Low-Chloride Diet Prevents the Development of Arterial Hypertension and Protects Kidney Function in Angiotensin II-Infused Mice.

INTRODUCTION: A comprehensive pathophysiological mechanism to explain the relationship between high-salt intake and hypertension remains undefined. Evidence suggests that chloride, as the accompanying anion of sodium in dietary salt, is necessary to develop hypertension. We evaluated whether reducing dietary Cl- while keeping a standard Na+ intake modified blood pressure, cardiac hypertrophy, renal function, and vascular contractility after angiotensin II (AngII) infusion. METHODS: C56BL/6J mice fed with standard Cl- diet or a low-Cl- diet (equimolar substitution of Cl- by a mixture of Na+ salts, both diets with standard Na+ content) received AngII (infusion of 1.5 mg/kg/day) or vehicle for 14 days. We measured systolic blood pressure (SBP), glomerular filtration rate (GFR), natriuretic response to acute saline load, and contractility of aortic rings from mice infused with vehicle and AngII, in standard and low-Cl- diet. RESULTS: The mice fed the standard diet presented increased SBP and cardiac hypertrophy after AngII infusion. In contrast, low-Cl- diet prevented the increase of SBP and cardiac hypertrophy. AngII-infused mice fed a standard diet presented hampered natriuretic response to saline load, meanwhile the low-Cl- diet preserved natriuretic response in AngII-infused mice, without change in GFR. Aortic rings from mice fed with standard diet or low-Cl- diet and infused with AngII presented a similar contractile response. CONCLUSION: We conclude that the reduction in dietary Cl- as the accompanying anion of sodium in salt is protective from AngII pro-hypertensive actions due to a beneficial effect on kidney function and preserved natriuresis.

Glutathione S-Transferase and Clusterin, New Players in the Ischemic Preconditioning Renal Protection in a Murine Model of Ischemia and Reperfusion.

BACKGROUND/AIMS: Renal ischemia and reperfusion injury (IRI) involves oxidative stress, disruption of microvasculature due to endothelial cell damage, loss of epithelial cell polarity secondary to cytoskeletal alterations, inflammation, and the subsequent transition into a mesenchymal phenotype. Ischemic preconditioning (IPC) has been proposed as a therapeutic strategy to avoid/ameliorate the IRI. Since previous results showed that IPC could have differential effects in kidney cortex vs. kidney medulla, in the present study we analyzed the effectiveness and molecular mechanisms implicated in IPC in both kidney regions. METHODS: We evaluated 3 experimental groups of BALB/c male mice: control (sham surgery); renal ischemia (30 min) by bilateral occlusion of the renal pedicle and reperfusion (48 hours) (I/R); and renal IPC (two cycles of 5 min of ischemia and 5 min of reperfusion) applied just before I/R. Acute kidney injury was evaluated by glomerular filtration rate (GFR), Neutrophil Gelatinase-Associated Lipocalin (NGAL) blood level, and histologic analysis. Oxidative stress was studied measurement the Glutathione S-Transferase (GST) activity, GSH/GSSG ratio, and lipoperoxidation levels. Inflammatory mediators (IL-1ß, IL-6, Foxp3, and IL-10) were quantified by qRT-PCR. The endothelial (PECAM-1), epithelial (AQP-1), mesenchymal (Vimentin, Fascin, and Hsp47), iNOS, clusterin, and Hsp27 expression were evaluated (qRT-PCR and/or Western blot). RESULTS: The IPC protocol prevented the decrease of GFR, reduced the plasma NGAL, and ameliorated morphological damage in the kidney cortex after I/R. The IPC also prevented the downregulation of GST activity, lipoperoxidation and ameliorated the oxidized glutathione. In addition, IPC prevented the upregulation of vimentin, fascin, and Hsp47, which was associated with the prevention of the downregulation of AQP1 after I/R. The protective effect of IPC was associated with the upregulation of Hsp27, Foxp3, and IL-10 expression in the renal cortex. However, the upregulation of iNOS, IL-1ß, IL-6, and clusterin by I/R were not modified by IPC. CONCLUSION: IPC conferred better protection in the kidney cortex as compared to the kidney medulla. The protective effect of IPC was associated with amelioration of oxidative stress, tubular damage, and the induction of markers of Treg lymphocytes activity in the cortical region. Further studies are needed to evaluate if lower tubular cell stress/damage after I/R may explain the preferential induction of Treg response in the kidney cortex induced by IPC.

l-NIL prevents the ischemia and reperfusion injury involving TLR-4, GST, clusterin, and NFAT-5 in mice.

On renal ischemia-reperfusion (I/R) injury, recruitment of neutrophils during the inflammatory process promotes local generation of oxygen and nitrogen reactive species, which, in turn, are likely to exacerbate tissue damage. The mechanism by which inducible nitric oxide synthase (iNOS) is involved in I/R has not been elucidated. In this work, the selective iNOS inhibitor l- N6-(1-iminoethyl)lysine (l-NIL) and the NOS substrate l-arginine were employed to understand the role of NOS activity on the expression of particular target genes and the oxidative stress elicited after a 30-min of bilateral renal ischemia, followed by 48-h reperfusion in Balb/c mice. The main findings of the present study were that pharmacological inhibition of iNOS with l-NIL during an I/R challenge of mice kidney decreased renal injury, prevented tissue loss of integrity, and improved renal function. Several novel findings regarding the molecular mechanism by which iNOS inhibition led to these protective effects are as follows: 1) a prevention of the I/R-related increase in expression of Toll-like receptor 4 (TLR-4), and its downstream target, IL-1ß; 2) reduced oxidative stress following the I/R challenge; noteworthy, this study shows the first evidence of glutathione S-transferase (GST) inactivation following kidney I/R, a phenomenon fully prevented by iNOS inhibition; 3) increased expression of clusterin, a survival autophagy component; and 4) increased expression of nuclear factor of activated T cells 5 (NFAT-5) and its target gene aquaporin-1. In conclusion, prevention of renal damage following I/R by the pharmacological inhibition of iNOS with l-NIL was associated with the inactivation of proinflammatory pathway triggered by TLR-4, oxidative stress, renoprotection (autophagy inactivation), and NFAT-5 signaling pathway.

High prevalence of undiagnosed liver cirrhosis and advanced fibrosis in type 2 diabetic patients.

UNLABELLED:  Background. Patients with type 2 diabetes mellitus (T2DM) are at risk for developing end-stage liver disease due to nonalcoholic steatohepatitis (NASH), the aggressive form of non-alcoholic fatty liver disease (NAFLD). Data on prevalence of advanced fibrosis among T2DM patients is scarce. AIM: To evaluate prevalence of steatosis, advanced fibrosis and cirrhosis using non-invasive methods in T2DM patients. MATERIAL AND METHODS: 145 consecutive T2DM patients (> 55 years-old) were prospectively recruited. Presence of cirrhosis and advanced fibrosis was evaluated by magnetic resonance imaging (MRI) and NAFLD fibrosis score (NFS) respectively. Exclusion criteria included significant alcohol consumption, markers of viral hepatitis infection or other liver diseases. Results are expressed in percentage or median (interquartile range). RESULTS: 52.6% of patients were women, the median age was 60 years old (57-64), mean BMI was 29.6 ± 4.7 kg/m2 and diabetes duration was 7.6 ± 6.9 years. A high prevalence of liver steatosis (63.9%), advanced fibrosis assessed by NFS (12.8%) and evidence of liver cirrhosis in MRI (6.0%) was observed. In a multivariate analysis GGT > 82 IU/L (P = 0.004) and no alcohol intake (P = 0.032) were independently associated to advanced fibrosis. CONCLUSION: A high frequency of undiagnosed advanced fibrosis and cirrhosis was observed in non-selected T2DM patients. Screening of these conditions may be warranted in this patient population.

Effect of cholecystectomy on bile acid synthesis and circulating levels of fibroblast growth factor 19.

UNLABELLED: Background and rationale for the study. FGF19/15 is a gut-derived hormone presumably governing bile acid (BA) synthesis and gallbladder (GB) refilling. FGF19 mRNA is present in human GB cholangiocytes (hGBECs); however, the physiological significance of GB-derived FGF19 remains unknown. We investigated whether hGBECs secrete FGF19 and the effects of cholecystectomy on serum FGF19 ([FGF19]s) and BA synthesis. MATERIAL AND METHODS: FGF19 expression was assessed by qRT-PCRs and immunostaining in hGBECs and terminal ileum, and quantified in bile and serum by ELISA. Basal and BA (chenodexycholic acid, CDCA) induced FGF19 expression and secretion was analyzed in primary cultured hGBECs and GB-d1 cell line. Pre and postprandial serum changes in [FGF19]s, 7α-hydroxy-4-cholestene-3-one (C4, a marker of BA synthesis) and BA were evaluated in plasma of gallstone disease patients at baseline and after cholecystectomy. RESULTS: FGF19 mRNA levels were ~250-fold higher in hGBECs compared to distal ileum. GB bile contained ~23-fold higher FGF19 levels compared to serum (p < 0.0001). CDCA induced dose-dependent expression and secretion of FGF19 in hGBECs and GB-d1 cells. Cholecystectomy increased plasma BA synthesis ≥ 2-fold (p < 0.0001), and altered the diurnal rhythm and significantly reduced [FGF19]s noon peak. BA serum levels, serum cholesterol and triglyceride content remained unchanged. CONCLUSIONS: In conclusion human GB cholangiocytes constitutively express and secrete high levels of FGF19 in a process regulated by BA. Resection of this organ doubles BA synthesis concomitantly with changes in [FGF19]s. These findings suggest a potential connection between GB cholangiocytes-derived FGF19 and BA metabolism that could lead to metabolic dysregulation following cholecystectomy.

[Quantification of visceral adipose tissue using magnetic resonance imaging compared with anthropometry, in type 2 diabetic patients]. / Medición volumétrica de grasa visceral abdominal con resonancia magnética y su relación con antropometría, en una población diabética.

BACKGROUND: Visceral fat accumulation is associated with the development of metabolic diseases. Anthropometry is one of the methods used to quantify it. AIM: to evaluate the relationship between visceral adipose tissue volume (VAT), measured with magnetic resonance imaging (MRI), and anthropometric indexes, such as body mass index (BMI) and waist circumference (WC), in type 2 diabetic patients (DM2). PATIENTS AND METHODS: Twenty four type 2 diabetic patients aged 55 to 78 years (15 females) and weighting 61.5 to 97 kg, were included. The patients underwent MRI examination on a Philips Intera® 1.5T MR scanner. The MRI protocol included a spectral excitation sequence centered at the fat peak. The field of view included from L4-L5 to the diaphragmatic border. VAT was measured using the software Image J®. Weight, height, BMI, WC and body fat percentage (BF%), derived from the measurement of four skinfolds with the equation of Durnin and Womersley, were also measured. The association between MRIVAT measurement and anthropometry was evaluated using the Pearson's correlation coefficient. RESULTS: Mean VAT was 2478 ± 758 ml, mean BMI29.5 ± 4.7 kg/m², and mean WC was 100 ± 9.7 cm. There was a poor correlation between VAT, BMI (r = 0.18) and WC (r = 0.56). CONCLUSIONS: BMI and WC are inaccurate predictors of VAT volume in type 2 diabetic patients.

Aminoguanidine Prevents the Oxidative Stress, Inhibiting Elements of Inflammation, Endothelial Activation, Mesenchymal Markers, and Confers a Renoprotective Effect in Renal Ischemia and Reperfusion Injury.

Oxidative stress produces macromolecules dysfunction and cellular damage. Renal ischemia-reperfusion injury (IRI) induces oxidative stress, inflammation, epithelium and endothelium damage, and cessation of renal function. The IRI is an inevitable process during kidney transplantation. Preliminary studies suggest that aminoguanidine (AG) is an antioxidant compound. In this study, we investigated the antioxidant effects of AG (50 mg/kg, intraperitoneal) and its association with molecular pathways activated by IRI (30 min/48 h) in the kidney. The antioxidant effect of AG was studied measuring GSSH/GSSG ratio, GST activity, lipoperoxidation, iNOS, and Hsp27 levels. In addition, we examined the effect of AG on elements associated with cell survival, inflammation, endothelium, and mesenchymal transition during IRI. AG prevented lipid peroxidation, increased GSH levels, and recovered the GST activity impaired by IRI. AG was associated with inhibition of iNOS, Hsp27, endothelial activation (VE-cadherin, PECAM), mesenchymal markers (vimentin, fascin, and HSP47), and inflammation (IL-1ß, IL-6, Foxp3, and IL-10) upregulation. In addition, AG reduced kidney injury (NGAL, clusterin, Arg-2, and TFG-ß1) and improved kidney function (glomerular filtration rate) during IRI. In conclusion, we found new evidence of the antioxidant properties of AG as a renoprotective compound during IRI. Therefore, AG is a promising compound to treat the deleterious effect of renal IRI.

Periodontal inflammation correlates with systemic inflammation and insulin resistance in patients with recent diagnosis of type 2 diabetes / La inflamación periodontal se correlaciona con la inflamación sistémica y la insulina. resistencia en pacientes con diagnóstico reciente de diabetes tipo 2

Background: diabetes and periodontitis are common comorbidities; however, the clinical implications of this association remain only partially known. This study was aimed to characterize the periodontal status of type 2 diabetic (T2D) patients and its correlation with metabolic and inflammatory parameters. Methods: patients (n = 30) with 5 or less years since the diagnosis of T2D (18 ­ 65 years old) were recruited. Anthropometric (Body Mass Index, BMI), metabolic (fasting glucose, glycated hemoglobin, insulin, HOMA-IR, HDL, LDL and total cholesterol, triglycerides) and inflammatory parameters (ultrasensitive C reactive protein, usCRP) were quantified. Periodontal evaluation included clinical attachment level (CAL), probing depth (PD), gingival level (GL) and bleeding on probing (BOP) average. Statistical significance was assessed by Mann-Whitney and Spearman correlation tests. Results: mean values of BOP, CAL, PD and GL were 39.3, 2.8, 2.8, and 0.1, respectively. BOP significantly correlated with BMI and HOMA-IR and was higher in patients with elevated usCRP >3 mg/L (p<0.05). Age and duration of T2D directly and inversely correlated with CAL and GL, respectively. BOP correlated with HOMA-IR and usCRP but not with patients´age, duration of T2D or BMI. Conclusions: in patients with recent diagnosis of T2D, BOP is associated with usCRP and HOMA-IR levels, suggesting that periodontal inflammation promotes insulin resistance possibly by increasing systemic inflammation. (AU)

Antecedentes: la diabetes y la periodontitis son comorbilidades comunes; sin embargo, las implicaciones clínicas de esta asociación siguen siendo solo parcialmente conocidas. El objetivo de este estudio fue caracterizar el estado periodontal de los pacientes con diabetes tipo 2 (T2D) y su correlación con los parámetros metabólicos e inflamatorios. Métodos: se reclutaron pacientes (n = 30) con 5 años o menos desde el diagnóstico de DM2 (18-65 años). Se cuantificaron parámetros antropométricos (índice de masa corporal, IMC), metabólicos (glucosa en ayunas, hemoglobina glucosilada, insulina, HOMA-IR, HDL, LDL y colesterol total, triglicéridos) y parámetros inflamatorios (proteína reactiva C ultrasensible, usCRP). La evaluación periodontal incluyó el nivel de inserción clínica (CAL), la profundidad de sondaje (PD), el nivel gingival (GL) y el promedio de sangrado al sondaje (BOP). La significación estadística se evaluó mediante pruebas de correlación de Mann-Whitney y Spearman. Resultados: los valores medios de BOP, CAL, PD y GL fueron 39.3, 2.8, 2.8 y 0.1, respectivamente. La BOP se correlacionó significativamente con el IMC y el HOMA-IR y fue mayor en pacientes con una usCRP elevada> 3 mg / L (p <0.05). La edad y la duración de T2D se correlacionaron directa e inversamente con CAL y GL, respectivamente. La BOP se correlacionó con HOMA-IR y usCRP pero no con la edad de los pacientes, la duración de T2D o IMC. Conclusiones: en pacientes con diagnóstico reciente de T2D, la BOP está asociada con los niveles de usCRP y HOMA-IR, lo que sugiere que la inflamación periodontal promueve la resistencia a la insulina posiblemente al aumentar la inflamación sistémica. (AU)

Medición volumétrica de grasa visceral abdominal con resonancia magnética y su relación con antropometría, en una población diabética / Quantification of visceral adipose tissue using magnetic resonance imaging compared with anthropometry, in type 2 diabetic patients

Background: Visceral fat accumulation is associated with the development of metabolic diseases. Anthropometry is one of the methods used to quantify it. aim: to evaluate the relationship between visceral adipose tissue volume (VAT), measured with magnetic resonance imaging (MRI), and anthropometric indexes, such as body mass index (BMI) and waist circumference (WC), in type 2 diabetic patients (DM2). Patients and Methods: Twenty four type 2 diabetic patients aged 55 to 78 years (15 females) and weighting 61.5 to 97 kg, were included. The patients underwent MRI examination on a Philips Intera® 1.5T MR scanner. The MRI protocol included a spectral excitation sequence centered at the fat peak. The field of view included from L4-L5 to the diaphragmatic border. VAT was measured using the software Image J®. Weight, height, BMI, WC and body fat percentage (BF%), derived from the measurement offour skinfolds with the equation of Durnin and Womersley, were also measured. The association between MRIVAT measurement and anthropometry was evaluated using the Pearson's correlation coefficient. Results: Mean VAT was 2478 ± 758 ml, mean BMI29.5 ± 4.7 kg/m², and mean WC was 100 ± 9.7 cm. There was a poor correlation between VAT, BMI (r = 0.18) and WC (r = 0.56). Conclusions: BMI and WC are inaccurate predictors of VAT volume in type 2 diabetic patients.