Tendon injuries represent a clinical challenge in regenerative medicine because their natural repair process is complex and inefficient. The high incidence of tendon injuries is frequently associated with sports practice, aging, tendinopathies, hypertension, diabetes mellitus, and the use of corticosteroids. The growing interest of scientists in using adipose-derived mesenchymal stem cells (ADMSC) in repair processes seems to be mostly due to their paracrine and immunomodulatory effects in stimulating specific cellular events. ADMSC activity can be influenced by GDF-5, which has been successfully used to drive tenogenic differentiation of ADMSC in vitro. Thus, we hypothesized that the application of ADMSC in isolation or in association with GDF-5 could improve Achilles tendon repair through the regulation of important remodeling genes expression. Lewis rats had tendons distributed in four groups: Transected (T), transected and treated with ADMSC (ASC) or GDF-5 (GDF5), or with both (ASC+GDF5). In the characterization of cells before application, ADMSC expressed the positive surface markers, CD90 (90%) and CD105 (95%), and the negative marker, CD45 (7%). ADMSC were also differentiated in chondrocytes, osteoblast, and adipocytes. On the 14th day after the tendon injury, GFP-ADMSC were observed in the transected region of tendons in the ASC and ASC+GDF5 groups, and exhibited and/or stimulated a similar genes expression profile when compared to the in vitro assay. ADMSC up-regulated Lox, Dcn, and Tgfb1 genes expression in comparison to T and ASC+GDF5 groups, which contributed to a lower proteoglycans arrangement, and to a higher collagen fiber organization and tendon biomechanics in the ASC group. The application of ADMSC in association with GDF-5 down-regulated Dcn, Gdf5, Lox, Tgfb1, Mmp2, and Timp2 genes expression, which contributed to a lower hydroxyproline concentration, lower collagen fiber organization, and to an improvement of the rats’ gait 24 h after the injury. In conclusion, although the literature describes the benefic effect of GDF-5 for the tendon healing process, our results show that its application, isolated or associated with ADMSC, cannot improve the repair process of partial transected tendons, indicating the higher effectiveness of the application of ADMSC in injured Achilles tendons. Our results show that the application of ADMSC in injured Achilles tendons was more effective in relation to its association with GDF-5.

Tissue engineering and cell-based therapy combine techniques that create biocompatible materials for cell survival, which can improve tendon repair. This study seeks to use a new fibrin sealant (FS) derived from the venom of Crotalus durissus terrificus, a biodegradable three-dimensional scaffolding produced from animal components only, associated with adipose-derived stem cells (ASC) for application in tendons injuries, considered a common and serious orthopedic problem. Lewis rats had tendons distributed in five groups: normal (N), transected (T), transected and FS (FS) or ASC (ASC) or with FS and ASC (FS + ASC). The in vivo imaging showed higher quantification of transplanted PKH26-labeled ASC in tendons of FS + ASC compared to ASC on the 14th day after transection. A small number of Iba1 labeled macrophages carrying PKH26 signal, probably due to phagocytosis of dead ASC, were observed in tendons of transected groups. ASC up-regulated the Tenomodulin gene expression in the transection region when compared to N, T and FS groups and the expression of TIMP-2 and Scleraxis genes in relation to the N group. FS group presented a greater organization of collagen fibers, followed by FS + ASC and ASC in comparison to N. Tendons from ASC group presented higher hydroxyproline concentration in relation to N and the transected tendons of T, FS and FS + ASC had a higher amount of collagen I and tenomodulin in comparison to N group. Although no marked differences were observed in the other biomechanical parameters, T group had higher value of maximum load compared to the groups ASC and FS + ASC. In conclusion, the FS kept constant the number of transplanted ASC in the transected region until the 14th day after injury. Our data suggest this FS to be a good scaffold for treatment during tendon repair because it was the most effective one regarding tendon organization recovering, followed by the FS treatment associated with ASC and finally by the transplanted ASC on the 21st day. Further investigations in long-term time points of the tendon repair are needed to analyze if the higher tissue organization found with the FS scaffold will improve the biomechanics of the tendons.

Background: Dact gene family encodes multifunctional proteins that are important modulators of Wnt and TGF-b signaling pathways. Given that these pathways coordinate multiple steps of limb development, we investigated the expression pattern of the two chicken Dact genes (Dact1 and Dact2) from early limb bud up to stages when several tissues are differentiating. Results: During early limb development (HH24-HH30) Dact1 and Dact2 were mainly expressed in the cartilaginous rudiments of the appendicular skeleton and perichondrium, presenting expression profiles related, but distinct. At later stages of development (HH31-HH35), the main sites of Dact1 and Dact2 expression were the developing synovial joints. In this context, Dact1 expression was shown to co-localize with regions enriched in the nuclear b-catenin protein, such as developing joint capsule and interzone. In contrast, Dact2 expression was restricted to the interzone surrounding the domains of bmpR-1b expression, a TGF-b receptor with crucial roles during digit morphogenesis. Additional sites of Dact expression were the developing tendons and digit blastemas. Conclusions: Our data indicate that Dact genes are good candidates to modulate and, possibly, integrate Wnt and TGF-b signaling during limb development, bringing new and interesting perspectives about the roles of Dact molecules in limb birth defects and human diseases. Developmental Dynamics 243:428-439, 2014. V C 2013 Wiley Periodicals, Inc.Key words: Dact; Dapper; Frodo; chicken embryo; Wnt; TGF-b; limb; chondrogenesis; appendicular skeleton; Sox9; cartilage; perichondrium; joint; digit blastema; tendon; digit morphogenesis; limb evolution Key findings:Dact1 and Dact2 are dynamically expressed during early chondrogenesis in sites that either overlap or complement Sox9 expression domains. Dact1 and Dact2 are coexpressed in developing joints, tendons, and digit blastemas. Dact1 mRNAs colocalize with nuclear b-catenin protein while Dact2 complements sites of bmpR-1b expression in developing synovial joints of digits.

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Core syllabus" in this work refers to knowledge topics that an instructor should necessarily and indispensably address during a discipline. This study describes the process of developing a regional human embryology core syllabus for undergraduate medical courses in Brazil, using a two-round modified Delphi method as a tool for reaching consensus. A list of 679 human embryology topics was generated based on three textbooks. The Delphi panel consisted of specialists (n = 51) with at least 2 years' medical experience in activities related to the contents of embryology or health sciences professionals with at least 5 years' experience in undergraduate medical education of embryology and other cognate disciplines. The panel rated the relevance of each topic on a Likert scale. Following consensus analysis, a list of 69 "core" topics was obtained. Then, in a second Delphi round, the panel was asked to "accept," "accept with modifications," or "reject" the new list. The research team performed a final revision/screening process and generated a core human embryology syllabus comprised of 63 topics. Comparing this regional syllabus with two international core syllabuses also built Delphi panels, 60.3% of the topics overlap with both syllabuses, and 39.7% of its content is unique. This study can be a valuable tool for decision-making in the embryology curriculum for health courses and reinforces the importance of local evaluation of international curricula of human embryology before implementing them, since the incidences of congenital anomalies vary in different regions of the world.