Project description:The eye is an intricate organ with limited representation in large-scale functional genomics datasets. The retinal pigment epithelium (RPE) serves vital roles in ocular development and retinal homeostasis. We interrogated the genetics of gene expression of cultured human fetal RPE (fRPE) cells under two metabolic conditions. Genes with disproportionately high fRPE expression are enriched for genes related to inherited ocular diseases. Variants near these fRPE-selective genes explain a larger fraction of risk for both age-related macular degeneration (AMD) and myopia than variants near genes enriched in 53 non-ocular human tissues. Increased mitochondrial oxidation of glutamine by fRPE promoted expression of lipid synthesis genes implicated in AMD. Expression and splice quantitative trait loci (e/sQTLs) analyses revealed shared and metabolic condition-specific loci of each type and several eQTLs not previously described in any tissue. Fine mapping of fRPE e/sQTLs across AMD and myopia genome-wide association data suggests new candidate genes, and mechanisms by which the same common variant of RDH5 contributes to both increased AMD risk and decreased myopia risk. Our study highlights the unique transcriptomic characteristics of fRPE and provides a resource to connect e/sQTLs in a critical ocular cell type to monogenic and complex eye disorders.
Project description:Hepatocyte transplantation has shown great potential for treating inherited liver diseases. However, its prolonged clinical therapeutic efficacy is still hindered by serious immune rejection from the host immunological responses to the allogeneic hepatocytes and there is still no an effective approach to generate clinically available autologous hepatocytes for transplantation therapy. Here, we report advanced medium conditions that allow 10,000-fold expansion of primary human hepatocytes from patients suffering inherited liver diseases, providing a new autologous hepatocytes source to this problem. Moreover, we developed a CRISPR–Cas9 genome-targeting system that combines Cas9 ribonucleoproteins and adeno-associated viral vector delivery of a homology-independent large donor (greater than three kilobase) to achieve efficient targeted integration at the AAVS1 safe harbor locus in patient-derived proliferating human hepatocytes (ProliHHs). We further applied this strategy to correct a pathogenic OTC and FAH mutation in ProliHHs and demonstrated improved gene expression, while preserving cell viability for the expansion and purification of edited ProliHHs. Importantly, these edited ProliHHs repopulate into injured mouse liver at a level near to primary human hepatocytes, and they undergo maturation to successfully treat the tyrosinemia mouse model following transplantation in vivo. Thus, this study provides a new autologous hepatocyte therapy techniques that enable large-scale expansion and ex vivo gene correction in patient-derived transplantable ProliHHs, which holds the potential for modeling and treating human liver disease.
Project description:Purpose: Describing the clinical and genetic features of an ethnically heterogeneous group of (inherited retinal diseases) IRD patients from different underrepresented countries, referring to specialized Italian Hospitals, and expanding the epidemiological spectrum of the IRD in understudied populations. Methods: The patients' phenotypes underwent were characterized by exhaustive ophthalmological examinations, including morpho-functional testing. Genetic testing was performed using next-generation sequencing (NGS) and gene sequencing panels targeting a specific set of genes, Sanger sequencing and-when necessary-multiplex ligation-dependent probe amplification (MLPA) to better identify the genotype. When possible, segregation analysis was performed in order to confirm unsolved cases. Results: The article reports the results of the phenotypes and genotypes of 123 IRD probands, 69 males and 54 females, mean age 41 (IQR, 54-30) years, disease onset at 13 (IQR, 27.25-5) years. Thirty-three patients out of 123 (26.8%) were Africans (North/Northwest Africa), 21 (17.1%) Asians, 19 (15.4%) Americans (South/Central America) and 50 (40.7%) Europeans (Eastern Europe). Retinitis pigmentosa was the most represented phenotype (56%), followed by cone dystrophy (11%) and Leber congenital amaurosis (7%), while ABCA4 was the most frequently mutated gene (18%), followed by USH2A (9%) and RPGR (5%). About ABCA4 variants found in Stargardt disease, macular and cone dystrophies were predominant in Asian (42%) and European (21%) patients. The most represented inheritance pattern was autosomal recessive, while a higher frequency of homozygous patients versus compound heterozygotes as compared to previous studies on Italian IRD patients was evidenced, reflecting a possible higher frequency of inbreeding marriages. Conclusion: Though limited by the relatively low number of patients, the present paper paints a picture of the clinical and genetic features of IRD patients from understudied ethnic groups referred to Italian specialized hospitals and extended the epidemiological studies on underrepresented world regional areas.
Project description:The aim of this study was to provide deeper insight into the complex network of molec-ular and cellular changes that underlie inherited retinal degeneration by systematically mapping the transcriptional changes that occur in the degenerating mouse retina.