Corrigendum to "Crystal structure of RNA helicase from Saint Louis encephalitis virus and discovery of its inhibitors" [Genes Dis 10 (2023) 389-392].

[This corrects the article DOI: 10.1016/j.gendis.2022.07.001.].

Facile and green fabrication of tumor- and mitochondria-targeted AIEgen-protein nanoparticles for imaging-guided photodynamic cancer therapy.

In recent years, aggregation-induced emission (AIE)-active materials have been emerging as a promising means for bioimaging and phototherapy. However, the majority of AIE luminogens (AIEgens) need to be encapsulated into versatile nanocomposites to improve their biocompatibility and tumor targeting. Herein, we prepared a tumor- and mitochondria-targeted protein nanocage by the fusion of human H-chain ferritin (HFtn) with a tumor homing and penetrating peptide LinTT1 using genetic engineering technology. The LinTT1-HFtn could serve as a nanocarrier to encapsulate AIEgens via a simple pH-driven disassembly/reassembly process, thereby fabricating the dual-targeting AIEgen-protein nanoparticles (NPs). The as designed NPs exhibited an improved hepatoblastoma-homing property and tumor penetrating ability, which is favorable for tumor-targeted fluorescence imaging. The NPs also presented a mitochondria-targeting ability, and efficiently generated reactive oxygen species (ROS) upon visible light irradiation, making them valuable for inducing efficient mitochondrial dysfunction and intrinsic apoptosis in cancer cells. In vivo experiments demonstrated that the NPs could provide the accurate tumor imaging and dramatic tumor growth inhibition with minimal side effects. Taken together, this study presents a facile and green approach for fabrication of tumor- and mitochondria-targeted AIEgen-protein NPs, which can serve as a promising strategy for imaging-guided photodynamic cancer therapy. STATEMENT OF SIGNIFICANCE: AIE luminogens (AIEgens) show strong fluorescence and enhanced ROS generation in the aggregate state, which would facilitate the image-guided photodynamic therapy [12-14]. However, the major obstacles that hinder biological applications are their lack of hydrophilicity and selective targeting [15]. To address this issue, this study presents a facile and green approach for the fabrication of tumor­ and mitochondria­targeted AIEgen-protein nanoparticles via a simple disassembly/reassembly of the LinTT1 peptide-functionalized ferritin nanocage without any harmful chemicals or chemical modification. The targeting peptide-functionalized nanocage not only restricts the intramolecular motion of AIEgens leading to enhanced fluorescence and ROS production, but also confers good targeting to AIEgens.

Crystal structure of the Ilheus virus helicase: implications for enzyme function and drug design.

BACKGROUND: The Ilheus virus (ILHV) is an encephalitis associated arthropod-borne flavivirus. It was first identified in Ilheus City in the northeast Brazil before spreading to a wider geographic range. No specific vaccines or drugs are currently available for the treatment of ILHV infections. The ILHV helicase, like other flavivirus helicases, possesses 5'-triphosphatase activity. This allows it to perform ATP hydrolysis to generate energy as well as sustain double-stranded RNA's unwinding during ILHV genome replication. Thus, ILHV helicase is an ideal target for inhibitor design. RESULTS: We determined the crystal structure of the ILHV helicase at 1.75-Å resolution. We then conducted molecular docking of ATP-Mn2+ to the ILHV helicase. Comparisons with related flavivirus helicases indicated that both the NTP and the RNA-ILHV helicase binding sites were conserved across intra-genus species. This suggested that ILHV helicase adopts an identical mode in recognizing ATP/Mn2+. However, the P-loop in the active site showed a distinctive conformation; reflecting a different local structural rearrangement. ILHV helicase enzymatic activity was also characterized. This was found to be relatively lower than that of the DENV, ZIKV, MVE, and ALSV helicases. Our structure-guided mutagenesis revealed that R26A, E110A, and Q280A greatly reduced the ATPase activities. Moreover, we docked two small molecule inhibitors of DENV helicase (ST-610 and suramin) to the ILHV helicase and found that these two molecules had the potential to inhibit the activity of ILHV helicase as well. CONCLUSION: High-resolution ILHV helicase structural analysis demonstrates the key amino acids of ATPase activities and could be useful for the design of inhibitors targeting the helicase of ILHV.

Liver injury in COVID-19: A minireview.

Coronavirus disease 2019 (COVID-19), caused by infection with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has escalated into a global tragedy afflicting human health, life, and social governance. Through the increasing depth of research and a better understanding of this disease, it has been ascertained that, in addition to the lungs, SARS-CoV-2 can also induce injuries to other organs including the liver. Liver injury is a common clinical manifestation of COVID-19, particularly in severe cases, and is often associated with a poorer prognosis and higher severity of COVID-19. This review focuses on the general existing information on liver injury caused by COVID-19, including risk factors and subpopulations of liver injury in COVID-19, the association between preexisting liver diseases and the severity of COVID-19, and the potential mechanisms by which SARS-CoV-2 affects the liver. This review may provide some useful information for the development of therapeutic and preventive strategies for COVID-19-associated liver injury.