The molecular mechanism underlying the proliferating and preconditioning effect of vitamin C on adipose-derived stem cells

Involvement of DKK1 secreted from adipose-derived stem cells in alopecia areata

Adipose-derived stem cells (ASCs) have shown efficacy in promoting hair growth, while DKK1 inhibits the WNT pathway, which is associated with hair loss. Our study focused on investigating the expression of DKK1 in alopecia areata (AA), a condition characterised by significant increases in the DKK1 levels in human and mouse ASCs. Treatment of interferon-γ increased the expression of DKK1 via STAT3 phosphorylation in ASCs. Treatment with recombinant DKK1 resulted in a decrease of cell growth in outer root sheath cells, whereas the use of a DKK1 neutralising antibody promoted hair growth. These results indicate that ASCs secrete DKK1, playing a crucial role in the progression and development of AA. Consequently, we generated DKK1 knockout (KO) ASCs using the Crispr/Cas9 system and evaluated their hair growth-promoting effects in an AA model. The DKK1 KO in ASCs led to enhanced cell motility and reduced cellular senescence by activating the WNT signalling pathway, while it reduced the expression of inflammatory cytokines by inactivating the NF-kB pathway. As expected, the intravenous injection of DKK1-KO-ASCs in AA mice, and the treatment with a conditioned medium derived from DKK1-KO-ASCs in hair organ culture proved to be more effective compared with the use of naïve ASCs and their conditioned medium. Overall, these findings suggest that DKK1 represents a novel therapeutic target for treating AA, and cell therapy using DKK1-KO-ASCs demonstrates greater efficiency.

Collagen VI Deficiency Impairs Tendon Fibroblasts Mechanoresponse in Ullrich Congenital Muscular Dystrophy

The pericellular matrix (PCM) is a specialized extracellular matrix that surrounds cells. Interactions with the PCM enable the cells to sense and respond to mechanical signals, triggering a proper adaptive response. Collagen VI is a component of muscle and tendon PCM. Mutations in collagen VI genes cause a distinctive group of inherited skeletal muscle diseases, and Ullrich congenital muscular dystrophy (UCMD) is the most severe form. In addition to muscle weakness, UCMD patients show structural and functional changes of the tendon PCM. In this study, we investigated whether PCM alterations due to collagen VI mutations affect the response of tendon fibroblasts to mechanical stimulation. By taking advantage of human tendon cultures obtained from unaffected donors and from UCMD patients, we analyzed the morphological and functional properties of cellular mechanosensors. We found that the length of the primary cilia of UCMD cells was longer than that of controls. Unlike controls, in UCMD cells, both cilia prevalence and length were not recovered after mechanical stimulation. Accordingly, under the same experimental conditions, the activation of the Hedgehog signaling pathway, which is related to cilia activity, was impaired in UCMD cells. Finally, UCMD tendon cells exposed to mechanical stimuli showed altered focal adhesions, as well as impaired activation of Akt, ERK1/2, p38MAPK, and mechanoresponsive genes downstream of YAP. By exploring the response to mechanical stimulation, for the first time, our findings uncover novel unreported mechanistic aspects of the physiopathology of UCMD-derived tendon fibroblasts and point at a role for collagen VI in the modulation of mechanotransduction in tendons.

Bee Venom Stimulates Growth Factor Release from Adipose-Derived Stem Cells to Promote Hair Growth

Limited evidence suggests that stimulating adipose-derived stem cells (ASCs) indirectly promotes hair growth. We examined whether bee venom (BV) activated ASCs and whether BV-induced hair growth was facilitated by enhanced growth factor release by ASCs. The induction of the telogen-to-anagen phase was studied in mice. The underlying mechanism was investigated using organ cultures of mouse vibrissa hair follicles. When BV-treated ASCs were injected subcutaneously into mice, the telogen-to-anagen transition was accelerated and, by day 14, the hair weight increased. Quantitative polymerase chain reaction (qPCR) revealed that BV influenced the expression of several molecules, including growth factors, chemokines, channels, transcription factors, and enzymes. Western blot analysis was employed to verify the protein expression levels of extracellular-signal-regulated kinase (ERK) and phospho-ERK. Both the Boyden chamber experiment and scratch assay confirmed the upregulation of cell migration by BV. Additionally, ASCs secreted higher levels of growth factors after exposure to BV. Following BV therapy, the gene expression levels of alkaline phosphatase (ALP), fibroblast growth factor (FGF)-1 and 6, endothelial cell growth factor, and platelet-derived growth factor (PDGF)-C were upregulated. The findings of this study suggest that bee venom can potentially be utilized as an ASC-preconditioning agent for hair regeneration.

Current Status of Tissue Regenerative Engineering for the Treatment of Uterine Infertility

With the recent developments in tissue engineering, scientists have attempted to establish seed cells from different sources, create cell sheets through various technologies, implant them on scaffolds with various spatial structures, or load scaffolds with cytokines. These research results are very optimistic, bringing hope to the treatment of patients with uterine infertility. In this article, we reviewed articles related to the treatment of uterine infertility from the aspects of experimental treatment strategy, seed cells, scaffold application, and repair criteria so as to provide a basis for future research.

Cartilage 3D bioprinting for rhinoplasty using adipose-derived stem cells as seed cells: Review and recent advances

Nasal deformities due to various causes affect the aesthetics and use of the nose, in which case rhinoplasty is necessary. However, the lack of cartilage for grafting has been a major problem and tissue engineering seems to be a promising solution. 3D bioprinting has become one of the most advanced tissue engineering methods. To construct ideal cartilage, bio-ink, seed cells, growth factors and other methods to promote chondrogenesis should be considered and weighed carefully. With continuous progress in the field, bio-ink choices are becoming increasingly abundant, from a single hydrogel to a combination of hydrogels with various characteristics, and more 3D bioprinting methods are also emerging. Adipose-derived stem cells (ADSCs) have become one of the most popular seed cells in cartilage 3D bioprinting, owing to their abundance, excellent proliferative potential, minimal morbidity during harvest and lack of ethical considerations limitations. In addition, the co-culture of ADSCs and chondrocytes is commonly used to achieve better chondrogenesis. To promote chondrogenic differentiation of ADSCs and construct ideal highly bionic tissue-engineered cartilage, researchers have used a variety of methods, including adding appropriate growth factors, applying biomechanical stimuli and reducing oxygen tension. According to the process and sequence of cartilage 3D bioprinting, this review summarizes and discusses the selection of hydrogel and seed cells (centered on ADSCs), the design of printing, and methods for inducing the chondrogenesis of ADSCs.

Effective and economical cell therapy for hair regeneration

We reviewed and summarized the latest reports on the characteristics of stem cells and follicular cells that are under development for hair loss treatment. Compared with conventional medicine, cell therapy could be effective in the long term with a single treatment while having mild adverse effects. Adipose-derived stem cells (ASCs) have the advantages of easy access and large isolation amount compared with dermal papilla cells (DPCs) and dermal sheath cup cells (DSCs), and promote hair growth through the paracrine effect. ASCs have a poor potential in hair neogenesis, therefore, methods to enhance trichogenecity of ASCs should be developed. DSCs can be isolated from the peribulbar dermal sheath cup, while having immune tolerance, and hair inductivity. Therefore, DSCs were first developed and finished the phase II clinical trial; however, the hair growth was not satisfactory. Considering that a single injection of DSCs is effective for at least 9 months in the clinical setting, they can be an alternative therapy for hair regeneration. Though DPCs are not yet studied in clinical trials, we should pay attention to DPCs, as hair loss is associated with gradual reduction of DPCs and DP cell numbers fluctuate over the hair cycle. DPCs could make new hair follicles with epidermal cells, and have an immunomodulatory function to enable allogeneic transplantation. In addition, we can expand large quantities of DPCs with hair inductivity using spheroid culture, hypoxia condition, and growth factor supplement. 'Off-the-shelf' DPC therapy could be effective and economical, and therefore promising for hair regeneration.

Stem cell secretome as a mechanism for restoring hair loss due to stress, particularly alopecia areata: narrative review

Background

Living organisms are continuously exposed to multiple internal and external stimuli which may influence their emotional, psychological, and physical behaviors. Stress can modify brain structures, reduces functional memory and results in many diseases such as skin disorders like acne, psoriasis, telogen effluvium, and alopecia areata. In this review, we aim to discuss the effect of secretome on treating alopecia, especially alopecia areata. We will shed the light on the mechanism of action of the secretome in the recovery of hair loss and this by reviewing all reported in vitro and in vivo literature.

Main body

Hair loss has been widely known to be enhanced by stressful events. Alopecia areata is one of the skin disorders which can be highly induced by neurogenic stress especially if the patient has a predisposed genetic background. This condition is an autoimmune disease where stress in this case activates the immune response to attack the body itself leading to hair cycle destruction. The currently available treatments include medicines, laser therapy, phototherapy, and alternative medicine therapies with little or no satisfactory results. Regenerative medicine is a new era in medicine showing promising results in treating many medical conditions including Alopecia. The therapeutic effects of stem cells are due to their paracrine and trophic effects which are due to their secretions (secretome).

Conclusion

Stem cells should be more used as an alternative to conventional  therapies due to their positive outcomes. More clinical trials on humans should be done to maximize the dose needed and type of stem cells that must be used to treat alopecia areata.

Ascorbic Acid/Retinol and/or Inflammatory Stimuli's Effect on Proliferation/Differentiation Properties and Transcriptomics of Gingival Stem/Progenitor Cells

The present study explored the effects of ascorbic-acid (AA)/retinol and timed inflammation on the stemness, the regenerative potential, and the transcriptomics profile of gingival mesenchymal stem/progenitor cells' (G-MSCs). STRO-1 (mesenchymal stem cell marker) immuno-magnetically sorted G-MSCs were cultured in basic medium (control group), in basic medium with IL-1β (1 ng/mL), TNF-α (10 ng/mL) and IFN-γ (100 ng/mL, inflammatory-medium), in basic medium with AA (250 µmol/L) and retinol (20 µmol/L) (AA/retinol group) or in inflammatory medium with AA/retinol (inflammatory/AA/retinol group; n = 5/group). The intracellular levels of phosphorylated and total β-Catenin at 1 h, the expression of stemness genes over 7 days, the number of colony-forming units (CFUs) as well as the cellular proliferation aptitude over 14 days, and the G-MSCs' multilineage differentiation potential were assessed. Next-generation sequencing was undertaken to elaborate on up-/downregulated genes and altered intracellular pathways. G-MSCs demonstrated all mesenchymal stem/progenitor cells characteristics. Controlled inflammation with AA/retinol significantly elevated NANOG (p < 0.05). The AA/retinol-mediated reduction in intracellular phosphorylated β-Catenin was restored through the effect of controlled inflammation (p < 0.05). Cellular proliferation was highest in the AA/retinol group (p < 0.05). AA/retinol counteracted the inflammation-mediated reduction in G-MSCs' clonogenic ability and CFUs. Amplified chondrogenic differentiation was observed in the inflammatory/AA/retinol group. At 1 and 3 days, the differentially expressed genes were associated with development, proliferation, and migration (FOS, EGR1, SGK1, CXCL5, SIPA1L2, TFPI2, KRATP1-5), survival (EGR1, SGK1, TMEM132A), differentiation and mineral absorption (FOS, EGR1, MT1E, KRTAP1-5, ASNS, PSAT1), inflammation and MHC-II antigen processing (PER1, CTSS, CD74) and intracellular pathway activation (FKBP5, ZNF404). Less as well as more genes were activated the longer the G-MSCs remained in the inflammatory medium or AA/retinol, respectively. Combined, current results point at possibly interesting interactions between controlled inflammation or AA/retinol affecting stemness, proliferation, and differentiation attributes of G-MSCs.

CircRNA_01477 influences axonal growth via regulating miR-3075/FosB/Stat3 axis

Circular RNAs (circRNAs) are important for the development and regeneration of the nervous system. We investigated the differential expression profiles of circRNA induced by spinal cord injury and reported that circRNA_01477 facilitates spinal astrocyte proliferation and migration after injury in rats. In this study, we further clarified the function and possible mechanism of action of circRNA_01477 in neurons. Fluorescence in situ hybridization assay revealed that circRNA_01477 is mainly localized in the neuronal cytoplasm. Knockdown of circRNA_01477 significantly increased axonal length. The circRNA_01477/microRNAs (miRNA)/messenger RNA (mRNA) interaction network was investigated using RNA sequencing. miRNA-3075 showed a remarkable increase after circRNA_01477 depletion, and either overexpression of miRNA-3075 or downregulation of its target gene FosB significantly promoted axonal growth. Luciferase reporter assay showed that miRNA-3075 could directly bind to the 3'UTR of FosB and negatively regulated FosB transcription. Dual silencing of circRNA_01477 and miR-3075 revealed that miR-3075 inhibition rescued the increased axon length caused by siCircRNA_01477. Finally, we verified that the Stat3 pathway was activated after FosB protein depletion in rat spinal neurons, while the NF-κB pathway was not altered. In summary, our study is the first to report that circRNA_01477 contributes to axon growth by functioning as miRNA sponge by regulating the miRNA-3075/FosB/Stat3 axis.

Ascorbic acid ameliorates corneal endothelial dysfunction and enhances cell proliferation via the noncanonical GLUT1-ERK axis

BACKGROUND

The pumping function of corneal endothelial cells (CECs) plays a pivotal role in the maintenance of corneal water homeostasis. Corneal endothelial dysfunction (CED) leads to corneal edema and opacity, but with the exception of keratoplasty, no optimal therapeutic strategies have been established for CED. In this study, we aimed to investigate the ameliorative effect of ascorbic acid (AA) on CED and the underlying mechanism of action in the corneal endothelium.

METHODS

Rabbit corneal endothelial damage was induced by anterior chamber injection of benzalkonium chloride (BAK). AA was topically administered to the corneal surface, and the transparency and thickness of the cornea were assessed by external eye photography, slit-lamp photography, and ultrasonic pachymetry. To further analyze the mechanism, rabbit CECs and immortalized human CECs (B4G12 cells) were cultured. A ferric reducing/antioxidant and AA (FRASC) assay was performed to measure the AA concentration. Cell proliferation was evaluated by cell counting and bromodeoxyuridine (BrdU) labeling assays, and protein expression was examined by liquid chromatography-mass spectrometry (LC/MS) and immunoblotting. The involvement of glucose transporter 1 (GLUT1) and phospho-ERK was evaluated via GLUT1-siRNA and phospho-ERK inhibitor (PD98059) treatment.

INTERPRETATION

We observed that topical AA ameliorates BAK-induced rabbit corneal endothelial damage. Furthermore, we demonstrated that AA is transported into B4G12 cells via GLUT1, and afterward, AA increases ERK phosphorylation and promotes cell proliferation. Our findings indicate that CEC proliferation stimulated via the noncanonical AA-GLUT1-ERK axis contributes to AA-enhanced healing of CED.

Cell penetration and chondrogenic differentiation of human adipose derived stem cells on 3D scaffold

The ability of cells to penetrate the scaffold and differentiate into chondrocyte is important in cartilage engineering. The aim of this research was to evaluate the use of silk fibroin 3D scaffold in facilitating the growth of stem cell and to study the role of L-ascorbic acid and platelet rich plasma (PRP) in proliferation and differentiation genes. Cell penetration and type II collagen content in the silk fibroin scaffold was analyzed by confocal microscopy. Relative expressions of CDH2, CCND1, CTNNB1 and COL2A1 were analyzed by reverse transcription-quantitative PCR (RT-qPCR). The silk fibroin 3D scaffold could facilitate cell penetration. L-ascorbic acid and PRP increased the expression of CDH2 and COL2A1 on the 21st day of treatment while PRP inhibited CTNNB1 and CCND1.

Hormesis and adult adipose-derived stem cells

This paper provides a detailed assessment of the occurrence of hormetic dose responses in adipose-derived stem cells (ADSCs) of animal models and humans. While a broad range of endpoints has been considered, the predominant research focus in the literature has involved cell proliferation and differentiation. Hormetic dose responses have been commonly reported for ADSCs, encompassing a broad range of chemicals, including pharmaceuticals, dietary supplements and endogenous agents as well as a broad range of physical stressors such as low frequency vibrations, electromagnetic frequency (EMF), heat and sound waves. Numerous agents upregulate key functions such as cell proliferation and differentiation in ADSCs, following the quantitative features of the hormesis dose response model. The paper also assesses the capacity of agents to selectively and dose-dependently activate cell proliferation and/or differentiation, their underlying mechanistic foundations and potential clinical implications. These findings indicate that hormetic dose responses are a prominent feature of ADSC biology and may have a determinant role in their potential clinical applications.

Culturing at Low Cell Density Delays Cellular Senescence of Human Bone Marrow-Derived Mesenchymal Stem Cells in Long-Term Cultures

Background and Objectives

Mesenchymal stem cells (MSCs) have immense therapeutic potential for treating intractable and immune diseases. They also have applications in regenerative medicine in which distinct treatments do not exist. Thus, MSCs are gaining attention as important raw materials in the field of cell therapy. Importantly, the number of MSCs in the bone marrow is limited and they are present only in small quantities. Therefore, mass production of MSCs through long-term culture is necessary to use them in cell therapy. However, MSCs undergo cellular senescence through repeated passages during mass production. In this study, we explored methods to prolong the limited lifetime of MSCs by culturing them with different seeding densities.

Methods and Results

We observed that in long-term cultures, low-density (LD, 50 cells/cm²) MSCs showed higher population doubling level, leading to greater fold increase, than high-density (HD, 4,000 cells/cm²) MSCs. LD-MSCs suppressed the expression of aging-related genes. We also showed that reactive oxygen species (ROS) were decreased in LD-MSCs compared to that in HD-MSCs. Further, proliferation potential increased when ROS were inhibited in HD-MSCs.

Conclusions

The results in this study suggest that MSC senescence can be delayed and that life span can be extended by controlling cell density in vitro. These results can be used as important data for the mass production of stem cell therapeutic products.

Human adipose-derived stem cells enriched with VEGF-modified mRNA promote angiogenesis and long-term graft survival in a fat graft transplantation model

Background

Fat grafting, as a standard treatment for numerous soft tissue defects, remains unpredictable and technique-dependent. Human adipose-derived stem cells (hADSCs) are promising candidates for cell-assisted therapy to improve graft survival. As free-living fat requires nutritional and respiratory sources to thrive, insufficient and unstable vascularization still impedes hADSC-assisted therapy. Recently, cytotherapy combined with modified mRNA (modRNA) encoding vascular endothelial growth factor (VEGF) has been applied for the treatment of ischemia-related diseases. Herein, we hypothesized that VEGF modRNA (modVEGF)-engineered hADSCs could robustly enhance fat survival in a fat graft transplantation model.

Methods

hADSCs were acquired from lipoaspiration and transfected with modRNAs. Transfection efficiency and expression kinetics of modRNAs in hADSCs were first evaluated in vitro. Next, we applied an in vivo Matrigel plug assay to assess the viability and angiogenic potential of modVEGF-engineered hADSCs at 1 week post-implantation. Finally, modVEGF-engineered hADSCs were co-transplanted with human fat in a murine model to analyze the survival rate, re-vascularization, proliferation, fibrosis, apoptosis, and necrosis of fat grafts over long-term follow-up.

Results

Transfections of modVEGF in hADSCs were highly tolerable as the modVEGF-engineered hADSCs facilitated burst-like protein production of VEGF in both our in vitro and in vivo models. modVEGF-engineered hADSCs induced increased levels of cellular proliferation and proangiogenesis when compared to untreated hADSCs in both ex vivo and in vivo assays. In a fat graft transplantation model, we provided evidence that modVEGF-engineered hADSCs promote the optimal potency to preserve adipocytes, especially in the long-term post-transplantation phase. Detailed histological analysis of fat grafts harvested at 15, 30, and 90 days following in vivo grafting suggested the release of VEGF protein from modVEGF-engineered hADSCs significantly improved neo-angiogenesis, vascular maturity, and cell proliferation. The modVEGF-engineered hADSCs also significantly mitigated the presence of fibrosis, apoptosis, and necrosis of grafts when compared to the control groups. Moreover, modVEGF-engineered hADSCs promoted graft survival and cell differentiation abilities, which also induced an increase in vessel formation and the number of surviving adipocytes after transplantation.

Conclusion

This current study demonstrates the employment of modVEGF-engineered hADSCs as an advanced alternative to the clinical treatment involving soft-tissue reconstruction and rejuvenation.

Epiregulin promotes hair growth via EGFR-medicated epidermal and ErbB4-mediated dermal stimulation

OBJECTIVES

EREG (epiregulin), a member of the epidermal growth factor (EGF) family, plays a role in inflammation, wound healing, normal physiology and malignancies. However, little is known about its function on hair growth.

MATERIALS AND METHODS

Cell growth assay, QPCR and immunostaining were carried out. Telogen-to-anagen transition and organ culture were conducted. ROS level was monitored by staining DCFDA.

RESULTS

We investigated the hair inductive effect of EREG and the mechanism of stimulation on DPCs and ORS cells during hair cycling. Whereas EREG promoted hair growth, EREG knockdown inhibited hair growth as evidenced by telogen-to-anagen transition and organ culture models. EREG was expressed in epidermal cells including ORS cells in vivo. EREG activated phospho-ErbB4 in DPCs during hair cycling and stimulated DPCs via ErbB4 activation in vitro. In terms of the underlying mechanism, reactive oxygen species (ROS) played a key role in DPC stimulation. EREG also activated phospho-EGF receptor (EGFR) in epidermal cells including matrix and ORS cells in vivo and stimulated ORS cells via EGFR activation in vitro.

CONCLUSIONS

EREG, which is released from ORS cells, activated EGFR and ErbB4 on epidermal cells and DPCs during hair cycling, respectively. As a result, EREG stimulated epidermal cells a positive feedback and DPCs via regulating ROS generation for hair growth. Therefore, EREG therapy may be a novel solution for hair loss treatment.

Ascorbic Acid, Inflammatory Cytokines (IL-1β/TNF-α/IFN-γ), or Their Combination's Effect on Stemness, Proliferation, and Differentiation of Gingival Mesenchymal Stem/Progenitor Cells

Objective

Ascorbic acid (AA) and controlled inflammatory stimuli are postulated to possess the ability to independently exert positive effects on a variety of proliferative, pluripotency, and differentiation attributes of gingival mesenchymal stem/progenitor cells (G-MSCs). The current study's objective was to explore and compare for the first time the impact of the major inflammatory cytokines (IL-1β/TNF-α/IFN-γ), AA, or their combination on multipotency/pluripotency, proliferative, and differentiation characteristics of G-MSCs.

Design

Human G-MSCs (n = 5) were isolated and cultured in basic medium (control group), in basic medium with major inflammatory cytokines; 1 ng/ml IL-1β, 10 ng/ml TNF-α, and 100 ng/ml IFN-γ (inflammatory group), in basic medium with 250 μmol/l AA (AA group) and in inflammatory medium supplemented by AA (inflammatory/AA group). All media were renewed three times per week. In stimulated G-MSCs intracellular β-catenin at 1 hour, pluripotency gene expression at 1, 3, and 5 days, as well as colony-forming units (CFUs) ability and cellular proliferation over 14 days were examined. Following a five-days stimulation in the designated groups, multilineage differentiation was assessed via qualitative and quantitative histochemistry as well as mRNA expression.

Results

β-Catenin significantly decreased intracellularly in all experimental groups (p = 0.002, Friedman). AA group exhibited significantly higher cellular counts on days 3, 6, 7, and 13 (p < 0.05) and the highest CFUs at 14 days [median-CFUs (Q25/Q75); 40 (15/50), p = 0.043]. Significantly higher Nanog expression was noted in AA group [median gene-copies/PGK1 (Q25/Q75); 0.0006 (0.0002/0.0007), p < 0.01, Wilcoxon-signed-rank]. Significant multilineage differentiation abilities, especially into osteogenic and chondrogenic directions, were further evident in the AA group.

Conclusions

AA stimulation enhances G-MSCs' stemness, proliferation, and differentiation properties, effects which are associated with a Wnt/β-catenin signaling pathway activation. Apart from initially boosting cellular metabolism as well as Sox2 and Oct4A pluripotency marker expression, inflammation appeared to attenuate these AA-induced positive effects. Current results reveal that for AA to exert its beneficial effects on G-MSCs' cellular attributes, it requires to act in an inflammation-free microenvironment.

Supporting Cell-Based Tendon Therapy: Effect of PDGF-BB and Ascorbic Acid on Rabbit Achilles Tenocytes in Vitro

Cell-based tendon therapies with tenocytes as a cell source need effective tenocyte in vitro expansion before application for tendinopathies and tendon injuries. Supplementation of tenocyte culture with biomolecules that can boost proliferation and matrix synthesis is one viable option for supporting cell expansion. In this in vitro study, the impacts of ascorbic acid or PDGF-BB supplementation on rabbit Achilles tenocyte culture were studied. Namely, cell proliferation, changes in gene expression of several ECM and tendon markers (collagen I, collagen III, fibronectin, aggrecan, biglycan, decorin, ki67, tenascin-C, tenomodulin, Mohawk, α-SMA, MMP-2, MMP-9, TIMP1, and TIMP2) and ECM deposition (collagen I and fibronectin) were assessed. Ascorbic acid and PDGF-BB enhanced tenocyte proliferation, while ascorbic acid significantly accelerated the deposition of collagen I. Both biomolecules led to different changes in the gene expression profile of the cultured tenocytes, where upregulation of collagen I, Mohawk, decorin, MMP-2, and TIMP-2 was observed with ascorbic acid, while these markers were downregulated by PDGF-BB supplementation. Vice versa, there was an upregulation of fibronectin, biglycan and tenascin-C by PDGF-BB supplementation, while ascorbic acid led to a downregulation of these markers. However, both biomolecules are promising candidates for improving and accelerating the in vitro expansion of tenocytes, which is vital for various tendon tissue engineering approaches or cell-based tendon therapy.

Partial regeneration of uterine horns in rats through adipose-derived stem cell sheets

Severe uterine damage and infection lead to intrauterine adhesions, which result in hypomenorrhea, amenorrhea and infertility. Cell sheet engineering has shown great promise in clinical applications. Adipose-derived stem cells (ADSCs) are emerging as an alternative source of stem cells for cell-based therapies. In the present study, we investigated the feasibility of applying ADSCs as seed cells to form scaffold-free cell sheet. Data showed that ADSC sheets expressed higher levels of FGF, Col I, TGFβ, and VEGF than ADSCs in suspension, while increased expression of this gene set was associated with stemness, including Nanog, Oct4, and Sox2. We then investigated the therapeutic effects of 3D ADSCs sheet on regeneration in a rat model. We found that ADSCs were mainly detected in the basal layer of the regenerating endometrium in the cell sheet group at 21 days after transplantation. Additionally, some ADSCs differentiated into stromal-like cells. Moreover, ADSC sheets transplanted into partially excised uteri promoted regeneration of the endometrium cells, muscle cells and stimulated angiogenesis, and also resulted in better pregnancy outcomes. Therefore, ADSC sheet therapy shows considerable promise as a new treatment for severe uterine damage.

Udenafil Induces the Hair Growth Effect of Adipose-Derived Stem Cells

Udenafil, which is a PDE₅ inhibitor, is used to treat erectile dysfunction. However, it is unclear whether udenafil induces hair growth via the stimulation of adipose-derived stem cells (ASCs). In this study, we investigated whether udenafil stimulates ASCs and whether increased growth factor secretion from ASCs to facilitate hair growth. We found that subcutaneous injection of udenafil-treated ASCs accelerated telogen-to-anagen transition in vivo. We also observed that udenafil induced proliferation, migration and tube formation of ASCs. It also increased the secretion of growth factors from ASCs, such as interleukin-4 (IL-4) and IL12B, and the phosphorylation of ERK1/2 and NFκB. Furthermore, concomitant upregulation of IL-4 and IL12B mRNA levels was attenuated by ERK inhibitor or NFκB knockdown. Application of IL-4 or IL12B enhanced anagen induction in mice and increased hair follicle length in organ culture. The results indicated that udenafil stimulates ASC motility and increases paracrine growth factor, including cytokine signaling. Udenafil-stimulated secretion of cytokine from ASCs may promote hair growth via the ERK and NFκB pathways. Therefore, udenafil can be used as an ASC-preconditioning agent for hair growth.

Harnessing the secretome of adipose-derived stem cells in the treatment of ischemic heart diseases

Adipose-derived stem cells (ASCs) are promising therapeutic cells for ischemic heart diseases, due to the ease and efficiency of acquisition, the potential of myocardial lineage differentiation, and the paracrine effects. Recently, many researchers have claimed that the ASC-based myocardial repair is mainly attributed to its paracrine effects, including the anti-apoptosis, pro-angiogenesis, anti-inflammation effects, and the inhibition of fibrosis, rather than the direct differentiation into cardiovascular lineage cells. However, the usage of ASCs comes with the problems of low cardiac retention and survival after transplantation, like other stem cells, which compromises the effectiveness of the therapy. To overcome these drawbacks, researchers have proposed various strategies for improving survival rate and ensuring sustained paracrine secretion. They also investigated the safety and efficacy of phase I and II clinical trials of ASC-based therapy for cardiovascular diseases. In this review, we will discuss the characterization and paracrine effects of ASCs on myocardial repair, followed by the strategies for stimulating the paracrine secretion of ASCs, and finally their clinical usage.

Generation of trichogenic adipose-derived stem cells by expression of three factors

BACKGROUND

Previous studies demonstrated that adipose-derived stem cells (ASCs) can promote hair growth, but unmet needs exist for enhancing ASC hair inductivity.

OBJECTIVE

Therefore, we introduced three trichogenic factors platelet-derived growth factor-A, SOX2, and β-catenin to ASCs (tfASCs) and evaluated whether tfASCs have similar characteristics as dermal papilla (DP) cells.

METHOD

Global gene expression was examined using NGS analysis. Telogen-to-anagen induction, vibrissae hair follicle organ culture and patch assay were used.

RESULTS

tfASC cell size is smaller than that of ASCs, and they exhibit short doubling time. tfASCs also resist aging and can be expanded until passage 12. Cell proportion in S and G₂/M increases in tfASCs, and tfASCs express high mRNA levels of cell cycle related genes. The mRNA expression of DP markers was notably higher in tfASCs. Moreover, NGS analysis revealed that the global gene expression of tfASCs is similar to that of DP cells. The injection of tfASCs accelerated the telogen-to-anagen transition and conditioned medium of tfASCs increased the anagen phase of vibrissal hair follicles. Finally, we found that the injection of 3D-cultured tfASCs at p 9 generated new hair follicles in nude mice.

CONCLUSION

Collectively, these results indicate that 1) tfASCs have similar characteristics as DP cells, 2) tfASCs have enhanced hair-regenerative potential compared with ASCs, and 3) tfASCs even at late passage can make new hair follicles in a hair reconstitution assay. Because DP cells are difficult to isolate/expand and ASCs have low hair inductivity, tfASCs and tfASC-CM are clinically good candidates for hair regeneration.

Minoxidil Promotes Hair Growth through Stimulation of Growth Factor Release from Adipose-Derived Stem Cells

Minoxidil directly promotes hair growth via the stimulation of dermal papilla (DP) and epithelial cells. Alternatively, there is little evidence for indirect promotion of hair growth via stimulation of adipose-derived stem cells (ASCs). We investigated whether minoxidil stimulates ASCs and if increased growth factor secretion by ASCs facilitates minoxidil-induced hair growth. Telogen-to-anagen induction was examined in mice. Cultured DP cells and vibrissae hair follicle organ cultures were used to further examine the underlying mechanisms. Subcutaneous injection of minoxidil-treated ASCs accelerated telogen-to-anagen transition in mice, and increased hair weight at day 14 post-injection. Minoxidil did not alter ASC proliferation, but increased migration and tube formation. Minoxidil also increased the secretion of growth factors from ASCs, including chemokine (C-X-C motif) ligand 1 (CXCL1), platelet-derived endothelial cell growth factor (PD-ECGF), and platelet-derived growth factor-C (PDGF-C). Minoxidil increased extracellular signal–regulated kinases 1/2 (ERK1/2) phosphorylation, and concomitant upregulation of PD-ECGF and PDGF-C mRNA levels were attenuated by an ERK inhibitor. Subcutaneous injection of CXCL1, PD-ECGF, or PDGF-C enhanced anagen induction in mice, and both CXCL1 and PDGF-C increased hair length in ex vivo organ culture. Treatment with CXCL1, PD-ECGF, or PDGF-C also increased the proliferation index in DP cells. Finally, topical application of CXCL1, PD-ECGF, or PDGF-C with 2% minoxidil enhanced anagen induction when compared to minoxidil alone. Minoxidil stimulates ASC motility and increases paracrine growth factor signaling. Minoxidil-stimulated secretion of growth factors by ASCs may enhance hair growth by promoting DP proliferation. Therefore, minoxidil can be used as an ASC preconditioning agent for hair regeneration.

Transplanted adipose-derived stem cells can be short-lived yet accelerate healing of acid-burn skin wounds: a multimodal imaging study

The incidence of accidental and intentional acid skin burns is rising. Current treatment strategies are mostly inadequate, leaving victims disfigured and without treatment options. Here, we have shown that transplantation of adipose-derived stem cells (ASCs) accelerates the process of acid burn wound-healing. Pre-conditioning of ASCs using ascorbic acid (AA) or hypoxic conditions provided additional benefit. While the wounds were ultimately healed in all mice, histological analysis revealed that, in non-transplanted animals, the number of hair follicles was reduced. Bioluminescent imaging (BLI) of transplanted ASCs revealed a gradual loss of transplanted cells, with a similar rate of cell death for each treatment group. The signal of fluorinated cells detected by a clinically applicable ¹⁹F MRI method correlated with the BLI findings, which points to ¹⁹F MRI as a reliable method with which to track ASCs after transplantation to skin wounds. No difference in therapeutic effect or cell survival was observed between labeled and non-labeled cells. We conclude that, despite being short-lived, transplanted ASCs can accelerate wound-healing and reduce hair loss in acid-burn skin injury. The fluorine nanoemulsion is a clinically applicable cell label capable of reporting on the survival of transplanted cells.

Hypoxia induces glucose uptake and metabolism of adipose‑derived stem cells

It has previously been demonstrated that hypoxia has diverse stimulatory effects on adipose‑derived stem cells (ASCs), however, metabolic responses under hypoxia remain to be elucidated. Thus, the present study aimed to investigate the glucose uptake and metabolism of ASCs under hypoxic conditions, and to identify the underlying molecular mechanisms. ASCs were cultured in 1% oxygen, and experiments were conducted in vitro. As determined by proteomic analysis and western blotting, GAPDH and enolase 1 (ENO1) expression were upregulated under hypoxia. In addition, lactate production was significantly increased, and mRNA levels of glycolytic enzymes, including GAPDH, ENO1, hexokinase 2 (HK2), and lactate dehydrogenase α (LDHα) were upregulated. Hypoxia‑inducible factor 1‑α (HIF‑1α) expression was increased as demonstrated by western blotting, and a pharmacological inhibitor of HIF‑1α significantly attenuated hypoxia‑induced lactate production and expression of glycolytic enzymes. It was also observed that hypoxia significantly increased glucose uptake in ASCs, and glucose transporter (GLUT)1 and GLUT3 expression were upregulated under hypoxia. Pharmacological inhibition of the HIF‑1α signaling pathways also attenuated hypoxia‑induced GLUT1 and GLUT3 expression. These results collectively indicate that hypoxia increases glucose uptake via GLUT1 and GLUT3 upregulation, and induces lactate production of ASCs via GAPDH, ENO1, HK2, and LDHα. Furthermore, HIF‑1α is involved in glucose uptake and metabolism of ASCs.

Hypoxia Suppresses Spontaneous Mineralization and Osteogenic Differentiation of Mesenchymal Stem Cells via IGFBP3 Up-Regulation

Hypoxia has diverse stimulatory effects on human adipose-derived stem cells (ASCs). In the present study, we investigated whether hypoxic culture conditions (2% O₂) suppress spontaneous mineralization and osteogenic differentiation of ASCs. We also investigated signaling pathways and molecular mechanisms involved in this process. We found that hypoxia suppressed spontaneous mineralization and osteogenic differentiation of ASCs, and up-regulated mRNA and protein expression of Insulin-like growth factor binding proteins (IGFBPs) in ASCs. Although treatment with recombinant IGFBPs did not affect osteogenic differentiation of ASCs, siRNA-mediated inhibition of IGFBP3 attenuated hypoxia-suppressed osteogenic differentiation of ASCs. In contrast, overexpression of IGFBP3 via lentiviral vectors inhibited ASC osteogenic differentiation. These results indicate that hypoxia suppresses spontaneous mineralization and osteogenic differentiation of ASCs via intracellular IGFBP3 up-regulation. We determined that reactive oxygen species (ROS) generation followed by activation of the MAPK and PI3K/Akt pathways play pivotal roles in IGFBP3 expression under hypoxia. For example, ROS scavengers and inhibitors for MAPK and PI3K/Akt pathways attenuated the hypoxia-induced IGFBP3 expression. Inhibition of Elk1 and NF-κB through siRNA transfection also led to down-regulation of IGFBP3 mRNA expression. We next addressed the proliferative potential of ASCs with overexpressed IGFBP3, but IGFBP3 overexpression reduced the proliferation of ASCs. In addition, hypoxia reduced the osteogenic differentiation of bone marrow-derived clonal mesenchymal stem cells. Collectively, our results indicate that hypoxia suppresses the osteogenic differentiation of mesenchymal stem cells via IGFBP3 up-regulation.

Boiling Method-Based Zinc Oxide Nanorods for Enhancement of Adipose-Derived Stem Cell Proliferation

Adipose-derived stem cells (ASCs) are typically expanded to acquire large numbers of cells for therapeutic applications. Diverse stimuli such as sphingosylphosphocholine and vitamin C have been used to increase the production yield and regenerative potential of ASCs. In the present study, we hypothesized that ZnO nanorods have promising potential for the enhancement of ASC proliferation. ZnO nanorods were prepared using three different methods: grinding and boiling at low temperature with and without surfactant. The physicochemical properties of the nanorods such as their crystallinity, morphology, size, and solvent compatibility were evaluated, and then, the ability of the synthesized ZnO nanorods to enhance ASC proliferation was investigated. Scanning electron microscopy images of all of the ZnO powders showed rod-shaped nanoflakes with lengths of 200-500 nm. Notably, although ZnO-G produced by the grinding method was well dispersed in ethanol, atomic force microscopy images of dispersions of both ZnO-B from boiling methods and ZnO-G indicated the presence of clusters of ZnO nanorods. In contrast, ZnO-B was freely dispersible in 5% dextrose of water and dimethyl sulfoxide, whereas ZnO-G and ZnO-M, produced by boiling with ethanolamine, were not. All three types of ZnO nanorods increased the proliferation of ASCs in a dose-dependent manner. These results collectively suggest that ZnO nanorods have promising potential for use as an agent for the enhancement of ASC proliferation.

Gingival Mesenchymal Stem/Progenitor Cells: A Unique Tissue Engineering Gem

The human gingiva, characterized by its outstanding scarless wound healing properties, is a unique tissue and a pivotal component of the periodontal apparatus, investing and surrounding the teeth in their sockets in the alveolar bone. In the last years gingival mesenchymal stem/progenitor cells (G-MSCs), with promising regenerative and immunomodulatory properties, have been isolated and characterized from the gingival lamina propria. These cells, in contrast to other mesenchymal stem/progenitor cell sources, are abundant, readily accessible, and easily obtainable via minimally invasive cell isolation techniques. The present review summarizes the current scientific evidence on G-MSCs' isolation, their characterization, the investigated subpopulations, the generated induced pluripotent stem cells- (iPSC-) like G-MSCs, their regenerative properties, and current approaches for G-MSCs' delivery. The review further demonstrates their immunomodulatory properties, the transplantation preconditioning attempts via multiple biomolecules to enhance their attributes, and the experimental therapeutic applications conducted to treat multiple diseases in experimental animal models in vivo. G-MSCs show remarkable tissue reparative/regenerative potential, noteworthy immunomodulatory properties, and primary experimental therapeutic applications of G-MSCs are very promising, pointing at future biologically based therapeutic techniques, being potentially superior to conventional clinical treatment modalities.

In vitro effects of vitamins C and E, n-3 and n-6 PUFA and n-9 MUFA on placental cell function and redox status in type 1 diabetic pregnant women

The aim of this investigation was to determine the in vitro effects of vitamin C and E, n-3 and n-6 PUFA and n-9 MUFA on placental cell proliferation and function in type 1 diabetes. Placenta tissues were collected from 30 control healthy and 30 type 1 diabetic women at delivery. Placental cells were isolated and were cultured in RPMI medium supplemented with vitamin C (50 μM), vitamin E (50 μM), n-3 PUFA (100 μM), n-6 PUFA (100 μM) or n-9 MUFA (100 μM). Cell proliferation, cell glucose uptake and intracellular oxidative status were investigated. Our results showed that basal placental cell proliferation, glucose uptake, malondialdehyde (MDA) and carbonyl proteins were higher while intracellular reduced glutathione (GSH) levels and catalase activities were lower in placentas from diabetic women as compared to controls. Vitamins C and E induced a modulation of placental cell proliferation and glucose consumption without affecting intracellular redox status in both diabetic and control groups. N-3 and n-6 PUFA diminished placental cell proliferation and enhanced intracellular oxidative stress while n-9 MUFA had no effects in the two groups. Co-administration of n-3 or n-6 PUFA and vitamin C or E were capable of reversing back the PUFA-decreased cell proliferation and normalizing placental cell function and redox status especially in diabetes. In conclusion, PUFA and antioxidant vitamin combinations may be beneficial in improving placenta function and in reducing placental oxidative stress in type 1 diabetic pregnancy.

Adipose tissue RNASeq reveals novel gene-nutrient interactions following n-3 PUFA supplementation and evoked inflammation in humans

Dietary consumption of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA) may protect against cardiometabolic disease through modulation of systemic and adipose inflammation. However, it is often difficult to detect the subtle effects of n-3 PUFA on inflammatory biomarkers in traditional intervention studies. We aimed to identify novel n-3 PUFA modulated gene expression using unbiased adipose transcriptomics during evoked endotoxemia in a clinical trial of n-3 PUFA supplementation. We analyzed adipose gene expression using RNA sequencing in the fenofibrate and omega-3 fatty acid modulation of endotoxemia (FFAME) trial of healthy individuals at three timepoints: before and after n-3 PUFA supplementation (n=8; 3600mg/day EPA/DHA) for 6weeks compared with placebo (n=6), as well as during a subsequent evoked inflammatory challenge (lipopolysaccharide 0.6ng/kg i.v.). As expected, supplementation with n-3 PUFA vs. placebo alone had only modest effects on adipose tissue gene expression, e.g., increased expression of immediate early response IER2. In contrast, the transcriptomic response to evoked endotoxemia was significantly modified by n-3 PUFA supplementation, with several genes demonstrating significant n-3 PUFA gene-nutrient interactions, e.g., enhanced transcriptional responses in specific immune genes IER5L, HES1, IL1RN, CCL18, IL1RN, IL7R, IL8, CCL3 and others. These data highlight potential mechanisms whereby n-3 PUFA consumption may enhance the immune response to an inflammatory challenge. In conclusion, unbiased transcriptomics during evoked inflammation reveals novel immune modulating functions of n-3 PUFA nutritional intervention in a dynamic pathophysiological setting.

Functional regulation of adipose-derived stem cells by PDGF-D

Platelet-derived growth factor-D (PDGF-D) was recently identified, and acts as potent mitogen for mesenchymal cells. PDGF-D also induces cellular transformation and promotes tumor growth. However, the functional role of PDGF-D in adipose-derived stem cells (ASCs) has not been identified. Therefore, we primarily investigated the autocrine and paracrine roles of PDGF-D in this study. Furthermore, we identified the signaling pathways and the molecular mechanisms involved in PDGF-D-induced stimulation of ASCs. It is of interest that PDGF-B is not expressed, but PDGF-D and PDGF receptor-β are expressed in ASCs. PDGF-D showed the strongest mitogenic effect on ASCs, and PDGF-D regulates the proliferation and migration of ASCs through the PI3K/Akt pathways. PDGF-D also increases the proliferation and migration of ASCs through generation of mitochondrial reactive oxygen species (mtROS) and mitochondrial fission. mtROS generation and fission were mediated by p66Shc phosphorylation, and BCL2-related protein A1 and Serpine peptidase inhibitor, clade E, member 1 mediated the proliferation and migration of ASCs. In addition, PDGF-D upregulated the mRNA expression of diverse growth factors such as vascular endothelial growth factor A, fibroblast growth factor 1 (FGF1), FGF5, leukemia inhibitory factor, inhibin, beta A, interleukin 11, and heparin-binding EGF-like growth factor. Therefore, the preconditioning of PDGF-D enhanced the hair-regenerative potential of ASCs. PDGF-D-induced growth factor expression was attenuated by a pharmacological inhibitor of mitogen-activated protein kinase pathway. In summary, PDGF-D is highly expressed by ASCs, where it acts as a potent mitogenic factor. PDGF-D also upregulates growth factor expression in ASCs. Therefore, PDGF-D can be considered a novel ASC stimulator, and used as a preconditioning agent before ASC transplantation.

Vitamin C promotes wound healing through novel pleiotropic mechanisms

Vitamin C (VitC) or ascorbic acid (AscA), a cofactor for collagen synthesis and a primary antioxidant, is rapidly consumed post-wounding. Parenteral VitC administration suppresses pro-inflammatory responses while promoting anti-inflammatory and pro-resolution effects in human/murine sepsis. We hypothesised that VitC could promote wound healing by altering the inflammatory, proliferative and remodelling phases of wound healing. Mice unable to synthesise VitC (Gulo(-/-) ) were used in this study. VitC was provided in the water (sufficient), withheld from another group (deficient) and supplemented by daily intra-peritoneal infusion (200 mg/kg, deficient + AscA) in a third group. Full thickness excisional wounds (6 mm) were created and tissue collected on days 7 and 14 for histology, quantitative polymerase chain reaction (qPCR) and Western blotting. Human neonatal dermal fibroblasts (HnDFs) were used to assess effects of In conclusion, VitC favorably on proliferation. Histological analysis showed improved wound matrix deposition and organisation in sufficient and deficient +AscA mice. Wounds from VitC sufficient and deficient + AscA mice had reduced expression of pro-inflammatory mediators and higher expression of wound healing mediators. Supplementation of HnDF with AscA induced the expression of self-renewal genes and promoted fibroblast proliferation. VitC favourably impacts the spatiotemporal expression of transcripts associated with early resolution of inflammation and tissue remodelling.

Megestrol Acetate Increases the Proliferation, Migration, and Adipogenic Differentiation of Adipose-Derived Stem Cells via Glucocorticoid Receptor

: Because adipose-derived stem cells (ASCs) are usually expanded to acquire large numbers of cells for therapeutic applications, it is important to increase the production yield and regenerative potential during expansion. Therefore, a tremendous need exists for alternative ASC stimuli during cultivation to increase the proliferation and adipogenic differentiation of ASCs. The present study primarily investigated the involvement of megestrol acetate (MA), a progesterone analog, in the stimulation of ASCs, and identifies the target receptors underlying stimulation. Mitogenic and adipogenic effects of MA were investigated in vitro, and pharmacological inhibition and small interfering (si) RNA techniques were used to identify the molecular mechanisms involved in the MA-induced stimulation of ASCs. MA significantly increased the proliferation, migration, and adipogenic differentiation of ASCs in a dose-dependent manner. Glucocorticoid receptor (GR) is highly expressed compared with other nuclear receptors in ASCs, and this receptor is phosphorylated after MA treatment. MA also upregulated genes downstream of GR in ASCs, including ANGPTL4, DUSP1, ERRF11, FKBP5, GLUL, and TSC22D3. RU486, a pharmacological inhibitor of GR, and transfection of siGR significantly attenuated MA-induced proliferation, migration, and adipogenic differentiation of ASCs. Although the adipogenic differentiation potential of MA was inferior to that of dexamethasone, MA had mitogenic effects in ASCs. Collectively, these results indicate that MA increases the proliferation, migration, and adipogenic differentiation of ASCs via GR phosphorylation.

SIGNIFICANCE

Magestrol acetate (MA) increases the proliferation, migration, and adipogenic differentiation of adipose-derived stem cells (ASCs) via glucocorticoid receptor phosphorylation. Therefore, MA can be applied to increase the production yield during expansion and can be used to facilitate adipogenic differentiation of ASCs.

Vascular endothelial growth factor 165-transfected adipose-derived mesenchymal stem cells promote vascularization-assisted fat transplantation

OBJECTIVE

To investigate the effect of vascular endothelial growth factor 165 (VEGF165) and adipose-derived mesenchymal stem cells (ASCs) in promoting the survival of fat grafts, and to provide new methods and theoretical evidence for increasing the survival rate of autologous fat particle grafts.

METHODS

The VEGF165 gene was recombined with the target fragment, and the recombinant gene was introduced into adenovirus pAdEasy-1 system; the virus was then packaged and the titer was detected. The control group received the same processing. ASCs were cultured and subcultured, and then identified with immunohistochemistry and adipogenic differentiation assay. The subsequent experiments were performed in three groups: the VEGF165 gene-virus group, blank virus group, and control group. After the viral solution was transfected into the ASCs, the viral transfection efficiency was detected using a tracing factor, EGFP. The expression of VEGF165 mRNA and protein in the transfected cells were determined. The proliferation of ASCs in each group was detected with the MTT assay.

RESULTS

(1) Recombinant adenoviral vector was constructed successfully in the two groups and the packaging was identified. The viral titer was 2.0 × 10(8) pfu/ml and 1.9 × 10(8) pfu/ml, which was in line with the requirements of the subsequent transfection experiments. (2) Immunohistochemistry and adipogenic differentiation results showed that the culture of ASCs was successful, and the cultured cells could serve as seed cells in this experiment. (3) The RT-PCR analysis showed that the relative optical density of VEGF165 mRNA expression was 0.76 ± 0.05 in the experimental group, and there were statistically significant differences compared with the values obtained for the other two groups (P < 0.05). (4) The western blot analysis showed that the relative optical density of VEGF165 protein expression in the experimental group was significantly higher than that in the other two groups (P < 0.05). (5) The proliferation of ASCs was significantly enhanced after transfection in the experimental group, relative to the other two groups (P < 0.05). This evidence indicated that VEGF165 significantly promoted the proliferation of ASCs.

CONCLUSION

After transfection with the VEGF165-adenoviral vector, ASCs demonstrate sustained expression of the target protein and obviously promote the proliferation of ASCs, which lay the foundation for the in vitro experiments on transplantation of VEGF165 combined with ASCs, for the treatment of tissue defects.

Pharmacological preconditioning with vitamin C attenuates intestinal injury via the induction of heme oxygenase-1 after hemorrhagic shock in rats

Pre-induction of heme oxygenase (HO)-1, which is regarded as an effective method of “organ preconditioning”, exerts beneficial effects during hemorrhagic shock (HS). However, the available HO-1 inducers exhibit disadvantages such as toxicity or complex technical requirements. Therefore, a safe and convenient HO-1 inducer would be promising and could be exploited in the treatment of foreseeable hemorrhaging, such as prior to major surgery. Here we investigated the effect of vitamin C (VitC), a common antioxidant, on intestinal HO-1 expression and examined whether VitC pretreatment prevented HS related intestinal tissue injuries after HO-1 induction. First, we conducted an in vitro study and found that HO-1 expression in rat intestinal epithelial cells (IEC-6) was induced by non-toxic VitC in a time and concentration dependent manner, and the mechanism was related to the activation of extracellular signal-regulated kinase 1/2 (ERK1/2). Next, we conducted an in vivo study and found that VitC induced intestinal HO-1 protein expression (mainly observed in the intestinal epithelial cells) and HO-1 activity in normal SD rats, and that these HO-1 levels were further enhanced by VitC in a rat model of HS. The HS related intestinal injuries, including histological damage, pro-inflammatory cytokine levels (tumor necrosis factor and interleukin-6), neutrophil infiltration and apoptosis decreased after VitC pretreatment, and this alleviating of organ injuries was abrogated after the inhibition of HO-1 activity by zinc protoporphyrin-IX. It was of note that VitC did little histological damage to the intestine of the sham rats. These data suggested that VitC might be applied as a safe inducer of intestinal HO-1 and that VitC pretreatment attenuated HS related intestinal injuries via the induction of HO-1.