Moon Jin Jeong

Aberrant mucosal wound repair in the absence of secretory leukocyte protease inhibitor

Secretory leukocyte protease inhibitor (SLPI) is a cationic serine protease inhibitor with anti-microbial and anti-inflammatory properties found in large quantities in mucosal fluids, including saliva. SLPI is expressed during cutaneous wound healing, however, its role in oral wound repair is unknown. We have used a novel approach involving a murine buccal mucosal acute wound model to investigate the role of SLPI in oral healing. In parallel to the observed cutaneous healing phenotype, an absence of SLPI results in markedly impaired oral wound healing associated with increased inflammation and raised elastase activity. Moreover, matrix deposition was decreased, while MMP activity was enhanced in the oral SLPI null wounds suggesting deregulated proteolysis. Intriguingly, regardless of genotype, reduced collagen deposition was observed in oral compared to dermal wounds, associated with reduced TGF-beta expression and decreased fibroblast collagen expression in vitro. We propose that SLPI is a pivotal endogenous factor necessary for optimal tissue repair including intra-oral wound healing. In addition, our model provides a unique opportunity to delineate the cellular and molecular mechanisms underlying the differences between dermal scarring and oral scar-free healing.

Formaldehyde exposure induces airway inflammation by increasing eosinophil infiltrations through the regulation of reactive oxygen species production

Formaldehyde (FA) is a well-known cytotoxic irritant to the airways, but the mechanism of airway inflammation due to FA has not been clarified. In the present study, C57BL/6 mice were exposed to two concentrations (5 and 10ppm) of FA for 6h/day, 5days/week, for 2 weeks. The FA-exposed mice had much higher number of CCR3(+) eosinophils than control mice, and showed upregulated gene expression of CC-chemokine receptor-3 (CCR3), eotaxin and intercellular adhesion molecules-1 (ICAM-1) as well as an increased expression of proinflammatory and Th2 cytokines, such as interleukin (IL)-1β, IL-4 and IL-5. In addition, FA exposure revealed a considerable increase in the serum levels of IgG1, IgG3, IgA and IgE compared to controls. Histopathological analysis of the lung tissues demonstrated eosinophils and mononuclear cell infiltration of the alveolar cell walls and alveolar spaces. Gene expression of thioredoxin (TRX), redox-regulating antioxidant proteins, was markedly suppressed in FA-exposed mice, and thereby intracellular ROS levels were increased along with increased FA concentration. These results were consistent with an increase in the number of CCR3-expressing eosinophils, and indicate that FA-induced ROS was generated from eosinophils recruited to the inflammatory sites of the airways.

Effect of Korean Red Ginseng Extract in a Steroid-induced Polycystic Ovary Murine Model

Experimental induction of polycystic ovary (PCO) in rodent resembling some aspects of human PCO syndrome was produced using the long-acting compound estradiol valerate (EV). Our previous study on the role of Korean red ginseng total saponins in a steroid-induced PCO rat model demonstrated that electro-acupuncture modulates nerve growth factor (NGF) concentration in the ovaries. In fact, the involvement of a neurogenic component in the pathology of PCO-related ovarian dysfunction is preceded by an increase in sympathetic outflow to the ovaries. In the present study, we tested the hypothesis that Korean red ginseng extract (KRGE) administration modulates sympathetic nerve activity in PCO-induced rats. This was done by analyzing NGF protein and NGF mRNA expression involved in the pathophysiological process underlying steroid-induced PCO. EV injection resulted in significantly higher ovarian NGF protein and NGF mRNA expression in PCO-induced rats compared to control rats, and PCO ovaries were counteracted by KRGE administration with significantly lower expression of NGF protein and NGF mRNA compared to EV treated ovaries. These results indicate that EV modulates the neurotrophic state of the ovaries, which may be a component of the pathological process by which EV induces cyst formation and anovulation in rodents.

Guided Tissue Regeneration of the Mixture of Human Tooth-Ash and Plaster of Paris in Dogs

This study evaluated the efficacy of periodontal tissue regeneration using guided tissue regeneration (GTR) with a mixture of tooth ash and plaster as a bone substitute material in the treatment of class II furcation defects in dogs. GTR was performed at the site of a surgically formed mandibular premolar bifurcation area in dogs. Four adult dogs were used in the animal study. The animals were in a good periodontal state without any systemic disease. A resorbable membrane (Bio-Gide®, Swiss) and bone graft material using a mixture of tooth ash and plaster were used to examine the biological activity. The defect in the control group was filled a Bio-Gide® only. For the experimental group, the defects were filled with a mixture of tooth ash and plaster and covered by a Bio-Gide®. Oral rinsing with 0.12% chlorhexidine was performed twice a day for 2 weeks. In control group, new bone formation was observed adjacent to the preexisting bone. Soft tissue ingrowth was also noted. In experimental group, new lamellar type trabecular bone formation as well as centum and PDL regeneration was observed in the base of the infrabony pocket. More bone regeneration would be expected when GTR is performed using a mixture of human tooth-ash and plaster of Paris as a bone graft material.

Therapeutic Effect of Korean Red Ginseng Extract on Infertility Caused by Polycystic Ovaries

Polycystic ovarian syndrome (PCOS) is a very common endocrine disorder in women of reproductive age. Nerve growth factor (NGF) may be involved in the pathogenesis of PCOS. In this study, we investigated the effect of Korean red ginseng extract (KRGE) on the ovarian morphology and NGF expression in an estradiol valerate (EV)-induced rat model. Polycystic ovaries were induced by a single intramuscular injection of estadiol valerate (4 mg, dissolved in sesame oil) in adult cycling rats. KRGE was administered orally (200 mg/kg body weight/day) for 60 consecutive days, beginning 60 days after the induction. Ovarian morphology was almost normalized and NGF was normalized in the EV+KRGE group. KRGE lowered the high numbers of antral follicles and increased the number of corpora lutea in the polycystic ovaries. The results are consistent with a beneficial effect of KRGE in the treatment of PCOS.

Secretory leukocyte protease inhibitor promotes differentiation and mineralization of MC3T3-E1 preosteoblasts on a titanium surface.

Mineralized bone matrix constituted with collagenous and non-collagenous proteins was synthesized by osteoblasts differentiated from mesenchymal stem cells. Secretory leukocyte protease inhibitor (SLPI), a serine protease inhibitor, promotes cell migration and proliferation, and suppresses the inflammatory response. Recent studies reported that SLPI regulates the formation of dentin and mineralization by odontoblasts and increases the adhesion and viability of preosteoblasts on a titanium (Ti) surface. Ti and its alloys are widely used implant materials in artificial joints and dental implants owing to their biocompatibility with bone. Therefore, this study aimed to examine whether SLPI can be an effective molecule in promoting differentiation and mineralization of osteoblasts on a Ti surface. In order to investigate the effects of SLPI on osteoblasts, an MTT assay, PCR, western blotting and Alizarin Redxa0S staining were performed. The results demonstrated that SLPI increased the viability of osteoblasts during differentiation on Ti discs compared with that of the control. The expression levels of SLPI mRNA and protein were higher than that of the control after treatment of osteoblasts with SLPI on Ti discs during differentiation. SLPI increased the formation of mineralized nodules and mRNA expression of alkaline phosphatase, dentin sialophosphoprotein, dentin matrix proteinxa01, bone sialoprotein, and collagenxa0I in osteoblasts on Ti discs compared with that of the control. In conclusion, SLPI increases the viability and promotes the differentiation and mineralization of osteoblasts on Ti surfaces, suggesting that SLPI is an effective molecule for achieving successful osseointegration between osteoblasts and a Ti surface.

Antioxidant and cytoprotective effects of morin against hydrogen peroxide-induced oxidative stress are associated with the induction of Nrf-2‑mediated HO-1 expression in V79-4 Chinese hamster lung fibroblasts

Natural phytochemicals of plant origin, including flavonoids, have been found to be potent antioxidants providing beneficial effects against oxidative stress-related diseases. The present study was carried out to investigate the antioxidant properties of morin, a flavonoid originally isolated from the flowering plants of the Moraceae family. Superoxide dismutase (SOD)‑like activity and 2,2‑azino‑bis‑(3‑ethylbenzothiazoline‑6‑sulfonic acid) (ABTS•+) radical scavenging activity were determined. We also investigated the cytoprotective effects of morin against hydrogen peroxide (H2O2)‑induced DNA damage and apoptosis in V79‑4 Chinese hamster lung fibroblasts. Our results demonstrated that morin had strong scavenging effects against ABTS•+ radicals with enhanced SOD activity, which varied in a dose-dependent manner. Morin was found to reduce H2O2‑induced intracellular reactive oxygen species generation and nuclear DNA damage, and it recovered cell viability damaged by H2O2 via inhibition of mitochondrial dysfunction‑mediated apoptosis. Notably, the treatment of V79‑4 cells with morin markedly enhanced the expression of heme oxygenase‑1 (HO‑1) but not quinone oxidoreductase-1, which was associated with the increased expression and phosphorylation of nuclear factor-erythroidxa02-related factorxa02 (Nrf2) and the downregulation of Kelch‑like ECH‑associated proteinxa01 expression. Based on our findings, we conclude that morin effectively ameliorated oxidative stress‑induced DNA damage through intrinsic free radical scavenging activity and activation of the Nrf2/HO-1 pathway.Natural phytochemicals of plant origin, including flavonoids, have been found to be potent antioxidants providing beneficial effects against oxidative stress-related diseases. The present study was carried out to investigate the antioxidant properties of morin, a flavonoid originally isolated from the flowering plants of the Moraceae family. Superoxide dismutase (SOD)‑like activity and 2,2‑azino‑bis‑(3‑ethylbenzothiazoline‑6‑sulfonic acid) (ABTS•+) radical scavenging activity were determined. We also investigated the cytoprotective effects of morin against hydrogen peroxide (H2O2)‑induced DNA damage and apoptosis in V79‑4 Chinese hamster lung fibroblasts. Our results demonstrated that morin had strong scavenging effects against ABTS•+ radicals with enhanced SOD activity, which varied in a dose-dependent manner. Morin was found to reduce H2O2‑induced intracellular reactive oxygen species generation and nuclear DNA damage, and it recovered cell viability damaged by H2O2 via inhibition of mitochondrial dysfunction‑mediated apoptosis. Notably, the treatment of V79‑4 cells with morin markedly enhanced the expression of heme oxygenase‑1 (HO‑1) but not quinone oxidoreductase-1, which was associated with the increased expression and phosphorylation of nuclear factor-erythroidxa02-related factorxa02 (Nrf2) and the downregulation of Kelch‑like ECH‑associated proteinxa01 expression. Based on our findings, we conclude that morin effectively ameliorated oxidative stress‑induced DNA damage through intrinsic free radical scavenging activity and activation of the Nrf2/HO-1 pathway.

Histologic comparison of polycystic ovary syndrome induced by estradiol valerate and letrozole

목적: 다낭성난소증후군(polycystic ovary syndrome, PCOS)을 estradiol valerate (EV)와 letrozole (LE)로 유발할 수 있는데 인간의 다낭성난소증후군과 가장 유사한 질환동물 모델이 무엇인가를 알아보고자 하였다. 연구방법: EV와 LE를 각각 랫드에 처리하여 PCOS를 유발시킨 후 희생시켜 난소를 적출하였다. 난소를 조직학적으로 관찰하여 다낭성 난소 변화 유발유무, 난소의 크기, 난포낭의 크기 및 수를 측정하고 난포 및 간질세포의 황체화 등을 비교 관찰하였다. 결과: LE처리군은 EV처리군에 비하여 난소의 크기 및 난포낭의 수가 유의하게 증가하고 난포막세포의 황체화가 뚜렷하여 인간의 PCOS와 더유사한 소견을 보였다. 결론: 랫드에서 LE처리에 의한 PCOS는 PCOS질환유발 동물 모델로 더 적합한 것으로 평가된다.

Thymosin β4 is associated with bone sialoprotein expression via ERK and Smad3 signaling pathways in MDPC-23 odontoblastic cells

Thymosin β4 (Tβ4) regulates the expression of molecules associated with dentinogenesis, including bone sialoprotein (BSP). BSP regulates the initiation of mineralization and the direction of dentin growth. However, the association between Tβ4 signaling and BSP expression in odontoblasts remains unclear. Therefore, the aim of the present study was to investigate Tβ4 mRNA expression in odontoblasts during dentinogenesis and the association between the Tβ4 signaling pathway and BSP expression in MDPC‑23 odontoblastic cells. Expression and localization of Tβ4 mRNA was determined by inxa0situ hybridization during mouse tooth development. The effect of Tβ4 signaling on BSP expression was investigated by reverse transcription polymerase chain reaction, western blot analysis, immunofluorescence and a luciferase reporter assay in the presence or absence of specific inhibitors of mitogen activated protein kinase kinase (PD98059) and mothers against decapentaplegic homolog 3 (Smad3; SIS3) in MDPC‑23 cells. The expression of Tβ4 mRNA in the odontoblast layer was highest at postnatal day 5, known as the advanced bell stage, when odontoblasts actively secrete dentin matrix proteins. Tβ4 increased BSP mRNA and protein levels in MDPC‑23 cells, but this was inhibited by PD98059 or SIS3 treatment. Tβ4 increased levels of phosphorylated (p) extracellular signal‑regulated kinase (ERK)1/2, pSmad3, pβ‑catenin, and runt‑related transcription factor 2 (Runx2) protein, but these effects were inhibited by PD98059 or SIS3. Tβ4 induced the nuclear translocation of Runx2 and pSmad3, while nuclear translocation of β‑catenin was decreased. Tβ4 significantly increased BSP promoter activity, which was decreased by PD98059 or SIS3 treatment. Tβ4 induced BSP expression in MDPC‑23 cells via ERK and Smad3 signaling pathways, suggesting its role as a signaling molecule in odontoblasts for regulating BSP secretion during dentinogenesis.

Bone Formation Effect of HA/β-TCP Composite Powders in Rabbit Calvarial Bone Defects: Histologic Study

This study evaluated the histology results of surgically created bone cavities in the calvaria of rabbits that were subsequently filled with a HA/ß-TCP composite powder developed in Korea (Dentium, Korea). Ten young adult rabbits were used. Four defects were surgically produced in the calvaria of each rabbit. These defects were classified into 4 groups: the control group, no graft materials; experimental group I, normal saline + graft materials; experimental group II, venous blood + graft materials; and experimental group III, graft materials only. The defects were randomly filled with the graft materials. The rabbits were sacrificed with at 1-, 2-, 4-, 6- and 8- weeks after surgery. The histology specimens were prepared using the general method with H & E staining at a 6 ㎛ thickness. Histologically, the degree of new bone formation was similar in all experimental groups. However, for experimental group II, many cells had gathered around the graft materials 1-week after surgery, and new bone formed slightly faster and than in the other groups. No bone formation was observed in the control group. Based on histology findings, the new HA/ß- TCP composite powders appeared to act as a scaffolding material for the regeneration of osseous defects.