Recent developments in artificial nucleic acid and drug delivery systems (DDS) present possibilities for the symbiotic engineering of oligonucleotide therapeutics, such as antisense oligonucleotides (ASOs), and small interfering RNA (siRNA). These technologies can also be applied for triplex-forming oligonucleotides (TFOs) to develop symbiotic genome-targeting tools and a new class of oligonucleotide drugs. Many reports have described the functionalization of TFOs and the enhancement of TFO activities. In particular, the tethering of crosslinking groups to TFOs enables irreversible triplex formation and is frequently exploited for antigene and genome-editing experiments. These crosslinkable TFOs have shown considerable potential for therapeutic application. In this review, we revisit these crosslinking techniques and explore the combination of these techniques with recent artificial oligonucleotide and DDS technologies.

The severity of the global COVID-19 pandemic, with a high transmission rate, 2.6-4.7% lethality and a huge economic impact, poses an urgent need for efficient medical treatments and vaccines. Currently, there are only non-specific treatments to assist the patients in acute respiratory distress during the inflammatory step following the preliminary infection by SARS-CoV-2. Clinical trials of drug repurposing were quickly launched at the international level. Specific treatments such as the transfusion of plasma from patients who have recovered into infected patients or the use of specific inhibitors of the viral RNA-polymerase complex are promising strategies to block infection. To complete the therapeutic arsenal, we believe that the opportunity of targeting the SARS-CoV-2 genome by RNA therapy should be deeply investigated. In the present paper, we propose to design specific antisense oligonucleotides targeting transcripts encoding viral proteins associated to replication and transcription of SARS-CoV-2, aiming to block infection. We designed antisense oligonucleotides targeting the genomic 5’ untranslated region (5’-UTR), open reading frames 1a and 1b (ORF1a and ORF1b) governing expression of the replicase/transcriptase complex, and the gene N encoding the nucleoprotein that is genome-associated. To maximize the probability of efficiency, we predicted the antisense oligonucleotides by using two design methods: i) conventional antisense oligonucleotides with 100% phosphorothioate modifications (ASO); ii) antisense locked nucleic acids GapmeR. After binding the viral RNA target, the hetero-duplexes antisense oligonucleotide-RNA are cleaved by RNAse H1. Nine potent ASO candidates were found and we selected five of them targeting ORF1a (3), ORF1b (1) and N (1). Nine GapmeR candidates were predicted with excellent properties and we retained four of them targeting 5’-UTR (1), ORF1a (3), ORF1b (1) and N (1). The most potent GapmeR candidate targets the 5’-UTR, a key genomic domain with multiple functions in the viral cycle. By this open publication, we are pleased to share these in silico results with the scientific community in hopes of stimulating innovation in translational research in order to fight the unprecedented COVID-19 pandemic. These antisense oligonucleotide candidates should be now experimentally evaluated.

A simple and rapid positive–negative colorimetric approach to determine the presence of antimony ions based on the use of gold nanoparticles conjugated with oligonucleotide (poly-A sequence) is developed. Colorimetric measurements reveal that the aggregates of modified gold nanoparticles were afforded after adding antimony ions, thus changing the solution color from pink to blue. The results of aptamer’s interaction on the gold nanoparticle surface with target analyte can be detected either by photometry or by the naked eye. The realized assay provides rapid (2 min), sensitive (detection limit 10 ng/mL), specific, and precise (variation coefficient less than 3.8%) detection of antimony (III) in drinking water

Although there is a several array of diagnostic and therapeutic choices for pancreatic cancer in recent years, a crucial medical approach for the refractory disease is still needed. Oligonucleotide therapeutics, such as those based on antisense RNAs, RNA interference, aptamers and decoys, are promising agents against pancreatic cancer because they identify a specific nucleotide sequence or protein and interfere with gene expression as molecular-targeted agents. Within just the past quarter-century, the diversity and feasibility of these drugs as diagnostic or therapeutic tools have dramatically increased. Actually, there have been several clinical and preclinical studies of oligonucleotides for patients with pancreatic cancer so far. To support the discovery of effective diagnostic or therapeutic options by using oligonucleotide-based strategies in the absence of satisfactory therapies for long-term survival and the rising trend of diseases, we summarize the current clinical trials of oligonucleotide therapeutics for pancreatic cancer patients with underlying preclinical or scientific data and focus on the possibility of oligonucleotides to target pancreatic cancer in clinical implications.

Antisense oligonucleotides (ASONs) have proven potential for the treatment of various diseases. However, their limited bioavailability restricts their clinical application. New structures with improved enzyme resistance stability and efficient drug delivery are needed. In this work, we propose a novel category of ASONs bearing anisamide conjugation at phosphorothioate sites for oncotherapy. ASONs can be conjugated with the ligand anisamide very efficiently and flexibly in solution. The conjugation sites and ligand amount both influence anti-enzymatic stability and cellular uptake, resulting in changes in antitumor activity that are detectable by cytotoxicity assay. T6 (with double end AA-conjugation) was identified as the optimal conjugate, and its antitumor activity and the underlying mechanism were examined further in vitro and in vivo. This paper presents a new strategy for the design of nucleic acid–based therapeutics with improved drug delivery and biophysical and biological efficacy.

The main problem in creating anti-coronavirus vaccines that target mainly proteins of the outer membrane of the virus remains the rapid variability of the RNA genome of the pathogen that encodes these proteins. In addition, the introduction of technologies that can provide affordable and fast production of flexible vaccine formulas that easily adapt to the emergence of new subtypes of SARS-CoV-2 is required. Universal oligonucleotide vaccine can take into account the dynamics of rapid changes in the virus genome, as well as be synthesized on automatic DNA synthesizers in large quantities in a short time. In this brief report, the effectiveness of four phosphorothioate constructs of the La-S-so type oligonucleotide vaccine will be evaluated for the first time on transgenic mice [B6.Cg-Tg (K18-ACE2)2]. In our primary trials, the oligonucleotide vaccine increased the survival rate of animals infected with SARS-CoV-2 and also reduced the destructive effects of the virus on the lung tissue of mice. The obtained results show the perspective of the development of vaccine constructs of the La-S-so type for the prevention of coronavirus infections, including those caused by SARS-СoV-2.

Here we investigated the longer-term effect of Ncald-ASOs by additional i.c.v. bolus injection at PND28. Two weeks after injection of 500 µg Ncald-ASO in wild-type mice, NCALD was significantly reduced in brain and spinal cord and well tolerated. Next, we performed a double-blinded preclinical study combining low-dose SMN-ASO (PND1) with 2x i.c.v. Ncald-ASO or CTRL-ASO (100 µg at PND2, 500 µg at PND28). Ncald-ASO re-injection significantly ameliorated electrophysiological defects and NMJ denervation at 2 months. Moreover, we developed and identified a nontoxic and highly efficient human NCALD-ASO that significantly reduced NCALD in hiPSCs-derived MNs. This improved both neuronal activity and growth cone maturation of SMA MNs, emphasizing the additional protective effect of NCALD-ASO treatment.

Successful management of the synthesis of secondary metabolites of essential oil plants is the basis for the economic growth of the essential oil industry. Against the backdrop of a growing global population and a decrease in land available for cultivation, simple and effective ways to increase the content of certain components in essential oils are becoming increasingly important. Selection is no longer keeping pace with market needs, which stimulates the search for faster methods to control the biosynthesis of secondary metabolites. In this article, using the genus Lavandula as an example, we will consider the prospects for use of antisense oligonucleotides (ASO), oligoilators, to rapidly increase the concentration of valuable components in essential oil. This article discusses the use of unmodified ASOs as regulators of plant secondary metabolism to increase the synthesis of individual valuable components, presenting a completely new way to increase the yield of valuable substances based on unique nucleotide sequences. The proposed approach is effective, affordable, safe, and also significantly reduces the time needed to obtain plants that synthesize the required concentrations of target substances. Oligoilators can the used along with oligonucleotide insecticides in complex formulations used for green agriculture. Further investigation is needed to determine maximum economic efficiency of this approach.

The synuclein family consists of α-, β-, and γ-Synuclein (α-Syn, β-Syn, and γ-Syn), expressed in the neurons and concentrated in synaptic terminals. While α-Syn is at the center of interest due to its implication in the pathogenesis of Parkinson’s disease (PD) and other synucleinopathies, limited information exists on the other members. The current study aimed at investigating the biological role of γ-Syn controlling the midbrain dopamine (DA) function. We generated two different mouse models with i) γ-Syn overexpression induced by an adeno-associated viral vector and ii) γ-Syn knockdown induced by a ligand-conjugated antisense oligonucleotide, to modify the endogenous γ-Syn transcription levels in midbrain DA neurons. The progressive overexpression of γ-Syn decreased DA neurotransmission in the nigrostriatal and mesocortical pathways. In parallel, mice evoked motor deficits in the rotarod and impaired cognitive performance as assessed by novel object recognition, passive avoidance, and Morris water maze tests. Conversely, acute γ-Syn knockdown selectively in DA neurons facilitated forebrain DA neurotransmission. Importantly, modifications in γ-Syn expression did not induce the loss of DA neurons or changes in α-Syn expression. Collectively, our data strongly suggest that DA re-lease/re-uptake processes in the nigrostriatal and mesocortical pathways are partially dependent on SNc/VTA γ-Syn transcription levels, and are linked to modulation of DA transporter function, similar to α-Syn.

Abstract Purpose of review: RNA therapeutics are a new and rapidly expanding class of drugs to prevent or treat a wide spectrum of diseases. We discuss the defining characteristics of the diverse family of molecules under the RNA therapeutics umbrella. Recent findings:RNA therapeutics are designed to regulate gene expression in a transient manner. For example, depending upon the strategy employed, RNA therapies offer the versatility to replace, supplement, correct, suppress, or eliminate the expression of a targeted gene. RNA therapies include antisense nucleotides, microRNAs and small interfering RNAs, RNA aptamers, and messenger RNAs. Further, we discuss the mechanism(s) by which different RNA therapies either reduce or increase the expression of their targets. Summary: We review the RNA therapeutics approved (and those in trials) to treat cardiovascular indications. RNA-based therapeutics are a new, rapidly growing class of drugs that will offer new alternatives for an increasing array of cardiovascular conditions.

Oligonucleotide conjugates with boron clusters have found applications in different fields of molecular biology, biotechnology, and biomedicine as potential agents for boron neutron capture therapy, siRNA components, and antisense agents. Particularly, closo-dodecaborate anion represents a high-boron containing residue with remarkable chemical stability and low toxicity, suitable for the engineering of different constructs for biomedicine and molecular biology. In the present work, we synthesized novel oligonucleotide conjugates of closo-dodecaborate attached to the 5'-, 3'-, or both terminal positions of DNA, RNA, 2'-O-Me RNA, and 2'-F-Py RNA oligomers. For their synthesis, we employed click reaction with the azido derivative of closo-dodecaborate. The key physicochemical characteristics of the conjugates have been investigated using high-performance liquid chromatography, gel electrophoresis, UV thermal melting, and circular dichroism spectroscopy. Incorporation of closo-dodecaborate residues at the 3'-end of all oligomers stabilized their complementary complexes, while analogous 5'-modification decreased duplex stability. Two boron clusters attached to the opposite ends of the oligomer only slightly influence the stability of complementary complexes of RNA oligonucleotide and its 2'-O-methyl and 2'-fluoro analogs. On the contrary, the same modification of DNA oligonucleotides significantly destabilized DNA/DNA duplex but gave a strong stabilization of the duplex with RNA target. According to CD spectroscopy results, two terminal closo-dodecaborate residues cause a prominent structural rearrangement of complementary complexes with a substantial shift from B-form to the A-form of the double helix. The revealed changes of key characteristics of oligonucleotides caused by incorporation of terminal boron clusters, such as the increase of hydrophobicity, change of duplex stability, and prominent structural changes for DNA conjugates, should be taken into account for the development of antisense oligonucleotides, siRNAs, or aptamers bearing boron clusters. These features may also be used for engineering of developing NA constructs with pre-defined properties.

Spinal and bulbar muscular atrophy (SBMA), also known as Kennedy’s disease, is a debilitating neuromuscular disease characterized by progressive muscular weakness and neuronal degeneration, affecting 1-2 individuals per 100,000 globally. While SBMA is relatively rare, recent studies have shown a significantly higher prevalence of the disease within the indigenous population of Western Canada compared to the general population. The disease is caused by a pathogenic expansion of polyglutamine residues in the androgen receptor protein, which acts as a key transcriptional regulator for numerous genes. SBMA has no cure, and current treatments are primarily supportive and focused on symptom management. Recently, a form of precision medicine known as antisense therapy has gained traction as a promising therapeutic option for numerous neuromuscular diseases. Antisense therapy uses small synthetic oligonucleotides to confer therapeutic benefit by acting on pathogenic mRNA molecules, serving to either degrade pathogenic mRNA transcripts or helping to modulate splicing. Recent studies have explored the suitability of antisense therapy for the treatment of SBMA, primarily focused on antisense-mediated mRNA knockdown approaches. Advancements in understanding the pathogenesis of SBMA and the development of targeted therapies offer hope for improved quality of life for individuals affected by this debilitating condition. Continued research is essential to optimize these genetic approaches, ensuring their safety and efficacy.

Despite being under development for decades, RNA therapeutics have only recently emerged as viable platform technologies. The COVID-19 mRNA vaccines have demonstrated the promise and power of the platform technology. In response, novel RNA drugs are entering clinical trials at an accelerating rate. As the skin is the largest and most accessible organ, it has always been a preferred target for drug discovery. This holds true for RNA therapies as well, and multiple candidate RNA-based drugs are currently in development for an array of skin conditions. In this mini review, we catalog the RNA therapies currently in clinical trials for different dermatological diseases. We summarize the main types of RNA-related drugs and use examples of drugs currently in development to illustrate their key mechanism of action.

Aptamers are versatile oligonucleotide ligands used for molecular recognition of diverse targets. However, application of aptamers to the field of amyloid β-protein (Aβ) has been limited so far. Aβ is an intrinsically disordered protein that exists in a dynamic conformational equilibrium, presenting time-dependent ensembles of short-lived, metastable structures and assemblies that have been generally difficult to isolate and characterize. Moreover, despite understanding of potential physiological roles of Aβ, this peptide has been linked to the pathogenesis of Alzheimer disease, and its pathogenic roles remain controversial. Accumulated scientific evidence thus far highlights undesirable or nonspecific interactions between selected aptamers and different Aβ assemblies likely due to metastable nature of Aβ or inherent affinity of RNA oligonucleotides to β-sheet-rich fibrillar structures of amyloidogenic proteins. Accordingly, lessons drawn from Aβ–aptamer studies emphasize that purity and uniformity of the protein target and rigorous characterization of aptamers’ specificity are important for realizing and garnering the full potential of aptamers selected for recongizing Aβ or other intrinsically disordered proteins. This review summarizes studies of aptamers selected for recognizing different Aβ assemblies and highlights controversies, difficulties, and limitations of such studies.