Role of DNA dioxygenase TET1 in cardiac fibrosis induced by high pressure / 中国药理学通报

Aim To investigate the mechanism of TET1 in cardiac fibrosis induced by high pressure. Methods Wistar rats and spontaneous hypertension rats(SHR) were selected to detected the expression of TET1, TGF-β, COL-1 and COL-3 in myocardium by Western blot; HE and Masson staining were used to detect myocardial pathological changes. Neonatal rat cardiac fibroblasts (NRCFs) were isolated from the ventricles of neonatal Sprague-Dawley rats and stimulated by 0 mm-Hg, 120 mmHg and 180 mmHg high pressure. Immunofluorescence was used to detect the changes of 5-hmC in the NRCFs. The changes of 5-hmC and 5-mC in TGF-β promoter region were detected by qRT-PCR. The expressions of TET1, TGF-β, COL-1 and COL-3 were detected by Western blot. Results Compared with Wistar rats, SHR showed increased blood pressure, increased fibrous collagen in ventricular tissues, and significantly increased expressions of TET1, TGF-P, COL-1 and COL-3. Compared with the 0 mmHg group, 120 mmHg and 180 mmHg group significantly induced the increase of TET1, 5-hmC, TGF-p, COL-1 and COL-3. TET1 knockdown significantly reduced the increase of 5-hmC, TGF-β, COL-1 and COL-3 under 180 mmHg pressure. Besides, knockdown TET1 significantly reduced the level of 5-hmC and increased the level of 5-mC and 5-hmC in the TGF-β promoter region. Conclusions High pressure induced cardiac fibrosis is associated with the promotion of TGF-β promoter demethylation and the increased of TGF-β expression by TET1.

TET methylcytosine oxidases: new insights from a decade of research

In primates, males compete for a mate, which is a non-sharable resource. This makes the conditions lessconducive for males to have stable relationships. One such special kind of relationship is a bond where theinteractions are reciprocated, equitable and differentiated. Bonds in macaque societies are based on the degreeof within-group contest competition for mates which is dependent on the synchronization of female fertilephase and reliability of fertility signals. Species of the Fascicularis group, including Nicobar subspecies, showintermediate reliability in the signals with mild peaks, and studies have shown reciprocity but no differentiation. We conducted a study on a group of wild Nicobar long-tailed macaques Macaca fascicularis umbrosusto understand the existing patterns of male-male relationships. We examined whether there is reciprocity inaffiliation among the individuals and whether the rate of affiliation is balanced. We also measured the dominance linearity and steepness in the group to understand the monopolizability of females. We used socialnetwork analysis to understand whether the relations are differentiated based on hierarchical position andwhether the high-ranking individuals are the most central individuals in the distribution of grooming in thegroup. We found that there is reciprocity among the males although that is not equitable. There was no rankrelated differentiation of affiliation among the males of the group. Instead, the identities of individualsinfluenced affiliation patterns. Our results correspond to the existent strong relationships but lack of social bondotherwise found in the Fascicularis group of macaques.

Chromatin remodeling factor lymphoid-specific helicase links with Epstein-Barr virus associated the follicular germinal center B cell lymphomas

Background: We assessed the frequency of epigenetic lesions, including lymphoid-specific helicase (LSH), 5-hydroxymethylcytosine (5-hmC) and E2F1, and the possible correlations among molecular findings, phenotype, clinical features, and outcome. Methods: We investigated 181 paraffin-embedded B-cell lymphoma samples using immunohistochemistry and in situ hybridization. Results: The levels of Ki67, LSH, 5-hmC, and E2F1 were all increased in germinal center B-cell lymphomas when compared with those in normal lymph nodes, and LSH was highly expressed in diffuse large B-cell lymphomas (DLBCLs) and Burkitt lymphomas (BLs) that were positive for Epstein-Barr virus (EBV) infection, indicating that LSH is linked to EBV infection in DLBCL and BL. Interestingly, LSH was mainly localized in the germinal centers of lymph nodes whereas 5-hmC staining localized to areas surrounding the germinal centers. Conclusions: These findings indicate a critical role for LSH as a biomarker and therapeutic target in follicular germinal center B-cell lymphoma.

Tet2 Regulates Osteoclast Differentiation by Interacting with Runx1 and Maintaining Genomic 5-Hydroxymethylcytosine (5hmC) / 基因组蛋白质组与生物信息学报·英文版

As a dioxygenase, Ten-Eleven Translocation 2 (TET2) catalyzes subsequent steps of 5-methylcytosine (5mC) oxidation. TET2 plays a critical role in the self-renewal, proliferation, and differentiation of hematopoietic stem cells, but its impact on mature hematopoietic cells is not well-characterized. Here we show that Tet2 plays an essential role in osteoclastogenesis. Deletion of Tet2 impairs the differentiation of osteoclast precursor cells (macrophages) and their maturation into bone-resorbing osteoclasts in vitro. Furthermore, Tet2 mice exhibit mild osteopetrosis, accompanied by decreased number of osteoclasts in vivo. Tet2 loss in macrophages results in the altered expression of a set of genes implicated in osteoclast differentiation, such as Cebpa, Mafb, and Nfkbiz. Tet2 deletion also leads to a genome-wide alteration in the level of 5-hydroxymethylcytosine (5hmC) and altered expression of a specific subset of macrophage genes associated with osteoclast differentiation. Furthermore, Tet2 interacts with Runx1 and negatively modulates its transcriptional activity. Our studies demonstrate a novel molecular mechanism controlling osteoclast differentiation and function by Tet2, that is, through interactions with Runx1 and the maintenance of genomic 5hmC. Targeting Tet2 and its pathway could be a potential therapeutic strategy for the prevention and treatment of abnormal bone mass caused by the deregulation of osteoclast activities.

5-Hydroxymethylome in Circulating Cell-free DNA as A Potential Biomarker for Non-small-cell Lung Cancer / 基因组蛋白质组与生物信息学报·英文版

Non-small-cell lung cancer (NSCLC), the most common type of lung cancer accounting for 85% of the cases, is often diagnosed at advanced stages owing to the lack of efficient early diagnostic tools. 5-Hydroxymethylcytosine (5hmC) signatures in circulating cell-free DNA (cfDNA) that carries the cancer-specific epigenetic patterns may represent the valuable biomarkers for discriminating tumor and healthy individuals, and thus could be potentially useful for NSCLC diagnosis. Here, we employed a sensitive and reliable method to map genome-wide 5hmC in the cfDNA of Chinese NSCLC patients and detected a significant 5hmC gain in both the gene bodies and promoter regions in the blood samples from tumor patients compared with healthy controls. Specifically, we identified six potential biomarkers from 66 patients and 67 healthy controls (mean decrease accuracy >3.2, P < 3.68E-19) using machine-learning-based tumor classifiers with high accuracy. Thus, the unique signature of 5hmC in tumor patient's cfDNA identified in our study may provide valuable information in facilitating the development of new diagnostic and therapeutic modalities for NSCLC.