Chemically modified in-vitro-transcribed mRNA encoding thrombopoietin stimulates thrombopoiesis in mice

Yu Zhang; Xiaodong Xi; Hang Yu; Liuyan Yang; Jinzhong Lin; Wen Yang; Junling Liu; Xuemei Fan; Yingjie Xu

doi:10.1016/j.omtn.2022.08.017

Chemically modified in-vitro-transcribed mRNA encoding thrombopoietin stimulates thrombopoiesis in mice

Mol Ther Nucleic Acids. 2022 Aug 13:29:657-671. doi: 10.1016/j.omtn.2022.08.017. eCollection 2022 Sep 13.

Authors

Yu Zhang¹, Xiaodong Xi², Hang Yu³, Liuyan Yang⁴, Jinzhong Lin⁵, Wen Yang¹, Junling Liu¹, Xuemei Fan¹, Yingjie Xu^{1

6}

Affiliations

¹ Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China.
² State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China.
³ Shanghai RNACure Biopharma Co., Ltd., Shanghai 200438, P.R. China.
⁴ State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao 266237, P.R. China.
⁵ State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200438, P.R. China.
⁶ Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education; Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China.

Abstract

The use of messenger RNA (mRNA) enables the transient production of therapeutic proteins with stable and predictable translational kinetics and without the risk of insertional mutagenesis. Recent findings highlight the enormous potential of mRNA-based therapeutics. Here, we describe the synthesis of chemically modified thrombopoietin (TPO) mRNA through in vitro transcription and in vivo delivery via lipid nanoparticles (LNPs). After delivery of TPO mRNA in mice, compared with normal physiological values, plasma TPO protein levels increased over 1000-fold in a dose-dependent manner. Moreover, through a single intravenous dose of TPO mRNA-loaded LNPs, both reticulated and total platelet count increased significantly in mice, demonstrating that TPO protein derived from the exogenous mRNA was able to maintain normal activity. Submicrogram quantity of N₁-methylpseudouridine-modified TPO mRNA showed a similar effect in promoting thrombopoiesis as that by the TPO receptor agonist romiplostim. In addition, a therapeutic value was established in anti-GPIbα (CD42b) antibody-induced thrombocytopenia mouse models that showed a fast recovery of platelet count. Our study demonstrated chemically modified in-vitro-transcribed TPO mRNA as a potentially safe therapeutic intervention to stimulate thrombopoiesis.

Keywords: MT: Oligonucleotides; Therapies and Applications; mRNA therapy; nanoparticle; platelet; thrombocytopenia; thrombopoiesis; thrombopoietin.