ABSTRACT
The cholinergic network affects various cellular functions including neurotransmission, and immune reactions. In Myasthenia Gravis (MG), diagnosis and symptomatic therapy are based on cholinergic modulation by acetylcholinesterase inhibitors (AChEI). In Alzheimer's disease (AD) a neurodegenerative disorder associated with inflammatory pathology, cholinergic systems cell loss occurs early. Treatments with special AChEI enhance cholinergic transmission and may act as anti-inflammatory agent via immunocompetent cells expressing alpha-7 acetylcholine receptor (AChR). In Multiple Sclerosis (MS) an inflammatory T-cell-mediated disease, demyelination and neurodegeneration follow neuroinflammation. MS treatment includes anti-inflammatory and immunomodulatory drugs. AChEI can induce cholinergic up-regulation with subsequent effect on neuroinflammation via alpha-7-AChR expressing cells. These effects are additional to the cognitive benefit induced by AChEI.
Subject(s)
Acetylcholine/metabolism , Cholinesterase Inhibitors/therapeutic use , Inflammation/drug therapy , Myasthenia Gravis/drug therapy , Alzheimer Disease/drug therapy , Alzheimer Disease/immunology , Alzheimer Disease/metabolism , Animals , Humans , Inflammation/immunology , Inflammation/metabolism , Multiple Sclerosis/drug therapy , Multiple Sclerosis/immunology , Myasthenia Gravis/immunology , Myasthenia Gravis/metabolismABSTRACT
The neuromuscular weakness associated with myasthenia gravis (MG) can be transiently relieved by pharmacological inhibitors of acetylcholinesterase (AChE). Here, we expand the anticholinesterase repertoire to include 2'-O-methyl-protected antisense oligonucleotides targeted to AChE mRNA (EN101). Using stimulated-single fiber electromyography, we show that EN101 treatment of rats with experimental autoimmune myasthenia gravis (EAMG), improved the mean consecutive difference (MCD) and blocking for 24h. This treatment was more efficient than pyridostigmine and was accompanied by marked improvement in stamina and clinical profile.
Subject(s)
Electromyography , Muscles/physiopathology , Myasthenia Gravis, Autoimmune, Experimental/drug therapy , Myasthenia Gravis, Autoimmune, Experimental/physiopathology , Oligonucleotides, Antisense/therapeutic use , Acetylcholinesterase/genetics , Animals , Electric Stimulation/methods , Exercise Test/methods , Female , Monitoring, Physiologic , Muscles/drug effects , Muscles/radiation effects , Myasthenia Gravis, Autoimmune, Experimental/chemically induced , Neuromuscular Junction/drug effects , Neuromuscular Junction/physiopathology , Neuromuscular Junction/radiation effects , Oligodeoxyribonucleotides , RNA, Messenger/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Inbred Lew , Receptors, Cholinergic/immunology , Time FactorsABSTRACT
We investigated the anti-inflammatory effects of acetylcholinesterase inhibitors (AChEI) at the cellular and molecular levels. AChEI suppressed lymphocyte proliferation and pro-inflammatory cytokine production, as well as extracellular esterase activity. Anti-inflammatory activity was mediated by the alpha7 nicotinic acetylcholine receptor (neuronal); the muscarinic receptor had the opposite effect. Treatment of the central nervous system (CNS) inflammatory disease, experimental autoimmune encephalomyelitis (EAE), with EN101, an anti-sense oligodeoxynucleotide, targeted to AChE mRNA, reduced the clinical severity of the disease and CNS inflammation intensity. The results of our experiments suggest that AChEI increase the concentration of extracellular acetylcholine (ACh), rendering it available for interaction with a nicotinic receptor expressed on lymphocytes. Our findings point to a novel role for AChEI which may be relevant in CNS inflammatory diseases such as EAE and multiple sclerosis. They also emphasize the importance of cholinergic balance in neurological disorders, such as Alzheimer's disease and myasthenia gravis, in which these drugs are used.
Subject(s)
Acetylcholinesterase/metabolism , Anti-Inflammatory Agents/pharmacology , Cholinesterase Inhibitors/pharmacology , Oligonucleotides, Antisense/pharmacology , Up-Regulation/drug effects , Acetylcholinesterase/genetics , Animals , Cell Proliferation/drug effects , Cytokines/metabolism , Drug Interactions , Lymphocyte Activation/drug effects , Lymphocytes/cytology , Lymphocytes/drug effects , Lymphocytes/physiology , Mice , Mice, Inbred C57BL , Oligodeoxyribonucleotides , Phytohemagglutinins/pharmacology , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction/methods , Spinal Cord/pathologyABSTRACT
Alternative splicing induces, under abnormal cholinergic neurotransmission, overproduction of the rare "readthrough" acetylcholinesterase variant AChE-R. We explored the pathophysiological relevance of this phenomenon in patients with myasthenia gravis (MG) and rats with experimental autoimmune MG (EAMG), neuromuscular junction diseases with depleted acetylcholine receptors. In MG and EAMG, we detected serum AChE-R accumulation. In EAMG, we alleviated electromyographic abnormalities by nanomolar doses of EN101, an antisense oligonucleotide that selectively lowers AChE-R in blood and muscle yet leaves unaffected the synaptic variant AChE-S. Whereas animals treated with placebo or conventional anticholinesterases continued to deteriorate, a 4 wk daily oral administration of EN101 improved survival, neuromuscular strength and clinical status in moribund EAMG rats. The efficacy of targeting only one AChE splicing variant highlights potential advantages of mRNA-targeted therapeutics for chronic cholinergic malfunctioning.
