• Title/Summary/Keyword: Metabolic Products

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Changes of Cytosolic $Ca^{2+}$ under Metabolic Inhibition in Isolated Rat Ventricular Myocytes

  • Kang, Sung-Hyun;Kim, Na-Ri;Joo, Hyun;Youm, Jae-Boum;Park, Won-Sun;Warda, Mohamed;Kim, Hyung-Kyu;Von Cuong, Dang;Kim, Tae-Ho;Kim, Eui-Yong;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.5
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    • pp.291-298
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    • 2005
  • To characterize cytosolic $Ca^{2+}$ fluctuations under metabolic inhibition, rat ventricular myocytes were exposed to $200{\mu}M$ 2,4-dinitrophenol (DNP), and mitochondrial $Ca^{2+}$, mitochondrial membrane potential (${\Delta}{\Psi}m$), and cytosolic $Ca^{2+}$ were measured, using Rhod-2 AM, TMRE, and Fluo-4 AM fluorescent dyes, respectively, by Laser Scanning Confocal Microscopy (LSCM). Furthermore, the role of sarcolemmal $Na^+$/$Ca^{2+}$ exchange (NCX) in cytosolic $Ca^{2+}$ efflux was studied in KB-R7943 and $Na^+$-free normal Tyrode's solution (143 mM LiCl ). When DNP was applied to cells loaded with Fluo-4 AM, Fluo-4 AM fluorescence intensity initially increased by $70{\pm}10$% within $70{\pm}10$ s, and later by $400{\pm}200$% at $850{\pm}45$ s. Fluorescence intensity of both Rhod-2 AM and TMRE were initially decreased by DNP, coincident with the initial increase of Fluo-4 AM fluorescence intensity. When sarcoplasmic reticulum (SR) $Ca^{2+}$ was depleted by $1{\mu}M thapsigargin plus $10{\mu}M ryanodine, the initial increase of Fluo-4 AM fluorescence intensity was unaffected, however, the subsequent progressive increase was abolished. KB-R7943 delayed both the first and the second phases of cytosolic $Ca^{2+}$ overload, while $Na^+$-free solution accelerated the second. The above results suggest that: 1) the initial rise in cytosolic $Ca^{2+}$ under DNP results from mitochondrial depolarization; 2) the secondary increase is caused by progressive $Ca^{2+}$ release from SR; 3) NCX plays an important role in transient cytosolic $Ca^{2+}$ shifts under metabolic inhibition with DNP.

Tissue Microarrays in Biomedical Research

  • Chung, Joon-Yong;Kim, Nari;Joo, Hyun;Youm, Jae-Boum;Park, Won-Sun;Lee, Sang-Kyoung;Warda, Mohamad;Han, Jin
    • Bioinformatics and Biosystems
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    • v.1 no.1
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    • pp.28-37
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    • 2006
  • Recent studies in molecular biology and proteomics have identified a significant number of novel diagnostic, prognostic, and therapeutic disease markers. However, validation of these markers in clinical specimens with traditional histopathological techniques involves low throughput and is time consuming and labor intensive. Tissue microarrays (TMAs) offer a means of combining tens to hundreds of specimens of tissue onto a single slide for simultaneous analysis. This capability is particularly pertinent in the field of cancer for target verification of data obtained from cDNA micro arrays and protein expression profiling of tissues, as well as in epidemiology-based investigations using histochemical/immunohistochemical staining or in situ hybridization. In combination with automated image analysis, TMA technology can be used in the global cellular network analysis of tissues. In particular, this potential has generated much excitement in cardiovascular disease research. The following review discusses recent advances in the construction and application of TMAs and the opportunity for developing novel, highly sensitive diagnostic tools for the early detection of cardiovascular disease.

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Milk Intake is Associated with Metabolic Syndrome - Using Data from the Korea National Health and Nutrition Examination Survey 2007~2010 (우유 섭취와 대사증후군의 관련성 - 2007~2010년 국민건강영양조사 자료를 이용하여)

  • Lee, Chang Jin;Joung, Hyojee
    • Korean Journal of Community Nutrition
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    • v.17 no.6
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    • pp.795-804
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    • 2012
  • This study aimed to examine associations between milk intake and metabolic syndrome. The subjects included 1,928 males and 3,103 females, aged 19 to 64 years, from the data of 'The Korean National Health and Nutrition Survey 2007-2010'. Daily intake of milk and dairy products was obtained by a 24 hour dietary recall method and divided into two categories by equivalent weight of one serving. The average individual intakes of milk and dairy products were 59.4 g and 74.1 g per day respectively. Milk intake was inversely associated with metabolic syndrome (OR: 0.69, 95% CI: 0.54~0.89), central obesity (OR: 0.75, 95% CI: 0.62~0.91), and hypertriglyceridemia (OR: 0.73, 95% CI: 0.59~0.90). The total intake of dairy products was also inversely associated with metabolic syndrome (OR: 0.74, 95% CI 0.60~0.92), central obesity (OR: 0.73, 95% CI: 0.62~0.86), hypertension (OR: 0.80, 95% CI: 0.65~0.99). The association between intakes of milk and dairy products and metabolic syndrome was significant in women, but not in men. These results indicate that increased consumption of milk and its products is associated with a reduced likelihood of metabolic syndrome and metabolic syndrome risk factors. Further research on causal relationship and dose-response association between milk intake and metabolic syndrome risk is necessary prior to applying the observed results in nutrition policies and programs to prevent the metabolic syndrome.

Differential Activation of Ras/Raf/MAPK Pathway between Heart and Cerebral Artery in Isoproterenol-induced Cardiac Hypertrophy

  • Kim, Hyun-Ju;Kim, Na-Ri;Joo, Hyun;Youm, Jae-Boum;Park, Won-Sun;Warda, Mohamed;Kang, Sung-Hyun;Thu, Vu-Thi;Khoa, Tran-Minh;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.5
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    • pp.299-304
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    • 2005
  • Cardiac hypertrophy contributes an increased risk to major cerebrovascular events. However, the molecular mechanisms underlying cerebrovascular dysfunction during cardiac hypertrophy have not yet been characterized. In the present study, we examined the molecular mechanism of isoproterenol (ISO)-evoked activation of Ras/Raf/MAPK pathways as well as PKA activity in cerebral artery of rabbits, and we also studied whether the activations of these signaling pathways were altered in cerebral artery, during ISO-induced cardiac hypertrophy compared to heart itself. The results show that the mRNA level of c-fos (not c-jun and c-myc) in heart and these genes in cerebral artery were considerably increased during cardiac hypertrophy. These results that the PKA activity and activations of Ras/Raf/ERK cascade as well as c-fos expression in rabbit heart during cardiac hypertrophy were consistent with previous reports. Interestingly, however, we also showed a novel finding that the decreased PKA activity might have differential effects on Ras and Raf expression in cerebral artery during cardiac hypertrophy. In conclusion, there are differences in molecular mechanisms between heart and cerebral artery during cardiac hypertrophy when stimulated with β2 adrenoreceptor (AR), suggesting a possible mechanism underlying cerebrovascular dysfunction during cardiac hypertrophy.

AMPK Activators from Natural Products: A Patent Review

  • Uddin, Mohammad Nasir;Sharma, Govinda;Choi, Hong Seok;Lim, Seong-Il;Oh, Won Keun
    • Natural Product Sciences
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    • v.19 no.1
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    • pp.1-7
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    • 2013
  • AMP-activated protein kinase (AMPK) is a major cellular energy sensor and master regulator of metabolic homeostasis. On activation, this cellular fuel sensing enzyme induces a series of metabolic changes to balance energy consumption via multiple downstream signaling pathways controlling nutrient uptake and energy metabolism. This pivotal role of AMPK has led to the development of numerous AMPK activators which might be used as novel drug candidates in the treatment of AMPK related disorders, diabetes, obesity, and other metabolic diseases. Consequently, a number of patents have been published on AMPK activators from natural products and other sources. This review covers the patented AMPK activators from natural products and their therapeutic potential in treatment or prevention of metabolic diseases including diabetes and obesity.

Regional Differences in Mitochondrial Anti-oxidant State during Ischemic Preconditioning in Rat Heart

  • Thu, Vu Thi;Cuong, Dang Van;Kim, Na-Ri;Youm, Jae-Boum;Warda, Mohamad;Park, Won-Sun;Ko, Jae-Hong;Kim, Eui-Yong;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.11 no.2
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    • pp.57-64
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    • 2007
  • Ischemic preconditioning (IPC) is known to protect the heart against ischemia/reperfusion (IR)-induced injuries, and regional differences in the mitochondrial antioxidant state during IR or IPC may promote the death or survival of viable and infarcted cardiac tissues under oxidative stress. To date, however, the interplay between the mitochondrial antioxidant enzyme system and the level of reactive oxygen species (ROS) in the body has not yet been resolved. In the present study, we examined the effects of IR- and IPC-induced oxidative stresses on mitochondrial function in viable and infarcted cardiac tissues. Our results showed that the mitochondria from viable areas in the IR-induced group were swollen and fused, whereas those in the infarcted area were heavily damaged. IPC protected the mitochondria, thus reducing cardiac injury. We also found that the activity of the mitochondrial antioxidant enzyme system, which includes manganese superoxide dismutase (Mn-SOD), was enhanced in the viable areas compared to the infarcted areas in proportion with decreasing levels of ROS and mitochondrial DNA (mtDNA) damage. These changes were also present between the IPC and IR groups. Regional differences in Mn-SOD expression were shown to be related to a reduction in mtDNA damage as well as to the release of mitochondrial cytochrome c (Cyt c). To the best of our knowledge, this might be the first study to explore the regional mitochondrial changes during IPC. The present findings are expected to help elucidate the molecular mechanism involved in IPC and helpful in the development of new clinical strategies against ischemic heart disease.

Protein Kinase C Activates ATP-sensitive Potassium Channels in Rabbit Ventricular Myocytes

  • Kim, Na-Ri;Youm, Jae-Boum;Joo, Hyun;Kim, Hyung-Kyu;Kim, Eui-Yong;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.4
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    • pp.187-193
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    • 2005
  • Several signal transduction pathways have been implicated in ischemic preconditioning induced by the activation of ATP-sensitive $K^+$ $(K_{ATP})$ channels. We examined whether protein kinase C (PKC) modulated the activity of $K_{ATP}$ channels by recording $K_{ATP}$ channel currents in rabbit ventricular myocytes using patch-clamp technique and found that phorbol 12,13-didecanoate (PDD) enhanced pinacidil-induced $K_{ATP}$ channel activity in the cell-attached configuration; and this effect was prevented by bisindolylmaleimide (BIM). $K_{ATP}$ channel activity was not increased by $4{\alpha}-PDD$. In excised insideout patches, PKC stimulated $K_{ATP}$ channels in the presence of 1 mM ATP, and this effect was abolished in the presence of BIM. Heat-inactivated PKC had no effect on channel activity. PKC-induced activation of $K_{ATP}$ channels was reversed by PP2A, and this effect was not detected in the presence of okadaic acid. These results suggest that PKC activates $K_{ATP}$ channels in rabbit ventricular myocytes.