Identification of a Bombyx mori gene encoding small heat shock protein BmHsp27.4 expressed in response to high-temperature stress

Elucidating the mechanisms underlying the response and resistance to high-temperature stress in the Lepidoptera is essential for understanding the effect of high-temperature on the regulation of gene expression. A tag (CATGAACGTGAAGAGATTCAG) matching the predicted gene BGIBMGA005823-TA in SilkDB identified the most significant response to high-temperature stress in a screen of the heat-treated digital gene expression library of Bombyx mori (B. mori) (Unpublished data). BLAST and RACE showed that the gene is located on chromosome 5 and has an open reading frame (ORF) of 741 bp. Phylogenetic analysis found that B. mori small heat shock protein 27.4 (BmHSP27.4) is in an evolutionary branch separate from other small heat shock proteins. Expression analysis showed that BmHsp27.4 is highly expressed in brain, eyes and fat bodies in B. mori. Its mRNA level was elevated at high-temperature and this increase was greater in females. The ORF without the signal peptide sequence was cloned into vector pET-28a(+), transformed and over-expressed in Escherichia coli Rosetta (DE3). Western blotting and immunofluorescence analysis with a polyclonal antibody, confirmed that the level of protein BmHSP27.4 increased at a high-temperature, in accordance with its increased mRNA level. In this study, BmHsp27.4 was identified as a novel B. mori gene with an important role in response to high-temperature stress.     

Developmental Hypothyroxinemia and Hypothyroidism Reduce Proliferation of Cerebellar Granule Neuron Precursors in Rat Offspring by Downregulation of the Sonic Hedgehog Signaling Pathway

Iodine deficiency (ID)-induced hypothyroxinemia and hypothyroidism during development result in dysfunction of the central nervous system, affecting psychomotor and motor function, although the underlying mechanisms causing these alterations are still unclear. Therefore, our aim is to study the effects of developmental hypothyroxinemia, caused by mild ID, and developmental hypothyroidism, caused by severe ID or methimazole (MMZ), on the proliferation of cerebellar granule neuron precursors (CGNPs), an excellent experimental model of cerebellar development and function. The sonic hedgehog (Shh) signaling pathway is essential for CGNP proliferation, and as such, its activation is also investigated here. A maternal hypothyroxinemia model was established in Wistar rats by administrating a mild ID diet, and two maternal hypothyroidism models were developed either by administrating a severe ID diet or MMZ water. Our results showed that hypothyroxinemia and hypothyroidism reduced proliferation of CGNPs on postnatal day (PN) 7, PN14, and PN21. Accordingly, the mean intensity of proliferating cell nuclear antigen and Ki67 nuclear antigen immunofluorescence was reduced in the mild ID, severe ID, and MMZ groups. Moreover, maternal hypothyroxinemia and hypothyroidism reduced expression of the Shh signaling pathway on PN7, PN14, and PN21. Our study supports the hypothesis that developmental hypothyroxinemia induced by mild ID, and hypothyroidism induced by severe ID or MMZ, reduce the proliferation of CGNPs, which may be ascribed to the downregulation of the Shh signaling pathway.     

CD33 in Alzheimer's Disease

The amyloid-beta peptide (Aβ) cascade hypothesis posits that Aβ accumulation is the fundamental initiator of Alzheimer's disease (AD), and mounting evidence suggests that impaired Aβ clearance rather than its overproduction is the major pathogenic event for AD. Recent genetic studies have identified cluster of differentiation 33 (CD33) as a strong genetic locus linked to AD. As a type I transmembrane protein, CD33 belongs to the sialic acid-binding immunoglobulin-like lectins, mediating the cell–cell interaction and inhibiting normal functions of immune cells. In the brain, CD33 is mainly expressed on microglial cells. The level of CD33 was found to be increased in the AD brain, which positively correlated with amyloid plaque burden and disease severity. More importantly, CD33 led to the impairment of microglia-mediated clearance of Aβ, which resulted in the formation of amyloid plaques in the brain. In this article, we review the recent epidemiological findings of CD33 that related with AD and discuss the levels and pathogenic roles of CD33 in this disease. Based on the contributing effects of CD33 in AD pathogenesis, targeting CD33 may provide new opportunities for AD therapeutic strategies.     

BIOCOCKTAIL对乳腺癌细胞MDA-MB-231凋亡的促进作用

目的从细胞凋亡方面观察BIOCOCKTAIL（益生菌微生物制剂）对乳腺癌细胞MDA-MB-231的抑制作用。方法采用FITC和PI双染色法及TUNEL法检测凋亡。结果通过FITC和PI双染色法,观察到BIOCOCKTAIL可显著增加乳腺癌细胞MDA-MB一231凋亡细胞。I组乳腺癌细胞系（8．1％绑38．7％,P〈0．05）,Ⅱ组乳腺癌细胞系（6．9％掷19．4％,P〈0．05）。TUNEL法检测MDA-MB-231细胞凋亡现象明显增多。结论BIOCOCKTAIL能够有效诱导乳腺癌细胞MDA-MB-231凋亡,有可能成为乳腺癌治疗的补充方案。     

Chromogranin B: intra‐ and extra‐cellular mechanisms to regulate catecholamine storage and release,in catecholaminergic cells and organisms

Chromogranin B (CHGB) is the major matrix protein in human catecholamine storage vesicles. CHGB genetic variation alters catecholamine secretion and blood pressure. Here, effective Chgb protein under‐expression was achieved by siRNA in PC12 cells, resulting in ~ 48% fewer secretory granules on electron microscopy, diminished capacity for catecholamine uptake (by ~ 79%), and a ~ 73% decline in stores available for nicotinic cholinergic‐stimulated secretion. In vivo, loss of Chgb in knockout mice resulted in a ~ 35% decline in chromaffin granule abundance and ~ 44% decline in granule diameter, accompanied by unregulated catecholamine release into plasma. Over‐expression of CHGB was achieved by transduction of a CHGB‐expressing lentivirus, resulting in ~ 127% elevation in CHGB protein, with ~ 122% greater abundance of secretory granules, but only ~ 14% increased uptake of catecholamines, and no effect on nicotinic‐triggered secretion. Human CHGB protein and its proteolytic fragments inhibited nicotinic‐stimulated catecholamine release by ~ 72%. One conserved‐region CHGB peptide inhibited nicotinic‐triggered secretion by up to ~ 41%, with partial blockade of cationic signal transduction. We conclude that bi‐directional quantitative derangements in CHGB abundance result in profound changes in vesicular storage and release of catecholamines. When processed and released extra‐cellularly, CHGB proteolytic fragments exert a feedback effect to inhibit catecholamine secretion, especially during nicotinic cholinergic stimulation.

     

Bioreduction of Cr(VI) by Bacillus sp. QH-1 isolated from soil under chromium-containing slag heap in high altitude area

A chromium-reducing strain QH-1, identified as Bacillus sp., was isolated from soil under chromium-containing slag heap in Qinghai high altitude area, China. The strain was found to resist 200 mg/L Cr(VI), and Cr(VI) negatively affects the metabolic activity of the cells, as well as the cell morphology of Bacillus sp. QH-1. The reduction efficiency of Cr(VI) at concentrations of Cr(VI) 25 mg/L, 50 mg/L, 100 mg/L and 200 mg/L were 99.48 %, 65.99 %, 23.22 % and 6.99 %, respectively, decreasing with increasing initial Cr(VI) concentration. This indicates that the toxicity of Cr(VI) increased with concentration. Energy dispersive X-ray analysis revealed that there was insoluble Cr(III) generated during Cr(VI) reduction. In order to apply strain QH-1 to remove Cr(VI) from groundwater, factors of concentration of electron donors (glucose) and temperature were investigated in a synthetic medium. The results demonstrated that glucose could promote the reduction of Cr(VI) by this strain, and the general trend of Cr(VI) reduction increased with temperature within the range of 4 to 37 °C. Cr(VI) was reduced effectively at 25 °C and 37 °C, and all of Cr(VI) was reduced after 96 h at 37 °C, while the reduction was slow at 4 °C and 15 °C, and it almost ceased after about 120 h. These results could be potentially useful for the bioremediation of Cr(VI) in groundwater.     

Taxonomic study of the genus Halolaguna Gozmány (Lepidoptera,Lecithoceridae) from China,with descriptions of two new species

The genus Halolaguna Gozmány, 1978 is studied in China. Two new species, Halolaguna flabellata sp. n. from Guangxi and Halolaguna discoidea sp. n. from Chongqing, Guangxi and Sichuan are described. The female of Halolaguna guizhouensis Wu, 2012 is reported for the first time. Photographs of adults and genitalia are provided. A checklist of all known Halolaguna species is included, along with a key to the Chinese species.     

BAsE-Seq: a method for obtaining long viral haplotypes from short sequence reads

Epidemiologists aim to inform the design of public health interventions with evidence on the evolution, emergence and spread of infectious diseases. Sequencing of pathogen genomes, together with date, location, clinical manifestation and other relevant data about sample origins, can contribute to describing nearly every aspect of transmission dynamics, including local transmission and global spread. The analyses of these data have implications for all levels of clinical and public health practice, from institutional infection control to policies for surveillance, prevention and treatment. This review highlights the range of epidemiological questions that can be addressed from the combination of genome sequence and traditional ‘line lists’ (tables of epidemiological data where each line includes demographic and clinical features of infected individuals). We identify opportunities for these data to inform interventions that reduce disease incidence and prevalence. By considering current limitations of, and challenges to, interpreting these data, we aim to outline a research agenda to accelerate the genomics-driven transformation in public health microbiology.