Dedifferentiated fat cells: an alternative source of adult multipotent cells from the adipose tissues

When adipose-derived stem cells （ASCs） arc retrieved from the stromal vascular portion of adipose tissue, a large amount of mature adipocytes are often discarded. However, by modified ceiling culture technique based on their buoyancy, mature adipocytes can be easily isolated from the adipose cell suspension and dediffercn- tiated into lipid-frce fibroblast-like cells, named dediffercntiated fat （DFAT） cells. DFAT cells rc-establish active proliferation ability and undertake multipotent capacities. Compared with ASCs and other adult stem cells, DFAT cells showed unique advantages in their abundance, isolation and homogeneity. In this concise review, the establishment and culture methods of DFAT cells arc introduced and the current profiles of their cellular nature are summarized. Under proper inducti~,n culture in vitro or environment in vivo, DFAT cells could demonstrate adipogenic, osteogenic, chondrogenie and myogenic potentials. In angiogenie conditions, DFAT cells could exhibit perivascular characteristics antt elicit neovascularization. Our preliminary findings also suggested the pericyte phenotype underlying such cell lineage, which supported a novel interpretation about the common origin of mesenchymal stem cells and tissue-specific stem cells within blood vessel walls. Current research on DFAT cells indicated that this alternative source of adult multipotent cells has great potential in tissue engineering and regenerative medicine.

Dedifferentiated fat cells:A cell source for regenerative medicine

The identification of an ideal cell source for tissue regeneration remains a challenge in the stem cell field. The ability of progeny cells to differentiate into other cell types is important for the processes of tissue reconstruction and tissue engineering and has clinical, biochemical or molecular implications. The adaptation of stem cells from adipose tissue for use in regenerative medicine has created a new role for adipocytes. Mature adipocytes can easily be isolated from adipose cell suspensions and allowed to dedifferentiate into lipidfree multipotent cells, referred to as dedifferentiated fat(DFAT) cells. Compared to other adult stem cells, the DFAT cells have unique advantages in their abundance, ease of isolation and homogeneity. Under proper condition in vitro and in vivo, the DFAT cells have exhibited adipogenic, osteogenic, chondrogenic, cardiomyogenc, angiogenic, myogenic, and neurogenic potentials. In this review, we first discuss the phenomena of dedifferentiation and transdifferentiation of cells, and then dedifferentiation of adipocytes in particular. Understanding the dedifferentiation process itself may contribute to our knowledge of normal growth processes, as well as mechanisms of disease. Second, we highlight new developments in DFAT cell culture and summarize the current understanding of DFAT cell properties. The unique features of DFAT cells are promising for clinical applications such as tissue regeneration.

Experimental study of the effect of adipose stromal vascular fraction cells on the survival rate of fat transplantation

Objective To investigate the effect of adipose stromal vascular fraction cells(SVFs)on the survival rate of fat ransplantation.Methods 0.5mL autologous fat tissue was mixed with: ① DiI-labeled autologous SVFs (Group A);②

Adipose tissue in bone regeneration-stem cell source and beyond

Adipose tissue(AT)is recognized as a complex organ involved in major homeostatic body functions,such as food intake,energy balance,immunomodulation,development and growth,and functioning of the reproductive organs.The role of AT in tissue and organ homeostasis,repair and regeneration is increasingly recognized.Different AT compartments(white AT,brown AT and bone marrow AT)and their interrelation with bone metabolism will be presented.AT-derived stem cell populations-adipose-derived mesenchymal stem cells and pluripotentlike stem cells.Multilineage differentiating stress-enduring and dedifferentiated fat cells can be obtained in relatively high quantities compared to other sources.Their role in different strategies of bone and fracture healing tissue engineering and cell therapy will be described.The current use of AT-or AT-derived stem cell populations for fracture healing and bone regenerative strategies will be presented,as well as major challenges in furthering bone regenerative strategies to clinical settings.

A rare case of intraoral lipoma in a six year-old child:a case report

One type of soft tissue lesions of the oral cavity is lipoma, which is a kind of benign tumor composed of mature lipid cells. Although the lipoma presents as one of the most common mesenchymal neoplasms, most tend to develop on the trunk and proximal portions of the extremities. However, lipomas in the oral and maxillofacial region are much less frequent. Here we present a case of an intraoral lipoma in a six year-old child.

Take-over:multiple mechanisms of inter-adipocyte communication

Adipose tissue mass in mammals is thought to expand with an increase in both volume and total number of the adipocytes.Recent findings suggest that in normal-weight as well as obese individuals,the adipocyte number is set during adolescence prior to adulthood,whereas the subsequent increase in size predominantly drives obesity.The simultaneous existence of large and small adipocytes and their unsynchronized growth,even within the same adipose tissue depot,argues against simple filling-up of emerging adipocytes with lipids and lipid droplets(LDs).Consequently,it is tempting to speculate about signals sent by large adipocytes to order small adipocytes the take-over of the burden of lipid loading.Currently there is experimental evidence for three distinct types of inter-adipocyte signals,i.e.cell-to-cell contacts,adipokines,and other soluble factors and microvesicles.Very recently,microvesicles have been shown(i)to harbour the glycosylphosphatidylinositol-anchored(c)AMP-degrading phosphodiesterase Gce1 and 5′-nucleotidase CD73,(ii)to be released from large adipocytes,(iii)to interact with small adipocytes,and(iv)to transfer Gce1 and CD73 to plasma membranes and LDs of small adipocytes where they degrade(c)AMP.This sequence of events leads to the up-regulation of lipid storage in small adipocytes in response to the microvesicle-encoded‘take-over’signal from large adipocytes.A model is proposed for the maturation of small adipocytes driven by large ones along a gradient of those inter-adipocyte signals.Pharmacological modulation of inter-adipocyte communication and thereby adipocyte maturation may be useful for the therapy of metabolic diseases.

Cytotoxicity and binding profiles of activated CrylAc and Cry2Ab to three insect cell lines

While CrylAc has been known to bind with larval midgut proteins cad- herin, APN （amino peptidase N）, ALP （alkaline phosphatase） and ABCC2 （adenosine triphosphate-binding cassette transporter subfamily C2）, little is known about the recep- tors of Cry2Ab. To provide a clue to the receptors of Cry2Ab, we tested the baseline cytotoxicity of activated Cry 1Ac and Cry2Ab against the midgut and fat body cell lines of Helicoverpa zea and the ovary cell line ofSpodopterafrugiperda （SFg）. As expected, the descending order of cytotoxicity of CrylAc against the three cell lines in terms of 50% lethal concetration （LC50） was midgut （31.0μg/mL） 〉 fat body （59.0μg/mL） and SF9 cell （99.6μg/mL）. By contrast, the fat body cell line （LC50 = 7.55μg/mL） was about twice more susceptible to Cry2Ab than the midgut cell line （16.0/xg/mL）, the susceptibility of which was not significantly greater than that of SF9 cells （27.0μg/mL）. Further, ligand blot showed the binding differences between CrylAc and Cry2Ab in the three cell lines. These results indicated that the receptors of Cry2Ab were enriched in fat body cells and thus largely different from the receptors of CrylAc, which were enriched in midgut cells.

Non-invasive focused ultrasound for abdominal circumference reduction:does it really work?

Aim:Non-invasive body contouring is a promising modality.However,due to a lack of good evidence-based data,the mechanism by which contouring occurs remains unclear.The purpose of this study was to evaluate the effect of treatment with the Contour I™ultrasound system(Ultrashape®,Syneron®,Israel)on abdominal circumference and to compare 2 power levels for efficacy and safety.Methods:A prospective,self-controlled double-blind design was used.Thirty-six women,aged 30-45 years,were randomized to receive treatment with the Contour I at high or low acoustic outputs in 3 successive sessions,1 month apart.Safety was evaluated by adverse events,local skin reaction,and pain.Efficacy was evaluated by the change in abdominal circumference relative to baseline and to the untreated thigh area(internal control).Patients were followed for 28 days after the last treatment session.Results:At 1 month after the first session,the mean reductions in abdominal circumference measured 1.65 cm(P<0.001)and 0.87 cm(P<0.019)in the high and low-power groups,respectively.At 1 month after the last session,the cumulative reductions in circumference were 2.56 cm(P<0.001)and 1.49 cm(P<0.012),respectively.There was no change in the internal-control circumference throughout treatment.There were no treatment-induced severe adverse events.Conclusion:Multiple successive treatments of the abdominal area with the Contour I lead to a significant progressive reduction in circumference.The magnitude of the reduction is directly correlated to the acoustic power output which suggests that the technology itself is the main cause for the contouring effect.