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Berillo O, Ouerd S, Idris-Khodja N, Rehman A, Richer C, Sinnett D, Kwitek AE, Paradis P, Schiffrin EL. Chromosome 2 Fragment Substitutions in Dahl Salt-Sensitive Rats and RNA Sequencing Identified Enpep and Hs2st1 as Vascular Inflammatory Modulators. Hypertension 2020; 77:178-189. [PMID: 33161775 DOI: 10.1161/hypertensionaha.120.15690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Chromosome 2 introgression from normotensive Brown Norway (BN) rats into hypertensive Dahl salt-sensitive (SS) background (SS-chromosome 2BN/Mcwi; consomic S2B) reduced blood pressure and vascular inflammation under a normal-salt diet (NSD). We hypothesized that BN chromosome 2 contains anti-inflammatory genes that could reduce blood pressure and vascular inflammation in rats fed NSD or high-salt diet (HSD). Four- to 6-week old male SS and congenic rats containing the BN chromosome 2 distal portion (SS.BN-[rs13453786-rs66377062]/Aek; S2Ba) and middle segment (SS.BN-[rs106982173-rs65057186]/Aek; S2Bb) were fed NSD or HSD (4% NaCl) up to age 12 to 13 weeks. Systolic blood pressure determined by telemetry was higher in SS rats fed HSD versus NSD. Systolic blood pressure was lower in both congenic rats than in SS under NSD, but similar under HSD versus SS. Reactive oxygen species generation using dihydroethidium staining, expression of vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1, and immune cell infiltration by immunofluorescence demonstrated that S2Ba rats present less inflammation under NSD and more under HSD versus SS rats. RNA sequencing and reverse transcription-quantitative PCR identified 2 differentially expressed genes encoded within BN chromosome 2 distal portion that could act as regulators of vascular inflammation. These were downregulated glutamyl aminopeptidase (Enpep) that was anti-inflammatory under NSD and upregulated heparan sulfate 2-O-sulfotransferase 1 (Hs2st1) that was proinflammatory under HSD. In conclusion, 2 differentially expressed genes encoded within introgressed BN chromosome 2 distal fragment were identified: Enpep associated with reduced vascular inflammation under NSD, and Hs2st1, associated with increased vascular inflammation under HSD.
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Affiliation(s)
- Olga Berillo
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Sofiane Ouerd
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Noureddine Idris-Khodja
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Asia Rehman
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Chantal Richer
- Sainte-Justine University Hospital, Montreal, QC, Canada (C.R., D.S.)
| | - Daniel Sinnett
- Sainte-Justine University Hospital, Montreal, QC, Canada (C.R., D.S.)
| | - Anne E Kwitek
- Department of Physiology, Medical College of Wisconsin, Milwaukee (A.E.K.)
| | - Pierre Paradis
- From the Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (O.B., S.O., N.I.-K., A.R., P.P., E.L.S.)
| | - Ernesto L Schiffrin
- Department of Medicine (E.L.S.), Sir Mortimer B. Davis-Jewish General Hospital, McGill University
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Wiessner JH, Garrett MR, Hung LY, Wille DF, Mandel NS. Improved methodology to induce hyperoxaluria without treatment using hydroxyproline. ACTA ACUST UNITED AC 2011; 39:373-7. [PMID: 21373921 DOI: 10.1007/s00240-011-0368-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 02/10/2011] [Indexed: 11/26/2022]
Abstract
The use of hydroxyproline (HP) to generate hyperoxaluria in the rat is a problem because it is impossible to separate the effect of oxalate on renal injury from the effects of HP and the large array of metabolic intermediates formed when HP is converted to oxalate. Previously, the Dahl salt-sensitive (SS) and Brown Norway (BN) rat strains were studied to determine genetic control of resistance or susceptibility to HP-induced renal injury and crystal deposition. To develop a better model to induce hyperoxaluria without causing injury from HP metabolites, animals were fed a diet containing various levels of added oxalate (0, 1, 2, 3, or 5%). After 5 weeks rats were killed and the kidneys were removed for microscopic evaluation of tubule changes and crystal deposition. The 3 and 5% oxalate-fed groups had a substantial increase in urine oxalate, about 50 and 140 μmol/g body weight over controls, respectively. Both the SS and BN 3% oxalate-fed animals showed only slightly elevated tubule area and no crystal deposition. However, BN animals fed 5% oxalate had a dramatic increase in their percent tubule areas compared to control BN rats and treated SS rats. Crystal deposition in the kidneys was only observed in the 5% oxalate-fed groups. The BN kidneys demonstrated a threefold higher crystal deposition compared to oxalate-fed SS rats. We conclude that oxalate-supplemented food is a better method of producing hyperoxaluria in the rat than using HP which may introduce metabolic intermediates injurious to the kidney.
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Affiliation(s)
- John H Wiessner
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
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Li Y, McLaren MC, McMartin KE. Involvement of urinary proteins in the rat strain difference in sensitivity to ethylene glycol-induced renal toxicity. Am J Physiol Renal Physiol 2010; 299:F605-15. [DOI: 10.1152/ajprenal.00419.2009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ethylene glycol (EG) exposure is a common model for kidney stones, because animals accumulate calcium oxalate monohydrate (COM) in kidneys. Wistar rats are more sensitive to EG than Fischer 344 (F344) rats, with greater COM deposition in kidneys. The mechanisms by which COM accumulates differently among strains are poorly understood. Urinary proteins inhibit COM adhesion to renal cells, which could alter COM deposition in kidneys. We hypothesize that COM accumulates more in Wistar rat kidneys because of lower levels of inhibitory proteins in urine. Wistar and F344 rats were treated with 0.75% EG in drinking water for 8 wk. Twenty-four-hour urine was collected every 2 wk for analysis of urinary proteins. Similar studies were conducted for 2 wk using 2% hydroxyproline (HP) as an alternative oxalate source. Total urinary protein was higher in F344 than Wistar rats at all times. Tamm-Horsfall protein was not different between strains. Osteopontin (OPN) levels in Wistar urine and kidney tissue were higher and were further increased by EG treatment. This increase in OPN occurred before renal COM accumulation. Untreated F344 rats showed greater CD45 and ED-1 staining in kidneys than untreated Wistars; in contrast, EG treatment increased CD45 and ED-1 staining in Wistars more than in F344 rats, indicating macrophage infiltration. This increase occurred in parallel with the increase in OPN and before COM accumulation. Like EG, HP induced markedly greater oxalate concentrations in the plasma and urine of Wistar rats compared with F344 rats. These results suggest that OPN upregulation and macrophage infiltration do not completely protect against COM accumulation and may be a response to crystal retention. Because the two oxalate precursors, EG and HP, produced similar elevations of oxalate, the strain difference in COM accumulation may result more so from metabolic differences between strains than from differences in urinary proteins or inflammatory responses.
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Affiliation(s)
- Yan Li
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | - Marie C. McLaren
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | - Kenneth E. McMartin
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana
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