Advanced virtual screening enables the discovery of a host-targeting and broad-spectrum antiviral agent.

We employed an advanced virtual screening (AVS) approach to identify potential inhibitors of human dihydroorotate dehydrogenase (DHODH), a validated target for development of broad-spectrum antivirals. We screened a library of 495118 compounds and identified 495 compounds that exhibited better binding scores than the reference ligands involved in the screening. From the top 100 compounds, we selected 28 based on their consensus docking scores and structural novelty. Then, we conducted in vitro experiments to investigate the antiviral activity of selected compounds on HSV-1 infection, which is susceptible to DHODH inhibitors. Among the tested compounds, seven displayed statistically significant antiviral effects, with Comp 19 being the most potent inhibitor. We found that Comp 19 exerted its antiviral effect in a dose-dependent manner (IC50 = 1.1 µM) and exhibited the most significant antiviral effect when added before viral infection. In the biochemical assay, Comp 19 inhibited human DHODH in a dose-dependent manner with the IC50 value of 7.3 µM. Long-timescale molecular dynamics simulations (1000 ns) revealed that Comp 19 formed a very stable complex with human DHODH. Comp 19 also displayed broad-spectrum antiviral activity and suppressed cytokine production in THP-1 cells. Overall, our study provides evidence that AVS could be successfully implemented to discover novel DHODH inhibitors with broad-spectrum antiviral activity.

A novel human tau knock-in mouse model reveals interaction of Abeta and human tau under progressing cerebral amyloidosis in 5xFAD mice.

BACKGROUND: Hyperphosphorylation and intraneuronal aggregation of the microtubule-associated protein tau is a major pathological hallmark of Alzheimer's disease (AD) brain. Of special interest is the effect of cerebral amyloid beta deposition, the second main hallmark of AD, on human tau pathology. Therefore, studying the influence of cerebral amyloidosis on human tau in a novel human tau knock-in (htau-KI) mouse model could help to reveal new details on their interplay. METHODS: We studied the effects of a novel human htau-KI under fast-progressing amyloidosis in 5xFAD mice in terms of correlation of gene expression data with human brain regions, development of Alzheimer's-like pathology, synaptic transmission, and behavior. RESULTS: The main findings are an interaction of human beta-amyloid and human tau in crossbred 5xFADxhtau-KI observed at transcriptional level and corroborated by electrophysiology and histopathology. The comparison of gene expression data of the 5xFADxhtau-KI mouse model to 5xFAD, control mice and to human AD patients revealed conspicuous changes in pathways related to mitochondria biology, extracellular matrix, and immune function. These changes were accompanied by plaque-associated MC1-positive pathological tau that required the htau-KI background. LTP deficits were noted in 5xFAD and htau-KI mice in contrast to signs of rescue in 5xFADxhtau-KI mice. Increased frequencies of miniature EPSCs and miniature IPSCs indicated an upregulated presynaptic function in 5xFADxhtau-KI. CONCLUSION: In summary, the multiple interactions observed between knocked-in human tau and the 5xFAD-driven progressing amyloidosis have important implications for future model development in AD.

Viromers as carriers for mRNA-mediated expression of therapeutic molecules under inflammatory conditions.

Therapeutic mRNA delivery has been described for several treatment options, such as vaccination and cancer immunotherapy. However, mRNA delivery has to be accompanied by the development and testing of suitable carrier materials due to the instability of mRNAs in human body fluids. In the present study, we investigated the ability of recently developed Viromers to deliver mRNAs in a classical inflammatory setting. We tested mRNAs coding for active components of preclinical (7ND) and approved (sTNF-RII) biologics, in vitro and in vivo. 7ND is an established blocker of the CCR2 axis, whereas sTNF-RII is the active component of the approved drug Etanercept. Viromer/mRNA complexes were transfected into murine macrophages in vitro. Protein expression was analysed using Luciferase reporter expression and mainly identified in spleen, blood and bone marrow in vivo. 7ND-mRNA delivery led to efficient blockage of monocytes infiltration in thioglycolate-induced peritonitis in mice, underlining the ability of Viromers to deliver a therapeutic mRNA cargo without overt toxicity. Therefore, we propose Viromer-based mRNA delivery as a suitable option for the treatment of inflammatory disorders beyond infusion of biological molecules.