• Tuberculosis and Respiratory Diseases
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• 제83권1호
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• pp.1-13
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• 2020

For the past three decades, more than a thousand of genetic studies have been performed to find out the genetic variants responsible for the risk of asthma. Until now, all of the discovered single nucleotide polymorphisms have explained genetic effects less than initially expected. Thus, clarification of environmental factors has been brought up to overcome the 'missing' heritability. The most exciting solution is epigenesis because it intervenes at the junction between the genome and the environment. Epigenesis is an alteration of genetic expression without changes of DNA sequence caused by environmental factors such as nutrients, allergens, cigarette smoke, air pollutants, use of drugs and infectious agents during pre- and post-natal periods and even in adulthood. Three major forms of epigenesis are composed of DNA methylation, histone modifications, and specific microRNA. Recently, several studies have been published on epigenesis in asthma and allergy as a powerful tool for research of genetic heritability in asthma albeit epigenetic changes are at the starting point to obtain the data on specific phenotypes of asthma. In this presentation, we mainly review the potential role of DNA CpG methylation in the risk of asthma and its sub-phenotypes including nonsteroidal anti-inflammatory exacerbated respiratory diseases.

• 한국발생생물학회지:발생과생식
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• 제4권1호
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• pp.7-12
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• 2000

수정에 의한 배 발생은 정자가 난자 내로 침입하여 정자와 난자의 반수체 핵질이 융합되고 이어 유사분열로 이어지는 과정에서 시작된다. 하지만 수정 및 초기 배 발생 동안 자웅 핵질과 난 세포질 구성 요소 상호간의 작용기전에 관해서는 명확히 알려져 있지 않은 부분이 많다. 수정보조기법인 세포질 내 정자 직접 주입법의 개발은 남성불임치료에 혁신적인 기술로 자리잡고 있을 뿐만 아니라 포유동물의 수정과정을 이해하는데 많은 도움을 주고 있다. 핵치환에 의한 복제동물 생산기법도 분화된 핵이 난 세포질 내에서 재 분화 (reprogramming)하여 발생하는 유일한 과정으로 세포질 구성요소들의 상호작용과 발생 조절 기능을 이해하는데 도움을 준다. 최근 몇 년간 돼지 난자 세포질에 정자 및 원형정자 직접주입, 세포질 이식, 세포질 융합 및 핵치환 한 후 난자의 발생과정을 간접 면역형광 분석법과 주사 전자현미경으로 조사하였다. 이러한 연구를 통해 체외수정, 세포질 이식 및 정자직접 주입법 등과 같은 임상치료기술 과 핵치환에 의한 복제동물생산 기법의 개선에 필요한 기초자료를 얻을 수 있었고, 포유동물 난자의 후생적 발생과정 (epigenesis)에 관해 공부할 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제24권6호
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• pp.463-472
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• 2020

Direct reprogramming, also known as a trans-differentiation, is a technique to allow mature cells to be converted into other types of cells without inducing a pluripotent stage. It has been suggested as a major strategy to acquire the desired type of cells in cell-based therapies to repair damaged tissues. Studies related to switching the fate of cells through epigenetic modification have been progressing and they can bypass safety issues raised by the virus-based transfection methods. In this study, a protocol was established to directly convert fully differentiated fibroblasts into diverse mesenchymal-lineage cells, such as osteoblasts, adipocytes, chondrocytes, and ectodermal cells, including neurons, by means of DNA demethylation, immediately followed by culturing in various differentiating media. First, 24 h exposure of 5-azacytidine (5-aza-CN), a well-characterized DNA methyl transferase inhibitor, to NIH-3T3 murine fibroblast cells induced the expression of stem-cell markers, that is, increasing cell plasticity. Next, 5-aza-CN treated fibroblasts were cultured in osteogenic, adipogenic, chondrogenic, and neurogenic media with or without bone morphogenetic protein 2 for a designated period. Differentiation of each desired type of cell was verified by quantitative reverse transcriptase-polymerase chain reaction/western blot assays for appropriate marker expression and by various staining methods, such as alkaline phosphatase/alizarin red S/oil red O/alcian blue. These proposed procedures allowed easier acquisition of the desired cells without any transgenic modification, using direct reprogramming technology, and thus may help make it more available in the clinical fields of regenerative medicine.