• Journal of Ginseng Research
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• 제41권1호
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• pp.23-30
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• 2017

Background: Ginsenoside Rg1 is a class of steroid glycoside and triterpene saponin in Panax ginseng. Many studies suggest that Rg1 suppresses adipocyte differentiation in 3T3-L1. However, the detail molecular mechanism of Rg1 on adipogenesis in 3T3-L1 is still not fully understood. Methods: 3T3-L1 preadipocyte was used to evaluate the effect of Rg1 on adipocyte development in the differentiation in a stage-dependent manner in vitro. Oil Red O staining and Nile red staining were conducted to measure intracellular lipid accumulation and superoxide production, respectively. We analyzed the protein expression using Western blot in vitro. The zebrafish model was used to investigate whether Rg1 suppresses the early stage of fat accumulation in vivo. Results: Rg1 decreased lipid accumulation in early-stage differentiation of 3T3-L1 compared with intermediate and later stages of adipocyte differentiation. Rg1 dramatically increased CAAT/enhancer binding protein (C/EBP) homologous protein-10 (CHOP10) and subsequently reduced the $C/EBP{\beta}$ transcriptional activity that prohibited the initiation of adipogenic marker expression as well as triglyceride synthase. Rg1 decreased the expression of extracellular signal-regulated kinase 1/2 and glycogen synthase kinase $3{\beta}$, which are also essential for stimulating the expression of $CEBP{\beta}$. Rg1 also reduced reactive oxygen species production because of the downregulated protein level of nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase 4 (NOX4). While Rg1 increased the endogenous antioxidant enzymes, it also dramatically decreased the accumulation of lipid and triglyceride in high fat diet-induced obese zebrafish. Conclusion: We demonstrated that Rg1 suppresses early-stage differentiation via the activation of CHOP10 and attenuates fat accumulation in vivo. These results indicate that Rg1 might have the potential to reduce body fat accumulation in the early stage of obesity.

• Journal of Nutrition and Health
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• 제55권1호
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• pp.70-84
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• 2022

Purpose: Skeletal muscles display significant heterogeneity in metabolic responses, owing to the composition of metabolically distinct fiber types. Recently, numerous studies have reported that in skeletal muscles, suppression of genes related to fatty acid channeling alters the triacylglycerol (TAG) synthesis and switches the energy substrates. However, such responses may differ, depending on the type of muscle fiber. Hence, we conducted in vitro and animal studies to compare the metabolic responses of different types of skeletal muscle fibers to the deficiency of fatty acyl-CoA synthetase (Acsl)6, one of the main fatty acid-activating enzymes. Methods: Differentiated skeletal myotubes were transfected with selected Acsl6 short interfering RNA (siRNA), and C57BL/6J mice were subjected to siRNA to induce Acsl6 deficiency. TAG accumulation and expression levels of insulin signaling proteins in response to acute glucose supplementation were measured in immortalized cell-based skeletal myotubes, oxidative muscles (OM), and glycolytic muscles (GM) derived from the animals. Results: Under conditions of high glucose supplementation, suppression of the Acsl6 gene resulted in decreased TAG and glycogen synthesis in the C2C12 skeletal myotubes. The expression of Glut4, a glucose transporter, was similarly downregulated. In the animal study, the level of TAG accumulation in OM was higher than levels determined in GM. However, a similar decrease in TAG accumulation was obtained in the two muscle types in response to Acsl6 suppression. Moreover, Acsl6 suppression enhanced the phosphorylation of insulin signaling proteins (Foxo-1, mTORc-1) only in GM, while no such changes were observed in OM. In addition, the induction ratio of phosphorylated proteins in response to glucose or Acsl6 suppression was significantly higher in GM than in OM. Conclusion: The results of this study demonstrate that Acsl6 differentially regulates the energy metabolism of skeletal muscles in response to glucose supplementation, thereby indicating that the fiber type or fiber composition of mixed muscles may skew the results of metabolic studies.

• 대한수의학회지
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• 제22권2호
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• pp.187-195
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• 1982

This paper dealt with the light microscopical and electron microscopical findings on the morphological changes of the liver of Korean native goat injected with toxin (culture filtrate) of Clostridium perfringens which was isolated from Korean native cattle died of acute Clostridium perfringens enterotoxemia. The results observed are summarized as follows. In the microscopical findings, hyperemia and minute hemorrhage of the liver parenchyma, dilatation of hepatic central vein and centrilobular necrosis of liver, cloudy swelling and hydropic degeneration of hepatic cells, and appearance of light eosinophilic granular bodies in the vacuoles were recognized. In the electron microscopical findings, appearance of pinocytotic vesicle (coated vesicle), fusion of these vesicles, formation of vacuole and accumulation of minute granular proteinous materials in the vacuole were observed in the hepatic cells. Decreased number of glycogen granules, swelling and destruction of mitochondria, proliferation of smooth-surfaced endoplasmic reticulum, enlargement of rough-surfaced endoplasmic reticulum, dispersal of thready agranular membranous structure and appearance of secondary lysosome were recognized in the hepatic cell cytoplasm.

• Journal of Genetic Medicine
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• 제6권2호
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• pp.161-165
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• 2009

폼페병은 상염색체 열성으로 유전되는 질환으로 GAA 효소의 결핍에 의해 심장과 골격근 조직의 라이소좀과 세포질에 당원이 축적된다. 전형적 영아형 폼페병은 심비대, 호흡부전, 근긴장 저하가 발생하고, 대부분 심폐 부전이나 호흡기 감염으로 1-2세 경에 사망에 이른다. 비전형적 영아형은 상대적으로 임상 양상이 경하고 진행이 느리다. 저자들은 영아기에 심근병증을 진단받고 서서히 근위부 근력의 약화가 진행되었던 남매에서 근생검, 효소 활성도 분석 및 GAA 유전자 분석으로 확진된 비전형적 영아형 폼페병을 경험하였기에 보고하는 바이다.

• The Korean Journal of Physiology and Pharmacology
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• 제15권2호
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• pp.107-114
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• 2011

Neurofibrillary tangle (NFT) is a characteristic hallmark of Alzheimer's disease. GSK3β has been reported to play a major role in the NFT formation of tau. Dysfunction of autophagy might facilitate the aggregate formation of tau. The present study examined the role of GSK3${\beta}$-mediated phosphorylation of tau species on their autophagic degradation. We transfected wild type tau (T4), caspase-3-cleaved tau at Asp421 (T4C3), or pseudophosphorylated tau at Ser396/Ser404 (T4-2EC) in the presence of active or enzyme-inactive GSK3${\beta}$. Trehalose and 3-methyladenine (3-MA) were used to enhance or inhibit autophagic activity, respectively. All tau species showed increased accumulation with 3-MA treatment whereas reduced with trehalose, indicating that tau undergoes autophagic degradation. However, T4C3 and T4-2EC showed abundant formation of oligomers than T4. Active GSK3${\beta}$ in the presence of 3-MA resulted in significantly increased formation of insoluble tau aggregates. These results indicate that GSK3${\beta}$-mediated phosphorylation and compromised autophagic activity significantly contribute to tau aggregation.

• Clinical and Experimental Pediatrics
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• 제51권6호
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• pp.650-654
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• 2008

당원병(GSD)과 점액다당류증(MPS)은 각각 독립된 유전 질환으로, 각기 다른 대사에 관여하는 효소의 결핍으로 인해 전구물질이 축적되어 임상 증상을 나타낸다. 간비대는 두 질환 모두에서 나타나는 중요한 임상 양상이다. 저자들은 이 드문 두 질환이 한 환자에서 동시에 발견되어 이에 보고하고자 한다. 16개월 남아가 2개월 동안 반복적인 중이염을 앓았고, 인근 병원을 다니던 중 우연히 간비대가 발견되었다. 환아는 이마가 튀어나온 조악한 얼굴 모양을 가지고 있었다. 환아의 간은 4횡지 정도로 촉지되었고, 그 성상은 부드럽고 무른 느낌이었으나 경계가 예리하게 만져졌다. 혈액 검사상, AST와 ALT가 85 IU/L, 77 IU/L로 약간 상승되어 있었다. 공복 저혈당은 보이지 않았고, 혈청 젖산, 요산, 콜레스테롤 모두 정상 소견을 보였다. 복부 초음파에서는 간의 메아리 발생 정도(echogenecity)가 증가되어 있었다. 간 생검을 실시하였고, 현미경 검사상 둥근 간세포들이 관찰되었는데, 그 간세포 내에는 Periodic Acid-Schiff 염색에서 진하게 염색되는 거대한 당원 입자들 다수와 이와 동반된 지방 공포(lipid vacuole)가 포함되어 있었다. 전자현미경에서 간세포의 핵과 세포질 모두에 당원 입자들이 포함되어 있었고 거대한 미토콘드리아도 관찰할 수 있었다. 생검을 통해 채취한 간 조직을 분석한 결과, 간의 당원 함량은 9.3%로 정상수치에 비해 증가되어 있었으나, 간의 glucose-6-phosphatase 활성도는 정상이어서 Ia형이 아닌 당원병으로 진단하게 되었다. 한편, X 선상 척추 앞면의 부리모양(beak-shape)와 J 모양의 안장(sella)과 같은 여러 골격의 이상 소견을 보였으며, 소변의 점액다당류 농도 또한 증가되어 있었다. Iduronate sulfatase 활성도가 0.1 nmol/hr/mg protein로 낮은 소견을 보여 헌터 증후군(제2형 점액다당류증, MPS type II)으로 진단할 수 있었다. 이에 저자들은 상기 환자가 당원병과 헌터증후군이 동시에 발견된 첫 환자로 생각되어 보고하는 바이다.

• Applied Microscopy
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• 제24권3호
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• pp.23-33
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• 1994

It is well known that dichlorvos (DDVP), an organophosphate insecticide in common use, is so easily and rapidly hydrolyzed and excreted that it has usually little toxic effect on human body. In these days, however, it is widely used as an industrial and domestic insecticide and as an anthelmintic agent for animals, so that the accident of chemical poisoning occurs frequently. DDVP acts as a powerful inhibitor of carboxylic esterase, which can cause accumulation of acetylcholine at the synapses so paralysis of muscle and the transmission failure in cholinergic synapses dueing to desensitization of acetylcholin receptor may occure. Moreover accumulation of the acetylcholine brings about the elevation of the cyclic-AMP, which alters the cellular metabolisms of nucleic acid, carbohydrate, protein and lipid. Present study has undertaken to investigate the cardiotoxic effect of DDVP by electron microscopic study. A total of 30 Sprague-Dawley strain rats, weighing about 250gm were used as experimental animals. 2mg/kg/day of DDVP is intraperitonealy injected 3 times with intervals of every other day. On 1 day, 3 days, 5 days, 7 days and 14 days after drug administration, the animals were sacrified by cervical dislocation. Left ventricular cardiac muscles were resected and sliced into $1mm^3$. The specimens were embedded with Epon 812 and prepared by routine methods for electron microscopical observation. All preparations were stained with lead citrate and uranyl acetate and then observed with Hitachi-600 transmission electron microscope. The results were as follows: 1. In the cardiac muscle of DDVP treated rats, mitochondria with disorganized double membrane and mitochondrial crista, and vacuole formation in mitochondrial matrix were observed. But structures of mitochondria were recovered to normal in 14 days group. 2. In the cardiac muscle of DDVP treated rats, cisternae of sarcoplasmic reticulum were dilated and sacculated. But these changes were recovered to normal in 14 days group. 3. In the cardiac muscle of DDVP treated rats, glycogen particles around damaged myofibrils were decreased. But amount of glycogen particles were restored in 14 days group. 4. In the cardiac muscle of DDVP treated rats, disruption and discontinuation of myofilaments and disorganization of Z-disc were observed. But the structures of myofibrils were recovered to normal in 14 days group. It is consequently suggested that DDVP would induce the reversible degenerative changes on the ultrastructures in cardiac muscle of rat.

• Animal cells and systems
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• 제12권4호
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• pp.313-319
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• 2008

The ultrastructure of oocytes during oogenesis and oocyte degeneration associated with follicle cells in female Sinonovacula constricta(Lamarck, 1818) were investigated by electron microscope observations. Ovarian follicles are surrounded by a matrix of vesicular connective tissue cells(VCT cells). VCT cells contain large quantities of glycogen particles and several lipid droplets in their cytoplasm. It is suggested that VCT cells act as a source of nutrients for vitellogenesis during oogenesis. In early vitellogenic oocytes, several coated vesicles, which appear at the basal region of the oocyte, lead to the formation of membrane-bound vesicles via endocytosis. The uptake of nutritive materials in coated vesicles formed by endocytosis appears through the formation of coated pits on the oolemma during vitellogenesis. During the late stage of oogenesis, yolk precursors(yolk granules), mitochondria and lipid droplets are present in the cytoplasm of late vitellogenic oocytes. In particular, proteinaceous yolk granules containing several different components are intermingles and form immature yolk granules. In the mature oocyte, small immature yolk granules are intermingled and form large mature yolk granules. Vitellogenesis occurs through a process of autosynthesis, involving combined activity of the Golgi complex, mitochondria and rough endoplasmic reticulum in the cytoplasm of vitellogenic oocytes. The process of heterosynthesis is where extraovarian precursors are incorporated into oocytes by endocytosis at the basal region of early vitellogenic oocytes before the formation of the vitelline coat. Follicle cells appear to play an important role in vitellogenesis and oocyte degeneration. The functions of attached follicle cells to the oocyte during oocyte degeneration are phagocytosis and digestion of phagosomes originating from oocyte degeneration. After digestion of phagosomes, it is assumed that the function of follicle cells can permit a transfer of yolk precursors necessary for vitellogenesis and allows for the accumulation of glycogen and lipid during oocyte degeneration, which can be employed by vitellogenic oocytes. Follicle cells of S. constricta may possess a lysosomal system for induction of oocyte breakdown and might resorb phagosomes in the cytoplasm for nutrient accumulation during oocyte degeneration.

• 한국수산과학회지
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• 제19권1호
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• pp.83-91
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• 1986

1983년 9월부터 1984년 8월까지 부산시 해운대 동백섬의 조간대에서 채집된 노래미. Agrammus agrammus를 대상으로 생식소의 발달과 간의 활성변화관계를 파악하기 위해 간숙도지수(HSI)의 연간변화를 조사하였고 아울러 생식주기에 따른 간세포의 활성변화를 광학 및 전자현미경적 방법에 의해 조사하였다. 간숙도지수(HSI)의 연간변화는 수컷의 경우 뚜렸하지 않으나 암컷의 경우는 추계에 증가하기 시작하여 난소가 성숙하는 동계에 최대에 이른다. 암컷에 있어서 난모세포들이 난황물질을 축적하는 시기에는 간세포들의 크기는 점차로 커지며 핵과 인도 역시 커진다. 이때에 글리코겐과 지방적들의 양은 점차로 감소되나 호염기성의 핵산물질(RNA)은 증가된다. 또한 간세포질내에는 조면소포체들이 발달 증가하는데 이들은 단백질합성과 vitellogenin 축적에 관여하고 핵근처에 나타나는 골지체는 lipoprotein 합성에 중요한 역할을 하는 것으로 간주된다. 방난 직전의 암컷의 간세포질내에는 글리코겐과 지방적들이 급격히 감소되나 호염기성물질(RNA)은 세포질의 주변구역에서 특히 고농도로 나타나고 있다. 그러나 방난 이후에는 이와 반대의 현상이 관찰된다. 수컷의 경우는 성적으로 성숙해 감에 따라 간세포질내에 호염기성물질이 점차로 증가하며, 암컷과 달리 글리코겐과 지방적의 양도 다량으로 관찰된다. 반면, 방정기 이후에는 간세포질내의 호염기성물질은 감소된다.

• Journal of Veterinary Science
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• 제23권1호
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• pp.4.1-4.15
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• 2022

Background: Flavonoids are natural polyphenols found widely in citrus fruit and peel that possess anti-adipogenic effects. On the other hand, the detailed mechanisms for the antiadipogenic effects of flavonoids are unclear. Objectives: The present study observed the anti-adipogenic effects of five major citrus flavonoids, including hesperidin (HES), narirutin (NAR), nobiletin (NOB), sinensetin (SIN), and tangeretin (TAN), on AMP-activated protein kinase (AMPK) activation in palmitate (PA)-treated HepG2 cells. Methods: The intracellular lipid accumulation and triglyceride (TG) contents were quantified by Oil-red O staining and TG assay, respectively. The glucose uptake was assessed using 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) assay. The levels of AMPK, acetyl-CoA carboxylase (ACC), and glycogen synthase kinase 3 beta (GSK3β) phosphorylation, and levels of sterol regulatory element-binding protein 2 (SREBP-2) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) expression were analyzed by Western blot analysis. The potential interaction between the flavonoids and the γ-subunit of AMPK was investigated by molecular docking analysis. Results: The flavonoid treatment reduced both intracellular lipid accumulation and TG content in PA-treated HepG2 cells significantly. In addition, the flavonoids showed increased 2-NBDG uptake in an insulin-independent manner in PA-treated HepG2 cells. The flavonoids increased the AMPK, ACC, and GSK3β phosphorylation levels and decreased the SREBP-2 and HMGCR expression levels in PA-treated HepG2 cells. Molecular docking analysis showed that the flavonoids bind to the CBS domains in the regulatory γ-subunit of AMPK with high binding affinities and could serve as potential AMPK activators. Conclusion: The overall results suggest that the anti-adipogenic effect of flavonoids on PA-treated HepG2 cells results from the activation of AMPK by flavonoids.