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Objective To investigate the effects of homocysteine(Hcy) on myocardial injury and its possible mechanisms.Methods The selected H9C2 cardiomyocytes were intervened with various concentrations of Hcy and 4-phenyl butyric acid(4-PBA).The H9C2 cells were divided into the control group,H400 group and H400P2 group.The control group used the common medium,the H400 group was added with 400 μmol/L Hcy,the H400P2 group was added with 2 mmol/L 4-PBBA on the basis of H400 group.The cell livability was detected by using cell counting kit-8 (CCK-8).Apoptosis was evaluated by using the terminal deoxynucleotidyl transferase mediated nick-end labelling(TUNEL) staining.The ERO1α expression was determined by using immunocytochemistry,and the protein expression difference was determined by using Western blot.Results The injury of Hey on H9C2 cardiomyocytes showed a concentration-dependent manner(F=2 039.958,P＜0.01).Compared with the control group,the apoptosis percentages and expression levels of PERK,p-PERK,CHOP and ERO1α in the H400 group were increased(P＜0.01);while which in the H400P2 group were decreased,the difference was statistically significant(P＜0.05).Conclusion Hcy mediates myocardial apoptosis through endoplasmic reticulum stress mechanism.
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Objective To investigate the relationship between plasma homocysteine (Hcy), Kv1.3 channel and cardiac troponinI (cTnI) in patients with acute ST-segment elevation myocardial infarction (STEMI). Methods According to the level of Hcy, 80 STEMI patients were divided into STEMI with Hhcy group (Hcy > 15 μmol/L, n=41) and control group (STEMI group, Hcy≤15μmol/L, n=39). The Hcy, blood lipid and cTnI were detected with automatic biochemistry analyzer, respectively. Peripheral lymphocytes were isolated by ficoll density gradient centrifugation. Real-time PCR was used to detect mRNA expression of Kv1.3, and Western blot assay was used to detect protein expression of Kv1.3. Results cTnI concentrations were obviously higher in STEMI with Hhcy group than those in STEMI group (μg/L:22.997 ± 5.880 vs. 12.881 ± 6.343;P0.05). The relative expression levels of Kv1.3 mRNA and protein were significantly higher in STEMI with Hhcy group (1.35±0.14, 0.85±0.12) than those in STEMI group (1.00 ± 0.07, 0.64 ± 0.05, P<0.05). Moreover, there was a positive relation between Hcy level and the mRNA and proteinexpression of Kv1.3 channel (r=0.299, r=0.542, P<0.05). There was a positive relation between protein expression levels of Kv1.3 channel and cTnI (r=0.644, P<0.05). Conclusion Our results support that Hcy could exacerbate the concentration of cTnI through playing an important role in the Kv1.3 mRNA and protein expression in lymphocytes.
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Objective To observe the influence of different level of hyperhomocysteinemia on mRNA and protein expressions of KV1 .3 ,CaN,NFAT,IL-6 and TNF-αin lymphocytes of patients with acute ST-segment elevation myocardial infarction (STEMI).Methods We selected 90 STEMI patients and divided them into three groups according to the level of plasma homocysteine:the first experimental group (STEMI group,Hcy30 μmol/L,n=30 ).Another 30 healthy examined people were selected as control group (n=3 0 ).Peripheral lymphocytes were isolated by Ficoll density gradient centrifugation.The Hcy in the plasma was measured with the IMX assays.Real-time quantitative PCR (RT-PCR)was used to detect mRNA expressions of KV1.3,CnAα,NFAT1,IL-6 and TNF-αand Western blot technique was used to detect the expressions of KV1.3,CnAαand NFAT1.Results The mRNA and protein expression levels of KV1.3,CnAαand NFAT1 in each experimental group were significantly higher than those in control group (P<0 .0 5 or P<0 .0 1 ).Multiple comparison in each experimental group showed that compared with that in the first experimental group,the expression level of the second experimental group increased (P<0.05 or P<0.01)and compared with first and second experimental groups,the expression level of the third experimental group increased (P<0.05 or P<0.01).The mRNA expression levels of IL-6 and TNF-αin each experimental group were significantly higher than those in control group (P<0.05 or P<0.01 ).Multiple comparison in each experimental group showed that compared with that in the first experimental group,the expression level of the second experimental group increased (P<0 .0 5 or P<0 .0 1 )and compared with first and second experimental groups,the expression level of the third experimental group increased (P<0.01).Plasma total Hcy levels were positively correlated with mRNA and protein expressions of KV1.3 in all observed groups (r=0.503 P=0.000,r=0.726 P=0.000).Conclusion The higher level of Hcy in plasma,the higher mRNA and protein expression levels of KV1.3,CnAα,NFAT1 and the higher mRNA expression levels of IL-6,TNF-αin the lymphocyte of STEMI patients,which may be one mechanism for Hcy exacerbating the inflammatory reaction of STEMI.
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Objective To investigate analgesic effects of the selective blocking of descending facilitation targeting μ opioid receptor positive neurons in the rostral ventromedial medulla ( RVM) in a rat model of bone cancer pain. Methods Forty-eight adult female Wistar rats weighing 180-200 g were randomly divided into 6 groups: group Ⅰ control ( n = 3) ;group Ⅱ bone cancer pain induced by intra-tibia inoculation of Walker 256 mammary gland carcinoma cells ( n = 9) ;group Ⅲ-Ⅵ received a single intra-RVM micro-injection of PBS (group Ⅲ), dermorphin (group Ⅳ) , saporin (group Ⅴ) and dermorphin-saporin ( group Ⅵ) respectively at 28 days before intra-tibia inoculation ( n = 9 each) . Starting from 3 to 20 days after intra-tibia inoculation, mechanical allodynia was assessed and recorded. The animals were sacrificed on 7, 14 and 20 days after intra-tibia inoculation, after repetitive non-noxious tactile stimulation of the hindpaw. The total number of Fos-positive neurons in the spinal dorsal horn was measured as a marker indicative of central sensitization. Results The animals developed nociceptive hypersensitivity after intra-tibia cancer cell inoculation in group Ⅱ -Ⅵ . Nociceptive hypersensitivity was significantly decreased during 4-7 days after the onset of nociception in group Ⅵ (dermorphin-saporin). The number of Fos positive neurons in bilateral spinal dorsal horn was significantly increased by intra-tibia inoculation of cancer cells in group Ⅱ-Ⅵ as compared with control group and was significantly lower at day 14 and 20 after inoculation in group Ⅵ (dermorphin-saporin) than in group Ⅱ - Ⅴ.Conclusion Selective blocking of descending facilitation targeting μ opioid receptor positive neurons in RVM can effectively reduce nociceptive hypersensitivity induced by intra-tibia inoculation of Walker56 mammary gland carcinoma cells.