Effects of muscle blood flow on muscle energy metabolism and contractility

Energy metabolism and contractility of rat’s femoral triceps muscles were investigated by varying blood flow levels with ligation of the femoral artery. The triceps were stimulated electrically to produce equivalent conditions as exercise loading, and phosphorus nuclear magnetic resonance (³¹P-NMR) spectra and muscle tension levels were monitored. The ratio of inorganic phosphate (Pi) to ‘Pi+phosphocreatine (PCr)’, i.e. Pi/(Pi+PCr), was obtained from ³¹P-NMR spectra. This ratio was related to the reduction of blood flow ratio (BFR) during and after the stimulation period, whereas before starting the stimulation, there was no significant correlation. These findings indicate: (i) muscle energy metabolism during decreased blood flow is influenced by the stimulation (loading) given to the muscle; and (ii) changes of muscle energy metabolism due to decreased muscle blood flow during the loading is evaluable by measuring ³¹P-NMR spectra. Muscle tension reached the plateau 8 min after starting the stimulation, regardless of BFR, but muscle tension ratio decreased as BFR became lower. This indicates that decreased blood flow diminishes muscle contractility, and then lowers muscle function levels. Our findings indicate that muscle blood flow plays an important role in muscle function, and blood flow and muscle function levels are evaluable by measuring ³¹P-NMR spectra of the muscle.     

细粒棘球绦虫疫苗候选分子EgA31的GST融合蛋白原核表达及纯化

目的 :构建细粒棘球绦虫疫苗候选分子EgA31重组质粒 ,表达及纯化EgA31 GST融合蛋白 ,为疫苗的研究奠定基础。方法 :PCR扩增EgA31cDNA ,将得到的cDNA经限制性内切酶酶切 ,然后亚克隆入pGEX 5X 3质粒 ,转化BL2 1宿主菌 ,IPTG诱导重组质粒的表达 ,亲和层析纯化表达产物 ,Bradford法测定重组蛋白含量 ,用SDS PAGE和Westernblot进行分析鉴定。结果 :SDS PAGE显示分离纯化的EgA31 GST融合蛋白为 4 5kDa ,测序检验重组质粒中EgA31cDNA序列正确。EgA31 GST融合蛋白免疫豚鼠得到的抗血清可与细粒棘球绦虫原头蚴总蛋白在 6 6kDa处特异性反应。结论 :EgA31 GST融合蛋白获得高效表达 ,并成功纯化 ,初步实验证明具有良好的免疫原性 ,可用于进一步疫苗的免疫注射实验     

Muscle metabolism during exercise using phosphorus-31 nuclear magnetic resonance spectroscopy in adolescents

Very little has been reported on muscle energetics during exercise in adolescents. This is attributable to the difficulty of subjecting children to muscle biopsy. The purpose of this study was to investigate the characteristics of muscle metabolism during exercisein vivo in adolescents by comparing firstly, with adults and secondly, the differences resulting from physical activity using phosphorus-31 nuclear magnetic resonance (³¹PNMR) spectroscopy. The subjects were boys aged 12 to 15 years, comprising 21 trained boys and 23 control boys, and 6 adults controls. The ratio of phosphocreatine (PCr):(PCr + P_i), where P_i is inorganic phosphate intracellular pH at exhaustion and the time constant of PCr during recovery were measured in all the subjects using³¹PNMR. Both groups of children showed higher values of PCr:(PCr + P_i) and intracellular pH at exhaustion than did the adult control group (P < 0.01 orP < 0.05). However, no significant differences were found between the trained boys and the control boys with respect to PCr:(PCr + P_i) and intracellular pH at exhaustion. On the other hand, we found the same values for PCr time constant in all groups. This result suggested no differences of the muscle oxidative capacity between children and adults. We concluded that the adolescents, aged 12 to 15 years in both the trained and control groups, had less glycolytic ability during exercise than the adults.     

Relationship of human adenoviruses 12, 18, and 31 as determined by hemagglutination inhibition.

Adenoviruses 12 and 31, but not Ad18, agglutinate rat blood cells at high titer, providing suitable blood cells be available and a prolonged contact period of virus with the erythrocytes is allowed. Purified virus particles show direct, and virus-free supernatants show direct and indirect, hemagglutination, ie, enhancement of HA by heterologous antiserum. Hemagglutination inhibition with rabbit antisera shows cross-reactions between Ad12 and Ad31 with titers 4--32 times lower than with homologous antigens; Ad18 antisera react with antigens from both of the other serotypes. No cross-reactions were seen with antisera from other adenoviruses. This suggests an antigenic relationship of the three viruses of subgroup IV in their fiber antigen gamma, in addition to the known relation in the hexon (epsilon), which is apparent in cross-neutralization.     

Morphological changes in the internal organs in chronic streptococcal infection

A histological and histochemical study was made of the internal organs of albino mice at various times (from 24 h to 27 weeks) after a single intraperitoneal injection of L-forms of -hemolytic group A streptococci. A progressive pathological process (myocarditis, hepatitis, glomerulonephritis) against a marked allergic bacground and leading to systemic lesions of the tissues was discovered.Institute of Human Morphology, Academy of Medical Sciences of the USSR. N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byullten' Éksperimental'noi Biologii i Meditsiny, Vol. 80, No. 9, pp. 111–115, September, 1975.     

Cell lines that support replication of a novel herpes simplex virus 1 UL31 deletion mutant can properly target UL34 protein to the nuclear rim in the absence of UL31

Previous results indicated that the herpes simplex virus 1 (HSV-1) U(L)31 gene is necessary and sufficient for localization of the U(L)34 protein exclusively to the nuclear membrane of infected Hep2 cells. In the current studies, a bacterial artificial chromosome containing the entire HSV-1 strain F genome was used to construct a recombinant viral genome in which a gene encoding kanamycin resistance was inserted in place of 262 codons of the 306 codon U(L)31 open reading frame. The deletion virus produced virus titers approximately 10- to 50-fold lower in rabbit skin cells, more than 2000-fold lower in Vero cells, and more than 1500-fold lower in CV1 cells, compared to a virus bearing a restored U(L)31 gene. The replication of the U(L)31 deletion virus was restored on U(L)31-complementing cell lines derived either from rabbit skin cells or CV1 cells. Confocal microscopy indicated that the majority of U(L)34 protein localized aberrantly in the cytoplasm and nucleoplasm of Vero cells and CV1 cells, whereas U(L)34 protein localized at the nuclear membrane in rabbit skin cells, and U(L)31 complementing CV1 cells infected with the U(L)31 deletion virus. We conclude that rabbit skin cells encode a function that allows proper localization of U(L)34 protein to the nuclear membrane. We speculate that this function partially complements that of U(L)31 and may explain why U(L)31 is less critical for replication in rabbit skin cells as opposed to Vero and CV1 cells.     

Expression of CD31 epitopes on human lymphocytes: CD31 monoclonal antibodies differentiate between naive (CD45RA+) and memory (CD45RA-) CD4-positive T cells

The CD31 antigen, a member of the immunoglobulin superfamily with a possible cell adhesion function, is expressed on approximately 50% of peripheral blood lymphoid cells at relatively low intensity (10-20% of the level on monocytes). In the accompanying paper we showed that a mAb, 5A2.G5, which identifies a glycosylation-dependent epitope of the CD31 antigen, bound to fewer lymphocytes than two other CD31 mAb, B2B1 and 2BD4, although the 3 antibodies bound equally well to monocytes. We have now analyzed the pattern of expression of epitopes of the CD31 antigen on lymphoid cell subpopulations using two-color immunofluorescence and flow cytometry. Large granular lymphocytes (CD16+), CD8-positive T cells and B cells (SMIg+) were mostly CD31-positive as indicated by the binding of mAb B2B1 and 2BD4. Single populations displaying some overlap with the negative control were obtained in each case. In contrast, CD4-positive T cells fell into two discrete populations with respect to CD31 antigen expression. mAb 5A2.G5 displayed weaker binding to all lymphoid cell types, indicating that the pattern of glycosylation of the CD31 antigen differs between lymphocytes (of all types) and cells of the myeloid lineages. The heterogeneity of CD31 antigen expression by CD4-positive cells was further examined by dual-labelling of purified CD4 cells with mAb B2B1 and CD45RA or CD29 mAb which identify naive and memory T cells respectively. The CD31 antigen was found to be preferentially expressed by the CD45RA-positive, naive cell population.     

miR-30a-3p靶向NOD1对心肌细胞缺氧复氧损伤的影响

目的　探究miR-30a-3p与NOD1的靶向关系，及其对心肌细胞缺氧复氧损伤的影响和机制。 方法　将细胞分为Ctrl组、H/R组、miR-30a-3p mimic组和miR-30a-3p inhibitor组，经过缺氧复氧处理后，转染相应的miRNA处理细胞，RT-PCR检测miR-30a-3p和NOD1基因表达水平，荧光素酶报告检测miR-30a-3p和NOD1靶向关系，Western blot检测NOD1、p-RPI2、p38 MAPK、NF-κB（p65）、cl-caspase-3蛋白表达水平，CCK8法检测细胞活性，Hoechst检测细胞凋亡，试剂盒检测LDH、CK、MDA、T-SOD水平。 结果　miR-30a-3p表达水平随缺氧复氧处理时间增长而下降，NOD1基因表达水平随缺氧复氧处理时间增长而升高。在荧光素酶报告实验中，NOD1 WT+miR-30a-3p mimic荧光素酶活性显著低于NOD1 WT+NC组。与Ctrl组比较，H/R组miR-30a-3p基因表达水平、细胞活性、T-SOD水平降低，NOD1、p-RPI2、p38 MAPK、NF-κB（p65）、cl-caspase-3蛋白表达水平、LDH、CK、MDA水平、细胞凋亡率升高；与H/R组比较，miR-30a-3p mimic组miR-30a-3p基因表达水平、细胞活性、T-SOD水平升高，NOD1、p-RPI2、p38 MAPK、NF-κB（p65）、cl-caspase-3蛋白表达水平、LDH、CK、MDA水平、细胞凋亡率降低，miR-30a-3p inhibitor组miR-30a-3p基因表达水平、细胞活性、T-SOD水平降低，NOD1、p-RPI2、p38 MAPK、NF-κB（p65）、cl-caspase-3蛋白表达水平、LDH、CK、MDA水平、细胞凋亡率升高。 结论　miR-30a-3p可靶向作用于NOD1，缓解心肌细胞缺氧复氧造成的损伤，其作用机制可能与调控NF-κB信号通路有关。     

miR-107抑制胶质瘤细胞的体外增殖、迁移和侵袭

目的探讨miR-107对胶质瘤细胞增殖、迁移和侵袭的调控机制。方法运用RT-qPCR检测人正常的星形胶质细胞系NHA、神经胶质瘤细胞系U87、A172、U251中miR-107和FOXK1的表达;将细胞分为miR-NC组(转染miR-NC)、miR-107组(转染miR-107 mimics)、si-NC组(转染si-NC)、si-FOXK1组(转染si-FOXK1)、miR-107+pcDNA3.1组(共转染miR-107 mimics和pcDNA3.1)和miR-107+pcDNA3.1-FOXK1组(共转染miR-107 mimics和pcDNA3.1-FOXK1);用脂质体法分别转染至U87细胞;CCK-8法检测细胞的增殖;Transwell小室实验检测细胞的迁移和侵袭;Western blot检测细胞中FOXK1的蛋白表达;双荧光素酶报告基因检测实验检测细胞的荧光活性。结果与正常的星形胶质细胞NHA相比,神经胶质瘤细胞U87、A172、U251中miR-107表达明显下调,FOXK1表达明显上调(P<0.05);过表达miR-107、敲减FOXK1均可抑制U87细胞的增殖、迁移和侵袭;miR-107可抑制野生型FOXK1的细胞荧光活性,并负向调控FOXK1的表达;过表达FOXK1可逆转miR-107对U87细胞增殖迁移侵袭的抑制作用。结论 miR-107抑制胶质瘤细胞增殖、迁移和侵袭的作用机制可能与靶向负调控FOXK1有关,将可为胶质瘤的诊断和治疗提供靶向治疗的依据。     

干扰lncRNA RHPN1-AS1表达通过靶向miR-339-5p对肝癌细胞增殖和凋亡的影响

目的:探讨长链非编码RNA PCNA1(lncRNA RHPN1)反义AS1(RHPN1-AS1)对肝癌细胞增殖和凋亡的影响及其作用机制。方法:将si-NC(lncRNA RHPN1-AS1阴性对照组)、si-RHPN1-AS1(沉默lncRNA RHPN1-AS1组)、pcDNA(真核表达载体组)、pcDNA-RHPN1-AS1(沉默lncRNA RHPN1-AS1真核表达载体组)、miR-NC(微小RNA-339-5p阴性对照组)及miR-339-5p(微小RNA-339-5p组)分别转染至肝癌细胞Huh7中,记为si-NC组、si-RHPN1-AS1组、pcDNA组、pcDNA-RHPN1-AS1组、miR-NC组和miR-339-5p组;将si-RHPN1-AS1质粒分别与anti-miRNC(微小RNA-339-5p抗结剂阴性对照)、anti-miR-339-5p(微小RNA-339-5p抗结剂)共转染至Huh7细胞中,记为si-RHPN1-AS1+anti-miR-NC组(沉默lncRNA RHPN1-AS1+微小RNA-339-5p抗结剂阴性对照组)、si-RHPN1-AS1+anti-miR-339-5p组(沉默lncRNA RHPN1-AS1+微小RNA-339-5p抗结剂组);转染均采用脂质体法。采用实时荧光定量聚合酶链反应(PCR)(RT-qPCR)检测正常肝细胞(THLE-2)、肝癌细胞株(Huh7、MHCCLM3、MHCC97H)中miR-339-5p和RHPN1-AS1表达水平;双荧光素酶报告实验检测RHPN1-AS1和miR-339-5p的靶向关系;用蛋白质印迹法检测细胞周期素D1(Cyclin D1)蛋白、P21蛋白、B细胞淋巴瘤/白血病-2(Bcl-2)及Bcl-2相关X蛋白(Bax)的表达水平;用流式细胞术检测细胞凋亡情况;用四甲基偶氮唑(MTT)比色法检测细胞活性。结果:与正常肝细胞THLE-2相比,肝癌细胞株Huh7、MHCCLM3、MHCC97H中RHPN1-AS1高表达,miR-339-5p低表达。RHPN1-AS1靶向调控miR-339-5p的表达。干扰RHPN1-AS1表达和miR-339-5p过表达的肝癌细胞Huh7中P21蛋白、Bax蛋白表达水平显著升高,Cyclin D1、Bcl-2水平显著降低,细胞活性显著降低,细胞凋亡率显著升高。下调miR-339-5p表达逆转了干扰RHPN1-AS1表达对肝癌细胞Huh7的增殖抑制和凋亡促进作用。结论:干扰RHPN1-AS1表达可抑制肝癌细胞的增殖,促进细胞凋亡,其机制可能与miR-339-5p表达有关,将可为肝癌的靶向治疗提供新靶点。