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AIM:To investigate the effect of circular RNA MYO9A-006(circMYO9A_006)on hypertrophic phenotype of cardiomyocytes and the underlying mechanism.METHODS:The effect of adenovirus-mediated overexpres-sion of circMYO9A_006 on the expression of hypertrophy-related proteins,including β-myosin heavy chain(β-MHC),skeletal muscle actin alpha 1(ACTA1)and atrial natriuretic peptide(ANP),was evaluated in neonatal mouse ventricular cardiomyocytes(NMVCs).Moreover,a neonatal rat ventricular cardiomyocyte(NRVC)model of phenylephrine(PE)-in-duced hypertrophy was established.The effect of circMYO9A_006 overexpression on NRVC size was ascertained using Phalloidin-iFluor 647 staining method.Dual-luciferase reporter assay was employed to measure the activity of potential in-ternal ribosome entry sites(IRES)in circMYO9A_006.The translation and intracellular location of the circMYO9A_006-translated protein,MYO9A-208aa,were verified using Western blot.To investigate the role of MYO9A-208aa in the ef-fect of circMYO9A_006 on the cardiomyocyte hypertrophic phenotype,we prepared and used the following adenoviruses:the recombinant circMYO9A_006-ORF adenovirus to express MYO9A-208aa,the recombinant circMYO9A_006-ATG-mut adenovirus that does not express MYO9A-208aa,the recombinant circMYO9A_006 adenovirus,and the adenovirus vector control.These were then employed to infect NRVCs.RESULTS:Successful adenovirus-mediated overexpression of circMYO9A_006 was observed in NMVCs.The increased expression of circMYO9A_006 notably reduced the expres-sion of hypertrophy-related proteins in NMVCs(P<0.01).Concurrently,overexpression of circMYO9A_006 substantially reduced the expression of hypertrophy-associated proteins and diminished the size of PE-induced NRVCs(P<0.05).Dual-luciferase reporter assay identified the activity of 2 IRES in circMYO9A_006.Western blot results indicated that circ-MYO9A_006 could produce the MYO9A-208aa protein with an anticipated molecular weight of 28 kD in NRVCs,primari-ly found in the cytoplasm.Elevated expression of both circMYO9A_006 and MYO9A-208aa consistently reduced the ex-pression of hypertrophy-associated proteins(P<0.01),and counteracted the enlarged size of PE-induced NRVCs(P<0.05).However,increased expression of circMYO9A_006-ATG-mut did not counteract the PE-induced hypertrophic phe-notype of NRVCs.CONCLUSION:circMYO9A_006 attenuates the hypertrophic phenotype of cardiomyocytes by synthe-sizing the MYO9A-208aa protein.
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ObjectiveTo investigate the effect of circSLC8A1_005 on the fibrotic phenotype of cardiac fibroblasts and the potential mechanism involved. MethodsThe effect of adenovirus-mediated overexpression of circSLC8A1_005 on the expression of fibrosis-related genes, collagen type I alpha 1 chain (Col1a1), collagen type Ⅲ alpha 1 chain (Col3a1) and smooth muscle actin alpha 2 (Acta2), in mouse cardiac fibroblasts (mCFs) were detected. The proliferation and migration activities of mCFs were detected by EdU and wound-healing assay, respectively. Dual luciferase reporter gene assay was performed to detect the activity of potential internal ribozyme entry site (IRES) in circSLC8A1_005. CircSLC8A1_005-translated protein, SLC8A1-605aa, and its intracellular distribution was identified by Western blot assay. The effect of SLC8A1-605aa protein on transcription activity of Sod2 gene was detected by the dual luciferase reporter gene assay. RNA binding protein immunoprecipitation (RIP) was utilized to verify the interaction between SLC8A1-605aa and superoxide dismutase 2 (Sod2) mRNA. Actinomycin D treatment was used to detect the effect of SLC8A1-605aa on Sod2 mRNA stability in mCFs. ResultsAn efficient adenovirus-mediated overexpression of circSLC8A1_005 was achieved in mCFs. The enforced expression of circSLC8A1_005 suppressed proliferation and migration of mCFs, and inhibited the expression of fibrosis-related genes in mCFs. The dual luciferase reporter gene assay revealed the activities of 2 IRES in circSLC8A1_005. Results of Western blot assay showed that circSLC8A1_005 could translate protein SLC8A1-605aa with the prospected molecular weight of 70 ku, which is predominantly distributed in the nucleus. Overexpression of the circSLC8A1_005 and SLC8A1-605aa could consistently inhibit the fibrotic phenotype of mCFs. SLC8A1-605aa could up-regulate superoxide dismutase 2 (Sod2) expression, but not at the transcriptional level. RIP assay indicated that SLC8A1-605aa could specifically interact with Sod2 mRNA, and the results of actinomycin D assay showed that SLC8A1-605aa could enhance the stability of Sod2 mRNA in mCFs. ConclusionCircSLC8A1_005 inhibits the fibrotic phenotype of cardiac fibroblasts via translating SLC8A1-605aa protein, and SLC8A1-605aa may be a potential target for the treatment of myocardial fibrosis.
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Objective To evaluate the anesthetic effect of ultrasound guided thoracic paraverte-bral blockade combined with intravenous dexmedetomidine in thoracoscopic sympathectomy. Methods Eighty patients (38 male and 42 female ) undergoing selected thoracoscopic sympathectomy,aged from 16 to 28 years,in ASA physical status Ⅰ or Ⅱ,were equally divided into study group and control group,40 patients in each,according to random number table.Fifteen mi-nutes before paravertebral blockade,while study group received loading dose (0.5 μg/kg)of dexme-detomidine (4 μg/ml)intravenously within 10 min and received continuous intravenous pumping (0.3-0.5 μg·kg-1·h-1 )throughout the operation,control group received isovolumetric normal saline in the same pattern.Patients'heart rate (HR),respiratory rate (RR),mean arterial pressure (MAP),SpO 2 ,observer's assessment of alertness/sedation (OAA/S)scale and adverse reactions were recorded in several time points,namely timing of entrance (T0 ),timing of paravertebral block-ade (T1 ),timing of skin incision (T2 ),timing of sympathectomy (T3 )and the end (T4 ),respective-ly.Results Compared to the control group,while MAP and HR in the study group were obviously decreased through T1-T4 (P <0.05),RR was obvious increased in T2 and T3 (P <0.05)and OAA/S scale was obviously lowered in the study group (P <0.05 ).The study group and the control group had one case and two cases of adverse reaction,respectively,with no significant difference between the two groups.Conclusion The application of ultrasound guided thoracic paravertebral blockade combined with intravenous dexmedetomidine in thoracoscopic sympathectomy is safe and effective.
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Objective To investigate the safety and effectiveness of ultrasound-guided paravertebral anaes-thesia combined with propofol in the thoracoscopic sympathectomy. Methods Total 63 male and 59 female patients with hyperhidrosis were recruited. The patients were equally divided into two groups:group A and C. Patients in group A received ultrasound-guided paravertebral anaesthesia combined with propofol. Patients in group C received general intravenous anesthesia with endotracheal intubation. The heart rate (HR),mean arterial pres-sure(MAP)and the oxygen saturation(SpO2)at the time of entering the operating room(T0),completing anesthe-sia(T1),incising the skin(T2),cutting the T4 sympathetic trunk(T3),completing the operation were record-ed. The awake time after operation ,VAS score after operation and postoperative throat discomfort were also record-ed. Results The two groups successfully completed the surgery. There were no significant differences of the HR , MAP and SpO2 at T0-T4 between the two groups. There were significant differences of the awake time after opera-tion,postoperative feeding time and hospitalization expenses. The VAS score after operation of group A were better than group C(P<0.05)at T2 h,T4 h,T8 h,and T12 h. There was no significant difference of VAS score at T24 h between the two groups. Conclusion Ultrasound-guided paravertebral anaesthesia combined with propofol can pro-vide a safe and effective approach for patients receiving the thoracoscopic sympathectomy.
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Objective To evaluate the effect of the noxious stimulation factor on γ-aminobutyric acid (GABA) distribution in dog spinal cord during propofol anesthesia.Methods Sixteen healthy mongrel dogs of both sexes,aged 12-18 months,weighing 10-12 kg,were randomly divided into 2 groups (n =8 each):noxious stimulation group (S group) and control group (C group).Anesthesia was induced with propofol 7 mg/kg.The animals were mechanically ventilated after tracheal intubation.Right femoral artery was cannulated for mean arterial pressure (MAP) and pulse rate monitoring.Anesthesia was maintained with propofol infusion at a constant rate of 70 mg· kg-1 · h-1.5 % formalin 300 μl was subcutaneously injected into the central region of tails in group S,while the equal volume of normal saline was injected instead of formalin in group C.MAP and pulse rate were recorded before injection of formalin or normal saline (T1) and after injection of formalin or normal saline (T2).The dogs were scarified by decapitation at 50 min of continuous propofol infusion and cervical 2-3 segments of the spinal cord were removed for determination of GABA level in different regions of the spinal cord (frontal horn,posterior horn,intermediate zone,frontal funiculus,posterior funiculus and lateral funiculus) by HPLC.Results MAP and pulse rate were significantly higher at T2 than at T1 in S group (P < 0.05).There were no significant differences in GABA level among the different regions of the spinal cord in C group (P > 0.05).Compared with C group,GABA level in the frontal horn and posterior horn was significantly increased (P < 0.05),and no significant change was found in the other regions of the spinal cord in S group (P > 0.05).Conclusion The noxious stimulation factor can induce an increase in GABA level in the frontal horn and posterior horn of dog spinal cord during propofol anesthesia.
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Objective To evaluate the reliability of PainVision method for assessment of postoperative pain in patients undergoing gynaecological laparoscopy.Methods Twenty ASA physical status Ⅰ-Ⅱ patients,aged 30-45 yr,undergoing gynaecological laparoscopy under fentanyl-propofol-cisatracurium anesthesia,were studied.Pain intensity was simultaneously assessed using PainVision method and visual analog scale (VAS) at 12,24 and 48 h after surgery.PainVision was a new method for quantitative measurement of pain intensity using a painless electrical stimulation (PainVision PS-2100 device).Pain degree was calculated from two parameters,current perception threshold and pain compatible electrical current by using PainVision.The former parameter was defined by the lowest electrical current detected ; the latter parameter defined by the electrical current judged as being compatible with the intensity of ongoing pain.Results There was a significant positive correlation between pain degree calculated by PainVision method and VAS scores,and the correlation coefficient was 0.902 (P < 0.01).Conclusion PainVision method can be applied for assessment of postoperative pain in patients undergoing gynaecological laparoscopy.