• Title/Summary/Keyword: molecular mechanisms

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Environmental Chemical-Dioxin Impacts on Biological Systems: A Review

  • Vo, Thuy Thi Bich;Le, Binh Thi Nguyen;Nong, Hai Van;Yang, Hyun;Jeung, Eui-Bae
    • Journal of Embryo Transfer
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    • v.28 no.2
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    • pp.95-111
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    • 2013
  • Worldwide there is concern about the continuing release of a broad range of environmental endocrine disrupting chemicals, including polychlorinated biphenyls, dioxins, phthalates, polybrominated diphenyl ethers (PBDEs), and other halogenated organochlorines persistent organic pollutants (POPs) into the environment. They are condemned for health adverse effects such as cancer, reproductive defects, neurobehavioral abnormalities, endocrine and immunological toxicity. These effects can be elicited via a number of mechanisms among others include disruption of endocrine system, oxidation stress and epigenetic. However, most of the mechanisms are not clear, thus several number of studies are ongoing trying to elucidate them in order to protect the public by reducing these adverse effects. In this review, we briefly limited review the process, the impacts, and the potential mechanisms of dioxin/dioxin like compound, particularly, their possible roles in adverse developmental and reproductive processes, diseases, and gene expression and associated molecular pathways in cells.

Distinct Differences between TNF Receptor 1- and TNF Receptor 2- mediated Activation of NFκB

  • Thommesen, Liv;Laegreid, Astrid
    • BMB Reports
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    • v.38 no.3
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    • pp.281-289
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    • 2005
  • Tumor necrosis factor (TNF) signaling is mediated via two distinct receptors, TNFR2 and TNFR1, which shows partially overlapping signaling mechanisms and biological roles. In the present study, TNFR2 and TNFR1 signal transduction mechanisms involved in activation of $NF{\kappa}B$ and CMV promoter-enhancer were compared with respect to their susceptibility towards inhibitors of intracellular signaling. For this, we used SW480 cells, where we have shown that TNF-signaling can occur independently through each of the two receptors. The TNFR1 response was inhibited by D609, bromophenacyl bromide (BPB), nordihydroguararetic acid (NDGA), and by sodium salicylate, while TNFR2-mediated activation of $NF{\kappa}B$ and CMV promoter-enhancer was resistant to these compounds. The signaling mechanisms known to be affected by these inhibitors include phospholipases as well as redox- and pH-sensitive intracellular components. Our results imply that TNFR2 signaling involved in $NF{\kappa}B$ activation proceeds independently of these inhibitor-sensitive signaling components, indicating distinct signaling pathways not shared with TNFR1.

Transcriptome Analysis and Expression Profiling of Molecular Responses to Cd Toxicity in Morchella spongiola

  • Xu, Hongyan;Xie, Zhanling;Jiang, Hongchen;Guo, Jing;Meng, Qing;Zhao, Yuan;Wang, Xiaofang
    • Mycobiology
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    • v.49 no.4
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    • pp.421-433
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    • 2021
  • Morchella is a genus of fungi with the ability to concentrate Cd both in the fruit-body and mycelium. However, the molecular mechanisms conferring resistance to Cd stress in Morchella are unknown. Here, RNA-based transcriptomic sequencing was used to identify the genes and pathways involved in Cd tolerance in Morchella spongiola. 7444 differentially expressed genes (DEGs) were identified by cultivating M. spongiola in media containing 0.15, 0.90, or 1.50 mg/L Cd2+. The DEGs were divided into six sub-clusters based on their global expression profiles. GO enrichment analysis indicated that numerous DEGs were associated with catalytic activity, cell cycle control, and the ribosome. KEGG enrichment analysis showed that the main pathways under Cd stress were MAPK signaling, oxidative phosphorylation, pyruvate metabolism, and propanoate metabolism. In addition, several DEGs encoding ion transporters, enzymatic/non-enzymatic antioxidants, and transcription factors were identified. Based on these results, a preliminary gene regulatory network was firstly proposed to illustrate the molecular mechanisms of Cd detoxification in M. spongiola. These results provide valuable insights into the Cd tolerance mechanism of M. spongiola and constitute a robust foundation for further studies on detoxification mechanisms in macrofungi that could potentially lead to the development of new and improved fungal bioremediation strategies.

Why Should We Consider Potential Roles of Oral Bacteria in the Pathogenesis of Sjögren Syndrome?

  • Sung-Ho Chang;Sung-Hwan Park;Mi-La Cho;Youngnim Choi
    • IMMUNE NETWORK
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    • v.22 no.4
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    • pp.32.1-32.20
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    • 2022
  • Sjögren syndrome (SS) is a chronic autoimmune disorder that primarily targets the salivary and lacrimal glands. The pathology of these exocrine glands is characterized by periductal focal lymphocytic infiltrates, and both T cell-mediated tissue injury and autoantibodies that interfere with the secretion process underlie glandular hypofunction. In addition to these adaptive mechanisms, multiple innate immune pathways are dysregulated, particularly in the salivary gland epithelium. Our understanding of the pathogenetic mechanisms of SS has substantially improved during the past decade. In contrast to viral infection, bacterial infection has never been considered in the pathogenesis of SS. In this review, oral dysbiosis associated with SS and evidence for bacterial infection of the salivary glands in SS were reviewed. In addition, the potential contributions of bacterial infection to innate activation of ductal epithelial cells, plasmacytoid dendritic cells, and B cells and to the breach of tolerance via bystander activation of autoreactive T cells and molecular mimicry were discussed. The added roles of bacteria may extend our understanding of the pathogenetic mechanisms and therapeutic approaches for this autoimmune exocrinopathy.

Isocitrate dehydrogenase mutations: new opportunities for translational research

  • Keum, Young-Sam;Choi, Bu Young
    • BMB Reports
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    • v.48 no.5
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    • pp.266-270
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    • 2015
  • Over the last decade, comprehensive genome-wide sequencing studies have enabled us to find out unexpected genetic alterations of metabolism in cancer. An example is the identification of arginine missense mutations of isocitrate dehydrogenases-1 and -2 (IDH1/2) in glioma, acute myeloid leukemia (AML), chondrosarcomas, and cholangiocarcinoma. These alterations are closely associated with the production of a new stereospecific metabolite, (R)-2-hydroxyglutarate (R-2HG). A large number of follow-up studies have been performed to address the molecular mechanisms of IDH1/2 mutations underlying how these events contribute to malignant transformation. In the meanwhile, the development of selective mutant IDH1/2 chemical inhibitors is being actively pursued in the scientific community and pharmaceutical industry. The present review article briefly discusses the important findings that highlight the molecular mechanisms of IDH1/2 mutations in cancer and provides a current status for development of selective mutant IDH1/2 chemical inhibitors. [BMB Reports 2015; 48(5): 266-270]

Molecular Mechanisms Governing IL-24 Gene Expression

  • Sahoo, Anupama;Im, Sin-Hyeog
    • IMMUNE NETWORK
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    • v.12 no.1
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    • pp.1-7
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    • 2012
  • Interleukin-24 (IL-24) belongs to the IL-10 family of cytokines and is well known for its tumor suppressor activity. This cytokine is released by both immune and nonimmune cells and acts on non-hematopoietic tissues such as skin, lung and reproductive tissues. Apart from its ubiquitous tumor suppressor function, IL-24 is also known to be involved in the immunopathology of autoimmune diseases like psoriasis and rheumatoid arthritis. Although the cellular sources and functions of IL-24 are being increasingly investigated, the molecular mechanisms of IL-24 gene expression at the levels of signal transduction, epigenetics and transcription factor binding are still unclear. Understanding the specific molecular events that regulate the production of IL-24 will help to answer the remaining questions that are important for the design of new strategies of immune intervention involving IL-24. Herein, we briefly review the signaling pathways and transcription factors that facilitate, induce, or repress production of this cytokine along with the cellular sources and functions of IL-24.

Control of asymmetric cell division in early C. elegans embryogenesis: teaming-up translational repression and protein degradation

  • Hwang, Sue-Yun;Rose, Lesilee S.
    • BMB Reports
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    • v.43 no.2
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    • pp.69-78
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    • 2010
  • Asymmetric cell division is a fundamental mechanism for the generation of body axes and cell diversity during early embryogenesis in many organisms. During intrinsically asymmetric divisions, an axis of polarity is established within the cell and the division plane is oriented to ensure the differential segregation of developmental determinants to the daughter cells. Studies in the nematode Caenorhabditis elegans have contributed greatly to our understanding of the regulatory mechanisms underlying cell polarity and asymmetric division. However, much remains to be elucidated about the molecular machinery controlling the spatiotemporal distribution of key components. In this review we discuss recent findings that reveal intricate interactions between translational control and targeted proteolysis. These two mechanisms of regulation serve to carefully modulate protein levels and reinforce asymmetries, or to eliminate proteins from certain cells.

Predictive Role of Computer Simulation in Assessing Signaling Pathways of Crizotinib-treated A549 Lung Cancer Cells

  • Xia, Pu;Mou, Fei-Fei;Wang, Li-Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3119-3121
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    • 2012
  • Non-small-cell lung cancer (NSCLC) is a leading cause of cancer deaths worldwide. Crizotinib has been approved by the U.S. Food and Drug Administration for the treatment of patients with advanced NSCLC. However, understanding of mechanisms of action is still limited. In our studies, we confirmed crizotinib-induced apoptosis in A549 lung cancer cells. In order to assess mechanisms, small molecular docking technology was used as a preliminary simulation of signaling pathways. Interesting, our results of experiments were consistent with the results of computer simulation. This indicates that small molecular docking technology should find wide use for its reliability and convenience.

Non-canonical targets play an important role in microRNA stability control mechanisms

  • Park, June Hyun;Shin, Chanseok
    • BMB Reports
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    • v.50 no.4
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    • pp.158-159
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    • 2017
  • MicroRNAs (miRNAs) regulate gene expression by guiding the Argonaute (Ago)-containing RNA-induced silencing complex (RISC) to specific target mRNA molecules. It is well established that miRNAs are stabilized by Ago proteins, but the molecular features that trigger miRNA destabilization from Ago proteins remain largely unknown. To explore the molecular mechanisms of how targets affect the stability of miRNAs in human Ago (hAgo) proteins, we employed an in vitro system that consisted of a minimal hAgo2-RISC in HEK293T cell lysates. Surprisingly, we found that miRNAs are drastically destabilized by binding to seedless, non-canonical targets. We showed that miRNAs are destabilized at their 3' ends during this process, which is largely attributed to the conformational flexibility of the L1-PAZ domain. Based on these results, we propose that non-canonical targets may play an important regulatory role in controlling the stability of miRNAs, instead of being regulated by miRNAs.

The Role of Intracellular Signaling Pathways in the Neurobiology of the Depressive Disorder (우울장애의 신경생물학적 기전으로서 세포 내 신호전달계의 역할)

  • Kim, Se-Hyun
    • Korean Journal of Biological Psychiatry
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    • v.18 no.4
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    • pp.189-196
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    • 2011
  • Major depressive disorder is characterized by cellular and molecular alterations resulting in the depressive behavioral phenotypes. Preclinical and clinical studies have demonstrated the deficits, including cell atrophy and loss, in limbic and cortical regions of patients with depression, which is restored with antidepressants by reestablishing proper molecular changes. These findings have implicated the involvement of relevant intracellular signaling pathways in the pathogenetic and therapeutic mechanisms of depressive disorders. This review summarizes the current knowledge of the signal transduction mechanisms related to depressive disorders, including cyclic-AMP, mitogen-activated protein kinase, Akt, and protein translation initiation signaling cascades. Understanding molecular components of signaling pathways regulating neurobiology of depressive disorders may provide the novel targets for the development of more efficacious treatment modalities.