No abstract

BackgroundAs an important factor affecting meat quality, intramuscular fat (IMF) content is a topic of worldwide concern. Emerging evidences indicate that microRNAs play important roles in adipocyte differentiation. However, miRNAome has neither been studied during porcine intramuscular preadipocyte differentiation, nor compared with subcutaneous preadipocytes. The objectives of this study were to identify porcine miRNAs involved in adipogenesis in primary preadipocytes, and to determine whether intramuscular and subcutaneous adipocytes differ in the expression and regulation of miRNAs.ResultsmiRNAomes in primary intramuscular and subcutaneous adipocytes during differentiation were first sequenced using the Solexa deep sequencing method. The sequences and relative expression levels of 224 known (98.2% in miRbase 18.0) and 280 potential porcine miRNAs were identified. Fifty-four of them changed in similar pattern between intramuscular vascular stem cells (IVSC) and subcutaneous vascular stem cells (SVSC) differentiation, such as miR-210, miR-10b and miR-99a. Expression levels of 10 miRNAs were reversely up-or down-regulated between IVSC and SVSC differentiation, 19 were up-or down-regulated only during IVSC differentiation and 55 only during SVSC differentiation. Additionally, 30 miRNAs showed fat-depot specific expression pattern (24 in cells of intramuscular origin and 6 in cells of subcutaneous origin). These adipogenesis-related miRNAs mainly functioned by targeting similar pathways in adipogenesis, obesity and syndrome.ConclusionComparison of miRNAomes in IVSC and SVSC during differentiation revealed that many different miRNAs are involved in adipogenesis, and they regulate SVSC and IVSC differentiation through similar pathways. These miRNAs may serve as biomarkers or targets for enhancing IMF content, and uncovering their function in IMF development will be of great value in the near future.

COVID-19 was initially identified in Hubei province, in which the number of confirmed cases increased sharply in the early stage. As a significant public health emergency, 28,600 nurses were sent to Wuhan to fight against COVID-19, accounting for nearly 68% of all frontline healthcare staff (Government of Hubei Province, 2020). These nurses risked their lives, undertook an enormous workload under high-intensity pressure, and experienced long working hours, which cause serious negative emotions (Chen et al., 2020), professional burnout (Morgantini et al., 2020), job dissatisfaction (Zhang et al., 2020 and even a tendency to leave (Song et al., 2020). The COVID-19 pandemic highlights the shortages of nurses that already exist, and widespread nursing shortages could lead to staff burnout and endanger patient safety.

Myelosuppression is one of the serious side effects of anticancer chemotherapeutic drugs that deteriorate the bodily functions of patients, thereby affecting the quality of life considerably. Prevention of myelosuppression in anticancer chemotherapy is an important research topic. A stabilized chemotherapy-induced myelosuppression animal model is necessary in experimental research. This study aimed to establish an optimized animal model of chemotherapy-induced bone marrow suppression. After C57BL/6 mice were treated with intermediate- and high-dose (25/50 mg/kg) cyclophosphamide (CTX) for 10 days, the body-weight, changes in thymus and spleen, number of white blood cells (WBCs), red blood cells (RBCs), and platelets (PLTs) and changes in bone marrow in the mice were systematically evaluated at the next 2, 7 and 14 days. Our results demonstrated that CTX treatments could significantly decrease the body-weight of mice, as well as the ratios of the weights of thymus and spleen to body-weight. The physiological structures of thymus and spleen were destroyed by CTX treatments. The number of WBCs and RBCs significantly declined after CTX treatments; however, the number of PLTs increased. Moreover, the expression of Sca1 in bone marrow cells decreased on Day 2 but increased on Day 14. The expression of CD34 decreased in bone marrow cells after CTX treatments. In conclusion, mice models, with high-dose CTX treatments for 10 days, can be an optimized animal model for chemotherapy-induced bone marrow suppression.