Publications by authors named "Nicholas M Snead"

Chronic hepatitis B is a global health concern with a high risk of end-stage liver disease. Current standard-of-care agents have low cure rates, and new therapies are needed. Small interfering RNAs (siRNAs) that target viral RNAs fulfill a gap not addressed by standard-of-care agents and may contribute to a functional cure.

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The natural product hinokitiol mobilizes iron across lipid bilayers at low concentrations and restores hemoglobinization in iron transporter protein-deficient systems. But hinokitiol fails to similarly mobilize iron at higher concentrations, limiting its uses in chemical biology and medicine. Here we show that at higher concentrations, hinokitiol:Fe(III) complexes form large, higher-order aggregates, leading to loss of transmembrane iron mobilization.

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New therapeutic strategies are needed for the growing unmet clinical needs in liver disease and fibrosis. Platelet activation and PDGF activity are recognized as important therapeutic targets; however, no therapeutic approach has yet addressed these two upstream drivers of liver fibrosis. We therefore designed a matrix-targeting glycan therapeutic, SBR-294, to inhibit collagen-mediated platelet activation while also inhibiting PDGF activity.

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Hepatitis delta virus (HDV) infects 10-20 million individuals worldwide and causes severe fulminant hepatitis with high likelihood of cirrhosis and hepatocellular carcinoma. HDV infection cannot occur in the absence of the surface antigen (HBsAg) of the hepatitis B virus. RNA interference is an effective mechanism by which to inhibit viral transcripts, and siRNA therapeutics sharing this mechanism have begun to demonstrate clinical efficacy.

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Article Synopsis
  • Current treatments for chronic hepatitis B virus (HBV) control viral levels but do not cure the infection or significantly lower viral protein production like surface antigen (HBsAg).
  • ARB-1740 is a promising new RNA interference agent that has shown the ability to reduce HBV RNA and inhibit various viral proteins, making it effective against multiple strains of HBV.
  • When combined with other treatments, ARB-1740 enhances liver HBsAg reduction and boosts the body's immune response, showing potential for curing HBV in the future.
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AB-423 is a member of the sulfamoylbenzamide (SBA) class of hepatitis B virus (HBV) capsid inhibitors in phase 1 clinical trials. In cell culture models, AB-423 showed potent inhibition of HBV replication (50% effective concentration [EC] = 0.08 to 0.

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Article Synopsis
  • * Compassionate use of various post-exposure treatments has taken place for patients brought back to Europe and the U.S., but their effectiveness against the new strain is still unknown.
  • * A study found that lipid-nanoparticle-encapsulated siRNAs can completely protect rhesus monkeys from the Ebola virus if treatment begins three days after exposure, demonstrating potential for effective therapy against this lethal disease.
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Optimization of small interfering RNAs (siRNAs) is important in RNA interference (RNAi)-based therapeutic development. Some specific chemical modifications can control which siRNA strand is selected by the RNA-induced silencing complex (RISC) for gene silencing. Intended strand selection will increase potency and reduce off-target effects from the unintended strand.

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The canonical exogenous trigger of RNA interference (RNAi) in mammals is small interfering RNA (siRNA). One promising application of RNAi is siRNA-based therapeutics, and therefore the optimization of siRNA efficacy is an important consideration. To reduce unfavorable properties of canonical 21mer siRNAs, structural and chemical variations to canonical siRNA have been reported.

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The manifestation of RNA interference (RNAi)-based therapeutics lies in safe and successful delivery of small interfering RNAs (siRNAs), the molecular entity that triggers and guides sequence-specific degradation of target mRNAs. Optimizing the chemistry and structure of siRNAs to achieve maximum efficacy is an important parameter in the development of siRNA therapeutics. The RNAi protein machinery can tolerate a variety of non-canonical modifications made to siRNAs, each of which imparts advantageous properties.

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RNA interference (RNAi) is a sequence-specific gene silencing, or 'knockdown', mechanism facilitated by short duplex strands of RNA with sequence complementarity to target mRNAs. RNAi has many different forms, including posttranscriptional gene silencing (PTGS), and transcriptional gene silencing (TGS). Here, we review the biogenesis and function of an endogenous set of small RNA gene regulators, called microRNAs, as well as the mechanism of exogenously delivered small interfering RNAs.

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RNA engineering for nanotechnology and medical applications is an exciting emerging research field. RNA has intrinsically defined features on the nanometre scale and is a particularly interesting candidate for such applications due to its amazing diversity, flexibility and versatility in structure and function. Specifically, the current use of siRNA to silence target genes involved in disease has generated much excitement in the scientific community.

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Ribozymes are potential therapeutic agents which suppress specific genes in disease-affected cells. Ribozymes have high substrate cleavage efficiency, yet their medical application has been hindered by RNA degradation, aberrant cell trafficking, or misfolding when fused to a carrier. In this study, we constructed a chimeric ribozyme escorted by the motor pRNA of bacteriophage phi29 to achieve proper folding and enhanced stability.

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