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In order to overcome the pandemic of COVID-19, messenger RNA (mRNA)-based vaccine has been extensively researched as a rapid and versatile strategy. Herein, we described the immunogenicity of mRNA-based vaccines for Beta and the most recent Omicron variants. The homologous mRNA-Beta and mRNA-Omicron and heterologous Ad5-nCoV plus mRNA vaccine exhibited high-level cross-reactive neutralization for Beta, original, Delta, and Omicron variants. It indicated that the COVID-19 mRNA vaccines have great potential in the clinical use against different SARS-CoV-2 variants.

The current COVID-19 epidemic has greatly accelerated the application of mRNA technology to our real world, and during this battle mRNA has proven it's unique advantages compared to traditional biopharmaceutical and vaccine technology. In order to overcome mRNA instability in human physiological environments, mRNA chemical modifications and nano delivery systems are two key factors for their in vivo applications. In this review, we would like to summarize the challenges for clinical translation of mRNA-based therapeutics, with an emphasis on recent advances in innovative materials and delivery strategies. The nano delivery systems include lipid delivery systems (lipid nanoparticles and liposomes), polymer complexes, micelles, cationic peptides and so on. The similarities and differences of lipid nanoparticles and liposomes are also discussed. In addition, this review also present the applications of mRNA to other areas than COVID-19 vaccine, such as infectious diseases, tumors, and cardiovascular disease, for which a variety of candidate vaccines or drugs have entered clinical trials. Furthermore, mRNA was found that it might be used to treat some genetic disease, overcome the immaturity of the immune system due to the small fetal size in utero, treat some neurological diseases that are difficult to be treated surgically, even be used in advancing the translation of iPSC technology et al. In short, mRNA has a wide range of applications, and its era has just begun., Graphical abstract Image 1

3'-Geranyl-mono-substituted chalcone Xanthoangelol (1b), a chalcone derivative, was previously reported to show selective cytotoxicity against human chronic myelogenous leukemia K562 cells with a half-maximal inhibitory concentration (IC50) of 3.98 μM. In the present study, we investigated the molecular mechanism underlying the cytotoxicity of 1b in K562 cells. Treatment with compound 1b caused K562 cells to adopt a typical apoptotic morphology. Flow cytometric analysis also confirmed the presence of an apoptotic cell population following treatment of Annexin-V-FITC and propidium iodide (PI) double-labeled K562 cells with 1b. Furthermore, we observed dissipation of the mitochondrial membrane potential, caspase-3 activation, and a reduction of the Bcl-2/Bax ratio in these cells, which suggest that the mitochondrial apoptotic pathway is induced by 1b in K562 cells. Collectively, our findings demonstrate that compound 1b notably induces mitochondrial-mediated apoptosis in K562 cells, which might have a potential anticancer activity.

Three series of prenylated and/or geranylated flavonoids were synthesized and evaluated for their α-glucosidase inhibitory activity. The 3',5'-digeranylated chalcone (16) was identified as a new α-glucosidase inhibitor whose activity (IC50=0.90 μM) was 50-fold more than that of acarbose (IC50=51.32 μM). Molecular docking studies revealed the existence of strong hydrophobic interaction and H-bonding between compound 16 and α-glucosidase's active site. The inhibitory mode analysis showed that 16 exhibited a competitive inhibitory mode.

Melanocortin 4 receptor (MC4R) is a key factor in regulating energy homeostasis, and null mutations occurring in the gene encoding MC4R cause severe early-onset morbid obesity in humans. Many obesity-causing mutations affecting MC4R clinically identified so far lead to failure of mutant receptors to shuttle to the plasma membrane. In this study, we show that a novel human MC4R antagonist, Ipsen 17, acted as an pharmacological chaperone of human MCR4. As tested with 12 obesity-causing human MC4R variants including S58C, E61K, N62S, I69T, P78L, C84R, G98R, T162I, R165W, W174C, C271Y, and P299H, Ipsen 17 was found to be the most universal pharmacological chaperone of MC4R reported so far because it can completely rescue nearly all mutant receptors (except P299H) with the highest potency (an EC50 value of approximately 10−8 M) and efficiency when compared with results for other tested pharmacological chaperones of MC4R including ML00253764, PBA, MTHP, PPPone, MPCI, DCPMP, and NBP described in the literature. Once restored to the plasma membrane, defective human MC4R variants responded to α-MSH stimulation with an EC50 value of approximately 10−8 M and displayed dramatically enhanced signaling ability (except for G98R) in a mutant-specific efficacy and potency profile. Taken together, these results indicate that Ipsen 17 represents a candidate for the development of a targeted treatment of severe early-onset morbid obesity caused by a large subset of inherited mutations in the human MC4R gene.

Four natural chalcones bearing prenyl or geranyl groups, i.e., bavachalcone (1a), xanthoangelol (1b), isobavachalcone (1c), and isoxanthoangelol (1d) were synthesized by using a regio-selective iodination and the Suzuki coupling reaction as key steps. The first total synthesis of isoxanthoangelol (1d) was achieved in 36% overall yield. A series of diprenylated and digeranylated chalcone analogs were also synthesized by alkylation, regio-selective iodination, aldol condensation, Suzuki coupling and [1,3]-sigmatropic rearrangement. The structures of the 11 new derivatives were confirmed by 1H NMR, 13C NMR and HRMS. The anticancer activity of these new chalcone derivatives against human tumor cell line K562 were evaluated by MTT assay in vitro. SAR studies suggested that the 5′-prenylation/geranylation of the chalcones significantly enhance their cytotoxic activity. Among them, Bavachalcone (1a) displayed the most potent cytotoxic activity against K562 with IC50 value of 2.7 μM. The morphology changes and annexin-V/PI staining studies suggested that those chalcone derivatives inhibited the proliferation of K562 cells by inducing apoptosis.