Identification of drugs including a dopamine receptor antagonist that selectively target cancer stem cells.

Selective targeting of cancer stem cells (CSCs) offers promise for a new generation of therapeutics. However, assays for both human CSCs and normal stem cells that are amenable to robust biological screens are limited. Using a discovery platform that reveals differences between neoplastic and normal human pluripotent stem cells (hPSC), we identify small molecules from libraries of known compounds that induce differentiation to overcome neoplastic self-renewal. Surprisingly, thioridazine, an antipsychotic drug, selectively targets the neoplastic cells, and impairs human somatic CSCs capable of in vivo leukemic disease initiation while having no effect on normal blood SCs. The drug antagonizes dopamine receptors that are expressed on CSCs and on breast cancer cells as well. These results suggest that dopamine receptors may serve as a biomarker for diverse malignancies, demonstrate the utility of using neoplastic hPSCs for identifying CSC-targeting drugs, and provide support for the use of differentiation as a therapeutic strategy.

A synthetic antibiotic class overcoming bacterial multidrug resistance.

The dearth of new medicines effective against antibiotic-resistant bacteria presents a growing global public health concern1. For more than five decades, the search for new antibiotics has relied heavily on the chemical modification of natural products (semisynthesis), a method ill-equipped to combat rapidly evolving resistance threats. Semisynthetic modifications are typically of limited scope within polyfunctional antibiotics, usually increase molecular weight, and seldom permit modifications of the underlying scaffold. When properly designed, fully synthetic routes can easily address these shortcomings2. Here we report the structure-guided design and component-based synthesis of a rigid oxepanoproline scaffold which, when linked to the aminooctose residue of clindamycin, produces an antibiotic of exceptional potency and spectrum of activity, which we name iboxamycin. Iboxamycin is effective against ESKAPE pathogens including strains expressing Erm and Cfr ribosomal RNA methyltransferase enzymes, products of genes that confer resistance to all clinically relevant antibiotics targeting the large ribosomal subunit, namely macrolides, lincosamides, phenicols, oxazolidinones, pleuromutilins and streptogramins. X-ray crystallographic studies of iboxamycin in complex with the native bacterial ribosome, as well as with the Erm-methylated ribosome, uncover the structural basis for this enhanced activity, including a displacement of the [Formula: see text] nucleotide upon antibiotic binding. Iboxamycin is orally bioavailable, safe and effective in treating both Gram-positive and Gram-negative bacterial infections in mice, attesting to the capacity for chemical synthesis to provide new antibiotics in an era of increasing resistance.

Salinomycin disturbs Golgi function and specifically affects cells in epithelial-to-mesenchymal transition.

Epithelial-to-mesenchymal transition (EMT) gives rise to cells with properties similar to cancer stem cells (CSCs). Targeting the EMT program to selectively eliminate CSCs is a promising way to improve cancer therapy. Salinomycin (Sal), a K+/H+ ionophore, was identified as highly selective towards CSC-like cells, but its mechanism of action and selectivity remains elusive. Here, we show that Sal, similar to monensin and nigericin, disturbs the function of the Golgi. Sal alters the expression of Golgi-related genes and leads to marked changes in Golgi morphology, particularly in cells that have undergone EMT. Moreover, Golgi-disturbing agents severely affect post-translational modifications of proteins, including protein processing, glycosylation and secretion. We discover that the alterations induced by Golgi-disturbing agents specifically affect the viability of EMT cells. Collectively, our work reveals a novel vulnerability related to the EMT, suggesting an important role for the Golgi in the EMT and that targeting the Golgi could represent a novel therapeutic approach against CSCs.

KARRIKIN UP-REGULATED F-BOX 1 (KUF1) imposes negative feedback regulation of karrikin and KAI2 ligand metabolism in Arabidopsis thaliana.

SignificanceKarrikins are chemicals in smoke that stimulate regrowth of many plants after fire. However, karrikin responses are not limited to species from fire-prone environments and can affect growth after germination. Putatively, this is because karrikins mimic an unknown signal in plants, KAI2 ligand (KL). Karrikins likely require modification in plants to become bioactive. We identify a gene, KUF1, that appears to negatively regulate biosynthesis of KL and metabolism of a specific karrikin. KUF1 expression increases in response to karrikin or KL signaling, thus forming a negative feedback loop that limits further activation of the signaling pathway. This discovery will advance understanding of how karrikins are perceived and how smoke-activated germination evolved. It will also aid identification of the elusive KL.

Promoting In Vivo NIR-II Fluorescent Imaging for Lipid in Lipid Metabolism Diseases Diagnosis.

Lipid metabolism diseases have become a tremendous risk worldwide, along with the development of productivity and particular attention to public health. It has been an urgent necessity to exploit reliable imaging strategies for lipids and thus to monitor fatty liver diseases. Herein, by converting the NIR-I signal to the NIR-II signal with IR1061 for the monitoring of lipid, the in vivo imaging of fatty liver disease was promoted on the contrast and visual effect. The main advantages of the imaging promotion in this work included a long emission wavelength, rapid response, and high signal-background-ratio (SBR) value. After promoting the NIR-I signal to NIR-II signal, IR1061 achieved higher SBR value and exhibited a dose-dependent fluorescence intensity at 1100 nm along with the increase of the EtOH proportion as well as steady and selective optical responses toward liposomes. IR1061 was further applied in the in vivo imaging of lipid in fatty liver diseases. In spite of the differences in body weight gain and TC level between healthy mice and fatty liver diseases two models, IR1061 achieved high-resolution imaging in the liver region to monitor the fatty liver disease status. This work might be informatic for the clinical diagnosis and therapeutical treatments of fatty liver diseases.

Uric acid-lowering effect of harpagoside and its protective effect against hyperuricemia-induced renal injury in mice.

Hyperuricemia (HUA) is caused by increased synthesis and/or insufficient excretion of uric acid (UA). Long-lasting HUA may lead to a number of diseases including gout and kidney injury. Harpagoside (Harp) is a bioactive compound with potent anti-inflammatory activity from the roots of Scrophularia ningpoensis. Nevertheless, its potential effect on HUA was not reported. The anti-HUA and nephroprotective effects of Harp on HUA mice were assessed by biochemical and histological analysis. The proteins responsible for UA production and transportation were investigated to figure out its anti-HUA mechanism, while proteins related to NF-κB/NLRP3 pathway were evaluated to reveal its nephroprotective mechanism. The safety was evaluated by testing its effect on body weight and organ coefficients. The results showed that Harp significantly reduced the SUA level and protected the kidney against HUA-induced injury but had no negative effect on safety. Mechanistically, Harp significantly reduced UA production by acting as inhibitors of xanthine oxidase (XOD) and adenosine deaminase (ADA) and decreased UA excretion by acting as activators of ABCG2, OAT1 and inhibitors of GLUT9 and URAT1. Moreover, Harp markedly reduced infiltration of inflammatory cells and down-regulated expressions of TNF-α, NF-κB, NLRP3 and IL-1ß in the kidney. Harp was a promising anti-HUA agent.

Karrikin signalling: impacts on plant development and abiotic stress tolerance.

Plants rely upon a diverse range of metabolites to control growth and development, and to overcome stress that results from suboptimal conditions. Karrikins (KARs) are a class of butenolide compounds found in smoke that stimulate seed germination and regulate various developmental processes in plants. KARs are perceived via a plant α/ß-hydrolase called KARRIKIN INSENSITIVE2 (KAI2), which also functions as a receptor for a postulated phytohormone, provisionally termed KAI2 ligand (KL). Considered natural analogues of KL, KARs have been extensively studied for their effects on plant growth and their crosstalk with plant hormones. The perception and response pathway for KAR-KL signalling is closely related to that of strigolactones, another class of butenolides with numerous functions in regulating plant growth. KAR-KL signalling influences seed germination, seedling photomorphogenesis, root system architecture, abiotic stress responses, and arbuscular mycorrhizal symbiosis. Here, we summarize current knowledge of KAR-KL signalling, focusing on its role in plant development, its effects on stress tolerance, and its interaction with other signalling mechanisms.

Meta-analysis of risk of major adverse cardiovascular events in adults with type 2 diabetes treated with bexagliflozin.

AIM: To explore the risk of major adverse cardiovascular events (MACE) associated with exposure to bexagliflozin. METHODS: The analysis included 4090 participants with type 2 diabetes (T2D) enrolled in nine phase 2 and 3 double-blind randomized controlled trials. All potential MACE were adjudicated by a blinded committee. The primary endpoint for the meta-analysis was the hazard ratio (HR) for the time to first occurrence of non-fatal stroke, non-fatal myocardial infarction (MI), cardiovascular (CV) death or hospitalization for unstable angina (MACE+), tested for non-inferiority to a ratio of 1.8. The secondary endpoints were time to first occurrence of (i) non-fatal stroke, non-fatal MI or CV death (MACE), tested for non-inferiority to a ratio of 1.3; and (ii) CV death or hospitalization for heart failure, tested for superiority. RESULTS: The HR for the primary endpoint of MACE+ was 0.80 (95% confidence interval [CI] 0.58, 1.09), which fulfilled the non-inferiority objective with a P value of less than 0.0001. Non-inferiority for the first key secondary endpoint of MACE was also shown (HR = 0.82; 95% CI 0.59, 1.13; P = 0.0023). Superiority for time to CV death or first hospitalization for heart failure was not shown. CONCLUSIONS: Bexagliflozin did not increase the risk of MACE in participants with T2D when compared with placebo or active control. Both the preapproval and postapproval thresholds for CV safety were met and bexagliflozin has been approved by the US Food and Drug Administration.

Mutagenetic analysis of the biosynthetic pathway of tetramate bripiodionen bearing 3-(2H-pyran-2-ylidene)pyrrolidine-2,4-dione skeleton.

BACKGROUND: Natural tetramates are a family of hybrid polyketides bearing tetramic acid (pyrrolidine-2,4-dione) moiety exhibiting a broad range of bioactivities. Biosynthesis of tetramates in microorganisms is normally directed by hybrid polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) machineries, which form the tetramic acid ring by recruiting trans- or cis-acting thioesterase-like Dieckmann cyclase in bacteria. There are a group of tetramates with unique skeleton of 3-(2H-pyran-2-ylidene)pyrrolidine-2,4-dione, which remain to be investigated for their biosynthetic logics. RESULTS: Herein, the tetramate type compounds bripiodionen (BPD) and its new analog, featuring the rare skeleton of 3-(2H-pyran-2-ylidene)pyrrolidine-2,4-dione, were discovered from the sponge symbiotic bacterial Streptomyces reniochalinae LHW50302. Gene deletion and mutant complementation revealed the production of BPDs being correlated with a PKS-NRPS biosynthetic gene cluster (BGC), in which a Dieckmann cyclase gene bpdE was identified by sit-directed mutations. According to bioinformatic analysis, the tetramic acid moiety of BPDs should be formed on an atypical NRPS module constituted by two discrete proteins, including the C (condensation)-A (adenylation)-T (thiolation) domains of BpdC and the A-T domains of BpdD. Further site-directed mutagenetic analysis confirmed the natural silence of the A domain in BpdC and the functional necessities of the two T domains, therefore suggesting that an unusual aminoacyl transthiolation should occur between the T domains of two NRPS subunits. Additionally, characterization of a LuxR type regulator gene led to seven- to eight-fold increasement of BPDs production. The study presents the first biosynthesis case of the natural molecule with 3-(2H-pyran-2-ylidene)pyrrolidine-2,4-dione skeleton. Genomic mining using BpdD as probe reveals that the aminoacyl transthiolation between separate NRPS subunits should occur in a certain population of NRPSs in nature.

Synthesis and antiproliferative activity of a tetrahydrofuran analog of FR901464.

FR901464 is a natural product that exhibits antiproliferative activity at single-digit nanomolar concentrations in cancer cells. Its tetrahydropyran-spiroepoxide covalently binds the spliceosome. Through our medicinal chemistry campaign, we serendipitously discovered that a bromoetherification formed a tetrahydrofuran. The tetrahydrofuran analog was three orders of magnitude less potent than the corresponding tetrahydropyran analogs. This study shows the significance of the tetrahydropyran ring that presents the epoxide toward the spliceosome.

Truncated derivatives of amphidinol 3 reveal the functional role of polyol chain in sterol-recognition and pore formation.

Here we examined the membrane binding and pore formation of amphidinol 3 (AM3) and its truncated synthetic derivatives. Importantly, both of the membrane affinity and pore formation activity were well correlated with the reported antifungal activity. Our data clearly demonstrated that the C1-C30 moiety of AM3 plays essential roles both in sterol recognition and stable pore formation. Based on the current findings, we updated the interacting model between AM3 and sterol, in which the moiety encompassing from C21 to C67 accommodates a sterol molecule with forming hydrogen bonds with the sterol hydroxy group and van der Waals contact between AM3 polyol and sterol skeleton. Although the conformation of the C1-C20 moiety of AM3 is hard to specify due to its flexibility, the region likely contributes to stabilization of pore structure.

Synthesis, in vitro Α-Glucosidase, and acetylcholinesterase inhibitory activities of novel Indol-Fused Pyrano[2,3-D]Pyrimidine compounds.

In this study, new indol-fused pyrano[2,3-d]pyrimidines were designed and synthesized. These products were obtained in moderate to good yields and their structures were assigned by NMR, MS, and IR analysis. Afterwards, the biological important of the products was highlighted by evaluating in vitro for α-glucosidase inhibitory activity as well as acetylcholinesterase (AChE) inhibitory activity. Eleven products revealed substantial inhibitory activity against α-glucosidase enzyme, among which, two most potent products 11d,e were approximately 93-fold more potent than acarbose as a standard antidiabetic drug. Besides that, product 11k exhibited good AChE inhibition. The substituents on the 5-phenyl ring, attached to the pyran ring, played a critical role in inhibitory activities. The biological potencies have provided an opportunity to further investigations of indol-fused pyrano[2,3-d]pyrimidines as potential anti-diabetic agents.

A Review of the Safety and Efficacy of Bexagliflozin for the Management of Type 2 Diabetes.

OBJECTIVE: To review the pharmacology of bexagliflozin in addition to its safety and efficacy from available clinical trials used for its approval, as well as available clinical evidence to date. DATA SOURCES: A search of the National Institutes of Health Clinical Trials Registry (http://www.clinicaltrials.gov) and PubMed database was performed from inception through June 1, 2023. STUDY SELECTION AND DATA EXTRACTION QUANTIFICATION: The following study designs were included: meta-analyses, systematic review, clinical trial, or observational study design. Abstracts and drug monographs were also reviewed. Narrative or scoping reviews were excluded. Only articles in the English language and those evaluating the pharmacology, pharmacokinetics, safety, or efficacy of bexaglifozin in humans were included. DATA SYNTHESIS: Bexagliflozin reduces hemoglobin A1c ~0.5% with similar reductions in systolic blood pressure and body weight to other SGLT2 inhibitors. No cardiovascular outcomes trial is published, nor ongoing at this time. Adverse effects are similar to other SGLT2 inhibitors (genital mycotic and urinary tract infections, increased urination) including a warning for lower extremity amputation similar to canagliflozin. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON TO EXISTING DRUGS: Although no cost-effectiveness data are available, statements from the manufacturer suggest a competitive price point. Given limited trial data, lower cost, if chosen, may create a temporary niche for bexagliflozin pending generic availability of other SGLT2 inhibitors. However, given lack of cardiovascular and renal outcome data, empagliflozin, dapagliflozin, or canagliflozin may be preferred. CONCLUSION: Bexagliflozin appears safe and effective as monotherapy and add-on pharmacological therapy for the treatment of T2D.

Identification of selective inhibitors of cancer stem cells by high-throughput screening.

Screens for agents that specifically kill epithelial cancer stem cells (CSCs) have not been possible due to the rarity of these cells within tumor cell populations and their relative instability in culture. We describe here an approach to screening for agents with epithelial CSC-specific toxicity. We implemented this method in a chemical screen and discovered compounds showing selective toxicity for breast CSCs. One compound, salinomycin, reduces the proportion of CSCs by >100-fold relative to paclitaxel, a commonly used breast cancer chemotherapeutic drug. Treatment of mice with salinomycin inhibits mammary tumor growth in vivo and induces increased epithelial differentiation of tumor cells. In addition, global gene expression analyses show that salinomycin treatment results in the loss of expression of breast CSC genes previously identified by analyses of breast tissues isolated directly from patients. This study demonstrates the ability to identify agents with specific toxicity for epithelial CSCs.

Asperuloside alleviates cyclophosphamide-induced myelosuppression by promoting AMPK/mTOR pathway-mediated autophagy.

Cyclophosphamide (CTX) is a common anticancer chemotherapy drug, and myelosuppression is the most common serious side effect. Asperuloside (ASP), the active component of Hedyotis diffusa Willd., may have the effect of ameliorating chemotherapy-induced myelosuppression. This study aimed to explore the effect and possible mechanism of ASP on CTX-induced myelosuppression. Male SPF C57BL/6 mice were randomly divided into five groups: control group, CTX (25 mg/kg) group, CTX + granulocyte-macrophage-colony stimulating factor (GM-CSF) (5 µg/kg) group, CTX + high-dose ASP (50 mg/kg) group and CTX + low-dose ASP (25 mg/kg) group, with six mice in each group. The body weight of mice was monitored every other day, the hematopoietic progenitor cell colony number was measured by colony forming unit, and the relevant blood indicators were detected. Femoral bone marrow was observed by hematoxylin-eosin, C-kit expression was detected by immunohistochemistry, and autophagy and adenine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway protein expressions were detected by immunohistochemistry and western blotting (WB). Then the AMPK inhibitor dorsomorphin was used to interfere with AMPK/mTOR pathway. Results showed that ASP significantly increased the body weight of CTX-induced mice, increased the number of hematopoietic progenitor cells, the expression of white blood cells, red blood cells, platelets, GM-CSF, thrombopoietin and erythropoietin in blood, and the expression of C-kit in bone marrow. In addition, ASP further promoted the expression of Beclin1 and LC-3II/I induced by CTX, and regulated the protein expressions in the AMPK/mTOR pathway. The use of dorsomorphin inhibited the alleviation effect of ASP on CTX-induced myelosuppression and the promotion effect of ASP on autophagy. In conclusion, ASP alleviated CTX-induced myelosuppression by promoting AMPK/mTOR pathway-mediated autophagy.

The residue of salinomycin in the muscles of olive flounder (Paralichthys olivaceus) and black rockfish (Sebastes Schlegeli) after oral administration analyzed by LC-Tandem-MS.

BACKGROUND: Salinomycin, an antibiotic, have potential as a veterinary drug for fish due to its anti-parasitic activity against several fish parasites. Thus the residual levels of salinomycin in muscles of two significant aquaculture species in Korea, olive flounder and black rockfish, were analyzed using HPLC-MS-MS. RESULTS: The proper method to analyze the residual salinomycin in fish muscles using LC-MS-MS was settled and the method was validated according to CODEX guidelines. The residues in three distinct groups for two fish species were analyzed using the matrix match calibration curves at points of five different times following oral administration. After oral administration, salinomycin rapidly breaks down in both olive flounder and black rockfish. After 7th days, the average residue in all groups of two fish spp. decreased below limit of quantitation (LOQ). CONCLUSION: Due to low residue levels in fish muscles, salinomycin may therefore be a treatment that is safe for both fish and humans. This result could contribute to establishment of MRL (minimal residual limit) for approval of salinomycin for use in aquaculture.

The pederin-producing bacteria density dynamics in Paederus fuscipes at different developmental stages.

Pederin, a defensive toxin in Paederus fuscipes, is produced by an uncultured Gram-negative symbiont, which establishes a stable symbiotic relationship with a female host before completion of metamorphosis. However, the transmission process of pederin-producing bacteria (PPB) in P. fuscipes at different life stages remains unknown. Herein, the PPB population dynamics and transcriptome atlas for P. fuscipes development (egg, first-instar larva, second-instar larva, pupa, and newly emerged female and male) were characterised. We found that a microbial layer containing PPB covered the eggshell, which could be sterilised by smearing the eggshell with streptomycin. Maternal secretions over the eggshell are likely the main PPB acquisition route for P. fuscipes offspring. The PPB density in eggs was significantly higher than that in other life stages (p < 0.05), which demonstrated that the beetle mothers gave more PPB than the larvae acquired. Physiological changes (hatching and eclosion) led to a decreased PPB density in P. fuscipes. Pattern recognition receptors related to Gram-negative bacteria recognition were identified from P. fuscipes transcriptomes across various life stages, which might be used to screen genes involved in PPB regulation. These results will help advance future efforts to determine the molecular mechanisms of PPB colonisation of P. fuscipes.

In vitro neuraminidase inhibitory concentrations (IC50) of four neuraminidase inhibitors in the Japanese 2022-23 season: Comparison with the 2010-11 to 2019-20 seasons.

To assess the extent of susceptibility to the four neuraminidase inhibitors (NAIs) approved in Japan of the epidemic viruses in the 2022-23 influenza season in Japan, we measured the 50 % inhibitory concentration (IC50) of oseltamivir, zanamivir, peramivir, and laninamivir in influenza virus isolates from patients. Viral isolation was done with specimens obtained prior to and after treatment, and the type/subtype was determined by RT-PCR using type- and subtype-specific primers. The IC50 was determined by a neuraminidase inhibition assay using a fluorescent substrate. Virus isolates, one A(H1N1)pdm09 and 74 A(H3N2), were measured in the 2022-23 season. The geometric mean IC50s of the 74 A(H3N2) isolated prior to treatment were 0.78 nM, 0.66 nM, 2.08 nM, and 2.85 nM for oseltamivir, peramivir, zanamivir, and laninamivir, respectively, comparable to those of the previous ten studied seasons. No A(H3N2) with highly reduced sensitivity to any of the NAIs was found in the 2022-23 season prior to or after drug administration. These results indicate that the sensitivity to these four commonly used NAIs has been maintained, at least for A(H3N2), in the 2022-23 influenza season in Japan, after the 2020-21 and 2021-22 seasons when the prevalence of influenza was extremely low.

Three mutations repurpose a plant karrikin receptor to a strigolactone receptor.

Uncovering the basis of small-molecule hormone receptors' evolution is paramount to a complete understanding of how protein structure drives function. In plants, hormone receptors for strigolactones are well suited to evolutionary inquiries because closely related homologs have different ligand preferences. More importantly, because of facile plant transgenic systems, receptors can be swapped and quickly assessed functionally in vivo. Here, we show that only three mutations are required to turn the nonstrigolactone receptor, KAI2, into a receptor that recognizes the plant hormone strigolactone. This modified receptor still retains its native function to perceive KAI2 ligands. Our directed evolution studies indicate that only a few keystone mutations are required to increase receptor promiscuity of KAI2, which may have implications for strigolactone receptor evolution in parasitic plants.

Iridoid Glycoside Cornuside Alleviates the Symptom of Gestational Diabetes Mellitus by Suppressing Inflammation and Regulating Beta Cell Function.

OBJECTIVE: Gestational diabetes mellitus (GDM) is a frequently occurring complication during pregnancy and has adverse effects on both mother and offspring. ß-Cell dysfunction and inflammation play important roles in GDM pathogenesis. Cornuside (CNS) is an iridoid glycoside that exhibits anti-inflammation activities. In the present study, we explored the effects of CNS on ß-cell and GDM. DESIGN: MIN6 ß-cell line cells were treated with varying concentrations of CNS. The content and secretion of insulin were measured. METHODS: The expression of Pdx1, Rac1, Piezo, and NeuroD1 and cell proliferation in CNS-treated MIN6 cells were detected. CNS was administered to GDM mice, and the symptoms of GDM, expression of IL-6 and TNF-α, and activation of NF-κB in GDM mice were measured. RESULTS: CNS promoted cell proliferation of MIN6 cells, enhanced insulin content and secretion, and expression of Pdx1, Rac1, Piezo, and NeuroD1 in MIN6 cells. CNS alleviated symptoms of GDM mice and decreased serum levels of IL-6 and TNF-α in GDM mice. CNS suppressed the expression of IL-6 and TNF-α, as well as the activation of NF-κB in the placenta of GDM mice. CONCLUSION: CNS ameliorates GDM symptoms by suppressing inflammation and enhancing ß-cell functions.