This study investigated the mechanism by which Jianpi Bushen Yiqi Decoction promotes acetylcholine receptor(AChR) clustering in myasthenia gravis through the Agrin/low-density lipoprotein receptor-related protein 4(LRP4)/muscle-specific receptor tyrosine kinases(MuSK) signaling pathway. A total of 114 female C57BL/6J mice were divided into the normal group, modeling group, and solvent control group. The normal group and the solvent control group were immunized with phosphate-buffered saline(PBS), while the modeling group was established as an experimental autoimmune myasthenia gravis(EAMG) model using the murine-derived AChR-α subunit R97-116 peptide fragment. After successful modeling, the mice were randomly assigned to the model group, the low-, medium-, and high-dose Jianpi Bushen Yiqi Decoction groups, and the prednisone group. After four weeks of continuous treatment, muscle strength was assessed using Lennon scores and grip strength tests. Immunofluorescence staining was conducted on differentiated C2C12 myotubes incubated with a drug-containing serum to observe the number of AChR clusters. The integrity of AChR on myofilaments in mouse gastrocnemius muscles was further assessed by immunofluorescence staining. Hematoxylin-Eosin(HE)staining was applied to examine pathological changes in the gastrocnemius muscles of EAMG mice treated with Jianpi Bushen Yiqi Decoction. Western blot was utilized to detect the expression of key proteins in the Agrin/LRP4/MuSK signaling pathway in both C2C12 myotubes and mouse gastrocnemius muscles. The results demonstrated that compared to the model group, the prednisone group exhibited a significant decrease in the body weights of mice, whereas no significant differences in the body weights of mice were observed among the low-, medium-, and high-dose Jianpi Bushen Yiqi Decoction groups. All treatment groups showed significantly improved grip strength and Lennon scores. Additionally, the formula promoted AChR clustering on myotubes and enhanced AChR integrity in gastrocnemius myofilaments and reduced inflammatory infiltration between muscle tissue and fibrous hyperplasia. Furthermore, Jianpi Bushen Yiqi Decoction upregulated the protein expression of AChRα1, Agrin, and p-MuSK in C2C12 myotubes and increased the protein expression of AChRα1, Agrin, MuSK, p-MuSK, LRP4, and docking protein 7(Dok-7)in gastrocnemius tissue. In conclusion, Jianpi Bushen Yiqi Decoction may promote AChR clustering by targeting key proteins in the Agrin/LRP4/MuSK signaling pathway, thereby improving neuromuscular junction function and enhancing muscle strength.
Animals ; Agrin/genetics* ; Mice ; Drugs, Chinese Herbal/administration & dosage* ; Signal Transduction/drug effects* ; Receptors, Cholinergic/genetics* ; Female ; Mice, Inbred C57BL ; Receptor Protein-Tyrosine Kinases/genetics* ; Neuromuscular Junction/metabolism* ; Myasthenia Gravis, Autoimmune, Experimental/physiopathology* ; Humans ; LDL-Receptor Related Proteins

Autoantibodies ; Calcium Channels ; Humans ; Myasthenia Gravis ; Receptors, Cholinergic/metabolism*

Artemisia capillaris Thunberg is a medicinal plant used as a traditional medicine in many cultures. It is an effective remedy for liver problems including hepatitis. Recent pharmacological reports have indicated that Artemisia species can exert various neurological effects. Previously, we reported a memory-enhancing effect of Artemisia species. However, the mechanisms underlying the neuroprotective effect of A. capillaris (AC) are still unknown. In the present study, we investigated the effect of an ethanol extract of AC on ischemic brain injury in a mouse model of transient forebrain ischemia. The mice were treated with AC for seven days, beginning one day before induction of transient forebrain ischemia. Behavioral deficits were investigated using the Y-maze. Nissl and Fluoro-jade B staining were used to indicate the site of injury. To determine the underlying mechanisms for the drug, we measured acetylcholinesterase activity. AC (200 mg·kg) treatment reduced transient forebrain ischemia-induced neuronal cell death in the hippocampal CA1 region. The AC-treated group also showed significant amelioration in the spontaneous alternation of the Y-maze test performance, compared to that in the untreated transient forebrain ischemia group. Moreover, AC treatment showed a concentration-dependent inhibitory effect on acetylcholinesterase activity in vitro. Finally, the effect of AC on forebrain ischemia was blocked by mecamylamine, a nonselective nicotinic acetylcholine receptor antagonist. Our results suggested that in a model of forebrain ischemia, AC protected against neuronal death through the activation of nicotinic acetylcholine receptors.
Acetylcholinesterase ; metabolism ; Animals ; Artemisia ; Cell Death ; drug effects ; Cholinergic Antagonists ; pharmacology ; Disease Models, Animal ; Ethanol ; chemistry ; Hippocampus ; pathology ; physiopathology ; Ischemic Attack, Transient ; drug therapy ; pathology ; physiopathology ; Male ; Mecamylamine ; pharmacology ; Memory ; drug effects ; Mice ; Mice, Inbred C57BL ; Models, Neurological ; Neuroprotective Agents ; administration & dosage ; pharmacology ; Phytotherapy ; Plant Components, Aerial ; chemistry ; Plant Extracts ; administration & dosage ; pharmacology ; Receptors, Cholinergic ; metabolism

BACKGROUND/AIMS: Urocortin 1, a corticotropin-releasing factor related peptide, increases colonic motility under stressful conditions. We investigated the effect of urocortin 1 on colonic motility using an experimental model with isolated rat colon in which the blood flow and intestinal nerves were preserved. Furthermore, we assessed whether this effect was mediated by adrenergic or cholinergic nerves. METHODS: Colonic motility was measured in the proximal and distal parts of resected rat colon. The colon resected from the peritoneum was stabilized, and then urocortin 1 (13.8, 138, 277, and 1,388 pM) was administered via a blood vessel. Motility index was measured in the last 5 min of the 15 min administration of urocortin 1 and expressed as percentage change from baseline. Subsequently, the change in motility was measured by perfusing urocortin 1 in colons pretreated with phentolamine, propranolol, hexamethonium, atropine, or tetrodotoxin. RESULTS: At concentrations of 13.8, 138, 277, and 1,388 pM, urocortin 1 increased the motility of proximal colon (20.4+/-7.2%, 48.4+/-20.9%, 67.0+/-25.8%, and 64.2+/-20.9%, respectively) and the motility of distal colon (3.3+/-3.3%, 7.8+/-7.8%, 71.1+/-28.6%, and 87.4+/-32.5%, respectively). The motility induced by urocortin 1 was significantly decreased by atropine to 2.4+/-2.4% in proximal colon and 3.4+/-3.4% in distal colon (p<0.05). However, tetrodotoxin, propranolol, phentolamine, and hexamethonium did not inhibit motility. CONCLUSIONS: Urocortin 1 increased colonic motility and it is considered that this effect was directly mediated by local muscarinic cholinergic receptors.
Animals ; Colon/*drug effects/physiology ; Injections, Intravenous ; Male ; Muscle Contraction/drug effects ; Neurotransmitter Agents/pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Cholinergic/chemistry/metabolism ; Urocortins/isolation & purification/*pharmacology

BACKGROUNDSingle-fiber electromyography (SFEMG) abnormality in the extensor digitorum communis (EDC) was reported in ocular myasthenia gravis (OMG), which indicated subclinical involvement beyond extraocular muscles in OMG patients. The relationship between the abnormal findings of SFEMG in EDC and the probability for OMG to develop generalized myasthenia gravis (GMG) is unknown. This retrospective study aimed to determine the predictive value of abnormality of SFEMG in EDC of OMG patients.

METHODSOne-hundred and two OMG patients underwent standard clinical diagnosis process and SFEMG test in EDC muscle when diagnosed and were clinically followed up for 5 years. The SFEMG data were compared between different clinical groups according to thymus status, onset age, and different outcome of OMG developing. Chances of progressing to GMG were compared between two different groups according to SFEMG and repetitive nerve stimulation (RNS) results, acetylcholine receptor antibody (AchRAb) titer, thymus status, and onset age.

RESULTSAbnormal SFEMG results were observed in 84 (82.4%) patients. The mean jitter, percentage of jitter >55 μs (%), and blocking were higher in OMG patients than in healthy volunteers. There were no statistical differences in jitter analysis between thymoma group and non-thymoma group (P = 0.65), or between the later OMG group and the later GMG group (P = 0.31), including mean jitter, percentage of jitter >55 μs (%), and blocking. Elderly group (≥45 years old) had a higher mean jitter than younger group (t = 2.235, P = 0.028). Total 55 OMG developed GMG, including 47 in abnormal SFEMG group while 8 in normal SFEMG group. There was no statistical difference in the conversion rates between the two groups (χ2 = 0.790, P = 0.140). RNS abnormality, AchRab titer, or onset age had no correlation with OMG prognosis (P = 0.150, 0.070, 0.120, respectively) while thymoma did (χ2 = 0.510, P = 0.020).

CONCLUSIONSFEMG test in the EDC showed high abnormality in OMG, suggesting subclinical involvement other than extraocular muscles. Nevertheless, the abnormal jitter analysis did not predict the prognosis of OMG according to clinical follow-up.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Electromyography ; methods ; Humans ; Middle Aged ; Myasthenia Gravis ; metabolism ; pathology ; physiopathology ; Prognosis ; Receptors, Cholinergic ; metabolism ; Retrospective Studies ; Young Adult

OBJECTIVETo observe the effects of subchronic benzo[a]pyrene (B[a]P) exposure on the neurobehavior and hippocampal acetylcholine (Ach) level, acetylcholinesterase (AChE) activity, and mRNA and protein expression of nicotinic acetylcholine receptor α7 subtype (nAChR α7) in rats, and to investigate the neurotoxic mechanism of B[a]P.

METHODSSixty healthy male SD rats were randomly divided into blank control group, solvent control group, and B [a]P exposure groups. Each rat in the exposure groups was intraperitoneally injected with B[a]P at 1.0, 2.5, or 6.25 mg/kg once every other day for 90 days. The learning and memory ability of the rats was examined by Morris water maze test and step-down test; the hippocampal Ach level was measured by alkaline hydroxylamine method; the AChE activity was measured by DNTB method; the mRNA and protein expression levels of hippocampal nAChR α7 were measured by quantitative PCR and Western blot.

RESULTSThe 2.5 and 6.25 mg/kg B[a]P exposure groups showed significantly lower learning and memory abilities than the blank control group and solvent control group (P < 0.05); also, the two groups had significantly lower hippocampal Ach levels than the blank control group, solvent control group, and 1.0 mg/kg B[a]P exposure group (P < 0.05). The 6.25 mg/kg B[a]P exposure group showed significantly lower hippocampal AChE activity than the blank control group, solvent control group, and 1.0 mg/kg B[a]P exposure group (P < 0.05). There were no significant differences in the mRNA and protein expression levels of nAChR α7 among all groups (P > 0.05). The hippocampal Ach level was negatively correlated with the mean escape latency period and total distance travelled (r = -0.567, P < 0.01; r = -0.503, P < 0.01) but positively correlated with the time in platform quadrant (r = 0.800, P < 0.01).

CONCLUSIONSubchronic B[a]P exposure may impair the learning and memory ability in rats, which is related to the downregulation of hippocampal Ach level.

Acetylcholine ; metabolism ; Acetylcholinesterase ; metabolism ; Animals ; Benzo(a)pyrene ; toxicity ; Hippocampus ; drug effects ; metabolism ; Male ; Maze Learning ; drug effects ; Memory ; drug effects ; Rats ; Rats, Sprague-Dawley ; Receptors, Cholinergic ; metabolism ; Toxicity Tests, Subchronic ; alpha7 Nicotinic Acetylcholine Receptor ; metabolism

PURPOSE: Central nervous system (CNS) and cardiovascular system (CVS) side effects of anticholinergic agents used to treat overactive bladder (OAB) are underreported. Hence, this review aimed to focus on the mechanisms of CNS and CVS side effects of anticholinergic drugs used in OAB treatment, which may help urologists in planning the rationale for OAB treatment. MATERIALS AND METHODS: PubMed/MEDLINE was searched for the key words "OAB," "anticholinergics," "muscarinic receptor selectivity," "blood-brain barrier," "CNS," and "CVS side effects." Additional relevant literature was determined by examining the reference lists of articles identified through the search. RESULTS: CNS and CVS side effects, pharmacodynamic and pharmacokinetic properties, the metabolism of these drugs, and the clinical implications for their use in OAB are presented and discussed in this review. CONCLUSIONS: Trospium, 5-hydroxymethyl tolterodine, darifenacin, and solifenacin seem to have favorable pharmacodynamic and pharmacokinetic properties with regard to CNS side effects, whereas the pharmacodynamic features of darifenacin, solifenacin, and oxybutynin appear to have an advantage over the other anticholinergic agents (tolterodine, fesoterodine, propiverine, and trospium) with regard to CVS side effects. To determine the real-life situation, head-to-head studies focusing especially on CNS and CVS side effects of OAB anticholinergic agents are urgently needed.
Benzhydryl Compounds ; Benzilates ; Benzofurans ; Cardiovascular System* ; Central Nervous System* ; Cholinergic Antagonists* ; Cresols ; Mandelic Acids ; Metabolism ; Pyrrolidines ; Quinuclidines ; Receptors, Muscarinic ; Tetrahydroisoquinolines ; Urinary Bladder, Overactive* ; Solifenacin Succinate

OBJECTIVE: To determine the role of miR-155 in the pathogenesis of generalized myasthenia gravis (GMG) and the effect of dexamethasone (DXM) on miR-155. METHODS: The expression of miR-155 in B cells from the GMG patients and healthy controls was analyzed by qPCR. The B cells were cultured with DXM and PBS. The B cell proliferation was examined by MTT; CD80 and CD86 frequencies were detected by flow cytometry; and anti-AChRIgG and isotypes anti-AChR-IgG1, 2, 3 in the supernatant were detected by ELISA. RESULTS: qPCR revealed that the expression of miR-155 in the B cells was much higher than that in the controls, and the miR155 expression decreased after DXM treatment. flow cytometry showed that there was no significant difference in the proliferation and the expressions of CD80 and CD86 in the B cells between the DXM group and the PBS group. The concentration of anti-AChR-IgG1 was obviously lower in the DXM group than in the PBS group, but the concentration of anti-AChRIgG, anti-AChR-IgG2, and anti-AchR-IgG3 was similar. CONCLUSION high expression of miR-155 may be associated with myasthenia gravis progression. DXM may disturb the antibody class switch of B cells by suppressing the expression of miR-155 and improve the symptom of MG patients.
Adult ; B-Lymphocytes ; cytology ; immunology ; metabolism ; B7-1 Antigen ; metabolism ; Cell Proliferation ; Cells, Cultured ; Dexamethasone ; therapeutic use ; Female ; Humans ; Immunoglobulin G ; immunology ; Male ; MicroRNAs ; genetics ; metabolism ; Middle Aged ; Myasthenia Gravis ; drug therapy ; genetics ; immunology ; Receptors, Cholinergic ; immunology ; Tetraspanin 28 ; metabolism ; Young Adult

OBJECTIVETo investigate the effect of penehyclidine hydrochloride on glutamate (Glu)release and N-methyl-D-aspartate receptor (NMDAR)1 expression in hippocampus CA1 with global cerebral ischemia/reperfusion rats.

METHODSSixty male Wistar rats were randomly allocated into three groups; group A received sham operation; group B received ischemia/reperfusion; group C received penehyclidine hydrochloride treatment (2 mg/kg) before ischemia/reperfusion (n=20). Global cerebral ischemia was induced according to Pulsinelli-Brierley method. All animals were divided into two experiments: (I) Microdialysis plus HPLC/FD were used to detect Glu level after reperfusion 1 h, 3 h, 6 h. (II) After reperfusion 3 h, the animals were decapitated on ice and the brains were immediately removed to detect NMDAR1 expression in CA1 area by immunohistochemistry.

RESULTSAfter penehyclidine hydrochloride treatment, extracellular Glu level in CA1 were significantly decreased compared with those of control group (P < 0.05 or 0.01); Total integrated OD, average gray value and positive-cell area of NMDAR1 in CA1 were also significantly decreased compared with those of control group (P < 0.05 or 0.01).

CONCLUSIONPenehyclidine hydrochloride might has protective effect in hippocampus CA1 on global cerebral ischemia/reperfusion animals. The protective mechanism might be involved in inhibiting Glu release and NMDAR1 expression.

Animals ; Brain Ischemia ; metabolism ; physiopathology ; CA1 Region, Hippocampal ; metabolism ; Cholinergic Antagonists ; pharmacology ; Glutamic Acid ; metabolism ; Male ; Quinuclidines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; metabolism ; Reperfusion Injury ; metabolism ; prevention & control

BACKGROUNDCa(2+) in the central nervous system plays important roles in brain physiology, including neuronal survival and regeneration in rats with injured facial motoneurons. The present research was to study the modulations of intracellular free Ca(2+) concentrations by cholinergic receptors in rat facial nucleus, and the mechanisms of the modulations.

METHODSThe fluorescence intensity of facial nucleus in Fluo-3 AM loaded acute brainstem slices was detected by applying intracellular free Ca(2+) measurement technique via confocal laser scanning microscope. The changes of fluorescence intensity of facial nucleus indicate the average changes of intracellular free Ca(2+) levels of the neurons.

RESULTSAcetylcholine was effective at increasing the fluorescence intensity of facial nucleus. Muscarine chloride induced a marked increase of fluorescence intensity in a concentration dependent fashion. The enhancement of fluorescence intensity by muscarine chloride was significantly reduced by thapsigargin (depletor of intracellular Ca(2+) store; P < 0.01), rather than Ca(2+) free artifical cerebrospinal fluid or EGTA (free Ca(2+) chelator; P > 0.05). And the increase of fluorescence intensity was also significantly inhibited by pirenzepine (M(1) subtype selective antagonist; P < 0.01) and 4-DAMP (M(3) subtype selective antagonist; P < 0.01). In addition, fluorescence intensity was markedly increased by nicotine. The enhancement of fluorescence intensity by nicotine was significantly reduced by EGTA, nifedipine (L-type voltage-gated Ca(2+) channel blocker), dihydro-beta-erythroidine (alpha4beta2 subtype selective antagonist), and in Ca(2+) free artificial cerebrospinal fluid (P < 0.01), but not in the presence of mibefradil (M-type voltage-gated Ca(2+) channel blocker) or thapsigargin (P > 0.05).

CONCLUSIONSThe data provide the evidence that muscarinic receptors may induce the increase of intracellular free Ca(2+) levels through the Ca(2+) release of intracellular Ca(2+) stores, in a manner related to M(1) and M(3) subtypes of muscarinic receptors in rat facial nucleus. Nicotine may increase intracellular free Ca(2+) concentrations via the influx of extracellular Ca(2+)+ mainly across L-type voltage-gated Ca(2+) channels, in a manner related to the alpha4beta2 subtype of nicotinic receptors.

Acetylcholine ; pharmacology ; Aniline Compounds ; administration & dosage ; Animals ; Brain Stem ; cytology ; drug effects ; metabolism ; Calcium ; metabolism ; Diamines ; pharmacology ; Facial Nerve ; cytology ; Female ; Fluorescent Dyes ; administration & dosage ; In Vitro Techniques ; Male ; Microscopy, Confocal ; Motor Neurons ; drug effects ; metabolism ; Muscarinic Agonists ; pharmacology ; Nicotine ; pharmacology ; Nicotinic Agonists ; pharmacology ; Piperidines ; pharmacology ; Pirenzepine ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Cholinergic ; metabolism ; Receptors, Muscarinic ; metabolism ; Receptors, Nicotinic ; metabolism ; Tropicamide ; pharmacology ; Xanthenes ; administration & dosage