Impaired clearance of amyloid-β (Aβ) contributes to Alzheimer’s disease (AD) pathogenesis, but its upstream modulators remain poorly defined. We report secreted Dickkopf (DKK) proteins—DKK1 through DKK4—as previously unrecognized ligands of low-density lipoprotein receptor–related protein 1 (LRP1), a principal Aβ clearance receptor. Analyses of cells derived from a patient with AD, postmortem tissue, and 5×FAD mice reveal that DKK1 and DKK3 are elevated in AD and reduce Aβ uptake and degradation in neurons and astrocytes. Mechanistically, DKKs inhibit Aβ clearance by competitively binding LRP1 and promoting its internalization. In 5×FAD mice, DKK3 overexpression worsens, while knockout improves, Aβ pathology and cognitive outcomes. A targeted high-throughput screen of ~3000 compounds identified SJ-300 as a potent and selective inhibitor of the DKK3-LRP1 interaction. SJ-300 restores Aβ clearance and rescues cognitive function and neuropathology in 5×FAD mice. These findings uncover DKK3-LRP1 axis as a contributor for Aβ metabolism and nominate SJ-300 as a promising therapeutic candidate for AD intervention.
Lung cancer remains the leading cause of cancer-related mortality worldwide, necessitating the development of new treatment strategies. Arachidonic acid (ARA), a polyunsaturated fatty acid, shows promise in cancer therapy due to its potential anti-tumor effects, although its role in lung cancer remains unclear. This study investigated the effects and underlying mechanism of ARA on A549 and NCI-H1299 lung cancer cells. In vitro assays were used to assess cell viability, apoptosis, colony formation, lipid droplet formation, and changes in cellular lipid content. ARA dose-dependently suppressed cell viability, facilitated apoptosis, and suppressed colony formation in both lung cancer cell lines. Network pharmacology analysis was performed to identify potential gene targets and pathways, uncovering 61 overlapping genes between ARA and lung cancer-related targets, with mitogen-activated protein kinase 1 (MAPK1) emerging as a key gene. Enrichment analyses suggested that the effects of ARA might be mediated through lipid metabolism and the extracellular signal-regulated kinase (ERK)/peroxisome proliferator-activated receptor gamma (PPARγ) signaling pathway. In both lung cancer cell lines, ARA treatment inhibited lipid droplet formation and decreased the cellular lipids. Immunoblotting further confirmed that ARA treatment significantly increased ERK phosphorylation while reducing PPARγ and fatty acid synthase (FASN) protein levels. In vitro experiments using GW9662, a PPARγ antagonist, confirmed that inhibiting lipid droplet formation impairs lung cancer cell viability and promotes apoptosis. Furthermore, in vivo experiments demonstrated that ARA significantly reduced tumor size and weight in a lung cancer xenograft model, further validating its anti-tumor effects. The potential of ARA as a therapeutic agent for lung cancer might involve lipid metabolism and relevant signaling pathways. A future study exploring the full therapeutic potential of ARA and underlying mechanisms in lung cancer is needed.
Extracellular vesicles (EV), important messengers in intercellular communication, can load and transport various bioactive components and participate in different biological processes. We previously isolated glioma human endothelial cells (GhECs) and found that GhECs, rather than normal human brain endothelial cells (NhECs), exhibit specific enrichment of MYO1C into EVs and promote the migration of glioma cells. In this study, we explored the mechanism by which MYO1C is secreted into EVs. We report that such secretion is dependent on RAB31, RAB27B, and FAS. When expression of RAB31 increases, MYO1C is enriched in secretory EVs. Finally, we identified an EV export mechanism for MYO1C that promotes glioma cell invasion and is dependent on RAB31 in GhECs. In summary, our data indicate that the knockdown of RAB31 can reduce enrichment of MYO1C in extracellular vesicles, thereby attenuating the promotion of glioma cell invasion by GhEC‐EVs.
Intraventricular hemorrhage in preterm neonates has become a major global health problem and is associated with a high risk of post-hemorrhagic hydrocephalus (PHH). Identifying diagnostic markers and therapeutic targets is a focal challenge in the PHH prevention and control. Here, this study applies multi-omics analyses to characterize the biochemical, proteomic, and metabolomic profiles of the cerebrospinal fluid (CSF) in clinical human cohorts to investigate disease development and recovery processes occurring due to PHH. Integrative multiomics analysis suggests that the over-representation of ferroptosis, calcium, calcium ion binding, and cell adhesion signaling pathways is associated with PHH. Bioinformatic analysis indicates that chondroitin sulfate proteoglycan 4 (CSPG4) is discovered as a CSF biomarker and positively correlated with the ventricular size and the rate of periventricular leukomalacia. Next, it is further demonstrated that these signaling pathways are dysregulated in the choroid plexus (ChP) in PHH by using in vitro cellular experiments and rat models of PHH, whereas CSPG4 silencing can suppress ferroptosis, cell adhesion function, and the intracellular flow of Ca2+. These findings broaden the understanding of the pathophysiological mechanisms of PHH and suggest that CSPG4 may be an effective therapeutic target for PHH.
BACKGROUND:Alzheimer's disease (AD) is one of the most common neurodegenerative diseases leading to dementia in elderly people. Microglia-mediated neuroinflammation plays an important role in AD pathogenesis, so modulation of neuroinflammation has emerged as an essential therapeutic method to improve AD. The current study aims to investigate whether MKP-1 can regulate microglia phenotype and inflammatory factor release in AD and explore its possible mechanisms.METHODS:Amyloid precursor protein/PS1 double transgenic mice and wild-type mice were selected to study the locations of microglia and amyloid-β (Aβ) plaques in different regions of mice brains. Changes in MKP-1 of microglia were detected using AD model mice and AD model cells. Changes in phenotype and the release of inflammatory factors within immortalized BV2 murine microglia were investigated by regulating the expression of MKP-1.RESULTS:The distribution of microglia and Aβ plaques in the AD brain was region-specific. MKP-1 expression was downregulated in AD mice, and in vitro, with increasing Aβ concentrations, MKP-1 expression was reduced. MKP-1 over-expression increased M2 microglia but decreased M1 microglia accompanied by changes in inflammatory factors and inhibition of MKP-1 yielded the opposite result.CONCLUSION:MKP-1 regulated microglia phenotype and inflammatory factor release in AD through modulation of the p38 signaling pathway.
Alzheimer’s disease (AD) is a complicated disease for which there are still no ideal one-target drugs, while multi-target drugs are closer to ideal drugs and will provide new solutions for the clinical treatment of AD. DL0410 is a promising multi-target drug candidate for AD treatment that is not only a significant inhibitor against both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) but also an antagonist of histamine H3 receptor (H3R), and its therapeutic efficacy in treating cognitive dysfunction has been validated in a series of AD-related animal models, including scopolamine-induced mice, D-galactose-induced and Aβ-induced mice, and APP/PS1 and SAMP8 mice. Although the structure of DL0410 has been analyzed using various detection techniques, such as MS and NMR, its three-dimensional crystal structure still requires further confirmation. In this study, the crystal of DL0410 was grown in aqueous solution, and its structure was detected using the X-ray diffraction method. The crystal data, atomic coordinates, bond lengths, angles, and hydrogen bonds of DL0410 were obtained. Its stability was proven by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Based on this study, the molecular docking of DL0410 with AChE, BuChE, and H3R was performed to uncover their interaction mechanisms and explain their bioactivities. This study provides important information for new multi-target drug design and the research and development of new drugs for AD treatment.
Objective To investigate the effect of 1,8-cineol on caspase 3 expression and NO production induced by Aβ25-35 in PC12 cells. Methods PC12 cells were cultured in vitro, and cell injury was induced by Aβ25-35 with a concentration of 20 μM. 1,8-cineol (1, 3, 10 μM) was pretreated before Aβ25-35 treatment. PC12 cell viability was evaluated by MTT detection assay. Caspase 3 protein expression was detected by Western blotting. The level of NO production in PC12 cells was measured using ELISA detection assay kit. Results In cultured PC12 cells in vitro, MTT results showed that 20 μM of Aβ25-35 reduced cell viability significantly compared with control group. The cell viability was increased by pretreatment with 1,8-cineol with concentrations of 3 and 10 μM compared with Aβ25-35 only group. Western blotting results showed compared with control group, caspase 3 expression was increased significantly in 20 μM Aβ25-35 group. Compared with Aβ25-35 group, 1,8-cineol of 3 and 10 μM group reduced caspase 3 protein expression significantly. The level of NO production in PC12 cells was increased significantly, which was decreased by pretreatment with 3 and 10 μM of 1,8-cineol. Conclusions: Our results revealed a protective effect of 1,8-cineol on Aβ25-35 induced PC12 cell injury through inhibition of caspase 3 expression and NO production.
DL0410, a dual-action cholinesterase inhibitor and histamine-3 receptor antagonist with a novel structural scaffold, may be a potential candidate for the treatment of Alzheimer's disease (AD). To the best of the authors' knowledge, this is the first study to demonstrate a reliable method for the measurement of DL0410 in rat plasma, brain, bile, urine and feces samples, and identification of its primary metabolites. The pharmacokinetic properties of DL0410 were analyzed by liquid chromatography-mass spectrometry at oral doses of 25, 50 and 100 mg/kg and intravenous dose of 5 mg/kg. The investigation of the excretion and metabolism of DL0410 was determined following liquid-liquid extraction for biliary, urinary and fecal samples. Finally, the cytochrome (CY)P450 isoforms involved in the production of DL0410 metabolites with recombinant human cytochrome P450 enzymes were characterized. The results suggested that DL0410 was not well absorbed; however, was distributed to the entorhinal cortex and hippocampus of the brain. A total of two common metabolites of the reduction of DL0140 in the bile, urine and feces were identified and CYP2D6 was involved in this reaction. The pharmacokinetic results of DL0410 provided information for the illustration of its pharmacodynamic properties, mechanism of action and promoted its continued evaluation as a therapeutic agent for AD treatment.
Alzheimer’s disease (AD), the most common form of dementia in adults, is a progressive neurodegenerative disorder of the brain characterized by loss of memory and steady deterioration of cognition. Here, a series of symmetrical molecules containing biphenyl/bibenzyl scaffolds (12–36) were designed, synthesized, and evaluated for their ability to inhibit both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). A biological evaluation showed that most of these biphenyl derivatives were potent AChE and BuChE inhibitors. Among them, compound 15 displayed the greatest ability to inhibit BuChE (IC50 = 0.74 µM) and was also a good AChE inhibitor (IC50 = 1.18 µM). Compound 19 was not only a potent AChE inhibitor (IC50 = 0.096 µM), but also a mild BuChE inhibitor (IC50 =1.25 µM). Overall, these results suggested that compound 19 may be a promising agent in the treatment of AD.
In our study, we attempted to investigate the influences of P-glycoprotein (P-gp) on DL0410, a novel synthetic molecule for Alzheimer’s disease (AD) treatment, for intestinal absorption and blood-brain barrier permeability in vitro and related binding mechanisms in silico. Caco-2, MDCK, and MDCK-MDR1 cells were utilized for transport studies, and homology modelling of human P-gp was built for further docking study to uncover the binding mode of DL0410. The results showed that the apparent permeability (Papp) value of DL0410 was approximately 1 × 10−6 cm/s, indicating the low permeability of DL0410. With the presence of verapamil, the directional transport of DL0410 disappeared in Caco-2 and MDCK-MDR1 cells, suggesting that DL0410 should be a substrate of P-gp, which was also confirmed by P-gp ATPase assay. In addition, DL0410 could competitively inhibit the transport of Rho123, a P-gp known substrate. According to molecular docking, we also found that DL0410 could bind to the drug binding pocket (DBP), but not the nucleotide binding domain (NBD). In conclusion, DL0410 was a substrate as well as a competitive inhibitor of P-gp, and P-gp had a remarkable impact on the intestine and brain permeability of DL0410, which is of significance for drug research and development.
DL0410, containing biphenyl and piperidine skeletons, was identified as an acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitor through high-throughput screening assays, and further studies affirmed its efficacy and safety for Alzheimer’s disease treatment. In our study, a series of novel DL0410 derivatives were evaluated for inhibitory activities towards AChE and BuChE. Among these derivatives, compounds 6-1 and 7-6 showed stronger AChE and BuChE inhibitory activities than DL0410. Then, pharmacophore modeling and three-dimensional quantitative structure activity relationship (3D-QSAR) models were performed. The R2 of AChE and BuChE 3D-QSAR models for training set were found to be 0.925 and 0.883, while that of the test set were 0.850 and 0.881, respectively. Next, molecular docking methods were utilized to explore the putative binding modes. Compounds 6-1 and 7-6 could interact with the amino acid residues in the catalytic anionic site (CAS) and peripheral anionic site (PAS) of AChE/BuChE, which was similar with DL0410. Kinetics studies also suggested that the three compounds were all mixed-types of inhibitors. In addition, compound 6-1 showed better absorption and blood brain barrier permeability. These studies provide better insight into the inhibitory behaviors of DL0410 derivatives, which is beneficial for rational design of AChE and BuChE inhibitors in the future.
Our previous studies demonstrated that LAPTM4B-35 is overexpressed in a variety of solid cancers including hepatocellular carcinoma (HCC), and is an independent factor for prognosis. LAPTM4B-35 overexpression causes carcinogenesis and enhances cancer growth, metastasis and multidrug resistance, and thus may be a candidate for therapeutic targeting. The present study shows ethylglyoxal bisthiosemicarbazon (ETS) has effective anticancer activity through LAPTM4B-35 targeting. Bel-7402 and HepG2 cell lines from human HCC were used as cell models in which LAPTM4B-35 is highly expressed, and a human fetal liver cell line was used as a control. The results showed ETS has a specific and pronounced lethal effect on HCC cells, but not on fetal liver cells in culture. ETS also attenuated growth and metastasis of human HCC xenograft in nude mice, and extended the life span of mice with HCC. ETS induced HCC cell apoptosis, and upregulated a large number of proapoptotic genes and downregulated antiapoptotic genes. When endogenous overexpression of LAPTM4B-35 was knocked down with RNAi, the killing effect of ETS on HepG2 cells was significantly attenuated. ETS also inhibited phosphorylation of LAPTM4B-35 Tyr285, which involves in activation of the PI3K/Akt signaling pathway induced by LAPTM4B-35 overexpression. In addition, the induction of alterations in quantity of c-Myc, Bcl-2, Bax, cyclinD1 and Akt-p molecules in HepG2 cells by LAPTM4B-35 overexpression could be reversed by ETS. Conclusion: ETS is a promising candidate for treatment of HCC through LAPTM4B-35 protein targeting.
1,1′-([1,1′-Biphenyl]-4,4′-diyl)bis(3-(piperidin-1-yl)propan-1-one)dihydrochloride (DL0410) is a novel synthetic dual acetylcholinesterase (AChE)/butyrocholinesterase (BuChE) inhibitor, which has shown a potential therapeutic effect on Alzheimer's disease (AD). In this study we examined whether DL0410 produced neuroprotective effects in an AD cellular model and an Aβ1–42-induced amnesia mouse model. The in vitro inhibitory activities against AChE and BuChE were estimated using Ellman's assay. Copper-induced toxicity in APPsw-SY5Y cells was used as AD cellular model, the cell viability was assessed using MTS assay, and cell apoptosis was evaluated based on mitochondrial membrane potential detection. Aβ1–42-induced amnesia mouse model was made in male mice by injecting aggregated Aβ1–42 (2 μg in 2 μL 0.1% DMSO) into the right cerebral ventricle. Before and after Aβ1–42 injection, the mice were orally administered DL0410 (1, 3, 9 mg·kg−1·d−1) or rivastigmine (2 mg·kg−1·d−1) for 3 and 11 d, respectively. Memory impairments were examined using Morris water maze (MWM) test and passive avoidance test. The expression levels of APP, CREB, BDNF, JNK and Akt in the mouse brains were measured with either immunohistochemistry or Western blotting. DL0410 exhibited in vitro inhibitory abilities against AChE and BuChE with IC50 values of 0.286±0.004 and 3.962±0.099 μmol/L, respectively, which were comparable to those of donepezil and rivastigmine. In APPsw-SY5Y cells, pretreatment with DL0410 (1, 3, and 10 μmol/L) decreased the phosphorylation of JNK and increased the phosphorylation of Akt, markedly decreased copper-stimulated Aβ1–42 production, reversed the loss of mitochondrial membrane potential, and dose-dependently increased the cell viability. In Aβ1–42-treated mice, DL0410 administration significantly ameliorated learning and memory deficits in MWM test and passive avoidance test. Furthermore, DL0410 administration markedly decreased Aβ1–40/42 deposits in mouse cerebral cortices, and significantly up-regulated neurotrophic CREB/BDNF. Meanwhile, Akt/JNK signaling pathway may play a key role in the neuroprotective effect of DL0410. DL0410 ameliorates cognitive deficit and exerts neuronal protection in AD models, implicating this compound as a candidate drug for the prevention and therapy of AD.
FOXC1 is a member of Forkhead box transcription factors that participates in embryonic development and tumorigenesis. Our previous study demonstrated that FOXC1 was highly expressed in triple-negative breast cancer. However, it remains unclear what is the relation between FOXC1 and ERα and if FOXC1 regulates expression of ERα. To explore relation between FOXC1 and ERα and discover regulation of ERα expression by FOXC1 in breast cancer, we analyzed data assembled in the Oncomine and TCGA, and found that there was significantly higher FOXC1 expression in estrogen receptor-negative breast cancer than that in estrogen receptor-positive breast cancer. Overexpression of FOXC1 reduced expression of ERα and cellular responses to estradiol (E2) and tamoxifen in the MCF-7 FOXC1 and T47D FOXC1 cells, while knockdown of FOXC1 induced expression of ERα and improved responses to estradiol (E2) and tamoxifen in BT549 FOXC1 shRNA and HCC1806 FOXC1 shRNA cells. In addition, overexpression of FOXC1 reduced expression of progesterone receptor (PR), Insulin receptor substrate 1 (IRS1), and XBP1 (X-Box Binding Protein 1) and significantly reduced luciferase activity caused by E2 using ERE luciferase reporter assay. These results suggested that FOXC1 regulated expression of ERα and affected sensitivity of tamoxifen treatment in breast cancer, and that FOXC1 may be used as a potential therapeutic target in ERα-negative breast cancer.
FOXC1 is a member of Forkhead box family transcription factors. We showed that FOXC1 level was increased in melanoma cells and tissues and correlated with hypomethylation of the FOXC1 gene. Overexpression of FOXC1 promoted proliferation, migration, invasion, colony formation and growth in 3D Matrigel of melanoma cells. FOXC1 increased MST1R and activated the PI3K/AKT pathway. Also, FOXC1 expression was associated with disease progression and poor prognosis of melanoma. We suggest that FOXC1 is a potential prognostic biomarker for treating melanoma and predicting outcome of patients.
Polypyrimidine tract-binding protein 1 (PTBP1) and its brainspecific homologue, PTBP2, are associated with pre-mRNAs and influence pre-mRNA processing, as well as mRNA metabolism and transport. They play important roles in neural differentiation and glioma development. In our study, we detected the expression of the two proteins in glioma cells and predicted that they may be sumoylated using SUMOplot analyses. We confirmed that PTBP1 and PTBP2 can be modified by SUMO1 with co-immunoprecipitation experiments using 293ET cells transiently co-expressing SUMO1 and either PTBP1 or PTBP2. We also found that SUMO1 modification of PTBP2 was enhanced by Ubc9 (E2). The mutation of the sumoylation site (Lys137) of PTBP2 markedly inhibited its modification by SUMO1. Interestingly, in T98G glioma cells, the level of sumoylated PTBP2 was reduced compared to that of normal brain cells. Overall, this study shows that PTBP2 is posttranslationally modified by SUMO1.
Phthiobuzone is a bis(thiosemicarbazone) derivative with a single chiral center which has been used as a racemate in the clinical treatment of herpes and trachoma diseases. In this study, its two enantiomers were prepared from chiral amino acids and their absolute configurations were investigated by electronic circular dichroism (ECD) combined with modern quantum-chemical calculations using time-dependent density functional theory. It was found that solvation changed both the conformational distribution and the ECD spectrum of each conformer. The theoretical ECD spectra of the two enantiomers were in good agreement with the experimentally determined spectra of the corresponding isomers in dimethyl sulfoxide. The ECD behavior of the bis(thiosemicarbazone) chromophore in a chiral environment is also discussed. Our results indicate that ECD spectroscopy may be a useful tool for the stereochemical evaluation of chiral drugs.
Inflammation is believed to be integral to the pathogenesis of Alzheimer's disease (AD). Arachidonic acid (AA) is the most important omega-6 fatty acid and a mediator of inflammatory pathways. High-sensitivity enzyme linked immunosorbent assay shows that AA and its various metabolites; prostaglandins, thromboxanes, and leukotriene B4 resulted in significantly higher secretion of both Abeta40 and 42 peptides. A combination of identical number of alternate cis and trans double bonds either at positions Δ5 or 7Z,13 or 15E (such as PGE(2), PGF(2α), THXB2 and PGF(2α)EA) or at positions Δ6Z,8E,10E,14Z (such as LB4) built in the 3-dimensional structure of 20-carbon fatty acyl chains believed to be responsible for their detrimental action. CP 24,879 and sesamin, 2 inhibitors of the AA pathway suppressed the production of amyloid-beta (Aβ) peptides. Immunoblotting experiments and use of SP-C99 transfected COS-7 cells suggested that AA and its metabolites-driven altered production of Aβ is mediated through gamma-secretase cleavage of amyloid precursor protein (APP). An early-onset AD transgenic mouse model expressing the double-mutant form of human amyloid precursor protein, Swedish (K670N/M671L) and Indiana (V717F), corroborated our in vitro findings by showing higher levels of Abeta and amyloid plaques in the brains, when they were fed chow supplemented with 2% AA. Our work not only supports that AA and its metabolites are involved in the production of Aβ and in the pathogenesis of AD but also contributes to clarify aspects of structure-activity relationship helpful for future nonsteroidal anti-inflammatory drugs (NSAIDs) research.
OBJECTIVE To investigate the in vitro anti-angiogenesis effect of platelet activating factor(PAF)receptor antagonist SY0916 on macrophage stimulated with PMA,and to analyze the anti-angiogenesis molecular mechanism of SY0916.METHODS The chemotaxis of primary mouse peritoneal macrophages induced by PAF and the inhibitory effect of SY0916 on macrophage was investigated using Boyden Chamber assay.The contents of IL-1β,TNF-α and VEGF induced by PMA in U937 macrophage cell supernatant were measured in turn by radio immunoassay,bioassay and ELISA,and the activity and amount of MMP-9 were determined by zymography and Western Blot.The mRNA expressions of IL-1β,TNF-α and VEGF were detected by RT-PCR,and the effect of SY0916 on DNA binding activity of NF-κB was analyzed by EMSA respectively.RESULTS It was shown that SY0916 had significant inhibitory effect on the chemotaxis of mouse peritoneal macrophage induced by PAF.The protein and mRNA expressions of IL-1β,TNF-α,VEGF and MMP-9 were both inhibited by SY0916 in a dose-dependent manner.And the activity of NF-κB was also inhibited by SY0916.CONCLUSION The anti-angiogenesis effect of SY0916 on macrophage may be related to down-regulating the expressions of IL-1β,TNF-α,VEGF and MMP-9 through blocking the DNA binding activity of NF-κB in inflammatory condition.