LINE-1 transcription activates long-range gene expression.

Long interspersed nuclear element-1 (LINE-1 or L1) is a retrotransposon group that constitutes 17% of the human genome and shows variable expression across cell types. However, the control of L1 expression and its function in gene regulation are incompletely understood. Here we show that L1 transcription activates long-range gene expression. Genome-wide CRISPR-Cas9 screening using a reporter driven by the L1 5' UTR in human cells identifies functionally diverse genes affecting L1 expression. Unexpectedly, altering L1 expression by knockout of regulatory genes impacts distant gene expression. L1s can physically contact their distal target genes, with these interactions becoming stronger upon L1 activation and weaker when L1 is silenced. Remarkably, L1s contact and activate genes essential for zygotic genome activation (ZGA), and L1 knockdown impairs ZGA, leading to developmental arrest in mouse embryos. These results characterize the regulation and function of L1 in long-range gene activation and reveal its importance in mammalian ZGA.

A TRIM66/DAX1/Dux axis suppresses the totipotent 2-cell-like state in murine embryonic stem cells.

2-cell-like cells (2CLCs)-which comprise only ∼1% of murine embryonic stem cells (mESCs)-resemble blastomeres of 2-cell-stage embryos and are used to investigate zygotic genome activation (ZGA). Here, we discovered that TRIM66 and DAX1 function together as negative regulators of the 2C-like state in mESCs. Chimeric assays confirmed that mESCs lacking TRIM66 or DAX1 function have bidirectional embryonic and extraembryonic differentiation potential. TRIM66 functions by recruiting the co-repressor DAX1 to the Dux promoter, and TRIM66's repressive effect on Dux is dependent on DAX1. A solved crystal structural shows that TRIM66's PHD finger recognizes H3K4-K9me3, and mutational evidence confirmed that TRIM66's PHD finger is essential for its repression of Dux. Thus, beyond expanding the scope of known 2CLC regulators, our study demonstrates that interventions disrupting TRIM66 or DAX1 function in mESCs yield 2CLCs with expanded bidirectional differentiation potential, opening doors for the practical application of these totipotent-like cells.

Mouse totipotent stem cells captured and maintained through spliceosomal repression.

Since establishment of the first embryonic stem cells (ESCs), in vitro culture of totipotent cells functionally and molecularly comparable with in vivo blastomeres with embryonic and extraembryonic developmental potential has been a challenge. Here we report that spliceosomal repression in mouse ESCs drives a pluripotent-to-totipotent state transition. Using the splicing inhibitor pladienolide B, we achieve stable in vitro culture of totipotent ESCs comparable at molecular levels with 2- and 4-cell blastomeres, which we call totipotent blastomere-like cells (TBLCs). Mouse chimeric assays combined with single-cell RNA sequencing (scRNA-seq) demonstrate that TBLCs have a robust bidirectional developmental capability to generate multiple embryonic and extraembryonic cell lineages. Mechanically, spliceosomal repression causes widespread splicing inhibition of pluripotent genes, whereas totipotent genes, which contain few short introns, are efficiently spliced and transcriptionally activated. Our study provides a means for capturing and maintaining totipotent stem cells.

Homotypic clustering of L1 and B1/Alu repeats compartmentalizes the 3D genome.

Organization of the genome into euchromatin and heterochromatin appears to be evolutionarily conserved and relatively stable during lineage differentiation. In an effort to unravel the basic principle underlying genome folding, here we focus on the genome itself and report a fundamental role for L1 (LINE1 or LINE-1) and B1/Alu retrotransposons, the most abundant subclasses of repetitive sequences, in chromatin compartmentalization. We find that homotypic clustering of L1 and B1/Alu demarcates the genome into grossly exclusive domains, and characterizes and predicts Hi-C compartments. Spatial segregation of L1-rich sequences in the nuclear and nucleolar peripheries and B1/Alu-rich sequences in the nuclear interior is conserved in mouse and human cells and occurs dynamically during the cell cycle. In addition, de novo establishment of L1 and B1 nuclear segregation is coincident with the formation of higher-order chromatin structures during early embryogenesis and appears to be critically regulated by L1 and B1 transcripts. Importantly, depletion of L1 transcripts in embryonic stem cells drastically weakens homotypic repeat contacts and compartmental strength, and disrupts the nuclear segregation of L1- or B1-rich chromosomal sequences at genome-wide and individual sites. Mechanistically, nuclear co-localization and liquid droplet formation of L1 repeat DNA and RNA with heterochromatin protein HP1α suggest a phase-separation mechanism by which L1 promotes heterochromatin compartmentalization. Taken together, we propose a genetically encoded model in which L1 and B1/Alu repeats blueprint chromatin macrostructure. Our model explains the robustness of genome folding into a common conserved core, on which dynamic gene regulation is overlaid across cells.

Tissue-specific transcription reprogramming promotes liver metastasis of colorectal cancer.

Metastasis, the development of secondary malignant growths at a distance from a primary tumor, is the cause of death for 90% of cancer patients, but little is known about how metastatic cancer cells adapt to and colonize new tissue environments. Here, using clinical samples, patient-derived xenograft (PDX) samples, PDX cells, and primary/metastatic cell lines, we discovered that liver metastatic colorectal cancer (CRC) cells lose their colon-specific gene transcription program yet gain a liver-specific gene transcription program. We showed that this transcription reprogramming is driven by a reshaped epigenetic landscape of both typical enhancers and super-enhancers. Further, we identified that the liver-specific transcription factors FOXA2 and HNF1A can bind to the gained enhancers and activate the liver-specific gene transcription, thereby driving CRC liver metastasis. Importantly, similar transcription reprogramming can be observed in multiple cancer types. Our data suggest that reprogrammed tissue-specific transcription promotes metastasis and should be targeted therapeutically.

The lncRNA Hand2os1/Uph locus orchestrates heart development through regulation of precise expression of Hand2.

Exploration and dissection of potential actions and effects of long noncoding RNA (lncRNA) in animals remain challenging. Here, using multiple knockout mouse models and single cell RNA sequencing, we demonstrate that the divergent lncRNA Hand2os1/Uph has a key complex modulatory effect on the expression of its neighboring gene HAND2 and subsequently on heart development and function. Short deletion of the Hand2os1 promoter in mouse diminishes Hand2os1 transcription to ∼8-32%, but fails to affect HAND2 expression and yields no discernable heart phenotypes. Interestingly, full-length deletion of Hand2os1 in mouse causes moderate yet prevalent upregulation of HAND2 in hundreds of cardiac cells, leading to profound biological consequences, including dysregulated cardiac gene programs, congenital heart defects and perinatal lethality. We propose that the Hand2os1 locus dampens HAND2 expression to restrain cardiomyocyte proliferation, thereby orchestrating a balanced development of cardiac cell lineages. This study highlights the regulatory complexity of the lncRNA Hand2os1 on HAND2 expression, emphasizing the need for complementary genetic and single cell approaches to delineate the function and primary molecular effects of an lncRNA in animals.

Effect of miR-145 on MCF-7 breast cancer cells by regulating disintegrin-metalloproteinase-17 / 医学研究生学报

Objective MicroRNA-145 (miR-145) is underexpressed in breast cancer. The study aimed to explore the regulatory effect of miR-145 on breast cancer MCF-7 cells by investigating the association of miR-145 with ADAM17 and EGFR. Methods The MCF-7 breast cancer cells were divided into three groups: the transfection group (transfected with microRNA-145 mimics), the control group (without transfection) and the nonsense sequence group (transfected with nonsense microRNA). MTT, transwell and real-time quantitative fluorescence polymerase chain reaction(qPCR) were respectively used to detect the proliferative capacity, invasive ability and expression of MCF-7 breast cancer cells after the transfection of miR-145 in three groups. ADAM17 and EGFR mRNA and protein levels in three groups of breast cancer MCF-7 cells were detected by qPCR and western blot. Results The results of qPCR showed that the relative expression of miR-145 was significantly higher in transfection group (13964.33±1265.30) than those in control group (1.00±0.05) and nonsense sequence group (1.03±0.15) and the difference was statistically significant (P<0.01); the expression of ADAM17 mRNA in transfection group (1.71±0.08) was significantly higher than that in control group (1.00±0.07) and the difference was statistically significant (P<0.01). Compared with the nonsense sequences at 24 h, 48 h, and 72 h, the inhibition rate of MCF-7 in transfection group was significantly increased (P<0.01). The results of transwell invasion showed that the number of transmembrane cells in transfection group [(56.20±2.17)/field] was significantly lower than those in control group [(92.80±3.90)/field] and nonsense sequence group [(91.80±4.97)/field of view ] (P < 0.01). Western blot results showed that the protein content of ADAM17 and EGFR in transfection group was significantly lower than those in the control group and the nonsense sequence group (P<0.01). Conclusion MiR-145 inhibits the proliferation and invasion of breast cancer MCF-7 cell line by acting on the ADAM17-EGFR signaling pathway.

An autoimmune disease variant of IgG1 modulates B cell activation and differentiation.

The maintenance of autoreactive B cells in a quiescent state is crucial for preventing autoimmunity. Here we identify a variant of human immunoglobulin G1 (IgG1) with a Gly396→Arg substitution (hIgG1-G396R), which positively correlates with systemic lupus erythematosus. In induced lupus models, murine homolog Gly390→Arg (G390R) knockin mice generate excessive numbers of plasma cells, leading to a burst of broad-spectrum autoantibodies. This enhanced production of antibodies is also observed in hapten-immunized G390R mice, as well as in influenza-vaccinated human G396R homozygous carriers. This variant potentiates the phosphorylation of the IgG1 immunoglobulin tail tyrosine (ITT) motif. This, in turn, alters the availability of phospho-ITT to trigger longer adaptor protein Grb2 dwell times in immunological synapses, leading to hyper-Grb2-Bruton's tyrosine kinase (Btk) signaling upon antigen binding. Thus, the hIgG1-G396R variant is important for both lupus pathogenesis and antibody responses after vaccination.

HER2/EGFR-AKT Signaling Switches TGFß from Inhibiting Cell Proliferation to Promoting Cell Migration in Breast Cancer.

TGFß signaling inhibits cell proliferation to block cancer initiation, yet it also enhances metastasis to promote malignancy during breast cancer development. The mechanisms underlying these differential effects are still unclear. Here, we report that HER2/EGFR signaling switches TGFß function in breast cancer cells from antiproliferation to cancer promotion. Inhibition of HER2/EGFR activity attenuated TGFß-induced epithelial-mesenchymal transition and migration but enhanced the antiproliferative activity of TGFß. Activation of HER2/EGFR induced phosphorylation of Smad3 at Ser208 of the linker region through AKT, which promoted the nuclear accumulation of Smad3 and subsequent expression of the genes related to EMT and cell migration. In contrast, HER2/EGFR signaling had no effects on the nuclear localization of Smad2. Knockdown of Smad3, but not Smad2, blocked TGFß-induced breast cancer cell migration. We observed a positive correlation between the nuclear localization of Smad3 and HER2 activation in advanced human breast cancers. Our results demonstrate a key role for HER2/EGFR in differential regulation of Smad3 activity to shift TGFß function from antitumorigenic to protumorigenic during breast cancer development.Significance: TGFß signaling can shift from inhibiting to promoting breast cancer development via HER2/EGFR AKT-mediated phosphorylation of Smad3 at S208, enhancing its nuclear accumulation and upregulation of EMT-related genes.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/21/6073/F1.large.jpg Cancer Res; 78(21); 6073-85. ©2018 AACR.

Effects of a nurse-led transitional care programme on readmission, self-efficacy to implement health-promoting behaviours, functional status and life quality among Chinese patients with coronary artery disease: A randomised controlled trial.

AIMS AND OBJECTIVES: To examine the effectiveness of a nurse-led transitional care programme on readmission, self-efficacy to implement health-promoting behaviours, functional status and life quality among Chinese patients with coronary artery disease. BACKGROUND: Coronary artery disease is a major cause of mortality in China. Transitional care could help to ensure improved patient outcomes. Nevertheless, our knowledge of how to perform transitional care for patients with coronary artery disease is insufficient in mainland China. DESIGN: Randomised controlled trial. METHODS: The nurse-led transitional care intervention in the experimental group adopted the Omaha system and Pender's health-promoting model as its frameworks. The control group received a comparable length routine care and follow-up contacts. Evaluations were conducted at baseline before discharge and after 7 months after discharge using hospital readmission rate, self-rated abilities for health practices scale and Seattle Angina Questionnaire for functional status and life quality. Data were collected between March 2014-October 2014. RESULTS: Compared with the control group, participants in the experimental group showed greater self-efficacy to implement health-promoting behaviours, more angina stability, less angina frequency, more satisfaction with treatment and better quality of life. The difference in readmission rate and physical limitations was not significant between the two groups. CONCLUSION: This study provides evidence for the effectiveness of a nurse-led transitional care programme in improving the ability to implement health-promoting behaviours, the functional status and life quality among Chinese patients with coronary artery disease. RELEVANCE TO CLINICAL PRACTICE: The nurse-led transitional care programme is helpful for coronary artery disease patients to promote their effective transfer from hospital to community and provide an evidence for nursing managers to train their nurses for transitional care knowledge and skills.

Effects of a nurse-led transitional care program on clinical outcomes, health-related knowledge, physical and mental health status among Chinese patients with coronary artery disease: A randomized controlled trial.

BACKGROUND: Coronary artery disease is a major cause of morbidity and mortality among adults worldwide, including China. After a hospital stay, transitional care could help to ensure improved patient care and outcomes, and reduce Medicare costs. Nevertheless, the results of the existing transitional care are not always satisfactory and our knowledge of how to perform effective transitional care for patients with coronary artery disease is limited in mainland China. OBJECTIVES: To examine the effectiveness of a nurse-led transitional care program on clinical outcomes, health-related knowledge, and physical and mental health status among Chinese patients with coronary artery disease. DESIGN: Randomized controlled trial. METHODS: The Omaha system and Pender's health promoting model were employed in planning and implementing this nurse-led transitional care program. The sample was comprised of 199 Chinese patients with coronary artery disease. The experimental group (n=100) received nurse-led transitional care intervention in addition to routine care. The nurse-led transitional care intervention included a structured assessment and health education, followed by 7 months of individual teaching and coaching (home visits, telephone follow-up and group activity). The control group (n=99) received a comparable length routine care and follow-up contacts. Evaluations were conducted at baseline and completion of the interventions using the perceived knowledge scale for coronary heart disease, the medical outcomes study 36-item short-form health survey and clinical measures (blood pressure, blood glucose, lipids, body mass index). Data were collected between March and October 2014. RESULTS: Compared with the control group, participants in the experimental group showed significant better clinical outcomes (systolic blood pressure, t=5.762, P=0.000; diastolic blood pressure, t=4.250, P=0.000; fasting blood glucose, t=2.249, P=0.027; total cholesterol, t=4.362, P=0.000; triglyceride, t=3.147, P=0.002; low density lipoprotein cholesterol, t=2.399, P=0.018; and body mass index, t=3.166, P=0.002), higher knowledge scores for coronary artery disease (total knowledge score, t=-7.099, P=0.000), better physical health status (t=-2.503, P=0.014) and mental health status (t=-2.950, P=0.004). CONCLUSIONS: This study provides evidence for the value of a nurse-led transitional care program using both the Omaha system and Pender's health promoting model as its theoretical framework. The structured interventions in this nurse-led transitional care program facilitate the use of this program in other settings.

Adipose angiotensin II type 1 receptor-associated protein ameliorates metabolic disorders via promoting adipose tissue adipogenesis and browning.

Adipose tissue is a complicated organ that not only stores excess energy, but also secrets many adipokines regulating whole-body energy hemostasis. Dysfunction of adipose tissue leads to metabolic disorders such as insulin resistance, hypertension, cardiovascular diseases. In this study, we generated a mouse model with overexpression of Angiotensin II type 1 receptor-associated protein (ATRAP) in adipose tissue specifically. Under a normal diet, ATRAP transgene (TgATRAP) mice showed similar bodyweight, fat mass and insulin sensitivity with wild-type controls (WT). When challenged with a high fat diet, TgATRAP mice ameliorated insulin sensitivity, decreased fat mass compared with WT. Morphology and gene expression of adipose tissue, indicated that adipogenesis, adipocyte browning and angiogenesis of adipose tissue were increased in TgATRAP mice. Overexpression of ATRAP induced adiponectin expression both in adipose tissue and primary adipocyte. Our data revealed that adipose ATRAP plays an important role in preventing metabolic disorders and adiponectin possibly mediates the effects of adipose ATRAP.

Histone H1 defect in escort cells triggers germline tumor in Drosophila ovary.

Drosophila ovary is recognized as one of the best model systems to study stem cell biology in vivo. We had previously identified an autonomous role of the histone H1 in germline stem cell (GSC) maintenance. Here, we found that histone H1 depletion in escort cells (ECs) resulted in an increase of spectrosome-containing cells (SCCs), an ovary tumor-like phenotype. Further analysis showed that the Dpp pathway is excessively activated in these SCC cells, while the expression of bam is attenuated. In the H1-depleted ECs, both transposon activity and DNA damage had increased dramatically, followed by EC apoptosis, which is consistent with the role of H1 in other somatic cells. Surprisingly, H1-depleted ECs acquired cap cell characteristics including dpp expression, and the resulting abnormal Dpp level inhibits SCC further differentiation. Most interestingly, double knockdown of H1 and dpp in ECs can reduce the number of SCCs to the normal level, indicating that the additional Dpp secreted by ECs contributes to the germline tumor. Taken together, our findings indicate that histone H1 is an important epigenetic factor in controlling EC characteristics and a key suppressor of germline tumor.

Isoform Switch of TET1 Regulates DNA Demethylation and Mouse Development.

The methylcytosine oxidase TET proteins play important roles in DNA demethylation and development. However, it remains elusive how exactly they target substrates and execute oxidation. Interestingly, we found that, in mice, the full-length TET1 isoform (TET1e) is restricted to early embryos, embryonic stem cells (ESCs), and primordial germ cells (PGCs). By contrast, a short isoform (TET1s) is preferentially expressed in somatic cells, which lacks the N terminus including the CXXC domain, a DNA-binding module that often recognizes CpG islands (CGIs) where TET1 predominantly occupies. Unexpectedly, TET1s can still bind CGIs despite the fact that its global chromatin binding is significantly reduced. Interestingly, global chromatin binding, but not targeted binding at CGIs, is correlated with TET1-mediated demethylation. Finally, mice with exclusive expression of Tet1s failed to erase imprints in PGCs and displayed developmental defects in progeny. These data show that isoform switch of TET1 regulates epigenetic memory erasure and mouse development.

NK cell development requires Tsc1-dependent negative regulation of IL-15-triggered mTORC1 activation.

Activation of metabolic signalling by IL-15 is required for natural killer (NK) cell development. Here we show that Tsc1, a repressor of mTOR, is dispensable for the terminal maturation, survival and function of NK cells but is critical to restrict exhaustive proliferation of immature NK cells and activation downstream of IL-15 during NK cell development. Tsc1 is expressed in immature NK cells and is upregulated by IL-15. Haematopoietic-specific deletion of Tsc1 causes a marked decrease in the number of NK cells and compromises rejection of 'missing-self' haematopoietic tumours and allogeneic bone marrow. The residual Tsc1-null NK cells display activated, pro-apoptotic phenotype and elevated mTORC1 activity. Deletion of Raptor, a component of mTORC1, largely reverses these defects. Tsc1-deficient NK cells express increased levels of T-bet and downregulate Eomes and CD122, a subunit of IL-15 receptor. These results reveal a role for Tsc1-dependent inhibition of mTORC1 activation during immature NK cell development.

The mediating role of emotional intelligence between negative life events and psychological distress among nursing students: A cross-sectional study.

BACKGROUND: Previous studies have highlighted that negative life events and emotional intelligence are significant predictors of mental health. However, whether emotional intelligence mediates the relationship between negative life events and psychological distress among nursing students have not been given adequate attention. OBJECTIVES: To explore the relationship among negative life events, emotional intelligence and psychological distress and to examine the mediating role of emotional intelligence in psychological distress among Chinese nursing students. DESIGN: A cross-sectional survey using convenience sampling. SETTINGS AND PARTICIPANTS: A total of 467 nursing students who were enrolled in a university in mainland of China. METHODS: A structured questionnaire was administered from September-November in 2013 to participants who consented to participate in the study. Independent variables were personal variables, emotional intelligence and negative life events. Outcome variable was psychological health. The means and standard deviations were computed. Student's t-test and one-way analysis of variance (ANOVA) were performed, to test the differences among the demographic characteristics on the psychological distress scores. Pearson correlation analyses and hierarchical regression analyses were performed. RESULTS: Negative life events were positively associated with psychological distress. Emotional intelligence was negatively associated with psychological distress and negative life events. Emotional intelligence mediated the relationship between negative life events and psychological distress. CONCLUSIONS: The findings support the theory of Salovey and his colleagues, and provide evidence for emotional intelligence as a factor that buffers effects of negative life events on psychological distress.

The landscape of accessible chromatin in mammalian preimplantation embryos.

In mammals, extensive chromatin reorganization is essential for reprogramming terminally committed gametes to a totipotent state during preimplantation development. However, the global chromatin landscape and its dynamics in this period remain unexplored. Here we report a genome-wide map of accessible chromatin in mouse preimplantation embryos using an improved assay for transposase-accessible chromatin with high throughput sequencing (ATAC-seq) approach with CRISPR/Cas9-assisted mitochondrial DNA depletion. We show that despite extensive parental asymmetry in DNA methylomes, the chromatin accessibility between the parental genomes is globally comparable after major zygotic genome activation (ZGA). Accessible chromatin in early embryos is widely shaped by transposable elements and overlaps extensively with putative cis-regulatory sequences. Unexpectedly, accessible chromatin is also found near the transcription end sites of active genes. By integrating the maps of cis-regulatory elements and single-cell transcriptomes, we construct the regulatory network of early development, which helps to identify the key modulators for lineage specification. Finally, we find that the activities of cis-regulatory elements and their associated open chromatin diminished before major ZGA. Surprisingly, we observed many loci showing non-canonical, large open chromatin domains over the entire transcribed units in minor ZGA, supporting the presence of an unusually permissive chromatin state. Together, these data reveal a unique spatiotemporal chromatin configuration that accompanies early mammalian development.

Changing Grains for the Prevention and Treatment of Kashin-Beck Disease in Children: a Meta-analysis.

To evaluate the efficacy of changing grains on the prevention and treatment of Kashin-Beck Disease (KBD) in children, community-based trials were acquired from seven electronic databases (up to July 2014). As a result, the methodological quality of the six trials that have been included into our analysis was low. The pooled ORs favoring the prevention and treatment effects of changing grains were 0.15 (95% CI: 0.03-0.70) and 2.13 (95% CI: 1.44-3.16) respectively by meta-analysis. Subgroup analysis demonstrated the pooled OR favoring treatment effect of exchanging grains rather than drying grains both compared with endemic grains. The results showed that changing grains had obvious effects on the prevention and treatment of KBD in children. However, the evidences were limited by the potential biases and confounders. Large and well-designed trials are still needed.

Substrate stiffness regulates B-cell activation, proliferation, class switch, and T-cell-independent antibody responses in vivo.

B cells use B-cell receptors (BCRs) to sense antigens that are usually presented on substrates with different stiffness. However, it is not known how substrate stiffness affects B-cell proliferation, class switch, and in vivo antibody responses. We addressed these questions using polydimethylsiloxane (PDMS) substrates with different stiffness (20 or 1100 kPa). Live cell imaging experiments suggested that antigens on stiffer substrates more efficiently trigger the synaptic accumulation of BCR and phospho-Syk molecules compared with antigens on softer substrates. In vitro expansion of mouse primary B cells shows different preferences for substrate stiffness when stimulated by different expansion stimuli. LPS equally drives B-cell proliferation on stiffer or softer substrates. Anti-CD40 antibodies enhance B-cell proliferation on stiffer substrates, while antigens enhance B-cell proliferation on softer substrates through a mechanism involving the enhanced phosphorylation of PI3K, Akt, and FoxO1. In vitro class switch differentiation of B cells prefers softer substrates. Lastly, NP67-Ficoll on softer substrates accounted for an enhanced antibody response in vivo. Thus, substrate stiffness regulates B-cell activation, proliferation, class switch, and T cell independent antibody responses in vivo, suggesting its broad application in manipulating the fate of B cells in vitro and in vivo.