GHS-R1a deficiency protects against lipopolysaccharide-induced spatial memory impairment in mice.

Neuroinflammation has been implicated in cognitive deficits of neurological and neurodegenerative diseases. There is abundant evidence that the application of ghrelin, an orexigenic hormone regulating appetite and energy balance, abrogates neuroinflammation and rescues associated memory impairment. However, the underlying mechanism is uncertain. In this study, we find that both intraperitoneal (i.p.) and intracerebroventricular (i.c.v.) administration of lipopolysaccharide (LPS) impairs spatial memory in mice. LPS treatment causes neuroinflammation and microglial activation in the hippocampus. Ghsr1a deletion suppresses LPS-induced microglial activation and neuroinflammation, and rescued LPS-induced memory impairment. Our findings thus suggest that GHS-R1a signaling may promote microglial immunoactivation and contribute to LPS-induced neuroinflammation. GHS-R1a may be a new therapeutic target for cognitive dysfunction associated with inflammatory conditions.

Engineered Basic Fibroblast Growth Factor Specifically Bonded with Injectable Extracellular Matrix Hydrogel for the Functional Restoration of Cerebral Ischemia in Rats.

Cerebral ischemia was one of the leading causes of mortality and disability worldwide. Extracellular matrix (ECM) hydrogel held great potential to replace volumetric brain tissue loss following ischemic injury but with limited regenerative effect for functional restoration when implanted alone. In the present study, an engineered basic fibroblast growth factor (EBP-bFGF) was constructed, which fused a specific ECM-binding peptide (EBP peptide) with bFGF. The recombinant EBP-bFGF showed typical binding capacity with ECM without affecting the bioactivity of bFGF both in vitro and in vivo. Furthermore, the EBP-bFGF was used for bioactive modification of ECM hydrogel to repair cerebral ischemia. The combination of EBP-bFGF and ECM hydrogels could realize the sustained release of bFGF in the ischemic brain and improve the regenerative effect of ECM, which protected the survival of neurons, enhanced angiogenesis, and decreased the permeability of blood-brain barrier, ultimately promoted the recovery of motor function. In addition, transcriptome analysis revealed neuregulin-1/AKT pathway involved in this process. Therefore, EBP-bFGF/ECM hydrogel would be a promising therapeutic strategy for cerebral ischemia.

New Insights into Microglial Mechanisms of Memory Impairment in Alzheimer's Disease.

Alzheimer's disease (AD) is the most common progressive and irreversible neurodegeneration characterized by the impairment of memory and cognition. Despite years of studies, no effective treatment and prevention strategies are available yet. Identifying new AD therapeutic targets is crucial for better elucidating the pathogenesis and establishing a valid treatment of AD. Growing evidence suggests that microglia play a critical role in AD. Microglia are resident macrophages in the central nervous system (CNS), and their core properties supporting main biological functions include surveillance, phagocytosis, and the release of soluble factors. Activated microglia not only directly mediate the central immune response, but also participate in the pathological changes of AD, including amyloid-beta (Aß) aggregation, tau protein phosphorylation, synaptic dissection, neuron loss, memory function decline, etc. Based on these recent findings, we provide a new framework to summarize the role of microglia in AD memory impairment. This evidence suggests that microglia have the potential to become new targets for AD therapy.