• Nutrition Research and Practice
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• 제4권6호
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• pp.455-461
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• 2010

The tumor microenvironment, particularly sufficient nutrition and oxygen supply, is important for tumor cell survival. Nutrition deprivation causes cancer cell death. Since apoptosis is a major mechanism of neuronal loss, we explored neuronal apoptosis in various microenvironment conditions employing neuroblastoma (NB) cells. To investigate the effects of tumor malignancy and differentiation on apoptosis, the cells were exposed to poor microenvironments characterized as serum-free, low-glucose, and hypoxia. Incubation of the cells in serum-free and low-glucose environments significantly increased apoptosis in less malignant and more differentiated N-type IMR32 cells, whereas more malignant and less differentiated I-type BE(2)C cells were not affected by those treatments. In contrast, hypoxia (1 % $O_2$) did not affect apoptosis despite cell malignancy. It is suggested that DLK1 constitutes an important stem cell pathway for regulating self-renewal, clonogenicity, and tumorigenicity. This raises questions about the role of DLK1 in the cellular resistance of cancer cells under poor microenvironments, which cancer cells normally encounter. In the present study, DLK1 overexpression resulted in marked protection from apoptosis induced by nutrient deprivation. This in vitro model demonstrated that increasing severity of nutrition deprivation and knock-down of DLK1 caused greater apoptotic death, which could be a useful strategy for targeted therapies in fighting NB as well as for evaluating how nutrient deprived cells respond to therapeutic manipulation.

• 대한한의학회지
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• 제23권1호
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• pp.50-60
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• 2002

Objectives: Sunghyangjunggisan (SHJS) is a commonly prescribed drug with a wide neuropharmacological spectrum. The water extracts of SHJS were found to be protective against neurotoxicity elicited by deprivation of serum and glucose. Methods: The morphological examination and Hoechst staining of nucleus also clearly showed that the extracts attenuated the cell shrinkage, membrane blebbing, representing typical neuronal apoptotic phenomena and nucleosome-sized fragmentation under the microscope in PC 12 rat pheochromocytoma cells. Results: Activation of protein kinase A (PKA) with dibutyl-cAMP and forskolin also protected during glucose deprivation, although it was not additive with the effect provided by phorbol ester. Interestingly, treatment with the protein kinase A inhibitor, KT5720, was not neuroprotective in the presence of SHJS. Electrophoretic mobility shift assays were used to characterize the neuroprotective binding of nuclear proteins to consensus sequences for AP-l, nuclear factor kappa B ($NF-{\kappa}B$) after glucose deprivation. When PC 12 cells are induced to undergo apoptosis by serum deprivation, AP-l and $NF-{\kappa}B$ DNA binding activity transiently increases to a slight degree. This stimulation is blocked by the water extracts of SHJS. The site of action of the drugs appeared to involve specific inhibition of AP-1 and nuclear factor kB binding activity. Conclusions: Taken together, these results suggested the possibility that the extracts of SHJS might provide a neurotrophic-like activity in PC 12 cells.

• Biomolecules & Therapeutics
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• 제17권2호
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• pp.144-150
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• 2009

Reactive oxygen species play a role in signal transduction and in many human diseases. B-cell activating factor (BAFF) plays a role for mature B cell generation and maintenance and for the incidence of autoimmune diseases. We previously reported that BAFF expression was induced by ROS. In this study, we investigated whether ROS-induced BAFF expression was affected by toll-like receptor (TLR) 4 or myeloid differentiation primary response gene (MyD) 88. BAFF expression was increased by serum deprivation that is an experimental modification to produce ROS. In contrast, TLR4 and MyD88 were decreased by serum deprivation. Although ROS production was decreased in TLR4-nonfunctional or MyD88-deficient splenocytes as compared to that in control mice, serum deprivation increased ROS production and augmented BAFF expression in both cells. $50{\mu}M\;H_2O_2$ also increased BAFF expression in TLR4-deficient or MyD88-deficient splenocytes. Collectively, results show that BAFF expression may be mediated by TLR4 or MyD88-independent manner and TLR4 or MyD88 may not be required in BAFF expression.

• 대한한의학회지
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• 제21권4호
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• pp.64-72
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• 2000

Objectives : This study was designed to investigate the neuroprotective effect of Hwansodan(Huanshao-dan) on the apoptosis induced by withdrawal of neurotrophic support. Methods : PCl2 pheochromocytoma cells have been used extensively as a model for studying the cellular and molecular effects of neuronal cells. The viability of cells was measured by MTT assay. We used DNA fragmentation and caspase 3-like protease activation assay. Results : The water extract of Hwansodan(Huanshao-dan) significantly showed protective effects on serum and glucose deprivation-induced apoptotic death. Hwansodan(Huanshao-dan) also prevents DNA fragmentation and caspase 3-like protease activation, representing typical neuronal apoptotic phenomena in PCl2 pheochromocytoma cells and induces tyrosine phosphorylation of proteins around 44 kDa, which was identified as ERK1 with electrophoretic gel mobility shift by Western blot. In addition, MAPK kinase(MEK) inhibitor PD98059 and Ras inactivator, ${\alpha}-hydroxyfarnesylphosphonic$ acid attenuated the neuroprotective effects of Hwansodan(Huanshao-dan) in serum-deprived PCl2 cells. Conclusions : These results indicate that Ras/MEK/ERK signaling pathway plays a key role in neuroprotective effects of Hwansodan(Huanshao-dan) in serum-deprived PCl2 cells. Taken together, we suggest the possibility that Hwansodan(Huanshao-dan) might provide a neurotrophic-like activity in PCl2 cells.

• Journal of Nutrition and Health
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• 제18권4호
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• pp.318-327
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• 1985

This study was designed to investigate the effect of early protein undernutrition of rats on later susceptibility to lead poisoning. Weanling rats, weighing about 55 grams, were malnourished by feeding low protein diets ( 12% and 5% casein diet ) during the four weeks of protein deprivation period. For the following 5 weeks, the malnourished rats were fed with 25% casein diet as rehabilitation diet. After the rehabilitation period, all rats were fed with 25% casein diet and the drinking water containing 2000ppm-Pb during the four weeks. The results obtained were as follows ; 1 ) Feed intake, body weight gain and food efficiency ratio were reduced in all rats exposed to lead, especially in rats fed with 5% casein diet during the four weeks of weanling period. 2 ) Enlargement of kidney and spleen were observed in all rats exposed to lead and were more remarkable in rats fed with 5% casein diet. 3 ) In rats exposed to lead, activity of serum glutamic oxaloacetic transaminase ( S- GOT ) was significantly increased by increasing the degree of early protein deprivation, whereas hematocrit value was significantly decreased. Activity of serum glutamic pyruvic transaminase ( S- GPT ) was shown a tendency to increase by increasing the degree of early protein deprivation, but the difference was not significant. 4) In rats exposed to lead, the amount of lead accumulation in kidney was increased by increasing the degree of early protein deprivation. The significant increase was shown in rats fed with 5% casein diet during the four weeks of weanling period. The results of the experiment suggest that early protein undernutrition, even after some period of rehabilitation, may enhance the later susceptibility to lead poisoning.

• BMB Reports
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• 제40권2호
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• pp.277-285
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• 2007

PCD (programmed cell death) is important mechanism for development, homeostasis and disease. To analyze the gene expression pattern in brain cells undergoing PCD in response to serum deprivation, we analyzed the cDNA microarray consisting of 2,300 genes and 7 housekeeping genes of cortical cells derived from mouse embryonic brain. Cortical cells were induced apoptosis by serum deprivation for 8 hours. We identified 69 up-regulated genes and 21 down-regulated genes in apoptotic cells. Based on the cDNA microarray data four genes were selected and analyzed by RT-PCR and northern blotting. To characterize the role of UNC-51-like kinase (ULK2) gene in PCD, we investigated cell death effect by ULK2. And we examined expression of several genes that related with PCD. Especially GAPDH was increased by ULK2. Theses findings indicated that ULK2 is involved in apoptosis through p53 pathway.

• 대한본초학회지
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• 제27권2호
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• pp.77-83
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• 2012

Objectives : This work was designed to investigate the effect of The root of Achyranthes japonica Nakai (AJN) water extract on serum deprivation reperfusion-induced apoptosis in PC-12 cells and transient middle cerebral artery occlusion (tMCAO)-induced ischemic brains of rats. Methods : Apoptosis in PC12 cells was induced by serum deprivation and reperfusion. The cells were treated with AJN water extract at doses of 0.5 and 1.0 mg/ml for 24 hr after inducing the apoptosis. Cell viability was determined by WST-1 assay. The expression of caspase-3 protein was determined by Western blot. Ischemic brains were prepared from tMCAO-induced ischemic rats after oral administration with AJN at dose of 50 and 100 mg/kg, and then brain infarction was measured by TTC staining. Results : AJN significantly increased the cell viability in apoptocic-induced PC-12 cells, and also decreased the expression of caspase-3 protein. Furthermore, the administration of AJN significantly inhibited tMCAO-induced brain infarction in rats. Conclusions : Our results suggest that AJN extract has a neuroprotective property via suppressing the apoptosis in PC12 cells and the infarction of ischemic brains.

• Molecules and Cells
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• 제41권3호
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• pp.234-243
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• 2018

In recent years, the interest towards the relationship between incretins and bone has been increasing. Previous studies have suggested that glucagon-like peptide-1 (GLP-1) and its receptor agonists exert beneficial anabolic influence on skeletal metabolism, such as promoting proliferation and differentiation of osteoblasts via entero-osseous-axis. However, little is known regarding the effects of GLP-1 on osteoblast apoptosis and the underlying mechanisms involved. Thus, in the present study, we investigated the effects of liraglutide, a glucagon-like peptide-1 receptor agonist, on apoptosis of murine MC3T3-E1 osteoblastic cells. We confirmed the presence of GLP-1 receptor (GLP-1R) in MC3T3-E1 cells. Our data demonstrated that liraglutide inhibited the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, as detected by Annexin V/PI and Hoechst 33258 staining and ELISA assays. Moreover, liraglutide upregulated Bcl-2 expression and downregulated Bax expression and caspase-3 activity at intermediate concentration (100 nM) for maximum effect. Further study suggested that liraglutide stimulated the phosphorylation of AKT and enhanced cAMP level, along with decreased phosphorylation of $GSK3{\beta}$, increased ${\beta}-catenin$ phosphorylation at Ser675 site and upregulated nuclear ${\beta}-catenin$ content and transcriptional activity. Pretreatment of cells with the PI3K inhibitor LY294002, PKA inhibitor H89, and siRNAs GLP-1R, ${\beta}-catenin$ abrogated the liraglutide-induced activation of cAMP, AKT, ${\beta}-catenin$, respectively. In conclusion, these findings illustrate that activation of GLP-1 receptor by liraglutide inhibits the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation through $cAMP/PKA/{\beta}-catenin$ and $PI3K/Akt/GSK3{\beta}$ signaling pathways.

• Asian-Australasian Journal of Animal Sciences
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• 제33권12호
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• pp.1940-1947
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• 2020

Objective: Combination of two stressors on alteration of mineral footprints in animals needs due attention to meet maximum production and welfare, particularly in grazing sheep. This study tested whether ewes (Ovis aries) exposed to water deprivation and thermal-humidity stressors had altered mineral footprints in their wool, serum, urine, and feces. Methods: Nine ewes (age = 3 years; mean body weight = 41±3.5 kg) were divided among a control group with free access to water, and treatment groups with water deprivation lasting either 2 h (2hWD) or 3 h (3hWD) after feeding. Using a 3×3 Latin square design, animals were assigned to treatment groups for three sampling periods of 21 days each (n = 9). Blood was collected by jugular venipuncture. Wool was collected at the end of periods 2 and 3. Metabolic crates designed with metal grated floors were used for urine and feces collection. We measured sodium (Na), magnesium (Mg), phosphorus (P), chloride (Cl), calcium (Ca), manganese (Mn), copper (Cu), iron (Fe), and zinc (Zn). Results: The wool mineral levels did not differ between the treatment groups, although K was marginally lower (p = 0.10) in the 2hWD group. The serum and urine mineral levels did not differ between the treatments (p>0.05). Fecal K was significantly lower in the 2hWD group than in the other groups (p≤0.05). Conclusion: In conclusion, water deprivation and thermal-humidity exposure altered the excretion of K, but not of other minerals, in the wool, urine, feces, or serum of ewes. Thus, no additional mineral supplementation is needed for water deprived ewes during thermalhumidity exposure.

• Biomolecules & Therapeutics
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• 제8권2호
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• pp.140-146
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• 2000

Recently, we reported that immunostimulation of primary rat cortical astrocyte caused stimulation of glucose deprivation induced apoptotic cell death. To enhance the understanding of the mechanism of the potentiated cell death of clucose-deprived astrocyte by immunostimulation, we investigated the effect of immunostimulation on the glucose deprivation induced cell death of rat C6 glioma cells. Co-treatment of C6 glioma cells with lipopolysaccharide (LPS, $1\;{\mu}\textrm{g}/ml$) and interferon ${\gamma}(IFN{\gamma},\;100U/ml)$ is serum free condition caused marked elevationo f nitric oxide production ($>50\;{\mu}M$). In this condition, glucose deprivation caused significant release of lactate dehdrogenase (LDH) from C6 glioma cells while control cells did not show LDH release. To investigate whether elevated level of nitric oxide is responsible for the enhanced LDH release in glucose-deprived condition, C6 glioma cells were treated with 3-morphorinosydnonimine (SIN-1) and it was observed that SIN-1 caused increase in LDH release from glucose-deprived C6 glioma cells. Treatment of C6 glioma cells with $25\;{\mu}M$ of pyrrolidinedithiocarbamate (PDTC) which inhibit Nuclear factor kB (NF-kB) activation, caused complete inhibition of nitric oxide production. Treatment of C6 glioma cells with NO synthase inhibitors, $N^{G}$-nitro-L-arginine (NNA) or L-$N{\omega}$-nitro-L-arginine methyl ester (L-NAME), caused inhibition of nitric oxide production and also glucose deprivation induced cell death of cytokine-stimulated C6 glioma cells. In addition, diaminohydroxypyrimidine (DAHP, 5 mM) which inhibits the synthesis of tetrahydrobiopterine (BH4), one of essential cofactors for iNOS activity, caused complete inhibition of NO production from immunostimulated C6 glioma cells. The results from the present study suggest that immunostimulation causes potentiation of glucose deprivation induced death of C6 glioma cells which is mediated at least in part by the increased production of nitric oxide. The vulnerability of immunostimulated C6 glioma cells to hypoglycemic insults may implicate that the elevated level of cytokines in various ischemic and neurodegenerative diseases may play a role in their pathogenesis.