Silencing of β1 integrin regulates airway remodeling by regulating the transcription of SOCE‑associated genes in asthmatic mice

Abstract

The incidence of asthma is increasing globally; however, current treatments are only able to cure a certain proportion of patients. There is an urgent need to develop novel therapies. β1 integrin serves a role in the pathophysiology of asthma through the development of airway remodeling. The aim of the present study was to investigate silencing of the β1 integrin gene in pre‑clinical models of allergic asthma. BALB/c mice were sensitized with ovalbumin through intraperitoneal injection and repeated aerosolized ovalbumin. A short hairpin RNA of the β1 integrin gene was designed and transfected into mouse models of asthma in vivo, in order to evaluate whether silencing of the β1 integrin gene affects airway smooth muscle cell proliferation and inflammation by regulating the mRNA expression of store‑operated Ca2+ entry (SOCE)‑associated genes. Silencing the β1 integrin gene may downregulate β1 integrin mRNA while not statistically decreasing α‑smooth muscle actin gene expression and airway smooth muscle thickness. β1 integrin silencing was able to downregulate the transcription of SOCE‑associated genes to normal levels, including calcium release‑activated calcium modulator 1 and short transient receptor potential channel member 1, but not stromal interaction molecule 1, in asthma. Silencing of the β1 integrin gene additionally maintained nuclear factor of activated T‑cells cytoplasmic 1 gene expression, and inflammatory cytokines interleukin‑4 and interferon‑γ at normal levels. The results of the present study provide evidence to suggest that silencing of the β1 integrin gene may be of therapeutic benefit for patients with asthma.

Figure 1.

Flowchart of the establishment of the mouse model. i.p., intraperitoneal injection; inh, inhalation; OVA, ovalbumin.

Figure 2.

Identification of β1 integrin short hairpin RNA vector.

Figure 3.

HE staining and measurement of airway smooth muscle thickness. Lung tissue sections were stained using HE. The morphological alterations in the stained sections were examined under microscopy. (A) HE staining in C. (B) HE staining in A. (C) Histogram exhibiting the increased airway smooth muscle thickness which occurred in A, T, BC, NC and PC. n=6. ***P<0.001 vs. C. C, control group; A, asthma group; T, transfection group; BC, blank control group; NC, negative control group; PC, positive control group; HE, hematoxylin and eosin.

Figure 4.

Effects of β1 integrin short hairpin RNA on the expression of β1 integrin, α-SMA and SOCE signaling pathway genes in the lungs of mice. Silencing β1 integrin affected six SOCE signaling pathway genes at the transcriptional level. The mRNA expression of (A) β1 integrin, (B) α-SMA, (C) STIM1, (D) ORAI1, (E) TRPC1 and (F) NFAT2 was measured. n=6. *P<0.05, **P<0.01 and ***P<0.001 vs. C. ^&P<0.05, ^&&P<0.01 and ^&&&P<0.001. C, control group; A, asthma group; T, transfection group; BC, blank control group; NC, negative control group; PC, positive control group; SMA, smooth muscle actin; SOCE, store-operated Ca²⁺ entry; STIM1, stromal interaction molecule 1; ORAI1, calcium release-activated calcium modulator 1; TRPC1, short transient receptor potential channel member 1; NFAT2, nuclear factor of activated T-cells cytoplasmic 1.

Figure 5.

ELISA analysis. Results of the ELISA analysis of (A) IL-4 and (B) IFN-γ expression levels. n=6. *P<0.05, **P<0.01 and ***P<0.001 vs. C. ^&P<0.05, ^&&P<0.01 and ^&&&P<0.001. C, control group; A, asthma group; T, transfection group; BC, blank control group; NC, negative control group; PC, positive control group; IL-4, interleukin-4; IFN-γ, interferon-γ.