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1.
Thromb J ; 19(1): 103, 2021 Dec 20.
Article in English | MEDLINE | ID: mdl-34930339

ABSTRACT

BACKGROUND: Antiphospholipid Syndrome (APS) is a multisystemic autoimmune disease characterized by arterial and venous thrombosis and / or obstetric morbidity in the presence of at least one circulating anti-phospholipid antibody. The spectrum of vascular events varies from deep venous thrombosis to catastrophic APS, a rare form characterized by acute multiorgan thrombosis and high mortality. CASE REPORT: We present the case of a 32-week pregnant woman arriving in the hospital emergency room with bilateral acute lower limb ischemia. In the obstetric evaluation, fetal death was declared. Computerized Tomography angiography showed pulmonary embolism of both pulmonary arteries, areas of splenic and right renal infarction and multiple arterial and venous thrombosis. The patient underwent urgent caesarean section and axillary-bifemoral bypass. No events registered. In the postoperative period, in an intensive care unit, treatment with rituximab and plasmapheresis were added to anticoagulant therapy. The laboratorial investigation was negative for thrombophilia and autoimmune diseases. CONCLUSION: Catastrophic APS develops quickly, with multiorgan involvement and high mortality rate. The presented case poses a multidisciplinary challenge, with the surgical approach of extra-anatomical revascularization being less invasive and guaranteeing immediate perfusion of the lower limbs. Although the serological tests were negative for anti-phospholipid antibodies, this case hardly fits into another diagnosis. Therefore, it was treated as a catastrophic APS, having shown a favorable evolution.

2.
Proc Natl Acad Sci U S A ; 115(20): E4651-E4660, 2018 05 15.
Article in English | MEDLINE | ID: mdl-29720442

ABSTRACT

Mucosal T lymphocytes from patients with ulcerative colitis (UC) were previously shown to display a deficiency in branched N-glycosylation associated with disease severity. However, whether this glycosylation pathway shapes the course of the T cell response constituting a targeted-specific mechanism in UC remains largely unknown. In this study, we demonstrated that metabolic supplementation of ex vivo mucosal T cells from patients with active UC with N-acetylglucosamine (GlcNAc) resulted in enhancement of branched N-glycosylation in the T cell receptor (TCR), leading to suppression of T cell growth, inhibition of the T helper 1 (Th1)/Th17 immune response, and controlled T cell activity. We further demonstrated that mouse models displaying a deficiency in the branched N-glycosylation pathway (MGAT5-/-, MGAT5+/-) exhibited increased susceptibility to severe forms of colitis and early-onset disease. Importantly, the treatment of these mice with GlcNAc reduced disease severity and suppressed disease progression due to a controlled T cell-mediated immune response at the intestinal mucosa. In conclusion, our human ex vivo and preclinical results demonstrate the targeted-specific immunomodulatory properties of this simple glycan, proposing a therapeutic approach for patients with UC.


Subject(s)
Acetylglucosamine/pharmacology , CD4-Positive T-Lymphocytes/immunology , Colitis, Ulcerative/immunology , N-Acetylglucosaminyltransferases/physiology , Polysaccharides/metabolism , Adaptive Immunity , Animals , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/metabolism , Case-Control Studies , Colitis, Ulcerative/chemically induced , Colitis, Ulcerative/drug therapy , Colitis, Ulcerative/metabolism , Cytokines/metabolism , Glycosylation , Humans , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptors, Antigen, T-Cell/metabolism
3.
Am J Physiol Renal Physiol ; 312(2): F312-F321, 2017 Feb 01.
Article in English | MEDLINE | ID: mdl-27852608

ABSTRACT

Diabetic nephropathy (DN) is the leading cause of kidney failure in the world. To understand important mechanisms underlying this condition, and to develop new therapies, good animal models are required. In mouse models of type 1 diabetes, the DBA/2J strain has been shown to be more susceptible to develop kidney disease than other common strains. We hypothesized this would also be the case in type 2 diabetes. We studied db/db and wild-type (wt) DBA/2J mice and compared these with the db/db BLKS/J mouse, which is currently the most widely used type 2 DN model. Mice were analyzed from age 6 to 12 wk for systemic insulin resistance, albuminuria, and glomerular histopathological and ultrastructural changes. Body weight and nonfasted blood glucose were increased by 8 wk in both genders, while systemic insulin resistance commenced by 6 wk in female and 8 wk in male db/db DBA/2J mice. The urinary albumin-to-creatinine ratio (ACR) was closely linked to systemic insulin resistance in both sexes and was increased ~50-fold by 12 wk of age in the db/db DBA/2J cohort. Glomerulosclerosis, foot process effacement, and glomerular basement membrane thickening were observed at 12 wk of age in db/db DBA/2J mice. Compared with db/db BLKS/J mice, db/db DBA/2J mice had significantly increased levels of urinary ACR, but similar glomerular histopathological and ultrastructural changes. The db/db DBA/2J mouse is a robust model of early-stage albuminuric DN, and its levels of albuminuria correlate closely with systemic insulin resistance. This mouse model will be helpful in defining early mechanisms of DN and ultimately the development of novel therapies.


Subject(s)
Albuminuria/pathology , Diabetes Mellitus, Type 2/pathology , Diabetic Nephropathies/pathology , Glomerular Basement Membrane/pathology , Insulin Resistance/physiology , Kidney/pathology , Albuminuria/etiology , Albuminuria/metabolism , Animals , Blood Glucose , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/metabolism , Diabetic Nephropathies/etiology , Diabetic Nephropathies/metabolism , Disease Models, Animal , Female , Glomerular Basement Membrane/metabolism , Insulin/blood , Kidney/metabolism , Male , Mice , Mice, Inbred DBA
4.
FASEB J ; 27(8): 2927-38, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23616567

ABSTRACT

Several clinical and animal studies suggest that "blood pressure goes with the kidney," that is, a normotensive recipient of a kidney genetically programmed for hypertension will develop hypertension. Intrarenal dopamine plays an important role in the pathogenesis of hypertension by regulating epithelial sodium transport. The candidate transport systems for L-DOPA, the source for dopamine, include the sodium-dependent systems B(0), B(0,+), and y(+)L, and the sodium-independent systems L (LAT1 and LAT2) and b(0,+). Renal LAT2 is overexpressed in the prehypertensive spontaneously hypertensive rat (SHR), which might contribute to enhanced L-DOPA uptake in the proximal tubule and increased dopamine production, as an attempt to overcome the defect in D1 receptor function. On the other hand, it has been recently reported that impaired arginine transport contributes to low renal nitric oxide bioavailability observed in the SHR renal medulla. Here we review the importance of renal amino acid transporters in the kidney and highlight pathophysiological changes in the expression and regulation of these transporters in essential hypertension. The study of the regulation of renal amino acid transporters may help to define the underlying mechanisms predisposing individuals to an increased risk for development of hypertension.


Subject(s)
Amino Acid Transport Systems/metabolism , Dopamine/metabolism , Hypertension/metabolism , Kidney/metabolism , Levodopa/metabolism , Animals , Humans , Models, Biological , Rats , Rats, Inbred SHR
5.
FASEB J ; 26(8): 3230-9, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22522110

ABSTRACT

The protein kinase liver kinase B1 (LKB1) regulates cell polarity and intercellular junction stability. Also, LKB1 controls the activity of salt-inducible kinase 1 (SIK1). The role and relevance of SIK1 and its downstream effectors in linking the LKB1 signals within these processes are partially understood. We hypothesize that SIK1 may link LKB1 signals to the maintenance of epithelial junction stability by regulating E-cadherin expression. Results from our studies using a mouse lung alveolar epithelial (MLE-12) cell line or human renal proximal tubule (HK2) cell line transiently or stably lacking the expression of SIK1 (using SIK1 siRNAs or shRNAs), or with its expression abrogated (sik1(+/+) vs. sik1(-/-) mice), indicate that suppression of SIK1 (∼40%) increases the expression of the transcriptional repressors Snail2 (∼12-fold), Zeb1 (∼100%), Zeb2 (∼50%), and TWIST (∼20-fold) by activating cAMP-response element binding protein. The lack of SIK1 and activation of transcriptional repressors decreases the availability of E-cadherin (mRNA and protein expression by ∼100 and 80%, respectively) and the stability of intercellular junctions in epithelia (decreases in transepithelial resistance). Furthermore, LKB1-mediated increases in E-cadherin expression are impaired in cells where SIK1 has been disabled. We conclude that SIK1 is a key regulator of E-cadherin expression, and thereby contributes to the stability of intercellular junctions.


Subject(s)
Cadherins/biosynthesis , Intercellular Junctions/drug effects , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/physiology , AMP-Activated Protein Kinase Kinases , Animals , Cell Line , Cyclic AMP Response Element-Binding Protein/metabolism , Humans , Intercellular Junctions/metabolism , Kidney Tubules, Proximal/metabolism , Mice , Snail Family Transcription Factors , Transcription Factors/biosynthesis
6.
Sci Transl Med ; 15(687): eabo1930, 2023 03 15.
Article in English | MEDLINE | ID: mdl-36921032

ABSTRACT

Autoimmune diseases are life-threatening disorders that cause increasing disability over time. Systemic lupus erythematosus (SLE) and other autoimmune diseases arise when immune stimuli override mechanisms of self-tolerance. Accumulating evidence has demonstrated that protein glycosylation is substantially altered in autoimmune disease development, but the mechanisms by which glycans trigger these autoreactive immune responses are still largely unclear. In this study, we found that presence of microbial-associated mannose structures at the surface of the kidney triggers the recognition of DC-SIGN-expressing γδ T cells, inducing a pathogenic interleukin-17a (IL-17a)-mediated autoimmune response. Mice lacking Mgat5, which have a higher abundance of mannose structures in the kidney, displayed increased γδ T cell infiltration into the kidney that was associated with spontaneous development of lupus in older mice. N-acetylglucosamine supplementation, which promoted biosynthesis of tolerogenic branched N-glycans in the kidney, was found to inhibit γδ T cell infiltration and control disease development. Together, this work reveals a mannose-γδ T cell-IL-17a axis in SLE immunopathogenesis and highlights glycometabolic reprogramming as a therapeutic strategy for autoimmune disease treatment.


Subject(s)
Autoimmune Diseases , Lupus Erythematosus, Systemic , Animals , Mice , Autoimmunity , Mannose , Interleukin-17/metabolism , Receptors, Antigen, T-Cell, gamma-delta/metabolism
7.
Am J Physiol Heart Circ Physiol ; 303(1): H57-65, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22467310

ABSTRACT

Cardiac hypertrophy (CH) generally occurs as the result of the sustained mechanical stress caused by elevated systemic arterial blood pressure (BP). However, in animal models, elevated salt intake is associated with CH even in the absence of significant increases in BP. We hypothesize that CH is not exclusively the consequence of mechanical stress but also of other factors associated with elevated BP such as abnormal cell sodium homeostasis. We examined the effect of small increases in intracellular sodium concentration ([Na(+)](i)) on transcription factors and genes associated with CH in a cardiac cell line. Increases in [Na(+)](i) led to a time-dependent increase in the expression levels of mRNA for natriuretic peptide and myosin heavy chain genes and also increased myocyte enhancer factor (MEF)2/nuclear factor of activated T cell (NFAT) transcriptional activity. Increases in [Na(+)](i) are associated with activation of salt-inducible kinase 1 (snflk-1, SIK1), a kinase known to be critical for cardiac development. Moreover, increases in [Na(+)](i) resulted in increased SIK1 expression. Sodium did not increase MEF2/NFAT activity or gene expression in cells expressing a SIK1 that lacked kinase activity. The mechanism by which SIK1 activated MEF2 involved phosphorylation of HDAC5. Increases in [Na(+)](i) activate SIK1 and MEF2 via a parallel increase in intracellular calcium through the reverse mode of Na(+)/Ca(2+)-exchanger and activation of CaMK1. These data obtained in a cardiac cell line suggest that increases in intracellular sodium could influence myocardial growth by controlling transcriptional activation and gene expression throughout the activation of the SIK1 network.


Subject(s)
Gene Expression/drug effects , Myocytes, Cardiac/physiology , Protein Serine-Threonine Kinases/physiology , Sodium/pharmacology , Transcription, Genetic/drug effects , Biopsy , Cardiomegaly/genetics , Cardiomegaly/metabolism , Cell Line , Heart Atria/cytology , Histone Deacetylases/metabolism , Humans , Hydrogen-Ion Concentration , MADS Domain Proteins/metabolism , MEF2 Transcription Factors , Monensin/pharmacology , Myocytes, Cardiac/metabolism , Myogenic Regulatory Factors/metabolism , NFATC Transcription Factors/metabolism , Phosphorylation , Plasmids , RNA/biosynthesis , RNA/genetics , Transcription Factors/biosynthesis , Transcription Factors/genetics , Transfection
8.
Biochem Biophys Res Commun ; 398(3): 553-8, 2010 Jul 30.
Article in English | MEDLINE | ID: mdl-20599757

ABSTRACT

The presence of high and low sodium affinity states for the Na(+)-dependent [(14)C]-l-alanine uptake in immortalized renal proximal tubular epithelial (PTE) cells was previously reported (Am. J. Physiol. 293 (2007) R538-R547). This study evaluated the role of H(2)O(2) on the Na(+)-dependent [(14)C]-l-alanine uptake of ASCT2 in immortalized renal PTE cells from Wistar Kyoto rat (WKY) and spontaneously hypertensive rat (SHR). Na(+) dependence of [(14)C]-l-alanine uptake was investigated replacing NaCl with an equimolar concentration of choline chloride in vehicle- and apocynin-treated cells. Na(+) removal from the uptake solution abolished transport activity in both WKY and SHR PTE cells. Decreases in H(2)O(2) levels in the extracellular medium significantly reduced Na(+)-K(m) and V(max) values of the low-affinity high-capacity component in SHR PTE cells, with no effect on the high-affinity low-capacity state of the Na(+)-dependent [(14)C]-l-alanine uptake. After removal of apocynin from the culture medium, H(2)O(2) levels returned to basal values within 1 to 3h in both WKY and SHR PTE cells and these were found stable for the next 24h. Under these experimental conditions, the Na(+)-K(m) and V(max) of the high-affinity low-capacity state were unaffected and the low-affinity high-capacity component remained significantly decreased 1day but not 4days after apocynin removal. In conclusion, H(2)O(2) in excess is required for the presence of a low-affinity high-capacity component for the Na(+)-dependent [(14)C]-l-alanine uptake in SHR PTE cells only. It is suggested that Na(+) binding in renal ASCT2 may be regulated by ROS in SHR PTE cells.


Subject(s)
Alanine/metabolism , Amino Acid Transport System ASC/metabolism , Hydrogen Peroxide/metabolism , Kidney Tubules, Proximal/metabolism , Sodium/metabolism , Animals , Cells, Cultured , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Hydrogen Peroxide/pharmacology , Kidney Tubules, Proximal/cytology , Kidney Tubules, Proximal/drug effects , Minor Histocompatibility Antigens , Rats , Rats, Inbred SHR , Rats, Inbred WKY
9.
Sci Rep ; 8(1): 3902, 2018 03 02.
Article in English | MEDLINE | ID: mdl-29500363

ABSTRACT

Disruption of the insulin-PI3K-Akt signalling pathway in kidney podocytes causes endoplasmic reticulum (ER) stress, leading to podocyte apoptosis and proteinuria in diabetic nephropathy. We hypothesised that by improving insulin sensitivity we could protect podocytes from ER stress. Here we use established activating transcription factor 6 (ATF6)- and ER stress element (ERSE)-luciferase assays alongside a novel high throughput imaging-based C/EBP homologous protein (CHOP) assay to examine three models of improved insulin sensitivity. We find that by improving insulin sensitivity at the level of the insulin receptor (IR), either by IR over-expression or by knocking down the negative regulator of IR activity, protein tyrosine-phosphatase 1B (PTP1B), podocytes are protected from ER stress caused by fatty acids or diabetic media containing high glucose, high insulin and inflammatory cytokines TNFα and IL-6. However, contrary to this, knockdown of the negative regulator of PI3K-Akt signalling, phosphatase and tensin homolog deleted from chromosome 10 (PTEN), sensitizes podocytes to ER stress and apoptosis, despite increasing Akt phosphorylation. This indicates that protection from ER stress is conferred through not just the PI3K-Akt pathway, and indeed we find that inhibiting the MEK/ERK signalling pathway rescues PTEN knockdown podocytes from ER stress.


Subject(s)
Endoplasmic Reticulum Stress , Phosphatidylinositol 3-Kinases/metabolism , Podocytes/physiology , Receptor, Insulin/metabolism , Signal Transduction , Animals , Apoptosis , Cells, Cultured , Insulin/metabolism , Mice , PTEN Phosphohydrolase/metabolism , Phosphorylation , Podocytes/cytology , Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism
10.
Front Immunol ; 9: 2754, 2018.
Article in English | MEDLINE | ID: mdl-30538706

ABSTRACT

The immune system is highly controlled and fine-tuned by glycosylation, through the addition of a diversity of carbohydrates structures (glycans) to virtually all immune cell receptors. Despite a relative backlog in understanding the importance of glycans in the immune system, due to its inherent complexity, remarkable findings have been highlighting the essential contributions of glycosylation in the regulation of both innate and adaptive immune responses with important implications in the pathogenesis of major diseases such as autoimmunity and cancer. Glycans are implicated in fundamental cellular and molecular processes that regulate both stimulatory and inhibitory immune pathways. Besides being actively involved in pathogen recognition through interaction with glycan-binding proteins (such as C-type lectins), glycans have been also shown to regulate key pathophysiological steps within T cell biology such as T cell development and thymocyte selection; T cell activity and signaling as well as T cell differentiation and proliferation. These effects of glycans in T cells functions highlight their importance as determinants of either self-tolerance or T cell hyper-responsiveness which ultimately might be implicated in the creation of tolerogenic pathways in cancer or loss of immunological tolerance in autoimmunity. This review discusses how specific glycans (with a focus on N-linked glycans) act as regulators of T cell biology and their implications in disease.


Subject(s)
Polysaccharides/immunology , T-Lymphocytes/immunology , Animals , Humans , Immune Tolerance/immunology , Lectins, C-Type/immunology , Lymphocyte Activation/immunology , Neoplasms/immunology , Self Tolerance/immunology
11.
BMC Evol Biol ; 6: 108, 2006 Dec 13.
Article in English | MEDLINE | ID: mdl-17166275

ABSTRACT

BACKGROUND: Comparative approaches using protostome and deuterostome data have greatly contributed to understanding gene function and organismal complexity. The family 2 G-protein coupled receptors (GPCRs) are one of the largest and best studied hormone and neuropeptide receptor families. They are suggested to have arisen from a single ancestral gene via duplication events. Despite the recent identification of receptor members in protostome and early deuterostome genomes, relatively little is known about their function or origin during metazoan divergence. In this study a comprehensive description of family 2 GPCR evolution is given based on in silico and expression analyses of the invertebrate receptor genes. RESULTS: Family 2 GPCR members were identified in the invertebrate genomes of the nematodes C. elegans and C. briggsae, the arthropods D. melanogaster and A. gambiae (mosquito) and in the tunicate C. intestinalis. This suggests that they are of ancient origin and have evolved through gene/genome duplication events. Sequence comparisons and phylogenetic analyses have demonstrated that the immediate gene environment, with regard to gene content, is conserved between the protostome and deuterostome receptor genomic regions. Also that the protostome genes are more like the deuterostome Corticotrophin Releasing Factor (CRF) and Calcitonin/Calcitonin Gene-Related Peptide (CAL/CGRP) receptors members than the other family 2 GPCR members. The evolution of family 2 GPCRs in deuterostomes is characterised by acquisition of new family members, with SCT (Secretin) receptors only present in tetrapods. Gene structure is characterised by an increase in intron number with organismal complexity with the exception of the vertebrate CAL/CGRP receptors. CONCLUSION: The family 2 GPCR members provide a good example of gene duplication events occurring in tandem with increasing organismal complexity during metazoan evolution. The putative ancestral receptors are proposed to be more like the deuterostome CAL/CGRP and CRF receptors and this may be associated with their fundamental role in calcium regulation and the stress response, both of which are essential for survival.


Subject(s)
Evolution, Molecular , Invertebrates/genetics , Receptors, G-Protein-Coupled/genetics , Secretin/genetics , Animals , Caenorhabditis elegans/genetics , Conserved Sequence , Drosophila melanogaster/genetics , Gene Duplication , Gene Expression , Genetic Linkage , Humans , Molecular Sequence Data , Phylogeny , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Amino Acid , Species Specificity , Takifugu/genetics
13.
Exp Gerontol ; 47(8): 644-53, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22687288

ABSTRACT

In the present study we hypothesized that age-associated changes in the renal aldosterone/mineralocorticoid receptor (MR) system may differ between normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). In WKY, body mass index significantly increased with age. Fat mass may operate as a confounding factor; therefore, WKY (WKY-FR) was pair-fed with SHR. Pair-feeding resulted in a 14% body weight reduction at the age of 52 weeks in WKY-FR. Renal oxidative stress was increased in aged WKY and SHR. Aged WKY and SHR had increased MR functionality, which correlated positively with increased plasma aldosterone levels, nuclear MR content and abundance of aldosterone effectors in the renal medulla. In contrast, decreases in nuclear MR content were observed in the renal cortex of both strains with aging. When compared to aged SHR, aged WKY-FR had decreased plasma aldosterone levels and decreased activation of the aldosterone/MR system in the renal medulla. Increases in renal oxidative stress and plasma aldosterone in aged WKY, to levels observed in SHR, were not sufficient to result in sustained increases in blood pressure. In conclusion, activation of the aldosterone/MR system is intensified by aging in SHR, whereas increases in body fat mass in WKY associate with hyperaldosteronism and oxidative stress.


Subject(s)
Aging/metabolism , Aldosterone/physiology , Food Deprivation/physiology , Hypertension/metabolism , Kidney/metabolism , Receptors, Mineralocorticoid/metabolism , Aging/physiology , Aldosterone/blood , Animals , Body Mass Index , Hydrogen Peroxide/metabolism , Hypertension/physiopathology , Lipid Peroxidation/physiology , Male , Potassium/urine , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Sodium/metabolism , Sodium/urine
14.
Mech Ageing Dev ; 132(6-7): 298-304, 2011.
Article in English | MEDLINE | ID: mdl-21699911

ABSTRACT

This study examined age-related changes in renal dopaminergic activity and expression of amino acid transporters potentially involved in renal tubular uptake of l-DOPA in Wistar Kyoto (WKY) and spontaneously hypertensive rats. Aging (from 13 to 91 weeks) was accompanied by increases in systolic blood pressure (SBP) in both WKY and SHR. The sum of urinary dopamine and DOPAC and the urinary dopamine/l-DOPA ratio were increased in aged SHR but not in aged WKY. The urinary dopamine/renal delivery of l-DOPA ratio was increased in both rat strains with aging. LAT2 abundance was increased in aged WKY and SHR. The expression of 4F2hc was markedly elevated in aged SHR but not in aged WKY. ASCT2 was upregulated in both aged WKY and SHR. Plasma aldosterone levels and urinary noradrenaline levels were increased in aged WKY and SHR though levels of both entities were more elevated in aged SHR. Activation of the renal dopaminergic system is more pronounced in aged SHR than in aged WKY and is associated with an upregulation of renal cortical ASCT2 in WKY and of LAT2/4F2hc and ASCT2 in SHR. This activation may be the consequence of a counter-regulatory mechanism for stimuli leading to sodium reabsorption.


Subject(s)
Aging/metabolism , Amino Acid Transport System ASC/biosynthesis , Amino Acid Transport System y+/biosynthesis , Dopamine/urine , Fusion Regulatory Protein 1, Light Chains/biosynthesis , Kidney Cortex/metabolism , 3,4-Dihydroxyphenylacetic Acid/urine , Animals , Male , Minor Histocompatibility Antigens , Rats , Rats, Inbred SHR , Rats, Inbred WKY
15.
Exp Gerontol ; 46(6): 468-74, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21316443

ABSTRACT

Oxidative stress has been hypothesized to play a role in aging and age-related disorders, such as hypertension. This study compared levels of oxidative stress and renal expression of oxidant and antioxidant enzymes in male normotensive Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR) at different ages (3 and 12 months). In the renal cortex of 3-month old SHR increases in hydrogen peroxide (H(2)O(2)) were accompanied by augmented expression of NADPH oxidase subunit Nox4 and decreased expression of antioxidant enzymes SOD1 and SOD3. A further increase in renal H(2)O(2) production and urinary TBARS was observed in 12-month old WKY and SHR as compared with 3-month old rats. Similarly, expressions of NADPH oxidase subunit p22(phox), SOD2 and SOD3 were markedly elevated with age in both strains. When compared with age-matched WKY, catalase expression was increased in 3-month old SHR, but unchanged in 12-month old SHR. Body weight increased with aging in both rat strains, but this increase was more pronounced in WKY. In conclusion, renal oxidative stress in 12-month old SHR is an exaggeration of the process already observed in the 3-month old SHR, whereas the occurrence of obesity in 12-month old normotensive rats may partially be responsible for the age-related increase in oxidative stress.


Subject(s)
Aging/metabolism , Antioxidants/metabolism , Hypertension/metabolism , Kidney/metabolism , Oxidants/metabolism , Oxidative Stress/physiology , Animals , Blood Pressure/physiology , Body Weight/physiology , Disease Models, Animal , Hydrogen Peroxide/metabolism , Hypertension/physiopathology , Male , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Superoxide Dismutase/metabolism , Superoxide Dismutase-1
16.
Oxid Med Cell Longev ; 2(3): 138-45, 2009.
Article in English | MEDLINE | ID: mdl-20592768

ABSTRACT

The aim of this study was to investigate whether the effects of aging on oxidative stress markers and expression of major oxidant and antioxidant enzymes associate with impairment of renal function and increases in blood pressure. To explore this, we determined age-associated changes in lipid peroxidation (urinary malondialdehyde), plasma and urinary hydrogen peroxide (H(2)O(2)) levels, as well as renal H(2)O(2) production, and the expression of oxidant and antioxidant enzymes in young (13 weeks) and old (52 weeks) male Wistar Kyoto (WKY) rats. Urinary lipid peroxidation levels and H(2)O(2) production by the renal cortex and medulla of old rats were higher than their young counterparts. This was accompanied by overexpression of NADPH oxidase components Nox4 and p22(phox) in the renal cortex of old rats. Similarly, expression of superoxide dismutase (SOD) isoforms 2 and 3 and catalase were increased in the renal cortex from old rats. Renal function parameters (creatinine clearance and fractional excretion of sodium), diastolic blood pressure and heart rate were not affected by aging, although slight increases in systolic blood pressure were observed during this 52-week period. It is concluded that overexpression of renal Nox4 and p22(phox) and the increases in renal H(2)O(2) levels in aged WKY does not associate with renal functional impairment or marked increases in blood pressure. It is hypothesized that lack of oxidative stress-associated effects in aged WKY rats may result from increases in antioxidant defenses that counteract the damaging effects of H(2)O(2).


Subject(s)
Aging , Antioxidants/metabolism , Blood Pressure/physiology , Kidney Cortex/metabolism , Oxidants/metabolism , Oxidative Stress , Animals , Catalase/metabolism , Heart Rate , Hydrogen Peroxide/blood , Hydrogen Peroxide/metabolism , Hydrogen Peroxide/urine , Kidney Cortex/enzymology , Lipid Peroxidation , Male , NADPH Oxidase 4 , NADPH Oxidases/metabolism , Rats , Rats, Inbred WKY , Superoxide Dismutase/metabolism
17.
Mol Cell Biochem ; 310(1-2): 191-201, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18095144

ABSTRACT

This study evaluated the effects of aldosterone upon Na+/H+ exchange (NHE) activity in immortalized proximal tubular epithelial (PTE) cells from the spontaneously hypertensive rat (SHR) and the normotensive controls (Wistar Kyoto rat; WKY). Increases in NHE activity after exposure to aldosterone occurred in time- and concentration-dependent manner in SHR PTE cells, but not in WKY PTE cells. The aldosterone-induced increases in NHE activity were prevented by spironolactone, but not by the glucocorticoid receptor antagonist Ru 38486. The presence of the mineralocorticoid receptor transcript was confirmed by PCR and NHE1, NHE2, and NHE3 proteins were detected by immunoblot analysis. Cariporide and EIPA, but not S3226, inhibited the aldosterone-induced increase in NHE activity, indicating that NHE1 is the most likely involved NHE isoform. Pretreatment of SHR PTE cells with actinomycin D attenuated the aldosterone-induced increases in NHE activity. The SHR PTE cells had an increased rate of H2O2 production when compared with WKY PTE cells. Treatment of cells with apocynin, a NADPH oxidase inhibitor, markedly reduced the rate of H2O2 production. The aldosterone-induced increase in NHE activity SHR PTE cells was completely prevented by apocynin. In conclusion, the aldosterone-induced stimulation of NHE1 activity is a genomic event unique in SHR PTE cells, which involves the activation of the mineralocorticoid receptor, but ultimately requires the availability of H2O2 in excess.


Subject(s)
Aldosterone/pharmacology , Genome/genetics , Kidney Tubules, Proximal/cytology , Kidney Tubules, Proximal/metabolism , Oxidative Stress/drug effects , Sodium-Hydrogen Exchangers/metabolism , Amiloride/analogs & derivatives , Amiloride/pharmacology , Animals , Cell Line , Cytochalasin B/pharmacology , Dactinomycin/pharmacology , Gene Expression Regulation/drug effects , Guanidines/pharmacology , Hydrogen Peroxide/metabolism , Hydrogen-Ion Concentration/drug effects , Immunoblotting , Kidney Tubules, Proximal/drug effects , Methacrylates/pharmacology , Mifepristone/pharmacology , Protein Isoforms/genetics , Protein Isoforms/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Inbred SHR , Receptors, Mineralocorticoid/genetics , Receptors, Mineralocorticoid/metabolism , Sodium-Hydrogen Exchanger 1 , Spironolactone/pharmacology , Sulfones/pharmacology
18.
Am J Physiol Regul Integr Comp Physiol ; 293(1): R538-47, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17475673

ABSTRACT

This study examined the inward transport of l-[(14)C]alanine, an ASCT2 preferential substrate, in monolayers of immortalized renal proximal tubular epithelial (PTE) cells from Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. The expression of ASCT2 in WKY and SHR PTE cells and kidney cortices from WKY and SHR was also evaluated. l-[(14)C]alanine uptake was highly dependent on extracellular Na(+). Replacement of NaCl by LiCl or choline chloride abolished transport activity in SHR and WKY PTE cells. In the presence of the system L inhibitor BCH, Na(+)-dependent l-alanine uptake in WKY and SHR PTE cells was inhibited by alanine, serine, and cysteine, which is consistent with amino acid transport through ASCT2. The saturable component of Na(+)-dependent l-alanine transport under V(max) conditions in SHR PTE cells was one-half of that in WKY PTE cells, with similar K(m) values. Differences in magnitude of Na(+)-dependent l-alanine uptake through ASCT2 between WKY and SHR PTE cells correlated positively with differences in ASCT2 protein expression, this being more abundant in WKY PTE cells. Abundance of ASCT2 transcript and protein in kidney cortices of SHR rats was also lower than that in normotensive WKY rats. In conclusion, immortalized SHR and WKY PTE cells take up l-alanine mainly through a high-affinity Na(+)-dependent amino acid transporter, with functional features of ASCT2 transport. The activity and expression of the ASCT2 transporter were considerably lower in the SHR cells.


Subject(s)
Amino Acid Transport System ASC/biosynthesis , Alanine/metabolism , Amino Acids/biosynthesis , Amino Acids/metabolism , Amino Acids/pharmacology , Ammonium Chloride/pharmacology , Animals , Blotting, Western , Cell Line , Choline/pharmacology , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Kidney Cortex/cytology , Kidney Cortex/drug effects , Kidney Cortex/metabolism , Kinetics , Lithium Chloride/pharmacology , Minor Histocompatibility Antigens , Potassium Chloride/pharmacology , RNA, Messenger/biosynthesis , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Reverse Transcriptase Polymerase Chain Reaction
19.
Bragança; s.n; 20160000. ilus, tab.
Thesis in Portuguese | BDENF | ID: biblio-1223676

ABSTRACT

O aumento da esperança média de vida torna as pessoas mais vulneráveis e dependentes, especialmente no que se refere às atividades quotidianas. A coxartrose é uma das osteoartroses mais comuns, manifestada por dor, limitação progressiva da mobilidade articular e atrofia muscular. A artroplastia total da anca tem-se afirmado como alternativa eficaz e com sucesso ao longo do tempo. Hoje em dia, a necessidade de recuperação funcional após a cirurgia é irrefutável. Neste contexto, a reabilitação assume um papel primordial, quer na maximização das capacidades e minimização dos défices pós-cirúrgicos da pessoa, quer no restabelecimento da sua autonomia e consequente retorno à vida social e profissional. Objetivo: Avaliar os efeitos de um programa de reabilitação instituído a pessoas submetidas a artroplastia total da anca. Metodologia: Foi realizado um programa de reabilitação às pessoas submetidas a artroplastia total da anca, com início no primeiro dia de pós-operatório até à consulta pós-operatória, baseado em exercícios resistidos, a 28 pessoas. Avaliaram-se a força muscular (Lafayette manual muscle tester), a amplitude articular (goniometria), a escala de Tinetti e o questionário WOMAC. A colheita de dados foi realizada em três momentos (admissão ­ T0, alta ­ T1 e primeira consulta pós-cirurgia ­ T2). Resultados: Após o programa verificou-se uma melhoria substancial da qualidade de marcha e dos domínios do questionário WOMAC, até ao dia da consulta de ortopedia, que em média foi de 41 dias. A força muscular, quer força máxima quer força média, diminuiu ligeiramente em T1 e em T2 aumentou, exceto nos isquiotibiais em que existe um incremento em todas as avaliações. Verificou-se ainda que os resultados obtidos são independentes da idade, sexo e existência de cirurgia ortopédica anterior. Conclusão: Comprova-se que um programa de reabilitação que forneça as competências necessárias às pessoas, em que se conjugue reabilitação em ambiente hospitalar e domiciliário, é crucial para uma recuperação rápida e eficaz.


The increase in the average life expectancy becomes people more vulnerable and dependent, especially with regard to daily activities. The coxarthrosis is one of the most common osteoarthrosis, manifested by pain, progressive limitation of joint mobility and muscle atrophy. Total hip arthroplasty has established itself as an effective alternative and successfully over time. Nowadays, the need for functional recovery after surgery is irrefutable. In this context, rehabilitation plays a major role both in maximizing skills and minimizing post-surgical deficits and in the restoration of their autonomy and consequent return to social and professional life. Objective: To evaluate the effects of a rehabilitation program established to people undergoing total hip arthroplasty. Methods: It was performed a rehabilitation program for people undergoing hip replacement, beginning on the first day after surgery to post-operative consultation, based on resistance exercises, to 28 people. Muscle strength (Lafayette manual muscle tester), the range of motion (goniometry), the Tinetti scale and WOMAC questionnaire were evaluated. The data collection was carried out in three stages (admission ­ T0, discharge ­ T1 and first post-surgery consultation ­ T2) Results: After the program there was a substantial improvement in the quality of gait and in the WOMAC questionnaire dimensions, until the day of the orthopaedic consultation, which on average was 41 days. Muscle strength, either maximum strength or average strength, decreased slightly in T1 and in T2 increased, except in the hamstrings where there is an increase in all evaluations. It was also found that the results are independent of age, sex and history of previous orthopaedic surgery. Conclusion: It is proved that a rehabilitation program that provides the skills needed by people, combining rehabilitation in hospital and at home, it is crucial for a fast and an efficient recovery.


Subject(s)
Humans , Aged , Life Expectancy , Exercise , Osteoarthritis, Hip , Hip
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