Mitochondrial dysfunction in GnRH neurons impaired GnRH production.

The onset establishment and maintenance of gonadotropin-releasing hormone (GnRH) secretion is an important phenomenon regulating pubertal development and reproduction. GnRH neurons as well as other neurons in the hypothalamus have high-energy demands and require a constant energy supply from their mitochondria machinery to maintain active functioning. However, the involvement of mitochondrial function in GnRH neurons is still unclear. In this study, we examined the role of NADH Dehydrogenase (Ubiquinone) Fe-S protein 4 (Ndufs4), a member of the mitochondrial complex 1, on GnRH neurons using Ndufs4-KO mice and Ndufs4-KO GT1-7 cells. Ndufs4 was highly expressed in GnRH neurons in the medial preoptic area (MPOA) and NPY/AgRP and POMC neurons in the arcuate (ARC) nucleus in WT mice. Conversely, there was a significant decrease in GnRH expression in MPOA and median eminence of Ndufs4-KO mice, followed by impaired peripheral endocrine system. In Ndufs4-KO GT1-7 cells, Gnrh1 expression was significantly decreased with or without stimulation with either kisspeptin or NGF, whereas, stimulation significantly increased Gnrh1 expression in control cells. In contrast, there was no difference in cell signaling activity including ERK and CREB as well as the expression of GPR54, TrkA and p75NTR, suggesting that Ndufs4 is involved in the transcriptional regulation system for GnRH production. These findings may be useful in understanding the mitochondrial function in GnRH neuron.

Spatial relationships of the bronchial arteries to the left recurrent laryngeal nerve in the sub-aortic arch area.

PURPOSE: To safely perform lymphadenectomy in the sub-aortic arch area during esophagectomy for esophageal cancer, we investigated the spatial relationships between the bronchial arteries (BAs) and the left recurrent laryngeal nerve (LRLN). METHODS: For this macro-anatomical study, 72 cadavers were used. RESULTS: Of the 195 dissected BAs, 15 (7.7%) arteries ran dorsally across the LRLN. Such a running pattern of the BA was found in 15 (20.8%) of the 72 cadavers. Fourteen (93.3%) of the 15 arteries ran anteriorly along the left side of the esophagus, and 13 (86.7%) passed further to the lateral side of the left main bronchus to reach the ventral surface of the tracheobronchus; we named this running pattern "Type III". Of the 51 arteries with the Type III pattern, 25.5% ran across the dorsal side of the LRLN. CONCLUSION: Approximately 20% of the cadavers had BAs running dorsally to the LRLN in the sub-aortic arch area. Most of these arteries had the Type III pattern. One-quarter of the BAs with the Type III pattern showed this running pattern. Care must be practiced to safely perform lymphadenectomy for esophageal cancer in patients with Type III BAs.

A new anatomical classification of the bronchial arteries based on the spatial relationships to the esophagus and the tracheobronchus.

PURPOSE: To reveal the patterns of the mediastinal course of the bronchial arteries (BAs). METHODS: The BAs were dissected to determine the positional relationships of their mediastinal courses with the tracheobronchus and the esophagus in 72 adult cadavers. RESULTS: The mediastinal courses of the 227 BAs found in this study were classified into 4 types. There were 61 and 163 BAs passing the right side (Type I) and the left side (Type II reaching dorsal surface (n = 98), or Type III reaching ventral surface (n = 65) of the tracheobronchus) of the esophagus, respectively. Three BAs originated from the subclavian artery (Type IV). All Type I BAs were right BAs, whereas 91.8% of the Type II BAs were left BAs. However, 43.1 and 56.9% of the Type III BAs were the right and left BAs, respectively. CONCLUSION: The classification of the mediastinal course of the BAs determined by the spatial relationships to the tracheobronchus and the esophagus may be clinically useful, because each category of this classification can be determined during esophagectomy and indicates whether the BA is a right or left BA.