Mesenchymal Stem Cell-Derived Extracellular Vesicle Isolation and Their Protein Cargo Characterization

In the present protocol, extracellular vesicles (EVs) released from a primary culture of human umbilical cord mesenchymal stem cells (MSCs) were isolated by ultracentrifugation processes, characterized by transmission electron microscopy (TEM) and measured by nanoparticle tracking analysis (NTA). Protein was extracted from EVs using RIPA buffer and then was assessed for integrity. The proteomic content of the total EV protein samples was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after labeling by tandem mass tag (TMT). This combined approach allowed the development of an effective strategy to study the protein cargo from MSC-derived EVs.

Identification of patients at risk of non-adherence to oral antirheumatic drugs in rheumatoid arthritis using the Compliance Questionnaire in Rheumatology: an ARCO sub-study

The ARCO study (Study on Adherence of Rheumatoid Arthritis patients to SubCutaneous and Oral Drugs), a multicenter, non-interventional retrospective study, was primarily designed to assess the percentage of patients [aged ≥18 years with an established rheumatoid arthritis (RA) diagnosis] with non-adherence to prescribed subcutaneous biologicals. This paper reports data for the secondary objective from a subset of patients, namely to evaluate non-adherence to prescribed oral antirheumatic drugs in RA patients in Spain using the validated Compliance Questionnaire Rheumatology (CQR). Patients also completed the Morisky-Green Medication Adherence Questionnaire, Beliefs about Medicines Questionnaire, and a questionnaire (developed and validated in Spain) on patient satisfaction with RA treatment and preferences. A total of 271 patients (76.7% females; mean age 55.6 years) were being treated with oral drugs for RA, of which 234 completed the CQR questionnaire. Non-adherence was reported in 49/234 (20.9%) patients. The proportion of non-adherence in younger patients (aged ≤48 years; 37.5%) was double that recorded in patients aged >48 years (p = 0.006). Patients with a perception of lower efficacy also had a higher risk of non-adherence (p = 0.012). Multivariable analysis showed that younger age and male gender were independently associated with risk of non-adherence. There was only slight agreement between the CQR and Morisky-Green assessment tools (kappa coefficient = 0.186), possibly reflecting the fact that both questionnaires measure slightly different aspects of medication adherence. In conclusion, one out of five RA patients was identified as at risk for non-adherence with the CQR, and this was more frequent in younger patients and in males.

Proteome analysis during chondrocyte differentiation in a new chondrogenesis model using human umbilical cord stroma mesenchymal stem cells

Umbilical cord stroma mesenchymal stem cells were differentiated toward chondrocyte-like cells using a new in vitro model that consists of the random formation of spheroids in a medium supplemented with fetal bovine serum on a nonadherent surface. The medium was changed after 2 days to one specific for the induction of chondrocyte differentiation. We assessed this model using reverse transcriptase-polymerase chain reaction, flow cytometry, immunohistochemistry, and secretome analyses. The purpose of this study was to determine which proteins were differentially expressed during chondrogenesis. Differential gel electrophoresis analysis was performed, followed by matrix-assisted laser desorption/ionization mass spectrometry protein identification. A total of 97 spots were modulated during the chondrogenesis process, 54 of these spots were identified as 39 different proteins and 15 were isoforms. Of the 39 different proteins identified 15 were down-regulated, 21 were up-regulated, and 3 were up- and down-regulated during the chondrogenesis process. Using Pathway Studio 7.0 software, our results showed that the major cell functions modulated during chondrogenesis were cellular differentiation, proliferation, and migration. Five proteins involved in cartilage extracellular matrix metabolism found during the differential gel electrophoresis study were confirmed using Western blot. The results indicate that our in vitro chondrogenesis model is an efficient and rapid technique for obtaining cells similar to chondrocytes that express proteins characteristic of the cartilage extracellular matrix. These chondrocyte-like cells could prove useful for future cell therapy treatment of cartilage pathologies.

Human amniotic membrane as an alternative source of stem cells for regenerative medicine

The human amniotic membrane (HAM) is a highly abundant and readily available tissue. This amniotic tissue has considerable advantageous characteristics to be considered as an attractive material in the field of regenerative medicine. It has low immunogenicity, anti-inflammatory properties and their cells can be isolated without the sacrifice of human embryos. Since it is discarded post-partum it may be useful for regenerative medicine and cell therapy. Amniotic membranes have already been used extensively as biologic dressings in ophthalmic, abdominal and plastic surgery. HAM contains two cell types, from different embryological origins, which display some characteristic properties of stem cells. Human amnion epithelial cells (hAECs) are derived from the embryonic ectoderm, while human amnion mesenchymal stromal cells (hAMSCs) are derived from the embryonic mesoderm. Both populations have similar immunophenotype and multipotential for in vitro differentiation into the major mesodermal lineages, however they differ in cell yield. Therefore, HAM has been proposed as a good candidate to be used in cell therapy or regenerative medicine to treat damaged or diseased tissues.

Isolation and characterization of mesenchymal stem cells from human amniotic membrane

INTRODUCTION

The human amniotic membrane is a highly abundant and readily available tissue that may be useful for regenerative medicine and cell therapy.

AIM

To compare two previously published protocols for the isolation of human amnion mesenchymal stromal cells (hAMSCs), including their phenotypic characterization and in vitro potential for differentiation toward osteogenic, adipogenic, and chondrogenic mesodermal lineages.

MATERIALS AND METHODS

Human placentas were obtained from selected caesarean-sectioned births. Two different protocols (Alviano et al. (1) and Soncini et al. (2) ) for the isolation of hAMSCs were performed. After monolayer expansion of adherent cells from both protocols, the cells were characterized by flow cytometry and for multipotentiality, as assessed by their capability to differentiate toward adipocyte-, osteoblast-, and chondrocyte-like cells.

RESULTS

Both protocols yielded hAMSCs that showed plastic adherence, fibroblast-like growth, and well-defined human MSC markers. The cell yield and mesodermal differentiation capability of hAMSCs were higher in cells isolated using the Soncini protocol.

CONCLUSIONS

Our data demonstrated the successful isolation of hAMSCs from full-term placentas using two published protocols. Differences between the two protocols in cell yield and in vitro differentiation potential are shown.

Potential use of the human amniotic membrane as a scaffold in human articular cartilage repair

The human amniotic membrane (HAM) is an abundant and readily obtained tissue that may be an important source of scaffold for transplanted chondrocytes in cartilage regeneration in vivo. To evaluate the potential use of cryopreserved HAMs as a support system for human chondrocytes in human articular cartilage repair. Chondrocytes were isolated from human articular cartilage, cultured and grown on the chorionic basement membrane side of HAMs. HAMs with chondrocytes were then used in 44 in vitro human osteoarthritis cartilage repair trials. Repair was evaluated at 4, 8 and 16 weeks by histological analysis. Chondrocytes cultured on the HAM revealed that cells grew on the chorionic basement membrane layer, but not on the epithelial side. Chondrocytes grown on the chorionic side of the HAM express type II collagen but not type I, indicating that after being in culture for 3-4 weeks they had not de-differentiated into fibroblasts. In vitro repair experiments showed formation on OA cartilage of new tissue expressing type II collagen. Integration of the new tissue with OA cartilage was excellent. The results indicate that cryopreserved HAMs can be used to support chondrocyte proliferation for transplantation therapy to repair OA cartilage.

Pig chondrocyte xenoimplants for human chondral defect repair: an in vitro model

The objective of this study was to evaluate the use of cultured porcine chondrocyte xenotransplantation for the repair of human chondral defects. Two-millimeter-diameter defects were drilled into explants of femoral cartilage from healthy adult donors. No cells were implanted in the chondral defects of the control group, while pig chondrocytes from normal femoral cartilage were deposited into the treated chondral defects. Cartilage explants were cultured for 4, 8, and 12 weeks. Tissue sections were processed for standard histologic staining and immunostaining with monoclonal antibodies against types I and II collagen, chondroitin-4-sulfate, chondroitin-6-sulfate, keratan sulfate, and integrin subunit beta1. The porcine origin of chondrocytes was confirmed using a specific pig monoclonal anti-CD46. Repair was only observed in the cell-treated defects. Mono- or bilayers of cells were detected after 4 culture weeks on the bottom of the defects, while after 8-12 weeks a repair tissue filled near 30-40 percent of the defect. At 8 weeks, the newly synthesized tissue was composed of a fibrous mesh including some cells. However, at 12 weeks it showed a hypercellular hyaline-like region. This hypercellular region showed excellent bonding with the native cartilage, cells were located in numerous lacunae, and a high content of proteoglycans as indicated by an intense toluidine blue stain was observed. The repaired tissue showed positive immunostaining for both type I and II collagen, as well as chondroitin-4-sulfate, chondroitin-6-sulfate, keratan sulfate, and integrin subunit beta1. Positive staining for porcine anti-CD46 was localized exclusively in the neo-synthesized tissue. We conclude that xenotransplantation of pig chondrocytes can repair, in an in vitro model, defects in human articular cartilage.