Sharaniza Ab-Rahim

Treatment Outcomes of Alginate-Embedded Allogenic Mesenchymal Stem Cells Versus Autologous Chondrocytes for the Repair of Focal Articular Cartilage Defects in a Rabbit Model:

Background: Mesenchymal stem cells (MSCs) represent a promising alternative form of cell-based therapy for cartilage injury. However, the capacity of MSCs for chondrogenesis has not been fully explored. In particular, there is presently a lack of studies comparing the effectiveness of MSCs to conventional autologous chondrocyte (autoC) treatment for regeneration of full-thickness cartilage defects in vivo. Hypothesis: Treatment with allogenic undifferentiated MSCs (alloMSCs) results in superior cartilage tissue regeneration profiles when compared with autoC for repair of focal articular cartilage defects. Study Design: Controlled laboratory study. Methods: Full-thickness articular cartilage defects were created on the weightbearing surface of the medial femoral condyles in both knees of New Zealand White rabbits (N = 30). Six weeks after the defect was induced, the right knee was treated with either alloMSCs (n = 12) or autoC (n = 18), while the left knee remained untreated (control). The rabbits were sacrificed at 6 months after treatment for assessment of cartilage tissue regeneration, which included the Brittberg morphologic score, histologic grading by O’Driscoll score, and quantitative analysis of glycosaminoglycans per total protein content. Results: Apart from significantly higher Brittberg scores in the alloMSC treatment group (8.8 ± 0.8) versus the autoC treatment group (6.6 ± 0.8) (P = .04), both treatments showed similar cartilage regenerative profiles. All outcome measures were significantly higher in the treatment groups compared with their respective controls (P < .05). Conclusion: AlloMSCs have similar effectiveness as autoC for repair of focal cartilage defects. Both treatments resulted in superior tissue regeneration compared with untreated defects. Clinical Relevance: The results have an implication of supporting the potential use of MSCs for cartilage repair after sports injuries or diseases, in view of similar efficacy but less patient morbidity and potential cost savings as compared with conventional autoC therapy.

The effect of TGF-β1 and β-estradiol on glycosaminoglycan and type II collagen distribution in articular chondrocyte cultures

Articular cartilage extracellular matrix (ECM) plays a crucial role in regulating chondrocyte functions via cell—matrix interaction, cytoskeletal organization and integrin‐mediated signaling. Factors such as interleukins, basic fibroblast growth factor (bFGF), bone morphogenic proteins (BMPs) and insulin‐like growth factor (IGF) have been shown to modulate the synthesis of extracellular matrix in vitro. However, the effects of TGF‐β1 and β‐estradiol in ECM regulation require further investigation, although there have been suggestions that these factors do play a positive role. To establish the role of these factors on chondrocytes derived from articular joints, a study was conducted to investigate the effects of TGF‐β1 and β‐estradiol on glycosaminoglycan secretion and type II collagen distribution (two major component of cartilage ECM in vivo). Thus, chondrocyte cultures initiated from rabbit articular cartilage were treated with 10 ng/ml of TGF‐β1, 10 nM of β‐estradiol or with a combination of both factors. Sulphated glycosaminoglycan (GAG) and type II collagen levels were then measured in both these culture systems. The results revealed that the synthesis of GAG and type II collagen was shown to be enhanced in the TGF‐β1 treated cultures. This increase was also noted when TGF‐β1 and β‐estradiol were both used as culture supplements. However, β‐estradiol alone did not appear to affect GAG or type II collagen deposition. There was also no difference between the amount of collagen type II and GAG being expressed when chondrocyte cultures were treated with TGF‐β1 when compared with cultures treated with combined factors. From this, we conclude that although TGF‐β1 appears to stimulate chondrocyte ECM synthesis, β‐estradiol fails to produce similar effects. The findings of this study confirm that contrary to previous claims, β‐estradiol has little or no effect on chondrocyte ECM synthesis. Furthermore, the use of TGF‐β1 may be useful in future studies looking into biological mechanisms by which ECM synthesis in chondrocyte cultures can be augmented, particularly for clinical application.

Autologous chondrocyte transplantation in the repair of full-thickness focal cartilage damage in rabbits

Purpose. To compare the efficacy of autologous chondrocyte transplantation (ACT) versus non-operative measures for cartilage repair in rabbits. Methods. Nine New Zealand white rabbits were used. Identical focal defects were created in the articular cartilage of both knees. One month later, the right knee was repaired via ACT, while the left knee was left untreated (control group). The quality of cartilage tissues in both knees was compared 3 months later, according to the quantitative analysis of glycosaminoglycan (GAG) in the cartilage and macroscopic examination of histology using the Brittberg/International Cartilage Research Society (ICRS) score. Results. Microscopic examination showed enhanced regeneration following ACT repair. Quantification analysis revealed significantly higher cellular expression of GAG in the ACT-treated knees (1.12 vs 0.81 μg GAGs/mg protein, p=0.008). The mean Brittberg/ICRS score was significantly higher in the treated knees (6.00 vs 1.89, p=0.007). Conclusion. ACT is superior to non-operative measures for repairing focal cartilage defects, as determined by favourable histological and immunohistological outcomes at the cellular level.

Proteome Comparisons between Pre-Chemotherapy and Post-Chemotherapy Serum of Metastatic Osteosarcoma Patients Reveals Potential Novel Biomarker

This study is the first to show on differential protein profiles between serum isolated from healthy individual and metastatic osteosarcoma patients at different stages (Pre- and post-chemotherapy). The analyses have identified significant number of proteins that involved in the progression of the osteosarcoma metastasis. This data could provide a new insight in the osteosarcoma biological processes and use as a potential biomarker for better OS prognosis. Osteosarcoma (OS), a malignant bone tumour, is commonly occurs in children and young adults between the ages of 10 to 30. Although the standard treatment for OS is advancing and significantly improved the survival rate in recent years, its poor prognosis continues to remain the major problem in managing the disease. In this study, we have conducted a series of systematic analysis to identify novel proteins associated with the metastatic progression of human OS using a 4-plex iTRAQ analysis. Pooled serum samples were collected from patients who were diagnosed with metastatic osteosarcoma. The serum was collected at two stages; pre-chemotherapy and post-chemotherapy. iTRAQ analysis identified 217 proteins with 104214 spectra from the patients’ plasma. The proteins identified were analysed using bioinformatics software and categorized according to their role in biological processes. Most of the proteins fall under cellular component organization or biogenesis (39.4%), cellular process (35.4%), biological regulation (20.0%) and immune system process (29.3%). In addition, these proteins have also shown to be significantly altered in their expression when compare between preand post-chemotherapy patients samples such as C-reactive proteins, vascular adhesion molecule-1 and gelsolin. To date, this is the first differential protein expression study to use metastatic osteosarcoma patients’ serum at different stages for the protein profiling. We have successfully generated a comprehensive data on the differentially expressed protein and the comparative study has revealed a significant amount of proteins expression has been altered. This data could provide a new insight in the OS biological processes and use as a potential biomarker for better OS prognosis.

Repair of rabbit focal articular cartilage defects with autologous chondrocytes embedded in alginate

To evaluate the ability of autologous chondrocyte transplantation to repair articular cartilage defects, autologous chondrocytes embedded in alginate beads were implanted in focal cartilage defects created in 9 New Zealand white rabbits. After 4 weeks of cartilage damage, the right knee was repaired via autologous chondrocyte-alginate constructs transplantation and the left knee was left untreated (control group). The quality of cartilage tissues of both knees was then compared at 3 months following the procedure, as reflected by the quantitative analysis of glucosaminoglycan (GAG) in the cartilage and histological examination of the tissue in accordance to the Brittberg scoring scale. Macroscopic examination showed better regeneration of the defective area following chondrocyte-alginate transplantation repair compared to the non-treated site. Biochemical analysis revealed significantly higher cellular expression of GAG in the treated knee as compared to the non-treated knee [1.12 ± 0.48 µg GAGs / mg protein vs. 0.81 ± 0.17 µg GAGs / mg protein, respectively; p=0.008]. The mean Brittberg scores was significantly higher in the treated knee as compared to control knee [6.00 ± 1.23 vs. 1.89 ± 1.54; p=0.007]. This result can be explained by the fact that chondrocytes cultured in alginate gel beads retained their ability to synthesize cartilage-specific molecules. The alginate beads were perfectly biocompatible with chondrocytes and surrounding cartilage tissue. These findings also indicated that chondrocyte-alginate transplantation has shown enhanced repair results compared to the nontreated measures.

Effect of TGF-β and β-Estradiol on Extracellular Matrix Secretion in Articular Chondrocyte Culture

Articular cartilage extracellular matrix (ECM) plays a crucial role in regulating chondrocyte functions via cell-matrix interaction, cytoskeletal organization and integrinmediated signaling. The effects of transforming growth factor-β (TGF- β) and β-estradiol on extracellular matrix have remained controversial in chondrocyte studies though it has been proven that cartilage responds to these factors in vivo. In our study, we examined the effect of these factors on modulating glycosaminoglycan secretion. Articular chondrocytes from rabbits were cultured, and the effects of supplementing 10ng/ml of TGF-β, 10nM of β-estradiol, and a combination of both factors were compared. The synthesis of sulphated glycosaminoglycan (GAG) was shown to be enhanced in the TGF-β treated cultures and when TGF-β and β-estradiol were both used. However, β-estradiol does not appear to affect GAG deposition.