Dual mRNA therapy restores metabolic function in long-term studies in mice with propionic acidemia

Abstract

Propionic acidemia/aciduria (PA) is an ultra-rare, life-threatening, inherited metabolic disorder caused by deficiency of the mitochondrial enzyme, propionyl-CoA carboxylase (PCC) composed of six alpha (PCCA) and six beta (PCCB) subunits. We herein report an enzyme replacement approach to treat PA using a combination of two messenger RNAs (mRNAs) (dual mRNAs) encoding both human PCCA (hPCCA) and PCCB (hPCCB) encapsulated in biodegradable lipid nanoparticles (LNPs) to produce functional PCC enzyme in liver. In patient fibroblasts, dual mRNAs encoded proteins localize in mitochondria and produce higher PCC enzyme activity vs. single (PCCA or PCCB) mRNA alone. In a hypomorphic murine model of PA, dual mRNAs normalize ammonia similarly to carglumic acid, a drug approved in Europe for the treatment of hyperammonemia due to PA. Dual mRNAs additionally restore functional PCC enzyme in liver and thus reduce primary disease-associated toxins in a dose-dependent manner in long-term 3- and 6-month repeat-dose studies in PA mice. Dual mRNAs are well-tolerated in these studies with no adverse findings. These studies demonstrate the potential of mRNA technology to chronically administer multiple mRNAs to produce large complex enzymes, with applicability to other genetic disorders.

Hepatocyte Nuclear Factor 4 alpha 2 Messenger RNA Reprograms Liver‐Enriched Transcription Factors and Functional Proteins in End‐Stage Cirrhotic Human Hepatocytes

“…Uridine was also globally replaced with N1‐methylpseudouridine. ( 21 , 22 , 23 , 24 ) These modifications have been shown to increase mRNA stability and translation efficiency, and prevent detection by toll‐like receptors that activate foreign RNA‐induced innate immune responses. ( 25 , 26 , 27 ) Unlike viral‐based vectors, nucleoside‐modified mRNA provides pulse‐like immediate gene expression with no need for host‐cell transcription, transient gene expression with no danger of integration into the host genome, and minimal activation of foreign RNA‐induced innate immune responses.…”

Severity modeling of propionic acidemia using clinical and laboratory biomarkers

“…Finally, in vivo 1- 13 C-propionate oxidation, ranked 20/301, clearly separated liver-transplanted participants from severely affected PA patients, and did not correlate with cystatin C–based eGFR. This suggests that in vivo propionate oxidation may be linked to the residual activity of propionyl-CoA carboxylase activity and has the potential to perform well in clinical assessment of gene 12 or mRNA therapies for propionic acidemia and MMUT -related methylmalonic acidemia 27 , 36 , 37 …”

Development of an engineered probiotic for the treatment of branched chain amino acid related metabolic diseases

“…For example, the small molecule, sodium phenylbutyrate, increases the activity of the branched-chain alpha-keto acid dehydrogenase enzyme complex and improves BCAA degradation [32]. Other groups have developed therapeutic mRNAs encoding missing or damaged pathway enzymes in PA or MMA patients [33,34]. However, a challenge remains that each of these types of therapies can only target single pathway enzyme within already small patient populations ( Figure 1).…”