• Korea Journal of Cosmetic Science
• /
• 제1권1호
• /
• pp.1-9
• /
• 2019

The identification of compounds with anti-senescence activity in cell culture system is a first step in aging research. Given that pyruvate can be used energy source by conversion to acetyl-CoA in mitochondria, and protects cultured cell from various stress-induced cell damage and cell death, synthetic media (e.g., DMEM) often includes 1 mM pyruvate, which is very higher than the pyruvate concentration in human blood (approximately 30 ��M). However, the use of medium containing high concentration of pyruvate is not suitable for screening anti-senescence compounds, because pyruvate also protects against the cellular senescence of primary human dermal fibroblasts (NHDFs) through NAD+ generated during conversion to lactate. In this study, four extracts, i.e., Sprouted seed and fruit complex, Poncirus trifoliata fruit extract, Jaum balancing complex, and Prunus mume extract were used for evaluation of different anti-senescence effect in the absence or presence of 0.1 mM pyruvate, similar to the physiological pyruvate concentration. The senescence in NHDFs cultured with DMEM in the presence of 0.1 mM pyruvate (approximately the physiological concentration in human blood) is accelerated, as observed in pyruvate deprivation conditions. The cytotoxicity of the Poncirus trifoliata fruit extract was protected by pyruvate, and Jaum balancing complex and Prunus mume extract had anti-senescence activity in the presence of 0.1 mM pyruvate, but not in the absence of pyruvate. Given that pyruvate is a powerful protector against both cytotoxicity and cellular senescence, the screening of candidate agents for anti-senescence in high pyruvate conditions using an in vitro cell culture system is not valid. Therefore, we recommend the use of a low concentration of pyruvate to evaluate the anti-senescence effects of candidates, which is more similar to in vivo aging conditions than excessive stress-induced senescence models, to exclude the effect of excessive pyruvate in vitro.

• Journal of Nutrition and Health
• /
• 제32권3호
• /
• pp.318-326
• /
• 1999

Apoptotic cell death, characterized by DNA fragmentation and morphological changes, has previously been shown to occur in vascular endothelial cells cultured with hydrogen peroxide. The present study examined the induction of apoptosis by hydrogen peroxide and whether pyruvate, a key glycolytic intermediate and $\alpha$-keto-monocarboxylate, can inhibit the apoptotic effects in bovine pulmonary artery endothelial cells(BPAECs). Culture with 500uM hydrogen peroxide resulted in 30% cell death and induced morphological changes and DNA fragmentation. Cell injury was inhibited by the treatment with pyruvate. Pyruvate(0.1-5.0mM), and cell viability increased in a dose-dependent manner. In the presence of pyruvate(10~20mM), the viability was improved to over 95%. In contrast, treatment with lactate, a reduced form of phyuvate, did not protect against cell death oxidative stress-induced loss of viability and apoptosis was examined with $\alpha$-cyano-3-hydroxycinnarmate(COHC) as a selective mitochondrial monocarboxylate transport blocker. Incubation with COHC(500uM) did not significantly affect cell viability in the presence of hydrogen peroxide. The cytoprotection by pyruvate(3mM)against hydrogen peroxide stress was abolished by COHC. This indicates that the cytoprotection by pyruvate against oxidative stress in endothelial cells is mediated, at least in part, by mitochondrial pyruvate uptake and hence endothelial enerygetics. However, cytosolic mechanisms related, at least in part, by mitochondrial pyruvate uptake and hence endothelial energetics. However, cytosolic mechanisms related to the glutathione system may also contribute. The results suggest that pyruvate has therapeutic potential in the treatment of oxidative stress-induced cytotoxicity associated with increased apoptosis.

• Reproductive and Developmental Biology
• /
• 제30권1호
• /
• pp.7-11
• /
• 2006

본 연구는 호르몬과 Na-pyruvate의 첨가가 개 미성숙난자의 체외성숙에 미치는 영향을 검토하였다. 개의 발정주기와 관계없이 암캐의 난소에서 회수한 난자를 NCSU-37 배양액에서 72시간 체외 배양하였다. 호르몬의 영향을 검토하기 위하여 배양액 중에 다양한 호르몬을 $24{\sim}72$시간 첨가하여 성숙율을 검사하였으며, Na-pyruvate 첨가 농도의 영향을 검토하였다. $E_2$ 단독 첨가구에서는 제2감수분열 중기(MII) 단계까지 성숙이 관찰되었으나(5.7%), 타 처리구에서는 MII기까지의 성숙이 이루어지지 않았다(P<0.05), $E_2$를 $6{\sim}24$시간만 처리하였을 때는 MII기로 성숙되는 난자가 없었으나 72시간 처리하였을 때는 6.0%로 유의적으로 높게 나타났다(P<0.05). Na-pyruvate의 농도를 0.25 mM 첨가한 구보다 2.5 mM 첨가한 구에서 제1감수분열 중기(MI) 단계까지의 성숙율이 증가하는 경향을 보였으나, MII 단계까지의 성숙율은 차이가 없었다. 본 실험의 결과는 개 난자의 체외성숙시 $E_2$가 첨가된 배양액에서 72시간 배양시에 성숙율을 증진시킬 수 있으나, Na-pyruvate의 농도는 개 체외배양에 있어 큰 영향을 미치지 않는 것을 나타낸다.

• 한국식품위생안전성학회지
• /
• 제18권3호
• /
• pp.146-152
• /
• 2003

당 대사에 관여하는 Pyruvate dehydrogenase phosphatase (PDP)는 해당과정에서의 대사 산물인 pyruvate 를 acetyl CoA로 만들어 구연산 회로로 진입시켜주는 효소인 Pyruvate dehydrogenase complex(PDP)의 활성을 조절하는 중요한 효소이다. PDP의 catalytic subunit는 PDP의 dihydrolipoamide acetyltransferase(E2), PDP regulatory subunit (PDPr), 그리고 칼슘 결합 도메인 등으로 구성되어 있는 것으로 추측되어지고 있다. 본 연구에서는 PDP 단백질을 분리정제하고 결정화 하고자하였다. PDP는 catalytic subunit(PDPc, Mr 52,600 Da)과, regulatory subunit (PDPr, 95,600 Da)으로 구성되어 있으며 칼슘 존재하에 PDPc는 dihydrolipoamide acetyltransferase(E2) component와 결합하여 기질인 인산 E1 component의 탈인산화율을 증가시킨다. PDPc는 intrinsic 칼슘 결합부위를 가지며 두 번째 칼슘 부위는 E2 존재 하에 형성된다. 이러한 특이한 상호반응을 이용한 GSH-Sepharose-GST-L2 matrix를 이용하여 약 1000 U/mg의 specific activity를 갖는 순수 PDPc를 약 80%의 yield로 얻어 결정화에 사용하였다.

• 한국가축번식학회지
• /
• 제19권1호
• /
• pp.9-14
• /
• 1995

This study was conducted to investigate the effect of energy source on development of in vitro development of in vitro matured and fertilized porcine 2-cell embryos. The relative preferences of glucose, lactate and pyruvate for in vitro development of porcine 2-cell embryos were determined. The results obtained are as follows. 1. 33.3, 20.8 and 29.2% of porcine embryos reached morula stage in addition to lactate, glucose, and both glucose and lactate in the culture medium as energy source, respectively. 2. 38.5, 15.4 and 26.9% of porcine embryos reached morula stage in addition to pyruvate, glucose, and both glucose and pyruvate in culture medium as energy source, respectively. 3. 42.9, 21.4 and 28.6% of porcine embryos reached morula stage in addition to pyruvate and lactate, glucse alone, and glucose, lactate and pyruvate in culture medium as energy source, respectively.

• The Korean Journal of Physiology
• /
• 제26권1호
• /
• pp.89-97
• /
• 1992

In hypoxic tissue conditions, pyruvate can not enter the Krebs cycle and lactic acid, produced from pyruvate, accumulates to induce lactic acidosis. Pyruvate, However, can also be converted to alanine by glutamate pyruvate transaminase, that could be enhanced by glutamate. Therefore, it would be a fundamental measure to treat the lactic acidosis in tissue hypoxic conditions when one can convert the accumulated lactic acid, through pyruvate, to alanine. To test the above hypothesis, we induced a lactic acidosis in cats and the effect of glutamate on recovery of acid base state and removal of the lactic acid from blood were assessed and the results were compared with those of bicarbonate administration, which is one of the most frequently used conventional measure for correction of the acid base state during lactic acidosis. The results were that glutamate and combined glutamate bicarbonate solutions not only restored the acid base status completely from the lactic acidosis in an hour or two, but also restored the blood level of lactate partially. We concluded that administration of glutamate solution to convert pyruvate into alanine is effective in preventing lactic acid accumulation and treating lactic acidosis.

• 대한약리학회지
• /
• 제10권1호
• /
• pp.21-39
• /
• 1974

Certain metabolic aspects of halothane's cardiac depressant action on the contractility of the myocardium were elucidated from a sudy of the effect of pyruvate on halothane-depressed rat atria. Approximately 6 mg% halothane was required to maintain a 50% depression of the contractility of rat atria suspended in a modified Krebs-Ringer bicarbonate glucose medium, pH 7.4, $30^{\circ}C$ for a 2 hr. period. Pyruvate was found to restore partially the contractility of halothane-depressed atria. The maximally effective concentration of pyruvate was 2.5 mM. There was minimal pyruvate effect on the force of contraction of control atria. The effect of pyruvate on halothane-depressed atria was shown to be due to the pyruvate and not the sodium ion of the sodium pyruvate. Pyruvate was found to produce no increase in the contractility of atria depressed by hypertonic medium, but caused a further depression. Selected aspects regarding the action of halothane on glucose metabolism in myocardial cells are discussed. The results are consistent with the hypothesis that at least a part of the negative inotropic action of halothane is due to an inhibition of glucose uptake or utilization in the glycolytic pathway.

• The Korean Journal of Physiology and Pharmacology
• /
• 제9권4호
• /
• pp.195-201
• /
• 2005

High extracellular glucose concentration was reported to suppress intracellular $Ca^{2+}$ clearing through altered sarcoplasmic reticulum (SR) function. In the present study, we attempted to elucidate the effects of pyruvate and fatty acid on SR function and reveal the mechanistic link with glucose-induced SR dysfunction. For this purpose, SR $Ca^{2+}$-uptake rate was measured in digitonin-permeabilized H9c2 cardiomyocytes cultured in various conditions. Exposure of these cells to 5 mM pyruvate for 2 days induced a significant suppression of SR $Ca^{2+}$-uptake, which was comparable to the effects of high glucose. These effects were accompanied with decreased glucose utilization. However, pyruvate could not further suppress SR $Ca^{2+}$-uptake in cells cultured in high glucose condition. Enhanced entry of pyruvate into mitochondria by dichloroacetate, an activator of pyruvate dehydrogenase complex, also induced suppression of SR $Ca^{2+}$-uptake, indicating that mitochondrial uptake of pyruvate is required in the SR dysfunction induced by pyruvate or glucose. On the other hand, augmentation of fatty acid supply by adding 0.2 to 0.8 mM oleic acid resulted in a dose-dependent suppression of SR $Ca^{2+}$-uptake. However, these effects were attenuated in high glucose-cultured cells, with no significant changes by oleic acid concentrations lower than 0.4 mM. These results demonstrate that (1) increased pyruvate oxidation is the key mechanism in the SR dysfunction observed in high glucose-cultured cardiomyocytes; (2) exogenous fatty acid also suppresses SR $Ca^{2+}$-uptake, presumably through a mechanism shared by glucose.

• Parasites, Hosts and Diseases
• /
• 제56권1호
• /
• pp.1-9
• /
• 2018

Giardia lamblia, an anaerobic, amitochondriate protozoan parasite causes parasitic infection giardiasis in children and young adults. It produces pyruvate, a major metabolic product for its fermentative metabolism. The current study was undertaken to explore the effects of pyruvate as a physiological antioxidant during oxidative stress in Giardia by cysteine-ascorbate deprivation and further investigation upon the hypothesis that oxidative stress due to metabolism was the reason behind the cytotoxicity. We have estimated intracellular reactive oxygen species generation due to cysteine-ascorbate deprivation in Giardia. In the present study, we have examined the effects of extracellular addition of pyruvate, during oxidative stress generated from cysteine-ascorbate deprivation in culture media on DNA damage in Giardia. The intracellular pyruvate concentrations at several time points were measured in the trophozoites during stress. Trophozoites viability under cysteine-ascorbate deprived (CAD) medium in presence and absence of extracellular pyruvate has also been measured. The exogenous addition of a physiologically relevant concentration of pyruvate to trophozoites suspension was shown to attenuate the rate of ROS generation. We have demonstrated that Giardia protects itself from destructive consequences of ROS by maintaining the intracellular pyruvate concentration. Pyruvate recovers Giardia trophozoites from oxidative stress by decreasing the number of DNA breaks that might favor DNA repair.

• BMB Reports
• /
• 제37권2호
• /
• pp.239-245
• /
• 2004

We have previously demonstrated that the redox reactant pyruvate prevents apoptosis in the oxidant model of bovine pulmonary artery endothelial cells (BPAEC), and that the anti-apoptotic mechanism of pyruvate is mediated in part via the mitochondrial matrix compartment. However, cytosolic mechanisms for the cytoprotective feature of pyruvate remain to be elucidated. This study investigated the pyruvate protection against endothelial cytotoxicity when the glycolysis inhibitor 2-deoxy-D-glucose (2DG) was applied to BPAEC. Millimolar 2DG blocked the cellular glucose uptake in a concentration- and time-dependent manner with >85% inhibition at $\geq$5 mM within 24 h. The addition of 2DG evoked BPAEC cytotoxicity with a substantial increase in lipid peroxidation and a marked decrease in intracellular total glutathione. Exogenous pyruvate partially prevented the 2DG-induced cell damage with increasing viability of BPAEC by 25-30%, and the total glutathione was also modestly increased. In contrast, 10 mM L-lactate, as a cytosolic reductant, had no effect on the cytotoxicity and lipid peroxidation that are evoked by 2DG. These results suggest that 2DG toxicity may be a consequence of the diminished potential of glutathione antioxidant, which was partially restored by exogenous pyruvate but not L-lactate. Therefore, pyruvate qualifies as a cytoprotective agent for strategies that attenuate the metabolic dysfunction of the endothelium, and cellular glucose oxidation is required for the functioning of the cytosolic glutathione/NADPH redox system.