Regeneration of kidney tissue using in vitro cultured fetal kidney cells

Transplanting fetal kidney cells (FKCs) can regenerate kidney. This requires in vitro expansion in cell number to acquire enough cells for transplantation. However, FKCs may change their cellular characteristics during expansion and, thus, may not regenerate kidney tissue upon transplantation. We investigated how cell culture period affects cellular characteristics and in vivo regenerative potential of FKCs. As the passage number increased, cell growth rate and colony forming ability decreased while senescence and apoptosis increased. To examine in vivo regenerative potential, FKCs cultured through different numbers of passages were implanted into the parenchyma of kidneys of immunodeficient mice using fibrin gel for 4 wk. Histological analyses showed passage-dependent kidney tissue regeneration, and the regeneration was better when cells from lower number of passages were implanted. This result shows that in vitro culture of FKCs significantly affects the cell characteristics and in vivo tissue regenerative potential.

Giant Vascular Eccrine Spiradenoma: Report of a Case with Immunohistochemical Study

We report a rare case of giant vascular eccrine spiradenoma (GVES) which developed in 56-yr-old Korean woman. It is a rare variant of eccrine spiradenoma (ES), which might be mistaken for angiomatous lesions in view of its florid vascularity and hemorrhagic features. Histogenesis of GVES is not clearly elucidated although it is known that ES presumably originates in the eccrine glands. To clarify the histogenesis of GVES, immunohistochemical stainings using various monoclonal antibodies were also performed. The tumor was composed of three types of cells, namely pale epithelial cells, small basal cells, and myoepithelial cells. Therefore, we conclude that GVES originated from eccrine gland and mainly differentiates toward secretory portion of secretory coil.

Tissue engineering of heart valves by recellularization of glutaraldehyde-fixed porcine valves using bone marrow-derived cells

To increase the biocompatibility and durability of glutaraldehyde (GA)-fixed valves, a biological coating with viable endothelial cells (ECs) has been proposed. However, stable EC layers have not been formed successfully on GA-fixed valves due to their inability to repopulate. In this study, to improve cellular adhesion and proliferation, the GA-fixed prostheses were detoxified by treatment with citric acid to remove free aldehyde groups. Canine bone marrow mononuclear cells (MNCs) were differentiated into EC-like cells and myofibroblast-like cells in vitro. Detoxified prostheses were seeded and recellularized with differentiated bone marrow-derived cells (BMCs) for seven days. Untreated GA-fixed prostheses were used as controls. Cell attachment, proliferation, metabolic activity, and viability were investigated and cell-seeded leaflets were histologically analyzed. On detoxified GA-fixed prostheses, BMC seeding resulted in uninhibited cell proliferation after seven days. In contrast, on untreated GA-fixed prostheses, cell attachment was poor and no viable cells were observed. Positive staining for smooth muscle a-actin, CD31, and proliferating cell nuclear antigen was observed on the luminal side of the detoxified valve leaflets, indicating differentiation and proliferation of the seeded BMCs. These results demonstrate that the treatment of GA-fixed valves with citric acid established a surface more suitable for cellular attachment and proliferation. Engineering heart valves by seeding detoxified GA-fixed biological valve prostheses with BMCs may increase biocompatibility and durability of the prostheses. This method could be utilized as a new approach for the restoration of heart valve structure and function in the treatment of end-stage heart valve disease.

Thymidylate Synthase, Thymidine Phosphorylase, VEGF and p53 Protein Expression in Primary Colorectal Cancer for Predicting Response to 5-fluorouracil-based Chemotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: In the treatment of advanced metastatic colorectal cancer, several new agents, such as irinotecan and oxaliplatin, have been developed, which have improved both disease free and overall survivals. Among these agents, 5-fluorouracil (5-FU) still remains one of the most active agents, and the selection of patients who can benefit from 5-FU-based chemotherapy is still important, as those unlikely to benefit could be spared the harmful side effects. The expression levels of thymidylate synthase (TS), thymidine phosphorylase (TP) and p53 have been known to be associated with the clinical response to 5-FU-based therapy as well as the prognosis, and that of vascular endothelial growth factor (VEGF) is associated with poor survival. MATERIALS AND METHODS: The relationship between the expressions of TS, TP, VEGF and p53 in primary tumors, using immunohistochemistry, and the response of 45 metastatic colorectal cancer patients (M: F=25: 20, median age 59 yrs) to 5-FU-based chemotherapy were evaluated. RESULTS: Thirty-seven patients were treated with 5-FU/ LV/irinotecan (FOLFIRI) and 8 with 5-FU/LV/oxaplatin (FOLFOX). The overall response rate was 28.9% (13/45). When immunohistochemically analyzed with monoclonal antibodies against TS, TP, VEGF and p53, 55.6% of the patients (25/45) were positive for TS, 48.9% (22/45) for TP, 82.2% (37/45) for VEGF, and 80% (36/45) for p53. There was a significant difference in the intensity of TS expression between the clinical responders and non-responders (p=0.036). In terms of the staining pattern of TS expression, diffuse staining was correlated with a poor response (p=0.012) and poor survival (p=0.045). However, there was no correlation between the expressions of TP, VEGF or P53 and the response to chemotherapy. CONCLUSION: These results suggest that the expression of TS in primary colorectal cancer might be an important prognostic factor for chemotherapy response and survival, and might be a useful therapeutic marker for the response of chemotherapy.

Regeneration of Renal Tissue Using Cell Transplantation in a Renal Failure Rat Model / 대한이식학회지

PURPOSE: Dialysis and renal transplantation, the current therapies for end-stage renal disease (ESRD), have limitations including severe complications, donor organ shortage, and graft failure. The present study investigated the possibility of using a tissue engineering technique for renal tissue reconstruction as a new method to replace the current treatments for ESRD. We restored renal structure in vivo by transplanting isolated renal cells in renal failure animal models. METHODS: Renal failure was surgically induced by 5/6 nephrectomy using silk tie method in Sprague-Dawley (SD) rats. Renal failure was confirmed by measuring the concentrations of blood urea nitrogen (BUN) and creatinine from blood samples. Renal cells were freshly isolated from newborn SD rat kidneys and implanted into renal failure- induced kidneys with fibrin gel matrix for 4 weeks. Retrieved specimens were examined by histological analyses. RESULTS: Renal failure-induced rats exhibited higher concentrations of BUN and creatinine compared to those of normal rats. Four weeks after cell transplantation, histological examination showed the reconstitution of vascular tufts of glomerular structures. CONCLUSION: Renal failure rat models were successfully created by 5/6 nephrectomy. This study showed a possibility of restoring the renal structures by transplanting renal cells with fibrin gel matrix in renal failure rat models. Further studies, such as investigation on renal function recovery by cell transplantation, are necessary to determine the clinical utility of this method for partial or full replacement of renal structure and function in the treatment of ESRD.

Activation of Stat Protein in Synovial Cell in Rheumatoid Arthritis / 대한류마티스학회지

OBJECTIVE: To characterize Stat activity in synovial tissue in rheumatoid arthritis (RA) in order to see if Stat molecule contributes to the pathogenesis of RA by regulatory expression of genes that play an important role in inflammation and tissue destruction. METHODS: Synovial tissue were obtained immediately after operative excision. Immuno-histochemistry was done with the antibodies for Stat 3 and Stat 5. Cells were stimulated with interleukin 6 (IL-6) and soluble interleukin 6 receptor (sIL-6R) or steroid using chambered slide. In supershift experiment, cell extracts were incubated with 0.5ng of 32P-labelled double-stranded oligonucleotide probe. Samples were resolved on 4.5% polyacrylamide gels, which was transferred to polyvinylidene fluoride membranes. Anti-phosphotyrosine Stat 3 antibody was used for Western blotting. RESULTS: Stat 3 was not shown on the synovial tissue section done by immuno-histochemistry. However, activated Stat 3 was expressed on cultured synovial cell stimulated with IL-6 and sIL-6R, and also with IL-6 and dexamethasone using chambered slide. In contrast to Stat 3, activated Stat 5 was expressed on the synovial tissue section, especially around blood vessel. CONCLUSION: Stat is activated in cultured synovial cells as shown in other immune associated cells, and IL-6 is the strong activator of Stat 3. Further analysis of the regulation of Stats in synovitis and the role of Stats in driving synovial inflammation will yield insight into the pathogenesis of RA and the development of novel therapeutic modality.