GCN5 mediates DNA-PKcs crotonylation for DNA double-strand break repair and determining cancer radiosensitivity.

BACKGROUND: DNA double-strand break (DSB) induction and repair are important events for determining cell survival and the outcome of cancer radiotherapy. The DNA-dependent protein kinase (DNA-PK) complex functions at the apex of DSBs repair, and its assembly and activity are strictly regulated by post-translation modifications (PTMs)-associated interactions. However, the PTMs of the catalytic subunit DNA-PKcs and how they affect DNA-PKcs's functions are not fully understood. METHODS: Mass spectrometry analyses were performed to identify the crotonylation sites of DNA-PKcs in response to γ-ray irradiation. Co-immunoprecipitation (Co-IP), western blotting, in vitro crotonylation assays, laser microirradiation assays, in vitro DNA binding assays, in vitro DNA-PK assembly assays and IF assays were employed to confirm the crotonylation, identify the crotonylase and decrotonylase, and elucidate how crotonylation regulates the activity and function of DNA-PKcs. Subcutaneous xenografts of human HeLa GCN5 WT or HeLa GCN5 siRNA cells in BALB/c nude mice were generated and utilized to assess tumor proliferation in vivo after radiotherapy. RESULTS: Here, we reveal that K525 is an important site of DNA-PKcs for crotonylation, and whose level is sharply increased by irradiation. The histone acetyltransferase GCN5 functions as the crotonylase for K525-Kcr, while HDAC3 serves as its dedicated decrotonylase. K525 crotonylation enhances DNA binding activity of DNA-PKcs, and facilitates assembly of the DNA-PK complex. Furthermore, GCN5-mediated K525 crotonylation is indispensable for DNA-PKcs autophosphorylation and the repair of double-strand breaks in the NHEJ pathway. GCN5 suppression significantly sensitizes xenograft tumors of mice to radiotherapy. CONCLUSIONS: Our study defines K525 crotonylation of DNA-PKcs is important for the DNA-PK complex assembly and DSBs repair activity via NHEJ pathway. Targeting GCN5-mediated K525 Kcr of DNA-PKcs may be a promising therapeutic strategy for improving the outcome of cancer radiotherapy.

TAB182 regulates glycolytic metabolism by controlling LDHA transcription to impact tumor radiosensitivity.

Metabolic reprogramming, a hallmark of cancer, is closely associated with tumor development and progression. Changes in glycolysis play a crucial role in conferring radiation resistance to tumor cells. How radiation changes the glycolysis status of cancer cells is still unclear. Here we revealed the role of TAB182 in regulating glycolysis and lactate production in cellular response to ionizing radiation. Irradiation can significantly stimulate the production of TAB182 protein, and inhibiting TAB182 increases cellular radiosensitivity. Proteomic analysis indicated that TAB182 influences several vital biological processes, including multiple metabolic pathways. Knockdown of TAB182 results in decreased lactate production and increased pyruvate and ATP levels in cancer cells. Moreover, knocking down TAB182 reverses radiation-induced metabolic changes, such as radioresistant-related lactate production. TAB182 is necessary for activating LDHA transcription by affecting transcription factors SP1 and c-MYC; its knockdown attenuates the upregulation of LDHA by radiation, subsequently suppressing lactate production. Targeted suppression of TAB182 significantly enhances the sensitivity of murine xenograft tumors to radiotherapy. These findings advance our understanding of glycolytic metabolism regulation in response to ionizing radiation, which may offer significant implications for developing new strategies to overcome tumor radioresistance.

A Dual Coverage Monitoring of the Bile Acids Profile in the Liver-Gut Axis throughout the Whole Inflammation-Cancer Transformation Progressive: Reveal Hepatocellular Carcinoma Pathogenesis.

Hepatocellular carcinoma (HCC) is the terminal phase of multiple chronic liver diseases, and evidence supports chronic uncontrollable inflammation being one of the potential mechanisms leading to HCC formation. The dysregulation of bile acid homeostasis in the enterohepatic circulation has become a hot research issue concerning revealing the pathogenesis of the inflammatory-cancerous transformation process. We reproduced the development of HCC through an N-nitrosodiethylamine (DEN)-induced rat model in 20 weeks. We achieved the monitoring of the bile acid profile in the plasma, liver, and intestine during the evolution of "hepatitis-cirrhosis-HCC" by using an ultra-performance liquid chromatography-tandem mass spectrometer for absolute quantification of bile acids. We observed differences in the level of primary and secondary bile acids both in plasma, liver, and intestine when compared to controls, particularly a sustained reduction of intestine taurine-conjugated bile acid level. Moreover, we identified chenodeoxycholic acid, lithocholic acid, ursodeoxycholic acid, and glycolithocholic acid in plasma as biomarkers for early diagnosis of HCC. We also identified bile acid-CoA:amino acid N-acyltransferase (BAAT) by gene set enrichment analysis, which dominates the final step in the synthesis of conjugated bile acids associated with the inflammatory-cancer transformation process. In conclusion, our study provided comprehensive bile acid metabolic fingerprinting in the liver-gut axis during the inflammation-cancer transformation process, laying the foundation for providing a new perspective for the diagnosis, prevention, and treatment of HCC.

A multidimensional strategy for uncovering comprehensive quality markers of Schisandra chinensis (Turcz.) Baill based on pharmacodynamics and chemical properties.

BACKGROUND: Quality control of Traditional Chinese Medicines (TCMs) has improved greatly, but there is still a lack of a convincing quality evaluation system for TCMs. Developing quality control markers of TCMs based on pharmacodynamics instead of content has been an attractive approach. However, on account of neglecting phytochemistry attributes of TCMs, part of effective markers might be short of specificity and inconvenient for detecting in production manufacture, which is adverse to control the quality of TCMs systematically. PURPOSE: To build a novel and multidimensional quality assessment approach for TCMs based on pharmacodynamics and chemical properties. METHODS: Schisandra chinensis (Turcz.) Baill (S. chinensis) was used as an example and a rat depression model was built by using a chronic unpredictable mild stress procedure. For identifying the antidepressive components of S. chinensis, we elucidated its antidepressant mechanism in first-step by using quantitative RT-PCR and immunoblotting techniques. And accordingly, correlation analysis between ingredients in vivo with target proteins and anti-inflammation experiments in vitro were carried out. On the other hand, HPLC fingerprint combinations with diverse chemometrics methods were applied to analyze 14 preparations of S. chinensis to obtain its characteristic chemical information. Finally, we ascertained the quality control markers of S. chinensis by integrating the efficacious and characteristic constituents. RESULTS: Our research indicated that S. chinensis treated depression by relieving disordered monoaminergic system and ameliorating neuroinflammation. Five effective substances (schisandrol A, schisandrin A, gomisin N, schisandrin B, and schisandrin C) were screened out according to their potential anti-depression efficacy. Besides, 21 common ingredients and 4 representative constituents of S. chinensis were identified by chemical analysis, whereas only 2 characteristic quantitative markers (schisandrol A, schisandrol B) were ultimately ascertained based on previous studies. CONCLUSION: 6 components, schisandrol A, schisandrin A, gomisin N, schisandrin B, schisandrin C, and schisandrol B, possessed efficacy, measurability, and specificity, were selected as the comprehensive markers for quality control of S. chinensis. We proposed a multidimensional strategy for identifying comprehensive quality markers for TCMs in this study.

Risk Factors Associated with Impairment in Pulmonary Diffusing Capacity among Patients with Noncystic Fibrosis Bronchiectasis.

This study aims to investigate the risk factors associated with impaired pulmonary diffusing capacity among patients with noncystic fibrosis bronchiectasis (NCFB) and compare the predictive value of several scoring systems for the impairment in these patients. Between July 2019 and June 2021, patients who were admitted to the hospital and diagnosed with NCFB were included in this study. Clinical data were collected and analyzed retrospectively. A total of 175 NCFB patients were included in the analysis. Multivariate logistic regression analysis revealed that impaired pulmonary diffusing capacity diagnosed by carbon monoxide diffusing capacity (DLCO) <80% prediction was associated with age, Reiff score, body mass index (BMI), comorbid chronic obstructive pulmonary disease (COPD), and interstitial lung disease (ILD). Disease duration, frequency of exacerbation, hemoglobin level, and COPD were independent risk factors for impaired pulmonary diffusing capacity diagnosed by DLCO/alveolar volume (VA) <80% prediction. Age, Reiff score, and smoking status were independent risk factors for decreased VA diagnosed by VA <80% prediction. The areas under the curve (AUC) for discrimination of DLCO <80% prediction were 0.822 (0.760-0.885) for Bronchiectasis Severity Index (BSI), 0.787 (0.718-0.856) for FACED, 0.795 (0.729-0.863) for E-FACED, and 0.767 (0.694-0.839) for modified Medical Research Council (mMRC) scores; the AUC for discrimination of DLCO/VA <80% prediction was 0.803 (0.727-0.880) for BSI, 0.752 (0.669-0.835) for FACED, 0.757 (0.676-0.839) for E-FACED, and 0.762 (0.679-0.845) for mMRC, respectively. The BSI had the largest AUC, but the differences between those scoring systems had no statistical significance (P=0.181 for DLCO <80% prediction and P=0.105 for DLCO/VA <80% prediction). The mMRC score (up to 2 grades) showed a high specificity for discriminating diffusing dysfunction (88.3% for DLCO <80% prediction and 76.1% for DLCO/VA <80% prediction). In NCFB patients, several factors such as age, Reiff score, BMI, exacerbation frequency, disease duration, and comorbid COPD and ILD were associated with impaired pulmonary diffusing capacity, which requires more attention in managing those patients. In addition, several scoring methods, including a simple index of mMRC, showed a comparable and moderate performance for predicting pulmonary diffusing impairment and would facilitate the systematic evaluation of the diffusing capacity of NCFB patients.

An Integrated Mutually Oriented "Chemical Profiling-Pharmaceutical Effect" Strategy for Screening Discriminating Markers of Underlying Hepatoprotective Effects to Distinguish Garden-Cultivated from Mountain-Cultivated Ginseng.

Garden-cultivated Ginseng (GG) and mountain-cultivated Ginseng (MG) both belong to Panax Ginseng C. A. Meyer. However, the effective substances which can be used to distinguish GG from MG remain obscure. Therefore, the purpose of this study was to screen for discriminating markers that can assist in the correct identification of GG and MG. HPLC Q-TOF/MS and various chemometrics methods were used to analyze the chemical profiles of 13 batches of Ginseng and to explore the characteristic constituents of both GG and MG. The hepatocyte-protecting effects of GG and MG were investigated through a paclitaxel-induced liver injury model. Through a combination of correlation analysis and bioinformatic techniques, markers for differentiation between GG and MG were ascertained. A total of 40 and 41 compounds were identified in GG and MG, respectively, and 15 characteristic ingredients contributed significantly to the discrimination of GG from MG. Correlation analysis and network pharmacology were applied and ginsenosides Rg1, Re, Rb1, Rc, Rb2, and Rg3 were found to be discriminating markers of GG and MG. Six markers for the identification of GG and MG were screened out by a step-wise mutually oriented "chemical profiling-pharmaceutical effect" correlation strategy, which is of great significance for future quality assessment of Ginseng products.

A systematic strategy for uncovering quality marker of Asari Radix et Rhizoma on alleviating inflammation based chemometrics analysis of components.

Asari Radix et Rhizoma (Asarum), a traditional Chinese medicine (TCM), has been applied in clinical generally. However, due to the lack of valid methods for Asarum quality control, inhomogenous quality and therapy issues have become severe with each passing day. In this study, we aimed to establish a comprehensive multi-system to explore the quality control markers underlying pharmaceutical effects based on chemometrics analysis on the total ingredients of Asarum. In brief, DNA barcoding technology was used to screen out the unadulterated herbs in the 15 batches Asarum collected from different origins. Then, the chemical profiles of volatile/nonvolatile components of 10 batches Asarum with definite resource were obtained by HPLC Q-TOF/MS and GC/MS. Combination with chemometrics methods, 14 characteristic ingredients and 4 qualitative and quantitative markers were figured out preliminarily. Moreover, correlation analysis between the characteristic ingredients and the cytokines integrating the virtual targets prediction of network pharmacology, 3 potential bioactive substance were ascertained. In conclusion, l-asarinin, 2-Methoxy-4-vinylphenol and safrole were considered as the potent candidates for quality control markers based on the comprehensive understanding for therapeutic effects and the chemical information of Asarum, which provided a novel perspective of the development for the quality control of TCM.

Surface modification of carbon nanotube with gelatin via mussel inspired method.

Carbon nanotube (CNT) has aroused much attention in biomedical field. However, the cytotoxicity and aggregation are critical factors that affect the application of carbon nanotube (CNT). Herein, gelatin was grafted on the surface of CNT via mussel-inspired method. The gelatin modified CNT can disperse homogeneously in water. The in vitro test showed that gelatin modified CNT showed much better biocompatibility than the native CNT, which may improve its potential application in biomedical field.

Particulate matter (PM10) induces cardiovascular developmental toxicity in zebrafish embryos and larvae via the ERS, Nrf2 and Wnt pathways.

Particulate matter (PM10) is one of the most important indicators of the pollution that characterizes air quality. Epidemiological studies have shown that PM10 can cause cardiovascular-related diseases in the population. And, we studied the developmental toxicity of PM10 and the underlying mechanism of its effects on the cardiovascular system of zebrafish embryo/larva. Changes in cardiac morphology, sinus venosus and bulbus arteriosus (SV-BA) distance, heart rate, vascular subintestinalis, blood flow, returned blood volume, and reactive oxygen species (ROS) level were measured, and changes in the expression levels of certain genes were assessed via RT-PCR. The results showed that PM10 caused a significant increase in pericardial sac area and SV-BA distance, a decrease in heart rate, inhibition of vascular subintestinalis growth, blood flow obstruction, reduced venous return, and other cardiovascular toxicities. PM10 induced an increase in the ROS level and significant increases in the expression levels of ERS signalling pathway factors and Nrf2 signalling pathway factors. The expression levels of the Wnt pathway-related genes also showed significant changes. Furthermore, ROS inhibitor N-Acetyl-l-cysteine (NAC) could ameliorate the cardiovascular toxicity of PM10 in zebrafish larvae. It is speculated that PM10 may result in cardiovascular toxicity by inducing higher ROS levels in the body, which could then induce ERS and lead to defects in the expression of genes related to the Wnt signalling pathway. The Nrf2 signalling pathway was activated as a stress compensatory mechanism during the early stage of PM10-induced cardiovascular injury. However, it was insufficient to counteract the PM10-induced cardiovascular toxicity.

Developmental toxicity induced by PM2.5 through endoplasmic reticulum stress and autophagy pathway in zebrafish embryos.

The aims of this study were to investigate the mechanism underlying the developmental toxicity of fine particulate matter (PM2.5) and provide a more thorough understanding of the toxicity of PM2.5 in an ecological environment. Zebrafish embryos at 4 h post-fertilization were exposed to PM2.5 at doses of 200, 300, 400, 500, 600 and 800 µg/mL for 120 h. The mortality, hatching rate, morphology score, body length, locomotor capacity, histological changes, antioxidant defense system, leukocyte migration, inflammation-related gene mRNA expression, endoplasmic reticulum stress (ERS) and autophagy were evaluated to study PM2.5-induced developmental toxicity and its underlying mechanisms. PM2.5 exposure significantly increased the mortality and malformations and reduced the hatching rate and body length of the zebrafish. PM2.5 significantly reduced the locomotor capacity of zebrafish larvae, increased the levels of ROS and disturbed the antioxidant defense system in zebrafish larvae. In addition, a histological examination showed that the heart, liver, intestines and muscle of the PM2.5-treated zebrafish exhibited abnormal changes and a significant increase in cellular autophagic accumulation. RT-PCR showed that the expression of genes related to inflammation (tgfß and cox2), ERS (hspa5, chop, ire1, xbp1s, and atf6) and autophagy (lc3, beclin1 and atg3) pathways was significantly increased in the PM2.5-treated zebrafish, indicating that PM2.5 induced inflammation and promoted ERS and autophagy responses via the activation of the IRE1-XBP1 and ATF6 pathways. Together, our data indicate that PM2.5 induced a dose- and time-dependent increase in developmental toxicity to zebrafish embryos. Additionally, ERS and autophagy may play important roles in PM2.5-induced developmental toxicity.