• Korean Journal of Microbiology
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• v.50 no.1
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• pp.27-32
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• 2014

Autophagy is one of the lysosomal degradation pathways to maintain cellular homeostasis. The damaged proteins or organelles are uptaken through extra- and intra-cellular stress, starvation and infected pathogens, subsequently, autophagosomes are fused with lysosomes to break down the molecules. Salmonella enterica serovar Typhimurium (S. Typhimurium), intracellular bacteria, cause acute gastroenteritis and food poisoning. Given that autophagy induced by S. Typhimurium plays an important role in the cells to control the infection, we identify whether the induction of autophagy with rapamycin, chemical inducer of autophagy, before infection regulates S. Typhimurium infection. After treatment of rapamycin or 3-methyladenine (3-MA), autophagy inhibitor, RAW264.7 cells were infected with S. Typhimurium. Pretretment of rapamycin decreased the growth rate of S. Typhimurium in the cells; otherwise, pretreatment of 3-MA increased the growth rate of S. Typhimurium. The expression of autophagy-related genes was significantly increased in the S. Typhimurium-infected cells pretreated with rapamycin. To examine whether induced autophagy by rapamycin control the infection with increase the production of reactive oxygen species (ROS) and nitric oxide (NO), antibacterial radical substrates were measured in infected cells followed by the treatment with either rapamycin or 3-MA. NO production increased in RAW264.7 cells; otherwise, ROS production remained unchanged during the infection. These findings suggest that inducing autophagy with rapamycin reveals antimicrobial activity as producing NO against S. Typhimurium infection in mouse macrophages.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.1
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• pp.44-48
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• 2015

Mucopolysaccharidosis (MPS) IIIA is a lysosomal storage disorder caused by abnormalities of the enzyme Heparan N-sulfatase that is required for degradation of heparan sulfate. The patient in this study was a 5 year-old boy who presented with macrocephaly and developmental delay. Urinary excretion of glycosaminoglycan was increased (26 g/moL creatinine, reference range: <7 g/moL creatinine) and a distinct band of heparan sulfate was shown in electrophoresis. Heparan N-sulfatase activity was significantly decreased in skin fibroblasts (0.2 pmoL/min/mg protein, reference range: 9-64 pmoL/min/mg protein). PCR and direct sequencing analysis of the SGSH gene showed compound heterozygous mutations: c.1040C>T (p.S347F) and c.703G>A (p.D235N). This is the first report for a Korean patient with MPS IIIA who was confirmed by biochemical investigation and molecular genetic analyses.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.95-101
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• 2018

The epidermis which is stratified by epithelial tissue renewal based on keratinocyte differentiation protects the organism from various environmental insults by forming a physical barrier. Autophagy is a mechanism which mediates lysosomal delivery and degradation of protein aggregates, damaged organelles and intracellular microorganisms. Recent reports have shown that autophagy has critical roles for proper terminal differentiation to stratum corneum via removing metabolic organelles and nuclei. However, whether increasing autophagy can activate epidermal differentiation is unknown. Here, we screened a library of natural single compounds and discovered that betaine specifically increased the LC3 positive cytosolic punctate vesicles and LC3-I to LC3-II conversion in HaCaT human keratinocyte cell line, indicating increased autophagy flux. mTOR pathway, which negatively regulates autophagy, was not affected by betaine treatment, suggesting betaine-induced autophagy through an mTOR-independent pathway. Betaine-induced autophagy was also observed in primary human keratinocyte and skin equivalent. Furthermore, epidermal thickness was increased in skin equivalent under betaine treatment. Overall, our finding suggests that betaine as a novel regulator of autophagy may induce epidermal turnover and improve the skin barrier abnormality of the aged epidermis.

• Journal of Ginseng Research
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• v.48 no.1
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• pp.31-39
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• 2024

Background: Ginsenoside Rg3, a primary bioactive component of red ginseng, has anti-cancer effects. However, the effects of Rg3-enriched ginseng extract (Rg3RGE) on apoptosis and autophagy in breast cancer have not yet been investigated. In the present study, we explored the anti-tumor effects of Rg3RGE on breast cancer cells stimulated CoCl₂, a mimetic of the chronic hypoxic response, and determined the operative mechanisms of action. Methods: The inhibitory mechanisms of Rg3RGE on breast cancer cells, such as apoptosis, autophagy and ROS levels, were detected both in vitro. To determine the anti-cancer effects of Rg3RGE in vivo, the cancer xenograft model was used. Results: Rg3RGE suppressed CoCl₂-induced spheroid formation and cell viability in 3D culture of breast cancer cells. Rg3RGE promoted apoptosis by increasing cleaved caspase 3 and cleaved PARP and decreasing Bcl2 under the hypoxia mimetic conditions. Further, we identified that Rg3RGE promoted apoptosis by inhibiting lysosomal degradation of autophagosome contents in CoCl₂-induced autophagy. We further identified that Rg3RGE-induced apoptotic cell death and autophagy inhibition was mediated by increased intracellular ROS levels. Similarly, in the in vivo xenograft model, Rg3RGE induced apoptosis and inhibited cell proliferation and autophagy. Conclusion: Rg3RGE-stimulated ROS production promotes apoptosis and inhibits protective autophagy under hypoxic conditions. Autophagosome accumulation is critical to the apoptotic effects of Rg3RGE. The in vivo findings also demonstrate that Rg3RGE inhibits breast cancer cell growth, suggesting that Rg3RGE has potential as potential as a putative breast cancer therapeutic.

• Journal of Life Science
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• v.24 no.11
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• pp.1180-1186
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• 2014

Autophagy, the lysosomal degradation pathway, is an intracellular recycling system that is necessary for the metabolic benefits of exercise and for producing lasting beneficial effects of exercise in various diseases. However, the most recent studies have only examined the effect of a single bout of exercise or resistance exercise on autophagic responses. To determine the differential effects of acute and chronic exercise on the expression of autophagy-related genes in D. melanogaster, white-eyed mutant D. melanogaster were assigned randomly to four groups: control, acute exercise, 2 hr chronic exercise, and 3 hr chronic exercise. The flies were exercised using a mechanized platform known as the Power Tower. Our results revealed that a single bout of exercise resulted in increased mRNA levels of the Atg8a gene (~20%, p<0.05). However, Atg1 and Atg6 mRNA expression were not induced by acute exercise. Transcript levels of Atg6 (~29%, p<0.05) related to the nucleation of autophagosomes were significantly induced by 2 hr of chronic exercise. However, this chronic exercise was not enough to increase Atg1 and Atg8a mRNA expression. On the other hand, 3 hr of exercise for 7 days significantly increased Atg1, Atg6, and Atg8a gene expression-about 57%, 37%, and 71%, respectively (p<0.05). These results suggest that a single bout of exercise is not enough to induce full activation of selected autophagy-related genes in D. melanogaster. Our results demonstrated that chronic regular exercise induced autophagy-related gene expression, suggesting that chronic regular exercise training might be required to activate autophagic responses important for producing beneficial effects of exercise in various diseases.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.650-654
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• 2008

Glycogen storage disease (GSD) and mucopolysaccharidosis (MPS) are both independently inherited disorders. GSD is a member of a group of genetic disorders involving enzymes responsible for the synthesis and degradation of glycogen. GSD leads to abnormal tissue concentrations of glycogen, primarily in the liver, muscle, or both. MPS is a member of a group of inherited lysosomal storage diseases, which result from a deficiency in specific enzymatic activities and the accumulation of partially degraded acid mucopolysaccharides. A case of a 16-month-old boy who presented with hepatomegaly is reported. The liver was four finger-breadth-palpable. A laboratory study showed slightly increased serum AST and ALT levels. The liver biopsy showed microscopic features compatible with GSD. The liver glycogen content was 9.3% which was increased in comparison with the reference limit, but the glucose-6-phosphatase activity was within the normal limit. These findings suggested GSD other than type I. Bony abnormalities on skeletal radiographs, including an anterior beak and hook-shaped vertebrae, were seen. The mucopolysaccharide concentration in the urine was increased and the plasma iduronate sulfatase activity was low, which fulfilled the diagnosis criteria for Hunter syndrome (MPS type II). To the best of the authors' knowledge, this is the first case of GSD and Hunter syndrome being identified at the same time.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1132-1138
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• 2005

Purpose : The mucopolysaccharidoses (MPSs) are a heterogeneous group of lysosomal storage disorders. They are caused by a deficiency of the enzymes involved in the degradation of glycosaminoglycans. Early recognition is important because recombinant enzyme replacement therapy is now available for MPS. We studied the clinical characteristics of 80 MPS children with the object of determining the epidemiological, clinical and radiological features in Korean MPS children. Methods : Diagnosis of MPS was confirmed by skin fibroblast enzyme analysis in 80 patients between February 1995 and December 2004. Charts were retrospectively reviewed for clinical and radiological findings, as well as for intelligence and speech evaluations. Results : Hunter syndrome (MPS type II) was the most prevalent type, appearing in 51/80 cases (64 %), followed by Sanfilippo syndrome (MPS III-18%), Hurler syndrome (MPS I-15%), and Morquio syndrome (MPS IV-4%). The average age at diagnosis was 5.5 years (range 1 to 20), and the male-to-female ratio was 4.7 : 1. Typical radiographic changes were observed in 45/54 cases (83%). Mitral regurgitation was the most common cardiac defect. Moderate to profound mental retardation and hearing loss were present in 14/35 cases (56%) and 33/38 cases (82%), respectively. Four MPS II patients had bone marrow transplantation, with mixed outcomes. Five MPS I patients are currently on enzyme replacement therapy. Conclusion : Our study showed a high proportion of MPS II cases (64%), which may represent population variability. By studying the clinical features of these patients, we hope to alert pediatricians of the warning signs of MPS.