Glucagon-like peptide-1 and vitamin D: anti-inflammatory response in diabetic kidney disease in db/db mice and in cultured endothelial cells.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) is a gut incretin hormone that stimulates insulin secretion and may affect the inflammatory pathways involved in diabetes mellitus. Calcitriol, an active form of vitamin D, plays an important role in renal, endothelial and cardiovascular protection. We evaluated the anti-inflammatory and histologic effects of a GLP-1 analogue (liraglutide) and of calcitriol in a db/db mouse diabetes model and in endothelial cells exposed to a diabetes-like environment. METHODS: Diabetic db/db mice were treated with liraglutide and calcitriol for 14 weeks, after which the kidneys were perfused and removed for mRNA and protein analysis and histology. Endothelial cells were stimulated with advanced glycation end products (AGEs), glucose, liraglutide and calcitriol. Total RNA and protein were extracted and analysed for the expression of selected inflammatory markers. RESULTS: Typical histological changes, glomerular enlargement and mesangial expansion were seen in db/db mice compared with control mice. Glomerular hypertrophy was ameliorated with liraglutide, compared with db/db controls. Liraglutide up-regulated endothelial nitric oxide synthase protein expression compared with the db/db control group and down-regulated p65 protein expression. Calcitriol did not further improve the beneficial effect observed on protein expression. In endothelial cells, liraglutide treatment exhibited a dose-dependent ability to prevent an inflammatory response in the selected markers: thioredoxin-interacting protein, p65, IL6 and IL8. In most gene and protein expressions, addition of calcitriol did not enhance the effect of liraglutide. CONCLUSIONS: The GLP-1 analogue liraglutide prevented the inflammatory response observed in endothelial cells exposed to a diabetes-like environment and in db/db mice at the level of protein expression and significantly ameliorated the glomerular hypertrophy seen in the diabetic control group. Copyright © 2016 John Wiley & Sons, Ltd.

Kruppel-like factors in an endothelial and vascular smooth muscle cell coculture model: impact of a diabetic environment and vitamin D.

Endothelial cells (EC) and vascular smooth muscle cells (VSMC) are involved in the development of local and diffuse vasculopathies by participating in inflammatory processes that can lead to uncontrolled vascular complications. Our aim was to study the possible interactions of EC and VSMC in an in vitro coculture model exposed to diabetic-like conditions and the effect of vitamin D on cellular pathways that might lead to an inflammatory response. EC and VSMC were isolated from different umbilical cords and stimulated in an in vitro coculture model in a diabetic-like environment and calcitriol for 24 h. Total RNA and protein were extracted from cells and analyzed for the expression of selected inflammatory-related markers. The EC-VSMC coculture in a diabetic-like environment induced the expression of inflammatory markers such as Kruppel-like factors, thioredoxin-interacting protein (TXNIP), IL-6, and IL-8. Addition of vitamin D to the EC-VSMC coculture induced selective changes in the inflammatory response. This model could lead to a better understanding of the interactions between EC and VSMC in the inflammatory processes involved in diabetes and emphasizes the role of vitamin D in the inflammatory response. The use of different donors strengthens the significance of our findings showing that genetic variations do not affect the impact of vitamin D on the expression of inflammatory-related proteins in our model.

Vitamin D manipulates miR-181c, miR-20b and miR-15a in human umbilical vein endothelial cells exposed to a diabetic-like environment.

BACKGROUND: High blood and tissue concentrations of glucose and advanced glycation end-products are believed to play an important role in the development of vascular complications in patients with diabetes mellitus (DM) and chronic kidney disease. MicroRNAs (miRNA) are non-coding RNAs that regulate gene expression in a sequence specific manner. MiRNA are involved in various biological processes and become novel biomarkers, modulators and therapeutic targets for diseases such as cancer, atherosclerosis, and DM. Calcitriol (the active form of vitamin D) may inhibit endothelial proliferation, blunt angiogenesis, and be a cardioprotective agent. Calcitriol deficiency is a risk factor for DM and hypertension. The aim of this project was to study the miRNA microarray expression changes in human umbilical vein endothelial cells (HUVEC) treated in a diabetic-like environment with the addition of calcitriol. METHODS: HUVEC were treated for 24 h with 200 µg/ml human serum albumin (HSA) and 100 mg/dl glucose (control group) or 200 µg/ml AGE-HSA, and 250 mg/dl glucose (diabetic-like environment), and physiological concentrations (10-10 mol/l) of calcitriol. miRNA microarray analysis and real time PCR to validate the miRNA expression profile and mRNA target gene expression were carried out. RESULTS: Compared to control, 31 mature human miRNA were differentially expressed in the presence of a diabetic-like environment. Addition of physiological concentrations of calcitriol revealed 39 differentially expressed mature human miRNA. MiR-181c, miR-15a, miR-20b, miR-411, miR-659, miR-126 and miR-510 were selected for further analysis because they are known to be modified in DM and in other biological disorders. The predicted targets of these miRNA (such as KLF6, KLF9, KLF10, TXNIP and IL8) correspond to molecular and biological processes such as immune and defense responses, signal transduction and regulation of RNA. CONCLUSION: This study identified novel miRNA in the field of diabetic vasculopathy and might provide new information about the effect of vitamin D on gene regulation induced by a diabetic-like environment. New gene targets that are part of the molecular mechanism and the therapeutic treatment in diabetic vasculopathy are highlighted.

[Laparoscopic management of peritoneal dialysis catheters].

INTRODUCTION: Peritoneal dialysis (PD) is one of the established methods for the management of patients with end-stage renal failure. Laparoscopy has been used to assist in the insertion of new catheters as well as for the salvage of malfunctioning peritoneal dialysis catheters (PDC). OBJECTIVES: The purpose of this retrospective study was to review our experience in the utilization of laparoscopy for the management of PDC. METHODS: We reviewed the charts of all consecutive patients who had undergone either a ap-assisted insertion of a PDC utilizing a modified peritoneoscopic Y-TEC [Medigroup, Inc, Oswego, Ill) technique (YT) under direct laparoscopic vision or laparoscopic-assisted procedures for the salvage of a malfunctioning PD catheter. RESULTS: Twenty nine patients had undergone 43 procedures that included the insertion of a new PD catheter using the modified YT technique, YT with simultaneous adhesiolysis and omentectomy; YT with repair of an epigastric hernia, omentectomy, adhesiolysis and repositioning of PDC; and ravage and repositioning of the obstructed PD catheter in all patients who needed repositioning of the catheter, the PDC was fixed with an intraperitoneal suture to the lower anterior abdominal wall. Postoperatively, malfunction of the catheter was found in one patient due to reclotting of PDC caused by oozing as a result of extensive adhesiolysis. One patient needed emergent laparotomy due to small bowel perforation that was missed during a difficult laparoscopic adhesiolysis. CONCLUSIONS: Laparoscopic surgery may be helpfuL for the diagnosis and the management of a malfunctioning PDC. A modified YT technique is safe and may be one of the alternative methods for the placement of a PDC.

Blood pressure values in 8-12 year old children with a history of intrauterine growth retardation.

BACKGROUND: Epidemiological studies have found that intrauterine growth retardation (IUGR) is closely related to hypertension and is associated with a reduced number of nephrons that may be a predisposing factor for the development of hypertension. OBJECTIVES: To determine whether blood pressure levels of children with a history of IUGR are higher than those of children without IUGR. METHODS: Diastolic, systolic and mean arterial blood pressure levels were measured in 64 children aged 8-12 years old with a history of IUGR (mean birth weight 1780 +/- 422 g) and compared with 64 age and gender-matched controls who had a normal birth weight (mean 3134 +/- 594 g). RESULTS: Contrary to previous reports, systolic blood pressure values were significantly lower in the IUGR group compared to the controls (91.6 +/- 11.3 vs. 96.6 +/- 13.9, P = 0.027). There was no difference in diastolic blood pressure values. In the IUGR group, systolic blood pressure correlated significantly with current weight (P < 0.01) and body mass index (P < 0.05), and diastolic blood pressure with weight gain between age 2 and 4 years (P < 0.05). None of the blood pressure values correlated with birth weight. CONCLUSIONS: Children born with IUGR have lower systolic blood pressure levels than matched controls at age 8-12 years. These data indicate that postnatal weight gain in this group has a greater impact on systolic blood pressure than birth weight.

The potential roles of FGF23 and Klotho in the prognosis of renal and cardiovascular diseases.

Fibroblast growth factor (FGF) 23 and Klotho are two factors associated with several metabolic disorders. Similar to humans, accelerated aging processes characterized by chronic vascular disease, bone demineralization, skin atrophy and emphysema have been recognized in FGF23-null mice and Klotho-deficient mice. The role of these factors in the control of mineral metabolism homeostasis have been shown recently, particularly at the level of parathyroid cells and also in modulating active vitamin D production, two phenomena which are relevant in the presence of chronic kidney disease. In addition, the hormonal affect of circulating FGF23 and Klotho proteins on vascular reactivity, either directly on endothelial cell functions or indirectly by modulating the brain endothelin-1-dependent sympathetic nervous system activity, has contributed to understanding their role in the pathophysiology of hypertension and atherosclerotic vasculopathies. Consequently, very recent clinical investigations seem to confirm the involvement of Klotho in modulating the severity and prognosis of human cardiovascular (CV) disorders and longevity. The present review reports data related to the possible interactive effects of Klotho and FGF23 on the prognosis of renal and CV diseases.

Endothelial pro-atherosclerotic response to extracellular diabetic-like environment: possible role of thioredoxin-interacting protein.

BACKGROUND. High blood and tissue concentrations of glucose and advanced glycation end-products (AGEs) are thought to play an important role in the development of vascular diabetic complications. Therefore, the impact of extracellular AGEs and different glucose concentrations was evaluated by studying the gene expressions and the underlying cellular pathways involved in the development of inflammatory pro-atherosclerotic processes observed in cultured endothelial cells. METHODS. Fresh human umbilical vein cord endothelial cells (HUVEC) were treated in the presence of elevated extracellular glucose concentrations (5.5-28 mmol/l) with and without AGE-human serum albumin (HSA). Affymetrix GeneChip(R) Human Gene 1.0 ST arrays were used for gene expression analysis (total 20 chips). Genes of interest were further validated using real-time PCR and western blot techniques. RESULTS. Microarray analysis revealed significant changes in some gene expressions in the presence of the different stimuli, suggesting that different pathways are involved. Six genes were selected for validation as follows: thioredoxin-interacting protein (TXNIP), thioredoxin (TXN), nuclear factor of kappa B (NF-kappaB), interleukin 6 (IL6), interleukin 8 (IL8) and receptor of advanced glycation end-products (RAGE). Interestingly, it was found that the association of AGEs together with the highest pathophysiological concentration of glucose (28 mmol/l) diminished the expression of these specific genes, excluding TXN. CONCLUSIONS. In the present model that mimics a diabetic environment, the relatively short-term experimental conditions used showed an unexpected blunting action of AGEs in the presence of the highest glucose concentration (28 mmol/l). The interactive cellular pathways involved in these processes should be further investigated.

Low extracellular Ca2+: a mediator of endothelial inflammation.

BACKGROUND: Recent studies have suggested that vitamin D and an imbalance in calcium homeostasis may have an impact on the cardiovascular system. The aim of this study was to assess the impact of different concentrations of extracellular Ca(2+) on human umbilical vein cord endothelial cells (HUVEC) by measuring its effect on parameters involved in the pathogenesis of vascular inflammatory responses. METHODS: HUVEC were grown in the 3.5, 4.5 or 5.8 mg/dL concentration of extracellular Ca(2+) for 2-3 weeks. Expression of adhesion molecules was analysed by flow cytometry. Endothelial nitric oxide synthase (eNOS), receptor of advanced glycation end-product (RAGE) and interleukin-6 (IL-6) mRNA expressions were determined by real-time PCR. eNOS, inhibitor kappa Balpha (IkappaBalpha) and phosphorylated IkappaBalpha protein levels by Western blot, eNOS activity by conversion of [(14)C]-arginine to [(14)C]-citrulline, IL-6 and osteoprotegerin (OPG) secretion by ELISA and DNA-binding activity of nuclear factor kappa B (NFkappaB)-p65 were assayed colorimetrically in nuclear extracts. RESULTS: In the presence of low Ca(2+) (3.5 mg/dL), protein expressions and activity of eNOS were diminished, while the protein expressions of intercellular adhesion molecule-1 (ICAM-1), as well as the mRNA expressions of RAGE and IL-6, were elevated. The protein secretions of IL-6 and OPG were also stimulated in low Ca(2+) concentration. At this concentration, the DNA-binding activity of NFkappaB was enhanced, probably due to the decreased level of IkappaBalpha. CONCLUSIONS: These results suggest that lower extracellular ionized Ca(2+) may play a relevant role in modifying endothelial cells functions.

Calcium, parathyroid hormone, and vitamin D: major determinants of chronic pain in hemodialysis patients.

BACKGROUND AND OBJECTIVES: Pain is a frequent complaint of hemodialysis (HD) patients, yet information regarding its causes and frequency is relatively scarce. The aim of this study was to evaluate the frequency and possible causes of chronic pain in patients who are on long-term HD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We prospectively enrolled 100 patients who were undergoing maintenance HD for at least 3 mo. Pain was evaluated using the Brief Pain Inventory. Data collected on each participant included age, gender, ethnic origin, body mass index, smoking habits, time on dialysis, type of blood access, comorbidities, and biochemical and hematologic parameters. RESULTS: The average age was 64.5 yr; the average time on dialysis 40.4 mo. Forty-five patients were male. Thirty-one participants were of Arabic origin. Fifty-three patients had diabetes, 36 of whom had diabetic retinopathy. Although 51 patients experienced chronic pain, only 19.6% described the pain as severe. Musculoskeletal pain, neuropathic pain, and headache were the most prevalent forms of pain. The presence of diabetic retinopathy and neuropathy (but not diabetes per se) and levels of intact parathyroid hormone, calcium, and calcitriol (but not 25-hydroxyvitamin D(3)) differed significantly between those who experienced chronic pain and those who did not. On a logistic regression model, higher serum calcium levels and intact parathyroid hormone levels >250 pg/ml were independently associated with chronic pain, as well as the presence of diabetic retinopathy. Calcitriol had a marginal effect. CONCLUSIONS: Disturbed mineral metabolism is strongly associated with chronic pain in long-term HD patients, along with microangiopathy.

Parathyroid hormone decreases endothelial osteoprotegerin secretion: role of protein kinase A and C.

Parathyroid hormone (PTH), which is elevated in patients with chronic renal failure, has been shown to participate in the development of vascular calcification. Previous studies have demonstrated that PTH may promote endothelial expressions of proinflammatory parameters. On the basis of these data, we evaluated whether PTH may have an impact on endothelial osteoprotegerin (OPG), a vascular-protective factor which may control vascular calcification. Endothelial cells were stimulated with 10(-12) to 10(-10) mol/l PTH. PKC and PKA are the main cellular pathways of PTH. Inhibitors and activators of PKC or PKA were used to determine whether these signaling pathways are involved in the control of endothelial OPG. PTH induced a decrease in OPG secretion and mRNA expression. Treatment of PTH-stimulated cells by calphostin C (PKC inhibitor) induced a further decrease in OPG secretion, while Rp-cAMP (PKA inhibitor) had no additional effect. In nonstimulated cells, a PKC activator significantly stimulated OPG secretion, while a PKA activator was associated with a decline. These effects were blunted in the presence of calphostin C and Rp-cAMP, respectively. An increase in OPG secretion induced by a PKC activator indicates that the basal OPG secretion is mediated through PKC. The decrease induced by a PKA activator, which is similar to the decrease observed with PTH, suggests that the action of PTH on OPG secretion and mRNA expression may be due to the PKA pathway.

[Stents in dialysis vascular access--do they promise improved high quality prolonged access use].

UNLABELLED: The life expectancy of dialysis patients depends, to a large extent, on blood access which provides uninterrupted and efficient treatment. Dialysis access created by a direct anastomosis between artery and vein usually allows normal dialysis for many years. Blood access by a bridge graft between artery and vein functions for a much shorter time and occludes chiefly because of endothelial hyperplasia at the graft vein anastomosis. This type of fistula is created when the veins of the patient are small. During the last few years the dialysis population is increasingly composed of adult and elderly patients suffering from diabetes mellitus, hypertension, dyslipidemias and atheromatous vascular disease so that a relatively large proportion of dialysis accesses are created using a bridge graft. Since we currently do not have the knowledge of how to arrest or delay the processes which lead to access occlusion, attempts are made to implement prophylactic strategies, find stenoses and dilate them before the access fails. Up to date, controlled trials have not succeeded in proving that this method prolongs access use. These trials did not describe the use of stents following dilatation. MATERIALS AND METHODS: Between July 2002 and May 2005, 238 angiographies were performed on blood accesses including 179 angioplasties of stenoses. In sixteen patients a stent was deployed during the angioplasty. RESULTS: In ten patients dialysis was performed using the same access up to the end of the study period, an average of 43 months from the creation of the access. Three patients died with a functioning access and in three the access occluded during the period of followup. DISCUSSION: This study shows that the use of stents following angioplasty of dialysis access stenoses can improve the duration of use of accesses created through grafts.

Calcitriol blunts the deleterious impact of advanced glycation end products on endothelial cells.

Advanced glycation end products (AGEs), which are elevated in diabetic and uremic patients, may induce vascular dysfunctions, and calcitriol may improve the cardiovascular complications. Therefore, we examined whether calcitriol may modify the endothelial response to AGEs stimulation. Knowing the importance of nuclear factor-kappaB in endothelial inflammatory responses, the effect of AGEs and calcitriol on this pathway was also studied. Calcitriol was added to endothelial cells previously incubated with AGE-human serum albumin (HSA). AGE-HSA induced a decrease in endothelial nitric oxide synthase (eNOS) mRNA expression and enzyme activity. Addition of calcitriol to AGE-HSA-treated endothelial cells improved the decreased action of AGEs on the eNOS system. AGE-HSA increased the AGEs receptor mRNA and protein, which were both blunted by calcitriol. The parallel elevation of interleukin-6 mRNA in the presence of AGE-HSA was also blunted by calcitriol. The NF-kappaB-p65 DNA binding activity was enhanced and associated with a decrease in inhibitor kappaBalpha (IkappaBalpha) and an increase in phosphorylated (p)-IkappaBalpha levels. Addition of calcitriol blunted the AGEs-induced elevation of NF-kappaB-p65 DNA binding activity, a phenomenon related to an increased expression of IkappaBalpha. This increase was correlated to declined p-IkappaBalpha levels. The present results support the concept that calcitriol may act as a vascular protective agent counteracting the probable deleterious actions of AGEs on endothelial cell activities.

Parathyroid hormone stimulates the endothelial nitric oxide synthase through protein kinase A and C pathways.

BACKGROUND: Parathyroid hormone (PTH), the major systemic calcium regulating hormone has been implicated in the development of hypertension and the occurrence of uraemic vascular changes. As nitric oxide synthase (NOS) is involved in the production of nitric oxide, and acute PTH effect is characterized by vasodilation, the effect of PTH on the endothelial NOS (eNOS) system was measured in cultured human umbilical cord vein endothelial cells (HUVEC) and the pathways possibly involved were studied. METHODS: The presence of the PTH receptor-1 (PTHR1) on the HUVEC membrane was examined by RT-PCR, immunocytochemistry and western blot. HUVEC were stimulated with 10(-12) to 10(-10) mol/l PTH. The eNOS mRNA expression was established by RT-PCR and the eNOS protein levels were determined by western blot. The eNOS activity was measured by the conversion of [(14)C]arginine to [(14)C]citrulline. RESULTS: PTHR1 has been found to be expressed in HUVEC and its expression is depressed by increasing concentrations of PTH. PTH induced a significant increase in eNOS mRNA (10(-11) mol/l: 1.87 +/- 0.16, P = 0.012; 10(-10) mol/l: 1.96 +/- 0.28, P = 0.007, fold of control), and protein expression. The eNOS activity was also significantly stimulated (10(-11) mol/l: 1139 +/- 203; 10(-10) mol/l: 1323 +/- 216 vs control: 621 +/- 154 cpm/150 mug protein, P < 0.01). The addition of calphostin C (PKC inhibitor) or Rp-cAMP (PKA inhibitor) reduced the eNOS mRNA, protein expression and activity of PTH-stimulated HUVEC. The combined treatment of calphostin C and Rp-cAMP abolished the eNOS protein expression and activity. CONCLUSION: PTH induces an increased activity of the eNOS system; probably both PKA and PKC pathways are involved in this activation. Such data may explain the vasodilation observed after acute treatment with PTH.

Blood-pressure categories in adolescence predict development of hypertension in accordance with the European guidelines.

BACKGROUND: It is estimated that by 2025, >1.5 billion adults worldwide will be hypertensive. Early identification of the population at risk would lead to improved utilization of preventive measures. We aimed to evaluate whether baseline body mass index (BMI) and blood-pressure (BP) values during adolescence (categorized according to the guidelines of the European Society of Hypertension-European Society of Cardiology) are of use in predicting the development of hypertension in young adulthood. METHODS: The study population consisted of 18,513 male regular army personnel who were initially recruited at 16.5 and 19 years of age between 1976 and 1996. The main outcome was the percentage of subjects who developed hypertension (> or =140 systolic and > or =90 diastolic) at ages 26 to 45 years. RESULTS: At baseline, BP categories were: optimal, 5961 (32.2%); normal, 7998 (43.2%); and high normal, 4554 (24.6%). Moreover, 1377 (7.4%) were overweight (BMI 25-30 kg/m(2)), and 199 (1.1%) were obese (BMI >30 kg/m(2)). At follow-up, 2277 (12.3%) subjects developed hypertension. The percentages progressing to hypertension were 9.46%, 11.99%, and 16.56% for optimal, normal, and high-normal categories, respectively (P < .01). Odds ratios (OR) for the development of hypertension in the normal and high-normal categories versus optimal were 1.30 (95% confidence interval [CI], 1.22-1.39) and 1.79 (95% CI, 1.67-1.93), respectively, adjusted for age and BMI. The ORs for hypertension in overweight and obese versus normal BMI were 1.75 (95% CI, 1.66-1.86) and 3.75 (95% CI, 3.45-4.07), adjusted for age and BP. Of 9762 remaining at ideal BMI at follow-up, the percentages progressing to hypertension were 5.3%, 6.4%, and 9.5% for optimal, normal, and high normal (at baseline) (P < .01). CONCLUSIONS: The risk of developing hypertension in young adulthood may be predicted by BP categories and BMI at adolescence.

Additive renoprotective effect of candesartan and tetrahydrobiopterin in rats after 5/6 nephrectomy.

BACKGROUND: Chronic treatment with candesartan cilexetil (C) improves the outcome of rats after 5/6 nephrectomy (Nx). Tetrahydrobiopterin (BH4), an essential cofactor for appropriate endothelial nitric oxide synthase (eNOS) activity, prevents an increase in blood pressure (BP) in Nx rats when given immediately after surgery. In the present study, we evaluated the renoprotective effect of a combined treatment. METHODS: Five groups of rats were studied: SHAM (sham-operated rats, n=12); SNx (untreated 5/6 nephrectomized rats, n=15); C (SNx rats treated with candesartan cilexetil, 5 mg/kg/day per os, n=11); C+BH4 (SNx rats treated with candesartan cilexetil and BH4, 10 mg/kg/day intraperitoneally, n=11); and BH4 (SNx rats treated with BH4, 10 mg/kg/day intraperitoneally, n=11). Treatment began 30 days after surgery, when hypertension and renal insufficiency have developed. This day was considered as day 1 of treatment for statistical comparisons. The study was continued until 50% mortality was achieved in the SNx rats (4 months after surgery). RESULTS: The survival rates were 100% for SHAM, 47% for SNx, 50% for BH4, 64% for C and 80% for C+BH4 (P<0.05 vs all). Untreated Nx rats developed hypertension, proteinuria (UP) and severe renal insufficiency. Mortality was associated with a lower renal function and increased urine protein excretion. In C and C+BH4 rats, systolic blood pressure (SBP) decreased significantly. BH4 alone had a mild non-significant effect on SBP. C and C+BH4 treatments attenuated significantly the increase in proteinuria found in SNx animals. The weight of the remnant kidneys as well as the severity of glomerulosclerosis were significantly lower in the C+BH4 rats. CONCLUSION: This study shows that in subnephrectomized rats, addition of BH4 to a treatment with candesartan had an additive renoprotective effect. The mechanism of such action may include a better control of BP associated with a blockade of actions of angiotensin II (Ag II), an improvement in nitric oxide synthesis and a balanced redox.

Halofuginone reduces the occurrence of renal fibrosis in 5/6 nephrectomized rats.

BACKGROUND: Halofuginone is a novel antifibrotic agent that can reverse the fibrotic process by specific inhibition of collagen type I synthesis. OBJECTIVES: To evaluate the effect of Halo on the development of glomerulosclerosis and interstitial fibrosis in the 5/6 nephrectomy rat model METHODS: Male Wistar rats were assigned to undergo 5/6 NX or sham operation, and then divided into three groups: 5/6 NX rats (NX-Halo and NX-Control) and sham. Systolic blood pressure, proteinuria and body weight were determined every 2 weeks. At sacrifice (10 weeks) creatinine clearance was evaluated and remnant kidneys removed for histologic examination, sirius red staining and in situ hybridization RESULTS: Systolic blood pressure increased progressively in both 5/6 NX groups. Halo slowed the increase in proteinuria in 5/6 NX rats. As expected, creatinine clearance was lower in 5/6 NX groups when compared to sham rats. Creatinine clearance was significantly higher in the NX-Halo group at the end of the study period. Histologic examination by light microscopy showed significantly less severe interstitial fibrosis and glomerulosclerosis in Halo-treated rats. The increase in collagen alpha1 (I) gene expression and collagen staining after nephrectomy was almost completely abolished by Halo. CONCLUSIONS: Halofuginone reduced proteinuria as well as the severity of interstitial fibrosis and glomerulosclerosis in 5/6 NX rats. The renal beneficial effect of Halo was also demonstrated by the blunted decrease in creatinine clearance observed in the treated animals.

Parathyroid hormone stimulates endothelial expression of atherosclerotic parameters through protein kinase pathways.

Parathyroid hormone (PTH), the major systemic calcium-regulating hormone, has been linked to uremic vascular changes. Considering the possible deleterious action of PTH on vascular structures, it seemed logical to evaluate the impact of PTH on the receptor of advanced glycation end products (RAGE) and interleukin 6 (IL-6) mRNA and protein expression, taking into account that such parameters might be involved in the pathogenesis of vascular calcification, atherosclerosis, and/or arteriolosclerosis. Human umbilical vein cord endothelial cells (HUVEC) were stimulated for 24 h with 10(-12)-10(-10) mol/l PTH. The mRNA expression of RAGE and IL-6 was established by reverse transcriptase/PCR techniques. RAGE protein levels were determined by Western blot and IL-6 secretion was measured by ELISA. The pathways by which PTH may have an effect on HUVEC functions were evaluated. PTH (10(-11)-10(-10)mol/l) significantly increased RAGE mRNA and protein expression. PTH also significantly increased IL-6 mRNA expression without changes at protein levels. The addition of protein kinase (PKC or PKA) inhibitors or nitric oxide (NO) synthase inhibitors significantly reduced the RAGE and IL-6 mRNA expression and the RAGE protein expression. PTH stimulates the mRNA expressions of RAGE and IL-6 and the protein expression of RAGE. These stimulatory effects are probably through PKC and PKA pathways and are also NO dependent. Such data may explain the possible impact of PTH on the atherosclerotic and arteriosclerotic progression.

Prehypertension and obesity in adolescents: a population study.

BACKGROUND: Current blood pressure (BP) classification is based on the recent recommendations of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC-7) and the 2003 European Society of Hypertension-European Society of Cardiology Guidelines for the Management of Arterial Hypertension. The JNC-7 introduced a new concept, prehypertension, and recommended health-promoting lifestyle modifications for these individuals. Obesity is also recognized as a major risk factor for the development of hypertension. We aimed to determine the prevalence of hypertension and obesity in a large cohort of adolescents and to assess whether prehypertension and body mass index (BMI) increase with increasing age. METHODS: A cross-sectional population-based study was performed using data collected during 1996 to 2002 in an army recruitment examination of 560,588 Israeli individuals 16.5 to 19 years of age. The subjects were divided according to gender and stratified by increasing 6-month intervals into five groups. Prehypertension was defined as BP 120 to 139 / 80 to 89 mm Hg. Overweight was defined as BMI 25 to < or = 30 and obesity as BMI >30 kg/m2. RESULTS: Mean systolic BP (SBP) and diastolic BP (DBP) were significantly higher in male subjects for all groups. By applying the JNC-7 criteria, 56.8% of male subjects and 35.8% of female subjects would be considered prehypertensive. There was a statistically significant increase in the mean SBP and DBP with age and BMI. Among male subjects 10.9% were overweight and 3.3% were obese; among female subjects, 11.1% were overweight and 3.2% were obese. The BMI did not increase with increasing age. The prevalence of prehypertension was significantly higher in obese subjects. CONCLUSIONS: Prehypertension is very common among Israeli adolescents. A substantial number of adolescents exhibit a BMI greater than normal. As both of these factors are known to be asssociated with increased cardiovascular risk, early institution of healthful lifestyle changes in a large proportion of this age group is recommended.

Advanced glycation end products stimulate tumor necrosis factor-alpha and interleukin-1 beta secretion by peritoneal macrophages in patients on continuous ambulatory peritoneal dialysis.

BACKGROUND: Advanced glycation end products, formed by the non-enzymatic glycation of proteins with reducing sugars, are thought to play a pathogenetic role in the vascular complications of diabetes, uremia and atherosclerosis. 132-microglobulin is a major constituent of amyloid fibrils in dialysis-related amyloidosis. AGE1-modified beta2m has been found in amyloid deposits of long-term hemodialysis patients. AGE-modified 132m has also been shown to enhance chemotaxis and increase tumor necrosis factor-alpha and interleukin-1 beta secretion by circulating and tissue monocytes/macrophages. OBJECTIVES: To investigate the effect of AGE-modified 132m and AGE-human serum albumin on TNF-alpha and IL-1beta secretion by human peritoneal macrophages derived from patients on continuous ambulatory peritoneal dialysis. METHODS: Human PMO were isolated from peritoneal dialysis effluent of stable CAPD patients and were incubated for 24 hours with AGE-modified beta2m, beta2m, AGE-HSA, HSA or lipopolysaccharide. TNF-alpha or IL-1beta secretion was measured by enzyme-linked immunosorbent assay in cell-free culture supernatants. RESULTS: Both AGE-modified beta2m and AGE-HSA significantly increased TNF-alpha and IL-1beta secretion by human PMO in a dose-dependent manner (50-200 microg/ml). In contrast, beta2m or HSA had no such stimulatory effect on TNF-alpha secretion but had a small significant increase in IL-1beta secretion. CONCLUSIONS: AGE-modified beta2m promotes in vitro TNF-alpha and IL-13 secretion by human PMO of CAPD patients. Activation of these macrophages by AGE-modified beta2m may be a contributory factor to the morphologic changes and altered permeability of the peritoneal membrane in long-term CAPD.