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Adult mammals are known for their poor ability to regenerate tissues, including tendons. On the other hand, urodeles have become an important model in regenerative studies for their remarkable ability to regenerate various body parts and organs throughout life, such as limbs, retinas, or even the brain. However, little is known about their capacity to regenerate injured tendons. If newts can also repair tendons without scar formation, they may be a suitable animal model for tendon regeneration studies in other adult vertebrates. Therefore, the present study used Iberian ribbed newts to characterize mechanical and structural regeneration of tendons following transection, using tensile tests and multiphoton microscopy. A digital flexor tendon in a hindlimb was transected either partially or completely, and regenerated tendon was examined 6 and 12 weeks after the operation. Tensile strength of regenerated tendons was significantly less than normal at 6 weeks, but was remarkably recovered at 12 weeks, reaching levels comparable to those of uninjured tendons. On the other hand, mouse tendons demonstrated poor recovery of strength even after 12 weeks. Multiphoton microscopy revealed that tendon‐like collagenous tissue bridges residual tendon stubs in newts, but disorganized scar‐like tissue filled the injured location in mice. These findings highlight the remarkable capacity of newts to recover from tendon injury and confirm the utility of newts as a model to study tendon regeneration. [ABSTRACT FROM AUTHOR]

Problem: In the cell column of anchoring villi, the cytotrophoblast differentiates into extravillous trophoblast (EVT) and invades the endometrium in contact with maternal immune cells. Recently, chemokines were proposed to regulate the decidual immune response. To investigate the roles of chemokines around the anchoring villi, we examined the expression profiles of chemokines in the first‐trimester trophoblast‐derived Swan71 cells using a three‐dimensional culture model. Method of Study: The gene expressions in the spheroid‐formed Swan71 cells were examined by microarray and qPCR analyses. The protein expressions were examined by immunochemical staining. The chemoattractant effects of spheroid‐formed Swan71 cells were examined by migration assay using monocyte‐derived THP‐1 cells. Results: The expressions of an EVT marker, laeverin, and matrix metalloproteases, MMP2 and MMP9, were increased in the spheroid‐cultured Swan71 cells. Microarray and qPCR analysis revealed that mRNA expressions of various chemokines, CCL2, CCL7, CCL20, CXCL1, CXCL2, CXCL5, CXCL6, CXCL8, and CXCL10, in the spheroid‐cultured Swan71 cells were up‐regulated as compared with those in the monolayer‐cultured Swan71 cells. These expressions were significantly suppressed by hypoxia. Migration assay showed that culture media derived from the spheroid‐formed Swan71 cells promoted THP‐1 cell migration. Conclusion: This study indicated that chemokine expressions in Swan71 cells increase under a spheroid‐forming culture and the culture media have chemoattractant effects. Since three‐dimensional cell assembling in the spheroid resembles the structure of the cell column, this study also suggests that chemokines play important roles in the interaction between EVT and immune cells in their early differentiation stage. [ABSTRACT FROM AUTHOR]

Since embryos change their morphology drastically in the gastrulation stage, mechanical characterization of young embryos is important as they also change their tissue stiffness with the stage of development. Herein, virtual compression tests were conducted assuming that the Xenopus laevis gastrula has a spherical shape with transverse anisotropy. Based on the design of experiments, we found that the Young's moduli and material anisotropy can be efficiently determined by measuring the reaction force and surface displacement when indenting the tester into an embryo. The proposed scheme may be a substantial step toward understanding the timing of cell-type specification during embryo development. [ABSTRACT FROM AUTHOR]