Search

Abstract Background Recently, extremely low frequency electromagnetic fields (ELF-EMF) have been studied with great interest due to their possible effects on human health. In this study, we evaluated the effect of 4.5 mT - 120 Hz ELF-EMF on the development of preneoplastic lesions in experimental hepatocarcinogenesis. Methods Male Fischer-344 rats were subjected to the modified resistant hepatocyte model and were exposed to 4.5 mT - 120 Hz ELF-EMF. The effects of the ELF-EMF on hepatocarcinogenesis, apoptosis, proliferation and cell cycle progression were evaluated by histochemical, TUNEL assay, caspase 3 levels, immunohistochemical and western blot analyses. Results The application of the ELF-EMF resulted in a decrease of more than 50% of the number and the area of γ-glutamyl transpeptidase-positive preneoplastic lesions (P = 0.01 and P = 0.03, respectively) and glutathione S-transferase placental expression (P = 0.01). The number of TUNEL-positive cells and the cleaved caspase 3 levels were unaffected; however, the proliferating cell nuclear antigen, Ki-67, and cyclin D1 expression decreased significantly (P ≤ 0.03), as compared to the sham-exposure group. Conclusion The application of 4.5 mT - 120 Hz ELF-EMF inhibits preneoplastic lesions chemically induced in the rat liver through the reduction of cell proliferation, without altering the apoptosis process.

Extracellular vesicles (EVs) represent an attractive source of biomarkers due to their biomolecular cargo. The aim of this study was to identify candidate protein biomarkers from plasma-derived EVs of patients with liver cirrhosis (LC) and hepatocellular carcinoma (HCC). Plasma-derived EVs from healthy participants (HP), LC, and HCC patients (eight samples each) were subjected to label-free quantitative proteomic analysis using LC-MS/MS. A total of 248 proteins were identified, and differentially expressed proteins (DEPs) were obtained after pairwise comparison. We found that DEPs mainly involve complement cascade activation, coagulation pathways, cholesterol metabolism, and extracellular matrix components. By choosing a panel of up- and down-regulated proteins involved in cirrhotic and carcinogenesis processes, TGFBI, LGALS3BP, C7, SERPIND1, and APOC3 were found to be relevant for LC patients, while LRG1, TUBA1C, TUBB2B, ACTG1, C9, HP, FGA, FGG, FN1, PLG, APOB and ITIH2 were associated with HCC patients, which could discriminate both diseases. In addition, we identified the top shared proteins in both diseases, which included LCAT, SERPINF2, A2M, CRP, and VWF. Thus, our exploratory proteomic study revealed that these proteins might play an important role in the disease progression and represent a panel of candidate biomarkers for the prognosis and diagnosis of LC and HCC.

Double labeling to identify different markers in the same tissue section represents a useful tool either for in situ diagnosis or characterization of molecular associations. Here, we present a protocol to detect senescence-associated β-galactosidase (SA-βGal) and immunoperoxidase (IPO) activity in fresh-frozen murine tissues. We describe steps for tissue collection, solution preparation, SA-βGal staining, IPO staining, hematoxylin counterstaining, microscopic observation, and signal quantification. This protocol can be used to detect in situ proteins alongside SA-βGal activity. For complete details on the use and execution of this protocol, please refer to Pacheco-Rivera et al. 1 ., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The identification of biomarkers for the early diagnosis of nonalcoholic fatty liver disease (NAFLD) is urgently needed. Here, we aimed to identify NAFLD biomarkers in the early stages of steatosis (SS) and nonalcoholic steatohepatitis (NASH) based on differential gene expression from bioinformatics data., Methods: A meta-analysis was performed from transcriptomic databases retrieved from public repositories containing data from biopsies of patients at various stages of NAFLD development. The status of the selected molecules was validated in the serum of patients with NAFLD by ELISA., Results: We identified 121 differentially expressed genes (DEGs) associated with SS and 402 associated with NASH. Gene Ontology (GO) enrichment revealed that the altered genes were primarily associated with dysfunction of primary cellular processes, and pathway analyses were mainly related to cholesterol metabolism. We identified ACSS2, PCSK9, and CYP7A1 as candidate biomarkers for SS and ANGPTL3, CD36, CYP51A1, FASN, FAS, FDFT1, and LSS as candidate biomarkers for NASH., Conclusions: By experimental validation of bioinformatics data from patients with NAFLD, we identified promising biomarkers for detecting SS and NASH that might be useful for screening and diagnosing early NAFLD stages in humans., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Liver diseases preceding the occurrence of hepatocellular carcinoma (HCC) play a crucial role in the progression and establishment of HCC, a malignancy ranked as the third deadliest cancer worldwide. Late diagnosis, alongside ineffective treatment, leads patients to a poor survival rate. This scenario argues for seeking novel alternatives for detecting liver alterations preceding the early occurrence of HCC. Experimental studies have reported that ABCC3 protein increases within HCC tumors but not in adjacent tissue. Therefore, we analyzed ABCC3 expression in public databases and investigated the presence of ABCC3 and its isoforms in plasma, urine and its release in extracellular vesicles (EVs) cargo from patients bearing cirrhosis and HCC. The UALCAN and GEPIA databases were used to analyze the expression of ABCC3 in HCC. The results were validated in a case-control study including 41 individuals bearing cirrhosis and HCC, and the levels of ABCC3 in plasma and urine samples, as well as EVs, were analyzed by ELISA and western blot. Our data showed that ABCC3 expression was higher in HCC tissues than in normal tissues and correlated with HCC grade and stage. ABCC3 protein levels were highly increased in both plasma and urine and correlated with liver disease progression and severity. The isoforms MRP3A and MRP3B of ABCC3 were significantly increased in both EVs and plasma/urine of patients bearing HCC. ABCC3 expression gradually increases in HCC tissues, and its protein levels are increased in both plasma and urine of patients with cirrhosis and HCC. MRP3A and MRP3B isoforms have the potential to be prognostic biomarkers of HCC.

Hepatocellular carcinoma (HCC) is a tumor with minimal chance of cure due to underlying liver diseases, late diagnosis, and inefficient treatments. Thus, HCC treatment warrants the development of additional strategies. Lactoferrin (Lf) is a mammalian multifunctional iron-binding glycoprotein of the innate immune response and can be found as either a native low iron form (native-Lf) or a high iron form (holo-Lf). Bovine Lf (bLf), which shares many functions with human Lf (hLf), is safe for humans and has several anticancer activities, including chemotherapy boost in cancer. We found endogenous hLf is downregulated in HCC tumors compared with normal liver, and decreased hLf levels in HCC tumors are associated with shorter survival of HCC patients. However, the chemoprotective effect of 100% iron saturated holo-bLf on experimental hepatocarcinogenesis has not yet been determined. We aimed to evaluate the chemopreventive effects of holo-bLf in different HCC models. Remarkably, a single dose (200 mg kg -1 ) of holo-bLf was effective in preventing early carcinogenic events in a diethylnitrosamine induced HCC in vivo model, such as necrosis, ROS production, and the surge of facultative liver stem cells, and eventually, holo-bLf reduced the number of preneoplastic lesions. For an established HCC model, holo-bLf treatment significantly reduced HepG2 tumor burden in xenotransplanted mice. Finally, holo-bLf in combination with sorafenib, the advanced HCC first-line treatment, synergistically decreased HepG2 viability by arresting cells in the G0/G1 phase of the cell cycle. Our findings provide the first evidence suggesting that holo-bLf has the potential to prevent HCC or to be used in combination with treatments for established HCC.

The worst-case scenario related to alcoholic liver disease (ALD) arises after a long period of exposure to the harmful effect of alcohol consumption along with other hepatotoxics. ALD encompasses a broad spectrum of liver-associated disorders, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Based on the chronic administration of different hepatotoxics, including ethanol, sucrose, lipopolysaccharide, and low doses of diethylnitrosamine over a short period, here we aimed to develop a multiple hepatotoxic (MHT)-ALD model in the mouse that recapitulates the human ALD-associated disorders. We demonstrated that the MHT-ALD model induces ADH1A and NXN, an ethanol metabolizer and a redox-sensor enzyme, respectively; promotes steatosis associated with the induction of the lipid droplet forming FSP27, inflammation identified by the infiltration of hepatic neutrophils-positive to LY-6G marker, and the increase of MYD88 level, a protein involved in inflammatory response; and stimulates the early appearance of cellular senescence identified by the senescence markers SA-β-gal activity and p-H2A.X Ser139 . It also induces fibrosis associated with increased desmin, a marker of hepatic stellate cells whose activation leads to the deposition of collagen fibers, accompanied by cell death and compensatory proliferation revealed by increased CASP3-mediated apoptosis, and KI67- and PCNA-proliferation markers, respectively. It also induces histopathological traits of malignancy and the level of the HCC marker, GSTP1. In conclusion, we provide a useful model for exploring the chronological ALD-associated alterations and stages, and addressing therapeutic approaches., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Aging is characterized by increased reactive species, leading to redox imbalance, oxidative damage, and senescence. The adverse effects of alcohol consumption potentiate aging-associated alterations, promoting several diseases, including liver diseases. Nucleoredoxin (NXN) is a redox-sensitive enzyme that targets reactive oxygen species and regulates key cellular processes through redox protein-protein interactions. Here, we determine the effect of chronic alcohol consumption on NXN-dependent redox interactions in the liver of aged mice. We found that chronic alcohol consumption preferentially promotes the localization of NXN either into or alongside senescent cells, declines its interacting capability, and worsens the altered interaction ratio of NXN with FLII, MYD88, CAMK2A, and PFK1 proteins induced by aging. In addition, carbonylated protein and cell proliferation increased, and the ratios of collagen I and collagen III were inverted. Thus, we demonstrate an emerging phenomenon associated with altered redox homeostasis during aging, as shown by the declining capability of NXN to interact with partner proteins, which is enhanced by chronic alcohol consumption in the mouse liver. This evidence opens an attractive window to elucidate the consequences of both aging and chronic alcohol consumption on the downstream signaling pathways regulated by NXN-dependent redox-sensitive interactions.

The severity of fibrosis is central to the therapeutic course for patients with chronic liver disease; therefore, early detection of liver fibrosis is critical for timely therapeutic interventions. Liver biopsy is the gold standard for the diagnosis of liver fibrosis; however, it is contraindicated in several pathological conditions. Activated hepatic stellate cells (HSCs) are the main cells for fibrotic tissue synthesis, such as that of alpha-smooth muscle actin (α-SMA). This study aimed to determine whether serum α-SMA levels are a suitable noninvasive, sensitive, and reliable liver fibrosis marker. Fibrosis was induced in male Wistar rats via chronic CCl 4 administration. Fibrosis was determined in the liver tissues by quantifying the hydroxyproline content and visualized using Masson's trichrome staining. Rats chronically administered CCl 4 exhibited a progressive increment in the hepatic collagen content, as well as both hepatic and serum α-SMA levels in a time-dependent manner. Moreover, serum levels of α-SMA significantly correlated with hepatic α-SMA levels ( p  ≤ 0.001), as well as with the severity of liver fibrosis ( p  ≤ 0.001). These findings suggest that increased levels of serum α-SMA can be considered a potential reliable and noninvasive biomarker for early liver fibrosis.

Non-alcoholic steatohepatitis (NASH) is a global public health concern that may progress into fibrosis, cirrhosis, and liver cancer, with limited curative treatment options. While the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is closely linked to NASH progression, nicotinic acid (NA), a vitamin used for the treatment of dyslipidemia, is an emerging pharmaceutical treatment for hepatic steatosis and fibrosis. Here, we investigated pharmacological effects of NA on experimental NASH and whether NLRP3 inflammasome/pyroptosis inhibition is an associated mechanism of action. Rats were fed a high-fat sucrose diet supplemented with cholesterol and a low dose of CCl 4 . NA significantly reduced inflammation by decreasing the protein levels of tumor necrosis factor-alpha and nuclear factor kappa B. Moreover, NA inhibited the formation of NLRP3- apoptosis-associated speck-like protein containing caspase recruitment domain-Caspase-1, decreasing interleukin-1beta, interleukin-18, and gasdermin D protein. In addition, NA reduced tumor growth factor-beta, alpha-smooth muscle actin, and hepatic levels of collagen-1, consequently decreasing extracellular matrix synthesis. Our results indicate that NA can inhibit NASH progression and encourage further basic and clinical studies on the use of NA for the treatment of human NASH., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Hepatocellular carcinoma (HCC) is a highly lethal liver cancer with late diagnosis; therefore, the identification of new early biomarkers could help reduce mortality. We determine the tissue and plasma status of five annexins during hepatocarcinogenesis by diethylnitrosamine-induced cirrhosis-HCC. We found that Anxa5 was the earliest upregulated gene at week 12 after HCC initiation, while Anxa1 and Anxa2 were upregulated in advanced HCC stages (weeks 18 and 22). Furthermore, the protein level of Annexin A1, A2, A5 and A10 was increased from the early stages. Immunofluorescence and subcellular fractionation revealed Annexin A1, A2, and A5 in the cytoplasm and nuclei of tumor cells. Notably, increased plasma levels of Annexin A5 significantly (r 2  = 0.8203) correlated with Annexin A5 levels in liver tissue from week 12 and gradually increased until week 22. Using the TCGA database, we found that the expression of ANXA2 (HR = 1.7, p = 0.0046) and ANXA5 (HR = 1.8, p = 0.00077) was associated with poor survival in HCC patients. In conclusion, we have identified Annexin A1 and A5 as potentially useful early biomarkers for poor prognosis in HCC patients., (© 2023. The Author(s).)

Following an Assessment by the Autonomous University of Hidalgo State and the National Institute of Genomic Medicine, this erratum corrects the authorship of this article by adding Dulce María MORENO-GARCÍA as the first author.

Introduction and Objectives: Administration of carbon tetrachloride (CCl 4 ), along with an hepatopathogenic diet, is widely employed as a chemical inducer to replicate human nonalcoholic steatohepatitis (NASH) in rodents; however, the role of the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome in this model remains unclear. We aimed to determine the relevance of NLRP3 inflammasome activation in the development of NASH induced by CCl 4 along with an hepatopathogenic diet in male Wistar rats., Materials and Methods: Animals were fed either a high fat, sucrose, and cholesterol diet (HFSCD) or a HFSCD plus intraperitoneal injections of low doses of CCl 4 (400 mg/kg) once a week for 15 weeks. Liver steatosis, inflammation, fibrosis, and NLRP3 inflammasome activation were evaluated using biochemical, histological, ultrastructural, and immunofluorescence analyses, western blotting, and immunohistochemistry., Results: Our experimental model reproduced several aspects of the human NASH pathophysiology. NLRP3 inflammasome activation was induced by the combined effect of HFSCD plus CCl 4 and significantly increased levels of both proinflammatory and profibrogenic cytokines and collagen deposition in the liver; thus, NASH severity was higher in the HFSCD+CCl 4 group than that in the HFSCD group, to which CCl 4 was not administered. Hepatic stellate cells, the most profibrogenic cells, were activated by HFSCD plus CCl 4 , as indicated by elevated levels of α-smooth muscle actin. Thus, activation of the NLRP3 inflammasome, triggered by low doses of CCl 4 , exacerbates the severity of NASH., Conclusions: Our results indicate that NLRP3 inflammasome activation plays a key role and may be an important therapeutic target for NASH treatment., Competing Interests: Conflicts of interest The authors have no conflicts of interest to declare., (Copyright © 2022 Fundación Clínica Médica Sur, A.C. Published by Elsevier España, S.L.U. All rights reserved.)

The clinical phenotype of LMNA -associated dilated cardiomyopathy (DCM) varies even among individuals who share the same mutation. LMNA encodes lamin AC, which interacts with the lamin-associated protein 2 alpha (LAP2α) encoded by the TMPO gene. The LAP2α/Arg690Cys polymorphism is frequent in Latin America and was previously found to disrupt LAP2α-Lamin AC interactions in vitro. We identified a DCM patient heterozygous for both a lamin AC truncating mutation (Ser431*) and the LAP2α/Arg690Cys polymorphism. We performed protein modeling and docking experiments, and used confocal microscopy to compare leukocyte nuclear morphology among family members with different genotype combinations (wild type, LAP2α Arg690Cys heterozygous, lamin AC/Ser431* heterozygous, and LAP2α Arg690Cys/lamin AC Ser431* double heterozygous). Protein modeling predicted that 690Cys destabilizes the LAP2α homodimer and impairs lamin AC-LAP2α docking. Lamin AC-deficient nuclei (Ser431* heterozygous) showed characteristic blebs and invaginations, significantly decreased nuclear area, and increased elongation, while LAP2α/Arg690Cys heterozygous nuclei showed a lower perimeter and higher circularity than wild-type nuclei. LAP2α Arg690Cys apparently attenuated the effect of LMNA Ser431* on the nuclear area and fully compensated for its effect on nuclear circularity. Altogether, the data suggest that LAP2α/Arg690Cys may be one of the many factors contributing to phenotype variation of LMNA -associated DCM.

Caffeine elicits protective effects against liver diseases, such as NASH; however, its mechanism of action involving the pyrin domain-containing-3 (NLRP3) inflammasome signaling pathway remains to be elucidated. This study aimed to evaluate the effect of caffeine on the NLRP3 inflammasome signaling pathway in a rat model of NASH. NASH was induced by feeding rats a high-fat, -sucrose, and -cholesterol diet (HFSCD) for 15 weeks along with a weekly low dose (400 mg/kg, i.p.) of CCl 4 . Caffeine was administered at 50 mg/kg p.o. The effects of HFSCD+CCl 4 and caffeine on the liver were evaluated using biochemical, ultrastructural, histological, and molecular biological approaches. The HFSCD+CCl 4 -treated rats showed fat accumulation in the liver, elevated levels of inflammatory mediators, NLRP3 inflammasome activation, antioxidant dysregulation, and liver fibrosis. Caffeine reduced necrosis, cholestasis, oxidative stress, and fibrosis. Caffeine exhibited anti-inflammatory effects by attenuating NLRP3 inflammasome activation. Moreover, caffeine prevented increases in toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) protein levels and mitigated the phosphorylation of mitogen-activated protein kinase (MAPK). Importantly, caffeine prevented the activation of hepatic stellate cells. This study is the first to report that caffeine ameliorates NASH by inhibiting NLRP3 inflammasome activation through the suppression of the TLR4/MAPK/NF-κB signaling pathway.

Hepatocellular carcinoma (HCC) is one of the deadliest cancers worldwide, often preceded by cirrhosis and usually diagnosed at advanced stages; therefore, identifying molecular changes at early stages is an attractive strategy for detection and timely treatment. Here, we investigated the progressive transcriptomic changes during experimental hepatocarcinogenesis to identify novel early tumor markers in an HCC model induced by chronic administration of sublethal doses of diethylnitrosamine. An analysis of differentially expressed genes showed that four processes associated with oxidation-reduction and detoxification were significantly over-represented during hepatocarcinogenesis progression, of which the Nuclear Factor, Erythroid 2 Like 2 pathway showed several dysregulated genes. Interestingly, we also identified 91 genes dysregulated at early HCC stages, but the expression of the indolethylamine N-methyltransferase gene (INMT), as well as the level of its encoding protein, were strongly downregulated. INMT was increased in perivenular hepatocytes of normal livers but decreased in livers of experimental HCC. Furthermore, a gene expression and survival analysis performed using data from the liver hepatocellular carcinoma project of The Cancer Genome Atlas Program revealed that INMT is also significantly downregulated in human HCC and is associated with poor overall survival. In conclusion, by performing a transcriptome analysis of the HCC progression, we identified that INMT is early downregulated in the rat hepatocarcinogenesis and is associated with poor prognosis in human HCC, suggesting that INMT downregulation may be a promising prognostic marker for HCC in high-risk populations., (© 2022 John Wiley & Sons Ltd.)

The activation of Nuclear Factor, Erythroid 2 Like 2 - Kelch Like ECH Associated Protein 1 (NRF2-KEAP1) signaling pathway plays a critical dual role by either protecting or promoting the carcinogenesis process. However, its activation or nuclear translocation during hepatocellular carcinoma (HCC) progression has not been addressed yet. This study characterizes the subcellular localization of both NRF2 and KEAP1 during diethylnitrosamine-induced hepatocarcinogenesis in the rat. NRF2-KEAP1 pathway was continuously activated along with the increased expression of its target genes, namely Nqo1, Hmox1, Gclc, and Ptgr1. Similarly, the nuclear translocation of NRF2, MAF, and KEAP1 increased in HCC cells from weeks 12 to 22 during HCC progression. Likewise, colocalization of NRF2 with KEAP1 was higher in the cell nuclei of HCC neoplastic nodules than in surrounding cells. Moreover, immunofluorescence analyses revealed that the interaction of KEAP1 with filamentous Actin was disrupted in HCC cells. This disruption may be contributing to the release and nuclear translocation of NRF2 since the cortical actin cytoskeleton serves as anchoring of KEAP1. In conclusion, this evidence indicates that NRF2 is progressively activated and promotes the progression of experimental HCC., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Homogeneous extremely low-frequency electromagnetic fields (ELF-EMFs) alter biological phenomena, including the cell phenotype and proliferation rate. Heterogenous vortex magnetic fields (VMFs), a new approach of exposure to magnetic fields, induce systematic movements on charged biomolecules from target cells; however, the effect of VMFs on living systems remains uncertain. Here, we designed, constructed, and characterized an ELF-VMF-modified Rodin's coil to expose SH-SY5Y cells. Samples were analyzed by performing 2D-differential-gel electrophoresis, identified by MALDI-TOF/TOF, validated by western blotting, and characterized by confocal microscopy. A total of 106 protein spots were differentially expressed; 40 spots were downregulated and 66 were upregulated in the exposed cell proteome, compared to the control cell proteome. The identified spots are associated with cytoskeleton and cell viability proteins, and according to the protein-protein interaction network, a significant interaction among them was found. Our data revealed a decrease in cell survival associated with apoptotic cells without effects on the cell cycle, as well as evident changes in the cytoskeleton. We demonstrated that ELF-VMFs, at a specific frequency and exposure time, alter the cell proteome and structurally affect the target cells. This is the first report showing that VMF application might be a versatile system for testing different hypotheses in living systems, using appropriate exposure parameters.© 2022 Bioelectromagnetics Society., (© 2022 Bioelectromagnetics Society.)

Nucleoredoxin (NXN), an oxidoreductase enzyme, contributes to cellular redox homeostasis by regulating different signaling pathways in a redox-dependent manner. By interacting with seven proteins so far, namely disheveled (DVL), protein phosphatase 2A (PP2A), phosphofructokinase-1 (PFK1), translocation protein SEC63 homolog (SEC63), myeloid differentiation primary response gene-88 (MYD88), flightless-I (FLII), and calcium/calmodulin-dependent protein kinase II type alpha (CAMK2A), NXN is involved in the regulation of several key cellular processes, including proliferation, organogenesis, cell cycle progression, glycolysis, innate immunity and inflammation, motility, contraction, protein transport into the endoplasmic reticulum, neuronal plasticity, among others; as a result, NXN has been implicated in different pathologies, such as cancer, alcoholic and polycystic liver disease, liver fibrogenesis, obesity, Robinow syndrome, diabetes mellitus, Alzheimer's disease, and retinitis pigmentosa. Together, this evidence places NXN as a strong candidate to be a master redox regulator of cell physiology and as the hub of different redox-sensitive signaling pathways and associated pathologies. This review summarizes and discusses the current insights on NXN-dependent redox regulation and its implication in different pathologies.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease. Lesions in the lung epithelium cause alterations in the microenvironment that promote fibroblast accumulation. Extracellular vesicles (EVs) transport proteins, lipids, and nucleic acids, such as microRNAs (miRNAs). The aim of this study was to characterize the differentially expressed miRNAs in the cargo of EVs obtained from the LL97 and LL29 fibroblast cell lines isolated from IPF lungs versus those derived from the CCD19 fibroblast cell line isolated from a healthy donors. We characterized EVs by ultracentrifugation, Western blotting, and dynamic light scattering. We identified miRNAs by small RNA-seq, a total of 1144 miRNAs, of which 1027 were known miRNAs; interestingly, 117 miRNAs were novel. Differential expression analysis showed that 77 miRNAs were upregulated and 68 were downregulated. In addition, pathway enrichment analyses from the Gene Ontology and Kyoto Encyclopedia of Genomes identified several miRNA target genes in the categories, cell proliferation, regulation of apoptosis, pathways in cancer, and proteoglycans in cancer. Our data reveal that miRNAs contained in EVs cargo could be helpful as biomarkers for fibrogenesis, diagnosis, and therapeutic intervention of IPF.

Hepatocellular carcinoma (HCC) is a health problem worldwide due to its high mortality rate, and the tumor microenvironment (TME) plays a key role in the HCC progression. The current ineffective therapies to fight the disease still warrant the development of preventive strategies. Quercetin has been shown to have different antitumor activities; however, its effect on TME components in preneoplastic lesions has not been fully investigated yet. Here, we aimed to evaluate the effect of quercetin (10 mg/kg) on TME components during the early stages of HCC progression induced in the rat. Histopathological and immunohistochemical analyses showed that quercetin decreases the size of preneoplastic lesions, glycogen and collagen accumulation, the expression of cancer stem cells and myofibroblasts markers, and that of the transporter ATP binding cassette subfamily C member 3 (ABCC3), a marker of HCC progression and multi-drug resistance. Our results strongly suggest that quercetin has the capability to reduce key components of TME, as well as the expression of ABCC3. Thus, quercetin can be an alternative treatment for inhibiting the growth of early HCC tumors.

Hepatocellular carcinoma expressing hepatobiliary progenitor markers, is considered of poor prognosis. By using a hepatocarcinogenesis model, laser capture microdissection, and RNA-Sequencing analysis, we identified an expression profile in GGT/KRT19-positive experimental tumors; 438 differentially expressed genes were found in early and late nodules along with increased collagen deposition. Dysregulated genes were involved in Fatty Acid Metabolism, RXR function, and Hepatic Stellate Cells Activation. Downregulation of Slc27a5, Acsl1, and Cyp2e1, demonstrated that Retinoid X Receptor α (RXRα) function is compromised in GGT/KRT19-positive nodules. Since RXRα controls NRF2 pathway activation, we determined the expression of NRF2 targeted genes; Akr1b8, Akr7a3, Gstp1, Abcc3, Ptgr1, and Txnrd1 were upregulated, indicating NRF2 pathway activation. A comparative analysis in human HCC showed that SLC27A5, ACSL1, CYP2E1, and RXRα gene expression is mutually exclusive with KRT19 gene expression. Our results indicate that the downregulation of Slc27a5, Acsl1, Rxrα, and Cyp2e1 genes is an early event within GGT/KRT19-positive HCC., (Copyright © 2021. Published by Elsevier Inc.)

Hepatocellular carcinoma (HCC), the most common primary liver cancer, arises after a long period of exposure to etiological factors. Nonalcoholic steatohepatitis (NASH) is ranked as the main risk factor for developing HCC; hence, experimental models of NASH leading to HCC have become key tools both to investigate the molecular mechanisms underlying the pathophysiology and to evaluate new putative drugs for treating chronic liver diseases in humans. Animal models of NASH induced by a high-fat diet (HFD) plus chemical inducers, such as the NASH-HCC (STAM), high-fat diet/diethylnitrosamine (HFD/DEN), choline-deficient high-fat diet/DEN (CDHFD/DEN), and Western diet/carbon tetrachloride (WD/CCl 4 ) models, are promising because they exacerbate liver damage and significantly shorten the experimental time. In this review, we critically summarize and discuss the ability of these models to recapitulate the liver alterations that precede and lead to HCC progression, as well as the impact of the diet in promoting liver injury progression. We also emphasize the strengths and weaknesses of the models' ability to closely mimic the stages of liver injury development that occur in humans. Based on the molecular mechanisms induced by the currently available NASH models leading to HCC, we argue that although several NASH models have importantly contributed to describing the disease chronology, the progress in emulating the progression from NASH to HCC has been partial. Thus, the development of novel NASH/HCC models remains an unmet need., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Hepatocellular carcinoma (HCC), which is the most frequent primary liver malignancy, is ranked as the sixth most common cancer and the third leading cause of cancer-related deaths worldwide, with its incidence expected to continue rising. One of the reasons is that most patients are diagnosed at an advanced stage when therapeutic options are ineffective. The development of HCC is attributed to a chronic exposition to either one or a combination of low amounts of different hepatotoxins, such as in hepatitis virus infection, alcohol consumption, aflatoxin from contaminated foods, metabolic factors, and exposure to chemical carcinogens from tobacco smoke (Forner et al., 2018). Integrative studies combining exome sequencing, transcriptome analysis, and the genomic characterization of HCC have shown that these etiological factors may raise the frequency of particular genetic alterations, resulting in intra-tumor heterogeneity that presents a huge challenge for treatment. For example, mutations in the catenin β-1 (CTNNB1) gene (a proto-oncogene in the WNT signaling pathway that encodes the β‍-catenin transcription factor) are strongly associated with alcohol-related HCC, whereas mutations in the telomerase reverse transcriptase (TERT) promoter and tumor protein p53 (TP53) genes are the most commonly observed in hepatitis B virus (HBV)‍-associated HCC (Calderaro et al., 2017; Cancer Genome Atlas Research Network, 2017). The above findings emphasize the molecular diversity of HCC and the associations of different etiologies with distinct mechanisms in HCC progression. Consequently, prevention strategies are still attractive for HCC management.

Chronic liver injury promotes the molecular alterations that precede the establishment of cancer. Usually, several decades of chronic insults are needed to develop the most common primary liver tumor known as hepatocellular carcinoma. As other cancer types, liver cancer cells are governed by a common set of rules collectively called the hallmarks of cancer. Although those rules have provided a conceptual framework for understanding the complex pathophysiology of established tumors, therapeutic options are still ineffective in advanced stages. Thus, the molecular alterations that precede the establishment of cancer remain an attractive target for therapeutic interventions. Here, we first summarize the chemopreventive interventions targeting the early liver carcinogenesis stages. After an integrative analysis on the plethora of molecular alterations regulated by anticancer agents, we then underline and discuss that two critical processes namely oxidative stress and genetic alterations, play the role of 'dirty work laborer' in the initial cell damage and drive the transformation of preneoplastic into neoplastic cells, respectively; besides, the activation of cellular senescence works as a key mechanism in attempting to prevent the onset and establishment of liver cancer. Whereas the detrimental effects of the binomial made up of oxidative stress and genetic alterations are either eliminated or reduced, senescence activation is promoted by anticancer agents. We argue that collectively, oxidative stress, genetic alterations, and senescence are key events that influence the fate of initiated cells and the establishment of the hallmarks of cancer., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, irreversible, and highly fatal disease. It is characterized by the increased activation of both fibroblast and myofibroblast that results in excessive extracellular matrix (ECM) deposition. Extracellular vesicles (EVs) have been described as key mediators of intercellular communication in various pathologies. However, the role of EVs in the development of IPF remains poorly understood. This study aimed to characterize the differentially expressed proteins contained within EVs cargo derived from the fibroblast cell lines LL97A (IPF-1) and LL29 (IPF-2) isolated from lungs bearing IPF as compared to those derived from the fibroblast cell lines CCD8Lu (NL-1) and CCD19Lu (NL-2) isolated from healthy donors. Isolated EVs were subjected to label-free quantitative proteomic analysis by LC-MS/MS, and as a result, 331 proteins were identified. Differentially expressed proteins were obtained after the pairwise comparison, including all experimental groups. A total of 86 differentially expressed proteins were identified in either one or more comparison groups. Of note, proteins involved in fibrogenic processes, such as tenascin-c (TNC), insulin-like-growth-factor-binding protein 7 (IGFBP7), fibrillin-1 (FBN1), alpha-2 collagen chain (I) (COL1A2), alpha-1 collagen chain (I) (COL1A1), and lysyl oxidase homolog 1 (LOXL1), were identified in EVs cargo isolated from IPF cell lines. Additionally, KEGG pathway enrichment analysis revealed that differentially expressed proteins participate in focal adhesion, PI3K-Akt, and ECM-receptor interaction signaling pathways. In conclusion, our findings reveal that proteins contained within EVs cargo might play key roles during IPF pathogenesis.

The potential role of hepatocytes versus hepatic progenitor cells (HPC) on the onset and pathogenesis of hepatocellular carcinoma (HCC) has not been fully clarified. Because the administration of 2-acetylaminofluorene (2AAF) followed by a partial hepatectomy, selectively induces the HPC proliferation, we investigated the effects of chronic 2AAF administration on the HCC development caused by the chronic administration of the carcinogen diethylnitrosamine (DEN) for 16 weeks in the rat. DEN + 2AAF protocol impeded weight gain of animals but promoted prominent hepatomegaly and exacerbated liver alterations compared to DEN protocol alone. The tumor areas detected by γ-glutamyl transferase, prostaglandin reductase-1, and glutathione S-transferase Pi-1 liver cancer markers increased up to 80% as early as 12 weeks of treatment, meaning 6 weeks earlier than DEN alone. This protocol also increased the number of Ki67-positive cells and those of CD90 and CK19, two well-known progenitor cell markers. Interestingly, microarray analysis revealed that DEN + 2AAF protocol differentially modified the global gene expression signature and induced the differential expression of 30 genes identified as HPC markers as early as 6 weeks of treatment. In conclusion, 2AAF induces the early appearance of HPC markers and as a result, accelerates the hepatocarcinogenesis induced by DEN in the rat. Thus, since 2AAF simultaneously administrated with DEN enriches HPC during hepatocarcinogenesis, we propose that DEN + 2AAF protocol might be a useful tool to investigate the cellular origin of HCC with progenitor features., (© 2021 The Authors. Molecular Carcinogenesis published by Wiley Periodicals LLC.)

To date, there is no effective treatment for alcoholic liver disease, despite its prevalence world-wide. Because alcohol consumption is associated with oxidative stress-induced liver injury and pro-inflammatory responses, naturally occurring antioxidants and/or anti-inflammatories may be potential therapeutics. Spermidine is an abundant, ubiquitous polyamine that has been found to display strong antioxidant and anti-inflammatory properties. To further investigate whether spermidine is an effective intervention for alcohol-induced liver disease, we examined its hepatoprotective properties using a two-hit, chronic ethanol and acute lipopolysaccharide (LPS)-induced mouse model of liver injury. We determined that spermidine administration prevented ethanol and LPS-induced increases in liver injury using plasma ALT as a readout. Furthermore, histological analysis of tissue from control and treated animals revealed that the pathology associated with ethanol and LPS treatment was prevented in mice additionally treated with spermidine. As predicted, spermidine also prevented ethanol and LPS-induced oxidative stress by decreasing the levels of both reactive oxygen species (ROS) and lipid peroxidation. We further determined that spermidine treatment prevented the nuclear translocation of nuclear factor κB (NFκB) by blocking the phosphorylation of the inhibitory protein, IκB, thereby preventing expression of pro-inflammatory cytokines. Finally, by measuring expression of known markers of hepatic stellate cell activation and monitoring collagen deposition, we observed that spermidine also prevented alcohol and LPS-induced hepatic fibrosis. Together, our results indicate that spermidine is an antioxidant thereby conferring anti-inflammatory and anti-fibrotic effects associated with alcoholic liver injury.

Alcoholic liver disease (ALD) is closely linked to oxidative stress induction. Antioxidant enzymes balance oxidative stress and function as intermediary signaling regulators. Nucleoredoxin (NXN), an antioxidant enzyme, regulates physiological processes through redox-sensitive interactions. NXN interacts with myeloid differentiation primary response gene-88 (MYD88) and flightless-I (FLII) to regulate toll-like receptor 4 (TLR4)/MYD88 pathway activation, but FLII also regulates key cell processes and is secreted into the bloodstream. However, the effects of chronic ethanol consumption recapitulated by either ethanol alone or in combination with lipopolysaccharides (LPS), as a two-hit ALD model, on FLII/NXN/MYD88 complex and FLII secretion have not been explored yet. In this study, we have demonstrated that ethanol feeding increased FLII protein levels, its nuclear translocation and plasma secretion, and modified its tissue distribution both in vivo and in vitro ALD models. Ethanol increased MYD88/FLII interaction ratio, and decreased NXN/MYD88 interaction ratio but this was partially reverted by two-hit model. While ethanol and two-hit model increased MYD88/TLR4 interaction ratio, two-hit model significantly decreased FLII nuclear translocation and its plasma secretion. Ethanol and LPS provoked similar effects in vitro; however, NXN overexpression partially reverted these alterations, and ethanol alone increased FLII secretion into culture medium. In summary, by analyzing the response of FLII/NXN/MYD88 complex during ALD early progression both in vivo and in vitro, we have discovered that the effects of chronic ethanol consumption disrupt this complex and identified FLII as a candidate non-invasive plasma biomarker for the early detection of ALD., (Copyright © 2020. Published by Elsevier Inc.)

Alcoholic liver disease (ALD) may be attributed to multiple hits driving several alterations. The aim of this work was to determine whether nucleoredoxin (NXN) interacts with flightless-I (FLII)/actin complex and how this ternary complex is altered during ALD progression induced by different ALD models. ALD was recapitulated in C57BL/6J female mice by the well-known ALD Lieber-DeCarli model, and by an in vitro human co-culture system overexpressing NXN. The effects of ethanol and low doses of lipopolysaccharides (LPS) and diethylnitrosamine (DEN) were also evaluated in vivo as a first approach of an ALD multi-hit protocol. We demonstrated that NXN interacts with FLII/actin complex. This complex was differentially altered in ALD in vivo and in vitro, and NXN overexpression partially reverted this alteration. We also showed that ethanol, LPS and DEN synergistically induced liver structural disarrangement, steatosis and inflammatory infiltration accompanied by increased levels of proliferation (Ki67), ethanol metabolism (CYP2E1), hepatocarcinogenesis (GSTP1) and LPS-inducible (MYD88 and TLR4) markers. In summary, we provide evidence showing that NXN/FLII/actin complex is involved in ALD progression and that NXN might be involved in the regulation of FLII/actin-dependent cellular functions. Moreover, we present a promising first approach of a multi-hit protocol to better recapitulate ALD pathogenesis., (© 2020 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society). Published by John Wiley & Sons Ltd.)

Akt kinase isoforms (Akt1, Akt2, and Akt3) have generally been thought to play overlapping roles in phosphoinositide 3-kinase (PI3K)-mediated-signaling. However, recent studies have suggested that they display isoform-specific roles in muscle and fat. To determine whether such isoform-specificity is observed with respect to alcoholic liver disease (ALD) progression, we examined the role of Akt1, Akt2, and Akt3 in hepatic inflammation, and pro-fibrogenic proliferation and migration using Kupffer cells, hepatic stellate cells (HSC), and hepatocytes in an ethanol and lipopolysaccharide (LPS)-induced two-hit model in vitro and in vivo. We determined that siRNA-directed silencing of Akt2, but not Akt1, significantly suppressed cell inflammatory markers in HSC and Kupffer cells. Although both Akt1 and Akt2 inhibited cell proliferation in HSC, only Akt2 inhibited cell migration. Both Akt1 and Akt2, but not Akt3, inhibited fibrogenesis in hepatocytes and HSC. In addition, our in vivo results show that administration of chronic ethanol, binge ethanol and LPS (EBL) in wild-type C57BL/6 mice activated all three Akt isoforms with concomitant increases in activated forms of phosphoinositide dependent kinase-1 (PDK1), mammalian target-of-rapamycin complex 2 (mTORC2), and PI3K, resulting in upregulation in expression of inflammatory, proliferative, and fibrogenic genes. Moreover, pharmacological blocking of Akt2, but not Akt1, inhibited EBL-induced inflammation while blocking of both Akt1 and Akt2 inhibited pro-fibrogenic marker expression and progression of fibrosis. Our findings indicate that Akt isoforms play unique roles in inflammation, cell proliferation, migration, and fibrogenesis during EBL-induced liver injury. Thus, close attention must be paid when targeting all Akt isoforms as a therapeutic intervention.

Hepatocellular carcinoma (HCC) arises after a long period of exposition to etiological factors that might be either independent or collectively contributing. Several rodent models resemble human HCC; however, the major limitation of these models is the lack of chronic injury that reproducibly mimics the molecular alterations as it occurs in humans. Thus, we hypothesized that chronic administration of different DEN treatments identifies the best-fit dose to induce the HCC and/or to determine whether small DEN doses act synergistically with other known hepatotoxins to induce HCC in mice. C57BL/6 J male mice were intraperitoneally injected twice a week for 6 weeks with different DEN doses ranging from 2.5 to 40 mg/kg body weight; then, selected doses (2.5, 5 and 20 mg/kg) for 6, 10, 14, and 18 weeks. We demonstrated that DEN at 20 mg/kg promoted reactive oxygen species and 4-hydroxynonenal production, cell proliferation inflammatory infiltrate, and fibrosis, which in turn induced liver cancer by week 18. These parameters were established by evaluating histopathological changes, HCC markers such as glutathione S-transferase placental-1 (Gstp1), Cytokeratin-19 (Ck19) and prostaglandin reductase-1 (Ptgr1); that of Cyp2e1, a DEN metabolizing enzyme; and the expression of the proliferation marker Ki67. While DEN at 2.5 and 5 mg/kg increased Gstp1 and Ck19, DEN at 20 mg/kg decreased them and Cyp2e1 expression and activity. In summary, our results demonstrate that DEN chronically administrated at 20 mg/kg induces the HCC, while DEN at 2.5 and 5 mg/kg could be useful in elucidating its synergistic effect with other hepatotoxic agents in mice., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Nucleoredoxin (NXN) is a redox-regulating protein potentially targeted by reactive oxygen species (ROS). It regulates molecular pathways that participate in several key cellular processes. However, the role of NXN in the alcohol liver disease (ALD) redox regulation has not been fully understood. Here, we investigated the effects of ethanol and ethanol plus lipopolysaccharide, a two-hit liver injury model (Ethanol/LPS), on NXN/dishevelled (DVL) interaction and on DVL-dependent phosphoinositides production both in mouse liver and in a co-culture system consisting of human hepatic stellate cells (HSC) and ethanol metabolizing-VL17A human hepatocyte cells. Ethanol and two-hit model increased Nxn protein and mRNA expression, and 4-hydroxynonenal adducts. Two-hit model promoted Nxn nuclear translocation and Dvl/Phosphatidylinositol 4-kinase type-IIα (Pi4k2a) interaction ratio but surprisingly decreased Dvl protein and mRNA levels and reverted ethanol-induced Nxn/Dvl and Dvl/frizzled (Fzd) interaction ratios. Ethanol resulted in a significant increase of Dvl protein and mRNA expression, and decreased Nxn/Dvl interaction ratio but promoted the interaction of Dvl with Fzd and Pi4k2a; formation of this complex induced phosphatidylinositol 4-phosphate [PI(4)P] production. Ethanol and LPS treatments provoked similar alterations on NXN/DVL interaction and its downstream effect in HSC/VL17A co-culture system. Interestingly, ROS and glutathione levels as well as most of ethanol-induced alterations were modified by NXN overexpression in the co-culture system. In conclusion, two-hit model of ethanol exposure disrupts NXN/DVL homeostatic status to allow DVL/FZD/PI4K2A complex formation and stimulates PI(4)P production. These results provide a new mechanism showing that NXN also participates in the regulation of phosphoinositides production that is altered by ethanol during alcoholic liver disease progression., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: The intrinsic heterogeneity of hepatocellular carcinoma (HCC) represents a great challenge for its molecular classification and for detecting predictive biomarkers. Aldo-keto reductase (Akr) family members have shown differential expression in human HCC, while AKR1B10 overexpression is considered a biomarker; AKR7A3 expression is frequently reduced in HCC., Aims: To investigate the time-course expression of Akr members in the experimental hepatocarcinogenesis., Methods: Using DNA-microarray data, we analyzed the time-course gene expression profile from nodules to tumors (4-17 months) of 17 Akr members induced by the resistant hepatocyte carcinogenesis model in the rat., Results: The expression of six members (Akr1c19, Akr1b10, Akr7a3, Akr1b1, Akr1cl1, and Akr1b8) was increased, comparable to that of Ggt and Gstp1, two well-known liver cancer markers. In particular, Akr7a3 and Akr1b10 expression also showed a time-dependent increment at mRNA and protein levels in a second hepatocarcinogenesis model induced with diethylnitrosamine. We confirmed that aldo-keto reductases 7A3 and 1B10 were co-expressed in nine biopsies of human HCC, independently from the presence of glypican-3 and cytokeratin-19, two well-known HCC biomarkers. Because it has been suggested that expression of Akr members is regulated through NRF2 activity at the antioxidant response element (ARE) sequences, we searched and identified at least two ARE sites in Akr1b1, Akr1b10, and Akr7a3 from rat and human gene sequences. Moreover, we observed higher NRF2 nuclear translocation in tumors as compared with non-tumor tissues., Conclusions: Our results demonstrate that Akr7a3 mRNA and protein levels are consistently co-expressed along with Akr1b10, in both experimental liver carcinogenesis and some human HCC samples. These results highlight the presence of AKR7A3 and AKR1B10 from early stages of the experimental HCC and introduce them as a potential application for early diagnosis, staging, and prognosis in human cancer.

Cellular senescence is characterized by irreversible cell arrest and is associated with the development of chronic diseases, including cancer. Here, we investigated the induction of cellular senescence during liver carcinogenesis. Liver cancer was induced in Fischer 344 rats with a weekly intraperitoneal injection of diethylnitrosamine (50mg/kg body weight) for 16 weeks. Double-detection of β-galactosidase with Ki67 for cell proliferation; a-SMA and Pdgfrb for cell specificity; p53, p21, p16, and cyclin D1, CDK2, and CDK4 for senescence-associated molecular pathways and γ-glutamyltranspeptidase (GGT) for hepatocarcinogenesis was assessed to determine the association of these markers with cellular senescence. DNA damage was measured through senescence-associated heterochromatin foci (SAHF) detection. Progressive cellular senescence was observed in both fibrotic septa and hepatocytes from week 10 to 18. The maximum peak of positive senescent and fibrotic cells was observed at week 16 and decreased at week 18, but cell proliferation remained high. Whereas the increased p16 expression and SAHF were concomitant with that of β-galactosidase, those of p53 and p21 were barely detected. Furthermore, β-galactosidase positive myofibroblast-like cells were mainly surrounding GGT-positive tumors. Our findings showed that in hepatocarcinogenesis by diethylnitrosamine, cellular senescence is associated with p16 pathway activation and is mainly localized in myofibroblast-like cells., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Alcoholic steatosis, instead of being innocuous, plays a critical role in liver inflammation and fibrogenesis. The severity of fatty liver is governed by the concerted balance between lipid transport, synthesis, and degradation. Whereas scavenger receptor class B, type I (SR-B1) is critical for reverse cholesterol uptake by the liver, peroxisome proliferator-activated receptor-gamma (PPARγ) coactivator-1α and -β (PGC1α and PGC1β) are critical for lipid degradation and synthesis, respectively. Because betaine is a lipotropic agent, we have evaluated its effects on alcoholic steatosis. Betaine effectively prevented chronic alcohol-mediated (i) impaired SR-B1 glycosylation, plasma membrane localization, and consequent impaired cholesterol transport; and (ii) up regulation of PGC-1β, sterol regulatory element-binding protein 1c and downstream lipogenic genes with concomitant increased liver cholesterol, triglycerides and hepatic lipid score. Similarly, because of its anti-inflammatory and anti-fibrotic effects in other organs, we evaluated the protective effects of thymosin β4 (Tβ4) against carbon tetrachloride (CCl4)-induced hepatotoxicity in rat. Tβ4 prevented CCl4-induced (i) necrosis, inflammatory infiltration and up-regulation of α1(2)collagen, alpha-smooth muscle actin (α-SMA), platelet derived growth factor beta (PDGF-β) receptor and fibronectin mRNA expression; (ii) down-regulation of adipogenic gene, PPARγ and the up-regulation of epigenetic repressor gene, methyl CpG binding protein 2 (MeCP2) mRNA levels, suggesting that the anti-fibrogenic actions of Tβ4 involve the prevention of trans-differentiation of quiescent hepatic stellate cells into myo-fibroblasts largely by up-regulating PPARγ and by down-regulating MeCP2 genes. We therefore conclude that betaine and Tβ4 can effectively protect against alcoholic hepatosteatosis and hepatic fibrogenesis, respectively.

Because scavenger receptor class B type 1 is the cholesterol uptake liver receptor, whereas peroxisome proliferator-activated receptor γ coactivator-1β (PGC-1β) and PGC-1α are critical for lipid synthesis and degradation, we investigated the roles of these signaling molecules in the actions of ethanol-polyunsaturated fatty acids and betaine on hepatosteatosis and steatohepatitis. Ethanol-polyunsaturated fatty acid treatment caused the following: i) hepatosteatosis, as evidenced by increased liver cholesterol and triglycerides, lipid score, and decreased serum adiponectin; ii) marked inhibition of scavenger receptor class B type 1 glycosylation, its plasma membrane localization, and its hepatic cholesterol uptake function; and iii) moderate steatohepatitis, as evidenced by histopathological characteristics, increased liver tumor necrosis factor α and IL-6, decreased glutathione, and elevated serum alanine aminotransferase. These actions of ethanol involved up-regulated PGC-1β, sterol regulatory element-binding proteins 1c and 2, acetyl-CoA carboxylase, and HMG-CoA reductase mRNAs/proteins and inactive non-phosphorylated AMP kinase; and down-regulated silence regulator gene 1 and PGC-1α mRNA/proteins and hepatic fatty acid oxidation. Betaine markedly blunted all these actions of ethanol on hepatosteatosis and steatohepatitis. Therefore, we conclude that ethanol-mediated impaired post-translational modification, trafficking, and function of scavenger receptor class B type 1 may account for alcoholic hyperlipidemia. Up-regulation of PGC-1β and lipid synthetic genes and down-regulation of silence regulator gene 1, PGC-1α, adiponectin, and lipid degradation genes account for alcoholic hepatosteatosis. Induction of proinflammatory cytokines and depletion of endogenous antioxidant, glutathione, account for alcoholic steatohepatitis. We suggest betaine as a potential therapeutic agent because it effectively protects against adverse actions of ethanol., (Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Alcohol-induced liver fibrosis and eventually cirrhosis is a leading cause of death. Acetaldehyde, the first metabolite of ethanol, up-regulates expression of the human α2(I) collagen gene (COL1A2). Early acetaldehyde-mediated effects involve phosphorylation and nuclear translocation of SMAD3/4-containing complexes that bind to COL1A2 promoter to induce fibrogenesis. We used human and mouse hepatic stellate cells to elucidate the mechanisms whereby acetaldehyde up-regulates COL1A2 by modulating the role of Ski and the expression of SMADs 3, 4, and 7. Acetaldehyde induced up-regulation of COL1A2 by 3.5-fold, with concomitant increases in the mRNA (threefold) and protein (4.2- and 3.5-fold) levels of SMAD3 and SMAD4, respectively. It also caused a 60% decrease in SMAD7 expression. Ski, a member of the Ski/Sno oncogene family, is colocalized in the nucleus with SMAD4. Acetaldehyde induces translocation of Ski and SMAD4 to the cytoplasm, where Ski undergoes proteasomal degradation, as confirmed by the ability of the proteasomal inhibitor lactacystin to blunt up-regulation of acetaldehyde-dependent COL1A2, but not of the nonspecific fibronectin gene (FN1). We conclude that acetaldehyde up-regulates COL1A2 by enhancing expression of the transactivators SMAD3 and SMAD4 while inhibiting the repressor SMAD7, along with promoting Ski translocation from the nucleus to cytoplasm. We speculate that drugs that prevent proteasomal degradation of repressors targeting COL1A2 may have antifibrogenic properties., (Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

We investigated whether the fibrogenic actions of acetaldehyde, the immediate oxidation product of ethanol, are mediated via Wingless (WNT) and/or β-catenin pathways in human hepatic stellate cells (HSC). First, we show that both β-catenin small inhibitory RNA and a dominant negative-MYC expression vector markedly down-regulated the expressions of fibrogenic genes in freshly isolated HSC. We further show that acetaldehyde up-regulated platelet-derived growth factor receptor beta mRNA and protein expressions ranging from 4.0- to 7.2-fold (P<0.001). Acetaldehyde induced MYC and collagen type-1 alpha-2 mRNA and protein expressions were WNT independent because DKK1, an antagonist of the canonical WNT/β-catenin pathway, completely failed to block these inductions. Acetaldehyde increased phospho-glycogen synthase kinase-3 beta (GSK3B) protein by 31% (P<0.01), whereas phospho-β-catenin protein decreased by 50% (P ≤ 0.01). Significantly, in contrast to 43% (P<0.01) inhibition of β-catenin nuclear translocation in nucleoredoxin (NXN)-overexpressed HSC, acetaldehyde profoundly stimulated β-catenin nuclear translocation by 51%, (P<0.01). Acetaldehyde also increased the cellular reactive oxygen species level 2-fold (P<0.001) with a concomitant 2-fold (P<0.001) increase in 4-hydroxynonenal adducts. Conversely, there was a 44% decrease (P<0.001) in glutathione levels with a concomitant 76% (P<0.001) decrease in the level of NXN/ disheveled (DVL) complex. Based on these findings, we conclude that actions of acetaldehyde are mediated by a mechanism that inactivates NXN by releasing DVL, leading to the inactivation of GSK3B, and thereby blocks β-catenin phosphorylation and degradation. Thus, the stabilized β-catenin translocates to the nucleus where it up-regulates the fibrogenic pathway genes. This novel mechanism of action of acetaldehyde has the potential for therapeutic interventions in liver fibrosis induced by alcohol., (Published by Elsevier Inc.)

Conversion of protein -SH groups to disulfides is an early event during protein oxidation, which has prompted great interest in the study of thiol proteins. Chemical carcinogenesis is strongly associated with the formation of reactive oxygen species (ROS). The goal of this study was to detect thiol proteins that are sensitive to ROS generated during diethylnitrosamine (DEN) metabolism in the rat liver. DEN has been widely used to induce experimental hepatocellular carcinoma. We used modified redox-differential gel electrophoresis (redox-DIGE method) and mass spectrometry MALDI-TOF/TOF to identify differential oxidation protein profiles associated with carcinogen exposure. Our analysis revealed a time-dependent increase in the number of oxidized thiol proteins after carcinogen treatment; some of these proteins have antioxidant activity, including thioredoxin, peroxirredoxin 2, peroxiredoxin 6 and glutathione S-transferase alpha-3. According to functional classifications, the identified proteins in our study included chaperones, oxidoreductases, activity isomerases, hydrolases and other protein-binding partners. This study demonstrates that oxidative stress generated by DEN tends to increase gradually through DEN metabolism, causes time-dependent necrosis in the liver and has an oxidative effect on thiol proteins, thereby increasing the number of oxidized thiol proteins. Furthermore, these events occurred during the hepatocarcinogenesis initiation period., (© 2013.)

Background: Transforming growth factor beta 1 (TGF-β1) is a pleiotropic cytokine that activates hepatic stellate cell (HSC) proliferation, but inhibits parenchymal cell proliferation. Therefore, we hypothesize that TGF-β1 regulates HSC proliferation and elucidated its molecular action., Methods: In order to elucidate the molecular mechanism whereby TGF-β1 up-regulates platelet derived growth factor beta (PDGF-β) receptor mRNA and induces a delayed proliferation of HSC, we used proliferation and apoptosis assays as well as RT-PCR, Western blot analysis, immunostaining, and flow cytometry in mouse and rat HSC., Results: We show that TGF-β1 markedly induces the proliferation of mouse HSC in culture with concomitant 2.1-fold (p < 0.001) stimulation in [(3) H]-thymidine incorporation into cellular DNA. This induction is maximal between 24 and 36 hours postcytokine exposure that is triggered by 7.6-fold (p < 0.001) up-regulation of PDGF-β receptor mRNA and associated increase in PDGF-β receptor protein after 48 hours. TGF-β1-dependent HSC proliferation is mimicked by H2 O2 that is inhibited by catalase, implying that TGF-β1 action is mediated via reactive oxygen species. HSC proliferation is blunted by PDGF-β receptor-neutralizing antibody as well as by specific inhibitors of PI3 kinase (PI3K), AKT, and p70(S6K) , indicating that the action of TGF-β1 involves the activation of PDGF-β receptor via the PI3K/AKT/p70(S6K) signaling pathway. TGF-β1 also induces a reorganization of actin and myosin filaments and cell morphology leading to the formation of palisades although their myosin and actin contents remained constant. These findings suggest that TGF-β1-mediated oxidative stress causes the transdifferentiation of HSC and primes them for extracellular matrix (ECM) deposition and scar contraction., Conclusions: We conclude that liver injury up-regulates TGF-β1 that inhibits parenchymal cell proliferation, but stimulates HSC proliferation leading to the production of ECM and type I collagen resulting in fibrosis., (Copyright © 2013 by the Research Society on Alcoholism.)