• The Korean Journal of Physiology and Pharmacology
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• v.5 no.5
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• pp.397-405
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• 2001

The ryanodine receptor, a $Ca^{2+}$ release channel of the sarcoplasmic reticulum (SR), is responsible for the rapid release of $Ca^{2+}$ that activates cardiac muscle contraction. In the excitation-contraction coupling cascade, activation of SR $Ca^{2+}$ release channel is initiated by the activity of sarcolemmal $Ca^{2+}$ channels, the dihydropyridine receptors. Previous study showed that the relaxation defect of diabetic heart was due to the changes of the expressional levels of SR $Ca^{2+}$ATPase and phospholamban. In the diabetic heart contractile abnormalities were also observed, and one of the mechanisms for these changes could include alterations in the expression and/or activity levels of various $Ca^{2+}$ regulatory proteins involving cardiac contraction. In the present study, underlying mechanisms for the functional derangement of the diabetic cardiomyopathy were investigated with respect to ryanodine receptor, and dihydropyridine receptor at the transcriptional and translational levels. Quantitative changes of ryanodine receptors and the dihydropyridine receptors, and the functional consequences of those changes in diabetic heart were investigated. The levels of protein and mRNA of the ryanodine receptor in diabetic rats were comparable to these of the control. However, the binding capacity of ryanodine was significantly decreased in diabetic rat hearts. Furthermore, the reduction in the binding capacity of ryanodine receptor was completely restored by insulin. This result suggests that there were no transcriptional and translational changes but functional changes, such as conformational changes of the $Ca^{2+}$ release channel, which might be regulated by insulin. The protein level of the dihydropyridine receptor and the binding capacity of nitrendipine in the sarcolemmal membranes of diabetic rats were not different as compared to these of the control. In conclusion, in diabetic hearts, $Ca^{2+}$ release processes are impaired, which are likely to lead to functional derangement of contraction of heart. This dysregulation of intracellular $Ca^{2+}$ concentration could explain for clinical findings of diabetic cardiomyopathy and provide the scientific basis for more effective treatments of diabetic patients. In view of these results, insulin may be involved in the control of intracellular $Ca^{2+}$ in the cardiomyocyte via unknown mechanism, which needs further study.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.3
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• pp.516-520
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• 2011

Osteoporosis is social problem around the world, because fracture of old age may lead to critical medical condition. Osteoclast is a main target for prevention and treatment of osteoporosis due to their responsibility for bone resorption. Saussureae Radix has been known that has gastro-protective, bronchodilatory effect and has a anti-biotic effect. Saussureae Radix has been widely used in Oriental medicine. However, the effect of extract of Saussureae Radix in osteoclast differentiation remains unknown. Thus, we examined the effect of Saussureae Radix in receptor activator of nuclear factor-${\kappa}$B ligand (RANKL)-induced osteoclast differentiation. From the results of our study, Here we found that Saussureae Radix significantly inhibited osteoclast differentiation induced by RANKL. Saussureae Radix suppressed the activation of NF${\kappa}$B in bone marrow macrophages (BMMs) treated with RANKL. Also, Saussureae Radix significantly inhibited the mRNA expression of c-Fos, tartrate-resistant acid phosphatase (TRAP), osteoclast-associated receptor (OSCAR), nuclear factor of activated T cells (NFAT)c1 and cathepsin K in BMMs treated with RANKL. Particularly, Saussureae Radix greatly inhibited the protein expression of c-fos and NFATc1. especially in the case of NFATc1 expression, a master transcription factor of the differentiation of osteoclasts is very important step for osteoclastogenesis. These results demonstrate that Saussureae Radix may be useful treatment option of bone-related disease such as osteoporosis and rheumatoid arthritis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.3
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• pp.554-561
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• 2009

Soyangin-Hyeongbangpaedok-san(SHBPDS) is a herbal formula used for the common cold or upper respiratory illness. In order to investigate the effect of SHBPDS, mice were orally administered with SHBPDS alcohol extract for 7 days followed by intravenous anti-CD3 injection. In addition, splenocytes and CD4 T cells were cultured with SHBPDS in response to anti-CD3 in vitro and cytokines and transcription factors were evaluated. In vivo treatment with SHBPDS significantly augmented the expressions of the percentage of CD4 T cells and CD 69, an indicator of early T cell activation. Serum levels of IL-4 were significantly increased but those of IFN-${\gamma}$ and IL-2 did not reach statistical significance. The expressions of IFN-${\gamma}$ and T-bet mRNA were significantly downregulated in SHBPDS treated mice while those of IL-4 and C-Maf were significantly upregulated. In vitro stimulation of splenocytes and CD4 T cells by SHBPDS resulted in a reduction in IFN-${\gamma}$ secretion and STAT4 activity. The IL-4 releases from both cells were slightly reduced, but STAT6 activity was rather increased. In conclusion, SHBPDS exerted an inhibition in the expression of IFN-${\gamma}$, T-bet and STAT4 while IL-4, C-Maf and STAT6 were increased. Further studies are required to examine its pharmacological effects using more appropriate animal experiments.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.4
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• pp.669-673
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• 2011

To prevent and treat the osteoporotic fracture, more attention should be paid in old age patients. Osteoclast which has ability to bone resorption is originated from hematopoietic cell line and plays a key role osteoporotic bone loss. Rubi Fructus has been widely used in Oriental medicine. Extracts of the leaves and fruit of Rubus species have been used in various countries as natural remedies to treat diabetes, infections, colic, and burns. However, the effect of extract of Rubi Fructus (fruit of Rubus coreanus Miq.) in osteoclast differentiation remains unknown. Thus, we evaluated the effect of Rubi Fructus on receptor activator of nuclear factor-kB ligand (RANKL)-induced osteoclast differentiation. Here we found that Rubi Fructus significantly inhibited osteoclast differentiation induced by RANKL. Rubi Fructus suppressed the activation of p38 pathway and NFkB in bone marrow macrophages (BMMs) treated with RANKL. Also, Rubi Fructus significantly inhibited the mRNA expression of c-Fos, tartrate-resistant acid phosphatase (TRAP), osteoclast-associated receptor (OSCAR), nuclear factor of activated T cells (NFAT)c1 and cathepsin K in BMMs treated with RANKL. Particularly, Rubi Fructus greatly inhibited the protein expression of c-fos and NFATc1. especially in the case of NFATc1 expression, a master transcription factor of the differentiation of osteoclasts is very important step for osteoclastogenesis. Taken together, our results demonstrated that Rubi Fructus may be useful treatment option of bone-related disease such as osteoporosis and rheumatoid arthritis.

• Journal of Life Science
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• v.23 no.10
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• pp.1280-1287
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• 2013

The current study investigated the effects of [6]-gingerol, a ginger phytochemical, on the expression of autophagy-related genes and the activation of antioxidative enzymes in the pancreas of mice with cerulein-induced acute pancreatitis. The following were studied: pancreatic edema, ${\alpha}$-amylase activity in serum, expression of autophagy genes, activities of antioxidative defense enzymes, such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the production of lipid peroxidation (LPO). The results revealed that cerulein-induced edema in the pancreas and ${\alpha}$-amylase activity in the cerulein group significantly increased compared with that of the control. However, that of the [6]-gingerol pretreated group was significantly decreased compared with that of the cerulein-alone injected group (positive control). There was no significant difference compared with that of control. The expression of autophagy-related proteins, including Beclin-1 and cleaved microtubule-associated protein 1 light chain 3, were significantly increased in the positive control but significantly decreased in the [6]-gingerol-pretreated group. Furthermore, the activities of SOD and GSH-Px in the positive control were decreased compared with those of the control. However, those of the [6]-gingerol pretreated group were significantly increased compared with those of the cerulein-alone group. The mRNA levels and antioxidant enzyme activities were similar. The production of LPO in the cerulein with and without [6]-gingerol groups was increased by 133.1% and 26.3%, respectively, compared with that of the control, whereas that of the [6]-gingerol-pretreated group was significantly decreased by 48.5% compared with that of the positive control. Therefore, [6]-gingerol may be a strong candidate in reducing autophagy and LPO production and in enhancing antioxidative enzyme activities to help prevent acute and chronic pancreatitis.

• Molecules and Cells
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• v.19 no.1
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• pp.114-123
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• 2005

Nitropyrene, the predominant nitropolycyclic hydrocarbon found in diesel exhaust, is a mutagenic and tumorigenic environmental pollutant that requires metabolic activation via nitroreduction and ring oxidation. In order to determine the role of ring oxidation in the mutagenicity of 1-nitropyrene, its oxidative metabolites, 1-nitropyrene 4,5-oxide and 1-nitropyrene 9,10-oxide, were synthesized and their mutation spectra were determined in the coding region of hprt gene of CHO cells by a PCR amplification of reverse-transcribed hprt mRNA, followed by a DNA sequence analysis. A comparison of the two metabolites for mutation frequencies showed that 1-nitropyrene 9,10-oxide was 2-times higher than 1-nitropyrene 4,5-oxide. The mutation spectrum for 1-nitropyrene 4,5-oxide was base substitutions (33/49), one base deletions (11/49) and exon deletions (5/49). In the case of 1-nitropyrene 9,10-oxide, base substitutions (27/50), one base deletions (15/50), and exon deletions (8/50) were observed. Base substitutions were distributed randomly throughout the hprt gene. The majority of the base substitutions in mutant from 1-nitropyrene 4,5-oxide treated cells were $A{\rightarrow}G$ transition (15/33) and $G{\rightarrow}A$ transition (8/33). The predominant base substitution, $A{\rightarrow}G$ transition (11/27) and $G{\rightarrow}A$ transition (8/27), were also observed in mutant from 1-nitropyrene 9,10-oxide treated cells. The mutation at the site of adenine and guanine was consistent with the previous results, where the sites of DNA adduct formed by these compounds were predominant at the sites of purines. A comparison of the mutational patterns between 1-nitropyrene 4,5-oxide and 1-nitropyrene 9,10-oxide showed that there were no significant differences in the overall mutational spectrum. These results indicate that each oxidative metabolite exhibits an equal contribution to the mutagenicity of 1-nitropyrene, and ring oxidation of 1-nitropyrene is an important metabolic pathway to the formation of significant lethal DNA lesions.

• Molecules and Cells
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• v.25 no.3
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• pp.390-396
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• 2008

Calreticulin (CRT) is one of the major $Ca^{2+}$ binding chaperone proteins of the endoplasmic reticulum (ER) and an unusual luminal ER protein. Postnatally elevated expression of CRT leads to impaired development of the cardiac conductive system and may be responsible for the pathology of complete heart block. In this study, the molecular mechanisms that affect $Ca^{2+}$-dependent signal cascades were investigated using CRT-overexpressing cardiomyocytes. In particular, we asked whether calreticulin plays a critical role in the activation of $Ca^{2+}$-dependent apoptosis. In the cells overexpressing CRT, the intracellular calcium concentration was significantly increased and the activity of PKC and level of SECAR2a mRNA were reduced. Phosphorylation of Akt and ERKs decreased compared to control. In addition the activity of the anti-apoptotic factor, Bcl-2, was decreased and the activities of pro-apoptotic factor, Bax, p53 and caspase 8 were increased, leading to a dramatic augmentation of caspase 3 activity. Our results suggest that enhanced CRT expression in mature cardiomyocytes disrupts intracellular calcium regulation, leading to calcium-dependent apoptosis.

• The Korea Journal of Herbology
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• v.30 no.6
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• pp.7-15
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• 2015

Objectives : Rosa laevigata Michx. has been used for the treatment of renal disease in traditional Korean medicine. In this study, we investigated cytoprotective effect of R. laevigata water extract (RLE) against oxidative stress induced by arachidonic acid (AA) + iron.Methods : To evaluate the protective effects of RLE against AA + iron-induced oxidative stress in HepG2 cell, cell viability and changes on apoptosis-related proteins were assessed by MTT and immunoblot analyses. The effects of RLE on reduced glutathione level, production of reactive oxygen species and mitochondrial membrane potential were also monitored. Furthermore, to verify underlying molecular mechanism, NF-E2-related factor 2 (Nrf2) was examined by immunoblot analysis. Additionally, Nrf2 transactivation and its downstream target genes expression were also determined by reporter gene and realtime RT-PCR analyses.Results : RLE pretreatment (30-300 μg/ml) prevented cells from AA + iron-mediated cell death in a concentration dependent manner. In addition, 100 μg/ml RLE inhibited AA + iron-induced glutathione depletion, reactive oxygen species production and mitochondrial dysfunction. RLE accumulated nuclear Nrf2 and also transactivated Nrf2, which was evidenced by antioxidant response element- and glutathione S-transferase A2-driven luciferase activities and mRNA level of glutamate-cysteine ligase catalytic subunit, NAD(P)H:quinone oxidoreductase 1 and sestrin 2. Moreover, protective effect of RLE against AA + iron was abolished in Nrf2 knockout cells.Conclusions : These results indicate that RLE has the ability to protect hepatocyte against oxidative stress through Nrf2 activation.

• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.277-285
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• 2001

Periodontal disease is characterized by inflammation and subsequent loss and/or damage to tooth-supporting tissues such as bone, cementum,and periodontal ligament. Periodontal ligament and cementum are the key tissues in the initial process of regeneration following periodontal disease. Therefore, studies on cementoblasts, which form cementum are emphasized. It is still unclear which cells cementoblast differentiate from. This study was conducted under the hypothesis that PDL fibroblast can differentiate into either cementoblast or osteoblast depending on the conditions of surrounding tissue. Clinically, with excessive traction force of orthodontic appliances or excessive occlusion hypercementosis is observed, and this has been confirmed histologically. Consequently, activation of cementoblast can be expected in rats when mechanical stimuli are given to PDL fibroblast. Therefore, the purpose of this article is to prove that PDL fibroblast differentiates into cementoblast in rats under mechanical stimuli using histologic and molecular methods. In this study, twenty rats were given hard diet. Ten of them were sacrificed after 1 week, and the others were sacrificed after two weeks. Slides were made from tooth specimen, and they were studied under the microscope. In addition, PDL fibroblast and cementum from the extracted teeth were analyzed with Northern blotting. In histologic examination, as time passed, PDL fibroblast migrated to the dentin side, differentiated into cementoblast, and formed new cementum. In Northern blotting, it was found that mRNA expression of cementoblast-specific proteins such as BSP, OC, OPN, and type I collagen were more prominent in rats sacrificed after 2 weeks of hard-diet than rats sacrificed after 1 week. From these findings we can conclude that PDL fibroblast can differentiate into cementoblast under mechanical stimuli. We think that 'Rat Models' used in this study will be beneficial to future studies regarding cementoblast.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.38-45
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• 2018

Acne is an inflammatory skin disease that occurs in puberty and young people. Propionibacterium acnes (P. acnes) is known to be a major cause of inflammation in acne. P. acnes proliferates within hair follicles blocked by overproduced sebum in the skin, and thereby activates monocytic cells to promote the secretion of pro-inflammatory cytokines. In this study, we investigated the possibility of Cnestis palala (Lour.) Merr. extract to diminish P. acnes-mediated inflammatory responses. We found that C. palala extract significantly attenuated P. acnes-induced pro-inflammatory cytokine expressions, such as $IL-1{\beta}$, IL-6, $TNF-{\alpha}$, iNOS, and COX-2 in mouse macrophage RAW264.7 cells. Moreover, we observed that C. palala extract inhibited $NF-{\kappa}B$ transcriptional activation, which is the major transcription factor of inflammatory cytokine expression. Therefore, it is expected that C. palala extract has a potential as a therapeutic agent or supplement for the treatment P. acnes-induced inflammatory responses.