DNA or Protein Methylation-Dependent Regulation of Activator Protein-1 Function

Modification macrophage to foam cells in atherosclerosis disease: some factors stimulate or inhibit this process

Background

Atherosclerosis is an arterial blood vessel disease that begins and progresses by turning macrophages into foam cells. Uptake of oxidized low-density lipoprotein (ox-LDL), cholesterol esterification and cholesterol efflux are the most important factors in the formation of foam cells and play an important role in atherosclerosis.

Methods

The present study is based on the data obtained from the PubMed database (1961-2024) using the MeSH search terms "Atherosclerosis", "Macrophages" and "Foam cells". Reviews for writing the main text and non-English-language articles were excluded.

Result

The interaction between ox-LDL and macrophages plays an important role in plaque initiation and promotion processes. Macrophages abnormally digest ox-LDL, resulting in the accumulation of lipids and formation of foam cells. This is an important step in the development of atherosclerosis. Also, several other factors such as inflammatory factors, growth factors, hormones, etc. can play an important role in the development of atherosclerotic lesions or counteract it by affecting the formation of foam cells.

Conclusion

Several factors can affect the progression of atherosclerosis by affecting macrophage activity or its conversion to foam cells. Also, some of these factors play a protective role against the development and atherosclerosis progression. In this paper, we reviewed some of these factors and their effect on atherosclerosis.

Rhein Alleviates Doxorubicin-Induced Myocardial Injury by Inhibiting the p38 MAPK/HSP90/c-Jun/c-Fos Pathway-Mediated Apoptosis

Doxorubicin (Dox) has been limited in clinical application due to its cardiac toxicity that varies with the dose. This study aimed to explore how Rhein modulates Dox-induced myocardial toxicity. The general condition and echocardiographic changes of mice were observed to evaluate cardiac function and structure, with myocardial cell injury and apoptosis checked by TUNEL and HE staining. The ELISA assessed markers of myocardial damage and inflammation. The TCMSP and SwissTargetPrediction databases were used to retrieve Rhein's targets while GeneCards was used to find genes related to Dox-induced myocardial injury. Intersection genes were analyzed by Protein-Protein Interaction Networks. The core network genes underwent GO and KEGG enrichment analysis using R software. Western blot was used to detect protein expression. Compared to the Dox group, there was no remarkable difference in heart mass /body mass ratio in the Rhein+Dox group. However, heart mass/tibia length increased. Mice in the Rhein+Dox group had significantly increased LVEF, LVPWs, and LVFS compared to those in the Dox group. Myocardial cell damage, inflammation, and apoptosis significantly reduced in the Rhein+Dox group compared to the model group. Eleven core network genes were selected. Further, Rhein+Dox group showed significantly downregulated expression of p38/p-p38, HSP90AA1, c-Jun/p-c-Jun, c-Fos/p-c-Fos, Bax, and cleaved-caspase-3/caspase-3 while Bcl-2 expression significantly upregulated compared to the Dox group. The study suggests that Rhein mediates cardioprotection against Dox-induced myocardial injury, at least partly, by influencing multiple core genes in the MAPK signaling pathway to inhibit myocardial cell apoptosis.

Comparative analysis of plasma affinity depletion methods: Impact on protein composition and phosphopeptide abundance in human plasma

Affinity-based protein depletion and TiO2 enrichment methods play a crucial role in detection of low-abundant proteins and phosphopeptides enrichment, respectively. Here, we assessed the effectiveness of HSA/IgG (HU2) and Human 7 (HU7) depletion methods and their impact on phosphopeptides coverage through comparative proteome analysis, utilizing in-solution digestion and nano-LC-Orbitrap mass spectrometry (MS). Our results demonstrated that both HU2 and HU7 affinity depletion significantly decreased high-abundant proteins by 1.5-7.8-fold (p < 0.001). A total of 1491 proteins were identified, with 48 proteins showing significant expression in the depleted groups. Notably, cadherin-13, neutrophil defensin 1, APM1, and desmoplakin variant protein were exclusively detected in the HU2/HU7-depleted groups. Furthermore, study on effect of depletion on phosphopeptides revealed an increase in tandem MS spectral counts with notable decrease (∼50%) in peptide spectrum matching in depleted groups, which was attributed to significant reduction in protein counts. Our post translation modification workflow for phosphoproteomics detected 42 phosphorylated peptides, corresponding to 12 phosphoproteins with unique peptide match ≥2 (high false discovery rates confidence). Among them, 10 phosphorylated proteins are highly expressed in depleted groups. Overall, these findings offer valuable insights in selection of protein depletion methods for comprehensive plasma proteomics analysis.

ERCC1 which affects lipids metabolism and actin dynamics in coal workers' pneumoconiosis is a candidate biomarker for early warning and diagnosis

The single-nucleotide polymorphisms of genes related to DNA damage repair and inflammasomes and mutated gene expression in coal workers' pneumoconiosis (CWP) were analysed to identify the risk factors of CWP and potential biomarkers for early warning and diagnosis. Further, mutated gene pathways were analysed based on proteome and metabolome. Han Chinese male subjects were randomly selected and divided into 4 or 5 groups according to the process of CWP. MassARRAY was used to sequence single-nucleotide polymorphism genotypes. Mutated gene expression in plasma was tested using enzyme-linked immunosorbent assay (ELISA). Odds ratios (ORs) and receiver operating characteristic curves (ROC) were calculated. The serum different proteins and metabolites were identified by Ultra Performance Liquid Chromatography Quadrupole time of flight/Mass Spectrum (UPLC-Q-TOF/MS) and analysed using bioinformation software. As CWP progressed, the CC and CA genotypes of ERCC1 rs3212986 decreased and increased significantly, respectively. AA (OR = 3.016) and CA (OR = 2.130) genotypes were identified as risk factors for stage II. ERCC1 significantly decreased in processing of CWP. The cutoff value of ERCC1 was 5.265 pg/ml, with a sensitivity of 90.0% and specificity of 86.7%. ERCC1 had an indirect interaction with activator protein-1 and insulin and its pathways were mainly made with molecules related to lipid metabolism and actin dynamics. ERCC1 is a candidate biomarker for detection and precise intervention in CWP. If it reaches the threshold, workers will change other jobs in time and will not develop and diagnose as pneumoconiosis and will help the employers spend less money. Meanwhile, the signal molecules of ERCC1 pathway could be as a candidate target for drug discovery.

BATF promotes tumor progression and association with FDG PET-derived parameters in colorectal cancer

PURPOSE

The purpose of the study was to evaluate the expression and function of basic leucine zipper ATF-like transcription factor (BATF) in colorectal cancer (CRC), and its correlation with 2-deoxy-2[18F]fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) parameters.

METHODS

The TIMER database, GEPIA database, TCGA, and GEO database were used to analyze the expression profile of BATF in human cancers. The reverse transcription‑quantitative PCR and western blot analyses were used to evaluate the mRNA level and protein expression in different CRC cell lines. The expression of BATF in SW620 and HCT116 cells was silenced and cell counting kit-8 assays and clonogenic assay were utilized to evaluate the role of BATF in CRC proliferation. The expression of tumor BATF and glucose transporter 1 (GLUT-1) were examined using immunohistochemical tools in 37 CRC patients undergoing preoperative 18F-FDG PET/CT imaging. The correlation between the PET/CT parameters and immunohistochemical result was evaluated.

RESULTS

In database, BATF was highly expressed in pan-cancer analyses, including CRC, and was associated with poor prognosis in CRC. In vitro, the results showed that knocking down of BATF expression could inhibit the proliferation of SW620 and HCT116 cells. In CRC patients, BATF expression was upregulated in tumor tissues compared with matched para-tumoral tissues, and was related with gender and Ki-67 levels. BATF expression was positively related to GLUT-1 expression and PET/CT parameters, including tumor size, maximum standard uptake value, metabolic tumor volume, and total lesion glycolysis. The multiple logistic analyses showed that SUVmax was an independent predictor of BATF expression. With 15.96 g/cm3 as the cutoff, sensitivity was 85.71%, specificity 82.61%, and area-under-the-curve 0.854.

CONCLUSION

BATF may be an oncogene associated with 18F-FDG PET/CT parameters in CRC. SUVmax may be an independent predictor of BATF expression.

Jun/Fos promotes migration and invasion of hepatocellular carcinoma cells by enhancing BORIS promoter activity

The Brother of the Regulator of Imprinted Sites (BORIS), as a specific indicator of hepatocellular carcinoma, exhibits a significant increase in expression. However, its upstream regulatory network remains enigmatic. Previous research has indicated a strong correlation between the Hippo pathway and the progression of hepatocellular carcinoma. It is well established that the Activator Protein-1 (AP-1) frequently engages in interactions with the Hippo pathway. Thus, we attempt to prove whether Jun and Fos, a major member of the AP-1 family, are involved in the regulation of BORIS expression. Bioinformatics analysis revealed the existence of binding sites for Jun and Fos within the BORIS promoter. Through a series of overexpression and knockdown experiments, we corroborated that Jun and Fos have the capacity to augment BORIS expression, thereby fostering the migration and invasion of hepatocellular carcinoma cells. Moreover, Methylation-Specific PCR and Bisulfite Sequencing PCR assays revealed that Jun and Fos do not have a significant impact on the demethylation of the BORIS promoter. However, luciferase reporter and chromatin immunoprecipitation experiments substantiated that Jun and Fos could directly bind to the BORIS promoter, thereby enhancing its transcription. In conclusion, these results suggest that Jun and Fos can promote the development of hepatocellular carcinoma by directly regulating the expression of BORIS. These findings may provide experimental evidence positioning BORIS as a novel target for the clinical intervention of hepatocellular carcinoma.

Activating Protein-1 (AP-1): A Promising Target for the Treatment of Fibrotic Diseases

The fibrosis of tissues and organs occurs via an aberrant tissue remodeling process characterized by an excessive deposition of extracellular matrix, which can lead to organ dysfunction, organ failure, and death. Because the pathogenesis of fibrosis remains unclear and elusive, there is currently no medication to reverse it; hence, this process deserves further study. Activating protein-1 (AP-1)-comprising Jun (c-Jun, JunB, JunD), Fos (c-fos, FosB, Fra1, and Fra2), and activating transcription factor-is a versatile dimeric transcription factor. Numerous studies have demonstrated that AP-1 plays a crucial role in advancing tissue and organ fibrosis via induction of the expression of fibrotic molecules and activating fibroblasts. This review focuses on the role of AP-1 in a range of fibrotic disorders as well as on the antifibrotic effects of AP-1 inhibitors. It also discusses the potential of AP-1 as a new therapeutic target in conditions involving tissue and organ fibrosis.

Huanglian ointment alleviates eczema by maintaining the balance of c-Jun and JunB and inhibiting AGE-RAGE-mediated pro-inflammation signaling pathway

BACKGROUND

Huanglian ointment exhibits clinical efficacy for repairing skin barriers and inhibiting skin inflammation, and has been used to ameliorate eczema for many years. However, the active components and mechanism of Huanglian ointment have not yet been elucidated.

PURPOSE

This study aimed to demonstrate the main active components and molecular mechanisms of Huanglian ointment for the treatment of eczema.

METHODS

The main active components of Huanglian ointment were identified by gas chromatography-mass spectrometry. Network pharmacology approach and molecular docking techniques to predict the potential molecular mechanisms of Huanglian ointment alleviating eczema. Furthermore, Biostir-AD®-induced guinea pigs and tumor necrosis α (TNF-α)/interferon γ (IFN-γ)-induced HaCaT cells were employed to investigate the effectiveness and mechanisms of Huanglian ointment using histopathological staining, enzyme-linked immunosorbent assay, MTT assay, and western blot analysis.

RESULTS

Fourteen chemistry components were identified in Huanglian ointment. In total, 78 intersecting gene targets were identified between Huanglian ointment and eczema, including Jun, inflammatory regulators, and chemokine factors. Intersecting gene targets were enriched for cytokine and chemokine receptor binding, and inflammatory related signaling pathways. The molecular docking results showed that the identified components had a stable binding conformation with core targets. In vivo experiments showed that Huanglian ointment markedly ameliorated eczema-like skin lesions, restored histopathological morphology, and decreased levels of TNF-α, IFN-γ, and interleukin 6. Moreover, Huanglian ointment effectively protected HaCaT cells against TNF-α/IFN-γ-induced cell death and overproduction of thymus- and activation-regulated chemokine, macrophage-derived chemokine, and regulated upon activation normal T cell-expressed and secreted factor. Subsequently, we found that Huanglian ointment repaired skin barriers by affecting c-Jun, JunB, and filaggrin expression, and suppressed inflammatory response by inhibiting AGE-RAGE signaling pathway, both in vivo and in vitro.

CONCLUSION

Our results demonstrated that Huanglian ointment repaired skin barriers and inhibited inflammation by maintaining the balance of c-Jun and JunB, and suppressing AGE-RAGE signaling pathway, thereby relieving eczema. These findings providing a molecular basis for treatment of eczema by Huanglian ointment.

Epigenetic Crosstalk between Malignant Plasma Cells and the Tumour Microenvironment in Multiple Myeloma

In multiple myeloma, cells of the bone marrow microenvironment have a relevant responsibility in promoting the growth, survival, and drug resistance of multiple myeloma plasma cells. In addition to the well-recognized role of genetic lesions, microenvironmental cells also present deregulated epigenetic systems. However, the effect of epigenetic changes in reshaping the tumour microenvironment is still not well identified. An assortment of epigenetic regulators, comprising histone methyltransferases, histone acetyltransferases, and lysine demethylases, are altered in bone marrow microenvironmental cells in multiple myeloma subjects participating in disease progression and prognosis. Aberrant epigenetics affect numerous processes correlated with the tumour microenvironment, such as angiogenesis, bone homeostasis, and extracellular matrix remodelling. This review focuses on the interplay between epigenetic alterations of the tumour milieu and neoplastic cells, trying to decipher the crosstalk between these cells. We also evaluate the possibility of intervening specifically in modified signalling or counterbalancing epigenetic mechanisms.

Anti-Inflammatory Activities of an Anti-Histamine Drug, Loratadine, by Suppressing TAK1 in AP-1 Pathway

Loratadine is an anti-histamine routinely used for treating allergies. However, recent findings have shown that Loratadine may also have anti-inflammatory functions, while their exact mechanisms have not yet been fully uncovered. In this paper, we investigated whether Loratadine can be utilized as an anti-inflammatory drug through a series of in vitro and in vivo experiments using a murine macrophage cell line and an acute gastritis mouse model. Loratadine was found to dramatically reduce the expression of pro-inflammatory genes, including MMP1, MMP3, and MMP9, and inhibit AP-1 transcriptional activation, as demonstrated by the luciferase assay. Therefore, we decided to further explore its role in the AP-1 signaling pathway. The expression of c-Jun and c-Fos, AP-1 subunits, was repressed by Loratadine and, correspondingly, the expression of p-JNK, p-MKK7, and p-TAK1 was also inhibited. In addition, Loratadine was able to reduce gastric bleeding in acute gastritis-induced mice; Western blotting using the stomach samples showed reduced p-c-Fos protein levels. Loratadine was shown to effectively suppress inflammation by specifically targeting TAK1 and suppressing consequent AP-1 signaling pathway activation and inflammatory cytokine production.

RuvBL1 Maintains Resistance to TRAIL-Induced Apoptosis by Suppressing c-Jun/AP-1 Activity in Non-Small Cell Lung Cancer

Lung cancer is the common malignant tumor with the highest death rate in the world. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as a potential anticancer agent induces selective apoptotic death of human cancer cells. Unfortunately, approximately half of lung cancer cell lines are intrinsically resistant to TRAIL-induced cell death. In this study, we identified RuvBL1 as a repressor of c-Jun/AP-1 activity, contributing to TRAIL resistance in lung cancer cells. Knocking down RuvBL1 effectively sensitized resistant cells to TRAIL, and overexpression of RuvBL1 inhibited TRAIL-induced apoptosis. Moreover, there was a negative correlation expression between RuvBL1 and c-Jun in lung adenocarcinoma by Oncomine analyses. High expression of RuvBL1 inversely with low c-Jun in lung cancer was associated with a poor overall prognosis. Taken together, our studies broaden the molecular mechanisms of TRAIL resistance and suggest the application of silencing RuvBL1 synergized with TRAIL to be a novel therapeutic strategy in lung cancer treatment.

The Role of AP-1 Transcription Factors in Plasma Cell Biology and Multiple Myeloma Pathophysiology

Multiple myeloma (MM) is an incurable hematologic malignancy characterized by the clonal expansion of malignant plasma cells within the bone marrow. Activator Protein-1 (AP-1) transcription factors (TFs), comprised of the JUN, FOS, ATF and MAF multigene families, are implicated in a plethora of physiologic processes and tumorigenesis including plasma cell differentiation and MM pathogenesis. Depending on the genetic background, the tumor stage, and cues of the tumor microenvironment, specific dimeric AP-1 complexes are formed. For example, AP-1 complexes containing Fra-1, Fra-2 and B-ATF play central roles in the transcriptional control of B cell development and plasma cell differentiation, while dysregulation of AP-1 family members c-Maf, c-Jun, and JunB is associated with MM cell proliferation, survival, drug resistance, bone marrow angiogenesis, and bone disease. The present review article summarizes our up-to-date knowledge on the role of AP-1 family members in plasma cell differentiation and MM pathophysiology. Moreover, it discusses novel, rationally derived approaches to therapeutically target AP-1 TFs, including protein-protein and protein-DNA binding inhibitors, epigenetic modifiers and natural products.