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Chemistry & Biodiversity May 2024This study carried out to investigate the anti-inflammatory and antinociceptive effect of tropane alkaloid (EB7) isolated from E. bezerrae. It evaluated the toxicity and...
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.
PubMed: 38777789
DOI: 10.1002/cbdv.202400786 -
Neuropeptides Aug 2024FMRFamide, a member of the neuropeptide family, is involved in numerous physiological processes. FMRFamide-activated sodium channels (FaNaCs) are a family of...
A Na channel receptor of FMRFamide in the cephalopod Sepiella japonica: Identification, characterisation, and expression profiling during different stages of gonadal development.
FMRFamide, a member of the neuropeptide family, is involved in numerous physiological processes. FMRFamide-activated sodium channels (FaNaCs) are a family of non-voltage-gated, amiloride-sensitive, Na-selective channels triggered by the neuropeptide FMRFamide. In the present study, the full-length cDNA of the FaNaC receptor of Sepiella japonica (SjFaNaC) was cloned. The cDNA of SjFaNaC was 3004 bp long with an open reading frame (ORF) of 1812 bp, encoding 603 amino acid residues with no signal peptide at the N-terminus. Sequence analysis indicated that SjFaNaC shared a high identity with other cephalopods FaNaCs and formed a sister clade with bivalves. The protein structure was predicted using SWISS-MODEL with AcFaNaC as the template. Quantitative real-time PCR (qRT-PCR) revealed that SjFaNaC transcripts were highly expressed in both female and male reproductive organs, as well as in the optic lobe and brain of the central nervous system (CNS). Results of in situ hybridisation (ISH) showed that SjFaNaC mRNA was mainly distributed in the medulla and deep retina of the optic lobe and in both the supraesophageal and subesophageal masses of the brain. Subcellular localisation indicated that the SjFaNaC protein was localised intracellularly and on the cell surface of HEK293T cells. In summary, these findings may lay the foundation for future exploration of the functions of SjFaNaC in cephalopods.
Topics: Animals; Male; Female; FMRFamide; Amino Acid Sequence; Sodium Channels; Cephalopoda; Gonads; Phylogeny; Gene Expression Profiling; Humans; Cloning, Molecular; Gene Expression Regulation, Developmental
PubMed: 38776655
DOI: 10.1016/j.npep.2024.102437 -
The Medical Letter on Drugs and... May 2024
Review
Topics: Humans; Hypertension; Antihypertensive Agents; Blood Pressure
PubMed: 38771738
DOI: 10.58347/tml.2024.1703a -
The American Journal of Case Reports May 2024BACKGROUND Nephrogenic diabetes insipidus (NDI) is a rare renal disorder that can be congenital, and is caused by mutations in either aquaporin 2 or arginine vasopressin...
A Rare Case of Congenital Nephrogenic Diabetes Insipidus Associated with Aquaporin 2 Gene Mutation and Subsequent Acute Lymphoblastic Leukemia: Impact of Steroids on Kidney Function.
BACKGROUND Nephrogenic diabetes insipidus (NDI) is a rare renal disorder that can be congenital, and is caused by mutations in either aquaporin 2 or arginine vasopressin receptor 2, or it can be secondary to kidney disease or electrolyte imbalance. The clinical signs of NDI include polyuria, compensatory polydipsia, hypernatremic dehydration, and growth retardation without prompt treatment. In this report, we present the case of a patient with congenital NDI who was later diagnosed with acute lymphoblastic leukemia (ALL). With dexamethasone treatment, he had uncontrolled polyuria and polydipsia. Our aim was to concentrate on the impact of steroids on the kidneys. CASE REPORT Our patient presented at the age of 9 months with signs of severe dehydration that were associated with polyuria. His laboratory examinations revealed hypernatremia and decreased urine osmolality. He was diagnosed with NDI and his exome sequence revealed a homozygous mutation at the nucleotide position AQP2 NM_000486.6: c.374C>T (p.Thr125Met). He was treated with hydrochlorothiazide and amiloride. Then, at age 19 months, he presented with gastroenteritis and a complete blood count (CBC) showed high white blood cell count and blast cells. He was diagnosed with (ALL) and began receiving chemotherapy, during which again developed polydipsia and polyuria, which could not be controlled with an increased dosage of hydrochlorothiazide. CONCLUSIONS We report a rare case of NDI caused by a missense mutation in the aquaporin 2 gene. One year later, the child developed ALL, and treatment with dexamethasone led to an uncompensated state of polydipsia and polyuria.
Topics: Humans; Male; Diabetes Insipidus, Nephrogenic; Aquaporin 2; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Infant; Dexamethasone; Mutation; Glucocorticoids
PubMed: 38769718
DOI: 10.12659/AJCR.943597 -
International Journal of Pharmaceutical... 2024Amiloride is a U.S. Food and Drug Administration-approved diuretic agent used to treat hypertension and congestive heart failure. Recent human and animal studies have...
Amiloride is a U.S. Food and Drug Administration-approved diuretic agent used to treat hypertension and congestive heart failure. Recent human and animal studies have suggested that amiloride may also have a role in treating anxiety through its acid-sensing ion channel antagonism. Intranasal administration of amiloride nasal spray via an extemporaneously compounded preparation has the potential for rapid delivery to the site of action to achieve therapeutic outcomes in individual patients with anxiety disorders. However, these patient-specific preparations do not have the pre-formulation characterization, including chemical stability, that conventional manufactured dosage forms have. The objective of this study was to assess the estimated chemical stability of compounded amiloride nasal spray over 6 months and 12 months utilizing accelerated degradation with high heat and the Arrhenius equation. A stability-indicating highperformance liquid chromatography analytical method was employed at appropriate intervals over a 12-month period to reveal that amiloride remained chemically stable over the period tested and by extrapolation. Physical stability and compatibility with the preservative benzyl alcohol were also confirmed via visual inspection, pH monitoring, and measurement of turbidity.
Topics: Amiloride; Drug Stability; Nasal Sprays; Drug Compounding; Administration, Intranasal; Chromatography, High Pressure Liquid; Hydrogen-Ion Concentration
PubMed: 38768504
DOI: No ID Found -
Archiv Der Pharmazie May 2024Lithium induces nephrogenic diabetes insipidus (NDI) and microcystic chronic kidney disease (CKD). As previous clinical studies suggest that NDI is dose-dependent and...
Lithium induces nephrogenic diabetes insipidus (NDI) and microcystic chronic kidney disease (CKD). As previous clinical studies suggest that NDI is dose-dependent and CKD is time-dependent, we investigated the effect of low exposition to lithium in a long-term experimental rat model. Rats were fed with a normal diet (control group), with the addition of lithium (Li group), or with lithium and amiloride (Li/Ami group) for 6 months, allowing obtaining low plasma lithium concentrations (0.25 ± 0.06 and 0.43 ± 0.16 mmol/L, respectively). Exposition to low concentrations of plasma lithium levels prevented NDI but not microcystic dilations of kidney tubules, which were identified as collecting ducts (CDs) on immunofluorescent staining. Both hypertrophy, characterized by an increase in the ratio of nuclei per tubular area, and microcystic dilations were observed. The ratio between principal cells and intercalated cells was higher in microcystic than in hypertrophied tubules. There was no correlation between AQP2 messenger RNA levels and cellular remodeling of the CD. Additional amiloride treatment in the Li/Ami group did not allow consistent morphometric and cellular composition changes compared to the Li group. Low exposition to lithium prevented overt NDI but not microcystic dilations of the CD, with differential cellular composition in hypertrophied and microcystic CDs, suggesting different underlying cellular mechanisms.
PubMed: 38704748
DOI: 10.1002/ardp.202400063 -
International Journal of Biological... Jun 2024Cardiovascular drugs (CVDs) are agents working on the heart and the vascular system to treat many cardiovascular disorders. Such disorders represent the leading cause... (Comparative Study)
Comparative Study
Cardiovascular drugs (CVDs) are agents working on the heart and the vascular system to treat many cardiovascular disorders. Such disorders represent the leading cause for morbidity and mortality worldwide. The treatment regimen includes different administered drugs on chronic basis. The cumulative drugs in human body coincides with exposure to electromagnetic radiations from different sources leading to drug-radiation interaction that may lead to drug photosensitization. Such photosensitization may lead to mutagenesis, cancer, and cell death due to molecular damage to DNA. This work involves the application of two bioluminescent genosensors; Terbium chloride and EvaGreen are utilized to investigate potential DNA damage caused by frequently used CVDs following UVA irradiation. A variety of CVDs are investigated. Ten drugs; Amiloride, Atorvastatin, Captopril, Enalapril, Felodipine, Hydrochlorothiazide, Indapamide, Losartan, Triamterene and Valsartan are studied. The study's findings showed that such drugs induced DNA damage following UVA irradiation. The induced DNA damage altered the fluorescence of terbium chloride and EvaGreen genosensors, proportionally. The results are confirmed by viscosity measurements reflecting the possible intercalation of CVDs with DNA. Also, the work is applied on calf thymus DNA to mimic the actual biological variability. The demonstrated bioluminescent genosensors provide automatic, simple and low-cost methods for assessing DNA-drug interactions.
Topics: DNA Damage; Cardiovascular Agents; DNA; Ultraviolet Rays; Animals; Fluorescent Dyes; Humans; Biosensing Techniques; Viscosity; Cattle; Terbium
PubMed: 38679270
DOI: 10.1016/j.ijbiomac.2024.131821 -
American Journal of Physiology. Renal... Jun 2024The epithelial Na channel (ENaC) γ subunit is essential for homeostasis of Na, K, and body fluid. Dual γ subunit cleavage before and after a short inhibitory tract...
The epithelial Na channel (ENaC) γ subunit is essential for homeostasis of Na, K, and body fluid. Dual γ subunit cleavage before and after a short inhibitory tract allows dissociation of this tract, increasing channel open probability (P), in vitro. Cleavage proximal to the tract occurs at a furin recognition sequence (RKRR, in the mouse γ subunit). Loss of furin-mediated cleavage prevents in vitro activation of the channel by proteolysis at distal sites. We hypothesized that RKRR mutation to QQQQ (γ) in 129/Sv mice would reduce ENaC P, impair flow-stimulated flux of Na (J) and K (J) in perfused collecting ducts, reduce colonic amiloride-sensitive short-circuit current (I), and impair Na, K, and body fluid homeostasis. Immunoblot of γ mouse kidney lysates confirmed loss of a band consistent in size with the furin-cleaved proteolytic fragment. However, γ male mice on a low Na diet did not exhibit altered ENaC P or flow-induced J, though flow-induced J modestly decreased. Colonic amiloride-sensitive I in γ mice was not altered. γ males, but not females, exhibited mildly impaired fluid volume conservation when challenged with a low Na diet. Blood Na and K were unchanged on a regular, low Na, or high K diet. These findings suggest that biochemical evidence of γ subunit cleavage should not be used in isolation to evaluate ENaC activity. Furthermore, factors independent of γ subunit cleavage modulate channel P and the influence of ENaC on Na, K, and fluid volume homeostasis in 129/Sv mice, in vivo. The epithelial Na channel (ENaC) is activated in vitro by post-translational proteolysis. In vivo, low Na or high K diets enhance ENaC proteolysis, and proteolysis is hypothesized to contribute to channel activation in these settings. Using a mouse expressing ENaC with disruption of a key proteolytic cleavage site, this study demonstrates that impaired proteolytic activation of ENaC's γ subunit has little impact upon channel open probability or the ability of mice to adapt to low Na or high K diets.
Topics: Animals; Epithelial Sodium Channels; Male; Female; Sodium; Proteolysis; Kidney Tubules, Collecting; Homeostasis; Furin; Mice; Colon; Potassium; Diet, Sodium-Restricted; Mice, 129 Strain; Mutation; Amiloride
PubMed: 38634134
DOI: 10.1152/ajprenal.00027.2024 -
International Journal of Molecular... Mar 2024Acid-sensing ion channels (ASICs) play a key role in the perception and response to extracellular acidification changes. These proton-gated cation channels are critical...
Acid-sensing ion channels (ASICs) play a key role in the perception and response to extracellular acidification changes. These proton-gated cation channels are critical for neuronal functions, like learning and memory, fear, mechanosensation and internal adjustments like synaptic plasticity. Moreover, they play a key role in neuronal degeneration, ischemic neuronal injury, seizure termination, pain-sensing, etc. Functional ASICs are homo or heterotrimers formed with (ASIC1-ASIC3) homologous subunits. ASIC1a, a major ASIC isoform in the central nervous system (CNS), possesses an acidic pocket in the extracellular region, which is a key regulator of channel gating. Growing data suggest that ASIC1a channels are a potential therapeutic target for treating a variety of neurological disorders, including stroke, epilepsy and pain. Many studies were aimed at identifying allosteric modulators of ASIC channels. However, the regulation of ASICs remains poorly understood. Using all available crystal structures, which correspond to different functional states of ASIC1, and a molecular dynamics simulation (MD) protocol, we analyzed the process of channel inactivation. Then we applied a molecular docking procedure to predict the protein conformation suitable for the amiloride binding. To confirm the effect of its sole active blocker against the ASIC1 state transition route we studied the complex with another MD simulation run. Further experiments evaluated various compounds in the Enamine library that emerge with a detectable ASIC inhibitory activity. We performed a detailed analysis of the structural basis of ASIC1a inhibition by amiloride, using a combination of in silico approaches to visualize its interaction with the ion pore in the open state. An artificial activation (otherwise, expansion of the central pore) causes a complex modification of the channel structure, namely its transmembrane domain. The output protein conformations were used as a set of docking models, suitable for a high-throughput virtual screening of the Enamine chemical library. The outcome of the virtual screening was confirmed by electrophysiological assays with the best results shown for three hit compounds.
Topics: Humans; Benzamidines; Amiloride; Molecular Docking Simulation; Acid Sensing Ion Channels; Pain
PubMed: 38612396
DOI: 10.3390/ijms25073584 -
Bone & Joint Research Apr 2024Osteosarcoma is the most common primary bone malignancy among children and adolescents. We investigated whether benzamil, an amiloride analogue and sodium-calcium...
AIMS
Osteosarcoma is the most common primary bone malignancy among children and adolescents. We investigated whether benzamil, an amiloride analogue and sodium-calcium exchange blocker, may exhibit therapeutic potential for osteosarcoma in vitro.
METHODS
MG63 and U2OS cells were treated with benzamil for 24 hours. Cell viability was evaluated with the MTS/PMS assay, colony formation assay, and flow cytometry (forward/side scatter). Chromosome condensation, the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay, cleavage of poly-ADP ribose polymerase (PARP) and caspase-7, and FITC annexin V/PI double staining were monitored as indicators of apoptosis. Intracellular calcium was detected by flow cytometry with Fluo-4 AM. The phosphorylation and activation of focal adhesion kinase (FAK) and signal transducer and activator of transcription 3 (STAT3) were measured by western blot. The expression levels of X-linked inhibitor of apoptosis protein (XIAP), B-cell lymphoma 2 (Bcl-2), B-cell lymphoma-extra large (Bcl-xL), SOD1, and SOD2 were also assessed by western blot. Mitochondrial status was assessed with tetramethylrhodamine, ethyl ester (TMRE), and intracellular adenosine triphosphate (ATP) was measured with BioTracker ATP-Red Live Cell Dye. Total cellular integrin levels were evaluated by western blot, and the expression of cell surface integrins was assessed using fluorescent-labelled antibodies and flow cytometry.
RESULTS
Benzamil suppressed growth of osteosarcoma cells by inducing apoptosis. Benzamil reduced the expression of cell surface integrins α5, αV, and β1 in MG63 cells, while it only reduced the expression of αV in U2OS cells. Benzamil suppressed the phosphorylation and activation of FAK and STAT3. In addition, mitochondrial function and ATP production were compromised by benzamil. The levels of anti-apoptotic proteins XIAP, Bcl-2, and Bcl-xL were reduced by benzamil. Correspondingly, benzamil potentiated cisplatin- and methotrexate-induced apoptosis in osteosarcoma cells.
CONCLUSION
Benzamil exerts anti-osteosarcoma activity by inducing apoptosis. In terms of mechanism, benzamil appears to inhibit integrin/FAK/STAT3 signalling, which triggers mitochondrial dysfunction and ATP depletion.
PubMed: 38569602
DOI: 10.1302/2046-3758.134.BJR-2023-0289.R1