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Naunyn-Schmiedeberg's Archives of... Jul 2023Pilocarpine is a selective M/M agonist of muscarinic acetylcholine receptor subtypes. Muscarinic acetylcholine receptors are G protein-coupled receptors. These receptors...
Pilocarpine is a selective M/M agonist of muscarinic acetylcholine receptor subtypes. Muscarinic acetylcholine receptors are G protein-coupled receptors. These receptors are different drug targets. The aim of the present work was to investigate the effect of pilocarpine on the expression of M muscarinic acetylcholine receptor, the AChE activity, IL-8 release response, and proliferation in K562 cells, via muscarinic receptor activation. Human chronic myeloid leukemic cell cultures were incubated with drugs. Proliferation assays were performed by BrdU assay. Expression of M muscarinic acetylcholine receptor and apoptosis proteins such as bcl, bax, cyt C, and caspases was assessed with the semiquantitative Western blotting method. Pilocarpine inhibits chronic myeloid cell proliferation and M muscarinic acetylcholine receptor protein expression. Pilocarpine increases caspase-8 and -9 expression levels, upregulating the proapoptotic protein Bax and downregulating the expression levels of the antiapoptotic protein Bcl-2. The apoptotic activity of pilocarpine is associated with an increase in AChE activity. M muscarinic acetylcholine receptors can activate multiple signal transduction systems and mediate inhibitory effects on chronic myeloid K562 cell proliferation depending on the presence of 1% FBS conditions. This apoptotic effect of pilocarpine may be due to the concentration of pilocarpine and the increase in AChE level. Our results suggest that inhibition of cell proliferation by inducing apoptosis of pilocarpine in K562 cells may be one of the targets. M selective agonist may have therapeutic potential in chronic myeloid leukemia.
Topics: Humans; Pilocarpine; Muscarinic Agonists; Tumor Necrosis Factor-alpha; bcl-2-Associated X Protein; Receptors, Muscarinic; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Receptor, Muscarinic M3
PubMed: 36781441
DOI: 10.1007/s00210-023-02418-4 -
Journal of Neurophysiology May 2023Emerging evidence suggests that the medial septum can control seizures occurring in focal epileptic disorders, thus representing a therapeutic target. Therefore, we...
Emerging evidence suggests that the medial septum can control seizures occurring in focal epileptic disorders, thus representing a therapeutic target. Therefore, we investigated whether continuous optogenetic activation of inhibitory parvalbumin (PV)-positive interneurons in the medial septum can reduce the occurrence of spontaneous seizures in the pilocarpine model of mesial temporal lobe epilepsy (MTLE). Light pulses (450 nm, 25 mW, 20-ms pulse duration) were delivered at 0.5 Hz (5 min ON, 10 min OFF) with a laser diode fiber light source between and after status epilepticus (SE) in PV-ChR2 mice ( = 8). Seizure rates were significantly lower during time periods of optogenetic stimulation () compared with before implementation of optogenetics () ( < 0.05). Moreover, between and after SE seizure rates were still significantly lower compared with before optogenetic stimulation (i.e., between and ) ( < 0.05). No seizures were recorded between and in all animals, and no seizures occurred up to 3 days after the end of optogenetic stimulation (). Our findings indicate that activation of PV interneurons in the medial septum abates seizures in the pilocarpine model of MTLE. Moreover, the persisting anti-ictogenic effects suggest that stimulation of the medial septum could alter the progression of MTLE. The medial septum could represent a therapeutic target to treat patients with focal epilepsy. In this study, we show that optogenetic activation of inhibitory parvalbumin-positive interneurons in the medial septum can block spontaneous seizures and prevents their reoccurrence for ∼5 days after the end of stimulation. Our findings suggest that the anti-ictogenic effects induced by stimulation of the medial septum could also alter the progression of mesial temporal lobe epilepsy.
Topics: Mice; Animals; Epilepsy, Temporal Lobe; Optogenetics; Pilocarpine; Parvalbumins; Status Epilepticus; Hippocampus; Disease Models, Animal
PubMed: 37073973
DOI: 10.1152/jn.00111.2023 -
European Journal of Pharmacology Dec 2023Neuroinflammation mediated by microglia made a significant contribution in the pathophysiology of epilepsy. Icariin (ICA), a bioactive ingredient isolated from...
Neuroinflammation mediated by microglia made a significant contribution in the pathophysiology of epilepsy. Icariin (ICA), a bioactive ingredient isolated from Epimedium, has been shown to present both antioxidant and anti-inflammatory properties. This study was to explore the potential therapeutic effects of icariin on mouse pilocarpine model of epilepsy and its underlying mechanisms in vivo and in vitro. To this end, we firstly measured the serum concentrations of the proinflammatory cytokines IL-1β and IL-6 from patients with temporal lobe epilepsy and found that patients with a higher seizure frequency showed correspondingly higher inflammatory reaction. Mouse pharmacokinetic study, transmembrane transportation assay, and cell viability assay collectively demonstrated that ICA was able to cross the blood-brain barrier and has good biocompatibility. The acute and chronic epilepsy models were next established in a pilocarpine mouse model of acquired epilepsy. Icariin has been identified that it could cross the blood-brain barrier and enter the hippocampus to exhibit therapeutic effects. ICA treatment dramatically promoted microglial polarization to the M2 phenotype in epilepsy mice both in the acute and chronic phases. Reduced release of M1-associated proinflammatory factors, such as IL-1β and IL-6, corroborates the altered glial cell polarization. Furthermore, ICA alleviated seizure intensity and mortality in acute phase epileptic mice. Models in the chronic group also showed improved general condition, cognition ability, and memory function after ICA treatment. Taken together, our research strongly suggested that icariin has the potential to treat epilepsy via inhibiting neuroinflammation by promoting microglial polarization to the M2 phenotype.
Topics: Humans; Mice; Animals; Pilocarpine; Interleukin-6; Neuroinflammatory Diseases; Epilepsy; Seizures; Anti-Inflammatory Agents; Microglia; Disease Models, Animal
PubMed: 37866741
DOI: 10.1016/j.ejphar.2023.176141 -
European Journal of Ophthalmology Jul 2021This study aimed to investigate whether topical pilocarpine affects ocular growth and refractive development as well as the underlying biochemical processes in early eye...
PURPOSE
This study aimed to investigate whether topical pilocarpine affects ocular growth and refractive development as well as the underlying biochemical processes in early eye development in rabbits.
METHODS
Twenty three-week-old New Zealand white rabbits were treated with 0.5% pilocarpine in the right eye for 6 weeks. The left eyes served as contralateral controls. The effects of pilocarpine on refractive error, corneal curvature and ocular biometrics were assessed using streak retinoscopy, keratometry, and A-scan ultrasonography, respectively. Eyeballs were enucleated for histological analysis. The ciliary body and sclera were homogenized to determine the mRNA and protein expression levels of five subtypes of muscarinic receptors.
RESULTS
Compared to control eyes, pilocarpine-treated eyes exhibited approximately -1.63 ± 0.54 D myopia accompanied by a 0.11 ± 0.04 mm increase in axial length (AL) ( 0.001, respectively). The anterior chamber depth (ACD) was reduced, whereas the lens thickness (LT) and vitreous chamber depth (VCD) increased ( 0.001, respectively). Corneal curvature decreased over time but was not significantly different between treated and control eyes. The mRNA and protein expression levels of five subtypes of muscarinic receptors were upregulated in the ciliary body and downregulated in the sclera.
CONCLUSIONS
Based on these results, pilocarpine can induce myopic shift, increase LT, elongate VCD and AL, and reduce muscarinic receptor expression in the sclera early in development. These changes raise the possibility that pilocarpine may promote axial elongation in ocular development and facilitate the emmetropization of hyperopic eyes.
Topics: Animals; Cornea; Eye; Humans; Hyperopia; Myopia; Pilocarpine; Rabbits; Refraction, Ocular
PubMed: 32524847
DOI: 10.1177/1120672120934962 -
Kathmandu University Medical Journal... 2022A 34 years old female presented with complains of photophobia since 6-7 months. On examination, she had anisocoria of 4 mm in room light which increased in bright light....
A 34 years old female presented with complains of photophobia since 6-7 months. On examination, she had anisocoria of 4 mm in room light which increased in bright light. The left pupil was dilated and unresponsive to direct and indirect light stimuli. It did however, constrict slowly on near fixation followed by slow redilatation on distance fixation. A diagnosis of Adie's tonic pupil was made since left pupil constricted with instillation of dilute pilocarpine 0.1%. Her symptoms of photophobia and blurred vision immediately resolved. Photochromatic glasses and dilute pilocarpine 0.1% three times a day were prescribed. Prompt symptomatic relief of photophobia and blurred vision was observed.
Topics: Female; Humans; Adult; Tonic Pupil; Photophobia; Pilocarpine; Pupil; Vision Disorders
PubMed: 36273305
DOI: No ID Found -
Biomedical Chromatography : BMC Apr 2024Temporal lobe epilepsy (TLE) is a common form of refractory epilepsy in adulthood. The metabolic profile of epileptogenesis is still poorly investigated. Elucidation of... (Review)
Review
Temporal lobe epilepsy (TLE) is a common form of refractory epilepsy in adulthood. The metabolic profile of epileptogenesis is still poorly investigated. Elucidation of such a metabolic profile using animal models of epilepsy could help identify new metabolites and pathways involved in the mechanisms of epileptogenesis process. In this study, we evaluated the metabolic profile during the epileptogenesis periods. Using a pilocarpine model of epilepsy, we analyzed the global metabolic profile of hippocampal extracts by untargeted metabolomics based on ultra-performance liquid chromatography-high-resolution mass spectrometry, at three time points (3 h, 1 week, and 2 weeks) after status epilepticus (SE) induction. We demonstrated that epileptogenesis periods presented different hippocampal metabolic profiles, including alterations of metabolic pathways of amino acids and lipid metabolism. Six putative metabolites (tryptophan, N-acetylornithine, N-acetyl-L-aspartate, glutamine, adenosine, and cholesterol) showed significant different levels during epileptogenesis compared to their respective controls. These putative metabolites could be associated with the imbalance of neurotransmitters, mitochondrial dysfunction, and cell loss observed during both epileptogenesis and epilepsy. With these findings, we provided an overview of hippocampal metabolic profiles during different stages of epileptogenesis that could help investigate pathways and respective metabolites as predictive tools in epilepsy.
Topics: Animals; Epilepsy; Epilepsy, Temporal Lobe; Hippocampus; Metabolome; Pilocarpine
PubMed: 38154955
DOI: 10.1002/bmc.5820 -
Clinical Pharmacology in Drug... Jan 2022Pilocarpine-induced salivary secretion could serve as a nontherapeutic target engagement biomarker in a clinical setting to test the activity of an M3 positive...
Pilocarpine-induced salivary secretion could serve as a nontherapeutic target engagement biomarker in a clinical setting to test the activity of an M3 positive allosteric modulator (PAM). The potentiating effect on the reactivity of the M3 receptor to the agonistic effect of pilocarpine would support the mechanism of action of an M3 PAM in a variety of therapeutic areas. The aim of this study was to determine the optimal pilocarpine dose needed for evaluation of this potentiating effect. Therefore, the effects of pilocarpine on salivary secretion rate and its pharmacokinetics were explored at single doses of 2.5, 5, and 10 mg of pilocarpine or placebo. The study also explored the test-retest variability of the pilocarpine-induced effects on salivary secretion. Pilocarpine caused a reproducible, dose-related increase in overall and maximum salivary secretion rate, in line with pilocarpine exposure. Oral doses of pilocarpine from 2.5 to 10 mg were safe and well tolerated, consistent with the published safety profile. These results support the use of pilocarpine in single-dose pharmacological challenge studies. The recommended dose for evaluating M3 PAM activity would be between 2.5 and 5 mg, showing a small increase in salivary secretion rate with room for further increase due to PAM activation.
Topics: Biomarkers, Pharmacological; Humans; Muscarinic Agonists; Pilocarpine; Receptor, Muscarinic M3; Salivation
PubMed: 34826362
DOI: 10.1002/cpdd.1048 -
Cerebral Cortex (New York, N.Y. : 1991) May 2021Pin1 is a unique isomerase that regulates protein conformation and function after phosphorylation. Pin1 aberration contributes to some neurological diseases, notably...
Pin1 is a unique isomerase that regulates protein conformation and function after phosphorylation. Pin1 aberration contributes to some neurological diseases, notably Alzheimer's disease, but its role in epilepsy is not fully understood. We found that Pin1-deficient mice had significantly increased seizure susceptibility in multiple chemical inducing models and developed age-dependent spontaneous epilepsy. Electrophysiologically, Pin1 ablation enhanced excitatory synaptic transmission to prefrontal cortex (PFC) pyramidal neurons without affecting their intrinsic excitability. Biochemically, Pin1 ablation upregulated AMPA receptors and GluA1 phosphorylation by acting on phosphorylated CaMKII. Clinically, Pin1 was decreased significantly, whereas phosphorylated CaMKII and GluA1 were increased in the neocortex of patients with epilepsy. Moreover, Pin1 expression restoration in the PFC of Pin1-deficient mice using viral gene transfer significantly reduced phosphorylated CaMKII and GluA1 and effectively suppressed their seizure susceptibility. Thus, Pin1-CaMKII-AMPA receptors are a novel axis controlling epileptic susceptibility, highlighting attractive new therapeutic strategies.
Topics: Animals; Brain; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Epilepsy; Genetic Predisposition to Disease; Humans; Male; Mice; Mice, Knockout; NIMA-Interacting Peptidylprolyl Isomerase; Pilocarpine; Receptors, AMPA; Signal Transduction
PubMed: 33569579
DOI: 10.1093/cercor/bhab004 -
Neurochemical Research Feb 2023c-Abl is a non-receptor tyrosine kinase that promotes intracellular apoptotic signaling in prolonged epileptic seizures. PTZ and pilocarpine-induced continuous epileptic...
c-Abl is a non-receptor tyrosine kinase that promotes intracellular apoptotic signaling in prolonged epileptic seizures. PTZ and pilocarpine-induced continuous epileptic convulsions cause neuronal death and gliosis. C-Abl is linked to oxidative stress, neuronal hyperexcitability, mitochondrial malfunction, and subsequent seizures. We investigated the involvement of c-Abl in epileptogenesis by employing its selective inhibitor Imatinib (1 & 3 mg/kg; i.p.) together with conventional medication valproate (110 mg/kg; i.p.) tends to be effective in decreasing seizures threshold provoked by PTZ for 15 days and pilocarpine for 37 days. Further, Imatinib was effective in preventing epileptic seizures arbitrated oxidative stress injury. Oxidative stress has been linked to excitotoxicity that is considered to pathogenic factor in epileptic brain damage. As ELIZA and biochemical estimations showed the high level of c-Abl as an indicator of neuronal oxidative and apoptosis under chronic PTZ & pilocarpine epileptic seizures marked by decreased antioxidants and elevated levels of caspase-3 that were successfully prevented with Imatinib treatment same as valproate (standard drug). Further, the aberrant c-Abl activation is also linked with neuroinflammation that is also predisposing factor in the development of seizures. Selective inhibition of c-Abl by Imatinib also showed anti-inflammatory activity marked with suppressed levels of NF-kB and pro-inflammatory mediators (TNF-alpha, IL-1β, and IL-6) suggesting the neuroprotective effect of Imatinib same as valproate (standard drug) in epilepsy. Therefore, the current study provides preclinical evidence of Imatinib as a potential treatment for seizures, as well as an understanding of potential role of c-Ablin epilepsy.
Topics: Animals; Mice; Anticonvulsants; Disease Models, Animal; Epilepsy; Imatinib Mesylate; Pentylenetetrazole; Pilocarpine; Seizures; Status Epilepticus; Valproic Acid
PubMed: 36239857
DOI: 10.1007/s11064-022-03758-y -
Neurobiology of Disease Mar 2023Status epilepticus (SE) is a life-threatening medical emergency with significant morbidity and mortality. SE is associated with a robust and sustained increase in serum...
Status epilepticus (SE) is a life-threatening medical emergency with significant morbidity and mortality. SE is associated with a robust and sustained increase in serum glucocorticoids, reaching concentrations sufficient to activate the dense population of glucocorticoid receptors (GRs) expressed among hippocampal excitatory neurons. Glucocorticoid exposure can increase hippocampal neuron excitability; however, whether activation of hippocampal GRs during SE exacerbates seizure severity remains unknown. To test this, a viral strategy was used to delete GRs from a subset of hippocampal excitatory neurons in adult male and female mice, producing hippocampal GR knockdown mice. Two weeks after GR knockdown, mice were challenged with the convulsant drug pilocarpine to induce SE. GR knockdown had opposing effects on early vs late seizure behaviors, with sex influencing responses. For both male and female mice, the onset of mild behavioral seizures was accelerated by GR knockdown. In contrast, GR knockdown delayed the onset of more severe convulsive seizures and death in male mice. Concordantly, GR knockdown also blunted the SE-induced rise in serum corticosterone in male mice. GR knockdown did not alter survival times or serum corticosterone in females. To assess whether loss of GR affected susceptibility to SE-induced cell death, within-animal analyses were conducted comparing local GR knockdown rates to local cell loss. GR knockdown did not affect the degree of localized neuronal loss, suggesting cell-intrinsic GR signaling neither protects nor sensitizes neurons to acute SE-induced death. Overall, the findings reveal that hippocampal GRs exert an anti-convulsant role in both males and females in the early stages of SE, followed by a switch to a pro-convulsive role for males only. Findings reveal an unexpected complexity in the interaction between hippocampal GR activation and the progression of SE.
Topics: Mice; Male; Female; Animals; Receptors, Glucocorticoid; Corticosterone; Status Epilepticus; Hippocampus; Seizures; Glucocorticoids; Pilocarpine; Convulsants
PubMed: 36702319
DOI: 10.1016/j.nbd.2023.106014