Adult Adipose-derived Mesenchymal Stem Cells Research Articles

Prevention of methylmercury-triggered ROS-mediated impairment of embryo development by co-culture with adult adipose-derived mesenchymal stem cells.

Methylmercury (MeHg) is a potent toxin that exerts deleterious effects on human health via environmental contamination. Significant effects of MeHg on neuronal development in embryogenesis have been reported. Recently, our group demonstrated that MeHg exerts toxic effects on pre- and post-implantation embryonic development processes from zygote to blastocyst stage. Our results showed that MeHg impairs embryo development by induction of apoptosis through reactive oxygen species (ROS) generation that triggers caspase-3 cleavage and activation, which, in turn, stimulates p21-activated kinase 2 (PAK2) activity. Importantly, ROS were identified as a key upstream regulator of apoptotic events in MeHg-treated blastocysts. Data from the current study further confirmed that MeHg exerts hazardous effects on cell proliferation, apoptosis, implantation, and pre- and post-implantation embryo development. Notably, MeHg-induced injury was markedly prevented by co-culture with adipose-derived mesenchymal stem cells (ADMSCs) in vitro. Furthermore, ADMSC injection significantly reduced MeHg-mediated deleterious effects on embryo, placenta, and fetal development in vivo. Further investigation of the regulatory mechanisms by which co-cultured ADMSCs could prevent MeHg-induced impairment of embryo development revealed that ADMSCs effectively reduced ROS generation and its subsequent downstream apoptotic events, including loss of mitochondrial membrane potential and activation of caspase-3 and PAK2. The collective findings indicate that co-culture with mesenchymal stem cells (MSCs) or utilization of MSC-derived cell-conditioned medium offers an effective potential therapeutic strategy to prevent impairment of embryo development by MeHg.

Effects and mechanism of annexin A1-overexpressing human adipose-derived mesenchymal stem cells in the treatment of mice with acute respiratory distress syndrome

Effects and mechanism of annexin A1-overexpressing human adipose-derived mesenchymal stem cells in the treatment of mice with acute respiratory distress syndrome

Impact of the Different Preparation Methods to Obtain Human Adipose-Derived Stromal Vascular Fraction Cells (AD-SVFs) and Human Adipose-Derived Mesenchymal Stem Cells (AD-MSCs): Enzymatic Digestion Versus Mechanical Centrifugation.

Autologous therapies using adipose-derived stromal vascular fraction (AD-SVFs) and adult adipose-derived mesenchymal stem cells (AD-MSCs) warrant careful preparation of the harvested adipose tissue. Currently, no standardized technique for this preparation exists. Processing quantitative standards (PQSs) define manufacturing quantitative variables (such as time, volume, and pressure). Processing qualitative standards (PQLSs) define the quality of the materials and methods in manufacturing. The purpose of the review was to use PQSs and PQLSs to report the in vivo and in vitro results obtained by different processing kits that use different procedures (enzymatic vs. non-enzymatic) to isolate human AD-SVFs/AD-MSCs. PQSs included the volume of fat tissue harvested and reagents used, the time/gravity of centrifugation, and the time, temperature, and tilt level/speed of incubation and/or centrifugation. PQLSs included the use of a collagenase, a processing time of 30 min, kit weight, transparency of the kit components, the maintenance of a closed sterile processing environment, and the use of a small centrifuge and incubating rocker. Using a kit with the PQSs and PQLSs described in this study enables the isolation of AD-MSCs that meet the consensus quality criteria. As the discovery of new critical quality attributes (CQAs) of AD-MSCs evolve with respect to purity and potency, adjustments to these benchmark PQSs and PQLs will hopefully isolate AD-MSCs of various CQAs with greater reproducibility, quality, and safety. Confirmatory studies will no doubt need to be completed.

Nanoscale Electrical Potential and Roughness of a Calcium Phosphate Surface Promotes the Osteogenic Phenotype of Stromal Cells.

Mesenchymal stem cells (MSCs) and osteoblasts respond to the surface electrical charge and topography of biomaterials. This work focuses on the connection between the roughness of calcium phosphate (CP) surfaces and their electrical potential (EP) at the micro- and nanoscales and the possible role of these parameters in jointly affecting human MSC osteogenic differentiation and maturation in vitro. A microarc CP coating was deposited on titanium substrates and characterized at the micro- and nanoscale. Human adult adipose-derived MSCs (hAMSCs) or prenatal stromal cells from the human lung (HLPSCs) were cultured on the CP surface to estimate MSC behavior. The roughness, nonuniform charge polarity, and EP of CP microarc coatings on a titanium substrate were shown to affect the osteogenic differentiation and maturation of hAMSCs and HLPSCs in vitro. The surface EP induced by the negative charge increased with increasing surface roughness at the microscale. The surface relief at the nanoscale had an impact on the sign of the EP. Negative electrical charges were mainly located within the micro- and nanosockets of the coating surface, whereas positive charges were detected predominantly at the nanorelief peaks. HLPSCs located in the sockets of the CP surface expressed the osteoblastic markers osteocalcin and alkaline phosphatase. The CP multilevel topography induced charge polarity and an EP and overall promoted the osteoblast phenotype of HLPSCs. The negative sign of the EP and its magnitude at the micro- and nanosockets might be sensitive factors that can trigger osteoblastic differentiation and maturation of human stromal cells.

Human adipose-derived mesenchymal stem cells: serial passaging, doubling time and cell senescence

Adult adipose-derived mesenchymal stem cells (AD-MSC) are very interesting to our research group because they are easy to harvest, they are abundant in humans, and they have potential clinical applications in autologous cell therapy for disc degeneration. We examined these cells through sequential serial passages to assess osteogenic and chondrogenic capabilities, mean doubling time and cell senescence. Osteogenic and chondrogenic potencies were maintained through 13 passages. Mean passage doubling time increased significantly with increasing passage number. When donor age was evaluated, passages 1-4 from older donors had significantly longer doubling times compared to cells from younger donors. Passages 5-11 showed similar findings when analyzed by donor age. The mean percent senescence increased significantly with cell passaging, rising from 0% at passage 1 to 3.4% at passage 13. These novel data suggest that caution should be exercised when using AD-MSC with long passage times.

381 LABELING AND ANALYSIS OF SWINE ADIPOSE-DERIVED STEM CELLS WITH CARBOXYFLUORESCEIN DIACETATE AND QUANTUM DOTS

The quantity, accessibility, and abundance of subcutaneous adipose tissue in humans make it an attractive alternative to bone marrow as a source of adult stem cells for therapeutic purposes. Adult adipose-derived mesenchymal stem cells can differentiate into a variety of lineages including adipose, bone, cartilage, and muscle. In addition, the use of adult stem cells for regenerative medicine rather than those from embryos avoids concerns with ethics, safety, and immunology. One important issue is the ability to track the transplanted stem cells during the regeneration process to evaluate the stem cell-mediated healing. The objective of this study was to compare the efficiency, longevity, and intensity of carboxyfluorescein diacetate, succinimidyl ester (CFDA SE) and quantum dot nanocrystal (Qtracker™, Invitrogen, Carlsbad, CA, USA) labeled adipose-derived stem cells (ADSC) over an in vitro culture period of 4 weeks. Adipose-derived stem cells (6 x 106) previously isolated and frozen at -196°C were thawed and cultured in 75-cm3 flasks with 14 mL of DMEM. Cells were grown to 80% confluence and trypsinized. After trypsinization, the cells were divided into 4 treatments (3 x 106 cells per treatment). The treatments were (1) unlabeled control, (2) labeled with 30 μM CFDA SE, (3) labeled with 15 nM Qtracker™, and (4) labeled with 15 nM Qtracker™, following the Invitrogen Qtracker™ protocol. Cells (1 x 106) were removed from each treatment every week for 4 weeks and fixed in formalin for later analysis. When all the samples were collected, they were analyzed using flow cytometry. Data were analyzed via chi-square test. The percentage of cells labeled with CFDA SE and Qtracker™ was 99.35 and 98.46%, respectively, immediately after labeling. By 1 wk, the percentage of cells labeled with CFDA SE and Qtracker™ had deceased (P < 0.01) to 0.11 and 1.48%, respectively. The CFDA SE-labeled cell percentages had decreased (P < 0.01) to 0% at 2, 3, and 4 wk, respectively. The Qtracker™-labeled cells also decreased (P < 0.01) to 0.745, 1.69 and 0.45% at 2, 3, and 4 wk, respectively. The high rate of cell division of these cells in vitro might be responsible for the rapid loss of both labels during the first week of culture. Previous results from our lab have shown that the CFDA SE is retained in the cells for up to 6 wk in vivo (Lima AS et al. 2006 Reprod. Fertil. Dev. 18, 208). Similar studies need to be done with the quantum dot-labeled cells to determine the Qtracker™ label’s longevity in vivo. In conclusion, quantum dots can be used to label ADSC, in vitro, for at least 4 wk, albeit at much lower levels than those observed during the week following labeling. Determination of a suitable label for high-percentage porcine ADSC labeling during long-term in vitro culture remains to be completed. This research was supported by the Intel Scholar’s Program and the Illinois Regenerative Medicine Institute.