Publications by authors named "Youngmi K Pak"

Exposure to environment-polluting chemicals (EPCs), which are ligands of the aryl hydrocarbon receptor (AhR), is associated with the development of type 2 diabetes (T2D). This study explores the mechanisms by which AhR ligands contribute to β-cell failure in T2D. Incubation of RINm5F rat pancreatic β-cells with low-dose 2,3,7,8-tetrachlorodibenzodioxin (TCDD), the most potent AhR ligand, inhibited glucose-stimulated insulin secretion (GSIS).

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Article Synopsis
  • Mitochondrial dysfunction is linked to obesity and diabetes, with environmental pollutants possibly increasing diabetes risk through dioxin-like substances that affect mitochondrial health and lung function.
  • A study of 1371 adults from the Korean Genome Epidemiologic Study found that dioxin-like mitochondria inhibitor substances (MIS) were associated with body mass index (BMI) and lung function, indicating a complex relationship between these factors.
  • Results suggested that higher levels of MIS negatively impacted mitochondrial function, which subsequently affected both BMI and lung health, emphasizing the need for better understanding of mitochondrial health in the context of metabolic disorders and aging.
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Article Synopsis
  • The study investigated the link between dietary intake and exposure to endocrine-disrupting chemicals (EDCs) among middle-aged Koreans, focusing on surrogate biomarkers like aryl hydrocarbon receptor ligands (AhRL) and mitochondrial function indicators (MIS-ATP and MIS-ROS).
  • Results indicated that fish consumption was positively correlated with higher AhRL levels, suggesting increased EDC exposure, while cruciferous vegetables showed a negative association with AhRL levels and a positive correlation with MIS-ATP levels.
  • Overall, higher fish intake appears to increase the risk of EDC-related bioactivity, contrasting with some protective effects of consuming cruciferous vegetables against high AhRL levels.
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Persistent organic pollutants (POPs) affect human health through the aryl hydrocarbon receptor (AhR) pathway and are implicated in mitochondrial dysfunction. Using data from the PIVUS study, we investigated the associations of serum AhR ligand (POP)-mediated luciferase activity (AhRL), mitochondrial ATP production inhibiting substances (MIS-ATP), and those affecting reactive oxygen species (MIS-ROS) with several metabolic syndrome (MetS) and cardiopulmonary function parameters. These include insulin resistance (HOMA-IR), inflammation, oxidative stress, and cardiopulmonary variables (FVC, FEV1, LV-EF, CCA distensibility).

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Parkinson's disease (PD) is a complex neurodegenerative disease in which neuroinflammation and oxidative stress interact to contribute to pathogenesis. This study investigates the in vivo neuroprotective effects of a patented yeast extract lysate in a lipopolysaccharide (LPS)-induced neuroinflammation model. The yeast extract lysate, named aldehyde-reducing composition (ARC), exhibited potent antioxidant and anti-aldehyde activities in vitro.

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Microplastics (MPs) are recognized as environmental pollutants with potential implications for human health. Considering the rapid increase in obesity rates despite stable caloric intake, there is a growing concern about the link between obesity and exposure to environmental pollutants, including MPs. In this study, we conducted a comprehensive investigation utilizing in silico, in vitro, and in vivo approaches to explore the brain distribution and physiological effects of MPs.

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Obesity is a chronic peripheral inflammation condition that is strongly correlated with neurodegenerative diseases and associated with exposure to environmental chemicals. The aryl hydrocarbon receptor (AhR) is a ligand-activated nuclear receptor activated by environmental chemical, such as dioxins, and also is a regulator of inflammation through interacting with nuclear factor (NF)-κB. In this study, we evaluated the anti-obesity and anti-inflammatory activity of HBU651, a novel AhR antagonist.

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Chronic exposure to some environmental polluting chemicals (EPCs) is strongly associated with metabolic syndrome, and insulin resistance is a major biochemical abnormality in the skeletal muscle in patients with metabolic syndrome. However, the causal relationship is inconsistent and little is known about how EPCs affect the insulin signaling cascade in skeletal muscle. Here, we investigated whether exposure to 100 pM of 2,3,7,8-tetrachlorodibenzodioxin (TCDD) as a low dose of dioxin induces insulin resistance in C2C12 myocytes.

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Obesity is closely linked to chronic inflammation in peripheral organs and the hypothalamus. Chronic consumption of a high-fat diet (HFD) induces the differentiation of Ly6c monocytes into macrophages in adipose tissue, the liver, and the brain, as well as the secretion of pro-inflammatory cytokines. Although cinnamon improves obesity and related diseases, it is unclear which components of cinnamon can affect macrophages and inflammatory cytokines.

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Loss of dopamine (DA) is one of the primary features of Parkinson's disease (PD); however, imbalances of non-dopaminergic neurotransmitters significantly contribute to the disabilities noted in advanced PD patients. DA-9805 is the ethanolic extraction of the root bark of × Andrews (), the root of (Hoffm.) Benth.

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The early prediction and identification of risk factors for diabetes may prevent or delay diabetes progression. In this study, we developed an interactive online application that provides the predictive probabilities of prediabetes and diabetes in 4 years based on a Bayesian network (BN) classifier, which is an interpretable machine learning technique. The BN was trained using a dataset from the Ansung cohort of the Korean Genome and Epidemiological Study (KoGES) in 2008, with a follow-up in 2012.

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Parkinson's disease (PD) is a multifactorial neurodegenerative disease with damages to mitochondria and endoplasmic reticulum (ER), followed by neuroinflammation. We previously reported that a triple herbal extract DA-9805 in experimental PD toxin-models had neuroprotective effects by alleviating mitochondrial damage and oxidative stress. In the present study, we investigated whether DA-9805 could suppress ER stress and neuroinflammation in vitro and/or in vivo.

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In our previous study, 20 nm-sized amorphous silica nanoparticles (20-SiNPs), but not 50 nm-sized amorphous silica nanoparticles (50-SiNPs), induced pulmonary inflammatory response in rats exposed repeatedly for 14 days (12.5, 25, and 50 μg/time, total six times). In this study, we tried to clarify the causes of different responses induced by both SiNPs using mice (12.

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Background: High circulating levels of dioxins and dioxin-like chemicals, acting via the aryl hydrocarbon receptor (AhR), have previously been linked to diabetes. We now investigated whether the serum AhR ligands (AhRL) were higher in subjects with metabolic syndrome (MetS) and in subjects who had developed a worsened glucose tolerance over time.

Methods: Serum AhRL at baseline was measured by a cell-based AhRL activity assay in 70-year-old subjects (n=911) in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study.

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Persistent organic pollutants(POPs) are suggested to be potential risk factors for gestational diabetes mellitus(GDM). We examined the hypothesis that the aryl hydrocarbon receptor trans-activating(AhRT) activity, a potential biomarker for the presence of POPs, could be a GDM risk factor in pregnant women. A total of 390 GDM and 100 normal pregnant(non-GDM) subjects in the Korea National Diabetes Program cohort voluntarily participated.

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Background: Persistent organic pollutants (POPs) may cause diabetes, in part through aryl hydrocarbon receptor (AhR) binding. Ensuing mitochondrial dysfunction is postulated to mediate this effect. We aim to investigate the association of POPs with incident diabetes indirectly by bio-assaying AhR ligand bioactivity and intracellular ATP level induced by participant serum samples.

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Hepatic hepcidin is a well-known major iron regulator and has been reported to be closely related to hepatitis C virus (HCV) replication. However, pharmacological targeting of the hepcidin in HCV replication has not been reported. A short-chain fatty acid, 4-Phenyl butyrate (4-PBA), is an acid chemical chaperone that acts as a histone deacetylase inhibitor (HDACi) to promote chromosomal histone acetylation.

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Parkinson's disease (PD) is a multifactorial neurodegenerative disease manifesting mitochondrial damages and neuroinflammation. Qi is defined as a natural power that can regulate the energy flow in Oriental medicine, whereas mitochondria generate energy power in Western medicine. We investigated whether Qi-enhancing component in Oriental herb medicines could activate mitochondrial activities.

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Exposure to environment-polluting chemicals (EPC) is associated with the development of diabetes. Many EPCs exert toxic effects via aryl hydrocarbon receptor (AhR) and/or mitochondrial inhibition. Here we investigated if the levels of human exposure to a mixture of EPC and/or mitochondrial inhibitors could predict the development of diabetes in a prospective study, the Korean Genome and Epidemiological Study (KoGES).

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Purpose: Elevated aryl hydrocarbon receptor (AhR) transactivating (AHRT) activity and uremia in chronic kidney disease (CKD) may interact with each other, further complicating the disease course. In this study, we prospectively estimated serum AHRT activity using a highly sensitive cell-based AhR-dependent luciferase activity assay in CKD patients and compared differences therein according to treatment modality.

Materials And Methods: Patients undergoing peritoneal dialysis (PD) (n=22) and hemodialysis (HD) (n=38) and patients with pre-dialysis CKD stage IV or V (n=28) were included.

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α-Naphthoflavone (αNF) is a prototype flavone, also known as a modulator of aryl hydrocarbon receptor (AhR). In the present study, we investigated the molecular mechanisms of αNF-induced cytotoxic effects in HT22 mouse hippocampal neuronal cells. αNF induced apoptotic cell death via activation of caspase-12 and -3 and increased expression of endoplasmic reticulum (ER) stress-associated proteins, including C/EBP homologous protein (CHOP).

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Moutan cortex, Angelica Dahurica root, and Bupleurum root are traditional herbal medicines used in Asian countries to treat various diseases caused by oxidative stress or inflammation. Parkinson's disease (PD) has been associated with mitochondrial dysfunction, but no effective treatment for mitochondrial dysfunction has yet been identified. In this study we investigated the neuroprotective effects of the triple herbal extract DA-9805 in experimental models of PD.

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We regret that there is an error in the labeling of Fig. 4 of the published original article. The concentration of MPP should be corrected to 1.

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An excess of reactive oxygen species (ROS) relative to the antioxidant capacity causes oxidative stress, which plays a role in the development of Parkinson's disease (PD). Because mitochondria are both sites of ROS generation and targets of ROS damage, the delivery of antioxidants to mitochondria might prevent or alleviate PD. To transduce the antioxidant protein human metallothionein 1A (hMT1A) into mitochondria, we computationally designed a cell-penetrating artificial mitochondria-targeting peptide (CAMP).

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