Therapeutic efficacy of rscAAVrh74.miniCMV.LIPA gene therapy in a mouse model of lysosomal acid lipase deficiency

Liver-directed AAV gene therapy normalizes disease symptoms and provides cross-correction in a model of lysosomal acid lipase deficiency

Lysosomal acid lipase deficiency (LAL-D) is caused by mutations in the LIPA gene, which encodes the lysosomal enzyme that hydrolyzes triglycerides and cholesteryl esters to free fatty acids and free cholesterol. The objective of this study was to develop a curative single-treatment therapy for LAL-D using adeno-associated virus (AAV). Treatment at both early (1-2 days) and late (8-week) timepoints with rscAAVrh74.LP1.LIPA, a liver-directed AAV gene therapy, normalized many disease measures in Lipa-/- mice when measured at 24 weeks of age, including hepatosplenomegaly, serum transaminase activity, organ triglyceride and cholesterol levels, and biomarkers of liver inflammation and fibrosis. For most measures, liver-directed therapy was superior to therapy utilizing a constitutive tissue expression approach. rscAAVrh74.LP1.LIPA treatment elevated LAL enzyme activity above wild-type levels in all tissues tested, including liver, spleen, intestine, muscle, and brain, and treatment elicited minimal serum antibody responses to transgenic protein. AAV treatment at 8 weeks of age with 1 × 1013 vg/kg extended survival significantly, with all AAV-treated mice surviving beyond the maximal lifespan of untreated Lipa-/- mice. These results show that this liver-directed LIPA gene therapy has the potential to be a transformative treatment for LAL-D.

The Liver and Lysosomal Storage Diseases: From Pathophysiology to Clinical Presentation, Diagnostics, and Treatment

The liver, given its role as the central metabolic organ, is involved in many inherited metabolic disorders, including lysosomal storage diseases (LSDs). The aim of this manuscript was to provide a comprehensive overview on liver involvement in LSDs, focusing on clinical manifestation and its pathomechanisms. Gaucher disease, acid sphingomyelinase deficiency, and lysosomal acid lipase deficiency were thoroughly reviewed, with hepatic manifestation being a dominant clinical phenotype. The natural history of liver disease in the above-mentioned lysosomal disorders was delineated. The importance of Niemann-Pick type C disease as a cause of cholestatic jaundice, preceding neurological manifestation, was also highlighted. Diagnostic methods and current therapeutic management of LSDs were also discussed in the context of liver involvement.

Lanifibranor Reduces Inflammation and Improves Dyslipidemia in Lysosomal Acid Lipase-Deficient Mice

Background and Aims

Recent studies showed that patients suffering from lysosomal acid lipase deficiency (LAL-D) benefit from enzyme replacement therapy; however, liver histopathology improved in some but not all patients. We hypothesized that the pan-peroxisome proliferator-activated receptor agonist lanifibranor may have beneficial effects on liver inflammation in LAL knockout (Lal-/-) mice based on its promising results in alleviating liver inflammation in patients with metabolic dysfunction-associated steatohepatitis.

Methods

Female Lal-/- mice were daily gavaged with lanifibranor or vehicle for 21 days. The effects of the treatment were assessed by measuring body and organ weights, plasma lipids and lipoproteins, as well as hematological parameters, followed by liver proteomics and metabolomics.

Results

Lanifibranor treatment slightly altered organ weights without affecting the total body weight of Lal-/- mice. We observed major changes in the proteome, with multiple proteins related to lipid metabolism, peroxisomal, and mitochondrial activities being upregulated and inflammation-related proteins being downregulated in the livers of treated mice. Hepatic lipid levels and histology remained unaltered, whereas plasma triacylglycerol and total cholesterol levels were decreased and the lipoprotein profile of lanifibranor-treated Lal-/- mice improved.

Conclusion

Lanifibranor treatment positively affected liver inflammation and dyslipidemia in Lal-/- mice. These findings suggest the necessity of a further combined study of lanifibranor with enzyme replacement therapy in Lal-/- mice to improve the phenotype. Moreover, there is a compelling rationale for conducting clinical trials to assess the efficacy of lanifibranor as a potential treatment option for LAL-D in humans.

Role of Mn-LIPA in Sex Hormone Regulation and Gonadal Development in the Oriental River Prawn, Macrobrachium nipponense

This study investigates the role of lysosomal acid lipase (LIPA) in sex hormone regulation and gonadal development in Macrobrachium nipponense. The full-length Mn-LIPA cDNA was cloned, and its expression patterns were analyzed using quantitative real-time PCR (qPCR) in various tissues and developmental stages. Higher expression levels were observed in the hepatopancreas, cerebral ganglion, and testes, indicating the potential involvement of Mn-LIPA in sex differentiation and gonadal development. In situ hybridization experiments revealed strong Mn-LIPA signaling in the spermatheca and hepatopancreas, suggesting their potential role in steroid synthesis (such as cholesterol, fatty acids, cholesteryl ester, and triglycerides) and sperm maturation. Increased expression levels of male-specific genes, such as insulin-like androgenic gland hormone (IAG), sperm gelatinase (SG), and mab-3-related transcription factor (Dmrt11E), were observed after dsMn-LIPA (double-stranded LIPA) injection, and significant inhibition of sperm development and maturation was observed histologically. Additionally, the relationship between Mn-LIPA and sex-related genes (IAG, SG, and Dmrt11E) and hormones (17β-estradiol and 17α-methyltestosterone) was explored by administering sex hormones to male prawns, indicating that Mn-LIPA does not directly control the production of sex hormones but rather utilizes the property of hydrolyzing triglycerides and cholesterol to provide energy while influencing the synthesis and secretion of self-sex hormones. These findings provide valuable insights into the function of Mn-LIPA in M. nipponense and its potential implications for understanding sex differentiation and gonadal development in crustaceans. It provides an important theoretical basis for the realization of a monosex culture of M. nipponense.

Recent insights into lysosomal acid lipase deficiency

Lysosomal acid lipase (LAL) is the sole enzyme known to degrade neutral lipids in the lysosome. Mutations in the LAL-encoding LIPA gene lead to rare lysosomal lipid storage disorders with complete or partial absence of LAL activity. This review discusses the consequences of defective LAL-mediated lipid hydrolysis on cellular lipid homeostasis, epidemiology, and clinical presentation. Early detection of LAL deficiency (LAL-D) is essential for disease management and survival. LAL-D must be considered in patients with dyslipidemia and elevated aminotransferase concentrations of unknown etiology. Enzyme replacement therapy, sometimes in combination with hematopoietic stem cell transplantation (HSCT), is currently the only therapy for LAL-D. New technologies based on mRNA and viral vector gene transfer are recent efforts to provide other effective therapeutic strategies.

Lysosomal Acid Lipase Deficiency: Genetics, Screening, and Preclinical Study

Lysosomal acid lipase (LAL) is a lysosomal enzyme essential for the degradation of cholesteryl esters through the endocytic pathway. Deficiency of the LAL enzyme encoded by the LIPA gene leads to LAL deficiency (LAL-D) (OMIM 278000), one of the lysosomal storage disorders involving 50-60 genes. Among the two disease subtypes, the severe disease subtype of LAL-D is known as Wolman disease, with typical manifestations involving hepatomegaly, splenomegaly, vomiting, diarrhea, and hematopoietic abnormalities, such as anemia. In contrast, the mild disease subtype of this disorder is known as cholesteryl ester storage disease, with hypercholesterolemia, hypertriglyceridemia, and high-density lipoprotein disappearance. The prevalence of LAL-D is rare, but several treatment options, including enzyme replacement therapy, are available. Accordingly, a number of screening methodologies have been developed for this disorder. This review summarizes the current discussion on LAL-D, covering genetics, screening, and the tertiary structure of human LAL enzyme and preclinical study for the future development of a novel therapy.