Quantitative Analysis of the Global Proteome in Peripheral Blood Mononuclear Cells from Patients with New-Onset Psoriasis

Cyanidin-3-O-glucoside ameliorates hydrogen peroxide-induced oxidative stress by regulating HMGCR-mediated cholesterol anabolism in HEK-293T cells

Cyanidin-3-O-glucoside (C3G), as a typical anthocyanin, exhibits excellent antioxidant effects. This study aimed to demonstrate the role and mechanism of C3G in regulating 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR)-mediated cholesterol anabolism on H2O2-induced oxidative stress in HEK-293T cells. Firstly, the inhibitory effect of C3G on oxidative stress was confirmed by CCK-8, ROS, and mitochondrial membrane potential (MMP) experiments. Then, proteomics was used to investigate and screen differentially expressed proteins in inhibiting cellular oxidative stress by C3G. HMGCR was screened as a key differentially expressed protein by proteomic analysis. The results verified that C3G could reduce cholesterol levels by inhibiting sterol regulatory element-binding protein (SREBP2)/HMGCR pathway, increasing ATP, and reducing acetyl-CoA. Finally, HMGCR had been shown to positively increase ROS accumulation and decrease MMP, which were reversed by intervention of C3G through a series of knockdown and overexpression experiments. In conclusion, the results demonstrated that C3G could inhibit the disorder of cholesterol synthesis in oxidative stress cells by regulating the ROS/SREBP2/HMGCR pathway.

Histone and Histone Acetylation-Related Alterations of Gene Expression in Uninvolved Psoriatic Skin and Their Effects on Cell Proliferation, Differentiation, and Immune Responses

Psoriasis is a chronic immune-mediated skin disease in which the symptom-free, uninvolved skin carries alterations in gene expression, serving as a basis for lesion formation. Histones and histone acetylation-related processes are key regulators of gene expression, controlling cell proliferation and immune responses. Dysregulation of these processes is likely to play an important role in the pathogenesis of psoriasis. To gain a complete overview of these potential alterations, we performed a meta-analysis of a psoriatic uninvolved skin dataset containing differentially expressed transcripts from nearly 300 individuals and screened for histones and histone acetylation-related molecules. We identified altered expression of the replication-dependent histones HIST2H2AA3 and HIST2H4A and the replication-independent histones H2AFY, H2AFZ, and H3F3A/B. Eight histone chaperones were also identified. Among the histone acetyltransferases, ELP3 and KAT5 and members of the ATAC, NSL, and SAGA acetyltransferase complexes are affected in uninvolved skin. Histone deacetylation-related alterations were found to affect eight HDACs and members of the NCOR/SMRT, NURD, SIN3, and SHIP HDAC complexes. In this article, we discuss how histone and histone acetylation-related expression changes may affect proliferation and differentiation, as well as innate, macrophage-mediated, and T cell-mediated pro- and anti-inflammatory responses, which are known to play a central role in the development of psoriasis.

A novel L-phenylalanine dipeptide inhibits prostate cancer cell proliferation by targeting TNFSF9

In the present study, a series of novel L-phenylalanine dipeptides were designed and synthesized by a multi-step sequence of reactions, including carbodiimide-mediated condensation, hydrolysis, mixed anhydride condensation, and nucleophilic substitution. Among them, compound 7c exhibited potent antitumor activity against prostate cancer cell PC3 in vitro and in vivo via inducing apoptosis. We investigated the significantly differentially expressed proteins in the cells caused by the compound 7c to unravel the molecular mechanisms underlying the regulation of PCa cell growth, which indicated that 7c mainly regulated the protein expression of apoptosis-related transcription factors, including c-Jun, IL6, LAMB3, OSMR, STC1, OLR1, SDC4 and PLAU; and 7c also regulated the protein expression of inflammatory cytokines including IL6, CXCL8, TNFSF9, TNFRSF12A and OSMR, and the phosphorylation levels of RelA. The action target confirmed that TNFSF9 protein is the critical binding target of 7c. These findings suggested that 7c could regulate the apoptosis and inflammatory response related signaling pathways for the inhibition of the proliferation of PC3 cells, implying that 7c could be considered a promising therapeutic candidate for PCa therapy.

Comparative proteomic analysis of the mitochondria of menstrual stem cells and ovarian cancer cells

Mitochondrial transplantation is a popular field of research in cell-free therapy. Menstrual stem cells (MenSCs) are potential donor cells for provision of foreign mitochondria. The present study aimed to investigate the potential effects of MenSC-derived mitochondria on ovarian cancer from the perspective of protein expression profiling. MenSCs were harvested from menstrual blood. The mitochondria were isolated from MenSCs and ovarian cancer cell line SKOV3. A label-free mitochondria proteomics and analysis were performed by comparing the protein expression in mitochondria of MenSCs and SKOV3 cells. The differentially expressed proteins with fold-change >2 were analyzed by Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway and protein domain enrichment, protein interaction networks and parallel reaction monitoring (PRM) analysis. In total, 592 proteins that were found to have increased expression in the mitochondria of MenSCs were analyzed. Functional enrichment analysis revealed these proteins were enriched in metabolism-associated pathway entries including 'oxidative phosphorylation' (OXPHOS) pathway. PRM analysis confirmed that four of 6 candidate proteins in the OXPHOS pathway showed similar increasing trends. The protein domain enrichment analysis showed that domains such as 'thioredoxin domain' were significantly enriched. Based on these findings, it was hypothesized that mitochondria from MenSCs have the potential to enhance progression of ovarian cancer likely mediated by the enrichment of OXPHOS-associated metabolic pathways.

Proteome-wide identification of S-sulfenylated cysteines reveals metabolic response to freezing stress after cold acclimation in Brassica napus

Redox regulation plays a wide role in plant growth, development, and adaptation to stresses. Sulfenylation is one of the reversible oxidative post-transcriptional modifications. Here we performed an iodoTMT-based proteomic analysis to identify the redox sensitive proteins in vivo under freezing stress after cold acclimation in Brassica napus. Totally, we obtained 1,372 sulfenylated sites in 714 proteins. The overall sulfenylation level displayed an increased trend under freezing stress after cold acclimation. We identified 171 differentially sulfenylated proteins (DSPs) under freezing stress, which were predicted to be mainly localized in chloroplast and cytoplasm. The up-regulated DSPs were mainly enriched in photosynthesis and glycolytic processes and function of catalytic activity. Enzymes involved in various pathways such as glycolysis and Calvin-Benson-Bassham (CBB) cycle were generally sulfenylated and the metabolite levels in these pathways was significantly reduced under freezing stress after cold acclimation. Furthermore, enzyme activity assay confirmed that the activity of cytosolic pyruvate kinase and malate dehydrogenase 2 was significantly reduced under H₂O₂ treatment. Our study provides a landscape of redox sensitive proteins in B. napus in response to freezing stress after cold acclimation, which proposes a basis for understanding the redox regulation in plant metabolic response to freezing stress after cold acclimation.

A Proteomic Study of the Effect of N-acetylcysteine on the Regulation of Early Pregnancy in Goats

Simple Summary

Early pregnancy regulation is an extremely complex process that is influenced by various factors. We previously mined the differentially expressed genes affected by N-acetyl-L-cysteine (NAC) in early pregnancy in goats via transcriptome sequencing. We found that NAC increased the number of lambs by affecting the immune pathway in ewes and enhancing antioxidation. Based on this, we here explored the effect of NAC on early pregnancy in goats at the protein level. The results showed a difference in the expression of uterine keratin and increases in the levels of antioxidant indices and hormones in doe serum.

Abstract

Dietary supplementation with N-acetyl-L-cysteine (NAC) may support early pregnancy regulation and fertility in female animals. The purpose of this study was to investigate the effect of supplementation with 0.07% NAC on the expression of the uterine keratin gene and protein in Qianbei-pockmarked goats during early pregnancy using tandem mass spectrometry (TMT) relative quantitative proteomics. The results showed that there were significant differences in uterine keratin expression between the experimental group (NAC group) and the control group on day 35 of gestation. A total of 6271 proteins were identified, 6258 of which were quantified by mass spectrometry. There were 125 differentially expressed proteins (DEPs), including 47 upregulated and 78 downregulated proteins, in the NAC group. Bioinformatic analysis showed that these DEPs were mainly involved in the transport and biosynthesis of organic matter and were related to the binding of transition metal ions, DNA and proteins and the catalytic activity of enzymes. They were enriched in the Jak-STAT signalling pathway, RNA monitoring pathway, amino acid biosynthesis, steroid biosynthesis and other pathways that may affect the early pregnancy status of does through different pathways and thus influence early embryonic development. Immunohistochemistry, real-time quantitative PCR and Western blotting were used to verify the expression and localization of glial fibrillary acidic protein (GFAP) and pelota mRNA surveillance and ribosomal rescue factor (PELO) in uterine horn tissue. The results showed that both PELO and GFAP were localized to endometrial and stromal cells, consistent with the mass spectrometry data at the transcriptional and translational levels. Moreover, NAC supplementation increased the levels of the reproductive hormones follicle-stimulating hormone (FSH), luteinizing hormone (LH), oestradiol (E2), progesterone (P4), superoxide dismutase (SOD), glutamate peroxidase (GSH-Px) and nitric oxide (NO) in the serum of does. These findings provide new insight into the mechanism by which NAC regulates early pregnancy and embryonic development in goats.

Strategy for Microscale Extraction and Proteome Profiling of Peripheral Blood Mononuclear Cells

Peripheral blood mononuclear cells (PBMCs) play vital roles in physiological and pathological processes and represent a rich source for disease monitoring. Typical molecular profiling on PBMCs involves the sorting of cell subsets and thus requires a large volume of peripheral blood (PB), which impedes the clinical practicability of omics tools in PBMC measurements. It would be clinically invaluable to develop a convenient approach for preparing PBMCs from small volumes of PB and for deep proteome profiling of PBMCs. To this end, here, we designed an apparatus (PBMC-mCap) for microscale enrichment and proteome analysis of PBMCs, which pushed the needed PB volume from the normal 2 mL or higher to 100 μL or lower, comparable to the volume of a drop of finger blood. A PBMC-specific mass spectra library containing 8869 proteins and 121,956 peptides was further built, which, in combination with the optimized data-independent acquisition strategy, helped to identify 6000 and 6500 proteins from PBMCs with 100 μL and 1 mL of PB as initial materials, respectively. Further application of the strategy for PBMC proteomes revealed a steady difference between gender (male vs female) and upon stimulus (COVID-19 vaccination). For the latter, we observed differentially expressed genes and pathways involving the activation of immune cells, including the NF-κB pathway, inflammation response, and antiviral response. Our strategy for the proteome analysis of microscale PBMCs may provide a convenient clinical toolkit for disease diagnosis and healthy state monitoring.

Proteomic Investigation of Molecular Mechanisms in Response to PEG-Induced Drought Stress in Soybean Roots

Roots are generally the critical drought sensors, but little is known about their molecular response to drought stress. We used the drought-tolerant soybean variety ‘Jiyu 47’ to investigate the differentially expressed proteins (DEPs) in soybean roots during the seedling stage based on the tandem mass tag (TMT) proteomics analysis. Various expression patterns were observed in a total of six physiological parameters. A total of 468 DEPs (144 up-regulated and 324 down-regulated) among a total of 8687 proteins were identified in response to drought stress in 24 h. The expression of DEPs was further validated based on quantitative real-time PCR of a total of five genes (i.e., GmGSH, GmGST1, GmGST2 k GmCAT, and Gm6PGD) involved in the glutathione biosynthesis. Results of enrichment analyses revealed a coordinated expression pattern of proteins involved in various cellular metabolisms responding to drought stress in soybean roots. Our results showed that drought stress caused significant alterations in the expression of proteins involved in several metabolic pathways in soybean roots, including carbohydrate metabolism, metabolism of the osmotic regulation substances, and antioxidant defense system (i.e., the glutathione metabolism). Increased production of reduced glutathione (GSH) enhanced the prevention of the damage caused by reactive oxygen species and the tolerance of the abiotic stress. The glutathione metabolism played a key role in modifying the antioxidant defense system in response to drought stress in soybean roots. Our proteomic study suggested that the soybean plants responded to drought stress by coordinating their protein expression during the vegetative stage, providing novel insights into the molecular mechanisms regulating the response to abiotic stress in plants.

TMT proteomic analysis for molecular mechanism of Staphylococcus aureus in response to freezing stress

The foodborne pathogen Staphylococcus aureus continues to challenge the food industry due to the pathogenicity and tolerance of the bacterium. As a common storage condition for frozen food during transportation, distribution, and storage, freezing does not seem to be entirely safe due to the cold tolerance of S. aureus. In addition, our study indicated that the biofilm formation ability of S. aureus was significantly increased in response to freezing stress. To explore the molecular mechanism regulating the response to freezing stress, the proteomics signature of S. aureus after freezing stress based on tandem mass tag (TMT) labeling and liquid chromatography tandem mass spectrometry (LC-MS/MS) was analyzed. Gene Ontology and pathway analysis revealed that ribosome function, metabolism, RNA repair, and stress response proteins were differentially regulated (P < 0.05). Furthermore, transpeptidase sortase A, biofilm operon icaADBC HTH-type negative transcriptional regulator IcaR, and HTH-type transcriptional regulator MgrA were involved in the modulation of increased biofilm formation in response to freezing stress (P < 0.05). Moreover, significant lysine acetylation and malonylation signals in the S. aureus response to freezing stress were observed. Collectively, the current work provides additional insight for comprehending the molecular mechanism of S. aureus in response to freezing stress and presents potential targets for developing strategies to control S. aureus. KEY POINTS: • TMT proteomic analysis was first used on S. aureus in response to freezing stress. • Ribosome-, metabolism-, and biofilm-related proteins change after freezing stress. • Increased biofilm formation in S. aureus responded to freezing stress.

Targeting NQO1/GPX4-mediated ferroptosis by plumbagin suppresses in vitro and in vivo glioma growth

BACKGROUND

Ferroptosis has attracted increasing interest in cancer therapy. Emerging evidences suggest that naturally occurring naphthoquinones exhibit potent anti-glioma effects via various mechanisms.

METHODS

The anti-glioma effects of plumbagin were evaluated by in vitro and in vivo experiments. Anti-glioma mechanism of plumbagin was studied by proteomics, flow cytometry, MDA assay, western blot, and RT-PCR. Gene knockdown/overexpression, molecular docking, PharmMappper database, and coimmunoprecipitation were used to study the targets of plumbagin.

RESULTS

Plumbagin showed higher blood-brain barrier penetration ability than that of lapachol and shikonin and elicited significant growth inhibitory effects in vitro and in vivo. Ferroptosis was the main mechanism of plumbagin-induced cell death. Mechanistically, plumbagin significantly downregulated the protein and mRNA levels of xCT and decreased GPX4 protein levels. NAD(P)H quinone dehydrogenase 1 (NQO1) was revealed as a plumbagin predictive target using PharmMappper database and molecular docking. Plumbagin enhanced NQO1 activity and decreased xCT expression, resulting in NQO1-dependent cell death. It also induced GPX4 degradation via the lysosome pathway and caused GPX4-dependent cell death.

CONCLUSIONS

Plumbagin inhibited in vitro and in vivo glioma growth via targeting NQO1/GPX4-mediated ferroptosis, which might be developed as a novel ferroptosis inducer or anti-glioma candidate.

Proteomic Studies of Psoriasis

In this review paper, we discuss the contribution of proteomic studies to the discovery of disease-specific biomarkers to monitor the disease and evaluate available treatment options for psoriasis. Psoriasis is one of the most prevalent skin disorders driven by a Th17-specific immune response. Although potential patients have a genetic predisposition to psoriasis, the etiology of the disease remains unknown. During the last two decades, proteomics became deeply integrated with psoriatic research. The data obtained in proteomic studies facilitated the discovery of novel mechanisms and the verification of many experimental hypotheses of the disease pathogenesis. The detailed data analysis revealed multiple differentially expressed proteins and significant changes in proteome associated with the disease and drug efficacy. In this respect, there is a need for proteomic studies to characterize the role of the disease-specific biomarkers in the pathogenesis of psoriasis, develop clinical applications to choose the most efficient treatment options and monitor the therapeutic response.

Analytical approaches to assess metabolic changes in psoriasis

Psoriasis is one of the most common human skin diseases, although its development is not limited to one tissue, but is associated with autoimmune reactions throughout the body. Overproduction of pro-inflammatory cytokines and growth factors systemically stimulates the proliferation of skin cells, which manifests as excessive exfoliation of the epidermis, and/or arthritis, as well as other comorbidities such as insulin resistance, metabolic syndrome, hypertension, and depression. Thus, there is a great need for a thorough analysis of the pathophysiology of psoriatic patients, including classical methods, such as spectrophotometry, chromatography, or Western blot, and also novel omics approaches such as lipidomics and proteomics. Moreover, the extensive pathophysiology forces increased research examining biological changes in both skin cells, and systemically. A wide range of techniques involved in lipidomic research based on a combination of mass spectrometry and different types of chromatography (RP-LC-QTOF-MS/MS, HILIC-QTOF-MS/MS or RP-LC-QTRAP-MS/MS), have allowed comprehensive assessment of lipid modification in psoriatic skin and provided new insight into the role of lipids and their mechanism of action in psoriasis. Moreover, proteomic analysis using gel-nanoLC-OrbiTrap-MS/MS, as well as MALDI-TOF/TOF techniques facilitates the description of panels of enzymes involved in lipidome modifications, and the response of the endocannabinoid system to metabolic changes. Psoriasis is known to alter the expression of proteins that are involved in the inflammatory and antioxidant response, as well as protein biosynthesis, degradation, as well as cell proliferation and apoptosis. Knowledge of changes in the lipidomic and proteomic profile will not only allow the understanding of psoriasis pathophysiology, but also facilitate proper and early diagnosis and effective pharmacotherapy.

A proteomic analysis of Bcl-2 regulation of cell cycle arrest: insight into the mechanisms

B cell lymphoma 2 (Bcl-2) is an important antiapoptotic gene that plays a dual role in the maintenance of the dynamic balance between the survival and death of cancer cells. In our previous study, Bcl-2 was shown to delay the G0/G1 to S phase entry by regulating the mitochondrial metabolic pathways to produce lower levels of adenosine triphosphate (ATP) and reactive oxygen species (ROS). However, the detailed molecular mechanisms or pathways by which Bcl-2 regulates the cell cycle remain unknown. Here, we compared the effects of Bcl-2 overexpression with an empty vector control in the NIH3T3 cell line synchronized by serum starvation, and evaluated the effects using proteomic analysis. The effect of Bcl-2 on cell cycle regulation was detected by monitoring Bcl-2 and p27 expression. The result of subsequent proteomic analysis of Bcl-2 overexpressing cells identified 169 upregulated and 120 downregulated proteins with a 1.5-fold change. These differentially expressed proteins were enriched in a number of signaling pathways predominantly involving the ribosome and oxidative phosphorylation, according to the data of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. These results indicated that Bcl-2 potentially acts at the translation level to influence proteins or enzymes of the respiratory chain or in the ribosome, and thereby regulates the cell cycle. Additionally, differentially expressed proteins involved in oxidative phosphorylation were determined to account for most of the effects of Bcl-2 on the cell cycle mediated by the mitochondrial pathway investigated in our previous study. These results can provide assistance for additional in-depth studies on the regulation of the cell cycle by Bcl-2. The results of the proteomic analysis determined the mechanism of Bcl-2-dependent delay of the cell cycle progression. In summary, the results of this study provide a novel mechanistic basis for identifying the key proteins or pathways for designing and developing precisely targeted cancer drugs.

Shenxiong glucose injection inhibits H2O2-induced H9c2 cell apoptosis by activating the ERK signaling pathway

BACKGROUND

Shenxiong glucose injection (SGI) is a traditional Chinese medicine injection composed of water extract of Salvia miltiorrhiza and Ligustrazine hydrochloride. SGI has shown strong antioxidant and anti-apoptotic properties. However, the mechanisms underlying its anti-apoptotic effect need to be addressed.

METHODS

H9c2 cell apoptosis model was established by treatment of hydrogen peroxide (H₂O₂). Cell survival rates were examined by MTS assay, cell apoptosis rates were determined by flow cytometry, levels of intracellular ROS were assessed by ROS kit, proteome phosphorylation was determined by phosphoproteomic analysis, and extracellular signal-regulated kinase (ERK), phosphorylated ERK, phosphorylated c-Jun, B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), Bcl-2, and cleaved caspase-3 were examined by Western blot.

RESULT

SGI showed protective effects against H₂O₂-induced reduced cell viability, elevated ROS, and increased apoptosis in H9c2 cells. Phosphorylation proteomics detected a total of 3369 proteins with 78 protein of upregulated phosphorylation and 104 protein of downregulated phosphorylation. Kyoto Encyclopedia Genes and Genomes pathway analyses of differentially phosphorylated proteins showed that the ERK pathway, the downstream pathway of the focal adhesion pathway related to apoptosis, was highly enriched, and the phosphorylation levels of ERK and c-Jun were confirmed by Western blot. In addition, the ERK pathway inhibitor PD98059 significantly inhibited the anti-apoptotic effect of SGI.

CONCLUSION

SGI antagonizes H₂O₂-induced cell apoptosis by activating the ERK pathway.

Decreased expression of PPARγ is associated with aortic endothelial cell apoptosis in intermittently hypoxic rats

PURPOSE

Increasing medical researche shows that endothelial dysfunction is one of the important causes of various cardiovascular diseases related to chronic intermittent hypoxia (CIH). This study aimed to identify target proteins in CIH-related vascular dysfunction.

METHODS

A comparative proteomics analysis was conducted in aortic samples of rats treated with CIH and controls with normoxia. Bioinformatics analyses were performed to determine the potential roles of major proteins. The expressions of target proteins were measured by western blotting. Cell apoptotic ratio was detected by flow cytometer.

RESULTS

A total of 3,593 proteins in aortic tissues of rats were quantified. Ninety-two upregulated proteins and 468 downregulated proteins were identified when the cutoff of fold change was set at 1.5 (CIH vs. normoxia). The results of bioinformatics analysis revealed that the differentially expressed proteins were enriched in the processes of energy metabolism and lipid metabolism. The reduced expression level of peroxisome proliferator-activated receptor γ (PPARγ) protein was identified in thoracic aortic tissues of rats with CIH by proteomics analysis and western blotting. In intermittent hypoxia-treated rat aortic endothelial cells, PPARγ protein levels were reduced, and the apoptosis rate and caspase-3 and Bax protein levels were markedly elevated. Importantly, forced expression of PPARγ by rosiglitazone in intermittent hypoxia-treated rat aortic endothelial cells not only attenuated caspase-3 and Bax protein levels but also reduced the rate of apoptosis.

CONCLUSION

PPARγ is critical in endothelial dysfunction of rats with CIH. Additional studies on these differentially expressed proteins associated with CIH-related endothelial dysfunction are necessary.

Comparative proteomic analysis of the sweetpotato provides insights into response mechanisms to Fusarium oxysporum f. sp. batatas

The Fusarium wilt disease caused by Fusarium oxysporum f. sp. batatas (Fob) is one of the devastating diseases of sweetpotato. However, the molecular mechanisms of sweetpotato response to Fob is poorly understood. In the present study, comparative quantitative proteomic analysis was conducted to investigate the defense mechanisms involved. Two sweetpotato cultivars with differential Fob infection responses were inoculated with Fob spore suspensions and quantitatively analyzed by Tandem Mass Tags (TMT). 2267 proteins were identified and 1897 of them were quantified. There were 817 proteins with quantitative ratios of 1.2-fold change between Fob-inoculated and mock-treated samples. Further, nine differentially expressed proteins were validated by Parallel Reaction Monitoring (PRM). According to Gene Ontology (GO) annotation information, the proteins functioned in molecular metabolism, cellular component formation, and biological processes. Interestingly, the results showed that sweetpotato resistant response to Fob infection included many proteins associated with signaling transduction, plant resistance, chitinase and subtilisin-like protease. The functions and possible roles of those proteins were discussed. The results provides first insight into molecular mechanisms involved in sweetpotato defense responses to Fob.

Fibroblast growth factor 1 ameliorates adipose tissue inflammation and systemic insulin resistance via enhancing adipocyte mTORC2/Rictor signal

Obesity‐induced activation and proliferation of resident macrophages and infiltration of circulating monocytes in adipose tissues contribute to adipose tissue inflammation and insulin resistance. These effects further promote the development of metabolic syndromes, such as type 2 diabetes, which is one of the most prevalent health conditions severely threatening human health worldwide. Our study examined the potential molecular mechanism employed by fibroblast growth factor 1 (FGF1) to improve insulin sensitivity. The leptin receptor‐deficient obese mice (db/db) served as an insulin‐resistant model. Our results demonstrated that FGF1‐induced amelioration of insulin resistance in obese mice was related to the decreased levels of pro‐inflammatory adipose tissue macrophages (ATMs) and plasma inflammatory factors. We found that FGF1 enhanced the adipocyte mTORC2/Rictor signalling pathway to inhibit C‐C chemokine ligand 2 (CCL2) production, the major cause of circulating monocytes infiltration, activation and proliferation of resident macrophages in adipose tissues. Conversely, these alleviating effects of FGF1 were substantially abrogated in adipocytes with reduced expression of mTORC2/rictor. Furthermore, a model of adipocyte‐specific mTORC2/Rictor‐knockout (AdRiKO) obese mice was developed to further understand the in vitro result. Altogether, these results demonstrated adipocyte mTORC2/Rictor was a crucial target for FGF1 function on adipose tissue inflammation and insulin sensitivity.

Quantitative analysis of differentially expressed proteins in psoriasis vulgaris using tandem mass tags and parallel reaction monitoring

Background

Psoriasis vulgaris (PV) is a chronic autoimmune inflammatory disease with epidermal hyperkeratosis and parakeratosis.

Methods

The study was to elucidate the pathogenesis of PV by quantitative proteomic analysis of skin lesion biopsies of PV and healthy tissues with tandem mass tags (TMTs) coupled with liquid chromatography–mass spectrometry (LC–MS)/MS.

Results

A total of 4562 differentially expressed proteins (DEPs) between PV lesional tissues (n = 11) and healthy tissues (n = 11) were identified, of which 299 were upregulated and 206 were downregulated using |fold change| > 1.3 as the cutoff threshold. The Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the DEPs were mainly enriched in the activation of immune cells (drug metabolism pathway, NOD-like pathway, and IL-17 pathway), cell proliferation (ribosomal pathway, DNA replication pathway, and base replication pathway), metabolism-related pathways (fatty acid biosynthesis and metabolism, PPAR pathway, glycerophospholipid metabolism, and cortisol synthesis and breakdown), and glandular secretion (saliva secretion, gastric acid secretion, and pancreatic fluid secretion). Thirteen DEPs that were relatively highly expressed in the drug metabolism pathway were validated with parallel reaction monitoring (PRM), of which MPO, TYMP, IMPDH2, GSTM4, and ALDH3A1 were highly expressed in PV, whereas CES1, MAOB, MGST1, and GSTT1 were less expressed in PV.

Conclusions

These findings confirmed that these proteins participate in the drug metabolism-other enzyme pathways and play crucial roles in the activation and proliferation of immune cells in the pathogenesis of PV.

Quantitative analysis of the global proteome in lung from mice with blast injury

AIM OF THE STUDY

The mechanism by which primary shock wave causes lung injury is unclear. The aim of this study is to find the changes of protein that can be helpful in understanding blast-induced lung injury.

MATERIAL AND METHODS

A quantitative analysis of their global proteome was conducted in lung from mice with blast injury using LC-MS/MS. Protein annotation, unsupervised hierarchical clustering, functional classification, functional enrichment and cluster, and protein-protein interaction analyses were performed. Furthermore, western blotting was used to validate the changed protein levels.

RESULTS

A total of 6498 proteins were identified, of which 5520 proteins were quantified. The fold-change cutoff was set at 1.2; 132 proteins were upregulated, and 104 proteins were downregulated. The bioinformatics analysis indicated that the differentially expressed proteins were involved in the cholesterol metabolism, asthma, nonalcoholic fatty liver disease. Remarkably, the processes related to the change of oxidative phosphorylation including the NADH dehydrogenase, Cytochrome C reductase, Cytochrome C oxidase and F-type ATPase were significantly upregulated, which were further verified by western blotting.

CONCLUSION

These results confirmed that the oxidative phosphorylation is critical to blast-induced lung injury. LC/MS-based profiling presented candidate target/pathways that could be explored for future therapeutic development.

Quantitative Proteomic Profile of Psoriatic Epidermis Identifies OAS2 as a Novel Biomarker for Disease Activity

Psoriasis is a common chronic inflammatory systemic disease. Epidermal proteins are considered to be important in maintaining skin barrier function, innate immunity, and inflammation. To define more possible roles of the epidermis in the pathogenesis of psoriasis, quantified proteomic analysis was used to screen and analyze the differentially expressed epidermal proteins between 16 psoriasis patients and 15 healthy controls. Upregulated differential expression proteins (DEPs) include several significant functional protein clusters, including antimicrobial peptides (AMPs) and antiviral proteins (AVPs). The levels of 2–5-oligoadenylate synthase 2 (OAS2) in both epidermis and serum levels were significantly elevated in psoriasis and were also positively correlated with Psoriasis Area Severity Index (PASI) scores and Body Surface Area (BSA) scores. Moreover, OAS2 expression in psoriatic skin significantly decreased after IL-17R mono-antibody treatment. It has been clarified that inflamed keratinocytes were the main source of abnormally increased OAS2 in psoriasis skin by immunofluorescence and primary cell cultures. Keratinocyte-derived OAS2 can be induced by not only IFNβ, but also psoriasis associated cytokines like IL-17A and IL-6. This study revealed that AMPs and AVPs are two important functional protein clusters altering innate immune in psoriatic epidermis. OAS2 is a novel potential sensitive biomarker, which could predict the severity and activity of psoriasis, and could also be used as an indicator to evaluate or monitor the efficacy of clinical treatment.

Changes in Proteome of Fibroblasts Isolated from Psoriatic Skin Lesions

The dermal fibroblasts are in constant contact with the cells of the immune system and skin epidermis. Therefore, they are essential for the development of lesions in psoriasis. The aim of this study was to assess the changes in the proteomic profile of fibroblasts in the dermis of psoriasis patients, and to discuss the most significant changes and their potential consequences. The proteomic results indicate that fibroblast dysfunction arises from the upregulation of proinflammatory factors and antioxidant proteins, as well as those involved in signal transduction and participating in proteolytic processes. Moreover, downregulated proteins in psoriatic fibroblasts are mainly responsible for the transcription/translation processes, glycolysis/ adenosine triphosphate synthesis and structural molecules. These changes can directly affect intercellular signaling and promote the hyperproliferation of epidermal cells. A better understanding of the metabolic effects of the proteomic changes observed could guide the development of new pharmacotherapies for psoriasis.

Integrated Proteomics and Metabolomics Reveal the Mechanism of Nephrotoxicity Induced by Triptolide

Triptolide (TP), the main active ingredient of Tripterygium wilfordii Hook F., has great potential in the treatment of autoimmune diseases. However, it has been found that the side effects of TP involve multiple organs and systems, of which the most serious side effects relate to the kidney. The mechanism of nephrotoxicity caused by TP requires further investigation. In the present study, we integrated proteomic and metabolomic methods to identify proteins and small molecule metabolites associated with TP-induced nephrotoxicity. There was a significant difference (p value <0.05) in the expression changes of 357 proteins for quantitative proteomics. In addition, high resolution metabolomic data showed significant changes in the levels of 9 metabolites, including hypoxanthine, PC(22:0/18:4), sphingosine, phenylalanine, etc. Finally, based on the Kyoto Encyclopaedia of Genes and Genomes (KEGG) database for network analysis, it was determined that the 7 differentially expressed proteins were highly correlated with these 9 metabolites. Enrichment analysis revealed that the metabolic pathways involved purine and pyrimidine metabolism, glycerol and phospholipid metabolism, sphingolipid metabolism, and amino acid metabolism. The key target proteins were verified by Western blot technology, and the mechanism of TP-induced nephrotoxicity was further elucidated to provide a basis for safe and rational application.

Quantitative proteomics analysis of differentially expressed proteins induced by astragaloside IV in cervical cancer cell invasion

Background

Cervical cancer remains the second leading cause of mortality in women in developing countries. While surgery, chemotherapy, radiotherapy, and vaccine therapy are being applied for its treatment, individually or in combination, the survival rate in advanced cervical cancer patients is still very low. Traditional Chinese medicine has been found to be effective in the treatment of cervical cancer. Astragaloside IV (AS-IV), a compound belonging to Astragalus polysaccharides, shows anticancer activity through several cell signaling pathways. However, the detailed molecular mechanism governing the anticancer activity of AS-IV remains unknown.

Material and methods

In our study, we performed tumor xenograft analysis, transwell cell migration and invasion assay, Western blot analysis, and iTRAQ combination by parallel reaction monitoring (PRM) analysis to study the molecular mechanism of AS-IV in the suppression of cervical cancer cell invasion.

Results

Our results showed that AS-IV suppressed cervical cancer cell invasion and induced autophagy in them, with the tumor growth curve increasing slowly. We also identified 32 proteins that were differentially expressed in the SiHa cells when treated with AS-IV, with 16 of them involved in the upregulation and 16 in the downregulation of these cells. These differentially expressed proteins, which were predominantly actin–myosin complexes, controlled cell proliferation and cell development by steroid binding and altering the composition of the cell cytoskeleton. DCP1A and TMSB4X, the two proteins regulating autophagy, increased in cervical cancer cells when treated with AS-IV.

Conclusions

We conclude that AS-IV could inhibit cervical cancer invasion by inducing autophagy in cervical cancer cells. Since iTRAQ combination by PRM has been observed to be useful in identifying macromolecular target compounds, it may be considered as a novel strategy in the screening of anticancer compounds used in the treatment of cervical cancer.

iTRAQ-based quantitative proteomic analysis of the inhibition of cervical cancer cell invasion and migration by metformin

In recent years the anti-diabetic drug metformin has been shown to inhibit tumor growth, but the underlying mechanism is unclear. Our previous results showed that metformin can destroy the sponge effect of long-chain non-coding RNA MALAT1/miR-142-3p and inhibit the proliferation of cervical cancer cells. Metformin can inhibit the PI3K/Akt signaling pathway and synergizes with Nelfinavir to inhibit the proliferation and invasion of cervical cancer cells. In this study, we used iTRAQ-based proteomics, mass spectrometry-based targeted proteomics, immunoblotting, and bioinformatics to analyze the molecular mechanism by which metformin inhibits the proliferation and invasion of cervical cancer cells. We found that 53 proteins were differentially expressed in cervical cancer cells after metformin treatment, of which 20 were up-regulated and 33 were down-regulated. Bioinformatics analysis showed that the 53 differentially expressed proteins are negative regulators of receptor signaling that inhibit cell growth and are mainly enriched in cell growth and apoptosis signaling pathways. We performed PRM verification on 11 of the differentially expressed proteins and found that they were all associated with apoptosis. We also found that metformin up-regulated the expression of the tumor suppressor IGFBP7 to inhibit the proliferation and invasion of cervical cancer cells. Our results indicate that metformin mainly regulates the insulin signaling pathway and interferes with cell proliferation and apoptosis to inhibit proliferation and invasion of cervical cancer cells. These differentially expressed proteins may become new targets for the treatment of cervical cancer.

Acetylome analysis of lysine acetylation in the plant pathogenic bacterium Brenneria nigrifluens

Protein lysine acetylation, a dynamic and reversible posttranslational modification, plays a crucial role in several cellular processes, including cell cycle regulation, metabolism, enzymatic activities, and protein interactions. Brenneria nigrifluens is a pathogen of walnut trees with shallow bark canker and can cause serious disease in walnut trees. Until now, a little has been known about the roles of lysine acetylation in plant pathogenic bacteria. In the present study, the lysine acetylome of B. nigrifluens was determined by high‐resolution LC‐MS/MS analysis. In total, we identified 1,866 lysine acetylation sites distributed in 737 acetylated proteins. Bioinformatics results indicated that acetylated proteins participate in many different biological functions in B. nigrifluens. Four conserved motifs, namely, LK^ac, K^ac*F, I*K^ac, and L*K^ac, were identified in this bacterium. Protein interaction network analysis indicated that all kinds of interactions are modulated by protein lysine acetylation. Overall, 12 acetylated proteins were related to the virulence of B. nigrifluens.

Mechanisms of ROS-induced mitochondria-dependent apoptosis underlying liquid storage of goat spermatozoa

Liquid storage of spermatozoa is important for artificial insemination and herd genetic breeding. However, the extended time of storage inducing the rapid decline in spermatozoa quality limits the development of this technology. The molecular mechanisms underlying liquid storage of spermatozoa remain largely unexplored. In this study, the effects of liquid storage on functional quality of spermatozoa were assessed in goat (Capra hircus). The time-dependent decline in spermatozoa motility showed a strong correlation with the significant increase in apoptosis. Moreover, apoptosis-related ultrastructural changes were observed, especially the defects in mitochondria. A significant decrease in mitochondrial membrane potential and changes in the expression of mitochondrial apoptosis-related proteins indicated mitochondrial dysfunction and mitochondrial apoptotic pathway activation. Notably, the abnormally high level of reactive oxygen species (ROS) caused by liquid storage resulted in oxidative damage to mitochondria and accelerated mitochondria-dependent apoptosis, as demonstrated by the addition of ROS scavenger N-acetylcysteine. Furthermore, critical differentially expressed proteins involved in mitochondria-dependent apoptosis and antioxidant defense were identified and profiled by quantitative proteomic analysis, facilitating the understanding of molecular regulation of ROS-induced mitochondria-dependent apoptosis. These outcomes provide insights into the mechanisms underlying liquid storage of goat spermatozoa and enhance the progress of semen storage technology.