Osteogenic Response of MC3T3-E1 and Raw264.7 in the 3DEncapsulated Co-Culture Environment

BACKGROUND@#Three-dimensional (3D) in vitro cultures recapitulate the physiological microenvironment and exhibit high concordance with in vivo conditions. Improving co-culture models with different kind of cell types cultured on a 3D scaffold can closely mimic the in vivo environment. In this study, we examined the osteogenic response of pre-osteoblast MC3T3-E1 cells and Raw264.7 mouse monocytes in a 3D-encapsulated co-culture environment composed of the Cellrix®3D culture system, which provides a physiologically relevant environment. @*METHODS@#The Cellrix® 3D Bio-Gel scaffolds were used to individually culture or co-culture two type cells in 3D microenvironment. Under 3D culture conditions, osteoblastic behavior was evaluated with an ALP assay and staining. ACP assay and TRAP staining were used as osteoclastic behavior indicator. @*RESULTS@#Treatment with osteoblastic induction factors (?3F) and RANKL had on positively effect on alkaline phosphatase activity but significantly inhibited to acid phosphatase activity during osteoclastic differentiation in 3D coculture. Interestingly, alkaline phosphatase activity or acid phosphatase activity in 3D co-culture was stimulated with opposite differentiation factors at an early stage of differentiation. We guess that these effects may be related to RANK– RANKL signaling, which is important in osteoblast regulation of osteoclasts. @*CONCLUSION@#In this study, the osteogenic response of 3D encapsulated pre-osteoblast MC3T3-E1 cells and mouse monocyte Raw264.7 cells was successfully demonstrated. Our 3D culture conditions will be able to provide a foundation for developing a high-throughput in vitro bone model to study the effects of various drugs and other agents on molecular pathways.

Osteogenic Response of MC3T3-E1 and Raw264.7 in the 3DEncapsulated Co-Culture Environment

BACKGROUND@#Three-dimensional (3D) in vitro cultures recapitulate the physiological microenvironment and exhibit high concordance with in vivo conditions. Improving co-culture models with different kind of cell types cultured on a 3D scaffold can closely mimic the in vivo environment. In this study, we examined the osteogenic response of pre-osteoblast MC3T3-E1 cells and Raw264.7 mouse monocytes in a 3D-encapsulated co-culture environment composed of the Cellrix®3D culture system, which provides a physiologically relevant environment. @*METHODS@#The Cellrix® 3D Bio-Gel scaffolds were used to individually culture or co-culture two type cells in 3D microenvironment. Under 3D culture conditions, osteoblastic behavior was evaluated with an ALP assay and staining. ACP assay and TRAP staining were used as osteoclastic behavior indicator. @*RESULTS@#Treatment with osteoblastic induction factors (?3F) and RANKL had on positively effect on alkaline phosphatase activity but significantly inhibited to acid phosphatase activity during osteoclastic differentiation in 3D coculture. Interestingly, alkaline phosphatase activity or acid phosphatase activity in 3D co-culture was stimulated with opposite differentiation factors at an early stage of differentiation. We guess that these effects may be related to RANK– RANKL signaling, which is important in osteoblast regulation of osteoclasts. @*CONCLUSION@#In this study, the osteogenic response of 3D encapsulated pre-osteoblast MC3T3-E1 cells and mouse monocyte Raw264.7 cells was successfully demonstrated. Our 3D culture conditions will be able to provide a foundation for developing a high-throughput in vitro bone model to study the effects of various drugs and other agents on molecular pathways.

Positive Effects of Bisphosphonates on Osteogenic Differentiation in Patient-Derived Mesenchymal Stem Cells for the Treatment of Osteoporosis

BACKGROUND: Recent evidence from in vitro and in vivo studies indicates that bisphosphonates may promote osteoblastic bone formation and potently inhibit osteoclast activity. However, little is known about the potential effect of bisphosphonates on the recruitment of osteoblastic precursors from patient-derived bone marrow stromal cells due to difficulties in accessing human bone marrow from healthy and disease subjects. METHODS: In this study, we evaluated the potential of using FDA-approved and clinically utilized bisphosphonates such as alendronate, ibandronate, and zoledronate to enhance the development of bone forming osteoblasts from osteoporosis patient- and healthy-person derived hBMSCs (op-MSCs and hp-MSCs, respectively). hBMSCs were obtained from postmenopausal women without endocrine diseases or receiving hormone replacement therapy. Cells were treated with or without a bisphosphonate (alendronate, ibandronate, and zoledronate) and analyzed over 21 days of culture. RESULTS: hBMSC from osteoporosis-patient with bisphosphonates treatment demonstrated a significant increase in Alizarin red staining after 7 days compared to that from healthy-person. Calcium contents and alkaline phosphatase (ALP) enzyme activity also demonstrated an increased propensity in hMSCs from osteoporosis-patient compared to those from healthy-person, although there were inter-individual variations.Gene expression levels varied among different donors. There were no significant differences in the effect on the osteoblastic differentiation of hBMSCs among alendronate, ibandronate, and zoledronate. Statistical significance in the osteoblastic differentiation of hBMSCs between the positive control group cultured in osteogenic mediumalone and groups cultured in osteogenic mediumsupplemented with bisphosphonate was not shown either.These results might be due to various cell types of hBMSCs from individual clinical patients and concentrations of bisphosphonate used. CONCLUSION: Our study using a clinically relevant in vitro model suggests that bisphosphonate treatment is more effective for patients with osteoporosis than its preventive effect for healthy person. In addition, patient-specific responses to bisphosphonates should be considered rather than bisphosphonate type prior to prescription. Further investigations are needed to determine how bisphosphonates influence hBMSCs function to mediate bone quality and turnover in osteoporotic patients. Such studies can generate novel approaches to treat age-related osteoporotic bone loss.

The Effect of Poloxamer 407-Based Hydrogel on the Osteoinductivity of Demineralized Bone Matrix

BACKGROUND: Demineralized bone matrix (DBM) is used for bone healing due to its osteoinductivity, but it requires a carrier for clinical application. Here, we report the effects on the osteoinductivity of DBM by use of a poloxamer 407-based hydrogel as the carrier, compared to sterile water. METHODS: DBM-W and DBM-H represent 27 wt% of DBM with sterile water and DBM with a poloxamer 407-based hydrogel, respectively. Both of the compositions were applied to human mesenchymal stem cell (MSC) cultures, and monitored for alkaline phosphatase (ALP) staining and ALP activity. Six 10-week-old athymic nude rats were used for abdominal muscle grafting with either DBM-W or DBM-H, and were tested by plane radiography, microfocus X-ray computed tomography (CT), and decalcified histology to evaluate ectopic bone formation. RESULTS: The DBM-W group showed stronger ALP staining at 7, 14, and 21 days of treatment, and significantly higher ALP activity at 7 and 14 days of treatment, compared to the DBM-H group. Plane radiography could not confirm the radio-opaque lesions in the rat ectopic bone formulation model. However, ectopic bone formation was observed in both groups by micro-CT. Compared to the DBM-H group, the DBM-W group showed higher bone volume, percent bone volume and trabecular number, and the difference in percent bone volume was statistically significant. Decalcified histology found bony tissue with lamellation in both groups. CONCLUSIONS: Our results suggest that poloxamer 407-based hydrogel has efficacy as a DBM carrier since it shows ectopic bone formation, but its effects on the quality and quantity of osteoblastic differentiation in rat abdominal ectopic bone and MSC are considered negative.

Characterization of Monoclonal Antibodies against Human Leukocyte Common Antigen (CD45)

BACKGROUND: The leukocyte common antigen (CD45) is a transmembrane-type protein tyrosine phosphatase that has five isoforms. METHODS: We generated seven murine mAbs against human CD45 by injecting cells from different origins, such as human thymocytes, PBMCs, and leukemic cell lines. By using various immunological methods including flow cytometry, immunohistochemistry, and immunoprecipitation, we evaluated the reactivity of those mAbs to CD45 of thymus as well as tonsil lysates. Furthermore, we transiently transfected COS-7 cells with each of gene constructs that express five human CD45 isoforms respectively, and examined the specificities of the mAbs against the transfected isoforms. RESULTS: In case of thymocytes, lymphocytes, and monocytes, all the seven mAbs demonstrated positive reactivities whereas none was reactive to erythrocytes and platelets. The majority of immune cells in formalin-fixed paraffin-embedded thymus and tonsil tissues displayed strong membranous immunoreactivity, and the main antigen was detected near 220 kDa in all cases. Among the mAbs, four mAbs (AP4, DN11, SHL-1, and P6) recognized a region commonly present in all the five isoforms. One mAb, YG27, recognized four isoforms (ABC, AB, BC, and O). Two mAbs, P1 and P14, recognized the isoforms that contain exon A encoded regions (ABC and AB). CONCLUSION: In this study, we confirmed that AP4, DN11, SHL-1, YG27 and P6, are mAbs reactive with the CD45 antigen whereas P1 and P14 are reactive with the CD45RA antigen.

Promoter hypermethylation and loss of heterozygosity of FHIT genes in squamous cell carcinoma of uterine cervix / 부인종양

OBJECTIVE: This study was to investigate the status of hypermethylation and loss of heterozygosity (LOH) in chromosome 3p tumor-suppressor gene for cervical carcinoma. METHODS: We examined the promoter methylation status of the chromosome 3p gene, fragile histidine triad (FHIT), in 37 samples of cervical squamous cell carcinoma and corresponding noncancerous tissues using a methylation-specific polymerase chain reaction. We also analyzed the 37 paired samples for LOH at two loci on chromosome 3p. RESULTS: Promoter hypermethylation in FHIT was detected in 24% of tumors, whereas no hypermethylation was detected in the corresponding noncancerous tissues. LOH in the regions of FHIT was observed in 10% of informative cases. There were no correlations between LOH and promoter hypermethylation for the gene. FHIT hypermethylation was associated with small tumors and, when adjusted for tumor size, correlated significantly with more frequent lymph node metastasis. CONCLUSION: Promoter hypermethylation and LOH of FHIT gene may play a role in cervical carcinogenesis. In addition, hypermethylation of FHIT may be associated with the status (aggressiveness) of cervical carcinoma.

Prevalence of Virulence Factors in Helicobacter pylori Isolated from Koreans and Proinflammatory Cytokine Gene Expression in Human Gastric Epithelial Cells Induced by H. pylori with Virulence Factors / 대한내과학회지

OBJECTIVES: CagA or cytotoxin-positive H. pylori may be associated with gastroduodenal diseases. However, controversies about this association also exist. Moreover, there could be geographic differences in the prevalence of virulence factors such as cagA or cytotoxin. In H. pylori infection, the gastric mucosa shows acute and chronic inflammation. However, the pathogenesis of such as an inflammation by H. pylori is not well elucidated. We performed this study 1) to determine prevalence of the genes of virulence factor such as cagA and cytotoxin in H. pylori, 2) to assess the correlation of their presence with clinical findings, and 3) to test whether the vacuolating cytotoxin of H. pylori could evoke proinflammatory cytokine gene expression in gastric epithelial cells. METHODS: 1) The prevalence of the cagA, vacA and adhesin genes in H. pylori strains isolated from Koreans was determined by PCR analysis. 2) H. pylori was cultured in Brucella broth containing 10% fetal bovine serum for 3 days using a shaker in a microaerophilic condition. Cytotoxin assay was performed by determining whether addition of the concentrated culture supernatants is able to cause vacuolization of HeLa cells. 3) After human gastric epithelial cells, Hs746T and AGS were incubated with the culture supernatants containing vacuolating cytotoxin, each RNAs were extracted from the gastric epithelial cells. And then various cytokine gene expression were assessed using RT-PCR. The expressed cytokine transcripts were quantified by RT-PCR and standard synthetic RNA. Among cytokines, IL-8 proteins were also measured by ELISA. RESULTS: 1) More than 95% of H. pylori isolates from Korean adults possessed cagA, vacA and adhesin genes. And 80.6% of H. pylori strains have expressed vacuolating cytotoxicity against HeLa cells within 24 hours. 2) There was no correlation between the virulence factors of H. pylori strains and clinical findings. 3) Cytotoxin-positive culture supernatants also caused vacuolization in gastric epithelial cells, both Hs746T and AGS. 4) Expression of mRNA for proinflammatory cytokines such as IL-1alpha: IL-8, MCP-1 and GM-CSF was much more upregulated by vacuolating cytotoxin-positive culture supernatants than cytotoxin-negative ones in both Hs746T and AGS cells. Number of molecules of the expressed IL-8 transcripts was parallel to the amounts of IL-8 protein secreted from gastric epithelial cells. CONCLUSION: These results suggest that virulence factors of H. pylori may not be factors determining disease entitiy in Korean patients infected with H. pylori. In addition, vacuolating cytotoxin secreted from H. pylori could give rise to vacuolization in gastric epithelial cells as well as induce proinflammatory cytokines from the cells.

Detection of a Familial Y/l5 Translocation by FISH, G-Banding, C-Banding, and Ag-NOR Stain / 대한임상병리학회지

Prenatal chromosome analysis of amniotic cells at 18 weeks of gestation showed a male fetus to carry a large 15p+ derivative chromosome inherited from his mother. Extra genetic material on the short arm of chromosome IS was silver-negative with Ag-NOR (nucleolus organizer regions) stain, but stained darkly with C-banding method like the distal heterochromatic segment of the Y long arm. Fluorescence in situ hybridization (FISH) using two DNA probes (DYZ1 and D15Zl) showed a red fluorescent signal on 15p+ In addition to a green chromosome 15 centromere signal, confirming 15p to be from the distal Yq heterochromatin.

Changes of Anti-H. influenzae Type b IgG in the Sera of Korean Infants and Children after Birth

PURPOSE: Most of invasive Haemophilus influenzae diseases occur in children under 5 years of age, and are due almost exclusively to type b strain. Although antibodies to several surface antigens of H. influenzae play a role in conferring immunity, antibody to the type b capsular polysaccharide appeared to have the most important protective functions. However, the antibody response to vaccines or natural infections are quite differ according to the ages and ethnic groups. This study was performed to investigate the need of Hib vaccination and its appropriate time in Korean infants. METHODS: Three hundred and forty-five Korean infants and children who were relatively well without history of Hib vaccination or infection were enrolled in the study. All subjects did not receive blood transfusion or blood products and also had no any immunological abnormalities. Anti-PRP IgG was measured in the sera of subjects using ELISA. PRP-albumin was used as a coating antigen. RESULTS: Geometric mean titer (GMT) of anti-PRP IgG in the sera of neonates was 0.594 g/ml and was gradually decreased to 0.186 g/ml and 0.111 g/ml at 2 and 3 months of age, respectively. Ant-PRP IgG was significantly low after 3 months of age, and was gradually increased after 10 months of age. Anti-PRP IgG level p> or = 0.15 g/ml was observed in 70.8% (17/24) in neonatal group, 41.6% (10/24) and 18.7% (3/16) in 2 and 3 months of age. Only 8.7% (10/115) showed anti-Hib IgG levels of p> or = 1.0 g/ml, which has been considered as a level of longterm protection, was observed in 37.5% (9/24) in neonates, 12.5% (3/24) in 2 months of age and less then 10% thereafter. CONCLUSIONS: These results suggest that congenital passive immunity can be obtained enough in Korean infants and was rapidly decreased during the period of 3 months after birth. Hib vaccination will be recommended at early infancy (2 months of age) to provide appropriate antibodies in Korean children.