The mechanisms underlying the remarkable capacity of the liver to regenerate are still not completely understood. Particularly, the cross-talk between cytokines and cellular components of the process is of utmost importance because they represent potential avenues for diagnostics and therapeutics. WNT1-inducible-signaling pathway protein 1 (WISP1) is a cytokine member of the CCN family, a family of proteins that play many different roles in liver pathophysiology.
View Article and Find Full Text PDFIntroduction: The phase 2 RAMONA study demonstrated that second-line nivolumab ± ipilimumab immunotherapy was feasible and effective in older patients with advanced esophageal squamous cell cancer (ESCC). Here, we presented results from functional status (FS) and quality-of-life (QoL) analyses.
Materials And Methods: Patients aged ≥65 years with advanced ESCC and disease progression following first-line therapy were enrolled for study treatment with nivolumab ± ipilimumab.
Introduction: WNT1-inducible signalling pathway protein 1 (WISP1) promotes progression of several tumor entities often correlating with worse prognosis. Here its expression regulation and role in the progression of chronic liver diseases (CLD) was investigated.
Methods: WISP1 expression was analyzed in human HCC datasets, in biopsies and serum samples and an HCC patient tissue microarray (TMA) including correlation to clinicopathological parameters.
Understanding the mechanisms that regulate T cell immunity is critical for the development of effective therapies for diseases associated with T cell dysfunction, including autoimmune diseases, chronic infections, and cancer. Co-inhibitory "checkpoint molecules," such as programmed cell death protein-1, balance excessive or prolonged immune activation by T cell-intrinsic signaling. Here, by screening for mediators of natural killer (NK) cell recognition on T cells, we identified the immunoglobulin superfamily ligand B7H6 to be highly expressed by activated T cells, including patient-infused CD19-targeting chimeric antigen receptor (CAR) T cells.
View Article and Find Full Text PDFTransforming growth factor (TGF)-β and toll-like receptors (TLRs) have been shown to independently modulate the proliferation of hepatocellular carcinoma (HCC). Since a direct cross-talk between these two signalling pathways in HCC has not been clearly described before, we aimed here to explore the possibility of such interaction. A human HCC tissue array (n = 20 vs.
View Article and Find Full Text PDFJ Cancer Res Clin Oncol
July 2023
Background: Small bowel adenocarcinoma (SBA) remains a rare malignancy accounting for less than 5% of all the gastrointestinal tract cancers. However, only limited data and expert guidelines are available for this entity. As a result, treatment concepts are predominantly derived from colorectal cancer.
View Article and Find Full Text PDFBackground: The overall survival of patients with advanced and refractory oesophageal squamous cell carcinoma, mostly aged 65 years and older, is poor. Treatment with PD-1 antibodies showed improved progression-free survival and overall survival. We assessed the safety and efficacy of combined nivolumab and ipilimumab therapy in this population.
View Article and Find Full Text PDFObjective: TGF-β2 (TGF-β, transforming growth factor beta), the less-investigated sibling of TGF-β1, is deregulated in rodent and human liver diseases. Former data from bile duct ligated and MDR2 knockout (KO) mouse models for human cholestatic liver disease suggested an involvement of TGF-β2 in biliary-derived liver diseases.
Design: As we also found upregulated in liver tissue of patients with primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), we now fathomed the positive prospects of targeting TGF-β2 in early stage biliary liver disease using the MDR2-KO mice.
Background: Advanced esophageal squamous cell cancer (ESCC) is frequently diagnosed in elderly patients. The impact of 2nd line chemotherapy is poorly defined. Recent data demonstrated effectiveness of checkpoint inhibitors in different squamous cell carcinomas.
View Article and Find Full Text PDFTGF-β1 is a major player in chronic liver diseases promoting fibrogenesis and tumorigenesis through various mechanisms. The expression and function of TGF-β2 have not been investigated thoroughly in liver disease to date. In this paper, we provide evidence that TGF-β2 expression correlates with fibrogenesis and liver cancer development.
View Article and Find Full Text PDFTransforming growth factor β (TGF-β) is cytostatic towards damage-induced compensatory hepatocyte proliferation. This function is frequently lost during hepatocarcinogenesis, thereby switching the TGF-β role from tumour suppressor to tumour promoter. In the present study, we investigate Smad7 overexpression as a pathophysiological mechanism for cytostatic TGF-β inhibition in liver damage and hepatocellular carcinoma (HCC).
View Article and Find Full Text PDFHepatocellular carcinoma (HCC) is a major public health problem due to increased incidence, late diagnosis and limited treatment options. TGF-β is known to provide cytostatic signals during early stages of liver damage and regeneration, but exerts tumor promoting effects in onset and progression of liver cancer. To understand the mechanistic background of such a switch, we systematically correlated loss of cytostatic TGF-β effects with strength and dynamics of its downstream signaling in 10 HCC cell lines.
View Article and Find Full Text PDFTransforming growth factor (TGF)-β is a central regulator in chronic liver disease, contributing to all stages of disease progression from initial liver injury through inflammation and fibrosis to cirrhosis and hepatocellular carcinoma. Liver damage-induced levels of active TGF-β enhance hepatocyte destruction and mediate hepatic stellate cell and fibroblast activation resulting in a wound-healing response, including myofibroblast generation and extracellular matrix deposition. Further evidence points to a decisive role of cytostatic and apoptotic functions mediated on hepatocytes, which is critical for the control of liver mass, with loss of TGF-β activities resulting in hyperproliferative disorders and cancer.
View Article and Find Full Text PDFWorld J Gastroenterol
November 2010
Aim: To analyse the influence of Smad7, antagonist of transforming growth factor (TGF)-β canonical signaling pathways on hepatic stellate cell (HSC) transdifferentiation in detail.
Methods: We systematically analysed genes regulated by TGF-β/Smad7 in activated HSCs by microarray analysis and validated the results using real time polymerase chain reaction and Western blotting analysis.
Results: We identified 100 known and unknown targets underlying the regulation of Smad7 expression and delineated 8 gene ontology groups.
Background & Aims: Adverse alcohol effects in the liver involve oxidative metabolism, fat deposition and release of fibrogenic mediators, including TGF-beta. The work presents an assessment of liver damaging cross-talk between ethanol and TGF-beta in hepatocytes.
Methods: To investigate TGF-beta effects on hepatocytes, microarray analyses were performed and validated by qRT-PCR, Western blot analysis and immunohistochemistry.
Chronic alcohol consumption is a risk factor for the development of chronic liver disease. Ethanol exerts its detrimental effects by various means: Directly via toxic metabolites, and indirectly by affecting the gut barrier leading to elevated levels of endotoxins in the blood challenging the liver. These factors, together with the resulting inflammatory and profibrogenic cytokine production, drive the organ's response, characterized by activation of hepatic stellate cells.
View Article and Find Full Text PDFAlcohol Clin Exp Res
January 2010
Alcohol is recognized as a direct hepatotoxin, but the precise molecular pathways that are important for the initiation and progression of alcohol-induced tissue injury are not completely understood. The current understanding of alcohol toxicity to organs suggests that alcohol initiates injury by generation of oxidative and nonoxidative ethanol metabolites and via translocation of gut-derived endotoxin. These processes lead to cellular injury and stimulation of the inflammatory responses mediated through a variety of molecules.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2009
The insertion efficiency of transmembrane (TM) helices by the Sec61 translocon depends on helix amino acid composition, the positions of the amino acids within the helix, and helix length. We have used an in vitro expression system to examine systematically the insertion efficiency of short polyleucine segments (L(n), n = 4 ..
View Article and Find Full Text PDFJ Gastroenterol Hepatol
March 2008
Currently, hepatic stellate cells (HSC) are thought to be the major fibrotic precursor cells that transdifferentiate to fibrogenic, extracellular matrix producing myofibroblasts in inflammatory liver tissue upon transforming growth factor-beta (TGF-beta) signaling, whereas hepatocytes are thought to respond with apoptosis to this cytokine. Starting out from in vitro experiments with primary hepatocyte cultures and immortalized AML-12 cells, TGF-beta signaling in this cell type was assessed and apoptosis was found to be only a minor effect. Instead, hepatocytes undergo epithelial mesenchymal transition (EMT), a physiological process in embryogenesis and of relevance for cancerous cell transformation.
View Article and Find Full Text PDFTransmembrane alpha-helices in integral membrane proteins are recognized co-translationally and inserted into the membrane of the endoplasmic reticulum by the Sec61 translocon. A full quantitative description of this phenomenon, linking amino acid sequence to membrane insertion efficiency, is still lacking. Here, using in vitro translation of a model protein in the presence of dog pancreas rough microsomes to analyse a large number of systematically designed hydrophobic segments, we present a quantitative analysis of the position-dependent contribution of all 20 amino acids to membrane insertion efficiency, as well as of the effects of transmembrane segment length and flanking amino acids.
View Article and Find Full Text PDFBiochem Biophys Res Commun
February 2007
Liver injury induces activation of hepatic stellate cells (HSCs) comprising expression of receptors, proliferation, and extracellular matrix synthesis triggered by a network of cytokines provided by damaged hepatocytes, activated Kupffer cells and HSCs. While 6 days after bile duct ligation in rats TGF-beta inhibited DNA synthesis in HSCs, it was enhanced after 14 days, indicating a switch from suppression to DNA synthesis stimulation during fibrogenesis. To delineate mechanisms modulating TGF-beta function, we analyzed crosstalk with signaling pathways initiated by cytokines in damaged liver.
View Article and Find Full Text PDFInter-helix hydrogen bonding involving asparagine (Asn, N), glutamine (Gln, Q), aspartic acid (Asp, D) or glutamic acid (Glu, E) can drive efficient di- or trimerization of transmembrane helices in detergent micelles and lipid bilayers. Likewise, Asn-Asn and Asp-Asp pairs can promote the formation of helical hairpins during translocon-mediated membrane protein assembly in the endoplasmic reticulum. By in vitro translation of model integral membrane protein constructs in the presence of rough microsomes, we show that Asn- or Asp-mediated interactions with a neighbouring transmembrane helix can enhance the membrane insertion efficiency of a marginally hydrophobic transmembrane segment.
View Article and Find Full Text PDFCurrent evidence favors a cycling receptor model for the import of peroxisomal matrix proteins. The yeast Pex14 protein together with Pex13p and Pex17p form the docking subcomplex at the peroxisomal membrane and interact in this cycle with both soluble import receptors Pex5p and Pex7p. In a first step of a structure-function analysis of Saccharomyces cerevisiae Pex14p, we mapped its binding sites with both receptors.
View Article and Find Full Text PDFWe describe a generic, GFP-based pipeline for membrane protein overexpression and purification in Escherichia coli. We exemplify the use of the pipeline by the identification and characterization of E. coli YedZ, a new, membrane-integral flavocytochrome.
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