客家人的红细胞血型分布

对父母双方上溯三代均为客家人的广东梅县200名 (其中男89人,女111人) 健康学生进行了红细胞血型ABO,MNSs,Rh,Kidd,Duffy,Diego,Xg,Lewis及P等系统的分布调查。结果显示,客家人的基因频率S=0.0250,NS=0,pl=0.0917和Fyb=0.0300,都是汉族人群中最低的。其它基因频率为r=0.6632,p=0.1863,q=0.1505;m=0.5250,n=0.4750,MS=0.0250,Ms=0.5000,Ns=0.4750,s=0.9750;C=0.6575,D=1.0000,E=0.1515,CDe=0.6226,cDE=0.1200,cDe=0.2189,CDE=0.0389;JKa=0.4642,JKb=0.4881,JK=0.0477;Fya=0.9700;Dia=0.0202,Dib=0.9798;Xga=0.3633,Xg=0.6367;P2=0.9083。发现了国内第二例Jk(a-b-)表型,未发现MNS型,NS型,NSs型,CCDEE型,CcDEE型,Fy(a-)型和Rho(-)型。Le(a+b-)型29人,Le(a+b+)型2人,Le(a-b+)型67人,Le(a-b-)型102人。客家人与国内19个群体的遗传距离计算结果表明,与客家人遗传距离最近的是福建汉族、湖南苗族、贵州汉族及广西侗族,其次为河南汉族、黑龙江汉族、陕西汉族,福建畲族及上海汉族,而与云南白族、辽宁满族、甘肃汉族、广西瑶族、广西壮族、内蒙汉族及四川彝族的遗传距离较远。与客家人遗传距离最远的是湖南土家族、海南苗族及海南黎族。     

Holocene Palynological Records in Lake Selincuo,Northern Xizang

Selincuo (31°34′–31°57′N, 88°31′–89°21′E)is one of the great lakes in northern Xizang surrounded by alpine grassland, composed mainly of Stipa purpurea, S, subssessifolia var. bassipulomosa. A 3.08 m long core has been taken from a water depth of 27 m, 3 km to the north from the lake. Palynological records of the core combined with surface sample results have revealed from the regional as well as local vegetational and environmental history since the last 12 000 a BP, a very low pollen concentration (19–209 grains/g), mainly of airborne pollen, which indicated a treeless alpine sparse vegetation. A great vegetation change took place at Ca. 9 600 a BP when alpine sparse vegetation was replaced by alpine grassland lasting until Ca. 6 000 a BP. Quite a number of tree pollen grains found in this time interval might be explained as a result of expansion of forests somewhere around the Xizang Plateau. These changes must have caused by climatic warming during the Early Holocene. During the last 6 000 years the vegetation had remained as the alpine grassland, although probably more luxurouste than before, but their was an obvious increase of arboreal pollen, such as the increase of Abies during Ca. 6 000–4 000 a BP, Picea 4 000–2 200 a BP, Pinus 2 200–1 000 a BP which indicated continuous expansion of forests growing around the plateaus. During the last 1 000 years both the concentration and proportion of the arboreal pollen decreased and those of Cypraceae pollen increased sharply. This might mean a reduction of the forests around the plateau and an expansion of swamps around the lake.     

HepaCAM inhibits clear cell renal carcinoma 786-0 cell proliferation via blocking PKCε translocation from cytoplasm to plasma membrane

p62/sequestosome-1 is a multifunctional adapter protein implicated in selective autophagy, cell signaling pathways, and tumorigenesis, and plays an important role at the crossroad between autophagy and cancer. But, the connection between autophagy and cancer is complex and in some cases contradictory. Human colorectal cancer tissues from patients were analyzed for expression of p62 and Microtubule-associated protein light chain 3 (LC3, an autophagosome marker) using immunostaining, western blotting, real-time PCR, and confocal microscopy. To study the effects of p62 on autophagy and cell growth, shRNA for p62 was applied and cell growth curve was monitored in human colorectal cancer cell. In vivo experiments were done using the mouse xenograft model. We showed that up-regulated expression of p62 and LC3 in colorectal cancer tissues. We also demonstrated that specifically knockdown the expression of p62 showed significantly inhibitory effects not only on autophagy activation, but also on tumor growth both in vitro and xenograft tumors model. The ectopic overexpression of p62 and autophagy activation contributes to colorectal tumorigenesis. p62 and autophagy will be therapy targets for the treatment of colorectal cancer.     

Mapping nucleolar localization sequences of 1A6/DRIM

Human 1A6/downregulated in metastasis (DRIM) is a nucleolar protein with multiple HEAT-repeat motifs (Huntington, elongation factor 3, a subunit of protein phosphatase 2A, target of rapamycin). The yeast homologue to 1A6/DRIM, Utp20, is part of the small subunit processome and functions in 18S RNA processing. In the present study, we utilized the green fluorescent protein as the fusion protein marker to investigate the sequence responsible for 1A6/DRIM accumulation in nucleolus. Deletion sequence analysis demonstrated that a single region located between amino acids 2744 and 2761 at the C-terminus of 1A6/DRIM is capable of nucleolar accumulation. Two basic amino acid clusters within this region are essential for nucleolar accumulation. The sequences required for nucleolar accumulation overlaps the putative nuclear localization signal of 1A6/DRIM.     

Volume-sensitive outwardly rectifying chloride channels are involved in oxidative stress-induced apoptosis of mesangial cells

Volume-sensitive outwardly rectifying (VSOR) Cl- channels have been electrophysiologically identified in human and mouse mesangial cells, but the functional role of VSOR Cl- channels in mesangial cell apoptosis is not clear. The aim of the present study was to demonstrate the role of VSOR Cl- channels in oxidative stress-induced mesangial cell apoptosis. H2O2-induced Cl- currents showed phenotypic properties of VSOR Cl- channels, including outward rectification, voltage-dependent inactivation at more positive potentials, sensitivity to hyperosmolarity, and inhibition by VSOR Cl- channel blockers. Moreover, blockage of VSOR Cl- channels by DIDS (100 microM), NPPB (10 microM) or niflumic acid (10 microM) rescued mesangial cell apoptosis induced by H2O2. Treatment with 150 microM H2O2 for 2h resulted in significant reduction of cell volume, in contrast, nuclear condensation and/or fragmentation were not observed and the caspase-3 activity was also not increased. The early-phase alterations in cell volume were markedly abolished by pretreatment with VSOR Cl- channel blockers. We conclude that VSOR Cl- channels are involved in H2O2-induced apoptosis in cultured mesangial cells and its mechanism is associated with apoptotic volume decrease processes.     

NMR solution structure of the tandem Src homology 3 domains of p47phox complexed with a p22phox-derived proline-rich peptide

The phagocyte NADPH oxidase plays a crucial role in host defense against microbial infections by generating reactive oxygen species. It is a multisubunit enzyme composed of membrane-bound flavocytochrome b558 as well as cytosolic components, including p47phox, which is essential for assembly of the complex. When phagocytes are activated, the cytosolic components of the NADPH oxidase translocate to flavocytochrome b558 due to binding of the tandem Src homology 3 (SH3) domains of p47phox to a proline-rich region in p22phox, a subunit of flavocytochrome b558. Using NMR titration, we first identified the proline-rich region of p22phox that is essential for binding to the tandem SH3 domains of p47phox. We subsequently determined the solution structure of the p47phox tandem SH3 domains complexed with the proline-rich peptide of p22phox using NMR spectroscopy. In contrast to the intertwined dimer reported for the crystal state, the solution structure is a monomer. The central region of the p22phox peptide forms a polyproline type II helix that is sandwiched by the N- and C-terminal SH3 domains, as was observed in the crystal structure, whereas the C-terminal region of the peptide takes on a short alpha-helical conformation that provides an additional binding site with the N-terminal SH3 domain. Thus, the C-terminal alpha-helical region of the p22phox peptide increases the binding affinity for the tandem SH3 domains of p47phox more than 10-fold.