Mutual regulation between miR-21 and the TGFß/Smad signaling pathway in human bronchial fibroblasts promotes airway remodeling.

OBJECTIVE: Airway remodeling is an important pathological feature of asthma. Excessive deposition of extracellular matrix (e.g., collagen) secreted from fibroblasts is a major factor contributing to airway remodeling. Currently, the mechanism by which collagen continues to be oversynthesized in the airway remains unclear. In this study, we investigated the role of the microRNA-21 (miR-21) and TGFß/Smad signaling pathway in human bronchial fibroblasts (HBFs), and explored the regulatory mechanism of airway remodeling. METHODS: HBFs were cultured in vitro and treated with the transforming growth factor ß (TGFß), receptor inhibitor (SB431542), and TGFß1. miR-21 and Smad7 overexpressing lentiviruses, as well as an miR-21 interfering lentivirus were constructed and transfected into HBFs. Western blotting was used to determine the expression of airway remodeling-related proteins and proteins in the TGFß/Smad signaling pathway. miR-21 expression was measured by quantitative real-time PCR. RESULTS: The high expression of miR-21 induced by TGFß1 was reduced following the treatment with the SB431542 in HBFs. Smad7 overexpression inhibited the elevated expression of the COL I protein induced by miR-21 overexpression in HBFs. Inhibiting miR-21 expression upregulated the level of Smad7 protein, thus reducing the expression of airway remodeling-related proteins induced by TGFß1 stimulation in HBFs. CONCLUSIONS: TGFß1 can induce miR-21 expression in HBFs through the TGFß/Smad signaling pathway to promote airway remodeling. miR-21 downregulates Smad7, activates the TGFß/Smad signaling pathway, and promotes airway remodeling. Mutual regulation between miR-21 and the TGFß/Smad signaling pathway in HBFs promotes airway remodeling.

The lncRNA CRNDE promotes colorectal cancer cell proliferation and chemoresistance via miR-181a-5p-mediated regulation of Wnt/ß-catenin signaling.

BACKGROUND: With more than 600,000 mortalities each year, colorectal cancer (CRC) is the third most commonly diagnosed type of cancer worldwide. Recently, mechanisms involving noncoding RNAs have been implicated in the development of CRC. METHODS: We examined expression levels of lncRNA CRNDE and miR-181a-5p in 64 cases of CRC tissues and cell lines by qRT-PCR. Gain-of-function and loss-of-function assays were performed to examine the effect of CRNDE and miR-181a-5p on proliferation and chemoresistance of CRC cells. Using fluorescence reporter and western blot assays, we also explored the possible mechanisms of CRNDE in CRC cells. RESULTS: In this study, we found that the expression levels of the CRNDE were upregulated in CRC clinical tissue samples. We identified microRNA miR-181a-5p as an inhibitory target of CRNDE. Both CRNDE knockdown and miR-181a-5p overexpression in CRC cell lines led to inhibited cell proliferation and reduced chemoresistance. We also determined that ß-catenin and TCF4 were inhibitory targets of miR-181a-5p, and that Wnt/ß-catenin signaling was inhibited by both CRNDE knockdown and miR-181a-5p overexpression. Significantly, we found that the repression of cell proliferation, the reduction of chemoresistance, and the inhibition of Wnt/ß-catenin signaling induced by CRNDE knockdown would require the increased expression of miR-181a-5p. CONCLUSIONS: Our study demonstrated that the lncRNA CRNDE could regulate the progression and chemoresistance of CRC via modulating the expression levels of miR-181a-5p and the activity of Wnt/ß-catenin signaling.

[Role of serum neutrophil elastase determination in the diagnosis of acute exacerbation of asthma in preschool children].

OBJECTIVE: To study the role of serum neutrophil elastase (NE) level in acute exacerbation of asthma in preschool children. METHODS: A total of 85 preschool children who were diagnosed with asthma between January 2008 and January 2010 were classified into acute exacerbation group (n=44) and non-acute exacerbation group (n=41). Thirty-five children who received physical examination served as the control group. The enzyme-linked immunosorbent assay was used to determine the serum levels of NE and interleukin-8 (IL-8). The receiver operating characteristic (ROC) curve was used for NE evaluation. RESULTS: Both the acute and non-acute exacerbation groups had higher serum levels of NE and IL-8 than the control group, and the acute exacerbation group had significantly higher serum levels of NE and IL-8 than the non-acute exacerbation group (P<0.05). The serum level of NE was positively correlated with that of IL-8 (r=0.48, P<0.05). With serum NE level >27.73 µg/L as the cut-off value for diagnosing acute exacerbation of asthma, the sensitivity was 65.9%, the specificity was 95.1%, and the area under the ROC curve was 0.87 (P<0.01). CONCLUSIONS: The determination of serum NE level in preschool children with asthma helps to diagnose the acute exacerbation of asthma.

[Changes in serum inflammatory factors in wheezing infants with community-acquired pneumonia].

OBJECTIVE: To study whether infantile wheezing pneumonia has similar immune mechanisms to asthma by determining the levels of serum inflammatory factors in wheezing infants with community-acquired pneumonia (CAP). METHODS: Forty-two infants with CAP but without wheezing, 47 infants with CAP and wheezing, and 30 healthy infants as a control were recruited in the study. The peripheral blood levels of C-reactive protein, procalcitonin, soluble triggering receptor expressed on myeloid cell-l, interferon-γ, interleukin-4, interleukin-10, and periostin were compared in the three groups. RESULTS: The serum levels of procalcitonin, soluble triggering receptor expressed on myeloid cell-l, interleukin-4 and interleukin-10 in the two CAP groups were higher than in the control group (P<0.05). The ratio of interferon-γ/interleukin-4 in the wheezing pneumonia group was lower than in the non-wheezing pneumonia and control groups (P<0.05). The serum level of periostin in the wheezing pneumonia group was higher than in the non-wheezing pneumonia and control groups (P<0.05). CONCLUSIONS: The unbalanced ratio of interferon-γ/interleukin-4 and airway eosinophilic inflammation in wheezing infants with pneumonia suggest infantile pneumonia with wheezing may has similar immune mechanisms to asthma.

Circular RNA Fibroblast Growth Factor Receptor 1 Promotes Pancreatic Cancer Progression by Targeting MicroRNA-532-3p/PIK3CB Axis.

OBJECTIVE: The aim of the study is to explore the contribution and mechanism of circular RNA fibroblast growth factor receptor 1 (circFGFR1) in pancreatic ductal adenocarcinoma (PDAC) progression. METHODS: Expressions of circFGFR1, microRNA (miR)-532-3p, and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta (PIK3CB) were assessed by quantitative real-time polymerase chain reaction or in situ hybridization. Fluorescence in situ hybridization determined the subcellular localization of circFGFR1. Immunohistochemistry was used to detect PIK3CB expression in PDAC tissues. Cell growth was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assays. Wound healing, transwell, and flow cytometry assays examined the migration, invasion, and apoptosis. Dual-luciferase and RNA pull-down assay verified the interactions between circFGFR1/PIK3CB and miR-532-3p. In vivo xenograft tumor growth and lung metastasis were assessed in nude mice. RESULTS: Functionally, knockdown of circFGFR1 restrained in vitro PDAC cell growth, migration, invasion, and in vivo xenograft tumor growth and lung metastasis. In addition, circFGFR1 could sponge miR-532-3p to upregulate PIK3CB level. Rescue experiments revealed that the tumor-suppressive effects caused by miR-532-3p mimics could be reversed by circFGFR1 or PIK3CB overexpression. CONCLUSIONS: Our data revealed that circFGFR1 driven the malignant progression of PDAC by targeting miR-532-3p/PIK3CB axis, suggesting that inhibition of circFGFR1 might be considered as a therapeutic target for PDAC.

[Roles of allergen testing in vitro and impulse oscillometry for lung function measurements in children with cough variant asthma].

OBJECTIVE: To study the roles of allergen testing in vitro and impulse oscillometry for lung function measurements in preschool children with cough variant asthma (CVA). METHODS: ethodsForty-four preschool children with acute asthma, 41 with chronic asthma, 46 with CVA, and 35 healthy preschool children as control were recruited in the study. Inhaled allergen, food allergen, and mite-specific IgE were determined by Pharmacia UniCAP System. Serum eosinophil cationic protein (ECP) and total IgE levels were measured. Lung function was assessed by impulse oscillometry. RESULTS: The positive rates of inhaled allergen and food allergen, and total IgE levels in the CVA, acute asthma and chronic asthma groups were higher than those in the control group (P<0.01). However, no significant differences were found among the three case groups. The serum ECP levels in the CVA group were lower than those in the acute asthma group (P<0.01), but did not show differences when compared with the chronic asthma group. The impulse oscillometry demonstrated that the respiratory total impedance (Zrs), airway resistance at 5 Hz (R5), airway resistance at 20 Hz (R20), subtracting R5 from R20 (R5-R20) and resonant frequency (Fres) in the CVA, acute asthma and chronic asthma groups were higher than those in the control group (P<0.01). Zrs, R5, R20, R5-R20, and Fres in the CVA and chronic asthma groups were lower than those in the acute asthma group (P<0.01). Serum ECP levels were positively correlated with Zrs, R5, R5-R20 and Fres (P<0.05) in the CVA and chronic asthma groups. CONCLUSIONS: The measurements of allergens, serum ECP and impulse oscillometry for lung function are helpful for the evaluation of airway inflammation and airway obstruction in preschool children with CVA.

Micropatterned Fibrous Scaffold Produced by Using Template-Assisted Electrospinning Technique for Wound Healing Application.

This paper describes the fabrication of a structural scaffold consisting of both randomly oriented nanofibers and triangular prism patterns on the scaffold surface using a combination technique of electrospinning and collector templates. The polycaprolactone (PCL) nanofibers were electrospun over a triangular prism pattern mold, which acted as a template. The deposited scaffold was removed from the template to produce a standalone structural scaffold of three-dimensional micropatterned nanofibers. The fabricated structural scaffold was compared with flat randomly oriented nanofibers based on in vitro and in vivo studies. The in vitro study indicated that the structural scaffold demonstrated higher fibroblast cell proliferation, cell elongation with a 13.48 ± 2.73 aspect ratio and 70% fibroblast cell orientation compared with flat random nanofibers. Among the treatment groups, the structural scaffold escalated the wound closure to 92.17% on day 14. Histological staining of the healed wound area demonstrated that the structural scaffold exhibited advanced epithelization of the epidermal layer accompanied by mild inflammation. The proliferated fibroblast cells and collagen fibers in the structural scaffold appeared denser and arranged more horizontally. These results determined the potential of micropatterned scaffolds for stimulating cell behavior and their application for wound healing.

Controlling cell elongation and orientation by using microstructural nanofibre scaffolds for accelerating tissue regeneration.

The topographic surface conditions of scaffolds can regulate cellular behaviours, such as by stimulating cellular migration and morphological changes to wound sites and have the potential to promote tissue regeneration. In this research, four types of engineered topographic surfaces, including arrays of hemisphere, pyramid, semi-cylinder, and triangle prism microstructures, were patterned on silicon moulds using microfabrication processes. The microstructural patterns were transferred onto the surface of polycaprolactone membranes and nanofibrous scaffolds by combining with the moulding approach and electrospinning technique, respectively. In vitro experimental results demonstrated that the triangular microstructural nanofibre provided a strong guiding performance to the filopodia of cultured C2C12 myoblast cells, thus inducing cellular elongation and alignment in the longitudinal direction and forming an elongated cell morphology. The cultured cells rapidly transitioned into an elongated morphology at an aspect ratio of 17.33 after 24 h of incubation, with 70% of the cell elongates aligning with the direction of triangular microstructural patterns. The cells cultured on the triangular microstructural nanofibre elongated four-fold compared with those in the flat nanofibre scaffold. Moreover, an in vivo study showed that wounds treated with the triangular microstructural nanofibre scaffold achieved 95.04% wound closure after 14 days and completed the reepithelialisation with an ordered collagen arrangement. Therefore, we believe that the engineered triangular nanofibrous scaffold may accelerate tissue regeneration and has potential for wound healing applications.

Development of Thermo-Responsive Polycaprolactone-Polydimethylsiloxane Shrinkable Nanofibre Mesh.

A thermally activated shape memory polymer based on the mixture of polycaprolactone (PCL) and polydimethylsiloxane (PDMS) was fabricated into the nanofibre mesh using the electrospinning process. The added percentages of the PDMS segment in the PCL-based polymer influenced the mechanical properties. Polycaprolactone serves as a switching segment to adjust the melting temperature of the shape memory electro-spun PCL-PDMS scaffolds to our body temperature at around 37 °C. Three electro-spun PCL-PDMS copolymer nanofibre samples, including PCL6-PDMS4, PCL7-PDMS3 and PCL8-PDMS2, were characterised to study the thermal and mechanical properties along with the shape memory responses. The results from the experiment showed that the PCL switching segment ratio determines the crystallinity of the copolymer nanofibres, where a higher PCL ratio results in a higher degree of crystallinity. In contrast, the results showed that the mechanical properties of the copolymer samples decreased with the PCL composition ratio. After five thermomechanical cycles, the fabricated copolymer nanofibres exhibited excellent shape memory properties with 98% shape fixity and above 100% recovery ratio. Moreover, biological experiments were applied to evaluate the biocompatibility of the fabricated PCL-PDMS nanofibre mesh. Owing to the thermally activated shape memory performance, the electro-spun PCL-PDMS fibrous mesh has a high potential for biomedical applications such as medical shrinkable tubing and wire.

[Exploration on the modification of macroscopic classification of colorectal cancer].

OBJECTIVE: To explore the feasibility and clinical significance of a modified macroscopic classification of colorectal cancer. METHODS: The data of 1379 patients with colorectal cancer surgically treated between 1975 and 2003 were retrospectively analyzed. The patients were divided into four groups according to the primary macroscopic appearance: protruding type (group 1), local ulcerative type (group 2), invasive type (group 3) and non-invasive ulcerative type (group 4). The new classification system was simplified into two types: non-invasive type (group A, including group 1 and 2) and invasive type (group B, including group 3 and 4). The histo-differentiation, invasive depth into the intestinal wall, distance and number of lymph node metastasis and 5-year survival rate were analyzed and compared among the groups. RESULTS: There was no significant difference between group 1 and 2, and between group 3 and 4 in histodifferentiation, invasive depth into the intestinal wall, distance and number of lymph node metastasis and 5-year survival rate (P>0.05). However, after modification of the primary macroscopic classification, a significant difference was observed in all the above mentioned parameters between group A and group B (P<0.05). CONCLUSION: Our results demonstrate that the clinicopathological characteristics of the group 1 and 2, and of the group 3 and 4 are similar to each other. So it is reasonable to merge the protruding type and local ulcerative type into non-invasive type, while invasive type and non-invasive ulcerative type into invasive type. This simplified macroscopic classification should be practical and instructive in diagnosis, treatment and prognosis of colorectal cancer.