Estrogen Attenuates Local Inflammasome Expression and Activation after Spinal Cord Injury.

17-estradiol (E2) is a neuroprotective hormone with a high anti-inflammatory potential in different neurological disorders. The inflammatory response initiated by spinal cord injury (SCI) involves the processing of interleukin-1beta (IL-1b) and IL-18 mediated by caspase-1 which is under the control of an intracellular multiprotein complex called inflammasome. We recently described in a SCI model that between 24 and 72 h post-injury, most of inflammasome components including IL-18, IL-1b, NLRP3, ASC, and caspase-1 are upregulated. In this study, we investigated the influence of E2 treatment after spinal cord contusion on inflammasome regulation. After contusion of T9 spinal segment, 12-week-old male Wistar rats were treated subcutaneously with E2 immediately after injury and every 12 h for the next 3 days. Behavioral scores were significantly improved in E2-treated animals compared to vehicle-treated groups. Functional improvement in E2-treated animals was paralleled by the attenuated expression of certain inflammasome components such as ASC, NLRP1b, and NLRP3 together with IL1b, IL-18, and caspase-1. On the histopathological level, microgliosis and oligodendrocyte injury was ameliorated. These findings support and extend the knowledge of the E2-mediated neuroprotective function during SCI. The control of the inflammasome machinery by E2 might be a missing piece of the puzzle to understand the anti-inflammatory potency of E2.

Study of carbon nano-tubes effects on the chondrogenesis of human adipose derived stem cells in alginate scaffold.

BACKGROUND: Osteoarthritis is one of the most common diseases in middle-aged populations in the World and could become the fourth principal cause of disability by the year 2020. One of the critical properties for cartilage tissue engineering (TE) is the ability of scaffolds to closely mimic the extracellular matrix and bond to the host tissue. Therefore, TE has been presented as a technique to introduce the best combination of cells and biomaterial scaffold and to stimulate growth factors to produce a cartilage tissue resembling natural articular cartilage. The aim of study is to improve differentiation of adipose derived stem cells (ADSCs) into chondrocytes in order to provide a safe and modern treatment for patients suffering from cartilage damages. METHODS: After functionalization, dispersions and sterilizing carbon nano-tubes (CNTs), a new type of nanocomposite gel was prepared from water-soluble CNTs and alginate. ADSCs seeded in 1.5% alginate scaffold and cultured in chondrogenic media with and without transforming growth factor-ß1 (TGF-ß1) for 7 and 14 days. The genes expression of sex determining region Y-box 9 (SOX9), types II and X collagens was assessed by real-time polymerase chain reaction and the amount of aggrecan (AGC) and type I collagen was measured by ELISA. RESULTS: Our findings showed that the expression of essential cartilage markers, SOX9, type II collagen and AGC, in differentiated ADSCs at the concentration of 1 µg/ml CNTs in the presence of TGF-ß1 were significantly increased in comparison with the control group (P < 0.001). Meanwhile, type X collagen expression and also type I collagen production were significantly decreased (P < 0.001). CONCLUSIONS: The results showed that utilized three-dimensional scaffold had a brilliant effect in promoting gene expression of chondrogenesis.

Comparison between Chondrogenic Markers of Differentiated Chondrocytes from Adipose Derived Stem Cells and Articular Chondrocytes In Vitro.

OBJECTIVE(S): Osteoarthritis is one of the most common diseases in middle-aged population in the world. Cartilage tissue engineering (TE) has been presented as an effort to introduce the best combination of cells, biomaterial scaffolds and stimulating growth factors to produce a cartilage tissue similar to the natural articular cartilage. In this study, the chondrogenic potential of adipose derived stem cells (ADSCs) was compared with natural articular chondrocytes cultured in alginate scaffold. MATERIALS AND METHODS: Human ADSCs were obtained from subcutaneous adipose tissue and human articular chondrocytes from non-weight bearing areas of knee joints. Cells were seeded in 1.5% alginate and cultured in chondrogenic media for three weeks with and without TGFß3. The genes expression of types II and X collagens was assessed by Real Time PCR and the amount of aggrecan (AGC) and type I collagen measured by ELISA and the content of glycosaminoglycan evaluated by GAG assay. RESULTS: Our findings showed that type II collagen, GAG and AGC were expressed, in differentiated ADSCs. Meanwhile, they produced a lesser amount of types II and X collagens but more AGC, GAG and type I collagen in comparison with natural chondrocytes (NCs). CONCLUSION: Further attempt should be carried out to optimize achieving type II collagen in DCs, as much as, natural articular chondrocytes and decline of the production of type I collagen in order to provide efficient hyaline cartilage after chondrogenic induction, prior to the usage of harvested tissues in clinical trials.

A comparative study of aggrecan synthesis between natural articular chondrocytes and differentiated chondrocytes from adipose derived stem cells in 3D culture.

INTRODUCTION: The main obstacle for tissue engineering is to find the most appropriate cell which is able to produce extracellular matrix (ECM) similar or better than natural chondrocytes in vitro. This study compared aggrecan synthesis's potential between differentiated chondrocytes (DCs) from adipose-derived stem cells (ADSCs) and natural articular chondrocytes (NCs) in 3D culture in vitro. MATERIALS AND METHODS: Human ADSCs were isolated from sub-cutaneous adipose tissue and then the surface markers including CD 14, 45 CD105, CD90, CD44 were analyzed by flow cytometry. Also human articular chondrocytes were yielded of non-weight bearing area of Knee cartilage. Both types of the cells were encapsulated in alginate scaffolds and cultured in chondrogenic medium with and without TGFß3 for 3 weeks. Then the extent of aggercan (AGC) production was evaluated by ELISA on days 14 and 21. RESULTS: Our findings indicated that differentiated chondrocytes (DCs) with and without TGFß3 synthesized more AGC than natural chondrocytes (NCs) on day 14. But DCs without TGFß3 had higher production than other groups on day 21. Application of TGFß3 resulted in an increase of amount of AGC in DCs on day 14 but a decrease on day 21 than same group. CONCLUSION: Since, aggrecan is an important chondrogenic marker, it was concluded that ADSCs can be possible reliable alternative cell source for cartilage tissue engineering in future.