Smad3 Phospho-Isoform Signaling in Nonalcoholic Steatohepatitis.

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis with insulin resistance, oxidative stress, lipotoxicity, adipokine secretion by fat cells, endotoxins (lipopolysaccharides) released by gut microbiota, and endoplasmic reticulum stress. Together, these factors promote NAFLD progression from steatosis to nonalcoholic steatohepatitis (NASH), fibrosis, and eventually end-stage liver diseases in a proportion of cases. Hepatic fibrosis and carcinogenesis often progress together, sharing inflammatory pathways.

Phospho-Smad3 signaling is predictive biomarker for hepatocellular carcinoma risk assessment in primary biliary cholangitis patients.

Introduction: Patients with primary biliary cholangitis (PBC) are at increased risk for development of hepatocellular carcinoma (HCC), particularly in the presence of comorbidities such as excessive alcohol consumption. Although liver fibrosis is an important risk factor for HCC development, earlier predictors of future HCC development in livers with little fibrosis are needed but not well defined. The transforming growth factor (TGF)-β/Smad signaling pathway participates importantly in hepatic carcinogenesis.

Role of phosphorylated Smad3 signal components in intraductal papillary mucinous neoplasm of pancreas.

Background: Malignant intraductal papillary mucinous neoplasm (IPMN) has poor prognosis. The carcinogenesis of IPMN is not clear. The aim of this study was to clarify transitions in phosphorylated Smad3 signaling during IPMN carcinogenesis.

Clinico-Pathological Importance of TGF-β/Phospho-Smad Signaling during Human Hepatic Fibrocarcinogenesis.

Chronic viral hepatitis is a global public health problem, with approximately 570 million persons chronically infected. Hepatitis B and C viruses increase the risk of morbidity and mortality from liver cirrhosis, hepatocellular carcinoma (HCC), and extrahepatic complications that develop. Hepatitis virus infection induces transforming growth factor (TGF)-β, which influences microenvironments within the infected liver.

S-1 monotherapy in a patient with cholangiolocellular carcinoma: A case report.

A 71-year-old man with alcoholic cirrhosis was found to have multiple hypervascular lesions in the liver on enhanced computed tomography. An ultrasound-guided biopsy of the lesion was performed. Immunohistochemical analysis for hepatocyte paraffin 1 expression was negative; cytokeratin (CK) 7, CK19, epithelial cell adhesion molecule and epithelial membrane antigens were positive; mucicarmine staining was negative.

Smad2/3 Linker Phosphorylation Is a Possible Marker of Pancreatic Stem/Progenitor Cells in the Regenerative Phase of Acute Pancreatitis.

Objectives: The aims of this study are to characterize cell proliferation and differentiation during regeneration after pancreatitis and pancreatic buds during development to evaluate the role of Smad2/3, phosphorylated at the specific linker threonine residues (pSmad2/3L-Thr) in positive cells.

Methods: Male C57BL/6 mice received hourly intraperitoneal injections of cerulein and were analyzed after induced pancreatitis. Pancreatitis-affected tissue sections and pancreatic buds were immunostained for pSmad2/3L-Thr, with other markers thought to be stem/progenitor markers of the pancreas.

Reversible Human TGF-β Signal Shifting between Tumor Suppression and Fibro-Carcinogenesis: Implications of Smad Phospho-Isoforms for Hepatic Epithelial-Mesenchymal Transitions.

Epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are observed during both physiological liver wound healing and the pathological fibrotic/carcinogenic (fibro-carcinogenetic) process. TGF-β and pro-inflammatory cytokine are considered to be the major factors accelerating liver fibrosis and promoting liver carcinogenesis. Smads, consisting of intermediate linker regions connecting Mad homology domains, act as the intracellular mediators of the TGF-β signal transduction pathway.

Phosphorylation status determines the opposing functions of Smad2/Smad3 as STAT3 cofactors in TH17 differentiation.

Transforming growth factor-β (TGF-β) and interleukin-6 (IL-6) are the pivotal cytokines to induce IL-17-producing CD4(+) T helper cells (TH17); yet their signalling network remains largely unknown. Here we show that the highly homologous TGF-β receptor-regulated Smads (R-Smads): Smad2 and Smad3 oppositely modify STAT3-induced transcription of IL-17A and retinoic acid receptor-related orphan nuclear receptor, RORγt encoded by Rorc, by acting as a co-activator and co-repressor of STAT3, respectively. Smad2 linker phosphorylated by extracellular signal-regulated kinase (ERK) at the serine 255 residue interacts with STAT3 and p300 to transactivate, whereas carboxy-terminal unphosphorylated Smad3 interacts with STAT3 and protein inhibitor of activated STAT3 (PIAS3) to repress the Rorc and Il17a genes.

Interstitial pneumonia induced by sorafenib in a patient with hepatocellular carcinoma: An autopsy case report.

Sorafenib is a multikinase inhibitor currently approved in Japan for the treatment of unresectable hepatocellular carcinoma. Interstitial pneumonia induced by sorafenib may have a fatal outcome, and therefore, has recently been the focus of many studies. The current report presents an autopsy case of diffuse alveolar damage (DAD) that occurred in a 59-year-old male, who had been treated with sorafenib.

Severe acute hepatitis in a printing company worker: a case study.

Objectives: It has been reported that chlorinated organic solvent is a cause of hepatitis.

Methods: we investigate clinical and pathological findings of a patient with severe acute hepatitis who was exposed to chlorinated organic solvents.

Results: A 34-year-old man who was exposed to chlorinated organic solvents including dichloromethane, 1,2-dichloropropane, and trichloroethylene, presented with general fatigue, vomiting, and diarrhea.

Linker phosphorylation of Smad3 promotes fibro-carcinogenesis in chronic viral hepatitis of hepatocellular carcinoma.

Epidemiological and clinical data point to a close association between chronic hepatitis B virus infection or chronic hepatitis C virus infection and development of hepatocellular carcinoma (HCC). HCC develops over several decades and is associated with fibrosis. This sequence suggests that persistent viral infection and chronic inflammation can synergistically induce liver fibrosis and hepatocarcinogenesis.

Smad3 phospho-isoform signaling in hepatitis C virus-related chronic liver diseases.

The risk of hepatocellular carcinoma (HCC) development increases as hepatitis virus C (HCV)-related liver diseases progress, especially in patients with active inflammation. Insight into hepatic carcinogenesis have emerged from recent detailed analyses of transforming growth factor-β and c-Jun-N-terminal kinase signaling processes directed by multiple phosphorylated (phospho)-isoforms of a Smad3 mediator. In the course of HCV-related chronic liver diseases, chronic inflammation and host genetic/epigenetic alterations additively shift the hepatocytic Smad3 phospho-isoform signaling from tumor suppression to carcinogenesis, increasing the risk of HCC.

Phosphorylation of Smad2/3 at specific linker threonine indicates slow-cycling intestinal stem-like cells before reentry to cell cycle.

Background: Quiescent (slow-cycling) and active (rapid-cycling) stem cells are demonstrated in small intestines. We have identified significant expression of Smad2/3, phosphorylated at specific linker threonine residues (pSmad2/3L-Thr), in murine stomach, and suggested these cells are epithelial stem cells.

Aim: Here, we explore whether pSmad2/3L-Thr could serve as a biomarker for small intestine and colon stem cells.

TGF-β/Smad signaling during hepatic fibro-carcinogenesis (review).

After hepatitis virus infection, plasma transforming growth factor (TGF)-β increases in either the acute or chronic inflammatory microenvironment. Although TGF-β is upregulated in patients with hepatocellular carcinoma, it is one of the most potent growth inhibitors for hepatocytes. This cytokine also upregulates extracellular matrix (ECM) production of hepatic stellate cells.

TGF-β signal shifting between tumor suppression and fibro-carcinogenesis in human chronic liver diseases.

Perturbation of transforming growth factor (TGF)-β signaling in hepatocytes persistently infected with hepatitis viruses promotes both fibrogenesis and carcinogenesis (fibro-carcinogenesis). Insights into hepatocytic fibro-carcinogenesis have emerged from recent detailed analyses of context-dependent and cell type-specific TGF-β signaling processes directed by multiple phosphorylated forms (phospho-isoforms) of Smad mediators. In the course of hepatitis virus-related chronic liver diseases, chronic inflammation, ongoing viral infection, and host genetic/epigenetic alterations additively shift hepatocytic Smad phospho-isoform signaling from tumor suppression to fibro-carcinogenesis, accelerating liver fibrosis and increasing risk of hepatocellular carcinoma (HCC).

Smad phospho-isoforms direct context-dependent TGF-β signaling.

Better understanding of TGF-β signaling has deepened our appreciation of normal epithelial cell homeostasis and its dysfunction in such human disorders as cancer and fibrosis. Smad proteins, which convey signals from TGF-β receptors to the nucleus, possess intermediate linker regions connecting Mad homology domains. Membrane-bound, cytoplasmic, and nuclear protein kinases differentially phosphorylate Smad2 and Smad3 to create C-tail (C), the linker (L), or dually (L/C) phosphorylated (p, phospho-) isoforms.

Phosphorylated Smad2 and Smad3 signaling: Shifting between tumor suppression and fibro-carcinogenesis in chronic hepatitis C.

Aim: Insight into hepatic fibrogenesis and carcinogenesis (fibro-carcinogenesis) caused by hepatitis C virus (HCV) infection has come from recent analyses of transforming growth factor (TGF)-β signaling. TGF-β type I receptor and pro-inflammatory cytokine-activated kinases differentially phosphorylate Smad2 and Smad3 to create C-terminally (C), linker (L) or dually (L/C) phosphorylated (p) isoforms. This study aimed to elucidate how HCV infection affected hepatic fibro-carcinogenesis, particularly via phospho-Smad signaling.

TGF-β signaling in onset and progression of hepatocellular carcinoma.

Transforming 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.

Gastrointestinal bleeding and blood transfusion in the elderly in Japan.

Background/aims: The incidence of gastrointestinal bleeding (GIB) increases with age and blood transfusion is frequently given for the management of GIB. In this report, we summarized our data of the patients with GIB and discussed the relationship between blood transfusion and age in patients with GIB.

Methodology: The patients were divided into two groups according to age, following elderly (≥75 years old) and younger (<75 years old) group.

Gastrointestinal bleeding associated with antithrombotic therapy in the elderly in Japan.

Background/aims: We summarize data of patients with gastrointestinal bleeding (GIB) and discuss the relationship between antithrombotic drug use and age in patients with GIB.

Methodology: One-hundred and twenty patients with GIB were divided into two groups according to age (=75 years old and <75 years old). The causes and clinical outcome of each group were compared.

Differential Regulation of TGF-β/Smad Signaling in Hepatic Stellate Cells between Acute and Chronic Liver Injuries.

Current evidence suggests that regulation of extracellular matrix (ECM) accumulation by fibrogenic transforming growth factor (TGF)-β and platelet-derived growth factor (PDGF) signals involves different mechanisms in acute and chronic liver injuries, even though hepatic stellate cells (HSC) are the principal effecter in both cases. As a result of chronic liver damage, HSC undergo progressive activation to become myofibroblasts (MFB)-like cells. Our current review will discuss the differential regulation of TGF-β signaling between HSC and MFB in vitro and in vivo.

Smad phosphoisoform signaling specificity: the right place at the right time.

Transforming growth factor (TGF)-β antagonizes mitogenic Ras signaling during epithelial regeneration, but TGF-β and Ras act synergistically in driving tumor progression. Insights into these apparently contradictory effects have come from recent detailed analyses of the TGF-β signaling process. Here, we summarize the different modes of TGF-β/Ras signaling in normal epithelium and neoplasms and show how perturbation of TGF-β signaling by Ras may contribute to a shift from tumor-suppressive to protumorigenic TGF-β activity during tumor progression.

Smad phosphoisoform signals in acute and chronic liver injury: similarities and differences between epithelial and mesenchymal cells.

Hepatocellular carcinoma (HCC) usually arises from hepatic fibrosis caused by chronic inflammation. In chronic liver damage, hepatic stellate cells undergo progressive activation to myofibroblasts (MFB), which are important extracellular-matrix-producing mesenchymal cells. Concomitantly, perturbation of transforming growth factor (TGF)-β signaling by pro-inflammatory cytokines in the epithelial cells of the liver (hepatocytes) promotes both fibrogenesis and carcinogenesis (fibro-carcinogenesis).

The specific linker phosphorylation of Smad2/3 indicates epithelial stem cells in stomach; particularly increasing in mucosae of Helicobacter-associated gastritis.

Background: The gastric corpus and antrum are believed to contain epithelial stem cells in the isthmus. However, the lack of useful markers has hindered studies of their origin. We explored whether Smad2/3, phosphorylated at specific linker threonine residues (pSmad2/3L-Thr), could serve as a marker for stem cells.