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15. Epigenetic priming by Dot1l in lymphatic endothelial progenitors ensures normal lymphatic development and function

Author

Yoo, Hyunjin, Lee, Young Jae, Park, Chanhyeok, Son, Dabin, Choi, Dong Yoon, Park, Ji-Hyun, Choi, Hee-Jin, La, Hyun Woo, Choi, Yun-Jung, Moon, Eun-Hye, Saur, Dieter, Chung, Hyung Min, Song, Hyuk, Do, Jeong Tae, Jang, Hoon, Lee, Dong Ryul, Park, Chankyu, Lee, Ok-Hee, Cho, Ssang-Goo, Hong, Seok-Ho, Kong, Gu, Kim, Jin-Hoi, Choi, Youngsok, and Hong, Kwonho

Published
2020
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16. The First Identification of Cryptosporidium parvum Virus-1 (CSpV1) in Hanwoo (Bos taurus coreanae) Calves in Korea.

Author

Chae, Jeong-Byoung, Shin, Seung-Uk, Kim, Serim, Jo, Young-Mi, Roh, Hyunsoo, Chae, Hansong, Kim, Won-Gyeong, Chae, Joon-Seok, Song, Hyuk, and Kang, Jung-Won

Subjects
CRYPTOSPORIDIUM, CRYPTOSPORIDIUM parvum, CATTLE, CALVES, DOUBLE-stranded RNA, POLYMERASE chain reaction
Abstract

Simple Summary: Cryptosporidium is a parasite that causes digestive diseases in cows, and a virus called Cryptosporidium parvum virus-1 (CSpV1) is associated with it. We investigated the presence and features of CSpV1 in diarrhea samples of Hanwoo calves (Korean indigenous cattle). Out of 140 samples, 70 were positive for Cryptosporidium and 70 were negative. CSpV1 was found in 20% of the samples, more commonly in those already positive for the parasite. This is the first study on CSpV1 in Korea, offering insights into the relationship between the parasite and virus in cows. Cryptosporidium is an obligate coccidian parasite that causes enteric diseases in bovine species. A double-stranded RNA virus associated with C. parvum oocysts, Cryptosporidium parvum virus-1 (CSpV1), has been characterized. However, the relationship between the abovementioned coccidian parasite and the virus has not been studied in the context of the known clinical outcomes. This study aimed to characterize the prevalence and molecular traits of CSpV1 in diarrheal feces of Hanwoo (Korean indigenous cattle) calves. Of the 140 fecal samples previously tested for C. parvum, which were obtained from Hanwoo calves aged 60 days, 70 tested positive and 70 tested negative. These samples were included in this study. By using the polymerase chain reaction (PCR) analysis targeting the RdRp gene of CSpV1, we detected CSpV1 in 28 samples (20.0%), with infection rates of 31.4% (22/70) in C. parvum-positive and 8.6% (6/70) in C. parvum-negative samples. CSpV1 samples detected in the same farm were clustered together. To the best of our knowledge, this is the first study to report the prevalence and molecular characteristics of CSpV1 in Hanwoo calves in the Republic of Korea, providing important insights into the relationship between C. parvum and CSpV1 in bovine hosts. [ABSTRACT FROM AUTHOR]

Published
2023
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17. A mutagenic study of functional and structural aspects of rat insulin-like growth factor binding protein-5

Author

Song, Hyuk

Subjects
572.8, Apoptosis, Mammary epithelial cells
Abstract

On going research in our laboratory is focussed on the potential role of Insulin-like growth factor binding protein-5 (IGFBP-5) in apoptosis of mammary epithelial cells. In order to increase our understanding of IGFBP-5 functions, the work described below focussed on the relationship between the structure of the binding protein and its important molecular interactions. Using site-directed mutagenesis, we have mutated two highly conserved amino acids, Gly203 and Gln209 (G203K and Q209A respectively) within the basic amino acid rich region (201- 218) in the C-terminal domain of rat IGFBP-5. After analysis of binding activity using three different methods - IGF ligand blotting, IGF solution phase equilibrium binding and biosensor measurement - we have shown that the mutation of either of these two residues results in a reduction in affinity of the binding protein for both IGF-I and IGF-II by approximately ten-fold. Furthermore, mutation of both amino acids (G203K/Q209A, termed the Double mutant) had a cumulative effect and results in the complete ablation of IGF-I binding and a several thousand-fold reduction in IGF-II binding. This reduction in IGF binding affinity was comparable to that observed for the C-terminally truncated mutant BP550 (residues 1-168), which suggests that Gly203 and Gln209 may be the major determinants for IGF binding in the C-terminal domain. In addition, using heparin ligand blots, we confirm that mutation of basic residues within the C-terminal 201- 218 region (Hep- mutant: R201L, K202E, K206Q and R214A) results in major attenuation of heparin binding, whereas the G203K and Q209A single mutants and the Double mutant have no reduction in heparin binding. Therefore, our data suggests a potential overlap of heparin- and IGF- binding domains in the C-terminal region of IGFBP-5, and based on this, we discuss a potential model to explain the observed lower IGF binding affinity of ECM-bound IGFBP-5. In an attempt to assess the separate contribution of the N- and C-terminal domains to IGF binding, we also made four chimeric IGFBP cDNAs, BP552, BP522, BP255 and BP225, by switching domains between rat IGFBP-5 and rat IGFBP-2. We were consistently unable to detect expression of BP225 protein in the baculovirus/insect cell system, so this chimera had to be excluded from further study. Recognition of BP552 and BP522 proteins by both anti-rat IGFBP-5 and anti-rat IGFBP-2 antisera confirms their identity as chimeric proteins made up of domains from the native binding proteins, while BP255 was only recognised by the anti-rat IGFBP-5. The IGF binding properties of unpurified BP552, BP522 and BP255 proteins were assessed by IGF ligand blotting and IGF solution phase binding assays. These experiments demonstrated that BP552 and BP522 had comparable affinities with native IGFBP, whereas we were unable to detect any binding of BP255 to IGF-I by either technique, and only very weak interaction with IGF-II. Purified BP552 and BP522 were also tested by biosensor analysis, and data confirmed the results from the previous experiments. From this we can conclude that the N-terminal domain of IGFBP-5 can co-operate with the C-terminal domain of IGFBP-2 to produce a high affinity IGF binding species, irrespective of which central domain is present, whereas preliminary evidence would suggest that this cooperation may not occur between the N-terminal domain of IGFBP-2 and the C-terminal domain of lGFBP-5. In addition to IGF binding, the IGFBP-5 protein contains consensus heparin binding motifs in both its C-terminal and central domains, although only the C-terminal site was previously shown to be functional. Using heparin ligand blotting, it was found that the ability of BP552 and BP550 to bind to heparin was equivalent to that of WTIGFBP-5, whereas WTIGFBP-2 and BP522 failed to bind. These results demonstrate that an active heparin binding site in BP552 and BP550 is contained within the central domain of IGFBP-5, and that this site is only active in the absence of the carboxy-terminal domain. We subsequently mutated two basic amino acids (RI36A:R137A) in the central consensus binding sites between residues 132-140. This resulted in the loss of heparin binding for BP550, confirming the importance of these two basic amino acids in the central domain heparin binding activity. In light of these findings, we suggest that C-terminally truncated fragments of IGFBP-5 generated in vivo by proteolysis could retain heparin/extracellular matrix (ECM) binding properties. Finally, we propose that our various IGFBP-5 mutants described above provide an opportunity to test the structure-function relationships of this binding protein in an appropriate biological context.

Published
2001

34. Effective Healing of Staphylococcus aureus -Infected Wounds in Pig Cathelicidin Protegrin-1-Overexpressing Transgenic Mice.

Author

Soundrarajan, Nagasundarapandian, Somasundaram, Prathap, Kim, Dohun, Cho, Hye-Sun, Jeon, Hyoim, Ahn, Byeonyong, Kang, Mingue, Song, Hyuk, and Park, Chankyu

Subjects
TRANSGENIC mice, MICE, HEALING, WOUND healing, ANTIMICROBIAL peptides, WOUNDS & injuries, CELL migration, STAPHYLOCOCCUS aureus
Abstract

Antimicrobial peptides (AMPs) are promising alternatives to existing treatments for multidrug-resistant bacteria-infected wounds. Therefore, the effect of protegrin-1 (PG1), a potent porcine AMP with broad-spectrum activity, on wound healing was evaluated. PG1-overexpressing transgenic mice were used as an in vivo model to evaluate its healing efficiency against Staphylococcus aureus-infected (106 colony forming units) wounds. We analyzed the wounds under four specific conditions in the presence or absence of antibiotic treatment. We observed the resolution of bacterial infection and formation of neo-epithelium in S. aureus-infected wounds of the mice, even without antibiotic treatment, whereas all wild-type mice with bacterial infection died within 8 to 10 days due to uncontrolled bacterial proliferation. Interestingly, the wound area on day 7 was smaller (p < 0.01) in PG1 transgenic mice than that in the other groups, including antibiotic-treated mice, suggesting that PG1 exerts biological effects other than bactericidal effect. Additionally, we observed that the treatment of primary epidermal keratinocytes with recombinant PG1 enhanced cell migration in in vitro scratch and cell migration assays. This study contributes to the understanding of broad-spectrum endogenous cathelicidins with potent antimicrobial activities, such as PG1, on wound healing. Furthermore, our findings suggest that PG1 is a potent therapeutic candidate for wound healing. [ABSTRACT FROM AUTHOR]

Published
2023
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42. Models and Molecular Markers of Spermatogonial Stem Cells in Vertebrates: To Find Models in Nonmammals

Author

Song, Hyuk, Park, Hyun-Jung, Lee, Won-Young, and Lee, Kyung Hoon

Subjects
endocrine system, integumentary system, Article Subject, skin and connective tissue diseases
Abstract

Spermatogonial stem cells (SSCs) are the germline stem cells that are essential for the maintenance of spermatogenesis in the testis. However, it has not been sufficiently understood in amphibians, reptiles, and fish because numerous studies have been focused mainly on mammals. The aim of this review is to discuss scientific ways to elucidate SSC models of nonmammals in the context of the evolution of testicular organization since rodent SSC models. To further understand the SSC models in nonmammals, we point out common markers of an SSC pool (undifferentiated spermatogonia) in various types of testes where the kinetics of the SSC pool appears. This review includes the knowledge of (1) common molecular markers of vertebrate type A spermatogonia including putative SSC markers, (2) localization of the markers on the spermatogonia that have been reported in previous studies, (3) highlighting the most common markers in vertebrates, and (4) suggesting ways of finding SSC models in nonmammals.

Published
2022
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48. INO80 Is Required for the Cell Cycle Control, Survival, and Differentiation of Mouse ESCs by Transcriptional Regulation.

Author

Yoo, Seonho, Lee, Eun Joo, Thang, Nguyen Xuan, La, Hyeonwoo, Lee, Hyeonji, Park, Chanhyeok, Han, Dong Wook, Uhm, Sang Jun, Song, Hyuk, Do, Jeong Tae, Choi, Youngsok, and Hong, Kwonho

Subjects
CELL cycle, CELL cycle regulation, GENETIC transcription regulation, EMBRYONIC stem cells, SOMATIC cells, MORPHOGENESIS
Abstract

Precise regulation of the cell cycle of embryonic stem cells (ESCs) is critical for their self-maintenance and differentiation. The cell cycle of ESCs differs from that of somatic cells and is different depending on the cell culture conditions. However, the cell cycle regulation in ESCs via epigenetic mechanisms remains unclear. Here, we showed that the ATP-dependent chromatin remodeler Ino80 regulates the cell cycle genes in ESCs under primed conditions. Ino80 loss led to a significantly extended length of the G1-phase in ESCs grown under primed culture conditions. Ino80 directly bound to the transcription start site and regulated the expression of cell cycle-related genes. Furthermore, Ino80 loss induced cell apoptosis. However, the regulatory mechanism of Ino80 in differentiating ESC cycle slightly differed; an extended S-phase was detected in differentiating inducible Ino80 knockout ESCs. RNA-seq analysis of differentiating ESCs revealed that the expression of genes associated with organ development cell cycle is persistently altered in Ino80 knockout cells, suggesting that cell cycle regulation by Ino80 is not limited to undifferentiated ESCs. Therefore, our study establishes the function of Ino80 in ESC cycle via transcriptional regulation, at least partly. Moreover, this Ino80 function may be universal to other cell types. [ABSTRACT FROM AUTHOR]

Published
2022
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49. Cisplatin Induces Apoptosis in Mouse Neonatal Testes Organ Culture.

Author

Park, Hyun-Jung, Kim, Ji-Soo, Lee, Ran, and Song, Hyuk

Subjects
ORGAN culture, SERTOLI cells, TESTIS, CISPLATIN, SPERMATOGENESIS, GENE expression, GERM cells
Abstract

Chemotherapy is used for childhood cancer but may lead to infertility in patients. Spermatogonia stem cells are present in the testes of prepubertal boys, although they do not produce sperm at this age. Herein, we evaluated the toxicity of cisplatin, a known medicine for cancer treatment, in neonatal mouse testes using in vitro organ culture. Mouse testicular fragments (MTFs) derived from 5.5-d postpartum mouse testes were exposed to 1–10 μg/mL cisplatin. The results showed that cisplatin significantly downregulated the expression of germ cell marker genes, including differentiated and undifferentiated, in a dose-dependent manner. In particular, a high dose of cisplatin (10 μg/mL) led to germ cell depletion. In addition, the expression levels of the Sertoli cell marker gene, the number of SOX9+ Sertoli cells, and the levels of SOX9 protein were markedly decreased in cisplatin-treated MTFs compared to controls. The mRNA expression of steroidogenic enzyme-related genes significantly increased in cisplatin-treated MTFs, except for estrogen receptor 1 (Esr1). Consistently, 3β-hydroxysteroid dehydrogenase protein was also observed in the interstitial regions of cisplatin-treated MTFs. Altogether, our findings showed a significant impairment in germ cell development, Sertoli cell survival, and steroidogenesis in the MTFs of cisplatin-treated mice. [ABSTRACT FROM AUTHOR]

Published
2022
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