Immunohistochemical Localization of Bone Morphogenetic Protein-signaling Smads during Long-bone Distraction Osteogenesis

2006 ◽  
Vol 54 (4) ◽  
pp. 407-415 ◽  
Author(s):  
Tasima Haque ◽  
Manuela Mandu-Hrit ◽  
Frank Rauch ◽  
Dominique Lauzier ◽  
Maryam Tabrizian ◽  
...  

In this study we investigated the expression of bone morphogenetic protein (BMP)-signaling Smads in distraction osteogenesis (DO). Osteotomy of the right tibia was performed in 14 skeletally mature white New Zealand male rabbits. Lengthening was started 1 week later at a rate of 0.5 mm/12 hr and was maintained for 3 weeks. Expression of Smad proteins 1, 4, 5, 6, 7, and 8 and Smad ubiquitin regulatory factors (Smurfs) 1 and 2 was evaluated in the distracted zone using immunohistochemistry. Expression of receptor-regulated Smads (R-Smads) 1, 5, and 8 showed a significant increase during the distraction phase, followed by a gradual decrease during the consolidation phase. Smad 4 showed significant expression during both distraction and the beginning of the consolidation phase. Smad 6 and Smad 7 were highly expressed during the consolidation phase. Staining for both Smurfs 1 and 2 was maximal at the end of the distraction period. Staining for all proteins was most intense in chondrocyte and fibroblast-like cells. Expression pattern of R-Smads correlated with our previously reported expression pattern of BMPs 2, 4, and 7 and their receptors. These results therefore suggest a role for the whole BMP signaling pathway including the Smad proteins in DO.

2017 ◽  
Vol 45 (1) ◽  
pp. 173-181 ◽  
Author(s):  
Georg Sedlmeier ◽  
Jonathan P. Sleeman

Given its importance in development and homeostasis, bone morphogenetic protein (BMP) signaling is tightly regulated at the extra- and intracellular level. The extracellular matrix (ECM) was initially thought to act as a passive mechanical barrier that sequesters BMPs. However, a new understanding about how the ECM plays an instructive role in regulating BMP signaling is emerging. In this mini-review, we discuss various ways in which the biochemical and physical properties of the ECM regulate BMP signaling.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Megan F Burke ◽  
Caitlin O’Rourke ◽  
Trejeeve Martyn ◽  
Hannah R Shakartzi ◽  
Timothy E Thayer ◽  
...  

Background: Matrix Gla protein (MGP) is an extracellular matrix protein that inhibits bone morphogenetic protein (BMP) signaling in vitro. MGP deficiency induces vascular calcification associated with osteogenic transdifferentiation of endothelial cells (via endothelial-mesenchymal transition, EndMT) and vascular smooth muscle cells (VSMCs). We previously reported that treatment with two pharmacologic inhibitors of BMP signaling reduced aortic calcification in MGP-/- mice. We hypothesized that BMP signaling is essential for EndMT and VSMC osteogenic transdifferentiation induced by MGP deficiency. Methods and Results: Aortic levels of mRNAs encoding markers of osteogenesis (Runx2 and osteopontin) and EndMT (nanog, Sox2, and Oct3/4) were greater in MGP-/- than in wild-type mice (P<0.01 for all). Aortic expression of markers of VSMC differentiation (α-smooth muscle actin, transgelin, and calponin) was less in MGP-/- than in wild-type mice (P<0.001 for all). Treatment of MGP-/- mice with the BMP signaling inhibitor, LDN-193189, reduced expression of both osteogenic and EndMT markers (P<0.05 for all) but did not prevent VSMC de-differentiation. Depletion of MGP in cultured wild-type VSMCs with siRNA specific for MGP (siMGP) was associated with a 30-40% reduction in levels of mRNAs encoding markers of VSMC differentiation (P<0.05 for all), an effect that was not prevented by LDN-193189. Incubation in phosphate-containing media induced greater calcification in siMGP-treated VSMCs than in cells treated with control siRNA (P<0.0001). Treatment with LDN-193189 reduced calcification in siMGP-treated VSMCs (50%, P=0.0003). Conversely, infection of MGP-/- VSMCs with adenovirus specifying MGP increased expression of markers of VSMC differentiation by 60-80% (P<0.01 for all) and decreased calcification by 74% (P=0.03). Conclusions: Inhibition of BMP signaling suppresses osteogenic and EndMT gene programs in MGP-/- mice and reduces calcification of siMGP-treated VSMCs. However, MGP deficiency induces VSMC de-differentiation via a BMP-independent mechanism. These findings suggest that the processes underlying vascular calcification in MGP deficiency are mediated by both BMP signaling-dependent and -independent mechanisms.


2017 ◽  
Vol 41 (11) ◽  
pp. 2417-2419 ◽  
Author(s):  
Gopal Shankar Krishnakumar ◽  
Alice Roffi ◽  
Davide Reale ◽  
Elizaveta Kon ◽  
Giuseppe Filardo

2014 ◽  
Vol 10 (10) ◽  
pp. 4390-4399 ◽  
Author(s):  
Lauren B. Priddy ◽  
Ovijit Chaudhuri ◽  
Hazel Y. Stevens ◽  
Laxminarayanan Krishnan ◽  
Brent A. Uhrig ◽  
...  

2017 ◽  
Vol 185 ◽  
pp. 89-96 ◽  
Author(s):  
Pablo Alberto Valdecantos ◽  
Rocío del Carmen Bravo Miana ◽  
Elina Vanesa García ◽  
Daniela Celeste García ◽  
Mariela Roldán-Olarte ◽  
...  

2021 ◽  
Vol 8 (2) ◽  
pp. 57-64
Author(s):  
Fangfang Li ◽  
Peixi Qin ◽  
Lisha Ye ◽  
Nishith Gupta ◽  
Min Hu

SMAD proteins mediate TGF-β signaling and thereby regulate the metazoan development; however, they are poorly defined in Haemonchus contortus–a common blood-sucking parasitic nematode of small ruminants. Here, we characterized an R-SMAD family protein in H. contortus termed HcSMA2, which is closely related to Caenorhabditis elegans SMA2 (CeSMA2) involved in the bone morphogenetic protein (BMP) signaling. Hcsma2 is transcribed in all developmental stages of H. contortus but highly induced in the adult male worms. The RNA interference with Hcsma2 retarded the transition of infective L3 into L4 larvae. Besides, the bimolecular fluorescence complementation revealed the interaction of HcSMA2 with a TGF-β-activated-R-SMAD (HcDAF8). Together these results show a BMP-like receptor-regulated SMAD in H. contortus that is required for larval differentiation and underscore an adaptive functional repurposing of BMP-signaling in parasitic worms.


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