Chunjin Li

Jilin University, Yung-chi, Jilin Sheng, China

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Publications (19)29.8 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The neurotrophin family of proteins is required for the survival and differentiation of the nervous system and is important to the development of reproductive tissues. The objectives of the present study were to detect the presence of the brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor protein in cumulus-oocyte complexes in pigs and to explore the role of microRNAs in the BDNF-induced in vitro maturation of oocytes. We demonstrate that both BDNF and tyrosine kinase receptor protein are expressed in porcine cumulus oocyte complexes. BDNF supplementation promotes the in vitro maturation of porcine oocytes. MiRNA-205 is downregulated during the BDNF-induced maturation of oocytes. The overexpression of miRNA-205 in granulosa cells and reporter gene assay shows that the marker gene ptx3 for cumulus expansion is the putative target gene of miR-205. Our data provide evidence that the BDNF-induced maturation of oocytes in pigs may be mediated by miR-205 through the regulation of potential target gene, ptx3.
    No preview · Article · Jan 2016 · Theriogenology
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    ABSTRACT: Polycystic ovary syndrome (PCOS) is a complex and heterogeneous endocrine disorder. To understand the pathogenesis of PCOS, we established rat models of PCOS induced by letrozole and employed deep sequencing to screen the differential expression of microRNAs (miRNAs) in PCOS rats and control rats. We observed vaginal smear and detected ovarian pathological alteration and hormone level changes in PCOS rats. Deep sequencing showed that a total of 129 miRNAs were differentially expressed in the ovaries from letrozole-induced rat model compared with the control, including 49 miRNAs upregulated and 80 miRNAs downregulated. Furthermore, the differential expression of miR-201-5p, miR-34b-5p, miR-141-3p, and miR-200a-3p were confirmed by real-time polymerase chain reaction. Bioinformatic analysis revealed that these four miRNAs were predicted to target a large set of genes with different functions. Pathway analysis supported that the miRNAs regulate oocyte meiosis, mitogen-activated protein kinase (MAPK) signaling, phosphoinositide 3-kinase/Akt (PI3K-Akt) signaling, Rap1 signaling, and Notch signaling. These data indicate that miRNAs are differentially expressed in rat PCOS model and the differentially expressed miRNA are involved in the etiology and pathophysiology of PCOS. Our findings will help identify miRNAs as novel diagnostic markers and therapeutic targets for PCOS.
    No preview · Article · Jan 2016 · DNA and Cell Biology
  • Chunjin Li · Xu Zhou
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    ABSTRACT: Melatonin is a neurohormone secreted by the pineal gland whose concentrations in the body are regulated by both the dark-light and seasonal cycles. The reproductive function of seasonal breeding animals is clearly influenced by the circadian variation in melatonin levels. Moreover, a growing body of evidence indicates that melatonin has important effects in the reproduction of some non-seasonal breeding animals. In males, melatonin affects reproductive regulation in three main ways. First, it regulates the secretion of two key neurohormones, GnRH and LH. Second, it regulates testosterone synthesis and testicular maturation. Third, as a potent free radical scavenger that is both lipophilic and hydrophilic, it prevents testicular damage caused by environmental toxins or inflammation. This review summarizes the existing data on the possible biological roles of melatonin in male reproduction. Overall, the literature data indicate that melatonin affects the secretion of both gonadotropins and testosterone while also improving sperm quality. This implies that it has important effects on the regulation of testicular development and male reproduction. Copyright © 2015. Published by Elsevier B.V.
    No preview · Article · Apr 2015 · Clinica chimica acta; international journal of clinical chemistry
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    ABSTRACT: Progesterone has been suggested to contribute to the regulation of spermatogenesis and to facilitate the production of viable sperm. Investigations have showed that polymorphism of progesterone receptor (PGR) is associated with some diseases. To analyze the potential relationship between male infertility and the +331G/A and progins polymorphisms of PGR gene. The cross-sectional study was carried out at the Department of Male Reproduction, Reproductive Medical Center, the Second Hospital of Jilin University. The restriction fragment length polymorphism (RFLP) technique was used to detect gene point mutations. Of the 145 semen samples analyzed, 35 were asthenozoospermic, 50 were oligoasthenozoospermic, 21 were azoospermic, 11 were teratozoospermic and 28 were from fertile male subjects. Statistical analyses revealed that the genotypes of the +331G/A polymorphisms were in Hardy-Weinberg equilibrium in both the fertile ((2)=0, p=0.534) and oligospermic groups ((2)=0.021, p=0.537). Similarly, the genotypes of the progins polymorphisms were also in Hardy-Weinberg equilibrium in both the fertile ((2)=0, p=1) and oligospermic groups ((2)=0.005, p=1). Our results indicated that polymorphisms of the +331G/A and progins of the PGR gene are unrelated to male infertility, at least in a Chinese population.
    Preview · Article · Feb 2015 · International Journal of Reproductive BioMedicine
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    ABSTRACT: 4-Methylcatechol (4-MC) is one of the metabolites of quercetin, which is a potential drug for neuroprotection and tumorigenesis inhibition. This study was performed to investigate the cytotoxic effect of 4-MC in mouse TM4 Sertoli cells. TM4 Sertoli cell viability was significantly inhibited by 4-MC in a time- and dose-dependent manner. The number of apoptotic and dead cells was significantly increased after 4-MC treatment. Caspase 3 activity increased by prolonged exposure of TM4 Sertoli cells to 200 μM 4-MC. The 4-MC significantly upregulated the mRNA level of Bax gene and considerably downregulated the Bcl-2 gene expression in a concentration-dependent manner. Results showed that 4-MC could induce TM4 Sertoli cell apoptosis, and the cytotoxic effect of 4-MC on TM4 Sertoli cells may be associated with upregulated Bax gene expression, which induced caspase cascade activation.
    No preview · Article · Dec 2014 · Cell Biology International
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    ABSTRACT: Ovarian follicular cysts are anovulatory follicular structures that have been identified in sows and are known to cause infertility. The pathogenesis of follicular cysts remains poorly understood. Hormones play key roles in the formation and persistence of cysts. The hormone inhibin is a member of the TGF-β superfamily and is named for its negative regulation of FSH, another hormone that controls follicular recruitment and growth. In the present study, 48 sows with follicular cysts and 60 normal sows with no cysts were screened for mutations in the inhibin-α gene to examine the association of inhibin-α gene polymorphisms with the presence of follicular cysts. The results show that the c.-42G>A and c.3222G>A polymorphisms are significantly associated with follicular cysts and that sows with c.-42GG and c.3222GG genotypes have lower risk of developing cysts. Our findings may provide novel biological biomarkers and promising gene therapy candidates for follicular cyst formation in sows, which would greatly benefit pig breeding programs. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Oct 2014 · Theriogenology
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    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.
    No preview · Article · Oct 2014 · Animal Reproduction Science
  • Wan-Hong Li · Shu-Xiong Chen · Lu Chen · Chunjin Li · Xu Zhou

    No preview · Article · Sep 2014
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    Chunjin Li · Xu Zhou
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    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.
    Preview · Article · Feb 2013 · Reproduction
  • Lina Tang · Lu Chen · Chunjin Li · Yanling Sun · Xu Zhou
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    ABSTRACT: The development of reproductive system in prepubertal gilts was affected not only by gonadotropins but also by other cytokines and growth factors. Recent studies have revealed that Neurotrophins (NTs) which are well known for their essential roles in neural system also expressed in mammalian reproductive organs and involved in the regulation of mammalian reproduction. Dietary energy level is an important factor affecting domestic animal reproductive performance including central effects on Hypothalamic Pituitary Gonadal (HPG) axis and local effects on gonads. In the present study, the expression of Neurotrophin-4 (NT-4) which is a member of NTs in reproductive tissues of prepubertal gilts including ovary, oviduct and uterus was studied by immunohistochemistry. The effects of dietary energy on NT-4 mRNA expression were also investigated by quantitative PCR. The results show that NT-4 was localized in all classes of follicles in ovaries of prepubertal gilts including primordial follicles, primary follicles and secondary follicles, NT-4 was localized in mucosal epithelial cells in oviducts and glandular epithelium and endometrial epithelium in uteri. Furthermore, different dietary energy levels altered mRNA expression level of NT-4 in ovaries, uteri and oviducts of prepubertal gilts. NT-4 mRNA expression level in ovaries and uteri was higher in high dietary energy group than that in mid and low-energy groups. In oviduct, the expression pattern of NT-4 mRNA among three different dietary energy groups is similar as that occurred in in ovaries and uteri but with more significant differences. These results suggest that NT-4 may be one of the signals that links metabolic status and neuroendocrine control of reproduction in pig.
    No preview · Article · Apr 2012
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    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.
    No preview · Article · Mar 2012 · Theriogenology
  • Chunjin Li · Xu Zhou
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    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.
    No preview · Article · Mar 2012 · Clinica chimica acta; international journal of clinical chemistry
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    ABSTRACT: The factor in the germline alpha (FIGLA) is a basic helix-loop-helix transcription factor that is essential for folliculogenesis and regulates expression of zona pellucida genes in mouse and human. But bovine homologue has not as yet been confirmed experimentally. Here, researchers present the first cDNA cloning and transcript expression analysis of the bovine FIGLA gene. Using RT-PCR and quantitative real-time PCR, researchers revealed that expression within adult cattle tissues is limited to the ovary. The researchers found that Germinal Vesicle (GV) oocytes, Metaphase II (Mil) oocytes, 4 and 8 cell embryos, morula and blastocysts were all shown to express mRNA for FIGLA and expression were different in bovine oocytes and IVF embryos at different stages (p<0.05) with the highest expression in Germinal Vesicle (GV) oocytes and lower expression in 8 cells and blastocysts embryos. There was no difference in mRNA levels for FIGLA gene among bovine IVF, PA (Parthenogenetic Activated) and NT (Nuclear Transfer) blastocysts (p>0.05). In situ hybridization the FIGLA RNA was only localized in ovarian follicle. The persistence of FIGLA in adult cowes suggests that it may regulate additional pathways that are essential for bovine ovarian and embryonic development.
    No preview · Article · Feb 2012
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    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 ejaculated. 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<0.01). A protein of approximately 27 KDa was detected by western blotting. The SRY transcript was detected in the midpiece of approximately half the spermatozoa by in situ hybridization, and the SRY protein was detected in the heads of half the spermatozoa by immunofluorescence, indicating that SRY mRNA and protein may only be present in Y-bearing spermatozoa. These results suggest that the SRY transcript and protein are present in bovine ejaculated Y-sperm. The roles of the SRY gene in spermatogenesis, sperm motility, and the sperm-oocyte interaction merit further investigation.
    Preview · Article · Oct 2011 · Asian Australasian Journal of Animal Sciences
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    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.
    No preview · Article · Jun 2011 · British Poultry Science
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    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.
    Preview · Article · Mar 2011 · Asian Australasian Journal of Animal Sciences
  • Lianwen Zheng · Chunjin Li · Yongfeng Sun · Zhuo Liu · Xu Zhou
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    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.
    No preview · Article · Jan 2011 · Clinica chimica acta; international journal of clinical chemistry
  • Chunjin Li · Lianwen Zheng · Chunqiang Wang · Xu Zhou
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    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.
    No preview · Article · Oct 2010 · Clinica chimica acta; international journal of clinical chemistry
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    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.
    Preview · Article · Jun 2009 · Immunogenetics

Publication Stats

43 Citations
29.80 Total Impact Points

Institutions

  • 2009-2016
    • Jilin University
      • • Department of Animal Science
      • • College of Animal Science and Veterinary Medicine
      Yung-chi, Jilin Sheng, China