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AIM: To explore the role of purinergic signaling mediated by ATP in the Alzheimer ’ s disease (AD)-related colon motility disorder and its related molecular mechanisms .METHODS:(1)Clinical trials:AD patients in our hospital were collected and studied .Radioimmunoassay was used for the determination of plasma motilin (MTL), cholecystokinin (CCK), vasoactive intestinal peptide (VIP) and nitric oxide (NO), and high-performance liquid chroma-tography ( HPLC) was applied to test the level of adenosine triphosphate ( ATP) .The patients were assessed by neuropsy-chology and scored accordingly .( 2 ) In animal experiments , AD mice received Morris water maze test , and the spatial learning and memory function were evaluated .The plasma levels of MTL , CCK, VIP and NO were examined by radioimmu-noassay , and the level of ATP was measured by HPLC .Choline acetyltransferase ( ChAT ) , VIP, nitric oxide synthase ( NOS) and ATP synthase were detected by immunohistochemistry .Western blot and immunohistochemistry were used to detect the expression of P2Y receptor.(3) In vitro, organ bath was applied to observe the effect of α,β-methylene ATP (α,β-MeATP), an agonist of P2Y receptor, on both spontaneous and electrically evoked contraction of colonic smooth muscle strip, and the technique of intracellular microelectrode was applied to observe the effect of α,β-MeATP on the membrane potential of colonic smooth muscle cells .RESULTS:Compared with control group , the levels of MTL and CCK were decreased (P<0.01), and the levels of NO and ATP were increased (P<0.05 or P<0.01), while the VIP level was not changed.Mini-Mental State Examination (MMSE) score was decreased (P<0.05), Alzheimer’s Disease Assess-ment Scale-Cognitive Subscale (ADAS-Cog) score, Neuropsychiatric Inventory (NPI) score and Alzheimer’s Disease Co-operative Study-Activities of Daily Living Scale ( ADCS-ADL ) were all increased as compared with control group ( P <0.01).The 4~6 d escape latency of APP/PS1 AD mice was significantly prolonged (P<0.05), and the space explora-tion ability distinctly reduced (P<0.05).In AD mice, the levels of MTL and CCK were decreased (P<0.01), and the levels of NO and ATP were increased (P<0.05 or P<0.01), while the VIP level was not changed .The protein expres-sion of colonic ATP synthase was significantly increased (P<0.05), but the expression of ChAT, VIP and NOS was not changed.The expression of P2Y receptor was increased (P<0.01).The results of in vitro experiment displayed that α,β-MeATP, from 20 μmol/L to 100 μmol/L, inhibited the spontaneous contraction of colonic smooth muscle strip in the nor-mal mice and AD mice ( P<0.05 or P<0.01 ) , and this inhibition was reversed by Na +channel inhibitor tetrodotoxin (TTX) (P<0.05 or P<0.01).In addition, the effect of α,β-MeATP at 100μmol/L on the AD mice was more obvious than that on the normal mice (P<0.05), and this inhibition was also antagonized by TTX (P<0.05 or P<0.01), pro-minent in AD group as compared with control group (P<0.05).In 10 Hz electrically evoked contraction of colonic smooth muscle strip,α,β-MeATP inhibited both the normal and AD mice (P<0.05 or P<0.01), while the inhibition was more obvious in the AD mice at the concentration of 40μmol/L or 100μmol/L (P<0.05 or P<0.01).CONCLUSION:AD patients and AD mice are accompanied by decreased MTL and CCK levels , and enhanced NO level , thus inducing colonic motor dysfunction along with AD .Meanwhile, ATP in plasma, purinergic neurons , and P2Y receptor expression are in-creased in the AD mice .Purinergic signaling mediated by ATP inhibits colonic smooth muscle strip contraction and further paralyzes the colonic movement function in AD .
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[ ABSTRACT] AIM: To explore the role of chemokine receptor CXCR 4 in the pathogenesis of protein C system (PCS) in ulcerative colitis (UC).METHODS:In vivo, the mice were divided into control group and UC group .The mac-roscopic score, microscopic score and ulcer index were assessed .The mRNA levels and activity of myeloperoxidase ( MPO) , cyclooxygenase-2 ( COX-2 ) , stromal cell-derived factor-1α( SDF-1α) and monocyte chemotactic protein 1 (MCP-1) both in colonic tissue and plasma were determined .The expression and location of CXCR4,β-arrestin, p-JNK, endothelial cell protein C receptor (EPCR) and thrombomodulin (TM) were detected.The activity of protein C (PC) and protein S ( PS) was measured in each group .In vitro, mouse colonic microvascular endothelial cells were isolated , cultured and identified.Both CXCR4-overexpressing and CXCR4-silencing colonic mucosa microvascular endothelial cells were con-structed.The effects of SDF-1αon the protein levels of EPCR , TM,β-arrestin and p-JNK, and on the activity of PC , PS and activated protein C ( APC) were observed .RESULTS:Compared with control group , UC mice showed increased gross score, histopathological score and ulcer index (P<0.05).The mRNA levels and activity of MPO, COX-2, SDF-1αand MCP-1 in colon and plasma were increased (P<0.01).The protein levels of CXCR4,β-arrestin and p-JNK were up-regu-lated, EPCR expression was down-regulated in colon, and the activity of PC and PS in plasma was decreased (P<0.05 or P<0.01).CXCR4 overexpression further aggravated SDF-1α-induced PCS inhibition in colonic mucosa microvascular en-dothelial cells, and further up-regulated the protein levels of β-arrestin and p-JNK (P<0.05).CONCLUSION:PCS is inhibited in UC.CXCR4 is involved in the regulation of PCS inhibition by mediating chemokines and acting on colonic mu -cosa microvascular endothelial cells through β-arrestin-JNK pathway .
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AIM:To explore the change of antithrombin Ⅲ( AT-Ⅲ) in the patients with atherosclerotic cere-bral infarction .METHODS:Chromogenic substrate assay was used to measure the activity of AT-Ⅲ in 55 patients with atherosclerotic cerebral infarction and 55 healthy controls , and the correlation analysis was applied to determine the AT-Ⅲactivity with the severity of damage in central nervous system and general biochemical parameters .The levels of TNF-αand IL-6 in the plasma were detected by ELISA .Immunocomplex in the plasma was measured by enzyme immunoassay (EIA). The number and phenotype of the monocytes in peripheral blood were analyzed by flow cytometry .ELISA was also applied to determine the secretion of TNF-αand IL-6 from the monocytes after the stimulation of immunocomplex .The expression of AT-Ⅲin human brain vascular endothelial cells after the stimulation of TNF-αand IL-6 was observed by Western blotting . RESULTS:The activity of AT-Ⅲsignificantly decreased in the patients with atherosclerotic cerebral infarction , and nega-tively correlated with the damage degree of nervous system function , systolic pressure , diastolic pressure , glucose , choles-terol, triglyceride, low-density lipoprotein cholesterol and homocysteine , while positively correlated with high-density lipo-protein.In addition, the plasma levels of TNF-αand IL-6 increased significantly , accompanied with the enhancement of immunocomplex level .The numbers of CD14 + CD16 + and CD14 + CD32 + monocytes in peripheral blood were not changed , while CD14 +CD64 +monocytes increased obviously .The secretion of TNF-αand IL-6 by monocytes were signifi-cantly enhanced after stimulated with immunocomplex , while the protein expression of AT-Ⅲ in the human brain vascular endothelial cells was down-regulated after co-incubated with TNF-αor IL-6.CONCLUSION:Decreased AT-Ⅲactivity in the patients with atherosclerotic cerebral infarction is one of the risk factors of cerebral infarction , and related with the dis-ease severity .The production of pro-inflammatory cytokines through immunocomplex from CD 14 +CD64 +monocytes may be involved in the mechanism .Improvement of AT-Ⅲactivity may protect against cerebral ischemia .
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Although we have understood only limited knowledge about the pathophysiological mechanisms of acute pancreatitis (AP),it has at least been proven that the activation of pancreatic zymogens inside the pancreatic acinar cells,as well as the inflammatory reaction resulting from the inflammatory mediators,including the cytokines and oxygen free radicals,constitute the main reason for the early pathological processes of AP. The inflammatory mediators also facilitate the complications such as lung injury and multiple organ dysfunctions. The bacterial translocation,which aggravates the pathological changes and increases the mortality in AP,causes the pathophysiological vicious circle in the later period of the disease. There is no doubt that the levels of the clinical prevention,diagnosis and treatment for AP will be greatly improved along with the elucidation of its pathogenesis.