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1.
Nat Immunol ; 22(11): 1440-1451, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34686860

RESUMO

Intestinal epithelial cell (IEC) damage by T cells contributes to graft-versus-host disease, inflammatory bowel disease and immune checkpoint blockade-mediated colitis. But little is known about the target cell-intrinsic features that affect disease severity. Here we identified disruption of oxidative phosphorylation and an increase in succinate levels in the IECs from several distinct in vivo models of T cell-mediated colitis. Metabolic flux studies, complemented by imaging and protein analyses, identified disruption of IEC-intrinsic succinate dehydrogenase A (SDHA), a component of mitochondrial complex II, in causing these metabolic alterations. The relevance of IEC-intrinsic SDHA in mediating disease severity was confirmed by complementary chemical and genetic experimental approaches and validated in human clinical samples. These data identify a critical role for the alteration of the IEC-specific mitochondrial complex II component SDHA in the regulation of the severity of T cell-mediated intestinal diseases.


Assuntos
Colite/enzimologia , Colo/enzimologia , Citotoxicidade Imunológica , Complexo II de Transporte de Elétrons/metabolismo , Células Epiteliais/enzimologia , Doença Enxerto-Hospedeiro/enzimologia , Mucosa Intestinal/enzimologia , Mitocôndrias/enzimologia , Linfócitos T/imunologia , Animais , Estudos de Casos e Controles , Comunicação Celular , Células Cultivadas , Colite/genética , Colite/imunologia , Colite/patologia , Colo/imunologia , Colo/ultraestrutura , Modelos Animais de Doenças , Complexo II de Transporte de Elétrons/genética , Células Epiteliais/imunologia , Células Epiteliais/ultraestrutura , Feminino , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/patologia , Humanos , Imunidade nas Mucosas , Mucosa Intestinal/imunologia , Mucosa Intestinal/ultraestrutura , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mitocôndrias/imunologia , Mitocôndrias/ultraestrutura , Fosforilação Oxidativa , Ácido Succínico/metabolismo , Linfócitos T/metabolismo
2.
Nat Immunol ; 17(5): 505-513, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26998764

RESUMO

The effect of alterations in intestinal microbiota on microbial metabolites and on disease processes such as graft-versus-host disease (GVHD) is not known. Here we carried out an unbiased analysis to identify previously unidentified alterations in gastrointestinal microbiota-derived short-chain fatty acids (SCFAs) after allogeneic bone marrow transplant (allo-BMT). Alterations in the amount of only one SCFA, butyrate, were observed only in the intestinal tissue. The reduced butyrate in CD326(+) intestinal epithelial cells (IECs) after allo-BMT resulted in decreased histone acetylation, which was restored after local administration of exogenous butyrate. Butyrate restoration improved IEC junctional integrity, decreased apoptosis and mitigated GVHD. Furthermore, alteration of the indigenous microbiota with 17 rationally selected strains of high butyrate-producing Clostridia also decreased GVHD. These data demonstrate a heretofore unrecognized role of microbial metabolites and suggest that local and specific alteration of microbial metabolites has direct salutary effects on GVHD target tissues and can mitigate disease severity.


Assuntos
Células Epiteliais/imunologia , Microbioma Gastrointestinal/imunologia , Doença Enxerto-Hospedeiro/imunologia , Intestinos/imunologia , Metaboloma/imunologia , Acetilação/efeitos dos fármacos , Animais , Transplante de Medula Óssea/efeitos adversos , Transplante de Medula Óssea/métodos , Butiratos/imunologia , Butiratos/metabolismo , Butiratos/farmacologia , Células Cultivadas , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Ácidos Graxos Voláteis/imunologia , Ácidos Graxos Voláteis/metabolismo , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Microbioma Gastrointestinal/fisiologia , Expressão Gênica/imunologia , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/microbiologia , Histona Acetiltransferases/genética , Histona Acetiltransferases/imunologia , Histona Acetiltransferases/metabolismo , Histona Desacetilases/genética , Histona Desacetilases/imunologia , Histona Desacetilases/metabolismo , Histonas/imunologia , Histonas/metabolismo , Immunoblotting , Intestinos/citologia , Intestinos/microbiologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T/imunologia , Linfócitos T/metabolismo , Transplante Homólogo
3.
J Biol Chem ; 300(1): 105502, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38016515

RESUMO

Fatty acid handling and complex lipid synthesis are altered in the kidney cortex of diabetic patients. We recently showed that inhibition of the renin-angiotensin system without changes in glycemia can reverse diabetic kidney disease (DKD) and restore the lipid metabolic network in the kidney cortex of diabetic (db/db) mice, raising the possibility that lipid remodeling may play a central role in DKD. However, the roles of specific enzymes involved in lipid remodeling in DKD have not been elucidated. In the present study, we used this diabetic mouse model and a proximal tubule epithelial cell line (HK2) to investigate the potential relationship between long-chain acyl-CoA synthetase 1 (ACSL1) and lipid metabolism in response to fatty acid exposure and inflammatory signals. We found ACSL1 expression was significantly increased in the kidney cortex of db/db mice, and exposure to palmitate or tumor necrosis factor-α significantly increased Acsl1 mRNA expression in HK-2 cells. In addition, palmitate treatment significantly increased the levels of long-chain acylcarnitines and fatty acyl CoAs in HK2 cells, and these increases were abolished in HK2 cell lines with specific deletion of Acsl1(Acsl1KO cells), suggesting a key role for ACSL1 in fatty acid ß-oxidation. In contrast, tumor necrosis factor-α treatment significantly increased the levels of short-chain acylcarnitines and long-chain fatty acyl CoAs in HK2 cells but not in Acsl1KO cells, consistent with fatty acid channeling to complex lipids. Taken together, our data demonstrate a key role for ACSL1 in regulating lipid metabolism, fatty acid partitioning, and inflammation.


Assuntos
Coenzima A Ligases , Nefropatias Diabéticas , Ácidos Graxos , Animais , Humanos , Camundongos , Coenzima A Ligases/metabolismo , Diabetes Mellitus/patologia , Nefropatias Diabéticas/metabolismo , Ácidos Graxos/metabolismo , Ligases , Palmitatos , Fator de Necrose Tumoral alfa
4.
Am J Physiol Renal Physiol ; 326(1): F30-F38, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37916286

RESUMO

Plasma nucleosides-pseudouridine (PU) and N2N2-dimethyl guanosine (DMG) predict the progression of type 2 diabetic kidney disease (DKD) to end-stage renal disease, but the mechanisms underlying this relationship are not well understood. We used a well-characterized model of type 2 diabetes (db/db mice) and control nondiabetic mice (db/m mice) to characterize the production and excretion of PU and DMG levels using liquid chromatography-mass spectrometry. The fractional excretion of PU and DMG was decreased in db/db mice compared with control mice at 24 wk before any changes to renal function. We then examined the dynamic changes in nucleoside metabolism using in vivo metabolic flux analysis with the injection of labeled nucleoside precursors. Metabolic flux analysis revealed significant decreases in the ratio of urine-to-plasma labeling of PU and DMG in db/db mice compared with db/m mice, indicating significant tubular dysfunction in diabetic kidney disease. We observed that the gene and protein expression of the renal tubular transporters involved with nucleoside transport in diabetic kidneys in mice and humans was reduced. In conclusion, this study strongly suggests that tubular handling of nucleosides is altered in early DKD, in part explaining the association of PU and DMG with human DKD progression observed in previous studies.NEW & NOTEWORTHY Tubular dysfunction explains the association between the nucleosides pseudouridine and N2N2-dimethyl guanosine and diabetic kidney disease.


Assuntos
Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Humanos , Camundongos , Animais , Nefropatias Diabéticas/metabolismo , Pseudouridina/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Nucleosídeos/metabolismo , Eliminação Renal , Rim/metabolismo , Guanosina/metabolismo
6.
J Biol Chem ; 296: 100120, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33234591

RESUMO

Increased myeloperoxidase (MPO) expression and activity are associated with atherosclerotic disease in patients with chronic kidney disease (CKD). However, the causal relationship between MPO and the development and progression of atherosclerosis in patients with CKD is unknown. Eight-week-old male low-density-lipoprotein-receptor-deficient mice were subjected to 5/6 nephrectomy, irradiated, and transplanted with bone marrow from MPO-deficient mice to induce bone marrow MPO deletion (CKD-bMPOKO) or bone marrow from WT mice as a control to maintain preserved bone marrow MPO(CKD-bMPOWT). The mice were maintained on a high-fat/high-cholesterol diet for 16 weeks. As anticipated, both groups of mice exhibited all features of moderate CKD, including elevated plasma creatinine, lower hematocrit, and increased intact parathyroid hormone but did not demonstrate any differences between the groups. Irradiation and bone marrow transplantation did not further affect body weight, blood pressure, creatinine, or hematocrit in either group. The absence of MPO expression in the bone marrow and atherosclerotic lesions of the aorta in the CKD-bMPOKO mice was confirmed by immunoblot and immunohistochemistry, respectively. Decreased MPO activity was substantiated by the absence of 3-chlorotyrosine, a specific by-product of MPO, in aortic atherosclerotic lesions as determined by both immunohistochemistry and highly sensitive LC-MS. Quantification of the aortic lesional area stained with oil red O revealed that CKD-bMPOKO mice had significantly decreased aortic plaque area as compared with CKD-bMPOWT mice. This study demonstrates the reduction of atherosclerosis in CKD mice with the deletion of MPO in bone marrow cells, strongly implicating bone-marrow-derived MPO in the pathogenesis of CKD atherosclerosis.


Assuntos
Aterosclerose/metabolismo , Medula Óssea/metabolismo , Peroxidase/metabolismo , Insuficiência Renal Crônica/metabolismo , Animais , Aterosclerose/patologia , Macrófagos/metabolismo , Masculino , Camundongos , Nefrectomia , Insuficiência Renal Crônica/patologia , Proteína Amiloide A Sérica/metabolismo
7.
Nephrol Dial Transplant ; 35(2): 303-312, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30137494

RESUMO

BACKGROUND: The clinical relevance of arachidonic acid (AA) metabolites in chronic kidney disease (CKD) progression is poorly understood. We aimed to compare the concentrations of 85 enzymatic pathway products of AA metabolism in patients with CKD who progressed to end-stage kidney disease (ESKD) versus patients who did not in a subcohort of Chronic Renal Insufficiency Cohort (CRIC) and to estimate the risk of CKD progression and major cardiovascular events by levels of AA metabolites and their link to enzymatic metabolic pathways. METHODS: A total 123 patients in the CRIC study who progressed to ESKD were frequency matched with 177 nonprogressors and serum eicosanoids were quantified by mass spectrometry. We applied serum collected at patients' Year 1 visit and outcome of progression to ESKD was ascertained over the next 10 years. We used logistic regression models for risk estimation. RESULTS: Baseline 15-hydroxyeicosatetraenoate (HETE) and 20-HETE levels were significantly elevated in progressors (false discovery rate Q ≤ 0.026). The median 20-HETE level was 7.6 pmol/mL [interquartile range (IQR) 4.2-14.5] in progressors and 5.4 pmol/mL (IQR 2.8-9.4) in nonprogressors (P < 0.001). In an adjusted model, only 20-HETE independently predicted CKD progression. Each 1 standard deviation increase in 20-HETE was independently associated with 1.45-fold higher odds of progression (95% confidence interval 1.07-1.95; P = 0.017). Principal components of lipoxygenase (LOX) and cytochrome P450 (CYP450) pathways were independently associated with CKD progression. CONCLUSIONS: We found higher odds of CKD progression associated with higher 20-HETE, LOX and CYP450 metabolic pathways. These alterations precede CKD progression and may serve as targets for interventions aimed at halting progression.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Ácidos Hidroxieicosatetraenoicos/metabolismo , Falência Renal Crônica/diagnóstico , Lipoxigenase/metabolismo , Insuficiência Renal Crônica/complicações , Estudos de Casos e Controles , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Falência Renal Crônica/etiologia , Falência Renal Crônica/metabolismo , Masculino , Pessoa de Meia-Idade
8.
J Biol Chem ; 293(19): 7238-7249, 2018 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-29581235

RESUMO

Increased myeloperoxidase (MPO) levels and activity are associated with increased cardiovascular risk among individuals with chronic kidney disease (CKD). However, a lack of good animal models for examining the presence and catalytic activity of MPO in vascular lesions has impeded mechanistic studies into CKD-associated cardiovascular diseases. Here, we show for the first time that exaggerated atherosclerosis in a pathophysiologically relevant CKD mouse model is associated with increased macrophage-derived MPO activity. Male 7-week-old LDL receptor-deficient mice underwent sham (control mice) or 5/6 nephrectomy and were fed either a low-fat or high-fat, high-cholesterol diet for 24 weeks, and the extents of atherosclerosis and vascular reactivity were assessed. MPO expression and oxidation products-protein-bound oxidized tyrosine moieties 3-chlorotyrosine, 3-nitrotyrosine, and o,o'-dityrosine-were examined with immunoassays and confirmed with mass spectrometry (MS). As anticipated, the CKD mice had significantly higher plasma creatinine, urea nitrogen, and intact parathyroid hormone along with lower hematocrit and body weight. On both the diet regimens, CKD mice did not have hypertension but had lower cholesterol and triglyceride levels than the control mice. Despite the lower cholesterol levels, CKD mice had increased aortic plaque areas, fibrosis, and luminal narrowing. They also exhibited increased MPO expression and activity (i.e. increased oxidized tyrosines) that co-localized with infiltrating lesional macrophages and diminished vascular reactivity. In summary, unlike non-CKD mouse models of atherosclerosis, CKD mice exhibit increased MPO expression and catalytic activity in atherosclerotic lesions, which co-localize with lesional macrophages. These results implicate macrophage-derived MPO in CKD-accelerated atherosclerosis.


Assuntos
Aorta/metabolismo , Aterosclerose/metabolismo , Falência Renal Crônica/complicações , Proteínas Musculares/metabolismo , Oxidantes/metabolismo , Peroxidase/metabolismo , Animais , Aterosclerose/sangue , Aterosclerose/etiologia , Aterosclerose/patologia , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Dieta com Restrição de Gorduras , Dieta Hiperlipídica , Gorduras na Dieta/administração & dosagem , Modelos Animais de Doenças , Progressão da Doença , Falência Renal Crônica/sangue , Falência Renal Crônica/fisiopatologia , Testes de Função Renal , Lipídeos/sangue , Lipoproteínas/sangue , Macrófagos/enzimologia , Masculino , Camundongos , Camundongos Knockout , Nefrectomia , Estresse Oxidativo , Hormônio Paratireóideo/sangue , Receptores de LDL/genética , Tirosina/análogos & derivados , Tirosina/metabolismo , Vasodilatação
9.
J Am Soc Nephrol ; 29(1): 295-306, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29021384

RESUMO

Studies of lipids in CKD, including ESRD, have been limited to measures of conventional lipid profiles. We aimed to systematically identify 17 different lipid classes and associate the abundance thereof with alterations in acylcarnitines, a metric of ß-oxidation, across stages of CKD. From the Clinical Phenotyping Resource and Biobank Core (CPROBE) cohort of 1235 adults, we selected a panel of 214 participants: 36 with stage 1 or 2 CKD, 99 with stage 3 CKD, 61 with stage 4 CKD, and 18 with stage 5 CKD. Among participants, 110 were men (51.4%), 64 were black (29.9%), and 150 were white (70.1%), and the mean (SD) age was 60 (16) years old. We measured plasma lipids and acylcarnitines using liquid chromatography-mass spectrometry. Overall, we identified 330 different lipids across 17 different classes. Compared with earlier stages, stage 5 CKD associated with a higher abundance of saturated C16-C20 free fatty acids (FFAs) and long polyunsaturated complex lipids. Long-chain-to-intermediate-chain acylcarnitine ratio, a marker of efficiency of ß-oxidation, exhibited a graded decrease from stage 2 to 5 CKD (P<0.001). Additionally, multiple linear regression revealed that the long-chain-to-intermediate-chain acylcarnitine ratio inversely associated with polyunsaturated long complex lipid subclasses and the C16-C20 FFAs but directly associated with short complex lipids with fewer double bonds. We conclude that increased abundance of saturated C16-C20 FFAs coupled with impaired ß-oxidation of FFAs and inverse partitioning into complex lipids may be mechanisms underpinning lipid metabolism changes that typify advancing CKD.


Assuntos
Carnitina/sangue , Ácidos Graxos/sangue , Falência Renal Crônica/sangue , Metabolismo dos Lipídeos , Oxirredução , Adulto , Idoso , Idoso de 80 Anos ou mais , Carnitina/análogos & derivados , Carnitina/química , Ácidos Graxos/química , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
10.
Am J Nephrol ; 48(4): 269-277, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30326477

RESUMO

BACKGROUND: The gut microbiota is altered in patients with chronic kidney disease (CKD), and cardiovascular risk increases with progressive CKD. This study examined the potential link between short chain fatty acids (SCFAs), which are produced by the gut microbiota, and cardiovascular outcomes in patients with CKD. METHODS: SCFAs were measured using a targeted liquid chromatography-mass spectrometry platform in baseline plasma samples from 214 patients with CKD enrolled in the Clinical Phenotyping Resource and Biobank Core; 81 patients with coronary artery disease (CAD) and 133 without CAD were randomly assigned to training and validation subsets. The primary outcome was a history of CAD and the secondary outcome was a composite history of cardiovascular disease (CVD) at enrollment. RESULTS: We found significantly higher levels of the SCFA valerate among patients with CAD as compared with patients without CAD in the training set (p < 0.001). The valerate concentrations were also significantly higher among subjects with composite outcomes of CVD compared to those without CVD (p = 0.006). These results were subsequently replicated in the validation set. Logistic regression analysis revealed a strong independent association between plasma valerate levels and CVD in both training and validation sets. When valerate was added to the base clinical model comprising of diabetes, hypertension, urinary protein-creatinine ratio, and estimated glomerular filtration rate, it increased the c-statistics for predicting CVD from 0.68 to 0.79 (p = 0.02) in the training set, an observation which was confirmed in the validation set. -Conclusion: This study provides evidence for alterations in gut-microbiota-derived SCFAs with advancing CKD, demonstrates the association of higher plasma valerate levels with pre-existing CVD, and reveals areas for future exploration of cardiovascular risk in patients with CKD.


Assuntos
Doença da Artéria Coronariana/diagnóstico , Microbioma Gastrointestinal/fisiologia , Ácidos Pentanoicos/sangue , Insuficiência Renal Crônica/complicações , Adulto , Idoso , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/etiologia , Progressão da Doença , Feminino , Taxa de Filtração Glomerular , Humanos , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Ácidos Pentanoicos/metabolismo , Valor Preditivo dos Testes , Prognóstico , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/fisiopatologia , Medição de Risco/métodos , Fatores de Risco
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