In this study very pure type A spermatogonia, pachytene spermatocytes, round sper-matids and Sertoli cells from rat testis were successfully isolated. The expression of the c-kit receptor,a specific receptor for kit l...In this study very pure type A spermatogonia, pachytene spermatocytes, round sper-matids and Sertoli cells from rat testis were successfully isolated. The expression of the c-kit receptor,a specific receptor for kit ligand (stem cell factor, steel factor), in these four kinds of cells was exam-ined by northern blot- The synthesis of the c-kit receptor by the spermatogonia was established by hy-bridization of total RNA with a specific cDNA for mouse c-kit receptor. Two mRNA transcripts migrat-ing at 4. 8 kb and 12kb were observed. A faint hybridization signal of 12kb transcript could be observed only in pachytene spermatocytes and round spermatids. In contrast, the Sertoli cells did not express c-kit receptor.In order to study the role of c-kit in spermatogenesis in the rat, the pattern of expression of c-kit in testes during the postnatal period was also investigated. Interestingly, the tissue of testis in rat also ex-pressed the same 2 species of mRNA migrating at 4. 8 kb and 12 kb. The testis of adult rat only ex-pressed the 4. 8 kb transcript, but did not expressed 12 kb transcript.These results indicated that the expression of c-kit receptor mainly originated from type A sper-matogonia. The c-kit receptor can be viewed as a marker of type A spermatogonia. After birth, the ex-pression of these rat testis mRNA transcripts that encode for c-kit is differentially regulated. Further-more, the presence of the 4. 8 kb transcript alone in the adult testis suggests that the 12 kb transcript may play a specific role in germ cell differentiation in immature rats.展开更多
This study examined the effect of astilbin on the proliferation of rat aortic smooth muscle cells (RASMCs) induced by angiotensin Ⅱ (AngⅡ) and explored the possible mechanisms. Cell proliferation model of RASMCs was...This study examined the effect of astilbin on the proliferation of rat aortic smooth muscle cells (RASMCs) induced by angiotensin Ⅱ (AngⅡ) and explored the possible mechanisms. Cell proliferation model of RASMCs was induced by treatmente with AngⅡ. Cells were randomly divided to 8 groups. Normally cultured VSMCs serves as blank control group; in AngⅡ model group, cells were treated with AngⅡ at 10–7 mol/L; in three astilbin groups, cells were treated with 10, 15, 30 mg/L of astilbin; in three AngⅡ+astilbin groups, cells were treated with AngⅡ (at 10–7 mol/L) and astilbin at 10, 15, 30 mg/L. Cell proliferation ability was detected by MTT method and the cell cycles and proliferation index were flow cytometrically determined. The expression of c-myc mRNA was assessed by using reverse transcription polymerase chain reaction (RT-PCR), and the expression of NF-κB in RASMCs was immunocytochemically observed. Our results showed that MTT metabo-lism in RASMCs in the basic and AngII stimulated situation was inhibited by astilbin, and the cells numbers of G0/G1 phase were increased and that of G2/S phase were decreased markedly. Not only highly expression of c-myc gene stimulated by AngⅡ could be inhibited by Astilbin significantly, but also the expression of NF-κB protein can be down regulated by Astilbin. We are led to conclude that astilbin astilbin can inhibit the AngⅡ-mediated proliferation of RASMCs by blocking the transition of RASMCs from G0/G1 phase to S phase and by down-regulating the expression of NF-κB, c-myc gene.展开更多
Objective Despite advances in the understanding of the genotype - phenotype correlation in multiple endocrine neoplasia type 2A and 2B (MEN 2A, MEN 2B), and familial medullary thyroid carcinoma (FMTC), the frequency a...Objective Despite advances in the understanding of the genotype - phenotype correlation in multiple endocrine neoplasia type 2A and 2B (MEN 2A, MEN 2B), and familial medullary thyroid carcinoma (FMTC), the frequency and prognostic relevance of RET protoonco-gene mutations in sporadic medullary thyroid carcinomas (MTCs) remain controversial. Methods To study somatic mutations in the RET protooncogene in Japanese and Chinese sporadic MTCs and to comparatively analyze the correlation between RET mutation and tumor differentiation, we investigated somatic mutations in the RET protooncogene in 20 Japanese and 20 Chinese sporadic MTCs by the polymerase chain reaction - restriction fragment length polymorphism (PCR- RFLP) method. Results Of the 40 sporadic MTCs, 13 had a point mutation in codon 918 of exon 16, a frequency of 32.5%. There was no significant difference in the frequency between Japanese and Chinese sporadic MTCs, as 3096 of the Japanese and 35% of the Chinese sporadic MTCs contained this mutation.展开更多
文摘In this study very pure type A spermatogonia, pachytene spermatocytes, round sper-matids and Sertoli cells from rat testis were successfully isolated. The expression of the c-kit receptor,a specific receptor for kit ligand (stem cell factor, steel factor), in these four kinds of cells was exam-ined by northern blot- The synthesis of the c-kit receptor by the spermatogonia was established by hy-bridization of total RNA with a specific cDNA for mouse c-kit receptor. Two mRNA transcripts migrat-ing at 4. 8 kb and 12kb were observed. A faint hybridization signal of 12kb transcript could be observed only in pachytene spermatocytes and round spermatids. In contrast, the Sertoli cells did not express c-kit receptor.In order to study the role of c-kit in spermatogenesis in the rat, the pattern of expression of c-kit in testes during the postnatal period was also investigated. Interestingly, the tissue of testis in rat also ex-pressed the same 2 species of mRNA migrating at 4. 8 kb and 12 kb. The testis of adult rat only ex-pressed the 4. 8 kb transcript, but did not expressed 12 kb transcript.These results indicated that the expression of c-kit receptor mainly originated from type A sper-matogonia. The c-kit receptor can be viewed as a marker of type A spermatogonia. After birth, the ex-pression of these rat testis mRNA transcripts that encode for c-kit is differentially regulated. Further-more, the presence of the 4. 8 kb transcript alone in the adult testis suggests that the 12 kb transcript may play a specific role in germ cell differentiation in immature rats.
基金supported by agrant from the National Natural Science Foundation of China(No.30500656)
文摘This study examined the effect of astilbin on the proliferation of rat aortic smooth muscle cells (RASMCs) induced by angiotensin Ⅱ (AngⅡ) and explored the possible mechanisms. Cell proliferation model of RASMCs was induced by treatmente with AngⅡ. Cells were randomly divided to 8 groups. Normally cultured VSMCs serves as blank control group; in AngⅡ model group, cells were treated with AngⅡ at 10–7 mol/L; in three astilbin groups, cells were treated with 10, 15, 30 mg/L of astilbin; in three AngⅡ+astilbin groups, cells were treated with AngⅡ (at 10–7 mol/L) and astilbin at 10, 15, 30 mg/L. Cell proliferation ability was detected by MTT method and the cell cycles and proliferation index were flow cytometrically determined. The expression of c-myc mRNA was assessed by using reverse transcription polymerase chain reaction (RT-PCR), and the expression of NF-κB in RASMCs was immunocytochemically observed. Our results showed that MTT metabo-lism in RASMCs in the basic and AngII stimulated situation was inhibited by astilbin, and the cells numbers of G0/G1 phase were increased and that of G2/S phase were decreased markedly. Not only highly expression of c-myc gene stimulated by AngⅡ could be inhibited by Astilbin significantly, but also the expression of NF-κB protein can be down regulated by Astilbin. We are led to conclude that astilbin astilbin can inhibit the AngⅡ-mediated proliferation of RASMCs by blocking the transition of RASMCs from G0/G1 phase to S phase and by down-regulating the expression of NF-κB, c-myc gene.
文摘Objective Despite advances in the understanding of the genotype - phenotype correlation in multiple endocrine neoplasia type 2A and 2B (MEN 2A, MEN 2B), and familial medullary thyroid carcinoma (FMTC), the frequency and prognostic relevance of RET protoonco-gene mutations in sporadic medullary thyroid carcinomas (MTCs) remain controversial. Methods To study somatic mutations in the RET protooncogene in Japanese and Chinese sporadic MTCs and to comparatively analyze the correlation between RET mutation and tumor differentiation, we investigated somatic mutations in the RET protooncogene in 20 Japanese and 20 Chinese sporadic MTCs by the polymerase chain reaction - restriction fragment length polymorphism (PCR- RFLP) method. Results Of the 40 sporadic MTCs, 13 had a point mutation in codon 918 of exon 16, a frequency of 32.5%. There was no significant difference in the frequency between Japanese and Chinese sporadic MTCs, as 3096 of the Japanese and 35% of the Chinese sporadic MTCs contained this mutation.
