The development and technologies of RNA therapeutics.

Since it was discovered for over 20 years ago, the potentiality of siRNAs in gene silencing in vitro and in vivo models has been recognized. Several studies in the new generation, molecular mechanisms, target attachment, and purification of RNA have supported the development of RNA therapeutics for a variety of applications. RNA therapeutics are growing rapidly with various platforms contributing to the standard of personalized medicine and rare disease treatment. Therefore, understanding the development and technologies of RNA therapeutics becomes a crucial point for new drug generation. Here, the primary purpose of this review is to provide a general view of six therapeutic categories that make up RNA-based therapeutic approaches, including RNA-target therapeutics, protein-targeted therapeutics, cellular reprogramming and tissues engineering, RNA-based protein replacement therapeutics, RNA-based genome editing, and RNA-based immunotherapies based on non-coding RNAs and coding RNA. Furthermore, we present an overview of the RNA strategies regarding viral approaches and nonviral approaches in designing a new generation of RNA technologies. The advantages and challenges of using RNA therapeutics are also discussed along with various approaches for RNA delivery. Therefore, this review is designed to provide updated reference evidence of RNA therapeutics in the battle against rare or difficult-to-treat diseases for researchers in this field.

Inhibition of Inflammatory Responses by Centella asiatica via Suppression of IRAK1-TAK1 in Mouse Macrophages.

Centella asiatica (L.) Urb. (C. asiatica) has been widely treated for inflammation-related diseases in China for thousands of years. While C. asiatica showed relevant effects as traditional medicine, the mechanism of C. asiatica suppressing inflammation has not been thoroughly investigated. Therefore, this study was conducted to reveal the anti-inflammatory mechanism of methanol fraction from C. asiatica (MCA) at the molecular level in murine macrophages. Levels of inflammation-related mediators were observed with treatment of MCA. MCA significantly suppressed nitric oxide production and iNOS expression in RAW 264.7 macrophages. Prostaglandin E2 production was alleviated by MCA via the downregulation of cyclooxygenase-2. MCA treatment also reduced pro-inflammatory tumor necrosis factor-[Formula: see text] and interleukin (IL)-6 levels. LPS/D-GalN-induced acute hepatitis in mouse was alleviated by MCA treatment. In addition, MCA decreased the phosphorylation of inhibitory [Formula: see text]B[Formula: see text] (I[Formula: see text]B[Formula: see text]) at Ser32/36 and thereby blocked I[Formula: see text]B[Formula: see text] degradation. TXY motif phosphorylation in the activation loops of mitogen-activated protein kinases (MAPKs) was also suppressed by MCA treatment. Further investigation revealed that MCA inhibited transforming growth factor-[Formula: see text]-activated kinase 1 (TAK1) phosphorylation and IL-1 receptor-associated kinase (IRAK1) degradation, the upstream kinases activating nuclear factor [Formula: see text]B and MAPKs. Taken together, MCA exhibited anti-inflammatory properties via the downregulation of IRAK1-TAK1 signaling pathways.

Anticancer effects of methanol extract of Myrmecodia platytyrea Becc. leaves against human hepatocellular carcinoma cells via inhibition of ERK and STAT3 signaling pathways.

Myrmecodia platytyrea Becc., a member of the Rubiaceae family, is found throughout Southeast Asia and has been traditionally used to treat cancer. However, there is limited pharmacological information on this plant. We investigated the anticancer effects of the methanol extract of Myrmecodia platytyrea Becc. leaves (MMPL) and determined the molecular mechanisms underlying the effects of MMPL on metastasis in human hepatocellular carcinoma (HCC) cells. MMPL dose-dependently inhibited cell migration and invasion in SK­Hep1 and Huh7 cells. In addition, MMPL strongly suppressed the enzymatic activity of matrix metalloproteinases (MMP­2 and MMP­9). Diminished telomerase activity by MMPL resulted in the suppression of both telomerase activity and telomerase-associated gene expression. The levels of urokinase-type plasminogen activator receptor (uPAR) expression as well as the phosphorylation levels of signal transducer and activator of transcription 3 (STAT3) and extracellular signal-regulated kinase (ERK) were also attenuated by MMPL. The above results collectively suggest that MMPL has anticancer effects in HCC and that MMPL can serve as an effective therapeutic agent for treating human liver cancer.

Suppression of inflammation by the rhizome of Anemarrhena asphodeloides via regulation of nuclear factor-κB and p38 signal transduction pathways in macrophages.

The rhizome of Anemarrhena asphodeloides Bunge (A. asphodeloides) has been used as a traditional East Asian medicine for the treatment of various types of inflammatory disease. However, to the best of our knowledge, there have been no systemic studies regarding the molecular mechanisms of action of the A. asphodeloides rhizome anti-inflammatory effects. The aim of the present study was to elucidate the anti-inflammatory effects and underlying mechanism of action of ethanol extracts of the rhizome of A. asphodeloides (EAA) in murine macrophages. Non-cytotoxic concentrations of EAA (10-100 µg/ml) significantly decreased the production of NO and interleukin (IL)-6 in lipopolysaccharide (LPS)-stimulated macrophages, while the production of tumor necrosis factor-α was not regulated by EAA. EAA-mediated reduction of nitric oxide (NO) was due to reduced expression levels of inducible NO synthase (iNOS). Furthermore, protein expression levels of LPS-induced cyclooxygenase-2, another inflammatory enzyme, were alleviated in the presence of EAA. EAA-mediated reduction of those proinflammatory mediators was due to inhibition of nuclear factor-κB (NF-κB) and activator protein 1 transcriptional activities followed by the stabilization of inhibitor of κ Bα and inhibition of p38, respectively. These results indicate that EAA suppresses LPS-induced inflammatory responses by negatively regulating p38 and NF-κB, indicating that EAA is a candidate treatment for alleviating inflammation.

Spilanthes acmella inhibits inflammatory responses via inhibition of NF-κB and MAPK signaling pathways in RAW 264.7 macrophages.

Spilanthes acmella Murr. (S. acmella) has been used traditionally in India and Sri Lanka to treat various inflammatory diseases. However, the anti­inflammatory effects and underlying mechanism of action of S. acmella are unclear. The present study assessed the anti­inflammatory properties of methanol extracts of S. acmella (MSA) in murine macrophages. MSA (≤300 µg/ml) inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)­stimulated RAW 264.7 macrophages through transcriptional inhibition of inducible nitric oxide synthase expression in a dose­dependent manner. Furthermore, the LPS­induced prostaglandin E2 production and cyclooxygenase­2 expression were inhibited by MSA (300 µg/ml). MSA treatment inhibited interleukin (IL)­6 production and decreased the mRNA expression levels of proinflammatory cytokines, including IL­6 and IL­1ß. In addition, no significant inhibition in tumor necrosis factor­α production was detected. Inhibitory effects of MSA on the production of inflammatory mediators were mediated by reduced activation of mitogen­activated protein kinases (MAPKs) and nuclear factor (NF)­κB. The LPS­induced phosphorylation of transforming growth factor beta­activated kinase 1, an upstream kinase of both MAPKs and NF­κB, was also inhibited by MSA treatment. Taken together, MSA inhibits the excessive inflammatory responses in LPS­stimulated murine macrophages by inhibiting the phosphorylation of MAPKs and NF­κB, implicating S. acmella in the treatment of severe inflammatory states based on its ethnopharmacological importance and its anti­inflammatory properties.