Interleukin-1beta impairment of transforming growth factor beta1 signaling by down-regulation of transforming growth factor beta receptor type II and up-regulation of Smad7 in human articular chondrocytes.

OBJECTIVE: Extracellular matrix deposition is tightly controlled by a network of regulatory cytokines. Among them, interleukin-1beta (IL-1beta) and transforming growth factor beta1 (TGFbeta1) have been shown to play antagonistic roles in tissue homeostasis. The purpose of this study was to determine the influence of IL-1beta on TGFbeta receptor type II (TGFbetaRII) regulation and TGFbeta1 responsiveness in human articular chondrocytes. METHODS: TGFbeta1-induced gene expression was analyzed through plasminogen activator inhibitor 1 and p3TP-Lux induction. Receptor-activated Smad (R-Smad) phosphorylation, TGFbeta receptors, and Smad expression were determined by Western blotting and real-time reverse transcription-polymerase chain reaction techniques. Signaling pathways were investigated using specific inhibitors, messenger RNA (mRNA) silencing, and expression vectors. RESULTS: IL-1beta down-regulated TGFbetaRII expression at both the protein and mRNA levels and led to inhibition of the TGFbeta1-induced gene expression and Smad2/3 phosphorylation. Moreover, IL-1beta strongly stimulated the expression of inhibitory Smad7. TGFbetaRII overexpression abolished the loss of TGFbeta1 responsiveness induced by IL-1beta. The decrease in TGFbetaRII required de novo protein synthesis and involved both the NF-kappaB and JNK pathways. CONCLUSION: We demonstrate that IL-1beta impairs TGFbeta1 signaling through down-regulation of TGFbetaRII, which is mediated by the p65/NF-kappaB and activator protein 1/JNK pathways, and secondarily through the up-regulation of Smad7. These findings show that there is cross-talk in the signaling of 2 regulatory cytokines involved in inflammation.

Anatomic study of the tendinous insertion lamina of the temporalis muscle.

Lengthening temporalis myoplasty is indicated in long-standing and congenital facial paralysis. Its principle is the transfer of the coronoid tendinous insertions onto the lip and the nasolabial fold. Knowledge of the anatomy of this strong and wide tendon is necessary for successful use of its anatomic advantages. A study on 10 cadavers (20 temporalis muscles) confirmed the surgical anatomy found during lengthening temporalis myoplasty procedures: the strong tendon, when freed from the coronoid process, is 4-6 cm wide.

[The temporal periosteum: anatomical study and surgical implications]. / Le périoste temporal: étude anatomique et intérêt chirurgical.

The periosteum of the temporal area is mentioned at different places in the literature: either against the osseous plane like everywhere in the human body, or between the deep and the superficial temporal fascia. The subperiosteal subtemporal approach in craniofacial surgery in children is in favour of a juxta-osseous localization of the periosteum. Ten premature still-born neonates and two adults cadavers have been dissected for this study and, permit anatomical and histological (with HES coloration) studies. With every specimen, the authors concluded that the temporal periosteum is against the outer table of the calvarium. It became thinner in adults because of direct insertions of the temporalis muscle in the calvaria. An anatomical description of the layers of the temporal area is realised and discussed with an extensive review of the literature. The authors have proposed a subperiosteal subtemporal approach in craniostenosis surgery.

[Anatomical study of the temporalis tendon. Value in temporalis lengthening myoplasty]. / Etude anatomique de la lame tendineuse d'insertion du muscle temporal. Intérêt dans la myoplastie d'allongement du temporal.

The lengthening temporalis myoplasty is indicated in long standing and congenital facial paralysis. Its principle is the transfer of the coronoid tendinous insertions onto the lip and the nasolabial fold. The knowledge of the anatomy of this strong and wide tendon is necessary to use successfully their anatomical advantages. A study of ten cadavers (20 temporalis muscles) confirmed the surgical anatomy found during lengthening temporalis myoplasty procedure: the strong tendon, when liberated from the coronoid process, is from 4 to 6 cm long.