Hak Sun Yu

Prof. Hak Sun Yu


Research Focus & Metrics

Academic Career Length

31Years (1996-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2005 in The Korean Journal of Parasitology
Verified
Journal Article
Open access
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HJHae Jin Jeong
Hae Jin Jeong
HYHak Sun Yu
Hak Sun Yu
Jeong HJ, et al. Korean J Parasitol. 2005 Jun;43(2):47-50. http://dx.doi.org/10.3347/kjp.2005.43.2.47

1 January 2011 in The Korean Journal of Parasitology
Verified
Journal Article
Open access
PDF file
SJSung Won Jang
Sung Won Jang
MCMin Kyoung Cho
Min Kyoung Cho
MPMi Kyung Park
Mi Kyung Park
SKShin Ae Kang
Shin Ae Kang
BNByoung-Kuk Na
Byoung-Kuk Na
HYHak Sun Yu
Hak Sun Yu
Many immune down-regulatory molecules have been isolated from parasites, including cystatin (cystain protease inhibitor). In a previous study, we isolated and characterized Type I cystatin (CsStefin-1) of the liver fluke, Clonorchis sinensis. To investigate whether the CsStefin-1 might be a new host immune modulator, we induced intestinal inflammation in mice by dextran sodium sulfate (DSS) and treated them with recombinant CsStefin-1 (rCsStefin-1). The disease activity index (DAI) increased in DSS only-treated mice. In contrast, the DAI value was significantly reduced in rCsStefin-1-treated mice than DSS only-treated mice. In addition, the colon length of DSS only-treated mice was shorter than that of rCsStefin-1 treated mice. The secretion levels of IFN-γ and TNF-α in the spleen and mesenteric lymph nodes (MLNs) were significantly increased by DSS treatment, but the level of TNF-α in MLNs was significantly decreased by rCsStefin-1 treatment. IL-10 production in both spleen and MLNs was significantly increased, and IL-10(+)F4/80(+) macrophage cells were significantly increased in the spleen and MLNs of rCsStefin-1 treated mice after DSS treatment. In conclusion, rCsStefin-1 could reduce the intestinal inflammation occurring after DSS treatment, these effects might be related with recruitment of IL-10 secreting macrophages.

1 June 2012 in Molecular and Biochemical Parasitology
Verified
Journal Article
Closed access
SSSu-Min Song
Su-Min Song
BHByung-In Han
Byung-In Han
EMEun-Kyung Moon
Eun-Kyung Moon
YLYu-Ran Lee
Yu-Ran Lee
HYHak Sun Yu
Hak Sun Yu
YHYeonchul Hong
Yeonchul Hong

8 April 2011 in Parasite Immunology
Verified
Journal Article
Closed access
PDF file
MCM. K. Cho
M. K. Cho
CLC. H. Lee
C. H. Lee
HYHak Sun Yu
Hak Sun Yu

25 April 2019 in Scientific Reports
Verified
Journal Article
Open access
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SKShin Ae Kang
Shin Ae Kang
MPMi-Kyung Park
Mi-Kyung Park
SPSang Kyun Park
Sang Kyun Park
JCJun Ho Choi
Jun Ho Choi
DLDa In Lee
Da In Lee
HYHak Sun Yu
Hak Sun Yu
Trichinella spiralisis a zoonotic nematode and food borne parasite and infection withT.spiralisleads to suppression of the host immune response and other immunopathologies. Alternative activated macrophages (M2) as well as Tregcells, a target for immunomodulation by the helminth parasite, play a critical role in initiating and modulating the host immune response to parasite. The precise mechanism by which helminths modulate host immune response is not fully understood. To determine the functions of parasite-induced M2 macrophages, we compared the effects of M1 and M2 macrophages obtained fromTrichinella spiralis-infected mice with those ofT.spiralisexcretory/secretory (ES) protein-treated macrophages on experimental intestinal inflammation and allergic airway inflammation.T.spiralisinfection induced M2 macrophage polarization by increasing the expression of CD206,ARG1, andFizz2. In a single application, we introduced macrophages obtained fromT.spiralis-infected mice andT.spiralisES protein-treated macrophages into mice tail veins before the induction of dextran sulfate sodium (DSS)-induced colitis, ovalbumin (OVA)-alum sensitization, and OVA challenge. Colitis severity was assessed by determining the severity of colitis symptoms, colon length, histopathologic parameters, and Th1-related inflammatory cytokine levels. Compared with the DSS-colitis group,T.spiralis-infected mice andT.spiralisES protein-treated macrophages showed significantly lower disease activity index (DAI) at sacrifice and smaller reductions of body weight and proinflammatory cytokine level. The severity of allergic airway inflammation was assessed by determining the severity of symptoms of inflammation, airway hyperresponsiveness (AHR), differential cell counts, histopathologic parameters, and levels of Th2-related inflammatory cytokines. Severe allergic airway inflammation was induced after OVA-alum sensitization and OVA challenge, which significantly increased Th2-related cytokine levels, eosinophil infiltration, and goblet cell hyperplasia in the lung. However, these severe allergic symptoms were significantly decreased inT. spiralis-infected mice andT. spiralisES protein-treated macrophages. Helminth infection and helminth ES proteins induce M2 macrophages. Adoptive transfer of macrophages obtained from helminth-infected mice and helminth ES protein-activated macrophages is an effective treatment for preventing and treating airway allergy in mice and is promising as a therapeutic for treating inflammatory diseases.

1 January 2010 in The Korean Journal of Parasitology
Verified
Journal Article
Closed access
PDF file
DKDong-Hee Kim
Dong-Hee Kim
HSHyun-Mi Son
Hyun-Mi Son
JKJoo Young Kim
Joo Young Kim
MCMin Kyoung Cho
Min Kyoung Cho
MPMee Kyung Park
Mee Kyung Park
HYHak Sun Yu
Hak Sun Yu
To know the prevalence of Enterobius vermicularis infection and what are the most important risk factors, we evaluated the incidence and risk factors of enterobiasis among children attended in kindergartens in Busan metropolitan city, Republic of Korea. A total of 1,674 children from 21 kindergartens in 11 of 16 autonomous districts of Busan were evaluated for E. vermicularis infection by the cellotape anal swab technique. The overall egg-positive rate for E. vermicularis was 10.7% (179/1,674), and the prevalence of enterobiasis in each kindergarten ranged between 0% and 32.4%. There was an increasing tendency of the egg positive rate according to the population density; the higher the population density communities had, the higher egg-positive rate for E. vermicularis was detected (P = 0.001). Among personal hygiene factors involving children, thumb-sucking (P = 0.036) and fingernail-trimming (P = 0.024) were highly associated with enterobiasis. In addition, taking anthelmintic medications against E. vermicularis infection was strongly associated with enterobiasis (P = 0.014). Moreover, parents' knowledge of enterobiasis was correlated significantly with the incidence of enterobiasis of their children (P = 0.006). In conclusion, we need to consider not only personal hygiene but also parents' knowledge about enterobiasis as a factor in order to develop new strategies for elimination or to complete reduction of enterobiasis in Korea.