculature is incomplete. The present study investigated the morphogenesis and volume densities of the renal microvasculature using computer-assisted tubular tracing, immunohistochemistry for CD34, and unbiased stereology. The earliest glomerular capillaries were observed at the lower cleft of the S-shaped nephrons, as simple loops connecting the afferent and efferent arterioles. In parallel with this, the peritubular capillaries were established. Noticeably, from early nephrogenesis on, the efferent arterioles of the early-formed glomeruli ran in close proximity to their own thick ascending limbs. In addition, the ascending vasa recta arising from the arcuate or interlobular veins also ran in close proximity to the thick descending limb. Thus, the tubules and vessels formed the typical countercurrent relation in the medulla. No loop bends were observed between descending and ascending vasa recta. The volume density of the cortical and medullary peritubular capillary increased 3.3- and 2.6-fold, respectively, from 2.34 (0.13) and 7.03 (0.09)% [means (SD)] at embryonic day 14.5 (E14.5) to 7.71 (0.44) and 18.27 (1.17)% at postnatal day 40 (P40). In contrast, the volume density of glomeruli changed only slightly during kidney development, from 4.61 (0.47)% at E14.5 to 6.07 (0.2)% at P7 to 4.19 (0.47)% at P40. These results reflect that the growth and formation of the renal microvasculature closely correspond to functional development of the tubules.
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Affiliation(s)
- Jie Zhang
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
| | - Jing Cong
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
- Department of Histology and Embryology, Shenyang Medical College, Shenyang, China
| | - Jie Yang
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
| | | | - Arne Andreasen
- Department of Biomedicine-Anatomy, Aarhus University, Aarhus, Denmark
| | - Shi-Jie Chang
- Department of Biomedical Engineering, College of Fundamental Science, China Medical University, Shenyang, China
| | - Kai-Yue Wang
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
| | - Ling Gu
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
| | - Xiao-Yue Zhai
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
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