Sungkun Chun

Prof. Sungkun Chun

Chonbuk National University
orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

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

Representative Publications

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1 August 2019 in BMC Infectious Diseases
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Journal Article
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SASu Jeong Ahn
Su Jeong Ahn
YBYun Hee Baek
Yun Hee Baek
KLKhristine Kaith S. Lloren
Khristine Kaith S. Lloren
WCWon-Suk Choi
Won-Suk Choi
JJJu Hwan Jeong
Ju Hwan Jeong
MSMin-Suk Song
Min-Suk Song
Background: In addition to seasonal influenza viruses recently circulating in humans, avian influenza viruses (AIVs) of H5N1, H5N6 and H7N9 subtypes have also emerged and demonstrated human infection abilities with high mortality rates. Although influenza viral infections are usually diagnosed using viral isolation and serological/molecular analyses, the cost, accessibility, and availability of these methods may limit their utility in various settings. The objective of this study was to develop and optimized a multiplex detection system for most influenza viruses currently infecting humans. Methods: We developed and optimized a multiplex detection system for most influenza viruses currently infecting humans including two type B (both Victoria lineages and Yamagata lineages), H1N1, H3N2, H5N1, H5N6, and H7N9 using Reverse Transcriptional Loop-mediated Isothermal Amplification (RT-LAMP) technology coupled with a one-pot colorimetric visualization system to facilitate direct determination of results without additional steps. We also evaluated this multiplex RT-LAMP for clinical use using a total of 135 clinical and spiked samples (91 influenza viruses and 44 other human infectious viruses). Results: We achieved rapid detection of seasonal influenza viruses (H1N1, H3N2, and Type B) and avian influenza viruses (H5N1, H5N6, H5N8 and H7N9) within an hour. The assay could detect influenza viruses with high sensitivity (i.e., from 100 to 0.1 viral genome copies), comparable to conventional RT-PCR-based approaches which would typically take several hours and require expensive equipment. This assay was capable of specifically detecting each influenza virus (Type B, H1N1, H3N2, H5N1, H5N6, H5N8 and H7N9) without cross-reactivity with other subtypes of AIVs or other human infectious viruses. Furthermore, 91 clinical and spiked samples confirmed by qRT-PCR were also detected by this multiplex RT-LAMP with 98.9% agreement. It was more sensitive than one-step RT-PCR approach (92.3%). Conclusions: Results of this study suggest that our multiplex RT-LAMP assay may provide a rapid, sensitive, cost-effective, and reliable diagnostic method for identifying recent influenza viruses infecting humans, especially in locations without access to large platforms or sophisticated equipment.

6 June 2014 in Science
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Journal Article
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SCSungkun Chun
Sungkun Chun
JWJoby J. Westmoreland
Joby J. Westmoreland
IBIldar T. Bayazitov
Ildar T. Bayazitov
DEDonnie Eddins
Donnie Eddins
APAmar K. Pani
Amar K. Pani
SZStanislav S. Zakharenko
Stanislav S. Zakharenko
Genes, synapses, and hallucinations: In a schizophrenia mouse model, Chun et al. found that an abnormal increase of dopamine D2 receptors in the brain's thalamic nuclei caused thalamocortical synapse deficits owing to reduced glutamate release. Antipsychotic agents or a dopamine receptor antagonist reversed this down-regulation. The defect was associated with the loss of a component of the microRNA processing machinery encoded by the dgcr8 gene. Science , this issue p. 1178

29 May 2018 in ACS Applied Materials & Interfaces
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Journal Article
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Arjun TiwariArjun Tiwari
Arjun Tiwari
THTae In Hwang
Tae In Hwang
JOJung-Mi Oh
Jung-Mi Oh
BMBikendra Maharjan
Bikendra Maharjan
SCSungkun Chun
Sungkun Chun
CKCheol Sang Kim
Cheol Sang Kim

24 April 2013 in Journal of Neuroscience
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Journal Article
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SCSungkun Chun
Sungkun Chun
IBIldar T. Bayazitov
Ildar T. Bayazitov
JBJay A. Blundon
Jay A. Blundon
SZStanislav S. Zakharenko
Stanislav S. Zakharenko
Cortical maps in sensory cortices are plastic, changing in response to sensory experience. The cellular site of such plasticity is currently debated. Thalamocortical (TC) projections deliver sensory information to sensory cortices. TC synapses are currently dismissed as a locus of cortical map plasticity because TC synaptic plasticity is thought to be limited to neonates, whereas cortical map plasticity can be induced in both neonates and adults. However, in the auditory cortex (ACx) of adults, cortical map plasticity can be induced if animals attend to a sound or receive sounds paired with activation of cholinergic inputs from the nucleus basalis. We now show that, in the ACx, long-term potentiation (LTP), a major form of synaptic plasticity, is expressed at TC synapses in both young and mature mice but becomes gated with age. Using single-cell electrophysiology, two-photon glutamate uncaging, and optogenetics in TC slices containing the auditory thalamus and ACx, we show that TC LTP is expressed postsynaptically and depends on group I metabotropic glutamate receptors. TC LTP in mature ACx can be unmasked by cortical disinhibition combined with activation of cholinergic inputs from the nucleus basalis. Cholinergic inputs passing through the thalamic radiation activate M1muscarinic receptors on TC projections and sustain glutamate release at TC synapses via negative regulation of presynaptic adenosine signaling through A1adenosine receptors. These data indicate that TC LTP in the ACx persists throughout life and therefore can potentially contribute to experience-dependent cortical map plasticity in the ACx in both young and adult animals.

28 November 2016 in Nature Medicine
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SCSungkun Chun
Sungkun Chun
FDFei Du
Fei Du
JWJoby J Westmoreland
Joby J Westmoreland
SHSeung Baek Han
Seung Baek Han
YWYong-Dong Wang
Yong-Dong Wang
SZStanislav S. Zakharenko
Stanislav S. Zakharenko

Verified
Journal Article
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JOJUNG MI OH
JUNG MI OH
EKEunhee Kim
Eunhee Kim
SCSungkun Chun
Sungkun Chun
Autophagy can result in cellular adaptation, as well as cell survival or cell death. Modulation of autophagy is increasingly regarded as a promising cancer therapeutic approach. Ginsenoside compound K (CK), an active metabolite of ginsenosides isolated from Panax ginseng C.A. Meyer, has been identified to inhibit growth of cancer cell lines. However, the molecular mechanisms of CK effects on autophagy and neuroblastoma cell death have not yet been investigated. In the present study, CK inhibited neuroblastoma cell proliferation in vitro and in vivo. Treatment by CK also induced the accumulation of sub-G1 population, and caspase-dependent apoptosis in neuroblastoma cells. In addition, CK promotes autophagosome accumulation by inducing early-stage autophagy but inhibits autophagic flux by blocking of autophagosome and lysosome fusion, the step of late-stage autophagy. This effect of CK appears to be mediated through the induction of intracellular reactive oxygen species (ROS) and mitochondria membrane potential loss. Moreover, chloroquine, an autophagy flux inhibitor, further promoted CK-induced apoptosis, mitochondrial ROS induction, and mitochondria damage. Interestingly, those promoted phenomena were rescued by co-treatment with a ROS scavenging agent and an autophagy inducer. Taken together, our findings suggest that ginsenoside CK induced ROS-mediated apoptosis and autophagic flux inhibition, and the combination of CK with chloroquine, a pharmacological inhibitor of autophagy, may be a novel therapeutic potential for the treatment of neuroblastoma.