Yazhuo Huang

Characterization of human ethmoid sinus mucosa derived mesenchymal stem cells (hESMSCs) and the application of hESMSCs cell sheets in bone regeneration

Mesenchymal stem cells (MSCs) have been extensively applied in the field of tissue regeneration. MSCs derived from various tissues exhibit different characteristics. In this study, a cluster of cells were isolated from human ethmoid sinus mucosa membrane and termed as hESMSCs. hESMSCs was demonstrated to have MSC-specific characteristics of self-renewal and tri-lineage differentiation. In particular, hESMSCs displayed strong osteogenic differentiation potential, and also remarkably promoted the proliferation and osteogenesis of rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. Next, hESMSCs were prepared into a cell sheet and combined with a PSeD scaffold seeded with rBMSCs to repair critical-sized calvarial defects in rats, which showed excellent reparative effects. Additionally, ELISA assays revealed that secreted cytokines, such as BMP-2, BMP-4 and bFGF, were higher in the hESMSCs conditioned medium, and immunohistochemistry validated that hESMSCs cell sheet promoted the expression of BMP signaling downstream genes in newly formed bone. In conclusion, hESMSCs were demonstrated to be a class of mesenchymal stem cells that possessed high self-renewal capacity along with strong osteogenic potential, and the cell sheet of hESMSCs could remarkably promote new bone regeneration, indicating that hESMSCs cell sheet could serve as a novel and promising alternative strategy in the management of bone regeneration.

Electrospun silk fibroin/poly(lactide-co-ε-caprolactone) nanofibrous scaffolds for bone regeneration

Background Tissue engineering has become a promising therapeutic approach for bone regeneration. Nanofibrous scaffolds have attracted great interest mainly due to their structural similarity to natural extracellular matrix (ECM). Poly(lactide-co-ε-caprolactone) (PLCL) has been successfully used in bone regeneration, but PLCL polymers are inert and lack natural cell recognition sites, and the surface of PLCL scaffold is hydrophobic. Silk fibroin (SF) is a kind of natural polymer with inherent bioactivity, and supports mesenchymal stem cell attachment, osteogenesis, and ECM deposition. Therefore, we fabricated hybrid nanofibrous scaffolds by adding different weight ratios of SF to PLCL in order to find a scaffold with improved properties for bone regeneration. Methods Hybrid nanofibrous scaffolds were fabricated by blending different weight ratios of SF with PLCL. Human adipose-derived stem cells (hADSCs) were seeded on SF/PLCL nanofibrous scaffolds of various ratios for a systematic evaluation of cell adhesion, proliferation, cytotoxicity, and osteogenic differentiation; the efficacy of the composite of hADSCs and scaffolds in repairing critical-sized calvarial defects in rats was investigated. Results The SF/PLCL (50/50) scaffold exhibited favorable tensile strength, surface roughness, and hydrophilicity, which facilitated cell adhesion and proliferation. Moreover, the SF/PLCL (50/50) scaffold promoted the osteogenic differentiation of hADSCs by elevating the expression levels of osteogenic marker genes such as BSP, Ocn, Col1A1, and OPN and enhanced ECM mineralization. In vivo assays showed that SF/PLCL (50/50) scaffold improved the repair of the critical-sized calvarial defect in rats, resulting in increased bone volume, higher trabecular number, enhanced bone mineral density, and increased new bone areas, compared with the pure PLCL scaffold. Conclusion The SF/PLCL (50/50) nanofibrous scaffold facilitated hADSC proliferation and osteogenic differentiation in vitro and further promoted new bone formation in vivo, suggesting that the SF/PLCL (50/50) nanofibrous scaffold holds great potential in bone tissue regeneration.

A regulatory loop containing miR-26a, GSK3β and C/EBPα regulates the osteogenesis of human adipose-derived mesenchymal stem cells

Elucidating the molecular mechanisms responsible for osteogenesis of human adipose-derived mesenchymal stem cells (hADSCs) will provide deeper insights into the regulatory mechanisms of this process and help develop more efficient methods for cell-based therapies. In this study, we analysed the role of miR-26a in the regulation of hADSC osteogenesis. The endogenous expression of miR-26a increased during the osteogenic differentiation. The overexpression of miR-26a promoted hADSC osteogenesis, whereas osteogenesis was repressed by miR-26a knockdown. Additionally, miR-26a directly targeted the 3′UTR of the GSK3β, suppressing the expression of GSK3β protein. Similar to the effect of overexpressing miR-26a, the knockdown of GSK3β promoted osteogenic differentiation, whereas GSK3β overexpression inhibited this process, suggesting that GSK3β acted as a negative regulator of hADSC osteogenesis. Furthermore, GSK3β influences Wnt signalling pathway by regulating β-catenin, and subsequently altered the expression of its downstream target C/EBPα. In turn, C/EBPα transcriptionally regulated the expression of miR-26a by physically binding to the CTDSPL promoter region. Taken together, our data identified a novel feedback regulatory circuitry composed of miR-26a, GSK3β and C/EBPα, the function of which might contribute to the regulation of hADSC osteogenesis. Our findings provided new insights into the function of miR-26a and the mechanisms underlying osteogenesis of hADSCs.

a comparison between bispectral index analysis and auditory-evoked potentials for monitoring the time to peak effect to calculate the plasma effect site equilibration rate constant of propofol

Background and objectives: To the best of our knowledge, the value of the plasma effect site equilibration rate constant (ke0) of propofol has not been reported in Chinese patients. The aim of this prospective, randomized study was to examine the characteristics of the time to peak effect (TPEAK) of propofol, a pharmacokinetic‐independent descriptor of blood‐brain equilibration, and ke0 derived from TPEAK with A‐line auditory‐evoked potential monitor and Aspect A‐2000 bispectral index monitor in Chinese patients. Methods: Two‐hundred ASA I patients received a submaximal bolus dose of propofol (1.5 mg kg−1). TPEAK was randomly measured by means of the A‐line auditory‐evoked potential monitor (Group AAI (auditory‐evoked potential index), n = 100) or the Aspect A‐2000 bispectral index monitor (Group BIS, n = 100). Using TPEAK and four previously validated pharmacokinetic parameter sets of propofol, the ke0 was estimated according to a method proposed recently. Results: The mean TPEAK was 145 ± 35 s (50‐224 s) and 74±24 s (38‐143 s) in Groups AAI and BIS, respectively (P < 0.01 between groups). There were no correlations between the patients age and TPEAKs (r = 0.147 and 0.031 for Groups AAI and BIS). The median ke0 in Group AAI was 0.64 min−1 with the model of Marsh, 0.17 min−1 with the Schnider model, 0.78 min−1 with the Tackley model and 0.93 min−1 with the Shafer model. The median ke0 in Group BIS was 1.87 min−1 with the model of Marsh, 0.83 min−1 with the Schnider model, 2.14 min−1 with the Tackley model and 2.48 min−1 with the Shafer model (P < 0.01 between groups and models). Conclusions: The TPEAK of propofol measured by the A‐line auditory‐evoked potential monitor is different from that measured by the Aspect A‐2000 bispectral index monitor. The TPEAKs of propofol from auditory‐evoked potential index and bispectral index, and the values of ke0 calculated based on TPEAKs are different from previous reports and appear to be not affected by age. Further studies need to be taken to validate clinically the ke0 values of propofol.

IL-17A Promotes RANTES Expression, But Not IL-16, in Orbital Fibroblasts Via CD40-CD40L Combination in Thyroid-Associated Ophthalmopathy

Purpose This present study aims to investigate the phenotype of IL-17A-producing T cells in thyroid-associated ophthalmopathy (TAO) and the role of IL-17A on RANTES and IL-16 expression in orbital fibroblasts (OFs) from TAO patients. Methods Blood samples were obtained from TAO patients and healthy controls and were subjected to ELISA and flow cytometry analysis. Primary human OFs cultured from surgical wastes were stimulated with IL-17A in the presence or absence of CD40L and were examined by qRT-PCR, ELISA, Western blotting, and apoptosis assays. Results We reported upregulated IL-17A, IFN-γ, RANTES, and IL-16 serum levels and increased frequency of IL-17A- and IFN-γ-producing T cells in peripheral blood mononuclear cells from patients with TAO compared with healthy controls. In addition, TAO orbital tissues were rich in T lymphocytes, expressing more IL-17A, IFN-γ, RANTES, and IL-16. Moreover, IL-17A could enhance the expression of RANTES, but not IL-16, in cultured primary OFs in cooperation with CD40L. We further validated that MAPK signaling was largely responsible for RANTES production in IL-17A-treated OFs. Finally, we demonstrated that IL-17A could not promote apparent apoptosis in OFs from TAO patients and healthy controls. Conclusions Our results indicate the potent effect of IL-17A-induced RANTES expression on OFs and elaborate a possible mechanism in understanding Th17 cells in the pathology of TAO and its potential as a target to immunotherapy of TAO and other autoimmune disorders.

Regulation of Orbital Fibrosis and Adipogenesis by Pathogenic Th17 Cells in Graves Orbitopathy

Context: T helper (Th)17 cells are correlated with many human autoimmune disorders, including Graves disease, and may play key roles in the pathogenesis of Graves orbitopathy (GO). Objective: To study the phenotype of Th17 cells in patients with GO and healthy subjects, investigate the fibrosis and adipogenesis in orbital fibroblasts (OFs) modulated by interleukin (IL)‐17A, and determine the interaction between Th17 cells and OFs. Design/Setting/Participants: Blood samples and orbital tissues from GO patients and healthy controls were collected. Main Outcome Measures: We conducted multicolor flow cytometry, immunohistochemical and immunofluorescent stainings, Western blotting, a PathScan intracellular signaling assay, Luminex and enzyme‐linked immunosorbent assays, and protein mass spectrum. Results: Interferon‐&ggr;‐ and IL‐22‐expressing Th17 cells are increased in GO patients, which are positively related to clinical activity score. Costimulatory molecules are highly expressed in GO orbits and most GO OFs are CD90+. IL‐17A promotes TGF‐&bgr;‐induced fibrosis in CD90+ OFs but impedes 15‐deoxy‐&Dgr;12,14‐prostaglandin J2‐induced adipogenesis in CD90− OFs. Th17 cells promote proinflammatory cytokine secretion in both CD90+ and CD90− OFs. Meanwhile, both CD90+ and CD90− OFs contribute to Th17 cell differentiation through prostaglandin E2 production, which can be attenuated by indomethacin. Furthermore, Th17 cells upregulate costimulatory molecule expression on OFs. Conclusion: Our findings unravel the pathogenicity of IL‐17A in the initiation and progression of GO. In‐depth interpretation of the molecular basis of OFs delineated by CD90 and Th17‐OF interaction will help to afford a novel approach to better therapeutic strategies for GO.

Enhanced bioactivity and osteoinductivity of carboxymethyl chitosan/nanohydroxyapatite/graphene oxide nanocomposites

Tissue engineering approaches combine a bioscaffold with stem cells to provide biological substitutes that can repair bone defects and eventually improve tissue functions. The prospective bioscaffold should have good osteoinductivity. Surface chemical and roughness modifications are regarded as valuable strategies for developing bioscaffolds because of their positive effects on enhancing osteogenic differentiation. However, the synergistic combination of the two strategies is currently poorly studied. In this work, a nanoengineered scaffold with surface chemistry (oxygen-containing groups) and roughness (Rq = 74.1 nm) modifications was fabricated by doping nanohydroxyapatite (nHA), chemically crosslinked graphene oxide (GO) and carboxymethyl chitosan (CMC). The biocompatibility and osteoinductivity of the nanoengineered CMC/nHA/GO scaffold was evaluated in vitro and in vivo, and the osteogenic differentiation mechanism of the nanoengineered scaffold was preliminarily investigated. Our data demonstrated that the enhanced osteoinductivity of CMC/nHA/GO may profit from the surface chemistry and roughness, which benefit the β1 integrin interactions with the extracellular matrix and activate the FAK–ERK signaling pathway to upregulate the expression of osteogenic special proteins. This study indicates that the nanocomposite scaffold with surface chemistry and roughness modifications could serve as a novel and promising bone substitute for tissue engineering.

Orbital radiotherapy plus three-wall orbital decompression in a patient with rare ocular manifestations of thyroid eye disease: case report

BackgroundThyroid eye disease (TED) is a debilitating autoimmune orbital disease that is often a result of Graves’ disease. Dysthyroid optic neuropathy (DON) is a rare but sight-threatening manifestation of TED with therapeutic challenges that can potentially lead to visual loss.Case presentationA 74-year-old man experienced active TED with extremely severe redness and swelling of the conjunctiva, loss of visual acuity and exacerbation of disfiguring proptosis. Computed tomography revealed the involvement of extraocular muscles resulting in optic nerve compression. He was in poor general condition and was intolerant to steroids. To achieve the optimal operating conditions for orbital decompression surgery, the patient was initially treated with orbital radiotherapy. The patient responded well, with improvements in clinical activity score and visual acuity.ConclusionThis case demonstrates a rare and severe case of DON with therapeutic challenges. To date, no cases has been reported of a patient with such severe and unusual ocular manifestations. Early awareness of the occurrence of optic nerve compression and prompt treatment are important to prevent irreversible outcomes. Orbital radiotherapy should be considered as a useful surgery-delaying alternative for DON, especially in patients who have contraindications to steroids.