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Verlander JW, Lee HW, Wall SM, Harris AN, Weiner ID. The proximal tubule through an NBCe1-dependent mechanism regulates collecting duct phenotypic and remodeling responses to acidosis. Am J Physiol Renal Physiol 2023; 324:F12-F29. [PMID: 36264886 PMCID: PMC9762982 DOI: 10.1152/ajprenal.00175.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 02/04/2023] Open
Abstract
The renal response to acid-base disturbances involves phenotypic and remodeling changes in the collecting duct. This study examines whether the proximal tubule controls these responses. We examined mice with genetic deletion of proteins present only in the proximal tubule, either the A variant or both A and B variants of isoform 1 of the electrogenic Na+-bicarbonate cotransporter (NBCe1). Both knockout (KO) mice have spontaneous metabolic acidosis. We then determined the collecting duct phenotypic responses to this acidosis and the remodeling responses to exogenous acid loading. Despite the spontaneous acidosis in NBCe1-A KO mice, type A intercalated cells in the inner stripe of the outer medullary collecting duct (OMCDis) exhibited decreased height and reduced expression of H+-ATPase, anion exchanger 1, Rhesus B glycoprotein, and Rhesus C glycoprotein. Combined kidney-specific NBCe1-A/B deletion induced similar changes. Ultrastructural imaging showed decreased apical plasma membrane and increased vesicular H+-ATPase in OMCDis type A intercalated cell in NBCe1-A KO mice. Next, we examined the collecting duct remodeling response to acidosis. In wild-type mice, acid loading increased the proportion of type A intercalated cells in the connecting tubule (CNT) and OMCDis, and it decreased the proportion of non-A, non-B intercalated cells in the connecting tubule, and type B intercalated cells in the cortical collecting duct (CCD). These changes were absent in NBCe1-A KO mice. We conclude that the collecting duct phenotypic and remodeling responses depend on proximal tubule-dependent signaling mechanisms blocked by constitutive deletion of proximal tubule NBCe1 proteins.NEW & NOTEWORTHY This study shows that the proximal tubule regulates collecting duct phenotypic and remodeling responses to acidosis.
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Affiliation(s)
- Jill W Verlander
- Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Hyun-Wook Lee
- Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Susan M Wall
- Renal Division, Emory University, Atlanta, Georgia
| | - Autumn N Harris
- Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
- Deparment of Small Animal Clinical Science, University of Florida College of Veterinary Medicine, Gainesville, Florida
| | - I David Weiner
- Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
- Nephrology and Hypertension Section, Gainesville Veterans Administration Medical Center, Gainesville, Florida
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Atchison DK, O'Connor CL, Converso-Baran K, Bergin IL, Zhang H, Wang Y, Hartman JR, Ju W, Smrcka AV, Ganesh SK, Bitzer M. Phospholipase Cε insufficiency causes ascending aortic aneurysm and dissection. Am J Physiol Heart Circ Physiol 2022; 323:H1376-H1387. [PMID: 36367690 PMCID: PMC9744656 DOI: 10.1152/ajpheart.00262.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 10/17/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022]
Abstract
Phospholipase Cε (PLCε) is a phospholipase C isoform with a wide range of physiological functions. It has been implicated in aortic valve disorders, but its role in frequently associated aortic disease remains unclear. To determine the role of PLCε in thoracic aortic aneurysm and dissection (TAAD) we used PLCε-deficient mice, which develop aortic valve insufficiency and exhibit aortic dilation of the ascending thoracic aorta and arch without histopathological evidence of injury. Fourteen days of infusion of Plce1+/+ and Plce1-/- mice with angiotensin II (ANG II), which induces aortic dilation and dissection, led to sudden death secondary to ascending aortic dissection in 43% of Plce1-/- versus 5% of Plce1+/+ mice (P < 0.05). Medial degeneration and TAAD were detected in 80% of Plce1-/- compared with 10% of Plce1+/+ mice (P < 0.05) after 4 days of ANG II. Treatment with ANG II markedly increased PLCε expression within the ascending aortic adventitia. Total RNA sequencing demonstrated marked upregulation of inflammatory and fibrotic pathways mediated by interleukin-1β, interleukin-6, and tumor necrosis factor-α. In silico analysis of whole exome sequences of 258 patients with type A dissection identified 5 patients with nonsynonymous PLCE1 variants. Our data suggest that PLCε deficiency plays a role in the development of TAAD and aortic insufficiency.NEW & NOTEWORTHY We describe a novel phenotype by which PLCε deficiency predisposes to aortic valve insufficiency and ascending aortic aneurysm, dissection, and sudden death in the setting of ANG II-mediated hypertension. We demonstrate PLCE1 variants in patients with type A aortic dissection and aortic insufficiency, suggesting that PLCE1 may also play a role in human aortic disease. This finding is of very high significance because it has not been previously demonstrated that PLCε directly mediates aortic dissection.
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Affiliation(s)
- Douglas K Atchison
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
- Division of Nephrology and Hypertension, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan
| | - Christopher L O'Connor
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Kimber Converso-Baran
- Frankel Cardiovascular Center Physiology and Phenotyping Core, University of Michigan, Ann Arbor, Michigan
| | - Ingrid L Bergin
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, Michigan
- In Vivo Animal Core Facility, University of Michigan, Ann Arbor, Michigan
| | - Hongyu Zhang
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Yu Wang
- Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - John R Hartman
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Wenjun Ju
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Alan V Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | - Santhi K Ganesh
- Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Markus Bitzer
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
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53
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Du Z, Yan Q, Shen E, Weinstein AM, Wang T. Regulation of glomerulotubular balance. IV. Implication of aquaporin 1 in flow-dependent proximal tubule transport and cell volume. Am J Physiol Renal Physiol 2022; 323:F642-F653. [PMID: 36108052 PMCID: PMC9705020 DOI: 10.1152/ajprenal.00167.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/06/2022] [Accepted: 09/14/2022] [Indexed: 12/14/2022] Open
Abstract
The water channel aquaporin-1 (AQP1) is the principal water pathway for isotonic water reabsorption in the kidney proximal tubule (PT). We investigated flow-mediated fluid (Jv) and [Formula: see text] ([Formula: see text]) reabsorption in PTs of the mouse kidney by microperfusion in wild-type (WT) and AQP1 knockout (KO) mice. Experiments were simulated in an adaptation of a mathematical model of the rat PT. An increase in perfusion rate from 5 to 20 nL/min increased Jv and [Formula: see text] in PTs of WT mice. AQP1 KO mice significantly decreased Jv at low and high flow rates compared with control. In contrast, [Formula: see text] was not reduced at either low or high flow rates. Cell volume showed no significant difference between WT and AQP1 KO mice. Renal clearance experiments showed significantly higher urine flow in AQP1 KO mice, but there was no significant difference in either Na+ and K+ or [Formula: see text] excretion. Acid-base parameters of blood pH, Pco2, [Formula: see text], and urine pH were the same in both WT and KO mice. In model calculations, tubules whose tight junction (TJ) water permeability (Pf) was that assigned to the rat TJ, showed no difference in Jv between WT and KO, whereas TJ Pf set to 25% of the rat predicted Jv concordant with our observations from AQP1 KO. These results affirm the dominance of AQP1 in mediating isotonic water reabsorption by the mouse PT and demonstrate that flow-stimulated [Formula: see text] reabsorption is intact and independent of AQP1. With reference to the model, the findings also suggest that TJ water flux in the PT is less prominent in the mouse than in the rat kidney.NEW & NOTEWORTHY We found an absence of flow-dependent modulation of fluid absorption but no effect on either proximal tubule (PT) [Formula: see text] absorption or acid-base parameters in the aquaporin 1 (AQP1) knockout mouse. We affirmed the dominance of the water channel AQP1 in mediating isotonic water reabsorption by the mouse PT and demonstrated that flow-stimulated [Formula: see text] reabsorption is independent of AQP1. With reference to the model, the findings also suggest that tight junctional water flux in the PT is less prominent in the mouse than rat kidney.
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Affiliation(s)
- Zhaopeng Du
- Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
| | - Qingshang Yan
- Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
| | - Emma Shen
- Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
| | - Alan M Weinstein
- Department of Physiology and Biophysics, Weill Medical College, Cornell University, New York, New York
| | - Tong Wang
- Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
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Sadana P, Edler M, Aghayev M, Arias-Alvarado A, Cohn E, Ilchenko S, Piontkivska H, Pillai JA, Kashyap S, Kasumov T. Metabolic labeling unveils alterations in the turnover of HDL-associated proteins during diabetes progression in mice. Am J Physiol Endocrinol Metab 2022; 323:E480-E491. [PMID: 36223521 PMCID: PMC9722254 DOI: 10.1152/ajpendo.00158.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 01/21/2023]
Abstract
Several aspects of diabetes pathophysiology and complications result from hyperglycemia-induced alterations in the structure and function of plasma proteins. Furthermore, insulin has a significant influence on protein metabolism by affecting both the synthesis and degradation of proteins in various tissues. To understand the role of progressive hyperglycemia on plasma proteins, in this study, we measured the turnover rates of high-density lipoprotein (HDL)-associated proteins in control (chow diet), prediabetic [a high-fat diet (HFD) for 8 wk] or diabetic [HFD for 8 wk with low-dose streptozotocin (HFD + STZ) in weeks 5-8 of HFD] C57BL/6J mice using heavy water (2H2O)-based metabolic labeling approach. Compared with control mice, HFD and HFD + STZ mice showed elevations of fasting plasma glucose levels in the prediabetic and diabetic range, respectively. Furthermore, the HFD and HFD + STZ mice showed increased hepatic triglyceride (TG) levels, total plasma cholesterol, and plasma TGs. The kinetics of 40 proteins were quantified using the proteome dynamics method, which revealed an increase in the fractional synthesis rate (FSR) of HDL-associated proteins in the prediabetic mice compared with control mice, and a decrease in FSR in the diabetic mice. The pathway analysis revealed that proteins with altered turnover rates were involved in acute-phase response, lipid metabolism, and coagulation. In conclusion, prediabetes and diabetes have distinct effects on the turnover rates of HDL proteins. These findings suggest that an early dysregulation of the HDL proteome dynamics can provide mechanistic insights into the changes in protein levels in these conditions.NEW & NOTEWORTHY This study is the first to examine the role of gradual hyperglycemia during diabetes disease progression on HDL-associated protein dynamics in the prediabetes and diabetic mice. Our results show that the fractional synthesis rate of HDL-associated proteins increased in the prediabetic mice whereas it decreased in the diabetic mice compared with control mice. These kinetic changes can help to elucidate the mechanism of altered protein levels and HDL dysfunction during diabetes disease progression.
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Affiliation(s)
- Prabodh Sadana
- Department of Pharmacy Practice, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Melissa Edler
- Department of Anthropology, Kent State University, Kent, Ohio
| | - Mirjavid Aghayev
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Andrea Arias-Alvarado
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Emilie Cohn
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Serguei Ilchenko
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
| | - Helen Piontkivska
- Department of Biological Sciences, and Brain Health Research Institute, Kent State University, Kent, Ohio
| | - Jagan A Pillai
- Lou Ruvo Center for Brain Health, Cleveland Clinic Foundation, Cleveland, Ohio
| | | | - Takhar Kasumov
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio
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Khattri RB, Kim K, Anderson EM, Fazzone B, Harland KC, Hu Q, Palzkill VR, Cort TA, O'Malley KA, Berceli SA, Scali ST, Ryan TE. Metabolomic profiling reveals muscle metabolic changes following iliac arteriovenous fistula creation in mice. Am J Physiol Renal Physiol 2022; 323:F577-F589. [PMID: 36007889 PMCID: PMC9602894 DOI: 10.1152/ajprenal.00156.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/22/2022] [Accepted: 08/22/2022] [Indexed: 12/31/2022] Open
Abstract
End-stage kidney disease, the most advanced stage of chronic kidney disease (CKD), requires renal replacement therapy or kidney transplant to sustain life. To accomplish durable dialysis access, the creation of an arteriovenous fistula (AVF) has emerged as a preferred approach. Unfortunately, a significant proportion of patients that receive an AVF experience some form of hand dysfunction; however, the mechanisms underlying these side effects are not understood. In this study, we used nuclear magnetic resonance spectroscopy to investigate the muscle metabolome following iliac AVF placement in mice with CKD. To induce CKD, C57BL6J mice were fed an adenine-supplemented diet for 3 wk and then randomized to receive AVF or sham surgery. Two weeks following surgery, the quadriceps muscles were rapidly dissected and snap frozen for metabolite extraction and subsequent nuclear magnetic resonance analysis. Principal component analysis demonstrated clear separation between groups, confirming a unique metabolome in mice that received an AVF. AVF creation resulted in reduced levels of creatine, ATP, and AMP as well as increased levels of IMP and several tricarboxylic acid cycle metabolites suggesting profound energetic stress. Pearson correlation and multiple linear regression analyses identified several metabolites that were strongly linked to measures of limb function (grip strength, gait speed, and mitochondrial respiration). In summary, AVF creation generates a unique metabolome profile in the distal skeletal muscle indicative of an energetic crisis and myosteatosis.NEW & NOTEWORTHY Creation of an arteriovenous fistula (AVF) is the preferred approach for dialysis access, but some patients experience hand dysfunction after AVF creation. In this study, we provide a detailed metabolomic analysis of the limb muscle in a murine model of AVF. AVF creation resulted in metabolite changes associated with an energetic crisis and myosteatosis that associated with limb function.
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Affiliation(s)
- Ram B Khattri
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Kyoungrae Kim
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Erik M Anderson
- Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Florida
- Malcom Randall Veterans Affairs Medical Center, Gainesville, Florida
| | - Brian Fazzone
- Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Florida
- Malcom Randall Veterans Affairs Medical Center, Gainesville, Florida
| | - Kenneth C Harland
- Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Florida
- Malcom Randall Veterans Affairs Medical Center, Gainesville, Florida
| | - Qiongyao Hu
- Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Florida
- Malcom Randall Veterans Affairs Medical Center, Gainesville, Florida
| | - Victoria R Palzkill
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Tomas A Cort
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Kerri A O'Malley
- Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Florida
- Malcom Randall Veterans Affairs Medical Center, Gainesville, Florida
| | - Scott A Berceli
- Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Florida
- Malcom Randall Veterans Affairs Medical Center, Gainesville, Florida
| | - Salvatore T Scali
- Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Florida
- Malcom Randall Veterans Affairs Medical Center, Gainesville, Florida
| | - Terence E Ryan
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
- Center for Exercise Science, University of Florida, Gainesville, Florida
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56
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Moore LG, Wesolowski SR, Lorca RA, Murray AJ, Julian CG. Why is human uterine artery blood flow during pregnancy so high? Am J Physiol Regul Integr Comp Physiol 2022; 323:R694-R699. [PMID: 36094446 PMCID: PMC9602899 DOI: 10.1152/ajpregu.00167.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/12/2022] [Accepted: 09/07/2022] [Indexed: 11/22/2022]
Abstract
In healthy near-term women, blood flow to the uteroplacental circulation is estimated as 841 mL/min, which is greater than in other mammalian species. We argue that as uterine venous Po2 sets the upper limit for O2 diffusion to the fetus, high uterine artery blood flow serves to narrow the maternal arterial-to-uterine venous Po2 gradient and thereby raise uterine vein Po2. In support, we show that the reported levels for uterine artery blood flow agree with what is required to maintain normal fetal growth. Although residence at high altitudes (>2,500 m) depresses fetal growth, not all populations are equally affected; Tibetans and Andeans have higher levels of uterine artery blood flow than newcomers and exhibit normal fetal growth. Estimates of uterine venous Po2 from the umbilical blood-gas data available from healthy Andean pregnancies indicate that their high levels of uterine artery blood flow are consistent with their reported, normal birth weights. Unknown, however, are the effects on placental gas exchange of the lower levels of uterine artery blood flow seen in high-altitude newcomers or hypoxia-associated pregnancy complications. We speculate that, by widening the maternal artery to uterine vein Po2 gradient, lower levels of uterine artery blood flow prompt metabolic changes that slow fetal growth to match O2 supply.
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Affiliation(s)
- Lorna G Moore
- Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, Colorado
| | | | - Ramón A Lorca
- Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, Colorado
| | - Andrew J Murray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Colleen G Julian
- Department of Biomedical Informatics, University of Colorado Denver, Aurora, Colorado
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Navarro Garrido A, Kim YC, Oe Y, Zhang H, Crespo-Masip M, Goodluck HA, Kanoo S, Sanders PW, Bröer S, Vallon V. Aristolochic acid-induced nephropathy is attenuated in mice lacking the neutral amino acid transporter B 0AT1 ( Slc6a19). Am J Physiol Renal Physiol 2022; 323:F455-F467. [PMID: 35979966 PMCID: PMC9484999 DOI: 10.1152/ajprenal.00181.2022] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/29/2022] [Accepted: 08/10/2022] [Indexed: 01/10/2023] Open
Abstract
B0AT1 (Slc6a19) mediates absorption of neutral amino acids in the small intestine and in the kidneys, where it is primarily expressed in early proximal tubules (S1-S2). To determine the role of B0AT1 in nephropathy induced by aristolochic acid (AA), which targets the proximal tubule, littermate female B0AT1-deficient (Slc6a19-/-), heterozygous (Slc6a19+/-), and wild-type (WT) mice were administered AA (10 mg/kg ip) or vehicle every 3 days for 3 wk, and analyses were performed after the last injection or 3 wk later. Vehicle-treated mice lacking Slc6a19 showed normal body and kidney weight and plasma creatinine versus WT mice. The urinary glucose-to-creatinine ratio (UGCR) and urinary albumin-to-creatinine ratio (UACR) were two to four times higher in vehicle-treated Slc6a19-/- versus WT mice, associated with lesser expression of early proximal transporters Na+-glucose cotransporter 2 and megalin, respectively. AA caused tubular injury independently of B0AT1, including robust increases in cortical mRNA expression of p53, p21, and hepatitis A virus cellular receptor 1 (Havcr1), downregulation of related proximal tubule amino acid transporters B0AT2 (Slc6a15), B0AT3 (Slc6a18), and Slc7a9, and modest histological tubular damage and a rise in plasma creatinine. Absence of B0AT1, however, attenuated AA-induced cortical upregulation of mRNA markers of senescence (p16), inflammation [lipocalin 2 (Lcn2), C-C motif chemokine ligand 2 (Ccl2), and C-C motif chemokine receptor 2 (Ccr2)], and fibrosis [tissue inhibitor of metallopeptidase 1 (Timp1), transforming growth factor-β1 (Tgfb1), and collagen type I-α1 (Col1a1)], associated with lesser fibrosis staining, lesser suppression of proximal tubular organic anion transporter 1, restoration of Na+-glucose cotransporter 2 expression, and prevention of the AA-induced fivefold increase in the urinary albumin-to-creatinine ratio observed in WT mice. The data suggest that proximal tubular B0AT1 is important for the physiology of renal glucose and albumin retention but potentially deleterious for the kidney response following AA-induced kidney injury.NEW & NOTEWORTHY Based on insights from studies manipulating glucose transport, the hypothesis has been proposed that inhibiting intestinal uptake or renal reabsorption of energy substrates has unique therapeutic potential to improve metabolic disease and kidney outcome in response to injury. The present study takes this idea to B0AT1, the major transporter for neutral amino acids in the intestine and kidney, and shows that its absence attenuates aristolochic acid-induced nephropathy.
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Affiliation(s)
- Aleix Navarro Garrido
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Young Chul Kim
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Yuji Oe
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Haiyan Zhang
- Department of Pathology, University of California-San Diego, San Diego, California
| | - Maria Crespo-Masip
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Helen A Goodluck
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Sadhana Kanoo
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Paul W Sanders
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Veterans Affairs Medical Center, Birmingham, Alabama
| | - Stefan Bröer
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Volker Vallon
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Affairs San Diego Healthcare System, San Diego, California
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58
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Steiner CA, Cartwright IM, Taylor CT, Colgan SP. Hypoxia-inducible factor as a bridge between healthy barrier function, wound healing, and fibrosis. Am J Physiol Cell Physiol 2022; 323:C866-C878. [PMID: 35912990 PMCID: PMC9467472 DOI: 10.1152/ajpcell.00227.2022] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/07/2022] [Accepted: 07/23/2022] [Indexed: 11/22/2022]
Abstract
The healthy mammalian intestine is lined by a single layer of epithelial cells. These cells provide a selectively permeable barrier to luminal contents and normally do so in an efficient and effective manner. Barrier function in the healthy mucosa is provided via several mechanisms including epithelial junctional complexes, mucus production, as well as mucosal-derived antimicrobial proteins. As tissue metabolism is central to the maintenance of homeostasis in the mucosa, intestinal [Formula: see text] levels are uniquely low due to counter-current blood flow and the presence of the microbiota, resulting in the stabilization of the transcription factor hypoxia-inducible factor (HIF). Ongoing studies have revealed that HIF molds normal intestinal metabolism and is central to the coordination of barrier regulation during both homeostasis and active disease. During acute inflammation, HIF is central to controlling the rapid restitution of the epithelium consistent with normal wound healing responses. In contrast, HIF may also contribute to the fibrostenotic response associated with chronic, nonresolving inflammation. As such, HIF may function as a double-edged sword in the overall course of the inflammatory response. Here, we review recent literature on the contribution of HIF to mucosal barrier function, wound healing, and fibrosis.
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Affiliation(s)
- Calen A Steiner
- Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- Department of Medicine and the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado
| | - Ian M Cartwright
- Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- Department of Medicine and the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado
| | - Cormac T Taylor
- School of Medicine, Conway Institute and Systems Biology Ireland, University College Dublin, Dublin, Ireland
| | - Sean P Colgan
- Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- Department of Medicine and the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado
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59
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LaFavers KA, Hage CA, Gaur V, Micanovic R, Hato T, Khan S, Winfree S, Doshi S, Moorthi RN, Twigg H, Wu XR, Dagher PC, Srour EF, El-Achkar TM. The kidney protects against sepsis by producing systemic uromodulin. Am J Physiol Renal Physiol 2022; 323:F212-F226. [PMID: 35759740 PMCID: PMC9359648 DOI: 10.1152/ajprenal.00146.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/17/2022] [Accepted: 06/23/2022] [Indexed: 11/22/2022] Open
Abstract
Sepsis is a significant cause of mortality in hospitalized patients. Concomitant development of acute kidney injury (AKI) increases sepsis mortality through unclear mechanisms. Although electrolyte disturbances and toxic metabolite buildup during AKI could be important, it is possible that the kidney produces a protective molecule lost during sepsis with AKI. We have previously demonstrated that systemic Tamm-Horsfall protein (THP; uromodulin), a kidney-derived protein with immunomodulatory properties, falls in AKI. Using a mouse sepsis model without severe kidney injury, we showed that the kidney increases circulating THP by enhancing the basolateral release of THP from medullary thick ascending limb cells. In patients with sepsis, changes in circulating THP were positively associated with a critical illness. THP was also found de novo in injured lungs. Genetic ablation of THP in mice led to increased mortality and bacterial burden during sepsis. Consistent with the increased bacterial burden, the presence of THP in vitro and in vivo led macrophages and monocytes to upregulate a transcriptional program promoting cell migration, phagocytosis, and chemotaxis, and treatment of macrophages with purified THP increases phagocytosis. Rescue of septic THP-/- mice with exogenous systemic THP improved survival. Together, these findings suggest that through releasing THP, the kidney modulates the immune response in sepsis by enhancing mononuclear phagocyte function, and systemic THP has therapeutic potential in sepsis.NEW & NOTEWORTHY Specific therapies to improve outcomes in sepsis with kidney injury have been limited by an unclear understanding of how kidney injury increases sepsis mortality. Here, we identified Tamm-Horsfall protein, known to protect in ischemic acute kidney injury, as protective in preclinical sepsis models. Tamm-Horsfall protein also increased in clinical sepsis without severe kidney injury and concentrated in injured organs. Further study could lead to novel sepsis therapeutics.
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Affiliation(s)
- Kaice A LaFavers
- Division of Nephrology and Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Chadi A Hage
- Division of Pulmonary Medicine, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Varun Gaur
- Southern Indiana Nephrology and Hypertension, Columbus, Indiana
| | - Radmila Micanovic
- Division of Nephrology and Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Takashi Hato
- Division of Nephrology and Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Shehnaz Khan
- Division of Nephrology and Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Seth Winfree
- Division of Nephrology and Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Anatomy, Cell Biology and Cellular Physiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Simit Doshi
- Division of Nephrology and Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Ranjani N Moorthi
- Division of Nephrology and Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Homer Twigg
- Division of Pulmonary Medicine, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Xue-Ru Wu
- Departments of Urology and Pathology, New York University, and Veterans Affairs New York Harbor Healthcare System, New York, New York
| | - Pierre C Dagher
- Division of Nephrology and Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Anatomy, Cell Biology and Cellular Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana
| | - Edward F Srour
- Division of Hematology and Oncology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Tarek M El-Achkar
- Division of Nephrology and Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Anatomy, Cell Biology and Cellular Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana
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60
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Hepokoski ML, Odish M, Lam MT, Coufal NG, Rolfsen ML, Shadel GS, Moyzis AG, Sainz AG, Takiar PG, Patel S, Leonard AJ, Samandari N, Hansen E, Trescott S, Nguyen C, Jepsen K, Cutter G, Gillespie MN, Spragg RG, Sasik R, Ix JH. Absolute quantification of plasma mitochondrial DNA by droplet digital PCR marks COVID-19 severity over time during intensive care unit admissions. Am J Physiol Lung Cell Mol Physiol 2022; 323:L84-L92. [PMID: 35699291 PMCID: PMC9273271 DOI: 10.1152/ajplung.00128.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/23/2022] [Accepted: 06/06/2022] [Indexed: 11/22/2022] Open
Abstract
Increased plasma mitochondrial DNA concentrations are associated with poor outcomes in multiple critical illnesses, including COVID-19. However, current methods of cell-free mitochondrial DNA quantification in plasma are time-consuming and lack reproducibility. Here, we used next-generation sequencing to characterize the size and genome location of circulating mitochondrial DNA in critically ill subjects with COVID-19 to develop a facile and optimal method of quantification by droplet digital PCR. Sequencing revealed a large percentage of small mitochondrial DNA fragments in plasma with wide variability in coverage by genome location. We identified probes for the mitochondrial DNA genes, cytochrome B and NADH dehydrogenase 1, in regions of relatively high coverage that target small sequences potentially missed by other methods. Serial assessments of absolute mitochondrial DNA concentrations were then determined in plasma from 20 critically ill subjects with COVID-19 without a DNA isolation step. Mitochondrial DNA concentrations on the day of enrollment were increased significantly in patients with moderate or severe acute respiratory distress syndrome (ARDS) compared with those with no or mild ARDS. Comparisons of mitochondrial DNA concentrations over time between patients with no/mild ARDS who survived, patients with moderate/severe ARDS who survived, and nonsurvivors showed the highest concentrations in patients with more severe disease. Absolute mitochondrial DNA quantification by droplet digital PCR is time-efficient and reproducible; thus, we provide a valuable tool and rationale for future studies evaluating mitochondrial DNA as a real-time biomarker to guide clinical decision-making in critically ill subjects with COVID-19.
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Affiliation(s)
- Mark L Hepokoski
- VA San Diego Healthcare System, San Diego, California
- Division of Pulmonary and Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Mazen Odish
- Division of Pulmonary and Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Michael T Lam
- VA San Diego Healthcare System, San Diego, California
- Division of Pulmonary and Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
- Salk Institute for Biological Sciences, La Jolla, California
| | - Nicole G Coufal
- Department of Pediatrics, University of California San Diego, San Diego, California
- Rady Children's Hospital, San Diego, California
| | - Mark L Rolfsen
- Department of Medicine, School of Medicine, University of California San Diego, San Diego, California
| | - Gerald S Shadel
- Salk Institute for Biological Sciences, La Jolla, California
| | | | - Alva G Sainz
- Salk Institute for Biological Sciences, La Jolla, California
- Department of Pathology, Yale School of Medicine, New Haven, Connecticut
| | - Puja G Takiar
- Department of Medicine, School of Medicine, University of California San Diego, San Diego, California
| | - Sagar Patel
- Division of Pulmonary and Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Austin J Leonard
- Department of Medicine, School of Medicine, University of California San Diego, San Diego, California
| | | | - Emily Hansen
- Department of Pediatrics, University of California San Diego, San Diego, California
| | - Samantha Trescott
- Department of Pediatrics, University of California San Diego, San Diego, California
| | - Celina Nguyen
- Department of Pediatrics, University of California San Diego, San Diego, California
| | - Kristen Jepsen
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California
| | - Gary Cutter
- Department of Biostatistics, School of Public Health, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Mark N Gillespie
- Department of Pharmacology, University of South Alabama, Mobile, Alabama
| | - Roger G Spragg
- Division of Pulmonary and Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Roman Sasik
- Center for Computational Biology & Bioinformatics, University of California San Diego, La Jolla, California
| | - Joachim H Ix
- VA San Diego Healthcare System, San Diego, California
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
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