Homologous serum increases fibronectin expression and cell adhesion in airway smooth muscle cells

The Cell Research Trends of Asthma: A Stem Frequency Analysis of the Literature

Objective

This study summarized asthma literature indexed in the Medical Literature Analysis and Retrieval System Online (MEDLINE) and explored the history and present trends of asthma cell research by stem frequency ranking to forecast the prospect of future work.

Methods

Literature was obtained from MEDLINE for the past 30 years and divided into three groups by decade as the retrieval time. The frequency of stemmed words in each group was calculated using Python with Apache Spark and the Natural Language Tool Kit for ranking. The unique stems or shared stems of 3 decades were summarized.

Results

A total of 1331, 4393, and 7215 records were retrieved from 3 decades chronologically, and the stem ranking of the top 50 were listed by frequency. The number of stems shared with 3 decades was 26 and with the first and last 2 decades was 5 and 13.

Conclusions

The number of cell research studies of asthma has increased rapidly, and scholars have paid more attentions on experimental research, especially on mechanistic research. Eosinophils, mast cells, and T cells are the hot spots of immunocyte research, while epithelia and smooth muscle cells are the hot spots of structural cell research. The research trend is closely linked with the development of experimental technology, including animal models. Early studies featured basic research, but immunity research has dominated in recent decades. The distinct definition of asthma phenotypes associated with genetic characteristics, immunity research, and the introduction of new cells will be the hot spots in future work.

Role of human airway smooth muscle in altered extracellular matrix production in asthma

1. The underlying abnormality in asthma is not fully understood; however, inflammation, airway remodelling and bronchial hyperresponsiveness are key factors. The plasma exudate from the microvascular leakage plays a significant role in remodelling, which includes extracellular matrix (ECM) protein deposition/breakdown and airway smooth muscle (ASM) hyperplasia/hypertrophy. 2. The ECM is an intricate network of macromolecules that forms the 'scaffolding' of the airways. This scaffolding not only acts as mechanical support that plays a crucial role in the maintenance of airway function and structure, but it is also a dynamic and complex network that has the potential to influence cellular function, including migration, differentiation and proliferation of a number of cell types. 3. In asthmatic airways, the profile of ECM proteins is altered. The deposition of collagen I, III, V, fibronectin, tenascin, hyaluronan, versican and laminin alpha2/beta2 is increased, whereas the deposition of collagen IV and elastin is decreased. 4. This imbalance in the ECM profile within the asthmatic airway could be due to: (i) increased de novo synthesis of ECM proteins; (ii) decreased activity of its degrading enzymes, namely matrix metalloproteinases (MMP); or (iii) upregulation of the tissue-specific inhibitors of metalloproteinases (TIMP). 5. One of the characteristic features of asthma is an increase in the amount of ASM within the airways. The ECM proteins/MMP/TIMP in and around the smooth muscle may play a contributory role in this increased growth. 6. The role of current asthma treatments in the prevention or reversal of airway ECM changes is an area that has only recently become of interest, with the majority of the in vivo work focusing on the effects of corticosteroids. 7. The evidence presented in this review indicates that the ASM may influence its own environment/proliferation through the production of ECM proteins, MMP and TIMP. Further studies are needed to fully understand the role of the ASM in the production of ECM proteins, MMP and TIMP andtheir potential influence in the mechanisms underlying asthma.

The production of extracellular matrix proteins by human passively sensitized airway smooth-muscle cells in culture: the effect of beclomethasone

Airway remodeling is a key feature of persistent asthma. Part of the remodeling process involves the laying down of extracellular matrix (ECM) proteins within the airways. In this study we compared the production of ECM proteins by human airway smooth-muscle (ASM) cells in culture after exposure to 10% serum from an asthmatic individual or 10% serum from a nonasthmatic individual with or without beclomethasone (0.01 to 100 nM). Enzyme-linked immunosorbent assays were done with antibodies to human fibronectin; perlecan; elastin; the laminin beta(1), gamma(1), beta(2), alpha(1) chains; thrombospondin; chondroitin sulfate; collagen types I, III, IV, and V; versican; and decorin. Serum from the asthmatic individual, when compared with that from the nonasthmatic individual, caused a significant increase in the production of fibronectin, perlecan, laminin gamma(1), and chondroitin sulfate. Beclomethasone caused a significant reduction in the number of cells exposed to serum from either the asthmatic or nonasthmatic individual, but did not reverse the increase in ECM protein induced by the former. These results suggest an interaction between the ASM and the allergic process that may alter components of the airway wall in asthma, and that corticosteroids may not prevent the fibrosis induced by resident cells within the airways.

Cell phenotype as a target of drug therapy in chronic inflammatory diseases

Many diseases share common pathological changes which could in principle be targets for new drugs. Vascular leakage of plasma and migration of cells into perivascular tissues are common to chronic inflammatory diseases such as asthma, atherosclerosis, arthritis, and proliferative nephropathy as well as some non-inflammatory proliferative disorders such as diabetes mellitus. Individual components of plasma have been shown to stimulate cellular proliferation, matrix deposition and phenotypic change, leading to tissue-damaging structural changes. Whereas most anti-inflammatory drugs either downregulate expression of inflammatory mediators or inhibit their actions on cells, there are alternate potential therapeutic strategies described here based on moderating vascular leakage or its consequences in chronic diseases. The hypothesis is that drugs that can modify a cell's phenotype could be used to limit structural changes which accompany inflammation and thus reduce permanent debility resulting from these diseases. Such drugs include the differentiating agents being developed for cancer therapy.

The effects of salbutamol, beclomethasone, and dexamethasone on fibronectin expression by cultured airway smooth muscle cells

Possible mechanisms of adverse drug effects in asthma include worsening of cellular hyperplasia and stimulation of extracellular matrix deposition. In this study, salbutamol, dexamethasone and beclomethasone were investigated to ascertain their ability to induce mitogenesis and stimulate fibronectin expression in cultured canine airway smooth muscle cells. In cells maintained in serum-free media for 72 h, salbutamol (1 nM-10 microM) caused mitogenesis. The control cells had 2.57 +/- 0.34 x 10(5) cells per ml (mean +/- SEM, N = 13), while salbutamol (1 microM) caused a maximal increase in cell number to 3.57 +/- 0.23 x 10(5) cells/ml (P < 0.01). In cells stimulated to replicate by addition of either fetal bovine serum or canine serum, no additional mitogenic effect of salbutamol was seen. Salbutamol did not have a detectable quantitative effect on fibronectin matrix expression. The glucocorticoids, beclomethasone and dexamethasone, significantly altered fibronectin expression by cultured airway smooth muscle cells. Beclomethasone increased fibronectin expression, while dexamethasone decreased expression.

Vascular leakage stimulates phenotype alteration in ocular cells, contributing to the pathology of proliferative vitreoretinopathy

Plasma leaking from damaged retinal blood vessels can have a significant impact on the pathologies of the posterior segment of the eye. Inflammation in the eye and metabolic change resulting from diabetes mellitus causes vascular leakage with alteration of the phenotype of retinal pigment epithelial (RPE) cells and fibrocytes, resulting in changes in cell function. Phenotypically altered cells then significantly contribute to the pathogenesis of retinopathies by being incorporated into tractional membranes in the vitreous, where they secrete matrix molecules, such as fibronectin, and express altered cell surface antigens. We hypothesize that there is a direct relationship between the leaking of plasma and the proliferation and phenotypic change of RPE cells and fibroblasts, thus exacerbating the pathology of retinal disease. If the hypothesis is correct, control of vascular leakage becomes an important target of therapy in proliferative vitreoretinopathy.