Function Of Adipose-derived Stem Cells Research Articles

Adipose-derived Stem Cells for Treatment of Diabetic Foot Ulcers: A Review

Abstract: This study investigates the therapeutic potential of adipose-derived stem cells (ASCs) in diabetic foot ulcers (DFUs). The goal is to further research regenerative medicine by improving knowledge of ASC-based therapies in diabetic wound management. A comprehensive literature review included studies from reputable databases, including PubMed and the Cochrane Library. We paid particular attention to the clinical, in vivo, and in vitro investigations of the utility and effectiveness of ASCs in treating DFU. We also highlighted novel isolation techniques and application methods for ASCs in chronic wound management. ASCs have shown great potential in regenerative interventions for diabetes, especially in DFU management. These cells facilitate wound repair by differentiating into different cell types, promoting angiogenesis, secreting growth factors, reducing inflammation, and increasing wound perfusion. However, the current body of research on ASC applications for DFU still requires further investigation. This shows the importance of thoroughly studying their biological mechanisms and therapeutic uses. This review establishes that ASC-based treatments effectively enhance outcomes for patients suffering from DFU. We recommend further investigation of the functionality of ASCs and therapeutic approaches to maximize their therapeutic potential in managing diabetic wounds, thereby advancing the development of regenerative medicine.

A vascular endothelial growth factor-loaded chitosanhyaluronic acid hydrogel scaffold enhances the therapeutic effect of adipose-derived stem cells in the context of stroke.

Adipose-derived stem cell, one type of mesenchymal stem cells, is a promising approach in treating ischemia-reperfusion injury caused by occlusion of the middle cerebral artery. However, its application has been limited by the complexities of the ischemic microenvironment. Hydrogel scaffolds, which are composed of hyaluronic acid and chitosan, exhibit excellent biocompatibility and biodegradability, making them promising candidates as cell carriers. Vascular endothelial growth factor is a crucial regulatory factor for stem cells. Both hyaluronic acid and chitosan have the potential to make the microenvironment more hospitable to transplanted stem cells, thereby enhancing the therapeutic effect of mesenchymal stem cell transplantation in the context of stroke. Here, we found that vascular endothelial growth factor significantly improved the activity and paracrine function of adipose-derived stem cells. Subsequently, we developed a chitosan-hyaluronic acid hydrogel scaffold that incorporated vascular endothelial growth factor and first injected the scaffold into an animal model of cerebral ischemia-reperfusion injury. When loaded with adipose-derived stem cells, this vascular endothelial growth factor-loaded scaffold markedly reduced neuronal apoptosis caused by oxygen-glucose deprivation/reoxygenation and substantially restored mitochondrial membrane potential and axon morphology. Further in vivo experiments revealed that this vascular endothelial growth factor-loaded hydrogel scaffold facilitated the transplantation of adipose-derived stem cells, leading to a reduction in infarct volume and neuronal apoptosis in a rat model of stroke induced by transient middle cerebral artery occlusion. It also helped maintain mitochondrial integrity and axonal morphology, greatly improving rat motor function and angiogenesis. Therefore, utilizing a hydrogel scaffold loaded with vascular endothelial growth factor as a stem cell delivery system can mitigate the adverse effects of ischemic microenvironment on transplanted stem cells and enhance the therapeutic effect of stem cells in the context of stroke.

Adipose Stem Cells and Their Interplay with Cancer Cells and Mitochondrial Reservoir: A New Promising Target.

Adipose-derived stem cells (ASCs) significantly influence tumor progression within the tumor microenvironment (TME). This review examines the pro-tumorigenic roles of ASCs, focusing on paracrine signaling, direct cell-cell interactions, and immunomodulation. ASC-mediated mitochondrial transfer through tunneling nanotubes (TNTs) and gap junctions (GJs) plays a significant role in enhancing cancer cell survival and metabolism. Cancer cells with dysfunctional mitochondria acquire mitochondria from ASCs to meet their metabolic needs and thrive in the TME. Targeting mitochondrial transfer, modulating ASC function, and influencing metabolic pathways are potential therapeutic strategies. However, challenges like TME complexity, specificity, safety concerns, and resistance mechanisms must be addressed. Disrupting the ASC-cancer cell-mitochondria axis offers a promising approach to cancer therapy.

Autologous Fat Transfer in Craniofacial Surgery

Over the past two decades, autologous fat transfer has garnered significant recognition and widespread adoption within esthetic and reconstructive surgical domains. In craniofacial surgery, fat transplantation is frequently employed to address soft tissue volumetric deficiencies and asymmetries that influence facial contours. While adipose tissue (AT) is widely regarded as an optimal choice for augmentation due to its abundant availability and biocompatibility, the unpredictability and heightened resorption rates observed with traditional lipofilling techniques present a challenge for clinicians. Adipose-derived stem cells (ASCs) housed within the grafted tissue play a pivotal role in graft survival and offer avenues for tissue repair due to their angiogenic, anti-inflammatory, and immunosuppressive properties. Micro Fragmentation of Adipose Tissue (MFAT), utilized in several FDA-approved processing devices, has demonstrated promising outcomes in treating osteoarthritic joints, with success primarily attributed to enhanced paracrine function of ASCs via preservation of the perivascular niche. Currently, its application for treating bone or articular defects in the craniofacial region, including abnormalities of the temporomandibular joint, remains limited. This scarcity underscores the need for further investigation prior to its widespread integration into clinical practice.

MiR-145-5p overexpression rejuvenates aged adipose stem cells and accelerates wound healing.

Adipose-derived stem cells (ADSCs) have been widely applied in translational and regenerative medicine. During aging, there is a recognized functional decline in ADSCs, which compromises their therapeutic effectiveness. Currently, the mechanisms of aging-induced stem cell dysfunction remain unclear, hence there is a need to elucidate these mechanisms and propose strategies for reversing this functional impairment. In this study, we found that ADSCs isolated from old donors (O-ADSCs) presented inferior phenotypes and decreased miR-145-5p levels compared to those from young donors (Y-ADSCs). To interrogate the role of miR-145-5p in ADSCs, gain- and loss-of-function assays were performed. The results indicated that miR-145-5p overexpression in O-ADSCs promoted cellular proliferation and migration, while reducing cell senescence. Further study demonstrated that miR-145-5p could regulate ADSCs function by targeting bone morphogenetic protein binding endothelial cell precursor-derived regulator (BMPER), which is a crucial modulator in angiogenesis. Moreover, in vivo experiments showed that miR-145-5p-overexpressing O-ADSCs accelerated wound healing by promoting wound re-epithelialization and angiogenesis. Collectively, this study indicates that miR-145-5p works as a positive regulator for optimizing O-ADSCs function, and may be a novel therapeutic target for restoring aging-associated impairments in stem cell function.

Aging and Metabolic Reprogramming of Adipose-Derived Stem Cells Affect Molecular Mechanisms Related to Cardiovascular Diseases.

We performed a systematic search of the PubMed database for English-language articles related to the function of adipose-derived stem cells in the pathogenesis of cardiovascular diseases. In preclinical models, adipose-derived stem cells protected arteries and the heart from oxidative stress and inflammation and preserved angiogenesis. However, clinical trials did not reiterate successful treatments with these cells in preclinical models. The low success in patients may be due to aging and metabolic reprogramming associated with the loss of proliferation capacity and increased senescence of stem cells, loss of mitochondrial function, increased oxidative stress and inflammation, and adipogenesis with increased lipid deposition associated with the low potential to induce endothelial cell function and angiogenesis, cardiomyocyte survival, and restore heart function. Then, we identify noncoding RNAs that may be mechanistically related to these dysfunctions of human adipose-derived stem cells. In particular, a decrease in let-7, miR-17-92, miR-21, miR-145, and miR-221 led to the loss of their function with obesity, type 2 diabetes, oxidative stress, and inflammation. An increase in miR-34a, miR-486-5p, and mir-24-3p contributed to the loss of function, with a noteworthy increase in miR-34a with age. In contrast, miR-146a and miR-210 may protect stem cells. However, a systematic analysis of other noncoding RNAs in human adipose-derived stem cells is warranted. Overall, this review gives insight into modes to improve the functionality of human adipose-derived stem cells.

HIF-1α increases the osteogenic capacity of ADSCs by coupling angiogenesis and osteogenesis via the HIF-1α/VEGF/AKT/mTOR signaling pathway

BackgroundStabilization and increased activity of hypoxia-inducible factor 1-α (HIF-1α) can directly increase cancellous bone formation and play an essential role in bone modeling and remodeling. However, whether an increased HIF-1α expression in adipose-derived stem cells (ADSCs) increases osteogenic capacity and promotes bone regeneration is not known.ResultsIn this study, ADSCs transfected with small interfering RNA and HIF-1α overexpression plasmid were established to investigate the proliferation, migration, adhesion, and osteogenic capacity of ADSCs and the angiogenic ability of human umbilical vein endothelial cells (HUVECs). Overexpression of HIF-1α could promote the biological functions of ADSCs, and the angiogenic ability of HUVECs. Western blotting showed that the protein levels of osteogenesis-related factors were increased when HIF-1α was overexpressed. Furthermore, the influence of upregulation of HIF-1α in ADSC sheets on osseointegration was evaluated using a Sprague–Dawley (SD) rats implant model, in which the bone mass and osteoid mineralization speed were evaluated by radiological and histological analysis. The overexpression of HIF-1α in ADSCs enhanced bone remodeling and osseointegration around titanium implants. However, transfecting the small interfering RNA (siRNA) of HIF-1α in ADSCs attenuated their osteogenic and angiogenic capacity. Finally, it was confirmed in vitro that HIF-1α promotes osteogenic differentiation and the biological functions in ADSCs via the VEGF/AKT/mTOR pathway.ConclusionsThis study demonstrates that HIF-1α has a critical ability to promote osteogenic differentiation in ADSCs by coupling osteogenesis and angiogenesis via the VEGF/AKT/mTOR signaling pathway, which in turn increases osteointegration and bone formation around titanium implants.Graphical

Mechanisms and applications of adipose-derived stem cell-extracellular vesicles in the inflammation of wound healing.

Wound healing is a sophisticated process consisting of serial phases with overlaps, including hemostasis, inflammation, proliferation, and remodeling. The inflammation response is an early response that plays a crucial role in eliminating microbes and clearing damaged cell debris. However, in some pathological circumstances, such as diabetes mellitus, ischemia, trauma, deep burn, etc., abnormal inflammation can cause impaired wound healing. Adipose-derived stem cells (ADSCs) belong to the mesenchymal stem cell (MSC) family and exhibit prospective applications in tissue regeneration and dermatological repairs. ADSC-secreted extracellular vesicles (ADSC-EVs) mimic the functions of ADSCs without the concerns of cell survival, immune response, or ethical issues. Studies have revealed that ADSC-EVs can inhibit abnormal inflammation responses and accelerate wound healing through various mechanisms. Moreover, some studies explored modifications in the cargo components of ADSC-EVs to enhance their therapeutic efficacy. Given the increasing studies focusing on the potential of ADSC-EVs in wound healing, how they interfere with different phases of this process has been investigated in pieces. In this review, we summarized all up-to-date evidence to map a clearer picture of the underlying mechanisms of ADSC-EVs in inflammation response. The applications of ADSC-EVs aiming at inflammation in the healing process were also reviewed to provide therapeutic strategies for future investigators.

Adipose-Derived Stem Cells (ADSCs) in preconditioning of hypoxic cultures compared to normoxic cultures to prevent the formation of fibrous tissue: a review article

Background: Stem cells are a key element in regenerative medicine for their ability to differentiate into various cell phenotypes. According to the literature review, one process that might improve the functionality of ADSCs is hypoxic culture conditions. Hypoxic oxygen culture conditions at 5% concentration are said to increase stem cell proliferation and viability after transplantation. Methods: A comprehensive literature search was conducted by the author to obtain relevant studies from the PubMed, MEDLINE, Embase, PreMEDLINE, Embase, PsycINFO, Scopus, and Cochrane databases for the last twenty years (January 2002 – July 2022). The author used a search strategy with the following keywords: Adipose-Derived Stem Cells, hypoxic culture, normoxic culture, or pre-conditioned stem cells. Discussion: Hypoxic culture preconditioning of ADSCs with an oxygen concentration of 5% can improve proliferation capabilities and stem cell viability post-transplantation. Hypoxic preconditioning will enhance the expression of HIF-1

Methylglyoxal Impairs the Pro-Angiogenic Ability of Mouse Adipose-Derived Stem Cells (mADSCs) via a Senescence-Associated Mechanism.

Adipose-derived stem cells (ADSCs) play a crucial role in angiogenesis and repair of damaged tissues. However, in pathological conditions including diabetes, ADSC function is compromised. This work aims at evaluating the effect of Methylglyoxal (MGO), a product of chronic hyperglycemia, on mouse ADSCs' (mADSCs) pro-angiogenic function and the molecular mediators involved. The mADSCs were isolated from C57bl6 mice. MGO-adducts and p-p38 MAPK protein levels were evaluated by Western Blot. Human retinal endothelial cell (hREC) migration was analyzed by transwell assays. Gene expression was measured by qRT-PCR, and SA-βGal activity by cytofluorimetry. Soluble factor release was evaluated by multiplex assay. MGO treatment does not impair mADSC viability and induces MGO-adduct accumulation. hREC migration is reduced in response to both MGO-treated mADSCs and conditioned media from MGO-treated mADSCs, compared to untreated cells. This is associated with an increase of SA-βGal activity, SASP factor release and p53 and p21 expression, together with a VEGF- and PDGF-reduced release from MGO-treated mADSCs and a reduced p38-MAPK activation in hRECs. The MGO-induced impairment of mADSC function is reverted by senolytics. In conclusion, MGO impairs mADSCs' pro-angiogenic function through the induction of a senescent phenotype, associated with the reduced secretion of growth factors crucial for hREC migration.

Extracellular Vesicles Derived from Adipose-Derived Stem Cells Facilitate Frostbite Wound Healing By Regulating SOCS3 Expression.

Though adipose-derived stem cells (ADSCs) have potential applications for the repair and regeneration of damaged tissues, limited studies have defined the function of ADSCs on dermal fibroblasts. Our RNA-seq sequencing identified differentially expressed SOCS3 in frostbite injury. In the current study, we aim to examine the hypothesis that extracellular vesicles derived from adipose-derived mesenchymal stem cells (ADSCs-EVs) may modulate SOCS3/TGF-β1 signaling in wound healing of frostbite injury. sh-SOCS3 and sh-TGF-β1 were introduced to explore the biological role of SOCS3 in frostbite injury by detecting the proliferation and migration of human skin fibroblast (HSF) cells and the wound healing in mice. Furthermore, the extracted ADSCs-EVs were interfered with HSF cells in vitro or injected into the frostbitten mouse model in vivo. Upregulation of SOCS3 occurred in the skin tissues of frostbitten mice. Compared to sh-NC, the wound healing rate of sh-SOCS3 presented higher on day 7(31.34±4.35 vs 41.83±3.74, p < 0.05) and day 14 (63.42±6.01 vs 88.99±5.12, p < 0.05) after injury. Silencing SOCS3 can promote frostbite wound healing. Moreover, SOCS3 downregulated TGF-β1 to suppress the proliferation and migration of HSF cells, thus impeding the skin wound healing. Additionally, ADSCs-EVs could enhance the proliferation and migration of HSF cells according to the results of CCK-8 assay (p < 0.05), scratch test (17.82±4.25 vs 49.78±2.54, p < 0.05) and Transwell assay (42.33±6.81 vs 91.33±7.02, p < 0.05), and regulate the expression of SOCS3/TGF-β1. The role of ADSCs-EVs in frostbite wound healing was also confirmed in vivo. ADSCs-EVs could promote frostbite wound healing by downregulating the expression of SOCS3 and upregulating the expression of TGF-β1 and collagen I. Collectively, ADSCs-EVs inhibit SOCS3 and facilitate the expression of TGF-β1, which promotes the proliferation and migration of HSF cells and subsequently enhances wound healing of frostbite injury.

Identification of hub genes regulating the cell activity and function of adipose-derived stem cells under oxygen-glucose deprivation.

While oxygen-glucose deprivation (OGD) has been widely utilized in many cell lines to mimic certain biological changes, it has yet to be validated in mesenchymal stem cells. We performed RNA sequencing on adipose-derived stem cells (ADSCs) under hypoxic and glucose-free conditions after 4h and 8h. A total of 335 common differentially expressed genes (DEGs) were identified in the two OGD groups compared with the normal control group, consisting of 292 upregulated and 43 downregulated genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that DEGs are mainly involved in metabolic processes, programmed cell death, and DNA-binding transcription activator activity. Protein‒protein interaction and hub gene analysis revealed various potential hub genes, in which response to oxygen levels, the IL-17-related biological function and the hypoxia-inducible factor 1 signaling pathway have been of vital importance. In summary, changes in transcription factor activity may play pivotal roles in oxygen-glucose deprivation. Through RNA sequencing, we have a deeper understanding of the changes in ADSCs after OGD treatment, providing more precise insight into predicting and regulating the stemness of ADSCs.

Living Microneedle Patch with Adipose‐Derived Stem Cells Embedding for Diabetic Ulcer Healing

AbstractStem cells have demonstrated values in diabetic ulcer (DU) treatments. Challenges in this area are focused on enhancing the localized curative effects of stem cells and improving diabetic wound healing efficiently. Herein, a novel living microneedle (MN) patch is presented as a localized delivery system of bioactive platelet derived growth factor D (PDGF‐D) and human adipose‐derived stem cells (ADSCs) for DU wound treatment. Compared with traditional complicated stem cell carriers, the MN patch can keep stem cell viability for ADSCs encapsulation and delivery, and possesses good mechanical strengths to penetrate the local skin wounds noninvasively. It is demonstrated that the delivery ADSCs are with the abilities of angiogenesis promotion during the DU wound healing; while the additive PDGF‐D can contribute significantly to the proliferation of ADSCs, strengthening the cell function of ADSCs and further facilitating the healing processes. Thus, living MN patches accelerate vascularization, tissue regeneration, and collagen deposition in a wounded diabetic mouse model, suggesting their potential application to DU wound healing and other therapeutic applications.

MiR-590-3p affects the function of adipose-derived stem cells (ADSCs) on the survival of skin flaps by targeting VEGFA.

IntroductionPartial necrosis of skin flaps is still a substantial problem in plastic and reconstructive surgery. In this study, the role of miR-590-3p in adipose-derived stem cells (ADSCs) transplantation in improving the survival of skin flap in a mouse model was delved into.MethodAn abdominal perforator flap model was established in mice. The histopathological examination of mice skin tissues after ADSCs transplantation was implemented using Hematoxylin & eosin (H&E) staining. Immunohistochemistry (IHC) or immunofluorescence (IF) staining was utilized to assess the PCNA or CD31 levels. The concentrations of VEGFA in the culture medium were quantified using a VEGFA ELISA kit.ResultThe damage of tissue in the skin flap was dramatically relieved by ADSCs transplantation. MiR-590-3p overexpression notably suppressed, while miR-590-3p knockdown facilitated skin flap survival by regulating PCNA, VCAM-1, and VEGFA levels. MiR-590-3p targeted VEGFA to regulate its expression. The knockdown of VEGFA significantly inhibited, while overexpression of VEGFA notably promoted the survival of skin flap.ConclusionADSCs transplantation promotes skin flap survival by boosting angiogenesis. The miR-590-3p/VEGFA axis modulates skin flap angiogenesis and survival in ADSCs. These results reveal that interfering with miR-590-3p in ADSCs could potentially be a novel therapeutic target for the improvement of skin flap survival.

NLRP3 downregulation enhances engraftment and functionality of adipose-derived stem cells to alleviate erectile dysfunction in diabetic rats.

BackgroundThe transplantation of adipose-derived stem cells (ASCs) is a most promising treatment for diabetic erectile dysfunction (DMED). However, the effect of high glucose on the post-transplantation survival of stem cells limits the efficacy of ASCs transplantation. Prolonging the survival time of ASCs in vivo after transplantation is a key issue in the utilization of ASCs for DMED. Herein, we aimed to investigate the therapeutic effect of ASCs by downregulating NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) as well as its mechanism of action in DMED.MethodsASCs were obtained by isolating subcutaneous fat from SD rats and were identified using lipogenic and osteogenic differentiation assays, as well as flow cytometric analysis. The shNLRP3 lentivirus with the best downregulating effect was screened, and shNLRP3 lentivirus (LV-shNLRP3) was transfected into ASCs (ASCsshNLRP3) to detect apoptosis and the reactive oxygen species (ROS) levels in each group under high glucose conditions. In DMED rats, ASCsLV-shNLRP3, ASCsLV-control, or phosphate buffered saline (PBS) were administrated via intra-cavernous injection, and normal rats served as normal controls. One week post-injection, animal imaging was performed to track the ASCs. Four weeks post-injection, erectile function was evaluated by measuring the intra-cavernosal pressure and mean arterial pressure. Corpus cavernosum pyroptosis and endothelial function were examined by western blotting and immunofluorescence.ResultsNLRP3-mediated pyroptosis might be a pathogenic mechanism of ED and DMED. ASCs were isolated successfully. Thereafter, the LV-shNLRP3 with the highest transfection efficiency was selected and used to modify ASCs successfully. LV-shNLRP3 could protect ASCs paracrine function under hyperglycemia through anti-apoptosis and anti-ROS deposition mechanisms. Furthermore, ASCsLV-shNLRP3 showed an advantage in the suppression of pyroptosis compared to ASCsLV-control. The ASCsLV-shNLRP3 group had improved cavernous endothelial function and smooth muscle injury, thus reversing erectile function, and was superior to the ASCsLV-control group.ConclusionsNLRP3 Inflammasome-mediated pyroptosis might be involved in DMED formation. Intra-cavernous injection of ASCsLV-shNLRP3 could suppress cavernosal pyroptosis, contributing to improved erectile function in DMED rats.

305-OR: Quiescence Abrogates Stress-Induced Senescence-Associated Secretion Phenotype in Adipose-Derived Stem Cells and May Enhance Their Therapeutic Effects on Diabetic Complications

The anti-inflammatory functions of adipose-derived stem cells (ADSC) are receiving much attention as potential treatment for diabetic complications, although it is not yet established. Cellular stresses render ADSC prematurely senescent, in which senescent ADSC propagate instead of suppressing inflammation in neighboring cells and tissues through their secretory profile, which is called senescence-associated secretion phenotype (SASP) . In diabetes, ADSC exhibit SASP, which decreases the feasibility of ADSC-based therapies. We previously reported that ADSC become quiescent when cultured on a substrate whose stiffness mimics that of adipose tissue. Here, we investigated the effect of quiescence on high glucose-induced SASP in ADSC. When cultured in three-dimensional (3D) gels, ADSC became quiescent and showed upregulated indolemine 2,3-dioxygene in response to tumor necrosis factor α and interferon γ stimulation to mimic inflammation ex vivo. High glucose treatment upregulated MCP-1 in ADSC cultured on plastic tissue culture plates, and their conditioned medium decreased the viability of HUVEC, an endothelial cell line. However, even under high glucose conditions, transferring ADSC from plastic to 3D gels attenuated MCP-1 expression, and their conditioned medium restored the viability of HUVEC. Transplantation of gels containing ADSC into mice resulted in vascular formation in those gels, and enhanced wound healing was suggested. These results open up the possibility that quiescence will eliminate SASP in ADSC even under hyperglycemia and promote the ability of ADSC to have therapeutic effects on diabetic complications. Disclosure M.Funaki: Board Member; Mechanogenic, Inc. H.Ogawa: None. T.Oya: None. A.Hata: None. M.Yoshida: None. N.Miyamoto: None. T.Ikuta: None. Y.Uemura: None. M.Akizuki: None. A.Tangoku: None. H.Yumoto: None.

Genetic Engineering of Adipose-Derived Stem Cells Using Biodegradable and Lipid-Like Highly Branched Poly(β-amino ester)s.

Biodegradable and lipid-like highly branched poly(β-amino ester)s, HPAESA, were developed to enhance the biological functions of adipose-derived stem cells by gene transfection. Biodegradability reduces the cytotoxicity of HPAESA and enables controlled DNA release. Lipid mimicry enhances cellular uptake and endosomal escape of HPAESA/DNA polyplexes. HPAESA are able to transfect rat adipose-derived stem cells (rADSs) and human ADSCs (hADSCs) with orders of magnitude higher efficiency than commercial gene transfection reagents, with cell viability exceeding 90%. Most importantly, HPAESA can effectively transfer the nerve growth factor (NGF)-encoding plasmid to rADSCs and induce high NGF secretion, which significantly promotes neurite outgrowth of PC12 cells.

VAP-PLGA microspheres (VAP-PLGA) promote adipose-derived stem cells (ADSCs)-induced wound healing in chronic skin ulcers in mice via PI3K/Akt/HIF-1α pathway

ABSTRACT Chronic skin ulcers are a primary global health problem. Velvet antler polypeptide (VAP) regulates endothelial cell migration and angiogenic sprout. Adipose-derived stem cells (ADSCs) are reported to make pivotal impacts upon wound healing. This study aimed to explore the role of VAP combined with ADSCs in wound healing of chronic skin ulcers. The effect of VAP on phenotypes of ADSCs, and VAP (PLGA microspheres) combining with ADSCs on wound healing of chronic skin ulcers in vivo was evaluated. VAP generally promoted the proliferation, migration and invasion of ADSCs, and ADSC-induced angiogenesis in human umbilical vein endothelial cells (HUVECs) through PI3K/Akt/HIF-1α pathway. VAP-PLGA (PLGA microspheres) enhanced the promoting effect of ADSCs on wound healing, pathological changes, and angiogenesis in chronic skin ulcers in vivo. VAP-PLGA intensified the effect of ADSCs on up-regulating the levels of p-PI3K/PI3K, p-Akt/Akt, HIF-1α, vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 (SDF-1), C-X-C motif chemokine receptor 4 (CXCR4), angiopoietin-4 (Ang-4), VEGF receptor (VEGFR), and transforming growth factor-β1 (TGF-β1), and down-regulating the levels of interleukin-1 β (IL-1β), IL-18 and IL-6 in wound tissues in chronic skin ulcers in vivo. Collectively, VAP promoted the growth, migration, invasion, and angiogenesis of ADSCs through activating PI3K/Akt/HIF-1α pathway, and VAP-PLGA enhanced the function of ADSCs in promoting wound healing in vivo, which was associated with angiogenesis, inflammation inhibition, and dermal collagen synthesis.

Effects of radiation and chemotherapy on adipose stem cells: Implications for use in fat grafting in cancer patients.

Autologous fat transplantation is a versatile tool in reconstructive surgery. Adipose-derived stem cells (ASCs) increase survival of fat grafts and thus are increasingly used for breast reconstruction in breast cancer patients. However, radiation and/or chemotherapy have been proposed to inhibit soft tissue regeneration in wound healing thus suggesting alteration in stem cell pathways. Therefore, elucidating effects of radiation and chemotherapy on ASCs is critical if one desires to enhance the survival of fat grafts in patients. This review outlines our work evaluating the function and recoverability of ASCs from radiation or chemotherapy patients, focusing specifically on their availability as a source of autologous stem cells for fat grafting and breast reconstruction in cancer patients. Even though evidence suggests radiation and chemotherapy negatively influence ASCs at the cellular level, the efficiency of the isolation and differentiation capacity did not appear influenced in patients after receiving chemotherapy treatment, although fat from radiated patients exhibited significantly altered ASC differentiation into endothelial-like cells. Further, the in vitro growth rates of patient’s ASCs do not differ significantly before or after treatment. Taken together, these studies suggest ASCs as an important new tool for grafting and reconstruction even when radiation and chemotherapy treatment are involved.

The whole profiling and competing endogenous RNA network analyses of noncoding RNAs in adipose-derived stem cells from diabetic, old, and young patients

BackgroundMesenchymal stem cells including adipose-derived stem cells (ASCs) have a considerable potential in the field of translational medicine. Unfortunately, multiple factors (e.g., older age, co-existing diabetes, and obesity) may impair cellular function, which hinders the overall effectiveness of autologous stem cell therapy. Noncoding RNAs—including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs)—have been shown to play important roles in stem cell biology. However, the overall diabetes-related and aging-related expression patterns and interactions of these RNAs in ASCs remain unknown.MethodThe phenotypes and functions of ASCs isolated from diabetic (D-ASCs), old (O-ASCs), and young (Y-ASCs) donors were evaluated by in vitro assays. We conducted high-throughput RNA sequencing (RNA-seq) in these ASCs to identify the differentially expressed (DE) RNAs. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein-protein interaction (PPI) analyses were performed to investigate mRNAs with significant differences among groups. The lncRNA- or circRNA-associated competing endogenous RNA (ceRNA) networks were constructed based on bioinformatics analyses and real-time polymerase chain reaction (RT-PCR) results. The miR-145-5p mimics were transfected into O-ASCs and verified by PCR.ResultsASCs from diabetic and old donors showed inferior migration ability and increased cellular senescence. Furthermore, O-ASCs have decreased capacities for promoting endothelial cell angiogenesis and fibroblast migration, compared with Y-ASCs. The DE miRNAs, mRNAs, lncRNAs, and circRNAs were successfully identified by RNA-seq in O-ASCs vs. Y-ASCs and D-ASCs vs. O-ASCs. GO and KEGG analyses demonstrated that DE mRNAs were significantly enriched in aging and cell senescence terms separately. PPI networks revealed critical DE mRNAs in the above groups. RNAs with high fold changes and low p values were validated by PCR. ceRNA networks were constructed based on bioinformatics analyses and validated RNAs. Additionally, the lncRNA RAET1E-AS1–miR-145-5p–WNT11/BMPER axis was validated by PCR and correlation analyses. Finally, the overexpression of miR-145-5p was found to rejuvenate O-ASCs phenotype and augment the functionality of these cells.ConclusionOur research may provide insights regarding the underlying mechanisms of ASC dysfunction; it may also offer novel targets for restoring therapeutic properties in ASCs.