Background: Tributyltin (TBT), a prevalent environmental antiseptic, contaminates seafood, fish, and drinking water, posing health risks. While TBT’s hepatic toxicity is well-known, its sex-specific effects on liver function remain poorly understood. Methods: To address this gap, a comprehensive analysis was conducted utilizing the Toxicant Exposures and Responses by Genomic and Epigenomic Regulators of Transcription (TaRGET) dataset. Chromatin accessibility changes and transcriptomic alterations were analyzed via ATAC-seq and RNA-seq in liver tissues from TBT-exposed male and female mice. In vitro experiments were performed to validate the key bioinformatic findings. Results: TBT exposure induced significant chromatin accessibility changes and transcriptomic alterations in male liver compared to female counterparts. Notably, Signal transducer and activator of transcription 3 (STAT3) was identified as a central regulator among differentially expressed genes (DEGs) in male liver cells. Functional validation experiments confirmed that TBT-mediated downregulation of STAT3 impaired liver cell function and contributed to increased hepatotoxicity in males. Conclusions: Our study highlights significant sex-dependent differences in TBT-induced hepatotoxicity and identifies STAT3 as a critical mediator in male liver cells, providing a novel perspective on the toxicology of TBT.
BackgroundPhosphodiesterase 7 (PDE7) plays a role in neurological function. Increased expression and activity of PDE7 has been detected in several central nervous system diseases. However, the role of PDE7 in regulating stress levels remains unclear. Thus, this study aimed to determine whether and how PDE7 involved in the stress-induced behavioral and neuron morphological changes.MethodsThe single prolonged stress (SPS) was used to build a stress exposure model in C57BL/6 J mice and detected PDE7 activity in hippocampus, amygdala, prefrontal cortex and striatum. Next, three doses (0.2, 1, and 5 mg/kg) of the PDE7 inhibitor BRL-50481 were intraperitoneally administered for 10 days, then behavioral, biochemical, and morphological tests were conducted.ResultsPDE7 activity in hippocampus of mice significantly increased at all times after SPS. BRL-50481 significantly attenuated SPS induced anxiety-like behavior and fear response in both context and cue. In addition, BRL-50481 increased the levels of key molecules in the cAMP signaling pathway which were impaired by SPS. Immunofluorescent staining and Sholl analysis demonstrated that BRL-50481 also restored the nucleus/cytoplasm ratio of hippocampal neurons and improved neuronal plasticity. These effects of BRL-50481 were partially blocked by the TrkB inhibitor ANA-12.ConclusionPDE7 inhibitors attenuate stress-induced behavioral changes by protecting the neuron cytoarchitecture and the neuronal plasticity in hippocampus, which is mediated at least partly through the activation of BDNF/TrkB signaling pathway. These results proved that PDE7 is a potential target for treating stress-induced behavioral and physiological abnormalities.
INTRODUCTION:Sevoflurane is an extensively used anesthetic for pediatric patients; however, numerous studies showed that sevoflurane (SEVO) may cause long-term neurodevelopmental toxicity. Dexmedetomidine (DEX) has been shown to be protective against SEVO-induced neurotoxicity, but the mechanism remains unclear. The effects and mechanisms of different DEX administration routes on SEVO-induced neurotoxicity and long-term cognitive defects were determined and further investigated the role of sex in these processes. METHODS:Male and female Sprague Dawley rats at postnatal day 7 (PND7) received an intraperitoneal injection of DEX (10 μg/kg) before or after exposure to 2.5% SEVO for 6 h, or before and after SEVO exposure. The respiratory and mortality rates of the pups were recorded during anesthesia. Neuroapoptosis was evaluated by TdT-mediated dUTP nick-end labeling staining. Immunohistochemistry and immunofluorescence were employed to detect the expression of caspase-3 in neuronal cells and neurons. The expression of GSK-3β and DISC1 was determined by Western blotting or RT-qPCR. Morris water maze (MWM) test was used to evaluate the learning and memory ability of rats until they were 3 weeks and 5 weeks old. RESULTS:Compared with the control group, exposure to 2.5% SEVO resulted in increased neuroapoptosis and decreased the expression of DISC1 at levels of mRNA and protein and phosphorylated GSK-3β in the developing brain. SEVO exposure during critical neurodevelopmental periods could cause persistent cognitive defects in adolescent male and female rats and inhibited DISC1 and phosphorylated GSK-3β protein expression. The neurotoxic impacts of SEVO were lessened by the administration of DEX (10 μg/kg) before or after exposure. CONCLUSION:Our findings suggest that DEX (10 μg/kg) mitigates the neurotoxic effects of SEVO on the developing rat brain as well as postnatal cognitive defects by regulating the DISC1/GSK-3β signaling.
Chronic ethanol consumption is a prevalent condition in contemporary society and exacerbates anxiety symptoms in healthy individuals. The activation of microglia, leading to neuroinflammatory responses, may serve as a significant precipitating factor; however, the precise molecular mechanisms underlying this phenomenon remain elusive. In this study, we initially confirmed that chronic ethanol exposure (CEE) induces anxiety-like behaviors in mice through open field test and elevated plus maze test. The cGAS/STING signaling pathway has been confirmed to exhibits a significant association with inflammatory signaling responses in both peripheral and central systems. Western blot analysis confirmed alterations in the cGAS/STING signaling pathway during CEE, including the upregulation of p-TBK1 and p-IRF3 proteins. Moreover, we observed microglial activation in the prefrontal cortex (PFC) of CEE mice, characterized by significant alterations in branching morphology and an increase in cell body size. Additionally, we observed that administration of CEE resulted in mitochondrial dysfunction within the PFC of mice, accompanied by a significant elevation in cytosolic mitochondrial DNA (mtDNA) levels. Furthermore, our findings revealed that the inhibition of STING by H-151 effectively alleviated anxiety-like behavior and suppressed microglial activation induced by CEE. Our study unveiled a significant association between anxiety-like behavior, microglial activation, inflammation, and mitochondria dysfunction during CEE.
BACKGROUND:Ethanol elicits a rapid stimulatory effect and a subsequent, prolonged sedative response, which are potential predictors of EtOH consumption by decreasing adenosine signaling; this phenomenon also reflects the obvious sex difference. cAMP (cyclic Adenosine Monophosphate)-PKA (Protein Kinase A) signaling pathway modulation can influence the stimulatory and sedative effects induced by EtOH in mice. This study's objective is to clarify the role of phosphodiesterase (PDE) in mediating the observed sex differences in EtOH responsiveness between male and female animals. METHODS:EtOH was administered i.p. for 7 days to identify the changes in PDE isoforms in response to EtOH treatment. Additionally, EtOH consumption and preference of male and female C57BL/6J mice were assessed using the drinking-in-the-dark and 2-bottle choice tests. Further, pharmacological inhibition of PDE7A heterozygote knockout mice was performed to investigate its effects on EtOH-induced stimulation and sedation in both male and female mice. Finally, Western blotting analysis was performed to evaluate the alterations in cAMP-PKA/Epac2 pathways. RESULTS:EtOH administration resulted in an immediate upregulation in PDE7A expression in female mice, indicating a strong association between PDE7A and EtOH stimulation. Through the pharmacological inhibition of PDE7A KD mice, we have demonstrated for the first time, to our knowledge, that PDE7A selectively attenuates EtOH responsiveness and consumption exclusively in female mice, whichmay be associated with the cAMP-PKA/Epac2 pathway and downstream phosphorylation of CREB and ERK1/2. CONCLUSIONS:Inhibition or knockdown of PDE7A attenuates EtOH responsivenessand consumption exclusively in female mice, which is associated with alterations in the cAMP-PKA/Epac2 signaling pathways, thereby highlighting its potential as a novel therapeutic target for alcohol use disorder.
Histone deacetylases (HDAC) are clinically validated and attractive epigenetic drug targets for human cancers. Several HDAC inhibitors have been approved for cancer treatment to date, however, clinical applications have been limited due to the poor pharmacokinetics, bioavailability, selectivity of the HDAC inhibitors and most of them need to be combined with other drugs to achieve better results. Here, we describe our efforts toward the discovery of a novel series of lactam-based derivatives as selective HDAC inhibitors. Intensive structural modifications lead to the identification of compound 24g as the most active Class I HDAC Inhibitor, along with satisfactory metabolic stability in vitro (t1/2, human = 797 min) and the desirable oral bioavailability (F = 92%). More importantly, compound 24g showed good antitumor efficacy in a TMD-8 xenograft model (TGI = 77%) without obvious toxicity. These results indicated that Class I HDAC Inhibitor could be potentially used to treat certain diffuse large B-cell lymphoma therapeutics.
Snail and histone deacetylases (HDACs) have an important impact on cancer treatment, especially for their synergy. Therefore, the development of inhibitors targeting both Snail and HDAC might be a promising strategy for the treatment of cancers. In this work, we synthesized a series of Snail/HDAC dual inhibitors. Compound 9n displayed the most potent inhibitory activity against HDAC1 with an IC50 of 0.405 mu M, potent inhibition against Snail with a K-d of 0.180 mu M, and antiproliferative activity in HCT-116 cell lines with an IC50 of 0.0751 mu M. Compound 9n showed a good inhibitory effect on NCI-H522 (GI(50) = 0.0488 mu M), MDA-MB-435 (GI(50) = 0.0361 mu M), and MCF7 (GI(50) = 0.0518 mu M). Docking studies showed that compound 9n can be well docked into the active binding sites of Snail and HDAC. Further studies showed that compound 9n increased histone H4 acetylation in HCT-116 cells and decreased the expression of Snail protein to induce cell apoptosis. These findings highlight the potential for the development of Snail/HDAC dual inhibitors as anti-solid tumour cancer drugs.& nbsp;(c) 2021 Elsevier Masson SAS. All rights reserved.
Activation of the TRAIL proapoptotic pathway can promote cancer cell apoptosis. Histone deacetylases (HDACs) also are promising drug targets for cancers, and their synergistic effect with TRAIL can improve the inhibitory effect on cancer cells. Therefore, the development of highly TRAIL-sensitive HDAC inhibitors might be a promising strategy for the treatment of cancers. We synthesized a series of HDAC inhibitors by introducing effective fragments sensitive to TRAIL. Compound IIc showed good inhibitory activity against HDAC1 and HCT116 cells and showed higher sensitivity to activating the expression of the TRAIL protein and promoting the apoptosis of HCT-116 cells compared with ONC201. The inhibitory activity of compound IIc (25 mg/kg) in the HCT-116 xenograft model was significantly greater than those of the positive control drugs (ONC201, chidamide). These findings suggested that development of highly TRAIL-sensitive HDAC inhibitors as colorectal tumor cancer drugs.
Apoptosis signal-regulating kinase 1 (ASK1), a member of the mitogen-activated protein kinase (MAPK) family, is implicated in many human diseases. Here, we describe the structural optimization of hit compound 7 and conduct further structure-activity relationship (SAR) studies that result in the development of compound 19 with a novel indole-2-carboxamide hinge scaffold. Compound 19 displays potent anti-ASK1 kinase activity and stronger inhibitory effect on ASK1 in AP1-HEK293 cells than previously described ASK1 inhibitor GS-4997. Besides improved in vitro activity, compound 19 also exhibits an appropriate in vivo PK profile. In a dextran sulfate sodium (DSS)-induced mouse model of ulcerative colitis (UC), compound 19 shows significant anti-UC efficacy and markedly attenuates DSS-induced body weight loss, colonic shortening, elevation in disease activity index (DAI) and inflammatory cell infiltration in colon tissues. Mechanistically, compound 19 represses the phosphorylation of ASK1-p38/JNK signaling pathways and suppresses the overexpression of inflammatory cytokines. Together, these findings suggest that ASK1 inhibitors can potentially be used as a therapeutic strategy for UC.
Apoptosis signal-regulating kinase 1 (ASK1, MAP3K5), a member of the mitogen-activated protein kinase (MAPK) signaling pathway, is involved in cell survival, differentiation, stress response, and apoptosis. ASK1 kinase inhibition has emerged as a promising therapeutic strategy for inflammatory disease. A series of novel ASK1 inhibitors with 1H-indazole scaffold were designed, synthesized and evaluated for their ASK1 kinase activity and AP1-HEK293 cell inhibitory effect. Systematic structure-activity relationship (SAR) efforts led to the discovery of promising compound 15, which showed excellent in vitro ASK1 kinase activity and potent inhibitory effects on ASK1 in AP1-HEK293 cells. In a tumor necrosis factor-α (TNF-α)-induced HT-29 intestinal epithelial cell model, compound 15 exhibited a significantly protective effect on cell viability comparable to that of GS-4997; moreover, compound 15 exhibited no obvious cytotoxicity against HT-29 cells at concentrations up to 25 μM. Mechanistic research demonstrated that compound 15 suppresses phosphorylation in the ASK1-p38/JNK signaling pathway in HT-29 cells, and regulates the expression levels of apoptosis-related proteins. Altogether, these results show that compound 15 may serve as a potential candidate compound for the treatment of inflammatory bowel disease (IBD).