Yue-Qi Sun

Human Pluripotent Stem Cell‐Derived Mesenchymal Stem Cells Prevent Allergic Airway Inflammation in Mice

We previously found that mesenchymal stem cells (MSCs) derived from human‐induced pluripotent stem cells (iPSCs) exerted immunomodulatory effects on Th2‐mediated allergic rhinitis in vitro. However, their contribution to the asthma and allergic rhinitis in animal models remains unclear. In this study, we developed a mouse model of ovalbumin (OVA)‐induced allergic inflammation in both the upper and lower airways and evaluated the effects of the systemic administration of human iPSC‐MSCs and bone marrow‐derived MSCs (BM‐MSCs) on allergic inflammation. Our results showed that treatments with both the iPSC‐MSCs and BM‐MSCs before the challenge phase protected the animals from the majority of allergy‐specific pathological changes. This protection included an inhibition of inflammatory cell infiltration and mucus production in the lung, a reduction in eosinophil infiltration in the nose, and a decrease in inflammatory cell infiltration in both the bronchoalveolar and nasal lavage fluids. In addition, treatment with iPSC‐MSCs or BM‐MSCs before the challenge phase resulted in reduced serum levels of Th2 immunoglobulins (e.g., IgE) and decreased levels of Th2 cytokines including interleukin (IL)‐4, IL‐5, or IL‐13 in the bronchoalveolar and/or nasal lavage fluids. Similar therapeutic effects were observed when the animals were pretreated with human iPSC‐MSCs before the sensitization phase. These data suggest that iPSC‐MSCs may be used as an alternative strategy to adult MSCs in the treatment of asthma and allergic rhinitis. STEM CELLS 2012;30:2692–2699

Insensitivity of Human iPS Cells-Derived Mesenchymal Stem Cells to Interferon-γ-induced HLA Expression Potentiates Repair Efficiency of Hind Limb Ischemia in Immune Humanized NOD Scid Gamma Mice.

Adult mesenchymal stem cells (MSCs) are immunoprivileged cells due to the low expression of major histocompatibility complex (MHC) II molecules. However, the expression of MHC molecules in human‐induced pluripotent stem cells (iPSCs)‐derived MSCs has not been investigated. Here, we examined the expression of human leukocyte antigen (HLA) in human MSCs derived from iPSCs, fetuses, and adult bone marrow (BM) after stimulation with interferon‐γ (IFN‐γ), compared their repair efficacy, cell retention, inflammation, and HLA II expression in immune humanized NOD Scid gamma (NSG) mice of hind limb ischemia. In the absence of IFN‐γ stimulation, HLA‐II was expressed only in BM‐MSCs after 7 days. Two and seven days after stimulation, high levels of HLA‐II were observed in BM‐MSCs, intermediate levels were found in fetal‐MSCs, and very low levels in iPSC‐MSCs. The levels of p‐STAT1, interferon regulatory factor 1, and class II transactivator exhibited similar phenomena. Moreover, p‐STAT1 antagonist significantly reversed the high expression of HLA‐II in BM‐MSCs. Compared to adult BM‐MSCs, transplanting iPSC‐MSCs into hu‐PBMNC NSG mice revealed markedly more survival iPSC‐MSCs, less inflammatory cell accumulations, and better recovery of hind limb ischemia. The expression of HLA‐II in MSCs in the ischemia limbs was detected in BM‐MSCs group but not in iPSC‐MSCs group at 7 and 21 days after transplantation. Our results demonstrate that, compared to adult MSCs, human iPSC‐MSCs are insensitive to proinflammatory IFN‐γ‐induced HLA‐II expression and iPSC‐MSCs have a stronger immune privilege after transplantation. It may attribute to a better therapeutic efficacy in allogeneic transplantation. Stem Cells 2015;33:3452–3467

Broncho-Vaxom Attenuates Allergic Airway Inflammation by Restoring GSK3β-Related T Regulatory Cell Insufficiency

Background Oral administration of bacterial extracts (eg, Broncho-Vaxom (BV)) has been proposed to attenuate asthma through modulating Treg cells. However, the underlying mechanism has not been fully characterized. This study sought to assess the effects of oral administration of BV on GSK-3β expression and Treg cells in ovalbumin (OVA)-induced asthmatic mice models. Method Asthmatic mice models were established with OVA challenge and treated with oral administration of BV. Next, infiltration of inflammatory cells including eosinophil and neutrophils, mucous metaplasia, levels of Th1/Th2/Treg-typed cytokines and expression of GSK3β and Foxp3 were examined in asthmatic mice models by histological analysis, Bio-Plex and western blot, respectively. Moreover, the frequencies of Treg cells were evaluated in cultured splenocytes by flow cytometry in the presence of BV or GSK3β siRNA interference. Results We found significant decrease of infiltrated inflammatory cells in bronchoalveolar lavage fluid (BALF) in asthmatic mice models after oral administration of BV. Oral administration of BV was shown to significantly suppress mucus metaplasia, Th2-typed cytokine levels and GSK3β expression while increasing Foxp3 production in asthmatic mice models. Moreover, BV significantly enhanced GSK3β-related expansion of Treg cells in cultured spleen cells in vitro. Conclusion Our findings provide evidence that oral administration of BV is capable of attenuating airway inflammation in asthmatic mice models, which may be associated with GSK3β-related expansion of Treg cells.

A bacterial extract of OM-85 Broncho-Vaxom prevents allergic rhinitis in mice.

Background According to the hygiene hypothesis, bacterial infections during early life contribute to a reduced incidence of asthma in animals. However, the effects of microbial products at a safe dose and within a rational time course on the prevention of allergic rhinitis (AR) have been inconclusive. This study investigated the immunomodulatory effects of oral administration of a bacterial extract, OM-85 Broncho-Vaxom (BV), with a low dose and general time course, which is currently used for respiratory infections in humans, on AR inflammation in mice. Methods We developed a mouse model of ovalbumin (OVA)-induced AR allergic inflammation in the nose mucosa of mice. Low doses of OM-85 BV were orally administered for 3 months (long term) before sensitization. We evaluated nasal symptoms, pathology in the nose, inflammatory cells, and the levels of T helper 1 (Th1)/Th2 cytokines in the nasal lavage fluids, and the serum levels of specific IgE and IgG1. We also observed enhanced effects of OM-85BV with 1 month (short term) of treatment. Results We found that long-term pretreatment with OM-85 BV protected the mice from the majority of allergy-specific symptoms; specifically, OM-85 BV suppressed nasal symptoms, inhibited eosinophil infiltration in the nose, inhibited inflammatory infiltrates and the Th2 response by reducing cytokines (IL-4, IL-5, or IL-13) in the nasal lavage fluids, and reduced IgE and IgG1 levels. Furthermore, short-term treatment with OM-85 BV decreased the levels of Th2 cytokines and IgE. Conclusion Taken together, our data suggested that OM-85 BV is a low-cost alternative candidate to prevent AR with simple oral administration.

Cluster subcutaneous allergen specific immunotherapy for the treatment of allergic rhinitis: a systematic review and meta-analysis.

Background Although allergen specific immunotherapy (SIT) represents the only immune- modifying and curative option available for patients with allergic rhinitis (AR), the optimal schedule for specific subcutaneous immunotherapy (SCIT) is still unknown. The objective of this study is to systematically assess the efficacy and safety of cluster SCIT for patients with AR. Methods By searching PubMed, EMBASE and the Cochrane clinical trials database from 1980 through May 10th, 2013, we collected and analyzed the randomized controlled trials (RCTs) of cluster SCIT to assess its efficacy and safety. Results Eight trials involving 567 participants were included in this systematic review. Our meta-analysis showed that cluster SCIT have similar effect in reduction of both rhinitis symptoms and the requirement for anti-allergic medication compared with conventional SCIT, but when comparing cluster SCIT with placebo, no statistic significance were found in reduction of symptom scores or medication scores. Some caution is required in this interpretation as there was significant heterogeneity between studies. Data relating to Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) in 3 included studies were analyzed, which consistently point to the efficacy of cluster SCIT in improving quality of life compared to placebo. To assess the safety of cluster SCIT, meta-analysis showed that no differences existed in the incidence of either local adverse reaction or systemic adverse reaction between the cluster group and control group. Conclusion Based on the current limited evidence, we still could not conclude affirmatively that cluster SCIT was a safe and efficacious option for the treatment of AR patients. Further large-scale, well-designed RCTs on this topic are still needed.

Effects of mesenchymal stem cells from human induced pluripotent stem cells on differentiation, maturation, and function of dendritic cells

BackgroundMesenchymal stem cells (MSCs) have potent immunomodulatory effects on multiple immune cells and have great potential in treating immune disorders. Induced pluripotent stem cells (iPSCs) serve as an unlimited and noninvasive source of MSCs, and iPSC-MSCs have been reported to have more advantages and exhibit immunomodulation on T lymphocytes and natural killer cells. However, the effects of iPSC-MSCs on dendritic cells (DCs) are unclear. The aim of this study is to investigate the effects of iPSC-MSCs on the differentiation, maturation, and function of DCs.MethodsHuman monocyte-derived DCs were induced and cultured in the presence or absence of iPSC-MSCs. Flow cytometry was used to analyze the phenotype and functions of DCs, and enzyme-linked immunosorbent assay (ELISA) was used to study cytokine production.ResultsIn this study, we successfully induced MSCs from different clones of human iPSCs. iPSC-MSCs exhibited a higher proliferation rate with less cell senescence than BM-MSCs. iPSC-MSCs inhibited the differentiation of human monocyte-derived DCs by both producing interleukin (IL)-10 and direct cell contact. Furthermore, iPSC-MSCs did not affect immature DCs to become mature DCs, but modulated their functional properties by increasing their phagocytic ability and inhibiting their ability to stimulate proliferation of lymphocytes. More importantly, iPSC-MSCs induced the generation of IL-10-producing regulatory DCs in the process of maturation, which was mostly mediated by a cell-cell contact mechanism.ConclusionsOur results indicate an important role for iPSC-MSCs in the modulation of DC differentiation and function, supporting the clinical application of iPSC-MSCs in DC-mediated immune diseases.

Local IL-25 contributes to Th2-biased inflammatory profiles in nasal polyps

IL‐25 has been proposed to play a key role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to evaluate the association of IL‐25 with the Th2‐biased inflammatory profiles in CRSwNP.

MicroRNAs Involved in Asthma After Mesenchymal Stem Cells Treatment

Administration of human bone marrow-derived mesenchymal stem cells (BM-MSCs) significantly alleviates allergic airway inflammation. There are no studies that refer to the role of microRNAs (miRNAs) after the BM-MSCs treatment in airway allergic inflammation. We induced a mouse model of asthma and performed the transplantation of BM-MSCs. We analyzed aberrant miRNAs and key immune regulators using both miRNA and messenger RNA (mRNA) polymerase chain reaction (PCR) arrays. We identified that 296 miRNAs were differently expressed after the induction of asthma and/or the treatment of BM-MSCs, in which 14 miRNAs presented the reverse variation tendency between asthma induction and BM-MSCs transplantation. Mmu-miR-21a-3p, mmu-miR-449c-5p, and mmu-miR-496a-3p were further confirmed to be differently expressed with additional samples and quantitative real-time PCR. With an mRNA PCR array, we identified 19 genes to be involved in the allergy induction and the administration of BM-MSCs. Further target genes analysis revealed that mmu-miR-21a-3p was significantly correlated with the immune regulator activin A receptor, Type IIA (Acvr2a). Mmu-miR-21a-3p had opposite expression with Acvr2a after asthma and BM-MSCs treatment. Acvr2a had binding sites for miR-21a for both mice and human, suggesting that miR-21/Acvr2a axis is conserved between human and mice. Dual-luciferase reporter assay showed that mmu-miR-21a-3p negatively regulated the transcript of Acvr2a. In addition, has-miR-21a inhibitor significantly increased the expression of Acvr2a mRNA in BEAS-2B cells under lipopolysaccharide stimulation. Our results suggest that there were different miRNA and mRNA profiles after asthma induction and BM-MSCs treatment, and the miR-21/Acvr2a axis is an important mechanism for the induction of asthmatic inflammation.

The expression patterns of Nogo-A, myelin associated glycoprotein and oligodendrocyte myelin glycoprotein in the retina after ocular hypertension: the expression of myelin proteins in the retina in glaucoma.

Nogo-A, a major myelin inhibitory protein, inhibits axon growth and synaptic function in the central nervous system. Glaucoma is a progressive neuropathy as a result of retinal ganglion cell (RGC) death. Synaptic degeneration is thought to be an early pathology of neurodegeneration in glaucoma and precedes RGC loss. Here experimental ocular hypertension model was induced in adult rats with laser coagulation of the episcleral and limbal veins. The expression of Nogo-A, myelin-associated glycoprotein (MAG) and oligodendrocyte myelin glycoprotein (OMgp) in the retina was investigated using immunohistochemistry and Western blotting. We found that Nogo-A was expressed in the RGCs and upregulated after the induction of ocular hypertension. OMgp was only expressed in the inner plexiform layer. There was no MAG expression in the retina. Our data provided, for the first time, the expression patterns of three myelin proteins in the adult retina and suggested an important role of Nogo-A in the RGC death and synaptic degeneration in glaucoma.

Extensive versus functional endoscopic sinus surgery for chronic rhinosinusitis with nasal polyps and asthma: A 1-year study.

Background Functional endoscopic sinus surgery (FESS) is considered to be the standard procedure for chronic rhinosinusitis with nasal polyps (CRSwNP). However, for CRSwNP that accompanies asthma, the results are not satisfying. Extensive endoscopic sinus surgery (EESS) aimed at reducing the inflammatory load has been indicated as a viable option for refractory chronic rhinosinusitis. Objective To evaluate the clinical outcomes and safety of EESS (middle turbinate and superior turbinate resection and total ethmoidectomy) for patients with CRSwNP and with asthma. Methods This was a prospective, single-institute cohort study conducted in a tertiary teaching hospital. Patients with CRSwNP and with asthma who were proceeding to surgery were enrolled. There were 23 patients in the EESS group and 24 patients in the FESS group. The preoperative disease severity was evaluated by the visual analog scale (VAS), Lund-Kennedy (L-K) endoscopy score, computed tomography Lund-Mackay score, asthma control test (ACT), and pulmonary function test. Clinical outcomes were comparatively evaluated between the two groups after a 1-year follow-up by using the VAS score, the postoperative endoscopic score (E score), L-K score, ACT score, and pulmonary function test. Results The disease severity (general VAS score, endoscopic L-K score, computed tomography score, ACT score) showed no significant differences between the two groups before surgery (p > 0.05). One year after surgery, both groups achieved significant improvement in the VAS score and endoscopic L-K score. The EESS group showed better improvement in the olfactory VAS score and E score compared with the FESS group (mean [standard deviation] change of olfactory VAS, 6.00 ∓ 3.67 versus 3.30 ∓ 3.44, p = 0.015; mean [standard deviation] E score, 0.31 ∓ 0.18 versus 0.66 ∓ 0.26, p < 0.001). No significant differences were found in the change of general nasal symptom VAS score, other individual VAS scores (nasal congestion, discharge, headache and/or facial pain), L-K score, ACT score, and pulmonary function between the two groups (p > 0.05). Conclusion EESS for patients with CRSwNP and with asthma may help to improve the subjective olfaction and endoscopic appearance.