Therapeutic Efficacy of Adipose-Derived Stem Cells for Bleomycin-Induced Idiopathic Pulmonary Fibrosis: A Comparative Study of Intravenous versus Intratracheal Administration.

To examine the comparative fate of adipose-derived stem cells (ASCs) as well as their impact on coronary microcirculation following either retrograde coronary venous (RCV) or arterial delivery. Local delivery of ASCs to the heart has been proposed as a practical approach to limiting the extent of myocardial infarction. Mouse models of mesenchymal stem cell effects on the heart have also demonstrated significant benefits from systemic (intravenous) delivery, prompting a question about the advantage of local delivery. There has been no study addressing the extent of myocardial vs. systemic disposition of ASCs in large animal models following local delivery to the myocardium. In an initial experiment, dose-dependent effects of ASC delivery on coronary circulation in normal swine were evaluated to establish a tolerable ASC dosing range for intracoronary (IC) delivery. In a set of subsequent experiments, an anterior acute myocardial infarction (AMI) was created by balloon occlusion of the proximal left anterior descending (LAD) artery, followed by either IC or RCV infusion of 10(7) (111)Indium-labeled autologous ASCs 6 days following AMI. Indices of microcirculatory resistance (IMR) and coronary flow reserve (CFR) were measured before sacrifices to collect tissues for analysis at 1 or 24 hr after cell delivery. IC delivery of porcine ASCs to normal myocardium was well tolerated up to a cumulative dose of 14 × 10(6) cells (approximately 0.5 × 10(6) cells/kg). There was evidence suggesting microcirculatory trapping of ASC: at unit doses of 50 × 10(6) ASCs, IMR and CFR were found to be persistently altered in the target LAD distribution at 7 days following delivery, whereas at 10 × 10(6) ASCs, only CFR was altered. In the context of recent MI, a significantly higher percentage of ASCs was retained at 1 hr with IC delivery compared with RCV delivery (57.2 ± 12.7% vs. 17.9 ± 1.6%, P = 0.037) but this initial difference was not apparent at 24 hr (22.6 ± 5.5% vs. 18.7 ± 8.6%; P = 0.722). In both approaches, most ASC redistributed to the pulmonary circulation by 24 hr postdelivery. There were no significant differences in CFR or IMR following ASC delivery to infarcted tissue by either route. Selective intravascular delivery of ASC by coronary arterial and venous routes leads to similarly limited myocardial cell retention with predominant redistribution of cells to the lungs. IC arterial delivery of ASC leads to only transiently greater myocardial retention, which is accompanied by obstruction of normal regions of coronary microcirculation at higher doses. The predominant intrapulmonary localization of cells following local delivery via both methods prompts the notion that systemic delivery of ASC might provide similarly beneficial outcomes while avoiding risks of inadvertent microcirculatory compromise.

Adipose-derived stem cells (ADSCs) have been used to control several autoimmune or inflammatory diseases due to immunosuppressive properties, but their role in obesity-associated inflammation remains unestablished. This study aims to evaluate the effects of ADSCs on obesity-induced white adipose tissue (WAT) inflammation and insulin resistance. We found that diet-induced obesity caused a remarkable reduction of ADSC fraction in mouse WAT. Delivery of lean mouse-derived ADSCs, which could successfully locate into WAT of obese mice, substantially improved insulin action and metabolic homeostasis of obese mice. ADSC treatment not only reduced adipocyte hypertrophy but also attenuated WAT inflammation by reducing crown-like structures of macrophages and tumor necrosis factor (TNF)-α secretion. Importantly, ADSC treatment remodeled the phenotypes of adipose-resident macrophages from proinflammatory M1 toward anti-inflammatory M2-like subtypes, as characterized by decreased MHC class II-expressing but increased interleukin (IL)-10-producing macrophages together with low expression of TNF-α and IL-12. Coculture of ADSCs through the transwell or conditional medium with induced M1 macrophages also reproduced the phenotypic switch toward M2-like macrophages, which was substantiated by elevated arginase 1, declined inducible nitric oxide synthase, inhibition of NF-κB activity, and activation of STAT3/STAT6. Taken together, our data support that ADSC supplement in obese mice could sustain IL-10-producing M2-like macrophages in WAT through paracrine action, thereby suggesting the crucial role of ADSCs in resolving WAT inflammation, maintaining adipose homeostasis, and proposing a potential ADSC-based approach for the treatment of obesity-related diseases.

Adipose-derived stem cells mitigate deleterious effects of radiation on bone and enhance radiated fracture healing by replacing damaged cells and stimulating angiogenesis. However, adipose-derived stem cell harvest and delivery techniques must be refined to comply with the US Food and Drug Administration restrictions on implantation of cultured cells into human subjects prior to clinical translation. The purpose of this study is to demonstrate the preservation of efficacy of adipose-derived stem cells to remediate the injurious effects of radiation on fracture healing utilizing a novel harvest and delivery technique that avoids the need for cell culture. Forty-four Lewis rats were divided into 4 groups: fracture control (Fx), radiated fracture control (XFx), radiated fracture treated with cultured adipose-derived stem cells (ASC), and radiated fracture treated with noncultured minimally processed adipose-derived stem cells (MP-ASC). Excluding the Fx group, all rats received a fractionated human-equivalent dose of radiation. All groups underwent mandibular osteotomy with external fixation. Following sacrifice on postoperative day 40, union rate, mineralization, and biomechanical strength were compared between groups at P < 0.05 significance. Compared with Fx controls, the XFx group demonstrated decreased union rate (100% vs 20%), bone volume fraction (P = 0.003), and ultimate load (P < 0.001). Compared with XFx controls, the MP-ASC group tripled the union rate (20% vs 60%) and demonstrated statistically significant increases in both bone volume fraction (P = 0.005) and ultimate load (P = 0.025). Compared with the MP-ASC group, the ASC group showed increased union rate (60% vs 100%) and no significant difference in bone volume fraction (P = 0.936) and ultimate load (P = 0.202). Noncultured minimally processed adipose-derived stem cells demonstrate the capacity to improve irradiated fracture healing without the need for cell proliferation in culture. Further refinement of the cell harvest and delivery techniques demonstrated in this report will enhance the ability of noncultured minimally processed adipose-derived stem cells to improve union rate and bone quality, thereby optimizing clinical translation.

Knee osteoarthritis (Knee OA) is an irreversible condition that causes bone deformity and degeneration of the articular cartilage that comprises the joints, resulting in chronic pain and movement disorders. The administration of cultured adipose-derived stem cells (ADSCs) into the knee joint cavity improves the clinical symptoms of Knee OA; however, the effect of synovial fluid (SF) filling the joint cavity on the injected ADSCs remains unclear. In this study, we investigated the effect of adding SF from Knee OA patients to cultured ADSCs prepared for therapeutic use in an environment that mimics the joint cavity. An increase in the viability of ADSCs was observed following the addition of SF. Gene expression profiling of SF-treated ADSCs using DNA microarrays revealed changes in several genes involved in cell survival. Of these genes, we focused on FOSL1, which is involved in the therapeutic effect of ADSCs and the survival and proliferation of cancer stem cells. We confirmed the upregulation of FOSL1 mRNA and protein expression using RT-PCR and western blot analysis, respectively. Next, we knocked down FOSL1 in ADSCs using siRNA and observed a decrease in cell viability, indicating the involvement of FOSL1 in the survival of ADSCs. Interestingly, in the knockdown cells, ADSC viability was also decreased by SF exposure. These results suggest that SF enhances cell viability by upregulating FOSL1 expression in ADSCs. For therapy using cultured ADSCs, the therapeutic effect of ADSCs may be further enhanced if an environment more conducive to the upregulation of FOSL1 expression in ADSCs can be established.

The management of chondral defects has long been a challenge because of the poor self-healing capacity of articular cartilage. Many approaches ranging from symptomatic treatment to structural cartilage regeneration have obtained very limited satisfactory results. Cartilage tissue engineering, which involves an optimized combination of novel scaffolds, cell sources and growth factors, has emerged as a promising strategy for cartilage regeneration and repair. In this study, the cellular morphologies and the adhesion, migration and proliferation capabilities of adipose-derived stem cells (ASCs) and chondrocytes seeded on 3D scaffolds composed of electrospun poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB) were evaluated. Next, TGF-β1/scaffolds with 4:1 co-culture of ASCs and chondrocytes were implanted into the full thickness cartilage defects in rabbit knee for 16 weeks. ASCs and chondrocytes seeded on the scaffolds showed better adhesion, migration and proliferation than that on petri dishes in vitro. Importantly, implantation with TGF-β1/scaffolds with delivery of ASCs and chondrocytes revealed desirable in vivo healing outcomes. These results demonstrate that ASCs have great potential in the field of tissue engineering. It is possible that the improvement in ASC-seeded electrospun 3D P3HB4HB scaffolds may ultimately lead to improved repair of cartilage injuries.

Burn injuries are under-appreciated injuries that involve tissue destruction associated with physiological and pathophysiological responses. The use of stem cell-based therapies has expanded in various diseases, particularly in burn wound repair. Adipose-derived stem cells (ADSCs) have recently been revealed as the regeneration medicine that affects ectodermal, mesodermal and endodermal tissue and organs for repairing damaged tissues. ADSCs can be easily harvested from adipose tissue and are widely used as research tools and therapeutics in preclinical and clinical wound healing trials. Based on the pathophysiology of three phases of burn injuries, we discussed various cell-based components and cytokines associated with ADSCs of three phases of burn injuries. In this review, recent research and therapeutic effects of ADSCs in burn wound are covered and stated separately in each phase. Based on the background knowledge, the differentiation potential and therapeutic applications of ADSCs is connected with these growth factors and cells. In addition, future direction and limits for ADSCs are mentioned in the final stage.

Objective To explore the effect of magnetic adipose-derived stem cells(ADSCs) on treating atherosclerotic erectile dysfunction(ASED). Methods ADSCs were extracted from para-epididymis fat of SD rats aged 2 to 3 months for culture and identification. ADSCs were labeled with the magnetic resonance contrast agent superparamagnetic iron oxide nanoparticles(SPIONs). Meanwhile, the labeling efficiency, as well as effect on cell viability and proliferation was evaluated using Prussian blue, trypan blue staining and MTT method. The paramagnetism of ADSCs after SPIONs labeling was evaluated through the action of the exterior magnetic field. The atherosclerosis rat model was constructed, and ADSCs were injected into the corpus cavernosum afterwards. Intracorporeal pressure(ICP) was determined in the normal group, atherosclerosis group, ADSCs treatment with no action of magnetic field group, and ADSCs treatment with action of exterior magnetic field group after 4 weeks.Contents of smooth muscle and endothelium in corpus cavernosum of rats were detected using immunohistochemical staining. In addition, SOD and NOS activities, as well as MDA content were detected by ELISA. Results ADSCs extracted from para-epididymis fat of rats had grown actively and had high purity. Besides, they showed multi-lineage differentiation. SPIONs could be effectively absorbed by ADSCs, which would not remarkably inhibit the proliferation and cell viability of ADSCs. Iron content in cell was positively correlated with the iron concentration in the labeled SPIONs, and ADSCs showed paramagnetism after SPIONs labeling. ADSCs transplantation could notably improve the erectile function of ASED rats and enhanced the endothelium and smooth muscle contents in corpus cavernosum. Moreover, it could also correct the oxidative stress state in corpus cavernosum tissue, and some ADSCs had differentiated into smooth muscle and endothelial cells. Conclusions ADSCs transplantation can markedly improve the erectile function of ASED rats. Furthermore, magnetic induction has promoted the colonization of ADSCs in the corpus cavernosum, which contributes to enhancing the therapeutic effect of ADSCs and provides a new thinking and concept for stem cell therapy. Key words: Plaque, Atherosclerotic; Erectile Dysfunction; Mesenchymal Stem Cells

Today adipose tissue is not just considered as the primary energy storage organ, but it is also recognized as an important endocrine tissue and an abundant source of mesenchymal stem cells (adipose-derived stem cells, ASCs). During the last decade, several studies have provided preclinical data on the safety and efficacy of ASCs, supporting their use in cell-based therapy for regenerative medicine purposes. Little is known about the effect of obesity on ASCs properties. Since ASCs differentiation and proliferation are determined by their niche, the differences in body fat distribution and the obesity-related co-morbidities may have several consequences. In this study we compared ASCs of subcutaneous adipose tissue from obese (obS-ASCs) and non-obese (nS-ASCs) donors in order to compare their immunophenotype and osteogenic and adipogenic potential. Moreover, in order to evaluate the possible difference between subcutaneous and visceral fat, obS-ASCs were also compared to ASCs derived from visceral adipose tissue of the same obese donors (obV-ASCs). Our results show that subcutaneous and visceral ASCs derived from obese donors have an impaired cell proliferation, clonogenic ability and immunophenotype. Nevertheless, obS-ASCs are able to differentiate toward osteogenic and adipogenic lineages, although to a small extent with respect to non-obese donors, whereas obV-ASCs lose most of their stem cell characteristics, including multi-differentiation potential. Taken together our findings confirm that not all ASCs present the same behavior, most likely due to their biological microenvironment in vivo. The specific stimuli which can play a key role in ASCs impairment, including the effects of the obesity-related inflammation, should be further investigated to have a complete picture of the phenomenon.

BackgroundFollowing recent findings from our group that curcumin preconditioning augments the therapeutic efficacy of adipose-derived stem cells in the healing of diabetic wounds in rats, we aimed to investigate the regenerative effects of curcumin preconditioned adipose-derived mesenchymal stem cells (ASCs) for better recovery of acid inflicted burns in this study.MethodsASCs were preconditioned with 5 μM curcumin for 24 hours and assessed for proliferation, migration, paracrine release potential and gene expression comparative to naïve ASCs. Subsequently, the healing capacity of curcumin preconditioned ASCs (Cur-ASCs) versus naïve ASCs was examined using acidic wounds in rats. For this, acid inflicted burns of 20 mm in diameter were made on the back of male Wistar rats. Then, 2 × 106 cells of Cur-ASCs and naïve ASCs were intradermally injected in the wound periphery (n = 6) for comparison with an untreated saline control. Post-transplantation, wounds were macroscopically analysed and photographed to evaluate the percentage of wound closure and period of re-epithelization. Healed wound biopsies were excised and used for histological evaluation and expression analysis of wound healing markers at molecular level by quantitative PCR and western blotting.ResultsWe found that Cur-ASCs exhibited greater proliferation, migration and paracrine potential in vitro. Further, Cur-ASCs showed more effective recovery than naïve ASCs as exhibited by gross morphology, faster wound closure and earlier re-epithelialization. Masson’s trichrome and hematoxylin and eosin staining demonstrated the improved architecture of the healing burns, as evidenced by reduced infiltration of inflammatory cells, compact collagen and marked granulation in Cur-ASC treated rats. Corroborating these findings, molecular assessment showed significantly reduced expressions of pro-inflammatory factors (interleukin-1 beta, interleukin-6, tumor necrosis factor alpha) a with striking upsurge of an oxidative marker (superoxide dismutase 1), pro-angiogenic factors (vascular endothelial growth factor, hepatocyte growth factor, hypoxia-inducible factor-1 alpha) and collagen markers (transforming growth factor beta 1, fibroblast growth factor-2, collagen type 1 alpha 1), verifying that Cur-ASCs modulate the regulation of pro-inflammatory and healing markers at burn sites.ConclusionsTreatment with Cur-ASCs resulted in faster re-epithelization of acid inflicted burns compared to the treatment with naïve ASCs. Based on observed findings, we suggest the transplantation of Cur-ASCs is a valuable therapy for the potent clinical management of acidic burns.

BackgroundChronic radiation dermatitis (CRD) is a late consequence of radiation with high incidence in patients receiving radiotherapy. Conventional therapies often yield unsatisfactory results. Therefore, this study aimed to explore the therapeutic potential and mechanism of adipose-derived stem cells (ADSCs) for CRD, paving the way for novel regenerative therapies in clinical practice.MethodsClinical CRD skin biopsies were analyzed to character the pathological changes of CRD skin and guided the animal modeling scheme. Subsequently, an in vivo analysisusing mouse CRD models was conducted to explore their effects of ADSCs on CRD, monitoring therapeutic impact for up to 8 weeks. Transcriptome sequencing and histologic sections analysis were performed to explore the potential therapeutic mechanism of ADSCs. Following observing extensive apoptosis of transplanted ADSCs, the therapeutic effect of ADSCs were compared with those of apoptosis-inhibited ADSCs. Multiphoton imaging and analysis of collagen morphologic features were employed to explain how translated ADSCs promote collagen remodeling at the microscopic level based on the contrast of morphology of collagen fibers.ResultsFollowing injection into CRD-afflicted skin, ADSCs therapy effectively mitigated symptoms of CRD, including acanthosis of the epidermis, fibrosis, and irregular collagen deposition, consistent with the possible therapeutic mechanism suggested by transcriptome sequencing. Notably, in vivo tracking revealed a significant reduction in ADSCs number due to extensive apoptosis. Inhibiting apoptosis in ADSCs partially tempered their therapeutic effects. Mechanically, analysis of collagen morphologic features indicated that translated ADSCs might promote dermal extracellular matrix remodeling through enlarging, lengthening, crimping, and evening collagen, counteracting the atrophy and rupture caused by irradiation.ConclusionsThis study demonstrated that ADSCs underwent substantial apoptosis upon local skin transplantation, and paradoxically, this apoptosis is essential for their efficacy in promoting the regeneration of late radiation-impaired skin. Mechanically, transplanted ADSCs could promote the remodeling and rearrangement of radiation-damaged dermal collagen matrix.

With great interest, we read about the article entitled “Photoaged Skin Therapy with Adipose-Derived Stem Cells,” published in the June of 2020 issue of Plastic and Reconstructive Surgery by Charles-de-Sá et al.1 In this study, 20 Brazilian candidates for face lifting were injected with in vitro–expanded, autologous, adipose-derived mesenchymal stem cells to evaluate the regeneration of dermal elastic matrix component after 3 to 4 months. The results showed a full regeneration of solar elastosis, which provided the clinical evidence and positive suggestions for prospective cell-mediated therapies for skin photoaging. However, we would like to raise questions with regard to the study in some respects. First, although in the Discussion section the authors declared that no adverse effects were observed, it has been reported that cell dysfunction and risk of neoplastic transformation should be taken seriously in aging stem cells.2–4 Mesenchymal stem cells derived from old donors exhibit elevated levels of reactive oxygen species, nitric oxide, lower superoxide dismutase activity, and upregulated p53 protein, so a strategy of flawless cell sorting for aged autologous therapy would be a significant issue.5 Therefore, it is necessary to assess and reconsider the safety of adipose-derived stem cells, especially for elderly donors over 60 years old. Second, the clinical data are also important to demonstrate the therapeutic efficacy of adipose-derived stem cells. Indeed, before skin biopsies were performed, application of some noninvasive detection technologies, such as dermoscopy, Raman spectroscopy, optical coherence tomography, or Visia imaging (Canfield Scientific, Inc., Parsippany, N.J.), would have been useful to analyze the changes in photoaged skin. Third, the nontreated skin specimens were considered to be the preinjection control group, while the adipose-derived, stem cell–treated skin specimens were obtained after a 3- to 4-month interval during face-lifting surgery, as described in the article. However, we hold the view that biopsy specimens are far more comparable at the same time point, since the influence of the time variable should not be omitted. Furthermore, the candidates will not suffer any extra pain if the specimens of both groups are harvested during face-lifting surgery at the same time. At last, a strictly sterile laboratory environment is needed for the time-consuming and complex process, which may limit its clinical use on a large scale. To summarize, the authors’ findings contribute to cell-mediated therapies for sun-aged skin. We expect further studies on more stringent evaluations of safety and therapeutic efficacy. DISCLOSURE The authors have no financial interest to declare in relation to the content of this communication. Yu Zhao, M.D.Qiang Dai, M.D.Ran Xiao, Ph.D.Research Center of Plastic Surgery HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, People’s Republic of China

Efficacy of adipose-derived stem cells in preventing peripheral nerve adhesion and promoting nerve regeneration: A laboratory investigation in a rat model

Mesenchymal stem cells have immense potential in applications of bone healing and regeneration. However, few studies have evaluated the therapeutic efficacy of adipose-derived stem cells (ASCs) and bone marrow stromal cells (BMSCs) in irradiated bone. The purpose of this study is to compare the ability of ASCs versus BMSCs to enhance healing outcomes in a murine model of irradiated mandibular fracture repair. Forty-eight isogenic male Lewis rats underwent radiation therapy followed by mandibular osteotomy with intraoperative placement of either ASCs or BMSCs. Animals were killed on postoperative day 40. Mandibles were analyzed for union rate, biomechanical strength, vascularity, and mineralization. Groups were compared at P < 0.05 significance. The ASC and BMSC groups demonstrated 92% and 75% union rates. Compared with the BMSC group, the ASC group demonstrated a trending increase in maximum load ( P = 0.095) on biomechanical strength analysis and a significant increase in vessel number ( P = 0.001), vessel thickness ( P = 0.035), and vessel volume fraction ( P = 0.007) on micro-computed tomography angiography analysis. No significant differences in bone mineralization were identified on micro-computed tomography analysis. This study demonstrates the superior therapeutic efficacy of ASCs over BMSCs in irradiated fracture healing as evidenced by union rate, vascular morphometry, and a trend in biomechanical strength. We posit that the robust vascular response induced by ASCs better recapitulates the sequence and synchronicity of physiologic bone healing compared with BMSCs, thereby improving the reliability of irradiated fracture repair.

Adipose-Derived Mesenchymal Stem Cells With Microfracture Versus Microfracture Alone: 2-Year Follow-up of a Prospective Randomized Trial

Adipose-derived stem cells (ASCs) transplanted along with autologous adipose tissue may improve fat graft survival; however, the efficacy of ASCs has been diluted by low vascularization. This study was designed to test the hypothesis that basic fibroblast growth factor (bFGF) may improve the effects of ASCs because it owns the property to boost angiogenesis. In the present study, human fat tissues were mixed with ASCs, ASCs plus 100 U bFGF, or medium as the control and then injected subcutaneously into immunologically compromised nude mice for 12 weeks. Our findings demonstrated that mixture with the ASCs significantly increased the weight and volume of the fat grafts compared to control grafts, and histological analysis revealed that both ASCs and ASCs plus bFGF grafts consisted predominantly of adipose tissue and had significantly less fibrosis but greater microvascular density compared with control and also grafts mixed with ASCs had a high expression of angiogenic factors. More importantly, the bFGF treated fat grafts shown elevate in survival, vascularization, and angiogenic factors expression when compared with the grafts that received ASCs alone. These results indicated that bFGF together with ASCs can enhance the efficacy of autologous fat transplantation and increase blood vessel generation involved in the benefits from bFGF.