In vitro immunomodulatory properties of osteogenic and adipogenic differentiated mesenchymal stem cells isolated from three inbred mouse strains

Adipogenic Differentiation of Mesenchymal Stem Cells Alters Their Immunomodulatory Properties in a Tissue-Specific Manner

Chronic inflammation is associated with formation of ectopic fat deposits that might represent damage-induced aberrant mesenchymal stem cell (MSC) differentiation. Such deposits are associated with increased levels of inflammatory infiltrate and poor prognosis. Here we tested the hypothesis that differentiation from MSC to adipocytes in inflamed tissue might contribute to chronicity through loss of immunomodulatory function. We assessed the effects of adipogenic differentiation of MSC isolated from bone marrow or adipose tissue on their capacity to regulate neutrophil recruitment by endothelial cells and compared the differentiated cells to primary adipocytes from adipose tissue. Bone marrow derived MSC were immunosuppressive, inhibiting neutrophil recruitment to TNFα-treated endothelial cells (EC), but MSC-derived adipocytes were no longer able to suppress neutrophil adhesion. Changes in IL-6 and TGFβ1 signalling appeared critical for the loss of the immunosuppressive phenotype. In contrast, native stromal cells, adipocytes derived from them, and mature adipocytes from adipose tissue were all immunoprotective. Thus disruption of normal tissue stroma homeostasis, as occurs in chronic inflammatory diseases, might drive "abnormal" adipogenesis which adversely influences the behavior of MSC and contributes to pathogenic recruitment of leukocytes. Interestingly, stromal cells programmed in native fat tissue retain an immunoprotective phenotype. Stem Cells 2017;35:1636-1646.

Comparison of TGF-β1 and NO production by mesenchymal stem cells isolated from murine lung and adipose tissues

CONTEXT

Mesenchymal stem cells (MSCs) are cell sources for tissues regeneration. By secretion of soluble factors including transforming growth factor-β (TGF-β1) and nitric oxide (NO), MSCs are also able to regulate the immune system. MSCs have been disclosed in lung and adipose tissues with insufficient comparison between the tissues.

OBJECTIVES

In this study, specific differentiation and the expression of surface antigens as well as TGF-β1 and NO productive levels were compared in murine lung-derived MSCs (LMSCs) and adipose tissue-derived MSCs (ADMSCs).

MATERIALS AND METHODS

MSCs were isolated from murine lung and adipose tissues and cultured. Both cell populations were characterized using multilineage potential and the expression of surface antigenic proteins, CD73, CD105, CD34, CD45, and CD11b. Finally, levels of TGF-β1 and NO were evaluated and compared in ADMSCs and LMSCs.

RESULTS

Expression of CD73 and CD105; lack of the expression of CD34, CD45, and CD11b markers; as well as adipocyte and osteocyte differentiations were detected in both adult stem cells. No significant difference was found in TGF-β1 and NO production between two stem cell populations.

CONCLUSION

Our data showed that LMSCs and ADMSCs have comparable phenotype and TGF-β1 and NO production.

Implantation of Autologous Adipose Tissue-Derived Mesenchymal Stem Cells in Foot Fat Pad in Rats

BACKGROUND

The foot fat pad (FFP) bears body weight and may become a source of foot pain during aging. This study investigated the regenerative effects of autologous adipose tissue-derived mesenchymal stem cells (AT-MSCs) in the FFP of rats.

METHODS

Fat tissue was harvested from a total of 30 male Sprague-Dawley rats for isolation of AT-MSCs. The cells were cultured, adipogenic differentiation was induced for 1 week, and the AT-MSCs were labeled with fluorescent dye before injection. AT-MSCs (5 × 10(4) in 50 µL of saline) were injected into the second infradigital pad in the right hindfoot of the rat of origin. Saline only (50 µL) was injected into the corresponding fat pad in the left hind paw of each rat. Rats (n = 10) were euthanized at 1, 2, and 3 weeks, and the second infradigital fat pads were dissected for histologic examination.

RESULTS

The fluorescence-labeled AT-MSCs were present in the foot pads throughout the 3-week experimental period. On histologic testing, the area of fat pad units (FPUs) in the fat pads that received AT-MSC injections was greater than that in the control fat pads. Although the thickness of septae was not changed by AT-MSC injections, the density of elastic fibers in the septae was increased in the fat pads with implanted AT-MSCs.

CONCLUSION

In this short-term study, the implanted AT-MSCs largely survived and might have stimulated the expansion of individual FPUs and increased the density of elastic fibers in the FFP in this rat model.

CLINICAL RELEVANCE

These data support the development of stem cell therapies for age-associated degeneration in FFP in humans.

The role of catecholamines in mesenchymal stem cell fate

Mesenchymal stem cells (MSCs) are multipotent stem cells found in many adult tissues, especially bone marrow (BM) and are capable of differentiation into various lineage cells such as osteoblasts, adipocytes, chondrocytes and myocytes. Moreover, MSCs can be mobilized from connective tissue into circulation and from there to damaged sites to contribute to regeneration processes. MSCs commitment and differentiation are controlled by complex activities involving signal transduction through cytokines and catecholamines. There has been an increasing interest in recent years in the neural system, functioning in the support of stem cells like MSCs. Recent efforts have indicated that the catecholamine released from neural and not neural cells could be affected characteristics of MSCs. However, there have not been review studies of most aspects involved in catecholamines-mediated functions of MSCs. Thus, in this review paper, we will try to describe the current state of catecholamines in MSCs destination and discuss strategies being used for catecholamines for migration of these cells to damaged tissues. Then, the role of the nervous system in the induction of osteogenesis, adipogenesis, chondrogenesis and myogenesis from MSCs is discussed. Recent progress in studies of signaling transduction of catecholamines in determination of the final fate of MSCs is highlighted. Hence, the knowledge of interaction between MSCs with the neural system could be applied towards the development of new diagnostic and treatment alternatives for human diseases.