H L Feng

Inner Mongolia University, Suiyüan, Inner Mongolia, China

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Publications (25)43.9 Total impact

  • Fertility and Sterility - FERT STERIL. 01/2011; 96(3).
  • S. Liu, H. L. Feng, Z.-J. Chen, A. Hershlag
    Fertility and Sterility - FERT STERIL. 01/2010; 94(4).
  • H. L. Feng, S. Liu, Z.-J. Chen, A. Hershlag
    Fertility and Sterility - FERT STERIL. 01/2010; 94(4).
  • Fertility and Sterility - FERT STERIL. 01/2009; 92(3).
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    ABSTRACT: The objectives of this study were to assess the mRNA expression and protein location of IGF receptors and its ligands in bovine oocytes and different stages of preimplantation embryos, and then evaluate the effect of different concentrations of IGF-II when added to either the maturation or culture medium on in vitro embryo development. For the assessment of mRNA expression by RT-PCR three replicates each of 100 oocytes, and 60 embryos at each of the 2-cell, 8-cell, morula and blastocyst stages of development were used. Immunocytochemical techniques were used to study the location of IGFs and their receptors for COC, oocytes, and embryos at the same stages of development (n=25). The effect of supplementing maturation medium with IGF-II was examined using groups of 20 oocytes exposed to 0 (control), 10, 20, 50 or 100 ng IGF-II/ml medium. Each treatment was replicated five times. To study the effect of IGF-II added to culture medium, groups of 10 zygotes were cultured in the presence of 0 (control), 50, 100 or 150 ng IGF-II/ml medium and the treatments replicated four times. The results showed that IGF-I mRNA could not be detected but IGF-II, IGF-IR and IGF-IIR mRNA existed in bovine preimplantation embryos. Proteins for IGF-II, IGF-IR and IGF-IIR were detected on the cell plasma membrane of cumulus cells of COC, immature and mature oocytes, and 2-cell stage embryos. They were observed in blastomere cytoplasm of 8-cell and morula stage embryos. In blastocysts, the IGF proteins were distributed in the trophectoderm but not in the inner cell mass. Adding 20 ng/ml IGF-II to maturation medium resulted in higher rates of post-fertilization development than control at 8-cell (58.2% versus 44.5%; p<0.05) and blastocyst (37.0% versus 25.0%; p<0.05) stages of development; and the number of viable cells per blastocyst were significantly higher (126+/-6 versus 103+/-5; p<0.05). When IGF-II was added to the culture medium, no significant treatment differences were observed at 8-cell embryo stage but the development rate of zygotes cultured in the presence of 100 ng IGF-II/ml medium to blastocysts was significantly higher than that of control (30.0% versus 19.2%; p<0.05). It was concluded that supplementation of in vitro maturation or culture media with IGF-II affects the development of bovine embryos and could be used to improve in vitro embryo production.
    Animal reproduction science 10/2008; 114(1-3):99-108. · 1.56 Impact Factor
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    ABSTRACT: Identification of sperm antigens that elicit immunoglobulin (Ig) production and knowledge of their roles in sperm transport and fertilization may enhance diagnosis and treatment of immunologic infertility. Sperm antigens recognized by a female patient's serum anti-sperm antibodies were characterized using an indirect immunobead-binding test, immunoblot analysis, and immunochemical labeling. The anti-sperm antibodies' effect on sperm function was evaluated by acrosome induction by calcium ionophore. Immunobeads specific for IgG were bound to the head of 79% of motile donor sperm. Immunochemical labeling of antibody-binding sites was restricted to the plasma membrane over the acrosomal crescent. No labeling was observed on the inner acrosomal membrane of acrosome-reacted sperm. The antibodies reacted with 35-, 40-, 47-, and 65-kd proteins extracted from acrosome-intact donor sperm. Sperm incubated in 1:4, 1:8, 1:16, and 1:32 dilutions of anti-sperm antibody-positive serum had similar rates of spontaneous acrosome reaction and significantly lower rates of ionophore-induced acrosome reaction compared with sperm incubated in control serum. These results suggest that sperm antigens recognized by the patient's serum anti-sperm antibodies are restricted to the acrosomal region of the plasma membrane. The antibodies may impair fertility by compromising the sperm's ability to undergo capacitation and/or acrosome reaction.
    Journal of Andrology 07/2008; 29(4):440-8. · 3.37 Impact Factor
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    ABSTRACT: The present study aimed to assess location and relative amounts of transforming growth factor alpha (TGFalpha) and its receptor (EGFR) in ovine oocytes and preimplantation embryos by using immunohistochemical technique that was graded on a relative scale of 0-3, with 0 representing absence of staining, and 3 exhibiting prominent staining, and to evaluate the effects of TGFalpha/EGF on in vitro development of preimplantation embryos by adding different concentrations of EGF and TGFalpha to culture medium. The results showed that EGFR was abundant in cell plasma membranes in immature and mature oocytes, cumulus cells of immature cumulus-oocyte complexes (COC), fertilized oocytes and at different stages of embryo development. However, the relative amounts in inner cell mass (ICM) (1+) was less than that in trophectoderm (TE) cells (2+) at the blastocysts stage. The staining pattern for TGFalpha was a similar to EGFR. However, the staining for TGFalpha slightly increased in the fertilized oocytes (1-2+) as compared to immature and mature oocytes (1+). TGFalpha was mainly detected in the cytoplasm close to the membrane in both ICM and trophectoderm (TE) cells. The developmental rate of 8-cell stage embryos cultured with 5 ng/ml TGFalpha was increased as compared to other treatments (P<0.05). There was no significant difference in the rate of development of blastocysts cultured with 5 ng/ml TGFalpha, 20 ng/ml EGF, 20 ng/ml EGF+5 ng/ml TGFalpha or the control treatment (P>0.05). In addition, there was no significant difference in the number of cells in blastocyst stage as compared with different treatments (P>0.05). However, TGFalpha alone enhanced cell survival rated (P<0.01) and reduced apoptosis. We concluded that TGFalpha can improve development of ovine preimplantation embryos at the 8-cell and blastocyst stages in vitro.
    Animal Reproduction Science 03/2008; 104(2-4):370-81. · 1.90 Impact Factor
  • Fertility and Sterility - FERT STERIL. 01/2008; 90.
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    ABSTRACT: Expression of T-complex testis expressed 5 (Tctex5), an orthologue of protein phosphatase-1 inhibitor-3 (PPP1R11), was enhanced in mouse testis and was also expressed in epididymis and spermatozoa. There were three transcripts of Tctex5 including one brain specific and two common transcripts dominant in mouse testis. Tctex5 protein isoforms (75, 52, 32, 25, and 14.3 kDa) were identified. Isoforms of 75 and 52 kDa were spermatogenic-specific and were found in protein fraction containing nuclei, mitochondria, and flagellum accessory, and also in protein fraction containing mainly membranes. Tctex5 was localized in nuclei of pachytene spermatocytes, round spermatocytes, cytoplasm of Sertoli cells in testis; cilia, secretion bodies and nuclei of epithelial cells and interstitium smooth muscle cells in epididymis; and head and principal piece of tail in epididymal spermatozoa. The results suggested that Tctex5 might be a specific protein phosphatase-1 inhibitor in sperm; various Tctex5 transcripts and isoforms and cellular locations imply its different roles in spermatogenesis. Nuclei-type isoforms (75 and 52 kDa) might take part in nucleus remodeling during spermatogenesis whilst membrane-type isoform (52 kDa) might be responsible for dephosphorylation of proteins during capacitation. The other isoforms might play general roles for all kinds of cell types.
    Molecular Reproduction and Development 10/2007; 74(9):1132-40. · 2.81 Impact Factor
  • Fertility and Sterility - FERT STERIL. 01/2007; 88.
  • Fertility and Sterility - FERT STERIL. 01/2007; 88.
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    ABSTRACT: Calcium plays a predominant role regulating many functional processes of spermatogenesis and fertilization. The purpose of the present study is to define the exact location of calcium as well as examine the role it plays during spermatogenesis and sperm capacitation. Testes and epididymides were obtained from adult healthy male hamsters. Spermatozoa were incubated with modified Tyrode's medium up to 4 h at 37 degrees Celsius for sperm capacitation in vitro. Samples of the testes and sperm cells were analyzed by cytochemical techniques to determine the location of calcium and Ca(2+)-ATPase and the percentage of acrosome reactions under light and electron microscopy. The data showed that (1) Sertoli cells exhibited numerous calcium precipitates as large, round, electron-dense bodies distributed throughout the cytoplasm and the mitochondrial matrix. Fine calcium precipitates existed in fewer numbers in the intracellular storage sites of spermatogonia and primary spermatocytes, in sharp distinction to secondary spermatocyte and spermatids, which showed an abundance of large and round calcium precipitates, especially in the mitochondrial matrix of spermatids. More calcium deposits were distributed in the plasma membrane (PM), acrosome membrane, and matrices of the acrosome and mitochondria following capacitation; (2) Ca(2+)-ATPase was found in the endoplasmic reticulum system and PM of noncapacitated spermatozoa as well as Sertoli cells. Capacitated spermatozoa showed a weak signal. These results suggest that the presence of calcium in spermatogenic cells might play a role in cell growth and differentiation during spermatogenesis. The Ca(2+)-ATPase function may be inhibited during capacitation, leading to an increase in acrosomal calcium level and triggering of acrosomal exocytosis.
    Microscopy Research and Technique 09/2006; 69(8):618-23. · 1.59 Impact Factor
  • H L Feng, Y B Han, A Hershlag, H Yang
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    ABSTRACT: The field of reproductive and developmental biology has been revolutionized by recent advanced studies. These studies indicate that stem cells are capable of forming gametes in vivo and in vitro in both mouse and human. This has provided powerful tools for undertaking new types of reproductive studies, and particularly might provide new technology and novel approaches in assisted reproductive medicine.
    Archives of Andrology 01/2006; 52(4):233-8. · 0.89 Impact Factor
  • H L Feng
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    ABSTRACT: About 15% of couples have reduced fertility and in approximately one-half of all cases the reason is male infertility, usually of genetic origin. Thus, in the context of research in genes involved in reproduction and sex determination, genetic anomalies in gametogenesis are being extensively studied. The most frequent pathogenic causes of male infertility are Y-chromosomal microdeletions (8-15%) in the long arm of the Y chromosome, which, by loss of specific DNA segments, leads to loss of vital genes for sperm production. Infertile men, who attend infertility clinics, rise to 15% among those with azoospermia or spermatogenesis problem. The new technique of intracytoplasmic sperm injection has allowed many infertile men to achieve their dreams of fatherhood. However, the spermatogenic defect is genetic anomalies, which might be a potential risk of transmitting this defect to future offspring. Therefore, genetic counseling of all couples with the diagnosis of male infertility is recommended before their enrolment in intrauterine insemination, in vitro fertilization, and intracytoplasmic sperm injection. The important role of genetic abnormalities in the causation of human male infertility is increasingly recognized. While much remains to be learned in this fast-moving field, considerable progress has been made in the clinical delineation of genetic forms of male infertility and in the characterization of the responsible genes and their mutations or deletions. This review should provide insight into the understanding of parthenogenesis of male infertility in the human.
    Archives of Andrology 01/2003; 49(1):19-27. · 0.89 Impact Factor
  • H L Feng, J I Sandlow, A E Sparks
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    ABSTRACT: To examine the expression of the heat shock protein hsp70-2, and the possible relationship with the pathogenesis of male infertility. Prospective study. Reproductive testing laboratory in a university hospital. Men undergoing testicular biopsy during an investigation of subfertility. Testicular tissues were obtained from biopsies of men undergoing infertility evaluation and subdivided into three groups: normal testes, maturational arrest and Sertoli cell-only syndrome. Immunostaining and Western blotting techniques determined expression of the heat shock protein hsp70-2 Expression of the heat shock protein hsp70-2 in the testes. The experimental data demonstrated that the heat shock protein hsp70-2 was expressed in the normal and maturation arrest testicular specimens. The heat shock protein hsp70-2 was strongly present in the cytoplasm of spermatocytes and spermatides in the adluminal compartment of the seminiferous epithelium in normal testis. However, maturation arrest testis tissue demonstrated light staining in spermatocytes and spermatides, and Sertoli-only specimens demonstrated no staining for the heat shock protein hsp70-2. The Western blotting data showed a 70-kDa heat shock protein in the normal and maturation arrest testicular tissues, but not in the Sertoli-only tissues. These results suggest that the heat shock protein hsp70-2 is expressed in spermatocytes and spermatides in normal and maturation arrest tissues. However, the expression of the heat shock protein hsp70-2 was low in maturation arrest, and no heat shock protein hsp70-2 was demonstrated in Sertoli-only specimens. Therefore the decreased expression of the heat shock protein hsp70-2 is associated with the pathogenesis of male infertility.
    Fertility and Sterility 01/2002; 76(6):1136-9. · 4.17 Impact Factor
  • Fertility and Sterility - FERT STERIL. 01/2000; 74(3).
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    ABSTRACT: The c-kit receptor is a proto-oncogene important in germ cell migration and maturation and has also been demonstrated on the acrosomal region of mature sperm. The purpose of the present study was to examine the ultrastructural location of the c-kit receptor in mouse testis and sperm. Testis and sperm from mature male mice were examined for the c-kit receptor utilizing electron microscopy and Western blot analysis techniques. Thin sections of mouse testis and sperm were stained with immunogold-labeled anti-c-kit antibodies. The protein from these testes and sperm was also utilized for Western blot analysis. The c-kit protein was localized within the mouse testes to the type A spermatogonia, the round spermatids, and the mature testicular spermatozoa. The c-kit receptor was noted to migrate from the lumen of the acrosomal vesicles in the early spermatids to the plasma membrane of the late spermatids. It was also noted in the acrosomal region of the testicular spermatozoa, as well as the sperm from the epididymis. Sperm undergoing the acrosome reaction demonstrated association of the c-kit receptor with the plasma membrane of the acrosome, but not on the acrosomal membrane itself. Western blot analysis demonstrated protein bands of 150 kDa in testis and intact sperm. The present study confirms the presence of the c-kit receptor in mouse testis and sperm. It also demonstrates that this receptor is localized to the region of the developing acrosome.
    The Journal of Urology 06/1999; 161(5):1676-80. · 3.75 Impact Factor
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    ABSTRACT: To examine the expression of the c-kit receptor and its ligand, stem cell factor, and their possible relation with apoptosis in infertile men. Prospective laboratory study. Urology laboratory in a university hospital. Men undergoing testicular biopsy during an investigation of subfertility. None. Expression of the c-kit receptor protein, stem cell factor, and apoptosis in the testes. The c-kit receptor was strongly present in Leydig cells and type A spermatogonia of normal testes, with decreased staining in Leydig cells and type A spermatogonia of testes with maturational arrest, and staining in only Leydig cells of Sertoli cell-only specimens. Stem cell factor was demonstrated in Leydig cells and Sertoli cells in all specimens. Western blotting demonstrated the 150-kd c-kit protein in the normal testes and the testes with maturational arrest, but not in the testes with the Sertoli cell-only pattern. Stem cell factor was expressed in all specimens, with a protein size of 45 kd. Increased apoptosis was demonstrated in type A spermatogonia and spermatocytes of tissue with maturational arrest compared with normal testicular tissue. C-kit receptor expression is decreased in subfertile testicular tissue compared with normal testicular tissue. Stem cell factor expression is present in Leydig cells and Sertoli cells. Increased apoptosis is seen in tissue with maturational arrest compared with normal tissue.
    Fertility and Sterility 02/1999; 71(1):85-9. · 4.17 Impact Factor
  • Theriogenology 01/1998; 49(1):370-370. · 2.08 Impact Factor
  • Theriogenology 01/1998; 49(1):372-372. · 2.08 Impact Factor

Publication Stats

260 Citations
43.90 Total Impact Points

Institutions

  • 2008
    • Inner Mongolia University
      Suiyüan, Inner Mongolia, China
  • 2007
    • The Chinese University of Hong Kong
      • Department of Obstetrics and Gynaecology
      Hong Kong, Hong Kong
  • 2006
    • NYU Langone Medical Center
      • Department of Obstetrics and Gynecology
      New York City, NY, United States
  • 1996–1999
    • University of Iowa
      • Department of Urology
      Iowa City, IA, United States