RESUMO
Brain-derived neurotrophic factor (BDNF)/tropomyosin-related kinase B (TrkB) pathway is associated with ischemic heart diseases (IHD). 7,8-dihydroxyflavone (7,8-DHF), BDNF mimetic, is a potent agonist of TrkB. We aimed to investigate the effects and the underlying mechanisms of 7,8-DHF on cardiac ischemia. Myocardial ischemic mouse model was induced by ligation of left anterior descending coronary artery. 7,8-DHF (5â¯mg/kg) was administered intraperitoneally two days after ischemia for four weeks. Echocardiography, HE staining and transmission electron microscope were used to examine the function, histology and ultrastructure of the heart. H9c2 cells were treated with hydrogen peroxide (H2O2), 7,8-DHF or TrkB inhibitor ANA-12. The effects of 7,8-DHF on cell viability, mitochondrial membrane potential (MMP) and mitochondrial superoxide generation were examined. Furthermore, mitochondrial fission and protein expression of mitochondrial dynamics (Mfn2 [mitofusin 2], OPA1 [optic atrophy 1], Drp1 [dynamin-related protein 1] and Fis-1 [fission 1]) was detected by mitotracker green staining and western blot, respectively. 7,8-DHF attenuated cardiac dysfunction and cardiomyocyte abnormality of myocardial ischemic mice. Moreover, 7,8-DHF increased cell viability and reduced cell death accompanied by improving MMP, inhibiting mitochondrial superoxide and preventing excessive mitochondrial fission of H2O2-treated H9c2 cells. The cytoprotective effects of 7,8-DHF were antagonized by ANA-12. Mechanistically, 7,8-DHF repressed OMA1-dependent conversion of L-OPA1 into S-OPA1, which was abolished by Akt inhibitor. In conclusion, 7,8-DHF protects against cardiac ischemic injury by inhibiting the proteolytic cleavage of OPA1. These findings provide a novel pharmacological effect of 7,8-DHF on mitochondrial dynamics and a new potential target for IHD.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/farmacologia , GTP Fosfo-Hidrolases/genética , Glicoproteínas de Membrana/genética , Isquemia Miocárdica/tratamento farmacológico , Atrofia Óptica Autossômica Dominante/tratamento farmacológico , Proteínas Tirosina Quinases/genética , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Flavonas/farmacologia , GTP Fosfo-Hidrolases/química , Coração/efeitos dos fármacos , Coração/fisiopatologia , Humanos , Peróxido de Hidrogênio/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Dinâmica Mitocondrial , Isquemia Miocárdica/genética , Isquemia Miocárdica/patologia , Fármacos Neuroprotetores/farmacologia , Atrofia Óptica Autossômica Dominante/genética , Atrofia Óptica Autossômica Dominante/patologiaRESUMO
BACKGROUND: A large proportion of the patients with papillary thyroid microcarcinoma are young women. Therefore, minimally invasive endoscopic thyroidectomy with central neck dissection (CND) emerged and showed well-accepted results with improved cosmetic outcome, accelerated healing, and comforting the patients. This study aimed to evaluate the safety and effectiveness of robotic total thyroidectomy with CND via bilateral axillo-breast approach (BABA), compared with conventional open procedure in papillary thyroid microcarcinoma. METHODS: One-hundred patients with papillary thyroid microcarcinoma from March 2014 to January 2015 in Jinan Military General Hospital of People's Liberation Army (PLA) were randomly assigned to robotic group or conventional open approach group (n = 50 in each group). The total operative time, estimated intraoperative blood loss, numbers of lymph node removed, visual analog scale (VAS), postoperative hospital stay time, complications, and numerical scoring system (NSS, used to assess cosmetic effect) were analyzed. RESULTS: The robotic total thyroidectomy with CND via BABA was successfully performed in robotic group. There were no conversion from the robotic surgeries to open or endoscopic surgery. The subclinical central lymph node metastasis rate was 35%. The mean operative time of the robotic group was longer than that of the conventional open approach group (118.8 ± 16.5 min vs. 90.7 ± 10.3 min, P < 0.05). The study showed significant differences between the two groups in terms of the VASs (2.1 ± 1.0 vs. 3.8 ± 1.2, P < 0.05) and NSS (8.9 ± 0.8 vs. 4.8 ± 1.7, P < 0.05). The differences between the two groups in the estimated intraoperative blood loss, postoperative hospital stay time, numbers of lymph node removed, postoperative thyroglobulin levels, and complications were not statistically significant (all P > 0.05). Neither iatrogenic implantation nor metastasis occurred in punctured porous channel or chest wall in both groups. Postoperative cosmetic results were very satisfactory in the robotic group. CONCLUSIONS: Robotic total thyroidectomy with CND via BABA is safe and effective for Chinese patients with papillary thyroid microcarcinoma who worry about the neck scars.
