Supplementary MaterialsImage_1. indicated in CGRP-immunoreactive neurons (CGRP+), ASIC2a was mostly expressed in the majority of IB4-binding neurons (IB4+), while ASIC2b was expressed in almost all non-myelinated DRG neurons. We also found that at least half of sensory neurons expressed multiple types of ASIC subunits, indicating prevalence of Xarelto supplier heteromeric channels. In mice with peripheral nerve injury, the expression level of ASIC1a and ASIC1b in L4 DRG and ASIC3 in L5 DRG were altered in CGRP+ neurons, but not in IB4+ neurons. Furthermore, the pattern of change varied among DRGs depending on their segmental level, which pointed to differential regulatory mechanisms between afferent types and Xarelto supplier anatomical location. The distinct expression pattern of ASIC transcripts in na?ve condition, and the differential regulation of ASIC subunits after peripheral nerve injury, suggest that ASIC subunits are involved in separate sensory modalities. hybridization, neuropathic pain, peptidergic afferents Introduction Tissue injury and inflammation heighten pain sensitivity to mechanical, thermal and chemical stimuli through peripheral and central mechanisms (Baron et al., 2010; Pinho-Ribeiro et al., 2017). At the site of injury or inflammation, protons are amongst the first components that are released, leading to local pH decrease and extracellular acidosis, which depolarizes nociceptive free nerve endings in the periphery and induces pain (Issberner et al., 1996; Baumann et al., 2004). Both Acid-Sensing Ion Channels (ASICs) and Transient Receptor Potential V1 (TRPV1) channels can be activated by protons and are amongst the main sensors for extracellular acidosis in the anxious program (Lingueglia, 2007; Sugiura et al., 2007). However, ASICs possess higher pH level of sensitivity (Wemmie et al., 2013) than TRPV1 channels which are activated with pH below 6.0 (Alawi and Keeble, 2010) making ASICs better candidates to sense small pH variations and respond to moderate acidification conditions. ASICs are members of the degenerinCepithelial sodium (DEGCENaC) channel family (Waldmann et al., 1996; Garca-A?overos et al., 1997; Waldmann et al., 1997) and are directly gated by extracellular protons. Functional ASIC channels are trimeric and composed of homologous or heterologous subunits (Jasti et al., 2007). Four genes (Asic1-4), encoding six different subunits Xarelto supplier (ASIC1a, ASIC1b, ASIC2a, Xarelto supplier ASIC2b, ASIC3, and ASIC4) through alternative splicing, have been identified in rodents (Garca-A?overos et al., 1997). ASIC channels are preferentially permeable to sodium (Na+), and to a lesser extent, other cations, such as potassium (K+), lithium (Li+), and proton (H+) (Fyfe et al., 1998). ASIC1a homotrimeric and ASIC1a/2b heterotrimeric channels are also permeable to calcium (Ca2+) (Yermolaieva et al., 2004; Sherwood et al., 2011). Thus, opening of these ASIC channels results in cation influx and neuronal activation. The different ASIC subunits have various acid activation threshold, leading to distinct pH sensitivity of ASIC channels based on their composition, which makes them more versatile in pH sensing Ctsd even under conditions of dramatic pH changes. The expression and distribution of different ASIC subunits remain unclear, because most currently available ASIC antibodies lack the needed specificity to differentiate them. Limited number of studies suggested that ASIC1a and ASIC2a/2b are the subunits mostly expressed in the central nervous system (Price et al., 1996; Waldmann et al., 1996; Lingueglia et al., 1997; Baron et al., 2008). In the peripheral nervous system, RNA for most ASIC subunits appears to be expressed in the human (Flegel et al., 2015) and rodent dorsal root ganglion (DRG) (Schuhmacher and Smith, 2016) with the exception of ASIC4 which has been either detected at very low level (Akopian et al., 2000) or not detected at all Xarelto supplier (Grnder et al., 2000). Similarly, electrophysiological experiments confirmed the presence of multiple types of ASIC currents in rodent DRG neurons (Mamet et al., 2002; Poirot et al., 2006). Using immunohistochemistry and hybridization, the expression.