Rice leaf inclination2, a VIN3-1ike protein, regulates leaf angle through modulating cell division of the collar

As an important agronomic trait, inclination of leaves is crucial Ior crop architecture and grain yields. 10 understand the molecular mechanism controlling rice leaf angles, one rice leaf inclination2 （1c2, three alleles） mutant was identified and functionally characterized. Compared to wild-type plants, lc2 mutants have enlarged leaf angles due to increased cell division in the adaxial epidermis of lamina joint. The LC2 gene was isolated through positional cloning, and encodes a vernalization insensitive 3-like protein. Complementary expression of LC2 reversed the enlarged leaf angles of lc2 plants, confirming its role in controlling leaf inclination. LC2 is mainly expressed in the lamina joint during leaf development, and particularly, is induced by the phytohormones abscisic acid, gibberellic acid, auxin, and brassinosteroids. LC2 is localized in the nucleus and defects of LC2 result in altered expression of cell division and hormone-responsive genes, indicating an important role of LC2 in regulating leaf inclination and mediating hormone effects.

Exosomes derived from microglia overexpressing miR-124-3p alleviate neuronal endoplasmic reticulum stress damage after repetitive mild traumatic brain injury

We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.

MicroRNA-363-3p inhibits colorectal cancer progression by targeting interferon-induced transmembrane protein 1

BACKGROUND The molecular mechanisms of colorectal cancer development and progression are far from being elucidated.AIM To investigate the role of microRNA-363-3p(miR-363-3p)in the progression of colorectal cancer.METHODS Real-time polymerase chain reaction was performed to detect miRNA expression in human colorectal cancer tissues and paired normal colorectal tissues.PITA 6 was utilized to predict the targets of miR-363-3p.Dual-luciferase reporter system was used to validate the target of miR-363-3p.Plate colony formation assay and wound-healing assay were performed to evaluate cancer cells’clonogenic survival ability and migration ability,respectively.Cell proliferation was examined by cell counting kit-8 assay.Immunohistochemical staining was used to determine the expression level of interferon-induced transmembrane protein 1(IFITM1)in colorectal cancer tissues and adjacent tissues.The TCGA and GTEx databases were used to compare the expression levels of IFITM1 mRNA in colorectal cancer tissues and normal colorectal tissues and analyze the correlation between the expression levels of IFITM1 mRNA and overall survival and disease-free survival of patients.A colorectal cancer cell line with a deficiency of IFITM1 was constructed,and the regulation effect of IFITM1 on the clonogenic growth of colorectal cancer cells was clarified.RESULTS MiR-363-3p was decreased in colorectal cancer tissues compared to normal colorectal tissues.IFITM1 was characterized as a direct target of miR-363-3p.Overexpression of miR-363-3p led to decreased clonogenic survival,proliferation,and migration of colorectal cancer cells,which could be reversed by forced IFITM1 expression.CONCLUSION MiR-363-3p can constrain clonogenic survival,proliferation,and migration of colorectal cancer cells via targeting IFITM1.

Potential role of chitinase 3-like-1 in inflammation-associated carcinogenic changes of epithelial cells

The family of mammalian chitinases includes members both with and without glycohydrolase enzymatic activity against chitin, a polymer of N-acetylglucosamine. Chitin is the structural component of fungi, crustaceans, insects and parasitic nematodes, but is completely absent in mammals. Exposure to antigens containing chitin- or chitin-like structures sometimes induces strong T helper type-I responses in mammals, which may be associated with the induction of mammalian chitinases. Chitinase 3-like-1 （CHI3L1）, a member of the mammalian chitinase family, is induced specifically during the course of inflammation in such disorders as inflammatory bowel disease, hepatitis and asthma. In addition, CHI3L1 is expressed and secreted by several types of solid tumors including glioblastoma, colon cancer, breast cancer and malignant melanoma. Although the exact function of CHI3L1 in inflammation and cancer is still largely unknown, CHI3L1 plays a pivotal role in exacerbating the inflammatory processes and in promoting angiogenesis and remodeling of the extracellular matrix. CHI3L1 may be highly involved in the chronic engagement of inflammation which potentiates development of epithelial tumorigenesis presumably by activating the mitogen-activated protein kinase and the protein kinase B signaling pathways. Anti-CHI3L1 antibodies or pan-chitinase inhibitors may have the potential to suppress CHI3Ll-mediated chronic inflammation and the subsequent carcinogenic change in epithelial cells.

Involvement of ERK1/2 and p38 MAPK in up-regulation of 14-3-3 protein induced by hydrogen peroxide preconditioning in PC12 cells

Objective To investigate the protective effects of hydrogen peroxide preconditioning （HPP） on the pheochromocytoma （PC12） cells treated with 1-methyl-4-phenylpyridinium （MPP^＋） and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 4′,6′-diamidino-2-phenylindole （DAPI） staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase （MAPK） were determined by Western blot. Enzyme-linked immunosorbent assay （ELISA） was used to measure the activity of extracellular signal-regulated protein kinase 1/2 （ERK1/2）. Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^＋ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^＋- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP＋ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.

Long non-coding RNA DPP10-AS1 represses the proliferation and invasiveness of glioblastoma by regulating miR-24-3p/CHD5 signaling pathway

This investigation aimed to unveil new prospective diagnosis-related biomarkers together with treatment targets against glioblastoma.Methods:The expression levels of long non-coding RNA(lncRNA)DPP10-AS1 were assessed using real-time quantitative polymerase chain reaction(RT-qPCR)within both the patient tissue specimens and glioblastoma cell lines.The relationship between lncRNA DPP10-AS1 expression in glioblastoma and patient prognosis was investigated.Cell Counting Kit-8(CCK-8),transwell,and clonogenic experiments were utilized to assess tumor cells’proliferation,invasiveness,and migratory potentials after lncRNA DPP10-AS1 expression was up or down-regulated.Using an online bioinformatics prediction tool,the intracellular localization of lncRNA DPP10-AS1 and its target miRNA were predicted,and RNA-FISH verified results.A dual-luciferase reporter experiment validated the relationship across miR-24-3p together with lncRNA DPP10-AS1.MiR-24-3p expression within glioblastoma was identified through RT-qPCR,and potential link across miR-24-3p and lncRNA DPP10-AS1 was assessed using Pearson correlation analysis.Moreover,influence from lncRNA DPP10-AS1/miR-24-3p axis upon glioblastoma cell progression was assessed in vivo via a subcutaneous xenograft tumor model.Results:The expression of lncRNA DPP10-AS1 was notably reduced in both surgical specimens of glioblastoma and the equivalent cell lines.Low level of lncRNA DPP10-AS1 in glioblastoma is following poor prognosis.The downregulation of lncRNA DPP10-AS1 in glioblastoma cells resulted in enhanced cellular proliferation,migration,and invasion capabilities,accompanied by downregulated E-cadherin and upregulated vimentin and N-cadherin.Additionally,the observed upregulation of lncRNA DPP10-AS1 demonstrated a substantial inhibitory function upon proliferation,invasion,and migratory capabilities of LN229 cells.Subcellular localization disclosed that lncRNA DPP10-AS1 had a binding site that interacted with miR-24-3p.Upregulated miR-24-3p was detected in glioblastomas,displaying an inverse correlation with lncRNA DPP10-AS1 expression.MiR-24-3p downstream target has been determined as chromodomain helicase DNA binding protein 5(CHD5).LncRNA DPP10-AS1 affected the invasion and proliferation of glioblastoma by controlling the miR-24-3p/CHD5 axis.Conclusion:The present study demonstrated that lncRNA DPP10-AS1 can inhibit the invasive,migratory,and proliferative properties of glioblastoma by regulating the miR-24-3p/CHD5 signaling pathway.Consequently,lncRNA DPP10-AS1 has potential as a tumor suppressor and might be utilized for accurate diagnosis and targeted treatments of glioblastomas.

Research progress of hsa-miR-495-3p and proteolipid protein 1 involvement in the pathogenesis of schizophrenia

Schizophrenia(SCZ)is a serious mental illness whose etiology and pathogenesis are not yet clear.The level of miRNA may be a crucial factor in the occurrence and development of SCZ.This study found that miR-495 may regulate the susceptibility gene of SCZ and that proteolipid protein 1(PLP1)as a risk gene for schizophrenia may be involved in its pathogenesis.In this article we review the research progress related to hsa-miR-495-3p(miR-495),PLP1,and schizophrenia.

胰岛素样生长因子-1、胰岛素样生长因子受体-1和胰岛素样生长因子结合蛋白-3在非小细胞肺癌患者血清中的表达及其临床意义

肿瘤患者中胰岛素样生长因子（insulin like growth factor，IGF）-1、胰岛素样生长因子受体-1（insulin like growth factor 1R,IGF-1R）与胰岛素样生长因子结合蛋白（insulin like growth factor binding protein,IGFBP）-3的含量比例对肿瘤的发生、发展和预后具有重要意义。

缺氧诱导因子-1α和BCL-2/腺病毒E1B19 kDa相关蛋白3在中耳胆脂瘤表达及意义

目的探讨缺氧诱导因子-1α(hypoxia inducible factor-1,HIF-1α)和BCL-2/腺病毒E1B19KDa相关蛋白3(Bcl2/adenovirus E1B 19 kD interacting protein 3,BNIP3)在中耳胆脂瘤中的表达及胆脂瘤上皮的凋亡情况。方法采用免疫组织化学方法检测30例中耳胆脂瘤标本与18例外耳道皮肤标本中HIF-1α和BNIP3蛋白的表达情况,使用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记(terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling,Tunel)检测20例中耳胆脂瘤标本和18例外耳道皮肤标本的凋亡情况。使用Pearson相关分析检验HIF-1α和BNIP3蛋白之间的相关性。结果 HIF-1α在胆脂瘤组和对照组的平均光密度分别为0.16±0.07和0.08±0.03,两组比较差异有统计学意义(t=4.279,P<0.01);BNIP3在胆脂瘤组和对照组的平均光密度分别为0.16±0.08和0.11±0.06,两组比较差异有统计学意义(t=2.463,P=0.0185);经pearson相关分析,在胆脂瘤上皮中,HIF-1α和BNIP3之间呈正相关(r=0.418,P=0.003);Tunel染色中,凋亡指数在胆脂瘤组和对照组分别为(52.8±12.5)%和(9.99±2.97)%,两组比较差异有统计学意义(t=14.166,P<0.01)。结论 HIF-1α和BNIP3在中耳胆脂瘤中的异常表达可能与胆脂瘤的高凋亡特性有关。

STRUCTURE,MOLECULAR WEIGHT AND BIOACTIVITIES OF(1→3)-β-D-GLUCANS AND ITS SULFATED DERIVATIVES FROM FOUR KINDS OF LENTINUS EDODES

Lentinan samples,(1→3)-β-D-glucans containing 4.6-15.2 wt% proteins,coded as L-I_1 L-I_2 L-I_3 and L-I_4(L-I)were isolated from four kinds of Lentinus edodes.These glucans were treated with acetone to remove the protein in orderto obtain free protein glucans coded as LNP-I_1,LNP-I_2.LNP-I_3 and LNP-I_4(LNP-I).The free-protein polysaccharideswere sulfated to give derivatives(S-LNP-I)with degree of substitution(DS)from 0.4-0.8.The structural features andweight-average molecular weight(M_w)of the samples were investigated by using infrared spectroscopy,elemental analysis,^(13)C-NMR,size exclusion chromatography combined with laser light scattering(SEC-LLS)and viscometry.The effects ofstructure and conformation of the polysaccharides on antitumor activities were assayed in vivo(Sarcoma 180 solid tumors)and in vitro(Sarcoma 180,HL-60,MCF-7 and Vero tumors).The results indicated that the predominant species of thesamples L-I and LNP-I in 0.2 mol/L NaCl aqueous solution existed as triple-helical chains with high rigidity and in dimethylsulfoxide(DMSO)as single-flexible chains.Interestingly,the antitumor activities of LNP-I are lower than those of the nativeglucans(L-I),whereas their sulfated derivatives have higher inhibition ratio against Sarcoma 180 than LNP-I.The resultsreveal that the binding of protein,sulfated modification and the triple helix conformation are important factors in theenhancement of the antitumor activities of polysaccharides on the whole.

沙颍河铅污染对儿童GH-IGF-1轴和体格发育的影响

目的：探讨沙颍河铅污染现状及其对儿童生长激素-胰岛素样生长因子-1（ GH-IGF-1）轴和体格发育的影响。方法：随机选择淮河沙颍河流域S县两个村庄作为调查点（依距河岸距离远近分别定为对照区和污染区）；原子吸收分光光度法检测河水和调查点饮用水及土壤中的铅含量。整群抽取两村庄小学8～13岁在校学生作为研究对象，伏安极谱法测定儿童血清铅含量；ELISA法检测儿童血清胰岛素样生长因子-1（ IGF-1）、胰岛素样生长因子结合蛋白3（IGFBP3）、生长激素（GH）和生长激素结合蛋白（GHBP）水平；电子体重计、身高坐高计、皮褶厚度计及Gulick卷尺分别测量体重、身高、皮褶厚度和胸围。结果：河水3个采样断面铅浓度均超过国家地表水水质标准Ⅴ级。污染区饮用水及土壤铅含量均高于对照区（ t＝2．663和2．300，P＜0．05）。污染区儿童血清铅含量高于对照区儿童（t＝3．227，P＝0．002）。污染区男孩身高、体重、皮褶厚度、胸围与对照区比较差异均无统计学意义（P均＞0．05）。两区女孩身高、体重和胸围差异均无统计学意义（P均＞0．05），但污染区女孩皮褶厚度高于对照区（t＝3．036，P＝0．003）。结论：沙颍河流域的饮用水中铅含量明显升高，污染区儿童血清GH-IGF-1轴相关因子水平受到影响。

Hyperoside protects the blood-brain barrier from neurotoxicity of amyloid beta 1–42

Mounting evidence indicates that amyloid β protein（Aβ） exerts neurotoxicity by disrupting the blood-brain barrier（BBB） in Alzheimer＇s disease. Hyperoside has neuroprotective effects both in vitro and in vivo against Aβ. Our previous study found that hyperoside suppressed Aβ1-42-induced leakage of the BBB, however, the mechanism remains unclear. In this study, bEnd.3 cells were pretreated with 50, 200, or 500 μM hyperoside for 2 hours, and then exposed to Aβ1-42 for 24 hours. Cell viability was determined using 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2-H-tetrazolium bromide assay. Flow cytometry and terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling assay were used to analyze cell apoptosis. Western blot assay was carried out to analyze expression levels of Bax, Bcl-2, cytochrome c, caspase-3, caspse-8, caspase-9, caspase-12, occludin, claudin-5, zonula occludens-1, matrix metalloproteinase-2（MMP-2）, and MMP-9. Exposure to Aβ1-42 alone remarkably induced bEnd.3 cell apoptosis; increased ratios of cleaved caspase-9/caspase-9, Bax/Bcl-2, cleav ed caspase-8/caspase-8, and cleaved caspase-12/caspase-12; increased expression of cytochrome c and activity of caspase-3; diminished levels of zonula occludens-1, claudin-5, and occludin; and increased levels of MMP-2 and MMP-9. However, hyperoside pretreatment reversed these changes in a dose-dependent manner. Our findings confirm that hyperoside alleviates fibrillar Aβ1-42-induced BBB disruption, thus offering a feasible therapeutic application in Alzheimer＇s disease.

Geniposide, the component of the Chinese herbal formula Tongluojiunao, protects amyloid-β peptide(1–42)-mediated death of hippocampal neurons via the non-classical estrogen signaling pathway

Tongluojiunao （TLJN） is an herbal medicine consisting of two main components, geniposide and ginsenoside Rg1. TLJN has been shown to protect primary cultured hippocampal neurons. How-ever, its mechanism of action remains unclear. In the present study, primary cultured hippocampal neurons treated with Aβ1-42 （10 μmol/L） signiifcantly increased the release of lactate dehydroge-nase, which was markedly reduced by TLJN （2 μL/mL）, speciifcally by the component geniposide （26 μmol/L）, but not ginsenoside Rg1 （2.5 μmol/L）. hTe estrogen receptor inhibitor, ICI182780 （1 μmol/L）, did not block TLJN-or geniposide-mediated decrease of lactate dehydrogenase under Aβ1-42-exposed conditions. However, the phosphatidyl inositol 3-kinase or mitogen-activated protein kinase pathway inhibitor, LY294002 （50 μmol/L） or U0126 （10 μmol/L）, respectively blo cked the decrease of lactate dehydrogenase mediated by TLJN or geniposide. hTerefore, these results suggest that the non-classical estrogen pathway （i.e., phosphatidyl inositol 3-kinase or mitogen-activated protein kinase） is involved in the neuroprotective effect of TLJN, speciifcally its component, geniposide, against Aβ1-42-mediated cell death in primary cultured hippocampal neurons.

Study of the SH3-domain GRB2-1ike 2 gene expression in laryngeal carcinoma

Background Laryngeal carcinoma is a common malignant tumor of the upper respiratory tract, and in 95% of cases the tumor is laryngeal squamous cell carcinoma （LSCC）. The abnormity of SH3-domain GRB2-1ike 2 （SH3GL2） gene was found in LSCC. In order to clarify the relationship between SH3GL2 gene and LSCC, we evaluated the expression of the SH3GL2 gene in LSCC. Method Real-time PCR, immunohistochemistry and Western blotting were used to detect the mRNA and protein expression and find the various rules of SH3GL2 gene in LSCC. Results The result of real-time PCR showed that the expression level of SH3GL2 mRNA in LSCC tissue was apparently down-regulated; immunohistochemical analysis showed that SH3GL2 protein was mainly located in cytoplasm, the rate of positive cells and SH3GL2 protein expression level were fluctuated with the pathological classification of LSCC; the result of Western blotting showed that SH3GL2 protein was down-regulated significantly in LSCC samples, especially in metastatic lymph nodes. Conclusions These results suggest that SH3GL2 is a LSCC related gene and its expression level is fluctuated with the pathological classification which indicate that SH3GL2 participates in the development and progression of LSCC. And it may be considered as a novel tumor marker to find both a new anti-oncogene and relative factors of invasion and metastasis of laryngeal carcinoma.

Comparison of three fluorescence labeling and tracking methods of endothelial progenitor cells in laser-injured retina

AIM： To compare three kinds of fluorescent probes for in vitro labeling and in vivo tracking of endothelial progenitor cells（EPCs） in a mouse model of laser-induced retinal injury.METHODS： EPCs were isolated from human umbilical cord blood mononuclear cells and labeled with three different fluorescent probes： 5-（and-6）-carboxyfluorescein diacetate succinimidyl ester（CFSE）, 1,1′-dilinoleyl-3,3,3′,3′-tetramethylindo-carbocyanine perchlorate linked acetylated low-density lipoprotein（Di I-Ac LDL）, and green fluorescent protein（GFP）. The fluorescent intensity of EPCs was examined by confocal microscopy. Survival rate of labeled EPCs was calculated with trypan blue staining, and their adhesive capability was assessed. A mouse model of retinal injury was induced by laser, and EPCs were injected into the vitreous cavity. Frozen section and fluorescein angiography on flat-mounted retinal samples was employed to track the labeled EPCs in vivo.RESULTS： EPCs labeled with CFSE and Di I-Ac LDL exhibited an intense green and red fluorescence at the beginning; the fluorescence intensity decreased gradually to 20.23% and 49.99% respectively, after 28 d. On the contrary, the florescent intensity of GFP-labeled EPCs increased in a time-dependent manner. All labeled EPCs showed normal morphology and no significant change in survival and adhesive capability. In the mouse model, transplantation of EPCs showed a protective effect against retinal injury. EPCs labeled with CFSE and Di I-Ac LDL were successfully tracked in mice during the development of retinal injury and repair; however, GFP-labeled EPCs were not detected in the laser-injured mouse retina.CONCLUSION： The three fluorescent markers used in this study have their own set of advantages and disadvantages. CFSE and Di I-Ac LDL are suitable for short-term EPClabeling, while GFP should be used for long-term labeling. The choice of fluorescent markers should be guided by the purpose of the study.

Synthesis and biological evaluation of 5'-phenyl-3'H-spiro-[indoline-3,2'-[1,3,4]oxadiazol]-2-one analogs

A series of 5＇-phenyl-3＇H-spiro[indoline-3,2＇-[l,3,4]thiadiazol]-2-one analogs were synthesized and their Bcl-2 protein inhibitory activities were studied. The lead compound was originally identified using a fluorescence polarization-based competitive binding assay. Among the 10 compounds investigated, I k showed good binding affinities to Bcl-xL and Mcl-l, with inhibition constants of 8.9 μmol/L and 3.4 μmol/L, respectively. While compound lc achieved tight binding affinities to Bcl-xL （Ki= 0.16 μmol/L）, has the potential to be a new lead compound.

A Cotton BURP Domain Protein Interacts With α-Expansin and Their Co-Expression Promotes Plant Growth and Fruit Production

Plant growth requires cell wall extension. The cotton AtRD22-Like I gene GhRDL1, predominately expressed in elongating fiber cells, encodes a BURP domain-containing protein. Here, we show that GhRDL1 is localized in cell wall and interacts with GhEXPA1, an α-expansin functioning in wall loosening. Transgenic cotton overexpressing GhRDL1 showed an increase in fiber length and seed mass, and an enlargement of endopleura cells of ovules. Expression of either GhRDL1 or GhEXPA1 alone in Arabidopsis led to a substantial increase in seed size; interestingly, their co-expression resulted in the increased number of siliques, the nearly doubled seed mass, and the enhanced biomass production. Cotton plants overexpressing GhRDL1 and GhEXPA1 proteins produced strikingly more fruits （bolls）, leading to up to 40% higher fiber yield per plant without adverse effects on fiber quality and vegetative growth. We demonstrate that engineering cell wall protein partners has a great potential in promoting plant growth and crop yield.

Survival,recovery and microcystin release of Microcystis aeruginosa in cold or dark condition

Microcystis often dominates phytoplankton in eutrophic lakes and must survive a long period of cold or dark conditions. However, the survival strategies of Microcystis to withstand cold or dark stress are less well known. In this study, we conducted experiments on the responses of two toxic Microcystis aeruginosa strains （FACHB-905 and FACHB-915） and their microcystin release in conditions of low temperature （15℃ or 4℃, with illumination） or darkness, and subsequent recovery in standard conditions （25℃ with illumination）. On exposure to 15℃, a small decrease in cell viability was observed, but the cell number increased gradually, suggesting that M. aeruginosa FACHB-905 and FACHB-915 cells seem in general tolerant in 15℃. Interestingly, our results show that a higher carotenoid content and microcystin release potentially enhance the fitness of surviving cells at 15℃. M. aeruginosa cells exposed to lower temperature light stress （4℃） did not completely lose viability and retained the ability to reinitiate growth. In darkness, the maximum quantum yield （Fv/Fm） and the maximum electron transport rate （ETRmax） values and cell viability of M. aeruginosa cells gradually decreased with time. During the recovery period, the photosynthetic efficiency of M. aeruginosa reverted to the normal level. Additionally, M. aeruginosa FACHB-905 and FACHB-915 exposed to low temperature had increased caspase-3-1ike activity and DNA fragmentation, which suggests the occurrence of a type of cell death in M. aeruginosa cells under cold stress similar to programmed cell death. Overall, our findings could confer certain advantages on the Microcystis for surviving cold or dark conditions encountered in the annual cycle, and help explain its repeated occurrence in water blooms in large and shallow lakes.

Transgenic mice designed to express human α-1,2-fucosyltransferase in combination of human DAF and CD59 to avoid xenograft rejection

The expression of human α-1,2-fucosyltransferase (HT) or complement regulatory proteins has been proved as an strategy to overcome hypercute rejection in discordant xenogeneic organ transplantation. In this study, we examined whether peripheral blood mononuclear cells (PBMCs) from polytransgenic mice expressing the human HT, and complement regulatory proteins (DAF and CD59), can provide more effective protection against xenograft rejection. Transgenic mice were produced by co-injection of gene constructs for human HT, DAF and/or CD59. Flow Cytometry (FCM) was used to screen the positive transgenic mice. PBMCs from transgenic mice were incubated with 15% human serum to evaluate natural antibody binding, complement activation and expression of adhesion molecules. Three transgenes were strongly expressed in PBMCs of transgenic mice, and HT expression signifi- cantly reduced expression of the major xenoepitope galactose-α-1,3-galactose (α-Gal). Functional studies with PBMCs showed that co-expression of HT and DAF or CD59 markedly increased their re- sistance to human serum-mediated cytolysis when compared with single transgenic PBMCs. Moreover, the combined expression of triple transgenes in PBMCs led to the greatest protection against human serum-mediated cytolysis, avoided hyperacute rejection and reduced expression of adhesion mole- cules. Strong co-expression of triple transgenes was completely protected from xenograft hyperacute rejection and partially inhibited acute vascular rejection. The studies suggest that engineering mice to express triple molecules represents an critical step toward prolonging xenograft survival and might be more suitable for xenotransplantation.

多发性硬化患者Sp3基因编码序列的突变筛查

Sp3（specific protein 3）基因是一种广泛存在于人体组织的核转录因子，属于Sp家族成员之一，它通过GCJGT盒与受其调控的基因启动子相结合，从而调控这些基因的表达，这些基因中许多与免疫反应有关，包括诱导凋亡的Fas基因，转化生长因子-β（TGF-β）、T细胞受体可变区Vα（TCRVα）基因及艾滋病毒1型（HIV-1）等。