Culture effects of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on cryopreserved human adipose-derived stromal/stem cell proliferation and adipogenesis

The optimized priming effect of FGF-1 and FGF-2 enhances preadipocyte lineage commitment in human adipose-derived mesenchymal stem cells

The cell-assisted lipotransfer technique, integrating adipose-derived mesenchymal stem cells (ADMSCs), has transformed lipofilling, enhancing fat graft viability. However, the multipotent nature of ADMSCs poses challenges. To improve safety and graft vitality and to reduce unwanted lineage differentiation, this study refines the methodology by priming ADMSCs into preadipocytes-unipotent, self-renewing cells. We explored the impact of fibroblast growth factor-1 (FGF-1), fibroblast growth factor-2 (FGF-2), and epidermal growth factor (EGF), either alone or in combination, on primary human ADMSCs during the proliferative phase. FGF-2 emerged as a robust stimulator of cell proliferation, preserving stemness markers, especially when combined with EGF. Conversely, FGF-1, while not significantly affecting cell growth, influenced cell morphology, transitioning cells to a rounded shape with reduced CD34 expression. Furthermore, co-priming with FGF-1 and FGF-2 enhanced adipogenic potential, limiting osteogenic and chondrogenic tendencies, and possibly promoting preadipocyte commitment. These preadipocytes exhibited unique features: rounded morphology, reduced CD34, decreased preadipocyte factor 1 (Pref-1), and elevated C/EBPα and PPARγ, alongside sustained stemness markers (CD73, CD90, CD105). Mechanistically, FGF-1 and FGF-2 activated key adipogenic transcription factors-C/EBPα and PPARγ-while inhibiting GATA3 and Notch3, which are adipogenesis inhibitors. These findings hold the potential to advance innovative strategies for ADMSC-mediated lipofilling procedures.

Complications of Injected Exogenous Growth Factor for Cosmetic Facial Rejuvenation: A Case Series and Sequential Therapy

BACKGROUND

Exogenous growth factor presents promising soft tissue regeneration, but the complications from injectable exogenous growth factor seem to be growing. However, there is no detailed summary of complications and sequential treatment protocols. It is noted that the injection of exogenous growth factor into the soft tissue is an unreasonable or even illegal procedure, which could cause uncontrollable tissue growth and some other complications.

METHODS

A total of 65 patients underwent analysis retrospectively for complications related to the injection of exogenous growth factor from 2017to 2022 at Xijing Hospital in China. Initially the symptoms mainly consisted of redness, skin temperature arisen, itching, tissue hypertrophy, localized swelling, mass, and lump, with later manifestations including ulcerations and purulent discharge. A comprehensive treatment scheme was formulated based on the location and size of the lumps as well as the type of complication. Post-treatment satisfaction was evaluated over a mean 16-month follow-up (range 6-39 months).

RESULTS

A total of 65 patients participated in the treatment. Drug injection therapy was initially performed on all patients. If injections were not effective, surgical treatment (debridement/excision/liposuction) was performed. Twenty-eight patients were managed with intralesional injections alone. Patients reported improved satisfaction in 23 cases (82.14%), full symptom resolution in 3 cases (10.72%), and no improvement in 2 cases (7.14%). Surgery was required for 37 patients. Postoperative improved satisfaction was reported in 30 cases (81.08%), full symptom resolution was recorded in 4 cases (10.82%), and no improvement was seen in 3 cases (8.10%).

CONCLUSIONS

This study highlights the management of complications arising from exogenous growth factor injections through the implementation of a sequential therapy approach. Specifically, this approach involves the initial administration of drug injection therapy, and if drug injection therapy proves ineffective, then surgical treatment is pursued. In conclusion, the injection of exogenous growth factors into soft tissues should be forbidden.

LEVEL OF EVIDENCE IV

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Reactive Oxygen Species (ROS)-Assisted Nano-Therapeutics Surface-Decorated with Epidermal Growth Factor Fragments for Enhanced Wound Healing

In this study, stimuli-responsive liberation of an epidermal growth factor fragment (EGFfr) is accomplished using nanofibrous meshes to improve wound healing effects. Electrospun nanofibers are fragmented by mechanical milling, followed by aminolysis to fabricate powdered nanofibrils (NFs). EGFfrs are covalently immobilized on NFs via thioketal linkers (EGFfr@TK@NF) for reactive oxygen species (ROS)-dependent liberation. EGFfr@TK@NF exhibits ROS-responsive liberation of EGFfr from the matrix at hydrogen peroxide (H2 O2 ) concentrations of 0-250 mm. Released EGFfr is confirmed to enhance the migration of HaCaT cell monolayers, and keratinocytic gene expression levels are significantly enhanced when H2 O2 is added to obtain the released fraction of NFs. An in vivo study on the dorsal wounds of mice reveals that EGFfr-immobilized NFs improve the expression levels of keratin1, 5, and 14 for 2 weeks when H2 O2 is added to the wound sites, suggesting that the wounded skin is re-epithelized with the original epidermis. Thus, EGFfrs-immobilized NFs are anticipated to be potential nanotherapeutics for wound treatment in combination with the conventional disinfection process with H2 O2 .

Perinatal triphenyl phosphate exposure induces metabolic dysfunctions through the EGFR/ERK/AKT signaling pathway: Mechanistic in vitro and in vivo studies

Triphenyl phosphate (TPhP), a widely used organophosphate-flame retardant, is ubiquitously found in household environments and may adversely affect human health. Evidence indicates that TPhP exposure causes metabolic dysfunctions in vivo; however, the underlying mechanism of such adverse effects has not been comprehensively investigated. Herein, we utilized two in vitro models including mouse and human preadipocytes to delineate adipogenic mechanisms of TPhP. The results revealed that both mouse and human preadipocytes exposed to TPhP concentration-dependently accumulated more fat through a significant upregulation of epidermal growth factor receptor (EGFR). We demonstrated that TPhP significantly promoted adipogenesis through the activation of EGFR/ERK/AKT signaling pathway as evident by a drastic reduction in adipogenesis of preadipocytes cotreated with inhibitors of EGFR and its major effectors. Furthermore, we confirmed the mechanism of TPhP-induced metabolic dysfunctions in vivo. We observed that male mice perinatally exposed to TPhP had a significant increase in adiposity, hepatic triglycerides, insulin resistance, plasma insulin levels, hypotension, and phosphorylated EGFR in gonadal fat. Interestingly, an administration of a potent and selective EGFR inhibitor significantly ameliorated the adverse metabolic effects caused by TPhP. Our findings uncovered a potential mechanism of TPhP-induced metabolic dysfunctions and provided implications on toxic metabolic effects posed by environmental chemicals.

Growth Factor Immobilization to Synthetic Hydrogels: Bioactive bFGF-Functionalized Polyisocyanide Hydrogels

With its involvement in cell proliferation, migration and differentiation basic fibroblast growth factor (bFGF) has great potential for tissue engineering purposes. So far, however, clinical translation of soluble bFGF-based therapies is unsuccessful, because the required effective doses are often supraphysiological, which may cause adverse effects. An effective solution is growth factor immobilization, whereby bFGF retains its bioactivity at increased efficacy. Studied carriers include films, solid scaffolds, and particles, as well as natural and synthetic hydrogels. However, these synthetic hydrogels poorly resemble the characteristics of the native extracellular matrix (ECM). In this work, bFGF is covalently conjugated to the synthetic, but highly biocompatible, polyisocyanide-based hydrogel (PIC-bFGF), which closely mimics the architecture and mechanical properties of the ECM. The growth factor conjugation protocol is straightforward and readily extrapolated to other growth factors or proteins. The PIC-bFGF hydrogel shows a prolonged bioactivity up to 4 weeks although no clear effects on the ECM metabolism are observed. Beyond the future potential of the PIC-bFGF hydrogel toward various tissue engineering applications, this work underlines that simple biological conjugation procedures are a powerful strategy to induce additional bioactivity in 3D synthetic cell culture matrices.

Expression Profile and Regulatory Properties of m6A-Modified circRNAs in the Longissimus Dorsi of Queshan Black and Large White Pigs

It is well known that N6-methyladenosine (m6A) is the most abundant modification in linear RNA molecules, but many circRNA molecules have now been found to have a wide range of m6A modification sites as well. However, there are few relevant studies and information on the expression profile and functional regulatory properties of m6A-modified circRNAs (m6A-circRNAs) in longissimus dorsi. In this study, a total of 12 putative m6A-circRNAs were identified and characterized in the longissimus dorsi of Queshan Black and Large White pigs-8 of them were significantly more expressed in the longissimus dorsi of Queshan Black than in Large White pigs, while the other 4 were the opposite. These 12 putative m6A-circRNAs were also found to act as miRNA sponge molecules to regulate fat deposition by constructing the ceRNA regulatory network. Enrichment analysis also revealed that the 12 m6A-circRNAs parent genes and their adsorbed miRNA target genes were widely involved in fat deposition and cell proliferation and differentiation-related pathways, such as the HIF-1 signaling pathway, the pentose phosphate pathway, the MAPK signaling pathway, the glycosphingolipid biosynthesis-lacto and neolacto series, and the TNF signaling pathway, suggesting that the analyzed m6A-circRNAs may be largely involved in the formation of pork quality. These results provide new information to study the regulatory properties of m6A-circRNAs in the formation of pork quality.

Mechanical dissection and culture of mouse cranial neural crest cells

Owing to the contribution of cranial neural crest cells (CNCCs) to the majority of craniofacial structures, they have been studied extensively for the pathogenesis of craniofacial diseases. To investigate and summarize how to isolate and culture the CNCCs from wild-type mice, a literature search was performed in online databases (PubMed and Web of Science) using optimized keywords "mouse," "cranial neural crest cell" and "culture." The literature was checked by two investigators according to the screening and exclusion criteria. Initially, 197 studies were retrieved from PubMed and 169 from Web of Science, and after excluding replicate studies, 293 articles were considered. Finally, 17 studies met all the criteria and were included in this review. The results showed that obtaining purified stem cells and balancing the need to promote cell growth and prevent unwanted early cell differentiation were the two key points in the isolation and culture of CNCCs. However, no standard criteria are available for answering these questions. Thus, it is important to emphasize the necessity for standardization of CNCC isolation, culture, and identification in research on craniofacial diseases.

Secretome of Adipose-Derived Stem Cells Cultured in Platelet Lysate Improves Migration and Viability of Keratinocytes

Chronic wounds depict a silent epidemic challenging medical professionals worldwide. Regenerative medicine uses adipose-derived stem cells (ADSC) in promising new therapies. In this study, platelet lysate (PL) as a xenogen-free substitute for foetal bovine serum (FBS) in ADSC culture was used to create an ADSC secretome containing cytokines for optimal wound healing conditions. The ADSC secretome was tested on keratinocytes for migrational behaviour and viability. Therefore, human ADSC were characterized under FBS (10%) and PL (5% and 10%) substitution, regarding morphology, differentiation, viability, gene and protein expression. ADSC were then cultured in 5% PL and their secretome was used for stimulation of keratinocyte migration and viability. To enhance the effect, ADSC were treated with Epithelial Growth Factor (EGF, 100 ng/mL) and hypoxia (1% O₂). In both PL and FBS groups, ADSC expressed typical stem cell markers. PL induced a significantly higher increase in cell viability compared to FBS substitution. ADSC secretome contained various beneficial proteins which enhance the wound healing capacity of keratinocytes. This could be optimized treating ADSC with hypoxia and EGF. In conclusion, the study shows that ADSC cultivated in 5% PL can effectively support wound healing conditions and can be considered as a promising new therapy for individual treatment of chronic wound disorders.

Effects of PLIN1 Gene Knockout on the Proliferation, Apoptosis, Differentiation and Lipolysis of Chicken Preadipocytes

Perilipin 1 (PLIN1) is one of the most abundant lipid droplet-related proteins on the surface of adipocytes. Our previous results showed that PLIN1 plays an important role in chicken lipid metabolism. To further reveal the role of PLIN1 in the growth and development of adipocytes, a chicken preadipocyte line with a PLIN1 gene knockout was established by the CRISPR/Cas9 gene editing technique, and the effects of the PLIN1 gene on the proliferation, apoptosis, differentiation and lipolysis of chicken preadipocytes were detected. The results showed that the CRISPR/Cas9 system effectively mediated knockout of the PLIN1 gene. After the deletion of PLIN1, the differentiation ability and early apoptotic activity of chicken preadipocytes decreased, and their proliferation ability increased. Moreover, knockout of PLIN1 promoted chicken preadipocyte lipolysis under basal conditions and inhibited chicken preadipocyte lipolysis under hormone stimulation. Taken together, our results inferred that PLIN1 plays a regulatory role in the process of proliferation, apoptosis, differentiation and lipolysis of chicken preadipocytes.

Potential of Epidermal Growth Factor-like Peptide from the Sea Cucumber Stichopus horrens to Increase the Growth of Human Cells: In Silico Molecular Docking Approach

The sea cucumber is prominent as a traditional remedy among Asians for wound healing due to its high capacity for regeneration after expulsion of its internal organs. A short peptide consisting of 45 amino acids from transcriptome data of Stichopus horrens (Sh-EGFl-1) shows a convincing capability to promote the growth of human melanoma cells. Molecular docking of Sh-EGFl-1 peptide with human epidermal growth factor receptor (hEGFR) exhibited a favorable intermolecular interaction, where most of the Sh-EGFl-1 residues interacted with calcium binding-like domains. A superimposed image of the docked structure against a human EGF–EGFR crystal model also gave an acceptable root mean square deviation (RMSD) value of less than 1.5 Å. Human cell growth was significantly improved by Sh-EGFl-1 peptide at a lower concentration in a cell proliferation assay. Gene expression profiling of the cells indicated that Sh-EGFl-1 has activates hEGFR through five epidermal growth factor signaling pathways; phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK), phospholipase C gamma (PLC-gamma), Janus kinase-signal transducer and activator of transcription (JAK-STAT) and Ras homologous (Rho) pathways. All these pathways triggered cells’ proliferation, differentiation, survival and re-organization of the actin cytoskeleton. Overall, this marine-derived, bioactive peptide has the capability to promote proliferation and could be further explored as a cell-growth-promoting agent for biomedical and bioprocessing applications.

Transcriptional and DNA Methylation Signatures of Subcutaneous Adipose Tissue and Adipose-Derived Stem Cells in PCOS Women

Polycystic ovary syndrome (PCOS) is often associated with metabolic syndrome features, including central obesity, suggesting that adipose tissue (AT) is a key organ in PCOS pathobiology. In this study, we compared both abdominal (ABD) and gluteofemoral (GF) subcutaneous AT in women with and without PCOS. ABD and GF subcutaneous ATs from PCOS and BMI/WHR-matched control women were analyzed by RT-qPCR, FACS and histology. ABD and GF adipose-derived stem cell (ASC) transcriptome and methylome were analyzed by RNA-seq and DNA methylation array. Similar to the control group with abdominal obesity, the GF AT of PCOS women showed lower expression of genes involved in lipid accumulation and angiogenesis compared to ABD depot. FACS analysis revealed an increase in preadipocytes number in both AT depots from PCOS. Further pathway analysis of RNA-seq comparisons demonstrated that the ASCs derived from PCOS are pro-inflammatory and exhibit a hypoxic signature in the ABD depot and have lower expression of adipogenic genes in GF depot. We also found a higher CpG methylation level in PCOS compared to control exclusively in GF-ASCs. Our data suggest that ASCs play an important role in the etiology of PCOS, potentially by limiting expansion of the healthy lower-body AT.

Bioprinted collagen-based cell-laden scaffold with growth factors for tympanic membrane regeneration in chronic perforation model

With the recent development of bioprinting technology, various attempts have been made to replace bioprinting technologies and regenerative medicine are more directed towards transplantation/reconstructive surgeries only with the implantation of scaffolds. The purpose of this study is to determine whether the growth factors, human umbilical cord serum (hUCS) and bFGF (basic fibroblast growth factor), have a synergistic effect on eardrum regeneration, when used with a cell-printed scaffold in a chronic tympanic membrane perforation (TMP) model. In this study, in vitro cellular activities for bioprinted cell-laden collagen scaffolds using human adipose stem cells (hASCs) and supplemented with 10 μg/mL hUCS and 10 ng/mL bFGF were performed. The mixture of the growth factors in the cell-laden structures effectively affects various in vitro cellular responses including the proliferation of hASCs and the migration of keratinocytes due to the synergistic effect of the growth factors and hASCs. For the in vivo evaluation, a rat TMP model was used, and the TMP regeneration was assessed by otoscopic examination, hearing threshold measurement, and histologic examination. Although the cell-laden structure containing hUCS was more enhancing effect compared to the structure with bFGF, more synergistic effect in the structure using hUCS/bFGF was observed. Based on the results, we believe that the cell-laden structure incorporating hUCS and bFGF can induce significant regeneration of chronic tympanic membrane perforation.

Combining Growth Factor and Stem Cell Therapy for Stroke Rehabilitation, A Review

Stroke is a serious, life-threatening condition demanding vigorous search for new therapies. Recent research has focused on stem cell-based therapies as a viable choice following ischemic stroke, based on studies displaying that stem cells transplanted to the brain not only survive but also cause functional recovery. Growth factors defined as polypeptides that regulate the growth and differentiation of many cell types. Many studies have demonstrated that combined use of growth factors may increase results by the stimulation of endogenous neurogenesis, anti-inflammatory, neuroprotection properties, and enhancement of stem cell survival rates and so may be more effective than a single stem cell therapy. This paper reviews and discusses the most promising new stroke recovery research, including combination treatment.

Effects of fibrous collagen/CDHA/hUCS biocomposites on bone tissue regeneration

Collagen- and bioceramic-based composites have been widely used in hard tissue engineering because they are analogous to the organic/inorganic constituents of native bones. However, biocomposites based on collagen and bioceramics show low mechanical stiffness and limited osteogenic activities. To elevate the low biophysical and biological activities, we have introduced a new biocomposite structure. Herein, we propose a biocomposite mimicking not only the physical structure of the extracellular matrix (ECM) structure but also the biochemical components of native bone tissues. Several components including fibrillated collagen, calcium-deficient hydroxyapatite (CDHA) obtained from α-tricalcium phosphate hydrolysis, and human umbilical cord serum (hUCS) were used to generate a unique structure of the biocomposite. The 3D-printed composites were topographically similar to the nanofibrous ECM and exhibited a mechanically stable structure. We also evaluated the in vitro biocompatibilities of the biocomposite using human adipose stem cells and found that the collagen/hUCS/CDHA scaffold accelerated the in vitro osteogenic differentiation of human adipose-derived stem cells and in vivo osteogenesis in a mastoid obliterated rat model.

Characterization of stem cells from human ovarian follicular fluid; a potential source of autologous stem cell for cell-based therapy

Human ovarian follicular fluid (HOFF) contains proteins, extracellular matrixes necessary for growth and maturation of oocytes as well as granulosa cells. Epithelial cells and stem cells can be isolated from HOFF. However, information regarding stem cells derived from HOFF is still lacking. The objectives of the present study were to isolate, characterize, and differentiate cells derived from HOFF. HOFF was collected during the routine aspiration of oocytes in an assisted fertilization program and subjected to cell isolation, characterization, and in vitro culture. After 24 h of culture, different cell morphologies including epithelial-like-, neural-like- and fibroblast-like cells were observed. Immunocytochemistry reveals the expression of pluripotent stem cell markers (OCT4, NANOG, SSEA4), epithelial marker (CK18), FSH- and LH-receptor. For in vitro culture, the isolated cells were continuously cultured in a growth medium; alpha MEM containing 10% FBS and epidermal growth factor (EGF). After 2 weeks of in vitro culture, cells with fibroblast-like morphology dominantly grow in the culture vessels and resemble mesenchymal stem cells (MSCs). HOFF-derived cells exhibited MSC expression of CD44, CD73, CD90, CD105, CD146, and STRO-1, and were capable of differentiation into osteoblasts, chondrocytes, and adipocytes. After induction of neural differentiation, HOFF-derived cells formed spheroidal structures and expressed neural stem cell markers including Nestin, β-tubulin III, and O4. Besides, the oocyte-like structure was observed after prolonged culture of HOFF. In conclusion, cells derived from follicular fluid exhibited stem cell characteristics, which could be useful for regenerative medicine applications and cell-based therapies.

Growth factors-based beneficial effects of platelet lysate on umbilical cord-derived stem cells and their synergistic use in osteoarthritis treatment

Poor viability of mesenchymal stem cells (MSCs) at the transplanted site often hinders the efficacy of MSCs-based therapy. Platelet lysate (PL) contains rich amounts of growth factors, which benefits cell growth. This study aimed to explore how human PL benefits umbilical cord-derived MSCs (huc-MSCs), and whether they have synergistic potential in osteoarthritis (OA) treatment. As quality control, flow cytometry and specific staining were performed to identify huc-MSCs, and ELISA was used to quantify growth factors in PL. CCK-8 and flow cytometry assays were performed to evaluate the effects of PL on the cell viability and cell cycle progression of huc-MSCs. Wound healing and transwell assays were conducted to assess the migration of huc-MSCs. RNA sequencing, real time PCR, and Western blot assays were conducted to explore the growth factors-based mechanism of PL. The in vitro results showed that PL significantly promoted the proliferation, cell cycle, and migration of huc-MSCs by upregulating relevant genes/proteins and activating beclin1-dependent autophagy via the AMPK/mTOR signaling pathway. The main growth factors (PDGF-AA, IGF-1, TGF-β, EGF, and FGF) contributed to the effects of PL in varying degrees. The in vivo data showed that combined PL and huc-MSCs exerted significant synergistic effect against OA. The overall study determined the beneficial effects and mechanism of PL on huc-MSCs and indicated PL as an adjuvant for huc-MSCs in treating OA. This is the first report on the growth factors-based mechanism of PL on huc-MSCs and their synergistic application. It provides novel knowledge of PLʹs roles and offers a promising strategy for stem cell-based OA therapy by combining PL and huc-MSCs.

Enhanced proliferative capacity of human preadipocytes achieved by an optimized cultivating method that induces transient activity of hTERT

Human mesenchymal stromal cells (MSC) are an important tool for basic and translational research. Large amounts of MSC are required for in vitro and in vivo studies, however, the limited life-span and differentiation ability in vitro hamper their optimal use. Here we report that 1:1 mixture of L15 and mTeSR1 culture media increased the life-span of IPI-SA3-C4, a normal non-immortalized human subcutaneous preadipocyte strain by 20% while retaining their adipogenic capacity and stable karyotype. The increased proliferative capacity was accompanied by increased expression of the stem markers POU5F1, SOX2, MYC and hTERT, and inhibition of hTERT activity abolished the growth advantage of L15-mTeSR1. Consequently, the described MSC culture would considerably enhance the utility of MSC for in vitro studies.

Epidermal growth factor stimulates exosomal microRNA-21 derived from mesenchymal stem cells to ameliorate aGVHD by modulating regulatory T cells

Regulatory T cells (Tregs), a subset of CD4⁺ T cells, may exert inhibitory effects on alloimmune responses including acute graft-versus-host disease (aGVHD), and several microRNAs are implicated in the pathophysiological process of GVHD. Therefore, we aimed in the present study to characterize the functional relevance of epidermal growth factor (EGF)-stimulated microRNA-21 (miR-21) in regulating bone marrow-derived mesenchymal stem cells (BMSCs) in a mouse model of aGVHD. We first isolated and cultured BMSCs and Tregs. Then, we examined effects of miR-21 knockdown or overexpression and EGF on cell activities of BMSCs and the expression of PTEN, Foxp3, AKT phosphorylation, and extent of c-jun phosphorylation by gain- and loss-of-function approaches. The results showed that miR-21 promoted the proliferation, invasion, and migration of BMSCs. Furthermore, miR-21 in BMSCs-derived exosomes inhibited PTEN, but enhanced AKT phosphorylation and Foxp3 expression in Tregs. In addition, EGF enhanced c-jun phosphorylation to elevate the miR-21 expression. Furthermore, EGF significantly increased the efficacy of BMSCs in a mouse model of aGVHD, manifesting in reduced IFN-γ expression and lesser organ damage. Moreover, EGF treatment promoted the Foxp3 expression of Tregs in BMSCs-treated aGVHD mice. Taken together, EGF induced the BMSCs-derived exosomal miR-21 expression, which enhanced Foxp3 expression in Tregs, thereby improving the therapeutic effect of BMSCs on aGVHD.

Bioactive borate glass triggers phenotypic changes in adipose stem cells

A bioactive borate glass, 13-93B3 (B3), has been used successfully in the clinic to treat chronic, nonhealing wounds without scarring. However, the mechanism by which B3 stimulates wound healing is poorly understood. Because adipose stem cells (ASCs) have been shown to have multiple roles in wound repair, we hypothesized that B3 triggers ASCs. In this study, we evaluate the effects of B3 on ASC survival, migration, differentiation, and protein secretion in vitro. In concentrations ≤10 mg/ml, B3 did not affect ASC viability under static conditions. B3 promoted the migration of ASCs but did not increase differentiation into bone or fat. B3 also decreased ASCs secretion of collagen I, PAI-1, MCP-1, DR6, DKK-1, angiogenin, IL-1, IGFBP-6, VEGF, and TIMP-2; increased expression of IL-1R and E-selectin; had a transient decrease in IL-6 secretion; and had a transient increase in bFGF secretion. Together, these results show that B3 alters the protein secretion of ASCs.

Transcriptome differences in adipose stromal cells derived from pre- and postmenopausal women

BACKGROUND

As the population ages, an increasing number of postmenopausal women are donors of adipose stromal cells (ASCs) and may benefit from autologous ASC-related treatments. However, the effect of menopausal status on ASCs has not been investigated.

METHODS

RNA sequencing data were downloaded, and differentially expressed genes (DEGs) were identified. Hierarchical clustering, Gene Ontology, and pathway analyses were applied to the DEGs. Two gene coexpression network analysis approaches were applied to the DEGs to provide a holistic view and preserve gene interactions. Hub genes of the gene coexpression network were identified, and their expression profiles were examined with clinical samples. ASCs from pre- and postmenopausal women were co-cultured with monocytes and T cells to determine their immunoregulatory role.

RESULTS

In total, 2299 DEGs were identified and presented distinct expression profiles between pre- and postmenopausal women. Gene Ontology and pathway analyses revealed some fertility-, sex hormone-, immune-, aging-, and angiogenesis-related terms and pathways. Gene coexpression networks were constructed, and the top hub genes, including TIE1, ANGPT2, RNASE1, PLVAP, CA2, and MPZL2, were consistent between the two approaches. Expression profiles of hub genes from the RNA sequencing data and clinical samples were consistent. ASCs from postmenopausal women elicit M1 polarization, while their counterparts facilitate CD3/4+ T cell proliferation.

CONCLUSIONS

The present study reveals the transcriptome differences in ASCs derived from pre- and postmenopausal women and provides holistic views by preserving gene interactions via gene coexpression network analysis. The top hub genes identified by this study could serve as potential targets to enhance the therapeutic potential of ASCs.

The superiority of conditioned medium derived from rapidly expanded mesenchymal stem cells for neural repair

Background

Spinal cord injury (SCI) is a complex and severe neurological condition. Mesenchymal stem cells (MSCs) and their secreted factors show promising potential for regenerative medicine. Many studies have investigated MSC expansion efficacy of all kinds of culture medium formulations, such as growth factor-supplemented or xeno-free medium. However, very few studies have focused on the potential of human MSC (hMSC) culture medium formulations for injured spinal cord repair. In this study, we investigated the effect of hMSC-conditioned medium supplemented with bFGF, EGF, and patient plasma, namely, neural regeneration laboratory medium (NRLM), on SCI in vitro and in vivo.

Methods

Commercial and patient bone marrow hMSCs were obtained for cultivation in standard medium and NRLM separately. Several characteristics, including CD marker expression, differentiation, and growth curves, were compared between MSCs cultured in standard medium and NRLM. Additionally, we investigated the effect of the conditioned medium (referred to as NRLM-CM) on neural repair, including inflammation inhibition, neurite regeneration, and spinal cord injury (SCI), and used a coculture system to detect the neural repair function of NRLM-MSCs.

Results

Compared to standard culture medium, NRLM-CM had superior in inflammation reduction and neurite regeneration effects in vitro and improved functional restoration in SCI rats in vivo. In comparison with standard culture medium MSCs, NRLM-MSCs proliferated faster regardless of the age of the donor. NRLM-MSCs also showed increased adipose differentiative potential and reduced CD90 expression. Both types of hMSC CM effectively enhanced injured neurite outgrowth and protected against H₂O₂ toxicity in spinal cord neuron cultures. Cytokine arrays performed in hMSC-CM further revealed the presence of at least 120 proteins. Among these proteins, 6 demonstrated significantly increased expression in NRLM-CM: adiponectin (Acrp30), angiogenin (ANG), HGF, NAP-2, uPAR, and IGFBP2.

Conclusions

The NRLM culture system provides rapid expansion effects and functional hMSCs. The superiority of the derived conditioned medium on neural repair shows potential for future clinical applications.

Fibroblast growth factor-2 stimulates proliferation of human adipose-derived stem cells via Src activation

Background

Human adipose-derived stem cells (hASCs) are a subset of mesenchymal stem cells (MSCs); it has been regarded as one of the most promising stem cells. We previously found that fibroblast growth factor-2 (FGF-2) enhanced the proliferation and differentiation of hASC. However, the mechanisms involved in the growth of hASCs by FGF-2 have not been investigated.

Methods

Human adipose-derived stem cells (hASCs) were cultured with FGF-2, and cell growth was assessed. Effects of FGF Receptor (FGFR) inhibitor (NVP-BGJ398), ERK1/2 inhibitor (PD98059), PI3K/Akt inhibitor (LY294002), JNK inhibitor (SP600125), and p38 MAPK inhibitor (SB203580) and Src inhibitor (PP1) on the proliferation were investigated. At the same time, we assessed the effect of FGFR inhibitor on several signaling enzymes such as ERK1/2, JNK, p38, and Akt, in protein level. The involvement of Src activation by FGF-2 was also examined.

Results

FGF-2 markedly promoted proliferation of hASCs at concentrations lower than 10 ng/ml and stimulated cell progression to the S and G2/M phases. Proliferation was blocked by the FGFR inhibitor (NVP-BGJ398) and various signaling pathway inhibitors, such as Erk1/2 inhibitor (PD98059), PI3K/Akt inhibitor (LY294002), JNK inhibitor (SP600125), and p38MAPK inhibitor (SB203580). The FGFR inhibitor reduced the activation of protein kinases, such as AKT, Erk1/2, JNK, and p38, in several signaling pathways. The downstream kinase of FGFR, Src, was activated by FGF-2, and its activation was canceled by the FGFR inhibitor. MEK1/2, a downstream kinase of Src, was parallelly regulated by FGF-2. The Src inhibitor (PP1) markedly blocked the proliferation of hASCs via inhibition of Src and MEK1/2.

Conclusion

Src activation is indispensable for FGF-2-mediated proliferation of ASCs, as well as the subsequent activation of multi-signaling pathways.

LncRNA TUG1 regulates FGF1 to enhance endothelial differentiation of adipose-derived stem cells by sponging miR-143

Adipose-derived stem cells (ADSCs) have emerged as a cell source for regeneration medicine. ADSCs possess the capacity to differentiate into endothelial cells and serve an essential role in vascular development and function. LncRNA taurine upregulated gene 1 (TUG1) has recently been linked with angiogenesis in hepatoblastoma. However, the roles of TUG1 in endothelial differentiation of ADSCs remain unidentified. Human adipose-derived stem cells (hADSCs) were obtained and characterized by flow cytometry, Oil red O and Alizarin Red staining. HADSCs were maintained in the endothelial differentiation medium and the expressions of TUG1, miR-143, and FGF1 were examined by qRT-PCR. To assess endothelial differentiation, the expressions of CD31, von Willebrand factor (vWF), VE-cadherin were examined by Western blot analysis, qRT-PCR, and immunofluorescence. Tube formation in Matrigel was examined. The interactions between TUG1 and miR-143, miR-143 and FGF1 were validated by luciferase assays. During the endothelial differentiation process, TUG1 and FGF1 were upregulated, whereas miR-143 was downregulated. TUG1 overexpression downregulated miR-143, upregulated FGF1, CD31, vWF, and VE-cadherin, and enhanced capillary tube formation. Luciferase assays showed that TUG1 interacted with miR-143, and FGF1 was a direct target of miR-143. Furthermore, the enhancement of endothelial differentiation induced by TUG1 overexpression was abolished by miR-143 overexpression. Our findings implicated that lncRNA TUG1 promoted endothelial differentiation of ADSCs by regulating the miR-143/FGF1 axis.

Establishment of an in vitro model of cultured viable human, porcine and canine skin and comparison of different media supplements

Transdermal drug delivery provides several advantages over conventional drug administration, such as the avoidance of first-pass metabolism and better patient compliance. In vitro research can abbreviate and facilitate the pharmaceutical development considerably compared to in vivo research as drug screening and clinical studies can be reduced. These advantages led to the development of corresponding skin models. Viable skin models are more useful than non-viable ones, due to the influence of skin metabolism on the results. While most in vitro studies concentrate on evaluating human-based models, the current study is designed for the investigation of both human and animal diseases. So far, there is little information available in the literature about viable animal skin cultures which are in fact intended for application in the veterinary and not the human field. Hence, the current study aims to fill the gap. For the in vitro viable skin model, specimens of human, porcine and canine skin were cultured over two weeks under serum-free conditions. To evaluate the influence of medium supplementation on skin viability, two different supplement mixtures were compared with basic medium. The skin specimens were maintained at a viability-level >50% until the end of the study. From the tested supplements, the addition of bovine pituitary extract and epidermal growth factor increased skin viability whereas hydrocortisone and insulin induced a decrease. This in vitro viable skin model may be a useful tool for the investigation of skin diseases, especially for the veterinary field.

Dual-chambered membrane bioreactor for coculture of stratified cell populations

We have developed a dual-chambered bioreactor (DCB) that incorporates a membrane to study stratified 3D cell populations for skin tissue engineering. The DCB provides adjacent flow lines within a common chamber; the inclusion of the membrane regulates flow layering or mixing, which can be exploited to produce layers or gradients of cell populations in the scaffolds. Computational modeling and experimental assays were used to study the transport phenomena within the bioreactor. Molecular transport across the membrane was defined by a balance of convection and diffusion; the symmetry of the system was proven by its bulk convection stability, while the movement of molecules from one flow line to the other is governed by coupled convection-diffusion. This balance allowed the perfusion of two different fluids, with the membrane defining the mixing degree between the two. The bioreactor sustained two adjacent cell populations for 28 days, and was used to induce indirect adipogenic differentiation of mesenchymal stem cells due to molecular cross-talk between the populations. We successfully developed a platform that can study the dermis-hypodermis complex to address limitations in skin tissue engineering. Furthermore, the DCB can be used for other multilayered tissues or the study of communication pathways between cell populations.

Stem Cell Therapy for Tendon Regeneration: Current Status and Future Directions

In adults the healing tendon generates fibrovascular scar tissue and recovers never histologically, mechanically, and functionally which leads to chronic and to degenerative diseases. In this review, the processes and mechanisms of tendon development and fetal regeneration in comparison to adult defect repair and degeneration are discussed in relation to regenerative therapeutic options. We focused on the application of stem cells, growth factors, transcription factors, and gene therapy in tendon injury therapies in order to intervene the scarring process and to induce functional regeneration of the lesioned tissue. Outlines for future therapeutic approaches for tendon injuries will be provided.

The role of stem cells in anti-aging medicine

Aging is the result of two overlapping processes, "intrinsic" and "extrinsic." Intrinsic structural changes occur as a consequence of physiologic aging and are genetically determined; extrinsic relates to exposure to harmful events and habits, like smoking, bad diet, alcohol consumption, lack of sleep, stress, sun exposure, environmental pollution, etc. Aging may be decelerated by improving bad habits or treating signs of aging with various esthetic methods, food supplements, and antioxidants. It is believed that we cannot stop aging entirely due to the intrinsic part, which leads to irreversible cell damage, as well as tissue and organ damage due to their limited ability to regenerate. Stem cells and their ability to exhibit telomerase activity, to self-renew, and to differentiate into all three embryonic tissues challenges aging as a process, which is not inevitable and can even possibly be reversed. Stem cells can promote regeneration of aged tissues and organs by replacing apoptotic and necrotic cells with healthy ones. In addition, they can have antiinflammatory and antiapoptotic properties by paracrine-secreting growth factors and cytokines on the site of administration. Autologous adipose-derived stem cells are the most promising because they can be easily harvested in huge numbers with minimally invasive liposuction and, as such, represent a powerful tool in anti-aging and regenerative medicine. In this contribution, the author discusses their properties and application in clinical practice.

Current and Future Perspectives on Skin Tissue Engineering: Key Features of Biomedical Research, Translational Assessment, and Clinical Application

The skin is responsible for several important physiological functions and has enormous clinical significance in wound healing. Tissue engineered substitutes may be used in patients suffering from skin injuries to support regeneration of the epidermis, dermis, or both. Skin substitutes are also gaining traction in the cosmetics and pharmaceutical industries as alternatives to animal models for product testing. Recent biomedical advances, ranging from cellular-level therapies such as mesenchymal stem cell or growth factor delivery, to large-scale biofabrication techniques including 3D printing, have enabled the implementation of unique strategies and novel biomaterials to recapitulate the biological, architectural, and functional complexity of native skin. This progress report highlights some of the latest approaches to skin regeneration and biofabrication using tissue engineering techniques. Current challenges in fabricating multilayered skin are addressed, and perspectives on efforts and strategies to meet those limitations are provided. Commercially available skin substitute technologies are also examined, and strategies to recapitulate native physiology, the role of regulatory agencies in supporting translation, as well as current clinical needs, are reviewed. By considering each of these perspectives while moving from bench to bedside, tissue engineering may be leveraged to create improved skin substitutes for both in vitro testing and clinical applications.

Development of keratin-based membranes for potential use in skin repair

The layers in skin determine its protective and hemostasis functions. This layered microstructure cannot be naturally regenerated after severe burns; we aim to reconstruct it using guided tissue regeneration (GTR). In GTR, a membrane is used to regulate tissue growth by stopping fast-proliferating cells and allowing slower cells to migrate and reconstruct specialized microstructures. Here, we proposed the use of keratin membranes crosslinked via dityrosine bonding. Variables from the crosslinking process were grouped within an energy density (ED) parameter to manufacture and evaluate the membranes. Sol fraction, spectrographs, and thermograms were used to quantify the non-linear relation between ED and the resulting crosslinking degree (CD). Mechanical and swelling properties increased until an ED threshold was reached; at higher ED, the CD and properties of the membranes remained invariable indicating that all possible dityrosine bonds were formed. Transport assays showed that the membranes allow molecular diffusion; low ED membranes retain solutes within their structure while the high ED samples allow higher transport rates indicating that uncrosslinked proteins can be responsible of reducing transport. This was confirmed with lower transport of adipogenic growth factors to stem cells when using low ED membranes; high ED samples resulted in increased production of intracellular lipids. Overall, we can engineer keratin membranes with specific CD, a valuable tool to tune microstructural and transport properties.

Brown-Like Adipocyte Progenitors Derived from Human iPS Cells: A New Tool for Anti-obesity Drug Discovery and Cell-Based Therapy?

Alternative strategies are urgently required to fight obesity and associated metabolic disorders including diabetes and cardiovascular diseases. Brown and brown-like adipocytes (BAs) store fat, but in contrast to white adipocytes, activated BAs are equipped to dissipate energy stored. Therefore, BAs represent promising cell targets to counteract obesity. However, the scarcity of BAs in adults is a major limitation for a BA-based therapy of obesity, and the notion to increase the BA mass by transplanting BA progenitors (BAPs) in obese patients recently emerged. The next challenge is to identify an abundant and reliable source of BAPs. In this chapter, we describe the capacity of human-induced pluripotent stem cells (hiPSCs) to generate BAPs able to differentiate at a high efficiency with no gene transfer. This cell model represents an unlimited source of human BAPs that in a near future may be a suitable tool for both therapeutic transplantation and for the discovery of novel efficient and safe anti-obesity drugs. The generation of a relevant cell model, such as hiPSC-BAs in 3D adipospheres enriched with macrophages and endothelial cells to better mimic the microenvironment within the adipose tissue, will be the next critical step.

Lipopolysaccharide promoted proliferation and adipogenesis of preadipocytes through JAK/STAT and AMPK-regulated cPLA2 expression

The proliferation and adipogenesis of preadipocytes played important roles in the development of adipose tissue and contributed much to the processes of obesity. On the other hand, lipopolysaccharide (LPS), also known as endotoxin, is a key outer membrane component of gram-negative bacteria in the gut microbiota, and has a dominant role in linking inflammation to high-fat diet-induced metabolic syndrome. Studies suggested the potential roles of LPS in hepatic steatosis and in obese mice models. However, the molecular mechanisms underlying LPS-regulated obesity remained largely unknown. Here we reported that LPS stimulated expression of cyosolic phospholipase A2 (cPLA2), one of inflammation regulators of obesity, in the preadipocytes. Pretreatment the inhibitors of JAK2, STAT3, STAT5 or AMPK significantly reduced LPS-increased mRNA and protein expression of cPLA2 together with phosphorylation of JAK2, STAT3, STAT5 and AMPK, separately. Similarly, transfection of siRNA against JAK2 or AMPK abolished expression of cPLA2 and phosphorylation of JAK2 or AMPK together with downregulated expression of JAK2 and AMPK protein. LPS enhanced activation of STAT3 and STAT5 via JAK2-dependent manner in the preadipocytes. Transfection of JAK2 or AMPK siRNA further proofed the independence of JAK2 and AMPK in LPS-treated preadipocytes. In addition, LPS-increased DNA synthesis, cell numbers and cell viability of preadipocytes were attenuated by AACOCF3, AG490, BML-275, cPLA2 siRNA, JAK2 siRNA or AMPK siRNA. Attenuation JAK2/STAT or AMPK-dependent cPLA2 expression reduced LPS-mediated adipogenesis of preadipocytes. Stimulation of arachidonic acid or AMPK activator, A-769662, increased cell numbers and cell viability and promoted differentiation of preadipocytes. Collectively, these results indicated that LPS increased preadipocytes proliferation and adipogenesis via JAK/STAT and AMPK-dependent cPLA2 expression. The mechanisms of LPS-stimulated cPLA2 expression may be a link between bacteria and obesity and provides the molecular basis for preventing metabolic syndrome or hyperplasic obesity.

Transcriptome analysis of adipose tissue from pigs divergent in feed efficiency reveals alteration in gene networks related to adipose growth, lipid metabolism, extracellular matrix, and immune response

Adipose tissue is hypothesized to play a vital role in regulation of feed efficiency (FE; efficiency in converting energy and nutrients into tissue), of which improvement will simultaneously reduce environmental impact and feed cost per pig. The objective of the present study was to sequence the subcutaneous adipose tissue transcriptome in FE-divergent pigs (n = 16) and identify relevant biological processes underpinning observed differences in FE. We previously demonstrated that high-FE pigs were associated with lower fatness when compared to their counterparts. Here, ontology analysis of a total of 209 annotated genes that were differentially expressed at a p < 0.01 revealed establishment of a dense extracellular matrix and inhibition of capillary formation as one underlying mechanism to achieve suppressed adipogenesis. Moreover, mechanisms ensuring an efficient utilization of lipids in high-FE pigs might be orchestrated by upstream regulators including CEBPA and EGF. Consequently, high-FE adipose tissue could exhibit more efficient cholesterol disposal, whilst inhibition of inflammatory and immune response in high-FE pigs may be an indicator of an optimally functioning adipose tissue. Taken together, adipose tissue growth, extracellular matrix formation, lipid metabolism and inflammatory and immune response are key biological events underpinning the differences in FE. Further investigations focusing on elucidating these processes would assist the animal production industry in optimizing strategies related to nutrient utilization and product quality.

Differential open chromatin profile and transcriptomic signature define depot-specific human subcutaneous preadipocytes: primary outcomes

Background

Increased lower body fat is associated with reduced cardiometabolic risk. The molecular basis for depot-specific differences in gluteofemoral (GF) compared with abdominal (A) subcutaneous adipocyte function is poorly understood. In the current report, we used a combination of Assay for Transposase-Accessible Chromatin followed by sequencing (ATAC-seq), RNA-seq, and chromatin immunoprecipitation (ChIP)-qPCR analyses that provide evidence that depot-specific gene expression patterns are associated with differential epigenetic chromatin signatures.

Methods

Preadipocytes cultured from A and GF adipose tissue obtained from premenopausal apple-shaped women were used to perform transcriptome analysis by RNA-seq and assess accessible chromatin regions by ATAC-seq. We measured mRNA expression and performed ChIP-qPCR experiments for histone modifications of active (H3K4me3) and repressed chromatin (H3K27me3) regions respectively on the promoter regions of differentially expressed genes.

Results

RNA-seq experiments revealed an A-fat and GF-fat selective gene expression signature, with 126 genes upregulated in abdominal preadipocytes and 90 genes upregulated in GF cells. ATAC-seq identified almost 10-times more A-specific chromatin-accessible regions. Using a combined analysis of ATAC-seq and global gene expression data, we identified 74 of the 126 abdominal-specific genes (59%) with A-specific accessible chromatin sites within 200 kb of the transcription start site (TSS), including HOXA3, HOXA5, IL8, IL1b, and IL6. Interestingly, only 14 of the 90 GF-specific genes (15%) had GF-specific accessible chromatin sites within 200 kb of the corresponding TSS, including HOXC13 and HOTAIR, whereas 25 of them (28%) had abdominal-specific accessible chromatin sites. ChIP-qPCR experiments confirmed that the active H3K4me3 chromatin mark was significantly enriched at the promoter regions of HOXA5 and HOXA3 genes in abdominal preadipocytes, while H3K27me3 was less abundant relative to chromatin from GF. This is consistent with their A-fat specific gene expression pattern. Conversely, analysis of the promoter regions of the GF specific HOTAIR and HOXC13 genes exhibited high H3K4me3 and low H3K27me3 levels in GF chromatin compared to A chromatin.

Conclusions

Global transcriptome and open chromatin analyses of depot-specific preadipocytes identified their gene expression signature and differential open chromatin profile. Interestingly, A-fat-specific open chromatin regions can be observed in the proximity of GF-fat genes, but not vice versa.

Trial registration

Clinicaltrials.gov, NCT01745471. Registered 5 December 2012.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0582-0) contains supplementary material, which is available to authorized users.

In vitro preconditioning of insulin-producing cells with growth factors improves their survival and ability to release insulin

Glucose-induced oxidative stress in the diabetic pancreas directly affects viability and the consequent therapeutic outcome of transplanted stem cells. Pretreatment of stem cells with growth factors induces tolerance in them against various stresses (hypoxia, thermal or hyperglycaemic). This study investigated the effect of pretreatment on insulin-producing cells (IPCs) differentiated from adipose-derived mesenchymal stem cells (ADMSCs), with a combination of stromal cell-derived factor 1 alpha (SDF1 α) and basic fibroblast growth factor (bFGF) against hyperglycaemic stress (17 or 33 mM glucose). The results showed that IPCs pretreated with a combination of SDF1α and bFGF exhibited maximally alleviated apoptosis, senescence and cell damage with a concomitantly increased release of insulin, enhanced cell proliferation and greater upregulation of Insulin 1, Insulin 2, Ngn3, Pdx1 and Nkx6.2 when stressed with 33 mM glucose. These findings may offer an improved therapeutic outcome for the treatment of diabetes.

Exposure of adipocytes to bisphenol-A in vitro interferes with insulin action without enhancing adipogenesis

Bisphenol-A (BPA) is a lipophilic compound widely used in the manufacture of plastic items and thought to play a role in the growing obesity epidemic. Recent publications suggest that BPA may have a pro-adipogenic effect. Here we explore the effect of low, but environmentally relevant, concentrations of BPA on adipogenesis using a variety of cellular models. Mouse 3T3-L1, C3H10T1/2 and human adipose-derived stromal cells (hADSCs) were cultured with BPA concentrations ranging from 0.1nM to 100μM. We failed to observe positive effects on differentiation at any dose or in any model. 3T3-L1 adipocytes differentiated with high concentrations of BPA showed decreased mRNA expression of several adipocyte markers. Mature adipocytes differentiated in the presence of BPA were insulin resistant, with an approximate 25% reduction in insulin-stimulated glucose uptake. This was accompanied by a significant decrease in insulin-stimulated Akt phosphorylation, and an increase in mRNA levels of inflammatory markers (i.e. IL-6, TNFα). In conclusion, low, but environmentally relevant, doses of BPA may contribute to the development of a chronic, low-grade inflammatory state in exposed adipocytes, which in turn may affect adipose tissue insulin sensitivity, independent of adipogenesis. These studies suggest an alternative mechanism by which BPA may contribute to the development of obesity.

Comparison of human platelet lysate alternatives using expired and freshly isolated platelet concentrates for adipose-derived stromal cell expansion

Pooled human platelet lysate (pHPL) has been used to expand adipose-derived stromal cells (ASCs) and can be formulated using fresh or expired buffy coats (BCs) which are then resuspended in either plasma or an additive solution. Not much is known about the effects that expired products and additive solutions have on ASC expansion, and the need for quality control and release criteria has been expressed. This pilot study compared proliferation, cell size, morphology and immunophenotype of ASCs expanded in the different pHPL alternatives versus foetal bovine serum (FBS). Quality control criteria were assessed prior to and during the manufacture of the pHPL alternatives. ASCs were then expanded in 1%, 2.5%, 5% or 10% of the different pHPL alternatives or in 10% FBS. Cell size, morphology, cell number and immunophenotype were measured using microscopy and flow cytometry. The majority of the pHPL alternatives were within the recommended ranges for the quality control criteria. ASCs expanded in the pHPL alternatives were smaller in size, displayed a tighter spindle-shaped morphology, increased cell growth and had a similar immunophenotype (with the exception of CD34 and CD36) when compared to ASCs expanded in FBS. Here we report on the effects that expired BC products and additive solutions have on ASC expansion. When taken together, our findings indicate that all of the pHPL alternatives can be considered to be suitable replacements for FBS for ASC expansion, and that expired BC products can be used as an alternative to fresh BC products.

Uncultivated stromal vascular fraction is equivalent to adipose-derived stem and stromal cells on porous polyurethrane scaffolds forming adipose tissue in vivo

OBJECTIVES/HYPOTHESIS

To find an alternative approach to contemporary techniques in tissue augmentation and reconstruction, tissue engineering strategies aim to involve adipose-derived stem and stromal cells (ASCs) harboring a strong differentiation potential into various tissue types such as bone, cartilage, and fat.

STUDY DESIGN

Animal research.

METHODS

The stromal vascular fraction (SVF) was used directly as a cell source to provide a potential alternative to contemporary ASC-based adipose tissue engineering. Seeded in TissuCol fibrin, we applied ASCs or SVF cells to porous, degradable polyurethane (PU) scaffolds.

RESULTS

We successfully demonstrated the in vivo generation of volume-stable, well-vascularized PU-based constructs containing host-derived mature fat pads. Seeded human stem cells served as modulators of host-cell migration rather than differentiating themselves. We further demonstrated that preliminary culture of SVF cells was not necessary.

CONCLUSIONS

Our results bring adipose tissue engineering, together with automated processing devices, closer to clinical applicability. The time-consuming and cost-intensive culture and induction of the ASCs is not necessary.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:E206-E213, 2018.

Human adipose tissue-derived tenomodulin positive subpopulation of stem cells: A promising source of tendon progenitor cells

Cell-based therapies are of particular interest for tendon and ligament regeneration given the low regenerative potential of these tissues. Adipose tissue is an abundant source of stem cells, which may be employed for the healing of tendon lesions. However, human adult multipotent adipose-derived stem cells (hASCs) isolated from the stromal vascular fraction of adipose tissue originate highly heterogeneous cell populations that hinder their use in specific tissue-oriented applications. In this study, distinct subpopulations of hASCs were immunomagnetic separated and their tenogenic differentiation capacity evaluated in the presence of several growth factors (GFs), namely endothelial GF, basic-fibroblast GF, transforming GF-β1 and platelet-derived GF-BB, which are well-known regulators of tendon development, growth and healing. Among the screened hASCs subpopulations, tenomodulin-positive cells were shown to be more promising for tenogenic applications and therefore this subpopulation was further studied, assessing tendon-related markers (scleraxis, tenomodulin, tenascin C and decorin) both at gene and protein level. Additionally, the ability for depositing collagen type I and III forming extracellular matrix structures were weekly assessed up to 28 days. The results obtained indicated that tenomodulin-positive cells exhibit phenotypical features of tendon progenitor cells and can be biochemically induced towards tenogenic lineage, demonstrating that this subset of hASCs can provide a reliable source of progenitor cells for therapies targeting tendon regeneration.

Homogeneity evaluation of mesenchymal stem cells based on electrotaxis analysis

Stem cell therapy that can restore function to damaged tissue, avoid host rejection and reduce inflammation throughout body without use of immunosuppressive drugs. The established methods were used to identify and to isolate specific stem cell markers by FACS or by immunomagnetic cell separation. The procedures for distinguishing population of stem cells took a time and needed many preparations. Here we suggest an electrotaxis analysis as a new method to evaluate the homogeneity of mesenchymal stem cells which can observe the stem cell population in culture condition and wide use to various types of stem cells. Human mesenchymal stem cell, adipose derived stem cell, tonsil derived stem cell and osteogenic differentiated cells migrated toward anode but the migration speed of differentiated cells was significantly decreased versus that of stem cells. In mixture of stem cells and differentiated cells condition, we identified that the ratio of stem cell versus differentiated cell was matched with the homogeneity evaluation data of stem cells based on electrotaxis analysis. As a result, our evaluation tool has the possibility of the wide use to stem cell homogeneity evaluation and might be used as the stem cell quality control during stem cell culture without any additional antibodies.

Effect of platelet-rich plasma on degeneration change of rotator cuff muscles: In vitro and in vivo evaluations

Atrophy with fatty degeneration is often seen in rotator cuff muscles with torn tendons. PRP has been reported to enhance tissue repair processes after tendon ruptures. However, the effect of PRP on atrophy and fatty degeneration of the muscle is not yet known. The aim of this study is to examine the effect of PRP on degeneration change of rotator cuff muscles in vitro and in vivo. A murine myogenic cell line and a rat rotator cuff tear model were used in this study and PRP was administrated into subacromial space which is widely used in clinical practice. In in vitro study, administration of PRP to C2C12 cells stimulated cell proliferation while inhibited both myogenic and adipogenic differentiation. In in vivo study, administration of PRP suppressed Oil Red-O positive lipid droplet formation. The expression of adipogenic genes was also decreased by PRP administration. In conclusion, PRP promoted proliferation of myoblast cells, while inhibiting adipogenic differentiation of myoblast cells and suppressing fatty degeneration change in rat torn rotator cuff muscles. Further investigations are needed to determine the clinical applicability of the PRP. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1806-1815, 2017.

Facial intramuscular lipoma occurrence following topical cosmetic injection with a mixture of basic fibroblast growth factor: A report of two cases

Growth factors and cytokines control cell growth, proliferation and differentiation via a network of inter- and intracellular signalling pathways, and are involved in skin self-renewing and wound healing. In recent years, topical and injectable growth factors and cytokines have emerged as an intriguing therapeutic modality that can be harnessed for aesthetic purposes. However, very little data are available on their long-term safety and tolerability. In this report, we describe two cases of patients, who developed intramuscular lipoma of the chin following topical injection with a mixture of basic fibroblast growth factor as the main ingredients for chin augmentation. Biopsies in the two cases were performed at our department, and revealed intramuscular lipoma. Our report indicates that the topical injection of growth factors can lead to tumorigenesis, so health care providers need to be aware of its potential consequences.

Making the Switch: Alternatives to Fetal Bovine Serum for Adipose-Derived Stromal Cell Expansion

Adipose-derived stromal cells (ASCs) are being used extensively in clinical trials. These trials require that ASCs are prepared using good manufacturing practices (GMPs) and are safe for use in humans. The majority of clinical trials in which ASCs are expanded make use of fetal bovine serum (FBS). While FBS is used traditionally in the research setting for in vitro expansion, it does carry the risk of xenoimmunization and zoonotic transmission when used for expanding cells destined for therapeutic purposes. In order to ensure a GMP quality product for cellular therapy, in vitro expansion of ASCs has been undertaken using xeno-free (XF), chemically-defined, and human blood-derived alternatives. These investigations usually include the criteria proposed by the International Society of Cellular Therapy (ISCT) and International Fat Applied Technology Society (IFATS). The majority of studies use these criteria to compare plastic-adherence, morphology, the immunophenotype and the trilineage differentiation of ASCs under the different medium supplemented conditions. Based on these studies, all of the alternatives to FBS seem to be suitable replacements; however, each has its own advantages and drawbacks. Very few studies have investigated the effects of the supplements on the immunomodulation of ASCs; the transcriptome, proteome and secretome; and the ultimate effects in appropriate animal models. The selection of medium supplementation will depend on the downstream application of the ASCs and their efficacy and safety in preclinical studies.

Brown-like adipose progenitors derived from human induced pluripotent stem cells: Identification of critical pathways governing their adipogenic capacity

Human induced pluripotent stem cells (hiPSCs) show great promise for obesity treatment as they represent an unlimited source of brown/brite adipose progenitors (BAPs). However, hiPSC-BAPs display a low adipogenic capacity compared to adult-BAPs when maintained in a traditional adipogenic cocktail. The reasons of this feature are unknown and hamper their use both in cell-based therapy and basic research. Here we show that treatment with TGFβ pathway inhibitor SB431542 together with ascorbic acid and EGF were required to promote hiPSCs-BAP differentiation at a level similar to adult-BAP differentiation. hiPSC-BAPs expressed the molecular identity of adult-UCP1 expressing cells (PAX3, CIDEA, DIO2) with both brown (ZIC1) and brite (CD137) adipocyte markers. Altogether, these data highlighted the critical role of TGFβ pathway in switching off hiPSC-brown adipogenesis and revealed novel factors to unlock their differentiation. As hiPSC-BAPs display similarities with adult-BAPs, it opens new opportunities to develop alternative strategies to counteract obesity.