Omega-3 fatty acid modulation of serum and osteocyte tumor necrosis factor-α in adult mice exposed to ionizing radiation.

Journal Article (Journal Article)

Chronic inflammation leads to bone loss and fragility. Proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) consistently promote bone resorption. Dietary modulation of proinflammatory cytokines is an accepted therapeutic approach to treat chronic inflammation, including that induced by space-relevant radiation exposure. As such, these studies were designed to determine whether an anti-inflammatory diet, high in omega-3 fatty acids, could reduce radiation-mediated bone damage via reductions in the levels of inflammatory cytokines in osteocytes and serum. Lgr5-EGFP C57BL/6 mice were randomized to receive diets containing fish oil and pectin (FOP; high in omega-3 fatty acids) or corn oil and cellulose (COC; high in omega-6 fatty acids) and then acutely exposed to 0.5-Gy 56 Fe or 2.0-Gy gamma-radiation. Mice fed the FOP diet exhibited consistent reductions in serum TNF-α in the 56 Fe experiment but not the gamma-experiment. The percentage osteocytes (%Ot) positive for TNF-α increased in gamma-exposed COC, but not FOP, mice. Minimal changes in %Ot positive for sclerostin were observed. FOP mice exhibited modest improvements in several measures of cancellous microarchitecture and volumetric bone mineral density (BMD) postexposure to 56 Fe and gamma-radiation. Reduced serum TNF-α in FOP mice exposed to 56 Fe was associated with either neutral or modestly positive changes in bone structural integrity. Collectively, these data are generally consistent with previous findings that dietary intake of omega-3 fatty acids may effectively mitigate systemic inflammation after acute radiation exposure and facilitate maintenance of BMD during spaceflight in humans.NEW & NOTEWORTHY This is the first investigation, to our knowledge, to test the impact of a diet high in omega-3 fatty acids on multiple bone structural and biological outcomes following space-relevant radiation exposure. Novel in biological outcomes is the assessment of osteocyte responses to this stressor. These data also add to the growing evidence that low-dose exposures to even high-energy ion species like 56 Fe may have neutral or even small positive impacts on bone.

Full Text

Duke Authors

Cited Authors

  • Little-Letsinger, SE; Turner, ND; Ford, JR; Suva, LJ; Bloomfield, SA

Published Date

  • March 2021

Published In

Volume / Issue

  • 130 / 3

Start / End Page

  • 627 - 639

PubMed ID

  • 33411639

Pubmed Central ID

  • PMC7988793

Electronic International Standard Serial Number (EISSN)

  • 1522-1601

International Standard Serial Number (ISSN)

  • 8750-7587

Digital Object Identifier (DOI)

  • 10.1152/japplphysiol.00848.2020


  • eng