• 제목/요약/키워드: molecular functions

검색결과 1,410건 처리시간 0.027초

Improving Effect of Silk Peptides on the Cognitive Function of Rats with Aging Brain Facilitated by D-Galactose

  • Park, Dong-Sun;Lee, Sun-Hee;Choi, Young-Jin;Bae, Dae-Kwon;Yang, Yun-Hui;Yang, Go-Eun;Kim, Tae-Kyun;Yeon, Sung-Ho;Hwang, Seock-Yeon;Joo, Seong-Soo;Kim, Yun-Bae
    • Biomolecules & Therapeutics
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    • 제19권2호
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    • pp.224-230
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    • 2011
  • In order to develop silk peptide (SP) preparations possessing cognition-enhancing effect, several candidates were screened through in vitro assays, and their effectiveness was investigated in facilitated brain aging model rats. Incubation of brain acetyl-cholinesterase with SP-PN (1-1,000 ${\mu}g/ml$) led to inhibition of the enzyme activity up to 35%, in contrast to a negligible effect of SP-NN. The expression of choline acetyltransferase (ChAT) mRNA of neural stem cells expressing ChAT gene (F3.ChAT) was increased by 24-hour treatment with 10 and 100 ${\mu}g/ml$ SP-NN (1.35 and 2.20 folds) and SP-PN (2.40 and 1.34 folds). Four-week subcutaneous injections with D-galactose (150 mg/kg) increased activated hippocampal astrocytes to 1.7 folds (a marker of brain injury and aging), decreased acetylcholine concentration in cerebrospinal fluid by 45-50%, and thereby impaired learning and memory function in passive avoidance and water-maze performances. Oral treatment with SP preparations (50 or 300 mg/kg) for 5 weeks from 1 week prior to D-galactose injection exerted recovering activities on acetylcholine depletion and brain injury/aging as well as cognitive deficit induced by D-galactose. The results indicate that SP preparations restore cognitive functions of facilitated brain aging model rats by increasing the release of acetylcholine, in addition to neuroprotective activity.

Formaldehyde에 반응하는 애기장대 단백질의 분리 (Isolation of formaldehyde-responsive proteins in Arabidopsis)

  • 권미;박현진;서재현
    • Journal of the Korean Wood Science and Technology
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    • 제35권4호
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    • pp.52-60
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    • 2007
  • 포르말린과 톨루엔 처리에 의한 애기장대의 표현형 변화 및 포르말린에 의한 단백질의 발현변화를 관찰하였다. 톨루엔의 휘발량이 포르말린보다 많음에도 불구하고 포르말린 처리구에서 애기장대의 표현형 변화가 더욱 현저한 것을 확인하였다. 포르말린에 의한 표현형의 변화가 미비한 6h 처리구에서도 애기장대 단백질의 발현에 많은 변화가 나타났으며 이러한 발현변화는 처리시간이 길어질수록 더욱 뚜렷하였다. 포르말린에 의하여 발현량이 변하는 단백질의 분자량을 automated gel electrophoresis system을 이용하여 예측한 후, 그 결과를 토대로 formaldehyde-responsive proteins을 분리하였다. 분리한 5개의 단백질은 전사수준에서 formaldehyde-dependent expression을 나타내었으며 formaldehyde-responsive proteins (FRP)으로 명명하였다. FRP5를 제외한 네 개의 단백질은 그 기능이 밝혀지지 않은 novel protein으로 식물의 방어기작에 관여하는 단백질과 높은 상동성을 나타내는 것을 알 수 있었다.

Silencing of NUF2 Inhibits Tumor Growth and Induces Apoptosis in Human Hepatocellular Carcinomas

  • Liu, Qiang;Dai, She-Jiao;Li, Hong;Dong, Lei;Peng, Yu-Ping
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권20호
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    • pp.8623-8629
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    • 2014
  • Background: As an important component of the NDC80 kinetochore complex, NUF2 is essential for kinetochore-microtubule attachment and chromosome segregation. Previous studies also suggested its involvement in development of various kinds of human cancers, however, its expression and functions in human hepatocellular carcinoma (HCC) are still unclear. Materials and Methods: In the present study, we aimed to test the hypothesis that NUF2 is aberrant in human HCCs and associated with cell growth. Results: Our results showed significantly elevated expression of NUF2 in human HCC tissues compared to adjacent normal tissues, and high expression of NUF2 in HCC cell lines. Using lentivirus-mediated silencing of NUF2 in HepG2 human HCC cells, we found that NUF2 depletion markedly suppressed proliferation and colony formation capacity in vitro, and dramatically hampered tumor growth of xenografts in vivo. Moreover, NUF2 silencing could induce cell cycle arrest and trigger cell apoptosis. Additionally, altered levels of cell cycle and apoptosis related proteins including cyclin B1, Cdc25A, Cdc2, Bad and Bax were also observed. Conclusions: In conclusion, these results demonstrate that NUF2 plays a critical role in the regulation of HCC cell proliferation and apoptosis, indicating that NUF2 may serve as a potential molecular target for therapeutic approaches.

Spatio-Temporal Expression Pattern of Grp 78, a Putative Hoxc8 Downstream Target Gene, During Murine Embryogenesis

  • Kang Jin Joo;Kwon Yunjeong;Lee Eun Young;Park Hyoung Woo;Yang Hye-Won;Kim Myoung Hee
    • 대한의생명과학회지
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    • 제11권3호
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    • pp.311-318
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    • 2005
  • Grp78, discovered as one of the putative target genes of Hoxc8, is a highly conserved stress protein and functions as a molecular chaperone in the endoplasmic reticulum (ER). In order to see the stage-specific expression pattern of Grp78 during development, mouse embryos from day 7.5 to 17.5 p.c. were isolated, and RT-PCR as well as in situ hybridization was performed. When RT-PCR was performed using Grp78 specific primers, periodic expression pattern was detected. And also a region-specific expression pattern was detected with a strong expression in the trunk part of day 11.5 p.c. embryo, like that of Hoxc8. When in situ hybridization was performed, Grp78 was revealed to be expressed in the endoderm, somite, neuroepithelium cells of neural tube in early embryos. In the case of late embryos, Grp78 expression was detected in the liver, segmental bronchus within cranial lobe of lung, ossification center within the cartilage primordium of rib and vertebra, submandibular gland, as well as metanephros. These expression patterns are very much similar to those of Hoxc8. Since Hoxc8 has been reported to regulate apoptosis during organogenesis, it might be possible that the apoptotic function could have been conveyed through the expression of Grp78, implying that the Grp78 is one of the Hoxc8 downstream target genes.

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In Vivo Excision and Amplification of Large Human Genomic Segments Using Cre/loxP-and EBNA-1/oriP-mediated Machinery

  • Yoon, Young-Geol;Choi, Ja-Young;Kim, Jung-Min;Lee, Jun-Hyoung;Kim, Sun-Chang
    • BMB Reports
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    • 제34권4호
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    • pp.322-328
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    • 2001
  • Excision and amplification of pre-determined, large genomic segments (taken directly from the genome of a natural host, which provides an alternative to conventional cloning in foreign vectors and hosts) was explored in human cells. In this approach, we devised a procedure for excising a large segment of human genomic DNA, the iNOS gene, by using the Cre/loxP system of bacteriophage P1 and amplifying the excised circles with the EBNA-1/oriP system of the Epstein-Barr virus. Two loxP sequences, each of which serves as a recognition site for recombinase Cre, were integrated unidirectionally into the 5'-UTR and 3'-UTR regions of the iNOS gene, together with an oriP sequence for conditional replication. The traps-acting genes cre and EBNA-1, which were under the control of a tetracycline responsive $P_{hcmv^*-1}$ promoter, were also inserted into the 5'-UTR and 3'-UTR regions of the iNOS gene, respectively, by homologous recombination. The strain carrying the inserted elements was stably maintained until the excision and amplification functions were triggered by the induction of cre and EBNA-1. Upon induction by doxycycline, Cre excised the iNOS gene that was flanked by two ZoxP sites and circularized it. The circularized iNOS gene was then amplified by the EBNA-1/oriP-system. With this procedure, approximately a 45.8-kb iNOS genomic fragment of human chromosome 17 was excised and successfully amplified in human cells. Our procedure can be used effectively for the sequencing of unclonable genes, the functional analysis of unknown genes, and gene therapy.

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Distinct mutations in MLH1 and MSH2 genes in Hereditary Non-polyposis Colorectal Cancer (HNPCC) families from China

  • Wei, Wenqian;Liu, Fangqi;Liu, Lei;Li, Zuofeng;Zhang, Xiaoyan;Jiang, Fan;Shi, Qu;Zhou, Xiaoyan;Sheng, Weiqi;Cai, Sanjun;Li, Xuan;Xu, Ye;Nan, Peng
    • BMB Reports
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    • 제44권5호
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    • pp.317-322
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    • 2011
  • Hereditary non-polyposis Colorectal Cancer (HNPCC) is an autosomal dominant inheritance syndrome. HNPCC is the most common hereditary variant of colorectal cancer (CRC), which accounts for 2-5% CRCs, mainly due to hMLH1 and hMSH2 mutations that impair DNA repair functions. Our study aimed to identify the patterns of hMSH2 and hMLH1 mutations in Chinese HNPCC patients. Ninety-eight unrelated families from China meeting Amsterdam or Bethesda criteria were included in our study. Germline mutations in MLH1 and MSH2 genes, located in the exons and the splice-site junctions, were screened in the 98 probands by direct sequencing. Eleven mutations were found in ten patients (11%), with six in MLH1 (54.5%) and five in MSH2 (45.5%) genes. One patient had mutations in both MLH1 and MSH2 genes. Three novel mutations in MLH1 gene (c.157_160delGAGG, c.2157dupT and c.-64G>T) were found for the first time, and one suspected hotspot in MSH2 (c.1168C>T) was revealed.

Characterization of two plasma membrane protein 3 genes (PutPMP3) from the alkali grass, Puccinellia tenuiflora, and functional comparison of the rice homologues, OsLti6a/b from rice

  • Chang-Qing, Zhang;Shunsaku, Nishiuchi;Shenkui, Liu;Tetsuo, Takano
    • BMB Reports
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    • 제41권6호
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    • pp.448-454
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    • 2008
  • Two full-length cDNAs, PutPMP3-1 and PutPMP3-2, encoding PMP3 family proteins were isolated from Puccinellia tenuiflora, a monocotyledonous halophyte. Expression of both genes was induced by low temperature, salt stress, dehydration, ABA, and $NaHCO_3$. Transcripts of PutPMP3-2 were more strongly induced by these stresses relative to those of PutPMP3-1, particularly under low temperature and dehydration conditions. Expression of PutPMP3-1 and PutPMP3-2 in yeast mutants lacking the PMP3 gene can functionally complement the membrane hyper-polarization and salt sensitivity phenotypes resulting from PMP3 deletion. To compare the functions of PutPMP3-1 and PutPMP3-2, the orthologous genes in rice (OsLti6a and OsLti6b) were isolated. Both OsLti6a and OsLti6b could functionally complement the loss of PMP3 in yeast. PutPMP3-2 and OsLti6a were more effective in reversing membrane hyperpolarization than PutPMP3-1 and OsLti6b. However, the four yeast transformants each showed similar levels of salt tolerance. These results imply that these PMP3 family members don't function identically under different stress tolerance conditions.

miR-374 promotes myocardial hypertrophy by negatively regulating vascular endothelial growth factor receptor-1 signaling

  • Lee, Jong Sub;Song, Dong Woo;Park, Jei Hyoung;Kim, Jin Ock;Cho, Chunghee;Kim, Do Han
    • BMB Reports
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    • 제50권4호
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    • pp.208-213
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    • 2017
  • Vascular endothelial growth factor (VEGF) is an essential cytokine that has functions in the formation of new blood vessels and regression of cardiac hypertrophy. VEGF/VEGF-receptor-1 (VEGFR1) signaling plays a key role in the regression of cardiac hypertrophy, whereas VEGF/VEGFR2 signaling leads to cardiac hypertrophy. In this study, we identified the prohypertrophic role of miR-374 using neonatal rat ventricular myocytes (NRVMs). Our results showed that overexpression of miR-374 activated G protein-coupled receptor-mediated prohypertrophic pathways by the inhibition of VEGFR1-dependent regression pathways. Luciferase assays revealed that miR-374 could directly target the 3'-untranslated regions of VEGFR1 and cGMP-dependent protein kinase-1. Collectively, these findings demonstrated that miR-374 was a novel pro-hypertrophic microRNA functioning to suppress the VEGFR1-mediated regression pathway.

Molecular Characterization and Tissue Distribution of Estrogen Receptor Genes in Domestic Yak

  • Fu, Mei;Xiong, Xian-Rong;Lan, Dao-Liang;Li, Jian
    • Asian-Australasian Journal of Animal Sciences
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    • 제27권12호
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    • pp.1684-1690
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    • 2014
  • Estrogen and its receptors are essential hormones for normal reproductive function in males and females during developmental stage. To better understand the effect of estrogen receptor (ER) gene in yak (Bos grunniens), reverse transcription-polymerase chain reaction (PCR) was carried out to clone $ER{\alpha}$ and $ER{\beta}$ genes. Bioinformatics methods were used to analyze the evolutionary relationship between yaks and other species, and real-time PCR was performed to identify the mRNA expression of $ER{\alpha}$ and $ER{\beta}$. Sequence analysis showed that the ER open reading frames (ORFs) encoded 596 and 527 amino acid proteins. The yak $ER{\alpha}$ and $ER{\beta}$ shared 45.3% to 99.5% and 53.9% to 99.1% protein sequence identities with other species homologs, respectively. Real-time PCR analysis revealed that $ER{\alpha}$ and $ER{\beta}$ were expressed in a variety of tissues, but the expression level of $ER{\alpha}$ was higher than that of $ER{\beta}$ in all tissues, except testis. The mRNA expression of $ER{\alpha}$ was highest in the mammary gland, followed by uterus, oviduct, and ovary, and lowest in the liver, kidney, lung, testis, spleen, and heart. The $ER{\beta}$ mRNA level was highest in the ovary; intermediary in the uterus and oviduct; and lowest in the heart, liver, spleen, lung, kidney, mammary gland, and testis. The identification and tissue distribution of ER genes in yaks provides a foundation for the further study on their biological functions.

Transient Knock Down of Grp78 Reveals Roles in Serum Ferritin Mediated Pro-inflammatory Cytokine Secretion in Rat Primary Activated Hepatic Stellate Cells

  • Wang, Chi-Mei;Li, Shan-Jen;Wu, Chi-Hao;Hu, Chien-Ming;Cheng, Hui-Wen;Chang, Jung-Su
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권2호
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    • pp.605-610
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    • 2014
  • Chronic liver diseases, including cancer, are characterized by inflammation and elevated serum ferritin (SF). However, the causal-relationship remains unclear. This study used primary rat hepatic stellate cells (HSC) as a model to investigate effects of physiological SF concentrations (10, 100 and 1000 pM) because HSCs play a central role in the development and progression of liver fibrosis. Physiological concentrations of SF, either horse SF or human serum, induced pro-inflammatory cytokine $IL1{\beta}$, IL6 and $TNF{\alpha}$ secretion in rat activated HSCs (all p<0.05). By contrast, treatment did not alter activation marker ${\alpha}SMA$ expression. The presence of SF markedly enhanced expression of Grp78 mRNA (p<0.01). Furthermore, transient knock down of Grp78 by endotoxin EGF-SubA abolished SF-induced $IL1{\beta}$ and $TNF{\alpha}$ secretion in activated HSCs (all p<0.05). In conclusion, our results showed that at physiological concentrations SF functions as a pro-inflammatory mediator in primary rat HSCs. We also provide a molecular basis for the action of SF and identified Grp78-associated ER stress pathways as a novel potential therapeutic target for resolution of fibrosis and possible prevention of liver cancer.