Two series of proteolysis targeting chimeras (PROTACs) containing the phthalimide degrons with different linker were identified. Compound A16 displayed the most potent inhibition against LNCaP and ...showed excellent AR degradation efficacy at 30 μM.
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•Two series of novel PROTACs and androgen receptor degradation efficacy have been discovered.•The best compound A16 displayed excellent binding affinity and AR degradation activity.•Molecular docking analysis illustrates the possible dual mechanism actions of these compounds with AR and E3 ligase.
As a continuation of our research on developing potent and potentially safe androgen receptor (AR) degrader, a series of novel proteolysis targeting chimeras (PROTACs) containing the phthalimide degrons with different linker were designed, synthesized and evaluated for their AR degradation activity against LNCaP (AR+) cell line. Most of the synthesized compounds displayed moderate to satisfactory AR binding affinity and might lead to antagonist activity against AR. Among them, compound A16 exhibited the best AR binding affinity (85%) and degradation activity against AR. Due to the strong fluorescence properties of pomalidomide derivatives, B10 was found to be effectively internalized and visualized in LNCaP (AR + ) cells than PC-3 (AR-) cells. Moreover, the molecular docking of A16 with AR and the active site of DDB1-CRBN E3 ubiquitin ligase complex provides guidance to design new PROTAC degrons targeting AR for prostate cancer therapy. These results represent a step toward the development of novel and improved AR PROTACs.
ObjectiveHypertension has become the leading cause of death worldwide. Data on hypertension management among Shenzhen elderly are sparse. Our study aims to investigate treated and controlled ...hypertension in Shenzhen elderly, and identify relevant predictors.DesignA cross-sectional study.SettingCommunities in Shenzhen, Guangdong, China.ParticipantsA cross-sectional study was conducted. We employed a convenience sampling method to select participants; 124 007 participants aged 65 years and older were recruited from January to December 2018 at local community health centres in Shenzhen.Main outcome measuresData on treatment, control and influencing factors of hypertension were obtained from a standard questionnaire, physical measurements and biochemical analyses.ResultsPrevalence of hypertension was 55.8% among the sample population. Among this group of hypertensive patients, those undergoing hypertension treatment and those with hypertension under control were 54.4% and 32.3%, respectively. Employing multivariate analysis, significant associations were found between treatment and older age, junior high school education and above (OR=1.25, p＜0.05), being widowed rather than being married or cohabiting (OR=1.28, p＜0.05), engaging in physical activity (OR=1.14, p＜0.05), ex-smoker (OR=1.19, p＜0.05), habitual drinker (OR=0.72, p＜0.05), history of cardiovascular disease (CVD) (OR=2.20, p＜0.05) and comorbidities, with a higher probability for those with obesity (OR=1.89, p＜0.05), central obesity (OR=1.10, p＜0.05), diabetes (OR=1.49, p＜0.05) or dyslipidaemia (OR=1.20, p＜0.05). Male sex (OR=0.91, p＜0.05), junior high school education and above (OR=1.28, p＜0.05), engaging in physical activity (OR=1.06, p＜0.05), history of CVD (OR=1.82, p＜0.05) and individuals who had diabetes (OR=1.52, p＜0.05) or dyslipidaemia (OR=1.05, p＜0.05) were associated with increased likelihood of control. Aged 80 years and older (OR=0.93, p＜0.05), habitual drinker (OR=0.73, p＜0.05) and central obesity (OR=0.94, p＜0.05) were negatively associated with control of hypertension.ConclusionsWe found a high prevalence of hypertension, but a low prevalence of treatment and control among Shenzhen elderly.
A simple, fast, and reliable method was established for simultaneous determination of 43 pesticides in Schizonepeta tenuifolia. The samples were prepared using solid-phase extraction (SPE) method. ...Pesticides were extracted from Schizonepeta tenuifolia using acetonitrile, cleaned with Pesticarb/NH2, and eluted by mixed solvents of acetonitrile and toluene (3 : 1, v/v). Selected pesticides were identified using DB-35MS capillary column and detected by gas chromatography mass spectrometry. Samples were quantified by external standard method. Recoveries for the majority of pesticides at spike levels of 0.2, 0.5, and 1 mg kg−1 ranged between 70 and 120% (except for Chlorothalonil, Thiamethoxam, and Dicofol), and the relative standard deviations (RSDs n = 6) were 1.32%–13.91%. Limits of detection (LODs) were 0.0011–0.0135 mg kg−1, whereas limits of quantification (LOQs) were 0.0038–0.0451 mg kg−1. The satisfactory accuracy and precision, in combination with a good separation and few interferences, have demonstrated the strong potential of this technique for its application in Schizonepeta tenuifolia analysis.
Acetaminophen (APAP) overdose can induce liver injury and is the most frequent cause of acute liver failure in the United States. We investigated the role of p62/SQSTM1 (referred to as p62) in ...APAP-induced liver injury (AILI) in mice. We found that the hepatic protein levels of p62 dramatically increased at 24 h after APAP treatment, which was inversely correlated with the hepatic levels of APAP-adducts. APAP also activated mTOR at 24 h, which is associated with increased cell proliferation. In contrast, p62 knockout (KO) mice showed increased hepatic levels of APAP-adducts detected by a specific antibody using Western blot analysis but decreased mTOR activation and cell proliferation with aggravated liver injury at 24 h after APAP treatment. Surprisingly, p62 KO mice recovered from AILI whereas the wild-type mice still sustained liver injury at 48 h. We found increased number of infiltrated macrophages in p62 KO mice that were accompanied with decreased hepatic von Willebrand factor (VWF) and platelet aggregation, which are associated with increased cell proliferation and improved liver injury at 48 h after APAP treatment. Our data indicate that p62 inhibits the late injury phase of AILI by increasing autophagic selective removal of APAP-adducts and mitochondria but impairs the recovery phase of AILI likely by enhancing hepatic blood coagulation.
p62 inhibits the late injury phase of acetaminophen-induced liver injury (AILI) by increasing autophagic selective removal of acetaminophen-adducts and mitochondria but impairs the recovery phase of AILI likely by enhancing hepatic blood coagulation. Display omitted
Non-small cell lung cancer (NSCLC) is one of the most common malignancies in the world. Icotinib and Gefitinib are two epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) that ...have been used to treat NSCLC. While it is well known that mutations of EGFR can affect the sensitivity of NSCLC to the EGFR-TKI, other mechanisms may also be adopted by lung cancer cells to develop resistance to EGFR-TKI treatment. Cancer cells can use multiple adaptive mechanisms such as activation of autophagy and Nrf2 to protect against various stresses and chemotherapeutic drugs. Whether autophagy or Nrf2 activation contributes to the resistance of NSCLC to EGFR-TKI treatment in wild-type EGFR NSCLC cells remains elusive. In the present study, we confirmed that Icotinib and Gefitinib induced apoptosis in EGFR mutant HCC827 but not in EGFR wild-type A549 NSCLC cells. Icotinib and Gefitinib did not induce autophagic flux or inhibit mTOR in A549 cells. Moreover, suppression of autophagy by chloroquine, a lysosomal inhibitor, did not affect Icotinib- or Gefitinib-induced cell death in A549 cells. In contrast, Brusatol, an Nrf2 inhibitor, significantly suppressed the cell survival of A549 cells. However, Brusatol did not further sensitize A549 cells to EGFR TKI-induced cell death. Results from this study suggest that inhibition of Nrf2 can decrease cell vitality of EGFR wild-type A549 cells independent of autophagy.
•Cancer cells use adaptive mechanisms against chemotherapy.•Autophagy is not essential for the drug resistance of lung cancer A549 cells.•Inhibition of Nrf2 decreases cell survival of lung cancer A549 cells.
Alcohol abuse is the major cause of experimental and human pancreatitis but the molecular mechanisms remain largely unknown. We investigated the role of transcription factor EB (TFEB), a master ...regulator of lysosomal biogenesis, in the pathogenesis of alcoholic pancreatitis.
Using a chronic plus acute alcohol binge (referred to as Gao-binge) mouse model, we analyzed pancreas injury, autophagic flux, zymogen granule removal, TFEB nuclear translocation and lysosomal biogenesis in GFP-LC3 transgenic mice, acinar cell-specific Atg5 knockout (KO) and TFEB KO mice as well as their matched wild type mice.
We found that Gao-binge alcohol induced typical features of pancreatitis in mice with increased serum amylase and lipase activities, pancreatic edema, infiltration of inflammatory cells, accumulation of zymogen granules (ZGs) and expression of inflammatory cytokines. While Gao-binge alcohol increased the number of autophagosomes, it also concurrently inhibited TFEB nuclear translocation and TFEB-mediated lysosomal biogenesis resulting in insufficient autophagy. Acinar cell-specific Atg5 KO and acinar cell-specific TFEB KO mice developed severe inflammatory and fibrotic pancreatitis in both Gao-binge alcohol and control diet-fed mice. In contrast, TFEB overexpression inhibited alcohol-induced pancreatic edema, accumulation of zymogen granules and serum amylase and lipase activities. In line with our findings in mice, decreased LAMP1 and TFEB nuclear staining were also observed in human alcoholic pancreatitis tissues.
our results indicate that TFEB plays a critical role in maintaining pancreatic acinar cell homeostasis. Impairment of TFEB-mediated lysosomal biogenesis by alcohol may lead to insufficient autophagy and promote alcohol-induced pancreatitis.
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The proteasome and the autophagy systems are two evolutionarily conserved mechanisms for degrading intracellular materials. They are functionally coupled and suppression of the proteasome promotes ...autophagy. Although suppression of the proteasome leads to cell death, suppression of autophagy can be either prodeath or prosurvival. To understand the underlining mechanism of this dichotomy and its potential clinical implications, we treated various transformed and nontransformed human cells with proteasome inhibitors. We found that whether autophagy served a prosurvival role in this scenario was contingent on the cellular oncogenic status. Thus, autophagy suppression enhanced apoptosis induced by proteasome inhibitors in transformed cells, but not in nontransformed cells. Oncogenic transformation enhanced the ability of cells to initiate autophagy in response to stress, reflecting a stronger dependence of transformed cells on autophagy for survival. Indeed, a combined use of bortezomib, the only Food and Drug Administration-approved proteasome inhibitor for clinical use, and chloroquine, which inhibits autophagy by disturbing lysosomal functions, suppressed tumor growth more significantly than either agent alone in a xenograft model. These findings indicate that suppression of both intracellular degradation systems could constitute a novel strategy for enhanced cancer control in a tumor-specific way.
Acetaminophen (APAP) overdose can cause liver injury and liver failure, which is one of the most common causes of drug-induced liver injury in the United States. Pharmacological activation of ...autophagy by inhibiting mechanistic target of rapamycin (mTOR) protects against APAP-induced liver injury likely via autophagic removal of APAP-adducts and damaged mitochondria. In the present study, we aimed to investigate the role of genetic ablation of mTOR pathways in mouse liver in APAP-induced liver injury and liver repair/regeneration.
Albumin-Cre (Alb-Cre) mice, mTORf/f and Raptorf/f mice (C57BL/6J background) were crossbred to produce liver-specific mTOR knockout (L-mTOR KO, Alb Cre+/-, mTORf/f) and liver-specific Raptor KO (L-Raptor, Alb Cre+/-, Raptor f/f) mice. Alb-Cre littermates were used as wild-type (WT) mice. These mice were treated with APAP for various time points for up to 48 h. Liver injury, cell proliferation, autophagy and mTOR activation were determined.
We found that genetic deletion of neither Raptor, an important adaptor protein in mTOR complex 1, nor mTOR, in the mouse liver significantly protected against APAP-induced liver injury despite increased hepatic autophagic flux. Genetic deletion of Raptor or mTOR in mouse livers did not affect APAP metabolism and APAP-induced c-Jun N-terminal kinase (JNK) activation, but slightly improved mouse survival likely due to increased hepatocyte proliferation.
Our results indicate that genetic ablation of mTOR in mouse livers does not protect against APAP-induced liver injury but may slightly improve liver regeneration and mouse survival after APAP overdose.
Autophagy is a lysosomal degradation pathway that can degrade bulk cytoplasm and superfluous or damaged organelles, such as mitochondria, to maintain cellular homeostasis. It is now known that ...dysregulation of autophagy can cause pathogenesis of numerous human diseases. Here, we discuss the critical roles that autophagy plays in the pathogenesis of liver diseases such as non-alcoholic and alcoholic fatty liver, drug-induced liver injury, protein aggregate-related liver diseases, viral hepatitis, fibrosis, aging and liver cancer. In particular, we discuss the emerging therapeutic potential by pharmacological modulation of autophagy for these liver diseases.
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