MicroRNA-221 promotes cell proliferation, migration, and differentiation by regulation of ZFPM2 in osteoblasts

Abstract

Bone fracture is a common medical condition, which may occur due to traumatic injury or disease-related conditions. Evidence suggests that microRNAs (miRNAs) can regulate osteoblast differentiation and function. In this study, we explored the effects and mechanism of miR-221 on the growth and migration of osteoblasts using MC3T3-E1 cells. The expression levels of miR-221 in the different groups were measured by qRT-PCR. Then, miR-221 mimic and inhibitor were transfected into MC3T3-E1 cells, and cell viability and migration were measured using the CCK-8 assay and the Transwell migration assay. Additionally, the expression levels of differentiation-related factors (Runx2 and Ocn) and ZFPM2 were measured by qRT-PCR. Western blot was used to measure the expression of cell cycle-related proteins, epithelial-mesenchymal transition (EMT)-related proteins, ZFPM2, and Wnt/Notch, and Smad signaling pathway proteins. miR-221 was significantly up-regulated in the patients with lumbar compression fracture (LCM) and trochanteric fracture (TF). miR-221 promoted ALP, Runx2, and OPN expressions in MC3T3-E1 cells. miR-221 overexpression significantly increased cell proliferation, migration, differentiation, and matrix mineralization, whereas suppression of miR-221 reversed these effects. Additionally, the results displayed that ZFPM2 was a direct target gene of miR-221, and overexpression of ZFPM2 reversed the promoting effects of miR-221 overexpression on osteoblasts. Mechanistic study revealed that overexpression of miR-221 inactivated the Wnt/Notch and Smad signaling pathways by regulating ZFPM2 expression. We drew the conclusions that miR-221 overexpression promoted osteoblast proliferation, migration, and differentiation by regulation of ZFPM2 expression and deactivating the Wnt/Notch and Smad signaling pathways.

MicroRNAs as Next Generation Therapeutics in Osteoporosis

“…miRNAs are generally regarded as post-transcriptional regulators that check the process of proliferation, apoptosis, differentiation and development [64]. Several miRNAs are documented to regulate the process of osteogenic proliferation, such as excessive expression of miR-221 and miR-215 in the mouse osteoblast cells encourages the proliferative capacity of the cells [65,66]. Likewise, downregulation of miR-185 results in the declined osteoblast proliferation [67].…”

Exosome: A Novel Nanocarrier Delivering Noncoding RNA for Bone Tissue Engineering

“…Studies on miRNAs have demonstrated that the regulation of the target genes affects the expression of regulators upstream and downstream of each signaling pathway, to regulate the osteogenic differentiation process [54]. Runx2 is a transcription factor that plays an important role in osteoblast differentiation [55], which is precisely or indirectly regulated by many miRNAs, including miR-221 [56,57], miR-133a-5p [58], miR-467g [59], miR-218 [60,61], and miR-210 [62]. The expression of Osx can be downregulated by some miR-NAs, inhibiting osteogenic differentiation, such as miR-145 [63] and miR-143 [64,65].…”

Synonymous Mutations of Porcine Igf1r Extracellular Domain Affect Differentiation and Mineralization in MC3T3-E1 Cells

“…Moreover, a certain amount of IGF-1R was detected in MC3T3-E1 cells (Joung et al, 2013). The cells were cultured in Dulbecco's minimal essential medium (DMEM) (Hyclone, United States) supplemented with 10% heat-inactivated fetal bovine serum and 1% streptomycin/penicillin (Gibco, United States) in an incubator with 5% CO 2 at 37 • C. At 80% cell confluence, the culture medium was changed to a differentiation medium that contained 50 mg/mL ascorbic acid (Sigma, United States) and 10 mmol/L β-glycerophosphate (Sigma, United States) (Zheng et al, 2018).…”