Protective effect of statin therapy on connective tissue growth factor induction by diabetes in vivo and high glucose in vitro.

Transcriptional activity of connective tissue growth factor (CTGF) promoter in transfected HEK293 cells was determined by luciferase assays. Secreted CTGF in cultured human mesangial cells was measured by enzyme-linked immunosorbent assay (ELISA). CTGF in urine and plasma was also measured in 405 subjects with/without type 2 diabetes. Our results showed that high glucose significantly increased transcription of the promoter in the transfected cells by more than 2.5-folds (p < 0.0005). CTGF secretion was induced by high glucose in the cells (p < 0.0005). These increases were inhibited by simvastatin. Urine CTGF was positively associated with plasma CTGF in both type 2 diabetes (p = 0.0005) and controls (p = 0.01). Urine CTGF levels in patients with macroalbuminuria were significantly higher than patients without macroalbuminuria (p < 0.05). In conclusion, our in vitro study suggests that statin may have a renal-protective effect through the inhibition of CTGF expression. Urine CTGF may be a good marker for the prediction of diabetic nephropathy.

A predominantly neolithic origin for European paternal lineages.

The relative contributions to modern European populations of Paleolithic hunter-gatherers and Neolithic farmers from the Near East have been intensely debated. Haplogroup R1b1b2 (R-M269) is the commonest European Y-chromosomal lineage, increasing in frequency from east to west, and carried by 110 million European men. Previous studies suggested a Paleolithic origin, but here we show that the geographical distribution of its microsatellite diversity is best explained by spread from a single source in the Near East via Anatolia during the Neolithic. Taken with evidence on the origins of other haplogroups, this indicates that most European Y chromosomes originate in the Neolithic expansion. This reinterpretation makes Europe a prime example of how technological and cultural change is linked with the expansion of a Y-chromosomal lineage, and the contrast of this pattern with that shown by maternally inherited mitochondrial DNA suggests a unique role for males in the transition.

High glucose induction of DNA-binding activity of the transcription factor NFkappaB in patients with diabetic nephropathy.

The aim of this study was to investigate whether high glucose induces aldose reductase (AKR1B1) expression through NFkappaB, which may contribute to the pathogenesis of diabetic nephropathy. 34 Caucasoid patients with type 1 diabetes were recruited; 20 nephropaths and 14 long-term uncomplicated subjects. Peripheral blood mononuclear cells (PBMCs) were cultured under normal or high glucose (25 mmol/l of d-glucose) with or without an aldose reductase inhibitor (ARI). High glucose increased NFkappaB binding activities in the PBMCs from nephropaths compared to the uncomplicated subjects (1.77+/-0.22 vs. 1.16+/-0.04, p=0.02). ARI induced a substantially greater decrease of NFkappaB binding activities in the nephropaths compared to the uncomplicated subjects (0.58+/-0.06 vs. 0.79+/-0.06, p=0.032). AKR1B1 protein levels in the nephropaths were increased under high glucose conditions and decreased in the presence of an ARI, whilst the silencing of the NFkappaB p65 gene in vitro reduced the transcriptional activities of AKR1B1 in luciferase assays. These results show that NFkappaB induces AKR1B1expression under high glucose conditions, and the pattern of expression differs between nephropaths and the uncomplicated subjects.

The SPINK1 N34S variant is associated with acute pancreatitis.

OBJECTIVE: Acute pancreatitis (AP) is a disease whose pathogenesis remains largely obscure. Genetic research has focussed attention upon the role of the pancreatic protease/protease inhibitor system. The aim of this study was to investigate the prevalence of genetic variants of the trypsin inhibitor, SPINK1, in acute pancreatitis. METHODS: We genotyped 468 patients with AP and 1117 healthy controls for SPINK1 alterations by single-strand conformation polymorphism analysis and by melting curve analysis using fluorescence resonance energy transfer probes. RESULTS: The c.101A>G (p.N34S) variant was detected in 24/936 alleles of patients and in 18/2234 alleles of healthy controls (odds ratio=3.240; 95% confidence interval: 1.766-5.945; P<0.001). In the UK patients, the mean age of patients with N34S was 11.9 years younger compared with N34S negative patients (P=0.023), but this was not apparent in the German patients. Allele frequencies for the c.163C>T (p.P55S) variant did not differ between patients and controls. CONCLUSION: The SPINK1 N34S variant is associated with acute pancreatitis. This supports the importance of premature protease activation in the pathogenesis of AP and suggests that mutated SPINK1 may predispose certain individuals to develop this disease.

Endothelial nitric oxide synthase polymorphisms are associated with hypertension and cardiovascular disease in renal transplantation.

AIM: Nitric oxide (NO), produced by the polymorphic endothelial nitric oxide synthase (NOS3), plays an important role in endothelial function. The aim was to determine the effect of NOS3 polymorphisms on hypertension and cardiovascular disease (CVD) in renal allograft recipients. METHODS: Three polymorphisms of NOS3 were examined in 168 renal allograft recipients. A 27 base pair repeat sequence in intron 4 (NOS3 a/b), a single G-->T substitution in exon 7 at nucleotide 894 and a T-786C substitution in the promoter region were studied. RESULTS: Significant differences in the frequencies of the 894T and -786C alleles between allograft recipients and controls (n = 141) were demonstrated (894T: 40.5% vs 30.1%, P < 0.01; -786C: 45.2% vs 34.4%, P < 0.01). There was a significant excess of both the 894T and -786C alleles in hypertensive allograft recipients compared with normotensive allograft recipients and controls (894T: 41.7%, 35.7% and 30.1%, respectively, P < 0.025; -786C: 47.4%, 37.1% and 34.4%, respectively, P < 0.01), and in allograft recipients with CVD compared with those without CVD and controls (894T: 47.2%, 38.6% and 30.1%, respectively, P < 0.025; -786C: 54.2%, 42.8% and 34.4%, respectively, P < 0.01). CONCLUSION: The 894T and -786C alleles of the NOS3 gene were significantly associated with both hypertension and CVD in renal allograft recipients.

Elevated activity of transcription factor nuclear factor of activated T-cells 5 (NFAT5) and diabetic nephropathy.

The expression of aldose reductase is tightly regulated by the transcription factor tonicity response element binding protein (TonEBP/NFAT5) binding to three osmotic response elements (OREs; OREA, OREB, and OREC) in the gene. The aim was to investigate the contribution of NFAT5 to the pathogenesis of diabetic nephropathy. Peripheral blood mononuclear cells (PBMCs) were isolated from the following subjects: 44 Caucasoid patients with type 1 diabetes, of whom 26 had nephropathy and 18 had no nephropathy after a diabetes duration of 20 years, and 13 normal healthy control subjects. In addition, human mesangial cells (HMCs) were isolated from the normal lobe of 10 kidneys following radical nephrectomy for renal cell carcinoma. Nuclear and cytoplasmic proteins were extracted from PBMCs and HMCs and cultured in either normal or high-glucose (31 mmol/l D-glucose) conditions for 5 days. NFAT5 binding activity was quantitated using electrophoretic mobility shift assays for each of the OREs. Western blotting was used to measure aldose reductase and sorbitol dehydrogenase protein levels. There were significant fold increases in DNA binding activities of NFAT5 to OREB (2.06 +/- 0.03 vs. 1.33 +/- 0.18, P = 0.033) and OREC (1.94 +/- 0.21 vs. 1.39 +/- 0.11, P = 0.024) in PBMCs from patients with diabetic nephropathy compared with diabetic control subjects cultured under high glucose. Aldose reductase and sorbitol dehydrogenase protein levels in the patients with diabetic nephropathy were significantly increased in PBMCs cultured in high-glucose conditions. In HMCs cultured under high glucose, there were significant increases in NFAT5 binding activities to OREA, OREB, and OREC by 1.38 +/- 0.22-, 1.84 +/- 0.44-, and 2.38 +/- 1.15-fold, respectively. Similar results were found in HMCs exposed to high glucose (aldose reductase 1.30 +/- 0.06-fold and sorbitol dehydrogenease 1.54 +/- 0.24-fold increases). Finally, the silencing of the NFAT5 gene in vitro reduced the expression of the aldose reductase gene. In conclusion, these results show that aldose reductase is upregulated by the transcriptional factor NFAT5 under high-glucose conditions in both PBMCs and HMCs.

Heat shock factor-1 and nuclear factor-kappaB are systemically activated in human acute pancreatitis.

CONTEXT: Nuclear factor-kappa B (NF-kappaB) is a transcription factor for a wide range of proinflammatory mediators while heat shock factor-1 (HSF-1) transcribes stress proteins that protect against cellular damage. Both are attractive therapeutic targets, undergoing investigation in other acute inflammatory conditions, such as sepsis. OBJECTIVE: To evaluate the role of the transcription factors NF-kappaB and HSF-1 in human acute pancreatitis and their relationship to cytokine/chemokine production, disease severity and outcome. PATIENTS: Twenty-four patients with acute pancreatitis and 12 healthy controls. MAIN OUTCOME MEASURES: Peripheral blood mononuclear cells were isolated. NF-kappaB and HSF-1 were measured by electrophoretic mobility shift assay. Soluble tumor necrosis factor (TNF) receptor II and interleukin-8 were measured by ELISA. Acute physiology scores (APS), APACHE II scores and final Atlanta designations of severity were also determined. RESULTS: Systemic NF-kappaB activation occurs in acute pancreatitis compared to healthy controls (P=0.004). However, there was no significant difference between those with mild and severe disease (P=0.685). Systemic activation of HSF-1 was observed in acute pancreatitis compared to healthy controls although this did not reach statistical significance (P=0.053). Activation, however, was greatest in those who had a final Atlanta designation of mild pancreatitis compared to those who had a severe attack of acute pancreatitis (P=0.036). Furthermore, HSF-1 was inversely correlated with acute physiology score (APS; r=-0.49, P=0.019) and APACHE II score (r=-0.47, P=0.026). CONCLUSIONS: Both NF-kappaB and HSF-1 are systemically activated in human acute pancreatitis. HSF-1 activation may protect against severity of pancreatitis.

The response of antioxidant genes to hyperglycemia is abnormal in patients with type 1 diabetes and diabetic nephropathy.

Increased flux of glucose through the polyol pathway may cause generation of excess reactive oxygen species (ROS), leading to tissue damage. Abnormalities in expression of enzymes that protect against oxidant damage may accentuate the oxidative injury. The expression of catalase (CAT), CuZn superoxide-dismutase (CuZnSOD), glutathione peroxidase (GPX), and Mn superoxide-dismutase (MnSOD) mRNA was quantified in peripheral blood mononuclear cells-obtained from 26 patients with type 1 diabetes and nephropathy, 15 with no microvascular complications after 20 years' duration of diabetes, and 10 normal healthy control subjects-that were exposed in vitro to hyperglycemia (HG) (31 mmol/l D-glucose). Under HG, there was a twofold increase in the expression of CAT, CuZnSOD, and GPX mRNA in the patients without complications and the control subjects versus patients with nephropathy (P < 0.0001), and MnSOD did not change in any of the groups. The aldose reductase inhibitor zopolrestat partially restored the levels of CAT, CuZnSOD, and GPX mRNA in the patients with nephropathy (P < 0.05). There was a highly significant correlation between increased aldose reductase (ALR2) expression, CAT, CuZnSOD, and GPX mRNA levels under HG conditions and polymorphisms of ALR2 in the patients with nephropathy (P < 0.00001). In conclusion, these results suggest that high glucose flux through aldose reductase inhibits the expression of antioxidant enzymes.

Glucose transporter polymorphisms are associated with clear-cell renal carcinoma.

Clear-cell renal cell carcinoma (CCRCC) is identified by abundant glycogen-rich cytoplasm, due to the aberrant influx and storage of glucose. The objective was to investigate the frequency of polymorphisms of the facilitative glucose transporter (GLUT1). GLUT1 is a downstream target of Hypoxia-inducible factor (HIF-1alpha), a mediator of hypoxia-controlled angiogenesis. In this study, we examine the allelic frequency of polymorphisms in the promoter and the second intron of the GLUT1 gene. Genomic DNA was extracted from normal tissue of 92 patients undergoing nephrectomy for CCRCC, and 99 normal cord blood DNA samples were used to provide control frequencies. The regions of DNA encompassing the polymorphisms were amplified and digested with appropriate endonuclases. The products were separated and viewed by gel electrophoresis. There was a highly significant decrease in the A-2841 genotype (P=0.0004) in the promoter region of those patients with CCRCC compared to the control population. There was also a significant decrease in the T+22999 allele in the intron 2 of those patents with CCRCC (P=0.004) compared to the same control population. This study suggests that GLUT1 is one of a number of genes that may increase susceptibility to developing CCRCC.

Cytochrome P450 2E1 high activity polymorphism in alcohol abuse and end-organ disease.

AIM: To investigate a possible role for a recently identified polymorphism in the gene of cytochrome P450 2E1, the presence of which is associated with high activity of the enzyme. METHODS: Two hundred and thirty-nine alcohol consumers, ICD 10.1/.2 (ALC), and 208 normal controls were studied. PCR amplification of the CYP2E1 gene region was performed to assess polymorphic variation. Fisher's exact test was used to assess the data. RESULTS: Twelve normal controls (5.8%) possessed the insertion. Five ALC (2.1%) had the insertion; of these 2 of 144 with alcohol induced chronic pancreatitis, none of 28 with alcoholic liver disease and 3 of 67 without end-organ disease had the polymorphism. A significantly Lower frequency of subjects possessed the insertion than normal controls [P=0.049 (genotype analysis P=0.03)]. To further assess, if there was a relationship to alcohol problems per se or end-organ disease, we compared patients with alcohol induced end-organ disease vs alcoholic controls without end-organ disease vs normal controls which again showed a significant difference [P=0.045 (genotype analysis, P=0.011)], further sub-group analysis did not identify which group(s) accounted for these differences. CONCLUSION: We have shown the frequencies of this high-activity polymorphism in alcohol related patient groups for the first time. The frequency is significantly less in alcoholics than normal controls, as with high activity polymorphisms of alcohol dehydrogenase. The biological significance, and whether the relevance is solely for alcoholism or is there a relationship to end-organ disease, would benefit from the assessment in the populations with a greater frequency of this polymorphism.

Association of the p22phox component of NAD(P)H oxidase with susceptibility to diabetic nephropathy in patients with type 1 diabetes.

OBJECTIVE: Increased production of reactive oxygen species (ROS) in diabetes is thought to play a major role in the pathogenesis of diabetic microvascular complications such as nephropathy and retinopathy. The NAD(P)H oxidase complex is an important source of ROS in the vasculature. The p22 subunit is polymorphic with a C242T variant that changes histidine-72 for a tyrosine in the potential heme binding site, together with a A640G in the 3' untranslated region. The aim was to investigate the frequency of these polymorphisms in 268 patients with type 1 diabetes with or without microvascular complications. RESEARCH DESIGN AND METHODS: There was a highly significant increase in the frequency of the T/T242 genotype in patients with nephropathy compared with those with retinopathy alone or no microvascular disease after 20 years' diabetes duration (uncomplicated) or normal healthy control subjects (33.3 vs. 6.5, 5.7, and 0.0%, respectively, P < 0.000001). Furthermore, the T242/G640 haplotype was found in 39.4% of the patients with nephropathy but in only 26.5% of the patients with retinopathy and 15.3 and 10.6% of the uncomplicated and normal control subjects, respectively. RESULTS: When these variants of NAD(P)H oxidase were analyzed together with aldose reductase (5'ALR2) susceptibility genotypes, >46.0% of the patients with nephropathy possessed a T242 allele with the Z-2 5'ALR2 allele compared with only 11.2% of the uncomplicated patients (P < 0.00003). CONCLUSIONS: In conclusion, these results suggest NAD(P)H oxidase together with the polyol pathway may contribute to the pathogenesis of diabetic nephropathy.

Polymorphisms of the vascular endothelial growth factor and susceptibility to diabetic microvascular complications in patients with type 1 diabetes mellitus.

There is increasing evidence implicating genetic factors in the susceptibility to diabetic microvascular complications. Recent studies suggest that increased expression of the cytokine vascular endothelial growth factor (VEGF) may play a role in the pathogenesis of diabetic complications. A number of polymorphisms in the promoter region of the VEGF gene have been identified. The aim was to investigate whether an 18 base pair (bp) deletion (D)/insertion (I) polymorphism at position -2549 in the promoter region of the VEGF gene is associated with the susceptibility to diabetic microvascular complications. Two hundred and thirty-two patients with type 1 diabetes mellitus (T1DM) and 141 normal healthy controls were studied. The D/D genotype was significantly increased in those patients with nephropathy (n=102) compared to those with no complications after 20 years duration of diabetes (uncomplicated, n=66) (40.2% vs. 22.7%, respectively, chi(2)=5.5, P<.05). The combination of polymorphisms of VEGF together with the aldose reductase (ALR2) gene showed that in the nephropaths, 8 of the 83 subjects had the VEGF I allele together with the Z+2 5'ALR2 allele compared with 27 of the 62 uncomplicated patients (chi(2)=26.7, P<.00001). The functional role of the D/I polymorphism was examined by cloning the region into a luciferase reporter assay system and transient transfection into HepG2 cells. The construct containing the 18 bp deletion had a 1.95-fold increase in transcriptional activity compared with its counterpart that had the insert (P<.01). These results suggest that polymorphisms in the promoter region of the VEGF gene together with the ALR2 may be associated with the pathogenesis of diabetic nephropathy.

p21(WAF1/CIP1) Expression is Differentially Regulated by Metformin and Rapamycin.

The mammalian target of rapamycin (mTOR) pathway plays an important role in the development of diabetic nephropathy and other age-related diseases. One of the features of DN is the elevated expression of p21(WAF1/CIP1). However, the importance of the mTOR signalling pathway in p21 regulation is poorly understood. Here we investigated the effect of metformin and rapamycin on mTOR-related phenotypes in cell lines of epithelial origin. This study reports that metformin inhibits high glucose-induced p21 expression. High glucose opposed metformin in regulating cell size, proliferation, and protein synthesis. These effects were associated with reduced AMPK activation, affecting downstream mTOR signalling. However, the inhibition of the mTOR pathway by rapamycin did not have a negative effect on p21 expression, suggesting that metformin regulates p21 upstream of mTOR. These findings provide support for the hypothesis that AMPK activation may regulate p21 expression, which may have implications for diabetic nephropathy and other age-related pathologies.

Significant correlation between association of polymorphism in codon 10 of transforming growth factor-beta1 T (29) C with type 1 diabetes and patients with nephropathy disorder.

Type 1 diabetes is an autoimmune disease that is caused by destruction of pancreatic beta-cells. Type 1 diabetes is a heterogenic disease with environmental factors as well as genetic components. It is well established that environmental factors can exert their effects only on genetically susceptible patients. There is increasing evidence that genes outside the major histocompatibility complex (MHC) region contribute to the pathogenesis of type 1 diabetes. Cytokines, due to their role in immune regulation, seem to play a crucial role in the pathogenesis of the disease. In order to investigate the immunosuppressive action of transforming growth factor-beta1 (TGF-beta1) in type 1 diabetes, 388 patients with type 1 diabetes and 229 normal controls were genotyped for the TGF-beta1 T (29) C gene polymorphism. The TGF-beta1 T (29) C gene polymorphism was amplified using ARMS-PCR. Practical part of this work was conducted in Molecular Medicine Research Group, Peninsula Medical School, Plymouth, UK. However, statistical analyses were performed in Department of pathology, Salmaniya Medical Complex, Kingdom of Bahrain. From three different genotypes of TT, TC, and CC of the TGF-beta1 T (29) C, the TC frequency increased in patients with type 1 diabetes compared to normal controls, P value = 0.00001. The TC frequency was significantly higher in patients with diabetic nephropathy (DN) in comparison with diabetic control, P value = 0.007. Further, the CC frequency was significantly less in patients compared to healthy normal control subjects, P value = 0.005. Genetic variation at the TGF-beta1 gene polymorphism T (29) C located in codon 10 is likely to confer significant susceptibility to advanced DN in patients with T1D. This is a small case-control study in Caucasians to investigate the role of the TGF-beta1 gene polymorphism T (29) C located in codon 10 in the genetic predisposition to T1D and DN. To our knowledge, this is the first genetic report highlighting the dual effects of TGF-beta1 in the onset of T1D as well as type 1 DN and can be a good model for extensive studies.

Polymorphisms of myo-inositol oxygenase gene are associated with Type 1 diabetes mellitus.

Myo-inositol oxygenase (MIOX) is the first and rate-limiting enzyme in myo-inositol (MI) metabolism pathway. The increase in MIOX enzyme activity is in proportion to serum glucose concentrations and may be responsible for the MI depletion found in the diabetic complications. The aim was to investigate whether single nucleotide polymorphisms (SNPs) in the MIOX gene are associated with Type 1 diabetes mellitus (T1D) and its complications. Four hundred thirty Caucasian patients with T1D were recruited: 172 patients had diabetic nephropathy, 140 had diabetic retinopathy/neuropathy, 118 patients had diabetes for ≥20 years without microvascular complications and 224 were normal controls. Three SNPs, rs761745 (C/T), and rs2232873 (A/G) in the promoter and rs1055271 (C/G) in the 3'-untranslated were genotyped commercially. The frequencies of the CC genotype (0.36 vs. 0.44; P=.034) and C allele (0.60 vs. 0.68; P=.011) of rs761745 were significantly lower in patients with T1D compared with normal controls. Patients with T1D had a decreased frequency of the combination genotypes of CC (rs761745), GG (rs2232873) and GC (rs1055271) compared with the normal controls (0.13 vs. 0.22, P=.0027, Pc=0.014). The haplotypes with C/G/G and C/G/C were less common in patients with T1D compared to normal controls (0.59 vs. 0.70, P=.021) and the haplotypes with T/G/C and T/G/G ware more common in patients with T1D compared to normal controls (0.37 vs. 0.26; P=.021). In summary, our results demonstrated that the polymorphism (rs761745) in the promoter region of MIOX gene may be associated with the development of T1D in our studied population.

Activation of NF-kappaB and MAP kinase cascades by hypothermic stress in endothelial cells.

Signal transduction pathways and transcription factors are likely to be important mediators of stress responses to ischaemia and reperfusion injury following renal transplantation. We have investigated the activation of the transcription factor nuclear factor kappaB (NF-kappaB) and the mitogen activated protein kinases (MAPK), p44/42 (ERK 1/2), p38 and c-Jun N-terminal kinase (JNK) during cold stress at 4 degrees C. Human umbilical vein endothelial cells (HUVECs) were subjected to 72 h of hypothermia in a renal preservation solution. NF-kappaB activation was assessed by electromobility shift assays and MAPK activation by immunoblotting. Cell viability and apoptosis was assessed. Hypothermia activated the NF-kappaB complex, ERK 1/2 and p38 MAPK pathway. There was a 6-fold increase in NF-kappaB in the nucleus within minutes of hypothermia, correlating with p38 (p = 0.01) and ERK 1/2 activation (p = 0.03). A significant relationship was found between ERK 1/2, p38 and NF-kappaB throughout the 72 h time course (p = 0.01). In contrast, hypothermia had no effect on JNK phosphorylation. Inhibition of MAPK with an MEK inhibitor (PD098059) blocked the activation of NF-kappaB but a specific p38 inhibitor (SB203580) had no effect on NF-kappaB. Increased lactate production after 48 h indicated a switch towards anaerobic metabolism during prolonged hypothermia. Endothelial cells had a high viability and no DNA fragmentation throughout the experiment. Activation of stress pathways during organ procurement may be important in the quality of stored grafts.