The Effect And Mechanism Of The Phosphodiesterase 4 Inhibitor Rolipram On Intracerebral Hemorrhage

Background and Objective:Intracerebral hemorrhage(ICH)is an important type of stroke,most patients have neurological dysfunction,which affects the quality of life.However,there has little progress in effective treatment of aecondary brain damager after ICH.Research showed,phosphodiesterase 4(PDE4)mediated brain damage.Rolipram was a highly selective inhibitor of PDE4,which could inhibit the hydrolysis of cyclic adenosine phosphate(c AMP)by PDE4,activate downstream adenylate-activated protein kinase(AMPK),which in turn activate ailent information regulation1(SIRT1),and ultimately exert anti-apoptotic and anti-inflammatory effects.However,it is not clear whether the PDE4 inhibitor rolipram is involved in the pathophysiological process of ICH and whether it plays a role through the c AMP/AMPK/SIRT1 signaling pathway.Therefore,this study took this as a starting point to explore the role of PDE4 inhibitor rolipram in ICH and explained the relevant mechanisms,in order to provide new ideas and new methods for the prevention and treatment of ICH.Content:1.Contruct a mouse animal model of ICH,and clarify the co-localization and expression of PDE4 with nerve cells in the brain after ICH,so as to determine the cellular basis of the involvement of PDE 4 in the pathological changes of ICH;2.To observe the effects of PDE4 inhibitor rolipram on brain edema,blood-brain barrier destruction,inflammation,neuronal apoptosis and neurological dysfunction in mice after ICH;3.To explore the changes of c AMP/AMPK/SIRT1 signal system after rolipram intervention in the treatment of ICH,in order to clarify the possible mechanism of rolipram’s brain protection.Methods:Part 1:1.The ICH model was established by collagenase injection to observe the expression and distribution of PDE4 in neuronal,microglia and astrocytes on the 3rd day after ICH;2.Male C57BL/6J mice were randomly divided into sham group,ICH+vehicle group and ICH+rolipram group.Mice were evaluated for neurological function score,brain water content,blood-brain barrier penetration,and tight junction protein expression after ICH.Part 2: 1.The protein sirtuin1(SIRT1)inhibitor sirtinol was used to reveal the underlying signaling pathways.2.Detection of neuronal apoptosis,c AMP/AMPK/SIRT1 pathway related protein expression level(c AMP,p-AMPK,AMPK,SIRT1)and the content of inflammatory factors(TNF-α,IL-6,IL-1β).Results:Part 1: 1.PDE4 and Neu N had obvious co-expression.2.ICH+vehicle group compared with the sham group,the degree of brain edema,Evans blue extravasation and neurological defict after ICH were significantly increased,while the intergrity of tight junctions ZO-1 and claudin-5 were significantly decreased.3.Rolipram could significantly alleviate the degree of brain edema after ICH,reduce leakage of Evans blue,improve neurological dysfunction,and increase the expression of ZO-1 and claudin-5 proteins.Part 2 1: Rolipram markedly reduced the number of TUNEL-positive neurons and the content of inflammatory factors TNF-α,IL-6,IL-1β and up-regulated proteins such as c AMP,p-AMPK and SIRT1 expression.2.The application of SIRT1 specific inhibitor could not only increase the water content of brain tissue,damage the blood-brain barrier and aggravate nerve function damage after ICH,but also increase the number of apoptotic cells and the expression of inflammatory factors,which reversed rolipram neuroprotection.Although sirtinol could inhibit the expression of SIRT1,it had no significant effect on the expression of p-AMPK.Therefore,it could be concluded that AMPK was the upstream effector protein of SIRT1.Conclusion:Rolipram inhibits PDE4,which can play a neuroprotective effect on ICH mice by activating the c AMP/AMPK/SIRT1 signaling pathway.