• Title/Summary/Keyword: molecular pathogenesis

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Transcriptome Analysis of Long-Term Exposure to Blue Light in Retinal Pigment Epithelial Cells

  • Jin, Hong Lan;Jeong, Kwang Won
    • Biomolecules & Therapeutics
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    • v.30 no.3
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    • pp.291-297
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    • 2022
  • Dry age-related macular degeneration (AMD) is a type of progressive blindness that is primarily due to dysfunction and the loss of retinal pigment epithelium (RPE). The accumulation of N-retinylidene-N-retinylethanolamine (A2E), a by-product of the visual cycle, causes RPE and photoreceptor degeneration that impairs vision. Genes associated with dry AMD have been identified using a blue light model of A2E accumulation in the retinal pigment epithelium and transcriptomic studies of retinal tissue from patients with AMD. However, dry macular degeneration progresses slowly, and current approaches cannot reveal changes in gene transcription according to stages of AMD progression. Thus, they are limited in terms of identifying genes responsible for pathogenesis. Here, we created a model of long-term exposure to identify temporally-dependent changes in gene expression induced in human retinal pigment epithelial cells (ARPE-19) exposed to blue light and a non-cytotoxic dose of A2E for 120 days. We identified stage-specific genes at 40, 100, and 120 days, respectively. The expression of genes corresponding to epithelial-mesenchymal transition (EMT) during the early stage, glycolysis and angiogenesis during the middle stage, and apoptosis and inflammation pathways during the late stage was significantly altered by A2E and blue light. Changes in the expression of genes at the late stages of the EMT were similar to those found in human eyes with late-stage AMD. Our results provide further insight into the pathogenesis of dry AMD induced by blue light and a novel model in vitro with which relevant genes can be identified in the future.

Characterization of binding specificity using GST-conjugated mutant huntingtin epitopes in surface plasmon resonance (SPR)

  • Cho, Hang-Hee;Kim, Tae Hoon;Kim, Hong-Duck;Cho, Jae-Hyeon
    • Korean Journal of Veterinary Service
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    • v.44 no.4
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    • pp.185-194
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    • 2021
  • Polyglutamine extension in the coding sequence of mutant huntingtin causes neuronal degeneration associated with the formation of insoluble polyglutamine aggregates in Huntington's disease (HD). Mutant huntingtin can form aggregates within the nucleus and processes of neurons possibly due to misfolding of the proteins. To better understand the mechanism by which an elongated polyglutamine causes aggregates, we have developed an in vitro binding assay system of polyglutamine tract from truncated huntingtin. We made GST-HD exon1 fusion proteins which have expanded polyglutamine epitopes (e.g., 17, 23, 32, 46, 60, 78, 81, and 94 CAG repeats). In the present emergence of new study adjusted nanotechnology on protein chip such as surface plasmon resonance strategy which used to determine the substance which protein binds in drug discovery platform is worth to understand better neurodegenerative diseases (i.e., Alzheimer disease, Parkinson disease and Huntington disease) and its pathogenesis along with development of therapeutic measures. Hence, we used strengths of surface plasmon resonance (SPR) technology which is enabled to examine binding specificity and explore targeted molecular epitope using its electron charged wave pattern in HD pathogenesis utilize conjugated mutant epitope of HD protein and its interaction whether wild type GST-HD interacts with mutant GST-HD with maximum binding affinity at pH 6.85. We found that the maximum binding affinity of GST-HD17 with GST-HD81 was higher than the binding affinities of GST-HD17 with other mutant GST-HD constructs. Furthermore, our finding illustrated that the mutant form of GST-HD60 showed a stronger binding to GST-HD23 or GST-HD17 than GST-HD60 or GST-HD81. These results indicate that the binding affinity of mutant huntingtin does not correlate with the length of polyglutamine. It suggests that the aggregation of an expanded polyglutamine might have easily occurred in the presence of wild type form of huntingtin.

Pathogenesis and prognosis of primary oral squamous cell carcinoma based on microRNAs target genes: a systems biology approach

  • Taherkhani, Amir;Dehto, Shahab Shahmoradi;Jamshidi, Shokoofeh;Shojaei, Setareh
    • Genomics & Informatics
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    • v.20 no.3
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    • pp.27.1-27.13
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    • 2022
  • Oral squamous cell carcinoma (OSCC) is the most prevalent head and neck malignancy, with frequent cervical lymph-node metastasis, leading to a poor prognosis in OSCC patients. The present study aimed to identify potential markers, including microRNAs (miRNAs) and genes, significantly involved in the etiology of early-stage OSCC. Additionally, the main OSCC's dysregulated Gene Ontology annotations and significant signaling pathways were identified. The dataset GSE45238 underwent multivariate statistical analysis in order to distinguish primary OSCC tissues from healthy oral epithelium. Differentially expressed miRNAs (DEMs) with the criteria of p-value < 0.001 and |Log2 fold change| > 1.585 were identified in the two groups, and subsequently, validated targets of DEMs were identified. A protein interaction map was constructed, hub genes were identified, significant modules within the network were illustrated, and significant pathways and biological processes associated with the clusters were demonstrated. Using the GEPI2 database, the hub genes' predictive function was assessed. Compared to the healthy controls, main OSCC had a total of 23 DEMs. In patients with head and neck squamous cell carcinoma (HNSCC), upregulation of CALM1, CYCS, THBS1, MYC, GATA6, and SPRED3 was strongly associated with a poor prognosis. In HNSCC patients, overexpression of PIK3R3, GIGYF1, and BCL2L11 was substantially correlated with a good prognosis. Besides, "proteoglycans in cancer" was the most significant pathway enriched in the primary OSCC. The present study results revealed more possible mechanisms mediating primary OSCC and may be useful in the prognosis of the patients with early-stage OSCC.

The Significance of N6-Methyladenosine RNA Methylation in Regulating the Hepatitis B Virus Life Cycle

  • Jae-Su Moon;Wooseong Lee;Yong-Hee Cho;Yonghyo Kim;Geon-Woo Kim
    • Journal of Microbiology and Biotechnology
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    • v.34 no.2
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    • pp.233-239
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    • 2024
  • N6-methyladenosine (m6A) RNA methylation has recently emerged as a significant co-transcriptional modification involved in regulating various RNA functions. It plays a vital function in numerous biological processes. Enzymes referred to as m6A methyltransferases, such as the methyltransferase-like (METTL) 3-METTL14-Wilms tumor 1 (WT1)-associated protein (WTAP) complex, are responsible for adding m6A modifications, while m6A demethylases, including fat mass and obesity-associated protein (FTO) and alkB homolog 5 (ALKBH5), can remove m6A methylation. The functions of m6A-methylated RNA are regulated through the recognition and interaction of m6A reader proteins. Recent research has shown that m6A methylation takes place at multiple sites within hepatitis B virus (HBV) RNAs, and the location of these modifications can differentially impact the HBV infection. The addition of m6A modifications to HBV RNA can influence its stability and translation, thereby affecting viral replication and pathogenesis. Furthermore, HBV infection can also alter the m6A modification pattern of host RNA, indicating the virus's ability to manipulate host cellular processes, including m6A modification. This manipulation aids in establishing chronic infection, promoting liver disease, and contributing to pathogenesis. A comprehensive understanding of the functional roles of m6A modification during HBV infection is crucial for developing innovative approaches to combat HBV-mediated liver disease. In this review, we explore the functions of m6A modification in HBV replication and its impact on the development of liver disease.

BONE METASTASIS MODEL OF ORAL SQUAMOUS CELL CARCINOMA (구강 편평상피세포암의 골전이 모델)

  • Park, Young-Wook;Oh, Yu-Jin;Lee, Hee-Su
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.32 no.2
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    • pp.118-125
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    • 2010
  • Background and Purpose: Bone metastases rarely occur in patients with oral squamous cell carcinoma (OSCC), so the molecular mechanisms of bone metastasis of OSCC remains unclear. Studies with animal models allow progresses in understanding the molecular events for bone metastasis and provide new targets for therapy. So we tried to establish a murine model for bone metastasis of oral squamous cell carcinoma. Materials and Methods: Human OSCC cells (KB cell line) were xenografted to nude mice via direct inoculation into the tibial marrow. Mice with tibial tumors were sacrificed once a week, until seven weeks after the injection of human tumor cells. Growth of tibial tumors were observed by histology. Expression of TGF-$\beta$ and CXCR-4 in bone OSCC (experimental) and subcutaneous tumor (control) was also evaluated by immunohistochemical staining. Results: Bone OSCC was successfully induced by intra-tibial injection of KB cells. Tumor mass was developed in the marrow tissues of tibia and finally invade the endosteum of tibia. Immunohistochemical staining showed higher expression of TGF-$\beta$ in bone tumors than in subcutaneous tumors. Conclusion: A murine model of bone metastasis of OSCC was suggested that imitated the clinical findings of distant vascular metastasis. This bone tumor model should facilitate understanding of the molecular pathogenesis of OSCC bone metastasis, and aid in the developement of treatment strategies against OSCC bone metastasis.

Construction of Luminescence- and Fluorescence-Tagged Burkholderia pseudomallei for Pathogen Tracking in a Mouse Model

  • Shin, Yong-Woo;Park, Deok Bum;Choi, Myung-Min;Chun, Jeong-Hoon;Seong, Baik-Lin;Rhie, Gi-Eun
    • Journal of Microbiology and Biotechnology
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    • v.28 no.3
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    • pp.498-502
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    • 2018
  • Molecular imaging is a powerful method for tracking various infectious disease-causing pathogens in host organisms. Currently, a dual molecular imaging method that can provide temporal and spatial information on infected hosts at the organism, organ, tissue, and cellular levels simultaneously has not been reported for Burkholderia pseudomallei, a high-risk pathogen that causes melioidosis. In this study, we have established an experimental method that provides spatiotemporal information on infected hosts using luminescent and fluorescent dual-labeled B. pseudomallei. Using this method, we visualized B. pseudomallei infection at the organism, organ, and tissue levels in a BALB/c mouse model by detecting its luminescence and fluorescence. The infection of B. pseudomallei at the cellular level was also visualized by its emitted fluorescence in infected macrophage cells. This method could be an extremely useful and applicable tool to study the pathogenesis of B. pseudomallei-related infectious diseases.

Identification and Characterization of the Vitro vulnificus Phosphomannomutase Gene

  • Lee, Jeong-Hyun;Park, Na-Young;Park, Soon-Jung;Choi, Sang-Ho
    • Journal of Microbiology and Biotechnology
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    • v.13 no.1
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    • pp.149-154
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    • 2003
  • Numerous virulence factors such as O antigen have been proposed to account for the fulminating and destructive nature of V. vulnificus infections. To better characterize the role of O antigen, a pmm gene encoding a phosphomannomutase was identified and cloned from V. vulnificus. The deduced amino acid sequence of the pmm was 42 to 71% similar to that reported from other Enterobacteriaceae. Functions of the pmm gene in virulence were assessed by the construction of an isogenic mutant, whose pmm gene was inactivated by allelic exchanges, and by evaluating its phenotype changes in vitro and in mice. The disruption of pmm resulted in a loss of more than 90% of phosphomannomutase, and reintroduction of recombinant pmm could complement the decrease of phosphomannomutase activity, indicating that the pmm gene encodes the phosphomannomutase of V. vulnificus. There was no difference in the $LD_50S$ of the wild-type and the pmm mutant in mice, but the $LD_50S$ observed by the mutant complemented with recombinant pmm were lower. Therefore, it appears that PMM is less important in the pathogenesis of V. vulnificus than would have been predicted by examining the effects of injecting purified LPS into animals, but it is not completely dispensable for virulence in mice.

The potential theragnostic (diagnostic+therapeutic) application of exosomes in diverse biomedical fields

  • Kim, Yong-Seok;Ahn, Jae-Sung;Kim, Semi;Kim, Hyun-Jin;Kim, Shin-Hee;Kang, Ju-Seop
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.2
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    • pp.113-125
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    • 2018
  • Exosomes are membranous vesicles of 30-150 nm in diameter that are derived from the exocytosis of the intraluminal vesicles of many cell types including immune cells, stem cells, cardiovascular cells and tumor cells. Exosomes participate in intercellular communication by delivering their contents to recipient cells, with or without direct contact between cells, and thereby influence physiological and pathological processes. They are present in various body fluids and contain proteins, nucleic acids, lipids, and microRNAs that can be transported to surrounding cells. Theragnosis is a concept in next-generation medicine that simultaneously combines accurate diagnostics with therapeutic effects. Molecular components in exosomes have been found to be related to certain diseases and treatment responses, indicating that they may have applications in diagnosis via molecular imaging and biomarker detection. In addition, recent studies have reported that exosomes have immunotherapeutic applications or can act as a drug delivery system for targeted therapies with drugs and biomolecules. In this review, we describe the formation, structure, and physiological roles of exosomes. We also discuss their roles in the pathogenesis and progression of diseases including neurodegenerative diseases, cardiovascular diseases, and cancer. The potential applications of exosomes for theragnostic purposes in various diseases are also discussed. This review summarizes the current knowledge about the physiological and pathological roles of exosomes as well as their diagnostic and therapeutic uses, including emerging exosome-based therapies that could not be applied until now.

Molecular Markers for Patients with Thymic Malignancies: not Feasible at Present?

  • Avci, Nilufer;Cecener, Gulsah;Deligonul, Adem;Erturk, Elif;Tunca, Berrin;Egeli, Unal;Tezcan, Gulcin;Akyildiz, Elif Ulker;Bayram, Ahmet Sami;Gebitekin, Cengiz;Kurt, Ender;Evrensel, Turkkan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.8
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    • pp.3457-3460
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    • 2014
  • Background: Thymomas and thymic carcinomas are rare malignancies and devising clinically effective molecular targeted therapies is a major clinical challenge. The aim of the study was to analyze BLC2 and vascular endothelial growth factor receptor (VEGFR) expression and KRAS and EGFR mutational status and to correlate them with the clinical characteristics of patients with thymomas and thymic carcinomas. Materials and Methods: A total of 62 patients (mean age: $50.4{\pm}13.2$ years) with thymomas and thymic carcinomas were enrolled. The expression of BLC2 and VEGFR in tumor cells and normal tissues was evaluated by RT-PCR. The mutational status of the KRAS and EGFR genes was investigated by PCR with sequence specific primers. Results: The BLC2 and VEGFR expression levels did not differ significantly between tumor and normal tissues. Moreover, there were no clearly pathogenic mutations in KRAS or EGFR genes in any tumor. None of the molecular markers were significantly related to clinical outcomes. Conclusions: Changes in levels of expression of BLC2 and VEGFR do not appear to be involved in thymic tumorigenesis. Moreover, our data suggest that KRAS and EGFR mutations do not play a major role in the pathogenesis of thymomas and thymic carcinomas.

Detection of Coinfection and Persistent Infection of Adenovirus and Varicella-Zoster Virus in Synovial Fluids from Synovitis Patients by Nested-PCR (Nested 중합효소연쇄반응을 이용하여 활막염 환자의 관절액으로부터 아데노바이러스와 대상포진바이러스의 이중감염과 지속감염의 검출)

  • Park, Hae-Kyung;Woo, So-Youn;Kim, Hyun-Jin
    • The Journal of Korean Society of Virology
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    • v.30 no.3
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    • pp.179-187
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    • 2000
  • The etiology of rheumatic arthritis (RA) is associated with a number of genetic and environmental factors, but is not definitively elucidated. Recently, more attention has been paid to the possibility of microbial etiology in the pathogenesis of RA, because many different infectious agents have been reported to precede the onset or exacerbation of RA. Adenovirus (ADV) may be one cause of persistent or recurrent inflammatory arthritis. Varicella zoster virus (VZV) arthritis is detected frequently in RA patients treated with low dose methotrexate. The demonstration of simultaneous presence of both viral agents of specific viral nucleic acid in synovial fluids from synovitis patients would provide more direct evidence for arthritis etiological relationship, but there are no confirmed results. Therefore, we studied the ability of adenovirus and VZV to establish coinfection and persistent infection in synovial fluid from synovitis patients. The presence of viral agents in the synovial fluid demonstrated by isolation of cell culture, enzyme immunoassay and nested-PCR. The synovial fluids were also investgated for the presence of viral nucleic acid by nested-PCR using specific primer. ADV produced 220 bp and VZV produced 447 bp by each nested-PCR with specific primers. We detected 4/6 cases (66.7%) with persistent infection of ADV and 5/6 cases (83.3%) of VZV with 13 synovial fluids (between 7 to 52 day intervals) from synovitis patients by monoclonal ErA and nested-PCR. 21/28 cases (75%) with coinfection of adenovirus and VZV with synovial fluids from synovitis patients by nested-PCR. ADV and VZV coinfection and persistent infection of synovial fluids may provide a chronic antigenic stimuli to the immune system therefore provoking a continuing inflammatory response and caused the possibility of synovitis and arthritis.

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