[Oligonucleotide therapeutics - an emerging novel class of compounds]

Effectiveness and Safety of Inclisiran, A Novel Long-Acting RNA Therapeutic Inhibitor of Proprotein Convertase Subtilisin/Kexin 9

Low-density cholesterol (LDL-C) has a causal association with coronary artery disease and acute coronary syndromes (ACS). Statins have been found to reduce LDL-C, and many randomized trials have documented the significant role of statins in prevention and treatment of ACS. Treatment with statin therapy is associated with few shortcomings. A healthy percentage of patients initiated on statin, discontinue it within a year of initiation predominantly because of its daily dosing schedule. There is considerable variability in treatment response to statins and in some percentage of patients with high risk for ACS, satins are not enough to help reach the LDL-C goal necessitating the development of alternate LDL-C lowering therapies. Inclisiran a small interfering ribonucleic acid molecule inhibitor is helpful in sustained reduction of LDL-C. A single dose can decrease LDL-C for around 6 months, showed promising results in the phase II trials. In conclusion, here we reviewed the possibilities of Inclisiran as LDL-C reducing therapy and compared with currently available newer nonstatin LDL-C lowering therapies.

Antisense Oligonucleotides Targeting Raf-1 Block Japanese Encephalitis Virus In Vitro and In Vivo

Japanese encephalitis virus (JEV) infections represent a major health concern in Southeast Asia since no effective treatments are available. Recently, several reports have demonstrated that inhibition of certain host cell proteins prevents viral infection. Raf-1 kinase is a central component of many signaling pathways involved in normal cell growth and oncogenic transformation, and Ras/Raf/ERK signaling activation has been observed during viral infections (including JEV infection). In this study, Raf-1 was confirmed to be upregulated by JEV infection, which suggested that Raf-1 might be important for JEV infection and might be a target for novel anti-JEV drugs. To determine the role of Raf-1 during the JEV infection process, antisense oligonucleotides (ASODNs) were used to downregulate Raf-1 expression in JEV-infected baby hamster kidney (BHK-21) cells and African green monkey kidney (Vero) cells. From five ASODNs candidates tested, Raf-1-1 (Raf-1 antisense) significantly downregulated Raf-1 protein expression levels, significantly inhibited cytopathic effect (CPE) in cultured cells, and reduced JEV RNA levels in cell medium without affecting cell viability. Furthermore, it also demonstrated that ASODN Raf-1-1 possessed therapeutic effects by using a lethal JEV infection mouse model. In conclusion, data presented in this report demonstrated that ASODN Raf-1-1 could suppress Raf-1 protein and that Raf-1 inhibition suppressed JEV replication in vitro and in vivo. These data provided evidence for targeting Raf-1 in the development of novel anti-JEV therapies. In addition, Raf-1-1 represents potential drugs that can be adapted for treating JEV infections.

Antibiotic-resistant bugs in the 21st century: A public health challenge

Antimicrobial resistance, which has been reported against almost every antibiotic discovered, is one of the most urgent public health problems, threatening to undermine the effectiveness of infectious disease treatment worldwide. Since penicillin ushered in the antibiotic era in the mid 20th century, the scientific world had engaged in a war between the development of antibacterial agents and bacterial resistance. During the first decade of the 21st century, grave concern has been expressed over the evolution of multi-drug resistant staphylococci, enterococci, and mycobacteria, which pose serious clinical and public health challenge to humans. The present picture is frighteningly similar to the pre-antibiotic era, with reports of nosocomial spread and intercontinental dissemination of multi-drug resistant bacteria. For infected patients, there is no magic bullet. The microbial pathogens appear to be gaining the upper hand, coupled with a recent dramatic reduction in antibiotic research by pharmaceutical companies because of the high cost of drug research. Several compounds that have recently been developed or resurrected to treat gram-positive infections are still unable to meet the armamentarium of resistance mechanisms of these pathogens. The situation is worse for gram-negative organisms, where no new drug is currently being developed against them. A multi-disciplinary approach to combat resistance is required, which must be applied, sustained, and continuously refined. The key components for maintaining effective antimicrobial chemotherapy will include better use of existing agents, coupled with continuous investment in new and innovative technologies, which must include diagnostics and vaccines in addition to new antimicrobial agents.

Modified concatemeric oligonucleotide complexes: new system for efficient oligonucleotide transfer into mammalian cells

Antisense oligonucleotides and double-stranded small interfering RNAs have become an important instrument for the manipulation of gene expression in molecular biology experiments and a promising tool for the development of gene-targeted therapeutics. One of the main impediments in the use of oligonucleotide-based therapeutics is their poor uptake by target cells. The formation of supramolecular concatemeric complexes by oligonucleotides was shown to promote their binding to various mammalian cells [Simonova, O.N.,Vladimirova, A.V., Zenkova, M.A., and Vlassov, V.V. (2006). Biochim. Biophys. Acta 1758, 413-418]. We attempted to improve the efficiency of oligonucleotide concatemer delivery into cells by the attachment of lipophilic cholesterol molecules to the components of concatemeric complexes. Uptake, cellular distribution, and biological activity of the supramolecular complexes formed by delivered antisense oligonucleotides and cholesterol-modified "carrier" oligonucleotides were studied. Our results demonstrate that incorporation of an antisense oligonucleotide into the self-assembling concatemeric system promotes its delivery into cells without the addition of any supplementary transfection agents and allows achieving specific inhibition of the target gene expression.