A glycoprotein with anti-inflammatory properties secreted by an Aspergillus nidulans modified strain

J C F Queiroz,P J Spencer,I Lebrun,C F P Teixeira,T M A D Zucchi

doi:10.1590/s1678-91992007000200010

Abstract

Total RNA from lipopolysaccharide (LPS)-stimulated rat macrophages used to treat protoplasts from an Aspergillus nidulans strain originated the RT2 regenerated strain, whose culture supernatant showed anti-inflammatory activity in Wistar rats. The protein fraction presenting such anti-inflammatory activity was purified and biochemically identified. The screening of the fraction responsible for such anti-inflammatory property was performed by evaluating the inhibition of carrageenan-induced paw edema in male Swiss mice. Biochemical analyses of the anti-inflammatory protein used chromatography, carbohydrates quantification of the protein sample, amino acids content analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Total sugar quantification revealed 32% glycosylation of the protein fraction. Amino acid analysis of such fraction showed a peculiar pattern presenting 29% valine. SDS-PAGE revealed that the protein sample is pure and its molecular weight is about 40kDa. Intravenous injection of the isolated substance into mice significantly inhibited carrageenan-induced paw edema. The isolated glycoprotein decreased carrageenan-induced paw edema in a prostaglandin-dependent phase, suggesting an inhibitory effect of the isolated glycoprotein on prostaglandin synthesis.

Highlights

To degrade substrate and absorb nutrients, fungi secrete a large spectrum of powerful enzymes into its environment [4]
The characterization of the factor produced by RT2 Aspergillus nidulans strain is very important to understand how Aspergillus fungi can cause invasive pulmonary infection without an immune response by the patients
The tests with samples from the first purification (Sephadex S100) were performed after 1, 3, and 6 hours (Fig. 2). This approach allowed the determination of the kinetics of the proteins effects on paw edema induced by carrageenan (1%) in male mice

Summary

Introduction

To degrade substrate and absorb nutrients, fungi secrete a large spectrum of powerful enzymes into its environment [4] They interact with the human environment by producing diseases in plants and animals and are used as food as well as for antibiotics production. According to Archer and Peberdy [2] and Gouka et al [10], Aspergillus fungi are excellent as receptor cells to express and secrete proteins of therapeutic importance Based on this potential, Zucchi et al [27] used total RNA from LPS-stimulated rat (Wistar) macrophages to treat protoplasts from an A. nidulans strain (UT448). The biochemical properties of the anti-inflammatory factor found by Zucchi et al [27] were purified and identified, and its activity in carrageenan-induced paw edema was tested in mice to verify which inflammatory mediator is blocked by this factor

Methods

Results

Conclusion