• The Korean Journal of Physiology and Pharmacology
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• v.20 no.3
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• pp.305-314
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• 2016

Inflammatory and fibrotic responses are accelerated during the reperfusion period, and excessive fibrosis and inflammation contribute to cardiac malfunction. NecroX compounds have been shown to protect the liver and heart from ischemia-reperfusion injury. The aim of this study was to further define the role and mechanism of action of NecroX-5 in regulating inflammation and fibrosis responses in a model of hypoxia/reoxygenation (HR). We utilized HR-treated rat hearts and lipopolysaccharide (LPS)-treated H9C2 culture cells in the presence or absence of NecroX-5 ($10{\mu}mol/L$) treatment as experimental models. Addition of NecroX-5 significantly increased decorin (Dcn) expression levels in HR-treated hearts. In contrast, expression of transforming growth factor beta 1 ($TGF{\beta}1$) and Smad2 phosphorylation (pSmad2) was strongly attenuated in NecroX-5-treated hearts. In addition, significantly increased production of tumor necrosis factor alpha ($TNF{\alpha}$), $TGF{\beta}1$, and pSmad2, and markedly decreased Dcn expression levels, were observed in LPS-stimulated H9C2 cells. Interestingly, NecroX-5 supplementation effectively attenuated the increased expression levels of $TNF{\alpha}$, $TGF{\beta}1$, and pSmad2, as well as the decreased expression of Dcn. Thus, our data demonstrate potential antiinflammatory and anti-fibrotic effects of NecroX-5 against cardiac HR injuries via modulation of the $TNF{\alpha}/Dcn/TGF{\beta}1/Smad2$ pathway.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.5
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• pp.531-546
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• 2017

Activation of Toll-like receptor-4 (TLR-4) in articular chondrocytes increases the catabolic compartment and leads to matrix degradation during the development of osteoarthritis. In this study, we determined the proteomic and genomic alterations in human chondrocytes during lipopolysaccharide (LPS)-induced inflammation to elucidate the underlying mechanisms and consequences of TLR-4 activation. Human chondrocytes were cultured with LPS for 12, 24, and 36 h to induce TLR-4 activation. The TLR-4-induced inflammatory response was confirmed by real-time PCR analysis of increased interleukin-1 beta ($IL-1{\beta}$), interleukin-6 (IL-6), and tumor necrosis factor alpha ($TNF-{\alpha}$) expression levels. In TLR-4-activated chondrocytes, proteomic changes were determined by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-mass spectroscopy analysis, and genomic changes were determined by microarray and gene ontology analyses. Proteomics analysis identified 26 proteins with significantly altered expression levels; these proteins were related to the cytoskeleton and oxidative stress responses. Gene ontology analysis indicated that LPS treatment altered specific functional pathways including 'chemotaxis', 'hematopoietic organ development', 'positive regulation of cell proliferation', and 'regulation of cytokine biosynthetic process'. Nine of the 26 identified proteins displayed the same increased expression patterns in both proteomics and genomics analyses. Western blot analysis confirmed the LPS-induced increases in expression levels of lamin A/C and annexins 4/5/6. In conclusion, this study identified the time-dependent genomic, proteomic, and functional pathway alterations that occur in chondrocytes during LPS-induced TLR-4 activation. These results provide valuable new insights into the underlying mechanisms that control the development and progression of osteoarthritis.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.3
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• pp.175-180
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• 2012

Yoga has been known to have stimulatory or inhibitory effects on the metabolic parameters and to be uncomplicated therapy for obesity. The purpose of the present study was to test the effect of an 8-week of yoga-asana training on body composition, lipid profile, and insulin resistance (IR) in obese adolescent boys. Twenty volunteers with body mass index (BMI) greater than the 95th percentile were randomly assigned to yoga (age $14.7{\pm}0.5$ years, n=10) and control groups (age $14.6{\pm}1.0$ years, n=10). The yoga group performed exercises three times per week at 40~60% of heart-rate reserve (HRR) for 8 weeks. IR was determined with the homeostasis model assessment of insulin resistance (HOMA-IR). After yoga training, body weight, BMI, fat mass (FM), and body fat % (BF %) were significantly decreased, and fat-free mass and basal metabolic rate were significantly increased than baseline values. FM and BF % were significantly improved in the yoga group compared with the control group (p<0.05). Total cholesterol (TC) was significantly decreased in the yoga group (p<0.01). HDL-cholesterol was decreased in both groups (p<0.05). No significant changes were observed between or within groups for triglycerides, LDL-cholesterol, glucose, insulin, and HOMA-IR. Our findings show that an 8-week of yoga training improves body composition and TC levels in obese adolescent boys, suggesting that yoga training may be effective in controlling some metabolic syndrome factors in obese adolescent boys.

• Biomolecules & Therapeutics
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• v.16 no.1
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• pp.1-8
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• 2008

Mitochondria are important sensor of apoptosis. $H_2O_2-induced$ cell death rate was enhanced by serum deprivation. In this study, we investigated whether serum deprivation using 0.5 or 3 % FBS induces apoptotic cell death through mitochondrial enzyme activation as compared to 10 % FBS. Apoptotic cell death was observed by chromosome condensation and the increase of sub-G0/G1 population. Serum deprivation reduced cell growth rate, which was confirmed by the decrease of S-phase population in cell cycle. Serum deprivation significantly increased caspase-9 activity and cytochrome c release from mitochondria into cytosol. Serum deprivation-induced mitochondrial changes were also indicated by the increase of ROS production and the activation of mitochondrial enzyme, succinate dehydrogenase. Mitochondrial enzyme activity increased by serum deprivation was reduced by the treatment with rotenone, mitochondrial electron transport inhibitor. In conclusion, serum deprivation induced mitochondrial apoptotic cell death through the elevation of mitochondrial changes such as ROS production, cytochrome c release and caspase-9 activation. It suggests that drug sensitivity could be enhanced by the increase of mitochondrial enzyme activity in serum-deprived condition.

• BMB Reports
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• v.57 no.1
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• pp.19-29
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• 2024

Mitochondrial DNA (mtDNA), a multicopy genome found in mitochondria, is crucial for oxidative phosphorylation. Mutations in mtDNA can lead to severe mitochondrial dysfunction in tissues and organs with high energy demand. MtDNA mutations are closely associated with mitochondrial and age-related disease. To better understand the functional role of mtDNA and work toward developing therapeutics, it is essential to advance technology that is capable of manipulating the mitochondrial genome. This review discusses ongoing efforts in mitochondrial genome editing with mtDNA nucleases and base editors, including the tools, delivery strategies, and applications. Future advances in mitochondrial genome editing to address challenges regarding their efficiency and specificity can achieve the promise of therapeutic genome editing.

• Journal of Ginseng Research
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• v.45 no.4
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• pp.473-481
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• 2021

Background: Mitochondrial dysfunction is one of the significant reasons for Alzheimer's disease (AD). Ginsenosides, natural molecules extracted from Panax ginseng, have been demonstrated to exert essential neuroprotective functions, which can ascribe to its anti-oxidative effect, enhancing central metabolism and improving mitochondrial function. However, a comprehensive analysis of cellular mitochondrial bioenergetics after ginsenoside treatment under Aβ-oxidative stress is missing. Methods: The antioxidant activities of ginsenoside Rb₁, Rd, Re, Rg₁ were compared by measuring the cell survival and reactive oxygen species (ROS) formation. Next, the protective effects of ginsenosides of mitochondrial bioenergetics were examined by measuring oxygen consumption rate (OCR) in PC12 cells under Aβ-oxidative stress with an extracellular flux analyzer. Meanwhile, mitochondrial membrane potential (MMP) and mitochondrial dynamics were evaluated by confocal laser scanning microscopy. Results: Ginsenoside Rg₁ possessed the strongest anti-oxidative property, and which therefore provided the best protective function to PC12 cells under the Aβ oxidative stress by increasing ATP production to 3 folds, spare capacity to 2 folds, maximal respiration to 2 folds and non-mitochondrial respiration to 1.5 folds, as compared to Aβ cell model. Furthermore, ginsenoside Rg1 enhanced MMP and mitochondrial interconnectivity, and simultaneously reduced mitochondrial circularity. Conclusion: In the present study, these results demonstrated that ginsenoside Rg₁ could be the best natural compound, as compared with other ginsenosides, by modulating the OCR of cultured PC12 cells during oxidative phosphorylation, in regulating MMP and in improving mitochondria dynamics under Aβ-induced oxidative stress.

• Biomolecules & Therapeutics
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• v.18 no.3
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• pp.235-245
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• 2010

Mitochondria have long been recognized as ATP engines for the cell and recently as a dynamic and mobile organelles that control cell death and life. This exquisite organelle is the site of reactive oxygen species production and is highly vulnerable to exogenous stresses, resulting in catastrophic damage to the cell. Mitochondrial dysfunction is linked to a wide range of age-associated degenerative diseases, such as metabolic syndrome, cardiovascular disease, and neurodegenerative diseases. Understanding the molecular mechanisms of mitochondria-dependent pathogenesis may provide important strategies to treat these diseases. Indeed, mitochondria are emerging therapeutic targets for the mitochondria-related diseases. In this paper, we review the recent concepts of mitochondrial biology and how mitochondria are involved in age-associated degenerative diseases. Furthermore, we summarize the therapeutics which target to improve mitochondrial functions.

• Journal of Ginseng Research
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• v.45 no.3
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• pp.371-379
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• 2021

Mitochondrial dysfunction contributes to the pathogenesis and prognosis of many common disorders, including neurodegeneration, stroke, myocardial infarction, tumor, and metabolic diseases. Ginsenosides, the major bioactive constituents of Panax ginseng (P. ginseng), have been reported to play beneficial roles in the molecular pathophysiology of these diseases by targeting mitochondrial dysfunction. In this review, we first introduce the types of ginsenosides and basic mitochondrial functions. Then, recent findings are summarized on different ginsenosides targeting mitochondria and their key signaling pathways for the treatment of multiple diseases, including neurological disorders, cancer, heart disease, hyperglycemia, and inflammation are summarized. This review may explain the common targets of ginsenosides against multiple diseases and provide new insights into the underlying mechanisms, facilitating research on the clinical application of P. ginseng.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.4
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• pp.189-194
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• 2011

ATP-sensitive $K^+$ channels ($K_{ATP}$) are major component of preventing ischemia-reperfusion injury. However, there is little information regarding to the expressional difference of $K_{ATP}$ and its function between left and right ventricles. In this study, we measured the lactate dehydrogenase release of rabbit heart slices in vitro and determined the difference of the $K_{ATP}$ expression at the both ventricles by measuring the level of $K_{ATP}$-forming Kir6.2 (OcKir6.2) mRNA using in situ hybridization. The hearts were preconditioned with 15 min hypoxia and reoxygenated for 15 min before a hypoxic period of 60 min, followed by reoxygenation for 180 min. With hypoxic preconditioning (100% $N_2$) with 15 min, left ventricles (LV) showed higher release of LDH comparing with right ventricles (RV). Adding $K_{ATP}$ blocker glibenclamide ($10{\mu}M$) prior to a hypoxic period of 60 min, hypoxic preconditioning effect of RV was more abolished than LV. With in situ hybridization, the optical density of OcKir6.2 was higher in RV. Therefore, we suggest that different $K_{ATP}$ expression between LV and RV is responsible for the different response to hypoxia and hypoxic preconditioning of rabbit hearts.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2008.04a
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• pp.49-52
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• 2008

Parkinson's disease is characterized by motor disturbances and dopaminergic neurodegeneration. parkin and PINK1, two most critical Parkinson's disease-associated genes, have been intensively studied to address the underlying molecular pathogenesis of the disease, but our understanding still remains unclear. Through generation and characterization of Drosophila mutants for PINK1, we show that PINK1 is required for mitochondrial integrity and function in both indirect flight muscles and dopaminergic neurons. Surprisingly, we find that PINK1 mutants share striking phenotypic similarities with parkin mutants. Indeed, transgenic expression of parkin dramatically ameliorates all PINK1 loss-of-function phenotypes, but not vice versa, implicating that Parkin acts downstream of PINK1 in maintaining mitochondrial integrity and function in both muscles and dopaminergic neurons. With the establishment of the PINK1-Parkin pathway, we are trying to further investigate the detailed molecular relationship between PINK1 and Parkin using both mammalian dopaminergic neuronal cells for biochemical analysis and Drosophila model animal for genetic analysis. We believe that elucidating the molecular function of Parkinson's disease-associated genes will be of big help for the ultimate understanding of the pathogenic mechanism of this disease and also for the development of effective drugs for Parkinson's disease.