In
Alzheimer's disease (AD), large populations of endothelial cells undergo angiogenesis due to
brain hypoxia and
inflammation. Substantial evidence from epidemiologic, pathologic, and clinical reports suggests that vascular factors are critical for the pathogenesis of AD. However, the precise mechanistic correlation between
inflammation and angiogenesis in AD has not been well elucidated.
Prostaglandin E2 (
PGE2), a key factor of the inflammatory response, has been known to promote angiogenesis. In this study, we demonstrated that
PGE2 acts through EP4 receptor and
protein kinase A to modulate
CCAAT/enhancer-binding protein delta (CEBPD) abundance in astrocytes. Attenuated vessel formation was observed in the brains of AppTg/Cebpd(-/-) mice. We showed that miR135a was responsive to the induction of CEBPD and further negatively regulated
thrombospondin 1 (THBS1) transcription by directly targeting its 3'-untranslated region (
3'UTR) in astrocytes. Furthermore,
conditioned media from astrocytes expressing miR135a promoted Human umbilical vein endothelial cells (HUVECs) tube-like formation, which correlated with the effects of
PGE2 on angiogenesis. Our results indicated that CEBPD contributes to the repression of THBS1 transcription by activating the expression of miR135a in astrocytes following
PGE2 treatment. We provided new evidence that astrocytic CEBPD increases angiogenesis during AD pathogenesis. This discovery supports the negative influence of CEBPD activation in astrocytes with respect to AD pathogenesis and implies that the CEBPD/miR135a/THBS1 axis could be a therapeutic target of AD.