Montgomery, unpublished data)
Montgomery, unpublished data). Since it has been well validated that miR-29 functions through the regulation of many different extracellular matrix related genes (van Rooij & Olson, 2012), we confirmed the regulation of a subset of these target genes. delivery of these miR-29 mimics during bleomycin-induced pulmonary fibrosis restores endogenous miR-29 function whereby decreasing collagen expression and blocking and reversing pulmonary fibrosis. Our data support the feasibility of using miRNA mimics to therapeutically increase miRNAs and indicate miR-29 to be a potent therapeutic miRNA for treating pulmonary fibrosis. has shown to be effective in a mouse model of hepatocellular and lung carcinoma (Kota for several days without observable side effects or effects on gene expression. However, therapeutic treatment with miR-29b mimic in the setting of pulmonary fibrosis restores the bleomycin-induced reduction of miR-29 and blocks and reverses pulmonary fibrosis, which coincides with a repression of miR-29 target genes that are induced during the disease process. Our data support the feasibility of using miRNA mimics to therapeutically increase miRNAs and indicate miR-29 to be a potent therapeutic miRNA as treatment for pulmonary fibrosis. Results and Discussion miR-29 mimicry and with increasing amount of miR-29b mimic compared to either untreated or mock-treated cells. An siRNA directly targeting was taken along as a positive control. *(was taken along as a positive control (Fig ?(Fig11B). To start exploring the applicability and distribution of miR-29 mimic, we injected mice intravenously with 10, 50, RSV604 racemate 100, or 125?mg per kg (mpk) and sacrificed them 4?days later. Northern blot analysis on multiple tissues indicated little to no increase in miR-29b in kidney or liver samples compared to saline control. Cardiac distribution was detected; however, this appeared to be quite variable and spleen delivery could be observed at the highest dose only. In contrast, delivery to the lungs could be observed at all 3 of the RAF1 highest doses 4?days after injection (Fig ?(Fig1C).1C). No effects on liver function (transaminase, ALT) were observed in the plasma, indicating that these miRNA mimics are well tolerated at these doses (Supplementary Fig S1). Real-time PCR exhibited similar results with strong dose-dependent distribution of the miR-29b mimic to the lung compared to saline-injected animals (Fig ?(Fig1D).1D). Additionally, real-time PCR analysis of miR-29 targets showed no regulation at the mRNA level in the treated animals except for at the highest dose in the spleen (Supplementary Fig S2). This suggests that the target genes are either at constant state in non-stressed animals and that mimics lower target genes when they are elevated, or that functional delivery was inadequate or insufficient. To gain more insights RSV604 racemate into the stability of miRNA mimics, we injected 125?mpk of miR-29b mimic and sacrificed the mice 1, 2, 4, or 7?days later. Robust presence of RSV604 racemate miR-29b mimic could be detected by both Northern blot and real-time PCR analysis 1?day after injection in all tissues examined; however, tissue clearance greatly differed thereafter (Fig ?(Fig1E1E and F). Liver and kidney rapidly cleared miR-29b mimic with minimal detection after day 1. Lung and spleen exhibited the most pronounced detection of miR-29b mimic over time, which sustained at least 2C4?days post-treatment (Fig ?(Fig1E1E and F). The increase was specific for miR-29b without any effect on miR-29a and miR-29c levels as measured by real-time PCR (Supplementary Fig S3). Also, here real-time PCR analysis of miR-29 targets showed no downregulation at the mRNA level in non-stressed animals (Supplementary Fig S4). Together, these data indicate that unformulated miR-29b mimic can increase the miRNA level with tissue-dependent clearance and delivery efficiency, without any clear effect on gene expression under baseline conditions. miR-29b mimic blunts bleomycin-induced pulmonary fibrosis Current treatments of tissue fibrosis mostly rely on targeting the inflammatory response; however, these are ultimately ineffective in preventing progression of the disease, underscoring the need for new mechanistic insights and therapeutic approaches (Friedman or expression; however, we did observe a significant difference in expression (Supplementary Fig RSV604 racemate S5 and P. Latimer and R. Montgomery, unpublished data). Since it has been well validated that miR-29 functions through the regulation of many different extracellular matrix related genes (van Rooij & Olson, 2012), we confirmed the regulation of a subset of these target genes. While a RSV604 racemate significant increase in and a pattern increase in expression were observed with bleomycin treatment in both saline and control-treated groups, the detection of and was significantly blunted in the presence of miR-29b mimic.