Chunjin Li

Jilin University, Yung-chi, Jilin Sheng, China

Are you Chunjin Li?

Claim your profile

Publications (10)18.57 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Nerve growth factor promotes the survival and differentiation of nervous cells and is thought to play an important role in the development of reproductive tissues. The aims of this work were to detect the presence of NGF and its receptor NTRK1 in bovine oviduct samples, and to investigate the regulatory interactions between NGF/NTRK1 and gonadotrophins in bovine oviduct epithelial cells. Both transcripts and proteins of NGF and NTRK1 were detected by RT-PCR and Western blotting, and the corresponding proteins were specifically immunolocalized in oviduct epithelial cells. In addition, real-time PCR experiments revealed that the levels of NGF and NTRK1 mRNA in oviduct epithelial cells treated with exogenous FSH or LH were greater than those in negative control cells (P < 0.05). Similarly, treatment with NGF significantly increased the expression of FSHR and LHR in oviduct epithelial cells via its effects on NTRK1 (P < 0.05). This process was suppressed by treatment with the NTRK1 inhibitor K252α. We conclude that NGF/NTRK1 may have a role in regulating the function of bovine oviducts via its interactions with gonadotrophins.
    Animal Reproduction Science. 01/2014;
  • Chunjin Li, Xu Zhou
    [Show abstract] [Hide abstract]
    ABSTRACT: Neurotrophins are a family of polypeptide growth factors that are required for the proliferation, differentiation, survival, and death of neuronal cells. A growing body of evidence suggests they may have broader physiological roles in various no-neuronal tissues. The testicles are complex non-neuronal organs in which diverse cell types interact to achieve correct spermatogenesis. Both neurotrophins and their receptors have been detected in various cell types from mammalian testes, suggesting that neurotrophins may regulate or mediate intercellular communication within this organ. This review summarizes the existing data on the cellular distribution and possible biological roles of neurotrophins in the testes. The literature data suggest that neurotrophins affect somatic cell growth and spermatogenesis, and implies that they play a role in regulating testicular development and male reproduction.
    Reproduction 02/2013; · 3.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The expression and localization of neurotrophin 4 (NT4) and its receptor, tyrosine kinase B (TRKB), in the bovine oviduct, and their interaction with gonadotrophins in bovine oviduct epithelial cells (BOECs), were examined. Transcripts for NT4 and TRKB were detected by reverse transcription polymerase chain reaction (RT-PCR) in bovine oviducts in the follicular and luteal phases, and their proteins were immunolocalized in BOECs. Based on real time PCR, NT4 mRNA did not differ significantly between the two phases of the cycle, although TRKB mRNA expression was higher (P < 0.05) in the luteal phase than that in follicular phase. The BOECs were treated with various concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in vitro; for NT4, mRNA and protein were higher (P < 0.05) than those in the control (based on real time PCR and enzyme-linked immunosorbent assay (ELISA) assays). The effects of NT4 and the TRKB inhibitor (K252a) on the expression of LH receptor (LHR) and FSH receptor (FSHR) in the oviduct epithelial cells were also studied using a monolayer culture model. Expression levels of LHR and FSHR mRNA in BOECs treated with various concentrations of NT4 were higher (P < 0.05) than those in the control. However, these expressions were blocked by treatment with K252α. We concluded that neurotrophin 4 may have a role in regulating the function of bovine oviducts by interacting with gonadotrophins.
    Theriogenology 03/2012; 78(1):39-48. · 2.08 Impact Factor
  • Chunjin Li, Xu Zhou
    [Show abstract] [Hide abstract]
    ABSTRACT: The presence of a complex population of gene transcripts in mature human sperm is well established, and numerous mRNAs and non-coding mRNAs have been identified in sperm of men and other mammalian species using microarray and RT-PCR. The traditional concept that RNAs in mature sperm are only remnants from spermatogenesis and have no biological functions is in doubt. The findings that reverse transcriptases in sperm are active and that sperm can independently activate translation of stored mRNAs suggest that sperm RNAs may have significant effects on male fertility. The differences in expression profiles among RNAs in mature sperm from fertile and infertile men, and the regulation of sperm RNAs in embryonic development make them appealing markers for therapeutic and diagnostic tools in male infertility. In this review, methods for the detection and description of the diversity of gene transcript in sperm are discussed along with their putative roles in functional aspects of sperm and in embryogenesis.
    Clinica chimica acta; international journal of clinical chemistry 03/2012; 413(13-14):1035-8. · 2.54 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 1. The goose major histocompatibility complex (MHC) class IIB cDNA (Ancy-MHCII) was cloned by homology cloning and rapid amplification of cDNA ends by polymerase chain reaction (RACE-PCR), and the genomic structure and tissue expression were investigated. 2. Three different 5'-RACE sequences (Ancy-MHC II5'-1, Ancy-MHC II5'-2, Ancy-MHC II5'-3), one 3'-RACE sequence (Ancy-MHC II-3') and two different full length Ancy-MHC IIB cDNA sequences (Ancy-CD01, Ancy-CD02), which came from different alleles at one locus or different loci, were determined. 3. The genomic organisation is composed of 6 exons and 5 introns, with a longer intron region than that of the chicken. The alleles encode 259 and 260 amino acids in the mature protein. 4. The number of non-synonymous substitutions (dN) in the peptide-binding region of exon 2 from 8 alleles was higher than that of the synonymous substitutions (dS). 5. Tissue-specific expression of Ancy-MHC II mRNA was detected in an adult goose using RT-PCR. These results showed that Ancy-MHC II mRNA was expressed in the lung, spleen, liver, intestine, heart, kidney, pancreas, brain, skin and muscle. This is consistent with the expression of MHC class IIB in various tissues from the chicken. 6. Sequences from goose, snipe and duck clustered together when compared with known MHC class IIB sequences from the other species, significantly differing from mammals and aquatic species, indicating a pattern consistent with accepted evolutionary pathways.
    British Poultry Science 06/2011; 52(3):318-27. · 1.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Neurotrophins, a family of growth factor, are not only required for the survival and differentiation of the nervous system but also important for the development of reproductive tissues. We identified the expression of brain-derived neurotrophic factor (BDNF) transcript and protein in human spermatozoa. The presence of BDNF in human spermatozoa was investigated using RT-PCR, immunofluorescence and Western blotting. Real-time PCR and ELISA were employed to determine expression levels of BDNF. BDNF mRNA and protein were detected in human spermatozoa. Immunofluorescence staining showed that BDNF protein was localized in the head, neck, and tail of human spermatozoa. The amount of BDNF mRNA expressed in spermatozoa of oligoasthenozoospermic group was lower than that of fertile group (P < 0.05). The concentration of BDNF in seminal plasma from oligoasthenozoospermic group (2.8 ± 0.7 ng/ml) was both lower than that from fertile group (3.6 ± 0.4 ng/ml) and asthenozoospermic group (3.4 ± 0.5 ng/ml) (P < 0.05). The data showed that the decrease in BDNF transcript and protein in oligoasthenozoospermic group may be associated with pathogenesis in some types of male infertility.
    Clinica chimica acta; international journal of clinical chemistry 01/2011; 412(1-2):44-7. · 2.54 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The sex-determining region on the Y (SRY) gene is important in mammalian sex determination and differentiation. We report a study of the abundance of SRY gene products in bovine ejaculate. RT-PCR experiments using RNA extracted from bovine spermatozoa with SRY-specific primers yielded a 456 bp product, but the amount of SRY mRNA in sperm was lower than that in the testes (p
    Asian Australasian Journal of Animal Sciences 01/2011; 24(10). · 0.64 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The neurotrophins, required for the survival and differentiation of the nervous system, are known to be important for the development of the reproductive tissues. However, the signals initiating the growth of follicles, gamete development, and transport and the development of zygote in the reproductive system of cows remain ambiguous. The purpose of the present study was to identify the transcripts and proteins of Neurotrophin 4 (NT4) and its receptor tyrosine kinase B (TrkB) in bovine reproductive tissues. The transcripts and immunoreactivity of NT4 and TrkB proteins were detected by reverse transcription polymerase chain reaction and western blot analysis. Using immunohistochemistry, the specific immunoreactivity of NT4 and TrkB were detected in the oocytes of primordial follicles and in the growing primary follicles. The NT4 and TrkB immunoreactivity was predominantly observed in granulosa cells, cumulus granulosa cells, cumulus oocyte complexes, theca cells of mature follicles, as well as in the oviduct epithelial cells, uterine gland cell, and epithelium cells of the uterus during the follicular and luteal phases in cows. Expressions of NT4 and TrkB mRNAs were not significantly different among the ovary, oviduct, and uterus of the follicular phase. For the luteal phase, the expression of NT4 mRNA in the ovary was significantly higher than that in the oviduct and uterus, and the expression of TrkB mRNA in the oviduct was significantly higher than that in the ovary and uterus, as determined by fluorescence quantitative reverse transcription polymerase chain reaction. The expression of NT4 mRNA was significantly higher than that of TrkB mRNA in the ovary and uterus, whereas NT4 mRNA expression was lower than that of TrkB mRNA in the oviduct during the luteal phase. The present study hypothesizes that NT4 participates in the regulation of both gonads and extra-gonadal reproductive tissues in cows.
    Asian Australasian Journal of Animal Sciences 01/2011; 24(3). · 0.64 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nerve growth factor (NGF) and the Tyrosine kinase receptor (TrkA) are expressed in mammalian ovaries and testes, where they are involved in oocyte maturation and spermatogenesis. We assessed the possibility that NGF and TrkA gene products are present in human spermatozoa, and explored differences in levels of NGF and TrkA in spermatozoa from oligoasthenozoospermic, asthenozoospermic and fertile men. The presence of NGF and TrkA in human spermatozoa was investigated using RT-PCR, immunofluorescence and Western blotting. Real-time PCR and ELISA were used to determine expression levels of NGF and TrkA. No NGF transcripts were detected in human spermatozoa. The levels of TrkA mRNA in spermatozoa from oligoasthenozoospermic samples were significantly lower than those in spermatozoa from fertile and asthenozoospermic samples (P<0.05). NGF concentrations in seminal plasma samples from oligoasthenozoospermic men were lower than those in seminal plasma from fertile and asthenozoospermic men, but these differences were not statistically significant (P>0.05). The levels of both NGF protein in seminal plasma and TrkA mRNA in spermatozoa are low in samples from oligoasthenozoospermic men.
    Clinica chimica acta; international journal of clinical chemistry 10/2010; 411(19-20):1482-6. · 2.54 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In order to understand the variations of genomic organization of the major histocompatibility complex (MHC) and provide data for the studies on disease resistance of avian species, the MHC class II polymorphism in Chinese Z-goose was investigated for the first time in the present study. Eight alleles, which probably came from different loci, were found in six different geese with only one obvious band in the restriction fragment length polymorphism data. The numbers of nonsynonymous substitutions (dN) in peptide binding region of exon 2 were higher than that of synonymous substitutions (dS), and no stop codons or frameshift mutations were found in this region, indicating that balance selection was in operation, and the sequences are not likely to be pseudogenes. In addition, we successfully obtained five different long MHC class II fragments (about 1,162 bp) in six geese and found that the length of intron 1 was longer than that in chicken and some other birds, but intron 2 seemed to be intermediate in length. The phylogenetic tree appeared to branch in an order consistent with accepted evolutionary pathway.
    Immunogenetics 06/2009; 61(6):443-50. · 2.89 Impact Factor

Publication Stats

9 Citations
18.57 Total Impact Points

Institutions

  • 2010–2014
    • Jilin University
      • College of Animal Science and Veterinary Medicine
      Yung-chi, Jilin Sheng, China