[Effects of hyperbaric oxygen therapy in the management of chronic wounds and its correlation with CD34(+) endothelial progenitor cells].

OBJECTIVE: To evaluate the effects of hyperbaric oxygen (HBO) therapy in the management of chronic wound and observe the correlation between wound healing and CD34+ endothelial progenitor cells (EPCs). METHODS: A total of 119 patients with chronic wound in lower extremities lasting > 3 months were recruited for this randomized, single-center, placebo-controlled clinical trial. The changes of CD34+ average count before and after HBO therapy were detected by flow cytometry (FACS). There were 97 patients on long-term HBO therapy and in 22 patients on hyperbaric air therapy as control group. The CD34/Scal-1+ and CD34/CXCR4 dual-positive populations of gated cell were determined respectively by FACs. The outcomes of two groups were compared. Treatment was administered within a single-place hyperbaric chamber for 90-min daily (session duration 120 min) for 5 days a week for 4 weeks (20 treatment sessions). RESULTS: The wound size decreased at the 4-week end point (62.7% ± 22.3% in the HBO group vs 34.4% ± 20.6% in the control group, P < 0.05). After 10 episodes of HBO therapies for chronic non-healing wound, the peripheral CD34+ EPCs average count rose from 0.24% ± 0.03% at pre-treatment to 1.32% ± 0.05% while the number was 1.75% ± 0.17% after 20 episodes of HBO (P < 0.05). Both were significantly different from that of the patients at pre-treatment. However the overall circulating white cell count was not significantly elevated. The CD34/Scal-1+ and CD34/CXCR4 dual-positive populations of gated cell in HBO group were 5.8 and 5.2 folds than those at pre-treatment respectively. The number of EPCs was positively correlated with wound healing in lower extremities (correlation coefficient 0.84; P < 0.01). CONCLUSION: Adjunctive treatment of HBO facilitates the healing of chronic non-healing wound in selected patients through the mobilization of EPCs.

Migration of bone marrow-derived mesenchymal stem cells induced by tumor necrosis factor-alpha and its possible role in wound healing.

We aimed to investigate the effect of tumor necrosis factor-alpha (TNF-alpha) on the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the migration ability of mesenchymal stem cells (MSCs) in the context of wound healing. We also explored the role of p38 mitogen-activated protein kinase and extracellular signal-regulated kinase (ERK) signaling pathways in the migration of MSCs. MSCs were isolated from the bone marrow and cultured. Immunocytochemistry, Western blotting, and reverse transcription-polymerase chain reaction were used to observe the effect of TNF-alpha on the expression of ICAM-1 and VCAM-1 in MSCs. The chemotaxis effect of TNF-alpha on MSCs was investigated by the trans-well system and the inhibition effect of TNF-alpha using its antibody. Western blotting analysis was used to observe the activation of JAK-STAT and mitogen-activated protein kinase signaling pathways, and ERK was inhibited with PD98059 and p38 with SB203580 to observe the effect of TNF-alpha on MSC migration and ICAM-1 expression. The expression of ICAM-1 could be up-regulated by 50 microg/L TNF-alpha (p<0.05), whereas that of VCAM-1 remained unchanged (p>0.05). Also, TNF-alpha showed a chemotaxis effect by enhancing the migration ability of MSCs (p<0.05). TNF-alpha at 50 microg/L increased the expression of phospho-ERK and phospho-p38, and SB203580, but not PD98059, could suppress the chemotaxis effect and up-regulation of ICAM-1 induced by TNF-alpha in MSCs (p<0.05). Thus, TNF-alpha could up-regulate the expression of ICAM-1 in MSCs and enhance the cells' migration ability, and the p38 signaling pathway might be involved in the TNF-alpha-induced migration ability for a role in wound repair and regeneration.