Search

Here we have developed an immunosorbent assay to accurately and sensitively monitor helicase unwinding a broad range of DNA substrate structures. This assay can be utilized to investigate diverse helicases' functions and to identify their inhibitors.

Inter-organelle interactions play a vital role in diverse biological processes. Thus, chemical tools are highly desirable for understanding the spatiotemporal dynamic interplay among organelles in live cells and

The development of triple-negative breast cancer (TNBC) is highly associated with G-quadruplex (G4); thus, targeting G4 is a potential strategy for TNBC therapy. Because concomitant histone deacetylases (HDAC) inhibition could amplify the impact of G4-targeting compounds, we designed and synthesized two novel series of G4/HDAC dual-targeting compounds by connecting the zinc-binding pharmacophore of HDAC inhibitors to the G4-targeting isaindigotone scaffold (

Reported herein is an in situ-generated hypervalent iodine-incorporating fluoroarylation of benzylidenecyclopropanes using commercially available HF·Py and aryl iodides as fluorine and aryl sources, respectively. The reaction proceeds via regioselective 1,2-fluoroiodination of a double bond followed by an iodonio-[3,3]-rearrangement of the formed cyclopropyl-I

Ligand-Induced duplex-quadruplex transition within the c-MYC promoter region is one of the most studied and advanced ideas for c-MYC regulation. Despite its importance, there is a lack of methods for monitoring such process in cells, hindering a better understanding of the essence of c-MYC G-quadruplex as a drug target. Here we developed a new fluorescent probe ISCH-MYC for specific c-MYC G-quadruplex recognition based on GTFH (G-quadruplex-Triggered Fluorogenic Hybridization) strategy. We validated that ISCH-MYC displayed distinct fluorescence enhancement upon binding to c-MYC G-quadruplex, which allowed the duplex-quadruplex transition detection of c-MYC G-rich DNA in cells. Using ISCH-MYC, we successfully characterized the induction of duplex to G-quadruplex transition in the presence of G-quadruplex stabilizing ligand PDS and further monitored and evaluated the altered interactions of relevant transcription factors Sp1 and CNBP with c-MYC G-rich DNA. Thus, our study provides a visualization strategy to explore the mechanism of G-quadruplex stabilizing ligand action on c-MYC G-rich DNA and relevant proteins, thereby empowering future drug discovery efforts targeting G-quadruplexes.

Palladium-based oxidative addition complex (OAC)-enabled C–N cross-couplings of aryl halides with amines toward the synthesis of amino-substituted indolyl-4(3H)-quinazolinones and their antitumor activity evaluation have been studied.

Reported herein is a hypervalent iodine(iii)-mediated ring-expansive difluorination of alkynylcyclopropanes featuring a Wagner–Meerwein-type rearrangement to access a variety of difluorinated alkylidenecyclobutanes.

Because of the lack of facile and accurate methods to track stress granule (SG) dynamics in live cells and in vivo, in-depth studies of the biological roles of this attractive membraneless organelle have been limited. Herein, we report the first small-molecule probe, TASG, for the selective, convenient and real-time monitoring of SGs. This novel molecule can simultaneously bind to SG RNAs, the core SG protein G3BP1, and their complexes, triggering a significant enhancement in fluorescence intensity, making TASG broadly applicable to SG imaging under various stress conditions in fixed and live cells, ex vivo and in vivo. Using TASG, the complicated endogenous SG dynamics were revealed in both live cells and C. elegans. Collectively, our work provides an ideal probe that has thus far been absent in the field of SG investigations. We anticipate that this powerful tool may create exciting opportunities to investigate the underlying roles of SGs in different organisms.

Supplementary Materials forpublication.

The geminal difluorocyclobutane core is a valuable structural element in medicinal chemistry. Strategies for gem-difluorocyclobutanes, especially the 2-substituted cases, are limiting and often suffer from harsh reaction conditions. Reported herein is a migratory gem-difluorination of aryl-substituted methylenecycloproanes (MCPs) for the synthesis of 2-arylsubstituted gem-difluorocyclobutanes. Commercially available Selectfluor (F-TEDA-BF4) and Py·HF were used as the fluorine sources. The protocol proceeds via a Wagner-Meerwein rearrangement with mild reaction conditions, good functional group tolerance, and moderate to good yields. The product could be readily transformed to gem-difluorocyclobutane-containing carboxylic acid, amine, and alcohol, all of which are useful building blocks for biologically active molecule synthesis.

Borylated aza-arenes are of great importance in the area of organic synthesis. A radical borylative cyclization of isocyanoarenes with N-heterocyclic carbene borane (NHC-BH3) under metal-free conditions was developed. The reaction allows the efficient assembly of several types of borylated aza-arenes (phenanthridines, benzothiazoles, etc.), which are difficult to access using alternative methods. Mild reaction conditions, a good functional-group tolerance, and generally good efficiencies were observed. The utility of these products is demonstrated, and the mechanism is discussed.

The homologous recombination repair (HRR) pathway is critical for repairing double-strand breaks (DSB). Inhibition of the HRR pathway is usually considered a promising strategy for anticancer therapy. The Bloom's Syndrome Protein (BLM), a DNA helicase, is essential for promoting the HRR pathway. Previously, we discovered quinazolinone derivative 9h as a potential BLM inhibitor, which suppressed the proliferation of colorectal cancer (CRC) cell HCT116. Herein, a new series of quinazolinone derivatives with N3-substitution was designed and synthesized to improve the anticancer activity and explore the structure-activity relationship (SAR). After evaluating their BLM inhibitory activity, the SAR was discussed, leading to identifying compound 21 as a promising BLM inhibitor. 21 exhibited the potent BLM-dependent cytotoxicity against the CRC cells but weak against normal cells. Further evaluation revealed that 21 could disrupt the HRR level while inhibiting BLM located on the DSB site and trigger DNA damage in the CRC cells. This compound effectively suppressed the proliferation and invasion of CRC cells, along with cell cycle arrest and apoptosis. Consequently, 21 might be a promising candidate for treating CRC, and the BLM might be a new potential therapeutic target for CRC.

α-Haloboronates are useful organic synthons that can be converted to a diverse array of α-substituted alkyl borons. Methods to α-haloboronates are limiting and often suffer from harsh reaction conditions. Reported herein is a photochemical radical C-H halogenation of benzyl N-methyliminodiacetyl (MIDA) boronates. Fluorination, chlorination, and bromination reactions were effective by using this protocol. Upon reaction with different nucleophiles, the C-Br bond in the brominated product could be readily transformed to a series of C-C, C-O, C-N, C-S, C-P, and C-I bonds, some of which are difficult to forge with α-halo sp2 -B boronate esters. An activation effect of B(MIDA) moiety was found.

The c-myc oncogene is an important regulator for cell growth and differentiation, and its aberrant overexpression is closely related to the occurrence and development of various cancers. Thus, the suppression of c-myc transcription and expression has been investigated for cancer treatment. In this study, various new bisacridine derivatives were synthesized and evaluated for their binding with c-myc promoter G-quadruplex and i-motif. We found that a9 could bind to and stabilize both G-quadruplex and i-motif, resulting in the downregulation of c-myc gene transcription. a9 could inhibit cancer cell proliferation and induce SiHa cell apoptosis and cycle arrest. a9 exhibited tumor growth inhibition activity in a SiHa xenograft tumor model, which might be related to its binding with c-myc promoter G-quadruplex and i-motif. Our results suggested that a9 as a dual G-quadruplex/i-motif binder could be effective in both oncogene replication and transcription and become a promising lead compound for further development with improved potency and selectivity.

DNA damage response (DDR) pathways are crucial for the survival of cancer cells and are attractive targets for cancer therapy. Bloom syndrome protein (BLM) is a DNA helicase that performs important roles in DDR pathways. Our previous study discovered an effective new BLM inhibitor with a quinazolinone scaffold by a screening assay. Herein, to better understand the structure-activity relationship (SAR) and biological roles of the BLM inhibitor, a series of new derivatives were designed, synthesized, and evaluated based on this scaffold. Among them, compound 9h exhibited nanomolar inhibitory activity and binding affinity for BLM. 9h could effectively disrupt BLM recruitment to DNA in cells. Furthermore, 9h inhibited the proliferation of the colorectal cell line HCT116 by significantly triggering DNA damage in the telomere region and inducing apoptosis, especially in combination with a poly (ADP-ribose) polymerase (PARP) inhibitor. This result suggested a synthetic lethal effect between the BLM and PARP inhibitors in DDR pathways.

Nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) are global epidemic public health problems with pathogenesis incompletely understood. Hepatocyte excessive apoptosis is a significant symbol for NAFLD/NASH patients, and therefore anti-apoptosis therapy could be used for NAFLD/NASH treatment. Up-regulation of BCL-2 has been found to be closely related with anti-apoptosis. BCL-2 gene promoter region has a C-rich sequence, which can form i-motif structure and play important role in regulating gene transcription. In this study, after extensive screening and evaluation, we found that acridone derivative A22 could up-regulate BCL-2 transcription and translation in vitro and in cells through selective binding to and stabilizing BCL-2 gene promoter i-motif. Our further experiments showed that A22 could reduce hepatocyte apoptosis in NAFLD/NASH model possibly through up-regulating BCL-2 expression. A22 could reduce inflammation, endoplasmic reticulum stress and cirrhosis in high-fat diet-fed mice liver model. Our findings provide a potentially new approach of anti-apoptosis for NAFLD/NASH treatment, and A22 could be further developed as a lead compound for NAFLD/NASH therapy. Our present study first demonstrated that gene promoter i-motif could be targeted for gene up-regulation for extended treatment of other important diseases besides cancer.

Benzothiazolium and benzoxazolium are common groups for the construction of hemicyanine dyes; however, their isosteric analogue benzoselenazolium have rarely been studied. Here, we report the development of the first benzoselenazolium-based hemicyanine dye for the selective detection of G-quadruplexes. This molecule, SEMA-1, was validated as a red-emitting and activatable fluorescent probe whose fluorescence would only be activated in the presence of G-quadruplexes in buffer solution. Consistent with this, SEMA-1 was found to accumulate in nucleoli and could be used to detect the high abundance of nucleolar rDNA and rRNA G-quadruplexes in fixed HeLa cells. On the other hand, due to the retained mitochondrial membrane potential in live HeLa cells, SEMA-1 was captured by mitochondria and had the potential to detect the mitochondrial G-quadruplexes. Collectively, this work demonstrates the value of developing G-quadruplex-specific fluorescent probes from novel benzoselenazolium-based hemicyanine scaffold.

I-motifs play key regulatory roles in biological processes, holding great potential as attractive therapeutic targets. In the present study, we developed a novel fluorescent probe G59 with strong and selective binding to the c-myc gene promoter i-motif. G59 had an i-motif-binding carbazole moiety conjugated with naphthalimide fluorescent groups. G59 could differentiate the c-myc i-motif from other DNA structures through selective activation of its fluorescence, with its apparent visualization in solution. The smart probe G59 showed excellent sensitivity, with a low fluorescent detection limit of 154 nM and effective stabilization to the c-myc i-motif. G59 could serve as a rapid and sensitive probe for label-free screening of selective c-myc i-motif binding ligands under neutral crowding conditions. To the best of our knowledge, G59 is the first fluorescent probe with high sensitivity for recognizing the i-motif structure and screening for selective binding ligands.

The indolyl-4(3

Promoting energy expenditure is known to curb obesity and can be exploited for its treatment. Our previous study has demonstrated that activation of HSF1/PGC-1α axis efficiently induced mitochondrial biogenesis and adaptive oxidation and thus ameliorating lipid accumulation, however, whether it can be a therapeutic approach for metabolic disorders treatment needs explored. Here, a high-efficient and specific HSF1/PGC-1α activator screening system was established and the natural clinical liver-protecting agent matrine was identified as a robust HSF1/PGC-1α activator. Matrine treatment efficiently induced mitogenesis and thermogenic program in primary mouse adipose stem cell derived adipocytes by enriching HSF1 to the promoter of Pgc-1α. Deficiency of PGC-1α in adipocytes diminished the browning induction ability of matrine. Oral administration of matrine to the obese mice induced by high fat and high cholesterol diet increased energy expenditure and corrected the degeneration of thermogenesis in brown adipose tissue (BAT). Also, matrine treatment markedly induced the transformation of brown-like adipocytes in subcutaneous white adipose tissue (sWAT) via a mechanism of HSF1/PGC-1α, thereby attenuating obesity and myriads of metabolic disorders. This led to an improvement in adaptive thermogenesis to cold stimuli. These findings are of great significance in understanding the regulation mechanisms of the HSF1/PGC-1α axis in thermogenesis and providing a novel therapeutic approach for obesity treatment. Matrine may have potential therapeutic implications for the treatment of obesity in clinics.

The mitochondrial DNA G-quadruplex (mtDNA G4) is a potential regulatory element for the regulation of mitochondrial functions; however, its relevance and specific roles in diseases remain largely unknown. Here, we engineered a set of chemical probes, including

Because of the lack of facile and accurate methods to track stress granule (SG) dynamics in live cells and

Tooth extraction is one of the most common causes of dental anxiety and pain, leading to the elevation of blood pressure (BP) and heart rate (HR). Such effects may be exaggerated and cause life-threatening accidents in patients with hypertension. Therefore, the pain and anxiety management of these patients is imperative. Virtual reality (VR) has been demonstrated to be a distraction method to relieve anxiety and pain in clinical operations. Thus, we hypothesized that VR can control the elevation of BP and HR in patients with hypertension. In this study, 96 eligible patients with controlled hypertension who needed tooth extraction were randomized to the VR or standard care group by stratified randomization of anxiety grade and gender. Their BP and HR were dynamically monitored. The corresponding systolic and diastolic BP and HR values were selected when systolic BP was at the highest point of the process. BP was converted into mean arterial pressure (MAP) for comparison per the following formula: MAP = (systolic BP + 2 × diastolic BP)/3. Statistical analyses were by intention to treat and conducted in SPSS. Nonparametric rank sum tests were used to compare the difference of ΔMAP and ΔHR between the VR and standard care groups. Multivariate linear regression was applied to evaluate the effect of VR on ΔMAP and ΔHR. The results showed that the VR technique significantly decreased the elevation of MAP ( P < 0.001) and HR ( P < 0.001), and this effect was found even after adjusting for baseline characteristics and additional surgical procedures (ΔMAP, P < 0.001, R2 = 0.276; ΔHR, P < 0.001, R2 = 0.152). VR did not increase the incidence of adverse events ( P = 0.677). In conclusion, the VR technique was effective in controlling BP and HR within an acceptable range and can help manage BP and HR during tooth extraction for patients with hypertension (Chinese Clinical Trial Registry: ChiCTR2100042132).

Background and purpose Nonalcoholic steatohepatitis (NASH) is the more severe form of metabolic associated fatty liver disease (MAFLD), and no pharmacologic treatment approved as yet. Identification of novel therapeutic targets and their agents are critical to overcome the current inadequacy of drug treatment for NASH. Experimental approach The correlation between heat shock factor 1 (HSF1) levels and the development of NASH and the target genes of HSF1 in hepatocyte were revealed by chromatin-immunoprecipitation sequencing. The effects and mechanisms of SYSU-3d in alleviating NASH were examined in relevant cell models and mouse models (the Ob/Ob mice, high-fat and high-cholesterol diet, the methionine-choline deficient diet fed mice). The drug-like properties of SYSU-3d in vivo were evaluated. Key results HSF1 is progressively reduced with mitochondrial dysfunction in NASH pathogenesis and activation of this transcription factor by its newly-identified activator SYSU-3d efficiently ameliorated all manifestations of NASH in mice. When activated, the phosphorylated HSF1 (Ser326) translocated to nucleus and bound to the promoter of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) to induce mitochondrial biogenesis, thus increasing mitochondrial adaptive oxidation and inhibiting oxidative stress. The deletion of HSF1 and PGC-1α or recovery of HSF1 in HSF1-deficiency cells revealed the HSF1/PGC-1α metabolic axis mainly responsible for the anti-NASH effects of SYSU-3d independent of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK). Conclusion and implications Activation of HSF1 is a practicable therapeutic approach for NASH treatment via the HSF1/PGC-1α/mitochondrial axis, and SYSU-3d would take into consideration as a potential candidate for the treatment of NASH.

Cancer metabolism is an attractive target of the therapeutic strategy for cancer. The present study identified bouchardatine (Bou) as a potent suppressor of rectal cancer growth by cycle-arresting independent of apoptosis. In cultured HCT-116 rectal cancer cells, Bou increased glucose uptake/oxidation and capacity of mitochondrial oxidation. These effects were associated with an upregulation of uncoupling protein 2 (UCP2) and the activation of its upstream Sirtuin 1 (SIRT1)/(Liver kinase B1) LKB1- (Adenosine monophosphate-activated protein kinase) AMPK axis. The pivotal role of UCP2 in the cancer-suppressing effect was demonstrated by overexpressing UCP2 in HCT-116 cells with similar metabolic effects to those produced by Bou. Interestingly, Bou activated peroxisome proliferators activated receptor γ coactivator 1α (PGC-1α) and recruited it to the promoter of UCP2 in HCT-116 cells along with deacetylation (thus activation) by SIRT1. The requirement of SIRT1 for the cancer-suppressing effect through the PGC-1α–UCP2 was confirmed by the reciprocal responses to Bou in HCT-116 with defected and overexpressed SIRT1. Whereas knockdown, mutation or pharmacological inhibition of SIRT1 all abolished Bou-induced deacetylation/activation of PGC-1α, the opposing effects were observed after overexpressing SIRT1. In mice, administration of Bou (50 mg/kg) also suppressed the growth of rectal cancer associated with increases the UCP2 expression and mitochondria capacity in the tumor. Collectively, our findings suggest that Bou has a therapeutic potential for the treatment of rectal cancer by disrupting the metabolic path of cancer cells via activating the PGC-1α-UCP2 axis with SIRT1 as its primary target.

Euphorhelipanes A (1) and B (2), two Euphorbia diterpenoids with a new 4-(5,5-dimethylheptan-2-yl)-2,7-dimethylbicyclo[4.3.0]nonane skeleton, were isolated from a 95% ethanol extract of the whole plants of Euphorbia helioscopia. Their structures were elucidated by spectroscopic data analysis, quantum chemical calculations, and single-crystal X-ray diffraction data. Compounds 1 and 2 represent the first examples of Euphorbia diterpenoids with a 5/6 fused carbon ring system, and their plausible biosynthetic pathways originating from jatrophanes are proposed. Compounds 1 and 2 showed a triglyceride-lowering effect in oleic-acid-stimulated HuH7 cells at concentrations of 1-50 μM.

The gut bacterium Akkermansia muciniphila has been increasingly recognized for its therapeutic potential in treating metabolic disorders, including obesity, diabetes, and metabolicdysfunction-associated fatty liver disease (MAFLD). However, its underlying mechanism involved in its well-known metabolic actions needs further evaluation. The present study explored the therapeutic effect and mechanism of A. muciniphila in intervening MAFLD by using a high-fat and high-cholesterol (HFC) diet induced obese mice model. Mice treated with A. muciniphila efficiently reversed MAFLD in the liver, such as hepatic steatosis, inflammatory, and liver injury. These therapeutic effects persisted after long-term drug withdrawal and were slightly weakened in the antibiotics-treated obese mice. A. muciniphila treatment efficiently increased mitochondrial oxidation and bile acid metabolism in the gut-liver axis, ameliorated oxidative stress-induced cell apoptosis in gut, leading to the reshaping of the gut microbiota composition. These metabolic improvements occurred with increased L-aspartate levels in the liver that transported from the gut. The administration of L-aspartate in vitro or in mice displayed the similar beneficial metabolic effects mentioned above and efficiently ameliorated MAFLD. Together, these data indicate that the anti-MAFLD activity of A. muciniphila correlated with lipid oxidation and improved gut–liver interactions through regulating the metabolism of L-aspartate. A. muciniphila could be a potential agent for clinical intervention in MAFLD.

Upregulation of platelet-derived growth factor receptor β (PDGFR-β) has been found to be associated with development of various types of cancers, which has become an attractive target for anti-tumor treatment. Previously, we have synthesized and studied an acridone derivative B19, which can selectively bind to and stabilize oncogene c-myc promoter i-motif, resulting in down-regulation of c-myc transcription and translation, however its effect on tumor cells apoptosis requires improvement. In the present study, we synthesized a variety of B19 derivatives containing a known anti-cancer fluorescent chromophore naphthalimide for the purpose of enhancing anti-cancer activity. After screening, we found that acridone-naphthalimide derivative WZZ02 could selectively stabilize PDGFR-β promoter G-quadruplex and destabilize its corresponding i-motif structure, without significant interaction to other oncogenes promoter G-quadruplex and i-motif. WZZ02 down-regulated PDGFR-β gene transcription and translation in a dose-dependent manner, possibly due to above interactions. WZZ02 could significantly inhibit cancer cell proliferation, and induce cell apoptosis and cycle arrest. WZZ02 exhibited tumor growth inhibition activity in MCF-7 xenograft tumor model, which could be due to its binding interactions with PDGFR-β promoter G-quadruplex and i-motif. Our results suggested that WZZ02 as a dual G-quadruplex/i-motif binder could be effective on both oncogene replication and transcription, which could become a promising lead compound for further development with improved potency and selectivity. The wide properties for the derivatives of 1,8-naphthalimide could facilitate further in-depth mechanistic studies of WZZ02 through various fluorescent physical and chemical methods, which could help to further understand the function of PDGFR-β gene promoter G-quadruplex and i-motif.