Aged ; Cell Dedifferentiation ; Chondrosarcoma ; pathology ; Humans ; Ribs ; pathology

When mature adipocytes are subjected to an in vitro dedifferentiation strategy referred to as ceiling culture, these mature adipocytes can revert to dedifferentiated fat (DFAT) cells. DFAT cells have many advantages compared with adipose-derived stem cells (ASCs) and bone marrow mesenchymal stem cells (BMSCs). For example, DFAT cells are homogeneous and could be obtained from donors regardless of their age. Furthermore, DFAT cells also have the same multi-lineage potentials and low immunogenicity as ASCs. As an excellent source of seed cells for tissue engineering and stem cell transplantation, DFAT cells have better prospects in the treatment of many clinical diseases, such as bone defects, neurological diseases, ischemic heart disease and kidney disease. It is necessary to make more intensive studies of DFAT cells. This article summarizes progresses in the immunological characteristics, differentiation ability and potential clinical applications of DFAT cells.
Adipocytes ; cytology ; Cell Dedifferentiation ; Cell Differentiation ; Cells, Cultured ; Humans ; Stem Cell Transplantation ; Tissue Engineering

Cell reprogramming is a progress in which the memory of a mature cell is erased and then the cell develops novel phenotype and function; ultimately, the fate of the cell changes. Cell reprogramming usually occurs at genes expression levels that no genomic DNA sequence change will be involved. By changing the programs of the genetic expressions of cells in terms of space and time, cell reprogramming alters the differentiation of cells and thus produces the required cells. Further research on cells reprogramming will elucidate the mechanisms that govern the cell development, and thus provides more information of the sources of seed cells used for regeneration medicine. More cells differentiated from many terminally differentiated cells will be obtained, which is extremely important for the understanding of molecular differentiation and for the development of cell replacement therapy. This article summarizes the classification, influencing factors, approaches and latest advances of cells reprogramming.
Animals ; Cell Dedifferentiation ; genetics ; Cell Differentiation ; genetics ; Cellular Reprogramming ; Gene Expression ; Humans ; Nuclear Transfer Techniques

Recent studies have confirmed that diverse adult tissue cells can be reprogrammed and induced to pluripotency, that is so-called induced pluripotent stem cells (iPS cells). But most of these dedifferentiated processes are induced by gene delivery with retroviral vectors. Some of the delivered genes are cancer causing. So, in current situation, these adult-derived embryonic stem-like cells cannot be used in clinical therapy to cure human diseases. Recently some articles that were published in the authoritative journals are receiving attentions. They show that, in mice and human, spermatogonial stem cells (SSCs) can be used for generating pluripotent stem cells without the exogenous genes and retroviruses, and they can also be used for autologous transplantation without ethical problems. These findings suggest that human SSCs may have considerable potential for cell-based, autologous organ regeneration therapy for various diseases. In this review, we describe and compare the methods that have been used to isolate, purificate and culture SSCs. We also describe the recent results in which SSCs can be transformed into pluripotent stem cells, and the pluripotent stem cells have potential applications in regenerative medicine and genetic medicine.
Cell Culture Techniques ; methods ; Cell Dedifferentiation ; physiology ; Cells, Cultured ; Humans ; Male ; Pluripotent Stem Cells ; cytology ; Spermatogonia ; cytology ; Stem Cells ; cytology

OBJECTIVETTo explore the method for inducing the dedifferentiation of epidermal cells into their progenitor stem cells in vitro without external gene intervention.

METHODSHEK cells obtained from Casacade were induced to reverse their differentiated process and produce immature stem-like cells, namely the dedifferentiation derived epidermal stem cells (dESCs), by induction with basic fibroblasts growth factors (bFGF) in vitro. Immunochemical staining, flow FACS analysis, RT-PCR and immunofluorescent staining were used to detect the phenotypic and functional changes of the differentiated epidermal cells, using human epidermal stem cells (ESCs) as the positive control.

RESULTSImmunohistochemical staining revealed that the expressions of β₁-integrin, CK19 and CK14 were up-regulated, while CK10 expression was down-regulated significantly after bFGF treatment. Two-color flow cytometric analysis of α₆-integrin and CD71 showed that the percentages of α₆(+)CD71(-), α₆(+)CD71(+) and CD71(+) expressing populations reached 13.24%, 58.26% and 23.12% of the total isolated cells, as compared with those of the control (0.12%, 3.06%, 51.50%) and positive control cells (37.49%, 45.13%, 5.86%). RT-PCR analysis indicated that the relative gene expressions of β₁-integrin, CK19 and CK14 increased in bFGF treatment group, whereas the expression of CK10 was significantly suppressed. Although there was no significant difference in the expression levels of β₁ integrin, CK19 and CK10 between the bFGF-treated and the positive controls, the expression of CK14 in bFGF-treated cells showed a 1.4-fold increase as compared with that in ESCs (P < 0.05). Immunofluorescent staining showed that a regional difference in the subcellular localization of telomerase between dESCs and ESCs.

CONCLUSIONbFGF can induce the epidermal cells to convert into epidermal precursor cells. Although they are more likely to be transient amplifying cells, the method for reprogramming somatic epidermal cells into their progenitors by bFGF induction other than genetic manipulation offers a new approach to generate residual healthy stem cells for wound repair and regeneration.

Cell Dedifferentiation ; Cell Proliferation ; Cells, Cultured ; Epidermis ; cytology ; Fibroblast Growth Factor 2 ; pharmacology ; Humans ; Induced Pluripotent Stem Cells ; cytology

We describe a 69-year-old woman who presented with a dedifferentiated extraskeletal myxoid chondrosarcoma arising in the left masticator space. Computed tomography and magnetic resonance imaging revealed a 5 cm sized mass in the left masticator space. Histologically, the tumor consisted of two distinct areas. The less cellular area was a low-grade extraskeletal myxoid chondrosarcoma, composed of strands or cords of uniform spindle cells and abundant myxoid stroma. The more cellular, dedifferentiated area corresponded to a high grade myxofibrosarcoma, consisting of anaplastic tumor cells in myxoid stroma and geographic necrosis. The tumor cells of the former area were positive for S-100 protein, microtubule-associated protein-2 (MAP-2) and class III beta-tubulin, but negative for cytokeratin, smooth muscle actin, and desmin. The tumor cells in the latter, pleomorphic area showed MAP-2 and beta-tubulin immunoreactivity with a high Ki-67 labeling index. Based on its histologic and immunohistochemical features, the tumor was considered a dedifferentiated extraskeletal myxoid chondrosarcoma.
Actins ; Aged ; Cell Dedifferentiation ; Chondrosarcoma ; Desmin ; Female ; Humans ; Keratins ; Magnetic Resonance Imaging ; Muscle, Smooth ; Necrosis ; S100 Proteins ; Tubulin

We describe a 69-year-old woman who presented with a dedifferentiated extraskeletal myxoid chondrosarcoma arising in the left masticator space. Computed tomography and magnetic resonance imaging revealed a 5 cm sized mass in the left masticator space. Histologically, the tumor consisted of two distinct areas. The less cellular area was a low-grade extraskeletal myxoid chondrosarcoma, composed of strands or cords of uniform spindle cells and abundant myxoid stroma. The more cellular, dedifferentiated area corresponded to a high grade myxofibrosarcoma, consisting of anaplastic tumor cells in myxoid stroma and geographic necrosis. The tumor cells of the former area were positive for S-100 protein, microtubule-associated protein-2 (MAP-2) and class III beta-tubulin, but negative for cytokeratin, smooth muscle actin, and desmin. The tumor cells in the latter, pleomorphic area showed MAP-2 and beta-tubulin immunoreactivity with a high Ki-67 labeling index. Based on its histologic and immunohistochemical features, the tumor was considered a dedifferentiated extraskeletal myxoid chondrosarcoma.
Actins ; Aged ; Cell Dedifferentiation ; Chondrosarcoma ; Desmin ; Female ; Humans ; Keratins ; Magnetic Resonance Imaging ; Muscle, Smooth ; Necrosis ; S100 Proteins ; Tubulin

OBJECTIVETo investigate the surface markers of adipose-derived stromal cells (ASCs) with high potential of adipogenic differentiation for increasing efficiency of adipose tissue engineering with selected seeds cells.

METHODSASCs were harvested from human adipose tissue by collagenase digestion. After proliferation and adipogenic induction of ASCs, the mature induced adipocytes floating in the induction medium were collected. Ceiling culture was used to culture adipocytes and then dedifferentiated adipocytes was obtained at the ceiling. The reproductive activity, adipogenic differentiation potency and expression of surface markers were compared between the dedifferentiated adipocytes and ASCs.

RESULTSThe reproductive activity between the dedifferentiation adipocytes and ASCs were similar. The potential of adipogenic differentiation of the dedifferentiated adipocytes was stronger than that of the ASCs. The expression of cell surface markers of both cells were almost the same. But the CD54 positive expression in dedifferentiated adipocytes was higher than that in ASCs.

CONCLUSIONThe CD54 expression maybe closely associated with high potential of adipogenic differentiation of dedifferentiated adipocytes. CU54 maybe the specific identification of cell surface marker of ASCs with high adipogenic differentiation.

Adipocytes ; cytology ; Adipose Tissue ; cytology ; Antigens, Surface ; Cell Culture Techniques ; Cell Dedifferentiation ; Cell Differentiation ; Cells, Cultured ; Humans ; Stromal Cells ; cytology ; Tissue Engineering ; methods

OBJECTIVETo explore the dedifferentiation phenomenon of human mature adipocytes cultured in vitro and to discuss the possibility of using dedifferentiation adipocytes (DA) as seed cells.

METHODSMature adipocytes and ASCs were harvested from human fat aspirates. Mature adipocytes were cultured and induced to DA by ceiling adherent culture method. Cell morphology were observed during the whole process. Viabilities of DA and ASCs were compared by MTT chromatometry and cell growth curves were drawn based on it. Cell surface markers of DA and ASCs were detected by flow cytometry. The adipogenic, osteogenic and chondrogenic ability of DA and ASCs were assessed by oil red O staining, alizarin bordeaux staining and alcian blue staining, respectively.

RESULTSHuman mature adipocytes can dedifferentiate into fibroblast-shaped DA. MTT chromatometry assay demonstrated that DA and ASCs both had strong reproductive activity, with no significant difference between them. Flow cytometry assay demonstrated that both DA and ASCs expressed HLA-ABC, CD29 and CD44, while didn't express CD45, CD34 and CD106. After two weeks of adipogenic differentiation, lipid droplets could be displayed by oil red O staining in both DA and ASCs. After two weeks of osteogenic differentiation, calcium salts mineralization in DA and ASCs could be detected by alizarin bordeaux staining. After two weeks of chondrogenic differentiation, matrix of cartilage cells in DA and ASCs could be detected by alcian blue staining.

CONCLUSIONSMature adipocytes can be dedifferentiated into DA in vitro. DA has strong reproductive activity, as well as osteogenic, chondrogenic ability and strong adipogenic ability. It expresses some of the stem cell-related cell surface proteins and is a promising seed cell for adipose tissue engineering.

Adipocytes ; cytology ; Adipose Tissue ; cytology ; Adolescent ; Adult ; Cell Culture Techniques ; Cell Dedifferentiation ; Cells, Cultured ; Female ; Humans ; Male ; Stem Cells ; cytology ; Young Adult

Myelinated Schwann cells in the peripheral nervous system express the p75 nerve growth factor receptor (p75NGFR) as a consequence of Schwann cell dedifferentiation during Wallerian degeneration. p75NGFR has been implicated in the remyelination of regenerating nerves. Although many studies have shown various mechanisms underlying Schwann cell dedifferentiation, the molecular mechanism contributing to the re-expression of p75NGFR in differentiated Schwann cells is largely unknown. In the present study, we found that lysosomes were transiently activated in Schwann cells after nerve injury and that the inhibition of lysosomal activation by chloroquine or lysosomal acidification inhibitors prevented p75NGFR expression at the mRNA transcriptional level in an ex vivo Wallerian degeneration model. Lysosomal acidification inhibitors suppressed demyelination, but not axonal degeneration, thereby suggesting that demyelination mediated by lysosomes may be an important signal for inducing p75NGFR expression. Tumor necrosis factor-alpha (TNF-alpha) has been suggested to be involved in regulating p75NGFR expression in Schwann cells. In this study, we found that removing TNF-alpha in vivo did not significantly suppress the induction of both lysosomes and p75NGFR. Thus, these findings suggest that lysosomal activation is tightly correlated with the induction of p75NGFR in demyelinating Schwann cells during Wallerian degeneration.
Axons ; Cell Dedifferentiation ; Chloroquine ; Demyelinating Diseases ; Lysosomes ; Myelin Sheath ; Nerve Growth Factor ; Peripheral Nervous System ; RNA, Messenger ; Schwann Cells ; Tumor Necrosis Factor-alpha ; Wallerian Degeneration