Patients with neuropathic pain often experience comorbid psychiatric disorders. Cellular plasticity in the anterior cingulate cortex (ACC) is assumed as a critical interface for pain perception and emotion. However, substantial efforts thus far are focused on intracellular mechanisms of plasticity rather than extracellular alterations that might trigger and facilitate intracellular changes. Laminin is a key element of extracellular matrix (ECM) consisting of one α-, β- and γ-chain and implicated in several pathophysiological processes. Here we showed that Laminin β1 (LAMB1) in ACC is significantly downregulated upon peripheral neuropathy. Knocking down ACC LAMB1 exacerbated pain sensitivity and induced anxiety and depression. Mechanistic analysis revealed that loss of LAMB1 causes actin dysregulation via interaction with integrin beta1 and subsequent Src-dependent RhoA/LIMK/cofilin pathway, leading to increased presynaptic transmitter release probability and abnormal postsynaptic spine remodeling, which in turn orchestrates structural and functional plasticity of pyramidal neurons and eventually results in pain hypersensitivity and anxiodepression. This study shed new light on the functional capability of ECM, LAMB1 in modulating pain plasticity and revealed a mechanism that conveys extracellular alterations to intracellular plasticity. Moreover, we identified cingulate LAMB1/integrin β1 as a promising therapeutic strategy for treatment of neuropathic pain and associated anxiodepression.
Zhen-Zhen Li, Wen-Juan Han, Zhi-Chuan Sun, Yun Chen, Jun-Yi Sun, Guo-Hong Cai, Wan-Neng Liu, Tao-Zhi Wang, Yang-Dan Xie, Hong-Hui Mao, Fei Wang, Sui-Bin Ma, Fu-Dong Wang, Rou-Gang Xie, Sheng-Xi Wu, Ceng Luo