The Investigation Of The Clinical Values Of CD40-CD40L System In The Acute Cerebral Infarctions And Its Possible Mechanisms In The Instability Of Atherosclerotic Plaques

Atherosclerosis(AS) is a chronic inflammatory disorder,in which immune regulation plays a crucial role.CD40 is a receptor for CD40 ligand(CD40L,CD154).They are a pair of complemented transmembrane proteins and belong to the TNF receptor(TNFR) superfamily and the TNF superfamily,respectively.CD40-CD40L system is an important cellular signal transduction pathway of humoral and cellular immunity and plays an important role in the antigen presentation and autoimmune diseases.There are mainly two forms of CD40L in vivo,which are cellular membrane-bound CD40L(mCD40L) and soluble CD40L(sCD40L).Recent studies have demonstrated that CD40-CD40L system participates in initiation,evolution,and acute complications after the rupture of atherosclerotic lesions.CD40 and CD40L were expressed by the epithelial cells, monocytes,macrophages and smooth muscle cells in the atherosclerotic plaques. However,they were not expressed or low expressed in the normal arteries.CD40L linkage with CD40 can induce human vascular endothelial cells to express adhesion molecules,such as selectin-E,VCAM-1,ICAM-1,and stimulate the release of chemokines and cytokines,such as IL-8,RANTES or macrophage inflammatory protein 1 a,which take part in the formation of atherosclerotic plaques.Block the interaction of CD40-CD40L with specific CD40L antibody could inhibit the development of atherosclerotic plaques and change the composition of atheroma in manners thought to favor plaque stability,e.g.,reduced relative content of macrophages and lipid,as well as increased relative content of smooth muscle cells and collagen.Therefore,CD40-CD40L system not only participates in the initial events of atherogenesis,but also involves the instability and breakdown of established plaques and induces atherosclerotic thrombosis.CD40-CD40L system related to atherosclerosis is the research focus in the acute coronal syndrome recently.Atherosclerosis is also the commen cause of acute cerebral infarctions.But there are few studies of CD40-CD40L system in the acute cerebral infarctions.Our researches focus on the expression of CD40L in the peripheral blood monocytes(PBMC) and serum sCD40L levels in different types of cerebral infarctions, pure carotid artery atherosclerotic stenosis and normal controls and analyzes the expression of CD40 in human carotid artery atherosclerotic plaques and its relationship with clinical stroke events.Therefore,the roles of CD40-CD40L system in acute cerebral infarction and plaque instability are evaluated.We further observe the expression and distributions of CD40 and CD40L in carotid artery atherosclerotic plaques and their relationship with MMP₉ and study the possible mechanisms of CD40-CD40L in the instability of plaques.We expect to find out a simple biomarker to evaluate plaque instability,etiology and severities of cerebral infarction and find out a new target for prevention and treatment of atherosclerosis and cerebral infarctions.Partâ… The clinical roles of the CD40L expression in peripheral blood monocytes and serum sCD40L levels in patients with acute cerebral infarctionsObjective The CD40L expression in peripheral blood monocytes(PBMC) and serum sCD40L levels were detected in patients with different types of acute cerebral infarctions and their roles in diagnosis of atherosclerotic cerebral infarctions and judgments of severity of cerebral infarctions were evaluated.Methods 82 patients with acute cerebral infarctions in the Department of Neurology of Changhai Hospital were recruited.They are classified with SSS-TOAST classification as large artery atherosclerosis type 30 cases,small-artery occlusion type 36 cases, cardioaortic embolism type 16 cases.17 patients with carotid artery stenosis without stroke were recruited as pure carotid artery stenosis and 20 normal people as normal control.Patients with acute cerebral infarction were scored with NIHSS,Barthel index and modified Rankin scale to systemly comment their neurological function,activities of daily living and disability situation.Expression of CD40L on peripheral blood monocytes was detected by direct immunofluorescence with flow cytometry and sCD40L levels were measured by ELISA mothed.Serum hs-CRP level was tested by immune scattering ratio with automatic biochemistry.Results 1.Serum hs-CRP levels in patients with large artery atherosclotic infarctions were higher than pure carotid artery stenosis(P＜0.05).2.The expression of CD40L on periphery blood monocytes in patients with atherosclerotic infarctions were higher than patients without atherosclerosis(P＜0.01).Sensitivity and specificity for its diagnosing atherosclerosis were higher than serum hs-CRP(P＜0.01).Expression of CD40L on periphery blood monocytes in patients with large artery atherosclerotic cerebral infarction was higher than pure carotid artery stenosis(P＜0.01).The sensitivity and specificity in judging atherosclerotic plaque instability were higher than serum hs-CRP (P＜0.01).CD40L expression on PBMC were higher in large artery atherosclerotic cerebral infarction than other types of cerebral infarction(P＜0.01).The sensitivity of CD40L expression on PBMC in diagnosing large artery atherosclerotic cerebral infarction was higher than hs-CRP(P＜0.01) and there were no significant differences in specificity(P＞0.05).3.There was positive correlation between the levels of serum sCD40L and NIHSS scores(r=0.537,P＜0.01) and their correlation was superior to hs-CRP(r=0.432,P＜0.01).There was inverse correlation between sCD40L levels and Barthel index(r=-0.515,P＜0.01) and their correlation was superior to hs-CRP(r=-0.510, P＜0.01).There was positive correlation between sCD40L levels and modified Rankin scales(r=0.589,P＜0.01) and its correlation was superior to hs-CRP(r=0.482,P＜0.01).Conclusion In patients with acute cerebral infarction,serum hs-CRP was related to atherosclerotic plaque instability and CD40L expression on PBMC was related to atherosclerosis,plaque instability and large artery atherosclerotic cerebral infarctions. The sensitivity and specificity of CD40L expression on PBMC in judging atherosclerosis and plaque instability and diagnosing large artery atherosclerotic cerebral infarction were more senetive than serum hs-CRP.Serum sCD40L levels were related to the severity of cerebral infarctions and had an inverse correlation with patients' ability of daily living and its correlations were superior to serum hs-CRP.Serum sCD40L is a good biomarker of the severity of cerebral infarctions.Partâ…¡The roles of CD40 in human carotid atherosclerosis and plaque instabilityObjective The CD40 mRNA and protein expression levels in human carotid artery atherosclerotic plaques and normal carotid artery were detected and its relationship with clinical stroke events was analyzed.The roles of CD40 in atherosclerosis and plaque instability were investigated.Methods 28 specimen of carotid artery atherosclerotic plaques were collected from carotid endarterectomy due to carotid atherosclerotic stenosis(＞70%) performed in the Department of Vascular Surgery of our hospital.The plaques were further divided into clinical stroke events group(n=15) and no clinical stroke events group(n=13) according to whether the patients had ischemic cerebral strokes before surgery.Another 8 cases of normal carotid artery in autopsy were taken as normal control.CD40 mRNA levels were measured by real time PCR and CD40 protein levels were detected by Western blotting in each group.Results CD40 mRNA levels in carotid artery atherosclerotic plaques were higher than normal carotid artery(P＜0.01) and higher in clinical stroke events group than no clinical stroke events group(P＜0.01).There was basically no expression of CD40 in normal carotid artery.The CD40 expression in carotid artery atherosclerosis with no clinical stroke events group was significant higher than normal carotid artery.The CD40 expression in carotid artery atherosclerosis with clinical stroke events group was higher than no clinical stroke events group.Conclusion Transcription and expression levels of CD40 in carotid atherosclerotic plaques were higher than normal carotid artery and even more significantl in patients with clinical stroke events.The results suggested that CD40 may participate in formation of carotid atherosclerosis and be related to the plaque instability.Partâ…¢The investigations of possible mechanisms of CD40-CD40L system in affecting the carotid artery atherosclerosis and plaque instabilityObjective CD40 and MMP₉ mRNA,protein expressions and their relationship in carotid artery atherosclerotic plaques were detected.Expression of CD40,CD40L and MMP₉ and their distributions in carotid atherosclerotic plaques were observed.The possible mechanisms of CD40-CD40L system in affecting carotid artery atherosclerosis and plaque instability were explored.Methods 28 specimen of carotid artery atherosclerotic plaques were collected from carotid endarterectomy due to carotid atherosclerotic stenosis(＞70%) performed in the Department of Vascular Surgery of our hospital.The plaques were further divided into clinical stroke events group(n=15) and no clinical stroke events group(n=13) according to whether the patients had ischemic cerebral strokes before surgery.Another 8 cases of normal carotid artery in autopsy were used as normal control.CD40 and MMP₉ mRNA levels were measured by real time PCR and CD40 and MMP₉ protein levels were detected by Western blotting in each group.Expression and distribution of CD40,CD40L and MMP₉ in atherosclerotic plaques were observed by immunochemistry.Results 1.CD40 and MMP₉ mRNA levels in carotid artery atherosclerotic plaques were higher than normal carotid artery(P＜0.01) and even more significant in clinical stroke events group than no clinical stroke events group(P＜0.01).2.There was positive correlation between CD40 and MMP₉ mRNA(r=0.964,P＜0.01).3.There was extremely rare expression of CD40 and MMP₉ protein in normal carotid artery.The expression of CD40 and MMP₉ protein was significant higher in carotid artery atherosclerosis with clinical stroke events than without clinical stroke events,and the expression of CD40 and MMP₉ protein in no clinical stroke events group higher than normal carotid artery.4. CD40 and CD40L were mainly expressed in edocthelial cells and smooth muscle cells. MMP₉ was located in the collagen and smooth muscle cells.CD40,CD40L and MMP₉ were more significantly expressed in the shoulder of the atherosclerotic plaques.The expressions of CD40,CD40L and MMP₉ were significantly higher in clinical event group than no clinical event group,and no clinical event group higher than normal controls.5.There were positive correlations between the expression of CD40 and MMP₉, CD40L and MMP₉(P＜0.01).Conclusion CD40-CD40L system may induce atherosclerosis and plaque instability probably by up-regulation of MMP₉ in carotid artery atherosclerosis. In conclusion,CD40-CD40L system is a sensitive biomarker in judging cerebral atherosclerosis,plaque instability and the severity of cerebral infarctions and diagnosing large artery atherosclerotic cerebral infarctions.The mechanism of CD40-CD40L system in atherosclerosis and plaque instability may be related to up-regulation of MMP₉. Further investigation of the mechanisms of CD40-CD40L system in atherosclerosis and plaque instability will be a novel potential therapeutic target for atherosclerosis and cerebral infarctions.