돌연변이 마이오실린 발현에 의한 섬유주세포 사멸 및 그 기전

임동희,손성수,김태은,기창원,Dong Hui Lim,Seongsoo Sohn,Tae Eun Kim,Changwon Kee 대한안과학회 2011 대한안과학회지 Vol.52 No.12

Purpose: To determine whether the expression of mutant myocilin can lead to death of human trabecular meshwork (HTM) cells and to determine whether the mechanism by which this occurs is apoptosis. Methods: HTM cells were transduced with a recombinant adenovirus expressing human mutant (Q368X) myocilin. The apoptotic death of HTM cells caused by expression of mutant myocilin was examined using a cell proliferation assay, flow cytometry, Western blot analysis, and immunocytochemistry. Results: It appeared that the expression of mutant myocilin itself was not sufficient to cause HTM cell death. Furthermore, the expression of mutant myocilin did not lead to apoptosis of HTM cells although it did elicit a protein unfolding response. Conclusions: Our data suggest that the mechanism of myocilin glaucoma is not apoptotic death of HTM cells caused by mutant myocilin expression, and that the actual mechanism remains unknown. J Korean Ophthalmol Soc 2011;52(12):1507-1513

마이오실린과 상호작용하는 단백질 탐색 및 선별

조명국,손성수,기창원,Myoung Kuk Cho,M,S,Sung Su Son,M,S,Chang Won Kee 대한안과학회 2006 대한안과학회지 Vol.47 No.4

Purpose: To identify novel proteins which bind to myocilin, using a yeast two-hybrid screening system. Methods: A bait plasmid of myocilin was constructed, and then transformed into yeast AH109. The transformed yeast cells were mated with yeast Y187 containing human skeletal muscle cDNA library plasmids in 2 X YPD medium. Mated diploid yeasts were plated on synthetic dropout medium (SD/-Trp-Leu-His and SD/-Trp-Leu-His-Ade). The positive clones grown on the selective medium were amplified, sequenced, and analyzed using the database of GenBank. The expression of selected genes in trabecular meshwork (TM) cells was detected by RT-PCR. Results: The expression of bait protein in yeast was confirmed by Western blot analysis. Extensive screening of a cDNA library led to the selection of twenty-four positive clones which represent eight genes, including six of cytoskeleton associated proteins such as α-actin, myosin regulatory light chain 2A, dynactin, syntrophin α1, microtubule associated protein 1B, and myosin binding protein C. Conclusions: Myocilin may interact with cytoskeleton associated proteins in TM cells. Further studies on their interactions will provide functional clues of myocilin.

Myocilin as a Potential Factor for the Fast Type Change in the Muscle Isoform Composition: A Mini Review

Yunsuk Choi(Yunsuk Choi),Hyunseok Jee(Hyunseok Jee) 대한운동학회 2023 아시아 운동학 학술지 Vol.25 No.1

BACKGROUND Various factors-based properties of the skeletal muscle are determined by mechanical stress, chemical stimuli, neuromuscular stimuli, different protein isoforms etc. The properties of the muscle are formed in the process of the balance between anabolism and catabolism. Especially, the anabolism on the way of the cell proliferation to its differentiation is accompanied by various controlling signal pathways. OBJECTIVE The purpose of this study focused on the mTOR/S6K system, Myosin, and Myocilin among these signaling pathways, especially on previously reported studies on the contribution of Myocilin to the skeletal muscle fiber type transformation. METHODS To identify the molecular pathways related to muscle development, the KEGG Mapper was used to present the mTOR-related signaling system that has not been identified so far. RESULTS Consequently, it suggests that it affects the myogenic process, through the path of PI3K->AKT- >MEF2->MyoC->mTOR->p70S6K->S6. CONCLUSIONS It also suggests that Myocilin serves as a potential effector to control skeletal muscle cell type. Furthermore, more detailed study on the potential target-oriented (to the fast or slow fiber type change) role of Myocilin for enhancing the health state by adjusted exercise programs developed by its optimal type, intensity, frequency, and time is awaited.

Molecular analysis of <i>myocilin</i> and <i>optineurin</i> genes in Korean primary glaucoma patients

Park, Joonhong,Kim, Myungshin,Park, Chan Kee,Chae, Hyojin,Lee, Seungok,Kim, Yonggoo,Jang, Woori,Chi, Hyun Young,Park, Hae-Young Lopilly,Park, Shin Hae D.A. Spandidos 2016 MOLECULAR MEDICINE REPORTS Vol.14 No.3

<P>To investigate the underlying genetic influences of primary glaucoma in Korea, molecular analysis was performed in 112 sporadic cases, and results compared with healthy controls. The <I>myocilin</I> (<I>MYOC</I>) and <I>optineurin</I> (<I>OPTN</I>) genes were directly sequenced in 112 unrelated patients, including 17 with primary open-angle glaucoma, 19 with juvenile open-angle glaucoma, and 76 with normal tension glaucoma. Healthy unrelated Korean individuals (n=100) were used as the non-selected population control. A total of three <I>MYOC</I> and four <I>OPTN</I> variants potentially associated with primary glaucoma were identified in 4 and 18 patients, respectively. A novel variant of <I>MYOC</I>, <I>p.Leu255Pro</I>, was predicted to be potentially pathogenic by <I>in silico</I> analysis. Another, <I>p.Thr353Ile</I>, has been previously reported. These two missense variants were detected in patients with a family history of glaucoma. Combined heterozygous variants <I>p.[Thr123=;Ile288=]</I> were identified in 2 of 112 (2%) patients but not in healthy controls. Among <I>OPTN</I> variants, a novel variant <I>p.Arg271Cys</I> was identified. Homozygous <I>p.[Thr34=;Thr34=]</I> (4/112, 4%), homozygous <I>p.[Met98Lys;Met98Lys]</I> (4/112, 4%), or combined heterozygous <I>p.[Thr34=;Arg545Gln]</I> (9/112, 8%) was significantly associated with the development of primary glaucoma [odds ratio (OR)=8.768, 95% confidence interval (CI)=1.972–38.988; relative risk=1.818, 95% CI=1.473–2.244; P=0.001]. The present study provides insight into the genetic or haplotype variants of <I>MYOC</I> and <I>OPTN</I> genes contributing to primary glaucoma. Haplotype variants identified in the present study may be regarded as potential contributing factors of primary glaucoma in Korea. Further studies, including those on additional genes, are required to elucidate the underlying pathogenic mechanism using a larger cohort to provide additional statistical power.</P>

Little evidence for association of the glaucoma gene <i>MYOC</i> with open-angle glaucoma

Sohn, Seongsoo,Hur, Wonhee,Choi, Young Ran,Chung, Yun Shin,Ki, Chang-Seok,Kee, Changwon BMJ Group 2010 British journal of ophthalmology Vol.94 No.5

<P><B>Background/aim</B></P><P>To determine if overexpression of the glaucoma gene <I>MYOC</I> is involved in the development of open-angle glaucoma (OAG) and if its promoter variants are associated with glaucoma in the Korean population.</P><P><B>Methods</B></P><P>Human trabecular meshwork cells were cultured in the presence of ophthalmic steroids such as fluorometholone, fluorometholone acetate, dexamethasone, prednisolone acetate and rimexolone. The cells were cultured at a hydrostatic pressure of 32 mm Hg above atmospheric pressure and induction of <I>MYOC</I> was evaluated by northern blot analysis. Genomic DNA was extracted from blood samples obtained from 74 normal controls and 168 unrelated Korean patients with OAG, including primary OAG, normal tension glaucoma and steroid-induced glaucoma. A 461 base pair (bp) DNA fragment of the <I>MYOC</I> promoter region was amplified using PCR and its genotype was analysed by directly sequencing the product.</P><P><B>Results</B></P><P>The potencies of steroid eye drops in <I>MYOC</I> induction in vitro was the same regardless of their potential for elevating intraocular pressure in vivo. Hydrostatic pressure had no effect on <I>MYOC</I> induction. A dinucleotide repeat polymorphism and three single nucleotide polymorphisms were identified, but no obvious differences in the genotype distribution and allele frequency of the variants between the control group and any type of OAG were observed.</P><P><B>Conclusion</B></P><P>Our data suggest that <I>MYOC</I> overexpression is not a cause or an effect of intraocular pressure elevation and that <I>MYOC</I> itself is not associated with OAG.</P>