Study on mechanism of hydroxy-a-sanshool on diabetic cardiomyopathy based on proteomics / 中国药理学通报

Aim To explore the mechanism of hydroxy-a-sanshool in the treatment of diabetic cardiomyopathy ( DCM) based on label-free quantitative proteomics detection technique. Methods DCM model was established by high fat diet and intraperitoneal injection of streptozotocin ( STZ) . They were divided into control group ( CON group ) , diabetic cardiomyopathy group (DCM group) and hydroxy-a-sanshool treatment group ( DCM + SAN group) . The cardiac function of mice was evaluated by echocardiography, the myocardial morphology was observed by pathology staining, the protective mechanism of hydroxy-a-sanshool on diabetic cardiomyopathy was speculated by proteomic technique , and the expression level of cAMP/PKA signaling pathway and key proteins were verified by Western blotting. Results Cardiac ultrasound and pathology staining showed that hydroxy-a-sanshool had protective effect on the heart of DCM mice. Label-free quantitative proteomic analysis was carried out between DCM + SAN group and DCM group, and 160 differential pro-teins were identified by proteomics, in which 127 proteins were up-regulated and 33 proteins were down regulated ; GO secondary functional annotations showed the biological process, molecular function and cellular component; KEGG enrichment analysis showed that cAMP signaling pathway was the most abundant; protein interaction network showed that PKA as the central node interacted with many proteins in the cAMP signaling pathway. Western blot showed that the relative expression of с AMP, PKA protein in DCM group was significantly lower than that in CON group ( P < 0. 05 ) , while the relative expression of cAMP, PKA protein in DCM + SAN group was significantly higher than that in DCM group ( P < 0. 05 ) . Conclusions Hydroxy-a-sanshool has protective effect on heart function of mice with diabetes, which plays a role through cAMP signaling pathway.

Application progress of proteomics in dry eye research / 国际眼科杂志(Guoji Yanke Zazhi)

The complex pathological mechanism of dry eye involves multiple pathways, such as immunity and inflammation, and requires an integral research program to control the whole picture. Various histological techniques can elucidate the complex physio-pathological state of organisms from a holistic and global perspective, thus providing more comprehensive biological information. Mass spectrometry can sensitively detect the changes of protein content in tear samples, providing convenience for proteomics research of dry eye. At present, proteomics has demonstrated its application in the identification of dry eye types, severity grading, and therapeutic effect evaluation. In addition, proteomics combined with metabolomics and microbiomics can more comprehensively explain the pathogenesis of dry eye. In the future, proteomics is expected to provide more powerful support for the precise diagnosis and treatment of dry eye, taking an advantage in targeted therapy.

Anemoside B4 inhibits SARS-CoV-2 replication in vitro and in vivo / 中草药·英文版

OBJECTIVE@#Anemoside B4 (AB4), the most abundant triterpenoidal saponin isolated from Pulsatilla chinensis, inhibited influenza virus FM1 or Klebsiella pneumoniae-induced pneumonia. However, the anti-SARS-CoV-2 effect of AB4 has not been unraveled. Therefore, this study aimed to determine the antiviral activity and potential mechanism of AB4 in inhibiting human coronavirus SARS-CoV-2 in vivo and in vitro.@*METHODS@#The cytotoxicity of AB4 was evaluated using the Cell Counting Kit-8 (CCK8) assay. SARS-CoV-2 infected HEK293T, HPAEpiC, and Vero E6 cells were used for in vitro assays. The antiviral effect of AB4 in vivo was evaluated by SARS-CoV-2-infected hACE2-IRES-luc transgenic mouse model. Furthermore, label-free quantitative proteomics and bioinformatic analysis were performed to explore the potential antiviral mechanism of action of AB4. Type I IFN signaling-associated proteins were assessed using Western blotting or immumohistochemical staining.@*RESULTS@#The data showed that AB4 reduced the propagation of SARS-CoV-2 along with the decreased Nucleocapsid protein (N), Spike protein (S), and 3C-like protease (3CLpro) in HEK293T cells. In vivo antiviral activity data revealed that AB4 inhibited viral replication and relieved pneumonia in a SARS-CoV-2 infected mouse model. We further disclosed that the antiviral activity of AB4 was associated with the enhanced interferon (IFN)-β response via the activation of retinoic acid-inducible gene I (RIG-1) like receptor (RLP) pathways. Additionally, label-free quantitative proteomic analyses discovered that 17 proteins were significantly altered by AB4 in the SARS-CoV-2 coronavirus infections cells. These proteins mainly clustered in RNA metabolism.@*CONCLUSION@#Our results indicated that AB4 inhibited SARS-CoV-2 replication through the RLR pathways and moderated the RNA metabolism, suggesting that it would be a potential lead compound for the development of anti-SARS-CoV-2 drugs.

Impairment of Autophagic Flux After Hypobaric Hypoxia Potentiates Oxidative Stress and Cognitive Function Disturbances in Mice / 神经科学通报·英文版

Acute hypobaric hypoxic brain damage is a potentially fatal high-altitude sickness. Autophagy plays a critical role in ischemic brain injury, but its role in hypobaric hypoxia (HH) remains unknown. Here we used an HH chamber to demonstrate that acute HH exposure impairs autophagic activity in both the early and late stages of the mouse brain, and is partially responsible for HH-induced oxidative stress, neuronal loss, and brain damage. The autophagic agonist rapamycin only promotes the initiation of autophagy. By proteome analysis, a screen showed that protein dynamin2 (DNM2) potentially regulates autophagic flux. Overexpression of DNM2 significantly increased the formation of autolysosomes, thus maintaining autophagic flux in combination with rapamycin. Furthermore, the enhancement of autophagic activity attenuated oxidative stress and neurological deficits after HH exposure. These results contribute to evidence supporting the conclusion that DNM2-mediated autophagic flux represents a new therapeutic target in HH-induced brain damage.

Proteomic analysis and validation of DNA repair regulation in the process of hepatocellular carcinoma recurrence / 临床肝胆病杂志

ObjectiveTo investigate the role and mechanism of DNA repair regulation in the process of hepatocellular carcinoma （HCC） recurrence. MethodsHCC tissue samples were collected from the patients with recurrence within two years or the patients with a good prognosis after 5 years， and the Tandem Mass Tag-labeled quantification proteomic study was used to analyze the differentially expressed proteins enriched in the four pathways of DNA replication， mismatch repair， base excision repair， and nucleotide excision repair， and the regulatory pathways and targets that play a key role in the process of HCC recurrence were analyzed to predict the possible regulatory mechanisms. The independent samples t-test was used for comparison of continuous data between two groups； a one-way analysis of variance was used for comparison between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsFor the eukaryotic replication complex pathway， there were significant reductions in the protein expression levels of MCM2 （P=0.018）， MCM3 （P=0.047）， MCM4 （P=0.014）， MCM5 （P=0.008）， MCM6 （P=0.006）， MCM7 （P=0.007）， PCNA （P=0.019）， RFC4 （P=0.002）， RFC5 （P<0.001）， and LIG1 （P=0.042）； for the nucleotide excision repair pathway， there were significant reductions in the protein expression levels of PCNA （P=0.019）， RFC4 （P=0.002）， RFC5 （P<0.001）， and LIG1 （P=0.042）； for the base excision repair pathway， there were significant reductions in the protein expression levels of PCNA （P=0.019） and LIG1 （P=0.042） in the HCC recurrence group； for the mismatch repair pathway， there were significant reductions in the protein expression levels of MSH2 （P=0.026）， MSH6 （P=0.006）， RFC4 （P=0.002）， RFC5 （P<0.001）， PCNA （P=0.019）， and LIG1 （P=0.042） in recurrent HCC tissue. The differentially expressed proteins were involved in the important components of MCM complex， DNA polymerase complex， ligase LIG1， long patch base shear repair complex （long patch BER）， and DNA mismatch repair protein complex. The clinical sample validation analysis of important differentially expressed proteins regulated by DNA repair showed that except for MCM6 with a trend of reduction， the recurrence group also had significant reductions in the relative protein expression levels of MCM5 （P=0.008）， MCM7 （P=0.007）， RCF4 （P=0.002）， RCF5 （P<0.001）， and MSH6 （P=0.006）. ConclusionThere are significant reductions or deletions of multiple complex protein components in the process of DNA repair during HCC recurrence.

Mechanisms of brain damage caused by inorganic fluoride using proteomics-based techniques / 环境与职业医学

Background Chronic excessive exposure to fluoride can cause damage to the central nervous system and a certain degree of learning and memory impairment. However, the associated mechanism is not yet clear and further exploration is needed. Objective Using 4D unlabelled quantitative proteomics techniques to explore differentially expressed proteins and their potential mechanisms of action in chronic excessive fluoride exposure induced brain injury. Methods Twenty-four SPF-grade adult SD rats, half male and half male, were selected and divided into a control group and a fluoride group by random number table method, with 12 rats in each group. Among them, the control group drank tap water (fluorine content<1 mg·L−1), the fluoride group drank sodium fluoride solution (fluorine content 10 mg·L−1), and both groups were fed with ordinary mouse feed (fluoride content<0.6 mg·kg−1). After 180 d of feeding, the SD rats were weighed, and then part of the brain tissue was sampled for pathological examination by hematoxylin-eosin (HE) staining and Nissl staining. The rest of the brain tissue was frozen and stored at −80 ℃. Three brain tissue samples from each group were randomly selected for proteomics detection. Differentially expressed proteins were screened and subcellular localization analysis was performed, followed by Gene Ontology (GO) function analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, cluster analysis, and protein-protein interaction analysis. Finally, Western blotting was used to detect the expression levels of key proteins extracted from the brain tissue samples. Results After 180 d of feeding, the average weight of the rats in the fluoride group was significantly lower than that in the control group (P<0.05). The brain tissue stained with HE showed no significant morphological changes in the cerebral cortex of the fluoride treated rats, and neuron loss, irregular arrangement of neurons, eosinophilic changes, and cell body pyknosis were observed in the hippocampus. The Nissl staining results showed that the staining of neurons in the cerebral cortex and hippocampus of rats exposed to fluoride decreased (Nissl bodies decreased). The proteomics results showed that a total of 6927 proteins were identified. After screening, 206 differentially expressed proteins were obtained between the control group and the fluoride group, including 96 up-regulated proteins and 110 down-regulated proteins. The differential proteins were mainly located in cytoplasm (30.6%), nucleus (27.2%), mitochondria (13.6%), plasma membrane (13.6%), and extracellular domain (11.7%). The GO analysis results showed that differentially expressed proteins mainly participated in biological processes such as iron ion transport, regulation of dopamine neuron differentiation, and negative regulation of respiratory burst in inflammatory response, exercised molecular functions such as ferrous binding, iron oxidase activity, and cytokine activity, and were located in the smooth endoplasmic reticulum membrane, fixed components of the membrane, chloride channel complexes, and other cellular components. The KEGG significantly enriched pathways included biosynthesis of secondary metabolites, carbon metabolism, and microbial metabolism in diverse environments. The results of differential protein-protein interaction analysis showed that the highest connectivity was found in glucose-6-phosphate isomerase (Gpi). The expression level of Gpi in the brain tissue of the rats in the fluoride group was lower than that in the control group by Western blotting (P<0.05). Conclusion Multiple differentially expressed proteins are present in the brain tissue of rats with chronic fluorosis, and their functions are related to biosynthesis of secondary metabolites, carbon metabolism, and microbial metabolism in diverse environments; Gpi may be involved in cerebral neurological damage caused by chronic overdose fluoride exposure.

Application of proteomics technology in dry eye disease and acupuncture treatment / 国际眼科杂志(Guoji Yanke Zazhi)

Dry eye disease(DED)refers to a condition characterized by reduced stability of the tear film or an imbalance in the microenvironment of the ocular surface, resulting from abnormalities in quality, quantity and kinetics of tear. This condition leads to various ocular discomforts and even visual impairment. The pathogenesis of DED is multifactorial and current treatment mainly focuses on symptom relief and preservation of visual function. Acupuncture has shown effectiveness in treating dry eye, although its underlying mechanism remains incompletely understood. Proteomics technology offers a comprehensive and systematic approach to studying the functions, structures and interactions of proteins. Its application in DED research can provide valuable insights into the dynamic changes in protein levels associated with different etiology or the course of DED and facilitate the identification of potential biomarkers. Furthermore, proteomics can systematically explore the regulatory mechanisms underlying acupuncture treatment for DED, providing a theoretical basis for acupuncture treatment research and contributing to the understanding of its effects at a fundamental level. This paper aims to explore the potential application of proteomics in both clinical and basic research on DED. Ultimately, it strives to offer scientific and effective strategies for the diagnosis and treatment of DED and advance our knowledge of the mechanisms underlying acupuncture therapy.

Comparative proteomics of proliferative diabetic retinopathy in people with Type 2 diabetes highlights the role of inflammation, visual transduction, and extracellular matrix pathways

Purpose: To explore the vitreous humor proteome from type 2 diabetes subjects with proliferative diabetic retinopathy (PDR) in the Indian population. Methods: We performed mass spectrometry?based label?free quantitative analysis of vitreous proteome of PDR (n = 13) and idiopathic macular hole (IMH; control) subjects (n = 14). Nine samples of PDR and 10 samples of IMH were pooled as case and control, respectively, and compared. Four samples each of PDR and IMH were analyzed individually without pooling to validate the results of the pooled analysis. Comparative quantification was performed using Scaffold software which calculated the fold changes of differential expression. Bioinformatics analysis was performed using DAVID and STRING software. Results: We identified 469 proteins in PDR and 517 proteins in IMH vitreous, with an overlap of 172 proteins. Also, 297 unique proteins were identified in PDR and 345 in IMH. In PDR vitreous, 37 proteins were upregulated (P < 0.05) and 19 proteins were downregulated compared to IMH. Protein distribution analysis clearly demonstrated a separation of protein expression in PDR and IMH. Significantly upregulated proteins included fibrinogen gamma chain, fibrinogen beta chain, and carbonic anhydrase 1 and downregulated proteins included alpha?1?antitrypsin, retinol?binding protein 3, neuroserpin, cystatin C, carboxypeptidase E and cathepsin?D. Conclusion: Diabetic retinopathy pathogenesis involves proteins which belong to inflammation, visual transduction, and extracellular matrix pathways. Validation?based experiments using enzyme?linked immunosorbent assay (ELISA) or western blotting are needed to establish cause and effect relationships of these proteins to the disease state, to develop them as biomarkers or drug molecules

Identification of potential urinary protein biomarkers in colorectal cancer: a pilot study using a proteomic approach

Colorectal cancer (CRC) is among the most diagnosed malignancies worldwide, and it is also the second leading cause of cancer-related deaths. Despite recent progress in screening programs, noninvasive accurate biomarkers are still needed in the CRC field. In this study, we evaluated and compared the urinary proteomic profiles of patients with colorectal adenocarcinoma and patients without cancer, aiming to identify potential biomarker proteins. Urine samples were collected from 9 patients with CRC and 9 patients with normal colonoscopy results. Mass spectrometry (label-free LC—MS/MS) was used to characterize the proteomic profile of the groups. Ten proteins that were differentially regulated were identified between patients in the experimental group and in the control group, with statistical significance with a p value ≤ 0.05. The only protein that presented upregulation in the CRC group was beta-2-microglobulin (B2M). Subsequent studies are needed to evaluate patients through different analysis approaches to independently verify and validate these biomarker candidates in a larger cohort sample. (AU)

Profiling of idiopathic macular hole vitreous proteome identifies the role of extracellular matrix remodelling, epithelial–mesenchymal transformation and unfolded protein-response pathways

Purpose: To analyze and describe the proteome of the vitreous humour in eyes with idiopathic macular holes. Methods: We performed mass spectrometry (MS)?based label?free quantitative analysis of the vitreous proteome of idiopathic macular hole (IMH) and control donor vitreous. Comparative quantification was performed using SCAFFOLD software which calculated fold changes of differential expression. Bioinformatics analysis was performed using DAVID and STRING software. Results: A total of 448 proteins were identified by LC?MS/MS in IMH and cadaveric eye vitreous samples, of which 199 proteins were common. IMH samples had 189 proteins that were unique and 60 proteins were present only in the control cadaveric vitreous. We found upregulation of several extracellular matrix (ECM) and cytoskeletal proteins, namely collagen alpha?1 (XVIII) chain, N?cadherin, EFEMP1/fibulin?3, basement membrane?specific heparan sulfate proteoglycan core protein, and target of Nesh?3. Several cytoskeleton proteins, namely tubulin, actin, and fibronectin levels, were significantly lower in IMH vitreous, probably reflecting increased ECM degradation. IMH vitreous also had a downregulation of unfolded protein response?mediated?mediated apoptosis proteins, possibly related to a state of increased cell survival and proliferation, along with a remodelling and aberrant production of ECM contents. Conclusion: The pathogenesis of macular holes may involve ECM remodelling, epithelial–mesenchymal transformation, downregulation of apoptosis, protein folding defects, and complement pathway. The vitreo?retinal milieu in macular holes contain molecules related to both ECM degradation and inhibition of the same, thereby maintaining a homeostasis.

Optimization and evaluation of tear protein elution from Schirmer’s strips in dry eye disease

Purpose: Extraction of tear protein from Schirmer’s strip is a prerequisite for the proper identification and screening of biomarkers in dry eye disease. The study compares different methods of extraction of tear proteins from the Schirmer’s strip. Methods: Reflex tear was collected from healthy controls (HC; n = 12), Stevens–Johnson syndrome (SJS; n = 3) and dry eye disease (DED; n = 3) patients using capillary tube. This tear was used to measure the volume absorbed by Schirmer’s strip per microliter. Different buffers (6) were used to compare the protein yield from the Schirmer’s strip in four different conditions. The tear proteins extracted using the highest protein yield buffer were analyzed by mass spectrometry. Results: A linear relationship between the tear volume and wetting length was observed (r = 0.0.997, n = 6). The highest yield was observed after incubation of the Schirmer’s strip in 100 mM ammonium bicarbonate (ABC) with 0.25% Nonidet P?40(NP?40) at 4°C for an hour (P < 0.00005). The in?solution digestion of tear eluted in the above condition 100 Mm ABC + 0.25% NP?40 with one?hour incubation yielded a total of 2119 proteins in HC, SJS, and DED. The unique protein observed in SJS and DED was 0.6% and 17.9%, respectively. The significantly expressed proteins are associated with innate immune response, proteolysis, wound healing, and defense response. Conclusion: A method for extraction of protein from Schirmer’s strip was optimized for increase in protein yield from the tear sample. SJS and DED tear samples have unique protein signature. The study will aid in better design of tear protein?based experimental study.

Dried blood spots: a robust tool for malaria surveillance in countries targeting elimination

With the advancements in analytical and molecular techniques, Dried Blood Spots (DBS) are re-emerging as attractive and cost-effective alternatives for global health surveillance. The use of DBS has been well-characterized in the neonatal screening of metabolic diseases, therapeutic screening as well as in epidemiological studies for biomonitoring. Malaria is one such infectious disease where DBS use can expedite molecular surveillance for assessing drug resistance and for refining drug usage policies. In India, malaria cases have reduced significantly over the past decade but to achieve malaria elimination by 2030, country-wide DBS-based screening should be conducted to identify the presence of molecular markers of artemisinin resistance and to study parasite reservoirs in asymptomatic populations. DBS has wide applications in genomics, proteomics, and metabolomic studies concerning both host and pathogen factors. Hence, it is a comprehensive tool for malaria surveillance that can capture both host and parasite information. In this review, we elucidate the current and prospective role of DBS in malaria surveillance and its applications in studies ranging from genetic epidemiology, parasite and vector surveillance, drug development and polymorphisms to ultimately how they can pave the roadmap for countries aiming malaria elimination

Effects of Rehmanniae Radix and Rehmanniae Radix Praeparata on proteomics and autophagy in mice with type 2 diabetes mellitus induced by high-fat diet coupled with streptozotocin / 中国中药杂志

To compare the pancreatic proteomics and autophagy between Rehmanniae Radix-and Rehmanniae Radix Praeparata-treated mice with type 2 diabetes mellitus(T2DM). The T2DM mouse model was established by high-fat diet coupled with streptozotocin(STZ, intraperitoneal injection, 100 mg·kg~(-1), once a day for three consecutive days). The mice were then randomly assigned into a control group, low-(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix groups, low-(150 mg·kg~(-1)) and high-dose(300 mg·kg~(-1)) catalpol groups, low-(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix Praeparata groups, low-(150 mg·kg~(-1)) and high-dose(300 mg·kg~(-1)) 5-hydroxymethyl furfuraldehyde(5-HMF) groups, and a metformin(250 mg·kg~(-1)) group. In addition, a normal group was also set and each group included 8 mice. The pancreas was collected after four weeks of administration and proteomics tools were employed to study the effects of Rehmanniae Radix and Rehmanniae Radix Praeparata on protein expression in the pancreas of T2DM mice. The expression levels of proteins involved in autophagy, inflammation, and oxidative stress response in the pancreatic tissues of T2DM mice were determined by western blotting, immunohistochemical assay, and transmission electron microscopy. The results showed that the differential proteins between the model group and Rehmanniae Radix/Rehmanniae Radix Prae-parata group were enriched in 7 KEGG pathways, such as autophagy-animal, which indicated that the 7 pathways may be associated with T2DM. Compared with the control group, drug administration significantly up-regulated the expression levels of beclin1 and phosphorylated mammalian target of rapamycin(p-mTOR)/mTOR and down-regulated those of the inflammation indicators, Toll-like receptor-4(TLR4) and Nod-like receptor protein 3(NLRP3), in the pancreas of T2DM mice, and Rehmanniae Radix showed better performance. In addition, the expression levels of inducible nitric oxide synthase(iNOS), nuclear factor erythroid 2-related factor 2(Nrf2), and heine oxygenase-1(HO-1) in the pancreas of T2DM mice were down-regulated after drug administration, and Rehmanniae Radix Praeparata demonstrated better performance. The results indicate that both Rehmanniae Radix and Rehmanniae Radix Praeparata can alleviate the inflammatory symptoms, reduce oxidative stress response, and increase the autophagy level in the pancreas of T2DM mice, while they exert the effect on different autophagy pathways.

Mechanism of Qiwei Guibao Granules in treatment of premature ovarian failure based on proteomics / 中国中药杂志

In this study, the underlying mechanism of Qiwei Guibao Granules(QWGB) in the treatment of premature ovarian fai-lure(POF) was explored by the proteomics technique. Firstly, the POF model was induced in mice by intragastric administration of Tripterygium wilfordii glycosides solution at 50 mg·kg~(-1) for 14 days. Ten days prior to the end of the modeling, the estrous cycle of mice was observed every day to evaluate the success of modeling. From the 1st day after modeling, the POF model mice were treated with QWGB by gavage every day and the treatment lasted four weeks. On the 2nd day after the end of the experiment, blood was collected from the eyeballs and the serum was separated by centrifugation. The ovaries and uterus were collected and the adipose tissues were carefully stripped. The organ indexes of the ovaries and uterus of each group were calculated. The serum estrogen(E_2) level of mice in each group was detected by ELISA. Protein samples were extracted from ovarian tissues of mice, and the differential proteins before and after QWGB intervention and before and after modeling were analyzed by quantitative proteomics using tandem mass tags(TMT). As revealed by the analysis of differential proteins, QWGB could regulate 26 differentially expressed proteins related to the POF model induced by T. wilfordii glycosides, including S100A4, STAR, adrenodoxin oxidoreductase, XAF1, and PBXIP1. GO enrichment results showed that the 26 differential proteins were mainly enriched in biological processes and cellular components. The results of KEGG enrichment showed that those differential proteins were involved in signaling pathways such as completion and coalescence cascades, focal adhesion, arginine biosynthesis, and terpenoid backbone biosynthesis. The complement and coalescence cascades signaling pathway was presumably the target pathway of QWGB in the treatment of POF. In this study, the proteomics technique was used to screen the differential proteins of QWGB in the treatment of POF in mice induced by T. wilfordii glycosides, and they were mainly involved in immune regulation, apoptosis regulation, complement and coagulation cascade reactions, cholesterol metabolism, and steroid hormone production, which may be the main mechanisms of QWGB in the treatment of POF.

Label-free target identification for natural products based on proteomics / 药学学报

Target identification and verification of natural products is an important and challenging work in the field of chemical biology. It is also an important job for researchers to apply chemical proteomics technology to biomedicine in order to identify target proteins of natural products. Target identification is critical to understanding its mechanisms and developing natural products as molecular probes and potential therapeutic drugs. Traditional approaches of small molecule target identification based on affinity have been shown to be successful, such as click-chemical probes, radioisotope labeling or photosensitized small-molecule probes. Nevertheless, these technologies require purified candidate target proteins, and modified small molecules with probes or linkers, such as adding agarose beads, biotin labels, fluorescent labeling or photo-affinity labeling. Many structure-activity relationship studies should be performed to ensure that the addition of small molecule labels undisturbed the original biological activity of the small molecules. Unfortunately, all these modifications are likely to alter their biological activity or binding specificity. To overcome the bottleneck of "target recognition", researchers have developed a series of new techniques for unmodified drug target identification. In this article, we reviewed the target identification techniques of natural product without structural modification in order to provide reference for the development of natural products.

Mechanism of HES1 regulating herceptin resistance in gastric cancer cells by ferroptosis / 药学学报

Drug resistance of cancer cells is the main causes of chemotherapy failure, and gene mutation or function loss is key factor to induce drug resistance. Previous studies have shown that hairy and enhancer of split 1 (HES1) is up-regulated in herceptin-resistant gastric cancer cells, and inhibition of its activity can reverse its resistance while the potential mechanism has not yet been elucidated. In this study, we employed CRISPR/Cas9 to establish HES1 knock-out cell line (△HES1/NCI N87R) to investigate the functions of HES1 in herceptin resistance of NCI N87R cells and its potential mechanisms. We investigated proteomics profiling of △HES1/NCI N87R cells based on quantitative proteomics. Gene ontology analysis was conducted by GeneSet Enrichment Analysis (GSEA) and Metascape database, and pathway enrichment analysis was done using GeneAnalytics database. The selected molecules were quantified by Western blot and some pathways were verified by using inhibitors. The results showed that the resistance to herceptin of △HES1/NCI N87R cells decreased compared to NCI N87R cells. Proteomic data demonstrated that the expression of 1 263 genes changed significantly in △HES1/NCI N87R cells, among which 761 genes were up-regulated while 502 ones down-regulated comparing with NCI N87R cells. Pathway analysis showed that ferroptosis, fatty acid β-oxidation, autophagy and glutathione metabolism, etc. exhibited notable changes in △HES1/NCI N87R cells. The functional studies showed that the levels of iron ion and malondialdehyde increased, and glutathione decreased in △HES1/NCI N87R cells. It was further found that Fer-1, a ferroptosis inhibitor, could reverse the expression of pTP53, solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) in △HES1/NCI N87R cell, and reduce the sensitivity of △HES1/NCI N87R cells to herceptin. It is suggested that HES1 regulated the resistance of NCI N87R cells to herceptin through TP53/SLC7A11/GPX4 signaling pathway, and targeting TP53/SLC7A11/GPX4 signal axis mediated by HES1 is a potential strategy to reverse herceptin resistance in gastric cancer.

Synthesis, evaluation and proteomic analysis of PROTAC based on parthenolide / 药学学报

As a natural product with a long history of medicinal use, parthenolide has aroused great interest of chemists and biologists. Existing studies have shown that it has anti-inflammatory, antitumor and other pharmacological activities, and also revealed its action on NF-κB signaling pathway, DNMT1 enzyme and Wnt/β-catenin signaling pathway. But its biological targets remain to be elucidated systematically. Proteolysis Targeting Chimeras (PROTAC) provides a new strategy for target discovery of natural products, which can be used to explore the panorama of protein changes in cells through proteomic investigation, so as to analyze their potential targets. Based on this idea, current study designed and synthesized 20 parthenolide-derived degraders. After measured their antitumor activity in vitro, selected compounds were carried out the proteomic experiment. Finally, 139 down-regulated differentially expressed proteins were identified and the discovery of parthenolide interacting protein was preliminarily explored.

Advances in histone epigenetic enzyme inhibitors based on proteomics / 药学学报

As an important component of nucleosomes on the chromatin of eukaryotic cells, histones play an important role in the development and progression of tumour diseases by regulating epigenetic post-translational modifications such as acetylation and methylation. In addition, development of inhibitors targeting methyltransferase and deacetylase provides novel therapeutic strategies for cancer treatment. Mass spectrometry-based proteomics can reveal the global changes of histone modifications under the action of drugs during disease progression, which in turn provides important support for revealing drug action mechanism, drug resistance mechanism, and investigating novel drug combination strategies. This article focuses on the progress and status of proteomic research on a variety of histone modifying enzyme inhibitors, including methyltransferase inhibitors and histone deacetylase inhibitors, which will help to understand the current and further utilization of proteomics in studying histone modifications.

Mining Novel Anti-Nocardia Drug Targets Based on Pan-genomics and Subtractive Proteomics / 中山大学学报(医学科学版)

ObjectiveNocardia is an apathogen that causes opportunistic infections in humans and has a global distribution. In recent years， resistance of Nocardia to commonly used drugs have been observed， highlighting the urgent need for the identification of new drug targets and the development of novel antimicrobial agents against Nocardia. MethodsThirty-one complete genome sequences of Nocardia strains were retrieved from the GenBank database. Pan-genomic analysis was performed using BPGA， and drug target candidates were screened using subtractive proteomics. Homology modeling was employed to predict the 3D structures of target proteins， and potential drugs targeting these proteins were predicted using DrugBank. Molecular docking techniques were utilized to validate the binding activity between the drugs and target proteins. ResultsThe pan-genomic analysis of the 31 Nocardia strains revealed 1 421 core proteins. Fifteen candidate drug target proteins were identified through subtractive proteomics analysis. Among them， the physicochemical properties of the OG1493 protein （such as amino acid count， molecular weight， isoelectric point， grand average of hydropathicity， fat index，and instability index Ⅱ） were found to be most suitable for a drug target protein. Using the DrugBank database， seven compounds， namely Adenosine-5'-Rp-Alpha-Thio-Triphosphate， alpha，beta-Methyleneadenosine 5'-triphosphate， Phosphoaminophosphonic Acid-Adenylate Ester ，Radicicol，2-Hydroxyestradiol， p-Coumaric acid， and Ethylmercurithiosalicylic acid were identified as potential compounds capable of exerting anti-Nocardia effects by targeting this protein. Molecular docking results indicated a strong binding affinity between the target protein and these compounds. The experimental result showed that that Radicicol could be a potential antibacterial drug targeting this particular protein. ConclusionPan-genomic analysis and subtractive proteomics are valuable approaches for mining novel anti-Nocardia drug targets.