American University of Beirut
Source: https://www.aub.edu.lb/fm/PLM/NMD/Pages/Research.aspx Parent: https://www.aub.edu.lb/fm/plm/Pages/default.aspx
Research
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Scopes of research
The Muhieddine M. Ahdab Neuromuscular Diagnostic (MMA-NMD) Laboratory research activities are divided into three axes that focus on: \ \
Axis 1 *Epidemiology and Pathophysiology of neuromuscular dystrophies in the Lebanese population *We aim particularly to characterize and correlate the clinico-pathologic, biochemical and molecular features of Limb-girdle muscular dystrophy type 2A and Duchenne muscular dystrophy in cohorts of Lebanese patients.
Axis 2 Mitochondrial thermogenesis\ Although the thermogenic function of mitochondria is well recognized, its impact on the temperature of the mitochondria, its surrounding, and its distribution pattern within cells, particularly in highly compartmentalized cells such as neuronal and muscle cells, is largely unknown. In 2018, we made a major discovery, using a novel and unique approach, where we have shown that human cells mitochondria operate at a sizzling 50°C (Chrétien et al., 2018). We also demonstrated that mitochondrial enzymes activity was maximal at or slightly above 50°C. Currently, we set out to develop various tools enabling further assessment of mitochondrial temperature as well as its distribution (thermal compartments) and behavior within highly compartmentalized cells. \
Axis 3 Mitochondrial Bioenergetics in Peripheral and Neuroinflammation\ In this research axis we aim to provide a highly integrated picture of the various interconnected intracellular metabolic, bioenergetic, and molecular events, in macrophages and microglia, depicting the role of mitochondrial bioenergetics in the inflammatory and neuroinflammatory processes as well as the impact of bioenergetics-associated deficiencies, whether environmentally or genetically induced, on such processes from immune cell differentiation, to phenotypic polarization and modulation of adapted intracellular “inflammatory" signaling pathways.
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Recent publications
- 1.Haidar, M. A., Shakkour, Z., Barsa, C., Tabet, M., Mekhjian, S., Darwish, H., Goli, M., Shear, D., Pandya, J. D., Mechref, Y., El Khoury, R*., Wang, K., & Kobeissy, F*. (2022). Mitoquinone Helps Combat the Neurological, Cognitive, and Molecular Consequences of Open Head Traumatic Brain Injury at Chronic Time Point. Biomedicines, 10(2), 250. https://doi.org/10.3390/biomedicines10020250
- 2.Tabet, M., El-Kurdi, M., Haidar, M. A., Nasrallah, L., Reslan, M. A., Shear, D., Pandya, J. D., El-Yazbi, A. F., Sabra, M., Mondello, S., Mechref, Y., Shaito, A., Wang, K. K., El-Khoury, R*., & Kobeissy, F*. (2022). Mitoquinone supplementation alleviates oxidative stress and pathologic outcomes following repetitive mild traumatic brain injury at a chronic time point. Experimental Neurology, 113987. https://doi.org/10.1016/j.expneurol.2022.113987
- 3.Chrétien, D., Bénit, P., Leroy, C., El-Khoury, R., Chang, YT., Lenaers, G., Rustin, P., Malgorzata Rak. (2020). Pitfalls in mitochondrial temperature monitoring using Charged fluorophores. Chemosensors. 8(4), 124; https://doi.org/10.3390/chemosensors8040124
- 4.Hotait, M., Nasreddine, W., El-Khoury, R., Dirani, M., Nawfal, O., & Beydoun, A. (2020). FARS2 Mutations: More Than Two Phenotypes? A Case Report. Frontiers in Genetics, 11, 787. https://doi.org/10.3389/fgene.2020.00787
- 5.El-Khoury, R., Traboulsi, S., Hamad, T., Lamaa, M., Sawaya, R., & Ahdab-Barmada, M. (2019). Divergent Features of Mitochondrial Deficiencies in LGMD2A Associated With Novel Calpain-3 Mutations. Journal of Neuropathology and Experimental Neurology, 78(1), 88–98. https://doi.org/10.1093/jnen/nly113
- 6.El-Khoury, R., Hajj, M., Khraibani, J., Audi, E., Monsef, C., & Farra, C. (2019). Novel pleiotropic BRCA2 pathogenic variants in Lebanese families. Cancer Genetics, 231–232, 32–35. https://doi.org/10.1016/j.cancergen.2018.12.005
- 7.El-Khoury, R., Ahdab-Barmada, M., Saade, M., & Farra, C. (2018). Molecular Characteristics of Duchenne Muscular Dystrophy in a Lebanese Cohort. Journal of Molecular and Genetic Medicine, 12(4). https://doi.org/10.4172/1747-0862.1000373
- 8.Chrétien, D., Bénit, P., Ha, H.-H., Keipert, S., El-Khoury, R., Chang, Y.-T., Jastroch, M., Jacobs, H. T., Rustin, P., & Rak, M. (2018). Mitochondria are physiologically maintained at close to 50 °C. PLoS Biology, 16(1), e2003992. https://doi.org/10.1371/journal.pbio.2003992
- 9.Abou Hassan, O. K., Karnib, M., El-Khoury, R., Nemer, G., Ahdab-Barmada, M., & BouKhalil, P. (2016). Linezolid Toxicity and Mitochondrial Susceptibility: A Novel Neurological Complication in a Lebanese Patient. Frontiers in Pharmacology, 7, 325. https://doi.org/10.3389/fphar.2016.00325
- 10.El-Khoury, R., Kaulio, E., Lassila, K. A., Crowther, D. C., Jacobs, H. T., & Rustin, P. (2016). Expression of the alternative oxidase mitigates beta-amyloid production and toxicity in model systems. Free Radical Biology & Medicine, 96, 57–66. https://doi.org/10.1016/j.freeradbiomed.2016.04.006
- 11.Prabhu, D., Goldstein, A. C., El-Khoury, R., Rak, M., Edmunds, L., Rustin, P., Vockley, J., & Schiff, M. (2015). ANT2-defective fibroblasts exhibit normal mitochondrial bioenergetics. Molecular Genetics and Metabolism Reports, 3, 43–46. https://doi.org/10.1016/j.ymgmr.2015.03.005
- 12.El-Khoury, R., Dufour, E., Rak, M., Ramanantsoa, N., Grandchamp, N., Csaba, Z., Duvillié, B., Bénit, P., Gallego, J., Gressens, P., Sarkis, C., Jacobs, H. T., & Rustin, P. (2013). Alternative oxidase expression in the mouse enables bypassing cytochrome c oxidase blockade and limits mitochondrial ROS overproduction. PLoS Genetics, 9(1), e1003182. \ https://doi.org/10.1371/journal.pgen.1003182
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