Prevailing vitamin D status influences mitochondrial and glycolytic bioenergetics in peripheral blood mononuclear cells obtained from adults.
Circulating peripheral blood mononuclear cells (PBMCs) are exposed to metabolic and immunological stimuli that influence their functionality. We hypothesized that prevailing vitamin D status [25(OH)D] would modulate the bioenergetic profile of PBMCs derived from humans.



38 participants (16 males, 22 females) ranging in body fat from 14-51% were studied. PBMCs were isolated from whole blood, counted and freshly seeded for bioenergetic analysis using the Seahorse XFe96 flux analyser. Whole body energy metabolism via indirect calorimetry, body composition by dual-energy X-ray absorptiometry, and relevant clinical biochemistry were measured. Data was analysed based on 25(OH)D cut-offs of <50nmol/L (Group 1, n=12), 50-75nmol/L (Group 2, n=15) and ≥75nmol/L (Group 3, n=11). A multivariate general linear model adjusting for age, fat mass, fat-free mass, parathyroid hormone and insulin sensitivity was used.



There were significant differences in cellular mitochondrial function between groups. Group 1 had significantly higher basal respiration (p=0.001), non-mitochondrial respiration (p=0.009), ATP production (p=0.001), proton leak (p=0.018), background glycolysis (p=0.023) and glycolytic reserve (p=0.039) relative to either Group 2 or Group 3; the latter two did not differ on any measures. There were no differences in bioenergetic health index (BHI), resting metabolic rates and systemic inflammatory markers between groups.



Inadequate vitamin D status adversely influenced bioenergetic parameters of PBMCs obtained from adults, in a pattern consistent with increased oxidative metabolism and activation of these cells.
School of Public Health, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia 6845, Australia.
Emily K
EK
Calton
School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia 6845, Australia.
Kevin N
KN
Keane
School of Public Health, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia 6845, Australia. Electronic address: m.soares@curtin.edu.au.
Mario J
MJ
Soares
School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia 6845, Australia.
Jordan
J
Rowlands
School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia 6845, Australia. Electronic address: philip.newsholme@curtin.edu.au.
Philip
P
Newsholme
D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D001823:Body Composition; D002151:Calorimetry; D019069:Cell Respiration; D004734:Energy Metabolism; D005260:Female; D006019:Glycolysis; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000378:metabolism; D014807:Vitamin D / Q000097:blood*; D055815:Young Adult
D010281:Parathyroid Hormone; D014807:Vitamin D
25(OH)D; Bioenergetics; Inflammation; Leukocytes; Peripheral Blood Mononuclear Cells; Proton leak; Vitamin D