Long Noncoding RNA GAS5 Promotes Osteogenic Differentiation of Human Periodontal Ligament Stem Cells by Regulating GDF5 and p38/JNK Signaling Pathway.

Qiaolin Yang,Peng Liu,Weiran Li,Yunfei Zheng,Yiping Huang,Xiaobei Li,Lingfei Jia,Yineng Han

doi:10.3389/fphar.2020.00701

Qiaolin Yang, Peng Liu + Show 6 more

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https://doi.org/10.3389/fphar.2020.00701

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Journal: Frontiers in pharmacology	Publication Date: May 20, 2020
Citations: 27	License type: CC BY 4.0

Affiliation: Stomatology Hospital, Peking University

Abstract

Both extracellular matrix (ECM) and stem cells contribute to the formation of bones. Accumulating evidence proved that the growth differentiation factor 5 (GDF5) plays a vital role in ECM osteogenesis regulation; the use of human periodontal ligament stem cells (hPDLSCs) may contribute to alveolar bone regeneration. Moreover, long noncoding RNAs (lncRNA) serves as a regulator in the growing process of cellular organisms including bone formation. Previous efforts has led us to the discovery that the expression of growth arrest specific transcript 5 (GAS5) changed in the osteogenic differentiation of hPDLSCs. Moreover, the expression of GAS5, as it turns out, is correlated to GDF5. This study attempts to investigate the inner workings of GAS5 in its regulation of osteoblastic differentiation of hPDLSCs. Cell transfection, Alkaline phosphatase (ALP) staining, Alizarin red S (ARS) staining, qRT-PCR, immunofluorescence staining analysis and western blotting were employed in this study. It came to our notice that GAS5 and GDF5 expression increased during osteogenesis induction of hPDLSCs. Knocking down of GAS5 inhibited the osteogenic differentiation of hPDLSCs, whereas overexpressing GAS5 promoted these effects. Molecular mechanism study further demonstrated that overexpressing GAS5 bolsters GDF5 expression and boosts the phosphorylation of JNK and p38 in hPDLSCs, with opposite effects in GAS5 knockdown group. To sum up, long noncoding RNA GAS5 serves to regulate the osteogenic differentiation of PDLSCs via GDF5 and p38/JNK signaling pathway. Our findings expand the theoretical understanding of the osteogenesis mechanism in hPDLSCs, providing new insights into the treatment of bone defects.

Highlights

Alveolar bone loss has been posing perplexing challenges in the field of oral disease for decades
The intensity of Alkaline phosphatase (ALP) staining was gradually enhanced at days 0, 3, and 7 of osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) (Figure 1B)
To determine how growth arrest specific transcript 5 (GAS5) and growth differentiation factor 5 (GDF5) influences the osteogenic differentiation of PDLSCs, we conducted examination of its expression pattern, and found that the expression of GAS5 and GDF5 exhibited a gradual upregulation during the osteogenic differentiation for 14 days (Figure 2)

Summary

Introduction

Alveolar bone loss has been posing perplexing challenges in the field of oral disease for decades. Bone is composed of calcified matrix—derived from extracellular matrix (ECM) and osteocytes (differentiated from osteoblasts). Extracellular matrix, a complicated complex of collagen, proteoglycans and glycoproteins, provides a specialized microenvironment for the proliferation, differentiation, aging and apoptosis of cells (Watt and Huck, 2013). ECM, essential in the bone formation process, forms a microenvironment to regulate bioactivities of osteoblasts, providing signals for osteoblasts via diversified passages like Wnt and MAPK signaling pathways (Khatiwala et al, 2009; Lisignoli et al, 2017). MSCs are an important group of multipotent cells that can differentiate into a broad range of cell types including osteoblasts(Pittenger et al, 1999). Equipped with self-renewal and multi-differentiation capacity, MSCs are regarded as essential seeding cells in bone tissue engineering (Quarto et al, 2001; Rastegar et al, 2010)

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