Development of an analytical HPLC methodology to study the effects of thymosin β4 on actin in sputum of cystic fibrosis patients

• Published in: Annals of the New York Academy of Sciences Vol. 1270; no. 1; pp. 86 - 92
• Main Authors: Badamchian, Mahnaz, Damavandy, Ali A., Goldstein, Allan L.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01-10-2012
• Subjects: actin; Actins - metabolism; Chromatography, High Pressure Liquid - methods; cystic fibrosis; Cystic Fibrosis - metabolism; HPLC; Humans; sputum; Sputum - chemistry; Thymosin - metabolism; thymosin β4
• ISSN: 0077-8923; 1749-6632
• DOI: 10.1111/j.1749-6632.2012.06671.x

A high‐performance liquid chromatography (HPLC) methodology is presented. Using bovine and rabbit F‐ and G‐actin, this methodology results in both fractions as being well‐resolved peaks, which were confirmed by dot blot immunoassay and fluorescence microscopy. F‐ and G‐actin were incubated with thymosin β4 (Tβ4) and DNase and then analyzed by HPLC, which indicated that Tβ4 and DNase inhibit G‐actin polymerization and that Tβ4 depolymerizes F‐actin in a dose‐ and time‐dependent manner. The F‐ and G‐actin content in sputum from healthy controls and cystic fibrosis (CF) patients were measured by HPLC before and after incubation with Tβ4, DNase, and gelsolin. These data demonstrate higher quantities of F‐actin in the sputum of CF patients compared to healthy individuals, and also demonstrate a significantly increased F/G‐actin ratio in CF sputum. Further, Tβ4, DNase, and gelsolin each increase the depolymerization of F‐actin in CF sputum in a dose‐dependent fashion that is additive when these agents are combined.