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Ion Channels in Immune Cells
Published in Shyam S. Bansal, Immune Cells, Inflammation, and Cardiovascular Diseases, 2022
Devasena Ponnalagu, Shridhar Sanghvi, Shyam S. Bansal, Harpreet Singh
The mammalian TRP channel superfamily comprises 28 cation-selective channels57. On the basis of their sequence and structural homology, TRP channel family members are classified into six main groups, which include canonical (TRPC), melastatin (TRPM), vanilloid (TRPV), mucolipin (TRPM), polycystin (TRPP), and ankyrin (TRPA) channel proteins57. All of the members of the TRP channel family of proteins comprise six transmembrane helices that combine as tetramers to form a cation-selective pore58. They exhibit polymodal activation properties and, therefore, become activated upon alteration in temperature, pH, and osmolarity12. A body of evidence shows their importance not only in the sensory system but also in various physiological and pathophysiological conditions like cancer, neural development, and cardiac and renal physiology.
Photobiomodulation Therapy in Orthopedics
Published in Kohlstadt Ingrid, Cintron Kenneth, Metabolic Therapies in Orthopedics, Second Edition, 2018
It is now known that TRP channel proteins are conserved throughout evolution and are found in most organisms, tissues and cell types. The TRP channel superfamily is now classified into seven related subfamilies: TRPC, TRPM, TRPV, TRPA, TRPP, TRPML and TRPN [28]. Light-sensitive ion channels are based on an opsin chromophore (isomerization of a cis-retinal molecule to the trans configuration) as illustrated in Drusophila photorecelptors [29].
Ion Channels of Reward Pathway in Drug Abuse
Published in Tian-Le Xu, Long-Jun Wu, Nonclassical Ion Channels in the Nervous System, 2021
Transient receptor potential (TRP) channels are a large family of non-selective cation channels. Besides traditional ligand-gated opening, mechanical force, chemical stress, and temperature also can lead to channel opening. Most TRP channels are permeable to Ca2+ with the exceptions of TRPM4 and TRPM5, which are only permeable to monovalent cations. The TRP superfamily contains six groups: TRPA (ankyrin), TRPC (canonical), TRPM (melastatin), TRPML (mucolipin), TRPP (polycystin), and TRPV (vanilloid). TRP channels were first identified in Drosophila melanogaster, and studies have found around 30 channels in mammals belonging to this superfamily. The diverse activation mechanisms and expression of these channels make them involved in a wide range of activities of the central and peripheral nervous systems. However, the roles of these channels in drug abuse have only recently begun to be explored, with one of the most thoroughly studied families of TRP channels in drug abuse being the TRPV family. The TRPV family contains six mammalian members: TRPV1-6. TRPV1-4 are all heat-activated channels, which exhibit cation non-selectivity and modest Ca2+ permeability. TRPV5 and TRPV6 are the only highly Ca2+-selective channels in the TRP family, and both are regulated by [Ca2+]i. In contrast with other TRPVs, the temperature sensitivity of TRPV5 and TRPV6 is relatively low. TRPV1-4 are also sensitive to a broad array of endogenous and synthetic ligands. For example, TRPV1 is activated by capsaicin, heat (≥43°C), and many other chemicals, including an endocannabinoid, anandamide; the topical analgesic, camphor; piperine in black pepper; and allicin in garlic (Caterina et al. 1997; Zygmunt et al. 1999; Xu, Blair, and Clapham 2005; McNamara, Randall, and Gunthorpe 2005; Macpherson et al. 2005). Activation of TRPV1 leads to membrane depolarization, and TRPV1-mediated current can be facilitated by extracellular acidification (Xu, Blair, and Clapham 2005). A pH change to <6, ethanol, and nicotine also have similar effects on TRPV1 activity (Trevisani et al. 2002; Liu et al. 2004).
Associations between weather conditions and osteoarthritis pain: a systematic review and meta-analysis
Published in Annals of Medicine, 2023
Lin Wang, Qinguang Xu, Yan Chen, Zhaohua Zhu, Yuelong Cao
Our finding may have broad applicability to those OA patients who are more vulnerable to weather conditions. An early European study reported that 67.2% of participants with OA attributed their pain to the weather [15]. Evidence from recent study also demonstrated the association of weather sensitivity and clinical symptoms and structural degradations in knee OA patients. 57.5% of weather-sensitive individuals more likely had severe knee pain, dysfunction and as well as cartilage defects [16]. When clinical research evidence increasingly demonstrates the aggravation of weather conditions such as T, RH and BP on OA pain, weather factors should be considered in OA management. Our finding may also contribute to the development of basic research on weather impacting OA pain. The function of Thermosensitive Transient Receptor Potential channels (Thermo-TRPs) was related with the weather stimulating, which may be the possible pathophysiological mechanisms of OA pain [44–47]. TRPs are a large family of proteins including 6 main subfamilies termed the TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPP (polycystin), TRPML (mucolipin), and TRPA (ankyrin) groups [48]. Andersson reported the TRPA-1 was overexpressed after exposure to cold temperatures (10 °C), and the mice demonstrated more nocifensive behaviour and mechanical pain sensitivity [49,50]. These quantitative analysis findings, positive or negative effect of BP, RH, and T on OA pain, may provide the basic theories and help to set weather parameters for future studies exploring these potential mechanisms.
Neuronal and non-neuronal TRPA1 as therapeutic targets for pain and headache relief
Published in Temperature, 2023
Luigi F. Iannone, Romina Nassini, Riccardo Patacchini, Pierangelo Geppetti, Francesco De Logu
The transient receptor potential (TRP) channel superfamily encompasses a group of more than 56 heterogeneous ion channels with a role in thermo- and osmo-sensation, sight, taste, smell, hearing, touch, and pain [1]. Genetic studies have demonstrated the involvement of TRP channels in several biological processes, and TRP mutations (channelopathies) have been associated with a variety of human disorders (e.g. polycystic kidney disease, skeletal dysplasia, familial episodic pain syndrome, and other disorders) [2]. In mammals, the TRP superfamily comprises six subfamilies and 28 members of nonselective cation permeable channels. They exhibit different calcium/sodium permeability ratios [3,4] and share a similar architecture, with minor differences: six transmembrane domains (S1-S6) assembling as homo- or hetero-tetramers with a cation-pore loop between S5 and S6. The amino (NH2) and carboxylic acid (COOH) termini are both localized in the cytosol [5]. The NH2 terminus domain contains several ankyrin repeats. TRP subfamilies are distinguished in TRP canonical (TRPC), TRP melastatin (TRPM), TRP polycystin (TRPP), TRP mucolipin (TRPML), TRP vanilloid (TRPV), and TRP ankyrin (TRPA) channels [5]. Most subfamilies include several members (e.g. TRPM and TRPV1 subfamilies), while the TRPA subfamily consists of only one member, the TRPA1 [6]. TRPs are activated or modulated by several endogenous and exogenous physicochemical stimuli, including intracellular mediators [7].
TRPV4 antagonists: a patent review (2015–2020)
Published in Expert Opinion on Therapeutic Patents, 2021
Brian G. Lawhorn, Edward J. Brnardic, David J. Behm
The mammalian TRP family supports a diverse range of channel function and consists of 28 channels divided into six subfamilies based on amino acid sequence homology: TRPA (ankyrin), TRPC (canonical), TRPM (melastatin), TRPML (mucolipin), TRPP (polycystin), and TRPV (vanilloid). The TRP channels sensitive to vanilloids (TRPVs), also referred to as nociceptors due to their involvement in pain sensation, are one of the largest and most diverse subfamilies, consisting of six family members, TRPV1–6. This patent review will focus on small molecule antagonists of TRPV4, an ion channel originally termed ‘OSM9-like transient receptor potential channel, member 4 (OTRPC4)’, ‘vanilloid-receptor related osmotically activated channel (VR-OAC)’ and ‘transient receptor potential 12ʹ and described as a Ca2+-permeable, nonselective cation channel that responded to changes in osmolarity [4–6].