RESUMO
Neurons rely heavily on high mitochondrial metabolism to provide sufficient energy for proper development. However, it remains unclear how neurons maintain high oxidative phosphorylation (OXPHOS) during development. Mitophagy plays a pivotal role in maintaining mitochondrial quality and quantity. We herein describe that G protein-coupled receptor 50 (GPR50) is a novel mitophagy receptor, which harbors the LC3-interacting region (LIR) and is required in mitophagy under stress conditions. Although it does not localize in mitochondria under normal culturing conditions, GPR50 is recruited to the depolarized mitochondrial membrane upon mitophagy stress, which marks the mitochondrial portion and recruits the assembling autophagosomes, eventually facilitating the mitochondrial fragments to be engulfed by the autophagosomes. Mutations Δ502-505 and T532A attenuate GPR50-mediated mitophagy by disrupting the binding of GPR50 to LC3 and the mitochondrial recruitment of GPR50. Deficiency of GPR50 causes the accumulation of damaged mitochondria and disrupts OXPHOS, resulting in insufficient ATP production and excessive ROS generation, eventually impairing neuronal development. GPR50-deficient mice exhibit impaired social recognition, which is rescued by prenatal treatment with mitoQ, a mitochondrially antioxidant. The present study identifies GPR50 as a novel mitophagy receptor that is required to maintain mitochondrial OXPHOS in developing neurons.
Assuntos
Mitocôndrias , Mitofagia , Neurônios , Receptores Acoplados a Proteínas G , Animais , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Neurônios/metabolismo , Mitocôndrias/metabolismo , Camundongos , Humanos , Fosforilação Oxidativa , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Espécies Reativas de Oxigênio/metabolismo , Camundongos Knockout , NeurogêneseRESUMO
Objective: To investigate the safety and feasibility of caudal-medial approach combined with "page-turning" middle lymphadenectomy in the laparoscopic right hemicolectomy. Methods: A descriptive cohort study was conducted. Clinical data of 35 patients who underwent laparoscopic radical right hemicolectomy using caudal-medial approach combined with "page-turning" middle lymphadenectomy at Department of Gastrointestinal Surgery, Guangdong Hospital of Chinese Medicine from April 2018 to May 2020 were retrospectively analyzed. All operations were performed consecutively by the same surgeon. The caudal-medial approach was used to dissect the right Toldt's fascia and the anterior pancreaticoduodenal space in a caudal-to-cranial and medial-to-lateral manner guided by the duodenum. The "page-turning" middle lymphadenectomy was used to dissect the mesocolon along the superior mesenteric vein with ileocolic vein, Henle's trunk and pancreas exposed preferentially. Results: All the 35 patients completed the operation successfully, and there was no damage and bleeding of superior mesenteric vessels and their branches. The operative time was (186.9±46.2) minutes, and the blood loss was 50 (10-200) ml. The first time to flatus was (2.1±0.6) days, and the time to fluid intake was (2.5±0.8) days. The postoperative hospital stay was 6 (3-18) d. The overall morbidity of postoperative complication was 8.6% (3/35), including grade II in 1 cases (2.8%) and grade IIIa in 2 case (5.7%) according to the Clavien-Dindo grading standard. The total number of lymph node dissected was 30.2±5.6, and the positive lymph node was 0 (0-7). Tumor staging revealed 5 cases of stage I, 18 cases of stage II, 11 cases of stage III, and 1 case of stage IVA. In this study, the median follow-up time was 15 (4-29) months. One patient died due to cerebrovascular accident 12 months after surgery, and no tumor recurrence or metastasis was observed in all other patients. Conclusions: Laparoscopic radical right hemicolectomy using caudal-medial approach combined with "page-turning" middle lymphadenectomy is safe and feasible. The anterior pancreaticoduodenal space is preferentially mobilized, which reduces the difficulty of central vascular dissection.