CD271-selected mesenchymal stem cells from adipose tissue enhance cartilage repair and are less angiogenic than plastic adherent mesenchymal stem cells

CD271 is a marker of bone marrow MSCs with enhanced differentiation capacity for bone or cartilage repair. However, the nature of CD271+ MSCs from adipose tissue (AT) is less well understood. Here, we investigated the differentiation, wound healing and angiogenic capacity of plastic adherent MSCs (PA MSCs) versus CD271+ MSCs from AT. There was no difference in the extent to which PA MSCs and CD271+ MSCs formed osteoblasts, adipocytes or chondrocytes in vitro. In contrast, CD271+ MSCs transplanted into athymic rats significantly enhanced osteochondral wound healing with reduced vascularisation in the repair tissue compared to PA MSCs and control animals; there was little histological evidence of mature articular cartilage formation in all animals. Conditioned medium from CD271+ MSC cultures was less angiogenic than PA MSC conditioned medium, and had little effect on endothelial cell migration or endothelial tubule formation in vitro. The low angiogenic activity of CD271+ MSCs and improved early stage tissue repair of osteochondral lesions when transplanted, along with a comparable differentiation capacity along mesenchymal lineages when induced, suggests that these selected cells are a better candidate than PA MSCs for the repair of cartilaginous tissue

Aspectos morfo-anatômicos de três espécies de Drosera, durante o desenvolvimento pós-seminal

Durante o processo de germinação, as sementes das três espécies (Drosera spathulata Labill., D. intermedia Dreves & Hayne e D. burmanni Vahl) rompem-se por meio de um opérculo e as plántulas desenvolvem pêlos unicelulares ancoradouros antes do estabelecimento da raiz primária. A porção apical dos cotilédones permanece no interior dos envoltórios das sementes e possui função haustorial. Diferentes tricomas são constatados nas folhas e cotilédones das plántulas, inclusive na superfície das emergências. Alguns aspectos morfo-anatômicos das folhas também são apresentados.During germination, the seeds of the three species (Drosera spathulata Labill., D. intermedia Dreves & Hayne e D. burmanni Vahl) rupture by way of an operculum with the seedlings forming anchorage hairs before the development of primary roots. The cotyledon apexes remain inside the seed integuments and have a haustorial function. Different trichomes are found on the leaves and cotyledons of seedlings, and on emergence surfaces. Some anatomical aspects of leaves are also presented

Adipose-derived stromal cells for osteoarticular repair: trophic function versus stem cell activity

The identification of multipotent adipose-derived stromal cells (ASC) has raised hope that tissue regeneration approaches established with bone-marrow-derived stromal cells (BMSC) can be reproduced with a cell-type that is far more accessible in large quantities. Recent detailed comparisons, however, revealed subtle functional differences between ASC and BMSC, stressing the concept of a common mesenchymal progenitor existing in a perivascular niche across all tissues. Focussing on bone and cartilage repair, this review summarises recent in vitro and in vivo studies aiming towards tissue regeneration with ASC. Advantages of good accessibility, high yield and superior growth properties are counterbalanced by an inferiority of ASC to form ectopic bone and stimulate long-bone healing along with their less pronounced osteogenic and angiogenic gene expression signature. Hence, particular emphasis is placed on establishing whether stem cell activity of ASC is so far proven and relevant for successful osteochondral regeneration, or whether trophic activity may largely determine therapeutic outcome.</jats:p