TRPV4 Is Required for Hypoxic Pulmonary Vasoconstriction

2015 ◽  
Vol 122 (6) ◽  
pp. 1338-1348 ◽  
Author(s):  
Neil M. Goldenberg ◽  
Liming Wang ◽  
Hannes Ranke ◽  
Wolfgang Liedtke ◽  
Arata Tabuchi ◽  
...  

Abstract Background: Hypoxic pulmonary vasoconstriction (HPV) is critically important in regionally heterogeneous lung diseases by directing blood toward better-oxygenated lung units, yet the molecular mechanism of HPV remains unknown. Transient receptor potential (TRP) channels are a large cation channel family that has been implicated in HPV, specifically in the pulmonary artery smooth muscle cell (PASMC) Ca2+ and contractile response to hypoxia. In this study, the authors probed the role of the TRP family member, TRPV4, in HPV. Methods: HPV was assessed by using isolated perfused mouse lungs or by intravital microscopy to directly visualize pulmonary arterioles in mice. In vitro experiments were performed in primary human PASMC. Results: The hypoxia-induced pulmonary artery pressure increase seen in wild-type mice (5.6 ± 0.6 mmHg; mean ± SEM) was attenuated both by inhibition of TRPV4 (2.8 ± 0.5 mmHg), or in lungs from TRPV4-deficient mice (Trpv4−/−) (3.4 ± 0.5 mmHg; n = 7 each). Functionally, Trpv4−/− mice displayed an exaggerated hypoxemia after regional airway occlusion (pao2 71% of baseline ± 2 vs. 85 ± 2%; n = 5). Direct visualization of pulmonary arterioles by intravital microscopy revealed a 66% reduction in HPV in Trpv4−/− mice. In human PASMC, inhibition of TRPV4 blocked the hypoxia-induced Ca2+ influx and myosin light chain phosphorylation. TRPV4 may form a heteromeric channel with TRPC6 as the two channels coimmunoprecipitate from PASMC and as there is no additive effect of TRPC and TRPV4 inhibition on Ca2+ influx in response to the agonist, 11,12-epoxyeicosatrienoic acid. Conclusion: TRPV4 plays a critical role in HPV, potentially via cooperation with TRPC6.

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 668
Author(s):  
Concetta Altamura ◽  
Maria Raffaella Greco ◽  
Maria Rosaria Carratù ◽  
Rosa Angela Cardone ◽  
Jean-François Desaphy

Ovarian cancer (OC) is the deadliest gynecologic cancer, due to late diagnosis, development of platinum resistance, and inadequate alternative therapy. It has been demonstrated that membrane ion channels play important roles in cancer processes, including cell proliferation, apoptosis, motility, and invasion. Here, we review the contribution of ion channels in the development and progression of OC, evaluating their potential in clinical management. Increased expression of voltage-gated and epithelial sodium channels has been detected in OC cells and tissues and shown to be involved in cancer proliferation and invasion. Potassium and calcium channels have been found to play a critical role in the control of cell cycle and in the resistance to apoptosis, promoting tumor growth and recurrence. Overexpression of chloride and transient receptor potential channels was found both in vitro and in vivo, supporting their contribution to OC. Furthermore, ion channels have been shown to influence the sensitivity of OC cells to neoplastic drugs, suggesting a critical role in chemotherapy resistance. The study of ion channels expression and function in OC can improve our understanding of pathophysiology and pave the way for identifying ion channels as potential targets for tumor diagnosis and treatment.


2020 ◽  
Vol 6 (12) ◽  
pp. eaaz3367 ◽  
Author(s):  
DongXu He ◽  
AiQin Mao ◽  
YouRan Li ◽  
SiuCheung Tam ◽  
YongTang Zheng ◽  
...  

Mammalian transient receptor potential (TRP) channels are major components of Ca2+ signaling pathways and control a diversity of physiological functions. Here, we report a specific role for TRPC1 in the entry of herpes simplex virus type 1 (HSV-1) into cells. HSV-1–induced Ca2+ release and entry were dependent on Orai1, STIM1, and TRPC1. Inhibition of Ca2+ entry or knockdown of these proteins attenuated viral entry and infection. HSV-1 glycoprotein D interacted with the third ectodomain of TRPC1, and this interaction facilitated viral entry. Knockout of TRPC1 attenuated HSV-1–induced ocular abnormality and morbidity in vivo in TRPC1−/− mice. There was a strong correlation between HSV-1 infection and plasma membrane localization of TRPC1 in epithelial cells within oral lesions in buccal biopsies from HSV-1–infected patients. Together, our findings demonstrate a critical role for TRPC1 in HSV-1 infection and suggest the channel as a potential target for anti-HSV therapy.


2017 ◽  
Vol 123 (6) ◽  
pp. 1647-1656 ◽  
Author(s):  
Ievgen Strielkov ◽  
Oleg Pak ◽  
Natasha Sommer ◽  
Norbert Weissmann

Hypoxic pulmonary vasoconstriction (HPV) is a physiological reaction, which adapts lung perfusion to regional ventilation and optimizes gas exchange. Impaired HPV may cause systemic hypoxemia, while generalized HPV contributes to the development of pulmonary hypertension. The triggering mechanisms underlying HPV are still not fully elucidated. Several hypotheses are currently under debate, including a possible decrease as well as an increase in reactive oxygen species as a triggering event. Recent findings suggest an increase in the production of reactive oxygen species in pulmonary artery smooth muscle cells by complex III of the mitochondrial electron transport chain and occurrence of oxygen sensing at complex IV. Other essential components are voltage-dependent potassium and possibly L-type, transient receptor potential channel 6, and transient receptor potential vanilloid 4 channels. The release of arachidonic acid metabolites appears also to be involved in HPV regulation. Further investigation of the HPV mechanisms will facilitate the development of novel therapeutic strategies for the treatment of HPV-related disorders.


2021 ◽  
Author(s):  
Amarnath Sen

Anosmia, ageusia and impaired chemesthetic sensations are quite common in coronavirus patients. Different mechanisms have been proposed to explain the anosmia and ageusia of COVID-19 patients, though for reversible anosmia and ageusia, which are resolved quickly, the proposed mechanisms seem to be incomplete. In addition, the reason behind the impaired chemesthetic sensations of some coronavirus patients remains unknown. It is proposed that in coronavirus patients, there is depletion of tryptophan (an essential amino acid), as ACE2, a key element in the process of absorption of tryptophan from food, is significantly reduced due to the attack of coronavirus which use ACE2 as the receptor for its entry into the host cells. Incidentally, the depletion of tryptophan should lead to deficiency of serotonin (5-HT) in SARS-COV-2 patients because tryptophan is the precursor in the synthesis of 5-HT. Such 5-HT deficiency not only explains fast resolved anosmia and ageusia, but also dysfunctional chemesthesis, given the fact that 5-HT is an important neuromodulator in the olfactory neurons and taste receptor cells and 5-HT also enhances the nociceptor activity of transient receptor potential channels (TRP channels) responsible for chemesthetic sensations. The female predominance of olfactory and gustatory dysfunctions can also be explained by considering low 5-HT levels in women. In addition, 5-HT deficiency worsens silent hypoxemia and explains why hypoxic pulmonary vasoconstriction is nearly absent in coronavirus patients leading to poor outcome. Hence, clinical trials should be conducted on coronavirus patients to find out how different selective serotonin reuptake inhibitors (SSRIs) and serotonin agonists work out in eliminating or improving the olfactory, gustatory and chemesthetic dysfunctions as well as hypoxemia.


2019 ◽  
Vol 7 (12) ◽  
pp. 108 ◽  
Author(s):  
Giorgio Santoni ◽  
Federica Maggi ◽  
Maria Beatrice Morelli ◽  
Matteo Santoni ◽  
Oliviero Marinelli

In mammals, the transient receptor potential (TRP) channels family consists of six different families, namely TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPML (mucolipin), TRPP (polycystin), and TRPA (ankyrin), that are strictly connected with cancer cell proliferation, differentiation, cell death, angiogenesis, migration, and invasion. Changes in TRP channels’ expression and function have been found to regulate cell proliferation and resistance or sensitivity of cancer cells to apoptotic-induced cell death, resulting in cancer-promoting effects or resistance to chemotherapy treatments. This review summarizes the data reported so far on the effect of targeting TRP channels in different types of cancer by using multiple TRP-specific agonists, antagonists alone, or in combination with classic chemotherapeutic agents, microRNA specifically targeting the TRP channels, and so forth, and the in vitro and in vivo feasibility evaluated in experimental models and in cancer patients. Considerable efforts have been made to fight cancer cells, and therapies targeting TRP channels seem to be the most promising strategy. However, more in-depth investigations are required to completely understand the role of TRP channels in cancer in order to design new, more specific, and valuable pharmacological tools.


2016 ◽  
Vol 64 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Hong-Hong Li ◽  
Li-Jian Xie ◽  
Ting-Ting Xiao ◽  
Min Huang ◽  
Jie Shen

Intracellular Ca2+ levels play a critical role in the regulation of vasodilation and vasoconstriction by stimulating pulmonary artery smooth muscle cell (PASMC) proliferation, which is important in the pathogenesis of pulmonary arterial hypertension (PAH); however, L-type Ca2+ channel antagonists are useful in only few patients with PAH. The present study sought to assess the effect of mibefradil, which blocks T-type Ca2+ channels, on PASMC proliferation and Ca2+ channel profile. Human PASMCs were stimulated with 25 ng/mL platelet-derived growth factor-BB (PDGF-BB) with and without 10 µM mibefradil or 100 nM sildenafil. After 48 or 72 h, PASMC proliferation and Ca2+ channel expression were assessed by MTT assays and western blot analysis, respectively. PDGF-BB-induced PASMC proliferation at 72 h (p<0.01), which was inhibited by both sildenafil and mibefradil (p<0.01). Transient receptor potential Ca2+ channel 6 (TRPC6) expression was significantly increased with PDGF-BB stimulation (p=0.009); however, no changes in TRPC1, TRPC3, CAV1.2, and CAV3.2 levels were observed. Although both TRPC1 and CAV1.2 expression levels were increased in PDGF-stimulated PASMCs on mibefradil and sildenafil treatment, it was not statistically significant (p=0.086 and 1.000, respectively). Mibefradil inhibits PDGF-BB-stimulated PASMC proliferation; however, the mechanism through which it functions remains to be determined. Further studies are required to elucidate the full therapeutic value of mibefradil for PAH.


2021 ◽  
Vol 12 (12) ◽  
Author(s):  
Yahui Zhang ◽  
Baohua Hou ◽  
Peiyu Liang ◽  
Xin Lu ◽  
Yifan Wu ◽  
...  

AbstractMultiple sclerosis (MS) is a chronic inflammatory autoimmune disease in the central nervous system (CNS). The NLRP3 inflammasome is considered an important regulator of immunity and inflammation, both of which play a critical role in MS. However, the underlying mechanism of NLRP3 inflammasome activation is not fully understood. Here we identified that the TRPV1 (transient receptor potential vanilloid type 1) channel in microglia, as a Ca2+ influx-regulating channel, played an important role in NLRP3 inflammasome activation. Deletion or pharmacological blockade of TRPV1 inhibited NLRP3 inflammasome activation in microglia in vitro. Further research revealed that TRPV1 channel regulated ATP-induced NLRP3 inflammasome activation through mediating Ca2+ influx and phosphorylation of phosphatase PP2A in microglia. In addition, TRPV1 deletion could alleviate mice experimental autoimmune encephalomyelitis (EAE) and reduce neuroinflammation by inhibiting NLRP3 inflammasome activation. These data suggested that the TRPV1 channel in microglia can regulate NLRP3 inflammasome activation and consequently mediate neuroinflammation. Meanwhile, our study indicated that TRPV1–Ca2+–PP2A pathway may be a novel regulator of NLRP3 inflammasome activation, pointing to TRPV1 as a potential target for CNS inflammatory diseases.


2018 ◽  
Vol 64 (10) ◽  
pp. 727-731 ◽  
Author(s):  
Linghuo Jiang ◽  
Yi Yang

Transient receptor potential (TRP) channels, an ancient family of cation channels, are highly conserved in eukaryotes and play various physiological functions, ranging from sensation of ion homeostasis to reception of pain and vision. Calcium-permeable TRP channels have been identified from the plant Arabidopsis thaliana (AtCsc1) and the budding yeast Saccharomyces cerevisiae (ScCsc1). In this study, we characterized the functions of the Csc1 homolog, orf19.4805, in Candida albicans. Orf19.4805 is a protein of 866 amino acids and 11 transmembrane domains, which shares 49% identity (69% similarity) in amino acid sequence with ScRsn1. Here, we demonstrate that deletion of the orf19.4805 gene causes C. albicans cells to be sensitive to SDS (sodium dodecyl sulfate) and antifungal drugs, and tolerance to zinc, manganese, and cadmium ions. Candida albicans cells lacking orf19.4805 show a defect in filamentation in vitro. Therefore, orf19.4805 is involved in the regulation of cation homeostasis and filamentation in C. albicans.


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