Weiping Qian

A novel label-free amperometric immunosensor for carcinoembryonic antigen based on Ag nanoparticle decorated infinite coordination polymer fibres

In this article, for the first time, a novel, high-yield and template-free method for the synthesis of Ag nanoparticle decorated thionine/infinite coordination polymer (AgNP/THI/ICP) fibres is proposed. The thionine can be adsorbed to the AgNP/THI/ICP fibres by π-conjugation and act as the redox probe. The AgNP/THI/ICP fibres not only favor the immobilization of antibody but also facilitate the electron transfer. It is found that the AgNP/THI/ICP fibres can be designed to act as a sensitive label-free electrochemical immunosensor for carcinoembryonic antigen (CEA) determination. Under the optimized conditions, the linear range of the proposed immunosensor is estimated to be from 50 fg/mL to 100 ng/mL and the detection limit is estimated to be 0.5 fg/mL at a signal-to-noise ratio of 3, respectively. The prepared immunosensor for detection of CEA shows high sensitivity, reproducibility and stability. Our study demonstrates that the proposed immunosensor has also been used to determine CEA successfully in diluted blood samples.

Isolation and characterization of lung resident mesenchymal stem cells capable of differentiating into alveolar epithelial type II cells

Controversies and risks continue to be reported about exogenous mesenchymal stem cell‐based therapies. In contrast with employing exogenous stem cells, making use of lung resident mesenchymal stem cells (LR‐MSCs) could be advantageous. Our study sought to isolate the LR‐MSCs and explore their potential to differentiate into alveolar epithelial type II cells (ATII cells). Total lung cells were first precultured, from which the Sca‐1+CD45−CD31− population was purified using fluorescence activated cell sorting (FACS). By these methods, it would seem that the Sca‐1+CD45−CD31− cells were LR‐MSCs. Similar to bone marrow derived mesenchymal stem cells (BM‐MSCs), these cells express Sca‐1, CD29, CD90, CD44 and CD106, but not CD31 or CD45. They share the same gene expression file with the BM‐MSCs and have a similar DNA content during long‐term culturing. Furthermore, they could be serially passaged with all these properties being sustained. Above all, LR‐MSCs could differentiate into ATII cells when co‐cultured with ATII cells in a trans‐well system. These findings demonstrated that the Sca‐1+CD45−CD31− cells appear to be LR‐MSCs that can differentiate into ATII cells. This approach may hold promise for their use in the treatment of lung disease.

Inhibition of Wnt/β-catenin signaling promotes epithelial differentiation of mesenchymal stem cells and repairs bleomycin-induced lung injury

Idiopathic pulmonary fibrosis is a progressive lung disorder of unknown etiology. Previous studies have shown that aberrant activation of the Wnt/β-catenin signaling cascade occurs in lungs of patients with idiopathic pulmonary fibrosis. Given the important roles of the Wnt/β-catenin signaling pathway in the development of pulmonary fibrosis, we targeted this pathway for the intervention of pulmonary fibrosis with XAV939, a small molecule that specifically inhibits Tankyrase 1/2, eventually leading to the degradation of β-catenin and suppression of the Wnt/β-catenin signaling pathway. Our results demonstrated that XAV939 significantly inhibited the activation of Wnt/β-catenin signaling and attenuated bleomycin-induced lung fibrosis in mice, and thus improved the survival of mice with lung injury. Interestingly, previous investigations have confirmed that endogenous and exogenous mesenchymal stem cells could be recruited to the injured lung, although the exact effects of these cells are debatable. To determine the effect of Wnt/β-catenin signaling in the epithelial differentiation of bone marrow-derived mesenchymal stem cells (BM-MSCs), we established a coculture system that contains BM-MSCs and alveolar type II epithelial cells. The in vitro experiments demonstrated that XAV939 could promote the differentiation of BM-MSCs into an epithelium-like phenotype in the coculture system. We also found that XAV939 could inhibit the proliferation and myofibroblast differentiation of NIH/3T3 fibroblasts. This work supports that inhibition of the Wnt/β-catenin signaling pathway may be exploited for the treatment of idiopathic pulmonary fibrosis for which effective treatment strategies are still lacking.

Inhibition of Wnt/β‐Catenin Signaling Promotes Engraftment of Mesenchymal Stem Cells to Repair Lung Injury

We sought to explore the treatment effects and the repair mechanisms of bone marrow derived mesenchymal stem cells (MSCs) during HCl‐induced acute lung injury (ALI). MSCs were delivered through the tail veins of rats 24 h after intranasal instillation of HCl. The results showed that MSCs did not ameliorate the histopathologic changes of ALI and pulmonary fibrosis. We found that the activated Wnt/β‐catenin signaling may regulate the differentiation of MSCs and is associated with lung fibroblasts activation, pulmonary fibrosis and tissue repair process in ALI rats. Immunofluorescence and histology analysis indicated that activated canonical Wnt/β‐catenin signaling induced most MSCs to differentiate into myofibroblasts or fibroblasts in vivo. However, inhibition of Wnt/β‐catenin signaling by Dickkopf‐1 (DKK1) promotes epithelial differentiation of MSCs induced by native alveolar epithelial cells which are beneficial to repair the injured lung epithelium. Inhibition of Wnt/β‐catenin signaling after MSCs transplantation ameliorated pulmonary fibrosis and improved pulmonary function which attenuated the lung injury. In vitro study, activation of the Wnt/β‐catenin signaling stimulated MSCs to express myofibroblasts markers, which was attenuated by DKK1. Furthermore, Wnt3α activated Wnt/β‐catenin signaling in lung fibroblasts to enhance the expression of collagen I, vimentin and α‐smooth muscle actin, but DKK1 attenuated these proteins expression. These findings demonstrated that canonical Wnt/β‐catenin signaling plays a key role in regulating differentiation of MSCs in vivo or in vitro and the pathogenesis of fibrotic diseases. Our study suggested that inhibition of abnormal activated Wnt/β‐catenin signaling would promote MSCs epithelial differentiation to repair lung injury and reduce pulmonary fibrosis. J. Cell. Physiol. 229: 213–224, 2014.

Activated Wnt signaling induces myofibroblast differentiation of mesenchymal stem cells, contributing to pulmonary fibrosis

Acute lung injury may lead to fibrogenesis. However, no treatment is currently available. This study was conducted to determine the effects of bone marrow-derived mesenchymal stem cells (MSCs) in a model of HCl-induced acute lung injury in Sprague-Dawley (SD) rats. Stromal cell-derived factor (SDF)-1 and its receptor CXC chemokine receptor (CXCR)4 have been shown to participate in mobilizing MSCs. Adenovirus carrying the CXCR4 gene was used to transfect MSCs in order to increase the engraftment numbers of MSCs at injured sites. Histological examination data demonstrated that the engraftment of MSCs did not attenuate lung injury and pulmonary fibrosis. The results showed that engraftment of MSCs almost differentiated into myofibroblasts, but rarely differentiated into lung epithelial cells. Additionally, it was demonstrated that activated canonical Wnt/β-catenin signaling in injured lung tissue regulated the myofibroblast differentiation of MSCs in vivo. The in vitro study results demonstrated that activation of the Wnt/β-catenin signaling stimulated MSCs to express myofibroblast markers; however, this process was attenuated by Wnt antagonist DKK1. Therefore, the results demonstrated that the aberrant activation of Wnt signaling induces the myofibroblast differentiation of engrafted MSCs, thus contributing to pulmonary fibrosis following lung injury.

Biomolecule-based formaldehyde resin microspheres loaded with Au nanoparticles: A novel immunoassay for detection of tumor markers in human serum

A surfactant-free and template-free method for the high-yield synthesis of biomolecule (serotonin)-based formaldehyde resin (BFR) microspheres is proposed for the first time. The colloidal microspheres loaded with Au nanoparticles (AuNPs) prepared by a convenient in-situ synthesis of AuNPs on BFR (AuNPs/BFR) microsphere surface show good stability. AuNPs/BFR microspheres not only favor the immobilization of antibody but also facilitate the electron transfer. It is found that the resultant AuNPs/BFR microspheres can be designed to act as a sensitive label-free electrochemical immunosensor for carcinoembryonic antigen (CEA) determination. The immunosensor is prepared by immobilizing capture anti-CEA on AuNPs/BFR microspheres assembled on thionine (TH) modified glassy carbon electrode (GCE). TH acts as the redox probe. Under the optimized conditions, the linear range of the proposed immunosensor is estimated to be from 25 pg/mL to 2000 pg/mL (R=0.998) and the detection limit is estimated to be 3.5 pg/mL at a signal-to-noise ratio of 3. The prepared immunosensor for detection of CEA shows high sensitivity, reproducibility and stability. Our study demonstrates that the immunosensor can be used for the CEA detection in humans serum.

Antagonistic effects of a mixture of low-dose nonylphenol and di-n-butyl phthalate (monobutyl phthalate) on the Sertoli cells and serum reproductive hormones in prepubertal male rats in vitro and in vivo.

The estrogenic chemical nonylphenol (NP) and the antiandrogenic agent di-n-butyl phthalate (DBP) are regarded as widespread environmental endocrine disruptors (EDCs) which at high doses in some species of laboratory animals, such as mice and rats, have adverse effects on male reproduction and development. Given the ubiquitous coexistence of various classes of EDCs in the environment, their combined effects warrant clarification. In this study, we attempted to determine the mixture effects of NP and DBP on the testicular Sertoli cells and reproductive endocrine hormones in serum in male rats based on quantitative data analysis by a mathematical model. In the in vitro experiment, monobutyl phthalate (MBP), the active metabolite of DBP, was used instead of DBP. Sertoli cells were isolated from 9-day-old Sprague-Dawley rats followed by treatment with NP and MBP, singly or combined. Cell viability, apoptosis, necrosis, membrane integrity and inhibin-B concentration were tested. In the in vivo experiment, rats were gavaged on postnatal days 23–35 with a single or combined NP and DBP treatment. Serum reproductive hormone levels were recorded. Next, Bliss Independence model was employed to analyze the quantitative data obtained from the in vitro and in vivo investigation. Antagonism was identified as the mixture effects of NP and DBP (MBP). In this study, we demonstrate the potential of Bliss Independence model for the prediction of interactions between estrogenic and antiandrogenic agents.

Intracellular surface-enhanced Raman scattering probes based on TAT peptide-conjugated Au nanostars for distinguishing the differentiation of lung resident mesenchymal stem cells.

Lung resident mesenchymal stem cells (LR-MSCs) are important regulators of pathophysiological processes including tissue repair and fibrosis, inflammation, angiogenesis and tumor formation. Therefore, increasing attention has focused on the functional differentiation of LR-MSCs. However, the distinction between the undifferentiated and differentiated LR-MSCs, which are closely related and morphologically similar, is difficult to achieve by conventional methods. In this study, by employing the TAT Peptide-conjugated Au nanostars (AuNSs) as an intracellular probe, we developed a method for the identification of LR-MSC differentiation by surface-enhanced Raman scattering (SERS) spectroscopy. SERS spectra were analyzed using principal component analysis (PCA) that allowed unambiguous distinction of subtypes and monitoring of component changes during cellular differentiation. Furthermore, to ascertain whether co-culture with alveolar epithelial type II (ATII) cells and incubation with transform growth factor (TGF)-β were involved in regulating the differentiation of LR-MSCs, we investigated the protein expression levels of epithelial markers and fibroblastic markers on LR-MSCs. Our results demonstrated that co-culture with ATII cells or incubation with TGF-β could induce the differentiation of LR-MSCs as confirmed by SERS analysis, a method that is capable of noninvasive characterization of and distinction between subtypes of LR-MSCs during differentiation. We have provided a new tool that may facilitate stem cell research.

Targeted inhibition of disheveled PDZ domain via NSC668036 depresses fibrotic process

In this study, we determined the effects of transforming growth factor-beta (TGF-β) and Wnt/β-catenin signaling on myofibroblast differentiation of NIH/3T3 fibroblasts in vitro and evaluated the therapeutic efficacy of NSC668036 in bleomycin-induced pulmonary fibrosis murine model. In vitro study, NSC668036, a small organic inhibitor of the PDZ domain in Dvl, suppressed β-catenin-driven gene transcription and abolished TGF-β1-induced migration, expression of collagen I and α-smooth muscle actin (α-SMA) in fibroblasts. In vivo study, we found that NSC668036 significantly suppressed accumulation of collagen I, α-SMA, and TGF-β1 but increased the expression of CK19, Occludin and E-cadherin that can inhibit pulmonary fibrogenesis. Because fibrotic lung exhibit aberrant activation of Wnt/β-catenin signaling, these data collectively suggest that inhibition of Wnt/β-catenin signaling at the Dvl level may be an effective approach to the treatment of fibrotic lung diseases.

Mixture effects of nonylphenol and di-n-butyl phthalate (monobutyl phthalate) on the tight junctions between Sertoli cells in male rats in vitro and in vivo.

The estrogenic chemical nonylphenol (NP) and the antiandrogenic agent di-n-butyl phthalate (DBP) are regarded as widespread environmental endocrine disruptors (EEDs) which at high doses in some species of laboratory animals have adverse effects on male reproduction and development. Given the ubiquitous coexistence of various classes of EEDs in the environment, their combined effects warrant investigation. In this study, we attempted to clarify the interactions of NP and DBP on tight junctions (TJs) between rat Sertoli cells. In the in vitro experiment, monobutyl phthalate (MBP), the active metabolite of DBP, was used instead of DBP. Sertoli cells were isolated from Sprague-Dawley rats, and treated with NP and MBP, singly or combined. The morphology of Sertoli cells, and structure and functionality of TJs were measured. In the in vivo experiment, rats were gavaged on postnatal day 23-35 with a single or combined NP and DBP treatment. Testicular weight and morphology of TJs were recorded. These data indicated that NP and DBP/MBP, either in single or in combination, induced the structural and function changes of Sertoli cell tight junctions, both in vivo and in vitro. The combined effect on the regulation of TJ proteins at both the protein and gene levels was correlated to the effect exerted by NP, suggesting that the structure and function of Sertoli cells were more sensitive to exposure to NP than MBP.