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1.
Cell Mol Life Sci ; 81(1): 337, 2024 Aug 09.
Article de Anglais | MEDLINE | ID: mdl-39120784

RÉSUMÉ

The α9α10 nicotinic cholinergic receptor (nAChR) is a ligand-gated pentameric cation-permeable ion channel that mediates synaptic transmission between descending efferent neurons and mechanosensory inner ear hair cells. When expressed in heterologous systems, α9 and α10 subunits can assemble into functional homomeric α9 and heteromeric α9α10 receptors. One of the differential properties between these nAChRs is the modulation of their ACh-evoked responses by extracellular calcium (Ca2+). While α9 nAChRs responses are blocked by Ca2+, ACh-evoked currents through α9α10 nAChRs are potentiated by Ca2+ in the micromolar range and blocked at millimolar concentrations. Using chimeric and mutant subunits, together with electrophysiological recordings under two-electrode voltage-clamp, we show that the TM2-TM3 loop of the rat α10 subunit contains key structural determinants responsible for the potentiation of the α9α10 nAChR by extracellular Ca2+. Moreover, molecular dynamics simulations reveal that the TM2-TM3 loop of α10 does not contribute to the Ca2+ potentiation phenotype through the formation of novel Ca2+ binding sites not present in the α9 receptor. These results suggest that the TM2-TM3 loop of α10 might act as a control element that facilitates the intramolecular rearrangements that follow ACh-evoked α9α10 nAChRs gating in response to local and transient changes of extracellular Ca2+ concentration. This finding might pave the way for the future rational design of drugs that target α9α10 nAChRs as otoprotectants.


Sujet(s)
Calcium , Récepteurs nicotiniques , Animaux , Rats , Acétylcholine/métabolisme , Acétylcholine/pharmacologie , Séquence d'acides aminés , Sites de fixation , Calcium/métabolisme , Simulation de dynamique moléculaire , Techniques de patch-clamp , Sous-unités de protéines/métabolisme , Sous-unités de protéines/génétique , Récepteurs nicotiniques/métabolisme , Récepteurs nicotiniques/génétique , Récepteurs nicotiniques/composition chimique , Xenopus laevis
2.
Front Cell Dev Biol ; 12: 1414935, 2024.
Article de Anglais | MEDLINE | ID: mdl-39108834

RÉSUMÉ

Ion channels are integral membrane proteins mediating ion flow in response to changes in their environment. Among the different types of ion channels reported to date, the super-family of TRP channels stands out since its members have been linked to many pathophysiological processes. The family comprises 6 subfamilies and 28 members in mammals, which are widely distributed throughout most tissues and organs and have an important role in several aspects of cellular physiology. It has been evidenced that abnormal expression, post-translational modifications, and channel trafficking are associated with several pathologies, such as cancer, cardiovascular disease, diabetes, and brain disorders, among others. In this review, we present an updated summary of the mechanisms involved in the subcellular trafficking of TRP channels, with a special emphasis on whether different post-translational modifications and naturally occurring mutagenesis affect both expression and trafficking. Additionally, we describe how such changes have been associated with the development and progress of diverse pathologies associated with the gain or loss of functional phenotypes. The study of these processes will not only contribute to a better understanding the role of TRP channels in the different tissues but will also present novel possible therapeutic targets in diseases where their activity is dysregulated.

3.
Cells ; 13(13)2024 Jul 06.
Article de Anglais | MEDLINE | ID: mdl-38995001

RÉSUMÉ

BACKGROUND: Extravillous trophoblasts (EVTs) form stratified columns at the placenta-uterus interface. In the closest part to fetal structures, EVTs have a proliferative phenotype, whereas in the closest part to maternal structures, they present a migratory phenotype. During the placentation process, Connexin 40 (Cx40) participates in both the proliferation and migration of EVTs, which occurs under hypoxia. However, a possible interaction between hypoxia and Cx40 has not yet been established. METHODS: We developed two cellular models, one with "low Cx40" (Jeg-3), which reflected the expression of this protein found in migratory EVTs, and one with "high Cx40" (Jeg-3/hCx40), which reflected the expression of this protein in proliferative cells. We analyzed the migration and proliferation of these cells under normoxic and hypoxic conditions for 24 h. Jeg-3 cells under hypoxia increased their migratory capacity over their proliferative capacity. However, in Jeg-3/hCx40, the opposite effect was induced. On the other hand, hypoxia promoted gap junction (GJ) plaque formation between neighboring Jeg-3 cells. Similarly, the activation of a nitro oxide (NO)/cGMP/PKG-dependent pathway induced an increase in GJ-plaque formation in Jeg-3 cells. CONCLUSIONS: The expression patterns of Cx40 play a crucial role in shaping the responses of EVTs to hypoxia, thereby influencing their migratory or proliferative phenotype. Simultaneously, hypoxia triggers an increase in Cx40 gap junction (GJ) plaque formation through a pathway dependent on NO.


Sujet(s)
Hypoxie cellulaire , Mouvement cellulaire , Prolifération cellulaire , Connexines , Gap Junction alpha-5 Protein , Jonctions communicantes , Trophoblastes , Trophoblastes/métabolisme , Humains , Jonctions communicantes/métabolisme , Connexines/métabolisme , Femelle , Grossesse , Lignée cellulaire , Modèles biologiques , Extravillous Trophoblasts
4.
Biology (Basel) ; 13(7)2024 Jun 25.
Article de Anglais | MEDLINE | ID: mdl-39056663

RÉSUMÉ

Glucotoxicity may exert its deleterious effects on pancreatic ß-cell function via a myriad of mechanisms, leading to impaired insulin secretion and, eventually, type 2 diabetes. ß-cell communication requires gap junction channels to be present among these cells. Gap junctions are constituted by transmembrane proteins of the connexins (Cxs) family. Two Cx genes have been identified in ß cells, Cx36 and Cx30.2. We have found evidence that the glucose concentration on its own is sufficient to regulate Cx30.2 gene expression in mouse islets. In this work, we examine the involvement of the Cx30.2 protein in the survival of ß cells (RIN-m5F). METHODS: RIN-m5F cells were cultured in 5 mM D-glucose (normal) or 30 mM D-glucose (high glucose) for 24 h. Cx30.2 siRNAs was used to downregulate Cx30.2 expression. Apoptosis was measured by means of TUNEL, an annexin V staining method, and the cleaved form of the caspase-3 protein was determined using Western blot. RESULTS: High glucose did not induce apoptosis in RIN-m5F ß cells after 24 h; interestingly, high glucose increased the Cx30.2 total protein levels. Moreover, this work found that the downregulation of Cx30.2 expression in high glucose promoted apoptosis in RIN-m5F cells. CONCLUSION: The data suggest that the upregulation of Cx30.2 protects ß cells from hyperglycemia-induced apoptosis. Furthermore, Cx30.2 may be a promising avenue of therapeutic investigation for the treatment of glucose metabolic disorders.

5.
Entropy (Basel) ; 26(7)2024 Jul 03.
Article de Anglais | MEDLINE | ID: mdl-39056937

RÉSUMÉ

In this study, we work with lattice Gaussian coding for a K-user Gaussian interference channel. Following the procedure of Etkin et al., in which the capacity is found to be within 1 bit/s/Hz of the capacity of a two-user Gaussian interference channel for each type of interference using random codes, we work with lattices to take advantage of their structure and potential for interference alignment. We mimic random codes using a Gaussian distribution over the lattice. Imposing constraints on the flatness factor of the lattices, the common and private message powers, and the channel coefficients, we find the conditions to obtain the same constant gap to the optimal rate for the two-user weak Gaussian interference channel and the generalized degrees of freedom as those obtained with random codes, as found by Etkin et al. Finally, we show how it is possible to extend these results to a K-user weak Gaussian interference channel using lattice alignment.

6.
Biol Res ; 57(1): 44, 2024 Jul 05.
Article de Anglais | MEDLINE | ID: mdl-38965573

RÉSUMÉ

BACKGROUND: Exposure of humans and animals to heavy metals is increasing day-by-day; thus, lead even today remains of significant public health concern. According to CDC, blood lead reference value (BLRV) ranges from 3.5 µg/dl to 5 µg/dl in adults. Recently, almost 2.6% decline in male fertility per year has been reported but the cause is not well established. Lead (Pb2+) affects the size of testis, semen quality, and secretory functions of prostate. But the molecular mechanism(s) of lead toxicity in sperm cells is not clear. Thus, present study was undertaken to evaluate the adverse effects of lead acetate at environmentally relevant exposure levels (0.5, 5, 10 and 20 ppm) on functional and molecular dynamics of spermatozoa of bucks following in vitro exposure for 15 min and 3 h. RESULTS: Lead significantly decreased motility, viable count, and motion kinematic patterns of spermatozoa like curvilinear velocity, straight-line velocity, average path velocity, beat cross frequency and maximum amplitude of head lateral displacement even at 5 ppm concentration. Pb2+ modulated intracellular cAMP and Ca2+ levels in sperm cells through L-type calcium channels and induced spontaneous or premature acrosome reaction (AR) by increasing tyrosine phosphorylation of sperm proteins and downregulated mitochondrial transmembrane potential. Lead significantly increased DNA damage and apoptosis as well. Electron microscopy studies revealed Pb2+ -induced deleterious effects on plasma membrane of head and acrosome including collapsed cristae in mitochondria. CONCLUSIONS: Pb2+ not only mimics Ca2+ but also affects cellular targets involved in generation of cAMP, mitochondrial transmembrane potential, and ionic exchange. Lead seems to interact with Ca2+ channels because of charge similarity and probably enters the sperm cell through these channels and results in hyperpolarization. Our findings also indicate lead-induced TP and intracellular Ca2+ release in spermatozoa which in turn may be responsible for premature acrosome exocytosis which is essential feature of capacitation for fertilization. Thus, lead seems to reduce the fertilizing capacity of spermatozoa even at 0.5 ppm concentrations.


Sujet(s)
Réaction acrosomique , Acrosome , Calcium , Plomb , Mobilité des spermatozoïdes , Spermatozoïdes , Mâle , Spermatozoïdes/effets des médicaments et des substances chimiques , Calcium/métabolisme , Mobilité des spermatozoïdes/effets des médicaments et des substances chimiques , Animaux , Acrosome/effets des médicaments et des substances chimiques , Plomb/toxicité , Réaction acrosomique/effets des médicaments et des substances chimiques , AMP cyclique/métabolisme , Bovins , Potentiel de membrane mitochondriale/effets des médicaments et des substances chimiques , Transduction du signal/effets des médicaments et des substances chimiques , Analyse du sperme , Altération de l'ADN/effets des médicaments et des substances chimiques , Composés organométalliques/toxicité , Composés organométalliques/pharmacologie
7.
Br J Pharmacol ; 181(22): 4546-4570, 2024 Nov.
Article de Anglais | MEDLINE | ID: mdl-39081110

RÉSUMÉ

BACKGROUND AND PURPOSE: Gastrointestinal tumours overexpress voltage-gated calcium (CaV3) channels (CaV3.1, 3.2 and 3.3). CaV3 channels regulate cell growth and apoptosis colorectal cancer. Gossypol, a polyphenolic aldehyde found in the cotton plant, has anti-tumour properties and inhibits CaV3 currents. A systematic study was performed on gossypol blocking mechanism on CaV3 channels and its potential anticancer effects in colon cancer cells, which express CaV3 isoforms. EXPERIMENTAL APPROACH: Transcripts for CaV3 proteins were analysed in gastrointestinal cancers using public repositories and in human colorectal cancer cell lines HCT116, SW480 and SW620. The gossypol blocking mechanism on CaV3 channels was investigated by combining heterologous expression systems and patch-clamp experiments. The anti-tumoural properties of gossypol were estimated by cell proliferation, viability and cell cycle assays. Ca2+ dynamics were evaluated with cytosolic and endoplasmic reticulum (ER) Ca2+ indicators. KEY RESULTS: High levels of CaV3 transcripts correlate with poor prognosis in gastrointestinal cancers. Gossypol blockade of CaV3 isoforms is concentration- and use-dependent interacting with the closed, activated and inactivated conformations of CaV3 channels. Gossypol and CaV3 channels down-regulation inhibit colorectal cancer cell proliferation by arresting cell cycles at the G0/G1 and G2/M phases, respectively. CaV3 channels underlie the vectorial Ca2+ uptake by endoplasmic reticulum in colorectal cancer cells. CONCLUSION AND IMPLICATIONS: Gossypol differentially blocked CaV3 channel and its anticancer activity was correlated with high levels of CaV3.1 and CaV3.2 in colorectal cancer cells. The CaV3 regulates cell proliferation and Ca2+ dynamics in colorectal cancer cells. Understanding this blocking mechanism maybe improve cancer therapies.


Sujet(s)
Inhibiteurs des canaux calciques , Canaux calciques de type T , Prolifération cellulaire , Tumeurs du côlon , Gossypol , Humains , Gossypol/pharmacologie , Gossypol/analogues et dérivés , Tumeurs du côlon/traitement médicamenteux , Tumeurs du côlon/anatomopathologie , Tumeurs du côlon/métabolisme , Inhibiteurs des canaux calciques/pharmacologie , Prolifération cellulaire/effets des médicaments et des substances chimiques , Canaux calciques de type T/métabolisme , Canaux calciques de type T/génétique , Points de contrôle de la phase G1 du cycle cellulaire/effets des médicaments et des substances chimiques , Calcium/métabolisme , Lignée cellulaire tumorale , Phase G0/effets des médicaments et des substances chimiques , Antinéoplasiques/pharmacologie
8.
Int J Mol Sci ; 25(14)2024 Jul 18.
Article de Anglais | MEDLINE | ID: mdl-39063089

RÉSUMÉ

Articular chondrocytes are the primary cells responsible for maintaining the integrity and functionality of articular cartilage, which is essential for smooth joint movement. A key aspect of their role involves mechanosensitive ion channels, which allow chondrocytes to detect and respond to mechanical forces encountered during joint activity; nonetheless, the variety of mechanosensitive ion channels involved in this process has not been fully resolved so far. Because some members of the two-pore domain potassium (K2P) channel family have been described as mechanosensors in other cell types, in this study, we investigate whether articular chondrocytes express such channels. RT-PCR analysis reveals the presence of TREK-1 and TREK-2 channels in these cells. Subsequent protein expression assessments, including Western blotting and immunohistochemistry, confirm the presence of TREK-1 in articular cartilage samples. Furthermore, whole-cell patch clamp assays demonstrate that freshly isolated chondrocytes exhibit currents attributable to TREK-1 channels, as evidenced by activation by arachidonic acid (AA) and ml335 and further inhibition by spadin. Additionally, exposure to hypo-osmolar shock activates currents, which can be attributed to the presence of TREK-1 channels, as indicated by their inhibition with spadin. Therefore, these findings highlight the expression of TREK channels in rat articular chondrocytes and suggest their potential involvement in regulating the integrity of cartilage extracellular matrix.


Sujet(s)
Cartilage articulaire , Chondrocytes , Canaux potassiques à pores à domaines en tandem , Animaux , Chondrocytes/métabolisme , Canaux potassiques à pores à domaines en tandem/métabolisme , Canaux potassiques à pores à domaines en tandem/génétique , Cartilage articulaire/métabolisme , Cartilage articulaire/cytologie , Rats , Cellules cultivées , Mâle , Mécanotransduction cellulaire , Techniques de patch-clamp
9.
Toxins (Basel) ; 16(6)2024 Jun 03.
Article de Anglais | MEDLINE | ID: mdl-38922152

RÉSUMÉ

Studies on the interaction sites of peptide toxins and ion channels typically involve site-directed mutations in toxins. However, natural mutant toxins exist among them, offering insights into how the evolutionary process has conserved crucial sequences for activities and molecular target selection. In this study, we present a comparative investigation using electrophysiological approaches and computational analysis between two alpha toxins from evolutionarily close scorpion species of the genus Tityus, namely, Tst3 and Ts3 from T. stigmurus and T. serrulatus, respectively. These toxins exhibit three natural substitutions near the C-terminal region, which is directly involved in the interaction between alpha toxins and Nav channels. Additionally, we characterized the activity of the Tst3 toxin on Nav1.1-Nav1.7 channels. The three natural changes between the toxins did not alter sensitivity to Nav1.4, maintaining similar intensities regarding their ability to alter opening probabilities, delay fast inactivation, and induce persistent currents. Computational analysis demonstrated a preference for the down conformation of VSD4 and a shift in the conformational equilibrium towards this state. This illustrates that the sequence of these toxins retained the necessary information, even with alterations in the interaction site region. Through electrophysiological and computational analyses, screening of the Tst3 toxin on sodium isoform revealed its classification as a classic α-NaTx with a broad spectrum of activity. It effectively delays fast inactivation across all tested isoforms. Structural analysis of molecular energetics at the interface of the VSD4-Tst3 complex further confirmed this effect.


Sujet(s)
Venins de scorpion , Scorpions , Venins de scorpion/composition chimique , Venins de scorpion/génétique , Animaux , Brésil , Humains , Xenopus laevis , Ouverture et fermeture des portes des canaux ioniques/effets des médicaments et des substances chimiques , Séquence d'acides aminés , Animaux venimeux
10.
Entropy (Basel) ; 26(6)2024 May 29.
Article de Anglais | MEDLINE | ID: mdl-38920472

RÉSUMÉ

This work analyzes the effect of wall geometry when a reaction-diffusion system is confined to a narrow channel. In particular, we study the entropy production density in the reversible Gray-Scott system. Using an effective diffusion equation that considers modifications by the channel characteristics, we find that the entropy density changes its value but not its qualitative behavior, which helps explore the structure-formation space.

11.
Methods Mol Biol ; 2796: 97-103, 2024.
Article de Anglais | MEDLINE | ID: mdl-38856897

RÉSUMÉ

The development of cell-based fluorescent assays has resulted in an incredible tool for searching new ion channels' modulators with a biophysical and clinical profile. Among all the ion channels, potassium (K+)-permeable channels represent the most diverse and relevant for cell function, making them attractive targets for drug discovery. Some of the cell-based assays for K+ channels take advantage of a thallium-sensitive dye whose fluorescence increased upon the binding of thallium (Tl+), an ion able to move through K+ channels. We optimize the FLIPR Potassium Assay Kit based on thallium influx to measure the Kv10.1 activity.


Sujet(s)
Thallium , Thallium/métabolisme , Humains , Colorants fluorescents/composition chimique , Cellules HEK293 , Fluorescence , Canaux potassiques éther-à-go-go
12.
Chembiochem ; : e202400506, 2024 Jun 25.
Article de Anglais | MEDLINE | ID: mdl-38923811

RÉSUMÉ

Autophagic flux plays a crucial role in various diseases. Recently, the lysosomal ion channel TRPML1 has emerged as a promising target in lysosomal storage diseases, such as mucolipidosis. The discovery of mucolipin synthetic agonist-1 (ML-SA1) has expanded our understanding of TRPML1's function and its potential therapeutic uses. However, ML-SA1 is a racemate with limited cellular potency and poor water solubility. In this study, we synthetized rac-ML-SA1, separated the enantiomers by chiral liquid chromatography and determined their absolute configuration by vibrational circular dichroism (VCD). In addition, we focused on investigating the impact of each enantiomer of ML-SA1 on the TRPML1-TFEB axis. Our findings revealed that (S)-ML-SA1 acts as an agonist for TRPML1 at the lysosomal membrane. This activation prompts transcription factor EB (TFEB) to translocate from the cytosol to the nucleus in a dose-dependent manner within live cells. Consequently, this signaling pathway enhances the expression of coordinated lysosomal expression and regulation (CLEAR) genes and activates autophagic flux. Our study presents evidence for the potential use of (S)-ML-SA1 in the development of new therapies for lysosomal storage diseases that target TRPML1.

13.
Molecules ; 29(10)2024 May 12.
Article de Anglais | MEDLINE | ID: mdl-38792145

RÉSUMÉ

The Cupressaceae family includes species considered to be medicinal. Their essential oil is used for headaches, colds, cough, and bronchitis. Cedar trees like Chamaecyparis lawsoniana (C. lawsoniana) are commonly found in urban areas. We investigated whether C. lawsoniana exerts some of its effects by modifying airway smooth muscle (ASM) contractility. The leaves of C. lawsoniana (363 g) were pulverized mechanically, and extracts were obtained by successive maceration 1:10 (w:w) with methanol/CHCl3. Guinea pig tracheal rings were contracted with KCl, tetraethylammonium (TEA), histamine (HIS), or carbachol (Cch) in organ baths. In the Cch experiments, tissues were pre-incubated with D-600, an antagonist of L-type voltage-dependent Ca2+ channels (L-VDCC) before the addition of C. lawsoniana. Interestingly, at different concentrations, C. lawsoniana diminished the tracheal contractions induced by KCl, TEA, HIS, and Cch. In ASM cells, C. lawsoniana significantly diminished L-type Ca2+ currents. ASM cells stimulated with Cch produced a transient Ca2+ peak followed by a sustained plateau maintained by L-VDCC and store-operated Ca2+ channels (SOCC). C. lawsoniana almost abolished this last response. These results show that C. lawsoniana, and its active metabolite quercetin, relax the ASM by inhibiting the L-VDCC and SOCC; further studies must be performed to obtain the complete set of metabolites of the extract and study at length their pharmacological properties.


Sujet(s)
Calcium , Chamaecyparis , Contraction musculaire , Muscles lisses , Extraits de plantes , Quercétine , Trachée , Animaux , Cochons d'Inde , Muscles lisses/effets des médicaments et des substances chimiques , Muscles lisses/métabolisme , Contraction musculaire/effets des médicaments et des substances chimiques , Quercétine/pharmacologie , Quercétine/composition chimique , Trachée/effets des médicaments et des substances chimiques , Trachée/métabolisme , Extraits de plantes/pharmacologie , Extraits de plantes/composition chimique , Chamaecyparis/composition chimique , Calcium/métabolisme , Mâle , Inhibiteurs des canaux calciques/pharmacologie , Histamine/métabolisme , Canaux calciques de type L/métabolisme , Feuilles de plante/composition chimique
14.
Mol Cell Endocrinol ; 591: 112275, 2024 Sep 15.
Article de Anglais | MEDLINE | ID: mdl-38777212

RÉSUMÉ

Metabolic changes are critical in the regulation of Ca2+ influx in central and peripheral neuroendocrine cells. To study the regulation of L-type Ca2+ channels by AMPK we used biochemical reagents and ATP/glucose-concentration manipulations in rat chromaffin cells. AICAR and Compound-C, at low concentration, significantly induce changes in L-type Ca2+ channel-current amplitude and voltage dependence. Remarkably, an overlasting decrease in the channel-current density can be induced by lowering the intracellular level of ATP. Accordingly, Ca2+ channel-current density gradually diminishes by decreasing the extracellular glucose concentration. By using immunofluorescence, a decrease in the expression of CaV1.2 is observed while decreasing extracellular glucose, suggesting that AMPK reduces the number of functional Ca2+ channels into the plasma membrane. Together, these results support for the first time the dependence of metabolic changes in the maintenance of Ca2+ channel-current by AMPK. They reveal a key step in Ca2+ influx in secretory cells.


Sujet(s)
AMP-Activated Protein Kinases , 5-Amino-imidazole-4-carboxamide , Canaux calciques de type L , Cellules chromaffines , Glucose , Animaux , Cellules chromaffines/métabolisme , Cellules chromaffines/effets des médicaments et des substances chimiques , Canaux calciques de type L/métabolisme , AMP-Activated Protein Kinases/métabolisme , Rats , Glucose/métabolisme , Glucose/pharmacologie , 5-Amino-imidazole-4-carboxamide/analogues et dérivés , 5-Amino-imidazole-4-carboxamide/pharmacologie , Adénosine triphosphate/métabolisme , Ribonucléotides/pharmacologie , Pyrimidines/pharmacologie , Calcium/métabolisme , Pyrazoles/pharmacologie , Cellules cultivées , Rat Wistar , Ouverture et fermeture des portes des canaux ioniques/effets des médicaments et des substances chimiques
15.
Cancers (Basel) ; 16(9)2024 Apr 27.
Article de Anglais | MEDLINE | ID: mdl-38730655

RÉSUMÉ

Despite the unique and complex nature of cancer pain, the activation of different ion channels can be related to the initiation and maintenance of pain. The transient receptor potential vanilloid 4 (TRPV4) is a cation channel broadly expressed in sensory afferent neurons. This channel is activated by multiple stimuli to mediate pain perception associated with inflammatory and neuropathic pain. Here, we focused on summarizing the role of TRPV4 in cancer etiology and cancer-induced pain mechanisms. Many studies revealed that the administration of a TRPV4 antagonist and TRPV4 knockdown diminishes nociception in chemotherapy-induced peripheral neuropathy (CIPN). Although the evidence on TRPV4 channels' involvement in cancer pain is scarce, the expression of these receptors was reportedly enhanced in cancer-induced bone pain (CIBP), perineural, and orofacial cancer models following the inoculation of tumor cells to the bone marrow cavity, sciatic nerve, and tongue, respectively. Effective pain management is a continuous problem for patients diagnosed with cancer, and current guidelines fail to address a mechanism-based treatment. Therefore, examining new molecules with potential antinociceptive properties targeting TRPV4 modulation would be interesting. Identifying such agents could lead to the development of treatment strategies with improved pain-relieving effects and fewer adverse effects than the currently available analgesics.

16.
Naunyn Schmiedebergs Arch Pharmacol ; 397(10): 7927-7938, 2024 10.
Article de Anglais | MEDLINE | ID: mdl-38753048

RÉSUMÉ

The present study aimed to evaluate the possible peripheral H2O2-induced antinociception and determine the involvement of opioidergic, cannabinoidergic and nitrergic systems, besides potassium channels in its antinociceptive effect. Prostaglandin E2 was used to induce hyperalgesia in male Swiss mice using the mechanical paw pressure test. H2O2 (0.1, 0.2, 0.3 µg/paw) promoted a dose-dependent antinociceptive effect that was not observed in contralateral paw. Female mice also showed antinociception in the model. The partial H2O2-induced antinociception was potentiated by the inhibitor of catalase enzyme, aminotriazole (40, 60, 80 µg/paw). The antinociception was not reversed by opioid and cannabinoid receptor antagonists naloxone, AM 251 and AM 630. The involvement of nitric oxide (NO) was observed by the reversal of H2O2-induced antinociception using the non-selective inhibitor of nitric oxide synthases L-NOarg and by inhibition of iNOS (L-NIL), eNOS (L-NIO) and nNOS (L-NPA). ODQ, a cGMP-forming enzyme selective inhibitor, also reversed the antinociception. The blockers of potassium channels voltage-gated (TEA), ATP-sensitive (glibenclamide), large (paxillin) and small (dequalinium) conductance calcium-activated were able to revert H2O2 antinociception. Our data suggest that H2O2 induced a peripheral antinociception in mice and the NO pathway and potassium channels (voltage-gated, ATP-sensitive, calcium-activated) are involved in this mechanism. However, the role of the opioid and cannabinoid systems was not evidenced.


Sujet(s)
Analgésiques , Peroxyde d'hydrogène , Animaux , Peroxyde d'hydrogène/métabolisme , Mâle , Souris , Femelle , Analgésiques/pharmacologie , Monoxyde d'azote/métabolisme , Hyperalgésie/traitement médicamenteux , Hyperalgésie/induit chimiquement , Hyperalgésie/métabolisme , Relation dose-effet des médicaments , Dinoprostone/métabolisme
17.
Chem Biodivers ; 21(8): e202400786, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38777789

RÉSUMÉ

This study carried out to investigate the anti-inflammatory and antinociceptive effect of tropane alkaloid (EB7) isolated from E. bezerrae. It evaluated the toxicity and possible involvement of ion channels in the antinociceptive effect of EB7, as well as its anti-inflammatory effect in adult zebrafish (Zfa). Docking studies with EB7 and COX-1 and 2 were also performed. The tested doses of EB7 (4, 20 and 40 mg/kg) did not show any toxic effect on Zfa during the 96h of analysis (LD50>40 mg/kg). They did not produce any alteration in the locomotor behavior of the animals. Furthermore, EB7 showed promising pharmacological effects as it prevented the nociceptive behavior induced by hypertonic saline, capsaicin, formalin and acid saline. EB7 had its analgesic effect blocked by amiloride involving the neuromodulation of ASICs in Zfa. In evaluating the anti-inflammatory activity, the edema induced by κ-carrageenan 3.5 % was reduced by the dose of 40 mg/kg of EB7 observed after the fourth hour of analysis, indicating an effect similar to that of ibuprofen. Molecular docking results indicated that EB7 exhibited better affinity energy when compared to ibuprofen control against the two evaluated targets binding at different sites in the cocrystallized COX-1 and 2 inhibitors.


Sujet(s)
Analgésiques , Simulation de docking moléculaire , Danio zébré , Animaux , Analgésiques/pharmacologie , Analgésiques/composition chimique , Analgésiques/isolement et purification , Tropanes/pharmacologie , Tropanes/isolement et purification , Tropanes/composition chimique , Oedème/traitement médicamenteux , Oedème/induit chimiquement , Carragénane/pharmacologie , Cyclooxygenase 2/métabolisme , Cyclooxygenase 1/métabolisme , Bignoniaceae/composition chimique , Relation dose-effet des médicaments , Relation structure-activité , Alcaloïdes/pharmacologie , Alcaloïdes/isolement et purification , Alcaloïdes/composition chimique , Canaux ioniques sensibles à l'acidité/métabolisme , Canaux ioniques sensibles à l'acidité/composition chimique , Anti-inflammatoires non stéroïdiens/pharmacologie , Anti-inflammatoires non stéroïdiens/composition chimique , Anti-inflammatoires non stéroïdiens/isolement et purification , Anti-inflammatoires/pharmacologie , Anti-inflammatoires/composition chimique , Anti-inflammatoires/isolement et purification , Structure moléculaire
18.
Cells ; 13(10)2024 May 17.
Article de Anglais | MEDLINE | ID: mdl-38786087

RÉSUMÉ

As in most cells, intracellular pH regulation is fundamental for sperm physiology. Key sperm functions like swimming, maturation, and a unique exocytotic process, the acrosome reaction, necessary for gamete fusion, are deeply influenced by pH. Sperm pH regulation, both intracellularly and within organelles such as the acrosome, requires a coordinated interplay of various transporters and channels, ensuring that this cell is primed for fertilization. Consistent with the pivotal importance of pH regulation in mammalian sperm physiology, several of its unique transporters are dependent on cytosolic pH. Examples include the Ca2+ channel CatSper and the K+ channel Slo3. The absence of these channels leads to male infertility. This review outlines the main transport elements involved in pH regulation, including cytosolic and acrosomal pH, that participate in these complex functions. We present a glimpse of how these transporters are regulated and how distinct sets of them are orchestrated to allow sperm to fertilize the egg. Much research is needed to begin to envision the complete set of players and the choreography of how cytosolic and organellar pH are regulated in each sperm function.


Sujet(s)
Acrosome , Cytosol , Spermatozoïdes , Mâle , Concentration en ions d'hydrogène , Animaux , Cytosol/métabolisme , Humains , Acrosome/métabolisme , Spermatozoïdes/métabolisme , Mammifères/métabolisme , Réaction acrosomique
19.
J Psychiatr Res ; 175: 259-270, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38754148

RÉSUMÉ

The CACNA1C gene encodes the alpha-1c subunit of the Cav1.2 calcium channel, a regulator of neuronal calcium influx involved in neurotransmitter release and synaptic plasticity. Genetic data show a role for CACNA1C in depressive symptoms underlying different psychiatric diagnoses. However, the mechanisms involved still require further exploration. This study aimed to investigate sex and region-specific changes in the Cacna1c gene and behavioral outcomes in mice exposed to chronic stress. Moreover, we evaluated the Nuclear factor of activated T-cells 5 (Nfat5) and the Brain-derived neurotrophic factor (Bdnf) as potential upstream and downstream Cacna1c targets and their correlation in stressed mice and humans with depression. Male and female Swiss mice were exposed to chronic unpredictable stress (CUS) for 21 days. Animal-integrated emotionality was assessed using the sucrose splash test, the tail suspension, the open-field test, and the elevated-plus-maze. Gene expression analysis was performed in the amygdala, prefrontal cortex, and hippocampus. Human data for in silico analysis was obtained from the Gene Expression Omnibus. CUS-induced impairment in integrated emotional regulation was observed in males. Gene expression analysis showed decreased levels of Cacna1c and Nfat5 and increased levels of Bdnf transcripts in the amygdala of stressed male mice. In contrast, there were no major changes in behavioral responses or gene expression in female mice after stress. The expression of the three genes was significantly correlated in the amygdala of mice and humans. The strong and positive correlation between Canac1c and Nfat5 suggests a potential role for this transcription factor in Canac1c expression. These changes could impact amygdala reactivity and emotional responses, making them a potential target for psychiatric intervention.


Sujet(s)
Amygdale (système limbique) , Facteur neurotrophique dérivé du cerveau , Canaux calciques de type L , Stress psychologique , Animaux , Facteur neurotrophique dérivé du cerveau/métabolisme , Facteur neurotrophique dérivé du cerveau/génétique , Canaux calciques de type L/métabolisme , Canaux calciques de type L/génétique , Stress psychologique/métabolisme , Mâle , Femelle , Souris , Amygdale (système limbique)/métabolisme , Humains , Modèles animaux de maladie humaine , Comportement animal/physiologie , Cortex préfrontal/métabolisme , Hippocampe/métabolisme , Adulte , Expression des gènes , Dépression/métabolisme , Dépression/physiopathologie
20.
Chem Biodivers ; 21(7): e202400538, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38639566

RÉSUMÉ

This is the first study to analyze the anti-inflammatory and antinociceptive effect of withanicandrin, isolated from Datura Ferox leaves, and the possible mechanism of action involved in adult zebrafish (ZFa). To this end, the animals were treated intraperitoneally (i. p.) with withanicandrin (4; 20 and 40 mg/kg; 20 µL) and subjected to locomotor activity and acute toxicity. Nociception tests were also carried out with chemical agents, in addition to tests to evaluate inflammatory processes induced by κ-Carrageenan 1.5 % and a Molecular Docking study. As a result, withanicandrin reduced nociceptive behavior by capsaicin at a dose of 40 mg/kg and by acid saline at doses of 4 and 40 mg/kg, through neuromodulation of TRPV1 channels and ASICs, identified through blocking the antinociceptive effect of withanicandrin by the antagonists capsazepine and naloxone. Furthermore, withanicandrin caused an anti-inflammatory effect through the reduction of abdominal edema, absence of leukocyte infiltrate in the liver tissue and reduction of ROS in thel liver tissue and presented better affinity energy compared to control morphine (TRPV1) and ibuprofen (COX-1 and COX-2).


Sujet(s)
Analgésiques , Danio zébré , Animaux , Analgésiques/pharmacologie , Analgésiques/composition chimique , Analgésiques/isolement et purification , Canaux ioniques sensibles à l'acidité/métabolisme , Simulation de docking moléculaire , Anti-inflammatoires/pharmacologie , Anti-inflammatoires/composition chimique , Anti-inflammatoires/isolement et purification , Carragénane , Relation structure-activité , Relation dose-effet des médicaments , Canaux cationiques TRPV/antagonistes et inhibiteurs , Canaux cationiques TRPV/métabolisme , Oedème/traitement médicamenteux , Oedème/induit chimiquement , Feuilles de plante/composition chimique , Structure moléculaire
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