DNA-dependent Protein Kinase Mediates V(D)J Recombination via RAG2 Phosphorylation

Hah, Young-Sool,Lee, Jung-Hwa,Kim, Deok-Ryong Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.3

V(D)J recombination, a site-specific gene rearrangement process occurring during the lymphocyte development, begins with DNA double strand breaks by two recombination activating gene products (RAG1/2) and finishes with the repair process by several proteins including DNA-dependent protein kinase (DNA-PK). In this report, we found that RAG2 was specifically phosphorylated by DNA-PK at the $365^{th}$ serine residue, and this phosphorylated RAG2 affected the V(D)J recombination activity in cells in the GFP expression-based assay. While the V(D)J recombination activity between wild-type RAG2 and mutant S365A RAG2 in the assay using a signal joint substrate was undistinguishable in DNA-PK deficient cells (M059J), the activity with wild-type RAG2 was largely increased in DNA-PK proficient cells (M059K) in comparison with mutant RAG2, suggesting that RAG2 phosphorylation by DNA-PK plays a crucial role in the signal joint formation during V(D)J recombination.

Induction of Melanogenesis by Rapamycin in Human MNT-1 Melanoma Cells

( Young Sool Hah ),( Hee Young Cho ),( Tae Yeon Lim ),( Dong Hwa Park ),( Hwa Mi Kim ),( Ji Mi Yoon ),( Jin Gu Kim ),( Chi Yeon Kim ),( Tae Jin Yoon ) 대한피부과학회 2012 Annals of Dermatology Vol.24 No.2

Background: Melanogenesis is one of the characteristic parameters of differentiation in melanocytes and melanoma cells. Specific inhibitors of phosphatidylinositol 3-kinase (PI3K), such as wortmannin and LY294002, stimulate melanin production in mouse and in human melanoma cells, suggesting that PI3K and mammalian target of rapamycin (mTOR) might be involved in the regulation of melanogenesis. Objective: The involvement of the mTOR pathway in regulating melanogenesis was examined using human MNT-1 melanoma cells, and the effects of the potent inhibitor of mTOR, rapamycin, in the presence or absence of α-melanocyte-stimulating hormone (α-MSH) were evaluated. Methods: In cells treated with rapamycin, cell viability, melanin content, and tyrosinase (TYR) activity were measured and compared with untreated controls. Protein levels of TYR, tyrosinase-related protein (TYRP)-1, TYRP-2, and microphthalmia-associated transcription factor (MITF) were also analyzed by Western blot. Results: In rapamycin-treated cells, the melanin content increased concomitantly with an elevation in TYR activity, which plays a major role in melanogenesis. There was also an up-regulation of TYR, TYRP-1, and MITF proteins. Combined treatment with rapamycin or wortmannin and α-MSH increased melanogenesis more strongly than α-MSH alone. Conclusion: Rapamycin-induced melanin formation may be mediated through the up-regulation of TYR protein and activity. Furthermore, rapamycin and wortmannin, inhibitors of mTOR and PI3K, respectively, have co-stimulatory effects with α-MSH in enhancing melanogenesis in melanocyte cells. (Ann Dermatol 24(2) 151∼157, 2012)

DNA-dependent Protein Kinase Mediates V(D)J Recombination via RAG2 Phosphorylation

( Young Sool Hah ),( Jung Hwa Lee ),( Deok Ryong Kim ) 생화학분자생물학회 2007 BMB Reports Vol.40 No.3

A20 suppresses inflammatory responses and bone destruction in human fibroblast-like synoviocytes and in mice with collagen-induced arthritis

Hah, Young-Sool,Lee, Young-Rae,Jun, Jin-Su,Lim, Hye-Song,Kim, Hyun-Ok,Jeong, Yong-Geun,Hur, Gang Min,Lee, Sang Yong,Chung, Myoung Ja,Park, Jin-Woo,Lee, Sang-Il,Park, Byung-Hyun Wiley Subscription Services, Inc., A Wiley Company 2010 Vol.62 No.8

<B>Objective</B><P>Nuclear factor-κB (NF-κB) has been implicated as a therapeutic target for the treatment of rheumatoid arthritis (RA). The purpose of this study was to determine whether A20, a universal inhibitor of NF-κB, might have antiarthritic effects.</P><B>Methods</B><P>An adenovirus containing A20 complementary DNA (AdA20) was used to deliver A20 to human rheumatoid fibroblast-like synoviocytes (FLS) in vitro as well as to mice with collagen-induced arthritis (CIA) in vivo via intraarticular injection into the ankle joints bilaterally.</P><B>Results</B><P>In vitro experiments demonstrated that AdA20 suppressed NF-κB activation, chemokine production, and matrix metalloproteinase secretion induced by tumor necrosis factor α in FLS. Mice with CIA that were treated with AdA20 had a lower cumulative disease incidence and severity of arthritis, based on hind paw thickness, radiologic and histopathologic findings, and inflammatory cytokine levels, than did control virus–injected mice. The protective effects of AdA20 were mediated by the inhibition of the NF-κB signaling pathway. The severity of arthritis was also significantly decreased in the untreated front paws, indicating a beneficial systemic effect of local suppression of NF-κB. Surprisingly, mice treated with AdA20 after the onset of CIA had significantly decreased arthritis severity from the onset of clinical signs to the end of the study.</P><B>Conclusion</B><P>These results suggest that using A20 to block the NF-κB pathway in rheumatoid joints reduces both the inflammatory response and the tissue destruction. The development of an immunoregulatory strategy based on A20 may therefore have therapeutic potential in the treatment of RA.</P>

Microscopic imaging

Young-Sool Hah(하영술) 대한견주관절의학회 2015 대한견주관절학회 학술대회논문집 Vol.2015 No.4

Vascular endothelial growth factor stimulates osteoblastic differentiation of cultured human periosteal-derived cells expressing vascular endothelial growth factor receptors

Hah, Young-Sool,Jun, Jin-Su,Lee, Seong-Gyun,Park, Bong-Wook,Kim, Deok Ryong,Kim, Uk-Kyu,Kim, Jong-Ryoul,Byun, June-Ho Springer-Verlag 2011 MOLECULAR BIOLOGY REPORTS Vol.38 No.2

겨우살이 추출물의 미백 효과

하영술(Young-Sool Hah),김은지(Eun-Ji Kim),구영민(Young Min Goo),길영숙(Young Sook Kil),신승미(Seung Mi Sin),김상곤(Sang Gon Kim),강하은(Ha Eun Kang),윤태진(Tae-Jin Yoon) 한국생명과학회 2022 생명과학회지 Vol.32 No.5

멜라닌 색소는 피부색의 주요 원인이다. 멜라닌 색소는 멜라닌 세포에서 생성된 다음 각질 세포로 전달되어 결국 피부 표면에 다양한 색상을 부여한다. 많은 탈색제 및 피부 미백제가 개발되었지만, 색소 침착을 감소시키기 위한 재료에 대한 수요는 여전히 증가하고 있다. 본 연구에서 천연 화합물을 사용하여 탈색 및 피부 미백에 대한 재료를 찾으려고 시도한 결과 겨우살이(Viscum album var. coloratum) 추출물이 색소침착을 억제할 수 있음을 발견하였다. 인간 멜라닌 세포에 겨우살이 추출물(mistletoe extracts, ME)을 처리했을 때 색소 침착이 극적으로 감소하였다. 프로모터 리포터 분석은 ME 처리가 HM3KO 흑색종 세포에서 microphthalmia-associated transcription factor (MITF), melanophilin (MLPH), tyrosinase related protein 2 (TRP-2), and tyrosinase (TYR) 유전자의 전사를 억제한다는 것을 보여주었다. 일관되게 ME는 MITF, TRP-1 및 TYR과 같은 색소 침착 관련 분자의 단백질 수준을 감소시켰다. 또한 ME는 cAMP Responsive Element Binding Protein (CREB), AKT 및 ERK의 인산화를 감소시켰다. 이러한 결과는 ME가 색소 침착과 관련된 세포 내 신호 전달의 조절을 통해 멜라닌 생성을 억제한다는 것을 시사한다. 끝으로 ME는 색소 침착에 대한 생체 내 평가 모델인 제브라피쉬 배아의 멜라닌 생성을 현저하게 억제하였다. Melanin pigments are the main cause of skin color. They are produced in melanocytes and then transferred to keratinocytes, which eventually gives the skin surface a variety of colors. Although many skin-lightening or depigmenting agents have been developed, the demand for materials to reduce pigmentation is still increasing. Here, we tried to find materials for skin-lightening or depigmentation using natural compounds and found that mistletoe (Viscum album var. coloratum) extracts (ME) had an inhibitory effect on tyrosinase activity. As a result, ME significantly reduced pigmentation in human primary melanocytes. In addition, a promoter reporter assay revealed that ME inhibited the transcription of microphthalmia-associated transcription factor (MITF), melanophilin (MLPH), tyrosinase-related protein-2 (TRP-2), and tyrosinase (TYR) genes in HM3KO melanoma cells. In addition, ME decreased the protein level for pigmentation-related molecules, such as TYR and TRP-1. Furthermore, it markedly inhibited the melanogenesis of zebrafish embryos, an in vivo evaluation model for pigmentation. To elucidate the action mechanism of ME, we investigated its effects on intracellular signaling. Eventually, the ME dramatically decreased the phosphorylation of the cAMP responsive element binding protein (CREB), AKT, and ERK. The data suggest that ME may inhibit the melanogenesis pathway by regulating the signaling pathway related to pigmentation. Taken together, these data propose that ME can be developed as a depigmenting or skin-lightening agent.

덱사메타손 유도 근위축 모델에서 추출 조건에 따른 녹차 추출물의 근감소증 보호 효과

하영술(Young-Sool Hah),조경환(Kyoung Hwan Cho),김은지(Eun Ji Kim),손용휘(Yong-Hwi Son),이정현(Jung Hyeon Lee),이다예(Da Ye Lee),추호진(Ho Jin Choo),서민균(Min Gyun Seo),제회순(Hoe Soon Je),김종철(Jong Cheol Kim),유준일(Jun-Il Yoo) 한국차학회 2020 한국차학회지 Vol.26 No.1

근감소증(Sarcopenia)은 나이가 들면서 동반되는 근육량과 근력의 감소를 말하며, 정상적인 일상 생활을 하는 데 있어 상당한 어려움을 겪게 된다. 고용량 또는 지속적인 글루코코르티코이드 (GCs)의 사용은 근위축 유발할 우려가 있다. 따라서, GC에 의해 발생한 근위축의 치료는 임상적 중요성을 가지고 있다. 천연물에서 유래한 성분으로 수행한 몇몇 연구는 이들 성분이 다양한 근위축 조건에서 근육의 약화 및 위축을 감소시키는데 효과적임을 제시하고 있다. 녹차 추출물(green tea extract, GTE)은 심혈관계질환을 포함하여 광범위한 건강 증진에 기여한다. 하지만 근위축에 미치는 GTE의 효과는 완전히 밝혀지지 않았다. 본 연구는 C2C12 myotubes 및 C57BL/6 마우스에서 덱사메타손에 의해 유도된 근위축에 대하여 여러 가지 추출 조건에서 추출한 GTE의 효과와 기본 메커니즘을 평가하기 위해 시행되었다. 시험관내 실험은 배양된 C2C12 myotube에서 덱사메타손을 처리하여 근위축 상태를 만든 후 실시하였으며 qPCR 및 웨스턴 블롯법을 사용하여 근위축 관련 유전자인 muscle atrophy F-box (MAFbx)의 발현을 비교 분석하였다. 덱사메타손-유도 근위축 마우스 모델은 8주령 C57BL/6 마우스에 고용량 덱사메타손(10 mg/kg body weight, i.p., 14 days)을 투여하여 제작하였다. 체중, 그립 강도, 러닝머신 테스트, 근 무게 및 조직학적 평가를 시행하였다. GTE는 MaFbx의 발현을 감소시켜 C2C12 myotubes에서 덱사메타손-유도 근위축을 억제하였다. 더욱이 덱사메타손에 의해 유도된 근 감소 C57BL/6 마우스에서, GTE(1000 mg/kg) 경구 투여는 러닝머신에서 달리는 시간과 그립 강도를 향상시켜 덱사메타손-유도 근 기능 감소를 어느 정도 회복하였다. 또한 GTE는 전경골근과 비복근의 근 무게와 근섬유 크기 감소를 보호하였다. 이상의 연구결과를 종합해 보면 GTE 소재는 근 감소의 예방 및 개선을 위한 기능성식품용 상업적 소재로서 높은 실용화 가능성을 시사한다. Glucocorticoids (GCs) are negative muscle protein regulators that cause muscle atrophy when used in high doses or after the sustained use of GCs in numerous pathological conditions. Thus, the development of a treatment for GC-induced muscle atrophy has clinical importance. Some natural products effectively prevent muscle loss in several muscle atrophy conditions. Green tea extract (GTE) has a broad range of health benefits, including liver injury, but its effects on muscle atrophy are unclear. In this study, GTE was isolated from different extraction processes, and the protective effect of GTE on dexamethasone (Dexa)-induced atrophy was investigated in C2C12 myotubes and C57BL/6 mice. In vitro experiments were conducted using the Dexa-induced atrophy in cultured C2C12 myotubes and were evaluated by the expression of muscle atrophy F-box (MAFbx) and MyoD using real-time PCR and western blots. Muscle dysfunction was established in male C57BL/6 mice (eight weeks old, n=6) treated with a relatively high dose of Dexa (10 mg/kg body weight, i.p., 14 days). The body weight, grip strength, treadmill test, muscle weight, and muscle histology were assessed. GTE preserved Dexa-induced muscle atrophy in C2C12 myotubes, as indicated by the decreased expression of MAFbx. In Dexa-induced muscle wasting C57BL/6 mice, the 1000 mg/kg GTE treatment rescued Dexa-induced muscle weakness, as indicated by the prolonged running exhaustive time and improved grip strength. GTE also preserved the muscles from gastrocnemius and tibialis anterior muscle mass and muscle fiber cross-sectional area losses. These results suggest that GTE ameliorates Dexa-induced skeletal muscle wasting by regulating MAFbx, which might be developed as a therapeutic agent for the treatment of muscle atrophy and weakness.

콩잎 추출물의 근위축 개선 효과

최혜영(Hye Young Choi),하영술(Young-Sool Hah),지영호(Yeong Ho Ji),하준영(Jun Young Ha),배환희(Hwan Hee Bae),이동열(Dong Yeol Lee),정원민(Won Min Jeong),정동규(Dong Kyu Jeong),유준일(Jun-Il Yoo),김상곤(Sang Gon Kim) 한국생명과학회 2023 생명과학회지 Vol.33 No.12

골격근량과 근력의 점진적인 감소를 특징으로 하는 근감소증은 고령화 인구에서 중요한 문제이다. 본 연구는 콩잎 추출물(Soybean Leaf extracts, SL)의 덱사메타손으로 유도된 근위축에 대한 치료적 가능성을 세포 및 동물 모델에서 조사하였다. 세포 실험 결과, SL은 C2C12 근섬유의 형태, 밀도 및 크기가 보존되어 통계적으로 유의미한 수준으로 덱사메타손에 의해 유발된 근위축을 완화하는 것으로 나타났다. 또한, SL 처리는 주요 근육 위축 조절 인자인 muscle RING-finger protein-1 (MuRF1)과 muscle atrophy F-box (MAFbx)의 발현을 mRNA 및 단백질 수준 모두에서 유의하게 하향 조절하였다. 마우스 모델에서 SL 투여는 특히 덱사메타손으로 인한 체중 감소와 근육 소모를 상쇄하여 비복근과 전경골근의 근육량을 보존하는 것으로 나타났다. 기능적으로도 SL을 투여한 마우스는 악력과 트레드밀 지구력이 향상되어 근육 성능이 개선되었다. 또한 SL은 골격근에서 근위축 관련 단백질인 MAFbx의 발현을 억제하여 덱사메타손 유도 근위축에 대한 보호 역할을 보여주었다. 이러한 연구 결과를 종합해 볼 때 SL은 근감소증과 같은 근육 소모 질환을 개선할 수 있는 유망한 천연 치료제가 될 수 있음을 시사한다. Sarcopenia, a condition characterized by the insidious loss of skeletal muscle mass and strength, represents a significant and growing healthcare challenge, impacting the mobility and quality of life of aging populations worldwide. This study investigated the therapeutic potential of soybean leaf extract (SL) for dexamethasone (Dexa)-induced muscle atrophy in vitro and in an in vivo model. In vitro experiments showed that SL significantly alleviated Dexa-induced atrophy in C2C12 myotube cells, as evidenced by preserved myotube morphology, density, and size. Moreover, SL treatment significantly reduced the mRNA and protein levels of muscle RING-finger protein-1 (MuRF1) and muscle atrophy F-box (MAFbx), key factors regulating muscle atrophy. In a Dexa-induced atrophy mouse model, SL administration significantly inhibited Dexa-induced weight loss and muscle wasting, preserving the mass of the gastrocnemius and tibialis anterior muscles. Furthermore, mice treated with SL exhibited significant improvements in muscle function compared to their counterparts suffering from Dexa-induced muscle atrophy, as evidenced by a notable increase in grip strength and extended endurance on treadmill tests. Moreover, SL suppressed the expression of muscle atrophy–related proteins in skeletal muscle, highlighting its protective role against Dexa-induced muscle atrophy. These results suggest that SL has potential as a natural treatment for muscle-wasting conditions, such as sarcopenia.

Fatty acid-binding protein 5 promotes cell proliferation and invasion in human intrahepatic cholangiocarcinoma

JEONG, CHI-YOUNG,HAH, YOUNG-SOOL,CHO, BOK IM,LEE, SEON MIN,JOO, YOUNG-TAE,JUNG, EUN-JUNG,JEONG, SANG-HO,LEE, YOUNG-JOON,CHOI, SANG-KYUNG,HA, WOO-SONG,PARK, SOON-TAE,HONG, SOON-CHAN Spandidos Publications 2012 Oncology Reports Vol.28 No.4