Effect Of Type 2 Diabetes On Thrombotic Pathology In Patients With Acute Ischemic Stroke And Its Mechanis

The first chapter:The role of diabetes mellitus on the thrombus composition in patients with acute ischemic strokeObjective:Diabetes mellitus(DM)indicated poor clinical prognosis for patients with acute ischemic stroke(AIS).Moreover,it is also unclear whether DM affects the hemostatic system as well as the histological composition of thrombi.Methods:The study included consecutive patients who had retrieved clots.Histologic staining for thrombus included Martius Scarlet Blue,hematoxylin and eosin,immunohistochemistry for von Willebrand factor.Diabetes mellitus history or admission hyperglycemia(≥7.8 mmol/L)were compared with the differences in clot composition.Results:In total,52 patients were examined;half of them had previously been diagnosed with diabetes mellitus.Diabetic patients showed higher serum glucose on admission(8.90 vs.7.40,P=0.012).The baseline characteristics(expect thrombus location and smoking history),procedural,in diabetic and non-diabetic patients,clinical outcomes were similar.As for histologic composition,thrombus in patients with diagnosed diabetes mellitus had fewer red blood cells(26.0%vs.42.9%,P=0.013),more fibrin(44.2%vs.28.3%,P=0.004),equivalent content of platelets(24.0%vs.21.5%,P=0.694)and von Willebrand factor(0.041 vs.0.031,P=0.234)than nonDM patients.However,there was no statistical difference in the content of fibrin(37.6%vs.34.3%,P=0.627),red blood cells(41.6%vs.27.3%,P=0.105),platelets(21.2%vs.24.2%,P=0.498),and von Willebrand factor(0.038 vs.0.034,P=0.284)between patients with or without hyperglycemia on admission.Conclusion:There were more fibrin and fewer RBCs components in diabetic clots than in patients without DM,while hyperglycemia on admission did not influence clot composition.More research is needed to confirm these findings.The second chapter:Effects of diabetes mellitus complicated by admission hyperglycemia on clot histological composition and ultrastructure in patients with acute ischemic strokeObjective:Type 2 diabetes mellitus(T2DM)affects the occurrence and prognosis of acute ischemic stroke(AIS).However,the impact of diabetes on thrombus characteristics is unclear.The relationship between the composition and ultrastructure of clots and DM with admission hyperglycemia was investigated.Methods:Consecutive patients with AIS who underwent endovascular thrombus retrieval between June 2017 and May 2021 were recruited.The thrombus composition and ultrastructure were evaluated using Martius scarlet blue stain and scanning electron microscopy.Clot perviousness was evaluated via thrombus attenuation increase on computed tomography angiography(CTA)versus non-contrast CT.Patients with admission hyperglycemia DM(ahDM)and those without DM(nonDM)were compared in terms of thrombus composition,ultrastructure,and perviousness.Results:On admission,higher NIHSS scores(17 vs.12,respectively,P=0.015)was evident in ahDM patients.After the 90-day follow-up,the rates of excellent outcomes(mRS 0-1)were lower in patients with ahDM(16.6%,P=0.038),but functional independence(mRS 0-2)and handicapped(mRS 3-5)were comparable between patients with ahDM and nonDM.The outcome of mortality was higher in patients with ahDM(33.3%,P=0.046)than in nonDM patients.Clots in patients with ahDM had more fibrin(39.4%vs.25.0%,respectively,P=0.007),fewer erythrocyte components(21.2%vs.41.5%,respectively,P=0.043),equivalent platelet fraction(27.7%vs.24.6%,respectively,P=0.587),and higher WBC counts(4.6%vs.3.3%,respectively,P=0.004)than in nonDM patients.The percentage of polyhedral erythrocytes in thrombi was significantly higher in ahDM patients than in nonDM patients(68.9%vs.45.6%,respectively,P=0.007).The proportion of pervious clots was higher in patients nonDM than in patients with ahDM(82.61%vs.40%,respectively,P=0.026).Conclusion:Patients with ahDM presented with greater stroke severity on admission and poorer functional outcomes after 3 months.Clots in patients with ahDM had more fibrin,leucocytes,and fewer erythrocyte components than in patients nonDM.The content of polyhedral erythrocytes and impervious clots proportion were significantly higher in thrombi of patients with AIS and ahDM.Further research is required to validate these findings.Advanced glycation end products induce platelet activation and shape change through Src/Syk/PLCγ2 kinase and RhoA/ROCK signaling pathwaysObjective:Diabetes mellitus has been proved to be related to platelet hyperreactivity.Advanced glycation end products(AGEs)generated in the hyperglycemia state may contribute to unregulated platelet activation during thrombosis.AGEs are well known for their ability to activate platelets,but their mechanisms of action remain unclear.The purpose of our study is to explore the potential mechanism of AGEs in platelet activation and its role in thrombosis.Method:Platelet aggregation induced by AGEs was detected by platelet aggregometry,and the activation and diffusion of platelets were observed by Western blotting,immunofluorescence and scanning electron microscope.Explore the related signal pathways through immunoprecipitation.Using FeCl3-induced carotid artery occlusion model,we explored the effect of diabetes on blood coagulation,and through the analysis of blood clots,we explored the effect of activated platelets on clot contraction.Results:We show that AGEs stimulate platelet activation through phosphorylation of the regulatory light chains of the contractile protein myosin Ⅱa(MLC).AGEs induced platelets shape change,spreading,and phosphorylation of MLC(serine 19)through a pathway that was ablated under conditions that blocked CD36 ligation.AGEs phosphorylated a number of proteins,including Syk and PLCγ2,in agreement with this.MLC phosphorylation was only partially inhibited when Syk,Ca2+mobilization,and MLC kinase(MLCK)were inhibited,indicating the existence of another pathway.AGEs activated RhoA and RhoA kinase(ROCK)to induce inhibitory phosphorylation of MLC phosphatase(MLCP).These data reveal new signaling events downstream of CD36 that are critical in promoting platelet aggregation by AGEs.Conclusion:Our research shows that AGEs can activate the downstream Src/Syk-PLC y2 and the platelet activation induced by RhoA/ROCK pathway by binding to platelet CD36.Activated platelets further induce blood clot contraction.This study revealed the potential mechanism of AGEs activating platelets.