Figure 5.

Follistatin-like 1 (FSTL1) suppresses inflammatory responses in cultured cardiac myocytes. A, FSTL1 diminishes lipopolysaccharide (LPS)-stimulated expression of proinflammatory genes in neonatal rat ventricular myocytes (NRVMs). NRVMs were pretreated with FSTL1 (250 ng/mL) or vehicle for 30 minutes, followed by stimulation with LPS (100 ng/mL) or vehicle for 6 hours. The mRNA expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) was measured by reverse transcription–polymerase chain reaction (RT-PCR) and expressed relative to β-actin levels (n=4). B, Effect of FSTL1 on bone morphogenetic protein-4 (BMP-4)–stimulated expression of proinflammatory cytokines. NRVMs were treated with BMP-4 protein (100 ng/mL) or vehicle along with FSTL1 protein (100 or 250 ng/mL) or vehicle for 18 hours. The transcript levels of TNF-α and IL-6 were determined by RT-PCR and expressed relative to β -actin levels (n=4). C, AMPK participates in the effect of FSTL1 on the LPS-induced increase in proinflammatory gene expression. After transduction with a dominant-negative form of AMPK tagged with c-myc (Ad-dn-AMPK) or β -galactosidase (Ad-β -gal) at a multiplicity of infection of 10 for 24 hours, NRVMs were pre-treated with FSTL1 (250 ng/mL) or vehicle for 30 minutes, followed by treatment with LPS (100 ng/mL) or vehicle for 6 hours. The mRNA levels were analyzed by RT-PCR and expressed relative to β -actin levels (n=4).