MiR‐342 controls Mycobacterium tuberculosis susceptibility by modulating inflammation and cell death

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) that places a heavy strain on public health. Host susceptibility to Mtb is modulated by macrophages, which regulate the balance between cell apoptosis and necrosis. However, the role of molecular switches that modulate apoptosis and necrosis during Mtb infection remains unclear. Here, we show that Mtb‐susceptible mice and TB patients have relatively low miR‐342‐3p expression, while mice with miR‐342‐3p overexpression are more resistant to Mtb. We demonstrate that the miR‐342‐3p/SOCS6 axis regulates anti‐Mtb immunity by increasing the production of inflammatory cytokines and chemokines. Most importantly, the miR‐342‐3p/SOCS6 axis participates in the switching between Mtb‐induced apoptosis and necrosis through A20‐mediated K48‐linked ubiquitination and RIPK3 degradation. Our findings reveal several strategies by which the host innate immune system controls intracellular Mtb growth via the miRNA‐mRNA network and pave the way for host‐directed therapies targeting these pathways.     

可逆两分子饱和反应动力系统的极限环

研究生化反应中一类可逆两分子饱和反应的数学模型dx/dt＝δ-xy cy^2,dy/dt=xy-cy^2-ay/b b,应用微分方程定性理论,完整地解决了该系统极限环的存在性,不存在性和唯一性。     

草酸在提高大豆磷吸收利用及抗铝性中的作用

将1mmol/L草酸（pH=6.0)加入到4种难溶性含磷化合物（FePO4、CaHPO4、AlPO4和磷矿粉）的水溶液中,其溶出磷的含量均显著提高,溶磷量随着反应时间的延长首先增大,然后有所下降。水培条件下大豆利用磷矿粉中磷的能力很差,加入1mmol/L草酸（pH=6.0)能促进大豆对磷矿粉中磷的吸收利用,表明草酸可能通过螯溶磷矿粉中的磷而提高了其有效磷的含量。200μmol/L铝离子能显著抑制大豆根的生长,而60μmol/L草酸能基本解除其抑制作用。     

岳西县来榜镇桑园土壤动物群落及其多样性研究

生物多样性保护是当今世界关注的热点 ,土壤是重要的地下生物宝库 ,土壤生物多样性的保护应予以足够重视。对土壤动物群落的研究 ,目前已有不少报道[3 ] ,但对桑园土壤动物群落及其多样性研究仍属空白。本项工作是在 1999年 1～ 9月对皖西大别山腹地岳西县来榜镇桑园土壤动物调查的基础上 ,探讨桑园这种特殊农业生态类型土壤动物群落多样性特征 ,为进一步提高桑园生产力提供科学依据 ,也为土壤生物多样性保护提供基础资料。1　研究地与方法1 1　研究地自然概况岳西县深处皖西大别山腹地 ,Ｅ115°5 5′～ 116°33′ ,Ｎ31°11′～ 30°39′ ,…     

己酸菌细胞分离及保活脱水技术的初步研究

对培养过程优化的基础上 ,利用絮凝技术将己酸菌细胞的 80 %以上从培养基中分离出来 ,其分离浓缩液的浓度达 8.0× 10 9cell/mL。菌体造型的粒径 0 .5mm× 1.0～ 2 .5mm ,在流化床上干燥 ,进气温度 6 5℃ ,出气温度 4 8℃ ,干菌体复活率达 85 %。     

Characterization of endocrine gland-derived vascular endothelial growth factor signaling in adrenal cortex capillary endothelial cells.

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) has been recently identified as a mitogen specific for the endothelium of steroidogenic glands. Here we report a characterization of the signal transduction of EG-VEGF in a responsive cell type, bovine adrenal cortex-derived endothelial (ACE) cells. EG-VEGF led to a time- and dose-dependent phosphorylation of p44/42 MAPK. This effect was blocked by pretreatment with pertussis toxin, suggesting that G alpha(i) plays an important role in mediating EG-VEGF-induced activation of MAPK signaling. The inhibitor of p44/42 MAPK phosphorylation PD 98059 resulted in suppression of both proliferation and migration in response to EG-VEGF. EG-VEGF also increased the phosphorylation of Akt in a phosphatidylinositol 3-kinase-dependent manner. Consistent with such an effect, EG-VEGF was a potent survival factor for ACE cells. We also identified endothelial nitric-oxide synthase as one of the downstream targets of Akt activation. Phosphorylation of endothelial nitric-oxide synthase in ACE cells was stimulated by EG-VEGF with a time course correlated to the Akt phosphorylation. Our data demonstrate that EG-VEGF, possibly through binding to a G-protein coupled receptor, results in the activation of MAPK p44/42 and phosphatidylinositol 3-kinase signaling pathways, leading to proliferation, migration, and survival of responsive endothelial cells.     

Molecular evidence suggesting the persistence of residual SARS‐CoV‐2 and immune responses in the placentas of pregnant patients recovered from COVID‐19

ObjectivesRecent studies have shown the presence of SARS‐CoV‐2 in the tissues of clinically recovered patients and persistent immune symptoms in discharged patients for up to several months. Pregnant patients were shown to be a high‐risk group for COVID‐19. Based on these findings, we assessed SARS‐CoV‐2 nucleic acid and protein retention in the placentas of pregnant women who had fully recovered from COVID‐19 and cytokine fluctuations in maternal and foetal tissues.Materials and MethodsRemnant SARS‐CoV‐2 in the term placenta was detected using nucleic acid amplification and immunohistochemical staining of the SARS‐CoV‐2 protein. The infiltration of CD14+ macrophages into the placental villi was detected by immunostaining. The cytokines in the placenta, maternal plasma, neonatal umbilical cord, cord blood and amniotic fluid specimens at delivery were profiled using the Luminex assay.ResultsResidual SARS‐CoV‐2 nucleic acid and protein were detected in the term placentas of recovered pregnant women. The infiltration of CD14+ macrophages into the placental villi of the recovered pregnant women was higher than that in the controls. Furthermore, the cytokine levels in the placenta, maternal plasma, neonatal umbilical cord, cord blood and amniotic fluid specimens fluctuated significantly.ConclusionsOur study showed that SARS‐CoV‐2 nucleic acid (in one patient) and protein (in five patients) were present in the placentas of clinically recovered pregnant patients for more than 3 months after diagnosis. The immune responses induced by the virus may lead to prolonged and persistent symptoms in the maternal plasma, placenta, umbilical cord, cord blood and amniotic fluid.     

一种简单通用的鸟类性别分子鉴定技术（简报）

我国幅员辽阔,生物类型多种多样,是世界上拥有鸟类种类最多的国家之一。截至1999年底,已知有鸟类1253种948亚种,隶属于21目83科,其中有多种为我国特有或珍稀濒危的鸟类。近年来由于环境污染、植被破坏及非法捕猎等种种原因,许多鸟类尤其是珍稀鸟类正逐步濒临灭绝。为了加紧