ABSTRACT
The level of sulfur dioxide (SO2) and viscosity in mitochondria play vital roles in various physiological and pathological processes. Abnormalities in mitochondrial SO2 and viscosity are closely associated with numerous biological diseases. It is of great significance to develop novel fluorescence probes for simultaneous detection of SO2 and viscosity within mitochondria. Herein, we have developed a water-soluble, mitochondrial-targeted and near-infrared fluorescent probe, CMBT, for the simultaneous detection of SO2 and viscosity. The probe CMBT incorporates benzothiazolium salt as a mitochondrial targeting moiety and 7-diethylaminocoumarin as a rotor for viscosity detection, respectively. Based on the prompt reaction between nucleophilic HSO3-/SO32- and the backbone of the benzothiazolium salt derivative, probe CMBT displayed high sensitivity and selectivity toward SO2 with a limit of detection as low as 0.17 µM. As viscosity increased, the twisted intramolecular charge transfer (TICT) process was restricted, resulting in fluorescence emission enhancement at 690 nm. Moreover, probe CMBT demonstrated exceptional mitochondrial targeting ability and was successfully employed to image variations of SO2 and viscosity in living cells and mice. The work highlights the great potential of the probe as a convenient tool for revealing the relationship between SO2 and viscosity in biological systems.
Subject(s)
Fluorescent Dyes , Mitochondria , Sulfur Dioxide , Sulfur Dioxide/analysis , Sulfur Dioxide/chemistry , Fluorescent Dyes/chemistry , Animals , Mitochondria/chemistry , Mitochondria/metabolism , Viscosity , Mice , Humans , Optical Imaging/methods , HeLa Cells , Limit of DetectionABSTRACT
Despite good hepatitis B virus (HBV) inhibition by nucleoside analogs (NAs), cases of hepatocellular carcinoma (HCC) still occur. This study proposed a non-invasive predictive model to assess HCC risk in patients with chronic hepatitis B (CHB) receiving NAs treatment. Data were obtained from a hospital-based retrospective cohort registered on the Platform of Medical Data Science Academy of Chongqing Medical University, from 2013 to 2019. A total of 501 patients under NAs treatment had their FIB-4 index updated semiannually by recalculation based on laboratory values. Patients were divided into three groups based on FIB-4 index values: < 1.45, 1.45-3.25, and ≥ 3.25. Subsequently, HCC incidence was reassessed every six months using Kaplan-Meier curves based on the updated FIB-4 index. The median follow-up time of CHB patients after receiving NAs treatment was 2.5 years. HCC incidences with FIB-4 index < 1.45, 1.45-3.25, and ≥ 3.25 were 1.18%, 1.32%, and 9.09%, respectively. Dynamic assessment showed that the percentage of patients with FIB-4 index < 1.45 significantly increased semiannually (P < 0.001), and of patients with FIB-4 index ≥ 3.25 significantly decreased (P < 0.001). HCC incidence was the highest among patients with FIB-4 index ≥ 3.25. The FIB-4 index effectively predicted HCC incidence, and its dynamic assessment could be used for regular surveillance to implement early intervention and reduce HCC risk.
Subject(s)
Antiviral Agents , Carcinoma, Hepatocellular , Hepatitis B, Chronic , Liver Cirrhosis , Liver Neoplasms , Humans , Hepatitis B, Chronic/complications , Hepatitis B, Chronic/drug therapy , Male , Female , Retrospective Studies , Antiviral Agents/therapeutic use , Middle Aged , Adult , Risk Factors , Nucleosides/therapeutic use , Incidence , Risk AssessmentABSTRACT
The ability to detect and visualize cellular events and associated biological analytes is essential for the understanding of their physiological and pathological functions. Cysteine (Cys) plays a crucial role in biological systems and lysosomal homeostasis. This puts forward higher requirements on the performance of the probe. Herein, we rationally designed a coumarin-based probe for the reversible, specific, sensitive, and rapid detection of Cys based on pH regulating reactivity. The obtained probe (ECMA) introduces a morpholine moiety to target lysosomes, and α,ß-unsaturated-ketone with an electron-withdrawing CN group served as a reversible reaction site for Cys. Importantly, ECMA was successfully applied to the real-time monitoring of Cys dynamics in living cells. Furthermore, cell imaging clearly revealed that exogenous Cys could induce the up-regulation of lysosomal ROS, which provided a powerful tool for investigating the relationship between oxidative stress and lysosomal Cys.
Subject(s)
Cysteine , Fluorescent Dyes , Lysosomes , Oxidative Stress , Lysosomes/metabolism , Lysosomes/chemistry , Fluorescent Dyes/chemistry , Fluorescent Dyes/chemical synthesis , Cysteine/chemistry , Cysteine/metabolism , Oxidative Stress/drug effects , Humans , Hydrogen-Ion Concentration , HeLa Cells , Optical Imaging , Molecular Structure , Coumarins/chemistry , Reactive Oxygen Species/metabolismABSTRACT
To effectively protect the host from viral infection while avoiding excessive immunopathology, the innate immune response must be tightly controlled. However, the precise regulation of antiviral innate immunity and the underlying mechanisms remain unclear. Here, we find that sirtuin3 (SIRT3) interacts with mitochondrial antiviral signaling protein (MAVS) to catalyze MAVS deacetylation at lysine residue 7 (K7), which promotes MAVS aggregation, as well as TANK-binding kinase I and IRF3 phosphorylation, resulting in increased MAVS activation and enhanced type I interferon signaling. Consistent with these findings, loss of Sirt3 in mice and zebrafish renders them more susceptible to viral infection compared to their wild-type (WT) siblings. However, Sirt3 and Sirt5 double-deficient mice exhibit the same viral susceptibility as their WT littermates, suggesting that loss of Sirt5 in Sirt3-deficient mice may counteract the increased viral susceptibility displayed in Sirt3-deficient mice. Thus, we not only demonstrate that SIRT3 positively regulates antiviral immunity in vitro and in vivo, likely via MAVS, but also uncover a previously unrecognized mechanism by which SIRT3 acts as an accelerator and SIRT5 as a brake to orchestrate antiviral innate immunity.
Subject(s)
Sirtuin 3 , Sirtuins , Virus Diseases , Animals , Mice , Adaptor Proteins, Signal Transducing/genetics , Immunity, Innate , Lysine , Sirtuin 3/genetics , Sirtuins/genetics , Zebrafish , Zebrafish ProteinsABSTRACT
The combination of small-interfering RNA (siRNA)-mediated gene silencing and chemotherapeutic agents for lung cancer treatment has attracted widespread attention in terms of a greater therapeutic effect, minimization of systemic toxicity, and inhibition of multiple drug resistance (MDR). In this work, three amphiphiles, CBN1-CBN3, were first designed and synthesized as a camptothecin (CPT) conjugate and gene condensation agents by the combination of CPT prodrugs and di(triazole-[12]aneN3) through the ROS-responsive phenylborate ester and different lengths of alkyl chains (with 6, 9, 12 carbon chains for CBN1-CBN3, respectively). CBN1-CBN3 were able to be self-assembled into liposomes with an average diameter in the range of 320-240 nm, showing the ability to effectively condense siRNA. Among them, CBN2, with a nine-carbon alkyl chain, displayed the best anticancer efficiency in A549 cells. In order to give nanomedicines a stealth property and PEGylation/dePEGylation transition, a GSH-responsive PEGylated TPE derivative containing a disulfide linkage (TSP) was further designed and prepared. A combination of CBN2/siRNA complexes and DOPE with TSP resulted in GSH/ROS dual-responsive lipid-polymer hybrid nanoparticles (CBN2-DP/siRNA NPs). In present GSH and H2O2, CBN2-DP/siRNA NPs were decomposed, resulting in the controlled release of CPT drug and siRNA. In vitro, CBN2-DP/siPHB1 NPs showed the best anticancer activity for suppression of about 75% of A549 cell proliferation in a serum medium. The stability of CBN2-DP/siRNA NPs was significantly prolonged in blood circulation, and they showed effective accumulation in the A549 tumor site through an enhanced permeability and retention (EPR) effect. In vivo, CBN2-DP/siPHB1 NPs demonstrated enhanced synergistic cancer therapy efficacy and tumor inhibition as high as 71.2%. This work provided a strategy for preparing lipid-polymer hybrid NPs with GSH/ROS dual-responsive properties and an intriguing method for lung cancer therapy.
Subject(s)
Camptothecin , Lung Neoplasms , Nanoparticles , RNA, Small Interfering , Reactive Oxygen Species , Animals , Humans , Mice , A549 Cells , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Biocompatible Materials/chemical synthesis , Camptothecin/chemistry , Camptothecin/pharmacology , Cell Proliferation/drug effects , Cell Survival/drug effects , Drug Screening Assays, Antitumor , Glutathione/chemistry , Glutathione/metabolism , Lipids/chemistry , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Lung Neoplasms/metabolism , Materials Testing , Molecular Structure , Nanoparticles/chemistry , Particle Size , Prohibitins , Reactive Oxygen Species/metabolism , RNA, Small Interfering/chemistryABSTRACT
Oxygen is essential for aerobic organisms, but little is known about its role in antiviral immunity. Here, we report that during responses to viral infection, hypoxic conditions repress antiviral-responsive genes independently of HIF signaling. EGLN1 is identified as a key mediator of the oxygen enhancement of antiviral innate immune responses. Under sufficient oxygen conditions, EGLN1 retains its prolyl hydroxylase activity to catalyze the hydroxylation of IRF3 at proline 10. This modification enhances IRF3 phosphorylation, dimerization and nuclear translocation, leading to subsequent IRF3 activation. Furthermore, mice and zebrafish with Egln1 deletion, treatment with the EGLN inhibitor FG4592, or mice carrying an Irf3 P10A mutation are more susceptible to viral infections. These findings not only reveal a direct link between oxygen and antiviral responses, but also provide insight into the mechanisms by which oxygen regulates innate immunity.
Subject(s)
Hypoxia-Inducible Factor-Proline Dioxygenases , Immunity, Innate , Interferon Regulatory Factor-3 , Oxygen , Proline , Zebrafish , Animals , Hypoxia-Inducible Factor-Proline Dioxygenases/metabolism , Hypoxia-Inducible Factor-Proline Dioxygenases/genetics , Interferon Regulatory Factor-3/metabolism , Hydroxylation , Humans , Proline/metabolism , Mice , Oxygen/metabolism , HEK293 Cells , Phosphorylation , Mice, Knockout , Signal Transduction , Mice, Inbred C57BLABSTRACT
ABSTRACT Despite good hepatitis B virus (HBV) inhibition by nucleoside analogs (NAs), cases of hepatocellular carcinoma (HCC) still occur. This study proposed a non-invasive predictive model to assess HCC risk in patients with chronic hepatitis B (CHB) receiving NAs treatment. Data were obtained from a hospital-based retrospective cohort registered on the Platform of Medical Data Science Academy of Chongqing Medical University, from 2013 to 2019. A total of 501 patients under NAs treatment had their FIB-4 index updated semiannually by recalculation based on laboratory values. Patients were divided into three groups based on FIB-4 index values: < 1.45, 1.45-3.25, and ≥ 3.25. Subsequently, HCC incidence was reassessed every six months using Kaplan-Meier curves based on the updated FIB-4 index. The median follow-up time of CHB patients after receiving NAs treatment was 2.5 years. HCC incidences with FIB-4 index < 1.45, 1.45-3.25, and ≥ 3.25 were 1.18%, 1.32%, and 9.09%, respectively. Dynamic assessment showed that the percentage of patients with FIB-4 index < 1.45 significantly increased semiannually (P < 0.001), and of patients with FIB-4 index ≥ 3.25 significantly decreased (P < 0.001). HCC incidence was the highest among patients with FIB-4 index ≥ 3.25. The FIB-4 index effectively predicted HCC incidence, and its dynamic assessment could be used for regular surveillance to implement early intervention and reduce HCC risk.
ABSTRACT
BACKGROUND: Due to the heterogeneity of low-grade gliomas (LGGs), the lack of randomized control trials, and strong clinical evidence, the effect of the extent of resection (EOR) is currently controversial. AIM: To determine the best choice between subtotal resection (STR) and gross-total resection (GTR) for individual patients and to identify features that are potentially relevant to treatment heterogeneity. METHODS: Patients were enrolled from the SEER database. We used a novel DL approach to make treatment recommendations for patients with LGG. We also made causal inference of the average treatment effect (ATE) of GTR compared with STR. RESULTS: The patients were divided into the Consis. and In-consis. groups based on whether their actual treatment and model recommendations were consistent. Better brain cancer-specific survival (BCSS) outcomes in the Consis. group was observed. Overall, we also identified two subgroups that showed strong heterogeneity in response to GTR. By interpreting the models, we identified numerous variables that may be related to treatment heterogeneity. CONCLUSIONS: This is the first study to infer the individual treatment effect, make treatment recommendation, and guide surgical options through deep learning approach in LGG research. Through causal inference, we found that heterogeneous responses to STR and GTR exist in patients with LGG. Visualization of the model yielded several factors that contribute to treatment heterogeneity, which are worthy of further discussion.
Subject(s)
Brain Neoplasms , Glioma , Humans , Brain Neoplasms/surgery , Glioma/surgery , Brain , Neurosurgical Procedures , Machine Learning , Treatment OutcomeABSTRACT
Prolyl hydroxylase domain (PHD)-containing enzyme 3 (PHD3) belongs to the Caenorhabditis elegans gene egl-9 family of prolyl hydroxylases. PHD3 catalyzes proline hydroxylation of hypoxia-inducible factor α (HIF-α) and promotes HIF-α proteasomal degradation through coordination with the pVHL complex under normoxic conditions. However, the relationship between PHD3 and the hypoxic response is not well understood. In this study, we used quantitative real-time PCR assay and O-dianisidine staining to characterize the hypoxic response in zebrafish deficient in phd3. We found that the hypoxia-responsive genes are upregulated and the number of erythrocytes was increased in phd3-null zebrafish compared with their wild-type siblings. On the other hand, we show overexpression of phd3 suppresses HIF-transcriptional activation. In addition, we demonstrate phd3 promotes polyubiquitination of zebrafish hif-1/2α proteins, leading to their proteasomal degradation. Finally, we found that compared with wild-type zebrafish, phd3-null zebrafish are more resistant to hypoxia treatment. Therefore, we conclude phd3 has a role in hypoxia tolerance. These results highlight the importance of modulation of the hypoxia signaling pathway by phd3 in hypoxia adaptation.
Subject(s)
Hypoxia-Inducible Factor-Proline Dioxygenases , Oxygen , Procollagen-Proline Dioxygenase , Zebrafish Proteins , Zebrafish , Animals , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Hypoxia-Inducible Factor-Proline Dioxygenases/genetics , Hypoxia-Inducible Factor-Proline Dioxygenases/metabolism , Procollagen-Proline Dioxygenase/genetics , Procollagen-Proline Dioxygenase/metabolism , Proline/metabolism , Zebrafish/genetics , Zebrafish/metabolism , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolism , Gene Deletion , Oxygen/metabolismABSTRACT
A novel dual-responsive nanoparticle (NP) system was aimed to be developed for the co-delivery of camptothecin (CPT) and plasmid encoding TNF-related apoptosis-inducing ligand (pTRAIL) DNA in cancer therapy. The combination of the prodrug CPT and the nucleic acid condensing di-(triazole-[12]aneN3) unit with 4-nitrobenzyl ester through alkyl chains resulted in three nitroreductase (NTR) responsive amphiphiles, CNN1-CNN3 (with 5, 8, and 11 carbon chains, respectively). Among them, CNN2 was the most effective in inhibiting the proliferation of HeLa cells in the presence of fusogenic lipid DOPE. The NPs composed of CNN2, pDNA, and DOPE were further co-assembled with ROS-responsive thioketal-linked amphiphilic polymer (TTP) to afford the core-shell NPs (CNN2-DT/pDNA) with an average size of 118 nm, which exhibited high drug-loading capacity, excellent serum tolerance, and good biocompatibility. In the presence of ROS, NTR, and NADH, the core-shell NPs were decomposed, leading to the efficient release of 80% CPT and abundant pDNA. The self-assembly and delivery process of CNN2-DT NPs and DNA were clearly observed through the AIE fluorescent imaging. In vitro and in vivo results demonstrated that the CNN2-DT/pTRAIL NPs synergistically promoted 68% apoptosis of tumor cells and inhibited tumor growth with negligible toxic side effects. This study showed that the combination of prodrug and nucleic acid through dual-responsive core-shell NPs provide a spatially and temporally-controlled strategy for cancer therapy.
Subject(s)
Nanoparticles , Neoplasms , Nucleic Acids , Prodrugs , Humans , HeLa Cells , Prodrugs/pharmacology , Reactive Oxygen Species , Nitroreductases , Camptothecin/pharmacology , Polyethylene GlycolsABSTRACT
SIRT7 is a member of the sirtuin family proteins with nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylase activity, which can inhibit the activity of hypoxia-inducible factors independently of its enzymatic activity. However, the role of SIRT7 in affecting hypoxia signaling in vivo is still elusive. Here, we find that sirt7-null zebrafish are more resistant to hypoxic conditions, along with an increase of hypoxia-responsive gene expression and erythrocyte numbers, compared with their wildtype siblings. Overexpression of sirt7 suppresses the expression of hypoxia-responsive genes. Further assays indicate that sirt7 interacts with zebrafish hif-1αa, hif-1αb, hif-2αa, and hif-2αb to inhibit their transcriptional activity and mediate their protein degradation. In addition, sirt7 not only binds to the hypoxia responsive element of hypoxia-inducible gene promoters but also causes a reduction of H3K18Ac on these promoters. Sirt7 may regulate hypoxia-responsive gene expression through its enzymatic and nonenzymatic activities. This study provides novel insights into sirt7 function and sheds new light on the regulation of hypoxia signaling by sirt7.
Subject(s)
Oxygen , Sirtuins , Zebrafish Proteins , Zebrafish , Animals , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Proteolysis , Sirtuins/genetics , Sirtuins/metabolism , Zebrafish/genetics , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolism , Anaerobiosis , Oxygen/metabolismABSTRACT
The deubiquitinating enzyme OTUB1 possesses canonical deubiquitinase (DUB) activity and noncanonical, catalytic-independent activity, which has been identified as an essential regulator of diverse physiological processes. Posttranslational modifications of OTUB1 affect both its DUB activity and its noncanonical activity of binding to the E2 ubiquitin-conjugation enzyme UBC13, but further investigation is needed to characterize the full inventory of modifications to OTUB1. Here, we demonstrate that SET7, a lysine monomethylase, directly interacts with OTUB1 to catalyze OTUB1 methylation at lysine 122. This modification does not affect DUB activity of OTUB1 but impairs its noncanonical activity, binding to UBC13. Moreover, we found using cell viability analysis and intracellular reactive oxygen species assay that SET7-mediated methylation of OTUB1 relieves its suppressive role on ferroptosis. Notably, the methylation-mimic mutant of OTUB1 not only loses the ability to bind to UBC13 but also relieves its suppressive role on Tert-Butyl hydroperoxide-induced cell death and Cystine starvation/Erastin-induced cellular reactive oxygen species. Collectively, our data identify a novel modification of OTUB1 that is critical for inhibiting its noncanonical activity.
Subject(s)
Deubiquitinating Enzymes , Ferroptosis , Histone-Lysine N-Methyltransferase , Ubiquitin-Conjugating Enzymes , Deubiquitinating Enzymes/metabolism , Lysine/metabolism , Protein Binding , Reactive Oxygen Species/metabolism , Ubiquitination , Humans , Histone-Lysine N-Methyltransferase/metabolismABSTRACT
Enzyme-responsive drug delivery systems have drawn much attention in the field of cancer theranostics due to their high sensitivity and substrate specificity under mild conditions. In this study, an amphiphilic polymer T1 is reported, which contains a tetraphenylethene unit and a poly(ethylene glycol) chain linked by an esterase-responsive phenolic ester bond. In aqueous solution, T1 formed stable micelles via self-assembly, which showed an aggregation-induced emission enhancement of 32-fold at 532 nm and a critical micelle concentration of 0.53 µM as well as esterase-responsive activity. The hydrophobic drug doxorubicin (DOX) was efficiently encapsulated into the micelles with a drug loading of 21%. In the presence of the esterase, the selective decomposition of drug-loaded T1 micelles was observed, and DOX was subsequently released with a half-life of 5 h. In vitro antitumor studies showed that T1@DOX micelles exhibited good therapeutic effects on HeLa cells, while normal cells remained mostly intact. In vivo anticancer experiments revealed that T1@DOX micelles indeed suppressed tumor growth and had reduced side effects compared to DOX·HCl. The present work showed the potential clinical application of esterase-responsive drug delivery in cancer therapy.
Subject(s)
Micelles , Polyethylene Glycols , Humans , Polyethylene Glycols/chemistry , HeLa Cells , Esterases , Drug Carriers/chemistry , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Polymers/chemistry , Drug Delivery Systems , Hydrogen-Ion ConcentrationABSTRACT
Hypoxia-inducible factor (HIF)1α, a main transcriptional regulator of the cellular response to hypoxia, also plays important roles in oxygen homeostasis of aerobic organisms, which is regulated by multiple mechanisms. However, the full cellular response to hypoxia has not been elucidated. In this study, we found that expression of SMYD3, a methyltransferase, augments hypoxia signaling independent of its enzymatic activity. We demonstrated SMYD3 binds to and stabilizes HIF1α via co-immunoprecipitation and Western blot assays, leading to the enhancement of HIF1α transcriptional activity under hypoxia conditions. In addition, the stabilization of HIF1α by SMYD3 is independent of HIF1α hydroxylation by prolyl hydroxylases and the intactness of the von Hippel-Lindau ubiquitin ligase complex. Furthermore, we showed SMYD3 induces reactive oxygen species accumulation and promotes hypoxia-induced cell apoptosis. Consistent with these results, we found smyd3-null zebrafish exhibit higher hypoxia tolerance compared to their wildtype siblings. Together, these findings define a novel role of SMYD3 in affecting hypoxia signaling and demonstrate that SMYD3-mediated HIF1α stabilization augments hypoxia signaling, leading to the impairment of hypoxia tolerance.
Subject(s)
Histone-Lysine N-Methyltransferase , Hypoxia , Methyltransferases , Zebrafish Proteins , Animals , Hypoxia/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Methyltransferases/metabolism , Signal Transduction , Von Hippel-Lindau Tumor Suppressor Protein/genetics , Von Hippel-Lindau Tumor Suppressor Protein/metabolism , Zebrafish/metabolism , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/metabolism , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolismABSTRACT
CONTEXT: Evidence has shown maternal androgen levels in both the general population and populations with hyperandrogenic disorders are inversely associated with offspring birth weight. CONTEXT: We aimed to investigate the causal effect of maternal testosterone levels in the general population on offspring birth weight and preterm delivery risk using a two-sample Mendelian randomization (MR) method. METHODS: We obtained independent genetic instruments from a sex-specific genome-wide association study with up to 230 454 females of European descent from the UK Biobank. Genetic instruments with consistent testosterone effects but no aggregate effect on sex hormone-binding globulin were used to perform the main analysis. Summary-level data of offspring birth weight adjusted for genotype were obtained from a study with 210 406 females of European descent. Summary-level data of preterm delivery were obtained from the FinnGen study (6736 cases and 116 219 controls). RESULTS: MR analysis showed that each SD (0.62 nmol/L) increase in testosterone levels could reduce the offspring birth weight by 37.26 g (95% CI,â 19.59-54.94 g; Pâ =â 3.62â ×â 10-5). Each SD increase in testosterone levels was also associated with an increased risk of preterm delivery (odds ratioâ =â 1.329; 95% CI, 1.161-1.520; Pâ =â 3.57â ×â 10-5). Similar results were found using different MR methods and multivariable MR analyses. CONCLUSION: This two-sample MR study showed genetically determined higher circulating testosterone levels in females from the general population were associated with low birth weight of offspring and increased risk of preterm delivery.
Subject(s)
Mendelian Randomization Analysis , Premature Birth , Birth Weight/genetics , Female , Genome-Wide Association Study , Humans , Infant, Newborn , Male , Polymorphism, Single Nucleotide , Premature Birth/epidemiology , Premature Birth/genetics , TestosteroneABSTRACT
As a main regulator of cellular responses to hypoxia, the protein stability of hypoxia-inducible factor (HIF)-1α is strictly controlled by oxygen tension dependent of PHDs-catalyzed protein hydroxylation and pVHL complex-mediated proteasomal degradation. Whether HIF-1α protein stability as well as its activity can be further regulated under hypoxia is not well understood. In this study, we found that OTUB1 augments hypoxia signaling independent of PHDs/VHL and FIH. OTUB1 binds to HIF-1α and depletion of OTUB1 reduces endogenous HIF-1α protein under hypoxia. In addition, OTUB1 inhibits K48-linked polyubiquitination of HIF-1α via its non-canonical inhibition of ubiquitination activity. Furthermore, OTUB1 promotes hypoxia-induced glycolytic reprogramming for cellular metabolic adaptation. These findings define a novel regulation of HIF-1α under hypoxia and demonstrate that OTUB1-mediated HIF-1α stabilization positively regulates HIF-1α transcriptional activity and benefits cellular hypoxia adaptation.
Subject(s)
Cell Hypoxia , Deubiquitinating Enzymes , Hypoxia-Inducible Factor 1, alpha Subunit , Signal Transduction , Cell Hypoxia/physiology , Deubiquitinating Enzymes/genetics , Deubiquitinating Enzymes/metabolism , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , UbiquitinationABSTRACT
Egg-laying defective nine 1 (EGLN1) functions as an oxygen sensor to catalyze prolyl hydroxylation of the transcription factor hypoxia-inducible factor-1 α under normoxia conditions, leading to its proteasomal degradation. Thus, EGLN1 plays a central role in the hypoxia-inducible factor-mediated hypoxia signaling pathway; however, the posttranslational modifications that control EGLN1 function remain largely unknown. Here, we identified that a lysine monomethylase, SET7, catalyzes EGLN1 methylation on lysine 297, resulting in the repression of EGLN1 activity in catalyzing prolyl hydroxylation of hypoxia-inducible factor-1 α. Notably, we demonstrate that the methylation mimic mutant of EGLN1 loses the capability to suppress the hypoxia signaling pathway, leading to the enhancement of cell proliferation and the oxygen consumption rate. Collectively, our data identify a novel modification of EGLN1 that is critical for inhibiting its enzymatic activity and which may benefit cellular adaptation to conditions of hypoxia.
Subject(s)
Histone-Lysine N-Methyltransferase , Hypoxia-Inducible Factor 1, alpha Subunit , Hypoxia-Inducible Factor-Proline Dioxygenases , Lysine , Animals , Catalysis , Humans , Hydroxylation , Hypoxia/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Hypoxia-Inducible Factor-Proline Dioxygenases/genetics , Hypoxia-Inducible Factor-Proline Dioxygenases/metabolism , Lysine/metabolism , Methylation , Oxygen/metabolism , Protein Processing, Post-TranslationalABSTRACT
Stimuli-responsive drug delivery systems (DDSs) based on amphiphilic polymers have attracted much attention. In this study, we reported an innovative H2O2-responsive amphiphilic polymer (TBP), bearing a H2O2-sensitive phenylboronic ester, AIE fluorophore tetraphenylethene (TPE) hydrophobic, and polyethylene glycol hydrophilic (PEG) moieties. TBP could self-assemble into micelles with an encapsulation efficiency as high as 74.9% for doxorubicin (DOX) in aqueous solution. In the presence of H2O2, TBP micelles was decomposed by oxidation, hydrolysis and rearrangement, leading to almost 80% DOX release from TBP@DOX micelles. TBP and the corresponding degradation products were biocompatible, while TBP@DOX micelles only displayed obvious toxicity toward cancer cells. Drug delivery process was clearly monitored by confocal laser scanning microscopic (CLSM) and flow cytometry (FCM) analysis. Moreover, in vivo anticancer study showed that TBP@DOX micelles were accumulated in tumor region of nude mice and effectively inhibited tumor growth. The results suggested that the reported H2O2-responsive amphiphilic polymer displayed great potential in drug delivery and tumor therapy.
Subject(s)
Antibiotics, Antineoplastic/pharmacology , Doxorubicin/pharmacology , Drug Delivery Systems , Hydrogen Peroxide/chemistry , Polymers/chemistry , Surface-Active Agents/chemistry , Animals , Antibiotics, Antineoplastic/chemistry , Cell Proliferation/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Doxorubicin/chemistry , Drug Liberation , Drug Screening Assays, Antitumor , Female , HEK293 Cells , HeLa Cells , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Molecular Structure , Protein Aggregates , Structure-Activity RelationshipABSTRACT
p53 is a classic tumor suppressor that functions in maintaining genome stability by inducing either cell arrest for damage repair or cell apoptosis to eliminate damaged cells in response to different types of stress. Posttranslational modifications (PTMs) of p53 are thought to be the most effective way for modulating of p53 activation. Here, we show that SIRT5 interacts with p53 and suppresses its transcriptional activity. Using mass spectrometric analysis, we identify a previously unknown PTM of p53, namely, succinylation of p53 at Lysine 120 (K120). SIRT5 mediates desuccinylation of p53 at K120, resulting in the suppression of p53 activation. Moreover, using double knockout mice (p53-/-Sirt5-/-), we validate that the suppression of p53 target gene expression and cell apoptosis upon DNA damage is dependent on cellular p53. Our study identifies a novel PTM of p53 that regulates its activation as well as reveals a new target of SIRT5 acting as a desuccinylase.
Subject(s)
Lysine , Protein Processing, Post-Translational , Sirtuins , Tumor Suppressor Protein p53 , Animals , DNA Damage , Lysine/metabolism , Mice , Mice, Knockout , Sirtuins/genetics , Sirtuins/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolismABSTRACT
TNFR-associated factor 6 (TRAF6) not only recruits TBK1/IKKε to MAVS upon virus infection but also catalyzes K63-linked polyubiquitination on substrate or itself, which is critical for NEMO-dependent and -independent TBK1/IKKε activation, leading to the production of type I IFNs. The regulation at the TRAF6 level could affect the activation of antiviral innate immunity. In this study, we demonstrate that zebrafish prmt2, a type I arginine methyltransferase, attenuates traf6-mediated antiviral response. Prmt2 binds to the C terminus of traf6 to catalyze arginine asymmetric dimethylation of traf6 at arginine 100, preventing its K63-linked autoubiquitination, which results in the suppression of traf6 activation. In addition, it seems that the N terminus of prmt2 competes with mavs for traf6 binding and prevents the recruitment of tbk1/ikkε to mavs. By zebrafish model, we show that loss of prmt2 promotes the survival ratio of zebrafish larvae after challenge with spring viremia of carp virus. Therefore, we reveal, to our knowledge, a novel function of prmt2 in the negative regulation of antiviral innate immunity by targeting traf6.