Adipose tissue is a source of multipotent stem cells and it has the ability to differentiate into several types of cell lineages such as neuron cells, osteogenic and adipogenic cells. Most studies on human adipose-derived stem cells (ASCs) have been carried out at the early passages. For clinical usage, ASCs need to be expanded in vitro for a period of time to get sufficient cells for transplantation into patients. However, the impact of long-term culture on ASCs molecular characteristics has not been established yet. Several studies have also shown that osteogenic and adipogenic cells have the ability to switch pathways during in vitro culture as they share the same progenitor cells. This data is important to ensure their functionality and efficacy before being used clinically in the treatment of bone diseases. Therefore, we aim to investigate the effect of long-term culture on the adipogenic, stemness and osteogenic genes expression during osteogenic induction of ASCs. In this study, the molecular characteristics of ASCs during osteogenic induction in long-term culture was analysed by observing their morphological changes during induction, analysis of cell mineralization using Alizarin Red staining and gene expression changes using quantitative RT-PCR. Morphologically, cell mineralization at P20 was less compared to P5, P10 and P15. Adipogenesis was not observed as negative lipid droplets formation was recorded during induction. The quantitative PCR data showed that adipogenic genes expression e.g. LPL and AP2 decreased but PPAR-γ was increased after osteogenic induction in long-term culture. Most stemness genes decreased at P5 and P10 but showed no significant changes at P15 and P20. While most osteogenic genes increased after osteogenic induction at all passages. When compared among passages after induction, Runx showed a significant increased at P20 while BSP, OSP and ALP decreased at later passage (P15 and P20). During long-term culture, ASCs were only able to differentiate into immature osteogenic cells.
The 'Dextran' and the 'Buffy-coat' methods for isolation of human leucocytes for DNA extraction were compared on the basis of DNA yield from the same amounts (10 ml) of blood. Human leucocytes from a total of 11 samples were isolated using both methods for each sample after which DNA was extracted. Extracted DNA samples were treated with ribonucleases and proteinase K after which the yields were quantitated by measuring absorbance at 260 nm. The 'Buffy-coat' method yielded a mean concentration of DNA of 476.7 micrograms/ml (range: 212 to 700 micrograms/ml) while the 'Dextran' method yielded 188.4 micrograms/ml (range: 64 to 340 micrograms/ml). The difference was confirmed by subjecting the extracted DNA samples to agarose gel electrophoresis.
Mammalian adipose tissue derived stem cells (AT-SC) have a tremendous potential in regenerative medicine for tissue engineering and somatic nuclear transfer (SNT). The isolation methods of human and bovine adipose tissue derived stem cells are compared in this paper to determine the feasibility and optimum method of isolation. The optimum isolation method will reduce the processing time, efforts and money as isolation is the first crucial and important step in stem cells research. Human abdominal subcutaneous adipose tissue and bovine abdominal subcutaneous adipose tissue are digested in three collagenase type 1 concentration 0.075%, 0.3% and 0.6% agitated at 1 h and 2 h under 37 °C in 5% CO2 incubator. The cultures are then morphologically characterised. Human adipose tissue stem cells are found to be best isolated using abdominal subcutaneous depot, using 0.075% collagenase type 1 agitated at 1 h under 37 °C in CO2 incubator. While bovine adipose tissue derived stem cells are best isolated using abdominal subcutaneous depot, using 0.6% collagenase type 1 agitated at 2 h under 37 °C in CO2 incubator.
A study was undertaken to evaluate the ability of flow cytometric analysis of intracellular myeloperoxidase (MPO) in differentiating populations of lymphocytes (L), monocytes (M) and granulocytes (G), by means of lysed whole blood method. Anticoagulated blood from 23 normal individuals was lysed with FACS lysing solution and permeabilized with FACS permeabilizing solution before subjected to direct immunofluorescence staining. The geometric means of the fluorescence intensity were measured using FACSCalibur flow cytometer (Becton Dickinson). Populations of L, M and G were gated based on their light scatter characteristics and expression of CD14 and CD45. Then, the fluorescence intensity of MPO expression was studied in these individual cell populations. The results showed that fluorescence intensity of MPO was the strongest in G and weakest in L, whereas M showed intermediate fluorescence intensity. Our findings reveal that discrimination of these three cell types is achievable based upon the sole expression of intracellular MPO.
Human exfoliated deciduous teeth (SHED) and adipose stem cells (ASC) were suggested as alternative cell choice for cardiac regeneration. However, the true functionability of these cells toward cardiac regeneration is yet to be discovered. Hence, this study was carried out to investigate the innate biological properties of these cell sources toward cardiac regeneration. Both cells exhibited indistinguishable MSCs characteristics. Human stem cell transcription factor arrays were used to screen expression levels in SHED and ASC. Upregulated expression of transcription factor (TF) genes was detected in both sources. An almost equal percentage of >2-fold changes were observed. These TF genes fall under several cardiovascular categories with higher expressions which were observed in growth and development of blood vessel, angiogenesis, and vasculogenesis categories. Further induction into cardiomyocyte revealed ASC to express more significantly cardiomyocyte specific markers compared to SHED during the differentiation course evidenced by morphology and gene expression profile. Despite this, spontaneous cellular beating was not detected in both cell lines. Taken together, our data suggest that despite being defined as MSCs, both ASC and SHED behave differently when they were cultured in a same cardiomyocytes culture condition. Hence, vigorous characterization is needed before introducing any cell for treating targeted diseases.