Research On Association And Possible Mechanism Between Cytotoxin-associated Gene-A-positive Helicobacter Pylori Strains Infection And Carotid Artery Atherogenesis

Hypertension disease, hyperlipemia, diabetes and smoking and so on are approved traditional high-risk factors on carotid atherosclerosis. But there were some carotid atherosclerotics without obvious traditional high-risk factors, and some patients with serious pathological change of carotid artery had slight clinical symptoms. These phenomenas were unable to be explained reasonably with the traditional theory. The researches indicated that Chlamydia pneumoniae, the cytomegalovirus, herpes simplex virus, Helicobacter pylori (Hp) and so on played important roles in carotid atherosclerosis. Recently, Hp is investigative focus on association between Hp and carotid atherosclerosis. Some researcher believed that there was association between Hp infection and carotid atherosclerosis, only cytotoxin-associated gene-A-positive Helicobacter pylori(Hp CagA+) strains was possible related with atherosclerosis formation, which would cause carotid atherosclerotic plaque unstable. But there was contrary opinion because there was not existence of Hp in carotid atherosclerotic plaque, therefore carotid atherosclerosis caused by Hp infection was not to be confidence. Cytotoxin-associated gene-A-positive Helicobacter pylori strains is the main strain in patients infected with Hp in China. Cerebrovascular disease incidence trends to be higher in our country. There is important clinical significance and social value in researching the association and possible mechanism between Hp CagA+ strains infection and carotid atherosclerosis.It is believed that atherosclerosis is one kind of chronic inflammatory diseases, in which inflammatory reaction and mechanism of immune-mediating played important roles. Hs-CRP, which is regarded as the marker of systemic inflammatory response, is related with dysfunction in endothelial cells and accelerates inflammatory response and plays the vital role in process of atherogenesis through many kinds of mechanism. Some researches indicated that there was no significant difference of serum CRP and IL-6 in carotid atherosclerosis patients infected with Hp CagA+ strains in comparision with cytotoxin-associated gene-A-negative Helicobacter pylori(Hp CagA - )strains. So association between Hp CagA+ strains and carotid atherosclerosis or hs-CRP needs to be studyed furtherly. YKL-40, called humanity cartilage glycoprotein 39 (humancartilage-gp 39, HCgp-39), is belongs to a member of 18-sugar base hydroltyic enzyme family, which is equally value with CRP as inflammatory marker. As a modulator of connective tissue cells and a migration factor of formidable endothelial cells and smooth muscle cells, YKL-40 may promote the connective tissue growth and the endothelial cell migration to cause atherogenesis. Hp CagA+ strains infection induces inflammatory reaction and strong immune response. Cell differentiation antigen 14(CD14) is activated as acceptor of Lipopolysaccharide(LPS) after combined with complex of LPS-LBP. Some research demonstrated that the CD14 density augmentation connected with Hp infection. Studies have shown that the level of soluble cell differentiation antigen 14 (sCD14) in patients infected Hp is higher than that of person without Hp infection. After CD14 was activated, it adjusted immune response by mean of many kinds to induce immunity regulatory protein or code gene in factor to be activated and express. In addition, CD14 stimulated the macrophage to product TNF-α, IL-1, IL-6, IFN, migration inhibiting factor, blood platelet growth factor, petrosilane class material as well as the active oxygen and so on. Aforesaid factors aggravated inflammation response and promoted smooth muscle cell's migration and the multiplication and caused atherogenesis. The related research and report at home and abroad are rarer between YKL-40,CD14 with Hp CagA+ strain infection and carotid artery atherogenesis at present.This research firstly carry on the clinical research, including collection of clinical carotid atherosclerotics and the carotid endarterectomy(CEA)cases, and detect hs-CRP, YKL-40, CD14 level and Hp-IgG antibody, Hp DNA in carotid atherosclerotic plaque, to investigate association and possible mechanism between Hp CagA+ strain infection and carotid atherosclerosis as well as clinical acute cerebrovascular accident occured in carotid atherosclerotics with Hp CagA+ strain infection.PART ONEInvestigation on Hp CagA+ strain infection condition and pathogenesis risk analyze in patients of carotid atherosclerosisObjective To observate pathological changes of carotid atherosclerosis as well as Hp infection situation, examinate blood fats, blood serum hs-CRP, blood plasma YKL-40, blood serum sCD14, analyze relations between Hp or Hp CagA+ strain and carotid atherosclerosis, and explore possible mechanism of carotid atherosclerosis caused by infection.Method From January to October in 2008 in our hospital, a total of 310 participants undergoing color ultra supersonic were chosen for our study after informed and consented. All objects were detailedly recorded cases datum. Control group and carotid atherosclerosis group were divided according to with or without carotid atherosclerosis. Blood serum Hp-IgG antibody, Hp-CagA-IgG antibody, blood fats, hs-CRP, blood plasma YKL-40and blood serum sCD14 levels were examinated by enzyme sign law, enzyme linked immunosorbent assay (ELISA) and immunonephelometry respectively.Result 1.Hp-IgG antibody positive rate was 62.50% in carotid atherosclerosis group, 38.73% in control group, positive rate in carotid atherosclerosis is obviously higher than that of control group(P<0.05). Relative risk was obviously high in person infected Hp. Its risk was still obviously high although adjustment hazard factor on age, sex, body weight, blood fats, blood pressure, blood sugar. 2.Hp-CagA-IgG antibody positive rate was 45.24% in carotid atherosclerosis group, 21.38% in control group, positive rate in carotid atherosclerosis group was obviously higher than that of control group(P<0.05). Relative risk was obviously high in persons infected Hp CagA+ strain, but persons infected Hp CagA- strains were no liability to catch carotid atherosclerosis. 3.In comparison with persons infected Hp CagA-strain and persons without Hp in all groups, Levels of TC, TG, LDL-C were obviously high in persons infected Hp CagA+ strain(P<0.05), HDL-C was obvious reducted(P<0.05). In comparison with person without Hp infection, Levels of TC, TG, LDL-C were high in persons infected Hp CagA- strains, HDL-C was low, but the difference was not significant from a statistical standpoint(P>0.05). 4.In comparison with persons infected Hp CagA-strain and persons without Hp infection in all groups, Levels of hs-CRP, YKL-40, sCD14 were obviously high in persons infected Hp CagA+ strain(P<0.05). In comparison with person without Hp infection, Levels of hs-CRP, YKL-40, sCD14 were high in persons infected Hp CagA - strains, but the difference was not significant from a statistical standpoint(P>0.05).Conclusion 1.Hp infection is hazard factor of carotid atherosclerosis through clinical research. 2.Comparison with the Hp CagA-strain infection, the relative risk was obviously high in persons infected Hp CagA+ strain. 3.The Hp CagA+ strain infection may promote and aggravate carotid atherosclerosis through affecting blood fats metabolism and the enhancement inflammatory reaction. PART TWOHp DNA detection and expression of YKL-40, CD14 in carotid atherosclerotic plaqueObjective Existence of Hp DNA and expression of YKL-40 and CD14 in carotid atherosclerotic plaque were detected.. Relation between YKL-40,CD14 and Hp CagA+ strain infection was observated to explore possible mechanism between Hp infection and carotid artery atherogenesis and risk between Hp CagA- strain infection and carotid atherosclerosis.Method A total of 54 patients with carotid atherosclerotic stenosis undergoing carotid endarterectomy (CEA) in vascular surgery department of our hospital from the 310 objects in the first part of research were choosed. All the patients were divided into Hp infection group and no Hp infection group, and further devided into Hp CagA+ strain infection group and Hp CagA- strain infection group according to Hp infection situation. Hp ureC DNA, YKL-40,CD14 in carotid atherosclerotic plaque was detected by PCR technology, immunohistochemical stains and image analysis respectively.Result 1.Hp ureC DNA were not detected in carotid atherosclerotic plaque of the 16 patients without Hp infection and were detected in 17 patients infected Hp CagA+ strain, the detectable rate is 53.13%. Among 6 patients infected Hp CagA- strain, 2 patients were detected for ureC DNA in mottling organization, the detectable rate is 33.33%. In terms of persons infected Hp CagA+ strain, relative risk was obviously high to catch carotid atherosclerosis. 2.Compared with patients infected Hp CagA- strain and patients without Hp infection, Levels of YKL-40,CD14 were obviously high in patients infected Hp CagA+ strain(P<0.05). Compared with no accompanied Hp infection in all groups, Levels of YKL-40,CD14 were high in persons infected Hp CagA- strain, but non-statistics significance (P>0.05). Positive dyeing area ratio of YKL-40, CD14 in patients with Hp DNA position were obviously higher than that of patients with Hp DNA negative(P<0.05).Conclusion 1.Research furtherly certified that Hp CagA+ strain infection has more risk to carotid atherosclerosis compared with Hp CagA- strain infection. 2.The Hp CagA+ strain infection may promote and aggravate carotid artery atherogenesis through enhancement inflammation response and immunity in plaque. 3.Hp DNA were detected in atherosclerotic plaque, the partial Hp infection factor may cause the partial inflammation material release to increasing, thus influence on atherogenesis.PART THREEResearch on relation between Hp CagA+ strain infection and acute ischemic cerebrovascular disease caused by carotid atherosclerosisObjective To research the relation between Hp CagA+ strain infection and acute ischemic cerebrovascular disease caused by carotid atherosclerosis through detecting Hp-CagA-IgG antibody in blood and carotid atherosclerotic plaque and blood serum hs-CRP.Method A total of 32 patients with carotid atherosclerotic sclerostenosis undergoing carotid endarterectomy complicating Hp CagA+ strain infection were selected. According to whether or not having acute ischemic cerebrovascular disease, all the patients were divided into symptomatic group and asymptomatic group. Hp-CagA-IgG antibody in blood and carotid atherosclerotic plaque were performed by Enzyme Linked Immunosorbent Assay (ELISA) and blood serum hs-CRP level was detected by immunonephelometry.Result 1.Compared with asymptomatic group, the density of blood serum Hp-CagA-IgG antibody was obviously high in symptoms group and had statistics significance(P<0.05). 2.Comparison with no symptoms group, level of hs-CRP was obviously high in symptomatic group and had statistics significance(P<0.05). 3.Comparison with no symptoms group, the density of Hp-CagA-IgG antibody in carotid atherosclerotic plaque was obviously high in symptoms group and had statistics significance(P<0.05).Conclusion Through strengthening the whole body and the partial inflammatory reaction and the immune response, Severe Hp infection possibly raises the contents of Hp-CagA-IgG antibody in blood and carotid atherosclerotic plaque as well as the blood serum hs-CRP to aggravates the carotid artery pathological change and affect carotid atherosclerotic plaque stability, which cause acute ischemic cerebrovascular disease.PART FOUREstablishment of a carotid arteriosclerosis model by transvenous injection of Hp CagA+ strainObjective To investigate possible mechanism between Hp CagA+ strain infection and carotid arteriosclerosis with a carotid arteriosclerosis model, which is established on New Zealand white rabbit by intravenous infusion of Hp CagA+ strain.Method A total of 48 healthy male New Zealand white rabbits were equally randomized into a control group of 6 and an experimental group of 42. Ordinary feed was feed in control group, and high fat feed was feed in experimental group. Blood fats, carotid intima-media thickness (IMT), macrography, histopathologic study were examinated respectively after 6th week to determine a hyperlipemia rabbit model establishment. The 36 hyperlipemia rabbit were equally randomized into high fat diet group, Hp infection group and Hp treatment group, which were feed with high fat feed. The rabbits in Hp infection group and Hp treatment group were firstly injected Hp CagA+ strain, the Hp treatment group simultaneously was feed the anti-Hp drugs, the high fat diet group was substitutes the SS1 vaccine by the isometric physiological saline to make similar process. When 8th week ( first infected 2 weeks later), Hp CagA+ strain was given again by the same way. And 6 rabbits were chooesed randomly from each group. Blood fats, blood serum hs-CRP, blood plasma YKL-40, Hp-CagA-IgG antibody as well as carotid IMT were detected by the way mentioned previously. Hp CagA DNA was detected by PCR method in carotid atherosclerotic plaque. The same indexes of all the surplus animals were detected on at 12th week.Result 1.Hyperlipemia rabbit model were successful established when at 6th week. The blood fats did not obviously change (P>0.05) at 8th week, 12th week. 2.When at 8th week, TC, TG, LDL-C, hs-CRP, YKL-40 were obviously higher in Hp infection group compared with high fat diet group and Hp treatment group(P<0.05), at the same time HDL-C was low and carotid IMT was obvious accumulation(P<0.05). Fatty streak was seen. Thickening of arterial wall and multi-layer lipid-laden macrophages were seen under the mirror. They were more different from that of high fat diet group and Hp treatment group (P<0.05). Compared with high fat diet group, blood fats, hs-CRP, YKL-40, carotid artery IMT in Hp treatment group werenot obvious change (P>0.05) and extent of atherosclerosis was consistent. 3.TC, TG, LDL-C, hs-CRP, YKL-40 were obviously higher in Hp infection group at 12th week than that of high fat diet group and Hp treatment group at 8th week(P<0.05), at the same time HDL-C was low (P<0.05), and extent of atherosclerosis was severe. Compared with the same indexes of 8th week, blood fats, hs-CRP, YKL-40 werenot obvious change in high fat diet group and in Hp treatment group (P>0.05), extent of atherosclerosis was severe. Compared with high fat diet group, blood fats, hs-CRP, YKL-40, extent of atherosclerosis in Hp treatment group werenot obvious change (P>0.05).Conclusion 1.Carotid arteriosclerosis model can be successfully established by intravenous injection of Helicobacter pylori on hyperlipidemia rabbit. 2.Hp CagA+ strain caused abnormal metabolism of blood fat. 3.Blood serum hs-CRP and blood plasma YKL-40 were elevated after Hp CagA+ strain infection. 4.The Hp CagA+ strain infection may promote and aggravate carotid arteriosclerosis through enhancement of inflammaory and immune response.