SMOC2, secreted modular calcium-binding protein 2, is a non-structural component of the extracellular matrix. It plays roles in various biological processes such as tissue remodeling. It is associated with multiple signaling pathways including TGF-β1/Smad3, integrin β3-FAK-paxillin, and BMP/TGF-β1. Its dysregulation is related to many diseases, highlighting its biological importance. Genetic models like KO mouse models are valuable for studying its functions [1-8].

In a rat heart failure (HF) model, SMOC2 expression was elevated, and its knockdown via transfection improved cardiac function and damage, inhibited the TGF-β1/Smad3 signaling pathway, and regulated autophagy-related molecules, suggesting it could be a therapeutic target for HF [1]. In a mouse model of nociception, KO of Smoc2 led to increased neuronal clusters, decreased mechanical threshold, and increased coupled activation of adjacent dorsal root ganglion (DRG) neurons induced by nociceptive mechanical stimuli, revealing its role in suppressing mechanical nociception [2]. In a mouse model of myocardial fibrosis induced by isoproterenol (ISO), SMOC2 knockdown reversed cardiac functional impairment and fibrosis by inhibiting the ILK/p38 signaling pathway [3]. In a mouse model with a SMOC2 mutation (c.1076 T > G), mutant SMOC2 inhibited BMP signaling by competitively binding to BMPR1B, causing growth plate defects and short-limbed dwarfism [4].

In conclusion, SMOC2 is involved in multiple biological processes. Through model-based research, it has been shown to play significant roles in diseases like heart failure, myocardial fibrosis, and nociceptive regulation. Gene knockout mouse models have been crucial in revealing these functions, providing potential therapeutic targets for related diseases.

References:

1. Ren, Yu, Wu, Yun, He, Wenshuai, Tian, Yingjie, Zhao, Xingsheng. 2023. SMOC2 plays a role in heart failure via regulating TGF-β1/Smad3 pathway-mediated autophagy. In Open medicine (Warsaw, Poland), 18, 20230752. doi:10.1515/med-2023-0752. https://pubmed.ncbi.nlm.nih.gov/37465345/

2. Zhang, Shuo, Cai, Bing, Li, Zhen, Li, Changlin, Zhang, Xu. 2022. Fibroblastic SMOC2 Suppresses Mechanical Nociception by Inhibiting Coupled Activation of Primary Sensory Neurons. In The Journal of neuroscience : the official journal of the Society for Neuroscience, 42, 4069-4086. doi:10.1523/JNEUROSCI.2132-21.2022. https://pubmed.ncbi.nlm.nih.gov/35437277/

3. Rui, Huang, Zhao, Fang, Yuhua, Lei, Hong, Jiang. 2023. Suppression of SMOC2 alleviates myocardial fibrosis via the ILK/p38 pathway. In Frontiers in cardiovascular medicine, 9, 951704. doi:10.3389/fcvm.2022.951704. https://pubmed.ncbi.nlm.nih.gov/36935650/

4. Long, Feng, Shi, Hongbiao, Li, Pengyu, Li, Jiangxia, Liu, Qiji. 2020. A SMOC2 variant inhibits BMP signaling by competitively binding to BMPR1B and causes growth plate defects. In Bone, 142, 115686. doi:10.1016/j.bone.2020.115686. https://pubmed.ncbi.nlm.nih.gov/33059102/