CLOCK and BMAL1 stabilize and activate RHOA to promote F-actin formation in cancer cells.

Circadian genes control most of the physiological functions in cancer cells, including cell proliferation, migration, and invasion. The CLOCK and BMAL1 complex plays a central role in circadian rhythms. Previous studies have shown that circadian genes may act as oncogenes or tumor-suppressor genes. In addition, F-actin, regulated by RHOA, has been shown to participate in tumor progression. However, the roles of the CLOCK and BMAL1 genes in the regulation of tumor progression via the RHOA-ROCK-CFL pathway remain largely unclear. Here we first indicate that the rearrangement of F-actin is regulated by CLOCK and BMAL1. We found that CLOCK and BMAL1 can upregulate RHOA expression by inhibiting CUL3-mediated ubiquitination and activate RHOA by reducing the interaction between RHOA and RhoGDI. Consequently, CLOCK and BMAL1 control the expression of the components of the RHOA-ROCK-CFL pathway, which alters the dynamics of F-actin/G-actin turnover and promotes cancer cell proliferation, migration, and invasion. In conclusion, our research proposes a novel insight into the role of CLOCK and BMAL1 in tumor cells.

Clock1a affects mesoderm development and primitive hematopoiesis by regulating Nodal-Smad3 signaling in the zebrafish embryo.

Circadian clock and Smad2/3/4-mediated Nodal signaling regulate multiple physiological and pathological processes. However, it remains unknown whether Clock directly cross-talks with Nodal signaling and how this would regulate embryonic development. Here we show that Clock1a coordinated mesoderm development and primitive hematopoiesis in zebrafish embryos by directly up-regulating Nodal-Smad3 signaling. We found that Clock1a is expressed both maternally and zygotically throughout early zebrafish development. We also noted that Clock1a alterations produce embryonic defects with shortened body length, lack of the ventral tail fin, or partial defect of the eyes. Clock1a regulates the expression of the mesodermal markers ntl, gsc, and eve1 and of the hematopoietic markers scl, lmo2, and fli1a Biochemical analyses revealed that Clock1a stimulates Nodal signaling by increasing expression of Smad2/3/4. Mechanistically, Clock1a activates the smad3a promoter via its E-box1 element (CAGATG). Taken together, these findings provide mechanistic insight into the role of Clock1a in the regulation of mesoderm development and primitive hematopoiesis via modulation of Nodal-Smad3 signaling and indicate that Smad3a is directly controlled by the circadian clock in zebrafish.

Molecular Characteristics of Methicillin-Resistant Staphylococcus epidermidis on the Abdominal Skin of Females before Laparotomy.

Staphylococcus epidermidis, especially methicillin-resistant strains, may be the source of surgical site infections and may be a reservoir of staphylococcal cassette chromosome mec (SCCmec) for S. aureus. The aim of this study was to investigate the prevalence of methicillin-resistant S. epidermidis (MRSE) on the abdominal skin of females before laparotomy and determine the molecular characteristics and antimicrobial susceptibility patterns of these isolates. MRSE was found in 54 of 157 isolates based on mecA gene detection, and there was no difference in icaA gene carriage rate between MRSE and methicillin-susceptible S. epidermidis (MSSE) isolates. Antimicrobial susceptibility profiles were determined by broth microdilution antimicrobial susceptibility testing according to the latest CLSI manuals. All MRSE isolates had unfavorable antimicrobial susceptibility patterns. Twenty-three MRSE strains (42.6%) were multi-drug resistant. SCCmec typing and pulsed field gel electrophoresis (PFGE) typing was performed. Thirty-nine (72.2%) had a single SCCmec type, whereas 1.9% had two types. Fourteen strains (25.9%) were non-typeable (NT). The most frequent MRSE genotype was SCCmec type IVa. High diversity with PFGE patterns was obtained for MRSE, and there were no isolates exhibiting identical pulsotype. The results confirm that methicillin-resistant strains are frequently present among S. epidermidis on the abdominal skin of females before laparotomy. Moreover, resistance profiles seem to have no association with the SCCmec types or PFGE types for most common antibiotics.

[Identification and functional analysis of a testis-specific E3 ubiquitin ligase gene Rnf148 in mouse].

OBJECTIVE: To investigate the temporal and spatial features of mouse Rnf148 gene expression and the function of RING finger domain of Rnf148 protein. METHODS: The whole RNA was extracted from different tissues of adult mice, embryo in four developmental stages, and testes of postnatal mice respectively. RT-PCR and Northern blotting analysis were used to investigate the expression of Rnf148 gene in the above tissues. The in vitro expression vector for GST-Rnf148 fused protein was constructed, which encompassing the entire RING domain of Rnf148 protein. GST-Rnf148 fused protein was expressed in Escherichia coli. BL21(DE3) cells and purified with glutathione-sepharose 4B. In vitro ubiquitination assay was performed to analyze whether GST-Rnf148 fused protein possess the function of E3 ubiquitin ligase. RESULTS: The Mice Rnf148 mRNA expression was only observed in testis, and Northern blotting confirmed that there was only one 1.2 kb mRNA band present in mice testis. Rnf148 mRNA started to appear in the testis of day 21 mice, and then increased dramatically and reached to the highest level in day 25, and continued to express thereafter. GST-Rnf148 fused protein was induced and purified, in vitro ubiquitination reaction showed that the recombinant protein has E3 ubiquitin ligase activity. CONCLUSION: Rnf148 gene is specifically expressed in mice testis.

[Identification and expression analysis of Macaca mulatta piwil4 gene].

To investigate the structure and expression pattern of rhesus monkey PIWIL4 protein, homologous comparison and reverse transcription PCR (RT-PCR) were carried out to identify rhesus monkey piwil4. The expression of piwil4 mRNA was tested in rhesus monkey heart, brain, colon, epididymis and testis, and the result showed that piwil4 mRNA was expressed in these rhesus monkey tissues. Bioinformatic analysis suggested that the rhesus PIWIL4 protein shared 97% identity in amino acids and the same domains such as PAZ and Piwi with the human PIWIL4 (HIWI2) protein. The immunohistochemical result indicated that PIWIL4 proteins had the same localization in adult testes of the two species, but the distribution of these proteins was altered dynamically at different developmental stages in rhesus monkey testes. PIWIL4 protein was expressed in the nucleus of convoluted seminiferous tubules in infant monkey testes, whereas it was expressed in the cytoplasm of adult monkey testes. The results suggest that piwil4 gene play a similar role in rhesus and human, and different localizations of PIWIL4 protein in infant monkey and adult monkey testes suggest that it functions differently at different developmental stages.

Human RING finger protein ZNF645 is a novel testis-specific E3 ubiquitin ligase.

A large number of testis-specific genes are involved in the complex process of mammalian spermatogenesis. Identification of these genes and their roles is important for understanding the mechanisms underlying spermatogenesis. Here we report on a novel human RING finger protein, ZNF645, which contains a C3HC4 RING finger domain, a C2H2 zinc-finger domain, and a proline-rich region, indicating that it has a structure similar to that of the c-Cbl-like protein Hakai. ZNF645 was exclusively expressed in normal human testicular tissue. Immunohistochemical analysis confirmed that ZNF645 protein was present in spermatocytes, round and elongated spermatids, and Leydig cells. Immunofluorescence staining of mature sperms further showed that the ZNF645 protein was localized over the postacrosomal perinuclear theca region and the entire length of sperm tail. An in vitro ubiquitination assay indicated that the RING finger domain of the ZNF645 protein had E3 ubiquitin ligase activity. Therefore, we suggest that ZNF645 might act as an E3 ubiquitin-protein ligase and play a role in human sperm production and quality control.

[Initial study on zili functions to the development of the germ layers during zebrafish early embryogenesis].

OBJECTIVE: To study the role for piwil2 gene (zili) in the development of the ectoderm, mesoderm and endoderm during early embryogenesis of zebrafish. METHODS: zili morpholino antisense oligonucleotide and 5 mis-pair control morpholino were used in this study. zili was cloned into expression vector. zili mRNA was synthesized in vitro. The antisense RNA probes of gsc, evel and sox17 were synthesized. zili-MO, zili-cMO and zili mRNA was microinjected into one-cell embryos, respectively. Whole-mount in situ hybridization was used to monitor the expressions of marker genes. RESULTS: Microinjection of zili-MO, which knocked down the expression of zili, downregulated the expression of the ectodermal and mesodermal marker gene gsc, promoting the expression of the ectodermal marker gene evel and resulting in the decrease of endodermal cell expressed sox17. The overexpression of zili, promoting the expression of gsc, inhibiting the expression of eve1 and resulting in the decrease of endodermal cell expressed sox17 were observed after microinjection of zili-mRNA. CONCLUSION: zili might have some effect on the formation of the ectoderm, mesoderm and endoderm during early embryogenesis and might be important for normal embryonic development.

c.822+126T>G/C: a novel triallelic polymorphism of the TSSK6 gene associated with spermatogenic impairment in a Chinese population.

TSSK6 is a member of the testis-specific serine/threonine kinase family. Male Tssk6 knockout mice are infertile owing to spermatogenic impairment, including sperm count reduction, a decrease in motile sperm number and motility rates, and an increase in the number of sperms with abnormal morphology. We investigated the possible association between variations of the TSSK6 gene and spermatogenic impairment in humans. Mutation screening of TSSK6 was carried out in 519 patients with azoospermia (n = 273) or severe oligozoospermia (n = 246) and in 359 controls with normozoospermia by denaturing high-performance liquid chromatography and DNA sequencing. The frequencies of alleles and genotypes of gene polymorphism were compared between patients and controls. A novel triallelic polymorphism in TSSK6, c.822+126T>G/C, was identified. The frequencies of genotype TT and allele T were increased dramatically in infertile patients compared with controls, whereas genotype TG, allele G and allele C frequencies were significantly higher in controls than in patients. Further study revealed that the allele C frequency of controls was remarkably higher than that of patients with oligospermia. Our findings, for the first time, suggested an association of c.822+126T>G/C in TSSK6 with spermatogenic impairment in humans in which allele T may be a risk factor for male infertility, while alleles C and G may decrease susceptibility to male infertility.

Identification of Linkage Disequilibrium SNPs from a Kidney-Yang Deficiency Syndrome Pedigree.

In order to probe the genetic traits of Kidney-yang Deficiency Syndrome (KDS), we employed a national standard of KDS diagnosis for the collection of KDS subjects. Each candidate KDS subject from a typical family was diagnosed by 5 independent physicians of Traditional Chinese Medicine (TCM), and repeated for 3 years, all on the first Saturday of December. Fifteen samples of genomic DNA were isolated and genotyped by Affymetrix 100 K arrays of single nucleotide polymorphism (SNP). Then appropriate tools were used for the analysis of linkage disequilibrium (LD) and bioinformatic mining of LD SNPs. The results indicated that our procedure of TCM diagnosis can effectively collect KDS subjects and therefore provide substantial basis for the linkage analysis of KDS. Five SNPs (i.e. rs514207, rs1054020, rs7685923, rs10515889 and rs10516202) were identified as LD SNPs from this KDS family, representing an unprecedented set of LD SNPs derived from TCM syndrome. These SNPs demonstrate midrange linkage disequilibrium within the KDS family. Two genes with established functions were identified within 100 bp of these SNPs. One is Homo sapiens double cortin domain containing 5, which interacts selectively with mono-, di- or tri-saccharide carbohydrate and involves certain signaling cascades. Another one, leucyl-tRNA synthetase, is also a pleiotropic gene response to cysteinyl-tRNA aminoacylation and protein biosynthesis. In conclusion, KDS is involved in special SNP linkage disequilibrium in the intragenic level, and genes within the flanks of these SNPs suggest some essential symptoms of KDS. However, definitive evidence to confirm or exclude these loci and to establish their biological activities will be required.

[Relationship between the R219K polymorphism of ATP-binding cassette transporter 1 gene and coronary heart disease].

To study the distribution of R219K polymorphism in ATP-Binding Cassette Transporter 1 (ABCA1) gene in Chinese Han population and the association of this polymorphism with coronary heart disease (CHD) . Genotypes were determined by PCR-RFLP approach in 417 unrelated healthy controls and 396 CHD patients. The frequencies of K allele and KK genotype for controls (0.465, 0.228) were significantly higher than those (0.381, 0.162) for patients (P<0.05). When the patients were divided into two subgroups by onset-age, the frequencies of K allele and KK genotype for early-onset patients (0.34, 0.111) were lower than those (0.419, 0.205) for late-onset patients and those for controls (P<0.05) , while there were no such differences between late-onset patients and controls. Patients with RR genotype had a higher plasma concentration of triglycerides (TG) when compared with that of KK genotype (P<0.05) . No significant differences of plasma high-density lipoprotein cholesterol (HDL-C) level were observed among patients with different genotypes. These data suggest that the R219K polymorphism in ABCA1 gene is correlated with CHD, and the ABCA1 gene KK genotype may has a function against atherosclerosis without detectable change of plasma HDL-C level in Chinese Han population.

Screening for ZNF230 gene mutation and analysis of its correlation with azoospermia.

OBJECTIVE: To investigate the possible association between ZNF230 gene and azoospermia. METHODS: Screening for mutation of all 6 exons of ZNF230 gene was performed by denaturing high performance liquid chromatography(DHPLC) in 99 patients with azoospermia and in 115 healthy men as controls. RESULTS: An A-->G transition at nucleotide 316 in exon 6 was identified. There were significant differences in the distribution profiles of both allele and genotype frequencies between patient group and control group (P < 0.01 and P < 0.05, respectively). In addition,there was a statistically significant difference in the serum follicle stimulating hormone (FSH) level between the patients with GG/GA genotype and those with AA genotype (P < 0.05). CONCLUSION: ZNF230 gene may be associated with azoospermia, and the A316G mutation may be correlated with the serum FSH level.

[Possible association between 278C/A single nucleotide polymorphism of FKBP6 and idiopathic azoospermia].

OBJECTIVE: To investigate 2 polymorphism sites in exon 3 and intron 2 of FKBP6 in Chinese population, while screening the gene mutations and polymorphisms in exons 3, 4 of FKBP6, and the association of these polymorphisms with azoospermia. METHODS: Possible variations of exons 3, 4 and genotypes and frequencies of 2 polymorphic loci were examined by denaturing high-performance liquid chromatography(DHPLC) and PCR-restriction fragment length polymorphism(PCR-RFLP) technique in 177 azoospermia patients and 231 control individuals. RESULTS: The observed allele frequencies conformed well to Hardy-Weinberg equilibrium. The frequency of 278A allele was significantly higher in controls than that in patients (P<0.05). C/T(s7797242) polymorphism was not found in either group and variations in exons 3, 4 were not detected. CONCLUSION: 278A polymorphism of FKBP6 gene was associated with idiopathic azoospermia, while C/T, 370G/A, 430G/C, 467T/C, 468G/A polymorphisms might be very rare in Chinese population.

[Association of APOA5 gene single nucleotide polymorphism with levels of lipids and coronary heart disease in Chinese].

OBJECTIVE: To investigate the single nucleotide polymorphism 4 (SNP4) of the apolipoprotein A5 (APOA5) gene possible association with coronary heart disease(CHD) and its distribution of in Chinese Han population. METHODS: APOA5 SNP4 genotyping was performed using polymerase chain reaction and Hae III restriction fragment length polymorphism analysis. RESULTS: APOA5 allelic frequencies of T, C were 0.435, 0.565 and 0.374, 0.626 in CHD group and control group, respectively. There is significant difference in allele and genotype frequencies between CHD group and control group (P<0.05). The levels of plasma high density lipoprotein in CHD patients with CC genotype were higher than those in CHD patients with other genotypes (P<0.01). The frequencies of T allele and C allele in Chinese was significantly different from those in Caucasians (0.374 vs 0.663, 0.626 vs 0.337, P<0.01). The C allele was much more common in Chinese population. CONCLUSION: The association is found between the Hae III polymorphism and CHD, There is a significant correlation between the CC genotype of the APOA5 and the levels of plasma high density lipoprotein-cholosteal in the CHD group.

[Construction of recombinant ZNF230/GFP fused plasmids and their expression and cellular localization].

To use green fluorescent protein as a marker to study the localization of the fusion protein, the mutant full length cDNAs of human ZNF230 and mouse znf230 with their stop codon TGA changed to TGG were obtained by PCR amplification, and then cloned into pGEM-Teasy vector. After the double enzyme cutting, the mutated human and mouse ZNF230(znf230) were inserted into mammalian expression plasmid pEGFP-N1. Thus we constructed the plasmid with fusion gene of ZNF230 and green fluorescent protein(GFP). Then the Cos cell was transfected with the fused gene by liposome. Fluorescence microscopy showed that green fluorescence protein expressed over the whole cell when transfected with vector pEGFP-N1. While after the transfection with pEGFP-ZNF230, the fluorescence located mainly on the nuclei of the cells. We demonstrated that the transfected Cos cell line can express human ZNF230 and mouse znf230 with high efficiency. When transfected with the constructed recombinant pEGFP-ZNF230 vector, the ZNF230 protein localizes mainly on the nucleus.

[A novel gene in APOA1/C3/A4/A5 cluster: apolipoprotein A5].

Using methods of comparative and functional genomics, a new gene coding for apolipoprotein A5 was identified in the vicinity of APOA1/C3/A4 cluster on human chromosome 11q23 by Pennaccio team and Vliet team. The open reading frame of human APOA5 encoded a 366-amino acid protein with high sequence homology to mouse Apoa5 and human APOA4. Mice expressing a human APOA5 transgene showed a decrease in plasma triglyceride concentrations to one-third of those in control mice; conversely, knockout mice lacking Apoa5 had four times as much plasma triglycerides as controls. Single nucleotide polymorphisms (SNPs) in APOA5 (S19W, -1131T>C) and APOA5 haplotype (APOA5*3) were independently associated with high plasma triglyceride levels. These findings indicate that APOA5 is an important determinant of plasma triglyceride levels, a major risk factor for coronary artery disease.

[Cloning, expression, and alternative splicing of the novel isoform of hTCP11 gene].

OBJECTIVE: To identify a novel isoform of hTCP11 gene and investigate its expression and alternative splicing. METHODS: According to the sequence of human ESTs which are highly homologous to hTCP11a, primers for PCR were synthesized. Then, the amplified fragments were cloned and sequenced; some methods including BLAST, ClustalW and RT-PCR were used for genomic analysis, study of alternative splicing and gene expression among multiple tissues and different testis tissues. RESULTS: A novel isoform of hTCP11 gene was isolated. It encodes a 440 amino acid protein that is highly homologous to the mouse 566 amino acid protein which is important to sperm function because it encodes the receptor for fertilization promoting peptide (FPP). Among TCP11a, TCP11b and TCP11c, the complicated alternative splicing was found. RT-PCR analysis of RNA extracted from human tissues revealed that the gene is only expressed in fertile adult testes, but not in azoospermic patient testes, fetal testes or other human tissues. CONCLUSION: Our results along with the mouse Tcp-11 function suggest that the isoforms of TCP11 gene play important roles in sperm function and fertility.

Identification of a novel human zinc finger protein gene ZNF313.

A novel human zinc finger protein gene that contains both ring finger and C(2)H(2) domain was first isolated by mRNA differential display between the testes of fertile adults and azoospermic patients followed by rapid amplification of cDNA ends (RACE). Total 6 exons of the human gene span a 17,484 bp genomic DNA sequence that was mapped to chromosome 20q13 by fluorescence in situ hybridization. The mature processed mRNA encodes a 228-amino acid protein with a C(3)HC(4) ring finger and three C(2)H(2) domains. Genomic analysis of the human gene identified two polyadenylation signals in exon 6 resulting in alternative 3'-untranslated regions. Results of Northern blot and RT-PCR of RNAs extracted from multiple tissues revealed that the gene has two transcripts of which the shorter transcript was expressed abundantly in fertile adult testes, but much less in testes of azoospermic patient, fetus as well as other human tissues. These data suggest that the gene may play a role in human spermatogenesis and male fertility.

[Cloning, expression and alternative splicing of a novel isoform of human TCP11b gene].

Based on homology analysis and RT-PCR, a novel isoform of human TCP11 gene was isolated. It encodes a 503 amino acid protein that is highly homologous to the mouse 566 amino acid protein Tcp-11. Tcp-11 is important to sperm function because it may be the receptor of fertilization promoting peptide (FPP). Complicated alternative splicing was found to exist between TCP11a and TCP11b genes. The gene has been mapped to human chromosome band 6p21 by fluorescence in situ hybridization. Results of Northern blot and RT-PCR analysis of RNA extracted from human tissues revealed that the gene was expressed in fertile adult testes only, but neither in azoospermic patient testes, fetal testes nor in other human tissues. Our results suggest that TCP11b gene may be important to human sperm function and male fertility.