Eur. Phys. J. E (2017) 40: 72
https://doi.org/10.1140/epje/i2017-11561-1

Regular Article

Effects of stimulated aggrecanolysis on nanoscale morphological and mechanical properties of wild-type and aggrecanase-resistant mutant mice cartilages

¹ Melbourne Central of Nanofabrication, Victorian Node of Australian National Fabrication Facility, 3149, Clayton, Victoria, Australia
² Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, 400714, Chongqing, China
³ Department of Paediatrics, University of Melbourne, 3010, Parkville, Victoria, Australia
⁴ Murdoch Childrens Research Institute, Royal Children’s Hospital, 3010, Parkville, Victoria, Australia
⁵ Department of Mechanical Engineering, University of Melbourne, 3010, Parkville, Victoria, Australia
⁶ Soft Matter and Interfaces Group, School of Engineering, RMIT University, 3001, Melbourne, Victoria, Australia

^* e-mail: wanghuabin@cigit.ac.cn
^** e-mail: Xuehua.zhang@rmit.edu.au

Received: 2 April 2017
Accepted: 27 July 2017
Published online: 16 August 2017

Abstract

A key event in arthritis pathogenesis is the degradation of aggrecan, the major component in articular cartilage. In this work, we investigate the effects of stimulated aggrecanolysis on the morphological and nanomechanical properties of cartilage harvested from wild-type mice and aggrecanase-resistant mutant mice named “Jaffa”. The cartilages were native or were subjected to stimulated aggrecanolysis by interleukin-1 (IL-1) treatment. The nanoscale morphological and mechanical properties of the sectioned cartilages were measured by using a sharp probe by atomic force microscopy (AFM). The IL-1 treatment resulted in a higher nanoroughess and stiffness of the cartilage from wild-type mice. However, the same treatment did not lead to any measurable change in the nanoroughness or stiffness of the cartilage from mutant mice Jaffa. This suggests that blocking aggrecanolysis by genetic modification has created the stability in the structures and mechanical properties of the cartilage at nanoscale. The present study provides insight into the mechanism of aggrecan degradation, which can complement the examination by biochemical and histological techniques.