ASIC2, also known as acid-sensing ion channel 2, is a mechanosensitive ion channel that plays crucial roles in multiple biological processes. It is involved in mechano-electrical transduction pathways, and has been linked to functions like blood pressure regulation, synaptic responses, and cell-specific physiological regulations. Its overall biological importance lies in its ability to translate mechanical forces into molecular signals, which is essential for normal physiological function [1,2,3]. Genetic models, such as knockout (KO) mouse models, have been instrumental in studying ASIC2's functions.

In KO mouse models, loss of ASIC2 led to various phenotypic changes. In arterial baroreceptors, blocking ASIC2 abrogated nearly all pressure-dependent neural discharge, indicating its functional necessity in mechano-electrical transduction, and it was found to form a complex and function synergistically with TRPV1 [1]. In renal afferent arterioles, ASIC2-null mice showed a decreased sensitivity of pressure-induced constriction, demonstrating its role in this process. Moreover, mice lacking both ASIC2 and βENaC had mild renal injury and increased mean arterial blood pressure [2]. In the context of drugs of abuse, Asic2-/-mice showed increased conditioned place preference to cocaine and morphine, suggesting ASIC2 plays a role in drug-reinforced behavior [3]. Mice lacking ASIC2 also displayed impairments in muscle spindle responses to stretch, motor coordination tasks, and had a specific effect on spinal alignment, identifying ASIC2 as a key component in proprioceptive sensing [4].

In conclusion, ASIC2 is essential for functions like mechano-electrical transduction, blood pressure regulation, drug-reinforced behavior, and proprioceptive sensing. Studies using ASIC2 KO mouse models have provided insights into its role in diseases related to these functions, such as renal injury, hypertension, and potential implications in drug-related disorders. These findings enhance our understanding of ASIC2's biological functions and offer potential targets for therapeutic interventions in associated disease areas.

References:

1. Yan, Xiaodong, Zhang, Sitao, Zhao, Haiyan, Wang, Wei, Zhang, Chen. 2021. ASIC2 Synergizes with TRPV1 in the Mechano-Electrical Transduction of Arterial Baroreceptors. In Neuroscience bulletin, 37, 1381-1396. doi:10.1007/s12264-021-00737-1. https://pubmed.ncbi.nlm.nih.gov/34215968/

2. Lu, Yan, Stec, David E, Liu, Ruisheng, Ryan, Michael, Drummond, Heather A. 2022. βENaC and ASIC2 associate in VSMCs to mediate pressure-induced constriction in the renal afferent arteriole. In American journal of physiology. Renal physiology, 322, F498-F511. doi:10.1152/ajprenal.00003.2022. https://pubmed.ncbi.nlm.nih.gov/35285274/

3. Fuller, Margaret J, Gupta, Subhash C, Fan, Rong, Radley, Jason J, Wemmie, John A. 2023. Investigating role of ASIC2 in synaptic and behavioral responses to drugs of abuse. In Frontiers in molecular biosciences, 10, 1118754. doi:10.3389/fmolb.2023.1118754. https://pubmed.ncbi.nlm.nih.gov/36793786/

4. Bornstein, Bavat, Watkins, Bridgette, Passini, Fabian S, Kröger, Stephan, Zelzer, Elazar. 2023. The mechanosensitive ion channel ASIC2 mediates both proprioceptive sensing and spinal alignment. In Experimental physiology, 109, 135-147. doi:10.1113/EP090776. https://pubmed.ncbi.nlm.nih.gov/36951012/