No abstract

The LGR6+ epithelial stem cells appear to hold great promise for the development of a clinically useful stem cell–based therapy for the repair of full-thickness wounds and hair regeneration. These results indicate that transplantation of LGR6+ epithelial stem cells promotes epithelialization, hair growth, and angiogenesis in tissues destined for scar formation.

Application of human alpha defensin 5 increases LGR stem cell migration into wound beds, leading to enhanced healing, bacterial reduction, and hair production through the augmentation of key Wnt and wound healing transcripts. These findings can be used to derive gut protein-based therapeutics in wound healing.

We offer suggestive evidence that GFP+ ADSC are found within the dermis 8 weeks after engraftment and coexpress the epithelial stem cell marker p63, indicating that ADSC may transdifferentiate into epithelial stem cells after fat grafting. These findings complement current understanding of how fat grafts may rejuvenate overlying skin.

Therapeutic, V.

Adenosine promotes cytoprotection under conditions of infection, ischemic preconditioning and oxidative stress. Previous studies from our laboratory indicate that the expression of the adenosine A1 receptor (A1AR) is induced by oxidative stress via activation of nuclear factor (NF)-kappaB. The prototypic transcription factor is composed of homo- or heterodimers of p50 and p65 subunits. To determine the role of NF-kappaB in the regulation of the A1AR in vivo, we compared the A1AR RNA and protein levels in the brains of mice lacking the p50 subunit of NF-kappaB (p50-/- mice) and age-matched B6129PF2/J (F2) controls. Radioligand binding assays in the cortex revealed a significantly lower number of A(1)AR (maximal binding capacity, Bmax) in the cortex of p50-/- mice (151+/-62 fmol/mg protein) versus 479+/-181 fmol/mg protein in the F2 (N=5 per strain, P<0.05), but no change in the equilibrium dissociation constant. Similar reductions in A1AR were measured in the hippocampus, brain stem and hypothalamus and in peripheral tissues, such as the adrenal gland, kidney and spleen. Estimation of the A1AR following purification by antibody affinity columns also indicated reduced A1AR in the p50-/- mice cortex, as compared with the F2 mice. A1AR immunocytochemistry indicates distinct neuronal labeling in the F2 cortex, which was substantially reduced in similar sections obtained from p50-/- mice. The p50-/- mice expressed lower levels of A1AR mRNA than F2 mice, as determined by real time PCR. Quantitation of the A1AR transducing G proteins by Western blotting show significantly less Galphai3, no change in Galphai1, but higher levels of Galphao and Gbeta in the cortices of p50-/-, as compared with F2 mice. Administration of bacterial lipopolysaccharide (LPS), an activator of NF-kappaB, increased A1AR expression in the cortices of F2 mice but not p50-/- mice. Cortical neurons cultures prepared from p50-/- mice showed a greater degree of apoptosis, compared with neurons from F2 mice. Activation of the A1AR reduced apoptosis with greater efficacy in cultures from F2 than p50-/- mice. Taken together, these data support a role for NF-kappaB in determining both the basal and LPS-stimulated A1AR expression in vivo which could contribute to neuronal survival.

Cancer stem cells (CSCs) or circulating tumor cells play an important role in tumor initiation, invasion, metastasis and resistance to anticancer therapies. Therapies that target gastric tumor CSCs have potential clinical application for preventing malignant gastric tumor progression and metastasis. We isolated CD44+ gastric cancer cells from the gastric cancer cell line AGS and Hs746T cells and maintained the cells in a novel stem cell culture. The cells were kept in an undifferentiated proliferative state and we characterized their cancer stem cell properties and chemotherapy-resistance behavior. The CD44+ cancer cells were also co-cultured with human adipose stem cells (ADSCs) to determine the chemotherapy-promotion effects of the adipose cells on the CD44+ cancer cells. The CD44+ gastric cancer cell model is a non-adhesion, 3-dimensional, spheroid phenotype. The non-adherent CD44+ cells have cancer stem cell properties and are highly chemo-resistant. However, these cells regained chemo-sensitivity when re-attached to an extracellular matrix-coated attachment surface. The human adipose stem cells significantly promoted the chemo-sensitivity of the non-adherent CD44+ gastric cancer cells. Integrin α2/β2 and the Wnt signaling pathways are involved in the mechanisms. We concluded that the in vitro non-adherent CD44+ gastric cancer cell model resembles the circulating gastric tumor cells in vivo. Introduction of an appropriate attachment surface significantly promotes chemo-sensitivity of the non-adherent CD44+ gastric cancer cells. The human adipose stem cells function as a 'living vehicle surface' for such a purpose in vivo.

When ischemia occurs in skeletal muscle, intra and extracellular changes result in an influx of calcium, lactic acid metabolism, reduction of intracellular pH, and adenosine triphosphate (ATP) depletion. These processes ultimately result in cell death if they are not interrupted by reperfusion. While the return of blood flow is necessary for cellular survival, reperfusion brings with it the possibility of increasing the spectrum of injury. As the ischemic muscle is flushed with oxygenated blood, reactive oxygen species and other harmful free radicals are produced and distributed throughout the area. 1-4 Keywords AbstractBackground The aim of this study was to determine the optimal salvage time window within which ischemic postconditioning can be used to ameliorate ischemia/reperfusion (I/R) injury in skeletal muscle. Methods A total of 48 Sprague-Dawley rats were divided into two groups: I/R only (control) and I/R with postconditioning. Subgroups were divided by duration of ischemia (2, 4, 6, and 8 hours). A pedicled gracilis muscle model was used. The postconditioning protocol consisted of six cycles of 15 seconds of reperfusion followed by 15 seconds of ischemia (total time ¼ 3 minutes). Muscles were harvested 24 hours after I/R injury to examine tissue viability, histology, myeloperoxidase activity, and protective gene expression. Results Postconditioning groups showed improved muscle viability after 4 and 6 hours of ischemia time as compared with controls (p < 0.05). Higher expression of mitochondrial complexes I, II, III, endothelial nitric oxide synthase, inducible nitric oxide synthase, and Bcl-2 were observed in the postconditioning group after 4 and 6 hours of ischemia (p < 0.05). Lower expression of tumor necrosis factor-α and caspase 3 was observed in the postconditioning group at 4 hours (p < 0.05). Myeloperoxidase activity was similar in both groups at all-time points except 8 hours ischemia, where the control group had higher activity (p < 0.05). Conclusion Results of this study demonstrate that the effective time window within which postconditioning is most effective for the salvage of skeletal muscle is between 4 and 6 hours of ischemia. Postconditioning offered improved mitochondrial and vascular function with decreased inflammation and cell death. This may be clinically useful as a postinjury salvage technique to attenuate I/R injury after 4 to 6 hours of ischemia.