Ubiquitin‐specific protease USP 34 controls osteogenic differentiation and bone formation by regulating BMP 2 signaling

Abstract

The osteogenic differentiation of mesenchymal stem cells (MSCs) is governed by multiple mechanisms. Growing evidence indicates that ubiquitin-dependent protein degradation is critical for the differentiation of MSCs and bone formation; however, the function of ubiquitin-specific proteases, the largest subfamily of deubiquitylases, remains unclear. Here, we identify USP34 as a previously unknown regulator of osteogenesis. The expression of USP34 in human MSCs increases after osteogenic induction while depletion of USP34 inhibits osteogenic differentiation. Conditional knockout of Usp34 from MSCs or pre-osteoblasts leads to low bone mass in mice. Deletion of Usp34 also blunts BMP2-induced responses and impairs bone regeneration. Mechanically, we demonstrate that USP34 stabilizes both Smad1 and RUNX2 and that depletion of Smurf1 restores the osteogenic potential of Usp34-deficient MSCs Taken together, our data indicate that USP34 is required for osteogenic differentiation and bone formation.

Mettl3-mediated m6A RNA methylation regulates the fate of bone marrow mesenchymal stem cells and osteoporosis

“…For alizarin red staining (ARS) staining, cells were fixed after 10 days induction of osteogenic differentiation with 4% polyoxymethylene for 15 min and stained with 1% Alizarin red S (pH 4.2, Sigma-Aldrich) for 5 min. Mineralized matrix stained with alizarin red were destained with 10% cetylpyridinium chloride in 10 mM sodium phosphate (pH 7.0), and the calcium concentration was determined by a spectrophotometer (Thermo Fisher Scientific) at 562 nm using a standard calcium curve in the same solution 62 , 63 .…”

AFF4 regulates osteogenic differentiation of human dental follicle cells

“…The experimental protocols were performed according to the manufacturer's protocol. 50 In brief, a transfection solution contained 50 nmol•L −1 Lipofectamine™ RNAiMAX in 200 µL of Opti-MEM® I Medium without serum was prepared and was incubated for 25 min at room temperature. When the cells reached 50%-70% confluence, they were diluted in complete growth medium without antibiotics, and the transfection solution with AFF4/control-siRNA was added and incubated with the cells for 10 h at 37°C in a CO 2 incubator.…”

Macrophage Polarization and Osteoporosis: A Review

“…BMP-2 belongs to the BMP family of proteins which fall under the umbrella of the TGF-β superfamily of cytokines. Several studies have illustrated that BMP-2 can stimulate bone mineralization as well as the differentiation of MSC into mature osteoblasts [ 79 , 80 , 81 , 82 ]. Mechanistically, the binding of BMP-2 to BMP receptors induced phosphorylation and activation of smad1, leading to the translocation of runt-related transcription factor 2 (RUNX2) into the nucleus to upregulate osteogenic factors including alkaline phosphatase (ALP) and osteocalcin (OC) in preosteoblastic cells [ 83 , 84 ].…”