Culture supernatant of adipose stem cells can ameliorate allergic airway inflammation via recruitment of CD4+CD25+Foxp3 T cells

Immunomodulatory Effect of Adipose Stem Cell-Derived Extra-Cellular Vesicles on Cytokine Expression and Regulatory T Cells in Patients with Asthma

Although mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) are as effective as MSCs in the suppression of allergic airway inflammation, few studies have evaluated the immunomodulatory capacity of MSC-derived EVs in patients with asthma. Thus, we assessed the effects of adipose stem cell (ASC)-derived EVs on cytokine expression and regulatory T cells (Tregs) in peripheral blood mononuclear cells (PBMCs) of asthmatic patients. PBMCs (1 × 106 cells/mL) were isolated from asthmatic patient and healthy controls and co-cultured with 1 μg/mL of ASC-derived EVs. Th (T helper) 1-, Th2-, and Treg-related cytokine expression, fluorescence-activated cell sorting analysis of CD4+CD25+FOXP3+ T cells, and co-stimulatory molecules were analyzed before and after ASC-derived EV treatment. The expression levels of IL-4 and costimulatory molecules such as CD83 and CD86 were significantly higher in PBMCs of asthmatic patients than in control PBMCs. However, ASC-derived EV treatment significantly decreased the levels of interleukin (IL)-4 and co-stimulatory molecules such as CD83 and CD86 in the phytohemagglutinin (PHA)-stimulated PBMC of asthmatic patients. Furthermore, ASC-derived EVs remarkably increased the transforming growth factor-β (TGF-β) levels and expression of Tregs in the PBMC of asthmatic patients. ASC-derived EVs induce Treg expansion and have immunomodulatory effects by downregulating IL-4 and upregulating TGF-β in PBMCs of asthmatic patients.

SCGB1C1 Plays a Critical Role in Suppression of Allergic Airway Inflammation through the Induction of Regulatory T Cell Expansion

The nanosized vesicles secreted from various cell types into the surrounding extracellular space are called extracellular vesicles (EVs). Although mesenchymal stem cell-derived EVs are known to have immunomodulatory effects in asthmatic mice, the role of identified pulmonary genes in the suppression of allergic airway inflammation remains to be elucidated. Moreover, the major genes responsible for immune regulation in allergic airway diseases have not been well documented. This study aims to evaluate the immunomodulatory effects of secretoglobin family 1C member 1 (SCGB1C1) on asthmatic mouse models. C57BL/6 mice were sensitized to ovalbumin (OVA) using intraperitoneal injection and were intranasally challenged with OVA. To evaluate the effect of SCGB1C1 on allergic airway inflammation, 5 μg/50 μL of SCGB1C1 was administrated intranasally before an OVA challenge. We evaluated airway hyperresponsiveness (AHR), total inflammatory cells, eosinophils in the bronchoalveolar lavage fluid (BALF), lung histology, serum immunoglobulin (Ig), the cytokine profiles of BALF and lung-draining lymph nodes (LLN), and the T cell populations in LLNs. The intranasal administration of SCGB1C1 significantly inhibited AHR, the presence of eosinophils in BALF, eosinophilic inflammation, goblet cell hyperplasia in the lung, and serum total and allergen-specific IgE. SCGB1C1 treatment significantly decreased the expression of interleukin (IL)-5 in the BALF and IL-4 in the LLN, but significantly increased the expression of IL-10 and transforming growth factor (TGF)-β in the BALF. Furthermore, SCGB1C1 treatment notably increased the populations of CD4+CD25+Foxp3+ regulatory T cells (Tregs) in asthmatic mice. The intranasal administration of SCGB1C1 provides a significant reduction in allergic airway inflammation and improvement of lung function through the induction of Treg expansion. Therefore, SCGB1C1 may be the major regulator responsible for suppressing allergic airway inflammation.

Long-term follow-up and exploration of the mechanism of stromal vascular fraction gel in chronic wounds

BACKGROUND

Chronic refractory wounds easily relapse and seriously affect the patients' quality of life. Previous studies have shown that stromal vascular fraction gel (SVF-gel) significantly promotes the early healing of chronic wounds; however, the mechanisms of SVF-gel function per se remain unclear, and a long-term follow-up is lacking. This study aims to explore the mechanisms of SVF-gel promoting the healing of chronic wounds and follow up the long-term efficacy of SVF-gel.

METHODS

Autologous SVF-gel transplantation was performed in 20 patients with chronic wounds (from March 2016 to September 2019), and the size of the wound before and after SVF-gel transplantation was observed. The conditioned medium (CM) was harvested from SVF-gel under serum-free, serum-deprivation and 10% fetal bovine serum (FBS) microenvironment in vitro, respectively. The concentration of the growth factors in the two kinds of gel-CM was tested, and their effects on the proliferation and migration of human dermal fibroblasts (HDFs) were detected.

RESULTS

All patients had 100% wound closure eventually, and the average time to complete closure was 28.3 ± 9.7 days. The time of follow-up ranged from 2 to 6 years, and there was no wound recurrence. Interestingly, the concentrations of epidermal growth factor and transforming growth factor β1 of the CM were higher in serum-free and serum-deprivation condition than in 10% FBS microenvironment (p < 0.05). Correspondingly, the proliferation and migration ability of HDFs treated with gel-CM from serum-free condition were stronger than those treated with gel-CM from serum-deprivation (2% FBS) or 10% FBS microenvironment (p < 0.05).

CONCLUSION

These results indicate that it is safe, effective, and lasting in effect to treat chronic wounds with SVF-gel and mechanisms of action that include secreting various cytokines and promoting cell proliferation and migration ability.

TRIAL REGISTRATION

Chinese Clinical Trail Registry, ChiCTR2000034624. Registered 12 July 2020-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=56058.

Immunomodulatory Effects of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Allergic Airway Disease

Mesenchymal stem cells (MSCs) have been reported as promising candidates for the treatment of various diseases, especially allergic diseases, as they have the capacity to differentiate into various cells. However, MSCs itself have several limitations such as creating a risk of aneuploidy, difficulty in handling them, immune rejection, and tumorigenicity, so interest in the extracellular vesicles (EVs) released from MSCs are increasing, and many studies have been reported. Previous studies have shown that extracellular vesicles (EVs) produced by MSCs are as effective as the MSCs themselves in suppression of allergic airway inflammation through the suppression of Th2 cytokine production and the induction of regulatory T cells (Treg) expansion. EVs are one of the substances secreted by paracrine induction from MSCs, and because it exerts its effect by delivering contents such as mRNA, microRNA, and proteins to the receptor cell, it can reduce the problems or risks related to stem cell therapy. This article reviews the immunomodulatory properties of MSCs-derived EVs and their therapeutic implications for allergic airway disease.

Therapeutic Effects of Human Pluripotent Stem Cell-Derived Mesenchymal Stem Cells on a Murine Model of Acute Type-2-Dominated Airway Inflammation

Allergic rhinitis and allergic asthma are the most common type-2 inflammatory diseases, which are hardly curable and cause heavy burden to general well-being. Mesenchymal stem cells (MSCs) are multipotent nonhematopoietic cells with potential immunomodulatory effects that have been showning to have a therapeutic effect on allergic diseases. Here, we investigated the effects of human induced pluripotent stem cell (iPSC)-derived MSCs on airway hyperresponsiveness and acute type-2-dominated inflammation throughout the upper and lower airways. In this study, human MSCs, MSC cell culture supernatant, and culture medium (control) was injected into the acute airway inflammatory model via the tail vein. Mouse behavioristics were recorded immediately and mouse lung function was measured 24 hours after the last ovalbumin (OVA) challenge. Histological staining, Luminex, Elisa and flow cytometry were employed to evaluate the effects on the production of total/OVA-specific IgG1 and IgE, cytokines expression in lung tissues, and inflammatory cells infiltration in the lung and spleen of the experimental mice. Expressions of eotaxin, IL-4, IL-5, IL-13, IL-33 in nasal and lung lavage were evaluated by Luminex and Elisa. We found that for this acute inflammatory mouse model, human MSC transplantation significantly mitigated the decreased motoring time and the increased lung function Rrs caused by OVA challenge. Serum OVA-IgG1, OVA-IgE, and eosinophil percentages in the splenocytes were significantly decreased. Injection of the MSC supernatant also showed the same trend, but not significantly changed. After treatment, IL-4 and IL-13 were significantly decreased in the lung tissue, and IL-5 and IL-13 were significantly decreased in lung lavage. In conclusion, both human MSC culture supernatant and cell transplantation could alleviate AHR and inflammation in acute inflammatory experimental animals, which demonstrated their potential for clinical therapeutics. Human iPSC-MSCs, MSC cell culture supernatant, or culture medium (control) was injected into the OVA-induced acute airway inflammatory model via the tail vein. Behavioral changes, AHR, serum OVA-specific IgG1 and IgE concentrations, and type-2 inflammations were alleviated.

Intranasally Administered Extracellular Vesicles from Adipose Stem Cells Have Immunomodulatory Effects in a Mouse Model of Asthma

Asthma is a chronic eosinophilic airway disease characterized by type 2 helper T cell-driven inflammation. Adipose stem cells (ASCs) and the ASC culture supernatant are known to improve allergic airway inflammation; however, the immunomodulatory effects of ASC-derived extracellular vesicles (EVs) on allergic airway diseases remain unclear. Thus, we assessed the effects of ASC-derived EVs on allergic airway inflammation in a mouse model of asthma. EVs were isolated from the culture supernatant of murine ASCs and characterized. Six-week-old female C57BL/6 mice were sensitized to ovalbumin (OVA) by intraperitoneal injection and challenged intranasally with OVA. Before the OVA challenge, 10 μg/50 μl of ASC-derived EVs was administered intranasally to the experimental group. ASC-derived EVs significantly attenuated airway hyperresponsiveness (AHR) in asthmatic mice (p = 0.023). ASC-derived EVs resulted in a remarkable reduction of the total number of inflammatory cells (p = 0.005) and eosinophils (p = 0.023) in the bronchoalveolar lavage fluid (BALF), the degree of eosinophilic lung inflammation (p < 0.001), and the serum total and OVA-specific immunoglobulin (Ig)E (p = 0.048 and p = 0.001) and total IgG1 (p < 0.001). Interleukin- (IL-) 4 was significantly inhibited with ASC-derived EV pretreatment in the BALF and lung draining lymph nodes (LLNs) (p = 0.040 and p = 0.011). Furthermore, ASC-derived EV administration resulted in a significant increase of the regulatory T cell (Treg) populations in LLNs. ASC-derived EVs alleviated AHR and allergic airway inflammation caused by the induction of Treg expansion in a mouse model of asthma. There seems to be a role for ASC-derived EVs as a modifier in allergic airway disease.

In search of elixir: Pharmacological agents against stem cell senescence

Stem cell senescence causes different complications. In addition to the aging phenomenon, stem cell senescence has been investigated in various concepts such as cancer, adverse drug effects, and as a limiting factor in cell therapy. This manuscript examines protective medicines and supplements which are capable of hindering stem cell senescence. We searched the databases such as EMBASE, PubMed, and Web of Science with the keywords "stem cell," "progenitor cell," "satellite," "senescence" and excluded the keywords "cancer," "tumor," "malignancy" and "carcinoma" until June 2020. Among these results, we chose 47 relevant studies. Our investigation indicates that most of these studies examined endothelial progenitor cells, hematopoietic stem cells, mesenchymal stem cells, adipose-derived stem cells, and a few others were about less-discussed types of stem cells such as cardiac stem cells, myeloblasts, and induced pluripotent stem cells. From another aspect, 17β-Estradiol, melatonin, metformin, rapamycin, coenzyme Q10, N-acetyl cysteine, and vitamin C were the most studied agents, while the main protective mechanism was through telomerase activity enhancement or oxidative damage ablation. Although many of these studies are in vitro, they are still worthwhile. Stem cell senescence in the in vitro expansion stage is an essential concern in clinical procedures of cell therapy. Moreover, in vitro studies are the first step for further in vivo and clinical studies. It is noteworthy to mention the fact that these protective agents have been used in the clinical setting for various purposes for a long time. Given that, we only need to examine their systemic anti-senescence effects and effective dosages.

Integrative Analysis of MicroRNAs and mRNAs in LPS-Induced Macrophage Inflammation Based on Adipose Tissue Stem Cell Therapy

Severe inflammation can lead to multiple organ dysfunction syndrome, which has high mortality. Adipose-derived stem cells have been shown to affect the inflammatory response of macrophages. However, the molecular mechanism of the anti-inflammatory capacity of adipose-derived stem cells (ADSCs) remains to be understood. In the present study, a macrophage inflammation model was established by LPS, and treated with different volumes of ADSC supernatant. Then, we investigated the key genes in the LPS group and treatment group by RT-PCR, RNA sequencing technology, and bioinformatics analysis. A total of 26 miRNAs and 11,882 mRNAs were differentially expressed between them. The expression of 15 of the miRNAs (9 upregulated and 6 downregulated) was confirmed by RT-PCR. GO and KEGG pathway analyses of the targets of the 9 significantly upregulated miRNAs showed that they were related to immune system process, inflammatory response, lipopolysaccharide, and TNF-α, NF-κB, Toll-like receptor, and MAPK signaling pathways. Moreover, a miRNA-mRNA network also revealed 8 important genes (Mapkapk2, Sepp1, Cers6, Snn, ZfP568, Ccdc93, Pofut1, Pik3cd). We finally confirmed the expression of these 8 targeted genes by performing the RT-PCR analysis. This study may provide a new understanding of the molecular mechanism of ADSCs in the inflammatory response related to multiple miRNAs and mRNAs.

Screening and Functional Pathway Analysis of Pulmonary Genes Associated with Suppression of Allergic Airway Inflammation by Adipose Stem Cell-Derived Extracellular Vesicles

Background

Although mesenchymal stem cell- (MSC-) derived extracellular vesicles (EVs) are as effective as MSCs in the suppression of allergic airway inflammation, few studies have explored the molecular mechanisms of MSC-derived EVs in allergic airway diseases. The objective of this study was to evaluate differentially expressed genes (DEGs) in the lung associated with the suppression of allergic airway inflammation using adipose stem cell- (ASC-) derived EVs.

Methods

C57BL/6 mice were sensitized to ovalbumin (OVA) by intraperitoneal injection and challenged intranasally with OVA. To evaluate the effect of ASC-derived EVs on allergic airway inflammation, 10 μg/50 μL of EVs were administered intranasally prior to OVA challenge. Lung tissues were removed and DEGs were compared pairwise among the three groups. DEG profiles and hierarchical clustering of the identified genes were analyzed to evaluate changes in gene expression. Real-time PCR was performed to determine the expression levels of genes upregulated after treatment with ASC-derived EVs. Enrichment analysis based on the Gene Ontology (GO) database and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were also performed to further identify the function of DEGs.

Results

Expression of paraoxonase 1 (PON1), brain-expressed X-linked 2 (Bex2), insulin-like growth factor binding protein 6 (Igfbp6), formyl peptide receptor 1 (Fpr1), and secretoglobin family 1C member 1 (Scgb1c1) was significantly increased in asthmatic mice following treatment with ASC-derived EVs. GO enrichment and KEGG pathway analysis showed that these genes were strongly associated with immune system processes and their regulation, cellular processes, single-organism processes, and biological regulation.

Conclusion

These results suggest that the DEGs identified in this study (PON1, Bex2, Igfbp6, Fpr1, and Scgb1c1) may be involved in the amelioration of allergic airway inflammation by ASC-derived EVs.

Application of Stem Cell-Derived Extracellular Vesicles in Allergic Airway Diseases

Mesenchymal stem cells (MSCs) have been reported to be promising candidates for the treatment of allergic airway diseases. However, MSCs themselves have several problems including immune rejection, risk of aneuploidy, difficulty of handling, and tumorigenicity. An increasing number of studies demonstrated that administration of conditioned media or extracellular vesicles (EVs) released by MSCs is as effective as the MSCs themselves in suppression of allergic airway inflammation. EVs can exert their effects by delivering their contents such as proteins, mRNAs, and microRNAs to recipient cells. Furthermore, the administration of MSCs-derived EVs may reduce potential safety risks associated with stem cell therapy, suggesting that MSCs-derived EVs may be a promising alternative to cell therapy for allergic airway diseases. This review examines the current understanding of the immunomodulatory properties of MSCs-derived EVs and its therapeutic implication for allergic airway diseases.

Mesenchymal Stem Cells Enhance Pulmonary Antimicrobial Immunity and Prevent Following Bacterial Infection

Background

Immunosuppressants such as cyclophosphamide (CTX) have been employed to treat a wide array of autoimmune diseases. The most unfavourable side effects of these drugs are their suppression on the antimicrobial immunity and increasing the risk of infection. As a promising substitution/adjunct, mesenchymal stem cells (MSCs) are currently being tested in several clinical trials. However, their influence on the recipients' antimicrobial immunity remains unclear.

Methods

In this study, C57BL/6 mice were treated with either CTX or MSCs, and then both the innate and adaptive immunity of the lung were determined. To investigate the influence of CTX and MSCs on the immune defence against infection, the treated mice were intranasally infected with opportunistic pathogen Haemophilus influenzae (Hi). Bacterial clearance and antibacterial immune responses were analysed.

Results

Our data showed that CTX strongly inhibited the proliferation of lung immune cells, including alveolar macrophages (AMs) and T cells, whereas MSCs increased the numbers of these cells. CTX suppressed the phagocytic activity of AMs; on the contrary, MSCs enhanced it. Notably, infusion of MSCs led to a remarkable increase of regulatory T cells and Th1 cells in the lung. When infected by Hi, CTX did not significantly impair the elimination of invaded bacteria. However, MSC-treated mice exhibited accelerated bacterial clearance and moderate inflammation and tissue damage.

Conclusion

Our study reported that unlike traditional immunosuppressants, modulation of MSCs on the recipient's immune response is more elegant. It could preserve and even enhance the antimicrobial defence, suggesting that MSCs are better choice for patients with high risk of infection or those who need long-term immunosuppressive regimen.

Dendritic cells and M2 macrophage play an important role in suppression of Th2-mediated inflammation by adipose stem cells-derived extracellular vesicles

Although stem cell-derived extracellular vesicles (EVs) have been shown to facilitate regeneration of injured tissue, there is no report that evaluates the immune-modulating effect of stem cell-derived EVs on Th2-mediated inflammation. In this study, we evaluated the immunomodulatory effects of adipose stem cells (ASCs)-derived EVs on Th2-mediated inflammation induced by Aspergillus protease antigen in lung epithelial cells. The EVs were isolated from supernatant of ASCs and the diameters of EVs were measured by using dynamic light scattering. The mice primary lung epithelial cells and mouse lung epithelial cell line (MLE12) were pre-treated with 200 ng/ml of Aspergillus protease and then treated with 1 μg/ml of ASC-derived EVs. Real time PCR was performed to determine the expression levels of eotaxin, IL-25, TGF-β, and IL-10 mRNAs after EV treatment. To evaluate the role of EVs in macrophage polarization and dendritic cells (DCs) differentiation, in vitro bone marrow-derived macrophage and DCs stimulation assay was performed. EV treatment significantly decreased the expression of eotaxin and IL-25 and increased TGF-β and IL-10 in both lung epithelial cells. EV treatment significantly increased the expression of co-stimulatory molecules such as CD40, CD80, and CD 86 in immature DCs. Furthermore, EV treatment significantly enhanced the gene expression of M2 macrophage marker such as Arg1, CCL22, IL-10, and TGF-β. In conclusion, EVs of ASCs ameliorated Th2-mediated inflammation induced by Aspergillus protease antigen through the activation of dendritic cells and M2 macrophage, accompanied by down-regulation of eotaxin and IL-25, and up-regulation of TGF-β and IL-10 in mouse lung epithelial cells.

Anti-inflammatory Property of Imperatorin on Alveolar Macrophages and Inflammatory Lung Injury

Imperatorin is one of the furanocoumarin derivatives and exists in many medicinal herbs with anticancer, antiviral, antibacterial, and antihypertensive activities. In this study, we examined the anti-inflammatory effects of imperatorin on inflammation-associated lung diseases. Imperatorin reduced iNOS and COX-2 expression and also IL-6 and TNFα production enhanced by zymosan. Imperatorin also inhibited the signaling pathways of JAK/STAT and NF-κB. Moreover, in vivo study also revealed that zymosan-induced immune cell infiltration, pulmonary fibrosis, and edema were relieved by imperatorin in mice. We found that imperatorin exerts anti-inflammatory effects that are associated with amelioration of lung inflammation, edema, and rapid fibrosis. Studies on alveolar macrophages also reveal that imperatorin reduced the production of pro-inflammatory mediators and cytokines and inhibited pro-inflammatory JAK1/STAT3 and NF-κB signaling pathways. These results indicate that imperatorin may be a potential anti-inflammatory agent for inflammatory-associated lung diseases.

Adoptive transfer of Trichinella spiralis-activated macrophages can ameliorate both Th1- and Th2-activated inflammation in murine models

Trichinella spiralis is a zoonotic nematode and food borne parasite and infection with T. spiralis leads to suppression of the host immune response and other immunopathologies. Alternative activated macrophages (M2) as well as T_reg cells, a target for immunomodulation by the helminth parasite, play a critical role in initiating and modulating the host immune response to parasite. The precise mechanism by which helminths modulate host immune response is not fully understood. To determine the functions of parasite-induced M2 macrophages, we compared the effects of M1 and M2 macrophages obtained from Trichinella spiralis-infected mice with those of T. spiralis excretory/secretory (ES) protein-treated macrophages on experimental intestinal inflammation and allergic airway inflammation. T. spiralis infection induced M2 macrophage polarization by increasing the expression of CD206, ARG1, and Fizz2. In a single application, we introduced macrophages obtained from T. spiralis-infected mice and T. spiralis ES protein-treated macrophages into mice tail veins before the induction of dextran sulfate sodium (DSS)-induced colitis, ovalbumin (OVA)-alum sensitization, and OVA challenge. Colitis severity was assessed by determining the severity of colitis symptoms, colon length, histopathologic parameters, and Th1-related inflammatory cytokine levels. Compared with the DSS-colitis group, T. spiralis-infected mice and T. spiralis ES protein-treated macrophages showed significantly lower disease activity index (DAI) at sacrifice and smaller reductions of body weight and proinflammatory cytokine level. The severity of allergic airway inflammation was assessed by determining the severity of symptoms of inflammation, airway hyperresponsiveness (AHR), differential cell counts, histopathologic parameters, and levels of Th2-related inflammatory cytokines. Severe allergic airway inflammation was induced after OVA-alum sensitization and OVA challenge, which significantly increased Th2-related cytokine levels, eosinophil infiltration, and goblet cell hyperplasia in the lung. However, these severe allergic symptoms were significantly decreased in T. spiralis-infected mice and T. spiralis ES protein-treated macrophages. Helminth infection and helminth ES proteins induce M2 macrophages. Adoptive transfer of macrophages obtained from helminth-infected mice and helminth ES protein-activated macrophages is an effective treatment for preventing and treating airway allergy in mice and is promising as a therapeutic for treating inflammatory diseases.

Mesenchymal stem cells for inflammatory airway disorders: promises and challenges

The regenerative and immunomodulatory characteristics of mesenchymal stem cells (MSCs) make them attractive in the treatment of many diseases. Although they have shown promising preclinical studies of immunomodulation and paracrine effects in inflammatory airway disorders and other lung diseases, there are still challenges that have to be overcome before MSCs can be safely, effectively, and routinely applied in the clinical setting. A good understanding of the roles and mechanisms of the MSC immunomodulatory effects will benefit the application of MSC-based clinical therapy. In this review, we summarize the promises and challenges of the preclinical and clinical trials of MSC therapies, aiming to better understand the role that MSCs play in attempt to treat inflammatory airway disorders.

Acanthamoeba profilin elicits allergic airway inflammation in mice

Background

In previous studies, we suggested that Acanthamoeba is a new aero-allergen and that patients who showed positive results for the skin-prick test response to Acanthamoeba cross-reacted with several pollen allergens. Additionally, patients with common antibodies reacted to the 13–15 kDa Acanthamoeba unknown allergen.

Objective

We examined whether profilin of Acanthamoeba is a human airway allergic agent because of its molecular weight.

Methods

We expressed recombinant Ac-PF (rAc-PF) protein using an Escherichia coli expression system and evaluated whether Ac-PF is an airway allergic agent using an allergic airway inflammation animal model.

Results

Airway hyperresponsiveness was increased in rAc-PF-inoculated mice. The number of eosinophils and levels of Th2 cytokines, interleukin (IL)-4, IL-5, and IL-13 were increased in the bronchial alveolar lavage fluid of rAc-PF-treated mice. The lungs of the rAc-PF-treated mice group showed enhanced mucin production and metaplasia of lung epithelial cells and goblet cells.

Conclusion

In this study, we demonstrated that rAc-PF may be an allergen in Acanthamoeba, but further studies needed to identify the mechanisms of allergenic reactions induced by Ac-PF.

Recently, the number of asthma patients have increased sharply. Among patients with asthma have a high serum IgE titer, but despite this, some of these patients do not react to known allergens in skin prick tests, that suggests the presence of unknown environmental allergens. The protozoa Acanthamoeba live in very diverse environment including water, soil, air and even human nasal cavities, throat, pharynx and lung. In previous study, Acanthamoeba could be a new aero-allergen. Patients who showed positive results for the skin-prick test response to Acanthamoeba, their serum could be cross-reacted with several pollen allergens as well as Acanthamoeba total proteins. Additionally, the patients have common antibodies reacted to the 13–15 kDa Acanthamoeba unknown allergen. Profilin, which is found in all eukaryotic organisms in most cells, is an actin-binding protein that interferes with nucleation and restructuring of new filaments. Recent studies showed that profilin functions as a pan-allergen recognized by IgE in approximately 20% of birch pollen and plant food allergic patients. In Acanthamoeba, two isoforms of profilin (Ac-PF) have been identified: profilin-I and profilin-II. We examined profilin from Acanthamoeba as a potential human airway allergic agent because of its molecular weight (13–14 kDa) and cross-reactivity with several pollen allergens in the skin prick test showing positive results for Acanthamoeba in chronic cough patients. In this study, we expressed recombinant Ac-PF (rAc-PF) protein using an Escherichia coli expression system and evaluated whether Ac-PF is an airway allergic agent using an asthma animal model. Our study showed that rAc-PF may be an allergen in Acanthamoeba, but further studies needed to identify the mechanisms of allergenic reactions induced by Ac-PF.

Cell sheet biofabrication by co-administration of mesenchymal stem cells secretome and vitamin C on thermoresponsive polymer

Cell sheet technology aims at replacement of artificial extracellular matrix (ECM) or scaffolds, popular in tissue engineering, with natural cell derived ECM. Adipose tissue mesenchymal stem cells (ASCs) have the ability of ECM secretion and presented promising outcomes in clinical trials. As well, different studies found that secretome of ASCs could be suitable for triggering cell free regeneration induction. The aim of this study was to investigate the effect of using two bio-factors: secretome of ASCs (SE) and vitamin C (VC) for cell sheet engineering on a thermosensitive poly N-isopropyl acryl amide-Methacrylic acid (P(NIPAAm-MAA)) hydrogel. The results revealed that using thermosensitive P(NIPAAm-MAA) copolymer as matrix for cell sheet engineering lead to a rapid ON⁄OFF adhesion/deadhesion system by reducing temperature without enzymatic treatment (complete cell sheet release takes just 6 min). In addition, our study showed the potential of SE for inducing ASCs sheet formation. H&E staining exhibited the properties of a well-formed tissue layer with a dense ECM in sheets prepared by both SE and VC factors, as compared to those of VC or SE alone. Functional synergism of SE and VC exhibited statistically significant enhanced functionality regarding up-regulation of stemness genes expression, reduced β-galactosidase associated senescence, and facilitated sheet release. Additionally, alkaline phosphatase activity (ALP), mineralized deposits and osteoblast matrix around cells confirmed a better performance of ostogenic differentiation of ASCs induced by VC and SE. It was concluded that SE of ASCs and VC could be outstanding biofactors applicable for cell sheet technology.

Autologous Adipose-Derived Stem Cells Reduce Burn-Induced Neuropathic Pain in a Rat Model

Background: Burn scar pain is considered as neuropathic pain. The anti-inflammation and anti-neuroinflammation effects of adipose-derived stem cells (ASCs) were observed in several studies. We designed a study using a murine model involving the transplantation of autologous ASCs in rats subjected to burn injuries. The aim was to detect the anti-neuroinflammation effect of ASC transplantation and clarify the relationships between ASCs, scar pain, apoptosis and autophagy. Methods: We randomized 24 rats into 4 groups as followings: Group A and B, received saline injections and autologous transplantation of ASCs 4 weeks after sham burn, respectively; Group C and D, received saline injections and autologous transplantation 4 weeks after burn injuries. A designed behavior test was applied for pain evaluation. Skin tissues and dorsal horn of lumbar spinal cords were removed for biochemical analysis. Results: ASC transplantation significantly restored the mechanical threshold reduced by burn injury. It also attenuated local inflammation and central neuroinflammation and ameliorated apoptosis and autophagy in the spinal cord after the burn injury. Conclusion: In a rat model, autologous ASC subcutaneous transplantation in post-burn scars elicited anti-neuroinflammation effects locally and in the spinal cord that might be related to the relief of post-burn neuropathic pain and attenuated cell apoptosis. Thus, ASC transplantation post-burn scars shows the potential promising clinical benefits.