Defects in chondrocyte maturation and secondary ossification in mouse knee joint epiphyses due to Snorc deficiency.

Objective: The role of Snorc, a novel cartilage specific transmembrane proteoglycan, was studied during skeletal development using two Snorc knockout mouse models. Hypothesizing that Snorc, like the other transmembrane proteoglycans, may be a coreceptor, we also studied its interaction with growth factors.

Methods: Skeletal development was studied in wild type (WT) and Snorc knockout mice during postnatal development by whole mount staining, X-ray imaging, histomorphometry, immunohistochemistry and qRT-PCR.

The transcriptional co-repressor TLE3 regulates development of trophoblast giant cells lining maternal blood spaces in the mouse placenta.

TLE3 is a transcriptional co-repressor that interacts with several DNA-binding repressors, including downstream effectors of the Notch signaling pathway. We generated Tle3-deficient mice and found that they die in utero and their death is associated with abnormal development of the placenta with major defects in the maternal vasculature. In the normal placenta, maternal blood spaces are lined, not as usual in the mammalian circulation by endothelial cells, but rather by specialized embryo-derived cells of the trophoblast cell lineage named trophoblast giant cells (TGC).

Ucma is not necessary for normal development of the mouse skeleton.

Ucma (Upper zone of growth plate and Cartilage Matrix Associated protein) is a highly conserved tyrosine-sulphated secreted protein of Mw 17 kDa, which is expressed by juvenile chondrocytes. To evaluate the physiological function of this novel cartilage protein, we generated a Ucma-deficient mouse strain by introducing a lacZ/neoR-cassette into the first exon of the Ucma gene. This mutation results in the complete loss of Ucma mRNA and protein expression.

The Wnt antagonist Wif-1 interacts with CTGF and inhibits CTGF activity.

Wnt inhibitory factor 1 (Wif-1) is a secreted antagonist of Wnt signalling. We recently demonstrated that this molecule is expressed predominantly in superficial layers of epiphyseal cartilage but also in bone and tendon. Moreover, we showed that Wif-1 is capable of binding to several cartilage-related Wnt ligands and interferes with Wnt3a-dependent Wnt signalling in chondrogenic cells.

Expression of HIF-1α in ischemia and reperfusion in human microsurgical free muscle tissue transfer.

Background: The aim of this study was to analyze the expression of hypoxia-inducible factor (HIF)-1α during ischemia and after reperfusion in muscle tissue in the context of microsurgical free muscle tissue transfer.

Methods: Ten patients with soft-tissue defects needing coverage with microsurgical free muscle flaps were included in this study. In all patients, the muscle samples were taken from free myocutaneous flaps.