2α-Substituted Vitamin D Derivatives Effectively Enhance the Osteoblast Differentiation of Dedifferentiated Fat Cells.

The active form of vitamin D3, 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3], is a principal regulator of calcium homeostasis through activation of the vitamin D receptor (VDR). Previous studies have shown that 2α-(3-hydroxypropyl)-1,25D3 (O1C3) and 2α-(3-hydroxypropoxy)-1,25D3 (O2C3), vitamin D derivatives resistant to inactivation enzymes, can activate VDR, induce leukemic cell differentiation, and increase blood calcium levels in rats more effectively than 1,25(OH)2D3. In this study, to further investigate the usefulness of 2α-substituted vitamin D derivatives, we examined the effects of O2C3, O1C3, and their derivatives on VDR activity in cells and mouse tissues and on osteoblast differentiation of dedifferentiated fat (DFAT) cells, a cell type with potential therapeutic application in regenerative medicine. In cell culture experiments using kidney-derived HEK293 cells, intestinal mucosa-derived CaCO2 cells, and osteoblast-derived MG63 cells, and in mouse experiments, O2C2, O2C3, O1C3, and O1C4 had a weaker effect than or equivalent effect to 1,25(OH)2D3 in VDR transactivation and induction of the VDR target gene CYP24A1, but they enhanced osteoblast differentiation in DFAT cells equally to or more effectively than 1,25(OH)2D3. In long-term treatment with the compound without the medium change (7 days), the derivatives enhanced osteoblast differentiation more effectively than 1,25(OH)2D3. O2C3 and O1C3 were more stable than 1,25(OH)2D3 in DFAT cell culture. These results indicate that 2α-substituted vitamin D derivatives, such as inactivation-resistant O2C3 and O1C3, are more effective than 1,25(OH)2D3 in osteoblast differentiation of DFAT cells, suggesting potential roles in regenerative medicine with DFAT cells and other multipotent cells.

Therapeutic potential of dedifferentiated fat cells in a rat model of osteoarthritis of the knee.

Introduction: Mature adipocyte-derived dedifferentiated fat cells (DFATs) represent a subtype of multipotent cells that exhibit comparable phenotypic and functional characteristics to adipose-derived stem cells (ASCs). In this study, we assessed the chondroprotective properties of intra-articularly administrated DFATs in a rat model of osteoarthritis (OA). We also investigated in vitro the expression of anti-inflammatory and chondroprotective genes in DFATs prepared from the infrapatellar fat pad (IFP) and subcutaneous adipose-tissue (SC) of human origin. Methods: In the cell transplantation experiment, rats were assigned to the DFAT and Control group (n = 10 in each group) and underwent anterior cruciate ligament transection (ACLT) accompanied by medial meniscus resection (MMx) to induce OA. One week later, they received intra-articular injections of 1 × 106 DFATs (DFAT group) or PBS (control group) four times, with a weekly administration frequency. Macroscopic and microscopic evaluations were conducted five weeks post-surgery. In the in vitro experiments. DFATs derived from the IFP (IFP-DFATs) and SC (SC-DFATs) were prepared from donor-matched tissue samples (n = 3). The gene expression of PTGS2, TNFAIP6, PRG4, BMP2, and BMP6 under TNF-α or IFN-γ stimulation in these cells was evaluated using RT-PCR. Furthermore, the effect of co-culturing synovial fibroblasts with DFATs on the gene expression of ADAMTS4 and IL-6 were evaluated. Results: Intra-articular injections of DFATs significantly inhibited cartilage degeneration in the rat OA model induced by ACLT and MMx. RT-PCR analysis revealed that both IFP-DFATs and SC-DFATs upregulated the expression of genes involved in immune regulation, anti-inflammation, and cartilage protection such as PTGS2, TNFAIP6, and BMP2, under stimulation by inflammatory cytokines. Co-culture with DFATs suppressed the expression of ADAMTS4 and IL6 in synovial fibroblasts. Conclusions: The intra-articular injection of DFATs resulted in chondroprotective effects in the rat OA model. Both SC-DFATs and IFP-DFATs induced the expression of anti-inflammatory and chondroprotective genes in vitro. These results indicate that DFATs appear to possess therapeutic potential in inhibiting cartilage degradation and could serve as a promising cellular resource for OA treatment.

Breast Lipofilling: Is the Bra Really Full? Clinical Bra Pressure Measurement and In Vitro Testing of Processed and Unprocessed Fat Cells.

BACKGROUND: Breast lipofilling, a popular cosmetic and reconstructive procedure, involves the transplantation of autologous fat to enhance breast volume and contour. Despite its widespread use, cell processing and the aftertreatment remain controversial. This study investigates the pressure applied by a compression bra and reports in vitro stress tests of processed and unprocessed fat cells. METHODS: Clinical bra pressure measurements were conducted on a cohort of 45 patients following lipofilling, reduction mammoplasties and DIEP flaps. Laboratory analysis included cell vitality testing using Resazurin assays of processed and unprocessed fat cells after exposure to mechanical or hyperbaric pressure. RESULTS: Our findings show a mean overall pressure value of the compression bra for all patients of 6.7 ± 5.7 mmHg (range 0-35). Cell processing is superior to sedimentation only regarding fat cell vitality. However, neither mechanical pressure within the specified range nor hyperbaric oxygen exposure significantly affected fat graft survival as measured by Resazurin assays. CONCLUSION: The in vitro measurements showed that it was impossible to harm fat cells with external pressure during lipofilling procedures, regardless of their processing. In the clinical context, the compression bra applied pressure values deceeding the perfusion pressure and may therefore not diminish oxygen supply nor harm the transplanted cells. Therefore, we recommend the use of a compression bra for all lipofilling procedures around the breast. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266.

Effects of aerobic, resistance, and high-intensity interval training on thermogenic gene expression in white adipose tissue in high fat diet induced obese mice.

OBJECTIVE: Global prevalence of obesity has continued to rise and poses public health concerns. Current anti-obesity medications are mainly focused on suppressing appetite. Thermogenic fat cells that increase energy expenditure may be a promising alternative target to combat obesity. Our study aims to investigate the effects of aerobic, resistance, and high-intensity interval training on thermogenic gene expression in white adipose tissue in high fat diet induced obese mice. METHODS: Fifty 6-week-old male C57BL/6 mice were initially divided into control group and high fat diet group for obesity induction. After 8 weeks of obesity induction, obese mice were subdivided into sedentary, aerobic exercise, resistance exercise, and high intensity interval training groups. Trained obese mice were submitted to 8 weeks of exercise. RESULTS: Our results showed that all three exercises significantly decreased body weight, and improved metabolic profiles including glucose tolerance, total cholesterol, and low-density lipoprotein cholesterol. Moreover, aerobic exercise training increases serum irisin levels and thermogenic gene expressions such as Prdm16, Cidea, and Pgc-1α in epididymal white adipose tissue of obese mice. CONCLUSION: Our findings suggest that when it comes to the adaption of thermogenic fat cells, the modality of exercise should be taken into consideration. Aerobic exercise may induce a modest increase in the expression levels of certain thermogenic genes in epididymal white adipose tissue.

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.

Icariin has the potential to induce the differentiation of bone marrow mesenchymal stem cells into brown fat cells via PDE5A inhibition.

Background: Bone marrow mesenchymal stem cells (BMMSCs) possess the ability of adipogenic differentiation. Icariin (ICA) is a prenylated flavonol glycoside with diverse pharmacological activities and has been reported to promote osteogenic differentiation of BMMSCs. Nevertheless, the effects of ICA on BMMSC adipogenic differentiation into brown fat cells are still unclear. This study aimed to explore the effects and mechanistic basis of ICA on the differentiation of BMMSCs into brown fat cells. Methods: Oil Red-O staining assay was applied to detect the adipogenic differentiation of BMMSCs after induction. RT-qPCR and Western blot were conducted to detect the expression of lipogenic markers PPARγ and FABP4 as well as the brown fat biomarkers BMP7, PGC-1α, and UCP1 in BMMSCs. Moreover, phosphodiesterase-5A (PDE5A) expression in BMMSCs treated with ICA was measured by RT-qPCR and Western blot. Results: ICA promoted the adipogenic differentiation of BMMSCs and increased the expression levels of lipogenic markers PPARγ and FABP4 and the brown fat biomarkers BMP7, PGC-1α, and UCP1 during the adipogenic differentiation of BMMSCs. Furthermore, PDE5A was identified as a target of ICA, and its expression was reduced by ICA treatment. Moreover, PDE5A inhibition enhanced BMP7, PGC-1α, and UCP1 levels in BMMSCs. Additionally, overexpression of PDE5A notably reversed the effects of ICA in the differentiation of BMMSCs into brown fat cells. Conclusion: ICA induces the differentiation of BMMSCs into brown fat cells via PDE5A inhibition, highlighting the therapeutic value of ICA for treating obesity-related diseases.

DFATs derived from infrapatellar fat pad hold advantage on chondrogenesis and adipogenesis to evade age mediated influence.

Background: Dedifferentiated fat cells (DFATs) are highly homogeneous and multipotent compared with adipose-derived stromal cells (SCs). Infrapatellar fat pad (IFP)-SCs have advanced chondrogenic potency; however, whether IFP-DFATs could serve as better cell material remains unclear. Here, we aimed to examine the influence of age and body mass index (BMI) on the features of IFPs and IFP-derived cells (IFP-SCs and IFP-DFATs) with exploration of the clinical utilization of IFP-DFATs. Methods: We collected IFPs with isolation of paired IFP-SCs and IFP-DFATs from individuals aged 65 years and older with distinct body weights who underwent total knee replacement for osteoarthritis (OA). Flow cytometry was used to characterize the cellular immunophenotypes. Adipogenesis and chondrogenesis were performed in vitro. Real-time qPCR, western blotting, and Oil Red O or Alcian blue staining were performed to evaluate inflammation, adipogenesis, and chondrogenesis. RNA sequencing and Seahorse analyses were conducted to explore the underlying mechanisms. Results: We found that IFPs from old or normal-weight individuals with knee OA were pro-inflammatory, and that interleukin-6 (IL-6) signaling was associated with multiple immune-related molecules, whereas IFP-derived cells could escape the inflammatory properties. Aging plays an important role in diminishing the chondrogenic and adipogenic abilities of IFP-SCs; however, this effect was avoided in IFP-DFATs. Generally, IFP-DFATs presented a steady state of chondrogenesis (less influenced by age) and consistently enhanced adipogenesis compared to paired IFP-SCs in different age or BMI groups. RNA sequencing and Seahorse analysis suggested that the downregulation of eukaryotic initiation factor 2 (EIF2) signaling and enhanced mitochondrial function may contribute to the improved cellular biology of IFP-DFATs. Conclusions: Our data indicate that IFP-DFATs are superior cell material compared to IFP-SCs for cartilage differentiation and adipogenesis, particularly in advanced aging patients with knee OA. The translational potential of this article: These results provide a novel concept and supportive evidence for the use of IFP-DFATs for cell therapy or tissue engineering in patients with knee OA. Using Ingenuity Pathway Analysis (IPA) of RNA-seq data and Seahorse analysis of mitochondrial metabolic parameters, we highlighted that some molecules, signaling pathways, and mitochondrial functions are likely to be jointly coordinated to determine the enhanced biological function in IFP-DFATs.

Dedifferentiated fat cells: current applications and future directions in regenerative medicine.

Stem cell therapy is the most promising treatment option for regenerative medicine. Therapeutic effect of different stem cells has been verified in various disease model. Dedifferentiated fat (DFAT) cells, derived from mature adipocytes, are induced pluripotent stem cells. Compared with ASCs and other stem cells, the DFAT cells have unique advantageous characteristics in their abundant sources, high homogeneity, easily harvest and low immunogenicity. The DFAT cells have shown great potential in tissue engineering and regenerative medicine for the treatment of clinical problems such as cardiac and kidney diseases, autoimmune disease, soft and hard tissue defect. In this review, we summarize the current understanding of DFAT cell properties and focus on the relevant practical applications of DFAT cells in cell therapy in recent years.

Low-Intensity Pulsed Ultrasound Promotes BMP9 Induced Osteoblastic Differentiation in Rat Dedifferentiated Fat Cells.

Dedifferentiated fat cells (DFATs) isolated from mature adipocytes have a multilineage differentiation capacity similar to mesenchymal stem cells and are considered as promising source of cells for tissue engineering. Bone morphogenetic protein 9 (BMP9) and low-intensity pulsed ultrasound (LIPUS) have been reported to stimulate bone formation both in vitro and in vivo. However, the combined effect of BMP9 and LIPUS on osteoblastic differentiation of DFATs has not been studied. After preparing DFATs from mature adipose tissue from rats, DFATs were treated with different doses of BMP9 and/or LIPUS. The effects on osteoblastic differentiation were assessed by changes in alkaline phosphatase (ALP) activity, mineralization/calcium deposition, and expression of bone related genes; Runx2, osterix, osteopontin. No significant differences for ALP activity, mineralization deposition, as well as expression for bone related genes were observed by LIPUS treatment alone while treatment with BMP9 induced osteoblastic differentiation of DFATs in a dose dependent manner. Further, co-treatment with BMP9 and LIPUS significantly increased osteoblastic differentiation of DFATs compared to those treated with BMP9 alone. In addition, upregulation for BMP9-receptor genes was observed by LIPUS treatment. Indomethacin, an inhibitor of prostaglandin synthesis, significantly inhibited the synergistic effect of BMP9 and LIPUS co-stimulation on osteoblastic differentiation of DFATs. LIPUS promotes BMP9 induced osteoblastic differentiation of DFATs in vitro and prostaglandins may be involved in this mechanism.

Intraosseous Hibernoma: A Rare Entity in Orthopedics With Peculiar Radiological Features.

Intraosseous hibernoma is a rare benign bone tumor derived from brown fat. It is typically found in the axial skeleton and is more commonly observed in women. It can manifest as a painful lesion or may be incidentally discovered. Intraosseous hibernoma often presents as a sclerotic lesion, although it can also manifest as a lytic lesion. Due to its varied radiographic appearance, it should be considered in the differential diagnosis of bone lesions as it can mimic metastatic lesions as well as other sclerotic and lytic bone lesions. Therefore, obtaining a biopsy of the lesion is crucial for an accurate diagnosis. In this report, we present the clinical, radiological, and histopathological findings of two cases of intraosseous hibernoma and provide a concise overview based on a review of the literature.

Immunomodulatory effect of human dedifferentiated fat cells: comparison with adipose-derived stem cells.

Dedifferentiated fat cells (DFATs), which are originated by the dedifferentiation of adipocytes, display surface markers of mesenchymal stem cells and are able to differentiate into different cell types, thus, yielding a huge therapeutic potential in repairing damaged tissues and organs. The use of allogeneic stem cells from healthy donors constitutes the basis of a new strategy for cell therapy in the field of transplantation and the first requirement for allografts is determining their immunological properties. In this study, human DFATs and ADSCs were passaged as in vitro models to investigate their immunomodulatory effects. Phenotypic analysis of cell surface markers and three-line differentiation protocols were used to identify stem cells. The immunogenic phenotypes of DFATs and ADSCs were analyzed by flow cytometry and a mixed lymphocyte reaction was used to assess their immune function. The characteristics of stem cells were confirmed by phenotypic identification of cell surface markers and three-line differentiation. Flow cytometry analysis showed that P3 generation DFATs and ADSCs contained human leukocyte antigen (HLA) class I molecules, but did not express HLA class II molecules and costimulatory molecules CD40, CD80 and CD86. Moreover, allogeneic DFATs and ADSCs could not induce the proliferation of peripheral blood mononuclear cells (PBMCs). In addition, both populations were shown to inhibit the Concanavalin A-stimulated proliferation of PBMCs and act as third-party cells responsible for inhibiting the mixed lymphocyte response. DFATs have immunosuppressive properties similar to ADSCs. Based on this, allogeneic DFATs have potential applications in tissue repair or cell therapy.

Automated image analysis method to detect and quantify fat cell infiltration in hematoxylin and eosin stained human pancreas histology images.

Fatty infiltration in pancreas leading to steatosis is a major risk factor in pancreas transplantation. Hematoxylin and eosin (H and E) is one of the common histological staining techniques that provides information on the tissue cytoarchitecture. Adipose (fat) cells accumulation in pancreas has been shown to impact beta cell survival, its endocrine function and pancreatic steatosis and can cause non-alcoholic fatty pancreas disease (NAFPD). The current automated tools (E.g. Adiposoft) available for fat analysis are suited for white fat tissue which is homogeneous and easier to segment unlike heterogeneous tissues such as pancreas where fat cells continue to play critical physiopathological functions. The currently, available pancreas segmentation tool focuses on endocrine islet segmentation based on cell nuclei detection for diagnosis of pancreatic cancer. In the current study, we present a fat quantifying tool, Fatquant, which identifies fat cells in heterogeneous H and E tissue sections with reference to diameter of fat cell. Using histological images from a public database, we observed an intersection over union of 0.797 to 0.962 and 0.675 to 0.937 for manual versus Fatquant analysis of pancreas and liver, respectively.

Bone marrow-derived dedifferentiated fat cells exhibit similar phenotype as bone marrow mesenchymal stem cells with high osteogenic differentiation and bone regeneration ability.

BACKGROUND: Mesenchymal stem cells (MSCs) are known to have different differentiation potential depending on the tissue of origin. Dedifferentiated fat cells (DFATs) are MSC-like multipotent cells that can be prepared from mature adipocytes by ceiling culture method. It is still unknown whether DFATs derived from adipocytes in different tissue showed different phenotype and functional properties. In the present study, we prepared bone marrow (BM)-derived DFATs (BM-DFATs), BM-MSCs, subcutaneous (SC) adipose tissue-derived DFATs (SC-DFATs), and adipose tissue-derived stem cells (ASCs) from donor-matched tissue samples. Then, we compared their phenotypes and multilineage differentiation potential in vitro. We also evaluated in vivo bone regeneration ability of these cells using a mouse femoral fracture model. METHODS: BM-DFATs, SC-DFATs, BM-MSCs, and ASCs were prepared from tissue samples of knee osteoarthritis patients who received total knee arthroplasty. Cell surface antigens, gene expression profile, and in vitro differentiation capacity of these cells were determined. In vivo bone regenerative ability of these cells was evaluated by micro-computed tomography imaging at 28 days after local injection of the cells with peptide hydrogel (PHG) in the femoral fracture model in severe combined immunodeficiency mice. RESULTS: BM-DFATs were successfully generated at similar efficiency as SC-DFATs. Cell surface antigen and gene expression profiles of BM-DFATs were similar to those of BM-MSCs, whereas these profiles of SC-DFATs were similar to those of ASCs. In vitro differentiation analysis revealed that BM-DFATs and BM-MSCs had higher differentiation tendency toward osteoblasts and lower differentiation tendency toward adipocytes compared to SC-DFATs and ASCs. Transplantation of BM-DFATs and BM-MSCs with PHG enhanced bone mineral density at the injection sites compared to PHG alone in the mouse femoral fracture model. CONCLUSIONS: We showed that phenotypic characteristics of BM-DFATs were similar to those of BM-MSCs. BM-DFATs exhibited higher osteogenic differentiation potential and bone regenerative ability compared to SC-DFATs and ASCs. These results suggest that BM-DFATs may be suitable sources of cell-based therapies for patients with nonunion bone fracture.

Obese mouse fat cell-derived extracellular vesicles transport miR-99a-5p to mitigate the proliferation and migration of non-small cell lung cancer cells.

OBJECTIVE: Fat cells-derived extracellular vesicles (FC-EVs) play a role in regulating the tumor microenvironment in cancers by transporting RNAs. MicroRNAs (miRNAs) are vital regulators of cancer development. This study was conducted to explore the role of FC-EVs in the proliferation and migration of non-small cell lung cancer (NSCLC) cells, providing targets for NSCLC treatment. METHODS: The obese mouse model was established via high-fat diet (HFD), followed by separation and characterization of FC-EVs (HFD-EVs). The levels of miR-99a-5p, precursor-miR-99a-5p, and heparan sulfate-glucosamine 3-sulfotransferase 3B1 (HS3ST3B1) were measured by RT-qPCR or Western blot assay. Cell proliferation and migration were evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and wound healing assays. The expression of Cy3-labeled miR-99a-5p in A549 cells (one NSCLC cell line) was observed via confocal microscopy. The binding of miR-99a-5p to HS3ST3B1 was analyzed by the dual luciferase assay. Rescue experiments were performed to confirm the role of HS3ST3B1 in NSCLC cells. RESULTS: miR-99a-5p was upregulated in adipose tissues, FCs, and HFD-EVs. HFD-EVs mitigated the proliferation and migration of NSCLC cells. HFD-EVs transported miR-99a-5p into A549 cells, which upregulated miR-99a-5p expression and inhibited HS3ST3B1 expression in A549 cells. HS3ST3B1 overexpression reversed the inhibition of HFD-EVs on the proliferation and migration of NSCLC cells. CONCLUSION: HFD-EVs transported miR-99a-5p into NSCLC cells and inhibited HS3ST3B1, thereby inhibiting proliferation and migration of NSCLC cells.

[Fat tissue as the primary target organ of insulin resistance in diabetes mellitus.] / A zsírszövet mint a 2-es típusú diabetest kíséro inzulinrezisztencia egyik célszerve.

Insulin resistance is a pathological condition in which the effect of endogenous or externally administered (exogenous) insulin to promote tissue glucose uptake and utilization falls short of that observed in metabolically healthy individuals. It affects the entire organism, but the pathogenetic and underlying molecular biological processes of its selected target tissues - the liver, muscle and adipose tissue - are partially different. Recently, knowledge about the role of adipose tissue has expanded significantly, and it increasingly seems that dysfunctional adipose tissue is the central player in these pathological events. The manuscript reviews the structure of adipose tissue, the regulation of adipogenesis and lipolysis, data on the relationship between the microbiome and adipose tissue, the typical differences of the acute and chronic insulin resistance as well as the therapeutic tools currently available to reduce adipose tissue insulin resistance. It may well be that a molecule with a selective adipose tissue attack point and enabling safe long-term use in humans is not yet within the hoped-for proximity, the first animal experimental observations related to the first "adipeuticum" being under development outline the promise of a new treatment option. Orv Hetil. 2023; 164(1): 3-10.

A Review of Structural Features, Biological Functions and Biotransformation Studies in Adipose Tissues and an Assessment of Progress and Implications.

Roles for adipose tissues in energy metabolism, health maintenance and disease onset have been established. Evidence indicates that white, brown and beige fats are quite different in terms of their cellular origin and biological characteristics. These differences are significant in targeting adipocytes to study the pathogenesis and prevention strategies of related diseases. The biotransformations of white, brown and beige fat cells constitute an intriguing topic worthy of further study, and the molecular mechanisms underlying the biotransformations of white, brown and beige fat cells remain to be elucidated. Hence, we herein collected evidence from studies on adipose tissue or adipocytes, and we extracted the structural features, biologic functions, and biotransformations of adipose tissue/adipocytes. The present review aimed to summarize the latest research progress and propose novel research directions with respect to adipose tissue and adipocytes. We posit that this work will provide new insights and opportunities in the effective treatment strategies for obesity, diabetes and other lipid-related diseases. It will also contribute to our knowledge of the basic biologic underpinnings of adipocyte biology.

Comparison of the yields and properties of dedifferentiated fat cells and mesenchymal stem cells derived from infrapatellar fat pads.

Introduction: Infrapatellar fat pad (IFP)-derived mesenchymal stem cells (MSCs) have high chondrogenic potential and are attractive cell sources for cartilage regeneration. During ceiling culture to acquire the characteristics of MSCs, mature adipocytes from fat tissue are known to undergo dedifferentiation, generating dedifferentiated fat (DFAT) cells. The purpose of the present study was to compare the yields and biological properties of IFP-derived MSCs and IFP-derived DFAT cells. Methods: IFPs were harvested from the knees of 8 osteoarthritis (OA) patients. DFAT cells were obtained using a ceiling culture of adipocytes isolated from the floating top layer of IFP digestion. MSCs were obtained by culturing precipitated stromal vascular fraction cells. We compared the P0 cell yields, surface antigen profile, colony formation ability, and multipotency of DFAT cells and MSCs. Results: The P0 cell yields per flask and the estimated total cell yields from 1 g of IFP were much greater for MSCs than for DFAT cells. Both MSCs and DFAT cells were positive for MSC markers. No obvious difference was observed in colony formation ability. In differentiation assays, DFAT cells produced greater amounts of lipid droplets, calcified tissue, and glycosaminoglycan than MSCs did. Adipogenic and chondrogenic gene expressions were upregulated in DFAT cells. Conclusions: IFP-derived DFAT cells showed higher adipogenic and chondrogenic potentials than IFP-derived MSCs, but they had a poor cell yield.

Adipose tissue in bone regeneration - stem cell source and beyond.

Adipose tissue (AT) is recognized as a complex organ involved in major home-ostatic 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 pluripotent-like 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.

Comparative study of dedifferentiated fat cell and adipose-derived stromal cell sheets for periodontal tissue regeneration: In vivo and in vitro evidence.

AIM: To compare the efficacy of adipocyte-derived dedifferentiated fat (DFAT) cell and adipose-derived stromal cell (ADSC) sheets for regenerative treatment of intra-bony periodontal defects. MATERIALS AND METHODS: DFAT cells were obtained using the ceiling culture method and were compared with ADSCs using Cell Counting Kit-8, colony formation assay, surface antigen identification, and multilineage differentiation assays. DFAT and ADSC sheets were prepared in a cell sheet culture medium. The biological characteristics of DFAT cell and ADSC sheets were compared using haematoxylin and eosin staining, quantitative reverse transcription polymerase chain reaction, and immunofluorescence staining. Micro-computed tomography and histological staining were used to compare the effects of the two cell sheets on the repair of periodontal intra-bony defects in rats. RESULTS: DFAT cells and ADSCs demonstrated mesenchymal stem cell characteristics. Both cell types were CD29-, CD90-, and CD146-positive and CD31-, CD34-, and CD45-negative. DFAT cells and ADSCs exhibited similar osteogenic and adipogenic differentiation capabilities and colony formation ability. DFAT cells displayed stronger proliferation capabilities compared with ADSCs. Compared with the ADSC sheets, DFAT cell sheets exhibited a higher expression of periodontal-related genes and proteins and greater ability to regenerate periodontal tissue. CONCLUSIONS: Our findings suggest that DFAT cell sheets are an ideal seed cell source and form of cell delivery for periodontal intra-bony defects.

Intraosseous Lipoma: A Report of a Case in the Mandibular Symphysis Region.

Intraosseous lipomas are benign lesions of the bone. In the jaws, they are very rare and in most cases incidentally discovered on panoramic radiographs taken in dental practice. They are usually asymptomatic and appear radiologically as a radiolucent image sometimes including some radio-opacities. Histologically, they consist of mature adipose tissue associated with variable degrees of necrotic fat and calcification. In this report, we describe a case of intraosseous lipoma in the mandibular symphysis region of a 37-year-old female as well as the treatment adopted.