Fig. 6

Analysis of cardiac myofilament and structural protein expression.

(a) Quantitative RT-PCR analysis of early developmental myofilament proteins including the atrial myosin light chain MLC2a, the myosin isoform α-MHC and cardiac troponin T (cTnT) in cells treated with 6.8 µM e-cigarette or tobacco cigarette extracts vs. control. (b-c) Immunohistochemistry (b) and quantification (c) of the myofilament proteins cardiac troponin T (cTnT) in combination with phalloidin and nuclear counterstain DAPI in control cells or those treated with 6.8 µM e-cigarette or 6.8 µM tobacco cigarette extracts. Scale bar = 100 µm for cTnT. (d) Quantitative RT-PCR analysis of mature developmental myofilament isoforms including the ventricular myosin light chain MLC2v and the myosin isoform β-MHC in cells treated 6.8 µM e-cigarette or tobacco cigarette extracts vs. control. (e) Quantitation of sarcomere length as measured from samples stained for α-actinin by immunohistochemistry comparing control vs. 6.8 µM e-cigarette or tobacco cigarette. (f-h) Quantitative RT-PCR (f) immunohistochemistry (g) and quantification of IHC (h) for the immature cardiac marker smooth muscle actin (SMA) in control vs. cells treated with 6.8 µM e-cigarette or tobacco cigarette extract. n ≥ 6 per group. Scale bar = 100 µm. * P < 0.05.