Growth differentiation factor 11 (GDF11) signaling in neural stem cell regulation: molecular and cellular insights.

内容摘要

Neurogenesis in adult mammalian brain persists in restricted areas, especially the subgranular zone (SGZ) of the hippocampus and the ventricular-subventricular zone (V-SVz), where neural stem cells (NSCs) occupy neurogenic niches. These NSC niches provide signals that regulate stem cell behavior. Among extrinsic modulators, Growth Differentiation Factor 11 (GDF11 or BMP11) which is a transforming growth factor-β (TGF-β) superfamily member, was shown to play key role in the NSC biology and brain aging. In this review, the most recent molecular mechanisms of GDF11 signaling in the regulation of NSC will be addressed. GDF11 plays mainly through activin type II receptors (ActRIIA/B) and ALK4/ALK5, activating classical Smad2/3 pathways that impact transcriptional networks controlling neural cell behavior. Moreover, GDF11 stimulates non-Smad signaling pathways - including ERK, p38, JNK, and PI3K/AKT - providing context-dependent integration of proliferative and anti-proliferative signals. Furthermore, GDF11 functions as a feedback regulator limiting the number of progenitor cells and organizing neurogenic timing. In the adult brain, GDF11 plays important role in neurovascular remodeling, glial inflammatory states, and extracellular matrix interactions. Despite its recognized roles, the effect of GDF11 on aging remains a subject of intense debate, characterized by conflicting reports regarding its circulating levels, tissue-specific dynamics, and dose-dependent effects. Recent evidence suggests that GDF11 acts as a context-dependent modulator, integrating systemic, vascular, and cellular cues to maintain NSC homeostasis and neurogenic potential. Therefore, elucidating the exact cellular and molecular mechanisms by which GDF11 controls NSC behavior is vital to advancing novel therapeutic strategies for neurodegenerative disorders and age-related cognitive decline.