scholarly journals A knock-in Drosophila model supports a conserved link between potassium channelopathy and involuntary movement

2020 ◽  
Author(s):  
Patrick Kratschmer ◽  
Edgar Buhl ◽  
Ko-Fan Chen ◽  
Simon Lowe ◽  
Dimitri M. Kullmann ◽  
...  

ABSTRACTBackgroundGenetic and in vitro studies have linked a heterozygous gain-of-function mutation (D434G) in the hSlo1 BK (Big potassium) channel to paroxysmal dyskinesia. However, support for this linkage from in vivo models has been lacking.ObjectivesWe aimed to re-create the equivalent mutation to hSlo1 D434G in the fruit fly, Drosophila, and examine how this mutation altered movement and action potential waveforms.MethodsWe generated a knock-in Drosophila model of hSlo1 D434G. We used video-tracking and infra-red beam-break systems to test whether locomotion was altered in this model, and patch-clamp electrophysiology to determine how the mutation affected action potential waveforms.ResultsWe identified profound motor dysfunction and sporadic leg twitches, as well as a reduced width and an enhancement of the afterhyperpolarization phase of action potentials, in the model background.ConclusionOur results support a conserved relationship between enhanced BK channel function and disrupted motor control across distantly related species.

2021 ◽  
Author(s):  
◽  
Tanisha Vithal

<p>Alzheimer’s disease (AD) is a neurodegenerative disease that is responsible for 50-80% of dementia cases and is characterised by lack of visuospatial perception, impairment of language and memory. One of the main physiological attributions towards this disease is the accumulation of large insoluble deposits of amyloid beta, a toxic peptide, which results in the generation of amyloid plaques found in between neurons in the brain. Currently no therapeutic treatments are available. Clusterin (CLU) is an apolipoprotein that when defective is the second highest genetic risk factor for AD. It has been strongly debated whether CLU counteracts or promotes AD pathology. With the roles of CLU including but not limited to acting as a chaperone for cholesterol transport and aiding autophagy functionality in cancer models, this thesis investigates these two specific functionalities by overexpressing CLU in an in vitro SH-SY5Y and in an in vivo AD model of Drosophila melanogaster (fruit fly). Conclusions from this study reveal that within D. melanogaster, CLU reduced Aβ42 levels and increased cholesterol effect through the blood brain barrier. Additionally, in human cells, CLU ameliorated the defective flux in autophagy. This thesis sheds light into how CLU plays a protective role within an Alzheimer’s disease mammalian system.</p>


2012 ◽  
Vol 166 (1) ◽  
pp. 276-296 ◽  
Author(s):  
Herbert M Himmel ◽  
Alexandra Bussek ◽  
Michael Hoffmann ◽  
Rolf Beckmann ◽  
Horst Lohmann ◽  
...  

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Kevin S. Chen ◽  
Krystal Menezes ◽  
Jarlath B. Rodgers ◽  
Darren M. O’Hara ◽  
Nhat Tran ◽  
...  

Abstract Background Parkinson’s disease is a disabling neurodegenerative movement disorder characterized by dopaminergic neuron loss induced by α-synuclein oligomers. There is an urgent need for disease-modifying therapies for Parkinson’s disease, but drug discovery is challenged by lack of in vivo models that recapitulate early stages of neurodegeneration. Invertebrate organisms, such as the nematode worm Caenorhabditis elegans, provide in vivo models of human disease processes that can be instrumental for initial pharmacological studies. Methods To identify early motor impairment of animals expressing α-synuclein in dopaminergic neurons, we first used a custom-built tracking microscope that captures locomotion of single C. elegans with high spatial and temporal resolution. Next, we devised a method for semi-automated and blinded quantification of motor impairment for a population of simultaneously recorded animals with multi-worm tracking and custom image processing. We then used genetic and pharmacological methods to define the features of early motor dysfunction of α-synuclein-expressing C. elegans. Finally, we applied the C. elegans model to a drug repurposing screen by combining it with an artificial intelligence platform and cell culture system to identify small molecules that inhibit α-synuclein oligomers. Screen hits were validated using in vitro and in vivo mammalian models. Results We found a previously undescribed motor phenotype in transgenic α-synuclein C. elegans that correlates with mutant or wild-type α-synuclein protein levels and results from dopaminergic neuron dysfunction, but precedes neuronal loss. Together with artificial intelligence-driven in silico and in vitro screening, this C. elegans model identified five compounds that reduced motor dysfunction induced by α-synuclein. Three of these compounds also decreased α-synuclein oligomers in mammalian neurons, including rifabutin which has not been previously investigated for Parkinson’s disease. We found that treatment with rifabutin reduced nigrostriatal dopaminergic neurodegeneration due to α-synuclein in a rat model. Conclusions We identified a C. elegans locomotor abnormality due to dopaminergic neuron dysfunction that models early α-synuclein-mediated neurodegeneration. Our innovative approach applying this in vivo model to a multi-step drug repurposing screen, with artificial intelligence-driven in silico and in vitro methods, resulted in the discovery of at least one drug that may be repurposed as a disease-modifying therapy for Parkinson’s disease.


Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 943
Author(s):  
Julia Whittle ◽  
Aaron Johnson ◽  
Matthew B. Dobbs ◽  
Christina A. Gurnett

Distal arthrogryposis and lethal congenital contracture syndromes describe a broad group of disorders that share congenital limb contractures in common. While skeletal muscle sarcomeric genes comprise many of the first genes identified for Distal Arthrogyposis, other mechanisms of disease have been demonstrated, including key effects on peripheral nerve function. While Distal Arthrogryposis and Lethal Congenital Contracture Syndromes display superficial similarities in phenotype, the underlying mechanisms for these conditions are diverse but overlapping. In this review, we discuss the important insights gained into these human genetic diseases resulting from in vitro molecular studies and in vivo models in fruit fly, zebrafish, and mice.


2021 ◽  
Author(s):  
◽  
Tanisha Vithal

<p>Alzheimer’s disease (AD) is a neurodegenerative disease that is responsible for 50-80% of dementia cases and is characterised by lack of visuospatial perception, impairment of language and memory. One of the main physiological attributions towards this disease is the accumulation of large insoluble deposits of amyloid beta, a toxic peptide, which results in the generation of amyloid plaques found in between neurons in the brain. Currently no therapeutic treatments are available. Clusterin (CLU) is an apolipoprotein that when defective is the second highest genetic risk factor for AD. It has been strongly debated whether CLU counteracts or promotes AD pathology. With the roles of CLU including but not limited to acting as a chaperone for cholesterol transport and aiding autophagy functionality in cancer models, this thesis investigates these two specific functionalities by overexpressing CLU in an in vitro SH-SY5Y and in an in vivo AD model of Drosophila melanogaster (fruit fly). Conclusions from this study reveal that within D. melanogaster, CLU reduced Aβ42 levels and increased cholesterol effect through the blood brain barrier. Additionally, in human cells, CLU ameliorated the defective flux in autophagy. This thesis sheds light into how CLU plays a protective role within an Alzheimer’s disease mammalian system.</p>


2019 ◽  
Vol 2 (4) ◽  
pp. 83-98 ◽  
Author(s):  
André De Lima Mota ◽  
Bruna Vitorasso Jardim-Perassi ◽  
Tialfi Bergamin De Castro ◽  
Jucimara Colombo ◽  
Nathália Martins Sonehara ◽  
...  

Breast cancer is the most common cancer among women and has a high mortality rate. Adverse conditions in the tumor microenvironment, such as hypoxia and acidosis, may exert selective pressure on the tumor, selecting subpopulations of tumor cells with advantages for survival in this environment. In this context, therapeutic agents that can modify these conditions, and consequently the intratumoral heterogeneity need to be explored. Melatonin, in addition to its physiological effects, exhibits important anti-tumor actions which may associate with modification of hypoxia and Warburg effect. In this study, we have evaluated the action of melatonin on tumor growth and tumor metabolism by different markers of hypoxia and glucose metabolism (HIF-1α, glucose transporters GLUT1 and GLUT3 and carbonic anhydrases CA-IX and CA-XII) in triple negative breast cancer model. In an in vitro study, gene and protein expressions of these markers were evaluated by quantitative real-time PCR and immunocytochemistry, respectively. The effects of melatonin were also tested in a MDA-MB-231 xenograft animal model. Results showed that melatonin treatment reduced the viability of MDA-MB-231 cells and tumor growth in Balb/c nude mice (p <0.05). The treatment significantly decreased HIF-1α gene and protein expression concomitantly with the expression of GLUT1, GLUT3, CA-IX and CA-XII (p <0.05). These results strongly suggest that melatonin down-regulates HIF-1α expression and regulates glucose metabolism in breast tumor cells, therefore, controlling hypoxia and tumor progression. 


2019 ◽  
Vol 26 (16) ◽  
pp. 2974-2986 ◽  
Author(s):  
Kwang-sun Kim

Vectors are living organisms that transmit infectious diseases from an infected animal to humans or another animal. Biological vectors such as mosquitoes, ticks, and sand flies carry pathogens that multiply within their bodies prior to delivery to a new host. The increased prevalence of Vector-Borne Diseases (VBDs) such as Aedes-borne dengue, Chikungunya (CHIKV), Zika (ZIKV), malaria, Tick-Borne Disease (TBD), and scrub typhus has a huge impact on the health of both humans and livestock worldwide. In particular, zoonotic diseases transmitted by mosquitoes and ticks place a considerable burden on public health. Vaccines, drugs, and vector control methods have been developed to prevent and treat VBDs and have prevented millions of deaths. However, development of such strategies is falling behind the rapid emergence of VBDs. Therefore, a comprehensive approach to fighting VBDs must be considered immediately. In this review, I focus on the challenges posed by emerging outbreaks of VBDs and discuss available drugs and vaccines designed to overcome this burden. Research into promising drugs needs to be upgraded and fast-tracked, and novel drugs or vaccines being tested in in vitro and in vivo models need to be moved into human clinical trials. Active preventive tactics, as well as new and upgraded diagnostics, surveillance, treatments, and vaccination strategies, need to be monitored constantly if we are to manage VBDs of medical importance.


2020 ◽  
Vol 26 (35) ◽  
pp. 4362-4372
Author(s):  
John H. Miller ◽  
Viswanath Das

No effective therapeutics to treat neurodegenerative diseases exist, despite significant attempts to find drugs that can reduce or rescue the debilitating symptoms of tauopathies such as Alzheimer’s disease, Parkinson’s disease, frontotemporal dementia, amyotrophic lateral sclerosis, or Pick’s disease. A number of in vitro and in vivo models exist for studying neurodegenerative diseases, including cell models employing induced-pluripotent stem cells, cerebral organoids, and animal models of disease. Recent research has focused on microtubulestabilizing agents, either natural products or synthetic compounds that can prevent the axonal destruction caused by tau protein pathologies. Although promising results have come from animal model studies using brainpenetrant natural product microtubule-stabilizing agents, such as paclitaxel analogs that can access the brain, epothilones B and D, and other synthetic compounds such as davunetide or the triazolopyrimidines, early clinical trials in humans have been disappointing. This review aims to summarize the research that has been carried out in this area and discuss the potential for the future development of an effective microtubule stabilizing drug to treat neurodegenerative disease.


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