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Wu L, Liu C, Chang DY, Zhan R, Zhao M, Man Lam S, Shui G, Zhao MH, Zheng L, Chen M. The Attenuation of Diabetic Nephropathy by Annexin A1 via Regulation of Lipid Metabolism Through the AMPK/PPARα/CPT1b Pathway. Diabetes 2021; 70:2192-2203. [PMID: 34103347 DOI: 10.2337/db21-0050] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 06/01/2021] [Indexed: 11/13/2022]
Abstract
Inflammation and abnormal metabolism play important roles in the pathogenesis of diabetic nephropathy (DN). Annexin A1 (ANXA1) contributes to inflammation resolution and improves metabolism. In this study, we assess the effects of ANXA1 in diabetic mice and proximal tubular epithelial cells (PTECs) treated with high glucose plus palmitate acid (HGPA) and explore the association of ANXA1 with lipid accumulation in patients with DN. It is found that ANXA1 deletion aggravates renal injuries, including albuminuria, mesangial matrix expansion, and tubulointerstitial lesions in high-fat diet/streptozotocin-induced diabetic mice. ANXA1 deficiency promotes intrarenal lipid accumulation and drives mitochondrial alterations in kidneys. In addition, Ac2-26, an ANXA1 mimetic peptide, has a therapeutic effect against lipid toxicity in diabetic mice. In HGPA-treated human PTECs, ANXA1 silencing causes FPR2/ALX-driven deleterious effects, which suppress phosphorylated Thr172 AMPK, resulting in decreased peroxisome proliferator-activated receptor α and carnitine palmitoyltransferase 1b expression and increased HGPA-induced lipid accumulation, apoptosis, and elevated expression of proinflammatory and profibrotic genes. Last but not least, the extent of lipid accumulation correlates with renal function, and the level of tubulointerstitial ANXA1 expression correlates with ectopic lipid deposition in kidneys of patients with DN. These data demonstrate that ANXA1 regulates lipid metabolism of PTECs to ameliorate disease progression; hence, it holds great potential as a therapeutic target for DN.
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Affiliation(s)
- Liang Wu
- Renal Division, Department of Medicine, Peking University First Hospital; Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
- Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Changjie Liu
- Institute of Cardiovascular Sciences, Institute of Systems Biomedicine, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education; Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Beijing Key Laboratory of Cardiovascular Receptors Research, Peking University Health Science Center, Beijing, China
| | - Dong-Yuan Chang
- Renal Division, Department of Medicine, Peking University First Hospital; Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
- Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Rui Zhan
- Institute of Cardiovascular Sciences, Institute of Systems Biomedicine, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education; Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Beijing Key Laboratory of Cardiovascular Receptors Research, Peking University Health Science Center, Beijing, China
| | - Mingming Zhao
- Institute of Cardiovascular Sciences, Institute of Systems Biomedicine, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education; Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Beijing Key Laboratory of Cardiovascular Receptors Research, Peking University Health Science Center, Beijing, China
- Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, Beijing, China
| | - Sin Man Lam
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Lipidall Technologies Co., Ltd., Changzhou, China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Ming-Hui Zhao
- Renal Division, Department of Medicine, Peking University First Hospital; Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
- Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Lemin Zheng
- Institute of Cardiovascular Sciences, Institute of Systems Biomedicine, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education; Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Ministry of Health, Beijing Key Laboratory of Cardiovascular Receptors Research, Peking University Health Science Center, Beijing, China
- Beijing Tiantan Hospital, China National Clinical Research Center for Neuro-logical Diseases, Advanced Innovation Center for Human Brain Protection, The Capital Medical University, Beijing, China
| | - Min Chen
- Renal Division, Department of Medicine, Peking University First Hospital; Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
- Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
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Joo MS, Koo JH, Kim TH, Kim YS, Kim SG. LRH1-driven transcription factor circuitry for hepatocyte identity: Super-enhancer cistromic analysis. EBioMedicine 2019; 40:488-503. [PMID: 30638865 PMCID: PMC6413675 DOI: 10.1016/j.ebiom.2018.12.056] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 12/19/2018] [Accepted: 12/26/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The injured liver loses normal function, with concomitant decrease of key identity genes. Super-enhancers contribute to mammalian cell identity. Here, we identified core transcription factors (TFs) that are active in hepatocytes, using genome-wide analysis and hierarchical ordering of super-enhancer distribution. METHODS Expression of core TFs was assessed in a cohort of patients with hepatitis or cirrhosis and animal models. Quantitative PCR, chromatin immunoprecipitation assays, and hydrodynamic gene delivery methods were used to assess gene regulation and hepatocyte viability. RNA-sequencing data were generated to investigate the role of LRH1 in hepatocyte protection from injury. RESULTS Network analysis of super-enhancer-associated gene interactions and expression arrays for cohorts of patients with hepatitis and cirrhosis enabled us to identify a super-enhancer-associated network, and LRH1, HNF4α, PPARα, and RXRα as core TFs. In mouse models, expression of core TFs was robustly inhibited by single and multiple challenge(s) with liver toxicant. RNA-seq analysis revealed changes in expression in the super-enhancer-associated genes sensitively biased toward repression by intoxication. LRH1 gene delivery prevented the loss of hepatic super-enhancer-associated signaling circuitry in toxicant-challenged mice, and protected the liver from injury, indicating the role of LRH1 in hepatocyte identity and viability. In hepatocytes, overexpression of each core TF promoted induction of other TFs. CONCLUSION Overall, this study identified LRH1-driven pathway as a circuitry responsible for hepatocyte identity by using cistromic analysis, improving our understanding of liver pathophysiology and identifying novel therapeutic targets.
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Affiliation(s)
- Min Sung Joo
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Ja Hyun Koo
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Tae Hyun Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Yun Seok Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Sang Geon Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea.
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Langley RJ, Tipper JL, Bruse S, Baron RM, Tsalik EL, Huntley J, Rogers AJ, Jaramillo RJ, O'Donnell D, Mega WM, Keaton M, Kensicki E, Gazourian L, Fredenburgh LE, Massaro AF, Otero RM, Fowler VG, Rivers EP, Woods CW, Kingsmore SF, Sopori ML, Perrella MA, Choi AMK, Harrod KS. Integrative "omic" analysis of experimental bacteremia identifies a metabolic signature that distinguishes human sepsis from systemic inflammatory response syndromes. Am J Respir Crit Care Med 2014; 190:445-55. [PMID: 25054455 PMCID: PMC4214130 DOI: 10.1164/rccm.201404-0624oc] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 07/17/2014] [Indexed: 12/31/2022] Open
Abstract
RATIONALE Sepsis is a leading cause of morbidity and mortality. Currently, early diagnosis and the progression of the disease are difficult to make. The integration of metabolomic and transcriptomic data in a primate model of sepsis may provide a novel molecular signature of clinical sepsis. OBJECTIVES To develop a biomarker panel to characterize sepsis in primates and ascertain its relevance to early diagnosis and progression of human sepsis. METHODS Intravenous inoculation of Macaca fascicularis with Escherichia coli produced mild to severe sepsis, lung injury, and death. Plasma samples were obtained before and after 1, 3, and 5 days of E. coli challenge and at the time of killing. At necropsy, blood, lung, kidney, and spleen samples were collected. An integrative analysis of the metabolomic and transcriptomic datasets was performed to identify a panel of sepsis biomarkers. MEASUREMENTS AND MAIN RESULTS The extent of E. coli invasion, respiratory distress, lethargy, and mortality was dependent on the bacterial dose. Metabolomic and transcriptomic changes characterized severe infections and death, and indicated impaired mitochondrial, peroxisomal, and liver functions. Analysis of the pulmonary transcriptome and plasma metabolome suggested impaired fatty acid catabolism regulated by peroxisome-proliferator activated receptor signaling. A representative four-metabolite model effectively diagnosed sepsis in primates (area under the curve, 0.966) and in two human sepsis cohorts (area under the curve, 0.78 and 0.82). CONCLUSIONS A model of sepsis based on reciprocal metabolomic and transcriptomic data was developed in primates and validated in two human patient cohorts. It is anticipated that the identified parameters will facilitate early diagnosis and management of sepsis.
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Langley RJ, Tsalik EL, van Velkinburgh JC, Glickman SW, Rice BJ, Wang C, Chen B, Carin L, Suarez A, Mohney RP, Freeman DH, Wang M, You J, Wulff J, Thompson JW, Moseley MA, Reisinger S, Edmonds BT, Grinnell B, Nelson DR, Dinwiddie DL, Miller NA, Saunders CJ, Soden SS, Rogers AJ, Gazourian L, Fredenburgh LE, Massaro AF, Baron RM, Choi AMK, Corey GR, Ginsburg GS, Cairns CB, Otero RM, Fowler VG, Rivers EP, Woods CW, Kingsmore SF. An integrated clinico-metabolomic model improves prediction of death in sepsis. Sci Transl Med 2013; 5:195ra95. [PMID: 23884467 DOI: 10.1126/scitranslmed.3005893] [Citation(s) in RCA: 329] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sepsis is a common cause of death, but outcomes in individual patients are difficult to predict. Elucidating the molecular processes that differ between sepsis patients who survive and those who die may permit more appropriate treatments to be deployed. We examined the clinical features and the plasma metabolome and proteome of patients with and without community-acquired sepsis, upon their arrival at hospital emergency departments and 24 hours later. The metabolomes and proteomes of patients at hospital admittance who would ultimately die differed markedly from those of patients who would survive. The different profiles of proteins and metabolites clustered into the following groups: fatty acid transport and β-oxidation, gluconeogenesis, and the citric acid cycle. They differed consistently among several sets of patients, and diverged more as death approached. In contrast, the metabolomes and proteomes of surviving patients with mild sepsis did not differ from survivors with severe sepsis or septic shock. An algorithm derived from clinical features together with measurements of five metabolites predicted patient survival. This algorithm may help to guide the treatment of individual patients with sepsis.
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Zhao X. Prevention of local lipotoxicity: a new renoprotective mechanism of peroxisome proliferator-activated receptor-alpha activation in hypertension and obesity? Hypertens Res 2009; 32:821-3. [PMID: 19680259 DOI: 10.1038/hr.2009.128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Cassuto H, Olswang Y, Heinemann S, Sabbagh K, Hanson RW, Reshef L. The transcriptional regulation of phosphoenolpyruvate carboxykinase gene in the kidney requires the HNF-1 binding site of the gene. Gene 2003; 318:177-84. [PMID: 14585510 DOI: 10.1016/s0378-1119(03)00775-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The transcription of the cytosolic form of phosphoenolpyruvate carboxykinase (PEPCK-C) gene is differentially regulated in each of the several PEPCK-C-expressing tissues. In the kidney, it is regulated by glucocorticoids and acidosis. Previously, we reported that in LLC-PK1 and derived kidney cell lines, mutation of the hepatic nuclear factor 1 (HNF-1) binding site in PEPCK-C gene promoter markedly reduced both the basal activity of the gene promoter and its response to acidic pH. Using the same kidney cell line, we now report that nuclear receptors robustly stimulate transcription from the PEPCK-C gene promoter. This stimulation is markedly reduced by mutation of the accessory factor 1 (AF1) site in the glucocorticoid responsive unit (GRU) residing within the glucocorticoid-responsive domain. The stimulation is likewise reduced by mutation of the HNF-1 site, residing outside the nuclear receptor-responsive domain of the PEPCK-C gene promoter. There is no binding similarity between HNF-1 and AF1 binding sites, as is evident from gel shift assays showing a lack of competition of either site for the binding of renal nuclear proteins to the other. We further assessed that the regulation of PEPCK-C gene transcription by acidosis is not mediated by nuclear receptors. This became evident from studies of transgenic mice harboring a rat PEPCK-C transgene driven by truncated 5' flanking region of the gene, which contains the HNF-1 site but lacks the glucocorticoid responsive domain. The full transcriptional response of this transgene to acidosis establishes that the truncated 5' flanking region (362 bp) of the PEPCK-C gene contains the information required for the acidosis-mediated regulation independent of the glucocorticoid domain. Taking together the previous and present results, it appears that acidosis and nuclear receptors regulate the renal transcription of the PEPCK-C gene via two independent domains in the 5' flanking region of the gene. These two modulations, as well as the basal activity of the gene, require intact HNF-1 binding site in the gene promoter.
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MESH Headings
- Ammonium Chloride/pharmacology
- Animals
- Binding Sites/genetics
- Cell Line
- DNA-Binding Proteins
- Electrophoretic Mobility Shift Assay
- Gene Expression Regulation, Enzymologic/drug effects
- Hepatocyte Nuclear Factor 1
- Hepatocyte Nuclear Factor 1-alpha
- Hepatocyte Nuclear Factor 1-beta
- Hydrogen-Ion Concentration
- Kidney/enzymology
- Kidney/metabolism
- Mice
- Mice, Transgenic
- Mutation
- Nuclear Proteins/metabolism
- Phosphoenolpyruvate Carboxykinase (GTP)/genetics
- Promoter Regions, Genetic/genetics
- Protein Binding
- RNA, Messenger/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Interferon/metabolism
- Regulatory Sequences, Nucleic Acid/genetics
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription, Genetic
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Affiliation(s)
- Hanoch Cassuto
- Department of Developmental Biochemistry, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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Portilla D, Dai G, McClure T, Bates L, Kurten R, Megyesi J, Price P, Li S. Alterations of PPARalpha and its coactivator PGC-1 in cisplatin-induced acute renal failure. Kidney Int 2002; 62:1208-18. [PMID: 12234291 DOI: 10.1111/j.1523-1755.2002.kid553.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND In this study we examined whether a recently characterized coactivator of Peroxisome proliferator activated receptor alpha (PPARalpha), Peroxisome proliferator activated receptor-gamma-coactivator-1 (PGC-1) plays a role in the regulation of fatty acid oxidation during cisplatin-induced nephrotoxicity. METHODS Studies in mouse kidneys used quantitative reverse transcription-polymerase chain reaction (RT-PCR) to measure peroxisomal acyl coenzyme A (acyl-CoA) and PGC-1 mRNA levels and in situ hybridization to localize PGC-1 mRNA. Studies in LLCPK1 cells used quantitative RT-PCR and biochemical assays to measure mRNA levels and enzyme activities of peroxisomal acyl-CoA, mitochondrial carnitine palmitoyl transferase (CPT) and PGC-1. Eletrophoretic mobility shift assays (EMSA) and Western blot analysis of nuclear extracts, and transient transfection of PGC-1 were used to examine the effect of cisplatin on PPARalpha-regulated fatty acid oxidation. RESULTS Cisplatin decreased mRNA levels of peroxisomal acyl-CoA enzyme in mouse kidney and also reduced the mRNA levels and enzyme activities of acyl-CoA and mitochondrial CPT-1 in LLCPK1 cells. DNA-protein binding studies demonstrated that exposure to cisplatin reduces PPARalpha/retinoid X receptor (RXRalpha) binding activity. Immunoblotting studies demonstrated that cisplatin had no effect on nuclear levels of PPARalpha or RXRalpha protein. In situ hybridization studies in mouse kidney demonstrated the localization of PGC-1 mRNA to proximal tubules and thick ascending limb of Henley (TALH) cells. Cisplatin diminished the expression of PGC-1 mRNA levels in mouse kidney and also in LLCPK1 cells. Transient expression of PGC-1 shows the nuclear localization of PGC-1 protein and increased PPARalpha transcriptional activity in LLCPK1 cells. CONCLUSIONS These results demonstrate that cisplatin deactivates PPARalpha by reducing its DNA binding activity and the availability of its tissue specific coactivator PGC-1.
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Affiliation(s)
- Didier Portilla
- Division of Nephrology, Departments of Internal Medicine and Physiology, University of Arkansas for Medical Sciences, 4301 W. Markham Street, Little Rock, AR 72205, USA.
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Eberhardt W, Akool ES, Rebhan J, Frank S, Beck KF, Franzen R, Hamada FMA, Pfeilschifter J. Inhibition of cytokine-induced matrix metalloproteinase 9 expression by peroxisome proliferator-activated receptor alpha agonists is indirect and due to a NO-mediated reduction of mRNA stability. J Biol Chem 2002; 277:33518-28. [PMID: 12093797 DOI: 10.1074/jbc.m202008200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rat renal mesangial cells express high levels of matrix metalloproteinase 9 (MMP-9) in response to inflammatory cytokines such as interleukin 1beta (IL-1beta). We tested whether ligands of the peroxisome proliferator-activated receptor (PPARalpha) could influence the cytokine-induced expression of MMP-9. Different PPARalpha agonists dose-dependently inhibited the IL-1beta-triggered increase in gelatinolytic activity mainly by decreasing the MMP-9 steady-state mRNA levels. PPARalpha agonists on their own had no effects on MMP-9 mRNA levels and gelatinolytic activity. Surprisingly, the reduction of MMP-9 mRNA levels by PPARalpha activators contrasted with an amplification of cytokine-mediated MMP-9 gene promoter activity and mRNA expression. The potentiation of MMP-9 promoter activity functionally depends on an upstream peroxisome proliferator-responsive element-like binding site, which displayed an increased DNA binding of a PPARalpha immunopositive complex. In contrast, the IL-1beta-induced DNA-binding of nuclear factor kappaB was significantly impaired by PPARalpha agonists. Most interestingly, in the presence of an inducible nitric-oxide synthase (iNOS) inhibitor, the PPARalpha-mediated suppression switched to a strong amplification of IL-1beta-triggered MMP-9 mRNA expression. Concomitantly, activators of PPARalpha potentiated the cytokine-induced iNOS expression. Using actinomycin D, we found that NO, but not PPARalpha activators, strongly reduced the stability of MMP-9 mRNA. In contrast, the stability of MMP-9 protein was not affected by PPARalpha activators. In summary, our data suggest that the inhibitory effects of PPARalpha agonists on cytokine-induced MMP-9 expression are indirect and primarily due to a superinduction of iNOS with high levels of NO reducing the half-life of MMP-9 mRNA.
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Affiliation(s)
- Wolfgang Eberhardt
- Pharmazentrum Frankfurt, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main D-60590, Germany.
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Ouali F, Djouadi F, Bastin J. Effects of fatty acids on mitochondrial beta-oxidation enzyme gene expression in renal cell lines. Am J Physiol Renal Physiol 2002; 283:F328-34. [PMID: 12110517 DOI: 10.1152/ajprenal.00324.2001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Regulatory effects of fatty acids on gene expression of medium-chain acyl-CoA dehydrogenase (MCAD), a mitochondrial beta-oxidation enzyme, were investigated in rabbit kidney cell lines derived from proximal tubule (RC.SV1), thick ascending limb of Henle's loop (RC.SV2), or collecting duct (RC.SV3). Exposure to long-chain fatty acids led to significant increases (2-fold) in MCAD mRNA abundance in RC.SV1 and RC.SV2 cells; kinetics and dose-response studies established that maximal MCAD gene stimulation was reached 4 h after addition of 50 microM oleate (C18:1) in the culture medium. These effects of fatty acids were totally abolished in the presence of 1 microg/ml actinomycin D, a transcription inhibitor. Staining of cellular lipids revealed that fatty acid-induced gene stimulation could occur in the absence of cellular fatty acid accumulation. Altogether, these data indicate that small changes in cellular fatty acid flux can have direct short-term effects on fatty acid oxidation enzyme gene expression in renal cells, and this might take part in the regulation of cellular fatty acid homeostasis in response to changes in tubular fluid composition.
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Affiliation(s)
- Fetta Ouali
- Institut National de la Santé et de la Recherche Médicale U319, Université Paris VII, 75015 Paris, France
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