CRISPR-Cas9 system: a novel and promising era of genotherapy for beta-hemoglobinopathies, hematological malignancy, and hemophilia

Gene therapy represents a significant potential to revolutionize the field of hematology with applications in correcting genetic mutations, generating cell lines and animal models, and improving the feasibility and efficacy of cancer immunotherapy. Compared to different genetic engineering tools, clustered regularly interspaced short palindromic repeats (CRISPR) CRISPR-associated protein 9 (Cas9) emerged as an effective and versatile genetic editor with the ability to precisely modify the genome. The applications of genetic engineering in various hematological disorders have shown encouraging results. Monogenic hematological disorders can conceivably be corrected with single gene modification. Through the use of CRISPR-CAS9, restoration of functional red blood cells and hemostasis factors were successfully attained in sickle cell anemia, beta-thalassemia, and hemophilia disorders. Our understanding of hemato-oncology has been advanced via CRIPSR-CAS9 technology. CRISPR-CAS9 aided to build a platform of mutated genes responsible for cell survival and proliferation in leukemia. Therapeutic application of CRISPR-CAS9 when combined with chimeric antigen receptor (CAR) T cell therapy in multiple myeloma and acute lymphoblastic leukemia was feasible with attenuation of CAR T cell therapy pitfalls. Our review outlines the latest literature on the utilization of CRISPR-Cas9 in the treatment of beta-hemoglobinopathies and hemophilia disorders. We present the strategies that were employed and the findings of preclinical and clinical trials. Also, the review will discuss gene engineering in the field of hemato-oncology as a proper tool to facilitate and overcome the drawbacks of chimeric antigen receptor T cell therapy (CAR-T).

Loss-of-function variant in spermidine/spermine N1-acetyl transferase like 1 (SATL1) gene as an underlying cause of autism spectrum disorder

Autism spectrum disorder (ASD) is a complicated, lifelong neurodevelopmental disorder affecting verbal and non-verbal communication and social interactions. ASD signs and symptoms appear early in development before the age of 3 years. It is unlikely for a person to acquire autism after a period of normal development. However, we encountered an 8-year-old child who developed ASD later in life although his developmental milestones were normal at the beginning of life. Sequencing the complete coding part of the genome identified a hemizygous nonsense mutation (NM_001367857.2):c.1803C>G; (p.Tyr601Ter) in the gene (SATL1) encoding spermidine/spermine N1-acetyl transferase like 1. Screening an ASD cohort of 28 isolated patients for the SATL1 gene identified another patient with the same variant. Although SATL1 mutations have not been associated with any human diseases, our data suggests that a mutation in SATL1 is the underlying cause of ASD in our cases. In mammals, mutations in spermine synthase (SMS), an enzyme needed for the synthesis of spermidine polyamine, have been reported in a syndromic form of the X-linked mental retardation. Moreover, SATL1 gene expression studies showed a relatively higher expression of SATL1 transcripts in ASD related parts of the brain including the cerebellum, amygdala and frontal cortex. Additionally, spermidine has been characterized in the context of learning and memory and supplementations with spermidine increase neuroprotective effects and decrease age-induced memory impairment. Furthermore, spermidine biosynthesis is required for spontaneous axonal regeneration and prevents α-synuclein neurotoxicity in invertebrate models. Thus, we report, for the first time, that a mutation in the SATL1 gene could be a contributing factor in the development of autistic symptoms in our patients.

Identification of Novel and Recurrent Variants in BTD, GBE1, AGL and ASL Genes in Families with Metabolic Disorders in Saudi Arabia

Background and Objectives: Inherited metabolic disorders (IMDs) are a group of genetic disorders characterized by defects in enzymes or transport proteins involved in metabolic processes. These defects result in an abnormal accumulation of metabolites and thus interfere with the body's metabolism. A variety of IMDs exist and differential diagnosis is often challenging. Our objective was to gain insight into the genetic basis of IMDs and the correlations between specific genetic mutations and clinical presentations in patients admitted at various hospitals in the Madinah region of the Kingdom of Saudi Arabia. Material and Methods: Whole exome sequencing (WES) has emerged as a powerful tool for diagnosing IMDs and allows for the identification of disease-causing genetic mutations in individuals suspected of IMDs. This ensures accurate diagnosis and appropriate management. WES was performed in four families with multiple individuals showing clinical presentation of IMDs. Validation of the variants identified through WES was conducted using Sanger sequencing. Furthermore, various computational analyses were employed to uncover the disease gene co-expression and metabolic pathways. Results: Exome variant data analysis revealed missense variants in the BTD (c.1270G > C), ASL (c.1300G > T), GBE1 (c.985T > G) and AGL (c.113C > G) genes. Mutations in these genes are known to cause IMDs. Conclusions: Thus, our data showed that exome sequencing, in conjunction with clinical and biochemical characteristics and pathological hallmarks, could deliver an accurate and high-throughput outcome for the diagnosis and sub-typing of IMDs. Overall, our findings emphasize that the integration of WES with clinical and pathological information has the potential to improve the diagnosis and understanding of IMDs and related disorders, ultimately benefiting patients and the medical community.

Controlled drug release contenders comprising starch/poly(allylamine hydrochloride) biodegradable composite films

The blending of natural polysaccharides with synthetic polymers has attracted much attention in drug delivery models owing to their remarkable biodegradable and biocompatible characteristics. This study focuses on the facile preparation of a sequence of composite films having Starch/Poly(allylamine hydrochloride) (ST/PAH) in different compositions to propose a novel drug delivery system (DDS). ST/PAH blend films were developed and characterized. FT-IR evaluation confirmed the involvement of intermolecular H-bonding between the ST and PAH counterparts in blended films. The water contact angle (WCA) ranged from 71° to 100° indicating that all the films were hydrophobic. TPH-1 (90 % ST and 10 % PAH) was evaluated for in vitro controlled drug release (CDR) at 37 ± 0.5 °C in a time-dependent fashion. CDR was recorded in phosphate buffer saline (PBS) and simulated gastric fluid (SGF). In the case of SGF (pH 1.2), the percentile drug release (DR) for TPH-1 was approximately 91 % in 110 min, while the maximum DR was 95 % in 80 min in PBS (pH 7.4) solution. Our results demonstrate that the fabricated biocompatible blend films can be a promising candidate for a sustained-release DDS for oral drug administration, tissue engineering, wound dressings, and other biomedical applications.

Hematopoietic stem cell transplant does not prevent neurological deterioration in infants with Farber disease: Case report and literature review

Farber disease (FD) is an inherited autosomal recessive disorder of lipid metabolism. The hallmark of the disease is systemic accumulation of ceramide due to lysosomal acid ceramidase deficiency. The involvement of the central nervous system is critical in this disorder leading to rapid deterioration and death within a few years after birth. Efforts to treat patients by hematopoietic stem cell transplant (HSCT) have resulted in favorable results in the absence of neurological manifestations. We report the outcomes of HSCT in two patients with FD who received early HSCT and had neurological deterioration posttransplant. We also present a new understanding of the limitations of HSCT in FD management based on our observations of the clinical course of the two patients after therapy.

Systemic ceramide accumulation leads to severe and varied pathological consequences

Farber disease (FD) is a severe inherited disorder of lipid metabolism characterized by deficient lysosomal acid ceramidase (ACDase) activity, resulting in ceramide accumulation. Ceramide and metabolites have roles in cell apoptosis and proliferation. We introduced a single-nucleotide mutation identified in human FD patients into the murine Asah1 gene to generate the first model of systemic ACDase deficiency. Homozygous Asah1^P361R/P361R animals showed ACDase defects, accumulated ceramide, demonstrated FD manifestations and died within 7–13 weeks. Mechanistically, MCP-1 levels were increased and tissues were replete with lipid-laden macrophages. Treatment of neonates with a single injection of human ACDase-encoding lentivector diminished the severity of the disease as highlighted by enhanced growth, decreased ceramide, lessened cellular infiltrations and increased lifespans. This model of ACDase deficiency offers insights into the pathophysiology of FD and the roles of ACDase, ceramide and related sphingolipids in cell signaling and growth, as well as facilitates the development of therapy.