• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.467-476
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• 2016

In the present study, we examined the effect of pertussis toxin (PTX) administered centrally in a variety of stress-induced blood glucose level. Mice were exposed to stress after the pretreatment of PTX (0.05 or 0.1 mg) i.c.v. or i.t. once for 6 days. Blood glucose level was measured at 0, 30, 60 and 120 min after stress stimulation. The blood glucose level was increased in all stress groups. The blood glucose level reached at maximum level after 30 min of stress stimulation and returned to a normal level after 2 h of stress stimulation in restraint stress, physical, and emotional stress groups. The blood glucose level induced by cold-water swimming stress was gradually increased up to 1 h and returned to the normal level. The intracerebroventricular (i.c.v.) or intrathecal (i.t.) pretreatment with PTX, a $G_i$ inhibitor, alone produced a hypoglycemia and almost abolished the elevation of the blood level induced by stress stimulation. The central pretreatment with PTX caused a reduction of plasma insulin level, whereas plasma corticosterone level was further up-regulated in all stress models. Our results suggest that the hyperglycemia produced by physical stress, emotional stress, restraint stress, and the cold-water swimming stress appear to be mediated by activation of centrally located PTX-sensitive G proteins. The reduction of blood glucose level by PTX appears to due to the reduction of plasma insulin level. The reduction of blood glucose level by PTX was accompanied by the reduction of plasma insulin level. Plasma corticosterone level up-regulation by PTX in stress models may be due to a blood glucose homeostatic mechanism.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.180-180
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• 1996

Previous studies have shown that kainic acid (KA) causes an elevation of hippocampal proenkephalin mRNA level. However, the role of proto-oncogene products, such as c-Fos, c-Jun and Fra proteins in the regulation of KA-induced proenkephalin mRNA increase in the hippocampus has not been well characterized. Thus, in the present study, the effect of cycloheximide (CHX) on KA-induced proenkephalin mRNA and immediate early gene products induction was examined. After pretreating with either vehicle or CHX (20 mg/kg, s.c.) for 30 min, KA (10 mg/kg) was administered s.c. The animals were sacrificed 1,2, or 8 hrs after KA administration. Total RNA and were isolated for Northern blot assay, and proteins were isolated for Western and electrophoretic gel-shift assays. First, we found that CHX inhibited KA-induced proenkephalin mRNA increase without altering intracellular proenkephalin protein level. Secondly, Western blot assays showed that KA increased c-Fos, c-Jun and Fra proteins at 1,2, and 8 hrs and CHX inhibited these immediate early gene products. Finally, electrophoretic gel shift assays revealed that KA increased both AP-1 and ENKCRE-2 DNA binding activities. Furthermore, CHX attenuated KA-induced AP-1 and ENKCRE-2 DNA binding activities. Both AP-1 and ENKCRE-2 DNA binding activities were abolished by cold AP-1 or ENKCRE-2 oligonucleotides, and further reduced by antibodies against c-Fos or c-Jun. Antibody against CREB reduced ENKCRE-2, but not AP-1, DNA binding activity. Our results suggest that on-going protein synthesis is required for elevation of hippocampal proenkephalin mRNA level induced by KA. All c-Fos, c-Jun, and Fra proteins appears to be involved in the regulation of hippocampal proenkephalin mRNA level induced by KA (This study was supported by a grant from KOSEF).

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.339-343
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• 2000

When plants are exposed to subfreezing temperatures ice crystals are forming within extracelluar space in leaves. The growth of ice crystal is closely related to the degree of freezing injury. It was shown that an antifreeze protein binds to an ice nucleator through hydrogen bonds to prevent growth of ice crystal and also reduces freezing damage. The antifreeze proteins in plants are similar to PR proteins but only the PR proteins induced upon cold acclimation were shown to have dual functions in antifreezing as well as antifungal activities. Three of the genes encoded for CLP, GLP, and TLP were isolated from barley and Kentucky bluegrass based on amino acid sequence revealed after purification and low temperature-inducibility as shown in analysis of the protein. The deduced amino acid of the genes cloned showed a signal for secretion into extracellular space where the antifreezing activity sup-posed to work. The western analysis using the antisera raised against the antifreeze proteins showed a positive correlation between the amount of the protein and the level of freeze tolerance among different cultivars of barely. Besides it was revealed that TLP is responsible for a freeze tolerance induced by a treatment of trinexapac ethyl in Kentucky bluegrass. Analysis of an overwintering wild rice, Oryza rufipogon also showed that an acquisition of freeze tolerance relied on accumulation of the protein similar to CLP. The more direct evidence for the role of CLP in freeze tolerance was made with the analysis of the transgenic tobacco showing extracellular accumulation of CLP and enhanced freeze tolerance measured by amount of ion leakage and rate of photosynthetic electron transport upon freezing. These antifreeze proteins genes will be good candidates for transformation into crops such as lettuce and strawberry to develop into the new crops capable of freeze-storage and such as rose and grape to enhance a freeze tolerance for a safe survival during winter.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2508-2512
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• 2012

Cold shock proteins (CSPs) are a family of proteins induced at low temperatures. CSPs bind to single-stranded nucleic acids through the ribonucleoprotein 1 and 2 (RNP 1 and 2) binding motifs. CSPs play an essential role in cold adaptation by regulating transcription and translation via molecular chaperones. The solution nuclear magnetic resonance (NMR) or X-ray crystal structures of several CSPs from various microorganisms have been determined, but structural characteristics of psychrophilic CSPs have not been studied. Therefore, we optimized the purification process to obtain highly pure Lm-Csp and determined the three-dimensional structure model of Lm-Csp by comparative homology modeling using MODELLER on the basis of the solution NMR structure of Bs-CspB. Lm-Csp consists of a ${\beta}$-barrel structure, which includes antiparallel ${\beta}$ strands (G4-N10, F15-I18, V26-H29, A46-D50, and P58-Q64). The template protein, Bs-CspB, shares a similar ${\beta}$ sheet structure and an identical chain fold to Lm-Csp. However, the sheets in Lm-Csp were much shorter than those of Bs-CspB. The Lm-Csp side chains, E2 and R20 form a salt bridge, thus, stabilizing the Lm-Csp structure. To evaluate the contribution of this ionic interaction as well as that of the hydrophobic patch on protein stability, we investigated the secondary structures of wild type and mutant protein (W8, F15, and R20) of Lm-Csp using circular dichroism (CD) spectroscopy. The results showed that solvent-exposed aromatic side chains as well as residues participating in ionic interactions are very important for structural stability. Further studies on the three-dimensional structure and dynamics of Lm-Csp using NMR spectroscopy are required.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.831-837
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• 2005

Low-temperature adaptation and cryoprotection were studied in Leuconostoc mesenteroides SYl, a strain isolated from Kimchi. L. mesenteroides SY1 cells grown in exponential growth phase at $30^{\circ}C$ were exposed to $15^{\circ}C,\;10^{\circ}C$, and $5^{\circ}C$ for 2, 4, and 6 h, respectively, and then frozen at $- 70^{\circ}C$ for 24 h. Survival ratio was measured after the cells were thawed. The freezing-thawing cycles were repeated four times. Preadapted cells survived better than non-adapted control cells, and the highest survival ratio ($96\%$) was observed for cells preadapted for 2 h at $5^{\circ}C$, whereas control cells showed only $22\%$. The 2D gel showed that two proteins (spots A and B) were induced in cells preadapted at lower temperatures. Spots A and B have the same molecular weight (7 kDa), but the pI was 4.6 for spot A and 4.3 for spot B. The first 29 and 15 amino acid sequences from spots A and B were determined, and they were identical, except for one amino acid. A csp gene was cloned, and nucleotide sequencing confirmed that the gene encoded spot A cold shock protein.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.80-80
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• 2005

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.67-73
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• 2002

The cellular responses of soil-borne bacterium, Pseudomonas sp. HK-6 to explosive 2,4,6-trinitrotoluene (TNT) were examined. Two stress shock proteins (SSPs), approximately 70-kDa DnaK and a 60-kDa GroEL were found in HK-6 cells in response to TNT. Analyses of SDS-PAGE and Western blot using anti-DnaK and GroEL revealed that SSPs were induced in HK-6 cells exposed to 0.5 M of TNT far 6-12 hrs. The maximum induction of proteins was achieved at 8-hr incubation point after HK-6 cells'exposure to TNT. Similar SSPs were found to be induced in HK-6 cells by heat shock (shift of temperature, from $30^{\circ}C$ to $42^{\circ}C$) or cold shock (shift of temperature,$30^{\circ}C$ to $4^{\circ}C$).2D-PAGE of soluble protein tractions from the culture of Pseudomonas sp. HX-6 exposed to TNT demonstrated that approximately 450 spots were observed on the silver stained gels ranging from pH 3 to pH 10. Among them, 12 spots significantly induced and expressed in response to TNT were selected and analyzed. Approximately 60-kDa protein, which was assumed highly expressed on the gel, was used for amino acid sequencing. N-terminal microsequencing with in-gel digestion showed that N-terminal sequence of the TNT-induced protein, <$^1XXAKDVKFGDSARKKML^17$, shared extensive similarity with $^1XXAKDVKFGDSARKKML^17$, N-terminal sequence of (P48216) GroEL of Pseudomonas putida.

• The Korea Journal of Herbology
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• v.31 no.6
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• pp.63-71
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• 2016

Objective : To suggest a scientific evidence of Aconitum carmichaeli Debx. (Aconiti Lateralis Radix Preparata: ALRP) as one of cooling and heating medicines on the regulation of body temperature, we investigated the effects of ALRP water extract on hypothyroidism. Methods : Hypothyroidism was induced by intradermal injection with PTU for 4 weeks in SD rats. ALRP extract or L-thyroxine as a control drug was orally administrated for 2 weeks with PTU injection in rats. The physiological and serological parameters were measured in rats. The histological change of thyroid tissues was observed by H&E staining, and also the expression of thermo-regulating proteins was determined by Western blot in dorsal root ganglia and brain tissues of rats. Results : The administration of ALRP extract in PTU-induced hypothyroidism rats was significantly increased body temperature, but did not changes on body weight, food and water intake. ALRP extract did not effect on the levels of TSH and T4 in the hypothyroidism rats. ALRP extract significantly decreased the levels of GPT, glucose, HDL-cholesterol, LDL-cholesterol, and total cholesterol in the hypothyroidism rats. In histological observation, the enlarged epithelium and atrophic follicles with higher concentration of follicular cells on hypothyroidism were improved by ALRP extract. In addition, ALRP extract increased the expression of TRPV1 and TRPM8 ion channel proteins in hypothyroidism rats. Conclusion : These results indicate that ALRP extract can improve PTU-induced hypothyroidism through regulation of body temperature and lipid accumulation. The action mechanism of ALRP extract is related with body temperature control by thermoregulation with TRP ion channels.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.530-537
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• 2019

Fuji, a major apple cultivar in Korea, is susceptible to white rot. Apple white rot disease appears on the stem and fruit; the development of which deteriorates fruit quality, resulting in decreases in farmers' income. Thus, it is necessary to characterize molecular markers related to apple white rot resistance. In this study, we screened for differentially expressed genes between uninfected apple fruits and those infected with Botryosphaeria dothidea, the fungal pathogen that causes white rot. Antimicrobial tests suggest that a gene expression involved in the synthesis of the substance inhibiting the growth of B. dothidea in apples was induced by pathogen infection. We identified seven transcripts induced by the infection. The seven transcripts were homologous to genes encoding a flavonoid glucosyltransferase, a metallothionein-like protein, a senescence-induced protein, a chitinase, a wound-induced protein, and proteins of unknown function. These genes have functions related to responses to environmental stresses, including pathogen infections. Our results can be useful for the development of molecular markers for early detection of the disease or for use in breeding white rotresistant cultivars.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.2.1-2.14
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• 2023

Background: Hypothermia is a crucial environmental factor that elevates the risk of cardiovascular disease, but the underlying effect is unclear. Objectives: This study examined the role of cold stress (CS) in cardiac injury and its underlying mechanisms. Methods: In this study, a chronic CS-induced myocardial injury model was used; mice were subjected to chronic CS (4℃) for three hours per day for three weeks. Results: CS could result in myocardial injury by inducing the levels of heat shock proteins 70 (HSP70), enhancing the generation of creatine phosphokinase-isoenzyme (CKMB) and malondialdehyde (MDA), increasing the contents of tumor necrosis factor-α (TNF-α), high mobility group box 1 (HMGB1) interleukin1b (IL-1β), IL-18, IL-6, and triggering the depletion of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). Multiple signaling pathways were activated by cold exposure, including pyroptosis-associated NOD-like receptor 3 (NLRP3)-regulated caspase-1-dependent/Gasdermin D (GSDMD), inflammation-related toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)-mediated nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK), as well as oxidative stressinvolved thioredoxin-1/thioredoxin-interacting protein (Txnip) signaling pathways, which play a pivotal role in myocardial injury resulting from hypothermia. Conclusions: These findings provide new insights into the increased risk of cardiovascular disease at extremely low temperatures.