Nimbolide Represses the Proliferation, Migration, and Invasion of Bladder Carcinoma Cells via Chk2-Mediated G2/M Phase Cell Cycle Arrest, Altered Signaling Pathways, and Reduced Transcription Factors-Associated MMP-9 Expression.

Nimbolide, an active chemical constituent of Azadirachta indica, reportedly has several physiological effects. Here, we assessed novel anticancer effects of nimbolide against bladder cancer EJ and 5637 cells. Nimbolide treatment inhibited the proliferation of both bladder cancer cell lines with an IC50 value of 3 µM. Treatment of cells with nimbolide induced G2/M phase cell cycle arrest via both Chk2-Cdc25C-Cdc2/cyclin B1-Wee1 pathway and Chk2-p21WAF1-Cdc2/cyclin B1-Wee1 pathway. Nimbolide increased JNK phosphorylation and decreased p38MAPK and AKT phosphorylation. Additionally, nimbolide impeded both wound healing migration and invasion abilities by suppressing matrix metalloproteinase-9 (MMP-9) activity. Finally, nimbolide repressed the binding activity of NF-κB, Sp-1, and AP-1 motifs, which are key transcription factors for MMP-9 activity regulation. Overall, our study indicates that nimbolide is a potential chemotherapeutic agent for bladder cancer.

Evaluation of Immunosuppressive Therapy Use for Tracheal Transplantation with Trachea-Mimetic Bellows Scaffolds in a Rabbit Model.

The objective of this study was to evaluate the use of immunosuppressive therapy with high-dose cyclosporine, high-dose azathioprine, and a combination of low-dose cyclosporine and azathioprine after tracheal reconstruction by using a trachea-mimetic graft of polycaprolactone (PCL) bellows-type scaffold in a rabbit model. Twenty-four healthy New Zealand white rabbits were used in the study. All underwent circumferential tracheal replacement using tissue-engineered tracheal graft, prepared from PCL bellows scaffold reinforced with silicone ring, collagen hydrogel, and human turbinate mesenchymal stromal cell (hTMSC) sheets. The control group (Group 1) received no medication. The three experimental groups were given daily cyclosporine intramuscular doses of 10 mg/kg (Group 2), azathioprine oral doses of 5 mg/kg (Group 3), and azathioprine oral doses of 2.5 mg/kg plus cyclosporine intramuscular doses of 5 mg/kg (Group 4) for 4 weeks or until death. Group 1 had longer survival times compared to Group 2 or Group 3. Each group except for Group 1 experienced decreases in amount of nutrition and weight loss. In addition, compared with the other groups, Group 2 had significantly increased serum interleukin-2 and interferon-γ levels 7 days after transplantation. The results of this study showed that the administration of cyclosporine and/or azathioprine after tracheal transplantation had no beneficial effects. Furthermore, the administration of cyclosporine had side effects, including extreme weight loss, respiratory distress, and diarrhea. Therefore, cyclosporine and azathioprine avoidance may be recommended for tracheal reconstruction using a native trachea-mimetic graft of PCL bellows-type scaffold in a rabbit model.

Bone regeneration of hydroxyapatite/alumina bilayered scaffold with 3 mm passage-like medullary canal in canine tibia model.

The aim of this study was to evaluate the bone regeneration of hydroxyapatite (HA)/alumina bilayered scaffold with a 3 mm passage-like medullary canal in a beagle tibia model. A porous HA/alumina scaffold was fabricated using a polymeric template-coating technique. HA/alumina scaffold dimensions were 10 mm in outer diameter, 20 mm in length, and with either a 3 mm passage or no passage. A 20 mm segmental defect was induced using an oscillating saw through the diaphysis of the beagle tibia. The defects of six beagles were filled with HA/alumina bilayered scaffolds with a 3 mm passage or without. The segmental defect was fixated using one bone plate and six screws. Bone regeneration within the HA/alumina scaffolds was observed at eight weeks after implantation. The evaluation of bone regeneration within the scaffolds after implantation in a beagle tibia was performed using radiography, computerized tomography (CT), micro-CT, and fluorescence microscopy. New bone successfully formed in the tibia defects treated with 3 mm passage HA/alumina scaffolds compared to without-passage HA/alumina scaffolds. It was concluded that the HA/alumina bilayered scaffold with 3 mm passage-like medullary canal was instrumental in inducing host-scaffold engraftment of the defect as well as distributing the newly formed bone throughout the scaffold at 8 weeks after implantation.

Chondrogenic differentiation of bovine bone marrow mesenchymal stem cells (MSCs) in different hydrogels: influence of collagen type II extracellular matrix on MSC chondrogenesis.

Bone marrow mesenchymal stem cells (MSCs) are candidate cells for cartilage tissue engineering. This is due to their ability to undergo chondrogenic differentiation after extensive expansion in vitro and stimulation with various biomaterials in three-dimensional (3-D) systems. Collagen type II is one of the major components of the hyaline cartilage and plays a key role in maintaining chondrocyte function. This study aimed at analyzing the MSC chondrogenic response during culture in different types of extracellular matrix (ECM) with a focus on the influence of collagen type II on MSC chondrogenesis. Bovine MSCs were cultured in monolayer as well as in alginate and collagen type I and II hydrogels, in both serum free medium and medium supplemented with transforming growth factor (TGF) beta1. Chondrogenic differentiation was detected after 3 days of culture in 3-D hydrogels, by examining the presence of glycosaminoglycan and newly synthesized collagen type II in the ECM. Differentiation was most prominent in cells cultured in collagen type II hydrogel, and it increased in a time-dependent manner. The expression levels of the of chondrocyte specific genes: sox9, collagen type II, aggrecan, and COMP were measured by quantitative "Real Time" RT-PCR, and genes distribution in the hydrogel beads were localized by in situ hybridization. All genes were upregulated by the presence of collagen, particularly type II, in the ECM. Additionally, the chondrogenic influence of TGF beta1 on MSCs cultured in collagen-incorporated ECM was analyzed. TGF beta1 and dexamethasone treatment in the presence of collagen type II provided more favorable conditions for expression of the chondrogenic phenotype. In this study, we demonstrated that collagen type II alone has the potential to induce and maintain MSC chondrogenesis, and prior interaction with TGF beta1 to enhance the differentiation.