Acceleration of healing of the medial collateral ligament of the knee by local administration of synthetic microRNA-210 in a rat model

Abstract

BackgroundInjury to the medial collateral ligament (MCL) of the knee joint is the most common ligament injury of the knee. Ligament healing generally takes a long time. Micro-ribonucleic acid (miRNA) is one of the noncoding RNAs and plays a crucial role in physiological function; miRNA (miR)-210 is known as a potent factor of angiogenesis, which is an important initiator of ligament healing. The purpose of this study is to examine the effect of local injection of double-stranded (ds) miR-210 on the healing of the MCL of rat knee joint.MethodsMCLs of Sprague-Dawley rats were cut transversely. After the fascia and skin were sutured, dsmiR-210 or control dsRNA was injected into the injured site of MCL. At 2 weeks and 4 weeks, histological analysis and immunofluorescence staining of vascular endothelial growth factor, isolectin B4, collagen type 1, and Ki67 as well as a mechanical test were performed. Analysis of complementary deoxyribonucleic acid (cDNA) microarray data was performed at 1 week.ResultsHistological analysis showed that parallel fibres in the injured site were organised at 2 weeks and became thicker at 4 weeks in the miR-210-treated group, whereas the injured site in controls was filled with loose fibrous tissues and was thinner than that in the miR-210-treated group. The number of blood vessels in the miR-210-treated group was significantly higher than that in controls (p < 0.05), and vascular endothelial growth factor, Ki67, and collagen type 1 in the miR-210-treated group were intensely expressed in the repaired site as compared to the control group. The mechanical test indicated that the ultimate failure load in the miR-210-treated group was significantly higher than that in the control group at 2 weeks. The cDNA microarray analysis showed significant upregulation of genes related to cell proliferation and cell differentiation, and genes involved in negative regulation of apoptosis.ConclusionThis study showed that local injection of dsmiR-210 could accelerate MCL healing in rat, which is likely due to stimulation of angiogenesis at the healing site.

Advanced Gene Therapy Strategies for the Repair of ACL Injuries

“…These vectors were employed to transfer reporter genes (GFP) [317,318,384] and therapeutic sequences (TGF-β, IGF-I) [317,318] in bovine ACL cells [317], chicken tendon cells [384], and bovine and human ACL explant (experimentally torn) tissue [317,318]. [389][390][391] Abbreviations: ACL, anterior cruciate ligament; rAAV, recombinant adeno-associated viral vectors; GFP, green fluorescent protein; miRNA, microRNA; TGF-β, transforming growth factor beta; IGF-I, insulin-like growth factor I; BMP-12, bone morphogenetic protein 12; shRNA, short hairpin RNA; GDF-5, growth differentiation factor 5; luc, luciferase; PLGA, polylactic-co-glycolic acid; PCL, polycaprolactone; PDA NPs, polydopamine nanoparticles; HA, hyaluronic acid; VEGF, vascular endothelial growth factor.…”

“…Therapeutic gene transfer (TGF-β, GDF-5, BMP-12) was capable of promoting wound healing with increased levels of collagen deposition and improved mechanical properties in injured mouse, rat, and rabbit tendons and ligaments for up to 6 months using nonviral vectors (TGF-β) [385], 4 weeks using adenoviral vectors (BMP-12) [319], and 3 weeks using rAAV vectors (GDF-5) [387,388]. Therapeutic RNAs have been also applied via biomaterials in animal models (Table 6) [335,384,386,[389][390][391], based on the delivery of shRNAs (decorin) [335] and miRNAs (TGF-β, angiogenic miR-210) [384,386,[389][390][391] using nonviral [384,386] and lentiviral vectors [335] or only as RNA solutions [389][390][391] delivered via rat tendon tissue grafts [335], type-I collagen hydrogels [389][390][391], PLGA nanospheres [384], and 3D-bioprinted composite (PCL, polydopamine-PDAnanoparticles-NPs, gelatin, HA, alginate) scaffolds [386] in experimentally created tendon and ligamentous lesions for tissue replacement and repair in vivo in rats [335,[389][390][391] and in chickens [384,386], allowing to suppress the expression of the specific marker (TGF-β) for up to 6 weeks [384] while enhancing matrix deposition and specific marker expression (type-I collagen, VEGF), mechanical stiffness, and healing for up to 12 weeks [335,…”