scholarly journals Lycorine Attenuates Autophagy in Osteoclasts via an Axis of mROS/TRPML1/TFEB to Reduce LPS-Induced Bone Loss

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Hyun-Jung Park ◽  
Malihatosadat Gholam-Zadeh ◽  
Jae-Hee Suh ◽  
Hye-Seon Choi

Lycorine, a plant alkaloid, exhibits anti-inflammatory activity by acting in macrophages that share precursor cells with osteoclasts (OCs). We hypothesized that lycorine might decrease bone loss by acting in OCs after lipopolysaccharide (LPS) stimulation, since OCs play a main role in LPS-induced bone loss. Microcomputerized tomography (μCT) analysis revealed that lycorine attenuated LPS-induced bone loss in mice. In vivo tartrate-resistant acid phosphatase (TRAP) staining showed that increased surface area and number of OCs in LPS-treated mice were also decreased by lycorine treatment, suggesting that OCs are responsible for the bone-sparing effect of lycorine. In vitro, the increased number and activity of OCs induced by LPS were reduced by lycorine. Lycorine also decreased LPS-induced autophagy in OCs by evaluation of decreased lipidated form of microtubule-associated proteins 1A/1B light chain 3B (LC3) (LC3II) and increased sequestosome 1 (p62). Lycorine attenuated oxidized transient receptor potential cation channel, mucolipin subfamily (TRPML1) by reducing mitochondrial reactive oxygen species (mROS) and decreased transcription factor EB (TFEB) nuclear translocation. Lycorine reduced the number and activity of OCs by decreasing autophagy in OCs via an axis of mROS/TRPML1/TFEB. Collectively, lycorine protected against LPS-induced bone loss by acting in OCs. Our data highlight the therapeutic potential of lycorine for protection against inflammatory bone loss.

Antioxidants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 588 ◽  
Author(s):  
Hyun-Jung Park ◽  
Malihatosadat Gholam Zadeh ◽  
Jae-Hee Suh ◽  
Hye-Seon Choi

Dauricine (DAC), an isoquinoline alkaloid, exhibits anti-inflammatory activity. We hypothesized that DAC may prevent the inflammatory bone loss induced by lipopolysaccharide (LPS). LPS-induced bone loss was decreased by DAC in female C57BL/6J mice as evaluated by micro-computerized tomography (μCT) analysis. In vivo tartrate-resistant acid phosphatase (TRAP) staining showed that the increased number of osteoclasts (OCs) in LPS-treated mice was attenuated by DAC, indicating that DAC exhibited bone sparing effects through acting on OCs. DAC also decreased the differentiation and activity of OCs after LPS stimulation in vitro. LPS-induced cytosolic reactive oxygen species (cROS) oxidized PP2A, a serine/threonine phosphatase, leading to the activation of IKKα/β, followed by the nuclear localization of p65. DAC decreased LPS-induced ROS, resulting in the recovery of the activity of PP2A by reducing its oxidized form. Consequently, DAC reduced the phosphorylation of IKKα/β to block the nuclear localization of p65, which decreased NF-κB activation. Taken together, DAC reduced the differentiation and activity of OCs by decreasing ROS via the ROS/PP2A/NF-κB axis, resulting in protection from LPS-induced bone loss. We have demonstrated that LPS-induced bone loss was inhibited by DAC via its action on OCs, implying the therapeutic potential of DAC against inflammatory bone loss.


Pharmacology ◽  
2018 ◽  
Vol 103 (1-2) ◽  
pp. 101-109 ◽  
Author(s):  
Hong-Qi Zhang ◽  
Yun-Jia Wang ◽  
Guan-Teng Yang ◽  
Qi-Le Gao ◽  
Ming-Xing Tang

It has been reported that taxifolin inhibit osteoclastogenesis in RAW264.7 cells. In our research, the inhibition effects of taxifolin on the osteoclastogenesis of human bone marrow-derived macrophages (BMMs) induced by receptor activator of NF-κB ligand (RANKL) as well as the protection effects in lipopolysaccharide-induced bone lysis mouse model have been demonstrated. In vitro, taxifolin inhibited RANKL-induced osteoclast differentiation of human BMMs without cytotoxicity. Moreover, taxifolin significantly suppressed RANKL-induced gene expression, including tartrate-resistant acid phosphatase, matrix metalloproteinase-9 nuclear factor of activated T cells 1 and cathepsin K, and F-actin ring formation. Further studies showed that taxifolin inhibit osteoclastogenesis via the suppression of the NF-κB signaling pathway. In vivo, taxifolin prevented bone loss in mouse calvarial osteolysis model. In conclusion, the results suggested that taxifolin has a therapeutic potential for osteoclastogenesis-related diseases such as osteoporosis, osteolysis, and rheumatoid arthritis.


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.


Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 619
Author(s):  
Hyun-Jung Park ◽  
Malihatosadat Gholam-Zadeh ◽  
Sun-Young Yoon ◽  
Jae-Hee Suh ◽  
Hye-Seon Choi

Loss of ovarian function is closely related to estrogen (E2) deficiency, which is responsible for increased osteoclast (OC) differentiation and activity. We aimed to investigate the action mechanism of E2 to decrease bone resorption in OCs to protect from ovariectomy (OVX)-induced bone loss in mice. In vivo, tartrate-resistant acid phosphatase (TRAP) staining in femur and serum carboxy-terminal collagen crosslinks-1 (CTX-1) were analyzed upon E2 injection after OVX in mice. In vitro, OCs were analyzed by TRAP staining, actin ring formation, carboxymethylation, determination of reactive oxygen species (ROS) level, and immunoprecipitation coupled with Western blot. In vivo and in vitro, E2 decreased OC size more dramatically than OC number and Methyl-piperidino-pyrazole hydrate dihydrochloride (MPPD), an estrogen receptor alpha (ERα) antagonist, augmented the OC size. ERα was found in plasma membranes and E2/ERα signaling affected receptor activator of nuclear factor κB ligand (RANKL)-induced actin ring formation by rapidly decreasing a proto-oncogene tyrosine-protein kinase, cellular sarcoma (c-Src) (Y416) phosphorylation in OCs. E2 exposure decreased physical interactions between NADPH oxidase 1 (NOX1) and the oxidized form of c-Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2), leading to higher levels of reduced SHP2. ERα formed a complex with the reduced form of SHP2 and c-Src to decrease c-Src activation upon E2 exposure, which blocked a signal for actin ring formation by decreased Vav guanine nucleotide exchange factor 3 (Vav3) (p–Y) and Ras-related C3 botulinum toxin substrate 1 (Rac1) (GTP) activation in OCs. E2/ERα signals consistently inhibited bone resorption in vitro. In conclusion, our study suggests that E2-binding to ERα forms a complex with SHP2/c-Src to attenuate c-Src activation that was induced upon RANKL stimulation in a non-genomic manner, resulting in an impaired actin ring formation and reducing bone resorption.


2021 ◽  
Vol 22 (1) ◽  
pp. 434
Author(s):  
Yuria Jang ◽  
Hong Moon Sohn ◽  
Young Jong Ko ◽  
Hoon Hyun ◽  
Wonbong Lim

Background: Recently, it was reported that leucine-rich repeat-containing G-protein-coupled receptor 4 (LGR4, also called GPR48) is another receptor for RANKL and was shown to compete with RANK to bind RANKL and suppress canonical RANK signaling during osteoclast differentiation. The critical role of the protein triad RANK–RANKL in osteoclastogenesis has made their binding an important target for the development of drugs against osteoporosis. In this study, point-mutations were introduced in the RANKL protein based on the crystal structure of the RANKL complex and its counterpart receptor RANK, and we investigated whether LGR4 signaling in the absence of the RANK signal could lead to the inhibition of osteoclastogenesis.; Methods: The effects of point-mutated RANKL (mRANKL-MT) on osteoclastogenesis were assessed by tartrate-resistant acid phosphatase (TRAP), resorption pit formation, quantitative real-time polymerase chain reaction (qPCR), western blot, NFATc1 nuclear translocation, micro-CT and histomorphological assay in wild type RANKL (mRANKL-WT)-induced in vitro and in vivo experimental mice model. Results: As a proof of concept, treatment with the mutant RANKL led to the stimulation of GSK-3β phosphorylation, as well as the inhibition of NFATc1 translocation, mRNA expression of TRAP and OSCAR, TRAP activity, and bone resorption, in RANKL-induced mouse models; and Conclusions: The results of our study demonstrate that the mutant RANKL can be used as a therapeutic agent for osteoporosis by inhibiting RANKL-induced osteoclastogenesis via comparative inhibition of RANKL. Moreover, the mutant RANKL was found to lack the toxic side effects of most osteoporosis treatments.


2014 ◽  
Vol 306 (4) ◽  
pp. H574-H584 ◽  
Author(s):  
Jack Rubinstein ◽  
Valerie M. Lasko ◽  
Sheryl E. Koch ◽  
Vivek P. Singh ◽  
Vinicius Carreira ◽  
...  

Transient receptor potential cation channels have been implicated in the regulation of cardiovascular function, but only recently has our laboratory described the vanilloid-2 subtype (TRPV2) in the cardiomyocyte, though its exact mechanism of action has not yet been established. This study tests the hypothesis that TRPV2 plays an important role in regulating myocyte contractility under physiological conditions. Therefore, we measured cardiac and vascular function in wild-type and TRPV2−/− mice in vitro and in vivo and found that TRPV2 deletion resulted in a decrease in basal systolic and diastolic function without affecting loading conditions or vascular tone. TRPV2 stimulation with probenecid, a relatively selective TRPV2 agonist, caused an increase in both inotropy and lusitropy in wild-type mice that was blunted in TRPV2−/− mice. We examined the mechanism of TRPV2 inotropy/lusitropy in isolated myocytes and found that it modulates Ca2+ transients and sarcoplasmic reticulum Ca2+ loading. We show that the activity of this channel is necessary for normal cardiac function and that there is increased contractility in response to agonism of TRPV2 with probenecid.


2014 ◽  
Vol 31 (1) ◽  
pp. 41-49
Author(s):  
Oleh Yadlovskyi ◽  
Tatiana Bukhtiarova ◽  
Lyudmila Bobkova ◽  
Irina Tatianshenko ◽  
Igor Monchak ◽  
...  

SUMMARY The study of features of pharmacodynamics of a new analgesic is an important and urgent task of modern pharmacology. These data allow us to clarify the nosology for application of an analgesic and to create a theoretical background to optimize its use. An effect mediated by the transient receptor potential cation channel, subfamily V, member 1 (TRPV1) activation can also be an effective mechanism of the analgesic action. We evaluated the possibility of TRPV1 participation in implementation of the analgesic effect with the antiviral action of amizonum during the experiment. It is known that amino acids Tyr511 and Ser512 are the main components of the active site of TRPV1. In this connection, dipeptide Tyr-Ser has been completely synthesized as a model of the active site of TRPV1. In the experiment model this was shown, using the spectrophotometric method, with the formation of the “capsaicin - Tyr- Ser” intermolecular complex at the level of the stability constant Kkor=0.998 and Kr=0.3•10-4 L/mol and the “amizonum - Tyr-Ser” weak intermolecular complex Kr=0.05•104 L/mol; Kkor= 0.995, respectively. The data verification was carried out in experiments in vitro (isolated ratportal vein) and in vivo (Tail-flick model), with the TRPV1 agonist. It was shown that the amplitude of smooth muscle (SM) contraction of the portal vein at a capsaicin concentration 0.1 μmol/L, 0.5 μmol/L capsazepine, and 1.0 μmol/L amizonum was +30.3±5.3%, -3.2± 2.7% and +7.1±3.2% from initial level, respectivelly. In a combined application of amizonum with capsaicin or capsazepine, the amplitude of contraction of the SM portal vein was 20.1± 1.3% and -3.0±1.4%, respectively. This indicates the absence of action of amizonum under combined use of capsaicinoids. The Tail-flick model showed atypical potentiation of the amizonum antinociception with the use of capsaicin. The obtained data suggest the low probability of the participation of TRPV1 in the implementation of the antinociceptive action of amizonum.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
David Zhang ◽  
Suelhem Mendoza ◽  
Aaron Bubolz ◽  
Makoto Suzuki ◽  
David Gutterman

Agonist-induced Ca 2+ entry in endothelial cells is important for the synthesis and release of vasoactive factors, although mechanisms of Ca 2+ entry remain largely unknown. Emerging evidence suggests that the transient receptor potential vanilloid 4 (TRPV4) channel, a Ca 2+ -permeant TRP channel, is expressed in endothelial cells and may be involved in the regulation of vascular tone. Here we investigated the potential role of TRPV4 channels in acetylcholine-induced vasodilation in vitro and in vivo using the TRPV4 knockout (TRPV4 −/− ) mice model. Carotid arteries were isolated and preconstricted with the thromboxane A2 mimetic U46619. Concentration-dependent relaxations to acetylcholine (10 −9 –10 −5 M) were markedly reduced in carotids of TRPV4 −/− vs. wild-type (WT) mice (maximal relaxations of 31±12% vs 53±4%, respectively; n=4 mice). There was no significant change in the ED50 for Ach. In both WT and TRPV4 −/− , acetylcholine-induced relaxations were blocked and converted to constrictions by the NO synthase inhibitor L-NAME (maximal relaxations of −25±6% and −24±7%, respectively). There was no difference in papaverine-induced relaxations between WT and TRPV4 −/− mice (maximal relaxations of 93±3% vs. 90±3%, respectively). U46619 caused similar contractions in carotid arteries from those mice. We also compared in vivo vasodilator effects of acetylcholine by measuring changes in blood pressure in those animals. Intravenous administration of acetylcholine (15 ng/gm bolus) decreased blood pressure by 32±6 mmHg in WT mice (from 90±15 to 57±10 mmHg; n=6), whereas blood pressure was reduced by only 10 mmHg in TRPV4 −/− mice (from 67±6 to 56±4 mmHg; n=12). Acetylcholine caused similar reductions in heart rate in WT and TRPV4 −/− mice, with mean changes of 365±57 and 292±40 beats/min, respectively. We conclude that the endothelium-dependent vasodilator response to acetylcholine is reduced both in vitro and in vivo in TRPV4 −/− mice, and these findings may provide novel insight into the mechanisms of Ca 2+ entry evoked by chemical agonists in endothelial cells. The paradoxically lower baseline blood pressure in TRPV4 −/− mice requires further investigation.


2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Xingchen Li ◽  
Yuan Cheng ◽  
Zhiqi Wang ◽  
Jingyi Zhou ◽  
Yuanyuan Jia ◽  
...  

AbstractTransient receptor potential vanilloid 4 (TRPV4) is a calcium-permeable cation channel that has been associated with several types of cancer. However, its biological significance, as well as its related mechanism in endometrial cancer (EC) still remains elusive. In this study, we examined the function of calcium in EC, with a specific focus on TRPV4 and its downstream pathway. We reported here on the findings that a high level of serum ionized calcium was significantly correlated with advanced EC progression, and among all the calcium channels, TRPV4 played an essential role, with high levels of TRPV4 expression associated with cancer progression both in vitro and in vivo. Proteomic and bioinformatics analysis revealed that TRPV4 was involved in cytoskeleton regulation and Rho protein pathway, which regulated EC cell migration. Mechanistic investigation demonstrated that TRPV4 and calcium influx acted on the cytoskeleton via the RhoA/ROCK1 pathway, ending with LIMK/cofilin activation, which had an impact on F-actin and paxillin (PXN) levels. Overall, our findings indicated that ionized serum calcium level was significantly associated with poor outcomes and calcium channel TRPV4 should be targeted to improve therapeutic and preventive strategies in EC.


2015 ◽  
Vol 93 (3) ◽  
pp. 171-176 ◽  
Author(s):  
Aruni Jha ◽  
Pawan Sharma ◽  
Vidyanand Anaparti ◽  
Min H. Ryu ◽  
Andrew J. Halayko

Airway smooth muscle (ASM) contraction controls the airway caliber. Airway narrowing is exaggerated in obstructive lung diseases, such as asthma and chronic obstructive pulmonary disease (COPD). The mechanism by which ASM tone is dysregulated in disease is not clearly understood. Recent research on ion channels, particularly transient receptor potential cation channel, subfamily A, member 1 (TRPA1), is uncovering new understanding of altered airway function. TRPA1, a member of the TRP channel superfamily, is a chemo-sensitive cation channel that can be activated by a variety of external and internal stimuli, leading to the influx of Ca2+. Functional TRPA1 channels have been identified in neuronal and non-neuronal tissues of the lung, including ASM. In the airways, these channels can regulate the release of mediators that are markers of airway inflammation in asthma and COPD. For, example, TRPA1 controls cigarette-smoke-induced inflammatory mediator release and Ca2+ mobilization in vitro and in vivo, a response tied to disease pathology in COPD. Recent work has revealed that pharmacological or genetic inhibition of TRPA1 inhibits the allergen-induced airway inflammation in vitro and airway hyper-responsiveness (AHR) in vivo. Collectively, it appears that TRPA1 channels may be determinants of ASM contractility and local inflammation control, positioning them as part of novel mechanisms that control (patho)physiological function of airways and ASM.


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