Research On Signal Conductive Mechanisms Of FKN Affecting Atherosclerosis And The Invention Of Captopril

Background: Fractalkine, a recently discovered newchemokine CX3CL1(fractalkine) which is overexpressed inatherosclerosis contributes to platelet activation andincreased thrombogenesis in vascular diseases. Combinationwith its receptor CX3CR1 mostly expressed on monocytes,lymphocytes, and natural killer (NK) cells the fractalkinecan inhance the NK cell-mediated endothelium damage, whichmay result in vascular injury. At the same time, FKN can alsomediate capture , firm adhesion and migration of monocytesand lymphocytes to the vascular endothelial cells underphysiologic flow conditions.. These indicate that FKN andCX3CR1 play an important role in the initiation anddevelopment of atherosclerosis.To explore the mechanism ofatherosclerosis, we find that interacting with CX3CR1 ,FKNcan coupled with its effective enzyme protein kinase C throughthe guanine nucleotide binding protein (G-protein),thenactivates the latter .the activated protein kinase C mayresults in phosphorylation of its target protein. being oneof the target proteins ,the Nuclear factor –κappaB (NF-κB),a redox-sensitive transcription factor,is activated throughthe phosphorylation of its 32',36'serine by PKC. Theactivated Nuclear factor –κappaB (NF-κB) gain the abilityto transfer from the cytoplasm to the nucleus .Afterconnected to the κappaB series of its aimed-gene tumornecrosis factor – α (TNF-α), NF-κB can induce thetranscription and translation of the latter .Thus ,wediscovered that there are perhaps a series of cascadedreaction during FKN/CX3CR1,G-coupled protein , proteinkinase C, Nuclear factor –κappaB and tumor necrosis factor–α when we explore the signal conductive mechanism ofFKN/CX3CR1 affecting athrosclerosis. We associate the fivepoints then explore the cause and effect relationships duringthem and the intervention of angiotensin converting enzymeinhibitor captopril in Our experiment.Objective: (1) To research the signal conductivemechanism of FKN/CX3CR1 affecting atherosclerosis .(2) Toresearch the function of G-coupled protein in the the signalconductive mechanism of FKN/CX3CR1 affectingatherosclerosis.(3) To research the function of protein kinaseC in the the signal conductive mechanism of FKN/CX3CR1affecting atherosclerosis.(4) To research the function ofNuclear factor –κappaB in the the signal conductivemechanism of FKN/CX3CR1 affecting atherosclerosis.(5) Toresearch the the intervention of angiotensin converting enzymeinhibitor captopril in the the signal conductive mechanism ofFKN/CX3CR1 affecting atherosclerosis.Method: (1)Peripheral blood monocytes were isolated fromfresh blood of healthy volunteers by Ficoll-Paque gradientcentrifugation.(2)Divide the extractive Peripheral bloodmonocytes into six groups :control group ,FKN group,G-protein inhibitor pertussis toxin(PTX)group, PKC inhibitorRO31-8220 group,inhibitor NF-κB PDTC group,FKN + captoprilgroup. ( 3 ) measure the Nuclear factor –κappaB(NF-KB)expression of monocytes from each group by immunehistochemsitry.(4)Collect the supernatant of monocytes fromeach group ,determin the expression of TNF-α by euzyme-linkedimmunosorbent assay(ELISA).Result :(1)The expression of NF-κB and TNF-α fromFKN group is increased compared with the control group .(2)The expression of NF-κB and TNF-α from G-proteininhibitor PTX group is decreased compared with the FKNgroup .(3)The expression of NF-κB and TNF-α from PKCinhibitor RO31-8220 group is decreased compared with theFKN group .(4)The expression of TNF-α from inhibitorNF-κB PDTC group is decreased compared with the FKNgroup .(5)The expression of NF-κB and TNF-α fromcaptopril group is decreased compared with the FKNgroup .conclusion : (1)FKN-CX3CR1 increase the expression ofNF-κB in Peripheral blood monocytes as one of thesignal conductive mechanisms of contributing to the progressionof atherosclerosis . (2)FKN-CX3CR1 increase the expressionof TNF-αin Peripheral blood monocytes as the othersignal conductive mechanism of contributing to the progressionof atherosclerosis .(3)Because CX3CR1 is a G-coupleprotein ,it can initiate intracellular signal conductivemechanism through coupling with G-protein afterinteracting with FKN.(4) Protein kinase C (PKC) play animportant role during the process that Peripheral bloodmonocytes synthesize NF-κB and TNF-α induced by FKN-CX3CR1. FKN-CX3CR1 perhaps initiate intracellular signalconductive mechanism through the process that FKN-CX3CR1 activate the PKC by coupled with G-protein andthen improve the expression of NF-κB and TNF-α.(5)NF-κB play an important role during the process thatPeripheral blood monocytes synthesize TNF-α induced byFKN-CX3CR1. FKN-CX3CR1 initiate intracellular signalconductive mechanism perhaps through the process inwhich FKN-CX3CR1 activate NF-KB by PKC which coupled withG-protein and then improve the expression of TNF-α.( 6 ) The signal conductive mechanisms of FKN -CX3CR1contributing to the progression of atherosclerosis are thefollowing series of cascaded reaction:FKN -CX3CR1 → →G-coupled protein→→ PKC→→ NF-κB→→ TNF-α。(7)Captopril participates in inhibiting Inflammatory andpreventing arteriosclerosis perhaps by reducing theexpression of NF-KB in Peripheral blood monocytesinduced by FKN-CX3CR1 . ( 8 ) Captopril participates ininhibiting Inflammatory and preventing atherosclerosisperhaps by reducing the expression of TNF -α inPeripheral blood monocytes induced by FKN-CX3CR1. It partlymaybe linked to inhibiting the expression of NF-κB.