scholarly journals Transient Receptor Potential Channel, Vanilloid 5, Induces Chondrocyte Apoptosis in a Rat Osteoarthritis Model Through the Mediation of Ca2+ Influx

2018 ◽  
Vol 46 (2) ◽  
pp. 687-698 ◽  
Author(s):  
Yingliang Wei ◽  
Dianbin Zheng ◽  
Xiaocheng Guo ◽  
Min Zhao ◽  
Linlin Gao ◽  
...  

Background/Aims: Chondrocyte apoptosis is the most common pathological feature in cartilage in osteoarthritis (OA). Transient receptor potential channel vanilloid 5 (TRPV5) is important in regulating calcium ion (Ca2+) influx. Accumulating evidences suggest that Ca2+ is a major intracellular second messenger that can trigger cell apoptosis. Therefore, we investigate the potential role of TRPV5 in mediating Ca2+ influx to promote chondrocyte apoptosis in OA. Methods: The monoiodoacetic acid (MIA)-induced rat OA model was assessed by macroscopic and radiographic analyses. Calmodulin protein immunolocalization was detected by immunohistochemistry. The mRNA and protein level of TRPV5, calmodulin and cleaved caspase-8 in articular cartilage were assessed by real time polymerase chain reaction and western blotting. Primary chondrocytes were isolated and cultured in vitro. TRPV5 small interfering RNA was used to silence TRPV5 in chondrocytes. Then, calmodulin and cleaved caspase-8 were immunolocalized by immunofluorescence in chondrocyte. Fluo-4AM staining was used to assess intracellular Ca2+ to reflect TRPV5 function of mediation Ca2+ influx. Annexin V-fluorescein isothiocyanatepropidium iodide flow cytometric analysis was performed to determine chondrocytes apoptosis. Western blotting techniques were used to measure the apoptosis-related proteins in chondrocyte level. Results: Here, we reported TRPV5 was up-regulated in MIA-induced OA articular cartilage. Ruthenium red (a TRPV5 inhibitor) can relieve progression of joint destruction in vivo which promoted us to demonstrate the effect of TRPV5 in OA. We found that TRPV5 had a specific role in mediating extracellular Ca2+ influx leading to chondrocytes apoptosis in vitro. The apoptotic effect was inhibited even reversed by silencing TRPV5. Furthermore, we found that the increase Ca2+ influx triggered apoptosis by up-regulating the protein of death-associated protein, FAS-associated death domain, cleaved caspase-8, cleaved caspase-3, cleaved caspase-6, and cleaved caspase-7, and the up-regulated proteins were abolished by silencing TRPV5 or 1, 2-bis-(o-Aminophenoxy)-ethane-N,N,N’,N’-tetraacetic acid, tetraacetoxymethyl ester (a Ca2+ chelating agent). Conclusion: The up-regulated TRPV5 could used be as an initiating factor that induces extrinsic chondrocyte apoptosis via the mediation of Ca2+ influx. These findings suggested TRPV5 could be an intriguing mediator for drug target in OA.

2018 ◽  
Vol 51 (5) ◽  
pp. 2309-2323 ◽  
Author(s):  
Yingliang Wei ◽  
Zhaofeng Jin ◽  
He Zhang ◽  
Shang Piao ◽  
Jinghan Lu ◽  
...  

Background/Aims: Chondrocyte apoptosis is a central pathological feature of cartilage in osteoarthritis (OA). Accumulating evidence suggests that calcium ions (Ca2+) are an important regulator of apoptosis. Previously, we reported that the transient receptor potential channel vanilloid (TRPV5) is upregulated in monoiodoacetic acid (MIA)-induced OA articular cartilage. Methods: The protein levels of TRPV5, phosphorylated Ca2+/calmodulin-dependent kinase II (p-CaMKII), and total CaMKII were detected in vivo using western blotting techniques. Primary chondrocytes were isolated and cultured in vitro. Then, p-CAMKII was immunolocalized by immunofluorescence in chondrocytes. Fluo-4AM staining was used to assess intracellular Ca2+. Annexin V-fluorescein isothiocyanate / propidium iodide flow cytometric analysis was performed to determine chondrocyte apoptosis. Western blotting techniques were used to measure the expression of apoptosis-related proteins. Results: We found that ruthenium red (aTRPV5inhibitor)or(1-[N,O-bis-(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperaze (KN-62) (an inhibitor of Ca2+/calmodulin-dependent kinase II (CaMKII) phosphorylation) can relieve or even reverse OA in vivo. We found that TRPV5 has a specific role in mediating extracellular Ca2+ influx leading to chondrocyte apoptosis in vitro. The apoptotic effect in chondrocytes was inhibited by KN-62. We found that activated p-CaMKII could elicit the phosphorylation of extracellular signal-regulated protein kinase 1/2, c-Jun N-terminal kinase, and p38, three important regulators of the mitogen-activated protein kinase (MAPK) cascade. Moreover, we also showed that activated p-CaMKII could elicit the phosphorylation of protein kinase B (Akt) and two important downstream regulators of mammalian target of rapamycin (mTOR): 4E-binding protein, and S61 kinase. Conclusion: Our results demonstrate that upregulated TRPV5 may be an important initiating factor that activates CaMKII phosphorylation via the mediation of Ca2+ influx. In turn, activated p-CaMKII plays a critical role in chondrocyte apoptosis via MAPK and Akt/mTOR pathways.


Marine Drugs ◽  
2020 ◽  
Vol 18 (10) ◽  
pp. 519
Author(s):  
Sarah Mazzotta ◽  
Gabriele Carullo ◽  
Aniello Schiano Moriello ◽  
Pietro Amodeo ◽  
Vincenzo Di Marzo ◽  
...  

Labdane diterpenes are widespread classes of natural compounds present in variety of marine and terrestrial organisms and plants. Many of them represents “natural libraries” of compounds with interesting biological activities due to differently functionalized drimane nucleus exploitable for potential pharmacological applications. The transient receptor potential channel subfamily V member 4 (TRPV4) channel has recently emerged as a pharmacological target for several respiratory diseases, including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Inspired by the labdane-like bicyclic core, a series of homodrimane-derived esters and amides was designed and synthesized by modifying the flexible tail in position 1 of (+)-sclareolide, an oxidized derivative of the bioactive labdane-type diterpene sclareol. The potency and selectivity towards rTRPV4 and hTRPV1 receptors were assessed by calcium influx cellular assays. Molecular determinants critical for eliciting TRPV4 antagonism were identified by structure-activity relationships. Among the selective TRPV4 antagonists identified, compound 6 was the most active with an IC50 of 5.3 μM. This study represents the first report of semisynthetic homodrimane TRPV4 antagonists, selective over TRPV1, and potentially useful as pharmacological tools for the development of novel TRPV4 channel modulators.


2004 ◽  
Vol 82 (5) ◽  
pp. 289-299 ◽  
Author(s):  
Andreas Bergdahl ◽  
Karl Swärd

Caveolae are flask-shaped invaginations in the membrane that depend on the contents of cholesterol and on the structural protein caveolin. The organisation of caveolae in parallel strands between dense bands in smooth muscle is arguably unique. It is increasingly recognised, bolstered in large part by recent studies in caveolae deficient animals, that caveolae sequester and regulate a variety of signalling intermediaries. The role of caveolae in smooth muscle signal transduction, as inferred from studies on transgenic animals and in vitro approaches, is the topic of the current review. Both G-protein coupled receptors and tyrosine kinase receptors are believed to cluster in caveolae, and the exciting possibility that caveolae provide a platform for interactions between the sarcoplasmic reticulum and plasmalemmal ion channels is emerging. Moreover, messengers involved in Ca2+ sensitization of myosin phosphorylation and contraction may depend on caveolae or caveolin. Caveolae thus appear to constitute an important signalling domain that plays a role not only in regulation of smooth muscle tone, but also in proliferation, such as seen in neointima formation and atherosclerosis.Key words: caveolin, RhoA, transient receptor potential channel, endothelin, spontaneous transient outward currents.


2017 ◽  
Vol 42 (1) ◽  
pp. 319-332 ◽  
Author(s):  
Yingliang Wei ◽  
Yanfang Wang ◽  
Yutong Wang ◽  
Lunhao Bai

Background: Autophagy, a self-protective mechanism of chondrocytes, has become a promising target to impede the progress of osteoarthritis (OA). Autophagy is regulated by cytosolic Ca2+ activity and may thus be modified by the Ca2+ permeable transient receptor potential channel vanilloid 5 (TRPV5). Therefore, we investigated the potential role of TRPV5 in mediating Ca2+ influx and in inhibiting chondrocyte autophagy in a rat OA model. Methods: The rat OA model was assessed by macroscopic and histological analyses. light chain 3B (LC3B) immunolocalization was detected by immunohistochemistry. TRPV5, LC3B and calmodulin in OA articular cartilage were assessed by real time polymerase chain reaction (RT-PCR) and western blotting. TRPV5 small interfering RNA (TRPV5 siRNA) were transfected into rat primary chondrocyte then the calmodulin and LC3B was detected by immunofluorescence. The functionality of the TRPV5 was assessed by Ca2+ influx. Western blot was used to measure autophagy-related proteins. Results: We constructed a monosodium iodoacetate (MIA) -induced rat OA model and found that ruthenium red (TRPV5 inhibitor) slowed the progression of joint destruction. We found that the TRPV5 and calmodulin were up-regulated but LC3B was down-regulated in articular cartilage following prolonged progression of OA. Furthermore, the up-regulated TRPV5 channel caused an increase in the Ca2+ influx in chondrocytes. The up-regulation of TRPV5 stimulated Ca2+ influx, which inhibited autophagy by increasing the production of calmodulin, phosphorylation of calmodulin dependent protein kinases II (p-CAMK II), phosphorylation of Beclin1 (p-Beclin1), and protein of B-cell lymphoma-2 (Bcl-2), and attenuating ratio of LC3-II/ LC3-. Conclusion: Up-regulated TRPV5 as an initiating factor inhibited chondrocyte autophagy via the mediation of Ca2+ influx.


Author(s):  
Tianshun Fang ◽  
Xianhao Zhou ◽  
Mingchao Jin ◽  
Jiangbo Nie ◽  
XIongfeng Li

Abstract Introduction Mechanical loading enhances the progression of osteoarthritis. However, its molecular mechanisms have not been established. Objective The aim of this review was to summarize the probable mechanisms of mechanical load-induced osteoarthritis. Methods A comprehensive search strategy was used to search PubMed and EMBASE databases (from the 15th of January 2015 to the 20th of October 2020). Search terms included “osteoarthritis”, “mechanical load”, and “mechanism”. Results Abnormal mechanical loading activates the interleukin-1β, tumour necrosis factor-α, nuclear factor kappa-B, Wnt, transforming growth factor-β, microRNAs pathways, and the oxidative stress pathway. These pathways induce the pathological progression of osteoarthritis. Mechanical stress signal receptors such as integrin, ion channel receptors, hydrogen peroxide-inducible clone-5, Gremlin-1, and transient receptor potential channel 4 are present in the articular cartilages. Conclusion This review highlights the molecular mechanisms of mechanical loading in inducing chondrocyte apoptosis and extracellular matrix degradation. These mechanisms provide potential targets for osteoarthritis prevention and treatment.


2012 ◽  
Vol 303 (6) ◽  
pp. L539-L549 ◽  
Author(s):  
Eda Yildirim ◽  
Michelle A. Carey ◽  
Jeffrey W. Card ◽  
Alexander Dietrich ◽  
Gordon P. Flake ◽  
...  

Transient receptor potential channels (TRPCs) are widely expressed and regulate Ca2+entry in the cells that participate in the pathophysiology of airway hyperreactivity, inflammation, and remodeling. In vitro studies point to a role for TRPC1-mediated Ca2+signaling in several of these cell types; however, physiological evidence is lacking. Here we identify TRPC1 signaling as proinflammatory and a regulator of lung hyperresponsiveness during allergen-induced pulmonary response. TRPC1-deficient ( Trpc1−/−) mice are hyposensitive to methacholine challenge and have significantly reduced allergen-induced pulmonary leukocyte infiltration coupled with an attenuated T helper type 2 (Th2) cell response. Upon in vitro allergen exposure, Trpc1−/−splenocytes show impaired proliferation and T cell receptor-induced IL-2 production. A high number of germinal centers in spleens of Trpc1−/−mice and elevated levels of immunoglobulins in their serum are indicative of dysregulated B cell function and homeostasis. Thus we propose that TRPC1 signaling is necessary in lymphocyte biology and in regulation of allergen-induced lung hyperresponsiveness, making TRPC1 a potential target for treatment of immune diseases and asthma.


2019 ◽  
Vol 21 (1) ◽  
pp. 130 ◽  
Author(s):  
Elena Bresciani ◽  
Roberta Possenti ◽  
Silvia Coco ◽  
Laura Rizzi ◽  
Ramona Meanti ◽  
...  

VGF gene encodes for a neuropeptide precursor of 68 kDa composed by 615 (human) and 617 (rat, mice) residues, expressed prevalently in the central nervous system (CNS), but also in the peripheral nervous system (PNS) and in various endocrine cells. This precursor undergoes proteolytic cleavage, generating a family of peptides different in length and biological activity. Among them, TLQP-21, a peptide of 21 amino acids, has been widely investigated for its relevant endocrine and extraendocrine activities. The complement complement C3a receptor-1 (C3aR1) has been suggested as the TLQP-21 receptor and, in different cell lines, its activation by TLQP-21 induces an increase of intracellular Ca2+. This effect relies both on Ca2+ release from the endoplasmic reticulum (ER) and extracellular Ca2+ entry. The latter depends on stromal interaction molecules (STIM)-Orai1 interaction or transient receptor potential channel (TRPC) involvement. After Ca2+ entry, the activation of outward K+-Ca2+-dependent currents, mainly the KCa3.1 currents, provides a membrane polarizing influence which offset the depolarizing action of Ca2+ elevation and indirectly maintains the driving force for optimal Ca2+ increase in the cytosol. In this review, we address the main endocrine and extraendocrine actions displayed by TLQP-21, highlighting recent findings on its mechanism of action and its potential in different pathological conditions.


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