Homeostatic balance of histone acetylation and deconstruction of repressive chromatin marker H3K9me3 during adipocyte differentiation of 3T3-L1 cells

나한흠,김근철 한국유전학회 2018 Genes & Genomics Vol.40 No.12

Background Adipocyte differentiation is completed by changing gene expression. Chromatin is closely related to gene expression. Therefore, its structure might be changed for adipocyte differentiation. Mouse 3T3-L1 preadipocytes have been used as a cell model to study molecular mechanisms of adipogenesis. Objective To examine changes of chromatin modification and expression of histone modifying enzymes during adipocyte differentiation. Methods Microscopic analysis and Oil Red O staining were performed to determine distinct phenotype of adipocyte differentiation. RT-PCR and Western blot analysis were used to examine expression levels of histone modifying enzymes during adipocyte differentiation. Histone modifications were examined by immunostaining analysis. Results Expression levels of P300 and cbp were increased during adipocyte differentiation. However, acetylation of histones was not quantitatively changed postdifferentiation of 3T3-L1 cells compared to that at pre-differentiation. RT-PCR and Western blot analyses showed that expression levels of hdac2 and hdac3 were increased during adipocyte differentiation, suggesting histone acetylation at chromatin level was homeostatically controlled by increased expression of both HATs and HDACs. Tri-methylation level of H3K9 (H3K9me3), but not that of H3K27me3, was significantly decreased during adipocyte differentiation. Decreased expression of setdb1 was consistent with reduced pattern of H3K9me3. Knock-down of setdb1 induced adipocyte differentiation. This suggests that setdb1 is a key chromatin modifier that modulates repressive chromatin. Conclusion These results suggest that there exist extensive mechanisms of chromatin modifications for homeostatic balance of chromatin acetylation and deconstruction of repressive chromatin during adipocyte differentiation.

사람 핵DNA로부터 FosB 유전자 프로모터 클로닝 및 활성도 분석

나한흠(Han-Heom Na),강윤성(Yoonsung Kang),김근철(Keun-Cheol Kim) 한국생명과학회 2017 생명과학회지 Vol.27 No.8

FosB (FBJ murine osteosarcoma viral oncogene homolog B) 유전자는 사람의 19번 염색체에 위치하고 있으며 약 43 KD의 단백질을 코딩하며, 발생 및 분화과정, 개체 유지, 발병 진행 등을 조절한다고 알려져 왔다. 본 연구에서는 바이오 마커 등의 가능성이 있다고 보고된 FosB 유전자의 프로모터를 클로닝하여 활성도를 분석하고자 하였다. FosB genomic DNA 서열을 확인한 결과, TSS upstream 방향의 약 1 Kb 안쪽 부위에 FosB 유전자 발현을 위한 중요한 요소들이 있을 것으로 추정하였고, 따라서 FosB genomic DNA의 upstream -1,555 부위부터 exon 1의 +73까지 부위에 대한 PCR 증폭을 수행하였다. 또한 클로닝 성공을 높이기 위하여 일차로 TA-1<SUP>st</SUP>FosBp plasmid를 얻은 후, 다시 TA-1stFosBp plasmid를 template로 Kpn1과 Nhe1 제한 효소 절단부위를 프라이머에 삽입한 후 제작하여 2차 PCR을 수행하였으며, TA-2<SUP>nd</SUP>FosBp 플라스미드를 제작한 후 제한 효소로 절단하여 pGL3-luc vector로 subcloning하였다. 제작된 pGL3-FosBp-luc를 이용하여 항암제에 대한 활성도를 분석하고자 A549 사람 폐암세포주에 pGL3-FosBp-luc 플라스미드를 transfection 한 후 luciferase 활성도 분석을 수행하였다. Luciferase 활성도 증가는 doxorubicin, taxol 등을 처리한 후 단백질 발현 양상과 비교 하였을 때도 일치되는 결과를 얻을 수 있었다. 그러므로 FosB프로모터 클로닝은 향후 유전자 발현 연구, 마커분석 등에 유용할 것으로 사료된다. The FBJ murine osteosarcoma viral oncogene homolog B (FosB) gene is located at chromosome 19, and encodes 43 Kda protein. Functionally, the FosB gene is important for differentiation, development, and pathogenesis. Furthermore, the FosB gene is suggested as possible biomarker for tracing disease prognosis. In this study, we constructed plasmid containing a FosB promoter region and evaluate its promoter activity. We analyzed the putative promoter region in FosB genomic DNA using bioinformatics program, and we found important regulatory elements in 1 Kb upstream from transcription start site (TSS). Therefore, we performed polymerase chain reaction (PCR) amplification on region from-1,555 upstream to +73 of the FosB genomic DNA, and PCR product was inserted into TA vector to create the TA-1stFosBp plasmid. We then prepared the primer sets, which contain a restriction enzyme site for Kpn1 and Nhe1, in order to reinsert into the TA vector to prepare TA-2<SUP>nd</SUP> FosBp plasmid. It was finally subcloned into pGL3-luc vector after enzyme cutting. To evaluate whether the cloned plasmid is useful in cell based experiment, we performed luciferase assay with pGL3-FosBp-luctransfection. FosB promoter activity was increased compared to empty vector, and this activity was significantly increased by treatment of doxorubicin and taxol. We obtained consistent data on regulation of FosB gene expression after anticancer drug treatment using Western blot analysis. The results suggest that promoter cloning of the human FosB gene is very useful for studying gene expression and analyzing biomarkers.

부저병 원인균 Paenibacillus larvae 특이 유전자 분석을 통한 진단마커 발굴

나한흠(Han-Heom Na),김근철(Keun-Cheol Kim) 한국생명과학회 2017 생명과학회지 Vol.27 No.1

부저병이란 Paenibacillus larvae감염에 의하여 꿀벌 유충의 괴사를 유도하는 질병이다. 우리나라에서는 2008년 봄, 국내에 처음으로 대량 발병 사례가 보고되었으며, 지속적인 2차 피해로 큰 후유증을 앓고 있다. 본 연구에서는 부저병을 효율적으로 관리할수 있는 진단방법을 조사하고자 하였다. 따라서 부저병의 원인균인 P. larvae에서 특이적으로 발현되고 있는 유전자들을 동정하고자 하였으며, 이 유전자들은 주로 부저병균의 독성을 유발하는 것으로 알려진 Toxin1, Toxin2A & 2B, SplA, CBP49, SevA&SevB 들이다. 이들은 1차 PCR 에서는 검출하기 어려웠지만, 2차 nested PCR방법을 이용하여 검출이 용이함을 알 수 있었다. 한편 여러가지 식물 추출물을 혼합한 배지에서 부저병균을 배양하였을 때, 부저병균의 성장저해와 일치하게 우리가 검증한 유전자들의 발현이 감소하는 것을 알 수 있었다. 이러한 결과들은 부저병 원인균의 특이 유전자들은 향후 PCR진단마커로서 활용 가능성이 있을 것으로 사료된다. Foulbrood disease is infected by Paenibacillus larvae on larval stage of honeybee, and is lethal disease to result in population death. This disease was manifested in 2008 in Korea, is still suffered by the secondary damages. In this study, we are to examine diagnostic PCR approaches to manage the Foulbrood disease. PCR amplification of 16S rRNA is generally using for microbial infection, but the specificity is little poor for the correct diagnosis. Therefore, we are to identify specific genes expressed in Paenibacillus larvae, and perform PCR analysis. We selected five distinct genes from literature references. Those genes are commonly known as toxic genes for host infection, and include Toxin1, Toxin2A & 2B, SplA, CBP49, and SevA&SevB. PCR amplification for these genes is difficult to detect at the first time. So, we performed the second PCR using the first PCR product as a template. This approach using the nested PCR was very useful for detecting large marker genes. When Paenibacillus larvae was cultured in the medium containing plant extracts, PCR amplification of the identified genes is correlated with the microbial growth inhibition. Therefore, these results suggest that the identified genes might be useful to study diagnostic PCR markers for honeybee Foulbrood disease.

Identification of Cleaved Haptoglobin in the Serum of Bee Venom-Hypersensitive Patients

류재민,나한흠,박진성,Byung-Soo Ahn,김근철 사단법인약침학회 2021 Journal of Acupuncture & Meridian Studies Vol.14 No.3

Background: Bee venom has been used as a therapeutic compound for various human diseases in oriental medicine; however, it can induce anaphylaxis in hypersensitive patients during treatment. Anaphylaxis is an acute allergic reaction that occurs after allergen exposure. IgE is released from immune-related cells such as mast cells and basophils during anaphylaxis. Various inflammatory mediators are also released into the bloodstream during the acute response. Objectives: We aimed to identify specific proteins from bee venom-hypersensitive patients. Methods: We analyzed the blood serum of control and bee venom-hypersensitive patients using two-dimensional (2D) electrophoresis. Results: An interesting protein spot with a molecular size of 10 kDa was identified at an isoelectric point (p.I.) of 5.5. Spots detected both before and after sweet bee venom therapy were not proteins induced by sweet bee venom. The 10 kDa protein was identified as the cleaved form of haptoglobin through liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Statistical analysis indicated that the presence of the spot was highly significant in the bee venom-hypersensitive group. Conclusion: The findings suggest that cleaved haptoglobin may be a significant diagnostic protein for anaphylaxis. In addition, a high incidence of bee venom hypersensitivity may be associated with the haptoglobin genotype.

암종양유전자 SETDB1과 FosB 발현에 대한 p53의 음성 조절기작

윤현지(Hyeon Ji Yun),나한흠(Han-Heom Na),김근철(Keun-Cheol Kim) 한국생명과학회 2020 생명과학회지 Vol.30 No.12

암세포에 항암제를 처리하게 되면, 세포증식, 이동성 또는 약물 내성과 관련된 많은 유전자들의 발현 변화가 발생하며, 유전자 발현 변화는 상호간의 조절 네트워크에 의해 밀접하게 연결될 수도 있다고 추측된다. 본 연구에서 p53 유전자 유무가 다른 A549와 H1299 인간 폐암세포에 독소루비신을 처리하면, 원종양유전자인 FosB의 발현은 증가하지만, 원종양유전자인 SETDB1의 발현은 감소하지만, 단백질 발현의 양적인 차이가 발생한다는 사실을 알 수 있었다. TF motif binding 분석 프로그램을 이용하여 SETDB1과 FosB 프로모터지역에서의 p53단백질의 결합가능성을 분석한 결과, SETDB1의 경우 18부위, FosB의 경우 21 부위의 p53 결합부위를 예측할 수 있었다. SETDB1과 FosB 프로모터의 subcloning하여 luciferase 분석을 수행한 결과, p53은 SETDB1과 FosB을 음성적으로 조절한다는 사실을 알 수 있었다. 또한, H1299 세포에 p53의 과발현은 SETDB1 과 FosB의 발현을 감소시킬 수 있음을 RT-PCR, western blot, qPCR, 면역염색 실험을 통해 확인하였다. 이러한 결과를 종합하여 본다면, p53에 의한 SETDB1과 FosB 유전자 발현 조절은 항암제 처리과정에서 나타나는 암세포의 사멸과 생존에 대한 기능적 조절 네트워크로 사료된다. Treatment with anticancer drugs changes the expression of multiple genes related to cell proliferation, migration, and drug resistance. These changes in gene expression may be connected to regulatory networks for each other. This study showed that doxorubicin treatment induces the expression of oncogenic FosB and decreases the expression of oncogenic SETDB1 in A549 and H1299 human lung cancer cells, which are different in tumor suppressor p53 status. However, a small difference was detected in the quantitative expression of those proteins in the two kinds of cells. To examine the potential regulation of SETDB1 and FosB by p53, we predicted putative p53 binding sites on the genomic DNA of SETDB1 and FosB using a TF motif binding search program. These putative p53 binding sites were identified as 18 sites in the promoter regions of SETDB1 and 21 sites in the genomic DNA of FosB. A luciferase assay confirmed that p53 negatively regulated the promoter activities of SETDB1 and FosB. Furthermore, the results of RT-PCR, western blot, qPCR, and immunostaining experiments indicated that the transfection of exogenous p53 decreases the expression of SETDB1 and FosB in H1299 cells. This indicates that p53 negatively regulates the expression of SETDB1 and FosB at the transcriptional level. Collectively, the downregulation of SETDB1 and FosB by p53 may provide functional networks for apoptosis and for the survival of cancer cells during anticancer drug treatment.

Dual Cytotoxic Responses Induced by Treatment of A549 Human Lung Cancer Cells with Sweet Bee Venom in a Dose-Dependent Manner

Yu-Na Hwang,In-Seo Kwon,나한흠,박진성,김근철 대한약침학회 2022 Journal of pharmacopuncture Vol.25 No.4

Objectives: Sweet bee venom (sBV) is purified from Apis mellifera, containing a high level of melittin—its main component. It has been used as a therapeutic agent for pain relief and anti-inflammation, as well as for treating neuronal abnormalities. Recently, there have been studies on the therapeutic application of sBV for anticancer treatment. In the present study, we investigated the pharmacological effect of sBV treatment in A549 human lung cancer cells. Methods: We used microscopic analysis to observe the morphological changes in A549 cells after sBV treatment. The MTT assay was used to examine the cytotoxic effect after dose-dependent sBV treatment. Molecular changes in sBV were evaluated by the expression of apoptosis marker proteins using western blot analysis. Results: Microscopic analysis suggested that the growth inhibitory effect occurred in a dose-dependent manner; however, cell lysis occurred at a concentration over 20 μg/mL of sBV. The MTT assay indicated that sBV treatment exhibited a growth inhibitory effect at a concentration over 5 μg/mL. On fluorescence activated cell sorting analysis, G0 dead cells were observed after G1 arrest at treatment concentrations up to 10 μg/mL. However, rapid cell rupture was observed at a concentration of 20 μg/mL. Western blot analysis demonstrated that sBV treatment modulated the expression of multiple cell death-related proteins, including cleaved-PARP, cleaved-caspase 9, p53, Bcl2, and Bax. Conclusion: sBV induced cell death in A549 human lung cancer cells at a pharmacological concentration, albeit causing hemolytic cell death at a high concentration.

Regulatory Effect of Cannabidiol (CBD) on Decreased β-Catenin Expression in Alopecia Models by Testosterone and PMA Treatment in Dermal Papilla Cells

Yoon-Jong Park,Jae-Min Ryu,나한흠,Hyun Suk Jung,Bokhye Kim,박진성,Byung-Soo Ahn,김근철 대한약침학회 2021 Journal of pharmacopuncture Vol.24 No.2

Objectives: The hair follicle is composed of more than 20 kinds of cells, and mesoderm derived dermal papilla cells and keratinocytes cooperatively contribute hair growth via Wnt/β-catenin signaling pathway. We are to investigate β-catenin expression and regulatory mechanism by CBD in alopecia hair tissues and dermal papilla cells. Methods: We performed structural and anatomical analyses on alopecia patients derived hair tissues using microscopes. Pharmacological effect of CBD was evaluated by β-catenin expression using RT-PCR and immunostaining experiment. Results: Morphological deformation and loss of cell numbers in hair shaft were observed in alopecia hair tissues. IHC experiment showed that loss of β-catenin expression was shown in inner shaft of the alopecia hair tissues, indicating that β-catenin expression is a key regulatory function during alopecia progression. Consistently, β-catenin expression was decreased in testosterone or PMA treated dermal papilla cells, suggesting that those treatments are referred as a model on molecular mechanism of alopecia using dermal papilla cells. RT-PCR and immunostaining experiments showed that β-catenin expression was decreased in RNA level, as well as decreased β-catenin protein might be resulted from ubiquitination. However, CBD treatment has no changes in gene expression including β-catenin, but the decreased β-catenin expression by testosterone or PMA was restored by CBD pretreatment, suggesting that potential regulatory effect on alopecia induction of testosterone and PMA. Conclusion: CBD might have a modulating function on alopecia caused by hormonal or excess of signaling pathway, and be a promising application for on alopecia treatment.

Multiple Comparative Analyses on Pharmacological Actions of Hemp Species Derived Phytocannabinoids in Human Colon Cancer Cells

Ju Hee Park(박주희),In Seo Kwon(권인서),Yu Na Hwang(황유나),Han Heom Na(나한흠),Tae Hyung Kwon(권태형),Jin Sung Park(박진성),Keun Cheol Kim(김근철) 한국약용작물학회 2023 한국약용작물학회 학술대회논문집 Vol.2023 No.1