1.Pattern-VEP in Child Amblyopia.
Sung Jin LEE ; Songhee PARK ; Hanho SHIN
Journal of the Korean Ophthalmological Society 1995;36(6):924-929
We assessed the potential clinical usefulness of pattern-visual evoked potentials (=PVEP) in the diagnosis of amblyopia. 15 children with bilateral amblyopia, 64 children with unilateral amblyopia and 11 children without amblyopia participated. After estimating of visual acuity for each eye. PVEP were also obtained. Of the 15 bilateral amblyopic children 12 (80%) showed abnormally lower amplitudes than normal children and amplitudes of the rest 3 patients were in normal range and their visual acuity were relatively upper range, 0.5-0.6. Of the 64 unilateral amblyopic children 4 of 9(44.4%) children who had 2 line difference of interocular visual acuity, 2 of 3(67.7%) children who had 3 line difference and all children except 1 who had 4 or more line difference(99.9%) showed abnormal interocular amplitude difference ratio(=IADR). As a result, bilateral and unilateral amblyopia can be identified by PVEP amplitude and IADR and abnormal IADR shows that interocular visual acuity differences is over 3-4 lines. We thought that PVEP could be used to find the amblyopic eye and monitor the effect of treatment in preverbal children also.
Amblyopia*
;
Child*
;
Diagnosis
;
Evoked Potentials
;
Humans
;
Reference Values
;
Visual Acuity
2.Pneumatic Displacement of Submacular Hemorrhage with Intravitreal Injection of SF6 Gas without Tissue Plasminogen Activator.
Yong Suk AHN ; Sung Jin LEE ; Songhee PARK
Journal of the Korean Ophthalmological Society 2003;44(12):2811-2815
PURPOSE: To assess the efficacy and safety of intravitreal injection of SF6 gas for the displacement of submacular hemorrhage without use of tissue plasminogen activator (tPA) METHODS: Three hundred microliter of pure SF6 gas 0.3 ml was injected into the vitreous cavity in 9 eyes with submacular hemorrhage involving the fovea because of myopic degeneration (3 eyes), trauma (3 eyes), age-related macular degeneration (2 eyes), macroaneurysm (1 eyes), branch retinal vein occlusion (1 eyes) and myopic degeneration (2 eyes) within 4 weeks after the onset of symptoms. The patients were instructed to maintain a prone position for less than 7 days. RESULTS: Initial visual acuity was ranged from hand motion to 0.2 and visual improvement was found in 7 eyes on the 7th day after the gas injection. On the 7th day after the gas injection, submacular hemorrhage was completely displaced in 2 eyes and slightly displaced with a reduction in the thickness of hemorrhage in 2 eyes. Transient elevation of intraocular pressure occured in 1 eye and was successfully controlled with medications. CONCLUSIONS: Intravitreal SF6 gas injection is simple and can displace submacular hemorrhage without use of tissue plasminogen activator in many cases with no serious complications.
Hand
;
Hemorrhage*
;
Humans
;
Intraocular Pressure
;
Intravitreal Injections*
;
Macular Degeneration
;
Prone Position
;
Retinal Vein Occlusion
;
Tissue Plasminogen Activator*
;
Visual Acuity
3.Functional Significance of Cytochrome P450 1A2 Allelic Variants, P450 1A2*8, *15, and *16 (R456H, P42R, and R377Q).
Young Ran LIM ; In Hyeok KIM ; Songhee HAN ; Hyoung Goo PARK ; Mi Jung KO ; Young Jin CHUN ; Chul Ho YUN ; Donghak KIM
Biomolecules & Therapeutics 2015;23(2):189-194
P450 1A2 is responsible for the metabolism of clinically important drugs and the metabolic activation of environmental chemicals. Genetic variations of P450 1A2 can influence its ability to perform these functions, and thus, this study aimed to characterize the functional significance of three P450 1A2 allelic variants containing nonsynonymous single nucleotide polymorphisms (P450 1A2*8, R456H; *15, P42R; *16, R377Q). Variants containing these SNPs were constructed and the recombinant enzymes were expressed and purified in Escherichia coli. Only the P42R variant displayed the typical CO-binding spectrum indicating a P450 holoenzyme with an expression level of approximately 170 nmol per liter culture, but no P450 spectra were observed for the two other variants. Western blot analysis revealed that the level of expression for the P42R variant was lower than that of the wild type, however the expression of variants R456H and R377Q was not detected. Enzyme kinetic analyses indicated that the P42R mutation in P450 1A2 resulted in significant changes in catalytic activities. The P42R variant displayed an increased catalytic turnover numbers (k(cat)) in both of methoxyresorufin O-demethylation and phenacetin O-deethylation. In the case of phenacetin O-deethylation analysis, the overall catalytic efficiency (k(cat)/K(m)) increased up to 2.5 fold with a slight increase of its K(m) value. This study indicated that the substitution P42R in the N-terminal proline-rich region of P450 contributed to the improvement of catalytic activity albeit the reduction of P450 structural stability or the decrease of substrate affinity. Characterization of these polymorphisms should be carefully examined in terms of the metabolism of many clinical drugs and environmental chemicals.
Biotransformation
;
Blotting, Western
;
Cytochrome P-450 CYP1A2*
;
Escherichia coli
;
Genetic Variation
;
Metabolism
;
Phenacetin
;
Polymorphism, Single Nucleotide
4.AMPA, not NMDA, activates RhoA GTPases and subsequetly phosphorylates moesin.
Su Jin KIM ; Songhee JEON ; Eun Young SHIN ; Eung Gook KIM ; Joobae PARK ; Chang Dae BAE
Experimental & Molecular Medicine 2004;36(1):98-102
Glutamate induced rapid phosphorylation of moesin, one of ERM family proteins involved in the ligation of membrane to actin cytoskeleton, in rat hippocampal cells (JBC, 277:16576-16584, 2002). However, the identity of glutamate receptor has not been explored. Here we show that a-amino- 3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor is responsible for glutamate-induced RhoA activation and phosphorylation of moesin. Glutamate induced phosphorylation at Thr-558 of moesin was still detectible upon chelation of Ca(2+), suggesting involvement of AMPA receptor instead of N-methyl D-Aspartate (NMDA) receptor in this phosphorylation of moesin. AMPA but not NMDA- induced moesin phosphorylation was independent of Ca(2+). Both AMPA and NMDA but not Kainate induced moesin phosphorylation at similar levels. However, the kinetics of phosphorylation varied greatly between AMPA and NMDA where AMPA treatment rapidly increased phosphomoesin, which reached a maximum at 10 min after treatment and returned to a basal level at 30 min. In contrast, NMDA-induced phosphorylation of moesin reached a maximum at 30 min after treatment and was remained at higher levels at 60 min. A possible involvement of RhoA and its downstream effector, Rho kinase in the AMPA receptor-triggered phosphorylation of moesin was also explored. The kinetics for the glutamate- induced membrane translocation of RhoA was similar to that of moesin phosphorylation induced by AMPA. Moreover, Y-27632, a specific Rho kinase inhibitor, completely blocked AMPA-induced moesin phosphorylation but had no effect on NMDA-induced moesin phosphorylation. These results suggest that glutamate-induced phosphorylation of moesin may be mediated through the AMPA receptor/RhoA/Rho kinase pathway.
Animals
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Calcium/metabolism
;
Cell Line
;
Excitatory Amino Acid Agonists/*metabolism
;
Glutamic Acid/metabolism
;
Kainic Acid/metabolism
;
Microfilament Proteins/*metabolism
;
N-Methylaspartate/*metabolism
;
Phosphorylation
;
Protein-Serine-Threonine Kinases/metabolism
;
Rats
;
Receptors, AMPA/metabolism
;
Receptors, N-Methyl-D-Aspartate/metabolism
;
Research Support, Non-U.S. Gov't
;
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/*metabolism
;
rhoA GTP-Binding Protein/*metabolism
5.Characterization of a Biflaviolin Synthase CYP158A3 from Streptomyces avermitilis and Its Role in the Biosynthesis of Secondary Metabolites.
Young Ran LIM ; Songhee HAN ; Joo Hwan KIM ; Hyoung Goo PARK ; Ga Young LEE ; Thien Kim LE ; Chul Ho YUN ; Donghak KIM
Biomolecules & Therapeutics 2017;25(2):171-176
Streptomyces avermitilis produces clinically useful drugs such as avermectins and oligomycins. Its genome contains approximately 33 cytochrome P450 genes and they seem to play important roles in the biosynthesis of many secondary metabolites. The SAV_7130 gene from S. avermitilis encodes CYP158A3. The amino acid sequence of this enzyme has high similarity with that of CYP158A2, a biflaviolin synthase from S. coelicolor A3(2). Recombinant S. avermitilis CYP158A3 was heterologously expressed and purified. It exhibited the typical P450 Soret peak at 447 nm in the reduced CO-bound form. Type I binding spectral changes were observed when CYP158A3 was titrated with myristic acid; however, no oxidative product was formed. An analog of flaviolin, 2-hydroxynaphthoquinone (2-OH NQ) displayed similar type I binding upon titration with purified CYP158A3. It underwent an enzymatic reaction forming dimerized product. A homology model of CYP158A3 was superimposed with the structure of CYP158A2, and the majority of structural elements aligned. These results suggest that CYP158A3 might be an orthologue of biflaviolin synthase, catalyzing C-C coupling reactions during pigment biosynthesis in S. avermitilis.
Amino Acid Sequence
;
Cytochrome P-450 Enzyme System
;
Genome
;
Myristic Acid
;
Oligomycins
;
Streptomyces*
6.MPTP-induced vulnerability of dopamine neurons in A53T α-synuclein overexpressed mice with the potential involvement of DJ-1 downregulation.
Seongmi LEE ; Seung Tack OH ; Ha Jin JEONG ; Sok Cheon PAK ; Hi Joon PARK ; Jongpil KIM ; Hyun Seok CHO ; Songhee JEON
The Korean Journal of Physiology and Pharmacology 2017;21(6):625-632
Familial Parkinson's disease (PD) has been linked to point mutations and duplication of the α-synuclein (α-syn) gene. Mutant α-syn expression increases the vulnerability of neurons to exogenous insults. In this study, we developed a new PD model in the transgenic mice expressing mutant hemizygous (hemi) or homozygous (homo) A53T α-synuclein (α-syn Tg) and their wildtype (WT) littermates by treatment with sub-toxic (10 mg/kg, i.p., daily for 5 days) or toxic (30 mg/kg, i.p., daily for 5 days) dose of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Tyrosine hydroxylase and Bcl-2 levels were reduced in the α-syn Tg but not WT mice by sub-toxic MPTP injection. In the adhesive removal test, time to remove paper was significantly increased only in the homo α-syn Tg mice. In the challenging beam test, the hemi and homo α-syn Tg mice spent significantly longer time to traverse as compared to that of WT group. In order to find out responsible proteins related with vulnerability of mutant α-syn expressed neurons, DJ-1 and ubiquitin enzyme expressions were examined. In the SN, DJ-1 and ubiquitin conjugating enzyme, UBE2N, levels were significantly decreased in the α-syn Tg mice. Moreover, A53T α-syn overexpression decreased DJ-1 expression in SH-SY5Y cells. These findings suggest that the vulnerability to oxidative injury such as MPTP of A53T α-syn mice can be explained by downregulation of DJ-1.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
;
Adhesives
;
Animals
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Apoptosis
;
Dopamine*
;
Dopaminergic Neurons*
;
Down-Regulation*
;
Hominidae
;
Humans
;
Mice*
;
Mice, Transgenic
;
Neurons
;
Parkinson Disease
;
Point Mutation
;
Synucleins
;
Tyrosine 3-Monooxygenase
;
Ubiquitin
7.Atomoxetine and Fluoxetine Activate AMPK-ACC-CPT1 Pathway in Human SH-SY5Y and U-87 MG Cells
Songhee JEON ; Jeong-Eun PARK ; Young Ho DO ; Renata SANTOS ; Seong Mi LEE ; Byung-Nyun KIM ; Jae Hoon CHEONG ; Yeni KIM
Psychiatry Investigation 2023;20(3):212-219
Objective:
Atomoxetine and fluoxetine are psychopharmacologic agents associated with loss of appetite and weight. Adenosine monophosphate-activated protein kinase (AMPK) is the cellular energy sensor that regulate metabolism and energy, being activated by fasting and inhibited by feeding in the hypothalamus.
Methods:
Human brain cell lines (SH-SY5Y and U-87 MG cells) were used to study the outcome of atomoxetine and fluoxetine treatment in the activity of AMPK-acetyl-CoA carboxylase (ACC)- carnitine palmitoyl transferase 1 (CPT1) pathway and upstream regulation by calcium/calmodulin-dependent kinase kinase β (CaMKKβ) using immunoblotting and CPT1 enzymatic activity measures.
Results:
Phosphorylation of AMPK and ACC increased significantly after atomoxetine and fluoxetine treatment in the first 30–60 minutes of treatment in the two cell lines. Activation of AMPK and inhibition of ACC was associated with an increase by 5-fold of mitochondrial CPT1 activity. Although the neuronal isoform CPT1C could be detected by immunoblotting, activity was not changed by the drug treatments. In addition, the increase in phospho-AMPK and phospho-ACC expression induced by atomoxetine was abolished by treatment with STO-609, a CaMKKβ inhibitor, indicating that AMPK-ACC-CPT1 pathway is activated through CaMKKβ phosphorylation.
Conclusion
These findings indicate that at the cellular level atomoxetine and fluoxetine treatments may activate AMPK-ACC-CPT1 pathways through CaMKKβ in human SH-SY5Y and U-87 MG cells.
8.Fabry disease exacerbates renal interstitial fibrosis after unilateral ureteral obstruction via impaired autophagy and enhanced apoptosis
Sungjin CHUNG ; Mina SON ; Yura CHAE ; Songhee OH ; Eun Sil KOH ; Yong Kyun KIM ; Seok Joon SHIN ; Cheol Whee PARK ; Sung-Chul JUNG ; Ho-Shik KIM
Kidney Research and Clinical Practice 2021;40(2):208-219
Background:
Fabry disease is a rare X-linked genetic lysosomal disorder caused by mutations in the GLA gene encoding alpha-galactosidase A. Despite some data showing that profibrotic and proinflammatory cytokines and oxidative stress could be involved in Fabry disease-related renal injury, the pathogenic link between metabolic derangement within cells and renal injury remains unclear.
Methods:
Renal fibrosis was triggered by unilateral ureteral obstruction (UUO) in mice with Fabry disease to investigate the pathogenic mechanism leading to fibrosis in diseased kidneys.
Results:
Compared to kidneys of wild-type mice, lamellar inclusion bodies were recognized in proximal tubules of mice with Fabry disease. Sirius red and trichrome staining revealed significantly increased fibrosis in all UUO kidneys, though it was more prominent in obstructed Fabry kidneys. Renal messenger RNA levels of inflammatory cytokines and profibrotic factors were increased in all UUO kidneys compared to sham-operated kidneys but were not significantly different between UUO control and UUO Fabry mice. Protein levels of Nox2, Nox4, NQO1, catalase, SOD1, SOD2, and Nrf2 were not significantly different between UUO control and UUO Fabry kidneys, while the protein contents of LC3-II and LC3-I and expression of Beclin1 were significantly decreased in UUO kidneys of Fabry disease mouse models compared with wild-type mice. Notably, TUNEL-positive cells were elevated in obstructed kidneys of Fabry disease mice compared to wild-type control and UUO mice.
Conclusion
These findings suggest that impaired autophagy and enhanced apoptosis are probable mechanisms involved in enhanced renal fibrosis under the stimulus of UUO in Fabry disease.
9.Fabry disease exacerbates renal interstitial fibrosis after unilateral ureteral obstruction via impaired autophagy and enhanced apoptosis
Sungjin CHUNG ; Mina SON ; Yura CHAE ; Songhee OH ; Eun Sil KOH ; Yong Kyun KIM ; Seok Joon SHIN ; Cheol Whee PARK ; Sung-Chul JUNG ; Ho-Shik KIM
Kidney Research and Clinical Practice 2021;40(2):208-219
Background:
Fabry disease is a rare X-linked genetic lysosomal disorder caused by mutations in the GLA gene encoding alpha-galactosidase A. Despite some data showing that profibrotic and proinflammatory cytokines and oxidative stress could be involved in Fabry disease-related renal injury, the pathogenic link between metabolic derangement within cells and renal injury remains unclear.
Methods:
Renal fibrosis was triggered by unilateral ureteral obstruction (UUO) in mice with Fabry disease to investigate the pathogenic mechanism leading to fibrosis in diseased kidneys.
Results:
Compared to kidneys of wild-type mice, lamellar inclusion bodies were recognized in proximal tubules of mice with Fabry disease. Sirius red and trichrome staining revealed significantly increased fibrosis in all UUO kidneys, though it was more prominent in obstructed Fabry kidneys. Renal messenger RNA levels of inflammatory cytokines and profibrotic factors were increased in all UUO kidneys compared to sham-operated kidneys but were not significantly different between UUO control and UUO Fabry mice. Protein levels of Nox2, Nox4, NQO1, catalase, SOD1, SOD2, and Nrf2 were not significantly different between UUO control and UUO Fabry kidneys, while the protein contents of LC3-II and LC3-I and expression of Beclin1 were significantly decreased in UUO kidneys of Fabry disease mouse models compared with wild-type mice. Notably, TUNEL-positive cells were elevated in obstructed kidneys of Fabry disease mice compared to wild-type control and UUO mice.
Conclusion
These findings suggest that impaired autophagy and enhanced apoptosis are probable mechanisms involved in enhanced renal fibrosis under the stimulus of UUO in Fabry disease.
10.Intranasal Administration of Melanin-Concentrating Hormone Reduces Stress-Induced Anxiety- and Depressive-Like Behaviors in Rodents
Ju-Young OH ; Quan Feng LIU ; Cai HUA ; Ha Jin JEONG ; Jae-Hwan JANG ; Songhee JEON ; Hi-Joon PARK
Experimental Neurobiology 2020;29(6):453-469
Major depressive disorder is a complex neuropsychiatric disorder with few treatment options. Non-targeted antidepressants have low efficacy and can induce series of side effects. While a neuropeptide, melanin-concentrating hormone (MCH), is known to exhibit regulator of affective state, no study to date has assessed the anti-depressive effects of MCH in a stress-induced depression model. This study aimed to evaluate the pharmacological effects of intranasal administration of MCH on depression-related behavior in stressed rats and mice. Using a number of behavioral tests, we found that MCH treatment significantly decreased anxiety- and depressive-like behaviors induced by stress. Notably, the effects of MCH were equivalent to those of fluoxetine. MCH treatment also restored the activity of the mammalian target of rapamycin (mTOR) signaling pathway and normalized the levels of synaptic proteins, including postsynaptic density 95, glutamate receptor 1, and synapsin 1, which were all downregulated by stress. Interestingly, the protective effects of MCH were blocked by the mTOR inhibitor, rapamycin. These results suggest that MCH exhibits antidepressant properties by modulating the mTOR pathway. Altogether, this study provides an insight into the molecular mechanisms involved in the antidepressant-like effects of MCH, thereby paving the way for the future clinical application of MCH.