[The progressive study on gene therapy for hyperphenylalaninemia rats].

Area of Science:

• Biotechnology
• Genetic Engineering
• Microbiology

Background:

• Hyperphenylalaninemia is a metabolic disorder characterized by elevated blood phenylalanine levels.
• Developing effective therapeutic strategies for hyperphenylalaninemia remains a significant challenge.
• Lactococcus lactis is a promising platform for delivering therapeutic enzymes due to its GRAS status.

Purpose of the Study:

• To construct a novel, highly effective genetically engineered Lactococcus lactis (L.L.) strain capable of expressing active phenylalanine ammonia-lyase (PAL) enzyme.
• To evaluate the efficacy of the engineered L.L. strain in reducing blood phenylalanine levels in a rat model of hyperphenylalaninemia.

Main Methods:

• Construction of translational and transcriptional fusion vectors in E. coli MC1061.
• Transformation of PAL cDNA into L.L. to create two engineered strains.
• Comparison of enzyme activity and in vivo efficacy in hyperphenylalaninemia rat models.

Main Results:

• Two engineered L.L. strains were successfully generated, with the translational fusion strain exhibiting higher PAL enzyme activity.
• Transcinnamic acid production peaked at 6 hours post-induction.
• Administration of the engineered L.L. (translational fusion strain) significantly reduced blood phenylalanine levels in hyperphenylalaninemia rats compared to controls.

Conclusions:

• The engineered L.L. translational fusion strain effectively reduces blood phenylalanine levels in hyperphenylalaninemia rats.
• This engineered L.L. strain shows superior therapeutic potential compared to other constructs.
• This study highlights the potential of genetically engineered L.L. as a probiotic therapy for hyperphenylalaninemia.