Mechanism of a Transcriptional Cross Talk between Transforming Growth Factor-β–regulated Smad3 and Smad4 Proteins and Orphan Nuclear Receptor Hepatocyte Nuclear Factor-4

We have shown previously that the transforming growth factor-β (TGFβ)-regulated Sma-Mad (Smad) protein 3 and Smad4 proteins transactivate the apolipoprotein C-III promoter in hepatic cells via a hormone response element that binds the nuclear receptor hepatocyte nuclear factor 4 (HNF-4). In the present study, we show that Smad3 and Smad4 but not Smad2 physically interact with HNF-4 via their Mad homology 1 domains both in vitro and in vivo. The synergistic transactivation of target promoters by Smads and HNF-4 was shown to depend on the specific promoter context and did not require an intact β-hairpin/DNA binding domain of the Smads. Using glutathione S-transferase interaction assays, we established that two regions of HNF-4, the N-terminal activation function 1 (AF-1) domain (aa 1–24) and the C-terminal F domain (aa 388–455) can mediate physical Smad3/HNF-4 interactions in vitro. In vivo, Smad3 and Smad4 proteins enhanced the transactivation function of various GAL4-HNF-4 fusion proteins via the AF-1 and the adjacent DNA binding domain, whereas a single tyrosine to alanine substitution in AF-1 abolished coactivation by Smads. The findings suggest that the transcriptional cross talk between the TGFβ-regulated Smads and HNF-4 is mediated by specific functional domains in the two types of transcription factors. Furthermore, the specificity of this interaction for certain target promoters may play an important role in various hepatocyte functions, which are regulated by TGFβ and the Smads

Malignancy and mortality in pediatric patients with inflammatory bowel disease: A multinational study from the porto pediatric IBD group

Background: The combination of the severity of pediatric-onset inflammatory bowel disease (IBD) phenotypes and the need for intense medical treatment may increase the risk of malignancy and mortality, but evidence regarding the extent of the problem is scarce. Therefore, the Porto Pediatric IBD working group of ESPGHAN conducted a multinational-based survey of cancer and mortality in pediatric IBD. Methods: A survey among pediatric gastroenterologists of 20 European countries and Israel on cancer and/or mortality in the pediatric patient population with IBD was undertaken. One representative from each country repeatedly contacted all pediatric gastroenterologists from each country for reporting retrospectively cancer and/or mortality of pediatric patients with IBD after IBD onset, during 2006-2011. Results: We identified 18 cases of cancers and/or 31 deaths in 44 children (26 males) who were diagnosed with IBD (ulcerative colitis, n = 21) at a median age of 10.0 years (inter quartile range, 3.0-14.0). Causes of mortality were infectious (n = 14), cancer (n = 5), uncontrolled disease activity of IBD (n = 4), procedure-related (n = 3), other non-IBD related diseases (n = 3), and unknown (n = 2). The most common malignancies were hematopoietic tumors (n = 11), of which 3 were hepatosplenic T-cell lymphoma and 3 Ebstein-Barr virus-associated lymphomas. Conclusions: Cancer and mortality in pediatric IBD are rare, but cumulative rates are not insignificant. Mortality is primarily related to infections, particularly in patients with 2 or more immunosuppressive agents, followed by cancer and uncontrolled disease. At least 6 lymphomas were likely treatment-associated by virtue of their phenotype. Copyright © 2013 Crohn's & Colitis Foundation of America, Inc

Malignancy and Mortality in Pediatric Patients with Inflammatory Bowel Disease: A Multinational Study from the Porto Pediatric IBD Group.

BACKGROUND: The combination of the severity of pediatric-onset inflammatory bowel disease (IBD) phenotypes and the need for intense medical treatment may increase the risk of malignancy and mortality, but evidence regarding the extent of the problem is scarce. Therefore, the Porto Pediatric IBD working group of ESPGHAN conducted a multinational-based survey of cancer and mortality in pediatric IBD. METHODS: A survey among pediatric gastroenterologists of 20 European countries and Israel on cancer and/or mortality in the pediatric patient population with IBD was undertaken. One representative from each country repeatedly contacted all pediatric gastroenterologists from each country for reporting retrospectively cancer and/or mortality of pediatric patients with IBD after IBD onset, during 2006-2011. RESULTS: We identified 18 cases of cancers and/or 31 deaths in 44 children (26 males) who were diagnosed with IBD (ulcerative colitis, n = 21) at a median age of 10.0 years (inter quartile range, 3.0-14.0). Causes of mortality were infectious (n = 14), cancer (n = 5), uncontrolled disease activity of IBD (n = 4), procedure-related (n = 3), other non-IBD related diseases (n = 3), and unknown (n = 2). The most common malignancies were hematopoietic tumors (n = 11), of which 3 were hepatosplenic T-cell lymphoma and 3 Ebstein-Barr virus-associated lymphomas. CONCLUSIONS: Cancer and mortality in pediatric IBD are rare, but cumulative rates are not insignificant. Mortality is primarily related to infections, particularly in patients with 2 or more immunosuppressive agents, followed by cancer and uncontrolled disease. At least 6 lymphomas were likely treatment-associated by virtue of their phenotype

The C/EBP family of transcription factors in the liver and other organs

Members of the CCAAT/enhancer-binding protein (C/EBP) family of transcription factors are pivotal regulators of liver functions such as nutrient metabolism and its control by hormones, acute-phase response and liver regeneration. Recent progress in clarification of regulatory mechanisms for the C/EBP family members gives insight into understanding the liver functions at the molecular level