Association between FABP2 Ala54Thr polymorphisms and type 2 diabetes mellitus risk: a HuGE Review and Meta‐Analysis

Many studies have examined the association between the FABP2 (rs1799883) Ala54Thr gene polymorphism and type 2 diabetes mellitus risk (T2DM) in various populations, but their results have been inconsistent. To assess this relationship more precisely, A HuGE review and meta‐analysis were performed. The PubMed and CNKI database was searched for case‐control studies published up to April 2014. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 13 studies, comprising 2020 T2DM cases and 2910 controls were included. Overall, for the Thr carriers (Ala/Thr and Thr/Thr) versus the wild‐type homozygotes (Ala/Ala), the pooled OR was 1.18 (95% CI = 1.04–1.34, P = 0.062 for heterogeneity), for Thr/Thr versus Ala/Ala the pooled OR was 1.17 (95% CI = 1.05–1.41 P = 0.087 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among Asians but not Caucasians. This meta‐analysis suggests that the FABP2 (rs1799883) Ala54Thr polymorphisms are associated with increased susceptibility to T2DM risk among Asians but not Caucasians.     

A cross-talk between epithelium and endothelium mediates human alveolar–capillary injury during SARS-CoV-2 infection

COVID-19, caused by SARS-CoV-2, is an acute and rapidly developing pandemic, which leads to a global health crisis. SARS-CoV-2 primarily attacks human alveoli and causes severe lung infection and damage. To better understand the molecular basis of this disease, we sought to characterize the responses of alveolar epithelium and its adjacent microvascular endothelium to viral infection under a co-culture system. SARS-CoV-2 infection caused massive virus replication and dramatic organelles remodeling in alveolar epithelial cells, alone. While, viral infection affected endothelial cells in an indirect manner, which was mediated by infected alveolar epithelium. Proteomics analysis and TEM examinations showed viral infection caused global proteomic modulations and marked ultrastructural changes in both epithelial cells and endothelial cells under the co-culture system. In particular, viral infection elicited global protein changes and structural reorganizations across many sub-cellular compartments in epithelial cells. Among the affected organelles, mitochondrion seems to be a primary target organelle. Besides, according to EM and proteomic results, we identified Daurisoline, a potent autophagy inhibitor, could inhibit virus replication effectively in host cells. Collectively, our study revealed an unrecognized cross-talk between epithelium and endothelium, which contributed to alveolar–capillary injury during SARS-CoV-2 infection. These new findings will expand our understanding of COVID-19 and may also be helpful for targeted drug development.Subject terms: Mechanisms of disease, Viral infection     

Phosphorylation and ubiquitination of dynamin-related proteins (AtDRP3A/3B) synergically regulate mitochondrial proliferation during mitosis

The balance between mitochondrial fission and fusion is disrupted during mitosis, but the mechanism governing this phenomenon in plant cells remains enigmatic. Here, we used mitochondrial matrix‐localized Kaede protein (mt‐Kaede) to analyze the dynamics of mitochondrial fission in BY‐2 suspension cells. Analysis of the photoactivatable fluorescence of mt‐Kaede suggested that the fission process is dominant during mitosis. This finding was confirmed by an electron microscopic analysis of the size distribution of mitochondria in BY‐2 suspension cells at various stages. Cellular proteins interacting with Myc‐tagged dynamin‐related protein 3A/3B (AtDRP3A and AtDRP3B) were immunoprecipitated with anti‐Myc antibody‐conjugated beads and subsequently identified by microcapillary liquid chromatography–quadrupole time‐of‐flight mass spectrometry (CapLC Q‐TOF) MS/MS. The identified proteins were broadly associated with cytoskeletal (microtubular), phosphorylation, or ubiquitination functions. Mitotic phosphorylation of AtDRP3A/AtDRP3B and mitochondrial fission at metaphase were inhibited by treatment of the cells with a CdkB/cyclin B inhibitor or a serine/threonine protein kinase inhibitor. The fate of AtDRP3A/3B during the cell cycle was followed by time‐lapse imaging of the fluorescence of Dendra2‐tagged AtDRP3A/3B after green‐to‐red photoconversion; this experiment showed that AtDRP3A/3B is partially degraded during interphase. Additionally, we found that microtubules are involved in mitochondrial fission during mitosis, and that mitochondria movement to daughter cell was limited as early as metaphase. Taken together, these findings suggest that mitotic phosphorylation of AtDRP3A/3B promotes mitochondrial fission during plant cell mitosis, and that AtDRP3A/3B is partially degraded at interphase, providing mechanistic insight into the mitochondrial morphological changes associated with cell‐cycle transitions in BY‐2 suspension cells.     

Drosophila female germline stem cells undergo mitosis without nuclear breakdown

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山岳型乡村旅游地“三生”空间演变及优化——德庆金林水乡的案例实证

以德庆县金林水乡为例,采用参与式观察和空间统计法,选取2000、2008年和2018年3个时段分析旅游发展对山岳型乡村旅游地"三生"空间的影响,并探讨了金林水乡"三生"空间的发展瓶颈及优化路径。研究发现:(1)旅游开发前,金林水乡土地结构与用地功能单一且呈片状分布;村落呈现传统乡村风貌,基础设施不健全;空间形态变化稳定,扩张缓慢。(2)旅游开发后,土地利用类型多样化,出现新型复合用地;土地功能利用复杂化,以服务旅游业为主;村庄景观风貌现代化,生活空间更加宜居。(3)旅游开发前后对比可得,土地平面占地规模化,空间用地以居民点为核心,呈圈层状向外围扩张;生产-生活-生态空间相互转化,乡村聚落重构特征较为显著;村落景观风貌的变化较大,呈现城镇化趋势。(4)金林水乡"三生"空间演化与旅游发展存在的问题表现在生产用地效率不高,生活用地质量较低,生态空间不断萎缩,在旅游产业发展上表现为旅游产品单一且缺乏创新,旅游服务功能不完善等。为此从生活空间的提质、生产空间增效、生态空间保护、旅游产业创新以及土地利用五方面提出优化建议。     

Genomic organization of the rat aromatic L-amino acid decarboxylase (AADC) locus: Partial analysis reveals divergence from the Drosophila dopa decarboxylase (DDC) gene structure

Aromatic L-amino acid decarboxylase (AADC) is responsible for the conversion of L-3,4-dihydroxyphenylalanine (L-DOPA) and L-5-hydroxytryptophan to dopamine and serotonin, respectively, which are important neurotransmitters. We characterized genomic clones derived from the rat AADC locus by Southern blot and nucleotide sequencing analyses to explore the exonal organization of the gene. Our results suggest that the rat AADC gene is relatively large, containing at least 12 exons and spanning at least 40 kb in the rat genome. In this study, nine exons corresponding to 71% of the published cDNA sequence were identified, the smallest of which was as short as 20 base pairs (bp). In the Drosophila dopa decarboxylase (DDC) gene, the sequences homologous to these nine exons are all present in the fourth exon. This implies that either multiple intron sequences have been added to the vertebrate AADC gene or alternatively, deleted from the invertebrate gene after the divergence of vertebrates and invertebrates during evolution.     

Maternal Transfer and Protective Role of the Alternative Complement Components in Zebrafish Danio rerio

Embryos of most fish develop externally and are exposed to an aquatic environment full of potential pathogens, whereas they have little or only limited ability to mount an efficient and protective response. How fish embryos survive pathogenic attacks remains poorly defined. Here we demonstrate that the maternal immunization of female zebrafish with formalin-killed Aeromonas hydrophila causes a significant increase in C3 and Bf contents in the mother, a corresponding rise in the offspring, and induces a remarkable increase in the hemolytic activities in both the mother and offspring. In addition, the embryos derived from the immunized mother are significantly more tolerant to A. hydrophila challenge than those from the unimmunized fish, and blocking C3 and Bf activities by injection of the antibodies against C3 and Bf into the embryos render them more susceptible to A. hydrophila. These results clearly show that the protection of zebrafish embryos against A. hydrophila can be achieved by the maternally-transferred immunity of the complement system operating via the alternative pathway. This appears to be the first report providing in vivo evidences for the protective role of the alternative complement components in the early embryos of zebrafish, paving the way for insights into the in vivo function of other maternally-transferred factors in fish.