The Role of Nucleotide-binding Oligomerization Domain 2 on the Immunomodulatory Function of Mesenchymal Stem Cells in Mouse Colitis Model

Mesenchymal stem cells (MSCs) are multipotent adult stromal cells that can self-renew and differentiate into various cell types of mesodermal lineage. Moreover, MSCs are recently known to possess regulatory function on immune cells which makes them a promising tool for the treatment of inflammatory and autoimmune diseases. The interaction between MSCs and immune cells through soluble factors and adhesion molecules has been reported to be crucial for the immunomodulatory effect of MSCs. Innate immune receptors, such as Toll-like receptors (TLRs) and Nod-like receptors (NLRs), are known to trigger an initial immune responses against microbial infection. Although studies suggest that activation of TLRs modulate the function of mesenchymal stem cells (MSCs), little is known about the role of NLRs on the MSC function. In this study, I investigated whether Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) and 2 (NOD2), well-known receptors in NLR family, regulate the functions of human umbilical cord blood-derived MSCs (hUCB-MSCs). TLR2, TLR4, NOD1, NOD2 and receptor interacting protein 2 (RIP2), an adaptor protein of NOD1 and NOD2 were expressed in hUCB-MSCs. Stimulation with each agonistPam3CSK4 for TLR2, Lipopolysaccharide (LPS) for TLR4, L-Ala-gamma-D-Glu-meso- diamino-pimelic acid (Tri-DAP) for NOD1, and muramyl dipeptide (MDP) for NOD2, led to Interleukin (IL)-8 production in hUCB-MSC, suggesting that the expressed receptors are functional in hUCB-MSC. None of agonists influenced proliferation of hUCB-MSCs. I next examined whether TLR and NLR agonists affect the differentiation of hUCB-MSCs. Pam3CSK4 and Tri-DAP strongly enhanced osteogenic differentiation through the induction of ERK phosphorylation in hUCB-MSCs, and LPS and MDP also slightly augmented osteogenesis. Treatment of U0126 (MEK1/2 inhibitor) restored osteogenic differentiation enhanced by Pam3CSK4. Tri-DAP and MDP slightly inhibited adipogenic differentiation of hUCB-MSCs, but Pam3CSK4 and LPS did not. On chondrogenic differentiation, all TLR and NLR agonists could promote chondrogenesis of hUCB-MSCs (Kim et al., 2010). Decreased levels or function of NOD2 are associated with Crohns disease. NOD2 is known to regulate intestinal inflammation, and also is expressed by human umbilical cord blood-derived mesenchymal stem cells, to regulate their differentiation. I investigated whether NOD2 is required for the anti-inflammatory activities of MSCs in mice with colitis. Colitis was induced in mice by administration of dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS). Mice then were given intraperitoneal injections of NOD2-activated hUCB-MSCs, and colon tissues and mesenteric lymph nodes were collected for histologic analyses. Administration of hUCB-MSCs reduced the severity of colitis in mice. The anti-inflammatory effects of hUCB-MSCs were greatly increased by activation of NOD2 by its ligand, MDP. Administration of NOD2-activated hUCB-MSCs increased anti-inflammatory responses in colons of mice, such as production of interleukin IL-10 and infiltration by T regulatory cells, and reduced production of inflammatory cytokines. A bromodeoxyuridine (BrdU) assay was used to determine the ability of hUCB-MSCs to inhibit proliferation of human mononuclear cells (hMNCs) in culture. Proliferation of mononuclear cells was inhibited significantly by co-culture with hUCB-MSCs that had been stimulated with MDP. MDP induced prolonged production of prostaglandin (PG)E2 in hUCB-MSCs via the NOD2–RIP2 pathway, which suppressed proliferation of mononuclear cells derived from hUCB. PGE2 produced by hUCB-MSCs in response to MDP increased production of IL-10 and T regulatory cells. In mice, production of PGE2 by MSCs and subsequent production of IL-10 were required to reduce the severity of colitis (Kim et al., 2013). Taken together, these findings suggest that (1) NOD1 and NOD2 as well as TLRs are involved in regulating the differentiation of MSCs, and that (2) activation of NOD2 is required for the ability of hUCB-MSCs to reduce the severity of colitis in mice and NOD2 signaling increases the ability of these cells to suppress mononuclear cell proliferation by inducing the production of PGE2.ABSTRACT LIST OF ABBREVIATION TABLE OF CONTENTS LITERATURE REVIEW CHAPTER I 1.1 INTRODUCTION 1.2 MATERIALS AND METHODS 1.2.1 Cell culture 1.2.2 Flow cytometric analysis 1.2.3 RNA extraction and RT-PCR 1.2.4 Cytokine production 1.2.5 hUCB-MSC proliferation 1.2.6 hUCB-MSC differentiation 1.2.7 Western Blot 1.2.8 Statistical Analysis 1.3 RESULTS 1.3.1 Expression of TLR2, TLR4, NOD1 and NOD2 1.3.2 Role of TLRs and NLRs in cell proliferation 1.3.3 Role of TLRs and NLRs in osteogenesis 1.3.4 Role of TLRs and NLRs in adipogenesis 1.3.5 Role of TLRs and NLRs in chondrogenesis 1.4 DISCUSSION CHAPTER II 2.1 INTRODUCTION 2.2 MATERIALS AND METHODS 2.2.1 Cell culture 2.2.2 Colitis induction 2.2.3 Histopathological evaluation 2.2.4 Cytokine production 2.2.5 Myeloperoxidase assay 2.2.6 Immunohistochemistry 2.2.7 Western Blot 2.2.8 Cell tracking 2.2.9 Mixed Lymphocyte Reaction 2.2.10 Nitric Oxide detection 2.2.11 RNA interference 2.2.12 Flow cytometric analyses 2.2.13 Statistical analyses 2.3 RESULTS 2.3.1 Protective effect of NOD2-activated hUCB-MSCs 2.3.2 Anti-inflammatory effect of NOD2-activated MSCs 2.3.3 NOD2 deficiency in protective effect of MSCs 2.3.4 Characterization of hUCB mononuclear cells 2.3.5 Immunosuppressive effect of NOD2-activated MSCs 2.3.6 PGE2 as a key regulatory factor from MSCs 2.3.7 NOD2-RIP2 pathway for the regulation of COX-2 2.3.8 IL-10 and Treg induction by NOD2-activated MSCs 2.3.9 PGE2 and IL-10 for colitis reduction in vivo 2.4 DISCUSSION GENERAL CONCLUSION REFERENCES 국문초록Docto

Relationship between Sleep Duration and Osteoarthritis in Middle-Aged and Older Women: A Nationwide Population-Based Study

(1) Background: Both long and short sleep durations have been associated with negative health outcomes, particularly in middle-aged and older adults. To date, there has been little research on the association between sleep and osteoarthritis. This study aimed to evaluate the relationship between sleep duration and radiographically confirmed osteoarthritis in middle-aged and older women. (2) Methods: This study included 5268 women aged ≥50 years from the Korea National Health and Nutrition Examination Survey. Sleep duration was categorized into four groups (≤5 h, 6 h, 7⁻8 h, and ≥9 h) using responses from a self-reported questionnaire, and 7⁻8 h was set as an appropriate sleep duration. Osteoarthritis was defined as Kellgren⁻Lawrence grade ≥2 in the knee or hip area in radiographic images with knee or hip joint pain. The odds ratios (ORs) and 95% confidence intervals (CIs) of osteoarthritis according to sleep duration were calculated using multiple logistic regression analyses. (3) Results: The prevalence of osteoarthritis according to sleep duration showed a U-shaped curve, with the nadir in the appropriate sleep category (7⁻8 h). Compared with the 7⁻8 h sleep duration, the ORs (95% CIs) of osteoarthritis in the short sleep duration (≤5 h/day) and long sleep duration (≥9 h/day) were 1.343 (1.072⁻1.682) and 1.388 (1.020⁻1.889), respectively, after adjusting for age, body mass index, current smoking, alcohol consumption, regular exercise, occupation, residential area, hypertension, type 2 diabetes, cardiovascular disease, and stroke. (4) Conclusions: Short and long sleep duration were positively associated with osteoarthritis in middle-aged and older women.ope

The Effect of Orthodontic Resin Cements Containing Fluoride on Fluoride-releasing and the Resistance to Enamel Decalcification

Objectives : The purpose of this study was to determine of fluoride-releasing of orthodontic resin cements containing fluoride and compare decalcification of tooth attached fluoride and non-fluoride resin cements. Methods : Total eighty premolar tooth were used in this study. Forty tooth were used for fluoride releasing measurement and forty tooth were used for decalcification measurement. Each forty tooth were randomly divided into four groups, and brackets were attached on tooth surface with Blugloo, Light Bond, Orthofolw(experimental groups) and Transbond cement(control group). After brackets were attached on tooth surface, forty tooth were immersed in artificial salival and then the quantity of fluoride releasing was measured ever day for 8days and then three-days intervals for 3 weeks. Forty tooth were immersed in decalcification solution for 48hours and then degree of decalcification was measured as lesion area, ΔF, and ΔQ using QLF. The data were analysed by one-way ANOVA and Pearson's correlation coefficient using SPSS 12.0program. Results : Fluoride release of experimental groups was higher than control group(p BG > OF > LB (p BG > OF > LB (p<0.05). As for correlation between fluoride release and lesion area, ΔF, and ΔQ showed negative correlation but there was no significant difference. Conclusions : This study shows that orthodontic reins cements containing fluoride release fluoride and prevent initial enamel decalcification caused by orthodontic treatment.ope

A comparative study of the effect of drilling depth on generation of compressive force by headless compression screws using conical and cylindrical type of drill bit

BACKGROUND: This study was conducted to measure the effect of different drilling depths on compression forces generated by two commonly used headless compression screws using the two different types of drill bit, the Acutrak® mini (conical type drill bit) and the Synthes 3.0 HCS® (cylindrical type drill bit). METHODS: A load cell was placed between two Sawbone blocks, which were 12 mm and 40 mm in thickness, respectively. After placing the guide pin into the center of the block, the drilling depth of the Acutrak® mini and Synthes HCS® screws ranged from 16 to 28 mm and 22 to 28 mm, respectively. The 24-mm screws were inserted and the compression force was measured immediately and at 30 min post-insertion. RESULTS: The Acutrak® mini generated greater compression force compared to the Synthes 3.0 HCS® when drilled to a depth of less than 24 mm. The compression force of the Acutrak® mini showed a strong inverse correlation with the drilling depth. There was no significant inverse correlation observed between the compression force of the Synthes HCS® and the drilling depth. CONCLUSIONS: If the screw length and the drill depth are the same, the Synthes 3.0 HCS® (cylindrical type drill bit) is safer and easier to use as it has no change in the compression force even when over-drilling because the compression force of the two screws is similar. As for the Acutrak® mini (conical type drill bit), while it is technically demanding due to varying compression force according to the drill depth, it can be used in certain cases because it can give stronger compression force through under-drilling.ope

Treatment of Non-union Distal Humerus Fractures after Operation.

PURPOSE: This study is a retrospective analysis of patients who had undergone surgical treatment for non-union of distal humerus fracture. We evaluated them in terms of causes of injury, radiologic findings, and clinical outcomes such as prognosis. MATERIALS AND METHODS: Seven consecutive radiologic patients who were confirmed to have nonunion of a distal humerus fracture underwent reoperations. These patients had already undergone operations for distal humerus fractures. This survey was held from 2005 to 2010. The average period up to diagnosis of non-union after the first operation was 7.4 months (4 to 16 months). The mean follow-up period was 24.6 months (12 to 65 months). Each patient was graded functionally according to the Mayo Elbow Performance Score and the Disabilities of the Arm, Shoulder and Hand Score. RESULTS: Osteosynthesis was performed by internal fixation with plates and screws and then a bone graft for non-union of the distal humerus fracture. The average range of motion within the elbow joints was found to be a flexion contracture of 18.8 degrees (0~30 degrees) and further flexion of 120.2 degrees (102~140 degrees). Among postoperative complications, three cases of medium-degree stiffness, two cases of medial column nonunion, and one case of dissociation of the internal fixator were reported. CONCLUSION: Stable internal fixation for maintenance reduction status is essential after accurate initial anatomical reduction. We concluded that nonunion could be prevented by additional surgical treatment such as autogenous bone graft, if it is necessary.ope

Single Portal Endoscopic Carpal Tunnel Release in Patients Older than 65 Years

Purpose: There have been few reports about the endoscopic carpal tunnel release (ECTR) in elderly patients and its efficacy and safety are not well-known. We evaluated the clinical outcomes of ECTR using Agee technique in patients older than 65 years. Materials and Methods: From October 2000 to January 2007, thirty-five patients (42 hands) who underwent ECTR using Agee technique were enrolled. The average age of the patients was 67.2 years (range, 65-71 years). The duration of symptoms averaged 10 months (range, 6-33 months). For evaluation of the clinical outcomes, physical examination and subjective assessment of the hand function using the Boston carpal tunnel questionnaire were performed at postoperative 1-year follow-up and compared with those obtained at preoperative evaluation. The mean follow-up period was 18 months (range, 12-24 months). Results: There were no neurovascular injury and scar tenderness. At postoperative 1-year follow-up, paresthesia, numbness, Phalen’s sign, tinel sign, two point discrimation, and grip power were significantly improved compared with those obtained at preoperation. According to the Boston questionnaire, symptom severity score improved from 3.43 preoperatively to 1.89 postoperatively, and functional status score improved from 3.18 preoperatively to 2.21 postoperatively (p<0.05). Thenar atrophy still remained in 32 hands (76.2%). Conclusion: Although thenar atrophy did not improve in many cases, symptom severity and functional status scores improved in most patients treated with ECTR. The single portal ECTR is a safe and efficacious treatment option in elderly patients with carpal tunnel syndrome.ope

Percutaneous Mini-open Reduction for Mason II or III Radial Head and Neck Fracture

PURPOSE: We wanted to evaluate the result of percutaneous, mini-open reduction for the treatment of Mason II or III radial head and neck fractures. MATERIALS AND METHODS: 13 patients (8 male, 5 female) with Mason II or III radial head and neck fractures were treated by 1 cm percutaneous mini-open reduction under fluoroscopy. The average age of our subjects was 29 years. Follow up duration was 18 months. RESULTS: Union was noted in all cases. Mean radial neck angulation was decreased from 33.2 degrees to 7.8 degrees. The mean change in angulation between the immediate post-operative and last follow-up was 0.7 degrees. The mean range of motion at the elbow joint was at last follow up, 133.1 degrees in flexion, 7.3 degrees in extension, 80 degrees in pronation and 84.3 degrees in supination. Postoperatively, mean Mayo Elbow Performance Index, American Shoulder and Elbow Surgeons elbow score, and Disabilities of the Arm, Shoulder and Hand score were 96.2, 97 and 1.2. Temporary posterior interosseous nerve palsy (1 case) and minimal cubitus valgus deformity (1 case) were noted. CONCLUSION: Selected Mason II or III radial head and neck fractures can be treated satisfactorily with percutaneous mini-open reductionope

Operative Treatment of Distal Clavicle Fracture with Acromioclavicular Joint Injury

Purpose: We wanted to evaluate the clinical and radiological outcomes and the prognosis of various surgical treatments for the distal clavicle fracture with an acromioclavicular joint injury. Materials and Methods: A retrospective study of 21 patients with a minimum of 12 months follow up was done. We classified acromioclavicular (AC) injury into type I (only intra-articular fracture (IAF), 5 cases), type II (IAF with widening of the AC joint > 7 mm, 9 cases) and type III (IAF with AC joint superior subluxation > 50%, 7 cases). The distal clavicle fractures were fixed using plate (9 cases), mini screws (1 case), K wire and tension band wiring (10 cases) and transarticular pinning (1 case). Acromioclavicular or coracoacromial ligament reconstruction was not done in all the cases. Results: In 20 of 21 cases, bone union was achieved at an average of 8.4 weeks. Traumatic arthritis (5 cases), AC joint widening (4 cases) and AC joint subluxation (2 cases) were noted at the last follow up. The average UCLA score was 32.6 in the type I AC joint injuries, 34 in type II and 34.1 in type III. There was no relationship between the clinical outcomes and the preoperative AC joint injury pattern, postoperative traumatic arthritis, AC joint widening or AC joint subluxation (p>0.05). Conclusion: Satisfactory results were achieved by acute reduction and firm fixation of the distal clavicle fracture with AC joint injury. There was no relationship between the pattern of AC joint injury, the residual radiologic findings and the functional outcome.ope

Treatment of Anterior Glenoid Rim Fracture with Comminuted Fragment Using Arthroscopic Reduction and AO Headless Compression Screw Fixation - A Case Report -

Purpose: We present a case of anterior glenoid rim comminuted fracture that was treated with arthroscopic reduction and an AO headless compression screw (HCS) fixation. Materials and Methods: A 31-year old man complained of left shoulder pain after falling down on stairs. The anterior glenoid comminuted fragments were arthroscopically reduced. Fixation with an AO HCS was done after placement of 1.1 mm Kirschner wire as a guide pin through a standard cannulated anterosuperior portal. Results: Twelve months after the operation, union of the fracture was achieved and the range of motion was fully recovered. He did not complain of any discomfort during his activities of daily living. Conclusion: An AO HCS had various screw sizes and this was good for fixation of a small glenoid fracture and a long drill bit and screw driver were useful for fixation of deep seated glenoid fracture. A short guide wire could be replaced by a 1.1 mm K-wire. An AO HCS was useful for fixation of an anterior glenoid rim comminuted fracture.ope

Association Between Platelet Count and Osteoarthritis in Women Older Than 50 Years

Background: Osteoarthritis (OA) is a multifactorial disease involving inflammatory processes. Platelets play important roles in both hemostasis and the inflammatory response; however, the relationship between platelet count and OA is unclear. Our aim was to evaluate the association between platelet count and knee and hip OA in Korean women. Methods: In this cross-sectional designed study, we included a total of 6011 women aged ⩾50 years from the 2010-2013 Korea National Health and Nutrition Examination Survey. Knee and hip OA were defined as Kellgren-Lawrence grade ⩾2 and presence of knee or hip pain, respectively. Platelet counts were divided into quartiles as follows: Q1, 150-212 (103/µl); Q2, 213-246 (103/µl); Q3, 247-283 (103/µl); and Q4, 284-450 (103/µl). Multiple logistic-regression analysis was conducted to calculate odds ratios and 95% confidence intervals. Receiver operating characteristic analysis was performed to determine the optimal platelet count cut-off with which to discriminate participants with knee and/hip OA versus those without OA. Results: Of the 6011 participants, 1141 (18.1%) had knee or hip OA. The mean age of participants without OA was 60.6 years, and that of participants with OA was 68.0 years. Compared with the lowest quartile, odds ratios (95% confidence intervals) for OA were 1.08 (0.84-1.39) for Q2, 0.94 (0.73-1.23) for Q3, and 1.35 (1.08-1.69) for Q4 after adjusting for confounders. The prevalence of OA was significantly higher with platelet counts ⩾288 × 103/µl, compared with platelet counts <288 × 103/µl. Conclusion: High platelet counts within the normal range are significantly associated with knee and hip OA.ope