• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.283-289
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• 2015

This study surveys the improvement characteristics in old-aged muscular mitochondria by bio-active materials coated fabric (BMCF). To observe the effects, the fabric (10 and 30%) was worn to old-aged rat then the oxygen consumption efficiency and copy numbers of mitochondria, and mRNA expression of apoptosis- and mitophagy-related genes were verified. By wearing the BMCF, the oxidative respiration significantly increased when using the 30% materials coated fabric. The mitochondrial DNA copy number significantly decreased and subsequently recovered in a dose-dependent manner. The respiratory control ratio to mitochondrial DNA copy number showed a dose-dependent increment. As times passed, Bax, caspase 9, PGC-$1{\alpha}$ and ${\beta}$-actin increased, and Bcl-2 decreased in a dose-dependent manner. However, the BMCF can be seen to have had no effect on Fas receptor. PINK1 expression did not change considerably and was inclined to decrease in control group, but the expression was down-regulated then subsequently increased with the use of the BMCF in a dose-dependent manner. Caspase 3 increased and subsequently decreased in a dose-dependent manner. These results suggest that the BMCF invigorates mitophagy and improves mitochondrial oxidative respiration in skeletal muscle, and in early stage of apoptosis induced by the BMCF is not related to extrinsic death-receptor mediated but mitochondria-mediated signaling pathway.

• Herbal Formula Science
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• v.28 no.1
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• pp.15-27
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• 2020

Objectives : We selected three herb-combined remedies, Bigihwan (BGH), Daechilgitang (DCGT) and Mokwhyangbinranghwan (MHBRH), through Donguibogam text-mining analysis, and evaluated their anti-cancer effects on human hepatocellular carcinoma Hep3B cells. Methods : Cytotoxicity was assessed by an MTT assay. Apoptosis rate, autophagy and ROS level were detected by flow cytometry. The autophagy was also observed by Cyto-ID staining fluorescence microscopy. The expression of autophagy, mitophagy and pexophagy regulatory proteins was detected by Western blot analysis. Results : BGH showed the strongest effect among the three prescriptions in inhibiting Hep3B cell viability, which was associated with the induction of apoptosis and autophagy. Autophagy blockers improved cell viability and reduced apoptosis after BGH and DCGT treatments, indicating that autophagy by these prescriptions enhanced Hep3B cells against their cytotoxicity. However, MHBRH enhanced the reduction of cell viability and apoptosis by autophagy blockers. Induction of autophagy by BGH treatment was associated with mitophagy due to mitochondrial dysfunction than DCGT and MHBRH-treated cells. In addition, induction of apoptosis by BGH treatment was ROS-dependent and showed the possibility of pexophagy involvement. Conclusion : Although further studies need to be conducted to study the efficacy and mechanism of accurate anticancer activity, the present results will serve as important sources of understanding the mechanism of action of herbal remedies prescribed for liver disease as documented in Donguibogam.

• International Journal of Oral Biology
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• v.42 no.3
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• pp.85-90
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• 2017

Mitochondria participate in various intracellular metabolic pathways such as generating intracellular ATP, synthesizing several essential molecules, regulating calcium homeostasis, and producing the cell's reactive oxygen species (ROS). Emerging studies have demonstrated newly discovered roles of mitochondria, which participate in the regulation of innate immune responses by modulating NLRP3 inflammasomes. Here, we review the recently proposed pathways to be involved in mitochondria-mediated regulation of inflammasome activation and inflammation: 1) mitochondrial ROS, 2) calcium mobilization, 3) nicotinamide adenine dinucleotide ($NAD^+$) reduction, 4) cardiolipin, 5) mitofusin, 6) mitochondrial DNA, 7) mitochondrial antiviral signaling protein. Furthermore, we highlight the significance of mitophagy as a negative regulator of mitochondrial damage and NLRP3 inflammasome activation, as potentially helpful therapeutic approaches which could potentially address uncontrolled inflammation.

• BMB Reports
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• v.51 no.6
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• pp.274-279
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• 2018

Mitochondria are crucial organelles that generate cellular energy and metabolites. Recent studies indicate that mitochondria also regulate immunity. In this review, we discuss key roles of mitochondria in immunity against pathogen infection and underlying mechanisms, focusing on discoveries using Caenorhabditis elegans. Various mitochondrial processes, including mitochondrial surveillance mechanisms, mitochondrial unfolded protein response ($UPR^{mt}$), mitophagy, and reactive oxygen species (ROS) production, contribute to immune responses and resistance of C. elegans against pathogens. Biological processes of C. elegans are usually conserved across phyla. Thus, understanding the mechanisms of mitochondria-mediated defense responses in C. elegans may provide insights into similar mechanisms in complex organisms, including mammals.

• Journal of Life Science
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• v.30 no.5
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• pp.460-467
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• 2020

Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed cancers in the word. Although radiation and chemotherapy are generally effective, there are various side effects that greatly limit the effectiveness of these treatments. Therefore, traditional herbs may have potential as important resources for the discovery of liver cancer therapeutics. In this study, we selected three Korean herbal medicine formulas from the Donguibogam, namely Bigihwan (BGH), Daechilgithang (DCGT), and Mokwhyangbinranghwan (MHBRH), and evaluated their anti-cancer effects on HCC cells. According to our results of three ethanol extracts, BGH was more effective at suppressing HCC growth than DCGT or MHBRH. Furthermore, flow cytometry analysis showed that inhibition of HCC proliferation by the three extracts was associated with the induction of apoptosis and autophagy. In particular, BGH significantly increased mitochondrial impairment and showed the possibility of inducing mitophagy in comparison with the other two extracts. BGH prominently upregulated the levels of microtubule-associated protein light chain-3 which was accompanied by a decrease in the expression of anti-apoptotic Bcl-2 without altering the expression of pro-apoptotic Bax. In addition, the levels of PTEN-induced kinase 1 were also markedly increased in BGH-treated HCC cells. Moreover, autophagy blocking improved cell viability and reduced apoptosis after the three treatments, indicating that autophagy by these extracts enhances HCC cells against cytotoxicity. In conclusion, our findings show that BGH demonstrates the highest anti-cancer activity among the three formulas and inhibits the proliferation of HCC cells through autophagy induction.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.221-234
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• 2019

Cancer is genetically, metabolically and infectiously induced life threatening disorder showing aggressive growing pattern with invasive tendency. In order to prevent this global menace from jeopardizing human life, enormous studies on carcinogenesis and treatment for chemotherapy resistance have been intensively researched. Hinokitiol (${\beta}$-thujaplicin) extracted from heart wood of cupressaceous is a well-known bioactive compound demonstrating anti-inflammation, anti-bacteria and anti-cancer effects on several cancer types via apoptosis and autophagy. This study proposed that hinokitiol activates transcription factor EB (TFEB) nuclear translocation for autophagy and lysosomal biogenesis regardless of nutrient condition in cancer cells. Mitophagy and ${\beta}$-catenin translocation into the nucleus under treatment of hinokitiol on non-small cell lung cancer (NSCLC) cells and HeLa cells were investigated. Hinokitiol exerted cytotoxicity on HeLa and HCC827 cells; moreover, artificially induced autophagy by overexpression of TFEB granted imperfect sustainability onto HeLa cells. Taken together, hinokitiol is the prominent autophagy inducer and activator of TFEB nuclear translocation. Alternative cancer therapy via autophagy is pros and cons since the autophagy in cancer cells is related to prevention and survival mechanism depending on nutrition. To avoid paradox of autophagy in cancer therapy, fine-tuned regulation and application of hinokitiol in due course for successful suppressing cancer cells are recommended.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.97-107
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• 2023

Aristolochic acid (AA), extracted from Aristolochiaceae plants, plays an essential role in traditional herbal medicines and is used for different diseases. However, AA has been found to be nephrotoxic and is known to cause aristolochic acid nephropathy (AAN). AA-induced acute kidney injury (AKI) is a syndrome in AAN with a high morbidity that manifests mitochondrial damage as a key part of its pathological progression. Melatonin primarily serves as a mitochondria-targeted antioxidant. However, its mitochondrial protective role in AA-induced AKI is barely reported. In this study, mice were administrated 2.5 mg/kg AA to induce AKI. Melatonin reduced the increase in Upro and Scr and attenuated the necrosis and atrophy of renal proximal tubules in mice exposed to AA. Melatonin suppressed ROS generation, MDA levels and iNOS expression and increased SOD activities in vivo and in vitro. Intriguingly, the in vivo study revealed that melatonin decreased mitochondrial fragmentation in renal proximal tubular cells and increased ATP levels in kidney tissues in response to AA. In vitro, melatonin restored the mitochondrial membrane potential (MMP) in NRK-52E and HK-2 cells and led to an elevation in ATP levels. Confocal immunofluorescence data showed that puncta containing Mito-tracker and GFP-LC3A/B were reduced, thereby impeding the mitophagy of tubular epithelial cells. Furthermore, melatonin decreased LC3A/B-II expression and increased p62 expression. The apoptosis of tubular epithelial cells induced by AA was decreased. Therefore, our findings revealed that melatonin could prevent AA-induced AKI by attenuating mitochondrial damage, which may provide a potential therapeutic method for renal AA toxicity.

• Journal of Life Science
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• v.34 no.1
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• pp.37-47
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• 2024

FUN14 domain-containing protein 1 (FUNDC1), an outer mitochondrial membrane protein, contributes to removal of damaged mitochondria through mitophagy. In this study, to elucidate the role of the FUNDC1 in the amyloid beta peptide (A_β)-induced neuropathy, changes in the degree of mitochondrial dysfunction and cell injury caused by A_β treatment were examined in the HT-22 neuronal cells in which the FUNDC1 expression was transiently silenced or overexpressed. We found that A_β treatment causes a time-dependent decrease of the FUNDC1 expression. In the A_β-treated cells, there were a drop in MTT reduction ability, depletion of cellular ATP, disruption of mitochondrial membrane potential, stimulation of cellular ROS production, and increased mitochondrial Ca²⁺ load. Activation of caspase-3 and induction of apoptotic cell death were also observed. Transient silencing of the FUNDC1 expression by transfection with the FUNDC1 small interfering RNA per se caused mitochondrial dysfunction and apoptotic cell death like the effect of A_β treatment. Conversely, in cells in which the FUNDC1 was transiently overexpressed by FUNDC1-Myc transfection, overexpression itself had no effect on the mitochondrial functional integrity and cell survival but showed a significant prevention effect against mitochondrial and cell injury caused by A_β treatment. Overall, these results suggest that the FUNDC1 is importantly involved in the A_β-induced mitochondrial dysfunction and cell injury in the HT-22 neuronal cells.

• Molecules and Cells
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• v.46 no.11
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• pp.655-663
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• 2023

Autophagy dysfunction is associated with human diseases and conditions including neurodegenerative diseases, metabolic issues, and chronic infections. Additionally, the decline in autophagic activity contributes to tissue and organ dysfunction and aging-related diseases. Several factors, such as down-regulation of autophagy components and activators, oxidative damage, microinflammation, and impaired autophagy flux, are linked to autophagy decline. An autophagy flux impairment (AFI) has been implicated in neurological disorders and in certain other pathological conditions. Here, to enhance our understanding of AFI, we conducted a comprehensive literature review of findings derived from two well-studied cellular stress models: glucose deprivation and replicative senescence. Glucose deprivation is a condition in which cells heavily rely on oxidative phosphorylation for ATP generation. Autophagy is activated, but its flux is hindered at the autolysis step, primarily due to an impairment of lysosomal acidity. Cells undergoing replicative senescence also experience AFI, which is also known to be caused by lysosomal acidity failure. Both glucose deprivation and replicative senescence elevate levels of reactive oxygen species (ROS), affecting lysosomal acidification. Mitochondrial alterations play a crucial role in elevating ROS generation and reducing lysosomal acidity, highlighting their association with autophagy dysfunction and disease conditions. This paper delves into the underlying molecular and cellular pathways of AFI in glucose-deprived cells, providing insights into potential strategies for managing AFI that is driven by lysosomal acidity failure. Furthermore, the investigation on the roles of mitochondrial dysfunction sheds light on the potential effectiveness of modulating mitochondrial function to overcome AFI, offering new possibilities for therapeutic interventions.

• Toxicological Research
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• v.33 no.3
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• pp.205-209
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• 2017

Transmembrane Protein 39A (TMEM39A) is a member of TMEM family. The understanding about this protein is still limited. The earlier studies indicated that TMEM39A was a key mediator of autoimmune disease. TMEM39A seems to be involved in systemic lupus erythematosus and multiple sclerosis in numerous of populations. All of these works stop at insufficient information by using gene functioning methods such as: Genome-wide association studies (GWASs) and/or follow-up study. It is the fact that the less understood of TMEM39A actually is the attraction to the scientist in near future. In this review the current knowledge about TMEM39A and its possible roles in cell biology, physiology and pathology will be described.