CD34+/CD45-dim stem cell mobilization by hyperbaric oxygen — Changes with oxygen dosage

Abstract

Because hyperbaric oxygen treatment mobilizes bone marrow derived-stem/progenitor cells by a free radical mediated mechanism, we hypothesized that there may be differences in mobilization efficiency based on exposure to different oxygen partial pressures. Blood from twenty consecutive patients was obtained before and after the 1st, 10th and 20th treatment at two clinical centers using protocols involving exposures to oxygen at either 2.0 or 2.5 atmospheres absolute (ATA). Post-treatment values of CD34+, CD45-dim leukocytes were always 2-fold greater than the pre-treatment values for both protocols. Values for those treated at 2.5 ATA were significantly greater than the 2.0 ATA treatment group by factors of 1.9 to 3-fold after the 10th and before and after the 20th treatments. Intracellular content of hypoxia inducible factors -1,-2, and -3, thioredoxin-1 and poly-ADP-ribose polymerase assessed in permeabilized CD34+ cells with fluorophore-conjugated antibodies were twice as high in all post- versus pre-treatment samples with no significant differences between 2.0 and 2.5 ATA protocols. We conclude that putative progenitor cell mobilization is higher with 2.5 versus 2.0 ATA treatments, and all newly mobilized cells exhibit higher concentrations of an array of regulatory proteins.

Measurements of CD34+/CD45-dim Stem Cells Predict Healing of Diabetic Neuropathic Wounds

“…Ratios appear to have value for predicting healing within 16 weeks, but the functional relevance of the HIF ratio is unknown. Prior work has suggested that SPCs with higher content of HIF-1 and -2 are those primed for prompt mobilization from the bone marrow; these cells may be preferentially sequestered in the peripheral vasculature; and lower HIF levels in circulating SPCs might occur due to protein degradation (15,19,34). The similarities in HIF ratios across 8 weeks (Supplementary Table 3) suggest that chronological age since mobilization and perhaps stresses sustained by the cells were similar.…”

“…A number of studies have demonstrated that wound healing can be improved by increasing the number of circulating SPCs and/or enhancing wound site recruitment (2,7,16,17). There also is evidence that some adjuncts to standard treatment such as negative pressure dressings and hyperbaric oxygen will mobilize SPCs to blood and may also modify regulatory protein content that improves vasculogenic function (11,15,18,19). Pharmacological agents that might be used incidental to DFU treatment or as an adjunct may also influence SPCs (20–32).…”

Effective Stepwise Anti-inflammatory Treatment for Markedly Disabling Neuropsychiatric Comorbidities: A Case Report

“…Recent publications have reported variable outcomes in great part because of using protocols that differ significantly in depth, duration, frequency and number of sessions [36][37][38]. It appears that HBOT can be effective in decreasing chronic inflammation in the brain by reducing pro-inflammatory cytokine activation and through provocation of stem cell activity [7][8][9][10]. The repeat brain SPECT indicated the valuable contribution of this technique as a functional imaging biomarker.…”

“…The treatments included 1) hyperbaric oxygen therapy (HBOT), 2) combination therapy of infused ketamine concurrent with transcranial magnetic stimulation (TMS), 3) injections of perispinal etanercept (PSE), and 4) non-invasive trans-nasal Sphenopalatine Ganglion (SPG) block. HBOT is believed to have anti-inflammatory effects, reducing the excess of proinflammatory cytokine activation such as TNF-alpha and facilitating improvement by provocation of stem cell activity [7][8][9][10]. The combination therapy of infused ketamine administered concurrent to TMS appears to address the abnormalities in brain circuits found both in treatment resistant depression and treatment resistant central pain [11][12][13][14][15][16].…”

Topical oxygen therapy & micro/nanobubbles: a new modality for tissue oxygen delivery

“…The Undersea and Hyperbaric Medical Society indicates the use of HBOT for several conditions, including decompression sickness, acute thermal burns, arterial insufficiencies, refractory osteomyelitis, and compromised grafts and flaps as well as necrotising and anaerobic soft tissue infections . In addition, new studies have revealed a possible regenerative component to HBOT therapy where the release of progenitor cells has been demonstrated with its use . While HBOT has advocates and numerous studies, and randomised clinical trials point to its efficacy, HBOT occasionally causes vasoconstriction, cellular toxicity and tissue damage .…”