PINK1 positively regulates HDAC3 to suppress dopaminergic neuronal cell death

Choi, Hyo-Kyoung,Choi, Youngsok,Kang, HeeBum,Lim, Eun-jin,Park, Soo-Yeon,Lee, Hyun-Seob,Park, Ji-Min,Moon, Jisook,Kim, Yoon-Jung,Choi, Insup,Joe, Eun-Hye,Choi, Kyung-Chul,Yoon, Ho-Geun IRL Press 2015 Human molecular genetics Vol.24 No.4

<P>Deciphering the molecular basis of neuronal cell death is a central issue in the etiology of neurodegenerative diseases, such as Parkinson's and Alzheimer's. Dysregulation of p53 levels has been implicated in neuronal apoptosis. The role of histone deacetylase 3 (HDAC3) in suppressing p53-dependent apoptosis has been recently emphasized; however, the molecular basis of modulation of p53 function by HDAC3 remains unclear. Here we show that PTEN-induced putative kinase 1 (<I>PINK1</I>), which is linked to autosomal recessive early-onset familial Parkinson's disease, phosphorylates HDAC3 at Ser-424 to enhance its HDAC activity in a neural cell-specific manner. PINK1 prevents H<SUB>2</SUB>O<SUB>2</SUB>-induced C-terminal cleavage of HDAC3 via phosphorylation of HDAC3 at Ser-424, which is reversed by protein phosphatase 4c. PINK1-mediated phosphorylation of HDAC3 enhances its direct association with p53 and causes subsequent hypoacetylation of p53. Genetic deletion of PINK1 partly impaired the suppressive role of HDAC3 in regulating p53 acetylation and transcriptional activity. However, depletion of HDAC3 fully abolished the PINK1-mediated p53 inhibitory loop. Finally, ectopic expression of phosphomometic-HDAC3<SUP>S424E</SUP> substantially overcomes the defective action of PINK1 against oxidative stress in dopaminergic neuronal cells. Together, our results uncovered a mechanism by which PINK1–HDAC3 network mediates p53 inhibitory loop in response to oxidative stress-induced damage.</P>

CFP1 role in germ cell development

Youngsok Choi 한국발생생물학회 2014 한국발생생물학회 학술발표대회 Vol.2014 No.9

Epigenetic change is dynamic during germ cell development. DNA methylation and histone modification are the most important epigenetic process to regulate the gene expressions. They are very close reciprocal relationship on the specific genomic regions called CpG islands (CGI). The CGIs are located on the promoter regions and recruit various epigenetic regulators including, CFP1, KDM2A, KDM2B, TET1 and MLL. They contain a common domain which is the zinc finger CxxC domain. The CxxC domain reads non-methylated CpG and recruits other regulatory elements such as SET1, PRC, COMPASS and SIN3A to modify Histone proteins. CFP1 contains a CxxC domain. CFP1 protein therefore imposes an ability to distinguish its important regulatory element, “non-methylated CpG” from the genome. After binding the CpG, CFP1 recruits SET1 complex, which is involved in the histone H3 lysin 4 (H3K4) methylation. However, the functional consequence of CFP1 in the germ cell development remains unknown. In this study, we demonstrated that CFP1 is critical for the both spermatogenesis and oogenesis using conditional knockout system.

The oocyte-specific transcription factor, Nobox, regulates the expression of <i>Pad6</i>, a peptidylarginine deiminase in the oocyte

Choi, Mikyung,Lee, Ok-Hee,Jeon, Sanghyun,Park, Miseon,Lee, Dong Ryul,Ko, Jeong-Jae,Yoon, Tae Ki,Rajkovic, Aleksandar,Choi, Youngsok Elsevier 2010 FEBS letters Vol.584 No.16

<P><B>Abstract</B></P><P>Nobox is an oocyte-specific transcriptional regulator. <I>Nobox</I> deficiency disrupts early folliculogenesis and the expression of oocyte-specific genes in mice. In the present study, we found that peptidylarginine deiminase 6 (<I>Pad6</I>) was downregulated in <I>Nobox</I>-null ovaries. <I>Pad6</I> is preferentially expressed in oocytes and its transcript is detectable at embryonic day 16.5. In addition, we identified one Nobox DNA-binding element (NBE) within the mouse <I>Pad6</I> promoter. The NBE includes a core sequence TAATTA. Sequence-specific binding of Nobox to the TAATTA motif was confirmed. <I>Nobox</I> overexpression augmented transcriptional activity of a <I>luciferase</I> reporter driven by mouse Pad6. Our findings indicate that Nobox is a critical regulator that orchestrates oocyte-specific genes such as <I>Pad6</I> during folliculogenesis.</P>

Role of CFP1 in spermatogenesis

Youngsok Choi 한국실험동물학회 2016 한국실험동물학회 학술발표대회 논문집 Vol.2016 No.08

Mutations in SOHLH1 gene associate with nonobstructive Azoospermia

Choi, Youngsok,Jeon, Sanghyun,Choi, Mikyung,Lee, Min-ho,Park, Miseon,Lee, Dong Ryul,Jun, Kyu-Yeon,Kwon, Youngjoo,Lee, Ok-Hee,Song, Seung-Hun,Kim, Ji-Young,Lee, Kyung-Ah,Yoon, Tae Ki,Rajkovic, Aleksand Wiley Subscription Services, Inc., A Wiley Company 2010 Human mutation Vol.31 No.7

<P>In a previous study, we found SOHLH1 (spermatogenesis and oogenesis-specific basic helix-loop-helix 1) as the first testis-specific basic helix-loop-helix transcription factor essential for spermatogonial differentiation. SOHLH1 therefore represents an excellent candidate gene for testicular failure such as nonobstructive azoospermia (NOA). We analyzed whether there were mutations in the SOHLH1 gene in 96 Korean patients with NOA. The sequence analysis discovered three novel variations: one intronic variant (c.346−1G>A), and two nonsynonymous exonic variants (c.91T>C and c.529C>A) with known single nucleotide polymorphisms (SNPs), which included six intronic variants, two synonymous, and two nonsynonymous variants. We examined the consequences of mutations in SOHLH1 using in vivo and in vitro assays. Analysis of transcripts from minigenes carrying the c.346−1G>A revealed that splicing site variation leads to the partial deletion at a cryptic splicing site within exon 4. This deletion results in SOHLH1 with a truncated bHLH domain. Transient transfection assay showed that the SOHLH1 mutant with the truncated domain disrupted the transcriptional activity of KIT promoter, whereas two missense mutations harboring either p.Arg37Gln or p.Pro269Ser did not have a significant effect on its transactivation. Our findings indicate that a splice-acceptor site mutation that probably causes a nonfunctional SOHLH1 protein results in nonobstructive azoospermia by the lack of normal spermatogenesis. Hum Mutat 31:788–793, 2010. © 2010 Wiley-Liss, Inc.</P>

Solute Carrier Family 19, Member 1 (<i>SLC19A1</i>) Polymorphisms (−43T>C, 80G>A, and 696C>T), and Haplotypes in Idiopathic Recurrent Spontaneous Abortion in a Korean Population

Rah, HyungChul,Choi, Yi Seul,Jeon, Young Joo,Choi, Youngsok,Cha, Sun Hee,Choi, Dong Hee,Ko, Jung Jae,Shim, Sung Han,Kim, Nam Keun Springer-Verlag 2012 Reproductive sciences Vol.19 No.5

<P>The objective was to investigate the association between idiopathic recurrent spontaneous abortion (RSA) and 3 SLC19A1 polymorphisms (-43T>C, 80G>A, and 696C>T). DNA from 269 patients with RSA and 125 controls were genotyped for the 3 SLC19A1 single nucleotide polymorphisms (SNPs) by polymerase chain reaction-restriction fragment length polymorphism. Homocysteine and folate levels of 100 patients with RSA were available for analysis. The combination genotypes of SLC19A1 -43TC/80GG, -43TC/80AA, and -43CC/80GA; 80GA/696TT, 80AA/696CC; and -43TC/696CC were less frequent in patients with RSA compared to controls (P < .05 for each). The -43C/80A/696??T and -43T/80G/696C haplotypes were more frequent in patients than controls, whereas -43T/80A/696C, -43C/80A/696C, -43C/80G/696C, -43C/80G/696T, and -43T/80G/696T haplotypes were less frequent in patients (P < .05 for each). The -43T/80G and 80A/696T haplotypes were more frequent in patients, while -43T/80A, -43C/80G, 80A/696C, 80G/696T, and -43C/696C haplotypes occurred less frequently in patients (P < .05 for each). The associations between idiopathic RSA occurrence and SLC19A1 -43T>C/80G>A/696C>T polymorphisms were identified and can be developed as biomarkers for RSA risk.</P>

Identification and Characterization of LHX8 DNA Binding Elements

박미리,Youngsok Choi,Sanghyun Jeon,Ji-Hye Jeong,Miseon Park,Dong-Ryul Lee,Tae Ki Yoon,Dong Hee Choi 한국발생생물학회 2012 발생과 생식 Vol.16 No.4

Lhx8 (LIM homeobox 8) gene encodes a LIM homeodomain transcriptional regulator that is preferentially expressed in germ cells and critical for mammalian folliculogenesis. However, Lhx8 DNA binding sequences are not characterized yet. We aimed to identify and characterize a cis-acting sequence of germ-cell specific transcriptional factor, Lhx8. To identify Lhx8DNA binding element, Cyclic Amplification of Sequence Target (CAST) Analysis was performed. Electrophoretic Mobility Shift Assay (EMSA) was processed for the binding specificity of Lhx8. Luciferase assay was for the transcriptional activity of Lhx8 through identified DNA binding site. We identified a putative cis-acting sequence, TGATTG as Lhx8 DNA binding element (LBE). In addition, Lhx8 binds to the LBE with high affinity and augments transcriptional activity of luciferase reporter driven by artificial promoter containing the Lhx8 binding element. These findings indicate that Lhx8 directly regulates the transcription of genes containing Lhx8 binding element in oocytes during early folliculogenesis

Regulatory mechanism for expression of IL1B receptors in the uterine endometrium and effects of IL1B on prostaglandin synthetic enzymes during the implantation period in pigs.

Seo, Heewon,Choi, Yohan,Shim, Jangsoo,Choi, Youngsok,Ka, Hakhyun Society for the Study of Reproduction [etc.] 2012 BIOLOGY OF REPRODUCTION Vol.87 No.2

<P>During the implantation period, the porcine conceptus secretes interleukin-1beta (IL1B) that may be involved in the establishment of pregnancy in pigs. However, the regulatory mechanism for IL1B receptor expression and the function of IL1B in the uterine endometrium are not well elucidated. In this study, we determined IL1B receptor expression in the uterine endometrium of pigs during pregnancy. IL1B receptor subtypes, IL1 receptor type I (IL1R1) and IL1 receptor accessory protein (IL1RAP) were expressed in the uterine endometrium with the expression being most abundant on Day 12 of pregnancy primarily in the luminal and glandular epithelial cells. Expression of IL1R1 mRNA increased in response to IL1B in a dose-dependent manner, and expression of IL1RAP mRNA increased in response to both IL1B and estradiol, indicating that expression of endometrial IL1B receptors was regulated cooperatively by IL1B and estrogen of conceptus origin. During the peri-implantation period, the porcine uterine endometrium actively synthesizes and secretes prostaglandins (PGs). IL1B increased expression of PTGS1 and PTGS2 genes that are rate-limiting for PG synthesis in the uterine endometrium. Collectively, the results indicated that IL1B regulates expression of IL1R1 and IL1RAP and stimulates expression of PTGS1 and PTGS2 that are considered to be the most rate-limiting enzymes for endometrial synthesis of PGs during the peri-implantation period of pregnancy in pigs.</P>

Role of estrogen and RAS signaling in repeated implantation failure

( Kwonho Hong ),( Youngsok Choi ) 생화학분자생물학회(구 한국생화학분자생물학회) 2018 BMB Reports Vol.51 No.5

In humans, hormonal regulation is crucial for the preparation of uterine environment leading to either successful implantation or menstrual cycle. Estrogen is a pivotal female steroid hormone that regulates the uterine dynamics along with progesterone in the estrous and menstrual cycles in humans. Estrogen signals act via nuclear estrogen receptor or membrane-bound receptor. The membrane-bound estrogen receptor plays a crucial role in the rapid response of estrogen in the uterine epithelium. Recently, RASD1 has received attention as a novel signal transducer of estrogen in various systems including female reproductive organs. In this review, we discuss the regulation of estrogen and RASD1 signaling in the uterus and also provide insights into RAS as a novel signaling molecule in repeated implantation failure. [BMB Reports 2018; 51(5): 225-229]

Conjugation of vascular endothelial growth factor to poly lactic-co-glycolic acid nanospheres enhances differentiation of embryonic stem cells to lymphatic endothelial cells

Yoo Hyunjin,Choi Dongyoon,Choi Youngsok 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.4

Objective: Pluripotent stem cell-derived lymphatic endothelial cells (LECs) show great promise in their therapeutic application in the field of regenerative medicine related to lymphatic vessels. We tested the approach of forced differentiation of mouse embryonal stem cells into LECs using biodegradable poly lactic-co-glycolic acid (PLGA) nanospheres in conjugation with growth factors (vascular endothelial growth factors [VEGF-A and VEGF-C]). Methods: We evaluated the practical use of heparin-conjugated PLGA nanoparticles (molecular weight ~15,000) in conjugation with VEGF-A/C, embryoid body (EB) formation, and LEC differentiation using immunofluorescence staining followed by quantification and quantitative real-time polymerase chain reaction analysis. Results: We showed that formation and differentiation of EB with VEGF-A/C-conjugated PLGA nanospheres, compared to direct supplementation of VEGF-A/C to the EB differentiation media, greatly improved yield of LYVE1(+) LECs. Our analyses revealed that the enhanced potential of LEC differentiation using VEGF-A/C-conjugated PLGA nanospheres was mediated by elevation of expression of the genes that are important for lymphatic vessel formation. Conclusion: Together, we not only established an improved protocol for LEC differentiation using PLGA nanospheres but also provided a platform technology for the mechanistic study of LEC development in mammals. Objective: Pluripotent stem cell-derived lymphatic endothelial cells (LECs) show great promise in their therapeutic application in the field of regenerative medicine related to lymphatic vessels. We tested the approach of forced differentiation of mouse embryonal stem cells into LECs using biodegradable poly lactic-co-glycolic acid (PLGA) nanospheres in conjugation with growth factors (vascular endothelial growth factors [VEGF-A and VEGF-C]).Methods: We evaluated the practical use of heparin-conjugated PLGA nanoparticles (molecular weight ~15,000) in conjugation with VEGF-A/C, embryoid body (EB) formation, and LEC differentiation using immunofluorescence staining followed by quantification and quantitative real-time polymerase chain reaction analysis.Results: We showed that formation and differentiation of EB with VEGF-A/C-conjugated PLGA nanospheres, compared to direct supplementation of VEGF-A/C to the EB differentiation media, greatly improved yield of LYVE1(+) LECs. Our analyses revealed that the enhanced potential of LEC differentiation using VEGF-A/C-conjugated PLGA nanospheres was mediated by elevation of expression of the genes that are important for lymphatic vessel formation.Conclusion: Together, we not only established an improved protocol for LEC differentiation using PLGA nanospheres but also provided a platform technology for the mechanistic study of LEC development in mammals.