Bipolaris oryzae is the causal agent of brown spot disease in rice and produces the dark pigment melanin. We isolated and characterized T4HR1 gene encoding 1,3,6,8-tetrahydroxynaphthalene (1,3,6,8-THN) reductase, whic...Bipolaris oryzae is the causal agent of brown spot disease in rice and produces the dark pigment melanin. We isolated and characterized T4HR1 gene encoding 1,3,6,8-tetrahydroxynaphthalene (1,3,6,8-THN) reductase, which converted 1,3,6,8-THN to scytalone in the melanin biosynthesis from B. oryzae. A sequence analysis showed that the T4HR1 gene encoded a putative protein of 268 amino acids showing 50% - 99% sequence identity to other fungal 1,3,6,8-THN reductases. Targeted disruption of the T4HR1 gene showed a different phenotype of mycelial color due to an accumulation of shunt products compared to those of wild-type on PDA plates using tricyclazole as a melanin biosynthesis inhibitor. A quantitative real-time PCR analysis showed that the expression of T4HR1 transcripts was enhanced by near-ultraviolet (NUV) irradiation and regulated by transcriptional factor BMR1, similar to three other melanin biosynthesis genes (polyketide synthase gene [PKS1], scytalone dehydratase gene [SCD1], and 1,3,8-THN reductase gene [THR1]) in the melanin biosynthesis of B. oryzae. These results suggested that common transcriptional mechanisms could regulate the enhanced gene expression of these melanin biosynthesis genes by NUV irradiation in B. oryzae.展开更多
To investigate the effects of oxidative stress on substantia nigra neuronal degeneration and death in patients with Parkinson＇s disease, we treated neuroblastoma cells （SK-N-SH） and glioma cells with Fenton＇s reag...To investigate the effects of oxidative stress on substantia nigra neuronal degeneration and death in patients with Parkinson＇s disease, we treated neuroblastoma cells （SK-N-SH） and glioma cells with Fenton＇s reagent, iron chelating agent, neuromelanin and dopamine melanin. We investigated the changes in expression of nine oxidative stress-related genes and proteins. The levels of mRNAs for heme-oxygenase-1 and glutathione S-transferase-ml were significantly reduced in SK-N-SH cells exposed to oxidative stress, and increased in glial cells treated with deferoxamine. These results revealed that SK-N-SH neurons react sensitively to oxidative stress, which implies different outcomes between these two types of cells in the substantia nigra. Moreover, the influences of neuromelanin and dopamine melanin on cell function are varied, and dopamine melanin is not a good model for neuromelanin.展开更多
旨在探究酪氨酸相关蛋白酶1(tyrosinase related protein 1,TYRP1)对香猪原代表皮黑素细胞黑色素生成的影响。本研究选用具有“两头乌”毛色特征的3月龄健康香猪3头,每头猪采取头部黑色皮肤组织和背部白色皮肤组织。通过HE染色观察不同...旨在探究酪氨酸相关蛋白酶1(tyrosinase related protein 1,TYRP1)对香猪原代表皮黑素细胞黑色素生成的影响。本研究选用具有“两头乌”毛色特征的3月龄健康香猪3头,每头猪采取头部黑色皮肤组织和背部白色皮肤组织。通过HE染色观察不同颜色香猪皮肤的毛囊结构及黑素细胞的分布特征;体外培养香猪原代表皮黑素细胞并通过多巴(L-Dopa)染色、实时荧光定量PCR和Western Blot方法进行鉴定;根据TYRP1基因序列构建5条siRNA,采用实时荧光定量PCR筛选出干扰效率最高的siRNA进行转染。成功干扰黑素细胞内TYRP1的表达后,分别通过实时荧光定量PCR、Western Blot、黑色素含量检测方法对黑素细胞内TYR、TYRP1及TYRP2的mRNA与蛋白相对表达量、细胞内总黑色素含量进行检测。结果显示,在香猪黑色和白色皮肤中都观察到完整的毛囊结构,黑素细胞主要分布在香猪黑色被毛皮肤中的毛囊外根鞘部位以及表皮。在MelM培养基作用下,黑素细胞生长旺盛,细胞形态、生长曲线、多巴染色、实时荧光定量PCR及Western Blot结果均表明培养的黑素细胞维持正常的生物学特性。敲降TYRP1后下调香猪表皮黑素细胞中黑色素生成相关基因TYR、TYRP1和TYRP2的mRNA和蛋白的表达,同时对黑色素的形成具有抑制作用。TYRP1基因能够影响香猪表皮黑素细胞黑色素的生成,研究结果可为探索TYRP1基因对香猪黑色素沉积的分子机制提供试验参考和基础数据。展开更多
文摘Bipolaris oryzae is the causal agent of brown spot disease in rice and produces the dark pigment melanin. We isolated and characterized T4HR1 gene encoding 1,3,6,8-tetrahydroxynaphthalene (1,3,6,8-THN) reductase, which converted 1,3,6,8-THN to scytalone in the melanin biosynthesis from B. oryzae. A sequence analysis showed that the T4HR1 gene encoded a putative protein of 268 amino acids showing 50% - 99% sequence identity to other fungal 1,3,6,8-THN reductases. Targeted disruption of the T4HR1 gene showed a different phenotype of mycelial color due to an accumulation of shunt products compared to those of wild-type on PDA plates using tricyclazole as a melanin biosynthesis inhibitor. A quantitative real-time PCR analysis showed that the expression of T4HR1 transcripts was enhanced by near-ultraviolet (NUV) irradiation and regulated by transcriptional factor BMR1, similar to three other melanin biosynthesis genes (polyketide synthase gene [PKS1], scytalone dehydratase gene [SCD1], and 1,3,8-THN reductase gene [THR1]) in the melanin biosynthesis of B. oryzae. These results suggested that common transcriptional mechanisms could regulate the enhanced gene expression of these melanin biosynthesis genes by NUV irradiation in B. oryzae.
基金the National Natural Science Foundation of China, No. 30600201the Tianjin Science and Technology Committee, No. 07JCYBJC09900
文摘To investigate the effects of oxidative stress on substantia nigra neuronal degeneration and death in patients with Parkinson＇s disease, we treated neuroblastoma cells （SK-N-SH） and glioma cells with Fenton＇s reagent, iron chelating agent, neuromelanin and dopamine melanin. We investigated the changes in expression of nine oxidative stress-related genes and proteins. The levels of mRNAs for heme-oxygenase-1 and glutathione S-transferase-ml were significantly reduced in SK-N-SH cells exposed to oxidative stress, and increased in glial cells treated with deferoxamine. These results revealed that SK-N-SH neurons react sensitively to oxidative stress, which implies different outcomes between these two types of cells in the substantia nigra. Moreover, the influences of neuromelanin and dopamine melanin on cell function are varied, and dopamine melanin is not a good model for neuromelanin.
文摘旨在探究酪氨酸相关蛋白酶1(tyrosinase related protein 1,TYRP1)对香猪原代表皮黑素细胞黑色素生成的影响。本研究选用具有“两头乌”毛色特征的3月龄健康香猪3头,每头猪采取头部黑色皮肤组织和背部白色皮肤组织。通过HE染色观察不同颜色香猪皮肤的毛囊结构及黑素细胞的分布特征;体外培养香猪原代表皮黑素细胞并通过多巴(L-Dopa)染色、实时荧光定量PCR和Western Blot方法进行鉴定;根据TYRP1基因序列构建5条siRNA,采用实时荧光定量PCR筛选出干扰效率最高的siRNA进行转染。成功干扰黑素细胞内TYRP1的表达后,分别通过实时荧光定量PCR、Western Blot、黑色素含量检测方法对黑素细胞内TYR、TYRP1及TYRP2的mRNA与蛋白相对表达量、细胞内总黑色素含量进行检测。结果显示,在香猪黑色和白色皮肤中都观察到完整的毛囊结构,黑素细胞主要分布在香猪黑色被毛皮肤中的毛囊外根鞘部位以及表皮。在MelM培养基作用下,黑素细胞生长旺盛,细胞形态、生长曲线、多巴染色、实时荧光定量PCR及Western Blot结果均表明培养的黑素细胞维持正常的生物学特性。敲降TYRP1后下调香猪表皮黑素细胞中黑色素生成相关基因TYR、TYRP1和TYRP2的mRNA和蛋白的表达,同时对黑色素的形成具有抑制作用。TYRP1基因能够影响香猪表皮黑素细胞黑色素的生成,研究结果可为探索TYRP1基因对香猪黑色素沉积的分子机制提供试验参考和基础数据。
