Discovery of Pyroptosis-inducing Drugs and Antineoplastic Activity Based on the ROS/ER Stress/Pyroptosis Axis.

BACKGROUND: Pyroptosis, a cell death process triggered by chemotherapy drugs, has emerged as a highly promising mechanism for combating tumors in recent years. As the lead of new drugs, natural products play an important role in the discovery of anticancer drugs. Compared to other natural products, the medicine food homologous natural products (MFHNP) exhibit a superior safety profile. Among a series of MFHNP molecular skeletons, this study found that only benzylideneacetophenone (1) could induce cancer cell pyroptosis. However, the anti-cancer activity of 1 remains to be improved. AIMS: This study aimed to find a pyroptosis inducer with highly effective antitumor activity by modifying the chalcone structure. METHODS: To examine the effect of the Michael receptor in compound 1 on the induction of pyroptosis, several analogs were synthesized by modifying the Michael acceptor. Subsequently, the anticancer activity was tested by MTT assay, and morphological indications of pyroptosis were observed in human lung carcinoma NCI-H460 and human ovarian cancer CP-70 cell lines. Furthermore, to improve the activity of the chalcone skeleton, the anticancer group 3,4,5- trimethoxyphenyl was incorporated into the phenyl ring. Subsequently, compounds 2-22 were designed, synthesized, and screened in human lung cancer cells (NCI-H460, H1975, and A549). Additionally, a quantitative structure-activity relationship (QSAR) model was established using the eXtreme Gradient Boosting (XGBoost) machine learning library to identify the pharmacophore. Furthermore, both in vitro and in vivo experiments were conducted to investigate the molecular mechanisms of pyroptosis induced by the active compound. RESULTS: α, ß-unsaturated ketone was the functional group of the chalcone skeleton and played a pivotal role in inducing cancer cell pyroptosis. QSAR models showed that the regression coefficients (R2) were 0.992 (A549 cells), 0.990 (NCI-H460 cells), and 0.998 (H1975 cells). Among these compounds, compound 7 was selected to be the active compound. Moreover, compound 7 was found to induce pyroptosis in lung cancer cells by upregulating the expression of CHOP by increasing the ROS level. Furthermore, it effectively suppressed the growth of lung cancer xenograft tumors. CONCLUSION: Compound 7 exhibits antineoplastic activity by regulating the ROS/ER stress/pyroptosis axis and is a kind of promising pyroptosis inducer.

Assembly of an active microbial consortium by engineering compatible combinations containing foreign and native biocontrol bacteria of kiwifruit.

Assembling functional bacterial biocontrol consortia is expected to expand the scope and efficiency of biocontrol agents. Generally, bacterial interspecies interactions lead to incompatibility events, as bacteria can produce antibacterial compounds and/or assemble contact-dependent killing (CDK) devices. Here, we aimed to assemble a bacterial consortium comprising Lysobacter enzymogenes OH11 and Bacillus safensis ZK-1 for the synergistic control of bacterial and fungal diseases of kiwifruit. ZK-1, a native kiwifruit biocontrol bacterium, is effective against Pseudomonas syringae pv. actinidiae (Psa) that causes bacterial kiwifruit canker, but has weak antifungal activity. OH11 is a foreign kiwifruit biocontrol agent with strong antifungal activity. While OH11 was unable to produce anti-Gram-negative metabolites, this strain could utilize type IV secretion system as an antibacterial CDK weapon. We first observed that OH11 could inhibit growth of ZK-1 by generating diffusible anti-Gram-positive antibiotic WAP-8294A2, whereas ZK-1 failed to generate diffusible antibacterial compound to inhibit growth of OH11. To disrupt this interspecies incompatibility, we generated a transgenic OH11-derived strain, OH11W, by deleting the WAP-8294A2 biosynthetic gene and found that OH11W did not kill ZK-1. We further observed that when OH11W and ZK-1 were co-inoculated on agar plates, no CDK effect was observed between them, whereas co-culture of OH11W or ZK-1 with Psa on agar plates resulted in Psa killing, suggesting L. enzymogenes and B. safensis assemble antibacterial CDK weapons against bacterial pathogens, and these CDK weapons did not affect the compatibility between OH11W and ZK-1. Based on these findings, we assembled an OH11W/ZK-1 dependent consortium that was shown to be functional in controlling bacterial canker and several representative fungal diseases of kiwifruit.

Design, synthesis and evaluation of monoketene compounds as novel potential Parkinson's disease agents by suppressing ER stress via AKT.

Curcumin is identified that it has the potential to treat Parkinson's disease (PD), but its instability limits its further application in clinic. The mono-carbonyl analogs of curcumin (MACs) with diketene structure can effectively improve its stability, but it is highly toxic. In the present study, a less cytotoxic and more stable monoketene MACs skeleton S2 was obtained, and a series of monoketene MACs were synthesized by combining 4-hydroxy-3­methoxy groups of curcumin. In the 6-OHDA-induced PD's model in-vitro, some compounds exhibited significant neurotherapeutic effect. The quantitative structure-activity relationship (QSAR) model established by the random forest algorithm (RF) for the cell viability rate of above compounds showed that the statistical results are good (R2 = 0.883507), with strong reliability. Among all compounds, the most active compound A4 played an important role in neuroprotection in the PD models both in vitro and in vivo by activating AKT pathway, and then inhibiting the apoptosis of cells caused by endoplasmic reticulum (ER) stress. In the PD model in-vivo, compound A4 significantly improved survival of dopaminergic neurons and the contents of neurotransmitters. It also enhanced the retention of nigrostriatal function which was better than the effect in the mice treated by Madopar, a classical clinical drug for PD. In summary, we screened out the compound A4 with high stability, less cytotoxic monoketene compounds. And these founding provide evidence that the compound A4 can protect dopaminergic neurons via activating AKT and subsequently suppressing ER stress in PD.

Synthesis and Characterization of Solution-Processible Donor-Acceptor Electrochromic Conjugated Copolymers Based on Quinoxalino[2',3':9,10]phenanthro[4,5-abc]phenazine as the Acceptor Unit.

Donor-acceptor (D-A) type conjugated polymers are of high interest in the field of electrochromism. In this study, three novel conjugated copolymers (PBPE-1, PBPE-2 and PBPE-3) based on quinoxalino[2',3':9,10]phenanthro[4,5-abc]phenazine (A) as the acceptor unit and 4,8-bis((2-octyldodecyl)oxy)benzo[1,2-b:4,5-b']dithiophene (D1) and 3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine (ProDOT-decyl2, D2) as the donor units with different donor-to-acceptor ratios were successfully synthesized through Stille coupling polymerization. The polymers were then characterized by cyclic voltammetry (CV), fourier transform infrared (FT-IR) spectoscopy, X-ray photoelectron spectroscopy (XPS), spectroelectrochemistry, thermogravimetry (TG), electrochromic switching and colorimetry. Optical band gap values were calculated as 1.99 eV, 2.02 eV and 2.03 eV, respectively. The three copolymers have good solubility, distinct redox peaks, wide absorption spectra, good thermal stabilities, bright color changes and significant electrochromic switching properties. Compared to the other two copolymers, the PBPE-3 film exhibited high coloration efficiency values of 513 cm2·C-1 at 504 nm and 475 cm2·C-1 at 1500 nm. The films have the advantage of exhibiting cathodic and anodic coloration.

Unlocking the bacterial contact-dependent antibacterial activity to engineer a biocontrol alliance of two species from natural incompatibility to artificial compatibility.

Plant growth-promoting rhizobacteria (PGPR) contain various biocontrol bacteria with broad-spectrum antimicrobial activity, and their single species has been extensively applied to control crop diseases. The development of complex biocontrol community by mixing two or more PGPR members together is a promising strategy to enlarge the efficacy and scope of biocontrol. However, an effective method to assess the natural compatibility of PGPR members has not yet been established to date. Here, we developed such a tool by using the bacterial contact-dependent antibacterial activity (CDAA) as a probe. We showed that the CDAA events are common in two-species interactions in the four selected representative PGPRs, represented by the incompatible interaction of Lysobacter enzymogenes strain OH11 (OH11) and Lysobacter antibioticus strain OH13 (OH13). We further showed that the CDAA between OH11 and OH13 is jointly controlled by a contact-dependent killing device, called the type IV secretion system (T4SS). By deleting the respective T4SS synthesis genes, the T4SS in both strains was co-inactivated and this step unlocked  their natural CDAA, resulting in an engineered, compatible mutant alliance that co-displayed antibacterial and antifungal activity. Therefore, this study reveals that releasing bacterial CDAA is effective to rationally engineer the biocontrol community.

Effects of Carbopol® 934 proportion on nanoemulsion gel for topical and transdermal drug delivery: a skin permeation study.

Nanoemulsions (NEs) are used as transdermal drug delivery systems for systematic therapeutic purposes. We hypothesized that the skin permeation profile of an NE could be modulated by incorporating it into a hydrogel containing differing proportions of thickening agent. The objectives of this study were as follows: 1) to determine the stability and skin irritability of NE gels (NGs) containing 1%, 2%, and 3% (w/w) Carbopol® 934 (CP934) (termed NG1, NG2, and NG3, respectively); 2) to compare the skin permeation profiles and drug deposition patterns of the NGs; and 3) to visualize the drug delivery routes of the NGs. Terbinafine and citral were incorporated into the NGs as model drugs. Ex vivo skin permeation tests indicated that the percutaneous flux rates of terbinafine decreased in the order NE (215 µg/cm2) > NG1 (213 µg/cm2) > NG2 (123 µg/cm2) > NG3 (74.3 µg/cm2). The flux rates of citral decreased in the order NE (1,026 µg/cm2) > NG1 (1,021 µg/cm2) > NG2 (541 µg/cm2) > NG3 (353 µg/cm2). The NGs accumulated greater amounts of the drugs in the stratum corneum and less in the epidermis/dermis than did the NE (P<0.05) over a period of 12 h. Laser scanning confocal microscopy indicated that the NGs altered the main drug delivery routes from skin appendages to intercellular paths. Histological images suggested that perturbations to the skin structure, specifically the size of the epidermal intercellular spaces and the separation distance of dermal collagen bundles, could be significantly minimized by increasing the proportion of CP934. These results suggest that adjustments of the CP934 proportions can be used to modulate the skin permeation profiles of NGs for specific therapeutic purposes.