Aromatic Ring-Fused Dipyrrins: Programmed [4 + 2]-Cycloaddition Pathway with Regio-selectivity upon Alkylamino-Substitution.

Sulfolenodipyrrins are employed as building blocks to concisely and efficiently construct aromatic rings (e.g., naphthoquinone, anthraquinone, fullerenes, and phthalimide) from fused dipyrrins by programmed [4 + 2]-cycloaddition reactions. Notably, alkylamino-substitution at the α-position not only enhances the reactivity of sulfolenodipyrrins but also results in the regio-selectivity of the cycloaddition reactions. Theoretical calculations in terms of frontier orbitals of dienes, energy of dienes, steric hindrance, and aromaticity have been conducted to understand the reason in depth. Additionally, the fusion of aromatic groups enables bathochromic absorption with up to ∼130 nm for the monoadducts and to ∼200 nm for the bis-adducts. The phthalimide annulation dipyrrin displays red emission, while the other mono- or bis-adducts do not, owing to the presence of typical acceptors such as quinone analogs or fullerene.

The triple-drug combination DBDx enhances the antitumor efficacy of PD-1 antibody associated with Treg modulation.

OBJECTIVE: This study investigated the antitumor efficacy of programmed cell death protein-1 (PD-1) antibody and DBDx, a triple-drug combination of dipyridamole, bestatin, and dexamethasone, and their related immunomodulation. MATERIALS AND METHODS: Mouse melanoma B16, mouse Lewis lung carcinoma, and mouse breast carcinoma 4T1 were used for evaluating the in vivo therapeutic efficacy of DBDx, PD-1 antibody, and their combination. The peripheral blood and tumor tissues of 4T1 tumor-bearing mice were collected to analyze regulatory T cells and measured using flow cytometry. RESULTS: The combination of PD-1 antibody and DBDx enhanced the therapeutic efficacy against B16 melanoma. The suppression of tumor growth by PD-1 antibody and DBDx was more significant than that by anti-PD-1 monotherapy. The tumor growth inhibition rates of PD-1 antibody, DBDx, and their combination were 54.0%, 72.4%, and 83.1%, respectively, suggesting a synergistic effect as determined by the coefficient of drug interaction. No significant changes were found in the body weights in all the above groups, indicating that the treated mice tolerated the applied drug doses. Similarly, enhanced therapeutic efficacy of the PD-1 antibody and DBDx combination was observed in murine Lewis lung carcinoma and 4T1 breast cancer models. In 4T1 breast cancer-bearing mice, the immunotherapy-related changes in lymphocytes in peripheral blood and tumor microenvironment were evaluated with flow cytometry. Compared with anti-PD-1 monotherapy, peripheral blood and tumor-infiltrating lymphocytes were found a lower ratio of regulatory T cell (Treg) subset cells and a higher ratio of CD8+/Treg cells. CONCLUSIONS: The combination of PD-1 antibody and DBDx could achieve enhanced therapeutic antitumor efficacy than anti-PD-1 monotherapy, suggesting potential for using the triple-drug combination DBDx in cancer immunotherapy.

Intermittent theta burst stimulation to the left dorsolateral prefrontal cortex improves cognitive function in polydrug use disorder patients: a randomized controlled trial.

Background: Polydrug abuse is common among opioid users. Individuals who use both heroin and methamphetamine (MA) have been shown to experience a wide range of cognitive deficits. Previous research shows that repetitive transcranial magnetic stimulation (rTMS) can change cerebral cortical excitability and regulate neurotransmitter concentration, which could improve cognitive function in drug addiction. However, the stimulation time, location, and possible mechanisms of rTMS are uncertain. Methods: 56 patients with polydrug use disorder were randomized to receive 20 sessions of 10 Hz rTMS (n = 19), iTBS (n = 19), or sham iTBS (n = 18) to the left DLPFC. All patients used MA and heroin concurrently. Cognitive function was assessed and several related proteins including EPI, GABA-Aα5, IL-10, etc. were quantified by ELISA before and after the treatment. Results: Baseline RBANS scores were lower than normal for age (77.25; IQR 71.5-85.5). After 20 treatment sessions, in the iTBS group, the RBANS score increased by 11.95 (95% CI 0.02-13.90, p = 0.05). In particular, there were improvements in memory and attention as well as social cognition. Following treatment, serum EPI and GABA-Aα5 were reduced and IL-10 was elevated. The improvement of immediate memory was negatively correlated with GABA-Aα5 (r = -0.646, p = 0.017), and attention was positively correlated with IL-10 (r = 0.610, p = 0.027). In the 10 Hz rTMS group, the improvement of the RBANS total score (80.21 ± 14.08 before vs.84.32 ± 13.80 after) and immediate memory (74.53 ± 16.65 before vs.77.53 ± 17.78 after) was statistically significant compared with the baseline (p < 0.05). However, compared with the iTBS group, the improvement was small and the difference was statistically significant. There was no statistically significant change in the sham group (78.00 ± 12.91 before vs.79.89 ± 10.92 after; p > 0.05). Conclusion: Intermittent theta burst stimulation to the left DLPFC may improve cognitive function in polydrug use disorder patients. Its efficacy appears to be better than that of 10 Hz rTMS. The improvement of cognitive function may be related to GABA-Aα5 and IL-10. Our findings preliminarily demonstrate the clinical value of iTBS to the DLPFC to augment neurocognitive recovery in polydrug use disorders.

The relationship between physical activity and depression among community-dwelling adults in Wuhan, China.

Background: While the association between physical activity (PA) and depression has been established, there is limited research on the effect of PA on the risk of depression among Chinese individuals. Thus, this study aimed to investigate the relationship between PA and depression among Chinese individuals. Methods: We used a stratified random sampling approach to recruit participants from five urban districts in Wuhan, China. A total of 5,583 permanent residents aged 18 years or older completed questionnaires, which included the International Physical Activity Questionnaire Short Form (IPAQ-SF) to measure PA, and the 9-item Patient Health Questionnaire (PHQ-9) to evaluate depressive symptoms. To control for potential confounders, multiple logistic regression was employed to assess the association of PA with depression. Results: The depression group had significantly lower weekly PA levels, measured in metabolic equivalent of task-minutes per week (MET-min/w), compared to the non-depression group [1,770 (693-4,200) MET-min/w vs. 2,772 (1,324-4,893) MET-min/w, p < 0.001]. In the fully adjusted model, the moderate and high PA level groups had lower odds ratios (ORs) for depressive symptoms compared to the low PA level group [OR (95% confidence interval (CI)) = 0.670 (0.523-0.858), 0.618 (0.484-0.790), respectively]. Among males, moderate and high levels of PA were associated with lower risk of depression compared to low PA levels [OR (95% CI) = 0.417 (0.268-0.649), 0.381 (0.244-0.593), respectively]. However, this association was not observed in females [OR (95% CI) = 0.827 (0.610-1.121), 0.782 (0.579-1.056), respectively]. The study found a significant interaction between PA levels and gender in relation to depression (P for interaction = 0.019). Conclusion: The findings suggest a negative association between PA and risk of depressive symptoms, indicating that moderate to high levels of PA may serve as a protective factor against depressive symptoms.

Isolation, Structure Elucidation, and First Total Synthesis of Quinomycins K and L, Two New Octadepsipeptides from the Maowei Sea Mangrove-Derived Streptomyces sp. B475.

Mangrove actinomycetia have been proven to be one of the promising sources for discovering novel bioactive natural products. Quinomycins K (1) and L (2), two rare quinomycin-type octadepsipeptides without intra-peptide disulfide or thioacetal bridges, were investigated from the Maowei Sea mangrove-derived Streptomyces sp. B475. Their chemical structures, including the absolute configurations of their amino acids, were elucidated by a combination of NMR and tandem MS analysis, electronic circular dichroism (ECD) calculation, advanced Marfey's method, and further unequivocally confirmed by the first total synthesis. The two compounds displayed no potent antibacterial activity against 37 bacterial pathogens and had no significant cytotoxic activity against H460 lung cancer cells.

Design, synthesis and biological evaluation of 2-((4-sulfamoylphenyl)amino)-pyrrolo[2,3-d]pyrimidine derivatives as CDK inhibitors.

To explore the potential use of CDK inhibitors in pancreatic ductal adenocarcinoma (PDAC) therapy, a series of novel 2-((4-sulfamoylphenyl)amino)-pyrrolo[2,3-d]pyrimidine derivatives was designed, synthesised, and investigated for inhibition on both CDK kinase activity and cellular proliferation of pancreatic cancer. Most of new sulphonamide-containing derivatives demonstrated strong inhibitory activity on CDK9 and obvious anti-proliferative activity in cell culture. Moreover, two new compounds suppressed cell proliferation of multiple human pancreatic cancer cell lines. The most potent compound 2g inhibited cancer cell proliferation by blocking Rb phosphorylation and induced apoptosis via downregulation of CDK9 downstream proteins Mcl-1 and c-Myc in MIA PaCa-2 cells. CDK9 knockdown experiment suggests its anti-proliferative activity is mainly mediated by CDK9. Additionally, 2g displayed moderate tumour inhibition effect in AsPC-1 derived xenograft mice model. Altogether, this study provided a new start for further optimisation to develop potential CDK inhibitor candidates for PDAC treatment by alone or combination use.

Mechanical behavior analysis of fully grouted bolt under axial load.

Based on the idea of discretization and the force balance analysis of each mass spring element, a spring-element analysis method for bolt is proposed. By analyzing the mechanical behavior of the bond interface of the fully grouted bolt, three coupling models of the bond interface, the slider model, the spring model and the spring-slider model, are proposed. Using the spring-element method, five load transfer models, namely the slider model, the spring model, the modified spring model, the spring-pulled slider model, and the spring-slider model, were deduced. And get the bolt displacement distribution function, axial force distribution function and shear stress distribution function under each model. The five proposed models are verified, analyzed and discussed by using the pull-out test of the smooth steel bolt and the threaded steel bolt. It is verified by experiments that this study is helpful to comprehensively understand the mechanical behavior of fully grouted bolts under axial load. The proposed spring element analysis method is simple and easy to understand and the results are reasonable.

Biodiversity and Spatiotemporal Distribution of Spontaneous Vegetation in Tangdao Bay National Wetland Park, Qingdao City, China.

Spontaneous vegetation plays an important role in protecting urban biodiversity and the maintenance of urban ecosystems. In this study, we investigated the species diversity, life-form composition, origin, flowering season, and spatiotemporal distribution of spontaneous vegetation in the exhibition and education area of Tangdao Bay National Wetland Park using the quadrat survey method. There were 65 spontaneous association types and 210 spontaneous plant species, belonging to 151 genera and 44 families. The associations and species of spontaneous plants in roadside habitats were found to be the highest. In addition, many species were found in woodland and lakeside habitats, whereas the lowest number of species were found in coastal habitats. The life-form composition included 76 annual and 94 perennial herb species. These plants were of various origins. There were 160 native, 9 domestically introduced, 2 introduced alien, and 39 invasive alien plant species, which predominantly came from the Americas. A single peak was observed from March to November for the spontaneous plant species that were in their growing season, including those of different life forms and from various sources. The same was true for spontaneous plants in their flowering season. During their growing season, the number of spontaneous plant species was highest during September and, during their flowering season, the number of species was highest in July. From April to September, the Shannon-Wiener diversity index for spontaneous vegetation in the roadside habitat was the highest, followed by those for the woodland and lakeside habitats, and that of the coastline habitat was the lowest. The monthly average Shannon-Wiener diversity index for spontaneous plant associations in the four habitats also varied, with a single peak. The diversity of spontaneous plants and alien invasive plants in Tangdao Bay National Wetland Park is high. The wise use and protection of spontaneous flowering plants with long ornamental seasons can effectively reduce the maintenance costs, resource consumption, and energy requirements of the park. Spontaneous plants should also be managed to reduce the harm from alien invasive plants in the park, and alien invasive plants should be removed from the park during their flowering seasons.

An EGFR/HER2-targeted conjugate sensitizes gemcitabine-sensitive and resistant pancreatic cancer through different SMAD4-mediated mechanisms.

Chemoresistance limits its clinical implementation for pancreatic ductal adenocarcinoma (PDAC). We previously generated an EGFR/HER2 targeted conjugate, dual-targeting ligand-based lidamycin (DTLL), which shows a highly potent antitumor effect. To overcome chemoresistance in PDAC, we aim to study DTLL efficacy when combined with gemcitabine and explore its mechanisms of action. DTLL in combination with gemcitabine show a superior inhibitory effect on the growth of gemcitabine-resistant/sensitive tumors. DTLL sensitizes gemcitabine efficacy via distinct action mechanisms mediated by mothers against decapentaplegic homolog 4 (SMAD4). It not only prevents neoplastic proliferation via ATK/mTOR blockade and NF-κB impaired function in SMAD4-sufficient PDACs, but also restores SMAD4 bioactivity to trigger downstream NF-κB-regulated signaling in SMAD4-deficient tumors and to overcome chemoresistance. DTLL seems to act as a SMAD4 module that normalizes its function in PDAC, having a synergistic effect in combination with gemcitabine. Our findings provide insight into a rational SMAD4-directed precision therapy in PDAC.

Porphyrindiene-Based Tandem Diels-Alder Reaction for Preparing Low-Symmetry π-Extended Porphyrins with Push-Pull Skeletons.

Tandem Diels-Alder reactions of masked porphyrindienes (i.e., sulfolenoporphyrins) with benzoquinones and stilbenes, followed by aromatization, have been developed to load porphyrin with mixed annulation units (i.e., terphenyl and naphthoquinone), furnishing the low-symmetry π-extended porphyrins (DxAy) with push-pull skeletons. All low-symmetrical chromophores display panchromatic absorption spectra, which look like a spectral combination of symmetrical congeners (D4/A4) in a certain ratio. Among them, tD2A2 with trans-arrangement of push/pull units possesses the largest maximum centered at 766 nm with the onset around 900 nm. The fusion of the electron-deficient naphthoquinone moiety on the porphyrin core results in the approximately quantitative regulation of the Eox1 and HOMOs (i.e., 0.10-0.13 V increase for the Eox1 and 0.14-0.16 eV decrease for the HOMOs per naphthoquinone unit). In brief, this work provides a new way to construct low-symmetry π-extended porphyrins with tunable properties resorting to the ratios and locations of the annulated push-pull units.

Polysaccharides of Brassica rapa L. attenuate tumor growth via shifting macrophages to M1-like phenotype.

Macrophages are the major tumor-infiltrating leukocytes, and tumor-associated macrophages (TAM) play a critical role in cancer-related inflammation since they show alternative polarization to M1 (tumor-inhibited macrophages) or M2 (tumor-promoted macrophages) phenotype. Brassica rapa L. (B. rapa) has been clinically proven to have anti-tumor and immunity-enhancing activity, and the polysaccharides of B. rapa (BRP) have been reported to have an immunoregulatory effect on macrophages. In this study, we focus on macrophage polarization to investigate the mechanism of anti-tumor response of BRP in vivo and in vitro. We found that BRP improved the expression of M1 markers, including iNOS, COX-2, HLA-DR, CD11b and M1-related cytokines. The expression of M2 markers Arg-1, CD206 and CD163 induced by IL-4 were inhibited by BRP treatment, resulting in the inhibition of tumor growth both in vivo and in co-culture experiments in vitro. The activation of STAT signaling pathway were significantly regulated by BRP, which are important signals in TAM polarization. Overall, the results indicated that BRP has anti-tumor effect through mediating macrophage polarization.

Evaluation of the Relationship Between BDNF Val66Met Gene Polymorphism and Attention Deficit Hyperactivity Disorder: A Meta-Analysis.

Background: Attention deficit hyperactivity disorder (ADHD) is a common neurobehavioral disorder in childhood. Brain-derived neurotrophic factor (BDNF) is widely distributed in the central nervous system and plays an important role in neural development. Despite several previous studies have examined the association between the Val66Met polymorphism BDNF and ADHD, the results are conflicting. Objective: This study aimed to evaluate the association between Val66Met polymorphism and ADHD in case-control and transmission disequilibrium test (TDT) studies using a meta-analysis. Methods: Keywords "rs6265" or "Val66Met" and "Attention deficit hyperactivity disorder" were used to search in the PubMed, Embase, Web of Science, Wanfang, and China National Knowledge Infrastructure databases before April 2021. Genotype data were extracted to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Results: Fifteen studies, comprising of 8,692 samples (containing 4,364 cases, 4,328 controls) and 1,578 families were included and results demonstrated that rs6265 was not associated with susceptibility to ADHD (OR = 0.95, 95% CI: 0.87-1.04, P = 0.291). Stratified analyses by study design, ethnicity, and sample size further supported that rs6265 was not associated with ADHD. Conclusion: The present study shows that the polymorphism of the BDNF Val66Met gene is not associated with susceptibility to ADHD.

Development of a novel multi-functional integrated bioconjugate effectively targeting K-Ras mutant pancreatic cancer.

Folate receptor (FR) overexpression occurs in a variety of cancers, including pancreatic cancer. In addition, enhanced macropinocytosis exists in K-Ras mutant pancreatic cancer. Furthermore, the occurrence of intensive desmoplasia causes a hypoxic microenvironment in pancreatic cancer. In this study, a novel FR-directed, macropinocytosis-enhanced, and highly cytotoxic bioconjugate folate (F)-human serum albumin (HSA)-apoprotein of lidamycin (LDP)-active enediyne (AE) derived from lidamycin was designed and prepared. F-HSA-LDP-AE consisted of four moieties: F, HSA, LDP, and AE. F-HSA-LDP presented high binding efficiency with the FR and pancreatic cancer cells. Its uptake in wild-type cells was more extensive than in K-Ras mutant-type cells. By in vivo optical imaging, F-HSA-LDP displayed prominent tumor-specific biodistribution in pancreatic cancer xenograft-bearing mice, showing clear and lasting tumor localization for 360 h. In the MTT assay, F-HSA-LDP-AE demonstrated potent cytotoxicity in three types of pancreatic cancer cell lines. It also induced apoptosis and caused G2/M cell cycle arrest. F-HSA-LDP-AE markedly suppressed the tumor growth of AsPc-1 pancreatic cancer xenografts in athymic mice. At well-tolerated doses of 0.5 and 1 mg/kg, (i.v., twice), the inhibition rates were 91.2% and 94.8%, respectively (P<0.01). The results of this study indicate that the F-HSA-LDP multi-functional bioconjugate might be effective for treating K-Ras mutant pancreatic cancer.

A recombinant scFv antibody-based fusion protein that targets EGFR associated with IMPDH2 downregulation and its drug conjugate show therapeutic efficacy against esophageal cancer.

The present study aimed to evaluate the anti-tumor efficacy of the epidermal growth factor receptor (EGFR)-targeting recombinant fusion protein Fv-LDP-D3 and its antibody-drug conjugate Fv-LDP-D3-AE against esophageal cancer. Fv-LDP-D3, consisting of the fragment variable (Fv) of an anti-EGFR antibody, the apoprotein of lidamycin (LDP), and the third domain of human serum albumin (D3), exhibited a high binding affinity for EGFR-overexpressing esophageal cancer cells, inhibited EGFR phosphorylation and down-regulated inosine monophosphate dehydrogenase type II (IMPDH2) expression. Fv-LDP-D3 was taken up by cancer cells through intensive macropinocytosis; it inhibited the proliferation and induced the apoptosis of esophageal cancer cells. In vivo imaging revealed that Fv-LDP-D3 displayed specific tumor-site accumulation and a long-lasting retention over a 26-day period. Furthermore, Fv-LDP-D3-AE, a pertinent antibody-drug conjugate prepared by integrating the enediyne chromophore of lidamycin into the Fv-LDP-D3 molecule, displayed highly potent cytotoxicity, inhibited migration and invasion, induced apoptosis and DNA damage, arrested cells at G2/M phase, and caused mitochondrial damage in esophageal cancer cells. More importantly, both of Fv-LDP-D3 and Fv-LDP-D3-AE markedly inhibited the growth of esophageal cancer xenografts in athymic mice at well tolerated doses. The present results indicate that Fv-LDP-D3, and Fv-LDP-D3-AE exert prominent antitumor efficacy associated with targeting EGFR, suggesting their potential as promising candidates for targeted therapy against esophageal cancer.

The recombinant defensin/HSA fusion protein that inhibits NF-κb associated with intensive macropinocytosis shows potent efficacy against pancreatic cancer.

KRAS mutation and NF-κB both play crucial role in pancreatic cancer; in addition, defensin, the peptide mediator in innate immunity, can inhibit NF-κB. Assuming a strategy that targets both NF-κB and concomitantly the mutated KRAS indirectly via intensive macropinocytosis, we designed and generated a recombinant protein DF2-HSA which consists of two molecules of human beta-defensin 2 (HBD2) and a moiety of human serum albumin (HSA). As shown, the recombinant protein DF2-HSA markedly down-regulated NF-κB in both KRAS mutant MIA PaCa-2 cells and wild type BxPC-3 cells. Determined by confocal microscopy, the uptake of DF2-HSA in MIA PaCa-2 cells was more intense than that in BxPC-3 cells. The uptake was blocked by the specific inhibitor EIPA, indicating that DF2-HSA internalized via macropinocytosis. DF2-HSA displayed more potent cytotoxicity to cancer cells than HBD2. DF2-HSA induced apoptosis in cancer cells. Notably, DF2-HSA inhibited tumor cell spheroid formation, an effect comparable to that of salinomycin. DF2-HSA inhibited tumor cell migration and invasion. As detected with scanning electron microscopy, DF2-HSA strongly depleted filopodia on cell surface; and salinomycin induced similar changes. By in vivo imaging, DF2-HSA displayed intense tumor-site accumulation and lasting retention for over 14 days; however, HBD2 showed much less tumor-site accumulation and a shorter retention time for only 24 h. DF2-HSA suppressed the growth of pancreatic cancer MIA PaCa-2 xenograft in athymic mice; and its combination with gemcitabine achieved higher antitumor efficacy. In summary, the recombinant defensin/HSA fusion protein that inhibits NF-κb associated with intensive macropinocytosis is highly effective against pancreatic cancer.

The novel ER stress inducer Sec C triggers apoptosis by sulfating ER cysteine residues and degrading YAP via ER stress in pancreatic cancer cells.

Pancreatic adenocarcinoma (PAAD) is one of the most lethal malignancies. Although gemcitabine (GEM) is a standard treatment for PAAD, resistance limits its application and therapy. Secoemestrin C (Sec C) is a natural compound from the endophytic fungus Emericella, and its anticancer activity has not been investigated since it was isolated. Our research is the first to indicate that Sec C is a broad-spectrum anticancer agent and could exhibit potently similar anticancer activity both in GEM-resistant and GEM-sensitive PAAD cells. Interestingly, Sec C exerted a rapid growth-inhibiting effect (80% death at 6 h), which might be beneficial for patients who need rapid tumor shrinkage before surgery. Liquid chromatography/mass spectrometry and N-acetyl-l-cysteine (NAC) reverse assays show that Sec C sulfates cysteines to disrupt disulfide-bonds formation in endoplasmic reticulum (ER) proteins to cause protein misfolding, leading to ER stress and disorder of lipid biosynthesis. Microarray data and subsequent assays show that ER stress-mediated ER-associated degradation (ERAD) ubiquitinates and downregulates YAP to enhance ER stress via destruction complex (YAP-Axin-GSK-ßTrCP), which also elucidates a unique degrading style for YAP. Potent anticancer activity in GEM-resistant cells and low toxicity make Sec C a promising anti-PAAD candidate.

Loading Phlorins with Fullerenes by a [4 + 2]-Cycloaddition Reaction: Regulation of the Regioselectivity by Pyrrole Linkage Modes.

Sulfolenopyrrole-based normal and N-confused phlorins have been constructed to address the seldom touched phlorin functionalization and simultaneously explore the effect of the pyrrole linkage modes (αα, αß) on the [4 + 2] cycloaddition reaction. The common sulfolenophlorin 1 contains two sulfolenopyrroles with the same reactivity upon tautomerization and undergoes stepwise [4 + 2]-cycloaddition with fullerene to furnish monoadduct 1-C60 and bisadduct 1-2C60 with a total yield up to 76%. By contrast, the presence of the confused pyrrole in 2 fixes the π-system owing to the low tendency to tautomerize and enables the two sulfolenopyrroles to exhibit in different fashions (i.e., normal NH-type and imino-type). Notably, under milder conditions (120 °C), the monofullerenoadduct 2-C60 forms rapidly and has been isolated from the [4 + 2] cycloaddition reaction of 2 and fullerene as the predominant fraction, accompanied by a trace amount of bisadduct 2-2C60. Raising the temperature to 140 °C did not improve the yield of 2-2C60. The structural analysis of 2-C60 indicates the attachment of fullerene at the iminopyrrole part. The high regioselectivity in the [4 + 2] cycloaddition of the imino-type sulfolenopyrrole unit has been rationalized thermodynamically by the DFT calculation on the relative energy of the two diene intermediates.

Mithramycin suppresses tumor growth by regulating CD47 and PD-L1 expression.

Mithramycin A (MIT) has reacquired extensive research attention due to its anti-solid tumor activity and improved pharmacological production. Mechanismly, MIT was broadly used as a c-Myc inhibitor, and c-Myc regulated CD47 and PD-L1 expression which has been demonstrated. However, how MIT affects immune check-point molecules remains unknown. In this study, we found CD47 expression was higher in melanoma of pan-tissue array. MIT inhibited CD47 expression both in mRNA and protein level in melanoma cells (SK-MEL-28 and B16). MIT inhibited c-Myc, Sp-1 and CD47 expression in a concentration-dependent way. MIT inhibited the surface CD47 expression and promoted the phagocytosis of SK-MEL-28 cells by THP-1 cells. We found MIT inhibited tumor growth in melanoma allograft mice and CD47 expression in tumor mass. We also found MIT upregulated PD-L1 expression in cancer cells possibly via inhibiting PD-L1 ubiquitination, increasing ROS and IFN-γ. Combination of MIT and anti-PD-1 antibody showed enhanced antitumor activity compared to MIT and anti-PD-1 antibody alone in MC38 allograft mice. Using immune checkpoint array we found MIT inhibited expression of FasL and Galectin3. These results suggest that MIT inhibits CD47 expression, while improves PD-L1 expression. Furthermore, the combination of MIT and anti-PD-1 antibody exerts potent antitumor effect.

Metabolomics Tools Assisting Classic Screening Methods in Discovering New Antibiotics from Mangrove Actinomycetia in Leizhou Peninsula.

Mangrove actinomycetia are considered one of the promising sources for discovering novel biologically active compounds. Traditional bioactivity- and/or taxonomy-based methods are inefficient and usually result in the re-discovery of known metabolites. Thus, improving selection efficiency among strain candidates is of interest especially in the early stage of the antibiotic discovery program. In this study, an integrated strategy of combining phylogenetic data and bioactivity tests with a metabolomics-based dereplication approach was applied to fast track the selection process. A total of 521 actinomycetial strains affiliated to 40 genera in 23 families were isolated from 13 different mangrove soil samples by the culture-dependent method. A total of 179 strains affiliated to 40 different genera with a unique colony morphology were selected to evaluate antibacterial activity against 12 indicator bacteria. Of the 179 tested isolates, 47 showed activities against at least one of the tested pathogens. Analysis of 23 out of 47 active isolates using UPLC-HRMS-PCA revealed six outliers. Further analysis using the OPLS-DA model identified five compounds from two outliers contributing to the bioactivity against drug-sensitive A. baumannii. Molecular networking was used to determine the relationship of significant metabolites in six outliers and to find their potentially new congeners. Finally, two Streptomyces strains (M22, H37) producing potentially new compounds were rapidly prioritized on the basis of their distinct chemistry profiles, dereplication results, and antibacterial activities, as well as taxonomical information. Two new trioxacarcins with keto-reduced trioxacarcinose B, gutingimycin B (16) and trioxacarcin G (20), together with known gutingimycin (12), were isolated from the scale-up fermentation broth of Streptomyces sp. M22. Our study demonstrated that metabolomics tools could greatly assist classic antibiotic discovery methods in strain prioritization to improve efficiency in discovering novel antibiotics from those highly productive and rich diversity ecosystems.