Clinical evaluation and mitochondrial DNA sequence analysis in two Chinese families with aminoglycoside-induced and non-syndromic hearing loss

We report here the clinical, genetic, and molecular characterization of two Chinese pedigrees with aminoglycoside-induced and non-syndromic hearing impairment. Clinical evaluation revealed the variable phenotype of hearing impairment including audiometric configuration in these subjects. Penetrances of hearing loss in BJ105 and BJ106 pedigrees are 67% and 33%, respectively. In particular, three of 10 affected matrilineal relatives of BJ105 pedigree had aminoglycoside-induced hearing loss, while seven affected matrilineal relatives in BJ105 pedigree and six affected matrilineal relatives in BJ106 pedigree did not have a history of exposure to aminoglycosides. Sequence analysis of the complete mitochondrial genomes in these pedigrees showed the identical homoplasmic A1555G mutation and distinct sets of mtDNA variants belonging to haplogroups F3 and M7b. These variants showed no evolutionary conservation, implying that mitochondrial haplotype may not play a significant role in the phenotypic expression of the A1555G mutation in these Chinese pedigrees. However, aminoglycosides and nuclear backgrounds appear to be major modifier factors for the phenotypic manifestation of the A1555G mutation in these Chinese families.     

Mesenchymal stromal cells ameliorate acute allergic rhinitis in rats

Mesenchymal stromal cells (MSCs) have been extensively investigated as a potential antiinflammatory treatment in many inflammatory‐related diseases; however, it remains unclear whether MSCs could be used to treat acute allergic rhinitis. A rat model of allergic rhinitis was treated with MSCs. The effect of MSCs on the inflammation of allergic rhinitis was evaluated by sneezing, nose rubbing, the pathology of the nasal mucosa, and the expression of interleukin 4, tumour necrosis factor alpha, and immunoglobulin E in the serum of rats. Also, the population of MSCs isolated from umbilical cords of humans was evaluated to determine if they could inhibit the symptoms and inflammation of acute allergic rhinitis in a rat model. We observed that this population of cells inhibited sneezing, nose rubbing, and changes in the pathology of the nasal mucosa. Intriguingly, we observed that MSCs reduced the expression of interleukin 4, tumour necrosis factor alpha, and immunoglobulin E in the serum. Furthermore, MSCs reduced the expression of histamine and the recruitment of macrophages in the nasal mucosa of allergic rhinitis rats. We reasoned that the effect of MSCs on allergic rhinitis might be through its regulation of the secretion of related cytokines from macrophages during the process of acute allergic rhinitis. This work suggested that MSCs from the umbilical cords of humans could be used as a positive clinical therapy for the human disease.     

Diurnal Expression Pattern,Allelic Variation,and Association Analysis Reveal Functional Features of the E1 Gene in Control of Photoperiodic Flowering in Soybean

Although four maturity genes, E1 to E4, in soybean have been successfully cloned, their functional mechanisms and the regulatory network of photoperiodic flowering remain to be elucidated. In this study, we investigated how the diurnal expression pattern of the E1 gene is related to photoperiodic length; and to what extent allelic variation in the B3-like domain of the E1 gene is associated with flowering time phenotype. The bimodal expression of the E1 gene peaked first at around 2 hours after dawn in long-day condition. The basal expression level of E1 was enhanced by the long light phase, and decreased by duration of dark. We identified a 5bp (3 SNP and 2-bp deletion) mutation, referred to an e1-b3a, which occurs in the middle of B3 domain of the E1 gene in the early flowering cultivar Yanhuang 3. Subcellular localization analysis showed that the putative truncated e1-b3a protein was predominately distributed in nuclei, indicating the distribution pattern of e1-b3a was similar to that of E1, but not to that of e1-as. Furthermore, genetic analysis demonstrated allelic variations at the E1 locus significantly underlay flowering time in three F₂ populations. Taken together, we can conclude the legume specific E1 gene confers some special features in photoperiodic control of flowering in soybean. Further characterization of the E1 gene will extend our understanding of the soybean flowering pathway in soybean.     

<Emphasis Type="Italic">Halomonas tibetensis</Emphasis> sp. nov., isolated from saline lakes on Tibetan Plateau

Strains pyc13^T and ZGT13 were isolated from Lake Pengyan and Lake Zigetang on Tibetan Plateau, respectively. Both strains were Gram-negative, catalase- and oxidase-positive, aerobic, rod-shaped, nonmotile, and nonflagellated bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains pyc13^T and ZGT13 belong to the genus Halomonas, with Halomonas alkalicola 56-L4-10aEn^T as their closest neighbor, showing 97.4% 16S rRNA gene sequence similarity. The predominant respiratory quinone of both strains was Q-9, with Q-8 as a minor component. The major fatty acids of both strains were C_18:1ω6c/C_18:1ω7c, C_16:1ω6c/C_16:1ω7c, C_16:0, and C_12:0 3OH. The polar lipids of both strains consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, glycolipid, phospholipids of unknown structure containing glucosamine, and unidentified phospholipids. The DNA G + C content of pyc13^T and ZGT13 were 62.6 and 63.4 mol%, respectively. The DNA-DNA hybridization values of strain pyc13^T were 34, 41, 61, 35, and 35% with the reference strains H. alkalicola 56-L4-10aEn^T, H. sediminicola CPS11^T, H. mongoliensis Z-7009^T, H. ventosae Al12^T, and H. fontilapidosi 5CR^T, respectively. Phenotypic, biochemical, genotypic, and DNA-DNA hybridization data showed that strains pyc13^T and ZGT13 represent a new species within the genus Halomonas, for which the name H. tibetensis sp. nov. is proposed. The type strain is pyc13^T (= CGMCC 1.15949^T = KCTC 52660^T).     

异种血清诱发肝纤维化模型中ECM变化的研究

为了观察异种血清诱发肝纤维化过程中细胞外基质（ECM）及其生成细胞的变化规律,经腹腔注射猪血清建立大鼠肝纤维化模型,以免疫组织化学方法显示肝内胶原（Col）Ⅰ、Ⅲ、Ⅳ、Ⅴ型和纤连蛋白（Fn）及其生成细胞。结果：①Fn最早在汇管区、小叶间隔内沉积,ColⅢ、Ⅳ、Ⅴ随之增多,停止血清注射后它们都明显减弱或消失;ColⅠ沉积出现最迟,但阳性迅速增强,停止注射后仍较强;②结蛋白（Dm）阳性的肝星状细胞（HSC,原称Ito细胞）其分布和数量变化与Fn和ColⅡ基本同步,而位于汇管区及细胞间隔的原始间叶细胞（PMC）Dm（-）。提示ECM生成细胞可能来自细胞骨架表型不同的PMC和HSC,本模型由于能清晰地显示ECM及其生成细胞而更适用于肝纤维化机制及防治的研究。     

Potential involvement of the cyclooxygenase-2 pathway in hepatocellular carcinoma-associated angiogenesis

Angiogenesis plays a crucial role in tumor development and growth. The present study was carried out to investigate the potential involvement of the cyclooxygenase-2 (Cox-2) pathway in the regulation of angiogenesis in hepatocellular carcinoma (HCC). We inhibited Cox-2 expression in HCC cell line HuH-7 by selective Cox-2 inhibitor (SC-58635) or Cox-2 siRNA. Conditioned media (CMs) from HuH-7 cells were used in angiogenic assays in vitro and in vivo. Compared with CMs from untreated and negative siRNA treated HuH-7 cells, CMs from SC-58635 and Cox-2 siRNA treated HuH-7 dramatically suppressed the proliferation, migration, and differentiation of human umbilical vein endothelial cells (HUVECs) in vitro and neovascularization in vivo. These inhibitory effects could be partially reversed by the addition of exogenous PGE2 to CMs. Furthermore, Cox-2 inhibition by SC-58635 resulted in PGE2 reduction accompanied by the down-regulation of four PGE2 receptor (EP receptor) subtypes. Treatment with SC-58635 led to the down-expression of proangiogenic factors such as VEGF, HGF, FGF2, ANGPT1 and ANGPT2 in HCC. An approximately 78% reduction of VEGF level has been found in the CM from SC-58635 treated HuH-7. Our results suggest an involvement of Cox-2 in the control of HCC-associated angiogenesis. PGE2 as a vital angiogenic factor may act directly on endothelial cells to promote HuH-7-stimulated angiogenic process. Moreover, Cox-2/PGE2/EP/VEGF pathway possibly also contributes to tumor angiogenesis in HCC. This study provides the rationale for clinical studies of Cox-2 inhibitors on the treatment or chemoprevention of HCC.     

Composition and structure of nucleolar skeleton (nucleolar matrix)

Purified nucleoli of HeLa cells were treated sequentially with nonionic detergent, nucleic acid enzyme, low salt and high salt. The residual nucleolar structure termed nucleolar skeleton (nucleolar matrix) was shown as a fine network under electron microscope with DGD embedding-unembedding technique. Such structures of BHK-21 cell and mouse liver cell are similar to that of HeLa cell. The protein composition of the nucleolar skeleton of HeLa cells was analyzed. The protein composition of such nucleolar residual shows obvious difference from the compositions of nuclear matrix and chromosome scaffold. The major protein composition of the nucleolar skeleton of HeLa cells contains 6–7 polypeptides. Their molecular weights are about 48, 43, 36 and 33 ku. Further studies show that actin and fibrillarin are two major protein components of nucleolar skeleton of HeLa cells.