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Purpose CD44 isoforms are highly expressed in cancer stem cells, initiating tumor growth and sustaining tumor self-renewal. Among these isoforms, CD44 variant 9 (CD44v9) is overexpressed in chronic inflammation-induced cancer. CD44 and the mesenchymal-to-epithelial transition (MET) receptor tyrosine kinase are coactivated in some gastric cancers (GCs). In this study, we characterized MET and CD44 expression and signaling in human GC cell lines and analyzed differences in the susceptibility of these lines to foretinib. Patients and methods We analyzed cell viability and the rate of apoptotic cells using MTS assays and flow cytometry, respectively. Gene and protein expression were assessed by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and immunoblotting, respectively. Results Foretinib treatment resulted in dose-dependent inhibition of growth in c-MET-amplified MKN45 and SNU620 cells with concomitant induction of apoptosis, but not in c-MET-reduced MKN28 and AGS cells. Foretinib treatment also significantly reduced phosphor-c-MET, phosphor-AKT, beta-catenin, and COX-2 protein expression in MKN45 and SNU620 cells. Interestingly, foretinib significantly reduced CD44, CD44v9, COX-2, OCT3/4, CCND1, c-MYC, VEGFA, and HIF-1a gene expression in CD44 and MET coactivated MKN45 cells and increased CD44s gene expression; in contrast, these drugs were only slightly active against SNU620 cells. Conclusion The results of this study indicate that foretinib could be a therapeutic agent for the prevention or treatment of GCs positive for CD44v9 and c-MET.

Significance Considering that Alzheimer’s disease (AD) is a chronic disease progressing over a long period of time, even a slight increase of BACE1 expression may have a profound effect on Aβ accumulation. We describe a previously unknown mechanism that negatively regulates BACE1 and BACE1-AS expression and demonstrate its pivotal role in the progression of Aβ and Tau pathologies and cognitive impairment in two mouse models of AD. Given the recent failures of the clinical trials using enzymatic inhibitors of BACE1, it is critical to explore alternative approaches such as down-regulating BACE1 and BACE1-AS transcription. Our finding that NRF2 negatively regulates BACE1 and BACE1-AS therefore suggests a potential for disease modification by NRF2-activating phytochemicals or synthetic small molecules in AD.

Vertical transmission from mother to child, the main route of chronic hepatitis B virus (HBV) infection in the East Asia, is considered one of the most important predictors for the response to antiviral therapies as well as its complications such as cirrhosis and hepatocellular carcinoma. Therefore, it is critical in both etiologic and prognostic aspects to confirm whether or not chronic HBV infection is acquired vertically. This study investigated whether mother-to-child infection could be proved by the phylogenetic analyses of HBV pre-S/S genes ever since several decades have elapsed in mother-child pairs with presumed vertical transmission. The pre-S and S regions of HBVs were compared and analyzed phylogenetically in a total of 36 adults (18 mother-child pairs) with chronic HBV infection. All of the isolates of HBV were genotype C and serotype adr. The divergence between mothers and offsprings was 0 to 1.5%. Phylogenetic trees revealed that 17 of 18 pairs (94%) with presumed vertical transmission were grouped into the same cluster. Vertical transmission from mother to child could be strongly suggested even in adults with a history of several decades of HBV infection using the phylogenetic analyses of pre-S and S genes. Graphical Abstract Keywords: Hepatitis B Virus, Multilocus Sequence Typing, Mutation, Infectious Disease Transmission, Vertical INTRODUCTION Chronic hepatitis B virus (HBV) infection is considered as a major risk factor of chronic liver diseases including cirrhosis and hepatocellular carcinoma (HCC). Parenteral infection during the adulthood is a main route of chronic HBV infection in western countries, whereas vertical (or perinatal) transmission from mother to child is thought of a critical one in the East Asia (1, 2). Of importance, the modes of infection, together with other factors such as viral titer, genotype, genetic mutations of HBV, age and gender of the host may determine the long-term clinical course of chronic HBV infection. The mode of vertical transmission, in particular, is one of the most important determinants for the therapeutic responsiveness to antiviral therapies, or the natural course in terms of hepatitis e antigen seroconversion and even the development of complications (3, 4, 5). Previous studies using a comparison of HBV DNA sequences and phylogenetic analyses have shown that HBV of chronically infected children originates mainly from their respective mothers or fathers (6, 7, 8). Although there has been hitherto a molecular evidence of vertical transmission of HBV in the pairs of mother-young child, it is improbable to identify exactly the mode of infection (especially vertical vs non-vertical) in real clinical settings because medical information from the adults for the source of HBV, relying on history taking alone, is highly obscure and there could be recall bias. There have been, so far, no reports about whether it was possible to demonstrate the molecular evidence of vertical transmission of HBV even after several decades of infection. Taken together, 'Vertical or non-vertical transmission' is so crucially informative that it enables clinicians to manage effectively the patients with chronic HBV infection and also foresee the prognosis or therapeutic responses. Therefore, this study was conducted to prove the vertical transmission by showing the molecular closeness of HBVs between adult patients with clinically presumed vertical transmission and their respective mothers with the phylogenetic analyses of pre-S/S genes of HBV. It must provide valuable information to design a further strategy of management if the mode of HBV infection can be disclosed even after long-term period of infection.

Excessive mitochondrial fission is a prominent early event and contributes to mitochondrial dysfunction, synaptic failure, and neuronal cell death in the progression of Alzheimer's disease (AD). However, it remains to be determined whether inhibition of excessive mitochondrial fission is beneficial in mammal models of AD. To determine whether dynamin-related protein 1 (Drp1), a key regulator of mitochondrial fragmentation, can be a disease-modifying therapeutic target for AD, we examined the effects of Drp1 inhibitor on mitochondrial and synaptic dysfunctions induced by oligomeric amyloid-β (Aβ) in neurons and neuropathology and cognitive functions in Aβ precursor protein/presenilin 1 double-transgenic AD mice. Inhibition of Drp1 alleviates mitochondrial fragmentation, loss of mitochondrial membrane potential, reactive oxygen species production, ATP reduction, and synaptic depression in Aβ-treated neurons. Furthermore, Drp1 inhibition significantly improves learning and memory and prevents mitochondrial fragmentation, lipid peroxidation, BACE1 expression, and Aβ deposition in the brain in the AD model. These results provide evidence that Drp1 plays an important role in Aβ-mediated and AD-related neuropathology and in cognitive decline in an AD animal model. Therefore, inhibiting excessive Drp1-mediated mitochondrial fission may be an efficient therapeutic avenue for AD.SIGNIFICANCE STATEMENTMitochondrial fission relies on the evolutionary conserved dynamin-related protein 1 (Drp1). Drp1 activity and mitochondria fragmentation are significantly elevated in the brains of sporadic Alzheimer's disease (AD) cases. In the present study, we first demonstrated that the inhibition of Drp1 restored amyloid-β (Aβ)-mediated mitochondrial dysfunctions and synaptic depression in neurons and significantly reduced lipid peroxidation, BACE1 expression, and Aβ deposition in the brain of AD mice. As a result, memory deficits in AD mice were rescued by Drp1 inhibition. These results suggest that neuropathology and combined cognitive decline can be attributed to hyperactivation of Drp1 in the pathogenesis of AD. Therefore, inhibitors of excessive mitochondrial fission, such as Drp1 inhibitors, may be a new strategy for AD.

Notch signaling pathways modulate various cellular processes, including cell proliferation, differentiation, adhesion and communication. Recent studies have demonstrated that Notch1 signaling also regulates hepatic glucose production and lipid synthesis. However, the effect of Notch1 signaling on hepatic lipid oxidation has not yet been directly investigated. To define the function of Notch1 signaling in hepatic lipid metabolism, wild type mice and Notch1 deficient antisense transgenic (NAS) mice were fed a high-fat diet. High-fat diet -fed NAS mice exhibited a marked reduction in hepatic triacylglycerol accumulation compared with wild type obese mice. The improved fatty liver was associated with an increased expression of hepatic genes involved in fatty acid oxidation. However, lipogenic genes were not differentially expressed in the NAS liver, suggesting lipolytic-specific regulatory effects by Notch1 signaling. Expression of fatty acid oxidative genes and the rate of fatty acid oxidation were also increased by inhibition of Notch1 signaling in HepG2 cells. In addition, similar regulatory effects on lipid accumulation were observed in adipocytes. Taken together, these data show that inhibition of Notch1 signaling can regulate the expression of fatty acid oxidation genes and may provide therapeutic strategies in obesity-induced hepatic steatosis.

Regression of cardiac hypertrophy and improvement of the functional capacity of failing hearts have reportedly been achieved by mechanical unloading in cardiac work. In this study, cardiac hypertrophy was first induced in rats by transverse aortic constriction and then mechanically unloaded by relieving the constriction after significant cardiac hypertrophy had developed. Hypertrophy was significantly regressed at the cellular and molecular levels at day 1, 3, and 7 after constriction relief. Gene profiling analysis revealed that 52 genes out of 9,911 genes probed on a gene array were specifically upregulated during the early regression period. Among these regression-induced genes, Eyes absent 2 ( eya2) was of particular interest because it is a transcriptional cofactor involved in mammalian organogenesis as well as Drosophila eye development. Adenovirus-mediated overexpression of eya2 in rat neonatal cardiomyocytes completely abrogated phenylephrine-induced development of cardiomyocyte hypertrophy as determined by cell size, sarcomere rearrangement and fetal gene re-expression. Our data strongly suggest that transcriptional programs distinct from those mediating cardiac hypertrophy may be operating during the regression of hypertrophy, and eya2 may be a key regulator of one of these programs.

Autophagic cell death is characterized by the accumulation of vacuoles in physiological and pathological conditions. However, its molecular event is unknown. Here, we show that Atg5, which is known to function in autophagy, contributes to autophagic cell death by interacting with Fas-associated protein with death domain (FADD). Down-regulation of Atg5 expression in HeLa cells suppresses cell death and vacuole formation induced by IFN-γ. Inversely, ectopic expression of Atg5 using adenoviral delivery induces autophagic cell death. Deletion mapping analysis indicates that procell death activity resides in the middle and C-terminal region of Atg5. Cells harboring the accumulated vacuoles triggered by IFN-γ or Atg5 expression become dead, and vacuole formation precedes cell death. 3-Methyladenine or expression of Atg5K130R mutant blocks both cell death and vacuole formation triggered by IFN-γ, whereas benzyloxycarbonyl-VAD-fluoromethyl ketone (Z-VAD-fmk) inhibits only cell death but not vacuole formation. Atg5 interacts with FADD via death domain in vitro and in vivo, and the Atg5-mediated cell death, but not vacuole formation, is blocked in FADD-deficient cells. These results suggest that Atg5 plays a crucial role in IFN-γ-induced autophagic cell death by interacting with FADD.

Eyes absent 2 (Eya2) is a transcription factor involved in a number of cellular and developmental processes. We have previously shown that Eya2 is up-regulated during regression of cardiac hypertrophy and blocks phenylephrine-induced development of cardiomyocyte hypertrophy in vitro, suggesting that Eya2 is a negative regulator of cardiac hypertrophy. In this study, we generated transgenic mice with cardiac-specific overexpression of Eya2 to elucidate the in vivo function of Eya2 in cardiac remodeling. Mild cardiac hypertrophy developed in Eya2 transgenic mice under baseline conditions with no obvious structural or functional defects. Eya2 overexpression inhibited development of cardiac hypertrophy as judged by the abrogation of increases in heart weight and cross-sectional cell surface areas and re-activation of fetal genes under pressure overload (4 weeks). Eya2 overexpression also prevented wall thinning, ventricular dilation, and deterioration of cardiac function as well as fibrosis and inflammation in the heart under long-term pressure overload (12 weeks). Gene expression profiling using the parametric analysis of gene set enrichment (PAGE) method revealed that gene sets related to mitochondrial biogenesis and metabolism were elevated in the Eya2 transgenic mice. We also observed that the PI3K/Akt/mTOR signaling cascade was preserved in the Eya2 transgenic mice, while it was significantly reduced in the wild type littermates under pressure overload. These results demonstrate that Eya2 prevents adverse cardiac remodeling under pressure overload partly through altering metabolic gene expression and preserving PI3K/Akt/mTOR signaling pathway.