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Biology subjects

Bernier, S. G.

Publications and source records attributed to Bernier, S. G..

3 recordsLinked to original sources

Enhanced lung delivery of an immunostimulatory duplex RNA augments the antitumor activity by reshaping systemic cytokine pharmacodynamics

The organ-specific enrichment of drug delivery vehicles, such as lipid nanoparticles (LNPs), can be leveraged to concentrate drugs at disease sites to increase efficacy and limit toxicity. For immunostimulatory therapeutics, however, tissue accumulation beyond diseased sites may also shape drug activity by determining which organs and cell populations first sense the agonist and initiate downstream immune responses. Here, we show that the anticancer efficacy of an immunostimulatory duplex RNA (dsRNA) can be augmented using LNPs that are formulated to preferentially target the lung, which dictates the systemic pharmacodynamics of the cytokines it elicits. The immunostimulatory dsRNA was formulated into LNPs engineered for either enhanced liver-(LiverLNPs) or lung-(LungLNPs) based delivery, matched for size, encapsulation efficiency, and in vitro potency. In mice, delivery of dsRNA in LungLNPs enhanced uptake into endothelial, epithelial, and resident immune cells populations and induced substantially higher circulating levels of type I, type III interferons and proinflammatory cytokines than dsRNA formulated in LiverLNPs. This significant systemic response induced by lung-enhanced delivery required competent retinoic acid-inducible gene I and Toll-like receptor 7 signaling. Functionally, LNPs that preferentially targeted the lungs induced significantly greater suppression of tumor growth in both subcutaneous and metastatic models of melanoma. LungLNP/dsRNA also induced cytokine secretion and inhibited tumor cell proliferation in a human lung cancer-on-a-chip model. Together, these results establish that pulmonary exposure can alter systemic pharmacodynamics and therapeutic activity of immunostimulatory RNA.

bioengineering↗

Control of Molecular Biochemistry and Cell Injury Responses through Highly Ordered Supramolecular Assembly of Flavonoids

Flavonoids are phytonutrients commonly found in plant-based foods and are generally known for their health benefits. However, their utility as potential therapeutics has not been explored because their presence in drug development tests can lead to false positives due to non-specific binding. Here, we employed molecular dynamic simulations (MDS) to examine flavonoid behavior and discovered that they form highly organized supramolecular assemblies that physically interact with disordered regions of enzymatic proteins and can physically interlink multiple protein molecules. These flavonoid assemblies adopt secondary structural patterns like those found in proteins and nucleic acids, and they physically influence molecular movement and tertiary protein structure, thereby modulating the biochemical activities of a diverse range of enzymes. Moreover, in the presence of flavonoids, human cells are protected against injury caused by ultraviolet radiation. These findings unveil a novel form of biochemical regulation wherein small molecules can modulate the function of larger proteins by forming supramolecular assemblies which results in enhanced molecular and cellular resilience. Single Sentence SummaryMolecular dynamic simulations led to the discovery that flavonoid phytonutrients can self-assemble into highly ordered supramolecular structures that interact with enzymatic proteins, slow biochemical activities, and protect cells against injury.

biochemistry↗

Broad-Spectrum Coronavirus Inhibitors Discovered by Modeling Viral Fusion Dynamics

Broad-spectrum therapeutics capable of inhibiting SARS-CoV-2, its variants, and related coronaviruses hold promise in curbing the spread of COVID-19 and averting future pandemics. Here, we employed a multidisciplinary approach that included molecular dynamics simulation (MDS) and artificial intelligence (AI)-based docking predictions to identify potent inhibitors that target a conserved region within the SARS-CoV-2 spike protein that mediates membrane fusion by undergoing large-scale mechanical rearrangements. In silico binding screens honed in on this region, leading to the discovery of FDA-approved drugs and novel molecules predicted to disrupt spike protein conformational changes. These compounds significantly inhibited SARS-CoV-2 infection and blocked the entry of spike protein-bearing pseudotyped , {beta}, {gamma}, {delta} variants as well as SARS-CoV and MERS-CoV in cultured human ACE2-expressing cells. The optimized lead compound significantly inhibited SARS-CoV2 infection in mice when administered orally.

microbiology↗