Transforming growth factor-beta (TGF-beta) and connective tissue growth factor (CTGF) are ubiquitously expressed in various forms of tissue fibrosis, including fibrotic diseases of the kidney. To clarify the common and divergent roles of these growth factors in the cells responsible for pathological extracellular matrix (ECM) deposition in renal fibrosis, the effects of TGF-beta and CTGF on ECM expression in primary human mesangial (HMCs) and human proximal tubule epithelial cells (HTECs) were studied. Both TGF-beta and CTGF significantly induced collagen protein expression with similar potency in HMCs. Additionally, alpha(2)(I)-collagen promoter activity and mRNA levels were similarly induced by TGF-beta and CTGF in HMCs. However, only TGF-beta stimulated collagenous protein synthesis in HTECs. HTEC expression of tenascin-C (TN-C) was increased by TGF-beta and CTGF, although TGF-beta was the more potent inducer. Thus both growth factors elicit similar profibrogenic effects on ECM production in HMCs, while promoting divergent effects in HTECs. CTGF induction of TN-C, a marker of epithelial-mesenchymal transdifferentiation (EMT), with no significant induction of collagenous protein synthesis in HTECs, may suggest a more predominant role for CTGF in EMT rather than induction of excessive collagen deposition by HTECs during renal fibrosis.

Progressive intrahepatic familial cholestasis (PFIC), previously called Byler's disease, is a syndrome in which children develop severe cholestasis progressing to biliary cirrhosis and chronic liver failure, usually during the first decade of life. Clinical features include jaundice, hepatomegaly, splenomegaly, growth retardation and severe pruritus. Laboratory tests demonstrate elevated bilirubin and bile acids, without an increase in serum gamma-glutamyl-transpeptidase or cholesterol. This study was performed to evaluate our experience with medical therapy as well as two types of surgical treatment used in children with PFIC, particularly partial external biliary diversion (PEBD) as an alternative method of therapy to liver transplantation (OLTx). Between 1979 and 1998 we have treated 46 children with PFIC (27 boys and 19 girls), aged 10 months to 19 yr (at the time of this study). Medical treatment with ursodeoxycholic (UDCA) was used in 39 patients for the period between 6 and 82 months. PEBD (cholecysto-jejuno-cutaneostomy) was performed in 16 patients, OLTx in eight children (including one after unsuccessful PEBD). Retrospective analysis of the clinical course and selected laboratory tests (bilirubin, ASPAT, ALAT, bile acids), and histopathological examinations were performed. Results of treatment were assessed by means of influence of the type of treatment on clinical symptoms, laboratory tests, progress of liver cirrhosis and hepatic failure, as well as physical development and survival. Medical therapy was effective in the long term in four (10%) of the patients resulting in clinical and biochemical normalization. Both surgical methods of therapy of PFIC, PEBD and OLTx, resulted in an 80% success rate and therefore should be used as complementary therapies. In patients before established liver cirrhosis, PEBD should be the first choice of treatment. Patients presenting with cirrhosis or after ineffective PEBD should qualify for OLTx. With this strategy most children with PIFC can be cured.

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The presence of the HLA-B35 allele has emerged as an important risk factor for the development of isolated pulmonary hypertension in patients with scleroderma, however the mechanisms underlying this association have not been fully elucidated. The goal of our study was to determine the molecular mechanisms that mediate the biological effects of HLA-B35 in endothelial cells (ECs). Our data demonstrate that HLA-B35 expression at physiological levels via adenoviral vector resulted in significantly increased endothelin-1 (ET-1) and a significantly decreased endothelial NO synthase (eNOS), mRNA, and protein levels. Furthermore, HLA-B35 greatly upregulated expression of chaperones, including heat shock proteins (HSPs) HSP70 (HSPA1A and HSPA1B) and HSP40 (DNAJB1 and DNAJB9), suggesting that HLA-B35 induces the endoplasmic reticulum (ER) stress and unfolded protein response in ECs. Examination of selected mediators of the unfolded protein response, including H chain binding protein (BiP; GRP78), C/Ebp homologous protein (CHOP; GADD153), endoplasmic reticulum oxidase, and protein disulfide isomerase has revealed a consistent increase of BiP expression levels. Accordingly, thapsigargin, a known ER stress inducer, stimulated ET-1mRNAand protein levels in ECs. This study suggests that HLA-B35 could contribute to EC dysfunction via ER stress-mediated induction of ET-1 in patients with pulmonary hypertension.

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