The neuromuscular junction disorders

Cannabinerol (CBNR) Influences Synaptic Genes Associated with Cytoskeleton and Ion Channels in NSC-34 Cell Line: A Transcriptomic Study

Cannabinoids are receiving great attention as a novel approach in the treatment of cognitive and motor disabilities, which characterize neurological disorders. To date, over 100 phytocannabinoids have been extracted from Cannabis sativa, and some of them have shown neuroprotective properties and the capacity to influence synaptic transmission. In this study, we investigated the effects of a less-known phytocannabinoid, cannabinerol (CBNR), on neuronal physiology. Using the NSC-34 motor-neuron-like cell line and next-generation sequencing analysis, we discovered that CBNR influences synaptic genes associated with synapse organization and specialization, including genes related to the cytoskeleton and ion channels. Specifically, the calcium, sodium, and potassium channel subunits (Cacna1b, Cacna1c, Cacnb1, Grin1, Scn8a, Kcnc1, Kcnj9) were upregulated, along with genes related to NMDAR (Agap3, Syngap1) and calcium (Cabp1, Camkv) signaling. Moreover, cytoskeletal and cytoskeleton-associated genes (Actn2, Ina, Trio, Marcks, Bsn, Rtn4, Dgkz, Htt) were also regulated by CBNR. These findings highlight the important role played by CBNR in the regulation of synaptogenesis and synaptic transmission, suggesting the need for further studies to evaluate the neuroprotective role of CBNR in the treatment of synaptic dysfunctions that characterize motor disabilities in many neurological disorders.

Canine Mobility Maintenance and Promotion of a Healthy Lifestyle

This article highlights the recommendations and considerations for maintaining a healthy canine lifestyle. A key component of a healthy lifestyle is the enhancement and optimization of mobility. Mobility is essential in maintaining a high quality of life and involves the interplay of a dog's structure, posture, body condition score, physical exercise, and a healthy human-animal bond throughout a dog's lifetime.

Identification and molecular characterization of propionylcholinesterase, a novel pseudocholinesterase in rice

Cholinesterase is consisting of acetylcholinesterase (AChE) and pseudocholinesterase in vertebrates and invertebrates. AChE gene has been identified in several plant species, while pseudocholinesterase gene has not yet been found in any plant species. In this study, we report that the AChE gene paralog encodes propionylcholinesterase (PChE), a pseudocholinesterase in rice. PChE was found to be located adjacent to AChE (Os07g0586200) on rice chromosome 7 and designated as Os07g0586100. Phylogenetic tree analysis showed a close relationship between rice AChE and PChE. PChE-overexpressing rice had higher hydrolytic activity toward propionylthiocholine than acetylthiocholine and showed extremely low activity against butyrylthiocholine. Therefore, the PChE gene product was characterized as a propionylcholinesterase, a pseudocholinesterase. The rice PChE displayed lower sensitivity to the cholinesterase inhibitor, neostigmine bromide, than electric eel, maize, and rice AChEs. The recombinant PChE functions as a 171 kDa homotetramer. PChE was expressed during the later developmental stage, and it was found be localized in the extracellular spaces of the rice leaf tissue. These results suggest that the rice plant possesses PChE, which functions in the extracellular spaces at a later developmental stage. To the best of our knowledge, this study provides the first direct evidence and molecular characterization of PChE in plants.

Effects of Natural Products on Neuromuscular Junction

Neuromuscular junction (NMJ) disorders result from damage, malfunction or absence of one or more key proteins involved in neuromuscular transmission, comprising a wide range of disorders. The most common pathology is antibody-mediated or downregulation of ion channels or receptors, resulting in Lambert-Eaton myasthenic syndrome, myasthenia gravis, and acquired neuromyotonia (Isaac's syndrome), and rarely congenital myasthenic syndromes caused by mutations in NMJ proteins. A wide range of symptomatic treatments, immunomodulating therapies, or immunosuppressive drugs have been used to treat NMJ diseases. Future research must be directed at better understanding of the pathogenesis of these diseases, and developing novel disease-specific treatments. Numerous secondary metabolites, especially alkaloids isolated from plants have been used to treat NMJ diseases in traditional and clinical practices. An ethnopharmacological approach has provided leads for identifying new treatment for NMJ diseases. In this review, we performed a literature survey in Pubmed, Science Direct, and Google Scholar to gather information on drug discovery from plant sources for NMJ disease treatments. To date, most research has focused on the effect of herbal remedies on cholinesterase inhibitory and antioxidant activities. This review provides leads for identifying potential new drugs from plant sources for the treatment of NMJ diseases.

New Insights into the Lactate Shuttle: Role of MCT4 in the Modulation of the Exercise Capacity

Lactate produced by muscle during high-intensity activity is an important end product of glycolysis that supports whole body metabolism. The lactate shuttle model suggested that lactate produced by glycolytic muscle fibers is utilized by oxidative fibers. MCT4 is a proton coupled monocarboxylate transporter preferentially expressed in glycolytic muscle fibers and facilitates the lactate efflux. Here we investigated the exercise capacity of mice with disrupted lactate shuttle due to global deletion of MCT4 (MCT4^-/-) or muscle-specific deletion of the accessory protein Basigin (iMSBsg^-/-). Although MCT4^-/- and iMSBsg^-/- mice have normal muscle morphology and contractility, only MCT4^-/- mice exhibit an exercise intolerant phenotype. In vivo measurements of compound muscle action potentials showed a decrement in the evoked response in the MCT4^-/- mice. This was accompanied by a significant structural degeneration of the neuromuscular junctions (NMJs). We propose that disruption of the lactate shuttle impacts motor function and destabilizes the motor unit.

Moonlighting nuclear pore proteins: tissue-specific nucleoporin function in health and disease

The nuclear pore complex is the main transportation hub for exchange between the cytoplasm and the nucleus. It is built from nucleoporins that form distinct subcomplexes to establish this huge protein complex in the nuclear envelope. Malfunctioning of nucleoporins is well known in human malignancies, such as gene fusions of NUP214 and NUP98 in hematological neoplasms and overexpression of NUP88 in a variety of human cancers. In the past decade, the incremental utilization of next-generation sequencing has unraveled mutations in nucleoporin genes in the context of an increasing number of hereditary diseases, often in a tissue-specific manner. It emerges that, on one hand, the central nervous system and the heart are particularly sensitive to mutations in nucleoporin genes. On the other hand, nucleoporins forming the scaffold structure of the nuclear pore complex are eminently mutation-prone. These novel and exciting associations between nucleoporins and human diseases emphasize the need to shed light on these unanticipated tissue-specific roles of nucleoporins that may go well beyond their role in nucleocytoplasmic transport. In this review, the current insights into altered nucleoporin function associated with human hereditary disorders will be discussed.

Impacts of massively parallel sequencing for genetic diagnosis of neuromuscular disorders

Neuromuscular disorders (NMD) such as neuropathy or myopathy are rare and often severe inherited disorders, affecting muscle and/or nerves with neonatal, childhood or adulthood onset, with considerable burden for the patients, their families and public health systems. Genetic and clinical heterogeneity, unspecific clinical features, unidentified genes and the implication of large and/or several genes requiring complementary methods are the main drawbacks in routine molecular diagnosis, leading to increased turnaround time and delay in the molecular validation of the diagnosis. The application of massively parallel sequencing, also called next generation sequencing, as a routine diagnostic strategy could lead to a rapid screening and fast identification of mutations in rare genetic disorders like NMD. This review aims to summarize and to discuss recent advances in the genetic diagnosis of neuromuscular disorders, and more generally monogenic diseases, fostered by massively parallel sequencing. We remind the challenges and benefit of obtaining an accurate genetic diagnosis, introduce the massively parallel sequencing technology and its novel applications in diagnosis of patients, prenatal diagnosis and carrier detection, and discuss the limitations and necessary improvements. Massively parallel sequencing synergizes with clinical and pathological investigations into an integrated diagnosis approach. Clinicians and pathologists are crucial in patient selection and interpretation of data, and persons trained in data management and analysis need to be integrated to the diagnosis pipeline. Massively parallel sequencing for mutation identification is expected to greatly improve diagnosis, genetic counseling and patient management.

Preparation, in vitro screening and molecular modelling of symmetrical bis-quinolinium cholinesterase inhibitors--implications for early myasthenia gravis treatment

This paper describes the preparation and in vitro evaluation of 18 newly prepared bis-quinolinium inhibitors on human recombinant acetylcholinesterase (AChE) and human plasmatic butyrylcholinesterase (BChE). Their inhibitory (IC(50)) and was compared to the chosen standards ambenonium dichloride, edrophonium chloride, BW284c51 and ethopropazine hydrochloride. One novel compound was found to be a promising inhibitor of hAChE (in nM range) and was better than edrophonium chloride or BW284c51, but was worse than ambenonium chloride. This compound also showed selectivity towards hAChE and it was confirmed as a non-competitive inhibitor of hAChE by kinetic analysis. A molecular modelling study further confirmed its binding to the peripheral active site of hAChE via apparent π-π or π-cationic interactions.

Travel medicine interventions and neurological disease

As a consequence of increased mobility worldwide, persons with underlying medical conditions set out on a journey more often than in the past. Among pre-existing medical conditions, some neurological diseases, including multiple sclerosis and other demyelinating diseases, Guillain-Barré syndrome and myasthenia gravis often create management problems to travel medicine practitioners. There is some concern that these conditions could be worsened either by naturally acquired infections or by some travel medicine interventions. The aim of this review is to suggest a practical approach to each of these conditions and to examine the feasibility and the impact of travel medicine interventions on the underlying disease.

Update on myasthenia gravis

Myasthenia gravis is an autoimmune disorder caused by autoantibodies against the nicotinic acetylcholine receptor on the postsynaptic membrane at the neuromuscular junction and characterised by weakness and fatigability of the voluntary muscles. It has a bimodal peak of incidence with first peak in the third decade and the second peak in the sixth decade. It is probably underdiagnosed in the very old population. Our understanding of the pathogenesis, immunology, and molecular biology of myasthenia gravis has greatly improved in last three decades. It is almost always possible to establish the diagnosis of myasthenia gravis with the current tests. The modern treatment is highly successful and the mortality of treated myasthenia gravis is practically zero. However, there are still important gaps in our knowledge of the origin of myasthenia gravis, the factors that contribute to chronic disease, and the way to cure the disease. In this article the current knowledge of the various aspects of myasthenia gravis are outlined.