Mesenchymal stem cell-derived exosomes (MSC-Ex) play important roles in tissue injury repair, however, the roles of MSC-Ex in skin damage repair and its mechanisms are largely unknown. Herein, we examined the benefit of human umbilical cord MSC-derived exosome (hucMSC-Ex) in cutaneous wound healing using a rat skin burn model. We found that hucMSC-Ex-treated wounds exhibited significantly accelerated re-epithelialization, with increased expression of CK19, PCNA, collagen I (compared to collagen III) in vivo. HucMSC-Ex promoted proliferation and inhibited apoptosis of skin cells after heat-stress in vitro. We also discovered that Wnt4 was contained in hucMSC-Ex, and hucMSC-Ex-derived Wnt4 promoted b-catenin nuclear translocation and activity to enhance proliferation and migration of skin cells, which could be reversed by b-catenin inhibitor ICG001. In vivo studies confirmed that the activation of Wnt/ b-catenin by hucMSC-Ex played a key role in wound re-epithelialization and cell proliferation. Furthermore, knockdown of Wnt4 in hucMSC-Ex abrogated b-catenin activation and skin cell proliferation and migration in vitro. The in vivo therapeutic effects were also inhibited when the expression of Wnt4 in hucMSC-Ex was interfered. In addition, the activation of AKT pathway by hucMSC-Ex was associated with the reduction of heat stress-induced apoptosis in rat skin burn model. Collectively, our findings indicate that exosome-delivered Wnt4 provides new aspects for the therapeutic strategy of MSCs in cutaneous wound healing. STEM CELLS

Human umbilical cord mesenchymal stem cells (hucMSCs) and their exosomes have been considered as potential therapeutic tools for tissue regeneration; however, the underlying mechanisms are still not well understood. In this study, we isolated and characterized the exosomes from hucMSCs (hucMSC-Ex) and demonstrated that hucMSC-Ex promoted the proliferation, migration, and tube formation of endothelial cells in a dose-dependent manner. Furthermore, we demonstrated that hucMSC-Ex promoted wound healing and angiogenesis in vivo by using a rat skin burn model. We discovered that hucMSC-Ex promoted b-catenin nuclear translocation and induced the increased expression of proliferating cell nuclear antigen, cyclin D3, N-cadherin, and b-catenin and the decreased expression of E-cadherin. The activation of Wnt/b-catenin is critical in the induction of angiogenesis by hucMSC-Ex, which could be reversed by b-catenin inhibitor ICG-001. Wnt4 was delivered by hucMSC-Ex, and the knockdown of Wnt4 in hucMSC-Ex abrogated b-catenin nuclear translocation in endothelial cells. The in vivo proangiogenic effects were also inhibited by interference of Wnt4 expression in hucMSC-Ex. Taken together, these results suggest that hucMSC-Ex-mediated Wnt4 induces b-catenin activation in endothelial cells and exerts proangiogenic effects, which could be an important mechanism for cutaneous wound healing. STEM CELLS TRANSLATIONAL MEDICINE 2015; 4:513-522 SIGNIFICANCEHuman umbilical cord mesenchymal stem cells (hucMSCs) and their exosomes have been considered as potential therapeutic tools for tissue regeneration; however, the underlying mechanisms are still not well understood. In this study, it is reported that hucMSC-Ex-mediated Wnt4 induces b-catenin activation in endothelial cells and exerts proangiogenic effects, which could be one of the important mechanisms responsible for cutaneous wound healing.

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Abstract. Recent advances in the Internet, in data mining, and in security technologies have gave rise to a new stream of research, known as privacy preserving data mining (PPDM). PPDM technologies allow us to extract relevant knowledge from a large amount of data, while hide sensitive data or information from disclosure. Several research questions have often being asked:(1) what kind of option available for privacy preserving? (2) Which method is more popular? (3) how to measure the performance of these algorithms? And (4) how effective of these algorithms in preserving privacy? To help answer these questions, we conduct an extensive review of 29 recent references from years 2000 to 2006 for analysis.

The prevalence of Lynch syndrome (LS) varies significantly in different populations, suggesting that ethnic features might play an important role. We enrolled 3330 consecutive Chinese patients who had surgical resection for newly diagnosed colorectal cancer. Universal screening for LS was implemented, including immunohistochemistry for mismatch repair (MMR) proteins, BRAF V600E mutation test and germline sequencing. Among the 3250 eligible patients, MMR protein deficiency (dMMR) was detected in 330 (10.2%) patients. Ninety-three patients (2.9%) were diagnosed with LS. Nine (9.7%) patients with LS fulfilled Amsterdam criteria II and 76 (81.7%) met the revised Bethesda guidelines. Only 15 (9.7%) patients with absence of MLH1 on IHC had BRAF V600E mutation. One third (33/99) of the MMR gene mutations have not been reported previously. The age of onset indicates risk of LS in patients with dMMR tumors. For patients older than 65 years, only 2 patients (5.7%) fulfilling revised Bethesda guidelines were diagnosed with LS. Selective sequencing of all cases with dMMR diagnosed at or below age 65 years and only of those dMMR cases older than 65 years who fulfill revised Bethesda guidelines results in 8.2% fewer cases requiring germline testing without missing any LS diagnoses. While the prevalence of LS in Chinese patients is similar to that of Western populations, the spectrum of constitutional mutations and frequency of BRAF V600E mutation is different. Patients older than 65 years who do not meet the revised Bethesda guidelines have a low risk of LS, suggesting germline sequencing might not be necessary in this population. What's new?The prevalence of Lynch syndrome (LS) varies significantly in different ethnic populations. In this study, the authors screened more than 3000 Chinese colorectal cancer patients for mutations associated with LS, including mismatch repair (MMR) and BRAF V600E mutations. They found that, while the prevalence of LS in Chinese patients is similar to that of Western populations, the spectrum of mutations is different, including many not previously reported. Older patients had a decreased risk of LS, suggesting that germline sequencing may not be necessary in this population.