Neuroglobin Facilitates Neuronal Oxygenation through Tropic Migration under Hypoxia or Anemia in Rat: How Does the Brain Breathe? / 神经科学通报·英文版

The discovery of neuroglobin (Ngb), a brain- or neuron-specific member of the hemoglobin family, has revolutionized our understanding of brain oxygen metabolism. Currently, how Ngb plays such a role remains far from clear. Here, we report a novel mechanism by which Ngb might facilitate neuronal oxygenation upon hypoxia or anemia. We found that Ngb was present in, co-localized to, and co-migrated with mitochondria in the cell body and neurites of neurons. Hypoxia induced a sudden and prominent migration of Ngb towards the cytoplasmic membrane (CM) or cell surface in living neurons, and this was accompanied by the mitochondria. In vivo, hypotonic and anemic hypoxia induced a reversible Ngb migration toward the CM in cerebral cortical neurons in rat brains but did not alter the expression level of Ngb or its cytoplasm/mitochondria ratio. Knock-down of Ngb by RNA interference significantly diminished respiratory succinate dehydrogenase (SDH) and ATPase activity in neuronal N2a cells. Over-expression of Ngb enhanced SDH activity in N2a cells upon hypoxia. Mutation of Ngb at its oxygen-binding site (His64) significantly increased SDH activity and reduced ATPase activity in N2a cells. Taken together, Ngb was physically and functionally linked to mitochondria. In response to an insufficient oxygen supply, Ngb migrated towards the source of oxygen to facilitate neuronal oxygenation. This novel mechanism of neuronal respiration provides new insights into the understanding and treatment of neurological diseases such as stroke and Alzheimer's disease and diseases that cause hypoxia in the brain such as anemia.

Clinical study of curative effects of partial sigmoidectomy and pelvic floor repair for treatment of pelvic floor dysfunction with dolichasigmoid / 中国实用妇科与产科杂志

OBJECTIVE: To explore the curative effects of the combined therapy of laparoscopic partial sigmoidectomy and anterior and posterior vaginal wall repair for the treatment of severe pelvic floor dysfunction(PFD).METHODS: The clinical data of 14 severe PDF patients(uterine prolapse in stage Ⅲ-Ⅳ）with dolichasigmoid were studied retrospectively from May 2017 to August 2018 in Shanghai Traditional Chinese Medical University. The surgical way was laparoscopic partial sigmoidectomy and anterior and posterior vaginal wall repair. The objective effects were assessed by comparing the position of each indication points of the preoperative and postoperative pelvic organs' prolapse(in POP-Q scale).Subjective effects were also assessed by comparing Clevel score of constipation,pelvic floor distress inventory-short form 20(PFDI-20),pelvic floor impact questionnaire short form(PFIQ-7)between preoperation and 6 months and 1 year after operation.RESULTS: All 14 patients were successfully operated on without any intra-operative and post-operative complications. The comparion of positions of the POP-Q indication points(AA,Ba,C,D,AP,BP)between preoperation and 1 year after operation showed the difference was statistically significant(P<0.01). PFDI-20,PFIQ-7 and Clevel constipation scores were also significantly different respectively(P<0.01).CONCLUSION: Laparoscopic partial sigmoidectomy combined with pelvic floor repair is an optional method in the treatment for pelvic floor dysfunction, which could effectively improve the constipation caused by dolichasigmoid and pelvic floor defect. It is also with low postoperative morbidity.