Genome-Wide Analysis of DNA Methylation and Acute Coronary Syndrome.

RATIONALE: Acute coronary syndrome (ACS) is a leading cause of death worldwide. Immune functions play a vital role in ACS development; however, whether epigenetic modulation contributes to the regulation of blood immune cells in this disease has not been investigated. OBJECTIVE: We conducted an epigenome-wide analysis with circulating immune cells to identify differentially methylated genes in ACS. METHODS AND RESULTS: We examined genome-wide methylation of whole blood in 102 ACS patients and 101 controls using HumanMethylation450 array, and externally replicated significant discoveries in 100 patients and 102 controls. For the replicated loci, we further analyzed their association with ACS in 6 purified leukocyte subsets, their correlation with the expressions of annotated genes, and their association with cardiovascular traits/risk factors. We found novel and reproducible association of ACS with blood methylation at 47 cytosine-phosphoguanine sites (discovery: false discovery rate <0.005; replication: Bonferroni corrected P<0.05). The association of methylation levels at these cytosine-phosphoguanine sites with ACS was further validated in at least 1 of the 6 leukocyte subsets, with predominant contributions from CD8+ T cells, CD4+ T cells, and B cells. Blood methylation of 26 replicated cytosine-phosphoguanine sites showed significant correlation with expressions of annotated genes (including IL6R, FASLG, and CCL18; P<5.9×10-4), and differential gene expression in case versus controls corroborated the observed differential methylation. The replicated loci suggested a role in ACS-relevant functions including chemotaxis, coronary thrombosis, and T-cell-mediated cytotoxicity. Functional analysis using the top ACS-associated methylation loci in purified T and B cells revealed vital pathways related to atherogenic signaling and adaptive immune response. Furthermore, we observed a significant enrichment of the replicated cytosine-phosphoguanine sites associated with smoking and low-density lipoprotein cholesterol (Penrichment≤1×10-5). CONCLUSIONS: Our study identified novel blood methylation alterations associated with ACS and provided potential clinical biomarkers and therapeutic targets. Our results may suggest that immune signaling and cellular functions might be regulated at an epigenetic level in ACS.

Molecular Aspects of the FAH Mutations Involved in HT1 Disease.

Hereditary tyrosinemia type 1 (HT1) is caused by the lack of fumarylacetoacetate hydrolase (FAH), the last enzyme of the tyrosine catabolic pathway. Up to now, around 100 mutations in the FAH gene have been associated with HT1, and despite many efforts, no clear correlation between genotype and clinical phenotype has been reported. At first, it seems that any mutation in the gene results in HT1. However, placing these mutations in their molecular context allows a better understanding of their possible effects. This chapter presents a closer look at the FAH gene and its corresponding protein in addition to provide a complete record of all the reported mutations causing HT1.

Molecular Pathogenesis of Liver Injury in Hereditary Tyrosinemia 1.

Untreated HT1 rapidly degenerates into very severe liver complications often resulting in liver cancer. The molecular basis of the pathogenic process in HT1 is still unclear. The murine model of FAH-deficiency is a suitable animal model, which represents all phenotypic and biochemical manifestations of the human disease on an accelerated time scale. After removal of the drug 2-(2-N-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC), numerous signaling pathways involved in cell proliferation, differentiation and cancer are rapidly deregulated in FAH deficient mice. Among these, the Endoplasmic reticulum (ER) pathway, the heat stress response (HSR), the Nrf2, MEK and ERK pathways, are highly represented. The p21 and mTOR pathways critical regulators of proliferation and tumorigenesis have also been found to be dysregulated. The changes in these pathways are described and related to the development of liver cancer.

Molecular changes associated with chronic liver damage and neoplastic lesions in a murine model of hereditary tyrosinemia type 1.

Hereditary tyrosinemia type 1 (HT1) is the most severe inherited metabolic disease of the tyrosine catabolic pathway, with a progressive hepatic and renal injury and a fatal outcome if untreated. Toxic metabolites accumulating in HT1 have been shown to elicit endoplasmic reticulum (ER) stress response, and to induce chromosomal instability, cell cycle arrest and apoptosis perturbation. Although many studies have concentrated on elucidating these events, the molecular pathways responsible for development of hepatocellular carcinoma (HCC) still remain unclear. In this study the fah knockout murine model (fah(-/-)) was used to investigate the cellular signaling implicated in the pathogenesis of HT1. Fah(-/-) mice were subjected to drug therapy discontinuation (Nitisinone withdrawal), and livers were analyzed at different stages of the disease. Monitoring of mice revealed an increasing degeneration of the overall physiological conditions following drug withdrawal. Histological analysis unveiled diffuse hepatocellular damage, steatosis, oval-like cells proliferation and development of liver cell adenomas. Immunoblotting results revealed a progressive and chronic activation of stress pathways related to cell survival and proliferation, including several stress regulators such as Nrf2, eIF2α, CHOP, HO-1, and some members of the MAPK signaling cascade. Impairment of stress defensive mechanisms was also shown by microarray analysis in fah(-/-) mice following prolonged therapy interruption. These results suggest that a sustained activation of stress pathways in the chronic HT1 progression might play a central role in exacerbating liver degeneration.

Cooperative pro-tumorigenic adaptation to oncogenic RAS through epithelial-to-mesenchymal plasticity.

In breast cancers, aberrant activation of the RAS/MAPK pathway is strongly associated with mesenchymal features and stemness traits, suggesting an interplay between this mitogenic signaling pathway and epithelial-to-mesenchymal plasticity (EMP). By using inducible models of human mammary epithelial cells, we demonstrate herein that the oncogenic activation of RAS promotes ZEB1-dependent EMP, which is necessary for malignant transformation. Notably, EMP is triggered by the secretion of pro-inflammatory cytokines from neighboring RAS-activated senescent cells, with a prominent role for IL-6 and IL-1α. Our data contrast with the common view of cellular senescence as a tumor-suppressive mechanism and EMP as a process promoting late stages of tumor progression in response to signals from the tumor microenvironment. We highlighted here a pro-tumorigenic cooperation of RAS-activated mammary epithelial cells, which leverages on oncogene-induced senescence and EMP to trigger cellular reprogramming and malignant transformation.

Human molecular chaperones share with SARS-CoV-2 antigenic epitopes potentially capable of eliciting autoimmunity against endothelial cells: possible role of molecular mimicry in COVID-19.

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), the cause of COVID-19 disease, has the potential to elicit autoimmunity because mimicry of human molecular chaperones by viral proteins. We compared viral proteins with human molecular chaperones, many of which are heat shock proteins, to determine if they share amino acid-sequence segments with immunogenic-antigenic potential, which can elicit cross-reactive antibodies and effector immune cells with the capacity to damage-destroy human cells by a mechanism of autoimmunity. We identified the chaperones that can putatively participate in molecular mimicry phenomena after SARS-CoV-2 infection, focusing on those for which endothelial cell plasma-cell membrane localization has already been demonstrated. We also postulate that post-translational modifications, induced by physical (shear) and chemical (metabolic) stress caused respectively by the risk factors hypertension and diabetes, might have a role in determining plasma-cell membrane localization and, in turn, autoimmune-induced endothelial damage.

Corrigendum: Green tea consumption is associated with reduced incident CHD and improved CHD-related biomarkers in the Dongfeng-Tongji cohort.

This corrects the article DOI: 10.1038/srep24353.

Identification of circulating microRNAs during the liver neoplastic process in a murine model of hereditary tyrosinemia type 1.

Hereditary tyrosinemia type 1 (HT1) is a severe inborn error of metabolism, impacting the tyrosine catabolic pathway with a high incidence of hepatocellular carcinoma (HCC). Using a HT1 murine model, we investigated the changes in profiles of circulating and hepatic miRNAs. The aim was to determine if plasma miRNAs could be used as non-invasive markers of liver damage in HT1 progression. Plasma and liver miRNAome was determined by deep sequencing after HT1 phenotype was induced. Sequencing analysis revealed deregulation of several miRNAs including let-7/miR-98 family, miR-21 and miR-148a, during manifestation of liver pathology. Three miRNAs (miR-98, miR-200b, miR-409) presenting the highest plasmatic variations among miRNAs found in both plasma and liver and with >1000 reads in at least one plasma sample, were further validated by RT-qPCR. Two of these miRNAs have protein targets involved in HT1 and significant changes in their circulating levels are detectable prior an increase in protein expression of alpha-fetoprotein, the current biomarker for HCC diagnosis. Future assessment of these miRNAs in HT1 patients and their association with liver neoplastic lesions might designate these molecules as potential biomarkers for monitoring HT1 damage progression, improving diagnosis for early HCC detection and the design of novel therapeutic targets.

Sleep Duration and Midday Napping with 5-Year Incidence and Reversion of Metabolic Syndrome in Middle-Aged and Older Chinese.

STUDY OBJECTIVES: Prospective evidence on the association of sleep duration and midday napping with metabolic syndrome (MetS) is limited. We aimed to examine the associations of sleep duration and midday napping with risk of incidence and reversion of MetS and its components among a middle-aged and older Chinese population. METHODS: We included 14,399 subjects from the Dongfeng-Tongji (DFTJ) Cohort Study (2008-2013) who were free of coronary heart disease, stroke, and cancer at baseline. Baseline data were obtained by questionnaires and health examinations. Odds ratios (ORs) and 95% confidence interval (CI) were derived from multivariate logistic regression models. RESULTS: After controlling for potential covariates, longer sleep duration (≥ 9 h) was associated with a higher risk of MetS incidence (OR, 1.29; 95% CI, 1.08-1.55) and lower reversion of MetS (OR, 0.80; 95% CI, 0.66-0.96) compared with sleep duration of 7 to < 8 h; whereas shorter sleep duration (< 6 h) was not related to incidence or reversion of MetS. For midday napping, subjects with longer napping (≥ 90 min) was also associated with a higher risk of MetS incidence and a lower risk of MetS reversion compared with those with napping of 1 to < 30 min (OR, 1.48; 95% CI, 1.05-2.10 and OR, 0.70; 95% CI, 0.52-0.94, respectively). Significance for incidence or reversion of certain MetS components remained in shorter and longer sleepers but disappeared across napping categories. CONCLUSIONS: Both longer sleep duration and longer midday napping were potential risk factors for MetS incidence, and concurrently exert adverse effects on MetS reversion.

Green tea consumption is associated with reduced incident CHD and improved CHD-related biomarkers in the Dongfeng-Tongji cohort.

Prospective studies on the association of green tea with risk of coronary heart disease (CHD) incidence were scarce. This study examined whether green tea can reduce CHD incidence and have a beneficial effect on CHD-related risk markers in middle-aged and older Chinese population. We included 19,471 participants who were free of CHD, stroke or cancer at baseline from September 2008 to June 2010, and were followed until October 2013. Cox proportional hazard models were used to examine the hazard ratios (HR) of CHD incidence in relation to green tea consumption. Linear regression models were used to evaluate the effect of green tea on 5-year changes of CHD-related biomarkers. Compared with non-green tea consumers, the multivariable-adjusted HR for CHD was 0.89 (95% CI, 0.81-0.98) in green tea consumers. Particularly, the reduced risk of CHD incidence with green tea consumption was more evident among participants who were male, more than 60 years old, overweight, or with diabetes mellitus. In addition, green tea consumption improved multiple CHD-related risk markers including total cholesterol, HDL-cholesterol, triglycerides, mean platelet volume, and uric acid. In conclusion, green tea consumption was associated with a reduced risk of CHD incidence in the middle-aged and older Chinese populations, and the association might be partly due to altered CHD-related biomarkers.

Dose-response relationship between serum uric acid levels and risk of incident coronary heart disease in the Dongfeng-Tongji Cohort.

BACKGROUND: In prospective studies, relationship of serum uric acid (SUA) with risk of coronary heart disease (CHD) incidence is inconsistent. We evaluated the association of SUA with incident CHD and the potential modifying effect of major CHD risk factors related to SUA among a middle aged and elderly Chinese population. METHODS: We included 16, 063 participants who were free of CHD, stroke, cancer and renal diseases at baseline from Sep. 2008 to June 2010, and were followed until Oct. 2013. Cox proportional hazard model was used to estimate the hazard ratios (HR) and 95% confidence interval (95% CI) of CHD incidence in relation to SUA. RESULTS: The adjusted HR for incident CHD increased gradually with the increasing SUA levels (P for linear trend=0.005), and the HR across sex-specific SUA quartile was 1.26 (95% CI: 1.09, 1.47), 1.13 (95% CI: 0.97, 1.31), 1.23 (95% CI: 1.06, 1.43) and 1.00 (reference; P for trend=0.014), respectively. In particular, the association was more evident in individuals with normal-weight and those without hypertension or metabolic syndrome (all P for interactions<0. 05). CONCLUSIONS: These findings suggested that higher SUA levels were independently associated with a dose-response increased risk of CHD incidence.

Geographical and Ethnic Distribution of Mutations of the Fumarylacetoacetate Hydrolase Gene in Hereditary Tyrosinemia Type 1.

Hereditary tyrosinemia type 1 (HT1) (OMIM 276700) is a severe inherited metabolic disease affecting mainly hepatic and renal functions that leads to a fatal outcome if untreated. HT1 results from a deficiency of the last enzyme of tyrosine catabolism, fumarylacetoacetate hydrolase (FAH). Biochemical findings include elevated succinylacetone in blood and urine; elevated plasma concentrations of tyrosine, methionine and phenylalanine; and elevated tyrosine metabolites in urine. The HT1 frequency worldwide is about 1 in 100,000 individuals. In some areas, where the incidence of HT1 is noticeably higher, prevalence of characteristic mutations has been reported, and the estimated incidence of carriers of a specific mutation can be as high as 1 out of 14 adults. Because the global occurrence of HT1 is relatively low, a considerable number of cases may go unrecognized, underlining the importance to establish efficient prenatal and carrier testing to facilitate an early detection of the disease. Here we describe the 95 mutations reported so far in HT1 with special emphasis on their geographical and ethnic distributions. Such information should enable the establishment of a preferential screening process for mutations most predominant in a given region or ethnic group.

Heat shock response associated with hepatocarcinogenesis in a murine model of hereditary tyrosinemia type I.

Hereditary Tyrosinemia type 1 (HT1) is a metabolic liver disease caused by genetic defects of fumarylacetoacetate hydrolase (FAH), an enzyme necessary to complete the breakdown of tyrosine. The severe hepatic dysfunction caused by the lack of this enzyme is prevented by the therapeutic use of NTBC (2-[2-nitro-4-(trifluoromethyl)benzoyl] cyclohexane-1,3-dione). However despite the treatment, chronic hepatopathy and development of hepatocellular carcinoma (HCC) are still observed in some HT1 patients. Growing evidence show the important role of heat shock proteins (HSPs) in many cellular processes and their involvement in pathological diseases including cancer. Their survival-promoting effect by modulation of the apoptotic machinery is often correlated with poor prognosis and resistance to therapy in a number of cancers. Here, we sought to gain insight into the pathophysiological mechanisms associated with liver dysfunction and tumor development in a murine model of HT1. Differential gene expression patterns in livers of mice under HT1 stress, induced by drug retrieval, have shown deregulation of stress and cell death resistance genes. Among them, genes coding for HSPB and HSPA members, and for anti-apoptotic BCL-2 related mitochondrial proteins were associated with the hepatocarcinogenetic process. Our data highlight the variation of stress pathways related to HT1 hepatocarcinogenesis suggesting the role of HSPs in rendering tyrosinemia-affected liver susceptible to the development of HCC.

A human CCT5 gene mutation causing distal neuropathy impairs hexadecamer assembly in an archaeal model.

Chaperonins mediate protein folding in a cavity formed by multisubunit rings. The human CCT has eight non-identical subunits and the His147Arg mutation in one subunit, CCT5, causes neuropathy. Knowledge is scarce on the impact of this and other mutations upon the chaperone's structure and functions. To make progress, experimental models must be developed. We used an archaeal mutant homolog and demonstrated that the His147Arg mutant has impaired oligomeric assembly, ATPase activity, and defective protein homeostasis functions. These results establish for the first time that a human chaperonin gene defect can be reproduced and studied at the molecular level with an archaeal homolog. The major advantage of the system, consisting of rings with eight identical subunits, is that it amplifies the effects of a mutation as compared with the human counterpart, in which just one subunit per ring is defective. Therefore, the slight deficit of a non-lethal mutation can be detected and characterized.

Synthesis and biological activities of a new class of heat shock protein 90 inhibitors, designed by energy-based pharmacophore virtual screening.

The design through energy-based pharmacophore virtual screening has led to aminocyanopyridine derivatives as efficacious new inhibitors of Hsp90. The synthesized compounds showed a good affinity for the Hsp90 ATP binding site in the competitive binding assay. Moreover, they showed an excellent antiproliferative activity against a large number of human tumor cell lines. Further biological studies on the derivative with the higher EC50 confirmed its specific influence on the cellular pathways involving Hsp90.

Chaperonopathies and chaperonotherapy. Hsp60 as therapeutic target in cancer: potential benefits and risks.

In this minireview we focus on Hsp60 as a target for anticancer therapy. We discuss the new concepts of chaperonopathies and chaperonotherapy and present information on Hsp60 localization in the cell membrane of human tumor cells. We describe novel mechanisms for Hsp60 reaching the extracellular environment that involve membrane-associated stages, as well as data on anti-Hsp60 antibodies found in human sera, both in normal subjects and patients affected by autoimmune diseases. Finally, we discuss possible therapeutic applications of anti-Hsp60 antibodies in cancer treatment, evaluating also side effects on non-tumor cells. In conclusion, the way for investigating Hsp60-targeted anti-tumor therapy is open, at least for those tumors that express Hsp60 on its surface and/or secrete it outside the cell, as is the search for the molecular mechanisms involved in Hsp60 translocation from cytosol to cell membrane: elucidation of this mechanism will greatly facilitate the optimization of chaperonotherapy centered on Hsp60 with anti-tumor efficacy and minimal side effects.

Hsp60, a novel target for antitumor therapy: structure-function features and prospective drugs design.

Heat shock protein 60 kDa (Hsp60) is a chaperone classically believed to be involved in assisting the correct folding of other mitochondrial proteins. Hsp60 also plays a role in cytoprotection against cell stressors, displaying for example, antiapoptotic potential. Despite the plethora of studies devoted to the mechanism of Hsp60's function, especially in prokaryotes, fundamental issues still remain unexplored, including the definition of its role in cancer. Key questions still unanswered pertain to the differences in structure-function features that might exist between the well-studied prokaryotic GroEL and the largely unexplored eukaryotic Hsp60 proteins. In this article we discuss these differences in sequence, structure, and roles of Hsp60, focusing on the human ortholog with the view of devising compounds to block its ability to favour tumor-cell growth and survival. Compounds currently known to directly or indirectly affect Hsp60 functions, such as protein folding, HIF-1α accumulation, or Hsp60-induced cell proliferation, are discussed along with strategies that might prove effective for developing Hsp60-targeting drugs for anticancer therapy.