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18
result(s) for
"Im, Doo Soon"
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β2-Adrenoreceptor is a regulator of the α-synuclein gene driving risk of Parkinson’s disease
by
Im, Doo Soon
,
Heutink, Peter
,
Bartels, Tim
in
Acetylation
,
Adrenergic beta-1 Receptor Agonists - pharmacology
,
Adrenergic beta-Antagonists - pharmacology
2017
Copy number mutations implicate excess production of α-synuclein as a possibly causative factor in Parkinson’s disease (PD). Using an unbiased screen targeting endogenous gene expression, we discovered that the β2-adrenoreceptor (β2AR) is a regulator of the α-synuclein gene (SNCA). β2AR ligands modulate SNCA transcription through histone 3 lysine 27 acetylation of its promoter and enhancers. Over 11 years of follow-up in 4 million Norwegians, the β2AR agonist salbutamol, a brain-penetrant asthma medication, was associated with reduced risk of developing PD (rate ratio, 0.66; 95% confidence interval, 0.58 to 0.76). Conversely, a β2AR antagonist correlated with increased risk. β2AR activation protected model mice and patient-derived cells. Thus, β2AR is linked to transcription of α-synuclein and risk of PD in a ligand-specific fashion and constitutes a potential target for therapies.
Journal Article
Loss of Parkinson Disease Protein 7 (PARK7) upregulates ROS and cell migration and is associated with recurrent pregnancy loss
by
Jiang, Huanhuan
,
Im, Doo Soon
,
Kaushik, Gaurav
in
Abortion, Habitual - etiology
,
Abortion, Habitual - genetics
,
Abortion, Habitual - metabolism
2025
Background
Successful implantation is dependent on a synchronous dialogue between several proteins that act to control cellular dynamics including actin and microtubule reorganisation and cell motility. An impaired crosstalk can lead to complications including recurrent pregnancy loss (RPL) though the precise mechanisms remain unclear. Parkinson disease protein 7 (
PARK7
; encoding DJ-1), characterised for its participation in neurodegeneration, has emerged as a novel cytoskeletal and antioxidant regulator however, the role of DJ-1 in early pregnancy is unknown.
Methods
We employed systems biology approaches and functional studies in both human and murine models to examine the expression and role of DJ-1 during the window of implantation. LC–MS/MS proteomics analysis was conducted to identify proteins with differential expression between decidualized endometrial stromal cells (EnSC) with and without DJ-1 knockdown. Further, DJ-1 expression was manipulated using loss and gain of function strategies to investigate its impact on reactive oxygen species (ROS), the actin cytoskeleton and cellular motility. Lastly, knockdown of Palladin (a key actin regulator) and overexpression of Glutathione peroxidase 3 (GPX3) were used to investigate the downstream effects.
Results
Endometrial DJ-1 had the highest expression during the implantation window and loss of DJ-1 was associated with pregnancy loss in both humans and mice. The proteomics data revealed dysregulation of cytoskeletal protein, Palladin and antioxidant enzymes. Knockdown of DJ-1 using siRNA led to elevated ROS levels, increased actin polymerisation and resulted in increased cell motility towards aneuploidic signals. Conversely, DJ-1 overexpression led to the reversal of these effects. Moreover, knockdown of downstream target Palladin restored abnormal actin polymerization and prevented cell motility towards aneuploidic chemotactic signals. Further, overexpression of GPX3 mitigated ROS production and restored cell migration.
Conclusions
Taken together, our findings identified an unexpected function of the DJ-1-Palladin axis in the endometrium and its function as a redox-sensitive chaperone and in cytoskeleton remodelling and migration. Thus, uncoupling of this axis may result in adverse pregnancy complications including recurrent pregnancy loss.
Journal Article
Cdk5-mediated JIP1 phosphorylation regulates axonal outgrowth through Notch1 inhibition
2022
Background
Activated Cdk5 regulates a number of processes during nervous system formation, including neuronal differentiation, growth cone stabilization, and axonal growth. Cdk5 phosphorylates its downstream substrates located in axonal growth cones, where the highly expressed c-Jun N-terminal kinase (JNK)-interacting protein1 (JIP1) has been implicated as another important regulator of axonal growth. In addition, stringent control of the level of intracellular domain of Notch1 (Notch1-IC) plays a regulatory role in axonal outgrowth during neuronal differentiation. However, whether Cdk5-JIP1-Notch1 cooperate to regulate axonal outgrowth, and the mechanism of such joint contribution to this pathway, is presently unknown, and here we explore their potential interaction.
Results
Our interactome screen identified JIP1 as an interactor of p35, a Cdk5 activator, and we sought to explore the relationship between Cdk5 and JIP1 on the regulation of axonal outgrowth. We demonstrate that JIP1 phosphorylated by Cdk5 at Thr205 enhances axonal outgrowth and a phosphomimic JIP1 rescues the axonal outgrowth defects in JIP1
−/−
and p35
−/−
neurons. Axonal outgrowth defects caused by the specific increase of Notch1 in JIP1
−/−
neurons are rescued by Numb-mediated inhibition of Notch1. Finally, we demonstrate that Cdk5 phosphorylation of JIP1 further amplifies the phosphorylation status of yet another Cdk5 substrate E3-ubiquitin ligase Itch, resulting in increased Notch1 ubiquitination.
Conclusions
Our findings identify a potentially critical signaling axis involving Cdk5-JIP1-Itch-Notch1, which plays an important role in the regulation of CNS development. Future investigation into the way this pathway integrates with additional pathways regulating axonal growth will further our knowledge of normal central nervous system development and pathological conditions.
Journal Article
Timing dependent neuronal migration is regulated by Cdk5-mediated phosphorylation of JIP1
2024
The mammalian brain, especially the cerebral cortex, has evolved to increase in size and complexity. The proper development of the cerebral cortex requires the coordination of several events, such as differentiation and migration, that are essential for forming a precise six-layered structure. We have previously reported that Cdk5-mediated phosphorylation of JIP1 at T205 modulates axonal out-growth. However, the spatiotemporal expression patterns and functions of these three genes (Cdk5, Cdk5r1 or p35, and Mapk8ip1 or JIP1) in distinct cell types during cortical development remain unclear. In this study, we analyzed single-cell RNA-sequencing data of mouse embryonic cortex and discovered that Cdk5, p35, and JIP1 are dynamically expressed in intermediate progenitors (IPs). Pseudotime analysis revealed that the expression of these three genes was concomitantly upregulated in IPs during neuronal migration and differentiation. By manipulating the expression of JIP1 and phospho-mimetic JIP1 using in utero electroporation, we showed that phosphorylated JIP1 at T205 affected the temporal migration of neurons.
Journal Article
Marked Prevention of Ischemic Brain Injury by Neu2000, an NMDA Antagonist and Antioxidant Derived from Aspirin and Sulfasalazine
by
Lee, Moon Jung
,
Im, Doo Soon
,
Noh, Ji-Hyun
in
Animals
,
Antioxidants - pharmacology
,
Aspirin - chemistry
2007
Excitotoxicity and oxidative stress mediate neuronal death after hypoxic—ischemic brain injury. We examined the possibility that targeting both N-methyl-d-aspartate (NMDA) receptor-mediated excitotoxicity and oxidative stress would result in enhanced neuroprotection against hypoxic—ischemia. 2-Hydroxy-5-(2,3,5,6-tetrafluoro-4-trifluoromethyl-benzylamino)-benzoic acid (Neu2000) was derived from aspirin and sulfasalazine to prevent both NMDA neurotoxicity and oxidative stress. In cortical cell cultures, Neu2000 was shown to be an uncompetitive NMDA receptor antagonist and completely blocked free radical toxicity at doses as low as 0.3 μmol/L. Neu2000 showed marked neuroprotection in a masked fashion using histology and behavioral testing in two rodent models of focal cerebral ischemia without causing neurotoxic side effects. Neu2000 protected against the effects of middle cerebral artery occlusion, even when delivered 8 h after reperfusion. Single bolus administration of the drug prevented gray and white matter degeneration and spared neurologic function for over 28 days after MACO. Neu2000 may be a novel therapy for combating both NMDA receptor-mediated excitotoxicity and oxidative stress, the two major routes of neuronal death in ischemia, offering profound neuroprotection and an extended therapeutic window.
Journal Article
beta2-Adrenoreceptor is a regulator of the alpha-synuclein gene driving risk of Parkinson's disease
by
Caldarone, Barbara J
,
Im, Doo Soon
,
Heutink, Peter
in
Acetylation
,
Adrenergic receptors
,
Asthma
2017
High expression of the α-synuclein gene (SNCA) is a risk factor for Parkinson's disease (PD), but certain drugs may mitigate this risk. Mittal et al. ran a small-molecule screen to identify compounds that regulate levels of SNCA expression and found that several β2-adrenoreceptor (β2AR) agonists reduced them (see the Perspective by Snyder). These compounds modulated epigenetic marks at the SNCA gene, effectively suppressing SNCA transcription. The authors looked at the pharmaceutical history of more than 4 million Norwegians over an 11-year period and found a reduced risk of PD among those that were taking one of the β2AR agonists for other medical problems.Science, this issue p. 891; see also p. 869 Copy number mutations implicate excess production of α-synuclein as a possibly causative factor in Parkinson's disease (PD). Using an unbiased screen targeting endogenous gene expression, we discovered that the β2-adrenoreceptor (β2AR) is a regulator of the α-synuclein gene (SNCA). β2AR ligands modulate SNCA transcription through histone 3 lysine 27 acetylation of its promoter and enhancers. Over 11 years of follow-up in 4 million Norwegians, the β2AR agonist salbutamol, a brain-penetrant asthma medication, was associated with reduced risk of developing PD (rate ratio, 0.66; 95% confidence interval, 0.58 to 0.76). Conversely, a β2AR antagonist correlated with increased risk. β2AR activation protected model mice and patient-derived cells. Thus, β2AR is linked to transcription of α-synuclein and risk of PD in a ligand-specific fashion and constitutes a potential target for therapies.
Journal Article
Parkinson Disease-Linked Parkin Mediates Redox Reactions That Lower Oxidative Stress In Mammalian Brain
by
Nguyen, Angela P
,
Schlossmacher, Michael G
,
Pileggi, Chantal
in
Cytosol
,
Glutaredoxin
,
Glutathione
2020
We recently hypothesized that parkin plays a role in redox homeostasis and provided evidence that it directly reduces hydrogen peroxide (H2O2) in vitro. Here, we examined this anti-oxidant activity in vivo. Informed by findings in human brain, we demonstrate that elevated oxidative stress promotes parkin insolubility in mice. In normal mouse brain parkin was partially oxidized, e.g., at cysteines 195 and 252, which was augmented by oxidative stress. Although under basal conditions H2O2 levels were unchanged in adult prkn-/- brain, a parkin-dependent reduction of cytosolic H2O2 was observed when mitochondria were impaired, either due to neurotoxicant exposure (MPTP) or Sod2 haploinsufficiency. In accordance, markers of oxidative stress, e.g., protein carbonylation and nitrotyrosination, were elevated in the cytosol but not in mitochondria from prkn-/- mice. Nevertheless, this rise in oxidative stress led to changes in mitochondrial enzyme activities and the metabolism of glutathione in cells and mammalian brain. In parkin's absence reduced glutathione concentrations were increased including in human cortex. This compensation was not due to new glutathione synthesis but attributed to elevated oxidized glutathione (GSSG)-reductase activity. Moreover, we discovered that parkin also recycled GSSG to its reduced form. With this reaction, parkin became S-glutathionylated, e.g., at cysteines 59 and human-specific 95. This oxidative modification was reversed by glutaredoxin. Our results demonstrate that cytosolic parkin mediates anti-oxidant reactions including H2O2 reduction and glutathione regeneration. These reducing activities lead to a range of oxidative modifications in parkin itself. In parkin-deficient brain oxidative stress rises despite changes to maintain redox balance. Competing Interest Statement The authors have declared no competing interest.
A safe and sustainable bacterial cellulose nanofiber separator for lithium rechargeable batteries
2019
Bacterial cellulose nanofiber (BCNF) with high thermal stability produced by an ecofriendly process has emerged as a promising solution to realize safe and sustainable materials in the large-scale battery. However, an understanding of the actual thermal behavior of the BCNF in the full-cell battery has been lacking, and the yield is still limited for commercialization. Here, we report the entire process of BCNF production and battery manufacture. We systematically constructed a strain with the highest yield (31.5%) by increasing metabolic flux and improved safety by introducing a Lewis base to overcome thermochemical degradation in the battery. This report will open ways of exploiting the BCNF as a “single-layer” separator, a good alternative to the existing chemical-derived one, and thus can greatly contribute to solving the environmental and safety issues.
Journal Article
Investigation of Climatic Factors Affecting the Amount of Foraged Matsutake Mushrooms in Korea
2024
Tricholoma matsutake is a valuable edible mushroom in Eastern Asia. Due to the challenges of artificial cultivation, T. matsutake cultivation has relied on foraging from pine forests. Changes in global climate variables, such as temperature and precipitation, could affect the amount of foraged T. matsutake. In this study, we investigated the correlation between the amount of foraged T. matsutake and climatic factors (average monthly temperature and precipitation) in Yangyang-gun using the augmented Dickey–Fuller test and the ordinary least squares method. Among the assessed correlations between the foraged T. matsutake and different climatic factors, the average temperature in August was significantly correlated with the amount of foraged T. matsutake, increasing by 1.5 tons when the temperature in August increased by 1 unit. Overall, this study identified a potentially strong positive correlation between the average temperature in August and amount of foraged T. matsutake.
Journal Article
Structural Basis of the Heterodimer Formation between Cell Shape-Determining Proteins Csd1 and Csd2 from Helicobacter pylori
by
Hesek, Dusan
,
Suh, Se Won
,
Yoon, Hye Jin
in
Amino Acid Sequence
,
Antibiotics
,
Bacterial Proteins - chemistry
2016
Colonization of the human gastric mucosa by Helicobacter pylori requires its high motility, which depends on the helical cell shape. In H. pylori, several genes (csd1, csd2, csd3/hdpA, ccmA, csd4, csd5, and csd6) play key roles in determining the cell shape by alteration of cross-linking or by trimming of peptidoglycan stem peptides. H. pylori Csd1, Csd2, and Csd3/HdpA are M23B metallopeptidase family members and may act as d,d-endopeptidases to cleave the d-Ala4-mDAP3 peptide bond of cross-linked dimer muropeptides. Csd3 functions also as the d,d-carboxypeptidase to cleave the d-Ala4-d-Ala5 bond of the muramyl pentapeptide. To provide a basis for understanding molecular functions of Csd1 and Csd2, we have carried out their structural characterizations. We have discovered that (i) Csd2 exists in monomer-dimer equilibrium and (ii) Csd1 and Csd2 form a heterodimer. We have determined crystal structures of the Csd2121-308 homodimer and the heterodimer between Csd1125-312 and Csd2121-308. Overall structures of Csd1125-312 and Csd2121-308 monomers are similar to each other, consisting of a helical domain and a LytM domain. The helical domains of both Csd1 and Csd2 play a key role in the formation of homodimers or heterodimers. The Csd1 LytM domain contains a catalytic site with a Zn2+ ion, which is coordinated by three conserved ligands and two water molecules, whereas the Csd2 LytM domain has incomplete metal ligands and no metal ion is bound. Structural knowledge of these proteins sheds light on the events that regulate the cell wall in H. pylori.
Journal Article