Mohamed Emara

Dr. Mohamed Emara


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 July 2017 in PLOS ONE
Verified
Journal Article
Open access
PDF file
FPFreshteh Palangi
Freshteh Palangi
SSSamson Samuel
Samson Samuel
RTRichard Thompson
Richard Thompson
CTChris R Triggle
Chris R Triggle
MEMohamed Emara
Mohamed Emara
Stress Granules (SGs) are dynamic ribonucleoprotein aggregates, which have been observed in cells subjected to environmental stresses, such as oxidative stress and heat shock (HS). Although pluripotent stem cells (PSCs) are highly sensitive to oxidative stress, the role of SGs in regulating PSC self-renewal and differentiation has not been fully elucidated. Here we found that sodium arsenite (SA) and HS, but not hydrogen peroxide (H2O2), induce SG formation in human induced (hi) PSCs. Particularly, we found that these granules contain the well-known SG proteins (G3BP, TIAR, eIF4E, eIF4A, eIF3B, eIF4G, and PABP), were found in juxtaposition to processing bodies (PBs), and were disassembled after the removal of the stress. Moreover, we showed that SA and HS, but not H2O2, promote eIF2α phosphorylation in hiPSCs forming SGs. Analysis of pluripotent protein expression showed that HS significantly reduced all tested markers (OCT4, SOX2, NANOG, KLF4, L1TD1, and LIN28A), while SA selectively reduced the expression levels of NANOG and L1TD1. Finally, in addition to LIN28A and L1TD1, we identified DPPA5 (pluripotent protein marker) as a novel component of SGs. Collectively, these results provide new insights into the molecular cues of hiPSCs responses to environmental insults.

6 March 2020 in BMC Complementary Medicine and Therapies
Verified
Journal Article
Open access
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MAMustafa Ardah
Mustafa Ardah
SGSimona Ghanem
Simona Ghanem
SASara Abdulla
Sara Abdulla
GLGuohua Lv
Guohua Lv
MEMohamed Emara
Mohamed Emara
OEOmar El-Agnaf
Omar El-Agnaf
Background: Recent studies indicated that seeded fibril formation and toxicity of α-synuclein (α-syn) play a main role in the pathogenesis of certain diseases including Parkinson’s disease (PD), multiple system atrophy, and dementia with Lewy bodies. Therefore, examination of compounds that abolish the process of seeding is considered a key step towards therapy of several synucleinopathies. Methods: Using biophysical, biochemical and cell-culture-based assays, assessment of eleven compounds, extracted from Chinese medicinal herbs, was performed in this study for their effect on α-syn fibril formation and toxicity caused by the seeding process. Results: Salvianolic acid B and dihydromyricetin were the two compounds that strongly inhibited the fibril growth and neurotoxicity of α-syn. In an in-vitro cell model, these compounds decreased the insoluble phosphorylated α-syn and aggregation. Also, in primary neuronal cells, these compounds showed a reduction in α-syn aggregates. Both compounds inhibited the seeded fibril growth with dihydromyricetin having the ability to disaggregate preformed α-syn fibrils. In order to investigate the inhibitory mechanisms of these two compounds towards fibril formation, we demonstrated that salvianolic acid B binds predominantly to monomers, while dihydromyricetin binds to oligomeric species and to a lower extent to monomers. Remarkably, these two compounds stabilized the soluble non-toxic oligomers lacking β-sheet content after subjecting them to proteinase K digestion. Conclusions: Eleven compounds were tested but only two showed inhibition of α-syn aggregation, seeded fibril formation and toxicity in vitro. These findings highlight an essential beginning for development of new molecules in the field of synucleinopathies treatment.

9 March 2022 in Journal of Infection and Public Health
Verified
Journal Article
Open access
STSwapna Thomas
Swapna Thomas
Allal OuhtitAllal Ouhtit
Allal Ouhtit
HKHebah Al Khatib
Hebah Al Khatib
AEAli Eid
Ali Eid
SMShilu Mathew
Shilu Mathew
HYHADI YASSINE
HADI YASSINE
Over the past two decades, diabetes mellitus (DM) has been receiving increasing attention among autoimmune diseases. The prevalence of type 1 and type 2 diabetes has increased rapidly and has become one of the leading causes of death worldwide. Therefore, a better understanding of the genetic and environmental risk factors that trigger the onset of DM would help develop more efficient therapeutics and preventive measures. The role and mechanism of respiratory viruses in inducing autoimmunity have been frequently reported. On the other hand, the association of DM with respiratory infections might result in severe complications or even death. Since influenza is the most common respiratory infection, DM patients experience disease severity and increased hospitalization during influenza season. Vaccinating diabetic patients against influenza would significantly reduce hospitalization due to disease severity. However, recent studies also report the role of viral vaccines in inducing autoimmunity, specifically diabetes. This review reports causes of diabetes, including genetic and viral factors, with a special focus on respiratory viruses. We further brief the burden of influenza-associated complications and the effectiveness of the influenza vaccine in DM patients.

25 February 2022 in The FEBS Journal
Verified
Journal Article
Open access
PDF file
IHIssam Hmila
Issam Hmila
VNVaikath N Nishant
Vaikath N Nishant
NMNour Majbour
Nour Majbour
DEDaniel Erskine
Daniel Erskine
ISIndulekha P. Sudhakaran
Indulekha P. Sudhakaran
OEOmar El-Agnaf
Omar El-Agnaf
Nanobodies (Nbs), the single-domain antigen-binding fragments of dromedary Heavy-chain antibodies (HCAb), are excellent candidates as therapeutic and diagnostic tools in synucleinopathies because of their small size, solubility and stability. Here, we constructed an immune nanobody library specific to the monomeric form of alpha-synuclein (α-syn). Phage display screening of the library allowed the identification of a nanobody, Nbα-syn01, specific for α-syn. Unlike previously developed nanobodies, Nbα-syn01 recognized the N-terminal region which is critical for in vitro and in vivo aggregation and contains many point mutations involved in early PD cases. The affinity of the monovalent Nbα-syn01 and the engineered bivalent format BivNbα-syn01 measured by Isothermal titration calorimetry revealed unexpected results where Nbα-syn01 and its bivalent format recognized preferentially α-syn fibrils compared to the monomeric form. Nbα-syn01 and BivNbα-syn01 were also able to inhibit α-syn-seeded aggregation in vitro and reduced α-syn-seeded aggregation and toxicity in cells showing their potential to reduce α-syn pathology. Moreover, both nanobody formats were able to recognize Lewy-body pathology in human post-mortem brain tissue from PD and DLB cases. Additionally, we present evidence through structural docking that Nbα-syn01 binds the N-terminal region of the α-syn aggregated form. Overall, these results highlight the potential of Nbα-syn01 and BivNbα-syn01 in developing into a diagnostic or a therapeutic tool for PD and related disorders.

15 December 2020 in Scientific Reports
Verified
Journal Article
Open access
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NSNuha T. Swaidan
Nuha T. Swaidan
SSSalam Salloum-Asfar
Salam Salloum-Asfar
FPFreshteh Palangi
Freshteh Palangi
KEKhaoula Errafii
Khaoula Errafii
NSNada H. Soliman
Nada H. Soliman
MEMohamed Emara
Mohamed Emara
Although many factors have been identified and used to enhance the iPSC reprogramming process, its efficiency remains quite low. In addition, reprogramming efficacy has been evidenced to be affected by disease mutations that are present in patient samples. In this study, using RNA-seq platform we have identified and validated the differential gene expression of five transcription factors (TFs) (GBX2, NANOGP8, SP8, PEG3,andZIC1) that were associated with a remarkable increase in the number of iPSC colonies generated from a patient with Parkinson's disease. We have applied different bioinformatics tools (Gene ontology, protein–protein interaction, and signaling pathways analyses) to investigate the possible roles of these TFs in pluripotency and developmental process. Interestingly,GBX2, NANOGP8, SP8, PEG3,andZIC1were found to play a role in maintaining pluripotency, regulating self-renewal stages, and interacting with other factors that are involved in pluripotency regulation includingOCT4, SOX2, NANOG,andKLF4. Therefore, the TFs identified in this study could be used as additional transcription factors that enhance reprogramming efficiency to boost iPSC generation technology.

3 November 2021 in Vaccines
Verified
Journal Article
Open access
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Amine ZaidiAmine Zaidi
Amine Zaidi
Amal ElmassadAmal Elmassad
Amal Elmassad
Hend Ali AlobaidliHend Ali Alobaidli
Hend Ali Alobaidli
RSRana Sayed
Rana Sayed
DADana Hamad Al-Ali
Dana Hamad Al-Ali
SDSuhad Daher-Nashif
Suhad Daher-Nashif
A population’s desire to take the COVID-19 vaccine is an important predictor of a country’s future pandemic management. This cross-sectional study examines the impact of psychological and sociodemographic factors on attitudes toward and intentions to take the COVID-19 vaccine among students and faculty at four colleges of health professions and sciences at Qatar University. The data were collected through an online survey using Google Forms. The survey was distributed through various online platforms. Data analysis was conducted using Stata 16. Of the 364 participants, 9.89% expressed a high mistrust of vaccine safety, and 21.7% were uncertain about their levels of trust; 28% expressed strong worries about unforeseen side effects, whereas 54.95% expressed moderate worries. Furthermore, 7.69% expressed strong concerns and 39.84% showed moderate concerns about commercial profiteering. Approximately 13% of the participants expressed a strong preference towards natural immunity, whilst 45.33% appeared to believe that natural immunity might be better than a vaccine. Importantly, 68.13% of the participants intended to receive the COVID-19 vaccine once it became available, compared to 17.03% who were uncertain and 14.83% who were unwilling to be vaccinated. Our findings differ from the data on vaccine hesitancy among the general population of Qatar. We argue that this gap is due to scientific knowledge and domain of education. Furthermore, although knowledge and awareness may affect vaccine attitudes, mental health and sociodemographic factors play a role in shaping attitudes towards vaccines.