Rapid and Efficient Production of Human Functional Mast Cells through a Three-Dimensional Culture of Adipose Tissue-Derived Stromal Vascular Cells.

Mast cells (MC) are innate immune cells involved in many physiological and pathological processes. However, studies of MC function and biology are hampered by the difficulties to obtain human primary MC. To solve this problem, we established a new method to produce easily and rapidly high numbers of MC for in vitro studies using human adipose tissue, which is an abundant and easy access tissue.

Corrupted adipose tissue endogenous myelopoiesis initiates diet-induced metabolic disease.

Activation and increased numbers of inflammatory macrophages, in adipose tissue (AT) are deleterious in metabolic diseases. Up to now, AT macrophages (ATM) accumulation was considered to be due to blood infiltration or local proliferation, although the presence of resident hematopoietic stem/progenitor cells (Lin-/Sca+/c-Kit+; LSK phenotype) in the AT (AT-LSK) has been reported. By using transplantation of sorted AT-LSK and gain and loss of function studies we show that some of the inflammatory ATM inducing metabolic disease, originate from resident AT-LSK.

Differential Hematopoietic Activity in White Adipose Tissue Depending on its Localization.

White adipose tissue (WAT) can be found in different locations in the body, and these different adipose deposits exhibit specific physiopathological importance according to the subcutaneous or abdominal locations. We have shown previously the presence of functional hematopoietic stem/progenitor cells (HSPC) in subcutaneous adipose tissue (SCAT). These cells exhibit a specific hematopoietic activity that contributes to the renewal of the immune cell compartment within this adipose deposit.

An Association between BK Virus Replication in Bone Marrow and Cytopenia in Kidney-Transplant Recipients.

The human polyomavirus BK (BKV) is associated with severe complications, such as ureteric stenosis and polyomavirus-associated nephropathy (PVAN), which often occur in kidney-transplant patients. However, it is unknown if BKV can replicate within bone marrow. The aim of this study was to search for BKV replication within the bone marrow of kidney-transplant patients presenting with a hematological disorder.

In situ production of innate immune cells in murine white adipose tissue.

White adipose tissue (WAT) is the focus of new interest because of the presence of an abundant and complex immune cell population that is involved in key pathologies such as metabolic syndrome. Based on in vivo reconstitution assays, it is thought that these immune cells are derived from the bone marrow (BM). However, previous studies have shown that WAT exhibits specific hematopoietic activity exerted by an unknown subpopulation of cells.

Adipose-derived stromal cells: Their identity and uses in clinical trials, an update.

In adults, adipose tissue is abundant and can be easily sampled using liposuction. Largely involved in obesity and associated metabolic disorders, it is now described as a reservoir of immature stromal cells. These cells, called adipose-derived stromal cells (ADSCs) must be distinguished from the crude stromal vascular fraction (SVF) obtained after digestion of adipose tissue.

Human adipose-derived stromal cells efficiently support hematopoiesis in vitro and in vivo: a key step for therapeutic studies.

Adipose-derived stromal cells (ADSCs) are close relatives of bone marrow mesenchymal stromal cells (BM-MSCs). The ease of access to subcutaneous fat pad and the abundance of stromal precursors make fat tissue an attractive source of stromal cells for clinicians. However, their ability to support hematopoietic stem cells in vitro and in vivo has not been established definitively.

Adipose tissue as a dedicated reservoir of functional mast cell progenitors.

White adipose tissue (WAT) is a heterogeneous tissue, found in various locations throughout the body, containing mature adipocytes and the stroma-vascular fraction (SVF). The SVF includes a large proportion of immune hematopoietic cells, among which, mast cells that contribute to diet-induced obesity. In this study, we asked whether mast cells present in mice adipose tissue could derive from hematopoietic stem/progenitor cells (HSPC) identified in the tissue.

The emergence of adipocytes.

In mammals, the adipose organ is composed of white adipocytes (primary site in energy storage) and of brown adipocytes (specialized in thermogenesis). Adipocytes arise from mesenchymal stem cells (MSCs) by a sequential pathway of differentiation. MSCs develop either from ectoderm or mesoderm and commit into different undifferentiated precursors, which upon the expression of key transcription factors enter a differentiation program to acquire their specific functions.

Vascular and endothelial regeneration.

Adipose tissue is the final tissue to develop and is strongly involved in energy homeostasis. It can represent up to 50% of body weight in obesity. Beside its metabolic role, endocrine functions appeared to play a key role in interconnecting adipose tissue with other tissues of the organism and in numerous physiological functions.

Transplantation of adipose derived stromal cells is associated with functional improvement in a rat model of chronic myocardial infarction.

Aims: To determine the effect of transplantation of undifferentiated and cardiac pre-differentiated adipose stem cells compared with bone marrow mononuclear cells (BM-MNC) in a chronic model of myocardial infarction.

Methods: Ninety-five Sprague-Dawley rats underwent left coronary artery ligation and after 1 month received by direct intramyocardial injection either adipose derived stem cells (ADSC), cardiomyogenic cells (AD-CMG) or BM-MNC from enhanced-Green Fluorescent Protein (eGFP) mice. The control group was treated with culture medium.

Virus-based gene transfer approaches and adipose tissue biology.

The status of adipose tissue changes rapidly. From a simple filler tissue, it successively acquires the status of metabolic active tissue, endocrine tissue, plastic tissue, and finally that of a large reservoir of cells suitable for cell therapy and regenerative medicine. All throughout this story, our knowledge has been largely dependent on genetic tools and gene transfer.

[Adipose tissue: a subtle and complex cell system].

White adipose tissue (WAT) represents a large amount of all adult tissues. For a long time, it was considered as a poorly active, overgrown and undesirable tissue. It was mainly studied for its involvement in energy metabolism and disorders, as well as for its endocrine functions.

Human subcutaneous adipose cells support complete differentiation but not self-renewal of hematopoietic progenitors.

Adipose tissue is now considered as an endocrine organ implicated in energy regulation, inflammation and immune response, and as a source of multipotent cells with a broad range of differentiation capacities. Some of these cells are of a mesenchymal type which can -- like their bone marrow (BM) counterpart -- support hematopoiesis, since in a previous study we were able to reconstitute lethally irradiated mice by cells isolated from adipose tissue. In the present study, we established that cells derived from the stroma-vascular fraction of human subcutaneous fat pads support the complete differentiation of hematopoietic progenitors into myeloid and B lymphoid cells.

Immunomodulatory effect of human adipose tissue-derived adult stem cells: comparison with bone marrow mesenchymal stem cells.

Like mesenchymal stem cells from bone marrow (BM-MSCs), adipose tissue-derived adult stem cells (ADAS cells) can differentiate into several lineages and present therapeutical potential for repairing damaged tissues. The use of allogenic stem cells can enlarge their therapeutical interest, provided that the grafted cells could be tolerated. We investigate here, for the first time, the immunosuppressive properties of ADAS cells compared with the well-characterized immunosuppressive properties of BM-MSCs.

Human bone marrow adipocytes support complete myeloid and lymphoid differentiation from human CD34 cells.

In humans, the role of bone marrow (BM) adipocytes in supporting haematopoiesis has been questioned. A co-culture system of CD34(+) cells seeded onto either BM undifferentiated mesenchymal stem cells or differentiated adipocytes showed that BM adipocytes did not support the maintenance of immature progenitors but enabled their complete differentiation along the myeloid and lymphoid pathways. These properties appear to be opposite to those of osteoblasts, although both cell types share a common mesenchymal progenitor.