biostudies-literatureUnknown21Gu PGuangdong Provincial Department of Science and TechnologyJiangmen Science and Technology BureauInternational Science and Technology Cooperation ProgrammeHereditary tyrosinemia type I (HT1) results from the loss of fumarylacetoacetate hydrolase (FAH) activity and can lead to lethal liver injury (LLI). Therapeutic options for HT1 remain limited. The <i>FAH</i> ^{<i>-</i>/<i>-</i>} pig, a well-characterized animal model of HT1, represents a promising candidate for testing novel therapeutic approaches to treat this condition. Here, we report an improved single-step method to establish a biallelic (<i>FAH</i> ^{<i>-</i>/<i>-</i>} ) mutant porcine model using CRISPR-Cas9 and cytoplasmic microinjection. We also tested the feasibility of rescuing HT1 pigs through inactivating the 4-hydroxyphenylpyruvic acid dioxygenase (<i>HPD</i>) gene, which functions upstream of the pathogenic pathway, rather than by directly correcting the disease-causing gene as occurs with traditional gene therapy. Direct intracytoplasmic delivery of CRISPR-Cas9 targeting <i>HPD</i> before intrauterine death reprogrammed the tyrosine metabolism pathway and protected pigs against <i>FAH</i> deficiency-induced LLI. Characterization of the F1 generation revealed consistent liver-protective features that were germline transmissible. Furthermore, <i>HPD</i> ablation ameliorated oxidative stress and inflammatory responses and restored the gene profile relating to liver metabolism homeostasis. Collectively, this study not only provided a novel large animal model for exploring the pathogenesis of HT1, but also demonstrated that CRISPR-Cas9-mediated <i>HPD</i> ablation alleviated LLI in HT1 pigs and represents a potential therapeutic option for the treatment of HT1.Molecular therapy. Methods & clinical development530-547https://www.ebi.ac.uk/biostudies/studies/S-EPMC8099604biostudies-literatureGenetically blocking <i>HPD via</i> CRISPR-Cas9 protects against lethal liver injury in a pig model of tyrosinemia type I.PMC8099604Bie YNGu WLuo HChen BYe XLiu WLiang CLiu YTian YXu TYang QGu PTang XfalseGenetically blocking <i>HPD via</i> CRISPR-Cas9 protects against lethal liver injury in a pig model of tyrosinemia type I.Hereditary tyrosinemia type I (HT1) results from the loss of fumarylacetoacetate hydrolase (FAH) activity and can lead to lethal liver injury (LLI). Therapeutic options for HT1 remain limited. The <i>FAH</i> ^{<i>-</i>/<i>-</i>} pig, a well-characterized animal model of HT1, represents a promising candidate for testing novel therapeutic approaches to treat this condition. Here, we report an improved single-step method to establish a biallelic (<i>FAH</i> ^{<i>-</i>/<i>-</i>} ) mutant porcine model using CRISPR-Cas9 and cytoplasmic microinjection. We also tested the feasibility of rescuing HT1 pigs through inactivating the 4-hydroxyphenylpyruvic acid dioxygenase (<i>HPD</i>) gene, which functions upstream of the pathogenic pathway, rather than by directly correcting the disease-causing gene as occurs with traditional gene therapy. Direct intracytoplasmic delivery of CRISPR-Cas9 targeting <i>HPD</i> before intrauterine death reprogrammed the tyrosine metabolism pathway and protected pigs against <i>FAH</i> deficiency-induced LLI. Characterization of the F1 generation revealed consistent liver-protective features that were germline transmissible. Furthermore, <i>HPD</i> ablation ameliorated oxidative stress and inflammatory responses and restored the gene profile relating to liver metabolism homeostasis. Collectively, this study not only provided a novel large animal model for exploring the pathogenesis of HT1, but also demonstrated that CRISPR-Cas9-mediated <i>HPD</i> ablation alleviated LLI in HT1 pigs and represents a potential therapeutic option for the treatment of HT1.2021-01-01T00:00:00Z2021 Jun2025-04-06T23:59:10.732Z2025-04-04T19:10:46.251ZS-EPMC80996043399710210.1016/j.omtm.2021.04.002