The p38 MAPK signaling pathway plays a key role in lung inflammation and the development of acute lung injury (ALI). We previously reported that the phenolic compound procyanidin B1 inhibits ...inflammation by suppressing the p38 MAPK signaling pathway. Here, we asked whether the monomer of procyanidin B1, epicatechin (EC), can alleviate LPS-induced ALI in mice, and if so, whether EC acts by inhibiting p38 MAPK. C57BL/6 mice were randomly divided into four groups (n = 8) and received EC alone, vehicle (sham group), LPS alone, or LPS and EC. LPS was administered via intraperitoneal injection and EC via nasogastric feeding. Lung histopathology, alveolocapillary membrane permeability, inflammation, and p38 MAPK pathway activation were assessed by immunohistochemistry, tissue wet/dry weight analysis, quantitative PCR, protein assays, ELISA, and western blot analysis using lung tissue and/or bronchoalveolar fluid. We also performed molecular modeling and in vitro enzymatic assays to examine the potential interaction between EC and p38 MAPK at the molecular level. We found that LPS caused an increase in ALI-associated lung pathology accompanied by activation of p-p38 pathway components and the transcription factor AP1. All of these effects were substantially reduced by treatment with EC. Furthermore, molecular modeling suggested that EC suppressed p38 MAPK signaling by hydrogen bonding with Glu71, Ala 111, Asp112, and Leu171 in the active site of p38α. In vitro kinase assays confirmed the ability of EC to directly inhibit purified p38 MAPK. Collectively, our data suggest that the naturally occurring compound EC could be a new therapeutic option for ALI.
•Epicatechin alleviates inflammation in LPS-induced acute lung injury in mice.•Epicatechin inhibits inflammatory injury by inhibiting activation of the p38 MAPK–AP1 signaling pathway.•Epicatechin inhibits p38 MAPK possibly by directly binding to the active site of p38 and inhibiting its catalytic activity.
A NIR fluorescent probe was developed for intestinal microbiota identification possessing active APN from human feces.
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A NIR fluorescent probe (DDAA) derived from fluorophore DDAO ...with alanine as the recognition group was developed for sensing aminopeptidase N (APN) in gut microbiota. Using DDAA as the real-time guidance tool for the fluorescence imaging of intestinal microorganism, target bacteria and saccharomycete possessing active APN were identified successfully from human feces.
The Pacific Decadal Oscillation (PDO), the dominant pattern of sea surface temperature anomalies in the North Pacific basin, is an important low-frequency climate phenomenon. Leveraging data spanning ...from 1871 to 2010, we employed machine learning models to predict the PDO based on variations in several climatic indices: the Niño3.4, North Pacific index (NPI), sea surface height (SSH), and thermocline depth over the Kuroshio–Oyashio Extension (KOE) region (SSH_KOE and Ther_KOE), as well as the Arctic Oscillation (AO) and Atlantic Multi-decadal Oscillation (AMO). A comparative analysis of the temporal and spatial performance of six machine learning models was conducted, revealing that the Gated Recurrent Unit model demonstrated superior predictive capabilities compared to its counterparts, through the temporal and spatial analysis. To better understand the inner workings of the machine learning models, SHapley Additive exPlanations (SHAP) was adopted to present the drivers behind the model’s predictions and dynamics for modeling the PDO. Our findings indicated that the Niño3.4, North Pacific index, and SSH_KOE were the three most pivotal features in predicting the PDO. Furthermore, our analysis also revealed that the Niño3.4, AMO, and Ther_KOE indices were positively associated with the PDO, whereas the NPI, SSH_KOE, and AO indices exhibited negative correlations.
We report on a naphthalimide ratiometric fluorescent probe for the real-time sensing and imaging of pathogenic bacterial glucosyltransferases, which are associated with the development of dental ...caries. Using a high-throughput screening method, we identified that several natural polyphenols from green tea were GTFs inhibitors that could eventually lead to suitable oral treatments to prevent the development of dental caries.
Gambogic acid (GA), a major ingredient of Garcinia hanburryi, is known to have diverse biological effects. The present study was designed to evaluate the anti-fibrotic effects of GA on hepatic ...fibrosis and reveal its underlying mechanism. We investigated the anti-fibrotic effect of GA on dimethylnitrosamine and bile duct ligation induced liver fibrosis in rats in vivo. The rat and human hepatic stellate cell lines (HSCs) lines were chose to evaluate the effect of GA in vitro. Our results indicated that GA could significantly ameliorate liver fibrosis associated with improving serum markers, decrease in extracellular matrix accumulation and HSCs activation in vivo. GA significantly inhibited the proliferation of HSC cells and induced the cell cycle arrest at the G1 phase. Moreover, GA triggered autophagy at early time point and subsequent initiates mitochondrial mediated apoptotic pathway resulting in HSC cell death. The mechanism of GA was related to inhibit heat shock protein 90 (HSP90) and degradation of the client proteins inducing PI3K/AKT and MAPK signaling pathways inhibition. This study demonstrated that GA effectively ameliorated liver fibrosis in vitro and in vivo, which provided new insights into the application of GA for liver fibrosis.
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•Gambogic acid ameliorated liver fibrosis in rats in vivo•Gambogic acid inhibited the proliferation of hepatic stellate cell.•Gambigic acid triggered autophagy, apoptosis and cell cycle arrest.•Gambigic acid inhibited PI3K/AKT and MAPK signaling pathways.•The mechanism was related to inhibit Heat shock protein 90 and its client proteins.
Melatonin is an endogenous indoleamine with a wide range of biological functions in the various organisms from bacteria to mammals. Evidence indicates that melatonin facilitates apoptosis in cancer ...cells and enhances the antitumor activity of chemotherapy in animals and clinical studies. However, the melatonin metabolism and the key metabolic targets in cancer cells still remain unknown. In this study, U118 and SH‐SY5Y tumor cell lines were used to investigate the metabolic pathways of melatonin in cancer cells. Interestingly, the inhibitory effect of melatonin on proliferation in SH‐SY5Y cells is more potent than that in U118 cells. In contrast, this inhibitory effect on the normal cells is absent. The antitumor effects of melatonin are positively associated with its metabolite N‐acetylserotonin (NAS). Unexpectedly, CYP1B1 is, for first time, identified to localize in the mitochondria of tumor cells, and it metabolizes melatonin to form NAS in situ, which subsequently triggers mitochondria‐dependent apoptosis in cancer cells. In normal cells, NAS does not induce apoptosis. A remarkable individual variation on CYP1B1 expression was also detected in human tumor tissue. These findings provide the novel mechanisms regarding the antitumor effects of melatonin in the level of mitochondria. Thus, we hypothesize that CYP1B1 overexpression in mitochondria would significantly enhance the antitumor effects of melatonin. Mitochondrial CYP1B1 can potentially serve as a specific target to modify the therapeutic and biological effects of melatonin on cancer patients.
Melatonin is a hormone identified in plants and pineal glands of mammals and possesses diverse physiological functions. Fisetin is a bio-flavonoid widely found in plants and exerts antitumor activity ...in several types of human cancers. However, the combinational effect of melatonin and fisetin on antitumor activity, especially in melanoma treatment, remains unclear. Here, we tested the hypothesis that melatonin could enhance the antitumor activity of fisetin in melanoma cells and identified the underlying molecular mechanisms. The combinational treatment of melanoma cells with fisetin and melatonin significantly enhanced the inhibitions of cell viability, cell migration and clone formation, and the induction of apoptosis when compared with the treatment of fisetin alone. Moreover, such enhancement of antitumor effect by melatonin was found to be mediated through the modulation of the multiply signaling pathways in melanoma cells. The combinational treatment of fisetin with melatonin increased the cleavage of PARP proteins, triggered more release of cytochrome-c from the mitochondrial inter-membrane, enhanced the inhibition of COX-2 and iNOS expression, repressed the nuclear localization of p300 and NF-κB proteins, and abrogated the binding of NF-κB on COX-2 promoter. Thus, these results demonstrated that melatonin potentiated the anti-tumor effect of fisetin in melanoma cells by activating cytochrome-c-dependent apoptotic pathway and inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways, and our study suggests the potential of such a combinational treatment of natural products in melanoma therapy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Cyclooxygenase (COX) is the rate-limiting enzyme in prostaglandins (PGs) biosynthesis. Previous studies indicate that COX-2, one of the isoforms of COX, is highly expressed in colon cancers and plays ...a key role in colon cancer carcinogenesis. Thus, searching for novel transcription factors regulating COX-2 expression will facilitate drug development for colon cancer. In this study, we identified XRCC5 as a binding protein of the COX-2 gene promoter in colon cancer cells with streptavidin-agarose pulldown assay and mass spectrometry analysis, and found that XRCC5 promoted colon cancer growth through modulation of COX-2 signaling. Knockdown of XRCC5 by siRNAs inhibited the growth of colon cancer cells in vitro and of tumor xenografts in a mouse model in vivo by suppressing COX-2 promoter activity and COX-2 protein expression. Conversely, overexpression of XRCC5 promoted the growth of colon cancer cells by activating COX-2 promoter and increasing COX-2 protein expression. Moreover, the role of p300 (a transcription co-activator) in acetylating XRCC5 to co-regulate COX-2 expression was also evaluated. Immunofluorescence assay and confocal microscopy showed that XRCC5 and p300 proteins were co-located in the nucleus of colon cancer cells. Co-immunoprecipitation assay also proved the interaction between XRCC5 and p300 in nuclear proteins of colon cancer cells. Cell viability assay indicated that the overexpression of wild-type p300, but not its histone acetyltransferase (HAT) domain deletion mutant, increased XRCC5 acetylation, thereby up-regulated COX-2 expression and promoted the growth of colon cancer cells. In contrast, suppression of p300 by a p300 HAT-specific inhibitor (C646) inhibited colon cancer cell growth by suppressing COX-2 expression. Taken together, our results demonstrated that XRCC5 promoted colon cancer growth by cooperating with p300 to regulate COX-2 expression, and suggested that the XRCC5/p300/COX-2 signaling pathway was a potential target in the treatment of colon cancers.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Glioblastoma multiforme (GBM) is one of the most refractory and palindromic central nervous system (CNS) neoplasms, and current treatments have poor effects in GBM patients. Hence, the identification ...of novel therapeutic targets and the development of effective treatment strategies are essential. Alantolactone (ATL) has a wide range of pharmacological activities, and its anti-tumor effect is receiving increasing attention. However, the molecular mechanism underlying the anti-GBM activity of ATL remains poorly understood.
The biological functions of ATL in GBM cells were investigated using migration/invasion, colony formation and cell cycle/apoptosis assays. The localization of nuclear factor kappa B (NF-κB) p50/p65 and its binding to the cyclooxygenase 2 (COX-2) promoter were determined using confocal immunofluorescence, a streptavidin-agarose pulldown assay and a chromatin immunoprecipitation (ChIP) assay. IKKβ kinase activity was determined using a cell IKKβ kinase activity spectrophotometry quantitative detection kit and a molecular docking study. LC-MS/MS analysis was performed to determine the ability of ATL to traverse the blood-brain barrier (BBB). The in vivo anti-tumor efficacy of ATL was also analyzed in xenografted nude mice. Western blot analysis was performed to detect the protein expression levels.
ATL significantly suppressed the growth of GBM in vivo and in vitro. ATL significantly reduced the expression of COX-2 by inhibiting the kinase activity of IKKβ by targeting the ATP-binding site and then attenuating the binding of NF-κB to the COX-2 promoter region. Furthermore, ATL induced apoptosis by activating the cytochrome c (cyt c)/caspase cascade signaling pathway. Moreover, ATL could penetrate the BBB.
ATL exerts its anti-tumor effects in human GBM cells at least in part via NF-κB/COX-2-mediated signaling cascades by inhibiting IKKβ kinase activity. ATL, which is a natural small molecule inhibitor, is a promising candidate for clinical applications in the treatment of CNS tumors.
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