Gene expression analysis in calcific tendinopathy of the rotator cuff.

We evaluated the expression of several genes involved in tissue remodelling and bone development in patients with calcific tendinopathy of the rotator cuff. Biopsies from calcified and non-calcified areas were obtained from 10 patients (8 women and 2 men; average age: 55 years; range: 40-68) with calcific tendinopathy of the rotator cuff. To evaluate the expression of selected genes, RNA extraction, cDNA synthesis and quantitative polymerase chain reaction (PCR) were performed. A significantly increased expression of tissue transglutaminase (tTG)2 and its substrate, osteopontin, was detected in the calcific areas compared to the levels observed in the normal tissue from the same subject with calcific tendinopathy, whereas a modest increase was observed for catepsin K. There was also a significant decrease in mRNA expression of Bone Morphogenetic Protein (BMP)4 and BMP6 in the calcific area. BMP-2, collagen V and vascular endothelial growth factor (VEGF) did not show significant differences. Collagen X and matrix metalloproteinase (MMP)-9 were not detectable. A variation in expression of these genes could be characteristic of this form tendinopathy, since an increased level of these genes has not been detected in other forms of tendon lesions.

Coeliac disease-associated risk variants in TNFAIP3 and REL implicate altered NF-kappaB signalling.

OBJECTIVE: Our previous coeliac disease genome-wide association study (GWAS) implicated risk variants in the human leucocyte antigen (HLA) region and eight novel risk regions. To identify more coeliac disease loci, we selected 458 single nucleotide polymorphisms (SNPs) that showed more modest association in the GWAS for genotyping and analysis in four independent cohorts. DESIGN: 458 SNPs were assayed in 1682 cases and 3258 controls from three populations (UK, Irish and Dutch). We combined the results with the original GWAS cohort (767 UK cases and 1422 controls); six SNPs showed association with p<1 x 10(-04) and were then genotyped in an independent Italian coeliac cohort (538 cases and 593 controls). RESULTS: We identified two novel coeliac disease risk regions: 6q23.3 (OLIG3-TNFAIP3) and 2p16.1 (REL), both of which reached genome-wide significance in the combined analysis of all 2987 cases and 5273 controls (rs2327832 p = 1.3 x 10(-08), and rs842647 p = 5.2 x 10(-07)). We investigated the expression of these genes in the RNA isolated from biopsies and from whole blood RNA. We did not observe any changes in gene expression, nor in the correlation of genotype with gene expression. CONCLUSIONS: Both TNFAIP3 (A20, at the protein level) and REL are key mediators in the nuclear factor kappa B (NF-kappaB) inflammatory signalling pathway. For the first time, a role for primary heritable variation in this important biological pathway predisposing to coeliac disease has been identified. Currently, the HLA risk factors and the 10 established non-HLA risk factors explain approximately 40% of the heritability of coeliac disease.

Six new coeliac disease loci replicated in an Italian population confirm association with coeliac disease.

BACKGROUND AND AIMS: The first genome wide association study on coeliac disease (CD) and its follow-up have identified eight new loci that contribute significantly towards CD risk. Seven of these loci contain genes controlling adaptive immune responses, including IL2/IL21 (4q27), RGS1 (1q31), IL18RAP (2q11-2q12), CCR3 (3p21), IL12A (3q25-3q26), TAGAP (6q25) and SH2B3 (12q24). METHODS: We selected the nine most associated single nucleotide polymorphisms to tag the eight new loci in an Italian cohort comprising 538 CD patients and 593 healthy controls. RESULTS: Common variation in IL2/IL21, RGS1, IL12A/SCHIP and SH2B3 was associated with susceptibility to CD in our Italian cohort. The LPP and TAGAP regions also showed moderate association, whereas there was no association with CCR3 and IL18RAP. CONCLUSION: This is the first replication study of six of the eight new CD loci; it is also the first CD association study in a southern European cohort. Our results may imply there is a genuine population difference across Europe regarding the loci contributing to CD.

Genomic organization and transcription of the human retinol dehydrogenase 10 (RDH10) gene.

A cDNA clone up-regulated in hydraulic lung edema in rabbit showed high similarity with human RDH10 mRNA, which encodes a protein involved in retinoic acid metabolism. We defined the organization of the human gene, which includes a unique transcriptional start site, a coding region with six translated exons and a 3' untranslated region containing at least two used polyadenylation sites. The two poly(A) signals are responsible for the production of the 3 and 4 kb RDH10 mRNA isoforms detected in several human tissues and cell lines.

Duodenal expression of a putative stimulator of Fe transport and transferrin receptor in anemia and hemochromatosis.

BACKGROUND & AIMS: Stimulator of Fe Transport (SFT) and transferrin receptor (TfR) are proteins involved in iron transport. This study evaluated iron metabolism protein expression in duodenal biopsy specimens from controls and patients with abnormal iron metabolism. METHODS: Twelve controls, 8 patients with iron deficiency anemia, 7 with HFE-related hemochromatosis, and 6 with non-HFE-related iron overload were studied. Immunohistochemistry was performed on duodenal biopsy specimens with anti-TfR and anti-SFT antibodies which recognize a putative stimulator of Fe transport of ~80 kilodaltons. RESULTS: In controls, the putative stimulator of Fe transport was expressed in the middle and distal part of the villi in the subapical cytoplasmatic region. Its expression increased in anemics and, to a lesser degree, in HFE-related hemochromatotics, whereas it was reduced in patients with non-HFE-related iron overload. TfR expression showed a crypt-to-tip gradient in controls, but not in anemics, in whom it was uniformly overexpressed. TfR expression was intermediate in HFE-related hemochromatotics and similar to controls in non-HFE-related iron overload. CONCLUSIONS: Expression of the putative stimulator of Fe transport and TfR increases in iron deficiency. Increased expression of both proteins is present only in HFE-related hemochromatotics suggesting that other factors may be involved in determining non-HFE-related iron overload phenotype.

Iron overload and gene expression in HepG2 cells: analysis by differential display.

The aim of the present study was to evaluate the effect of iron overload on gene expression in HepG2 cells by differential display. Iron-treated cells showed a 50% decrease in apolipoprotein B100 (Apo B100) and a 2- and 3-fold increase in semaphorin cd100 and aldose reductase mRNA, respectively, with parallel variations in Apo B100 and aldose reductase proteins. These effects were time-dependent. Vitamin E prevented the increase in aldose reductase expression, but had no effect on Apo B100 and semaphorin cd100. Treatment with hydrogen peroxide and 4-hydroxy-2,3-nonenal increased only aldose reductase mRNA. These data suggest that iron can affect mRNA levels by lipid peroxidation-dependent and -independent pathways.

Marshall-Marchetti-Krantz urethropexy and Burch colposuspension for stress urinary incontinence in women with low pressure and hypermobility of the urethra: early results of a prospective randomized clinical trial.

OBJECTIVE: The aim of the study was to compare the effects of Burch colposuspension and Marshall-Marchetti-Krantz urethropexy with videourethroscopic control in the correction of stress urinary incontinence in patients with low pressure and hypermobility of the urethra. STUDY DESIGN: Thirty women were randomly assigned to undergo 1 of the 2 surgical procedures from November 1993 to May 1996 (15 Burch colposuspensions and 15 Marshall-Marchetti-Krantz urethropexies) and were evaluated subjectively and objectively for stress urinary incontinence at 2 and 12 months. Data obtained were analyzed with the Student t test, the Fisher exact test, and the Wilcoxon signed rank test. RESULTS: At 1 year of follow-up 15 women in the Marshall-Marchetti-Krantz urethropexy group (100%) and 10 women in the Burch colposuspension group (66%) were subjectively considered cured (P =.02, 2-tailed Fisher exact test), and stress test results were negative in 14 women (93%) and 8 women (53%), respectively (P =.017, 2-tailed Fisher exact test). The resumption of spontaneous voiding was attained after 6.5 +/- 3.3 days in the Burch colposuspension group and in 20.5 +/- 13.4 days in the Marshall-Marchetti-Krantz urethropexy group (P <.001, 2-tailed Wilcoxon rank sum test). CONCLUSION: The high cure rate and low associated morbidity mark the Marshall-Marchetti-Krantz procedure with videourethroscopic control as more effective than Burch colposuspension in repairing stress urinary incontinence associated with low pressure and hypermobility of the urethra.

Nitric oxide reduces nontransferrin-bound iron transport in HepG2 cells.

Nitric oxide (NO) donors S-nitroso-N-acetylpenicillamine (SNAP) and sodium nitroprusside (SNP) modulate iron regulatory protein (IRP) activity and may, therefore, affect iron uptake through transferrin receptor expression. However, iron also enters the cell as nontransferrin-bound iron (NTBI), and the aim of this study was to evaluate the effects of NO donors on NTBI transport in HepG2 cells, a model of liver physiology. Incubation with SNP and SNAP led to a time- and concentration-dependent reduction in Fe3+ and Fe2+ uptake, thus indicating an effect on the transporter rather than on the reductase. In terms of Fe2+ uptake, no variations in the Michaelis-Menten constant (Km) and a reduction in maximum uptake (Vmax) (50, 33, and 16.6 fmol/microgram protein/min in control, SNP-, and SNAP-treated cells, respectively) were detected, which suggested a decrease in the number of putative NTBI transport protein(s). Gel shift assays showed that IRP activity was reduced by SNP and slightly increased by SNAP. Northern blot analysis of transferrin receptor messenger RNA (mRNA) levels showed variations similar to those observed for IRPs, but both NO donors increased L-ferritin mRNA levels and had no effect on the stimulator of Fe transport (SFT) mRNA. In conclusion, NO donors significantly reduce NTBI transport in HepG2 cells, an effect that seems to be IRP and SFT independent. Moreover, the reduction in NTBI uptake after NO treatment suggests that this form of iron may play a minor role in the increased hepatic iron stores observed in inflammation or that other liver cells are more involved in this pathological condition.

Fe-nitrilotriacetic acid--binding proteins associated with rat liver plasma membranes.

The uptake of nontransferrin-bound iron by hepatocytes is known to occur and may contribute to the deposition of iron and resulting injury during hemochromatosis. To examine the proteins that may function in the transport of nontransferrin-bound iron, the properties of FeNTA-binding to rat liver basolateral plasma membranes were characterized. The binding of 55FeNTA to purified liver basolateral plasma membranes was measured using a simple centrifugation assay. The binding activity could be solubilized with 0.1% octylglucoside; apparent molecular weight Mapp approximately 210 kd for the binding complex was determined by gel filtration chromatography. Immobilized metal affinity chromatography was used to further purify binding protein(s) from rat liver plasma membranes and at least six polypeptides were identified by silver staining. If associated in a stoichiometric complex, the molecular mass of these proteins would predict a size of approximately 227 kd in fairly close agreement with the gel filtration experiments. The characterization of FeNTA-binding proteins associated with basolateral membranes is the first step towards understanding elements responsible for the uptake of nontransferrin-bound iron by the liver.

Genetic hemochromatosis: pathogenesis, diagnosis, and therapy.

Genetic hemochromatosis is an autosomal recessive disease characterized by increased intestinal iron absorption and consequent tissue iron overload. The hemochromatosis gene has been localized on the short arm of chromosome 6, in close proximity to the HLA locus, but has yet to be identified. Neither the gene product nor the pathogenetic defect have been characterized. Clinical manifestations vary according to the degree of iron overload, ranging from the asymptomatic state to the features of cirrhosis and hepatocellular carcinoma. Early diagnosis remains essential, since the survival of patients without established cirrhosis is comparable to that of the general population. Transferrin saturation and ferritin levels are suggestive of the diagnosis, but measurement of the hepatic iron concentration still remains the gold standard, despite the utilization of computerized tomography and magnetic resonance imaging. Routine phlebotomies constitute the principal therapeutic option, despite the recent preliminary data on oral iron chelators.

Evidence for a low Km transporter for non-transferrin-bound iron in isolated rat hepatocytes.

Non-transferrin-bound iron (NTBI) plays an important role in the hepatocellular injury induced by iron overload. However, the mechanism responsible for NTBI uptake into hepatocytes remains poorly defined. The purpose of this study was to define the kinetics of NTBI uptake by isolated rat hepatocytes and to characterize the uptake process. NTBI uptake was time and temperature dependent, exhibited a Michaelis-Menten constant (Km) value of 1.25 microM and maximum uptake of 241 pmol.10(6) cells-1.min-1, and 55Fe was incorporated in part into intracellular ferritin. Uptake was Ca2+ dependent, exhibiting 15 and 80% of maximal uptake in the presence of 0.6 and 0.75 mM CaCl2, respectively. The putative NTBI transporter was highly specific; divalent (Zn2+, Mn2+, Cd2+, and Co2+) or trivalent (La3+) cations did not inhibit Fe3+ uptake. Reduction from Fe3+ to Fe2+ was not essential for uptake or the process occurred deep within the membrane bilayer, since the Fe2+ chelator ferrozine did not influence 55Fe uptake. These data provide evidence for a low Km plasma membrane transporter for NTBI, which should be functional at physiological serum concentrations and saturated in iron-overload diseases, such as hemochromatosis.

A major histocompatibility complex class I-related Fc receptor for IgG on rat hepatocytes.

Intestinal epithelial cells of the neonatal rat and mouse have been shown to express a major histocompatibility complex (MHC) class I-like Fc receptor, or FcRn, which transports IgG in an apical to basolateral direction. Previous studies have suggested the possible expression of this receptor beyond the neonatal period within the liver. Since bile contains high levels of IgG, we sought to determine whether the FcRn was functionally expressed by adult rat hepatocytes. Using primers specific for FcRn, which did not cross hybridize with MHC class I transcripts, FcRn DNA was amplified by reverse transcriptase polymerase chain reaction from RNA of adult rat hepatocytes. This RNA contained functional FcRn transcripts as it encoded a beta 2-microglobulin-associated cell surface protein as determined by immunoprecipitation of biotinylated cell surface proteins with a polyclonal anti-FcRn specific antiserum. Western blotting of hepatocyte canalicular (apical) and sinusoidal (basolateral) plasma membranes with an FcRn-specific monoclonal antibody further confirmed the protein expression and suggested that FcRn was enriched on the canalicular surface membranes. FcRn, on the surface of hepatocytes, was biologically functional as it bound Fc fragments of IgG at pH 6.0 but not 8.0, which is the same pH dependence observed for FcRn in rat neonatal enterocytes. Thus, FcRn is functionally expressed outside of the neonatal period on the canalicular cell surface of adult hepatocytes. This suggests that hepatocyte FcRn may bind luminal IgG, providing a potential functional communication between parenchymal immune cells and bile.

Prevalence of cholelithiasis in alcoholic and genetic haemochromatotic cirrhosis.

The prevalence of cholelithiasis and possible related factors was evaluated in 350 consecutive patients with alcoholic cirrhosis (218 cases, 174 male and 44 female, mean age 58 +/- 9 years) or genetic haemochromatotic cirrhosis (132 cases, 115 male and 17 female, mean age 53 +/- 10 years). At enrollment patients with alcoholic cirrhosis were significantly older than those with genetic haemochromatotic cirrhosis (P < 0.01), and their clinical status was more severe (Child's class B/C in 99 alcoholic cirrhosis cases versus 27 genetic haemochromatotic cirrhosis cases, P < 0.01). The overall frequency of cholelithiasis was 31% (67 cases) in the alcoholic cirrhosis group and 30% (40 cases) in the genetic haemochromatotic cirrhosis group, without differences according to gender, classes of age (< or = 49, 50-59, > or = 60 years), or HBsAg positivity in either group. In addition, in the genetic haemochromatotic cirrhosis group the presence of diabetes (45 cases), alcohol misuse (38 cases) and beta-thalassemia trait (13 cases) did not influence the prevalence of cholelithiasis. Body mass index, serum cholesterol and triglycerides, and the severity of the underlying liver disease (Child's class) did not distinguish patients with or without cholelithiasis. In conclusion, the frequency of cholelithiasis was high in both alcoholic cirrhosis and genetic haemochromatotic cirrhosis, and was three times higher than that reported in controls from the general population of the same area.

Saturability of hepatic iron deposits in genetic hemochromatosis.

The relationship of pretreatment serum ferritin and hepatic iron concentration to body iron removed by venesections was evaluated in 33 patients with genetic hemochromatosis. The median values of the three variables considered were 1,950 micrograms/L (range = 255 to 10,000), 1,175 micrograms/100 mg dry weight (range = 270 to 4,310) and 10 gm (range = 2 to 41), respectively. At basal liver biopsy 18 patients had cirrhosis, 6 patients had fibrosis and 9 patients had a normal pattern; siderosis was degree 3 in 6 patients and degree 4 in 27 patients. The results of fitting a polynomial regression of second degree showed that the curve of serum ferritin on iron removed was a straight line (R2 = 0.79, with a significant coefficient of linearity, p less than 0.01, and a nonsignificant coefficient of curvature), whereas that of hepatic iron concentration on iron removed showed a curvature (R2 = 0.62, with significant coefficient of linearity and curvature, p less than 0.01) and reached a plateau. The sigmoid model fit the curve of hepatic iron concentration on iron removed (R2 = 0.61), which suggested a saturation of hepatic iron storage capability; the asymptote corresponded to a hepatic iron concentration of about 2,000 micrograms/100 mg. In alcoholic patients (17 cases) the location of the sigmoid was greater than in nonalcoholic patients. Our results suggest that iron deposition occurs in the liver before other organs are involved and that with massive iron overload hepatic deposits reach saturation, after which hepatic iron concentration does not always reflect the amount of total stores. Alcohol consumption could slow the saturation of hepatic iron deposits.

[Survival and development of neoplasms in 56 patients with idiopathic hemochromatosis]. / Sopravvienza e sviluppo di neoplasie in 56 pazienti con emocromatosi idiopatica.

Fifty-six patients with idiopathic hemochromatosis (50 men and 6 women, mean age 49.7 +/- SD 11.1 and 60.8 +/- SD 10.3 years respectively) were studied and followed up for a median period of 44 months (range 3-168). At basal liver biopsy 44 patients had cirrhosis and 12 fibrosis. Iron depletion was achieved in 39 of the 46 cases who underwent iron removal by erythrocytapheresis. Eighteen patients died, 11 from malignancy and 7 from other causes. A total of 14 malignant neoplasms were observed (6 hepatocellular and 8 extrahepatic), of which 6 (5 hepatocellular and 1 pancreatic) were already evident at enrollment. Cumulative survival rates at 3, 5 and 8 years were 75.4%, 64.2% and 54.4% respectively, significantly lower than those in the general population. Probabilities of developing cancer in the 50 patients without cancer at diagnosis were 5.5%, 14.9% and 44.4% at 3, 5 and 8 years respectively.

Cholelithiasis in cirrhosis: analysis of 500 cases.

The prevalence of cholelithiasis (gallstones or previous cholecystectomy) was evaluated in a series of 500 cirrhotic patients from Northern Italy (329 males and 171 females, mean age 58 +/- 11 (SD) yr and 61 +/- 10 yr, respectively). Cirrhosis was related to chronic alcohol abuse in 180 cases, non-A non-B (NANB) hepatitis in 160, hepatitis B virus (HBV) in 94 (including 38 with concomitant alcohol abuse), idiopathic hemochromatosis in 44, and miscellaneous causes in the remaining 22 (including 15 with primary biliary cirrhosis). One hundred and sixteen patients (23.2%) had gallstones, and 31 others (6.2%) had previously undergone cholecystectomy, with an overall prevalence of cholelithiasis of 29.4%. The frequency was similar in both sexes (91/329 males, 27.7% vs. 56/171 females, 32.7%; p = NS), showed a slight increase with age, and differed significantly according to etiology (p less than 0.05), with the highest prevalence in the miscellaneous group and the alcoholics (36.4% and 33.3%, respectively). No significant difference was found in the prevalence of cholelithiasis according to Child's A, B, or C class.