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Updated: Mar 1, 2026
Sub-acute Cerebral Microhemorrhages Induced by Lipopolysaccharide Injection in Rats
Published on: October 17, 2018
Effects of phosphodiesterase 3A modulation on murine cerebral microhemorrhages
Rachita K Sumbria1,2, Vitaly Vasilevko3, Mher Mahoney Grigoryan2
1Department of Biopharmaceutical Sciences, School of Pharmacy, Keck Graduate Institute, Claremont, CA, USA.
Background:
Cerebral microbleeds (CMB) are MRI-demonstrable cerebral microhemorrhages (CMH) which commonly coexist with ischemic stroke. This creates a challenging therapeutic milieu, and a strategy that simultaneously protects the vessel wall and provides anti-thrombotic activity is an attractive potential approach. Phosphodiesterase 3A (PDE3A) inhibition is known to provide cerebral vessel wall protection combined with anti-thrombotic effects. As an initial step in the development of a therapy that simultaneously treats CMB and ischemic stroke, we hypothesized that inhibition of the PDE3A pathway is protective against CMH development.
Methods:
The effect of PDE3A pathway inhibition was studied in the inflammation-induced and cerebral amyloid angiopathy (CAA)-associated mouse models of CMH. The PDE3A pathway was modulated using two approaches: genetic deletion of PDE3A and pharmacological inhibition of PDE3A by cilostazol. The effects of PDE3A pathway modulation on H&E- and Prussian blue (PB)-positive CMH development, BBB function (IgG, claudin-5, and fibrinogen), and neuroinflammation (ICAM-1, Iba-1, and GFAP) were investigated.
Results:
Robust development of CMH in the inflammation-induced and CAA-associated spontaneous mouse models was observed. Inflammation-induced CMH were associated with markers of BBB dysfunction and inflammation, and CAA-associated spontaneous CMH were associated primarily with markers of neuroinflammation. Genetic deletion of the PDE3A gene did not alter BBB function, microglial activation, or CMH development, but significantly reduced endothelial and astrocyte activation in the inflammation-induced CMH mouse model. In the CAA-associated CMH mouse model, PDE3A modulation via pharmacological inhibition by cilostazol did not alter BBB function, neuroinflammation, or CMH development.
Conclusions:
Modulation of the PDE3A pathway, either by genetic deletion or pharmacological inhibition, does not alter CMH development in an inflammation-induced or in a CAA-associated mouse model of CMH. The role of microglial activation and BBB injury in CMH development warrants further investigation.
Insights
Phosphodiesterase 3A (PDE3A) inhibition did not prevent cerebral microhemorrhages (CMH) in mouse models. Further research is needed to understand the roles of microglial activation and blood-brain barrier injury in CMH development.
Area of Science:
- Neuroscience
- Vascular Biology
- Pharmacology
Background:
- Cerebral microbleeds (CMB) often coexist with ischemic stroke, complicating treatment.
- A dual-acting therapy protecting vessel walls and preventing thrombosis is desirable.
- Phosphodiesterase 3A (PDE3A) inhibition offers potential for both vessel protection and anti-thrombotic effects.
Purpose of the Study:
- To investigate if PDE3A pathway inhibition protects against cerebral microhemorrhage (CMH) development.
- To evaluate PDE3A modulation in inflammation-induced and cerebral amyloid angiopathy (CAA)-associated mouse models of CMH.
Main Methods:
- Studied PDE3A inhibition using genetic deletion and pharmacological (cilostazol) approaches in mouse models.
- Assessed CMH development (H&E, Prussian blue staining).
- Investigated blood-brain barrier (BBB) function and neuroinflammation markers.
Main Results:
- CMH developed robustly in both inflammation-induced and CAA models.
- Genetic PDE3A deletion reduced endothelial and astrocyte activation in the inflammation model but did not affect CMH or BBB.
- Cilostazol did not alter CMH, BBB function, or neuroinflammation in the CAA model.
Conclusions:
- PDE3A pathway modulation, via genetic or pharmacological means, did not impact CMH development in the studied mouse models.
- The roles of microglial activation and BBB injury in CMH require further investigation.
