Adipose-derived Progenitor Cells Research Articles

Isolation of multipotent progenitor cells from pleura and pericardium for tracheal tissue engineering purposes.

Tissue engineering (TE) of long tracheal segments is conceptually appealing for patients with inoperable tracheal pathology. In tracheal TE, stem cells isolated from bone marrow or adipose tissue have been employed, but the ideal cell source has yet to be determined. When considering the origin of stem cells, cells isolated from a source embryonically related to the trachea may be more similar. In this study, we investigated the feasibility of isolating progenitor cells from pleura and pericard as an alternative cells source for tracheal tissue engineering. Porcine progenitor cells were isolated from pleura, pericard, trachea and adipose tissue and expanded in culture. Isolated cells were characterized by PCR, RNA sequencing, differentiation assays and cell survival assays and were compared to trachea and adipose‐derived progenitor cells. Progenitor‐like cells were successfully isolated and expanded from pericard and pleura as indicated by gene expression and functional analyses. Gene expression analysis and RNA sequencing showed a stem cell signature indicating multipotency, albeit that subtle differences between different cell sources were visible. Functional analysis revealed that these cells were able to differentiate towards chondrogenic, osteogenic and adipogenic lineages. Isolation of progenitor cells from pericard and pleura with stem cell features is feasible. Although functional differences with adipose‐derived stem cells were limited, based on their gene expression, pericard‐ and pleura‐derived stem cells may represent a superior autologous cell source for cell seeding in tracheal tissue engineering.

A Novel Fat Making Strategy With Adipose-Derived Progenitor Cell-Enriched Fat Improves Fat Graft Survival.

A low survival rate is one of the main challenges in fat grafting. This study aimed to evaluate whether microfat obtained by a novel strategy promoted the survival and retention of fat grafts. A 5-mm-diameter blunt tip cannula with large side holes (~30 mm2/hole) was used to obtain macrofat. A novel strategy based on a newly invented extracorporeal cutting device was then used to cut the macrofat into microfat, which was named adipose-derived progenitor cell enrichment fat (AER fat); Coleman fat was used as the control. Aliquots (0.5 mL) of both types of fat were transplanted into 10 nude mice and analyzed 10 weeks later. Western blotting, flow cytometry, and immunofluorescence were performed to assess the AER fat characteristics and underlying mechanisms. The retention rate of fat grafts in AER fat-treated animals was significantly higher than that in the Coleman group (mean [standard deviation] 54.6% [13%] vs 34.8% [9%]; P < 0.05) after 10 weeks. AER fat contained more dipeptidyl peptidase-4-expressing progenitor cells (3.3 [0.61] × 103 vs 2.0 [0.46] × 103 cells/mL; P < 0.05), adipose-derived plastic-adherent cells (6.0 [1.10] × 104 vs 2.6 [0.17] × 104 cells/mL; P < 0.001), and viable adipocytes than Coleman fat. Moreover, histologic analysis showed that AER fat grafts had better histologic structure and higher capillary density. AER fat transplantation is a potential strategy to improve the survival and long-term retention of fat grafts. AER fat contained more dipeptidyl peptidase-4-expressing progenitor cells.

The Efficacy of Cell-Assisted Lipotransfer Versus Conventional Lipotransfer in Breast Augmentation: A Systematic Review and Meta-Analysis

Cell-assisted lipotransfer (CAL) is novel and controversial technique for breast augmentation. This review and meta-analysis aimed to assess the clinical efficacy of CAL as compared with conventional lipotransfer. PubMed databases were searched with no restrictions for randomized controlled trials (RCTs) and observational studies with control groups. Keywords included "fat graft," "lipotransfer," "lipofilling," "autologous fat," "fat transplantation," "stromal vascular fraction (SVF)," "stem cell," "adipose tissue-derived stromal cell (ADSC)," "adipose tissue-derived stromal cell (ASC)," "called adipose derived progenitor cells (ADRC)," "cell-assisted," "progenitor-enriched," "cell-enhanced" and "breast." Review Manager software (RevMan, version 5.3) was used to compute the pooled effect estimates for fat survival rate and complication rates. Outcomes were expressed as standard mean differences (SMDs) or odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses were performed based on different methods of cell-enhanced fat preparation. Six studies were included (ntotal = 353 adult patients). The fat survival rate was significantly higher in the CAL group than in the control group (SMD = 1.79, 95% CI = 0.28, 3.31; P = 0.02). There were no significant differences in complication rates between the CAL group and the control group (OR = 1.34, 95% CI = 0.65, 2.73; P = 0.43). Subgroup analyses found no significant differences between the SVF and control groups in fat survival rate (SMD = 1.52, 95% CI = -0.21, 3.24; P = 0.08) among both manual and automatic subgroups (P = 0.28 and P = 0.10, respectively). The data analysis showed a significant heterogeneity between manual and automatic subgroups (I2 = 57.0%, P = 0.15). This study suggests that cell-assisted lipotransfer is superior to conventional lipotransfer for improved fat survival rate in breast augmentation. However, analyses comparing the SVF-enhanced fat graft with the conventional fat graft noted no differences in fat survival rate. It is necessary to determine which protocol is most beneficial for patients, establish standardized methods of SVF isolation or adipose tissue-derived stromal cells (ADSCs) culture, and a constant percentage of injected cells in the graft. The long-term efficacy and safety of CAL should also be evaluated in further studies, and additional RCTs with larger sample sizes and better comparability are needed. 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 the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Rotator Cuff Repair: A Biological Approach to Improve Outcomes

Biologic agents are increasingly being used within the field of orthoapedic surgery to treat a variety of musculoskeletal conditions. Most agents attempt to stimulate or manipulate the local cellular environment to increase the innate healing response. This is especially appealing for the management of rotator cuff disease, since most pathology is secondary to chronic, degenerative changes within the rotator cuff tendon. The most commonly used biologic agents in the management of rotator cuff disease are platelet-rich plasma, cell-based approaches using bone marrow or adipose-derived progenitor cells, and extracellular matrix “patches.” The past decade has seen a substantial increase in demand for these agents, yet data to support their use are currently limited. Physicians must remain well educated about these agents as new information becomes available. The following chapter offers background and review of the literature for the most commonly used biologic agents in the management of rotator cuff disease.

Human Osteogenic Adipose-Derived Progenitor Cells as a Source of Vascular Endothelial Growth Factor

Human Osteogenic Adipose-Derived Progenitor Cells as a Source of Vascular Endothelial Growth Factor

Noggin depletion in adipocytes promotes obesity in mice

ObjectiveObesity has increased to pandemic levels and enhanced understanding of adipose regulation is required for new treatment strategies. Although bone morphogenetic proteins (BMPs) influence adipogenesis, the effect of BMP antagonists such as Noggin is largely unknown. The aim of the study was to define the role of Noggin, an extracellular BMP inhibitor, in adipogenesis. MethodsWe generated adipose-derived progenitor cells and a mouse model with adipocyte-specific Noggin deletion using the AdiponectinCre transgenic mouse, and determined the adipose phenotype of Noggin-deficiency. ResultsOur studies showed that Noggin is expressed in progenitor cells but declines in adipocytes, possibly allowing for lipid accumulation. Correspondingly, adipocyte-specific Noggin deletion in vivo promoted age-related obesity in both genders with no change in food intake. Although the loss of Noggin caused white adipose tissue hypertrophy, and whitening and impaired function in brown adipose tissue in both genders, there were clear gender differences with the females being most affected. The females had suppressed expression of brown adipose markers and thermogenic genes including peroxisome proliferator activated receptor gamma coactivator 1 alpha (PGC1alpha) and uncoupling protein 1 (UCP1) as well as genes associated with adipogenesis and lipid metabolism. The males, on the other hand, had early changes in a few BAT markers and thermogenic genes, but the main changes were in the genes associated with adipogenesis and lipid metabolism. Further characterization revealed that both genders had reductions in VO2, VCO2, and RER, whereas females also had reduced heat production. Noggin was also reduced in diet-induced obesity in inbred mice consistent with the obesity phenotype of the Noggin-deficient mice. ConclusionsBMP signaling regulates female and male adipogenesis through different metabolic pathways. Modulation of adipose tissue metabolism by select BMP antagonists may be a strategy for long-term regulation of age-related weight gain and obesity.

Epigenetic and Transcriptome Profiling Identifies a Population of Visceral Adipose-Derived Progenitor Cells with the Potential to Differentiate into an Endocrine Pancreatic Lineage

Type 1 diabetes (T1D) is characterized by the loss of insulin-producing β-cells in the pancreas. T1D can be treated using cadaveric islet transplantation, but this therapy is severely limited by a lack of pancreas donors. To develop an alternative cell source for transplantation therapy, we carried out the epigenetic characterization in nine different adult mouse tissues and identified visceral adipose-derived progenitors as a candidate cell population. Chromatin conformation, assessed using chromatin immunoprecipitation (ChIP) sequencing and validated by ChIP-polymerase chain reaction (PCR) at key endocrine pancreatic gene promoters, revealed similarities between visceral fat and endocrine pancreas. Multiple techniques involving quantitative PCR, in-situ PCR, confocal microscopy, and flow cytometry confirmed the presence of measurable (2–1000-fold over detectable limits) pancreatic gene transcripts and mesenchymal progenitor cell markers (CD73, CD90 and CD105; >98%) in visceral adipose tissue-derived mesenchymal cells (AMCs). The differentiation potential of AMCs was explored in transgenic reporter mice expressing green fluorescent protein (GFP) under the regulation of the Pdx1 (pancreatic and duodenal homeobox-1) gene promoter. GFP expression was measured as an index of Pdx1 promoter activity to optimize culture conditions for endocrine pancreatic differentiation. Differentiated AMCs demonstrated their capacity to induce pancreatic endocrine genes as evidenced by increased GFP expression and validated using TaqMan real-time PCR (at least 2–200-fold relative to undifferentiated AMCs). Human AMCs differentiated using optimized protocols continued to produce insulin following transplantation in NOD/SCID mice. Our studies provide a systematic analysis of potential islet progenitor populations using genome-wide profiling studies and characterize visceral adipose-derived cells for replacement therapy in diabetes.

Perivascular Stem Cells Diminish Muscle Atrophy Following Massive Rotator Cuff Tears in a Small Animal Model.

Rotator cuff tears are a common cause of shoulder pain and often necessitate operative repair. Muscle atrophy, fibrosis, and fatty infiltration can develop after rotator cuff tears, which may compromise surgical outcomes. This study investigated the regenerative potential of 2 human adipose-derived progenitor cell lineages in a murine model of massive rotator cuff tears. Ninety immunodeficient mice were used (15 groups of 6 mice). Mice were assigned to 1 of 3 surgical procedures: sham, supraspinatus and infraspinatus tendon transection (TT), or TT and denervation via suprascapular nerve transection (TT + DN). Perivascular stem cells (PSCs) were harvested from human lipoaspirate and sorted using fluorescence-activated cell sorting into pericytes (CD146 CD34 CD45 CD31) and adventitial cells (CD146 CD34 CD45 CD31). Mice received no injection, injection with saline solution, or injection with pericytes or adventitial cells either at the time of the index procedure ("prophylactic") or at 2 weeks following the index surgery ("therapeutic"). Muscles were harvested 6 weeks following the index procedure. Wet muscle weight, muscle fiber cross-sectional area, fibrosis, and fatty infiltration were analyzed. PSC treatment after TT (prophylactic or therapeutic injections) and after TT + DN (therapeutic injections) resulted in less muscle weight loss and greater muscle fiber cross-sectional area than was demonstrated for controls (p < 0.05). The TT + DN groups treated with pericytes at either time point or with adventitial cells at 2 weeks postoperatively had less fibrosis than the TT + DN controls. There was less fatty infiltration in the TT groups treated with pericytes at either time point or with adventitial cells at the time of surgery compared with controls. Our findings demonstrated significantly less muscle atrophy in the groups treated with PSCs compared with controls. This suggests that the use of PSCs may have a role in the prevention of muscle atrophy without leading to increased fibrosis or fatty infiltration. Improved muscle quality in the setting of rotator cuff tears may increase the success rates of surgical repair and lead to superior clinical outcomes.

Partial Cranial Cruciate Ligament Tears Treated with Stem Cell and Platelet-Rich Plasma Combination Therapy in 36 Dogs: A Retrospective Study.

To evaluate outcomes in 36 dogs with a partial cranial cruciate ligament (CCL) tear treated with autologous bone marrow aspirate concentrate (BMAC) or adipose-derived progenitor cells (ADPC) with platelet-rich plasma (PRP) combination. Medical records of client-owned dogs diagnosed with an early partial (≤50%) tear of the craniomedial band of the CCL that was treated with BMAC-PRP or ADPC-PRP were reviewed from 2010 to 2015. Signalment, medical history, physical and orthopedic examination, objective temporospatial gait analyses, radiographs, day 0 and day 90 diagnostic arthroscopy findings, treatment, and outcome were among the data collected. A functional owner questionnaire, including the validated Helsinki chronic pain index (HCPI), was sent to owners whose dog was known to not have had a tibial plateau leveling osteotomy (TPLO). Statistical analysis was performed on data, where significance was established at p < 0.05. Stifle arthroscopy findings at 90 days posttreatment were available on 13 of the 36 dogs. In nine dogs, a fully intact CCL with marked neovascularization and a normal fiber pattern was found with all previous regions of disruption healed. One dog revealed significant improvement and received an additional injection. The remaining three dogs had a >50% CCL tear, and a TPLO was performed. Four additional dogs were known to have had a TPLO performed elsewhere. Baseline and day 90 posttreatment objective gait analyses were available on 11 of the 36 dogs. A significant difference was found between the treated limb total pressure index percent (TPI%) at day 0 and day 90 (p = 0.0124), and between the treated limb and contralateral limb TPI% at day 0 (p = 0.0003). No significant difference was found between the treated limb and contralateral limb TPI% at day 90 (p = 0.7466). Twelve questionnaires were returned, of which eight were performance/sporting dogs. Seven of the eight had returned to sport; the remaining dog had just begun a return to sport conditioning program 6 months posttreatment. All 12 respondents believed that their dog had an excellent or very good quality of life and rated their dog's procedural outcome as excellent or good. The use of BMAC-PRP and ADPC-PRP shows promise for the treatment of early partial CCL tears in dogs. Further studies are needed and should be randomized, blinded, and controlled.

The Use of Adipose-Derived Progenitor Cells and Platelet-Rich Plasma Combination for the Treatment of Supraspinatus Tendinopathy in 55 Dogs: A Retrospective Study.

To report clinical findings and outcomes for 55 dogs with supraspinatus tendinopathy (ST) treated with adipose-derived progenitor cells and platelet-rich plasma (ADPC-PRP) therapy. Medical records of client-owned dogs diagnosed with ST that were treated with ADPC-PRP combination therapy were reviewed from 2006 to 2013. Data collected included signalment, medical history, limb involvement, prior treatments, physical and orthopedic examination, objective temporospatial gait analysis findings, diagnostic imaging results (radiography, magnetic resonance imaging, musculoskeletal ultrasonography), arthroscopy findings, and outcome. Following ultrasound-guided injection of ADPC-PRP, objective gait analysis was available on 25 of the 55 dogs at 90 days post ADPC-PRP therapy. Following treatment, a significant increase in total pressure index percentage (TPI%) was noted in the injured (treated) forelimb at 90 days post treatment (p = 0.036). At 90 days following treatment, 88% of cases had no significant difference in TPI% of the injured limb to the contralateral limb. The remaining 12% of cases had significantly improved (p = 0.036). Bilateral shoulder diagnostic musculoskeletal ultrasound revealed a significant reduction in tendon size (CSA) in the treated tendon at 90 days following treatment when compared to the initial CSA (p = 0.005). All cases showed significant improvement in fiber pattern of the affected supraspinatus tendon by the ultrasound shoulder pathology rating scale. These findings suggest that ADPC-PRP therapy should be considered for dogs with ST.

Circulating microRNAs: Understanding the Limits for Quantitative Measurement by Real‐Time PCR

Ever since the discovery of small, non-coding RNAs in circulation, microRNAs have gained significant attention as biomarkers or, in some instances, regulators of disease and/or associated complications. Until now, most articles published use real-time quantitative PCR (qPCR) for assessment of

Implications of Immediate Autologous Fat Grafting and Expanded Adipose-Derived Progenitor Cells on Hypertrophic Scar Maturation in a Swine Model

INTRODUCTION: Hypertrophic scar formation is unpredictable and poorly understood, afflicting both the pediatric and adult populations. Treatment methods with conservative and invasive approaches have low rates of compliance and high rates of morbidity. The purpose of this study is to develop a reproducible scar model and investigate a new technique of scar modification through the use of adipose-derived progenitor stromal cells (ASCs). METHODS: 20 thermal deep-partial thickness contact burns were created on the dorsum of three 8-week old domestic swine and allowed to mature for 10 weeks. Scars were then injected with 2 cc saline, expanded autologous ASCs, or 2 cc fresh lipoaspirate and sampled at 2 week intervals up to 10 weeks post injection. Volumetric analysis with a 3-D scanner, mechanical elasticity testing through negative pressure transduction, and standardized photography evaluation with Image J was performed. Biopsies were taken at 2 week intervals and histologically analyzed for collagen deposition and vascularity. RNA sequencing was performed on scar tissue samples, cultured cells, and fresh lipoaspirate. RESULTS: Volumetric analysis demonstrates a reduction in average scar thickness at 6 weeks when injected with ASCs (-1.601 cc³) and autologous fat (-1.965 cc³) relative to controls (-0.121 cc³, p<0.05). A decrease in overall tissue compliance is observed with fat or ASC injection when compared to unburned skin at 8 weeks (35.99/ 37.94 vs 49.36 mmHg*mm, p<0.01). Scars treated with fat or ASCs increase the rate at which erythema resolves. RNA sequencing suggests regulation of fibroblast gene expression and a decreased inflammatory profile when scars are injected with fat cells. CONCLUSION: Early results suggest that autologous fat and/or ASCs may improve healing of hypertrophic scarring by altering the cellular and structural components during wound remodeling up to 14 weeks after injury. This may have beneficial applications in early treatment of large or cosmetically sensitive immature burn scars (Figures 1 and 2).Figure 1: 3-D volumetric analysis of hypertrophic scars. Scans at 2 and 4 weeks were superimposed (top left, top middle, top right) and thickness differences (arrow) calculated between time points (bottom).Figure 2: Biochemical evaluation through negative pressure transduction demonstrates a decrease in overall elasticity in all injected wounds (saline, cells, fat) up to 4 weeks. Elasticity increases in each wound starting around week 6.

Adipose Derived Stem Cells for Musculoskeletal Regeneration: Recent Patents and Future Perspectives

The multifunctional “adipose organ” is involved in thermal, metabolic and hormonal body balance. The high content of adult mesenchymal stem cells is recommending adipose tissue as an appealing reservoir of cells to be used in regenerative therapies. Adipose derived stem cells (ASC) have remarkable proliferative and differentiation potential. This paper reviews current scientific knowledge regarding the importance of ASC in the context of regenerative medicine. Recent patents and applications describing methods of human ASC isolation and their use for regenerating musculoskeletal tissues (bone, cartilage, intervertebral disc, tendon and skeletal muscle) are discussed. Several challenges related to cell based product development are presented. Future directions as well as the importance of new genomic technologies in cell source selection and design of patient - oriented treatment algorithms, are outlined. Keywords: Adipose, bone, cartilage, musculoskeletal, regeneration, stem cells, CELL SOURCE, REGENERATIVE THERAPIES, Adipose Derived Progenitor Cells, CARTILAGE DEFECTS, CHONDROGENESIS

Isolation and Biological Characteristics of Chicken Adipose-Derived Progenitor Cells

Adipose-derived stem cells/adipose-derived progenitor cells (ADPCs) are multipotent stem cells that can differentiate in vitro into many cell types. However, the vast majority of experimental materials were obtained from human, mouse, rabbit, and other mammals but rarely from poultry. In this study, ADPCs were isolated from 1-day-old chicks. Primary ADPCs were subcultured to passage 15. The surface markers of ADPCs, CD29, CD44, CD71, and CD73, were detected by immunofluorescence and RT-polymerase chain reaction assays. The growth curves of different passages were all typically sigmoidal. In addition, ADPCs of different passages were successfully induced to differentiate into osteoblasts, adipocytes, and myocardial cells. The results suggest that the ADPCs isolated from chicken possess similar biological characteristics with those derived from other species, and their multilineage differentiation provides many potential applications.

Ectopic Fibrogenesis Induced by Transplantation of Adipose-Derived Progenitor Cell Suspension Immediately After Lipoinjection

Adipose tissue has its own tissue-specific progenitor cells, a subpopulation of which has been shown to have multipotency and called adipose stem cells or adipose-derived mesenchymal stem cells (1,2). During a clinical trial in which soft tissue is augmented by transplantation of progenitor-enriched adipose tissue (cell-assisted lipotransfer), we have encountered incidence of an unexpected complication: local ectopic subcutaneous fibrogenesis. Patients participating in the trial did so under informed consent approved by individual review boards. Cell-assisted lipotransfer was designed based on the finding that aspirated fat tissue contains many fewer vessels and adipose progenitor cells than intact fat tissue. This may explain the tendency of transplanted aspirated fat tissue to atrophy during the first 6 months posttransplantation (3). In the relevant clinical trial, the stromal vascular fraction (SVF) comprising 10% to 40% adipose progenitor cells was freshly isolated from aspirated fat by means of collagenase digestion and transplanted together with aspirated fat tissue grafts (4). In 146 cases, SVF cells were used as a cell pellet, mixed with and attached to aspirated fat tissue grafts before injecting into fatty and muscular layers of breast mounds. On the other hand, in two cases, SVF cells isolated from 600 mL aspirated fat were separately injected as a cell suspension in 60 mL of saline into both breast mounds (30 mL/side) immediately after conventional lipoinjection. Although grafted fat survived well and fibrogenesis in the breasts or surrounding tissues was not seen in the former group, fibrous tissue formation was observed in both cases of the latter group 3 months after treatment. In the two cases, breast mounds were somewhat hard to the touch; inspection by CT scan detected unexpected fibrosis in the subcutaneous fat layers. In the thinner patient of the two (Fig. 1), fibrous tissue approximately 10 mm thick had formed on the sternum and caused anterior elevation of the skin, which was treated with local injections of triamcinolone acetonide at 6 and 8 months. Furthermore, lymphadenopathy was seen at the left abdominal wall and the left inguinal region at 3 months and gradually disappeared by 12 months.FIGURE 1.: CT scan images taken before (Pre) and 3, 6, 12, and 36 months after treatment. Normal mammary glands and the thin fatty layers around them are visible before treatment. Substantial fibrosis had occurred, both diffusely in the transplanted fat surviving around the mammary glands and in the subcutaneous layer over the sternum, at 3 months. The fibrotic mass over the sternum was treated twice with local injections of triamcinolone acetonide at 6 and 8 months and dissipated, but diffuse fibrosis in the breasts remains at 36 months.Fibrogenesis results from persistent inflammation, in which tissue remodeling and repair processes are impaired and injured cells are replaced not with cells of the same type but with connective or scar tissue (5). As fibrogenesis was seen only when SVF cells were injected separately as a cell suspension, a nonphysiological microenvironment in which adherent adipose progenitor cells are suspended in saline solution may give rise to the unexpected differentiation and migration of the cells. After large-volume lipoinjection, tissue injury, edema, hemorrhage, and local inflammation are commonly seen, and transplanted adipose progenitor cells are temporarily placed in and stimulated by ischemic and inflammatory microenvironments. These findings provide some insights into a therapeutic strategy for future cell-based therapies involving adherent stem/progenitor cells. Previous experimental studies demonstrated that transplanted bone marrow-derived mesenchymal stem cells differentiated into myofibroblasts and contributed to liver fibrosis after acute or chronic liver injury (6,7). In cell-based therapies using adherent mesenchymal stem cells, the possibility of unfavorable behaviors such as differentiation into myofibroblasts should be taken into account, even if the cells are derived from adult tissue and have not been substantially manipulated. It may be a resolution to adhere adipose-derived adherent stem or progenitor cells to cells, tissue, extracellular matrix, or biological scaffold before administration to avoid their unexpected behaviors. Kotaro Yoshimura Noriyuki Aoi Hirotaka Suga Keita Inoue Hitomi Eto Department of Plastic Surgery University of Tokyo School of Medicine Tokyo, Japan Katsujiro Sato Cellport Clinic Yokohama Yokohama Excellent III Building 2F Kanagawa, Japan Masakazu Kurita Kiyonori Harii Department of Plastic Surgery Kyorin University School of Medicine Tokyo, Japan Toshitsugu Hirohi Ritz Cosmetic Surgery Clinic Tokyo Shinagawa-ku, Tokyo, Japan

Evaluation of adult equine bone marrow‐ and adipose‐derived progenitor cell chondrogenesis in hydrogel cultures

Bone marrow mesenchymal stem cells (BM-MSCs) and adipose-derived progenitor cells (ADPCs) are potential alternatives to autologous chondrocytes for cartilage resurfacing strategies. In this study, the chondrogenic potentials of these cell types were compared by quantifying neo-tissue synthesis and assaying gene expression and accumulation of extracellular matrix (ECM) components of cartilage. Adult equine progenitor cells encapsulated in agarose or self-assembling peptide hydrogels were cultured in the presence or absence of TGFbeta1 for 3 weeks. In BM-MSCs-seeded hydrogels, TGFbeta1 stimulated ECM synthesis and accumulation 3-41-fold relative to TGFbeta1-free culture. In ADPC cultures, TGFbeta1 stimulated a significant increase in ECM synthesis and accumulation in peptide (18-29-fold) but not agarose hydrogels. Chromatographic analysis of BM-MSC-seeded agarose and peptide hydrogels cultured in TGFbeta1 medium showed extensive synthesis of aggrecan-like proteoglycan monomers. ADPCs seeded in peptide hydrogel also synthesized aggrecan-like proteoglycans, although to a lesser extent than seen in BM-MSC hydrogels, whereas aggrecan-like proteoglycan synthesis in ADPC-seeded agarose was minimal. RT-PCR analysis of TGFbeta1 cultures showed detectable levels of type II collagen gene expression in BM-MSC but not ADPC cultures. Histological analysis of TGFbeta1-cultured peptide hydrogels showed the deposition of a continuous proteoglycan- and type II collagen rich ECM for BM-MSCs but not ADPCs. Therefore, this study showed both protein and gene expression evidence of superior chondrogenesis of BM-MSCs relative to ADPCs.

Osteo-maturation of adipose-derived stem cells required the combined action of vitamin D3, β-glycerophosphate, and ascorbic acid

This study investigated the effects of various components [vitamin D3 (VD3), β-glycerophosphate (BGP), and ascorbic acid (AA)] on the potential of human adipose-derived progenitor cells (ADPCs) to transdifferentiate into osteoblast-like cells. ADPCs were induced under four different supplement groups: (1) VD3+BGP+AA, (2) VD3 alone, (3) BGP+AA, and (4) no VD3, BGP or AA. Mineralization studies and presence of bone matrix-related proteins by immunostaining showed that the Group 1 ADPCs showed their ability to undergo osteoblastic differentiation. Further evaluation was made by estimation of levels of RUNX-2 and TAZ genes. Group 1 ADPCs showed the consistent expression of RUNX-2 and TAZ levels over the study period of 28days. The study showed good correlation among various parameters evaluated to conclude that ADPCs could be an alternative source for generating osteoblast-like cells.