Biology subjects

Alsayegh, K.

Publications and source records attributed to Alsayegh, K..

3 recordsLinked to original sources

bioRxiv2026

Establishment of the Saudi Bank of Induced Pluripotent Stem Cells (SBiPSCs): A National Platform for iPSC-Based Research and Therapy

BackgroundThe global landscape of induced pluripotent stem cell (iPSC) resources remains heavily skewed toward European, North American, and East Asian populations, leaving the Middle East and North Africa (MENA) region critically underrepresented. This disparity hinders the application of precision medicine in populations with unique genetic backgrounds, particularly those with high rates of consanguinity and distinctive rare disease profiles. To address this gap, we established the Saudi Bank of Induced Pluripotent Stem Cells (SBiPSCs), at King Abdullah International Medical Research Centre (KAIMRC). The bank comprises two major complementary arms: one dedicated to the derivation and biobanking of iPSCs from individuals with rare and common genetic disorders, and a second focused on Human Leukocyte Antigen (HLA)-based iPSC banking to support the development of immunocompatible cell therapies. MethodsSBiPSCs operates within King Abdulaziz Medical City in Jeddah under the Ministry of National Guard for Health Affairs (MNGHA)s ethical and clinical framework. To establish the repository, we implemented a clinic-guided enrolment strategy in which treating physicians, briefed on the banks objectives, recruited patients with confirmed genetic diagnoses. Peripheral blood samples were collected, processed, and cells were reprogrammed using non-integrating episomal plasmids. All derived lines underwent rigorous quality control in accordance with International Society for Stem Cell Research (ISSCR) standards, including assessment of pluripotency markers, genomic integrity, and trilineage differentiation potential. To demonstrate our iPS characterization workflow and translational utility, iPSCs from a Saudi patient with familial Long QT Syndrome (LQTS) and a healthy sibling were differentiated into functional cardiac organoids. Simultaneously, for the HLA-based banking arm, the Saudi Stem Cell Donor Registry (SSCDR) database was leveraged to identify donors predicted to provide maximal coverage for the Saudi population. ResultsTo date, SBiPSCs has successfully generated 37 iPSC lines derived from 19 Saudi patients and healthy donors. All lines exhibit robust expression of pluripotency markers, maintain normal karyotypes, and demonstrate differentiation capacity. To demonstrate our characterization pipeline and translational utility, iPSCs from an LQTS patient and a healthy sibling were generated, validated, and differentiated into beating cardiac organoids that recapitulated the disease phenotype, with microelectrode array analysis confirming prolonged field potential durations mirroring the clinical QT prolongation. Furthermore, the HLA-based banking arm has expanded to include two homozygous iPSC lines, which together provide immunological compatibility for approximately 9% of the Saudi population. ConclusionsSBiPSCs represents the first centralized iPSC repository in the MENA region. The SBiPSCs is well-positioned to accelerate the translation of stem cell research into scalable, immunocompatible cell therapies and precision medicine applications aligned with national and regional healthcare priorities.

genetics↗

bioRxiv2023

HLA-Based Banking of Human Induced Pluripotent Stem Cells in Saudi Arabia

Human iPSCs derivation and use in clinical studies are transforming medicine. Yet, there is a high cost and long waiting time for autologous iPS-based cellular therapy, and the genetic engineering of hypo-immunogenic iPS cell lines is hampered with numerous hurdles. Therefore, it is increasingly interesting to create cell stocks based on HLA haplotype distribution in a given population. In this study, we assessed the potential of HLA-based iPS banking for the Saudi population. First, we analyzed the HLA database of the Saudi Stem Cell Donor Registry (SSCDR), which contains high-resolution HLA genotype data of 64,315 registered Saudi donors at the time of analysis. We found that only 13 iPS lines would be required to cover 30% of the Saudi population, 39 iPS lines would offer 50% coverage and 596 for more than 90% coverage. Next, As a proof-of-concept, we launched the first HLA-based banking of iPSCs in Saudi Arabia. Using clinically relevant methods, we generated the first iPSC line from a homozygous donor for the most common HLA haplotype in Saudi. The two generated clones expressed pluripotency markers, could be differentiated into all three germ layers, beating cardiomyocytes and neuronal progenitors. To ensure that our reprogramming method generates genetically stable iPSCs, we assessed the mutational burden in the generated clones and the original blood sample from which the iPSCs were derived using whole-genome sequencing. All detected variants were found in the original donor sample and were classified as benign according to current guidelines of the American College of Medical Genetics and Genomics (ACMG). This study sets a road map for introducing iPS-based cell therapy in the Kingdom of Saudi Arabia.

genetics↗

bioRxiv2022

Modulation of the microhomology-mediated end joining pathway suppresses large deletions and enhances homology-directed repair following CRISPR-Cas9-induced DNA breaks

CRISPR-Cas9, an efficient genome editing tool, has been widely used in research and holds great promise in the clinic. However, large unintended rearrangements of the genome occur frequently after CRISPR-Cas9 editing and their potential risk cannot be ignored. In this study, we detected large deletions (LDs) induced by CRISPR-Cas9 in human embryonic stem cells (hESCs) and found the microhomology end joining (MMEJ) DNA repair pathway plays a predominant role in LD. We genetically targeted PARP1, RPA, POLQ and LIG3, which play critical roles in MMEJ, during CRISPR-Cas9 editing. By analyzing LD events in two independent gene loci, CD9 and PIGA, using flow cytometry and long-read individual molecule sequencing (IDMseq), we showed that knocking down PARP1 and LIG3 does not alter the frequency of Cas9-induced LD, while knocking down or inhibiting POLQ dramatically reduces LD. Knocking down RPA increases LD frequency, and overexpression of RPAs consistently reduces LD frequency. Interestingly, small-molecule inhibition of POLQ and delivery of recombinant RPA proteins also dramatically increase the efficiency of homology-directed repair (HDR). In conclusion, RPA and POLQ play opposite roles in Cas9-induced LD, modulation of POLQ and RPA can reduce LD and improve HDR, thus holding promise for safe and precise genome editing.

molecular biology↗