Fig. 7.

RES inhibits immunoproteasome activity and PTEN degradation in vitro. A, The proteasome activities (caspase-like, trypsin-like and chymotrypsin-like) were measured in neonatal rat cardiomyocytes (NRCMs) treated with RES (100 μM) or vehicle and stimulated with Ang II (100 nM) for 24 h (n = 6). B, Representative immunoblotting analyses of β1i, β2i and β5i protein levels in NRCMs treated as in A (n = 3, left). Quantification of the relative protein levels (right). GAPDH as an internal control. C, Lysates from NRCMs treated with Ang II or saline in the presence or absence or RES before harvest were immunoprecipitated with anti-PTEN. The ubiquitin-conjugated PTEN was detected by immunoblotting with anti-ubiquitin (Ub, upper) and anti-PTEN (lower). Quantification of the relative Ub-PTEN level (right, n = 3). D, Input showed the expression of corresponding proteins (Ub and PTEN) in whole cell lysates (right).