The regulatory role of serum response factor pathway in neutrophil inflammatory response

Identification of the MRTFA/SRF pathway as a critical regulator of quiescence in cancer

Chemoresistance is a major driver of cancer deaths. One understudied mechanism of chemoresistance is quiescence. We used single cell culture to identify, retrieve, and RNA-Seq profile primary quiescent ovarian cancer cells (qOvCa). We found that many qOvCa differentially expressed genes are transcriptional targets of the Myocardin Related Transcription Factor/Serum Response Factor (MRTF/SRF) pathway. We also found that genetic disruption of MRTF-SRF interaction, or an MRTF/SRF inhibitor (CCG257081) impact qOvCa gene expression and induce a quiescent state in cancer cells. Suggesting a broad role for this pathway in quiescence, CCG257081 treatment induced quiescence in breast, lung, colon, pancreatic and ovarian cancer cells. Furthermore, CCG081 (i) maintained a quiescent state in patient derived breast cancer organoids and, (ii) induced tumor growth arrest in ovarian cancer xenografts. Together, these data suggest that MRTF/SRF pathway is a critical regulator of quiescence in cancer and a possible therapeutic target.

Circ_0076490 silencing inhibits MAPK1 expression to decrease the proliferation and increase apoptosis of Jurkat cells by regulating miR-144-3p in myasthenia gravis

BACKGROUND

Myasthenia gravis (MG) is a both neuromuscular junction and antibody-mediated autoimmune disease, and its pathogenesis involves the regulation of circular RNAs (circRNAs). However, the role of circ_0076490 in MG and the underlying mechanism remain unknown.

METHODS

RNA levels of circ_0076490, microRNA-144-3p (miR-144-3p), and mitogen-activated protein kinase 1 (MAPK1) were detected by quantitative real-time polymerase chain reaction. Cell viability and proliferation were investigated by cell counting kit-8 and 5-Ethynyl-29-deoxyuridine assays, respectively. Cell cycle and apoptosis were assessed by flow cytometry analysis. The putative binding relationship of miR-144-3p and circ_0076490 or MAPK1 was predicted by circular RNA interactome and TargetScan online databases, respectively, and identified through dual-luciferase reporter assay and RNA pull-down assay.

RESULTS

We observed dramatic increases of circ_0076490 and MAPK1 expression and a decrease of miR-144-3p expression in the peripheral blood of MG patients in comparison with healthy controls. Reduced expression of circ_0076490 induced an inhibitory effect on the proliferation of Jurkat cells and a promoting effect on cell apoptosis. Additionally, miR-144-3p was identified as a target miRNA of circ_0076490, and its depletion attenuated circ_0076490 knockdown-mediated effects on the proliferation and apoptosis of Jurkat cells. MAPK1 was a target gene of miR-144-3p and its overexpression rescued decreased cell proliferation and increased cell apoptosis induced by miR-144-3p introduction. Furthermore, circ_0076490 regulated MAPK1 expression by interacting with miR-144-3p.

CONCLUSION

Circ_0076490 knockdown inhibited proliferation and induced apoptosis of Jurkat cells through the regulation of the miR-144-3p/MAPK1 axis, providing potential targets for developing improved therapy of MG.

RAGE/DIAPH1 and atherosclerosis through an evolving lens: Viewing the cell from the "Inside - Out"

BACKGROUND AND AIMS

In hyperglycemia, inflammation, oxidative stress and aging, Damage Associated Molecular Patterns (DAMPs) accumulate in conditions such as atherosclerosis. Binding of DAMPs to receptors such as the receptor for advanced glycation end products (RAGE) activates signal transduction cascades that contribute to cellular stress. The cytoplasmic domain (tail) of RAGE (ctRAGE) binds to the formin Diaphanous1 (DIAPH1), which is important for RAGE signaling. This Review will detail the evidence linking the RAGE/DIAPH1 signaling pathway to atherosclerosis and envisages future therapeutic opportunities from the "inside-out" point of view in affected cells.

METHODS

PubMed was searched using a variety of search terms, including "receptor for advanced glycation end products" along with various combinations including "and atherosclerosis," "soluble RAGE and atherosclerosis," "statins and RAGE," "PPAR and RAGE" and "SGLT2 inhibitor and RAGE."

RESULTS

In non-diabetic and diabetic mice, antagonism or global deletion of Ager (the gene encoding RAGE) retards progression and accelerates regression of atherosclerosis. Global deletion of Diaph1 in mice devoid of the low density lipoprotein receptor (Ldlr) significantly attenuates atherosclerosis; mice devoid of both Diaph1 and Ldlr display significantly lower plasma and liver concentrations of cholesterol and triglyceride compared to mice devoid of Ldlr. Associations between RAGE pathway and human atherosclerosis have been identified based on relationships between plasma/serum concentrations of RAGE ligands, soluble RAGEs and atherosclerosis.

CONCLUSIONS

Efforts to target RAGE/DIAPH1 signaling through a small molecule antagonist therapeutic strategy hold promise to quell accelerated atherosclerosis in diabetes and in other forms of cardiovascular disease.

Identification of Two Genetic Loci Associated with Leukopenia after Chemotherapy in Patients with Breast Cancer

PURPOSE

To identify molecular predictors of grade 3/4 neutropenic or leukopenic events (NLE) after chemotherapy using a genome-wide association study (GWAS).

EXPERIMENTAL DESIGN

A GWAS was performed on patients in the phase III chemotherapy study SUCCESS-A (n = 3,322). Genotyping was done using the Illumina HumanOmniExpress-12v1 array. Findings were functionally validated with cell culture models and the genotypes and gene expression of possible causative genes were correlated with clinical treatment response and prognostic outcomes.

RESULTS

One locus on chromosome 16 (rs4784750; NLRC5; P = 1.56E-8) and another locus on chromosome 13 (rs16972207; TNFSF13B; P = 3.42E-8) were identified at a genome-wide significance level. Functional validation revealed that expression of these two genes is altered by genotype-dependent and chemotherapy-dependent activity of two transcription factors. Genotypes also showed an association with disease-free survival in patients with an NLE.

CONCLUSIONS

Two loci in NLRC5 and TNFSF13B are associated with NLEs. The involvement of the MHC I regulator NLRC5 implies the possible involvement of immuno-oncological pathways.

Nanotechnology for Enhanced Cytoplasmic and Organelle Delivery of Bioactive Molecules to Immune Cells

Immune cells stand as a critical component of the immune system to maintain the internal environment homeostasis. The dysfunction of immune cells can result in various life-threatening diseases, including refractory infection, diabetes, cardiovascular disease, and cancer. Therefore, strategies to standardize or even enhance the function of immune cells are critical. Recently, nanotechnology has been highly researched and extensively applied for enhancing the cytoplasmic delivery of bioactive molecules to immune cells, providing efficient approaches to correct in vivo and in vitro dysfunction of immune cells. This review focuses on the technologies and challenges involved in improving endo-lysosomal escape, cytoplasmic release and organelle targeted delivery of different bioactive molecules in immune cells. Furthermore, it will elaborate on the broader vision of applying nanotechnology for treating immune cell-related diseases and constructing immune therapies and cytopharmaceuticals as potential treatments for diseases.

Cumulus cells of euploid versus whole chromosome 21 aneuploid embryos reveal differentially expressed genes

RESEARCH QUESTION

Can cumulus cells be used as a non-invasive target for the study of determinants of preimplantation embryo quality?

DESIGN

Cumulus cells were collected from monosomy 21, trisomy 21 and euploid embryos and subjected to RNA sequencing analysis and real-time polymerase chain reaction assays. The differential gene expression was analysed for different comparisons.

RESULTS

A total of 3122 genes in monosomy 21 cumulus cells and 19 genes in trisomy 21 cumulus cells were differentially expressed compared with euploid cumulus cells. Thirteen of these genes were differentially expressed in both monosomy and trisomy 21, compared with euploid, including disheveled segment polarity protein 2 (DVL2), cellular communication network factor 1 (CCN1/CYR61) and serum response factor (SRF), which have been previously implicated in embryo developmental competence. In addition, ingenuity pathway analysis revealed cell-cell contact function to be affected in both monosomy and trisomy 21 cumulus cells.

CONCLUSIONS

These findings support the use of cumulus cell gene expression analysis for the development of biomarkers evaluating oocyte quality for patients undergoing fertility preservation of oocytes.

New function of a well-known promoter: Enhancer activity of minimal CMV promoter enables efficient dual-cassette transgene expression

BACKGROUND

Co-expression of multiple genes in single vectors has achieved varying degrees of success by employing two promoters and/or application of viral 2A-peptide or the internal ribosome entry-site (IRES). However, promoter interference, potential functional-interruption of expressed-proteins by 2A-generated residual peptides or weaker translation of IRES-mediated downstream genes has curtailed their utilization. Thus, there is the need for single vectors that robustly express multiple proteins for enhanced gene therapy applications.

METHODS

We engineered lentiviral-vectors for dual-cassette expression of green fluorescent protein and mCherry in uni- or bidirectional architectures using the short-version (Es) of elongation factor 1α (EF) promoter and simian virus 40 promoter (Sv). The regulatory function of a core fragment (cC) from human cytomegalovirus promoter was investigated with cell-lineage specificity in NIH3T3 (fibroblast) and hematopoietic cell lines U937 (monocyte/macrophage), LCL (lymphoid), DAMI (megakaryocyte) and MEL (erythroid).

RESULTS

The cC element in reverse-orientation not only boosted upstream Es promoter to levels comparable to full-length EF in DAMI, U937 and 3T3 cells, but also blocked the suppression of downstream Sv promoter by Es in U937 and 3T3 cells with further improved Sv activity in DAMI cells. Such lineage-restricted up-regulation is likely attributed to two protein-binding domains of cC and diverse expression of related factors in different cell types for enhancer and terminator activities, but not spacing function.

CONCLUSIONS

Such a newly developed dual-cassette vector could be advantageous, particularly in hematopoietic cell-mediated gene/cancer therapy, by allowing for independent and robust co-expression of therapeutic gene(s) and/or a selectable gene or imaging marker in the same cells.

Molecular Mechanisms of Leukocyte Migration and Its Potential Targeting-Lessons Learned From MKL1/SRF-Related Primary Immunodeficiency Diseases

Megakaryoblastic leukemia 1 (MKL1) deficiency is one of the most recently discovered primary immunodeficiencies (PIDs) caused by cytoskeletal abnormalities. These immunological “actinopathies” primarily affect hematopoietic cells, resulting in defects in both the innate immune system (phagocyte defects) and adaptive immune system (T-cell and B-cell defects). MKL1 is a transcriptional coactivator that operates together with serum response factor (SRF) to regulate gene transcription. The MKL/SRF pathway has been originally described to have important functions in actin regulation in cells. Recent results indicate that MKL1 also has very important roles in immune cells, and that MKL1 deficiency results in an immunodeficiency affecting the migration and function of primarily myeloid cells such as neutrophils. Interestingly, several actinopathies are caused by mutations in genes which are recognized MKL(1/2)-dependent SRF-target genes, namely ACTB, WIPF1, WDR1, and MSN. Here we summarize these and related (ARPC1B) actinopathies and their effects on immune cell function, especially focusing on their effects on leukocyte adhesion and migration. Furthermore, we summarize recent therapeutic efforts targeting the MKL/SRF pathway in disease.

Genetic Variation, GWAS and Accuracy of Prediction for Host Resistance to Sparicotyle chrysophrii in Farmed Gilthead Sea Bream (Sparus aurata)

Gilthead sea bream (Sparus aurata) belongs to a group of teleost which has high importance in Mediterranean aquaculture industry. However, industrial production is increasingly compromised by an elevated outbreak of diseases in sea cages, especially a disease caused by monogeneans parasite Sparicotyle chrysophrii. This parasite mainly colonizes gill tissues of host and causes considerable economical losses with mortality and reduction in growth. The aim of current study was to explore the genetics of host resistance against S. chrysophrii and investigate the potential for genomic selection to possibly accelerate genetic progress. To achieve the desired goals, a test population derived from the breeding nucleus of Andromeda Group was produced. This experimental population was established by crossing of parents mated in partial factorial crosses of ∼8 × 8 using 58 sires and 62 dams. The progeny obtained from this mating design was challenged with S. chrysophrii using a controllable cohabitation infection model. At the end of the challenge, fish were recorded for parasite count, and all the recorded fish were tissue sampled for genotyping by sequencing using 2b-RAD methodology. The initial (before challenge test) and the final body weight (after challenge test) of the fish were also recorded. The results obtained through the analysis of phenotypic records (n = 615) and the genotypic data (n = 841, 724 offspring and 117 parents) revealed that the resistance against this parasite is lowly heritable (h² = 0.147 with pedigree and 0.137 with genomic information). We observed moderately favorable genetic correlation (R_g = −0.549 to −0.807) between production traits (i.e., body weight and specific growth rate) and parasite count, which signals a possibility of indirect selection. A locus at linkage group 17 was identified that surpassed chromosome-wide Bonferroni threshold which explained 22.68% of the total genetic variance, and might be playing role in producing genetic variation. The accuracy of prediction was improved by 8% with genomic information compared to pedigree.

Identification the prognostic value of glutathione peroxidases expression levels in acute myeloid leukemia

Background

Glutathione peroxidases (GPXs) are an enzyme family with peroxidase activity. Abnormal GPX expression is associated with carcinogenesis. However, the potential role of the GPX gene family in acute myeloid leukemia (AML) remains to be comprehensively examined.

Methods

We analyzed GPX mRNA expression levels and determined the correlation between gene expression and the prognostic value via multiple universally acknowledged databases including the Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), PROGgeneV2, UALCAN, Cancer Cell Line Encyclopedia (CCLE), and The European Bioinformatics Institute (EMBL-EBI) databases. The functional network of differentially expressed GPXs was investigated via the NetworkAnalyst platform. Correlated genes as well as kinase, microRNA (miRNA), and transcription factor (TF) targets were identified using LinkedOmics.

Results

We observed that the transcriptional expression levels of GPX-1, -2, -4, -7, and -8 had significant difference between AML patients samples and normal samples, and that AML patients with high expression of GPX-1, -3, -4, and -7 were associated with poorer prognosis of overall survival (OS). Functional enrichment analysis showed that the differentially expressed GPXs were mainly enriched in response to oxidative stress, regulation of immune response, and inflammatory response, along with glutathione metabolism and ferroptosis. Overexpression of correlated genes, PSMB10, VPS13D, NDUFS8, ATP5D, POLR2E, and HADH were linked to adverse OS in AML. Regulatory network analysis indicated that differentially expressed GPXs regulated cell proliferation, cancer progression, apoptosis, and cell cycle signaling via pathways involving cancer-related kinases (such as DAPK1 and SRC), miRNAs (such as miR-202 and miR-181), and TFs (such as SRF and E2F1).

Conclusions

Our findings offer novel insights into the differential expression and prognostic potential of the GPX family in AML, and lay a foundation for subsequent research of GPX’s role in the carcinogenesis and regulatory network of AML.

A β2-Integrin/MRTF-A/SRF Pathway Regulates Dendritic Cell Gene Expression, Adhesion, and Traction Force Generation

β2-integrins are essential for immune system function because they mediate immune cell adhesion and signaling. Consequently, a loss of β₂-integrin expression or function causes the immunodeficiency disorders, Leukocyte Adhesion Deficiency (LAD) type I and III. LAD-III is caused by mutations in an important integrin regulator, kindlin-3, but exactly how kindlin-3 regulates leukocyte adhesion has remained incompletely understood. Here we demonstrate that mutation of the kindlin-3 binding site in the β2-integrin (TTT/AAA-β2-integrin knock-in mouse/KI) abolishes activation of the actin-regulated myocardin related transcription factor A/serum response factor (MRTF-A/SRF) signaling pathway in dendritic cells and MRTF-A/SRF-dependent gene expression. We show that Ras homolog gene family, member A (RhoA) activation and filamentous-actin (F-actin) polymerization is abolished in murine TTT/AAA-β2-integrin KI dendritic cells, which leads to a failure of MRTF-A to localize to the cell nucleus to coactivate genes together with SRF. In addition, we show that dendritic cell gene expression, adhesion and integrin-mediated traction forces on ligand coated surfaces is dependent on the MRTF-A/SRF signaling pathway. The participation of β2-integrin and kindlin-3-mediated cell adhesion in the regulation of the ubiquitous MRTF-A/SRF signaling pathway in immune cells may help explain the role of β2-integrin and kindlin-3 in integrin-mediated gene regulation and immune system function.

Mass spectrometry identification of potential biomarker proteins in the 150-kD electrophoretic band in patients with schizophrenia

BACKGROUND

Diagnosing schizophrenia is primarily based on the presentation of defined signs and symptoms, none of which is pathognomonic for this group of syndromes. However, few significant genome-wide associations between schizophrenia and individual have detected. Protein profiling of candidate serum biomarkers in schizophrenia is therefore an area of great interest.

METHODS

In the present study, we used a combination of 7% polyethylene glycol (PEG) enrichment of immune complexes and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to separate abnormal band, then analyse the band with liquid chromatography mass spectrometry (LC-MS).

RESULTS

There is a special 150-kD electrophoretic band in patients with schizophrenia, bipolar disorder, or depression relative to healthy controls (each 30 samples). Analysis of the band using LC-MS resulted in the identification of 11 serum proteins whose abundance was altered between patients and controls. Among them, 8 proteins (CFH, CFB, cDNA FLJ75416, zinc finger protein 729, isoform 2 of nidogen-1, diaphanous-1, cDNA FLJ77762, and cDNA FLJ58411) were up regulated, while one protein (isoform 1 of collagen alpha-1 (II) was down regulated in patients with schizophrenia, but only zinc finger protein 729 has statistics significance (P < .05). No differences were noted with regard to thrombospondin-1 or collagen alpha-2 (I) among the 3 groups. These proteins take part in several biological functions such as focal adhesion, complement cascades, ECM-receptor interaction, and Staphylococcus aureus infection.

CONCLUSIONS

The 150-kD electrophoretic band or zinc finger protein 729 may become biomarkers in patients with schizophrenia. In the future increasing sample size and function research of zinc finger protein 729 should be executed continuously.

Overexpression of serum response factor is correlated with poor prognosis in patients with gastric cancer

Serum response factor (SRF) is highly expressed in many tumors, including gastric cancer. However, the exact prognostic utility of SRF in patients with gastric cancer remains unclear. Therefore, in this study, we investigated the expression and prognostic value of SRF in patients with gastric cancer. SRF expression was detected by immunohistochemistry in 149 gastric cancer samples. The relationship between SRF expression and clinicopathological characteristics along with the prognostic significance of SRF in disease-free survival and overall survival of patients was analyzed. We found that the expression of SRF was significantly increased in gastric cancer tissues compared with adjacent noncancerous tissues. Overexpression of SRF was significantly correlated with histologic differentiation, invasion depth, lymph node metastasis, and TNM stage. Furthermore, disease-free survival rate and overall survival rate were both significantly lower for patients with high SRF expression. Multivariate Cox regression analysis identified high SRF expression as an independent prognostic factor for disease-free survival but not for overall survival. Our findings indicate that overexpression of SRF may play an important role in human gastric cancer recurrence and prognosis. SRF may serve as a predictive marker for prognosis of gastric cancer.

Naringenin inhibits spinal cord injury-induced activation of neutrophils through miR-223

Naringenin (NR), a flavonoid abundant in citrus fruits has been reported to possess anti-inflammatory properties. The present study aimed to investigate the protective of naringenin in rats after spinal cord injury (SCI) and the underlying mechanisms associated with neuroinflammation. Adult male Sprague-Dawley rats were subjected to laminectomy at T9-T11 and compression with a vascular clip. The spinal cords spanning the injury site about 0.8cm were collected for testing. There were five groups (n=7 in each group): (a) Control group; (b) sham group group; (c) SCI+saline; (d) SCI+NR (50mg/kg, p.o.) group and (e) SCI+NR (100mg/kg, p.o.) group. Different doses of NR (50mg/kg, p.o. and 100mg/kg, p.o.) or saline were administered once daily for 11 consecutive days, from 3days prior to surgery to 7days after surgery. The expression level of miR-223, NLRP3 and IL-1β were measured by RT- qPCR. The accumulation of neutrophils at the site of compression, as evaluated by measuring the tissue myeloperoxidase activity, significantly increased with time following the compression, peaking at 24h post compression. The expression of miR-223 was significant elevated in (b). However, spinal cord myeloperoxidase activity and the expression of miR-223 did not increase in sham-operated animals. NR significantly inhibited a SCI-induced activation of neutrophils through repressed miR-223 in group (d) and (e). There was a better effect in group (e) than group (d). miR-223 is thought to act as a fine-tuner of granulocyte production and the inflammatory response. Our findings suggested that repeated administration of naringenin (100mg/kg, p.o) may provide the protective effect of the spinal cord injury in rats, possibly through inhibiting neuroinflammation.

Vaccine-induced modulation of gene expression in turbot peritoneal cells. A microarray approach

We used a microarray approach to examine changes in gene expression in turbot peritoneal cells after injection of the fish with vaccines containing the ciliate parasite Philasterides dicentrarchi as antigen and one of the following adjuvants: chitosan-PVMMA microspheres, Freund́s complete adjuvant, aluminium hydroxide gel or Matrix-Q (Isconova, Sweden). We identified 374 genes that were differentially expressed in all groups of fish. Forty-two genes related to tight junctions and focal adhesions and/or actin cytoskeleton were differentially expressed in free peritoneal cells. The profound changes in gene expression related to cell adherence and cytoskeleton may be associated with cell migration and also with the formation of cell-vaccine masses and their attachment to the peritoneal wall. Thirty-five genes related to apoptosis were differentially expressed. Although most of the proteins coded by these genes have a proapoptotic effect, others are antiapoptotic, indicating that both types of signals occur in peritoneal leukocytes of vaccinated fish. Interestingly, many of the genes related to lymphocytes and lymphocyte activity were downregulated in the groups injected with vaccine. We also observed decreased expression of genes related to antigen presentation, suggesting that macrophages (which were abundant in the peritoneal cavity after vaccination) did not express these during the early inflammatory response in the peritoneal cavity. Finally, several genes that participate in the inflammatory response were differentially expressed, and most participated in resolution of inflammation, indicating that an M2 macrophage response is generated in the peritoneal cavity of fish one day post vaccination.

Community Structure Reveals Biologically Functional Modules in MEF2C Transcriptional Regulatory Network

Gene regulatory networks are useful to understand the activity behind the complex mechanisms in transcriptional regulation. A main goal in contemporary biology is using such networks to understand the systemic regulation of gene expression. In this work, we carried out a systematic study of a transcriptional regulatory network derived from a comprehensive selection of all potential transcription factor interactions downstream from MEF2C, a human transcription factor master regulator. By analyzing the connectivity structure of such network, we were able to find different biologically functional processes and specific biochemical pathways statistically enriched in communities of genes into the network, such processes are related to cell signaling, cell cycle and metabolism. In this way we further support the hypothesis that structural properties of biological networks encode an important part of their functional behavior in eukaryotic cells.