MicroRNA-138 regulates osteogenic differentiation of human stromal (mesenchymal) stem cells in vivo

Abstract

Elucidating the molecular mechanisms that regulate human stromal (mesenchymal) stem cell (hMSC) differentiation into osteogenic lineage is important for the development of anabolic therapies for treatment of osteoporosis. MicroRNAs (miRNAs) are short, noncoding RNAs that act as key regulators of diverse biological processes by mediating translational repression or mRNA degradation of their target genes. Here, we show that miRNA-138 (miR-138) modulates osteogenic differentiation of hMSCs. miRNA array profiling and further validation by quantitative RT-PCR (qRT-PCR) revealed that miR-138 was down-regulated during osteoblast differentiation of hMSCs. Overexpression of miR-138 inhibited osteoblast differentiation of hMSCs in vitro, whereas inhibition of miR-138 function by antimiR-138 promoted expression of osteoblast-specific genes, alkaline phosphatase (ALP) activity, and matrix mineralization. Furthermore, overexpression of miR-138 reduced ectopic bone formation in vivo by 85%, and conversely, in vivo bone formation was enhanced by 60% when miR-138 was antagonized. Target prediction analysis and experimental validation by luciferase 3′ UTR reporter assay confirmed focal adhesion kinase, a kinase playing a central role in promoting osteoblast differentiation, as a bona fide target of miR-138. We show that miR-138 attenuates bone formation in vivo, at least in part by inhibiting the focal adhesion kinase signaling pathway. Our findings suggest that pharmacological inhibition of miR-138 by antimiR-138 could represent a therapeutic strategy for enhancing bone formation in vivo.regulatory RNA | bone biology | osteoblastic differentiation

Scaffold‐Based microRNA Therapies in Regenerative Medicine and Cancer

“…Cationic lipids are among the most commonly utilized nonviral vectors for gene therapy applications. The use of commercial cationic lipids in biomaterial-based approaches to deliver miRNA therapeutics is exemplified by the widespread use of Lipofectamine 2000 [53][54][55][56] along with Lipofectamine RNAiMAX [57] and SiPORT NeoFx. [58] Generally, cationic lipids complex with the miRNA cassettes through electrostatic interaction, and the overall positive charge of the complex dictates the cellular uptake, although neutrally charged liposomes can also encapsulate the cargo within their core.…”

“…[107] Many distinct scaffold types have been tuned to serve the purpose of miRNA delivery, including several hydrogels, [58,92,106,[108][109][110][111][112][113][114] electrospun fibers, [63,[115][116][117][118] and more prolifically porous or spongy scaffolds. [46,47,50,54,55,96,112,[119][120][121][122][123][124][125][126][127][128][129][130] Before reviewing the details of their applications, summarized in Table 2 and described further in the next section, we will discuss the key characteristics making these materials amenable to miRNA delivery. First very general qualities must be fulfilled: biocompatibility, bioresorbability and ease of fabrication.…”

“…CaPs exist in forms of different stoichiometric proportion of calcium to phosphate; this includes brushite, tricalcium phosphate (TCP), and hydroxyapatite (HA), the mineral component found in teeth and bone. [140] β-TCP scaffolds were used by Deng et al in preclinical studies of lentiviral miR-31 inhibition, [45,120] and HA/TCP scaffolds were utilized, in combination with Lipofectamine 2000, by Eskildsen et al to deliver miR-138 inhibitors in vitro, [54] and more recently by Wang and co-workers to deliver miR-26a mimics in vivo. [55] Similarly, nHA/PCL and carboxy-methyl-cellulose/zinc-doped nHA composite scaffolds have been combined with Lipofectamine 2000 and X-treme Gene transfection reagent respectively.…”

Bone marrow stroma-derived miRNAs as regulators, biomarkers and therapeutic targets of bone metastasis

“…23 MiR-138 inhibited osteogenesis by directly targeting signaling through focal adhesion kinase leading to attenuated bone formation in vivo. 24 Importantly, treatment of human mesenchymal stem cells (MSCs) with anti-miR-138 oligonucleotides increased osteogenic capacity and bone formation. 24 Several miRNAs were shown to exhibit dichotomous roles during osteoclastogenesis by simultaneously enhancing and suppressing differentiation ( Figure 1 and Table 1), including miR-223 (Sugatani and Hruska 13,25 ) and the miR-29 family.…”

Realizing the potential of gene-based molecular therapies in bone repair

“…(72) The miRNA have recently been shown to regulate osteogenic commitment of mesenchymal stem cells. (73) The miRNAs can act as negative regulators of osteogenesis, (74)(75)(76)(77)(78)(79) or as promoters of osteoblast differentiation (Fig. 4).…”