• 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.

• KSBB Journal
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• v.32 no.3
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• pp.224-232
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• 2017

Resveratrol has been actively investigated as an anticancer drug since it induces cell growth inhibition and apoptosis in many cancer cells. Resveratrol acts through modulation of multiple pathways and genes. In this study, we found resveratrol reduced cell growth and mammosphere formation in MDA-MB-231 triple-negative human breast cancer cells. This suppressive effect of resveratrol is accompanied by a reduction in Bmi-1 gene expression. We also observed that knock-down of Bmi-1 gene by small interfering RNA effectively sensitizes breast cancer cells to resveratrol treatment. Our data demonstrate, for the first time, that resveratrol down-regulates Bmi-1 expression in human breast cancer cells and suggest that specific molecular targeting of Bmi-1 can be combined with a chemotherapeutic strategy to improve the response of breast cancer cells to resveratrol.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.6
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• pp.401-406
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• 2017

Objectives: Headache is the most common complaint of patients suffering from temporomandibular joint disorders (TMDs). Thus, temporomandibular joint (TMJ) examinations maybe necessary in patients with headache. Considering the high prevalence of bruxism and TMDs in patients with headache the effects of conservative TMD treatment on headache should be assessed. Materials and Methods: Patients were questioned about headaches in the past three months. Those responding affirmatively to this question were examined for TMD and bruxism. After the examinations, 219 patients remained in the study and received self-management instructions. Patients were requested to modify oral habits except when eating or sleeping. The degree of pain (visual analogue scale), headache disability index (HDI), frequency of headaches (FH) per month and TMD intensity were evaluated. Results: The median levels of pain, HDI, FH, and TMD intensity were 8, 44, 8, and 7, respectively, before modifying oral habits and decreased to 4, 24, 2, and 3, respectively, after intervention. These decreases were statistically significant. Conclusion: Having patients maintain free space between the teeth and relax muscles can be an efficient method to treat headache and TMD, especially when repeated frequently.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.3
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• pp.119-124
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• 2003

To elucidate the molecular mechanism of pharmacological action of local anesthetics, we studied membrane actions of tetracaine, bupivacaine, lidocaine, prilocaine and procaine. Fluorescence polarization of n-(9-anthroyloxy)stearic acid (n-AS) was used to examine the effects of these local anesthetics on differential rotational mobility of different positions of the number of synaptosomal plasma membrane vesicle (SPMV) phospholipid carbon atoms. The four membrane components differed with respect to 3, 6, 9 and 16-(9-anthroyloxy)stearic acid (3-AS, 6-AS, 9-AS and 16-AP) probes, indicating that differences in the membrane fluidity might be present. Degrees of the rotational mobility of 3-AS, 6-AS, 9-AS and 16-AP were different depending on depth of hydrocarbon interior. In a dose-dependentmanner, tetracaine, bupivacaine, lidocaine, prilocaine and procaine decreased anisotropy of 3-AS, 6-AS, 9-AS and 16-AP in the hydrocarbon interior of the SPMV. These results indicate that local anesthetics have significant disordering effects on hydrocarbon interior of the SPMV, thus affecting the transport of $Na^+$ and $K^+$ in nerve membranes and leading to anesthetic action.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.2
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• pp.370-374
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• 2005

Streptococcus mutans (S. mutans) is known as the causative bacterial playing the most important role informing plaque and it is being noticed as major causative bacteria of dental caries. Therefore, development of more effective, substantial and safe preventive agent against dental caries and periodontal disease is honestly required. The present study was designed to investigate the effect of Cyperus rotundus (Cyperaceae) methanol extracts on the growth, acid production, adhesion, and insoluble glucan synthesis of S. mutans. The methanol extract of C. rotundus showed concentration dependent inhibitory activity against the growth and acid production of S. mutans, and produced significant inhibition at the concentration of 0.5, 1, 2 and 4 mg/ml compared to the control group. The extracts markedly inhibited S. mutans adherence to HA treated with saliva, and cell adherence was repressed by more than 50% at the concentration of 0.5 mg/ml and complete inhibition was observed at the concentration of 4 mg/ml. On the activity of glucosyltransferase which synthesizes water insoluble glucan from sucrose, methanol extract of C. rotundus showed more than 10% inhibition over the concentration of 2 mg/ml. Thus, the application of C. rotundus can be considered a useful and a practical method for the prevention of dental caries.

• International Journal of Stem Cells
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• v.11 no.2
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• pp.177-186
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• 2018

Background and Objectives: Glial scarring and inflammation after spinal cord injury (SCI) interfere with neural regeneration and functional recovery due to the inhibitory microenvironment of the injured spinal cord. Stem cell transplantation can improve functional recovery in experimental models of SCI, but many obstacles to clinical application remain due to concerns regarding the effectiveness and safety of stem cell transplantation for SCI patients. In this study, we investigated the effects of transplantation of human mesenchymal stem cells (hMSCs) that were genetically modified to express Olig2 in a rat model of SCI. Methods: Bone marrow-derived hMSCs were genetically modified to express Olig2 and transplanted one week after the induction of contusive SCI in a rat model. Spinal cords were harvested 7 weeks after transplantation. Results: Transplantation of Olig2-expressing hMSCs significantly improved functional recovery in a rat model of contusive SCI model compared to the control hMSC-transplanted group. Transplantation of Olig2-expressing hMSCs also attenuated glial scar formation in spinal cord lesions. Immunohistochemical analysis showed that transplanted Olig2-expressing hMSCs were partially differentiated into Olig1-positive oligodendrocyte-like cells in spinal cords. Furthermore, NF-M-positive axons were more abundant in the Olig2-expressing hMSC-transplanted group than in the control hMSC-transplanted group. Conclusions: We suggest that Olig2-expressing hMSCs are a safe and optimal cell source for treating SCI.

• Restorative Dentistry and Endodontics
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• v.48 no.2
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• pp.12.1-12.11
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• 2023

Objectives: The present study evaluated the pulp response of human mandibular incisors subjected to in-office dental bleaching using gels with medium or high concentrations of hydrogen peroxide (HP). Materials and Methods: The following groups were compared: 35% HP (HP35; n = 5) or 20% HP (HP20; n = 4). In the control group (CONT; n = 2), no dental bleaching was performed. The color change (CC) was registered at baseline and after 2 days using the Vita Classical shade guide. Tooth sensitivity (TS) was also recorded for 2 days post-bleaching. The teeth were extracted 2 days after the clinical procedure and subjected to histological analysis. The CC and overall scores for histological evaluation were evaluated by the Kruskal-Wallis and Mann-Whitney tests. The percentage of patients with TS was evaluated by the Fisher exact test (α = 0.05). Results: The CC and TS of the HP35 group were significantly higher than those of the CONT group (p < 0.05) and the HP20 group showed an intermediate response, without significant differences from either the HP35 or CONT group (p > 0.05). In both experimental groups, the coronal pulp tissue exhibited partial necrosis associated with tertiary dentin deposition. Overall, the subjacent pulp tissue exhibited a mild inflammatory response. Conclusions: In-office bleaching therapies using bleaching gels with 20% or 35% HP caused similar pulp damage to the mandibular incisors, characterized by partial necrosis, tertiary dentin deposition, and mild inflammation.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.5
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• pp.423-433
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• 2024

Dental pulp stem cells (DPSCs) are a type of adult stem cell present in the dental pulp tissue. They possess a higher proliferative capacity than bone marrow mesenchymal stem cells. Their ease of collection from patients makes them well-suited for tissue engineering applications, such as tooth and nerve regeneration. Chios gum mastic (CGM), a resin extracted from the stems and leaves of Pistacia lentiscus var. Chia, has garnered attention for its potential in tissue regeneration. This study aims to confirm alterations in cell proliferation rates and induce differentiation in human DPSCs (hDPSCs) through CGM treatment, a substance known for effectively promoting odontogenic differentiation. Administration of CGM to hDPSC cells was followed by an assessment of cell survival, proliferation, and odontogenic differentiation through protein and gene analysis. The study revealed that hDPSCs exhibited low sensitivity to CGM toxicity. CGM treatment induced cell proliferation by activating cell-cycle proteins through the Wnt/β-catenin pathway. Additionally, the study demonstrated that CGM enhances alkaline phosphatase activation by upregulating the expression of collagen type I, a representative matrix protein of dentin. This activation of markers associated with odontogenic and bone differentiation ultimately facilitated the mineralization of hDPSCs. This study concludes that CGM, as a natural substance, fosters the cell cycle and cell proliferation in hDPSCs. Furthermore, it triggers the transcription of odontogenic and osteogenic markers, thereby facilitating odontogenic differentiation.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.4
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• pp.371-376
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• 2017

The caudal subnucleus of the spinal trigeminal nucleus (medullary dorsal horn; MDH) receives direct inputs from small diameter primary afferent fibers that predominantly transmit nociceptive information in the orofacial region. Recent studies indicate that reactive oxygen species (ROS) is involved in persistent pain, primarily through spinal mechanisms. In this study, we aimed to investigate the role of xanthine/xanthine oxidase (X/XO) system, a known generator of superoxide anion ($O_2{^-}$), on membrane excitability in the rat MDH neurons. For this, we used patch clamp recording and confocal imaging. An application of X/XO ($300{\mu}M/30mU$) induced membrane depolarization and inward currents. When slices were pretreated with ROS scavengers, such as phenyl N-tert-butylnitrone (PBN), superoxide dismutase (SOD), and catalase, X/XO-induced responses decreased. Fluorescence intensity in the DCF-DA and DHE-loaded MDH cells increased on the application of X/XO. An anion channel blocker, 4,4-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), significantly decreased X/XO-induced depolarization. X/XO elicited an inward current associated with a linear current-voltage relationship that reversed near -40 mV. X/XO-induced depolarization reduced in the presence of $La^{3+}$, a nonselective cation channel (NSCC) blocker, and by lowering the external sodium concentration, indicating that membrane depolarization and inward current are induced by influx of $Na^+$ ions. In conclusion, X/XO-induced ROS modulate the membrane excitability of MDH neurons, which was related to the activation of NSCC.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.392-397
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• 2007

We investigated whether ethanol extracts of the safflower seeds containing phenolic compounds were responsible for the bone-protecting effects. Crude ethanol extract (CEE) of the safflower seeds was fed for 4 weeks at the level of 1% in diet to female Sprague-Dawley rats that had been subjected to bilateral ovariectomy (OVX). The CEE effects (OVX+CEE) were evaluated by comparing results obtained from OVX, Sham, and OVX injected with $17{\beta}$-estradiol ($OVX+E_2$) groups. OVX resulted in a dramatic reduction in the trabecular bone mass of the proximal tibia (approximately 40% of the Sham group) and an increase in fat deposition in bone marrow. In $OVX+E_2$ group, the bone loss was completely prevented as well as marrow adiposity. In OVX+CEE group, approximately 80% of the bone mass was maintained compared with Sham group and fat deposition in the bone marrow was prevented. Meanwhile, the partially purified ethanol extract containing the phenolic compounds stimulated proliferation of the ROS 17/2.8 osteoblast-like cells in a dose-dependent manner, as potently as positive controls of $E_2$ and genistein. The present data demonstrate that the ethanol extracts of safflower seeds reduced bone loss caused by estrogen deficiency. The bone-protecting effect of safflower seeds seems to be mediated, at least partly, by the stimulating effect of the phenolic compounds on the growth of osteoblasts.