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Paschall RE, Quimby JM, Cianciolo RE, McLeland SM, Lunn KF, Elliott J. Assessment of peritubular capillary rarefaction in kidneys of cats with chronic kidney disease. J Vet Intern Med 2023; 37:556-566. [PMID: 36807589 DOI: 10.1111/jvim.16656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 02/03/2023] [Indexed: 02/20/2023] Open
Abstract
BACKGROUND Hypoxia is a key driver of fibrosis and is associated with capillary rarefaction in humans. OBJECTIVES Characterize capillary rarefaction in cats with chronic kidney disease (CKD). ANIMALS Archival kidney tissue from 58 cats with CKD, 20 unaffected cats. METHODS Cross-sectional study of paraffin-embedded kidney tissue utilizing CD31 immunohistochemistry to highlight vascular structures. Consecutive high-power fields from the cortex (10) and corticomedullary junction (5) were digitally photographed. An observer counted and colored the capillary area. Image analysis was used to determine the capillary number, average capillary size, and average percent capillary area in the cortex and corticomedullary junction. Histologic scoring was performed by a pathologist masked to clinical data. RESULTS Percent capillary area (cortex) was significantly lower in CKD (median 3.2, range, 0.8-5.6) compared to unaffected cats (4.4, 1.8-7.0; P = <.001) and was negatively correlated with serum creatinine concentrations (r = -.36, P = .0013), glomerulosclerosis (r = -0.39, P = <.001), inflammation (r = -.30, P = .009), and fibrosis (r = -.30, P = .007). Capillary size (cortex) was significantly lower in CKD cats (2591 pixels, 1184-7289) compared to unaffected cats (4523 pixels, 1801-7618; P = <.001) and was negatively correlated with serum creatinine concentrations (r = -.40, P = <.001), glomerulosclerosis (r = -.44, P < .001), inflammation (r = -.42, P = <.001), and fibrosis (r = -.38, P = <.001). CONCLUSIONS AND CLINICAL IMPORTANCE Capillary rarefaction (decrease in capillary size and percent capillary area) is present in kidneys of cats with CKD and is positively correlated with renal dysfunction and histopathologic lesions.
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Affiliation(s)
- Rene E Paschall
- Department of Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio, USA
| | - Jessica M Quimby
- Department of Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio, USA
| | - Rachel E Cianciolo
- Department of Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio, USA
| | - Shannon M McLeland
- Department of Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio, USA
| | - Katharine F Lunn
- Department of Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio, USA
| | - Jonathan Elliott
- Department of Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio, USA
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2
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Selenium Deficiency-Induced Oxidative Stress Causes Myocardial Injury in Calves by Activating Inflammation, Apoptosis, and Necroptosis. Antioxidants (Basel) 2023; 12:antiox12020229. [PMID: 36829789 PMCID: PMC9951920 DOI: 10.3390/antiox12020229] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/07/2023] [Accepted: 01/10/2023] [Indexed: 01/21/2023] Open
Abstract
Selenium (Se) is essential for human and animal health, but there have been few studies on the mechanisms of injury in dairy cows with Se deficiency. This study aimed to evaluate the effects of Se deficiency on myocardial injury in weaned calves. The Se-D group had significantly lower myocardial Se concentrations than the Se-C group. Histological analysis indicated that Se deficiency induced a large area of necrosis in the myocardium, accompanied by inflammatory changes. Se deficiency significantly decreased the expression of 10 of the 21 selenoprotein genes and increased the expression of SEPHS2. Furthermore, we found that oxidative stress occurred in the Se-D group by detection of redox-related indicators. Additionally, TUNEL staining showed that Se deficiency causes severe apoptosis in the myocardium, which was characterized by activating the exogenous apoptotic pathway and the mitochondrial apoptotic pathway. Se deficiency also induced necroptosis in the myocardium by upregulating MLKL, RIPK1, and RIPK3. Moreover, Se-deficient calves have severe inflammation in the myocardium. Se deficiency significantly reduced anti-inflammatory factor levels while increasing pro-inflammatory factor levels. We also found that the NF-κB pathway and MAPK pathway were activated in Se-deficient conditions. Our findings suggest that Se deficiency causes myocardial injury in weaned calves by regulating oxidative stress, inflammation, apoptosis, and necroptosis.
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Iacobini C, Vitale M, Haxhi J, Pesce C, Pugliese G, Menini S. Mutual Regulation between Redox and Hypoxia-Inducible Factors in Cardiovascular and Renal Complications of Diabetes. Antioxidants (Basel) 2022; 11:2183. [PMID: 36358555 PMCID: PMC9686572 DOI: 10.3390/antiox11112183] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 08/30/2023] Open
Abstract
Oxidative stress and hypoxia-inducible factors (HIFs) have been implicated in the pathogenesis of diabetic cardiovascular and renal diseases. Reactive oxygen species (ROS) mediate physiological and pathophysiological processes, being involved in the modulation of cell signaling, differentiation, and survival, but also in cyto- and genotoxic damage. As master regulators of glycolytic metabolism and oxygen homeostasis, HIFs have been largely studied for their role in cell survival in hypoxic conditions. However, in addition to hypoxia, other stimuli can regulate HIFs stability and transcriptional activity, even in normoxic conditions. Among these, a regulatory role of ROS and their byproducts on HIFs, particularly the HIF-1α isoform, has received growing attention in recent years. On the other hand, HIF-1α and HIF-2α exert mutually antagonistic effects on oxidative damage. In diabetes, redox-mediated HIF-1α deregulation contributes to the onset and progression of cardiovascular and renal complications, and recent findings suggest that deranged HIF signaling induced by hyperglycemia and other cellular stressors associated with metabolic disorders may cause mitochondrial dysfunction, oxidative stress, and inflammation. Understanding the mechanisms of mutual regulation between HIFs and redox factors and the specific contribution of the two main isoforms of HIF-α is fundamental to identify new therapeutic targets for vascular complications of diabetes.
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Affiliation(s)
- Carla Iacobini
- Department of Clinical and Molecular Medicine, “La Sapienza” University, 00189 Rome, Italy
| | - Martina Vitale
- Department of Clinical and Molecular Medicine, “La Sapienza” University, 00189 Rome, Italy
| | - Jonida Haxhi
- Department of Clinical and Molecular Medicine, “La Sapienza” University, 00189 Rome, Italy
| | - Carlo Pesce
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal Infantile Sciences (DINOGMI), Department of Excellence of MIUR, University of Genoa Medical School, 16132 Genoa, Italy
| | - Giuseppe Pugliese
- Department of Clinical and Molecular Medicine, “La Sapienza” University, 00189 Rome, Italy
| | - Stefano Menini
- Department of Clinical and Molecular Medicine, “La Sapienza” University, 00189 Rome, Italy
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Creamer DG, Schmiedt CW, Bullington AC, Caster CM, Schmiedt JM, Hurley DJ, Berghaus RD. Influence of exposure to microbial ligands, immunosuppressive drugs and chronic kidney disease on endogenous immunomodulatory gene expression in feline adipose-derived mesenchymal stem cells. J Feline Med Surg 2022; 24:e43-e56. [PMID: 35302413 PMCID: PMC11104253 DOI: 10.1177/1098612x221083074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Feline autologous mesenchymal stem cells (MSCs) show promise for immunomodulatory activity, but the functional impact of chronic kidney disease (CKD), concurrent immunosuppressive drug administration or infection is unknown. The study objectives compare endogenous cytokine gene expression (interleukin [IL]-6, IL-10, IL-12p40, IL-18 and transforming growth factor beta [TGF-β]) in adipose-derived MSCs (aMSCs) from cats with and without CKD, following in vitro exposure to microbial ligands and treatment with common immunosuppressive drugs. METHODS Previously obtained aMSCs, phenotype CD44+, CD90+, CD105+ and MHCII-, from cats with (n = 6) and without (n = 6) CKD were compared via real-time PCR (RT-PCR) for immunomodulatory gene expression. aMSCs were exposed in vitro to lipopolysaccharide (LPS), peptidoglycan or polyinosinic:polycytidylic acid (Poly I:C), simulating bacterial or viral exposure, respectively. aMSCs were also exposed to ciclosporin, dexamethasone or methotrexate. Gene expression was measured using RT-PCR, and Cq was utilized after each run to calculate the delta cycle threshold. RESULTS aMSCs isolated from healthy and CKD cats showed no significant differences in gene expression in the five measured cytokines. No significant changes in measured gene expression after drug treatment or microbial ligand stimulation were observed between normal or CKD affected cats. Proinflammatory genes (IL-6, IL-12p40 and IL-18) showed altered expression in aMSCs from both groups when compared with the same cells in standard culture after exposure to methotrexate. Poly I:C altered IL-6 and TGF-β gene expression in aMSCs from both healthy and CKD cats when compared with the same cells in standard culture. CONCLUSIONS AND RELEVANCE The five genes tested showed no statistical differences between aMSCs from healthy or CKD cats. There was altered cytokine gene expression between the control and treatment groups of both healthy and CKD cats suggesting feline aMSCs have altered function with immunosuppressive treatment or microbial ligand exposure. Although the current clinical relevance of this pilot study comparing brief exposure to select agents in vitro in aMSCs from a small number of cats is unknown, the study highlights a need for continued investigation into the effects of disease and concurrent therapies on use of cell-based therapies in feline patients.
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Affiliation(s)
- Danielle G Creamer
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Chad W Schmiedt
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Anna Claire Bullington
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Courtney M Caster
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Jennifer M Schmiedt
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - David J Hurley
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Roy D Berghaus
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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5
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Grimes JA, Lourenço BN, Coleman AE, Rissi DR, Schmiedt CW. MicroRNAs are differentially expressed in the serum and renal tissues of cats with experimentally induced chronic kidney disease: a preliminary study. Am J Vet Res 2022; 83:426-433. [PMID: 35239506 DOI: 10.2460/ajvr.21.08.0136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To identify differentially expressed microRNA in the serum and renal tissues of cats with experimentally induced chronic kidney disease (CKD). SAMPLE Banked renal tissues and serum from 4 cats. PROCEDURES Cats previously underwent 90-minute unilateral ischemia with delayed contralateral nephrectomy 3 months after ischemia. Tissues were collected from the contralateral kidney at the time of nephrectomy and from the ischemic kidney 6 months after nephrectomy (study end). Serum was collected prior to ischemia (baseline serum) and at study end (end point serum). Total RNA was isolated from tissues and serum, and microRNA sequencing was performed with differential expression analysis between the contralateral and ischemic kidney and baseline and end point serum. RESULTS 20 microRNAs were differentially expressed between ischemic and contralateral kidneys, and 52 microRNAs were differentially expressed between end point and baseline serum. Five microRNAs were mutually differentially expressed between ischemic and contralateral kidneys and baseline and end point serum, with 4 (mir-21, mir-146, mir-199, and mir-235) having increased expression in both the ischemic kidney and end point serum and 1 (mir-382) having increased expression in the ischemic kidney and decreased expression in end point serum. Predicted target search for these microRNA revealed multiple genes previously shown to be involved in the pathogenesis of feline CKD, including hypoxia-inducible factor-1α, transforming growth factor-β, hepatocyte growth factor, fibronectin, and vascular endothelial growth factor A. CLINICAL RELEVANCE MicroRNAs were differentially expressed after CKD induction in this preliminary study. Regulation of renal fibrosis in feline CKD may occur through microRNA regulation of mRNAs of pro- and anti-fibrotic genes.
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Affiliation(s)
- Janet A Grimes
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA
| | - Bianca N Lourenço
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA
| | - Amanda E Coleman
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA
| | - Daniel R Rissi
- Athens Veterinary Diagnostic Laboratory, Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA
| | - Chad W Schmiedt
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA
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Lourenço BN, Coleman AE, Berghaus RD, Tarigo JL, Schmiedt CW, Brown SA. Characterization of the intrarenal renin-angiotensin system in cats with naturally occurring chronic kidney disease. J Vet Intern Med 2022; 36:647-655. [PMID: 35352404 PMCID: PMC8965263 DOI: 10.1111/jvim.16361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/07/2022] [Accepted: 01/07/2022] [Indexed: 11/28/2022] Open
Abstract
Background The role of the renin‐angiotensin‐aldosterone system in cats with chronic kidney disease (CKD) is incompletely understood. Objective To characterize components of the intrarenal renin‐angiotensin system (RAS) in cats with CKD. Animals Eleven cats with naturally occurring CKD (CKD group) and 8 healthy control cats. Methods Renal tissue samples were evaluated by reverse‐transcription polymerase chain reaction for renin, angiotensinogen, angiotensin‐converting enzyme (ACE), and angiotensin II type 1 receptor transcript levels, and by liquid chromatography‐mass spectrometry for quantification of angiotensin I, II, III, and IV concentrations. Linear mixed models were used to compare gene transcript levels and concentrations of angiotensin peptides between groups. Results Cats of the CKD group were significantly older (P < .001) and more likely to be neutered (P = .007) than healthy control cats. Kidneys from cats with CKD had significantly higher transcript levels of angiotensinogen (P < .001) and lower transcript levels of ACE (P < .001) than those from control cats. Renal angiotensin I concentrations were increased in CKD compared with control kidneys (P = .001). No other significant differences in renal transcript levels or angiotensin peptide concentrations were noted between groups. Conclusion and Clinical Importance The intrarenal RAS might be activated in cats with CKD. Small sample size and differences in age, neuter status, and dietary sodium intake between groups might have limited the ability to identify a significant difference in concentration of renal angiotensin II.
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Affiliation(s)
- Bianca N Lourenço
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Amanda E Coleman
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Roy D Berghaus
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Jaime L Tarigo
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Chad W Schmiedt
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Scott A Brown
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.,Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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Quimby J, Erickson A, Mcleland S, Cianciolo R, Maranon D, Lunn K, Elliott J, Lawson J, Hess A, Paschall R, Bailey S. Renal Senescence, Telomere Shortening and Nitrosative Stress in Feline Chronic Kidney Disease. Vet Sci 2021; 8:vetsci8120314. [PMID: 34941841 PMCID: PMC8703545 DOI: 10.3390/vetsci8120314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/12/2021] [Accepted: 12/02/2021] [Indexed: 01/15/2023] Open
Abstract
Kidney tissues from cats with naturally occurring chronic kidney disease (CKD) and adult and senior cats without CKD were assessed to determine whether telomere shortening and nitrosative stress are associated with senescence in feline CKD. The histopathologic assessment of percent global glomerulosclerosis, inflammatory infiltrate, and fibrosis was performed. Senescence and nitrosative stress were evaluated utilizing p16 and iNOS immunohistochemistry, respectively. Renal telomere length was evaluated using telomere fluorescent in situ hybridization combined with immunohistochemistry. CKD cats were found to have significantly increased p16 staining in both the renal cortex and corticomedullary junction compared to adult and senior cats. Senior cats had significantly increased p16 staining in the corticomedullary junction compared to adult cats. p16 staining in both the renal cortex and corticomedullary junction were found to be significantly correlated with percent global glomerulosclerosis, cortical inflammatory infiltrate, and fibrosis scores. p16 staining also correlated with age in non-CKD cats. Average telomere length was significantly decreased in CKD cats compared to adult and senior cats. CKD cats had significantly increased iNOS staining compared to adult cats. Our results demonstrate increased renal senescence, telomere shortening, and nitrosative stress in feline CKD, identifying these patients as potential candidates for senolytic therapy with translational potential.
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Affiliation(s)
- Jessica Quimby
- Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH 43210, USA; (A.E.); (R.P.)
- Correspondence: ; Tel.: +1-614-292-3551
| | - Andrea Erickson
- Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH 43210, USA; (A.E.); (R.P.)
| | - Shannon Mcleland
- International Veterinary Renal Pathology Service, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA; (S.M.); (R.C.)
| | - Rachel Cianciolo
- International Veterinary Renal Pathology Service, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA; (S.M.); (R.C.)
| | - David Maranon
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80521-1618, USA; (D.M.); (S.B.)
| | - Katharine Lunn
- Department of Clinical Sciences, North Carolina State University, Raleigh, NC 27695-0001, USA;
| | - Jonathan Elliott
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London E16 2PX, UK;
| | - Jack Lawson
- Department of Clinical Sciences and Services, Royal Veterinary College, Herts AL9 7TA, UK;
| | - Ann Hess
- Department of Statistics, Colorado State University, Fort Collins, CO 80521-4593, USA;
| | - Rene Paschall
- Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH 43210, USA; (A.E.); (R.P.)
| | - Susan Bailey
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80521-1618, USA; (D.M.); (S.B.)
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Spencer S, Wheeler-Jones C, Elliott J. Hypoxia and chronic kidney disease: Possible mechanisms, therapeutic targets, and relevance to cats. Vet J 2021; 274:105714. [PMID: 34252550 DOI: 10.1016/j.tvjl.2021.105714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 07/01/2021] [Accepted: 07/06/2021] [Indexed: 10/20/2022]
Abstract
There is mounting evidence that kidney ischaemia/hypoxia plays an important role in feline chronic kidney disease (CKD) development and progression, as well as in human disease and laboratory animal models. Ischaemic acute kidney injury is widely accepted as a cause of CKD in people and data from laboratory species has identified some of the pathways underlying this continuum. Experimental kidney ischaemia in cats results in morphological changes, namely chronic tubulointerstitial inflammation, tubulointerstitial fibrosis, and tubular atrophy, akin to those observed in naturally-occurring CKD. Multiple situations are envisaged that could result in acute or chronic episodes of kidney hypoxia in cats, while risk factors identified in epidemiological studies provide further support that kidney hypoxia contributes to spontaneously occurring feline CKD. This review evaluates the evidence for the role of kidney ischaemia/hypoxia in feline CKD and the proposed mechanisms and consequences of kidney hypoxia. As no effective treatments exist that substantially slow or prevent feline CKD progression, there is a need for novel therapeutic strategies. Targeting kidney hypoxia is one such promising approach, with therapies including those that attenuate the hypoxia-inducible factor (HIF) pathway already being utilised in human CKD.
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Affiliation(s)
- Sarah Spencer
- Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
| | - Caroline Wheeler-Jones
- Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 0TU, UK
| | - Jonathan Elliott
- Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 0TU, UK
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Lourenço BN, Schmiedt CW, Alabady MS, Stanton JB, Coleman AE, Brown CA, Rissi DR, Brown SA, Tarigo JL. Analysis of genes associated with proinflammatory and profibrotic pathways upregulated in ischemia-induced chronic kidney disease in cats. Am J Vet Res 2021; 82:589-597. [PMID: 34166083 DOI: 10.2460/ajvr.82.7.589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To use RNA sequencing (RNAseq) to characterize renal transcriptional activities of genes associated with proinflammatory and profibrotic pathways in ischemia-induced chronic kidney disease (CKD) in cats. SAMPLES Banked renal tissues from 6 cats with experimentally induced CKD (renal ischemia [RI] group) and 9 healthy cats (control group). PROCEDURES Transcriptome analysis with RNAseq, followed by gene ontology and cluster analyses, were performed on banked tissue samples of the right kidneys (control kidneys) from cats in the control group and of both kidneys from cats in the RI group, in which unilateral (right) RI had been induced 6 months before the cats were euthanized and the ischemic kidneys (IKs) and contralateral nonischemic kidneys (CNIKs) were harvested. Results for the IKs, CNIKs, and control kidneys were compared to identify potential differentially expressed genes and overrepresented proinflammatory and profibrotic pathways. RESULTS Genes from the gene ontology pathways of collagen binding (eg, transforming growth factor-β1), metalloendopeptidase activity (eg, metalloproteinase [MMP]-7, MMP-9, MMP-11, MMP-13, MMP-16, MMP-23B, and MMP-28), chemokine activity, and T-cell migration were overrepresented as upregulated in tissue samples of the IKs versus control kidneys. Genes associated with the extracellular matrix (eg, TIMP-1, fibulin-1, secreted phosphoprotein-1, matrix Gla protein, and connective tissue growth factor) were upregulated in tissue samples from both the IKs and CNIKs, compared with tissues from the control kidneys. CONCLUSIONS AND CLINICAL RELEVANCE Unilateral ischemic injury differentially altered gene expression in both kidneys, compared with control kidneys. Fibulin-1, secreted phosphoprotein-1, and matrix Gla protein may be candidate biomarkers of active kidney injury in cats.
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Affiliation(s)
- Bianca N Lourenço
- From the Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Chad W Schmiedt
- From the Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Magdy S Alabady
- From the Department of Plant Biology, Franklin College of Arts and Sciences, and Georgia Genomics and Bioinformatics Core, University of Georgia, Athens, GA 30602
| | - James B Stanton
- From the Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Amanda E Coleman
- From the Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Cathy A Brown
- From the Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Daniel R Rissi
- From the Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Scott A Brown
- From the Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
- From the Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Jaime L Tarigo
- From the Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
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Packer M. Mutual Antagonism of Hypoxia-Inducible Factor Isoforms in Cardiac, Vascular, and Renal Disorders. ACTA ACUST UNITED AC 2020; 5:961-968. [PMID: 33015417 PMCID: PMC7524787 DOI: 10.1016/j.jacbts.2020.05.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/07/2020] [Accepted: 05/07/2020] [Indexed: 02/06/2023]
Abstract
Hypoxia-inducible factor (HIF)-1α and HIF-2α promote cellular adaptation to acute hypoxia, but during prolonged activation, these isoforms exert mutually antagonistic effects on the redox state and on proinflammatory pathways. Sustained HIF-1α signaling can increase oxidative stress, inflammation, and fibrosis, actions that are opposed by HIF-2α. Imbalances in the interplay between HIF-1α and HIF-2α may contribute to the progression of chronic heart failure, atherosclerotic and hypertensive vascular disorders, and chronic kidney disease. These disorders are characterized by activation of HIF-1α and suppression of HIF-2α, which are potentially related to mitochondrial and peroxisomal dysfunction and suppression of the redox sensor, sirtuin-1. Hypoxia mimetics can potentiate HIF-1α and/or HIF-2α; ideally, such agents should act preferentially to promote HIF-2α while exerting little effect on or acting to suppress HIF-1α. Selective activation of HIF-2α can be achieved with drugs that: 1) inhibit isoform-selective prolyl hydroxylases (e.g., cobalt chloride and roxadustat); or 2) promote the actions of the redox sensor, sirtuin-1 (e.g., sodium-glucose cotransporter 2 inhibitors). Selective HIF-2α signaling through sirtuin-1 activation may explain the effect of sodium-glucose cotransporter 2 inhibitors to simultaneously promote erythrocytosis and ameliorate the development of cardiomyopathy and nephropathy.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, Texas.,Imperial College, London, United Kingdom
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11
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Lourenço BN, Coleman AE, Tarigo JL, Berghaus RD, Brown CA, Rissi DR, Stanton JB, Brown SA, Schmiedt CW. Evaluation of profibrotic gene transcription in renal tissues from cats with naturally occurring chronic kidney disease. J Vet Intern Med 2020; 34:1476-1487. [PMID: 32468592 PMCID: PMC7379026 DOI: 10.1111/jvim.15801] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 04/15/2020] [Accepted: 05/01/2020] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Increased gene transcription of hypoxia-induced mediators of fibrosis in renal tissue has been identified in experimentally induced, ischemic chronic kidney disease (CKD). OBJECTIVE To characterize hypoxia-induced profibrotic pathways in naturally occurring CKD in cats. ANIMALS Twelve client-owned cats with CKD and 8 healthy control cats. METHODS In this prospective, cross-sectional study, bilateral renal tissue samples were assessed histologically for inflammation, tubular atrophy, and fibrosis, and by reverse transcription-quantitative PCR for characterization of transcript levels of hypoxia-inducible factor-1α (HIF1A), matrix metalloproteinases-2 (MMP2), -7 (MMP7), and -9 (MMP9), tissue inhibitor of metalloproteinase-1 (TIMP1), transforming growth factor-β1 (TGFB1), and vascular endothelial growth factor-A (VEGFA). Linear mixed models were used to compare gene transcription between diseased and healthy kidneys, and to examine the association between transcript levels and serum creatinine concentration for all cats, and between transcript levels and histologic scores of diseased kidneys. RESULTS Kidneys from cats with CKD had significantly higher transcript levels of HIF1A, MMP2, MMP7, MMP9, TIMP1, and TGFB1 (all P < .001), and lower levels of VEGFA (P = .006) than those from control cats. Transcript levels of MMP7 (P = .05) and TIMP1 (P = .005) were positively associated with serum creatinine in cats with CKD, but not in control cats. In diseased kidneys, transcript levels of MMP2 (P = .002), MMP7 (P = .02), and TIMP1 (P = .02) were positively, whereas those of VEGFA (P = .003) were negatively, associated with histologic score severity. CONCLUSION AND CLINICAL SIGNIFICANCE Evaluation of the expression of the corresponding proteins in larger populations could identify therapeutic targets and/or biomarkers of tubulointerstitial fibrosis in cats.
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Affiliation(s)
- Bianca N Lourenço
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Amanda E Coleman
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Jaime L Tarigo
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Roy D Berghaus
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Cathy A Brown
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Daniel R Rissi
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - James B Stanton
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Scott A Brown
- Departments of Small Animal Medicine & Surgery and Physiology & Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Chad W Schmiedt
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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