Runx1 Messenger RNA Delivered by Polyplex Nanomicelles Alleviate Spinal Disc Hydration Loss in a Rat Disc Degeneration Model

Abstract

Vertebral disc degenerative disease (DDD) affects millions of people worldwide and is a critical factor leading to low back and neck pain and consequent disability. Currently, no strategy has addressed curing DDD from fundamental aspects, because the pathological mechanism leading to DDD is still controversial. One possible mechanism points to the homeostatic status of extracellular matrix (ECM) anabolism, and catabolism in the disc may play a vital role in the disease’s progression. If the damaged disc receives an abundant amount of cartilage, anabolic factors may stimulate the residual cells in the damaged disc to secrete the ECM and mitigate the degeneration process. To examine this hypothesis, a cartilage anabolic factor, Runx1, was expressed by mRNA through a sophisticated polyamine-based PEG-polyplex nanomicelle delivery system in the damaged disc in a rat model. The mRNA medicine and polyamine carrier have favorable safety characteristics and biocompatibility for regenerative medicine. The endocytosis of mRNA-loaded polyplex nanomicelles in vitro, mRNA delivery efficacy, hydration content, disc shrinkage, and ECM in the disc in vivo were also examined. The data revealed that the mRNA-loaded polyplex nanomicelle was promptly engulfed by cellular late endosome, then spread into the cytosol homogeneously at a rate of less than 20 min post-administration of the mRNA medicine. The mRNA expression persisted for at least 6-days post-injection in vivo. Furthermore, the Runx1 mRNA delivered by polyplex nanomicelles increased hydration content by ≈43% in the punctured disc at 4-weeks post-injection (wpi) compared with naked Runx1 mRNA administration. Meanwhile, the disc space and ECM production were also significantly ameliorated in the polyplex nanomicelle group. This study demonstrated that anabolic factor administration by polyplex nanomicelle-protected mRNA medicine, such as Runx1, plays a key role in alleviating the progress of DDD, which is an imbalance scenario of disc metabolism. This platform could be further developed as a promising strategy applied to regenerative medicine.

RUNX1 promotes liver fibrosis progression through regulating TGF‐β signalling

“…Loss of RUNX1 function has been shown to impair differentiation between myeloid and lymphoid lines and can result in the development of leukaemia. [9][10][11]17,18 The haematological diseases associated with RUNX1 gene include Platelet Disorder diseases, Myeloid Malignancies and Acute Myeloid Leukaemia. 16 RUNX members modulate the transcription of their target genes via recognize the core consensus binding sequence 5′-TGTGGT-3′.…”

“…Previous studies about RUNX1 gene function have concentrated mainly on the field of haematology. Loss of RUNX1 function has been shown to impair differentiation between myeloid and lymphoid lines and can result in the development of leukaemia 9–11,17,18 . The haematological diseases associated with RUNX1 gene include Platelet Disorder diseases, Myeloid Malignancies and Acute Myeloid Leukaemia 16 .…”

Recent advances of metal-based nanoparticles in nucleic acid delivery for therapeutic applications

“…PM safely carries the mRNA to cells and mouse lungs [ 61 ]. Polyplex Nanomicelles (PNM) efficiently deliver Runx1 mRNA to primary BMSCs and are shown to play a role in alleviating the progress of vertebral disc degenerative disease after injection of PNM-Runx1 to rat disc degeneration model [ 62 ]. Dbait is a small double-stranded DNA molecule that is utilized as a radiosensitizer.…”

Application of single and cooperative different delivery systems for the treatment of intervertebral disc degeneration

“…Polymeric micelles have a hydrophilic core and a hydrophobic coating and have been used in the clinical treatment of ovarian cancer ( Lee et al, 2018 ). Zhang et al ( Chang et al, 2022a ) used polymeric micelles loaded with mRNA to improve the synthesis of ECM. Dendrimers are branched polymers, and their size, mass, and shape can be tightly controlled ( Mitchell et al, 2021 ).…”