• Preventive Nutrition and Food Science
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• v.13 no.2
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• pp.84-89
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• 2008

This study was designed to investigate the protective effect of a methanol extract of Chungkookjang (CKJ) on high glucose induced oxidative stress in LLC-$PK_1$ cells (renal tubular epithelial cells), which are susceptible to oxidative stress. Freeze dried CKJ powder was extracted with methanol, and the extract solution was concentrated, and then used in this study. To determine the protective effect of CKJ extract, oxidative stress was induced by exposing of LLC-$PK_1$ cells to high glucose (30 mM) or normal glucose (5 mM) for 24 hr. Exposure of LLC-$PK_1$ cells to high glucose for 24 hr resulted in a significant (p<0.05) decrease in cell viability, catalase, SOD and GSH-px activity and a significant (p<0.05) increase in intracellular ROS level and thiobarbituric acid reactive substances (TBARS) formation in comparison to the cells treated with 5 mM glucose. CKJ extract treatment decreased intracellular ROS level and TBARS formation, and increased cell viability and activities of antioxidant enzymes including catalase, SOD and GSH-px in high glucose pretreated LLC-$PK_1$ cells. These results suggest that CKJ extract may be able to protect LLC-$PK_1$ cells from high glucose-induced oxidative stress, partially through the antioxidative defense systems.

• The Korean Journal of Physiology
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• v.30 no.2
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• pp.257-267
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• 1996

Diabetes mellitus is associated with a wide range of pathophysiologic changes in the kidney. This study was designed to examine the mechanisms by which glucose modulates the expression of polarized membrane transport functions in primary cultured rabbit renal proximal tubule cells. Results are as follows: The rate of 30 minute $Rb^{+}$ uptake was significantly higher($137.76{\pm}5.40%$) in primary renal tubular cell cultures treated with 20 mM glucose than that of 5 mM glucose. Not the level of mRNA for the ${\alpha}$ subunit of Na, K-ATPase but that of ${\beta}$ subunit was elevated in primary cultures treated with high glucose. The initial rate of methyl-${\alpha}$-D-glucopyranoside(${\alpha}$-MG) uptake was significantly lower($71.91{\pm}3.02%$) in monolayers treated with 20 mM glucose than that of 5 mM glucose. There was a tendency of an increase in phlorizin binding site in cells treated with 5 mM glucose. However, 3-O-methyl-D-glucose(3-O-MG) uptake was not affected by glucose concentration in culture media. TPA inhibited $Rb^{+}$ uptake by $63.61{\pm}1.94\;and\;45.80{\pm}1.36%$ and ${\alpha}$-MG uptake by $48.54{\pm}3.69\;and\;41.87{\pm}6.70%$ in the cells treated with 5 and 20 mM glucose, respectively. Also TPA inhibited mRNA expression of Na/glucose cotransporter in cells grown in 5mM glucose medium. cAMP significantly stimulated ${\alpha}$-MG uptake by $114.65{\pm}5.70%$ in cells treated with 5mM glucose, while it did not affect ${\alpha}$-MG uptake in cell treated with 20 mM glucose. However, cAMP inhibited $Rb^{+}$ uptake by $76.69{\pm}4.16\;and\;66.87{\pm}2.41%$ in cells treated with 5 and 20 mM glucose, respectively. In conclusion, the activity of the renal proximal tubular Na,K-ATPase is elevated in high glucose concentration. In contrast, the activity of the Na/glucose cotransport system is inhibited. High glucose may in part affect the activity of the Na,K-ATPase and the Na/glucose cotransport system by controlling the protein kinase C and/or A signal transduction pathway in primary cultured renal proximal tubule cells.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5687-5692
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• 2013

Type 2 diabetes mellitus (T2DM) has contributed to advanced breast cancer development over the past decades. However, the mechanism underlying this contribution is poorly understood. In this study, we determined that high glucose enhanced proteasome activity was accompanied by enhanced proliferation, migration and invasion, as well as suppressed apoptosis, in human breast cancer MCF-7 cells. Proteasome inhibitor bortezomib (BZM) pretreatment mitigated high glucose-induced MCF-7 cell growth and invasion. Furthermore, high glucose increased protein kinase C delta ($PKC{\delta}$)-phosphorylation. Administration of the specific $PKC{\delta}$ inhibitor rottlerin attenuated high glucose-stimulated cancer cell growth and invasion. In addition, $PKC{\delta}$ inhibition by both rottlerin and $PKC{\delta}$ shRNA significantly suppressed high glucose-induced proteasome activity. Our results suggest that $PKC{\delta}$-dependent ubiquitin proteasome system activation plays an important role in high glucose-induced breast cancer cell growth and metastasis.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.345-351
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• 2011

High glucose leads to physio/pathological alterations in diabetes patients. We investigated collagen production in human gingival cells that were cultured in high concentrations of glucose. Collagen synthesis and secretion were increased when the cells were exposed to high concentrations of glucose. We examined endoplasmic reticulum (ER) stress response because glucose metabolism is related to ER functional status. An ER stress response including the expression of glucose regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), inositol requiring enzyme alpha (IRE-$1{\alpha}$) and phosphoreukaryotic initiation factor alpha (p-eIF-$2{\alpha}$) was activated in the presence of high glucose. Activating transcription factor 4 (ATF-4), a downstream protein of p-eIF-$2{\alpha}$ as well as a transcription factor for collagen, was also phosphorylated and translocalized into the nucleus. The chemical chaperone 4-PBA inhibited the ER stress response and ATF-4 phosphorylation as well as nuclear translocation. Our results suggest that high concentrations of glucose-induced collagen are linked to ER stress and the associated phosphorylation and nuclear translocation of ATF-4.

• Korean Journal of Acupuncture
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• v.20 no.2
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• pp.93-100
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• 2003

Effects of Wisoo and Baekwhe acupuncture on serum glucose and lipid composition were investigated in high fat diet induced diabetic rat. Plasma glucose, free fatty acids and $\Beta-lipoprotein$ concentration showed a high reduction in wisoo acupuncture group compared to those of control group, however the values of baekwhe acupuncture group showed no significantly different those of control group. Plasma triglyceride and LDL-cholesterol concentration showed a tendency to decrease in the wisoo acupuncture groups, however the values of baekwhe showed no significantly different those of control group. Total cholesterol concentration showed a high reduction in wisoo acupuncture groups and HDL-cholesterol concentration showed a high values in wisoo acupuncture group, however these values no significantly different in all treatment groups.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.4
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• pp.205-209
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• 2011

Gestational diabetes mellitus(GDM) is likely to develop type 2 diabetes mellitus, cardiovascular disease, metabolic syndrome after delivery. Infants of diabetic women have higher incidence of congenital malformations than those of non-diabetic women. This study was performed to determine elevation factors associated with increased blood glucose in 350 pregnant women. Subjects were examined in June, 2011 to September, 2011 in Geongnam province. Fasting blood glucose, total cholesterol, triglyceride levels were measured by Olympus AU 680, and their body mass index (BMI) calculated. The mean total cholesterol levels were 223.22 mg/dL, triglyceride 188.38 mg/dL, and fasting blood glucose 100.18 mg/dL. Serum glucose level was significantly higher in the age group of 40 years($109.51{\pm}16.26mg/dL$) than 20 years and 30 years. And increase in triglyceride(>250 mg/dL) was significantly related to high blood glucose level($110.83{\pm}24.78mg/dL$), and increase in BMI(>26) was significantly related to high blood glucose level($114.03{\pm}27.09mg/dL$). However, cholesterol levels were not significantly related to high blood glucose level. In conclusion, the significant elevation factors in relation to the glucose levels were age, triglyceride, and BMI.

• Journal of Nutrition and Health
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• v.35 no.8
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• pp.834-839
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• 2002

This study aimed to investigate the effects of chromium picolinatec (CrP) supplementation on the glucose and lipid metabolism of rats. Five-week-old male Sprague-Dawley rats were fed a high-fat diet fir 110 days and further treated with CrP or placebos for 6 weeks. The effect of CrP supplementation on body weight, blood glucose, insulin and lipid levels was examined. The results suggested that body weight gain was not significantly different between the control and the CrP supplemented group. Plasma glucose, triglyceride and cholesterol levels in the CrP treated group significantly decreased compared to those of the control group (p < 0.05). The total lipid, triglyceride and cholesterol concentrations in the livers of the CrP treated group significantly decreased compared to those of the control group (p < 0.05). These results indicate that supplementation of chromium picolinate ran reduce triglyceride and glucose concentrations in the blood and total lipid and total cholesterol levels in the liver.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.213-217
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• 2003

The effects of glucose concentration on the production of PHB by fed-batch culture of Ralstonia eutropha were investigated. In the range of glucose concentration of $2.5\;{\sim}\;40\;g/l$, it was found that the high glucose concentration was not favorable for the PHB formation after the phosphate limitation. It was further confirmed by the specific PHB synthesis rates and yields. The PHB concentration decreased much with the increase of glucose concentration. But if the glucose concentration was very low, e.g. 2.5 g/l, the cell growth and PHB synthesis also could be limited because of inadequate glucose supply. Itwould be better to maintain the glucose concentration at about 9.0 g/l to obtain high DCW, PHB concentration and productivity.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.6
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• pp.878-885
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• 2017

Objective: Glucose is an essential fuel in the energy metabolism and synthesis pathways of all mammalian cells. In lactating animals, glucose is the major precursor for lactose and is a substrate for the synthesis of milk proteins and fat in mammary secretory (alveolar) epithelial cells. However, clear utilization of glucose in mammary cells during lactogenesis is still unknown, due to the lack of in vitro analyzing models. Therefore, the objective of this study was to test the reliability of the mammary alveolar (MAC-T) cell as an in vitro study model for glucose metabolism and lactating system. Methods: Undifferentiated MAC-T cells were cultured in three types of Dulbecco's modified Eagle's medium with varying levels of glucose (no-glucose: 0 g/L, low-glucose: 1 g/L, and high-glucose: 4.5 g/L) for 8 d, after which differentiation to casein secretion was induced. Cell proliferation and expression levels of apoptotic genes, Insulin like growth factor-1 (IGF1) receptor, oxytocin receptor, ${\alpha}S1$, ${\alpha}S2$, and ${\beta}$ casein genes were analyzed at 1, 2, 4, and 8 d after differentiation. Results: The proliferation of MAC-T cells with high-glucose treatment was seen to be significantly higher. Expression of apoptotic genes was not affected in any group. However, expression levels of the mammary development related gene (IGF1 receptor) and lactation related gene (oxytocin receptor) were significantly higher in the low-glucose group. Expressions of ${\alpha}S1-casein$, ${\alpha}S2-casein$, and ${\beta}-casein$ were also higher in the low-glucose treated group as compared to that in the no-glucose and high-glucose groups. Conclusion: The results demonstrated that although a high-glucose environment increases cell proliferation in MAC-T cells, a low-glucose treatment to MAC-T cells induces higher expression of casein genes. Our results suggest that the MAC-T cells may be used as an in vitro model to analyze mammary cell development and lactation connected with precise biological effects.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.199-203
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• 2016

An enzyme-free optical method is proposed for estimating high concentrations of glucose in a glucose-lactose mixture, based on a predictive equation that takes advantage of the reflective optical power observed at two discrete wavelengths. Compared to the conventional absorption spectroscopy method based on Beer's Law, which is mainly valid for concentrations below hundreds of mg/dL, the proposed scheme, which relies on reflection signals, can be applied to measure higher glucose concentrations, of even several g/dL in a glucose-lactose mixture. Two probe wavelengths of 1160 and 1300 nm were selected to provide a linear relationship between the reflective power and pure glucose/lactose concentration, where the relevant linear coefficients were derived to complete the predictive equation. Glucose concentrations from 2 to 7 g/dL in a glucose-lactose mixture were efficiently estimated, using the established predictive equation based on monitored reflective powers. The standard error of prediction was 1.17 g/dL.