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Background: In view of the current interest in exploring the clinical use of mesenchymal stem cells (MSCs) from different sources, we performed a side-by-side comparison of the biological properties of MSCs isolated from the Wharton's jelly (WJ), the most abundant MSC source in umbilical cord, with bone marrow (BM)-MSCs, the most extensively studied MSC population., Methods: MSCs were isolated and expanded from BM aspirates of hematologically healthy donors (n = 18) and from the WJ of full-term neonates (n = 18). We evaluated, in parallel experiments, the MSC immunophenotypic, survival and senescence characteristics as well as their proliferative potential and cell cycle distribution. We also assessed the expression of genes associated with the WNT- and cell cycle-signaling pathway and we performed karyotypic analysis through passages to evaluate the MSC genomic stability. The hematopoiesis-supporting capacity of MSCs from both sources was investigated by evaluating the clonogenic cells in the non-adherent fraction of MSC co-cultures with BM or umbilical cord blood-derived CD34 + cells and by measuring the hematopoietic cytokines levels in MSC culture supernatants. Finally, we evaluated the ability of MSCs to differentiate into adipocytes and osteocytes and the effect of the WNT-associated molecules WISP-1 and sFRP4 on the differentiation potential of WJ-MSCs., Results: Both ex vivo-expanded MSC populations showed similar morphologic, immunophenotypic, survival and senescence characteristics and acquired genomic alterations at low frequency during passages. WJ-MSCs exhibited higher proliferative potential, possibly due to upregulation of genes that stimulate cell proliferation along with downregulation of genes related to cell cycle inhibition. WJ-MSCs displayed inferior lineage priming and differentiation capacity toward osteocytes and adipocytes, compared to BM-MSCs. This finding was associated with differential expression of molecules related to WNT signaling, including WISP1 and sFRP4, the respective role of which in the differentiation potential of WJ-MSCs was specifically investigated. Interestingly, treatment of WJ-MSCs with recombinant human WISP1 or sFRP4 resulted in induction of osteogenesis and adipogenesis, respectively. WJ-MSCs exhibited inferior hematopoiesis-supporting potential probably due to reduced production of stromal cell-Derived Factor-1α, compared to BM-MSCs., Conclusions: Overall, these data are anticipated to contribute to the better characterization of WJ-MSCs and BM-MSCs for potential clinical applications.

Background: Little is known about the effect of smoking cessation on airway inflammation. Secretory Leukocyte Protease Inhibitor (SLPI), Clara Cell protein 16 (CC16), elafin and human defensin beta-2 (HBD-2) protect human airways against inflammation and oxidative stress. In this longitudinal study we aimed to investigate changes in sputum and nasal lavage SLPI, CC16, elafin and HBD-2 levels in healthy smokers after 6 and 12 months of smoking cessation., Methods: Induced sputum and nasal lavage was obtained from healthy current smokers (n = 76) before smoking cessation, after 6 months of smoking cessation (n = 29), after 1 year of smoking cessation (n = 22) and from 10 healthy never smokers. SLPI, CC16, elafin and HBD-2 levels were measured in sputum and nasal lavage supernatants by commercially available ELISA kits., Results: Sputum SLPI and CC-16 levels were increased in healthy smokers before smoking cessation versus never-smokers (p = 0.005 and p = 0.08 respectively). SLPI and CC16 levels did not differ before and 6 months after smoking cessation (p = 0.118 and p = 0.543 respectively), neither before and 1 year after smoking cessation (p = 0.363 and p = 0.470 respectively). Nasal lavage SLPI was decreased 12 months after smoking cessation (p = 0.033). Nasal lavage elafin levels were increased in healthy smokers before smoking cessation versus never-smokers (p = 0.007), but there were no changes 6 months and 1 year after smoking cessation., Conclusions: Only nasal lavage SLPI decrease after 1 year after smoking cessation. We may speculate that there is an ongoing inflammatory process stimulating the production of counter-regulating proteins in the airways of healthy ex-smokers.