40 research outputs found

    Loss of Asxl1 Alters Self-Renewal and Cell Fate of Bone Marrow Stromal Cell, Leading to Bohring-Opitz-like Syndrome in Mice

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    De novo ASXL1 mutations are found in patients with Bohring-Opitz syndrome, a disease with severe developmental defects and early childhood mortality. The underlying pathologic mechanisms remain largely unknown. Using Asxl1-targeted murine models, we found that Asxl1 global loss as well as conditional deletion in osteoblasts and their progenitors led to significant bone loss and a markedly decreased number of bone marrow stromal cells (BMSCs) compared with wild-type littermates. Asxl1(-/-) BMSCs displayed impaired self-renewal and skewed differentiation, away from osteoblasts and favoring adipocytes. RNA-sequencing analysis revealed altered expression of genes involved in cell proliferation, skeletal development, and morphogenesis. Furthermore, gene set enrichment analysis showed decreased expression of stem cell self-renewal gene signature, suggesting a role of Asxl1 in regulating the stemness of BMSCs. Importantly, re-introduction of Asxl1 normalized NANOG and OCT4 expression and restored the self-renewal capacity of Asxl1(-/-) BMSCs. Our study unveils a pivotal role of ASXL1 in the maintenance of BMSC functions and skeletal development

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    miR-203 Suppresses Tumor Growth and Angiogenesis by Targeting VEGFA in Cervical Cancer

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    Background/Aims: MicroRNA (miRNA) plays important roles in the development of different cancers. In this study, we investigated the roles and mechanisms of miR-203 in human cervical cancer. Methods: miR-203 expression was detected in cervical cancer tumors and cell lines by qRT-PCR. The methylation status in the promoter region of miR-203 was examined by methylation-specific PCR. The functional effect of miR-203 was determined by both in vitro and in vivo assays. Results: miR-203 was frequently down-regulated in cervical cancer tumors and cell lines. This down-regulation of miR-203 was associated with methylation of the miR-203 promoter. Furthermore, miR-203 down-regulated vascular endothelial growth factor alpha (VEGFA) expression by directly targeting its 3'-untranslated region. Functional assays revealed that miR-203 suppressed cervical cancer cell proliferation, tumor growth, and angiogenesis in nude mice, whereas forced expression of VEGFA rescued this inhibitory effect. Conclusion: Our collective findings indicate that miR-203 functions as a tumor suppressor by targeting VEGFA, resulting in the inhibition of tumor growth and angiogenesis. Thus, miR-203 may be a potential therapeutic target and prognostic marker in cervical cancer

    Association between Promoter Methylation of Gene ERCC3 and Benzene Hematotoxicity

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    Benzene is a primary industrial chemical and a ubiquitous environmental pollutant. ERCC3 is a key player in nucleotide excision repair. Recent studies suggested that site-specific methylation is a possible mechanism of the transcriptional dysregulation by blocking transcription factors binding. We previously found that the average promoter methylation level of ERCC3 was increased in benzene-exposed workers. In order to test whether specific CpG sites of ERCC3 play an important role in benzene-induced epigenetic changes and whether the specific methylation patterns are associated with benzene hematotoxicity, we analyzed the promoter methylation levels of individual CpG sites, transcription factor binding motif and the correlation between aberrant CpG methylation and hematotoxicity in 76 benzene-exposed workers and 24 unexposed controls in China. Out of all the CpGs analyzed, two CpG units located 43 bp upstream and 99 bp downstream of the transcription start site of ERCC3 (CpG 2–4 and CpG 17–18, respectively), showed the most pronounced increase in methylation levels in benzene-exposed workers, compared with unexposed controls (Mean ± SD: 5.86 ± 2.77% vs. 4.92 ± 1.53%, p = 0.032; 8.45 ± 4.09% vs. 6.79 ± 2.50%, p = 0.024, respectively). Using the JASPAR CORE Database, we found that CpG 2–4 and CpG 17–18 were bound by three putative transcription factors (TFAP2A, E2F4 and MZF1). Furthermore, the methylation levels for CpG 2–4 were correlated negatively with the percentage of neutrophils (β = −0.676, p = 0.005) in benzene-exposed workers. This study demonstrates that CpG-specific DNA methylation in the ERCC3 promoter region may be involved in benzene-induced epigenetic modification and it may contribute to benzene-induced hematotoxicity

    Interlukin-4 weakens resistance to stress injury and megakaryocytic differentiation of hematopoietic stem cells by inhibiting Psmd13 expression

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    Abstract Thrombocytopenia is a major and fatal complication in patients with acute myeloid leukemia (AML), which results from disrupted megakaryopoiesis by leukemic niche and blasts. Our previous research revealed that elevated interleukin-4 (IL-4) in AML bone marrow had adverse impact on multiple stages throughout megakaryopoiesis including hematopoietic stem cells (HSCs), but the specific mechanism remains unknown. In the present study, we performed single-cell transcriptome analysis and discovered activated oxidative stress pathway and apoptosis pathway in IL-4Rαhigh versus IL-4Rαlow HSCs. IL-4 stimulation in vitro led to apoptosis of HSCs and down-regulation of megakaryocyte-associated transcription factors. Functional assays displayed higher susceptibility of IL-4Rαhigh HSCs to tunicamycin and irradiation-induced apoptosis, demonstrating their vulnerability to endoplasmic reticulum (ER) stress injury. To clarify the downstream signaling of IL-4, we analyzed the transcriptomes of HSCs from AML bone marrow and found a remarkable down-regulation of the proteasome component Psmd13, whose expression was required for megakaryocytic-erythroid development but could be inhibited by IL-4 in vitro. We knocked down Psmd13 by shRNA in HSCs, and found their repopulating capacity and megakaryocytic differentiation were severely compromised, with increased apoptosis in vivo. In summary, our study uncovered a previous unrecognized regulatory role of IL-4-Psmd13 signaling in anti-stress and megakaryocytic differentiation capability of HSCs

    A Large Retrospective Study of 12714 Cases of LEEP Conization Focusing on Cervical Cancer That Colposcopy-Directed Biopsy Failed to Detect

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    Punch biopsy is important in the diagnosis of cervical cancer. However, it may fail to detect early cervical cancers. A retrospective study was performed in the largest academic women’s hospital in China to demonstrate cervical cancer that colposcopy-directed biopsy failed to detect. Methods. Patients who were diagnosed with high-grade squamous intraepithelial lesion (HSIL), adenocarcinoma in situ (AIS), and persistent low-grade squamous intraepithelial lesion (LSIL) via colposcopy-directed biopsy and had further undergone loop electrosurgical excision procedure (LEEP) conization were included. These procedures were performed at Obstetrics and Gynecology Hospital of Fudan University from July 1, 2013, to December 31, 2016. In total, 5.98% (760/12714) of patients who underwent conization were diagnosed with invasive cervical cancer. Persistent LSIL (0.24%), HSIL (6.37%), and AIS (24.31%) were detected cancer by conization. Histological subtypes included squamous cell carcinoma (92.0%), adenocarcinoma (5.1%), adenosquamous carcinoma (1.8%), adenoid basal type carcinoma (0.9%), and small cell neuroendocrine carcinoma (0.1%). Cytology reports consisted of HSIL (45.4%), atypical squamous cells of undetermined significance (ASC-US) (16.1%), and LSIL (11.6%), and atypical squamous cells cannot exclude HSIL (ASC-H) (9.3%), squamous cell carcinoma (0.9%), AGC (atypical glandular cells, 0.9%), AIS (0.4%), and NILM (negative for intraepithelial lesion or malignancy, 15.4%). The sensitivity of high-risk human papillomavirus (hrHPV) screening (96.4%) was significantly higher than that of cytology (84.6%) (P<0.01), with sensitivity of cotesting at 99.8% and a ratio of double-negative results at 0.2%. The sensitivity of cytology and hrHPV screening of different cervical cancer histologic subtypes was also demonstrated. In this large retrospective study, we systematically reported the cytology, hrHPV, pathology, and stages of cervical cancer that colposcopy-directed biopsy failed to detect
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