Stem cell mobilization by hyperbaric oxygen.
Level 3 - non-randomized controlled study
Controlled clinical trial paired with animal mechanistic experiments; human randomization details are not specified in the abstract.
PubMed 16299259 · doi:10.1152/ajpheart.00888.2005
What was done
Investigators evaluated whether hyperbaric oxygen (HBO2; 2.0 atmospheres absolute for 2 hours) mobilizes bone marrow stem/progenitor cells via a nitric oxide (*NO)-dependent mechanism. Human peripheral blood was analyzed for circulating CD34(+) cells, total white cell count, and colony-forming cells (CFCs) after a single exposure and across 20 treatments. Parallel mechanistic studies in wild-type mice, endothelial *NO synthase (eNOS) knockout mice, and mice given a *NO synthase inhibitor assessed stem cell factor, bone marrow *NO concentrations, and Sca-1(+)/CD34(+) cell mobilization.
What was found
In humans, a single HBO2 session doubled circulating CD34(+) cells, and 20 treatments increased them 8-fold without significantly altering total white cell counts. Colony-forming cells rose from 16 +/- 2 to 26 +/- 3 CFCs/100,000 monocytes plated, with growth enhancement restricted to immediate posttreatment samples. In mice, HBO2 increased circulating stem cell factor by 50%, circulating Sca-1(+)/CD34(+) cells 3.4-fold, CFCs 2-fold, and bone marrow *NO by 1,008 +/- 255 nM. Mobilization was absent in eNOS knockout mice and prevented by *NO synthase inhibition in wild-type mice.
Why it matters
This study demonstrates that hyperbaric oxygen can stimulate hematopoietic stem and progenitor cell mobilization from bone marrow into the bloodstream and identifies an endothelial nitric oxide synthase pathway as the underlying mechanism.
Limits
The abstract reports no participant or animal sample sizes, demographic characteristics, or human control group details. Clinical durability, homing efficiency, and therapeutic tissue repair capacity in humans were not evaluated.
Cited by
- supports Hyperbaric oxygen therapy activates stem cells, increases stem cell production, clears senescent cells, and increases telomere length.