Defining the identity of human adipose-derived mesenchymal stem cells

Role of Mesenchymal Stem/Stromal Cells in Head and Neck Cancer-Regulatory Mechanisms of Tumorigenic and Immune Activity, Chemotherapy Resistance, and Therapeutic Benefits of Stromal Cell-Based Pharmacological Strategies

Head and neck cancer (HNC) entails a heterogenous neoplastic disease that arises from the mucosal epithelium of the upper respiratory system and the gastrointestinal tract. It is characterized by high morbidity and mortality, being the eighth most common cancer worldwide. It is believed that the mesenchymal/stem stromal cells (MSCs) present in the tumour milieu play a key role in the modulation of tumour initiation, development and patient outcomes; they also influence the resistance to cisplatin-based chemotherapy, the gold standard for advanced HNC. MSCs are multipotent, heterogeneous and mobile cells. Although no MSC-specific markers exist, they can be recognized based on several others, such as CD73, CD90 and CD105, while lacking the presence of CD45, CD34, CD14 or CD11b, CD79α, or CD19 and HLA-DR antigens; they share phenotypic similarity with stromal cells and their capacity to differentiate into other cell types. In the tumour niche, MSC populations are characterized by cell quiescence, self-renewal capacity, low reactive oxygen species production and the acquisition of epithelial-to-mesenchymal transition properties. They may play a key role in the process of acquiring drug resistance and thus in treatment failure. The present narrative review examines the links between MSCs and HNC, as well as the different mechanisms involved in the development of resistance to current chemo-radiotherapies in HNC. It also examines the possibilities of pharmacological targeting of stemness-related chemoresistance in HNSCC. It describes promising new strategies to optimize chemoradiotherapy, with the potential to personalize patient treatment approaches, and highlights future therapeutic perspectives in HNC.

Isolation and identification of a mesenchymal stem/stromal cell-like population from pediatric urethral tissue

Mesenchymal stem cells (MSCs) are important seed cells for cell therapy and tissue engineering because of their multidirectional differentiation potential, high proliferative capacity, low immunogenicity, and immunomodulatory ability. In this study, we successfully isolated and cultured a population of mesenchymal stem-like cells from pediatric urethra (PU-MSLCs). The cells had a spindle-shaped fibroblast-like morphology, similar to MSCs derived from other tissues. The PU-MSLCs highly expressed MSC surface markers CD29, CD73, CD90, and CD105 but were negative for leukocyte common antigen CD45, and MHC class II-encoded molecule HLA-DR. After in vitro induction, the PU-MSLCs had the potential to differentiate into adipocytes, osteocytes, and chondrocytes. The PU-MSLCs maintained a normal karyotype and showed no tumorigenicity during long-term cultivation. We thus demonstrated that the mesenchymal stem/stromal cell-like population obtained from pediatric urethra tissue is capable of self-renewal and multidirectional differentiation, has promising application prospects for cell therapy and tissue engineering, and is expected to contribute to urethral tissue reconstruction.

Roles of mesenchymal stromal cells in the head and neck cancer microenvironment

Head and neck cancer (HNC), a common malignancy worldwide, is associated with high morbidity and mortality rates. Squamous cell carcinoma is the most common HNC type, followed by salivary gland carcinomas, head and neck sarcomas, and lymphomas. The microenvironment of HNCs comprises various cells that regulate tumor development. Recent studies have reported that the tumor microenvironment, which modulates cancer progression, regulates cancer treatment response. However, the presence of different types of stromal cells in cancers is a major challenge to elucidate the role of individual cells in tumor progression. The role of mesenchymal stromal cells (MSCs), which are a component of the tumor microenvironment, in HNC is unclear. The major impediment for characterizing the role of MSCs in cancer progression is the lack of MSC-specific markers and their phenotypic similarity with stromal cells. This review aimed to summarize the latest findings on the role of MSCs in the progression of HNC to improve our understanding of HNC pathophysiology.

Functional Comparison between Healthy and Multiple Myeloma Adipose Stromal Cells

Multiple myeloma (MM) is an incurable B cell neoplasia characterized by the accumulation of tumor plasma cells within the bone marrow (BM). As a consequence, bone osteolytic lesions develop in 80% of patients and remain even after complete disease remission. We and others had demonstrated that BM-derived mesenchymal stromal cells (MSCs) are abnormal in MM and thus cannot be used for autologous treatment to repair bone damage. Adipose stromal cells (ASCs) represent an interesting alternative to MSCs for cellular therapy. Thus, in this study, we wondered whether they could be a good candidate in repairing MM bone lesions. For the first time, we present a transcriptomic, phenotypic, and functional comparison of ASCs from MM patients and healthy donors (HDs) relying on their autologous MSC counterparts. In contrast to MM MSCs, MM ASCs did not exhibit major abnormalities. However, the changes observed in MM ASCs and the supportive property of ASCs on MM cells question their putative and safety uses at an autologous or allogenic level.

FGF23 and Fetuin-A Interaction and Mesenchymal Osteogenic Transformation

Recently, we found a strict bone association between Fibroblast growth factor 23 (FGF23) and Fetuin-A, both involved in cardiovascular and mineral bone disorders. In this study, an uninvestigated bone marrow positivity for both was found. Though the role of exogenous FGF23 on mesenchymal cells (MSCs) was reported, no information is as yet available on the possible production of this hormone by MSCs. To further analyze these uninvestigated aspects, we studied human primary cells and mouse and human cell lines by means of immunostaining, qRT-PCR, enzyme linked immunosorbent assays, chromatin immunoprecipitation, transfection, and a streamlined approach for the FGF23⁻Fetuin-A interaction called Duolink proximity ligation assay. Mesenchymal cells produce but do not secrete FGF23 and its expression increases during osteo-differentiation. Fibroblast growth factor 23 is also involved in the regulation of Fetuin-A by binding directly to the Fetuin-A promoter and then activating its transcription. Both FGF23 overexpression and addition induced an upregulation of Fetuin-A in the absence of osteo-inducer factors. Fibroblast growth factor 23 and Fetuin-A promoter were increased by osteo-inducer factors with this effect being abolished after FGF23 silencing. In conclusion, both FGF23 and Fetuin-A are present and strictly linked to each other in MSCs with FGF23 driving Fetuin-A production. This mechanism suggests a role for these two proteins in the osteoblast differentiation.

Validation of reference and identity-defining genes in human mesenchymal stem cells cultured under unrelated fetal bovine serum batches for basic science and clinical application

The molecular profile of human mesenchymal stem cells (MSCs) have emerged as a key factor in defining their identity. Nevertheless, the effect of fetal bovine serum (FBS) batches or origin on MSC molecular signature has been neglected. In this frame, chemical fingerprint of FBS batches from unrelated countries showed strong correlation between chemical composition and country of origin. Thus, the aim of this study was to evaluate in stem cells isolated from bone marrow (BMMSCs) and umbilical cord-blood (CBMSCs) the effects of independently collected FBS batches on both twelve commonly used reference genes (RGs) and a selected panel of thirty-eight genes crucial for MSC definition in both research and clinical settings. Gene expression stability was estimated comparing the outcomes of two applets: geNorm and NormFinder. The bioinformatics analysis emphasized that, in a panorama of general balance, few RG candidates (YWHAZ/UBC for BMMSCs, RPLP0/EF1A for CBMSCs and EF1A/TBP for both MSCs scored together) showed superior stability. In addition, a wider study on genes involved in differentiation/proliferation/stemness processes, often used to define MSC potency, showed that these genes exhibited no major transcriptional modulation after treatment with different FBS, and allowed the identification of genes strongly discriminating between BM- and CBMSC populations. Therefore, in conclusion, FBS origin does not dramatically impact the general molecular profile of MSCs, although we could identify validated candidates able to allow more reliable comparison of data regarding MSC identity and potency and obtained by research laboratories and clinical manufacturers using different sera.

Structural Fat Grafting to Improve Outcomes of Vocal Folds’ Fat Augmentation: Long-term Results

Objective

Evaluating the long-term outcomes of vocal fold structural fat grafting.

Study Design

Case series with chart review.

Setting

University hospital.

Subjects and Methods

Seventy-nine dysphonic patients (16-82 years; 55 with unilateral laryngeal paralysis and 24 with vocal fold scarring) underwent vocal fold fat injection. Fat was harvested by low-pressure liposuction and then processed by centrifugation. Refined fat aliquots were placed in the vocal fold and paraglottic space in multiple tunnels to enhance graft neovascularization. All patients were followed for 12 months, 15 for 3 years, and 5 for 10 years with videolaryngostroboscopy, maximal phonation time (MPT) measurement, Voice Handicap Index (VHI) questionnaire, and GRBAS (grade, roughness, breathiness, asthenia, strain) perceptual evaluation. Laryngeal computed tomography (CT) and/or magnetic resonance imaging (MRI) studies were performed in 16 patients 3 to 28 months postoperatively; MRI was repeated in 5 cases 12 to 18 months after the first radiological study.

Results

The voice quality of all patients improved after surgery, and long-term stability was confirmed by MPT, GRBAS, and VHI ( P ranging between .004 and <.001). The results achieved 1 year postoperatively remained stable at 3 and 10 years. Videolaryn-gostroboscopy showed improved glottic closure in all patients despite a limited amount of fat resorption. CT and MRI demonstrated survival of the fat grafts in all of the 16 examined cases. Serial MRI scans showed no change in graft size over time.

Conclusions

The reported clinical and radiological data demonstrate that fat is an effective filler for permanent vocal fold augmentation if the refined micro-aliquots are placed in multiple tunnels.

Effects of donor age on human adipose-derived adherent stromal cells under oxidative stress conditions

Objective

Adipose-derived stromal vascular fractions (SVFs) are heterogeneous complex populations of cells with therapeutic efficacy for tissue generation and vascular stabilization. SVFs have cardiomyogenic potential, and many researchers have examined the possibility of SVF transplantation for heart disease. In cell-based therapies, donor age affects the regenerative capability, cell yield, and differentiation potential of adult tissues; however, opposing or controversial results have been found in humans. We examined whether SVF transplantation into impaired heart tissue shows differential effects according to donor age.

Methods

We investigated differences in protein expression in human umbilical vein endothelial cells (HUVECs) co-cultured with adipose-derived adherent stromal cells (ADASs) from donors of different ages [>40-year-olds (40s group) and >60-year-olds (60s group)] under oxidative stress conditions.

Results

Although co-culturing HUVECs with ADASs ameliorated inflammation due to increased oxidative stress conditions, few differences were observed between the ADASs from the 40s and 60s groups. Moreover, the Database for Annotation, Visualization, and Integrated Discovery classification tool revealed differentially expressed genes in the Kyoto Encyclopedia of Genes and Genomes pathway associated with cytokine–cytokine receptor interaction in response to ADASs.

Conclusion

Protein expression profiles were unchanged in HUVECs induced by isolated ADASs from donors of different ages under oxidative stress conditions.

Hair Follicle Morphogenesis in the Treatment of Mouse Full-Thickness Skin Defects Using Composite Human Acellular Amniotic Membrane and Adipose Derived Mesenchymal Stem Cells

Early repair of skin injury and maximal restoration of the function and appearance have become important targets of clinical treatment. In the present study, we observed the healing process of skin defects in nude mice and structural characteristics of the new skin after transplantation of isolated and cultured adipose derived mesenchymal stem cells (ADMSCs) onto the human acellular amniotic membrane (AAM). The result showed that ADMSCs were closely attached to the surface of AAM and grew well 24 h after seeding. Comparison of the wound healing rate at days 7, 14, and 28 after transplantation showed that ADMSCs seeded on AAM facilitated the healing of full-thickness skin wounds more effectively as compared with either hAM or AAM alone, indicating that ADMSCs participated in skin regeneration. More importantly, we noticed a phenomenon of hair follicle development during the process of skin repair. Composite ADMSCs and AAM not only promoted the healing of the mouse full-thickness defects but also facilitated generation of the appendages of the affected skin, thus promoting restoration of the skin function. Our results provide a new possible therapy idea for the treatment of skin wounds with respect to both anatomical regeneration and functional restoration.

Protein O-mannosylation is crucial for human mesencyhmal stem cells fate

Human mesenchymal stem cells (MSC) are promising cell types in the field of regenerative medicine. Although many pathways have been dissected in the effort to better understand and characterize MSC potential, the impact of protein N- or O-glycosylation has been neglected. Deficient protein O-mannosylation is a pathomechanism underlying severe congenital muscular dystrophies (CMD) that start to develop at the embryonic developmental stage and progress in the adult, often in tissues where MSC exert their function. Here we show that O-mannosylation genes, many of which are putative or verified glycosyltransferases (GTs), are expressed in a similar pattern in MSC from adipose tissue, bone marrow, and umbilical cord blood and that their expression levels are retained constant during mesengenic differentiation. Inhibition of the first players of the enzymatic cascade, POMT1/2, resulted in complete abolishment of chondrogenesis and alterations of adipogenic and osteogenic potential together with a lethal effect during myogenic induction. Since to date, no therapy for CMD is available, we explored the possibility of using MSC extracellular vesicles (EVs) as molecular source of functional GTs mRNA. All MSC secrete POMT1 mRNA-containing EVs that are able to efficiently fuse with myoblasts which are among the most affected cells by CMD. Intriguingly, in a pomt1 patient myoblast line EVs were able to partially revert O-mannosylation deficiency and contribute to a morphology recovery. Altogether, these results emphasize the crucial role of protein O-mannosylation in stem cell fate and properties and open the possibility of using MSC vesicles as a novel therapeutic approach to CMD.

Human cord blood-derived platelet lysate enhances the therapeutic activity of adipose-derived mesenchymal stromal cells isolated from Crohn's disease patients in a mouse model of colitis

Introduction

Due to their immunomodulatory properties, mesenchymal stromal cells (MSCs) have been used for auto-immune disease treatment. Crohn disease (CD) and ulcerative colitis are two major inflammatory bowel diseases (IBDs), resulting from pathological immune responses to environmental or microbial antigens. Preclinical and clinical studies have suggested that MSC-based cellular therapy hold promising potential for IBD treatment. However, open issues include the selection of the proper cell dose, the source and the optimal route of administration of MSCs for more effective results. Platelet lysate has gained clinical interest due to its efficacy in accelerating wound healing. Thus, we propose to combine the administration of MSCs with a human umbilical cord blood-derived platelet lysate (hCBPL) as a novel strategy to improve MSC-based therapy for IBD resolution.

Methods

Colitis was induced in 8-week-old C57BL/6J mice by daily oral administration of dextran sulphate sodium (DSS) (1.5 % w/v in tap water) for 9 days. MSCs were isolated from adipose tissue of CD patients (adCD-MSCs), expanded in proliferation medium, resuspended in hCBPL or PBS and administrated via enema for three times (1 × 10⁶ cells/mouse/time) every other day starting on day +7 from DSS induction. The colitis evolution was evaluated by daily monitoring of body weight, stool consistency and bleeding. Histopathological analysis was performed. Inflammatory cytokine plasma levels were determined. adCD-MSCs stained with lipophilic membrane dye Nile Red, were injected in DSS mice as described above. Colon section of mice sacrificed 24 hours after last cell administration, were analyzed by confocal microscopy.

Results

We found that adCD-MSCs could be easily isolated and expanded from CD patients. Upon injection, adCD-MSCs exerted a therapeutic effect on DSS-induced colitis. Moreover, hCBPL increased adCD-MSCs efficacy by significantly reducing colitis scores, extension of the colon inflamed area and plasma levels of inflammatory mediators. Finally, Nile Red staining of MSCs is very efficient, stable and does not impair their vitality and function. Nile Red-labelling was clearly detected in the colitic area of adCD-MSCs injected mice and it was significantly brighter in the colon sections of mice that had received adCD-MSCs/hCBPL.

Conclusions

In summary, with this study we propose a novel and promising adCD-MSC/hCBPL-based therapy for refractory IBDs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0166-2) contains supplementary material, which is available to authorized users.