Protective effect of Agrimonia pilosa polysaccharides on dexamethasone-treated MC3T3-E1 cells via Wnt/β-Catenin pathway.

Wei Huang,Chunqing Meng,Shuo Tian,Hong Wang,Huan Deng,Wenbo Yang,Shengyang Jin

doi:10.1111/jcmm.14868

Abstract

A water‐soluble polysaccharide (APP‐AW) was isolated from Agrimonia pilosa and prepared to three sulphated derivatives (S1, S2 and S3). The results showed that pre‐treatment with APP‐AW, S1, S2 and S3 each at the concentration of 50 μg/mL for 48 hours was able to prevent cytotoxicity induced by 1 μmol/L dexamethasone (Dex) in MC3T3‐E1 cells via inhibition of apoptosis, which is in line with the findings in flow cytometry analysis. Meanwhile, the decreased ALP activity, collagen content, mineralization, BMP2, Runx2, OSX and OCN protein expression in DEX‐treated MC3T3‐E1 cells were reversed by the addition of APP‐AW, S1, S2 and S3. Moreover, APP‐AW, S1, S2 and S3 rescued DEX‐induced increase of Bax, cytochrome c and caspase‐3 and decrease of Bcl‐2, Wnt3, β‐catenin and c‐Myc protein expression in MC3T3‐E1 cells. Our findings suggest that pre‐treatment with APP‐AW, S1, S2 and S3 could significantly protect MC3T3‐E1 cells against Dex‐induced cell injury via inhibiting apoptosis and activating Wnt/β‐Catenin signalling pathway, thus application of these polysaccharides may be a promising alternative strategy for steroid‐induced avascular necrosis of the femoral head (SANFH) therapy.

Highlights

Long-term and excessive use of GCs usually resulted in serious adverse effects including steroid-induced avascular necrosis of the femoral head (SANFH), which eventually leading to bone mass loss and bone structure deterioration if not remedied in time.[1,2]
The results showed that exposure of APP-AW significantly attenuated cell loss induced by Dex in osteoblasts via inhibition of apoptosis.[11]
Mouse pre-osteoblastic MC3T3-E1 cells were purchased from China Center for Type Culture Collection (CCTCC) (Wuhan China) and grown in Dulbecco's Modified Eagle's medium (DMEM) supplemented with 10% foetal bovine serum (FBS), penicillin (100 U/mL) and streptomycin (100 μg/mL) at 37°C in a humidified incubator containing 5% CO2

Summary

Introduction

Long-term and excessive use of GCs (ie dexamethasone) usually resulted in serious adverse effects including steroid-induced avascular necrosis of the femoral head (SANFH), which eventually leading to bone mass loss and bone structure deterioration if not remedied in time.[1,2] Available therapies for SANFH include artificial joint replacement surgery and drug remedies most of which are unsatisfactory.[3]. Long-term and excessive use of GCs (ie dexamethasone) usually resulted in serious adverse effects including steroid-induced avascular necrosis of the femoral head (SANFH), which eventually leading to bone mass loss and bone structure deterioration if not remedied in time.[1,2]. The aetiology and pathogenesis of SANFH remains controversial, it has been widely accepted that the imbalance between osteoblastic bone formation and osteoclastic bone resorption results in excessive bone loss, leading to various chronic bone diseases including SANFH.[5]. Numerous in vitro and in vivo studies strongly suggested that GCs were able to inhibit the growth and differentiation of bone cells, affecting the reconstruction and resorption of bones and decreasing the bone conversion rate, which further leads to bone destruction, and the deposit of apoptotic bone cells.[8].

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Discussion

Conclusion