Correction: An integrated anti-arrhythmic target network of compound Chinese medicine Wenxin Keli revealed by combined machine learning and molecular pathway analysis

Correction for 'An integrated anti-arrhythmic target network of a Chinese medicine compound, Wenxin Keli, revealed by combined machine learning and molecular pathway analysis' by Taiyi Wang et al., Mol. BioSyst., 2017, 13, 1018-1030.

An integrated anti-arrhythmic target network of a Chinese medicine compound, Wenxin Keli, revealed by combined machine learning and molecular pathway analysis

Deciphering the compound Wenxin Keli's anti-arrhythmic pharmacological mechanism by integrating network pharmacology and experimental verification methods.

Polymorphisms in Toll-like receptor 3 are associated with asthma-related phenotypes in the Chinese Han patients

Toll-like receptor (TLR) 3 mediates antivirus immunity and is involved in asthma exacerbation and development. However, the genetic association between TLR3 and asthma remains unclear. This study aimed to evaluate the effects of polymorphisms within TLR3 on asthma risk and asthma-related phenotypes in the Chinese Han population. A total number of 462 unrelated adult patients with asthma and 398 healthy volunteers were enrolled in this study. The genotypes of tagging single nucleotide polymorphisms (SNPs) in TLR3 gene were determined using multiplex SNaPshot SNP genotyping assays. Case-control and case-only studies were used to assess any links with asthma and asthma-related phenotypes. The results showed that the genetic variants in TLR3 were associated with asthma-related phenotypes, including eosinophil counts, serum immunoglobulin E levels and lung function. However, there was no obvious association between the TLR3 SNPs and asthma susceptibility or asthma severity. TLR3 polymorphisms may play a considerable role in the pathogenesis of asthma. It will help in better understanding the pathogenesis of asthma and development of more effective strategies for the prevention, prediction and treatment of asthma.

The change of plasma pituitary adenylate cyclase-activating polypeptide levels after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Elevated circulating pituitary adenylate cyclase-activating polypeptide (PACAP) levels have been demonstrated to be associated with clinical outcomes of severe traumatic brain injury. The current study aimed to confirm whether elevated plasma PACAP levels are predictive of clinical outcomes of aneurysmal subarachnoid hemorrhage (aSAH).

MATERIALS AND METHODS

One hundred and eighteen aSAH patients and 118 controls were recruited. Plasma PACAP concentrations were determined using enzyme-linked immunosorbent assay. Patients were followed up until death or completion of 6 months after aSAH. An unfavorable outcome was defined as Glasgow Outcome Scale score of 1-3.

RESULTS

The admission PACAP levels were significantly elevated in all patients (296.6 ± 119.7 pg/ml) compared with controls (77.1 ± 17.9 pg/ml, P < 0.001). Plasma PACAP levels were independently associated with clinical severity indicated by World Federation of Neurological Surgeons (WFNS) score (t = 4.745, P < 0.001) and Fisher score (t = 4.239, P < 0.001) using a multivariate linear regression. PACAP was identified as an independent predictor for 6-month mortality [odds ratio (OR), 1.014; 95% confidence interval (CI), 1.005-1.030; P < 0.001] and 6-month unfavorable outcome (OR, 1.012; 95% CI, 1.006-1.028; P < 0.001) and 6-month overall survival (hazard ratio, 1.016; 95% CI, 1.008-1.023; P < 0.001) using a binary logistic regression analysis and a Cox's proportional hazard analysis, respectively. PACAP had similar predictive values compared with WFNS score and Fisher score according to the receiver operating characteristic curve analysis.

CONCLUSIONS

Higher plasma PACAP levels are associated with clinical severity and long-term prognosis of aSAH patients, and PACAP has potential to be a good prognostic biomarker of aSAH.

Direct molecular typing of Bordetella pertussis from nasopharyngeal specimens in China in 2012-2013

Data on the molecular epidemiology of Bordetella pertussis are limited in developing countries where whole-cell pertussis vaccines (WCVs) have been used. The aim of this study was to determine the genotypes of circulating B. pertussis in China by direct molecular typing of clinical specimens. DNA extracts of 122 nasopharyngeal swabs (NPs) positive for B. pertussis by polymerase chain reaction (PCR) (targeting IS481 and ptx-Pr) from 2012 to 2013 were used for typing using the multiple-locus variable number tandem repeat analysis (MLVA) and also by PCR-based multilocus sequence typing (MLST) of B. pertussis virulence genes (ptxP, prn, and fim3). One hundred and eight DNA extracts (89 %) generated a complete MLVA type (MT). Among the 18 MTs obtained, MT55 (52 %) and MT104 (13 %) were the most common. MT27, which is linked to the ptxP3 allele and is prevalent in many developed countries using acellular pertussis vaccines (ACVs), was only found in 7 (6 %) DNA extracts. Eighty-seven DNA extracts (71 %) produced a complete multiantigen sequence typing (MAST) type. Of them, 77 (89 %) had the ptxP1/prn1/fim3-1 allele profile. Four DNA extracts (5 %) had the ptxP3/prn2/fim3-2 profile and 3 (4 %) had the ptxP3/prn1/fim3-2 allele profile. These seven DNA extracts also harbored MT27. Our result shows that B. pertussis circulating in China was different from those found in countries where ACVs have been in use, supporting the notion that selection pressure induced by WCVs and ACVs on the bacterial population differs.

Dissection of allelic interactions among Pto-miR257 and its targets and their effects on growth and wood properties in Populus

MicroRNAs (miRNAs) have important roles in the regulation of genes; however, for trees few studies have explored the potential impact of the interactions between miRNAs and their target genes. Here, we performed transcript profiling and association genetics (single-SNP, haplotype-based and multi-SNP associations) to study the genetic regulatory relationship of Pto-miR257 and its 12 target genes in 435 individuals of a natural population of Populus tomentosa. Expression profiling of Pto-miR257 and its targets showed a negative relationship between their expression levels. Of the 61 single-nucleotide polymorphisms (SNPs) detected in Pto-miR257, 6 in the pre-mature region strongly affected its secondary stability and 1 in the mature region could alter its target spectrum. Among the 1029 SNPs in the targets, 3 were located in target sites that could change the binding affinity of Pto-miR257. Single-SNP association analysis revealed that SNPs in Pto-miR257 and target genes associated with both growth and wood property traits, in agreement with haplotype-based identifications. Multi-SNP association found that 10 targets shared at least one common trait with Pto-miR257, with phenotypic variance from 0.5 to 8.5%, suggesting a possible internal genetic interaction between them. Epistasis analysis showed significant epistatic interactions among Pto-miR257 and its targets. Therefore, our study demonstrated Pto-miR257 and its 12 targets had roles in wood formation and revealed the genetic interaction network between the miRNA and its targets under additive, dominant and epistatic models. Thus, association genetics can be used to decipher the interactions between miRNAs and their target genes and to help understand the genetic architecture of complex traits.

[Tissue heterogeneity analysis of CGG-repeat mutation in two fragile X affected male fetuses]

OBJECTIVE

To compare the CGG-repeat-length and its methylation status in fetal tissues and to explicate the heterogeneity of CGG repeats.

METHOD

Multiple tissues from a full mutation(August 2013) and a mosaic aborted fetus of 23-week gestation(May 2012) were collected and genomic DNA from these tissues was extracted. The CGG-repeat-length and methylation status in fetal tissues were determined by a combined strategy of Southern blotting and GC-Rich PCR. FMR1 expression was measured by real time PCR and Western blotting.

RESULT

CGG-repeat-length in different tissues of each fetus was similar.A major methylated band in the full mutation range (540 CGG repeats) was detected in the brain, skin, testis and kidney tissues of Case 1. An unmethylated premutation band with 160 CGG repeats, and another two bands with 470 and 1 100 CGG repeats in the full mutation range were shown in the brain, skin, testis, lung, stomach, gut, liver, kidney, heart and blood of Case 2. However, the methylation status of CGG repeats in the mosaic fetus was heterogeneous among different tissues. The lowest premutation ratio was in the brain of the mosaic fetus compared with other tissues, and correspondingly FMR1 expression in its brain was minimum.

CONCLUSION

This study clarify the tissue heterogeneity of CGG repeats and provides information for the genetic counseling and clinical diagnosis in fragile X syndrome. Based on the fact that the mosaic fetus' mother is a carrier of full mutation, it is speculated that the maternal CGG repeat has contracted before the differentiation of trilaminar germ disc.

Streptococcus mutans copper chaperone, CopZ, is critical for biofilm formation and competitiveness

The oral cavity is a dynamic environment characterized by hundreds of bacterial species, saliva, and an influx of nutrients and metal ions such as copper. Although there is a physiologic level of copper in the saliva, the oral cavity is often challenged with an influx of copper ions. At high concentrations copper is toxic and must therefore be strictly regulated by pathogens for them to persist and cause disease. The cariogenic pathogen Streptococcus mutans manages excess copper using the copYAZ operon that encodes a negative DNA-binding repressor (CopY), the P1-ATPase copper exporter (CopA), and the copper chaperone (CopZ). These hypothetical roles of the copYAZ operon in regulation and copper transport to receptors led us to investigate their contribution to S. mutans virulence. Mutants defective in the copper chaperone CopZ, but not CopY or CopA, were impaired in biofilm formation and competitiveness against commensal streptococci. Characterization of the CopZ mutant biofilm revealed a decreased secretion of glucosyltransferases and reduced expression of mutacin genes. These data suggest that the function of copZ on biofilm and competitiveness is independent of copper resistance and CopZ is a global regulator for biofilm and other virulence factors. Further characterization of CopZ may lead to the identification of new biofilm pathways.

Clinical significance of group B streptococcus testing in late pregnancy

PURPOSE

This study aimed to detect the maternal group B streptococcus (GBS) by real-time PCR method, aiming to understand its germ-carrying situations and clinical significance.

MATERIALS AND METHODS

The secretions of one-third inferior segment of maternal vagina of 1,540 pregnant and postnatal women were collected for GBS detection by real-time PCR method, and the impacts of positive results on the fetus were observed.

RESULTS

The detection rate of GBS was 5.6% (86/1540); the premature birth rate of GBS-positive pregnant women was 29.1% (25/86), the miscarriage rate was 19.8% (17/86), the premature rupture rate was 26.7% (23/86), and the fetal distress rate was 24.4% (21/86).

CONCLUSIONS

The GBS germ-carriers showed increased rates of premature birth, miscarriage, premature rupture, and fetal distress, thus forming adverse effects towards the maternal and infant outcomes.

miR-125a-5p expression is associated with the age of breast cancer patients

Dysregulated miR-125 observed in multiple cancer types has suggested that it is involved in malignant proliferation and invasion. However, the clinical significance of miR-125 in human breast cancer (BC) has not yet been fully elucidated. In the present study, the expression of miR-125a-5p/3p and miR-125b in 143 pairs of BC and normal adjacent tissues (NATs) was measured by real-time quantitative PCR, and the correlation between expression and clinicopathological features was explored. miR-125a-5p and miR-125b were significantly down-regulated in BC tissue samples compared with their matched NAT samples, while the difference in miR-125a-3p expression between BC tissues and NATs was not statistically significant. The expression level of miR-125a-5p was found to be significantly higher in younger patients (<35 years) than in older patients (≥35, P = 0.005). When the patients were divided into three groups according to age (<35, 36-48, and ≥48 years), a gradual reduction in miR-125a-5p expression was observed in BC tissue samples that correlated to increases in age (P = 0.009). There were no significant correlations between miR-125 expression and other clinicopathological features including tumor size, histological grade, hormone receptor status, Her-2 status, and lymph node metastasis. Taken together, these findings suggest that miR-125a-5p may play an important role in BC progression in an age-dependent manner, and that the down-regulation of miR-125a-5p and miR-125b may serve as independent predictors for breast cancer.

Integrated analysis of gene expression and genomic aberration data in osteosarcoma (OS)

Cytogenetic analyses have revealed that complex karyotypes with numerous and highly variable genomic aberrations including single-nucleotide polymorphisms (SNPs) and copy number variants (CNVs), are observed in most of the conventional osteosarcomas (OSs). Several genome-wide studies have reported that the dysregulated expression of many genes is correlated with genomic aberrations in OS. We first compared OS gene expression in Gene Expression Omnibus (GEO) data sets and genomic aberrations in International Cancer Genome Consortium (ICGC) database to identify differentially expressed genes (DEGs) associated with SNPs or CNVs in OS. Then the function annotation of SNP- or CNV-associated DEGs was performed in terms of gene ontology analysis, pathway analysis and protein-protein interactions (PPIs). Finally, the expression of genes correlated with both SNPs and CNVs were confirmed by quantitative reverse-transcription PCR. Eight publicly available GEO data sets were obtained, and a set of 979 DEGs were identified (472 upregulated and 507 downregulated DEGs). Moreover, we obtained 1039 SNPs mapped in 938 genes, and 583 CNV sites mapped in 2915 genes. Comparing genomic aberrations and DGEs, we found 41 SNP-associated DEGs and 124 CNV-associated DEGs, in which 7 DGEs were associated with both SNPs and CNVs, including WWP1, EXT1, LDHB, C8orf59, PLEKHA5, CCT3 and VWF. The result of function annotation showed that ossification, bone development and skeletal system development were the significantly enriched terms of biological processes for DEGs. PPI network analysis showed that CCT3, COPS3 and WWP1 were the significant hub proteins. We conclude that these genes, including CCT3, COPS3 and WWP1 are candidate driver genes of importance in OS tumorigenesis.

Isolation, partial characterization, and cloning of an extracellular chitinase from the entomopathogenic fungus Verticillium lecanii

The entomopathogenic fungus Verticillium lecanii is a well-known biocontrol agent of fungal phytopathogens, as well as insect pests. A 42-kDa chitinase belonging to family 18 of the glycosyl hydrolases was isolated and partially characterized. Chitinase was purified using successive column chromatography on phenyl-sepharose, DEAE-sepharose, and CM-sepharose. The enzyme showed the highest activity at 40°C and pH 4.6. Enzyme activity was strongly activated in the presence of Mg(2+). The purified enzyme showed inhibitory activity of spore germination against several plant pathogens, particularly Fusarium moniliforme. The genomic DNA and cDNA sequences were resolved by polymerase chain reaction amplification and sequencing. Protein modeling and comparative investigation of different chitinase amino acids showed that chitinases are conserved in parasitic fungi.

Modification of vectors for functional genomic analysis in plants

Simple, efficient, and economical recombinant plant binary expression vectors for deciphering large-scale functional genomic research in plants and promoting crop improvement by genetically engineering and biotechnology is in great demand. In this research, using the pCHF3, pCAMBIA1301, pCAMBIA3300, pCAMBIA3301 vectors, we successfully constructed general plant binary expression vectors carrying CaMV35S and Arabidopsis rd29A promoters mediating multiple cloning sites (

MCS

SacI, KpnI, SmaI, BamHI, XbaI, SalI, and PstI). Meanwhile, a series of applicative binary expression vectors that can be utilized for subcellular localization were constructed by fusion of the MCS and eGFP. Subsequently, the recombinant vectors were successfully transferred into Arabidopsis thaliana and Nicotiana benthamiana for further investigation of functional elements in these plant binary expression vectors. Our results demonstrated that this system was a convenient and versatile vector system for phenotypic, functional, subcellular localization, and promoter activity analysis, and it provided a relatively high-efficiency and reliable platform for researchers in vector construction and may facilitate large-scale functional genomics analysis in plants.

Shape memory embracing fixator for Vancouver type B and type C periprosthetic femoral fractures

The purpose of this study was to analyze clinical and radiographical results of a group of patients with periprosthetic femoral fractures treated with the shape memory embracing fixator. We retrospectively reviewed twelve patients in whom a total of twelve periprosthetic femoral fractures were treated with the shape memory embracing fixator between August 2004 and February 2013. The patients were 3 men and 9 women (mean age, 69.9 years; range 42-92 years). The average duration of follow-up was 39.3 months (range 4-103 months). In one case, bone grafting was used. Postoperative evaluation was based on radiographs and Harris hip scores. All fractures healed at on average 4.4 months (range: 3 to 6 months) after surgery. None of the patients developed nonunion or malunion during the follow up. And there was no implant failure and no infection during follow up. The average Harris hip score at the final follow-up examination was 84.8 points. Results show that the shape memory embracing fixator is a safe and effective means for Vancouver type B and type C periprosthetic femoral fractures following hip arthroplasty.

First Report of Bacterial Blight of Guar Caused by Xanthomonas axonopodis pv. cyamopsidis in China

Bacterial blight was observed on field-grown guar (Cyamopsis tetragonoloba L.) for the first time in China. The disease outbreak occurred in the Xinjiang Uyghur Autonomous Region after several weeks of unusually heavy rains during late summer 2013. The disease incidence was generally 40 to 50%, although values as high as 80% were observed in several fields. Initial field symptoms included water-soaked spots on leaves, pods, petioles, and stems. During later stages of infection, the color of the spots became dark. We also observed large, angular, necrotic lesions at leaf tips, black streaks on petioles and stems, split stems, defoliation, wilting or top withering, vascular necrosis, and dieback. Samples of diseased leaves, stems, petioles, pods, and seeds were surface sterilized, ground, and then plated onto King's B medium. Plates were incubated at 28°C for 72 h. Fifteen bacterial strains with yellow-pigmented, opaque, and round colonies were isolated. These strains were aerobic, gram-negative rods with a single, polar flagellum. They were positive for H₂S, esculin, oxidase, tobacco hypersensitivity, indole production from tryptophan, nitrate reduction to nitrite, and the utilization of glucose, mannose, trehalose, galactose, and starch. The maximum salt tolerance of the strains was 2 to 3%. Pathogenicity tests using eight strains were conducted in July 2013. A bacterial culture was suspended in sterile water with a final concentration of 10⁸ CFU/ml. Eight 4-week-old guar plants were inoculated by (i) spraying the bacterial suspension on the leaves until runoff, or (ii) puncturing the stems with a needle that had been dipped into the bacterial suspension. Sterile water was used as a negative control. Plants were kept in a mist room with 100% relative humidity for 24 h. Stem and leaf symptoms similar to those of the original plants were observed on the inoculated guar plants within 10 days of inoculation. No symptoms developed on the negative control plants. Yellow bacterial colonies re-isolated from inoculated plant tissues were morphologically identical to the original. 16S rDNA was amplified using universal primers (Pa 5'-AGTTTGATCCTGGCTCAG-3' and Ph 5'-TACCTTGTTACGACTTCGTCCCA-3') and sequenced. A BLAST search of the NCBI GenBank database indicated that the 16S rDNA sequences of three strains (accession nos. KF563926, KF563927, and KF563928) had 99.9% identity to Xanthomonas axonopodis strain XV938 (AF123091). Under greenhouse conditions, bacterial strains wilted asparagus bean and pea but rarely infected bean, kidney bean, faba bean, mung bean, soybean, red bean, pea, garbanzo bean, and peanut. Based on morphology, pathogenicity tests, 16S rDNA sequencing, and host plant specificity, the pathogen was confirmed as X. axonopodis pv. cyamopsidis (synonym: X. campestris pv. cyamopsidis [Patel et al., 1953]). To our knowledge, this is the first report of bacterial blight of guar caused by X. axonopodis pv. cyamopsidis in China. Guar has recently been introduced in Xinjiang Province. Our findings indicate that bacterial blight may pose a threat to the economic sustainability of guar production in the region. References: (1) I. A. Milyutina et a1. FEMS Microbiol. Lett. 239:17, 2004. (2) I. M. G. Almeida et al. Summa Phytopathol. 18:255, 1992. (3) J. D. Mihail et al. Plant Dis. 69:811, 1985.

Effect of CYP1A2 polymorphism on the pharmacokinetics of agomelatine in Chinese healthy male volunteers

WHAT IS KNOWN AND OBJECTIVE

Agomelatine is a melatonin (MT) analogue with agonistic properties and has been proven to be effective for various types of depressive symptoms. Following oral administration, agomelatine is primarily metabolized by the hepatic cytochrome P450 isoenzyme CYP1A2. The purpose of this study was to assess the influence of CYP1A2 single nucleotide polymorphisms (SNPs, rs762551, rs2069514, rs2472304, rs2470890) on agomelatine pharmacokinetics in the Chinese population.

METHODS

Seventy-two healthy Chinese male volunteers enrolled in the study received an oral dose of 25 mg of agomelatine after providing written informed consent. CYP1A2 SNPs were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Agomelatine plasma concentrations were determined by high performance liquid chromatography-tandem mass spectrometry, and the pharmacokinetics analyses were evaluated by nonparametric methods.

RESULTS AND DISCUSSION

After a single oral dose of 25 mg agomelatine, no significant differences existed in agomelatine pharmacokinetics between the rs2069514 GG homozygotes (n = 35) and the rs2069514 AG allele (n = 35) in all subjects. The mean agomelatine AUC0-7 , AUC0-∞ and Cmax for the rs762551 CC homozygotes (n = 9), rs2470890 CC homozygotes (n = 54) and rs2472304 GG homozygotes (n = 51) were much higher than the rs762551 AA allele (n = 31), rs2470890 CT allele (n = 17) and rs2472304 AG allele (n = 20) respectively (P < 0.05).

WHAT IS NEW AND CONCLUSION

The rs762551 A, rs2470890 T and rs2472304 A genotype presented a significantly lower level of agomelatine exposure (AUC, Cmax ) compared with the rs762551 C, rs2470890 C and rs2472304 G genotype in Chinese healthy subjects. It suggested that the rs762551, rs2470890 and rs2472304 genetic polymorphism might be associated with the marked interindividual variability of agomelatine, and the pharmacokinetic profile of agomelatine may be different in different races.

Root Rot of Chinese Jujube (Ziziphus jujuba) Caused by Cytospora sacculus in China

Ziziphus jujuba Mill. (Rhamanaceae), commonly known as Chinese jujube, is a plant that is native to China and widely distributed in China and South Korea. Chinese jujube is a traditional Chinese medicine and food that has been used for thousands of years. From spring 2011 to spring 2012, Chinese jujube trees (<4 years old) from commercial orchards in Kashi and Akzo developed symptoms of severe wilting, chlorosis, and stunting. The taproot and lateral roots exhibited black, sunken, necrotic lesions, and progression of these symptoms eventually caused mortality of infected trees. In April 2011 and 2012, 15 trees with root rot symptoms were collected from different orchards, and a fungus was recovered consistently from symptomatic rhizome samples that had been surface-sterilized with 0.1% mercuric chloride and plated onto potato dextrose agar (PDA). Thirteen isolates were obtained. Colony growth on PDA was initially white but gradually turned grayish yellow-brown, with the lower side of the plate turning a deep yellow-brown. Colony texture was felty and slightly raised with no concentric growth zones. Pycnidia formed abundantly after 30 days, and each exuded a dull orange cirrhus containing conidia. The conidiomatal stromata were immersed in the bark, erumpent, discoid, convex to conical, and 1.53 ± 0.13 mm in diameter. Discs were dark brown or grey, nearly flat, circular, and up to 0.6 mm in diameter, with one to eight lateral ostioles. Ostioles were brown, 40 to 80 mm in diameter, and located above the disc surface. Locules were globose, with four to eight in a stroma, undivided, and did not share common walls. Conidia were hyaline, eguttulate, and allantoid, with sizes of 12 to 20 × 1.0 to 1.5 μm. The agar culture and conidiomatal stromata morphology were in accordance with descriptions of Cytospora sacculus (1,4). PCR amplification of the internal transcribed (ITS) spacer region of rDNA (using primers ITS1/4), combined with amplification of the β-tubulin gene (using primers BT1a/BT1b) (2,3), followed by sequencing of the amplified DNA, led to identification of isolate 6T-17 as Valsa ceratosperma (anamorph C. sacculus). The sequence of the ITS1-5.8s-ITS2 region of rDNA (GenBank Accession No. JX560175) matched the ITS sequence of V. ceratosperma Accession AB369475 with 99% similarity, and the β-tubulin gene sequence (KC840674) resulted in a 99% match with that of V. ceratosperma Accession EU219136. Mycelial plugs of a culture of each fungal isolate on PDA were inoculated onto 10 rhizomes of 2-month-old seedlings of Z. jujube, and maintained in a greenhouse at 25 to 30°C. Ten rhizomes of 2-month-old seedlings of Z. jujuba were inoculated with non-colonized PDA plugs as the control treatment. After 2 months, all inoculated seedlings showed chlorotic leaves and root rot symptoms similar to those observed in the original commercial orchards. No symptoms were observed on the control plants. The pathogen was reisolated successfully from symptomatic plants but not from the control plants, fulfilling Koch's postulates. To our knowledge, this is the first report of C. sacculus causing a root rot of Z. jujuba trees in China. References: (1) G. C. Adams et al. Stud. Mycol. 52:83, 2005. (2) G. M. Arruda et al. Plant Pathol. 54:53, 2005. (3) J. Baskarathevan et al. Eur. J. Plant Pathol. 132:549, 2012. (4) J. B. Kepley et al. J. Arbor. 26:326, 2000.

The isolation and characterization of a telomerase immortalized goat trophoblast cell line

Trophoblast cells play vital roles in the processes of embryonic implantation and placentation. Many toxicological compounds can induce the malfunction of trophoblast cells, resulting in implantation failure or early embryonic loss. The finite lifespan of primary trophoblast cells limits investigation of the long-term effects of some toxicological compounds on trophoblast cells in vitro. In this study, primary goat trophoblast cells were purified by density gradient centrifugation and specific immuno-affinity purification. Then, the purified cells were immortalized through transfection of a plasmid containing the human telomerase reverse transcriptase (hTERT) gene. hTERT-transfected goat trophoblast cells (hTERT-GTCs) could steadily express hTERT gene and exhibit higher telomerase activity, and persistently proliferate without any signs of senescence up to 50 passages. The immortalized goat trophoblast cells still possessed the basic and key properties of normal primary goat trophoblast cells to express the specific intracellular marker cytokeratin 7 (CK-7) and secrete chorionic gonadotrophin β-subunit (CG-β) and placental lactogen (PL). Further studies showed that the immortalized goat trophoblast cells expressed vimentin and non-classical MHC class I antigen and exhibited invasive phenotype, suggesting that the immortalized goat trophoblasts resembled human extravillous trophoblasts. In addition, this cell line did not show neoplastic transformation either in vivo or in vitro. We concluded the immortalized goat trophoblast cells by hTERT transfection retained the basic and key characteristics of primary trophoblast cells and may provide a useful model to study the effects of some toxicological compounds on trophoblast cells.