Effects of IL-1β on hippocampus cell apoptosis and learning ability of vascular dementia rats

Vascular dementia (VD) is a type of memory, cognition, and behavior disorder caused by ischemic stroke or hemorrhagic stroke. It is a common pathogenesis of dementia that is only second to Alzheimer's disease. Inflammation plays a key role in VD. Interleukin-1β (IL-1β) is a kind of pro-inflammatory cytokine, while its mechanism in VD occurrence and development is still unclear.

The healthy male rats were randomly divided into three groups, including sham group, VD model group (established by bilateral common carotid artery ligation), and IL-1β group (treated by IL-1β monoclonal antibody intracerebroventricular injection on based on model group). Rat learning ability was evaluated by Morris water maze assay. IL-1β expression in brain tissue and peripheral blood was examined by using Real Time-PCR and enzyme-linked immunosorbent assay (ELISA), respectively. Hippocampus apoptosis was detected by caspase 3 activity detection kit. B-cell lymphoma-2 (Bcl-2) and p38 mitogen-activated protein kinase (MAPK) protein levels were assessed by Western blot assay.

IL-1β expression was increased, caspase 3 activity was enhanced, Bcl-2 level was declined, and p-P38 phosphorylation was elevated in brain tissue and peripheral blood from VD model group compared to sham group (p<0.05). IL-1β monoclonal antibody significantly reduced IL-1β expression, improved learning ability, attenuated caspase 3 activity, increased Bcl-2 level, and declined p-P38 expression in VD rats compared to model group (p<0.05).

IL-1β can delay VD occurrence and development through the P38-MAPK signaling pathway to regulate cell apoptosis and improve learning ability.