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Yuan Chang Yan

Publications and source records attributed to Yuan Chang Yan.

5 recordsLinked to original sources
PubMed2005

[Cyclosporin a induces titin expression in human trophoblast cells through the MEK/ERK1/2 signal pathway].

To investigate the role of MEK/ERK1/2 signal pathway in the regulation of cyclosporin A(CsA) -induced titin expression in human trophoblast cells. With RT-PCR and Western Blot, We examined the titin expression level of human trophoblast cells treated with different concentrations of CsA for various duration, then detected total ERK1/2 and phosphorated ERK1/2 level with Western Blot, and observed effect of U0126 on transcription of titin mRNA in human trophoblast cells stimulated by cyclosporin A. It was found that CsA could activate ERK1/2 in time-dependent and dosage-dependent manner, and induced titin to be expressed in human trophoblast cells. U0126, a MEK inhibitor, inhibited the transcription of titin in dosage-dependent manner. These results indicated that MEK/ERK1/2 signal pathway may play an important role in the expression of titin in human trophoblast induced by cyclosporin A.

Blotting, Western↗
PubMed2003

Cloning of rat sp56, the homologue of mouse sperm ZP3 receptor-sp56.

Mouse sp56 is considered as one of the candidates for mouse zona pellucida 3 (mZP3) receptor. Up to date, its homologue has only been cloned from guinea pig, namely AM67. Based on the cDNA sequence of mouse sp56, we designed a pair of primer to amplify its homologue from rat testis cDNA. Using RT-PCR, two fragments of 743 bp and 938 bp were amplified. The PCR products show very high homology to mouse sp56. However, the 743 bp product completely lacks one of the seven Sushi domains of mouse sp56. Using the 743 bp product as the probe to detect the expression profile of sp56 in rat tissues, Northern blot shows that a approximately 2.0 kb mRNA expresses specifically in testis. Employed the RACE method, two full cDNA sequences of rat sp56 were obtained. A Mr approximately 42 KD band was detected in denatured and non-reducing protein sample of rat testis and sperm with anti-mouse sp56 monoclonal antibody by Western blot method. Rat sp56 was localized on rat sperm head by the indirect immunofluorescence method. Rat sp56 immunoreactivity was detected from the early pachytene spermatocytes and throughout the spermatogenesis. Its cloning will further our understanding of the mechanism of the sperm-egg recognition and binding.

Animals↗
PubMed2002

Subunit composition and function of GABAA receptors of rat spermatozoa.

GABA triggers mammalian sperm acrosome reaction (AR). Here, evidence is presented, showing that rat spermatozoa contain GABAA receptors, composed of alpha5, beta1 and beta3 subunits. The effects of GABAA receptor agonist and antagonist on the induction of AR in rat spermatozoa were assessed using the chlortetracycline assay. Muscimol, a GABAA receptor agonist, triggered AR; whereas bicuculline, a GABAA receptor antagonist and picrotoxin, a GABAA receptor/Cl- channel blocker, inhibited the ability of GABA or progesterone to induce AR. In conclusion, GABAA receptors appear to mediate the action of progesterone in inducing AR in rat spermatozoa.

Animals↗
PubMed2002

Identification of gamma1 subunit of GABA(A) receptor in rat testis.

The isoform type of gamma subunits of GABA(A) receptor is a molecular determinant of its pharmacological characteristics. At present, the existence of GABA(A) receptor in mammalian sperm is still a controversy. By using degenerate primers designed according to highly conserved region in all three gamma (gamma1, gamma2 and gamma3) subunits cloned in rat brain, we performed reverse transcription polymerase chain reaction (RT-PCR) to examine the expression pattern of gamma subunits of GABA(A) receptor in rat testis. Only one 370 bp fragment was obtained from RT-PCR in rat testis and sequencing results showed that it represented gamma1 subunit, but not gamma2 or gamma3 subunit. Using the cloned fragment as probe, a 3.8 kb transcript which in size as same as gamma1 subunit in rat brain was detected in rat testis mRNA by performing Northern blot assay. Furthermore, results of in situ hybridization assay confirmed that gamma1 subunit was expressed in round spermatids and spermatozoa, maybe also in secondary spermatocyte. These evidences proved that gamma1 subunit of GABA(A) receptor is exclusively expressed in rat testis and this feature may be the structural basis of the specific function of GABA(A) receptors in sperm acrosome reaction.

Animals↗