GDF11 Is a Novel Protective Factor Against Vascular Calcification

Caspase-3/gasdermin-E axis facilitates the progression of coronary artery calcification by inducing the release of high mobility group box protein 1

Coronary artery calcification (CAC) is commonly observed in atherosclerotic plaques, which is a pathogenic factor for severe coronary artery disease (CAD). The phenotype changes of vascular smooth muscle cells (VSMCs) are found to participate in CAC progression, which is mainly induced by vascular inflammation and oxidative stress (OS). HMGB1, a critical inflammatory cytokine, is recently reported to induce arterial calcification, which is regulated by the Caspase-3/gasdermin-E (GSDME) axis. However, the function of the Caspase-3/GSDME axis in CAC is unknown. Herein, the involvement of the Caspase-3/GSDME axis in CAC was studied to explore the possible targets for CAC. CAC model was constructed in mice, which was verified by red cytoplasm in coronary artery tissues, increased macrophage infiltration, aggravated inflammation, and enhanced RAGE signaling, accompanied by an increased release of HMGB1 and an activated Caspase-3/ GSDME axis. In β-GP-treated MOVAS-1 cells, calcification, the ROS accumulation, enhanced LDH and HMGB1 release, enlarged macrophage production, aggravated inflammation, and activated RAGE signaling were observed, which were markedly abolished by the transfection of si-HMGB1 and si-GSDME. Moreover, the calcification deposition, the activity of Caspase-3/ GSDME axis, release of HMGB1, macrophage infiltration, cytokine production, and RAGE signaling in CAC mice were notably alleviated by VSMCs-specific GSDME knockdown, not by hematopoietic stem cells (HSCs)-specific GSDME knockdown. Collectively, Caspase-3/GSDME axis facilitated the progression of CAC by inducing the release of HMGB1.

GDF11 slows excitatory neuronal senescence and brain ageing by repressing p21

As a major neuron type in the brain, the excitatory neuron (EN) regulates the lifespan in C. elegans. How the EN acquires senescence, however, is unknown. Here, we show that growth differentiation factor 11 (GDF11) is predominantly expressed in the EN in the adult mouse, marmoset and human brain. In mice, selective knock-out of GDF11 in the post-mitotic EN shapes the brain ageing-related transcriptional profile, induces EN senescence and hyperexcitability, prunes their dendrites, impedes their synaptic input, impairs object recognition memory and shortens the lifespan, establishing a functional link between GDF11, brain ageing and cognition. In vitro GDF11 deletion causes cellular senescence in Neuro-2a cells. Mechanistically, GDF11 deletion induces neuronal senescence via Smad2-induced transcription of the pro-senescence factor p21. This work indicates that endogenous GDF11 acts as a brake on EN senescence and brain ageing.