Research progress on dedifferentiated fat cells and their application in oral and maxillofacial bone tissue engineering / 口腔疾病防治

@#The identification of suitable seed cells represents a critical scientific problem to be solved in the field of oral and maxillofacial bone tissue regeneration. The application of adipose-derived stem cells (ASCs) in tissue and organ repair and regeneration has been studied extensively. In recent years, dedifferentiated fat (DFAT) cells have also shown broad application prospects in the field of bone tissue engineering. DFAT cells express stem cell-related markers and have the potential to differentiate into adipocytes, osteoblasts, chondrocytes, nerve cells, cardiomyocytes and endothelial cells. In addition, DFAT cells also have the advantages of minimally invasive acquisition, strong proliferation and high homogeneity. Currently, all studies involving the application of DFAT cells in scaffold-based and scaffold-free bone tissue engineering can confirm their effectiveness in promoting bone regeneration. However, cytological research still faces some challenges, including relatively low cell culture purity, unclear phenotypic characteristics and undefined dedifferentiation mechanisms. It is believed that with the continuous development and improvement of isolation, culture, identification and directional induction of osteogenic differentiation methods, DFAT cells are expected to become excellent seed cells in the field of oral and maxillofacial bone tissue engineering in the future.

Vitamin C enhanced myocardial differentiation of dedifferentiated fat cells / 中国病理生理杂志

[ ABSTRACT] AIM:In order to observe the myocardial differentiation capacity of the dedifferentiated fat ( DFAT) cells treated with vitamin C in vitro.METHODS: DFAT cells were dedifferentiated from the mature rat adipocytes with ceiling adherent culture.The DFAT cells of passage 3 were used in the study.Vitamin C and/or neonatal rat heart tissue lysate were added into the culture medium to induce myocardial differentiation for 3 weeks.The cell morphology was ob-served under microscope.The myocardial-specific markers, such as cTnT, GATA-4 and NKx2.5, were examined by the methods of immunofluorescence, PCR and Western blot.RESULTS:Mature rat adipocytes dedifferentiated into fibroblast-like DFAT cells after ceiling adherent culture.The DFAT cells spontaneously differentiated into cardiomyocyte-like cells under normal culture condition with a low incidence.After treated with neonatal rat heart cell lysate, the DFAT cells be-came cardiomyocyte-like cells that had bigger size, longer shape and myotubule-structure.The expression of cTnT, GATA-4 and NKx2.5 was remarkably increased at both mRNA and protein levels as compared with the normal cultured DFAT cells.The expression of cTnT, GATA-4 and NKx2.5 was further increased in DFAT cells after treating with vitamin C.No spontaneous beating cell was observed.CONCLUSION:Vitamin C enhances the differentiation of DFAT cells into cardio-myocyte-like cells.

Alcohol affects the femoral head intramedullary adipocytes / 中国组织工程研究

BACKGROUND:Alcohol has become pathogenic factors of avascular necrosis, and the alcohol induced abnormal lipid metabolism in bone marrow may be the important reason for the onset of avascular necrosis, but the mechanism is not clear yet. OBJECTIVE:To observe the changes of structure and function of fat cel s under the action of alcohol, in order to analyze the pathogenesis of alcoholic femoral head necrosis. METHODS:Primary adipocytes in vitro culture technique was used to obtain rabbit femoral head intramedul ary adipose tissue, and then the fat cel s were separated, and the phenotype was identified with oil red O staining. The passaged stable intramedul ary fat cel s were col ected. Coverslip was cut into 1 cm × 1 cm in size, and placed in the 24-wel culture plate before planting. The cel s were randomly divided into alcohol group and control group, 24 holes (each hole for a sample) in each group. The control group was without alcohol, while the alcohol group was added with 0.15 mol/L alcohol. At 4, 6, 8 and 10 days, the culture medium was replaced. Medium was changed and no longer adding alcohol, and then cultured for 10 days. When the culture terminated, the coverslip was removed for oil red O staining. Final y, the morphology and the number of the fat cel s were observed under light microscope. RESUTLS AND CONCLUSION:With time prolonging, the number of fat cel s in the alcohol group was significantly more than that in the control group (Pnumber of intramedul ary fat cel s in the control group was respectively (99.80±10.82), (0.40±94.71), (1 000.20± 41.85) and (1 059.80±26.79)/cm2, the number of fat cel s increased with the time of alcohol influence. Alcohol can promote the intramedul ary fat cel s to increase and enlarge, and this may be the main reason for femoral head necrosis, as long-term alcoholism can lead to bone marrow fat tissue increasing, intraosseous pressure increasing and perfusion reducing, thus resulting ischemia.

Viability of Cells in Aspirated Fat Tissue after 1 Year Cryopreservation

PURPOSE: The use of an autogenous fat graft has become a common procedure in plastic surgery. However, questions remain concerning on the viability of fat cells and preservation method of aspirated fat. The purpose of this study is to examine the viability of fat cells stored at -20degrees C in the freezer for 1 year after harvest from abdominal liposuction. METHODS: Eighteen adults(aged from 24 to 65 years, 16 female and 2 male) were selected for this study. Harvested aspirated fat tissues were obtained by suction-assisted lipectomy and frozen at -20degrees C commercial refrigerator for one year(average 12.5 months). The viability of fat cells in specimens were measured after thawing. The numbers of viable cells were measured on a fluorescence microscope after staining with fluorescein diacetate and propidium iodide. GPDH(Glycerol-3-phosphate dehydrogenase) activity was measured. Cell culture was done for 3 weeks. RESULTS: There were no viable cells under the fluorescence microscope, no detectable GPDH activity, and no cultured cells. CONCLUSION: These findings suggest that aspirated fat after frozen storage for one year at -20degrees C freezer is inadequate to reuse.

Lipoma y Lipomatosis / Lipoma and Lipomatosis

Los lipomas son tumores benignos compuestos por células grasas. Ellos son los tumores mesenquimales más comunes. Se encuentran en el tejido subcutáneo y menos frecuente en órganos internos. Usualmente presentan poca dificultad de diagnóstico y morbilidad. Los lipomas típicamente se desarrollan como masas elásticas discretas en el tejido subcutáneo y tejidos blandos profundos en el adulto. Muchos signos cutáneos y algunos síndromes son anatómicamente muy complejos y pueden estar asociados con un lipoma subyacente. Recientemente un número de nuevas entidades y variantes han sido descriptas. Su reconocimiento es importante para evitar el diagnósitco fallido y terapias inapropiadas. Lipoma condroide, miolipoma y lipoma pleomórfico de células ahusadas puramente cutáneo, son neoplasias biológicamente benignas que pueden simular sarcomas morfológicamente. El advenimiento de las investigaciones moleculares y citogenéticas de las neoplasias lipomatosas tienden a contribuir más al entendimiento de la biología de aquéllas y guiar a la modificación de los esquemas de clasificación convencional.

Lipomas are benign tumors componed of mature fat cells. They are the most common benign mesenchymal tumor. Lipomas are found in the subcutaneous tissues and, less commonly, in internal organs. They usually present with little difficulty in diagnosis or morbidity. Lipomas typically develop as discrete rubbery masses in the subcutaneous tissues of the trunk and proximal extremity. Are the most common neoplasms of subcutaneous and deep soft tissues in adults. Most cutaneous signatures and someone syndromes are anatomically more complex and can associated with an underlying lipoma. In recent years a number of "new" entities and variants have been described. Their recognition is important to avoid diagnostic pitfalls and inappropriare therapy. Chondroid lipoma, myolipoma, and purely cutaneous spindle-cell/pleomorphic lipoma are biologically benign neoplasms which may mimic sarcomas morphologically. The advent of cytogenetic and molecular investigations of lipomatous neoplasms has contributed to a better understanding of the biology of these neoplasms and led to a modification of conventional classification schemes.

Experimental study on the damage to cells from fat removal and suction under negative pressures / 中华医学美学美容杂志

Objective To study the injury percentage of fat cells from human bodies by three methods and four suctioned negative pressures. Methods Fat tissue was removed from lower abdomen by excision, aspiration and suction. A pair of sharp scissors was used to cut excisied adipose tissue into 3mm diameter fat particles. A 4 mm diameter pipet and four negative pressures (-25 kPa, -50 kPa, -76 kPa and -101 kPa) were used to suction fat tissue. The samples were fixed in 10 % buffered formalin, stained with hematoxylin eosin and Wilder's silver methods. The fat cells were observed under light microscope. Results The injury percentage of fat cells removed by three methods were (8.6? 1.8) %, (15.7?2.4) % and (38.4?4.2) % respectively;all of them had significant differences among them. The injury percents of fat cells suctioned under-25 kPa,-50 kPa, -76 kPa and -101 kPa were (26.3?2.5) %, (27.6? 2.6) %, (36.8?3.5) % and (68.9?7.4) % respectively. There were no significant differences between the first two but there were among other groups. Conclusions The injury extent of fat cells has significant differences among 3 methods, in which the excision is the least and the suction is the most serious. The injury extent of fat cells has no significant differences when the pressure is lower than -25 kPa. But when the pressure is higher than -50 kPa, the higher the pressure, the more serious the injury extent.

Expression of sortilin gene on osteogenic and adipogenic differentiation in mesenchymal stem cells / 中国病理生理杂志

AIM: To characterize the gene expression of sortilin on adipogenic and osteogenic differentiation in mesenchymal stem cells (MSCs) in vitro and explore its significance.METHODS: MSCs derived from human bone marrow were isolated and cultured in vitro ,then were stimulated in osteogenic medium and adipogenic medium,respectively. Osteopontin and lipoprotein lipase were detected by RT-PCR. Sortilin expression was analyzed by semiquantitative RT-PCR. RESULTS: 1.MSCs displayed the potential of differentiation into osteoblast and adipocyte. 2.Sortilin was upregulated one day after osteogenic induction and remained upregulated for a week. The expression of sortilin was significant increased on day 3( P 0.05).CONCLUSION: Sortilin may be useful to modulate the osteogenic differentiation and may not be necessary for adipocyte commitment in MSCs. The regulation of sortilin expression may provide new protocal and strategy for the treatment of osteoporosis and osteopenic disease.