Noninvasive predictors of nonalcoholic steatohepatitis in Korean patients with histologically proven nonalcoholic fatty liver disease

Background/AimsThe aims of this study were (1) to identify the useful clinical parameters of noninvasive approach for distinguishing nonalcoholic steatohepatitis (NASH) from nonalcoholic fatty liver disease (NAFLD), and (2) to determine whether the levels of the identified parameters are correlated with the severity of liver injury in patients with NASH.MethodsOne hundred and eight consecutive patients with biopsy-proven NAFLD (age, 39.8±13.5 years, mean±SD; males, 67.6%) were prospectively enrolled from 10 participating centers across Korea.ResultsAccording to the original criteria for NAFLD subtypes, 67 patients (62.0%) had NASH (defined as steatosis with hepatocellular ballooning and/or Mallory-Denk bodies or fibrosis ≥2). Among those with NAFLD subtype 3 or 4, none had an NAFLD histologic activity score (NAS) below 3 points, 40.3% had a score of 3 or 4 points, and 59.7% had a score >4 points. Fragmented cytokeratin-18 (CK-18) levels were positively correlated with NAS (r=0.401), as well as NAS components such as lobular inflammation (r=0.387) and ballooning (r=0.231). Fragmented CK-18 was also correlated with aspartate aminotransferase (r=0.609), alanine aminotransferase (r=0.588), serum ferritin (r=0.432), and the fibrosis stage (r=0.314). A fragmented CK-18 cutoff level of 235.5 U/L yielded sensitivity, specificity, and positive and negative predictive values of 69.0%, 64.9%, 75.5% (95% CI 62.4-85.1), and 57.1% (95% CI 42.2-70.9), respectively, for the diagnosis of NASH.ConclusionsSerum fragmented CK-18 levels can be used to distinguish between NASH and NAFL. Further evaluation is required to determine whether the combined measurement of serum CK-18 and ferritin levels improves the diagnostic performance of this distinction

Label-free cell separation and sorting in microfluidic systems

Cell separation and sorting are essential steps in cell biology research and in many diagnostic and therapeutic methods. Recently, there has been interest in methods which avoid the use of biochemical labels; numerous intrinsic biomarkers have been explored to identify cells including size, electrical polarizability, and hydrodynamic properties. This review highlights microfluidic techniques used for label-free discrimination and fractionation of cell populations. Microfluidic systems have been adopted to precisely handle single cells and interface with other tools for biochemical analysis. We analyzed many of these techniques, detailing their mode of separation, while concentrating on recent developments and evaluating their prospects for application. Furthermore, this was done from a perspective where inertial effects are considered important and general performance metrics were proposed which would ease comparison of reported technologies. Lastly, we assess the current state of these technologies and suggest directions which may make them more accessible

Molecular Pathogenesis of Radiation-Induced Cell Toxicity in Stem Cells

Radiation therapy is an effective cancer therapy, but damage to normal tissues surrounding the tumor due to radiotherapy causes severe complications. The importance of the therapeutic area between tumor suppression and normal tissue injury has long been highlighted in radiation therapy. Recent advances in stem cell biology have shown that stem cell (SC) responses to genotoxic stresses of ionizing radiation can improve the therapeutic effect of radiation by repairing damaged cells. In contrast, cancer stem cells (CSCs), a small subpopulation of cells within tumors, are generally resistant to chemotherapy and radiotherapy and cause tumor recurrence. Although the underlying mechanisms are not clearly understood in detail, efforts are still underway to identify SC treatment or CSC resistant pathogenesis of DNA damage agents such as radiation therapy. In response to radiation, CSCs differ from normal SCs in their biological properties due to severe deregulation of the self-renewal ability in CSCs. Differences of cleavage mode, cell cycle characteristics, replication potential, and activation/inactivation of DNA damage treatment and cancer-specific molecular pathways between normal SCs and CSCs confer a malignant phenotype upon CSCs. However, further studies are needed to identify normal SC and CSC-specific targets. In this review, we summarize the current advances in research regarding how normal SCs and CSCs respond to ionizing radiation, with a special emphasis on cell toxicity, radiosensitivity, signaling networks, DNA damage response (DDR) and DNA repair. In addition, we discuss strategies to develop new diagnostic and therapeutic techniques for predicting responses to cancer treatment and overcoming radiation-related toxicity

Phenylboronic Acid Conjugated Doxorubicin Nanocomplex As a Delivery System for Anticancer Drugs in Hepatocellular Carcinoma

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Systems approach to characterize the metabolism of liver cancer stem cells expressing CD133

Liver cancer stem cells (LCSCs) have attracted attention because they cause therapeutic resistance in hepatocellular carcinoma (HCC). Understanding the metabolism of LCSCs can be a key to developing therapeutic strategy, but metabolic characteristics have not yet been studied. Here, we systematically analyzed and compared the global metabolic phenotype between LCSCs and non-LCSCs using transcriptome and metabolome data. We also reconstructed genome-scale metabolic models (GEMs) for LCSC and non-LCSC to comparatively examine differences in their metabolism at genome-scale. We demonstrated that LCSCs exhibited an increased proliferation rate through enhancing glycolysis compared with non-LCSCs. We also confirmed that MYC, a central point of regulation in cancer metabolism, was significantly up-regulated in LCSCs compared with non-LCSCs. Moreover, LCSCs tend to have less active fatty acid oxidation. In this study, the metabolic characteristics of LCSCs were identified using integrative systems analysis, and these characteristics could be potential cures for the resistance of liver cancer cells to anticancer treatments

HBV‐Induced Increased N6 Methyladenosine Modification of PTEN RNA Affects Innate Immunity and Contributes to HCC

Background and aimsEpitranscriptomic modification of RNA has emerged as the most prevalent form of regulation of gene expression that affects development, differentiation, metabolism, viral infections, and most notably cancer. We have previously shown that hepatitis B virus (HBV) transcripts are modified by N6 methyladenosine (m6 A) addition. HBV also affects m6 A modification of several host RNAs, including phosphatase and tensin homolog (PTEN), a well-known tumor suppressor. PTEN plays a critical role in antiviral innate immunity and the development of hepatocellular carcinoma (HCC). Reports have shown that PTEN controlled interferon regulatory factor 3 (IRF-3) nuclear localization by negative phosphorylation of IRF-3 at Ser97, and PTEN reduced carcinogenesis by inhibiting the phosphatidylinositol-3-kinase (PI3K)/AKT pathway.Approach and resultsHere, we show that HBV significantly increases the m6 A modification of PTEN RNA, which contributes to its instability with a corresponding decrease in PTEN protein levels. This is reversed in cells in which the expression of m6 A methyltransferases is silenced. PTEN expression directly increases activated IRF-3 nuclear import and subsequent interferon synthesis. In the absence of PTEN, IRF-3 dephosphorylation at the Ser97 site is decreased and interferon synthesis is crippled. In chronic HBV patient biopsy samples, m6 A-modified PTEN mRNA levels were uniformly up-regulated with a concomitant decrease of PTEN mRNA levels. HBV gene expression also activated the PI3K/AKT pathway by regulating PTEN mRNA stability in HCC cell lines.ConclusionsThe m6 A epitranscriptomic regulation of PTEN by HBV affects innate immunity by inhibiting IRF-3 nuclear import and the development of HCC by activating the PI3K/AKT pathway. Our studies collectively provide new insights into the mechanisms of HBV-directed immune evasion and HBV-associated hepatocarcinogenesis through m6 A modification of the host PTEN mRNAs

Serine Protease HtrA2/Omi Deficiency Impairs Mitochondrial Homeostasis and Promotes Hepatic Fibrogenesis via Activation of Hepatic Stellate Cells

The loss of mitochondrial function impairs intracellular energy production and potentially results in chronic liver disease. Increasing evidence suggests that mitochondrial dysfunction in hepatocytes contributes to the activation of hepatic stellate cells (HSCs), thereby resulting in hepatic fibrogenesis. High-temperature requirement protein A2 (HtrA2/Omi), a mitochondrial serine protease with various functions, is responsible for quality control in mitochondrial homeostasis. However, little information is available regarding its role in mitochondrial damage during the development of liver fibrosis. This study examined whether HtrA2/Omi regulates mitochondrial homeostasis in hepatocyte during the development of hepatic fibrogenesis. In this study, we demonstrated that HtrA2/Omi expression considerably decreased in liver tissues from the CCl4-induced liver fibrotic mice model and from patients with liver cirrhosis. Knockdown of HtrA2/Omi in hepatocytes induced the accumulation of damaged mitochondria and provoked mitochondrial reactive oxygen species (mtROS) stress. We further show that the damaged mtDNA isolated from HtrA2/Omi-deficient hepatocytes as a form of damage-associated molecular patterns can induce HSCs activation. Moreover, we found that motor neuron degeneration 2-mutant mice harboring the missense mutation Ser276Cys in the protease domain of HtrA2/Omi displayed altered mitochondrial morphology and function, which increased oxidative stress and promoted liver fibrosis. Conversely, the overexpression of HtrA2/Omi via hydrodynamics-based gene transfer led to the antifibrotic effects in CCl4-induced liver fibrosis mice model through decreasing collagen accumulation and enhancing anti-oxidative activity by modulating mitochondrial homeostasis in the liver. These results suggest that suppressing HtrA2/Omi expression promotes hepatic fibrogenesis via modulating mtROS generation, and these novel mechanistic insights involving the regulation of mitochondrial homeostasis by HtrA2/Omi may be of importance for developing new therapeutic strategies for hepatic fibrosis