• Title/Summary/Keyword: Gene regulation

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Salmonella Invasion Gene Regulation: A Story of Environmental Awareness

  • Jones Bradley D.
    • Journal of Microbiology
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    • v.43 no.spc1
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    • pp.110-117
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    • 2005
  • Salmonella enterica serovar Typhimurium causes human gastroenteritis and a systemic typhoid-like infection in mice. A critical virulence determinant of Salmonella is the ability to invade mammalian cells. The expression of genes required for invasion is tightly regulated by environmental conditions and a variety of regulatory genes. The hilA regulator encodes an OmpR/ToxR family transcriptional regulator that activates the expression of invasion genes in response to both environmental and genetic regulatory factors. Work from several laboratories has highlighted that regulation of hilA expression is a key point for controlling expression of the invasive phenotype. A number of positive regulators of hilA expression have been identified including csrAB, sirA/barA, pstS, hilC/sirC/sprA, fis, and hilD. HilD, an AraC/XylS type transcriptional regulator, is of particular importance as a mutation in hilD results in a 14-fold decrease in chromosomal hilA::Tn5lacZY-080 expression and a 53-fold decrease in invasion of HEp-2 cells. It is believed that HilD directly regulates hilA expression as it has been shown to bind to hilA promoter sequences. In addition, our research group, and others, have identified genes (hilE, hha, pag, and lon) that negatively affect hilA transcription. HilE appears to be an important Salmonella-specific regulator that plays a critical role in inactivating hilA expression. Recent work in our lab has been directed at understanding how environmental signals that affect hilA expression may be processed through a hilE pathway to modulate expression of hilA and the invasive phenotype. The current understanding of this complex regulatory system is reviewed.

Effects of isorhamnetin on the regulation of mitochondrial function in C2C12 muscle cells (Isorhamnetin의 근육세포 미토콘드리아 기능조절에 미치는 효과)

  • Lee, Mak-Soon;Kim, Yangha
    • Journal of Nutrition and Health
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    • v.54 no.4
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    • pp.335-341
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    • 2021
  • Purpose: Muscle mitochondria play a key role in regulating fatty acid and glucose metabolism. Dysfunction of muscle mitochondria is associated with metabolic diseases such as obesity and type 2 diabetes. Isorhamnetin (ISOR), also known as 3-O-methylquercetin, a quercetin metabolite, is a naturally occurring flavonoid in many plants. This study evaluated the effects of ISOR on the regulation of the mitochondrial function of C2C12 muscle cells. Methods: C2C12 muscle cells were differentiated for 5 days, and then treated in various concentrations of ISOR. Cytotoxicity was determined by assessing cell viability using the water-soluble tetrazolium salt-8 assay principle at different concentrations of ISOR and time points. Levels of the mitochondrial DNA (mtDNA) content and gene expression were measured by quantitative real-time polymerase chain reaction. The citrate synthase (CS) activity was quantified by the enzymatic method. Results: ISOR at a concentration of 10 µM did not show any cytotoxic effects. ISOR increased the mtDNA copy number in a time- or dose-dependent manner. The messenger RNA levels of genes involved in mitochondrial function, such as peroxisome proliferator-activated receptor-γ coactivator-1α, and uncoupling protein 3 were significantly stimulated by the ISOR treatment. The CS activity was also significantly increased in a time- or dose-dependent manner. Conclusion: These results suggest that ISOR enhances the regulation of mitochondrial function, which was at least partially mediated via the stimulation of the mtDNA replication, mitochondrial gene expression, and CS activity in C2C12 muscle cells. Therefore, ISOR may be useful as a potential food ingredient to prevent metabolic diseases-associated muscle mitochondrial dysfunction.

LPS-Induced Modifications in Macrophage Transcript and Secretion Profiles Are Linked to Muscle Wasting and Glucose Intolerance

  • Heeyeon Ryu;Hyeon Hak Jeong;Seungjun Lee;Min-Kyeong Lee;Myeong-Jin Kim;Bonggi Lee
    • Journal of Microbiology and Biotechnology
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    • v.34 no.2
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    • pp.270-279
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    • 2024
  • Macrophages are versatile immune cells that play crucial roles in tissue repair, immune defense, and the regulation of immune responses. In the context of skeletal muscle, they are vital for maintaining muscle homeostasis but macrophage-induced chronic inflammation can lead to muscle dysfunction, resulting in skeletal muscle atrophy characterized by reduced muscle mass and impaired insulin regulation and glucose uptake. Although the involvement of macrophage-secreted factors in inflammation-induced muscle atrophy is well-established, the precise intracellular signaling pathways and secretion factors affecting skeletal muscle homeostasis require further investigation. This study aimed to explore the regulation of macrophage-secreted factors and their impact on muscle atrophy and glucose metabolism. By employing RNA sequencing (RNA-seq) and proteome array, we uncovered that factors secreted by lipopolysaccharide (LPS)-stimulated macrophages upregulated markers of muscle atrophy and pro-inflammatory cytokines, while concurrently reducing glucose uptake in muscle cells. The RNA-seq analysis identified alterations in gene expression patterns associated with immune system pathways and nutrient metabolism. The utilization of gene ontology (GO) analysis and proteome array with macrophage-conditioned media revealed the involvement of macrophage-secreted cytokines and chemokines associated with muscle atrophy. These findings offer valuable insights into the regulatory mechanisms of macrophage-secreted factors and their contributions to muscle-related diseases.

Cloning and Regulation of Schizosaccharomyces pombe Gene Encoding Ribosomal Protein S20

  • Lee, Yoon-Jong;Kim, Kyunghoon;Park, Eun-Hee;Ahn, Ki-Sup;Kim, Daemyung;Lim, Chang-Jin
    • Journal of Microbiology
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    • v.39 no.1
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    • pp.31-36
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    • 2001
  • A cDNA clone encoding the ribosomal protein S20 has been isolated from the Schizosaccharomyces pombe cDNA library by colony hybridization. The insert contained in the original plasmid pYJ10 was transferred intro shuttle vector pRS316 generate plasmid pYJll. The dDNA insert of plasmid pYJll, contains 484 nucleotides and encodes a protein of 118 amino acids with a calculated mass of 13,544 daltons. The deduced amino acid sequence of S. pombe ribosomal protein S20 is very homologous with fruit fly, rat, and budding yeast counterparts. It is also homologous with Xenopus S22 ribosomal protein. S. pombe ribosomal protein S20 appears to be relatively hydruphobic except the C-terminal region. The 728 bp upstream region of the S20 gene was amplified from chromosomal DNA and transferred into the BamHI/EcoRI site of the promoterles $\beta$-galactosidase gene of the vector YEp357R, which resulted in fusion plasmid pYS20. The synthesis of $\beta$-galactosidase from the fusion plasmid appeared to be the highest in the mid-exponential phase. The S. pombe cells with the fusion plasmid grown at 35$\^{C}$ gave lower $\beta$-galactosidase activity than the cells grown at 30$\^{C}$. Computer analysis showed the consensus sequence CAGTCACA in the upstream regions of various ribosomal protein genes in S. pombe, which would be involved in the coordinated expression of small ribosomal proteins.

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Induction of Apoptotic Cell Death by Healthful Decoction Utilizing Phellinus Linteus in Human Lung Carcinoma Cells (상황을 이용한 보건기능 개선제의 인체폐암세포 apoptosis 유발에 관한 연구)

  • Park Cheol;Lee Yong Tae;Kang Kyung Hwa;choi Byung Tae;Jeong Young Kee;Choi Yung Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.3
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    • pp.759-766
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    • 2004
  • In the present study, we investigated the effects of aqueous extract of the healthful decoction utilizing Phellinus linteus (HDPL) on the cell growth of human lung carcinoma tumor cell line A549. Exposure of A549 cells to HDPL resulted in growth inhibition and induction of apoptosis in a dose-dependent manner as measured by hemocytometer counts, fluorescence microscopy and flow cytometric analysis. This increase in apoptosis was associated with inhibition and/or degradation of apoptotic target proteins such as poly(ADP-ribose) polymerase (PARP), b-catenin and phospholipase C- 1 (PLC- 1) protein. HDPL treatment induced the down-regulation of anti-apoptotic Bcl-2 expression, an anti-apoptotic gene, however, the level of Bax. a pro-apoptotic gene, was increased by HDPL treatment. In addition, HDPL-induced apoptotis of A549 cells was connected with activation of caspase-3 and caspase-9 protease in a dose-dependent manner, however, the levels of inhibitor of apoptosis proteins family were remained unchanged. Taken together, these results indicated that the anti-proliferative effects of HDPL were associated with the induction of apoptotic cell death through regulation of several major growth regulatory gene products such as Bcl-2 family expression and caspase protease activity, and HDPL may have therapeutic potential in human lung cancer.

Genes Frequently Coexpressed with Hoxc8 Provide Insight into the Discovery of Target Genes

  • Kalyani, Ruthala;Lee, Ji-Yeon;Min, Hyehyun;Yoon, Heejei;Kim, Myoung Hee
    • Molecules and Cells
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    • v.39 no.5
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    • pp.395-402
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    • 2016
  • Identifying Hoxc8 target genes is at the crux of understanding the Hoxc8-mediated regulatory networks underlying its roles during development. However, identification of these genes remains difficult due to intrinsic factors of Hoxc8, such as low DNA binding specificity, context-dependent regulation, and unknown cofactors. Therefore, as an alternative, the present study attempted to test whether the roles of Hoxc8 could be inferred by simply analyzing genes frequently coexpressed with Hoxc8, and whether these genes include putative target genes. Using archived gene expression datasets in which Hoxc8 was differentially expressed, we identified a total of 567 genes that were positively coexpressed with Hoxc8 in at least four out of eight datasets. Among these, 23 genes were coexpressed in six datasets. Gene sets associated with extracellular matrix and cell adhesion were most significantly enriched, followed by gene sets for skeletal system development, morphogenesis, cell motility, and transcriptional regulation. In particular, transcriptional regulators, including paralogs of Hoxc8, known Hox co-factors, and transcriptional remodeling factors were enriched. We randomly selected Adam19, Ptpn13, Prkd1, Tgfbi, and Aldh1a3, and validated their coexpression in mouse embryonic tissues and cell lines following $TGF-{\beta}2$ treatment or ectopic Hoxc8 expression. Except for Aldh1a3, all genes showed concordant expression with that of Hoxc8, suggesting that the coexpressed genes might include direct or indirect target genes. Collectively, we suggest that the coexpressed genes provide a resource for constructing Hoxc8-mediated regulatory networks.

Molecular Prognostic Profile of Egyptian HCC Cases Infected with Hepatitis C Virus

  • Zekri, Abdel-Rahman N.;Hassan, Zeinab K.;Bahnassy, Abeer A.;Sherif, Ghada M.;ELdahshan, Dina;Abouelhoda, Mohamed;Ali, Ahmed;Hafez, Mohamed M.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5433-5438
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    • 2012
  • Background: Hepatocellular carcinoma (HCC) is a common and aggressive malignancy. Despite of the improvements in its treatment, HCC prognosis remains poor due to its recurrence after resection. This study provides complete genetic profile for Egyptian HCC. Genome-wide analyses were performed to identify the predictive signatures. Patients and Methods: Liver tissue was collected from 31 patients with diagnosis of HCC and gene expression levels in the tumours and their adjacent non-neoplastic tissues samples were studied by analyzing changes by microarray then correlate these with the clinico-pathological parameters. Genes were validated in an independent set by qPCR. The genomic profile was associated with genetic disorders and cancer focused on gene expression, cell cycle and cell death. Molecular profile analysis revealed cell cycle progression and arrest at G2/M, but progression to mitosis; unregulated DNA damage check-points, and apoptosis. Result: Nine hundred fifty eight transcripts out of the 25,000 studied cDNAs were differentially expressed; 503 were up-regulated and 455 were down-regulated. A total of 19 pathways were up-regulated through 27 genes and 13 pathways were down-regulated through 19 genes. Thirty-seven genes showed significant differences in their expression between HCC cases with high and low Alpha Feto Protein ($AFP{\geq}600$ IU/ml). The validation for the microarray was done by real time PCR assay in which PPP3CA, ATG-5, BACE genes showed down-regulation and ABCG2, RXRA, ELOVL2, CXR3 genes showed up-regulation. cDNA microarrays showed that among the major upregulated genes in HCC are sets. Conclusion: The identified genes could provide a panel of new diagnostic and prognostic aids for HCC.

MicroRNAs and Metastasis-related Gene Expression in Egyptian Breast Cancer Patients

  • Hafez, Mohamed M.;Hassan, Zeinab K.;Zekri, Abdel Rahman N.;Gaber, Ayman A.;Rejaie, Salem S. Al;Sayed-Ahmed, Mohamed M.;Shabanah, Othman Al
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.2
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    • pp.591-598
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    • 2012
  • Aim and background: MicroRNAs (miRNAs) are a class of naturally occurring small noncoding RNAs that regulate gene expression, cell growth, differentiation and apoptosis by targeting mRNAs for translational repression or cleavage. The present study was conducted to study miRNAs in Egyptian breast cancer (BC) and their relation to metastasis, tumor invasion and apoptosis in addition to their association with the ER and PR statuses. Methods: Real Time RT-PCR was performed to identify the miRNA expression level of eight miRNAs and eight metastatic-related genes in 40 breast cancer samples and their adjacent non-neoplastic tissues. The expression levels of each miRNA relative to U6 RNA were determined using the $^{2-{\Delta}}CT$ method. Also, miRNA expression profiles of the BC and their corresponding ANT were evaluated. Results: The BC patients showed an up-regulation in miRNAs (mir-155, mir-10, mir-21 and mir-373) with an upregulation in MMP2, MMp9 and VEGF genes. We found down regulation in mir-17p, mir-126, mir-335, mir-30b and also TIMP3, TMP1 and PDCD4 genes in the cancer tissue compared to the adjacent non-neoplastic tissues. Mir -10b, mir -21, mir-155 and mir373 and the metastatic genes MMP2, MMP9 and VEGF were significantly associated with an increase in tumor size (P < 0.05). No significant difference was observed between any of the studied miRNAs regarding lymph node metastasis. Mir-21 was significantly over-expressed in ER-/PR-cases. Conclusion: Specific miRNAs (mir-10, mir-21, mir-155, mir-373, mir-30b, mir-126, mir-17p, mir-335) are associated with tumor metastasis and other clinical characteristics for BC, facilitating identification of individuals who are at risk.

Cytotoxic Evaluation of Plant Essential Oils in Human Skin and Lung Cells

  • Ahn, Changhwan;Park, Mi-Jin;Kim, Jae-Woo;Yang, Jiyoon;Lee, Sung-Suk;Jeung, Eui-Bae
    • Journal of the Korean Wood Science and Technology
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    • v.46 no.2
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    • pp.166-177
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    • 2018
  • Plant essential oils are defined as fragrant volatile oils extracted from leaves, stems, fruits, flowers, and roots of a plant. Such oils are composed of multiple components and multiple functions. By accumulation of inductive information, various plant essential oils have been studied for using in therapeutic medicine for various diseases. Despite of the apparent advantages of essential oils as a source of therapeutic medicines, plant essential oils have many limitations, including cytotoxic side effects. Therefore, it is necessary to evaluate the toxicity and the mechanisms of cytotoxicity of such oils. In this study, we evaluated the cytotoxicity to human-derived cell lines of 10 plant essential oils provided by National Institute of Forest Science (i.e., Larix kaempferi; Abies holophylla; Zanthoxylum ailanthoides; Pinus parviflora; Tsuga sieboldti; Chamaecyparis pisifera; Cryptomeria japonica; Pinus densiflora; Illicium anisatum; Pinus thunbergii). Cytotoxicity evaluations were accomplished by using CCK-assays and PCR-based cytotoxicity-related marker gene analyses with A549 cell line, and the Detroit551 cell line which are lung and skin cell line. The genes were analyzed included caspase-3 has a role in cell apoptosis, and the other cyclinA, cyclinB, cyclinD, and cyclinE regulated cell cycling for the cell proliferation. By examining the five cytotoxicity-related marker genes by performing real-time PCR and examined the cytostatic gene regulation associated with the various essential oils. The results of this study showed that the degree of cytotoxicity and the cytostatic gene regulation which could give precious information for using the plant essential oil for the clinical usages.

Expression of a Cu-Zn Superoxide Dismutase Gene in Response to Stresses and Phytohormones in Rehmannia Glutinosa

  • Park, Myoung-Ryoul;Ryu, Sang-Soo;Yoo, Nam-Hee;Yu, Chang-Yeon;Yun, Song-Joong
    • Korean Journal of Medicinal Crop Science
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    • v.13 no.5
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    • pp.270-275
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    • 2005
  • Superoxide dismutases (SOD) are metalloenzymes that convert $O_2^-\;to\;H_2O_2$. Rehmannia glutinosa is highly tolerant to paraquat-induced oxidative stress. The primary objective of this study was to characterize regulation of SOD gene expression in R. glutinosa in response to oxidative stresses and hormones. A full-length putative SOD clone (RgCu-ZnSOD1) was isolated from the leaf cDNA library of R. glutinosa using an expressed sequence tag clone as a probe. RgCu-ZnSOD1 cDNA is 777 bp in length and contains an open reading frame for a polypeptide consisted of 152 amino acid residues. The deduced amino acid sequence of the clone shows highest sequence similarity to the cytosolic Cu-ZnSODs. The two to three major bands with several minor ones on the Southern blots indicate that RgCu-ZnSOD1 is a member of a small multi-gene family. RgCuZnSOD1 mRNA was constitutively expressed in the leaf, flower and root. The expression of RgCu-ZnSOD1 mRNA was increased about 20% by wounding and paraquat, but decreased over 50% by ethylene and $GA_3$. This result indicates that the RgCu-ZnSOD1 expression is regulated differentially by different stresses and phytohormones at the transcription level. The RgCu-ZnSOD1 sequence and information on its regulation will be useful in investigating the role of SOD in the paraquat tolerance of R. glutinosa.