Biology subjects

Yelgen, G.

Publications and source records attributed to Yelgen, G..

3 recordsLinked to original sources

bioRxiv2023

Enhancing In Vitro SMN Protein Expression and Cell Viability through Xeno-Nucleic Acid-Based ASOs in Spinal Muscular Atrophy

Spinal Muscular Atrophy (SMA) stands as a devastating ailment arising from the dearth of functional SMN (Survival Motor Neuron) protein due to genetic anomalies within the SMN1 gene. This condition is marked by the consequential attrition of motor neurons, precipitating a progressive decline in muscular strength and culminating in the disruption of neuromuscular junctions. Existing therapeutic approaches encompassing Zolgensma, Nursinersen, and Evrysdi employ innovative genetic therapeutic strategies involving transgene delivery, Antisense Oligonucleotide (ASO) technology, and modulation of pre-mRNA processing to enhance functional SMN protein expression. However, the ASO therapeutics remain suboptimal in establishing a sustained panacea for SMA, as they inadequately maintain consistent levels of functional SMN protein expression. In this study, we present a discerning inquiry into focusing on XNA-DNA-ASO products that exhibit enhanced safety and stability compared to conventional DNA/RNA-ASO sequences. Through precise targeting of the ISSN-1 region within SMN2 genes intron 7, our approach seeks to amplify SMN protein expression. Employing Xeno Nucleic Acid (XNA) bases, known for their augmented hydrophobicity and stability, our strategy surmounts previous limitations associated with chemical modifications, showcasing heightened endonuclease resistance. Comparative analyses with conventional DNA/RNA-ASO products substantiate the superiority of XNA-DNA-ASO sequences, underscoring elevated SMN protein expression and reduced toxicity. In a comprehensive evaluation, our gene therapy paradigm is scrutinized within a type 1 SMA fibroblast cell line. Utilizing diverse analytical methodologies, encompassing Annexin V-PI analysis for cytotoxicity, MTT assays for mitochondrial activity, and flow cytometry for SMN protein expression profile, we gauge therapeutic impact and potential toxicity. In conclusion, our investigation not only spotlights the promise of XNA-DNA-ASO sequences but also holds implications for refining SMA treatment strategies, converging on minimized dosages, lowered toxicity, and heightened therapeutic efficacy, thus shaping the landscape of gene therapy for SMA.

genetics↗

bioRxiv2022

Autonomous Remotely Controlled Closed System Transgenic Cell Technologies Robot: CRISPR.BOT

In manually advancing experimental processes, the stages may be long-term and need to be repeated. Human errors with the repetition of the steps turn into a time-consuming and high-cost for the experiment processes. For this reason, autonomous liquid processing systems are promising technologies. However, in addition to the high cost of fully automatic systems, their maintenance is also quite expensive. Furthermore, conventional systems usually require system-specific protocols and laboratory equipment. Here, we aimed to show that the autonomous robotic systems may provide a closed and error-free molecular biology bench to perform genetic engineering automatically, quickly, and practically 7-24. In this way, researchers can save time from repetitive experiment processes and perform BSL3 experiments including pathogens without human contact. In this study, we built CRISPR.BOT robotic systems to perform Green Fluorescent Protein (GFP) encoding plasmid DNA transfer into bacteria, lentiviral transduction of the gene-of-interests including GFP encoding gene and CRISPR-Cas9 with gRNAs genetic editing system to a human cell line. Furthermore, we showed that CRISPR.BOT system achieved to accomplish single-cell subcloning of GFP+ CRISPR-gRNA+ cells with 90-100% purity. This study suggests that CRISPR.BOT-like approaches may reduce manpower in a safely closed bench in which molecular biology and genetic engineering can be done by robots in a closed system without touching pathogenic microorganisms (virus or bacteria, for example, SARS CoV-2 virus). Furthermore, LEGO Mindstorms robots showed to have the potential to be used in daily laboratory routines with their cost-effectiveness reduced by up to 50 times compared to normal commercial robots.

molecular biology↗

bioRxiv2022

Exon7 Targeted CRISPR-Prime Editing Approaches for SMN2 Gene Editing in Spinal Muscular Atrophy (SMA) Disease Can Increase In Vitro SMN Expression

Spinal Muscular Atrophy (SMA) is a fatal neuromuscular disease characterized by motor neuron loss and advanced muscle weakness, which occurs in functional SMN (Survival Motor Neuron) protein deficiency with SMN1 gene-induced deletions and mutations. The incidence of SMA, which is an autosomal recessive disease, is 1/10,000 in the world. The SMN protein acts as a molecular chaperone in the formation of the spliceosome complex, which catalyzes the splicing of pre-mRNA, enabling mRNAs and non-coding RNAs to mature. Since the current SMN1-encoding Adeno-associated virus (AAV) or SMN2 gene targeting antisense oligonucleotide-based strategies cannot provide long-term stable SMN expression in neuron cells, more effective methods need to be developed. CRISPR technology, which adds a new dimension to genetic engineering and gene therapies, makes it possible to treat many genetic diseases. In terms of SMA, some previous studies in the literature prove that it is possible to treat SMA with the CRISPR strategy. Homology Directed Repair (HDR)-based CRISPR technology, which results in a high rate of in-del (insertion-deletion) mutations rather than editing, was shown unsuitable for therapeutic applications. CRISPR-Prime editing (PE) technology is a new generation of gene editing approach that precisely provides various genomic modifications without the need for double-strand breakage or donor DNA sequences. CRISPR-Prime Editing method has also been used in rare diseases such as sickle cell anemia and Tay-Sachs, and their efficiency in editing various pathogenic mutations has been demonstrated. However, CRISPR Prime Editing-mediated gene editing for Spinal Muscular Atrophy (SMA) have not yet been investigated. The c.840 T-C transition and c.859 G-C transformations in the SMN2 gene and the correction of these point mutations with a single pegRNA at the same time were investigated for the first time in this study. Here, we showed that CRISPR-PE systems could increase SMN2 gene activity and SMN protein expression by ensuring exon 7 participation by editing c.840 T-C transition and c.859 G-C transformations. The fact that Prime Editing method showed the efficacy and stability of modifications in SMN2 genes that were investigated in SMN-low Jurkat cells as a proof-of-concept. This study enabled the next step with the CRISPR-Prime Editing approach to be tested ex vivo in primary cell lines from SMA patients and SMN-low neuronal cells.

genetics↗