The Role of Mitochondria-Linked Fatty-Acid Uptake-Driven Adipogenesis in Graves Orbitopathy.

CONTEXT: Depot-specific expansion of orbital adipose tissue (OAT) in Graves orbitopathy (GO; an autoimmune condition producing proptosis, visual impairment and reduced quality of life) is associated with fatty acid (FA)-uptake-driven adipogenesis in preadipocytes/fibroblasts (PFs). OBJECTIVE: This work sought a role for mitochondria in OAT adipogenesis in GO. METHODS: Confluent PFs from healthy OAT (OAT-H), OAT from GO (OAT-GO) and white adipose tissue in culture medium compared with culture medium containing a mixed hormonal cocktail as adipogenic medium (ADM), or culture-medium containing FA-supplementation, oleate:palmitate:linoleate (45:30:25%) with/without different concentration of mitochondrial biosubstrate adenosine 5'-diphosphate/guanosine 5'-diphosphate (ADP/GDP), AICAR (adenosine analogue), or inhibitor oligomycin-A for 17 days. Main outcome measures included oil-red-O staining and foci count of differentiated adipocytes for in vitro adipogenesis, flow cytometry, relative quantitative polymerase chain reaction, MTS-assay/106 cells, total cellular-ATP detection kit, and Seahorse-XFe96-Analyzer for mitochondria and oxidative-phosphorylation (OXPHOS)/glycolysis-ATP production analysis. RESULTS: During early adipogenesis before adipocyte formation (days 0, 4, and7), we observed OAT-specific cellular ATP production via mitochondrial OXPHOS in PFs both from OAT-H and OAT-GO, and substantially disrupted OXPHOS-ATP/glycolysis-ATP production in PFs from OAT-GO, for example, a 40% reduction in OXPHOS-ATP and trend-increased glycolysis-ATP production on days 4 and 7 compared with day 0, which contrasted with the stable levels in OAT-H. FA supplementation in culture-medium triggered adipogenesis in PFs both from OAT-H and OAT-GO, which was substantially enhanced by 1-mM GDP reaching 7% to 18% of ADM adipogenesis. The FA-uptake-driven adipogenesis was diminished by oligomycin-A but unaffected by treatment with ADP or AICAR. Furthermore, we observed a significant positive correlation between FA-uptake-driven adipogenesis by GDP and the ratios of OXPHOS-ATP/glycolysis-ATP through adipogenesis of PFs from OAT-GO. CONCLUSION: Our study confirmed that FA uptake can drive OAT adipogenesis and revealed a fundamental role for mitochondria-OXPHOS in GO development, which provides potential for therapeutic interventions.

Vibration-assisted anesthesia in eyelid surgery.

PURPOSE: To investigate whether a vibrating device applied in a circular motion to the forehead reduces the pain of local anesthetic injection in upper eyelid surgery. DESIGN: Prospective, interventional, cross-over, randomized, controlled clinical trial. PARTICIPANTS: Eighty patients undergoing bilateral upper eyelid surgery under local anesthesia. INTERVENTION: A vibrating device was applied in a circular motion to participants' foreheads while local anesthetic was injected into 1 eyelid. During injection of anesthetic on the contralateral lid, the device was applied to the forehead in static fashion with the vibration switched off (placebo). The order of intervention was randomized. MAIN OUTCOME MEASURES: After both injections had been given, participants were asked to specify their pain ratings for each injection on a scale of 0 to 10, with 0 representing no pain and 10 indicating the worst pain imaginable. Participants were also asked to qualitatively compare the 2 sides. RESULTS: The mean pain scores were 3.3 for the vibration-assisted side and 4.5 for the placebo. This difference was statistically significant (P=0.0003); 73% of participants found the vibrated side to be better than the placebo, with 35% finding it a lot or quite a bit better. CONCLUSIONS: Vibration-assisted anesthesia during upper eyelid surgery has a beneficial effect that is highly statistically significant and is clinically significant in terms of patients' qualitative assessment of pain. Further research is needed to determine whether this constitutes a quantitatively clinically significant improvement in pain management. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.