Harvest tissue source does not alter the protective power of stromal cell therapy after intestinal ischemia and reperfusion injury.

BACKGROUND: Transplantation of mesenchymal stromal cells (MSCs) may be a novel treatment for intestinal ischemia. The optimal stromal cell source that could yield maximal protection after injury, however, has not been identified. We hypothesized that (1) MSCs would increase survival and mesenteric perfusion, preserve intestinal histologic architecture, and limit inflammation after intestinal ischemia and reperfusion (I/R) injury, and (2) MSCs harvested from different sources of tissue would have equivalent protective properties to the intestine after I/R inury. METHODS: Adult male mice were anesthetized, and a midline laparotomy was performed. The intestines were eviscerated, the small bowel mesenteric root was identified, and baseline intestinal perfusion was determined using laser Doppler imaging. Intestinal ischemia was established by temporarily occluding the superior mesenteric artery for 60 min with a noncrushing clamp. After ischemia, the clamp was removed and the intestines were allowed to recover. Before abdominal closure, 2 × 10(6) human umbilical cord-derived MSCs, bone marrow-derived MSCs, or keratinocytes in 250 µL of phosphate-buffered saline vehicle were injected into the peritoneum. Animals were allowed to recover for 12 or 24 h (perfusion, histology, and inflammatory studies) or 7 d (survival studies). Survival data was analyzed using the log-rank test. Perfusion was expressed as a percentage of the baseline, and 12- and 24-h data was analyzed using one-way analysis of variance and the Student t-test. Nonparametric data was compared using the Mann-Whitney U-test. A P value of <0.05 was considered statistically significant. RESULTS: All MSCs increased 7-d survival after I/R injury and were superior to vehicle and keratinocytes (P < 0.05). All MSCs increased mesenteric perfusion more than vehicle at 12 and 24 h after injury (P < 0.05). All MSCs provided superior perfusion compared with keratinocytes at 24 h after injury (P < 0.05). Administration of each MSC line improved intestinal histology after I/R injury (P < 0.05). Multiple proinflammatory chemokines were downregulated after the application of MSCs, suggesting a decreased inflammatory response after MSC therapy. CONCLUSIONS: Transplantation of MSCs after intestinal I/R injury, irrespective of a tissue source, significantly increases survival and mesenteric perfusion and at the same time limits intestinal damage and inflammation. Further studies are needed to identify the mechanism that these cells use to promote improved outcomes after injury.

Human Adipose Stromal Cells Increase Survival and Mesenteric Perfusion Following Intestinal Ischemia and Reperfusion Injury.

OBJECTIVE: Intestinal ischemia can quickly escalate to bowel necrosis and perforation. Transplantation of stem cells presents a novel treatment modality for this problem. We hypothesized that: human adipose-derived stromal cells (hASCs) would increase survival and mesenteric perfusion to a greater degree compared with differentiated cellular controls following ischemic intestinal injury, and improved outcomes with hASC therapy would be associated with preservation of intestinal histological and tight junction architecture, and lower levels of systemic inflammation following intestinal injury. METHODS: hASCs and keratinocytes (differentiated cellular control) were cultured on polystyrene flasks at 37°C in 5% CO2 in air. Adult male C57Bl6J mice were anesthetized and a midline laparotomy performed. The intestines were eviscerated, the small bowel mesenteric root identified, and intestinal ischemia was established by temporarily occluding the superior mesenteric artery for 60 min with a noncrushing vascular clamp. Following ischemia, the clamp was removed, and the intestines were returned to the abdominal cavity. Before abdominal closure, 2 million hASCs or keratinocytes in 250 µL of phosphate-buffered saline (carrier for cells and control solution) were infused into the peritoneum. Animals were allowed to recover for 12 or 24 h (perfusion, histology, cytokine, and immunofluoresence studies), or 7 days (survival studies). Intestinal perfusion was assessed by laser Doppler imaging. Intestinal tissue segments were stained with hematoxylin and eosin, as well as antibodies for the tight junction protein claudin-1. Separate aliquots of intestine, liver, and lung tissue were homogenized and assessed for inflammatory cytokines via multiplex beaded assay. RESULTS: Animals administered hASCs following intestinal ischemia and reperfusion (I/R) injury had significantly greater 7-day survival and better postischemic recovery of mesenteric perfusion compared with vehicle or keratinocyte therapy. hASCs also abated intestinal mucosal destruction, facilitated preservation of intestinal tight junctions, and decreased the systemic inflammatory response to injury. CONCLUSIONS: Human adipose-derived stromal cells improved survival and mesenteric perfusion and attenuated the mucosal damage associated with intestinal I/R injury. hASCs should be considered as a plausible cell source for novel cellular treatment plans following intestinal ischemia.