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Mitchell EP, Church ME, Nemser SM, Yakes BJ, Evans ER, Reimschuessel R, Lemberger K, Thompson PN, Terio KA. Pathology and Epidemiology of Oxalate Nephrosis in Cheetahs. Vet Pathol 2017; 54:977-985. [PMID: 28891390 DOI: 10.1177/0300985817728556] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
To investigate cases of acute oxalate nephrosis without evidence of ethylene glycol exposure, archived data and tissues from cheetahs ( Acinonyx jubatus) from North America ( n = 297), southern Africa ( n = 257), and France ( n = 40) were evaluated. Renal and gastrointestinal tract lesions were characterized in a subset of animals with ( n = 100) and without ( n = 165) oxalate crystals at death. Crystals were confirmed as calcium oxalate by Raman spectroscopy in 45 of 47 cheetahs tested. Crystals were present in cheetahs from 3.7 months to 15.9 years old. Cheetahs younger than 1.5 years were less likely to have oxalates than older cheetahs ( P = .034), but young cheetahs with oxalates had more oxalate crystals than older cheetahs ( P < .001). Cheetahs with oxalate crystals were more likely to have renal amyloidosis, interstitial nephritis, or colitis and less likely to have glomerular loop thickening or gastritis than those without oxalates. Crystal number was positively associated with renal tubular necrosis ( P ≤ .001), regeneration ( P = .015), and casts ( P ≤ .001) but inversely associated with glomerulosclerosis, renal amyloidosis, and interstitial nephritis. Crystal number was unrelated to the presence or absence of colitis and was lower in southern African than American and European animals ( P = .01). This study found no evidence that coexisting chronic renal disease (amyloidosis, interstitial nephritis, or glomerulosclerosis), veno-occlusive disease, gastritis, or enterocolitis contributed significantly to oxalate nephrosis. Oxalate-related renal disease should be considered as a potential cause of acute renal failure, especially in young captive cheetahs. The role of location, diet, stress, and genetic predisposition in the pathogenesis of oxalate nephrosis in cheetahs warrants further study.
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Affiliation(s)
- Emily P Mitchell
- 1 Department of Research and Scientific Services, National Zoological Gardens of South Africa, Pretoria, South Africa.,2 Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Molly E Church
- 3 Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Sarah M Nemser
- 4 Veterinary Laboratory Investigation and Response Network, Office of Research, Center for Veterinary Medicine, U.S. Food and Drug Administration, Laurel, MD, USA
| | - Betsy Jean Yakes
- 5 Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, USA
| | - Eric R Evans
- 4 Veterinary Laboratory Investigation and Response Network, Office of Research, Center for Veterinary Medicine, U.S. Food and Drug Administration, Laurel, MD, USA
| | - Renate Reimschuessel
- 4 Veterinary Laboratory Investigation and Response Network, Office of Research, Center for Veterinary Medicine, U.S. Food and Drug Administration, Laurel, MD, USA
| | | | - Peter N Thompson
- 7 Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Karen A Terio
- 8 Zoological Pathology Program, University of Illinois, Brookfield, IL, USA
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AllR Controls the Expression of Streptomyces coelicolor Allantoin Pathway Genes. Appl Environ Microbiol 2015; 81:6649-59. [PMID: 26187964 DOI: 10.1128/aem.02098-15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 07/10/2015] [Indexed: 11/20/2022] Open
Abstract
Streptomyces species are native inhabitants of soil, a natural environment where nutrients can be scarce and competition fierce. They have evolved ways to metabolize unusual nutrients, such as purines and its derivatives, which are highly abundant in soil. Catabolism of these uncommon carbon and nitrogen sources needs to be tightly regulated in response to nutrient availability and environmental stimulus. Recently, the allantoin degradation pathway was characterized in Streptomyces coelicolor. However, there are questions that remained unanswered, particularly regarding pathway regulation. Here, using a combination of proteomics and genetic approaches, we identified the negative regulator of the allantoin pathway, AllR. In vitro studies confirmed that AllR binds to the promoter regions of allantoin catabolic genes and determined the AllR DNA binding motif. In addition, effector studies showed that allantoic acid, and glyoxylate, to a lesser extent, inhibit the binding of AllR to the DNA. Inactivation of AllR repressor leads to the constitutive expression of the AllR regulated genes and intriguingly impairs actinorhodin and undecylprodigiosin production. Genetics and proteomics analysis revealed that among all genes from the allantoin pathway that are upregulated in the allR mutant, the hyi gene encoding a hydroxypyruvate isomerase (Hyi) is responsible of the impairment of antibiotic production.
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Mdluli K, Booth MPS, Brady RL, Rumsby G. A preliminary account of the properties of recombinant human Glyoxylate reductase (GRHPR), LDHA and LDHB with glyoxylate, and their potential roles in its metabolism. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1753:209-16. [PMID: 16198644 DOI: 10.1016/j.bbapap.2005.08.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Revised: 07/08/2005] [Accepted: 08/08/2005] [Indexed: 11/19/2022]
Abstract
Human lactate dehydrogenase (LDH) is thought to contribute to the oxidation of glyoxylate to oxalate and thus to the pathogenesis of disorders of endogenous oxalate overproduction. Glyoxylate reductase (GRHPR) has a potentially protective role metabolising glyoxylate to the less reactive glycolate. In this paper, the kinetic parameters of recombinant human LDHA, LDHB and GR have been compared with respect to their affinity for glyoxylate and related substrates. The Km values and specificity constants (Kcat/K(M)) of purified recombinant human LDHA, LDHB and GRHPR were determined for the reduction of glyoxylate and hydroxypyruvate. K(M) values with glyoxylate were 29.3 mM for LDHA, 9.9 mM for LDHB and 1.0 mM for GRHPR. For the oxidation of glyoxylate, K(M) values were 0.18 mM and 0.26 mM for LDHA and LDHB respectively with NAD+ as cofactor. Overall, under the same reaction conditions, the specificity constants suggest there is a fine balance between the reduction and oxidation reactions of these substrates, suggesting that control is most likely dictated by the ambient concentrations of the respective intracellular cofactors. Neither LDHA nor LDHB utilised glycolate as substrate and NADPH was a poor cofactor with a relative activity less than 3% that of NADH. GRHPR had a higher affinity for NADPH than NADH (K(M) 0.011 mM vs. 2.42 mM). The potential roles of LDH isoforms and GRHPR in oxalate synthesis are discussed.
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Affiliation(s)
- K Mdluli
- Department of Immunology and Molecular Pathology, University College London, UK
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