MYST family histone acetyltransferases regulate reproductive diapause initiation.

Histone acetylation, a crucial epigenetic mechanism, has been suggested to play a role in diapause regulation, but this has not been confirmed through gene loss-of-function studies. In this work, we investigated the involvement of MYST family genes, which are key writers of histone acetylation, in initiating reproductive diapause using the cabbage beetle Colaphellus bowringi as a model. We identified C. bowringi orthologs of MYST, including Tip60, KAT6A, KAT7, and KAT8, from previous transcriptomes. Analyses of phylogenetic trees and protein domains indicated that these MYST proteins are structurally conserved across animal species. Expression of these MYST genes was found to be enriched in heads and ovaries of C. bowringi. Under reproductive photoperiod conditions, RNAi targeting MYST genes, especially KAT8, suppressed ovarian growth and yolk deposition, resembling the characteristics of diapausing ovaries. Additionally, KAT8 knockdown led to the upregulation of diapause-related genes, such as heat shock proteins and diapause protein 1, and the emergence of diapause-like guts. Moreover, KAT8 knockdown reduced the expression of a crucial enzyme involved in juvenile hormone (JH) biosynthesis, likely due to decreased H4K16ac levels. Consequently, our findings suggest that MYST family genes, specifically KAT8, influence the JH signal, thereby regulating the initiation of reproductive diapause.

Assembly of an iron-based complex into a metal-organic framework: a space confinement strategy for isolation of mono-iron complexes to protect from dimerization.

Non-heme mononuclear iron complexes, especially when supported by tripodal tetradentate ligands, show promising C-H bond activation efficiency in catalytic reactions. Nevertheless, they intrinsically decay readily to their dinuclear form, and the dimerization process is inevitable in homogenous solution, which dramatically hinders their further application. Hence, we demonstrate that the mononuclear iron complex [(TPA)FeII-2L]2+ (L = labile ligands, mainly solvent molecules) was successfully encapsulated in a highly robust metal-organic framework UiO-66 via a two-step "ship-in-a-bottle" strategy. The nearly perfect size matching of the octahedral cages of the host UiO-66 provides ideal space confinement for the guest complex to protect from dimerization and dramatically increases the mono-nuclear complex stability compared to its un-confined state. The successful encapsulation of [(TPA)FeII-2L]2+ in UiO-66 was verified thoroughly by spectroscopy, microscopy, N2 adsorption, and electrochemistry characterization techniques. This work shows that encapsulating an unstable molecular complex in MOFs via a two-step "ship-in-a-bottle" strategy highlights opportunities for extending the heterogenization of homogeneous complexes.

Trichodimerol inhibits inflammation through suppression of the nuclear transcription factor-kappaB/NOD-like receptor thermal protein domain associated protein 3 signaling pathway.

Excessive inflammation causes chronic diseases and tissue damage. Although there has been drug treatment, its side effects are relatively large. Searching for effective anti-inflammatory drugs from natural products has become the focus of attention. First isolated from Trichoderma longibraciatum, trichodimerol is a natural product with TNF inhibition. In this study, lipopolysaccharide (LPS)-induced RAW264.7 macrophages were used as a model to investigate the anti-inflammatory activity of trichodimerol. The results of nitric oxide (NO) detection, enzyme-linked immunosorbent assay (ELISA), and reactive oxygen species (ROS) showed that trichodimerol could reduce the production of NO, ROS, and the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α. Western blotting results showed that trichodimerol could inhibit the production of inflammatory mediators such as cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) and the protein expression of nuclear transcription factor-kappaB (NF-κB), p-IKK, p-IκB, Toll-like receptor 4 (TLR4), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), cysteinyl aspartate specific proteinase (Caspase)-1, and ASC, which indicated that trichodimerol may inhibit inflammation through the NF-κB and NLRP3 pathways. At the same time, molecular docking showed that trichodimerol can directly combine with the TLR4-MD2 complex. Hence, trichodimerol inhibits inflammation by obstructing the interaction between LPS and the TLR4-MD2 heterodimer and suppressing the downstream NF-κB and NLRP3 pathways.

N-Acetyldopamine Dimer Attenuates DSS-Induced Ulcerative Colitis by Suppressing NF-κB and MAPK Pathways.

Ulcerative Colitis (UC) is a major form of chronic inflammatory bowel disease of the colonic mucosa and exhibits progressive morbidity. There is still a substantial need of small molecules with greater efficacy and safety for UC treatment. Here, we report a N-acetyldopamine dimer (NADD) elucidated (2R,3S)-2-(3',4'-dihydroxyphenyl)-3-acetylamino-7-(N-acetyl-2″-aminoethyl)-1,4-benzodioxane, which is derived from traditional Chinese medicine Isaria cicadae, exhibits significant therapeutic efficacy against dextran sulfate sodium (DSS)-induced UC. Functionally, NADD treatment effectively relieves UC symptoms, including weight loss, colon length shortening, colonic tissue damage and expression of pro-inflammatory factors in pre-clinical models. Mechanistically, NADD treatment significantly inhibits the expression of genes in inflammation related NF-κB and MAPK signaling pathways by transcriptome analysis and western blot, which indicates that NADD inhibits the inflammation in UC might through these two pathways. Overall, this study identifies an effective small molecule for UC therapy.

Proliferatins suppress lipopolysaccharide-induced inflammation via inhibition of the NF-κB and MAPK signaling pathways.

Three previously undescribed polyketides [proliferatin A-C (1-3)] with anti-inflammatory activity were isolated from Fusarium proliferatum. 1-3 attenuated the production of inflammatory signal messengers including nitric oxide (NO), reactive oxygen species, proinflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß), as well as the related proteins nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Transcriptome analyses based on RNA-seq indicated the potential anti-inflammatory mechanism of 1-3 involved in the nuclear factor kappa-B (NF-κB) and mitogen activated protein kinases (MAPKs) signaling pathways. Experimental evaluation of the protein levels revealed that 1-3 can inhibit the phosphorylation of IκB kinase (IKK), the degradation of NF-κB Inhibitor-α (IκBα), the phosphorylation of nuclear factor-κB (NF-κB) and can reduce NF-κB transportation to the nucleus. Interestingly, 1-3 decreased the phosphorylation of MAPKs including p-p38, p-ERK, and p-JNK. Molecular docking models suggest that binding of 1-3 to TLR4-MD-2 complex may lead to inhibition of NF-κB and MAPK signaling pathways, which was confirmed in vitro by surface plasmon resonance (SPR) assays. 1-3 can thus constitute potential therapeutic candidates for the treatment of inflammation-associated diseases.

Investigation of the Anti-Inflammatory Activity of Fusaproliferin Analogues Guided by Transcriptome Analysis.

Background: Excessive inflammation results in severe tissue damage as well as serious acute or chronic disorders, and extensive research has focused on finding new anti-inflammatory hit compounds with safety and efficacy profiles from natural products. As promising therapeutic entities for the treatment of inflammation-related diseases, fusaproliferin and its analogs have attracted great interest. However, the underlying anti-inflammatory mechanism is still poorly understood and deserves to be further investigated. Methods: For the estimation of the anti-inflammatory activity of fusaproliferin (1) and its analogs (2-4) in vitro and in vivo, lipopolysaccharide (LPS)-induced RAW264.7 macrophages and zebrafish embryos were employed. Then, transcriptome analysis was applied to guide subsequent western blot analysis of critical proteins in related signaling pathways. Surface plasmon resonance assays (SPR) combined with molecular docking analyses were finally applied to evaluate the affinity interactions between 1-4 and TLR4 and provide a possible interpretation of the downregulation of related signaling pathways. Results: 1-4 significantly attenuated the production of inflammatory messengers, including nitric oxide (NO), reactive oxygen species (ROS), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß), as well as nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in LPS-induced RAW264.7 macrophages. Transcriptome analyses based on RNA-seq indicated the ability of compound 1 to reverse LPS stimulation and the nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPKs) signaling pathways contribute to the anti-inflammatory process. Experimental verification at the protein level revealed that 1 can inhibit the activation of inhibitor of NF-κB kinase (IKK), degradation of inhibitor of NF-κB (IκB), and phosphorylation of NF-κB and reduce nuclear translocation of NF-κB. 1 also decreased the phosphorylation of MAPKs, including p38, extracellular regulated protein kinases (ERK), and c-Jun N-terminal kinase (JNK). SPR assays and molecular docking results indicated that 1-4 exhibited affinity for the TLR4 protein with KD values of 23.5-29.3 µM. Conclusion: Fusaproliferin and its analogs can be hit compounds for the treatment of inflammation-associated diseases.

Aureonitol Analogues and Orsellinic Acid Esters Isolated from Chaetomium elatum and Their Antineuroinflammatory Activity.

Overexpression of various pro-inflammatory factors in microglial cells tends to induce neurodegenerative diseases, for which there is no effective therapy available. Aureonitol (1) and seven analogues, including six previously undescribed [elatumenol A-F (2-4, 6-8, respectively)], along with two new orsellinic acid esters [elatumone A and B (9 and 10)], were isolated from Chaetomium elatum. The structures of the compounds were established through comprehensive analysis of spectroscopic data, including high-resolution mass spectra and one- and two-dimensional NMR, and absolute configurations determined by the Mosher method, dimolybdenum tetraacetate-induced circular dichroism, and theoretical calculations including electronic circular dichroism and NMR. Metabolites 3, 4, 7, and 8 exhibited antineuroinflammatory activity by attenuating the production of inflammatory mediators, such as nitric oxide, interleukin-6, interleukin-1ß, tumor necrosis factor-α, and reactive oxygen species. Western blot results indicated 8 decreases the level of inducible nitric oxide synthase and cyclooxygenase-2 and suppresses the expression of Toll-like receptor 4 and nuclear factor kappa-B (NF-κB) as well as the phosphorylation of the inhibitor of NF-κB and p38 mitogen-activated protein kinases in lipopolysaccharide-activated BV-2 microglial cells.

Independent Microevolution Mediated by Mobile Genetic Elements of Individual Clostridium difficile Isolates from Clade 4 Revealed by Whole-Genome Sequencing.

Horizontal gene transfer of mobile genetic elements (MGEs) accounts for the mosaic genome of Clostridium difficile, leading to acquisition of new phenotypes, including drug resistance and reconstruction of the genomes. MGEs were analyzed according to the whole-genome sequences of 37 C. difficile isolates with a variety of sequence types (STs) within clade 4 from China. Great diversity was found in each transposon even within isolates with the same ST. Two novel transposons were identified in isolates ZR9 and ZR18, of which approximately one third to half of the genes showed heterogenous origins compared with the usual intestinal bacterial genes. Most importantly, catD, known to be harbored by Tn4453a/b, was replaced by aac(6') aph(2'') in isolates 2, 7, and 28. This phenomenon illustrated the frequent occurrence of gene exchanges between C. difficile and other enterobacteria with individual heterogeneity. Numerous prophages and CRISPR arrays were identified in C. difficile isolates of clade 4. Approximately 20% of spacers were located in prophage-carried CRISPR arrays, providing a new method for typing and tracing the origins of closely related isolates, as well as in-depth studies of the mechanism underlying genome remodeling. The rates of drug resistance were obviously higher than those reported previously around the world, although all isolates retained high sensitivity to vancomycin and metronidazole. The increasing number of C. difficile isolates resistant to all antibiotics tested here suggests the ease with which resistance is acquired in vivo. This study gives insights into the genetic mechanism of microevolution within clade 4. IMPORTANCE Mobile genetic elements play a key role in the continuing evolution of Clostridium difficile, resulting in the emergence of new phenotypes for individual isolates. On the basis of whole-genome sequencing analysis, we comprehensively explored transposons, CRISPR, prophage, and genetic sites for drug resistance within clade 4 C. difficile isolates with different sequence types. Great diversity in MGEs and a high rate of multidrug resistance were found within this clade, including new transposons, Tn4453a/b with aac(6') aph(2'') instead of catD, and a relatively high rate of prophage-carried CRISPR arrays. These findings provide important new insights into the mechanism of genome remodeling within clade 4 and offer a new method for typing and tracing the origins of closely related isolates.

Antitumor activities of biscoumarin and dihydropyran derivatives.

Rising worldwide cancer incidence and resistance to current anti-cancer drugs necessitate the need for new pharmaceutical compounds and drug delivery system. Two novel series of biscoumarin (1-4) and dihydropyran (5-16) derivatives were synthesized via a one-pot multicomponent condensation reaction and evaluated for their antitumor activity in vitro. The X-ray crystal structure analysis of four representative compounds 2, 7, 10 and 13 confirmed the structures of these compounds. Compounds 1-4 showed the most potent antitumor activity among the total 16 derivatives. More interestingly, preliminary mechanism studies revealed that the most potent compound 4 induced apoptosis and arrested the cell cycle at the S phase in HUTU80 cells. Additionally, the increased accumulation of HUTU80 cells in the sub G1 peak further pointed to the occurence of the cell apoptosis. The selectivity index analysis demonstrated that all the biscoumarin compounds (SI=3.1-7.5) possess higher selectivity towards intestinal epithelial adenocarcinoma cell line (HuTu80) than positive control drug carboplatin (SI=1.6-1.8). The biscoumarin compounds also showed no obvious acute toxicity on mice.