Information-Centric Networking (ICN) provides substantial flexibility for users. One of the most important features of ICN is the universal in-network caching. The characteristics of ICN make it substantially different from traditional caching systems. In this paper we propose an age-based cooperative caching scheme in response to the special characteristics of ICN. We leverage the coupling between routing and caching in ICN to develop a light-weight collaboration mechanism that adaptively pushes popular contents to the network edge. We evaluate our approach using real traces and realistic network topology. Results show that our approach can significantly reduce network delay and traffic, and outperforms existing schemes.