Antisense oligonucleotide and thyroid hormone conjugates for obesity treatment

Yang Cao,Tomoko Matsubara,Wei Gao,Peixin Li,Lingyi Tang,Fang Yuan,Hu Huang,Zhengxia Liu,Linxiu Peng,Zhibin Guan,Jinjun Shan,Can Zhao,Zhuyuan Fang,Xiang Lu,Qin Yang

doi:10.1038/s41598-017-09598-z

Abstract

Using the principle of antibody-drug conjugates that deliver highly potent cytotoxic agents to cancer cells for cancer therapy, we here report the synthesis of antisense-oligonucleotides (ASO) and thyroid hormone T3 conjugates for obesity treatment. ASOs primarily target fat and liver with poor penetrance to other organs. Pharmacological T3 treatment increases energy expenditure and causes weight loss, but is contraindicated for obesity treatment due to systemic effects on multiple organs. We hypothesize that ASO-T3 conjugates may knock down target genes and enrich T3 action in fat and liver. Two established ASOs are tested. Nicotinamide N-methyltransferase (NNMT)-ASO prevents diet-induced obesity in mice. Apolipoprotein B (ApoB)-ASO is an FDA approved drug for treating familial hypercholesterolemia. NNMT-ASO and ApoB-ASO are chemically conjugated with T3 using a non-cleavable sulfo-SMCC linker. Both NNMT-ASO-T3 (NAT3) and ApoB-ASO-T3 (AAT3) enhance thyroid hormone receptor activity. Treating obese mice with NAT3 or AAT3 decreases adiposity and increases lean mass. ASO-T3 enhances white fat browning, decreases genes for fatty acid synthesis in liver, and shows limited effects on T3 target genes in heart and muscle. Furthermore, AAT3 augments LDL cholesterol-lowering effects of ApoB-ASO. Therefore, ASO and hormone/drug conjugation may provide a novel strategy for obesity and hyperlipidemia treatment.

Highlights

The antibody-drug conjugates (ADCs) or immunoconjugates have emerged as a novel class of drugs for targeted cancer therapy[1, 2]
Thyroid hormone T3 was first reacted with sulfo-SMCC to generate maleimide-activated T3
AAT3 decreased Apolipoprotein B (ApoB) expression to the similar degree as ApoB-antisense oligonucleotides (ASO) (AA) in cultured hepatocytes (Fig. 1d), while NAT3 failed to knock down Nicotinamide N-methyltransferase (NNMT) expression in cultured hepatocytes, adipocytes or adipose tissue (Fig. 1e)

Summary

Introduction

The antibody-drug conjugates (ADCs) or immunoconjugates have emerged as a novel class of drugs for targeted cancer therapy[1, 2]. Significant efforts have been made towards designing ASO modifications to improve the penetrance to organs other than liver and fat[9] This limitation of ASOs to treat neurological, muscular and cardiac diseases turns to be advantageous to design ASO-drug conjugates to target fat and liver for obesity treatment. Another important consideration for choosing ASOs is that, similar to cellular uptake of ADC, ASO internalization is shown to be largely through endocytosis[10, 11]. The maleimide group of Sulfo-SMCC is unusually stable because of the cyclohexane bridge in the spacer arm This significantly increases ADC drug stability in circulation. Sulfo-SMCC has been widely used in the synthesis of ADCs including FDA-approved ado-trastuzumab emtansine

Methods

Results

Conclusion