Design and Evaluation of a Novel Peptide-Drug Conjugate Covalently Targeting SARS-CoV-2 Papain-like Protease.

Coronavirus disease 2019 (COVID-19) pandemic, a global health threat, was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 papain-like cysteine protease (PLpro) was recognized as a promising drug target because of multiple functions in virus maturation and antiviral immune responses. Inhibitor GRL0617 occupied the interferon-stimulated gene 15 (ISG15) C-terminus-binding pocket and showed an effective antiviral inhibition. Here, we described a novel peptide-drug conjugate (PDC), in which GRL0617 was linked to a sulfonium-tethered peptide derived from PLpro-specific substrate LRGG. The EM-C and EC-M PDCs showed a promising in vitro IC50 of 7.40 ± 0.37 and 8.63 ± 0.55 µM, respectively. EC-M could covalently label PLpro active site C111 and display anti-ISGylation activities in cellular assays. The results represent the first attempt to design PDCs composed of stabilized peptide inhibitors and GRL0617 to inhibit PLpro. These novel PDCs provide promising opportunities for antiviral drug design.

An overview of the safety, clinical application and antiviral research of the COVID-19 therapeutics.

Since a novel coronavirus pneumonia outbreak in late December 2019, coronavirus disease -19 (COVID-19) epidemic has gradually spread worldwide, becoming a major public health event. No specific antivirals are currently available for COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The treatments for COVID-19 are mainly based on the experiences of similar virus such SARS-CoV, MERS-CoV, HIV and influenza viruses. Scientists have taken great efforts to investigate the effective methods for the treatment of COVID-19. Up to now, there are over 1000 clinical studies for COVID-19 all over the world. In this article, we reviewed the current options for COVID-19 therapy including small molecules such as Remdesivir, Favipiravir, Lopinavir/Ritonavir etc, peptide inhibitors of ACE2, Traditional Chinese Medicines and Biologics such as SARS-CoV-2-specific neutralizing antibodies, mesenchymal stem cells and vaccines etc. Meanwhile, we systematically reviewed their clinical safety, clinical applications and progress of antiviral researches. The therapeutic effect of these antiviral drugs is summarized and compared, hoping to provide some ideas for clinical options of COVID-19 treatment and also provide experiences for the life-threatening virus diseases in the future.

Electroacupuncture ameliorates cardiopulmonary bypass induced apoptosis in lung via ROS/Nrf2/NLRP3 inflammasome pathway.

AIMS: Electroacupuncture (EAc) has a pulmonary protective effect during cardiopulmonary bypass (CPB), but its molecular mechanisms including inflammasome activation signaling pathways remains unclear. MATERIALS AND METHODS: Male Sprague Dawley rats were divided into control, CPB + EAc and CPB groups. Lung injury model was developed by CPB treatment and EAc (2/100 Hz) was carried out before CPB in the CPB + EAc group. Lung tissues were collected at two time points (0.5 h; 2 h) to determine cytokines release by ELISA kits, and protein expressions by Western blot. Serum collected at two time points (0.5 h; 2 h) from CPB and CPB + EAc treated groups were used in NR8383 cells to confirm the effect of EAc. KEY FINDINGS: CPB significantly increased the inflammatory mediators, histological damage and expression of inflammasome related protein and apoptosis, when compared with control group. The level of tumor necrosis factor-α(TNF-α), interleukin (IL)-18 and IL-1ß in the CPB + EAc treated group was significantly decreased along with histological changes compared to CPB. Moreover, EAc inhibited the activation of Nod like receptor protein-3 (NLRP3) inflammasome complex, caspase-8 and activated NF-E2-related factor 2 (p-Nrf2). In addition, serum from the CPB + EAc group prevented CPB induced activation of inflammasome and related mediators, reducing ROS generation and apoptosis in NR8383 macrophages. SIGNIFICANCE: These findings indicate that EAc had a critical anti-apoptotic role by suppression of ROS/Nrf2/NLRP3 inflammasome pathway. EAc might be a possible therapeutic treatment for CPB-induced acute lung injury.

Surface Coordination of Black Phosphorus with Modified Cisplatin.

Black phosphorus (BP) is a two-dimensional (2D) nanomaterial with high charge-carrier mobility, a tunable direct bandgap, and a unique in-plane anisotropic structure; however, the easiness of BP oxidation into P xO y species in ambient conditions largely limits its applications. In this study, modified cisplatin-Pt-NO3 [Pt(NH3)2(NO3)2] is used for surface coordination with BP nanosheets to generate Pt@BP, which maintains the surface morphology and properties of BP nanosheets for more than 24 h in ambient conditions. In addition, Pt@BP interacts with DNA both in vitro and in cell. Pt@BP shows a good cellular uptake rate and significantly increases the drug sensitivity of cisplatin-resistant cancer cell lines (A2780 and HepG2) compared with unmodified cisplatin. Our study is the first attempt to stabilize bare BP with cationic cisplatin species, and the generated Pt@BP could be used for potential synergistic photothermal/chemotherapy of cisplatin-resistant cancer.

Black Phosphorus Nanosheets Passivation Using a Tripeptide.

In the past several years, 2D black phosphorus (BP) has captured the research community's interest because of its unique electronic, photonic, and mechanical properties. However, the intrinsic instability of BP limits its preservation and practical application. Despite kinds of BP passivation strategies being well-documented, the use of metal ligand coordination or polymer modification may have potential long-term detrimental effects on human bodies. Here, a tailored tripeptide Fmoc-Lys-Lys-Phe (Fmoc-KKF) is synthesized for surface modification of BP nanosheets. Compared with bare BP with rapid degradation, the BP@FKK complex exhibits excellent stability, thereby significantly increasing the life span. Significantly, the BP@FKK shows favorable cell compatibility and enhanced cellular uptake compared to the bare BP.

Protective Effects of Acupuncture in Cardiopulmonary Bypass-Induced Lung Injury in Rats.

Acute lung injury caused by cardiopulmonary bypass (CPB) increases the mortality after cardiac surgery. Our previous clinical study suggested that electroacupuncture (EAc) has a protective effect during CPB, but the mechanism was unclear. So, we design this study to investigate the effects of EAc on CPB-induced lung injury and the underlying mechanism. Male Sprague Dawley rats were randomly divided into control, CPB, and CPB + EAc groups. A lung injury model was created by CPB surgery to serve as the CPB group, and EAc (2/100 Hz) was used before CPB in the CPB + EAc group. Lung tissue was collected at 0.5, 1, and 2 h after CPB. Pulmonary malondialdehyde (MDA) concentrations as well as superoxide dismutase (SOD), myeloperoxidase (MPO), and caspase-3 activity were determined. c-Jun N-terminal kinase (JNK), ERK, p38 and cleaved caspase 3 in the lung were analyzed by western blotting. A549 cells were treated by rat serum from the CPB and CPB + EAc groups, and cleaved caspase-3 activity was detected by fluorescent immunohistochemistry. CPB significantly increased the MPO activity, MDA content, apoptosis, caspase-3 activity, and phosphorylated p38 but decreased SOD activity compared with the control group. EAc significantly increased SOD activity at 0.5 and 2 h (p < 0.01 vs CPB) and reduced CPB-induced histological changes, MPO activity at 1 and 2 h (p < 0.05 vs CPB), MDA content at 2 h (p < 0.05 vs CPB), caspase-3 activity at 1 h (p < 0.05 vs CPB), and phosphorylated p38 and JNK at 0.5 h after CPB. The serum from the CPB group increased more positive staining cells of cleaved caspase-3 than that from the CPB + EAc group. EAc reversed the CPB-induced lung inflammation, oxidative damage, and apoptosis; the mechanism may involve decreased phosphorylation of p38 along with caspase-3 activity and activation.

SiRNA Delivery with PEGylated Graphene Oxide Nanosheets for Combined Photothermal and Genetherapy for Pancreatic Cancer.

Since the successful exfoliation of graphene from graphite in 2004, graphene and graphene oxide (GO) have been considered the most promising two-dimensional (2D) nanomaterials with distinguished physical and chemical characteristics and have attracted great attention in many different fields. Graphene oxide is well-known for its distinct physiochemical properties and shows only minimal cytotoxicity compared to carbon nanotubes. Until now, only limited efforts have been invested in utilizing GO for gene therapy in pancreatic cancer treatments. In this study, we utilized multi-functionalized monolayer GO as a gene delivery system to efficiently co-deliver HDAC1 and K-Ras siRNAs (small interfering RNAs targeting the HDAC1 gene and the G12C mutant K-Ras gene, respectively) to specifically target pancreatic cancer cells MIA PaCa-2. The systematic mechanistic elucidation of the dual gene silencing effects indicated the inactivation of both the HDAC1 and the K-Ras gene, thereby causing apoptosis, proliferation inhibition and cell cycle arrest in treated MIA PaCa-2 cells. The synergistic combination of gene silencing and NIR light thermotherapy showed significant anticancer efficacy, inhibiting in vivo tumor volume growth by >80%. Furthermore, GO can be metabolized in the mouse model within a reasonable period of time without obvious side effects. Based on preliminary in vivo application, this study for the first time indicates the promising potential of functionalized GO as a vehicle for gene therapy delivery with low toxicity for the treatment of pancreatic adenocarcinoma.

Chuanxiong-type preparations for acute ischemic stroke.

BACKGROUND: Stroke, 88% of which are ischemic, is a common cause of death and disability all over the world. Chuanxiong has been reported to be beneficial in treating stroke. However, the strength of evidence to support its use is unclear. OBJECTIVES: To assess the safety and efficacy of chuanxiong for acute ischemic stroke. SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register (last searched January 2008), the Chinese Stroke Trials Register (last searched December 2007), the trials register of the Cochrane Complementary Medicine Field (last searched December 2007), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2007), MEDLINE (1966 to December 2007), EMBASE (1980 to December 2007), CNKI (1979 to December 2007), AMED (1985 to December 2007) and CBM-disc (1979 to December 2007). We also handsearched appropriate journals and relevant conference proceedings and searched ongoing trials and research registers. SELECTION CRITERIA: All randomised controlled trials comparing the clinical outcomes of chuanxiong with placebo or no treatment in patients with acute ischemic stroke (within 14 days of onset). DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials for inclusion, four review authors interviewed study authors to confirm randomisation, and two review authors assessed trial quality, extracted and analysed data. MAIN RESULTS: Two trials involving 161 participants were included. Both trials were of low quality. Neither of the trials reported the mortality rate or dependency of the participants and no reliable evidence is available in this review. AUTHORS' CONCLUSIONS: In the two poor quality trials published, there is insufficient evidence to suggest any clinical recommendations. Well-designed and performed high-quality trials are needed.

Identification of small molecules rescuing fragile X syndrome phenotypes in Drosophila.

Fragile X syndrome is caused by the functional loss of the fragile X mental retardation 1 (FMR1) gene. Deletion of the FMR1 ortholog in Drosophila melanogaster (Fmr1) recapitulates many phenotypes associated with fragile X syndrome. We have discovered that Fmr1 mutant Drosophila die during development when reared on food containing increased levels of glutamate, which is consistent with the theory that FMR1 loss results in excess glutamate signaling. Using this lethal phenotype, we screened a chemical library of 2,000 compounds and identified nine molecules that rescued the lethality, including three that implicate the GABAergic inhibitory pathway. Indeed, GABA treatment rescued several known Fmr1 mutant phenotypes in flies, including mushroom bodies defects, excess Futsch translation and abnormal male courtship behavior. These data are consistent with GABAergic inhibition of the enhanced excitatory pathway in fragile X syndrome. In addition, our screen reveals that the muscarinic cholinergic receptors may have a role in fragile X syndrome in parallel to the GABAergic pathway. These results point to potential therapeutic approaches for treating fragile X syndrome.