Panoply™ Human CD38 Knockdown Stable Cell Line

Cardiac hypertrophy is an early sign of the clinical course of heart failure and is regulated by multiple signaling pathways. Here, researchers investigated the role and mechanism of CD38 in angiotensin II (Ang-II)-induced cardiac hypertrophy. After 14 days of Ang-II infusion via osmotic minipump, both CD38 knockout mice and wild-type mice developed similar hypertension. However, compared with CD38 knockout mice, wild-type mice had more severe cardiac hypertrophy and fibrosis. RNAi-induced CD38 knockdown consistently reduced the gene expression of atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) and the generation of reactive oxygen species in Ang-II-stimulated H9c2 cells. In addition, SIRT3 expression was increased in CD38 knockdown H9c2 cells, where SIRT3 may further activate the FOXO3 antioxidant pathway. Angiotensin II-induced intracellular Ca2+ release was significantly reduced in CD38 knockdown H9c2 cells, which may be related to the reduced nuclear translocation of NFATc4 and the inhibition of ERK/AKT phosphorylation. The researchers speculated that CD38 may play an important role in cardiac hypertrophy by inhibiting SIRT3 expression and activating the Ca2+-NFAT signaling pathway. Therefore, CD38 may become a new target for the treatment of cardiac hypertrophy.

To confirm the protective role of CD38 deficiency in angiotensin II (Ang-II)-induced cardiac hypertrophy, the researchers constructed a stable CD38 knockdown H9c2 cell line using CD38-specific shRNA constructs, and confirmed the reduced CD38 expression in the cell line by Western blotting (Figure 1A and B). The stable cell line was stimulated with Ang-II for 48 hours, and as expected, the mRNA expression of BNP was upregulated by Ang-II in a dose-dependent manner (Figure 1C). Ang-II significantly increased the expression of ANP and BNP. However, knockdown of CD38 significantly reduced the Ang-II-induced expression of ANP and BNP (markers of cardiac hypertrophy) (Figure 1D and E). Next, H9c2 cells were stained with crystal violet. As shown in Figure 1F and G, the size of Ang-II-induced cardiomyocytes was much larger than that of untreated cells in the normal cell line, while CD38 knockdown cells did not increase in size after Ang-II stimulation.

Figure 1. CD38 deficiency attenuated Ang-II-induced cardiac hypertrophy in vitro. (Guan X H, et al., 2017)