A GTPase-activating protein-binding protein (G3BP1)/antiviral protein relay conveys arteriosclerotic Wnt signals in aortic smooth muscle cells

Association of plasma microRNA-16-5p and abdominal aortic calcification in maintenance hemodialysis patients

Recent studies have shown that microRNA-16-5p (miR-16-5p) plays a crucial role in the pathological mechanism of vascular calcification. Nevertheless, the expression profile of miR-16-5p in maintenance hemodialysis (MHD) patients who are predisposed to vascular calcification remains unknown. This study aims to investigate the potential associations between calcification risk and serum miR-16-5p expression among MHD patients. This cross-sectional study involved 132 MHD patients from the Dialysis Center of Beijing Friendship Hospital between 1 January 2019 and 31 December 2020. The degree of calcification in MHD patients was assessed using the Abdominal aortic calcification (AAC) score, and miR-16-5p expression was quantified using quantitative real-time polymerase chain reaction (qRT-PCR) with the 2-ΔΔCT method. Statistical analyses, including spearman correlation, linear regression and logistic regression analysis were used to explore the associations between laboratory parameters and AAC score. Calcifications were observed in 79(59.80%) patients. The linear regression showed a one-quartile decrease in miR-16-5p expression led to a significant increase in the AAC score by 5.336 (95% CI: 2.670-10.662, p = 0.000). Multivariate logistic regression analyses revealed that decreased miR-16-5p expression, reduced serum urea nitrogen, elevated white blood cell count, and longer dialysis vintage were significantly associated with an increased incidence of vascular calcification. The Area Under the Curve (AUC) of the Receiver Operating Characteristic (ROC) of the miR-16-5p-based logistic regression model was 0.842 (95% CI: 0.771-0.913, p = 0.000). There was an independent association between miR-16-5p expression and calcification degree. Lower miR-16-5p expression levels seem to be a potential risk factor of vascular calcification in MHD patients.

Wnt16 Promotes Vascular Smooth Muscle Contractile Phenotype and Function via Taz (Wwtr1) Activation in Male LDLR-/- Mice

Wnt16 is expressed in bone and arteries, and maintains bone mass in mice and humans, but its role in cardiovascular physiology is unknown. We show that Wnt16 protein accumulates in murine and human vascular smooth muscle (VSM). WNT16 genotypes that convey risk for bone frailty also convey risk for cardiovascular events in the Dallas Heart Study. Murine Wnt16 deficiency, which causes postnatal bone loss, also reduced systolic blood pressure. Electron microscopy demonstrated abnormal VSM mitochondrial morphology in Wnt16-null mice, with reductions in mitochondrial respiration. Following angiotensin-II (AngII) infusion, thoracic ascending aorta (TAA) dilatation was greater in Wnt16-/- vs Wnt16+/+ mice (LDLR-/- background). Acta2 (vascular smooth muscle alpha actin) deficiency has been shown to impair contractile phenotype and worsen TAA aneurysm with concomitant reductions in blood pressure. Wnt16 deficiency reduced expression of Acta2, SM22 (transgelin), and other contractile genes, and reduced VSM contraction induced by TGFβ. Acta2 and SM22 proteins were reduced in Wnt16-/- VSM as was Ankrd1, a prototypic contractile target of Yap1 and Taz activation via TEA domain (TEAD)-directed transcription. Wnt16-/- VSM exhibited reduced nuclear Taz and Yap1 protein accumulation. SiRNA targeting Wnt16 or Taz, but not Yap1, phenocopied Wnt16 deficiency, and Taz siRNA inhibited contractile gene upregulation by Wnt16. Wnt16 incubation stimulated mitochondrial respiration and contraction (reversed by verteporfin, a Yap/Taz inhibitor). SiRNA targeting Taz inhibitors Ccm2 and Lats1/2 mimicked Wnt16 treatment. Wnt16 stimulated Taz binding to Acta2 chromatin and H3K4me3 methylation. TEAD cognates in the Acta2 promoter conveyed transcriptional responses to Wnt16 and Taz. Wnt16 regulates cardiovascular physiology and VSM contractile phenotype, mediated via Taz signaling.

Superfamily II helicases: the potential therapeutic target for cardiovascular diseases

Cardiovascular diseases (CVDs) still maintain high morbidity and mortality globally. Helicases, a unique class of enzymes, are extensively implicated in the processes of nucleic acid (NA) metabolism across various organisms. They play a pivotal role in gene expression, inflammatory response, lipid metabolism, and so forth. However, abnormal helicase expression has been associated with immune response, cancer, and intellectual disability in humans. Superfamily II (SFII) is one of the largest and most diverse of the helicase superfamilies. Increasing evidence has implicated SFⅡ helicases in the pathogenesis of multiple CVDs. In this review, we comprehensively review the regulation mechanism of SFⅡ helicases in CVDs including atherosclerosis, myocardial infarction, cardiomyopathies, and heart failure, which will contribute to the investigation of ideal therapeutic targets for CVDs.

Role(s) of G3BPs in Human Pathogenesis

Ras-GTPase-activating protein (SH3 domain)-binding proteins (G3BP) are RNA binding proteins that play a critical role in stress granule (SG) formation. SGs protect critical mRNAs from various environmental stress conditions by regulating mRNA stability and translation to maintain regulated gene expression. Recent evidence suggests that G3BPs can also regulate mRNA expression through interactions with RNA outside of SGs. G3BPs have been associated with a number of disease states, including cancer progression, invasion, metastasis, and viral infections, and may be useful as a cancer therapeutic target. This review summarizes the biology of G3BP including their structure, function, localization, role in cancer progression, virus replication, mRNA stability, and SG formation. We will also discuss the potential of G3BPs as a therapeutic target. SIGNIFICANCE STATEMENT: This review will discuss the molecular mechanism(s) and functional role(s) of Ras-GTPase-activating protein (SH3 domain)-binding proteins in the context of stress granule formation, interaction with viruses, stability of RNA, and tumorigenesis.

Molecular Mechanisms of Vascular Health: Insights From Vascular Aging and Calcification

Cardiovascular disease is the most common cause of death worldwide, especially beyond the age of 65 years, with the vast majority of morbidity and mortality due to myocardial infarction and stroke. Vascular pathology stems from a combination of genetic risk, environmental factors, and the biologic changes associated with aging. The pathogenesis underlying the development of vascular aging, and vascular calcification with aging, in particular, is still not fully understood. Accumulating data suggests that genetic risk, likely compounded by epigenetic modifications, environmental factors, including diabetes and chronic kidney disease, and the plasticity of vascular smooth muscle cells to acquire an osteogenic phenotype are major determinants of age-associated vascular calcification. Understanding the molecular mechanisms underlying genetic and modifiable risk factors in regulating age-associated vascular pathology may inspire strategies to promote healthy vascular aging. This article summarizes current knowledge of concepts and mechanisms of age-associated vascular disease, with an emphasis on vascular calcification.

Epigenetic regulation in cardiovascular disease: mechanisms and advances in clinical trials

Epigenetics is closely related to cardiovascular diseases. Genome-wide linkage and association analyses and candidate gene approaches illustrate the multigenic complexity of cardiovascular disease. Several epigenetic mechanisms, such as DNA methylation, histone modification, and noncoding RNA, which are of importance for cardiovascular disease development and regression. Targeting epigenetic key enzymes, especially the DNA methyltransferases, histone methyltransferases, histone acetylases, histone deacetylases and their regulated target genes, could represent an attractive new route for the diagnosis and treatment of cardiovascular diseases. Herein, we summarize the knowledge on epigenetic history and essential regulatory mechanisms in cardiovascular diseases. Furthermore, we discuss the preclinical studies and drugs that are targeted these epigenetic key enzymes for cardiovascular diseases therapy. Finally, we conclude the clinical trials that are going to target some of these processes.

Immune Regulator Retinoic Acid-Inducible Gene I (RIG-I) in the Pathogenesis of Cardiovascular Disease

Retinoic acid-inducible gene I (RIG-I) is a cytosolic pattern recognition receptor that contains two CARD domains, an RNA helicase domain, and a C-terminal domain. RIG-I initiates antiviral innate immunity by recognizing exogenous viral RNAs/DNAs. However, some studies have reported that RIG-I activation leads to damage in various organs and tissues in diverse circumstances. Recent studies have shown that RIG-I is involved in cancer, lupus nephritis, immunoglobulin A nephropathy, Crohn’s disease, and atherosclerosis. These reports indicate that RIG-I not only participates in antiviral signaling pathways but also exerts an influence on non-viral infectious diseases. RIG-I is widely expressed in immune and non-immune cells including smooth muscle cells, endothelial cells, and cardiomyocytes. A succinct overview of RIG-I and its signaling pathways, with respect to the cardiovascular system, will aid in the development of novel therapeutics for cardiovascular diseases. In this review, we summarize the structure, activation, signaling pathways, and role of RIG-I in cardiovascular diseases.

The roles of G3BP1 in human diseases (review)

Ras-GTPase-activating protein binding protein 1 (G3BP1) is a multifunctional binding protein involved in a variety of biological functions, including cell proliferation, metastasis, apoptosis, differentiation and RNA metabolism. It has been revealed that G3BP1, as an antiviral factor, can interact with viral proteins and regulate the assembly of stress granules (SGs), which can inhibit viral replication. Furthermore, several viruses have the ability to hijack G3BP1 as a cofactor, recruiting translation initiation factors to promote viral proliferation. However, many functions of G3BP1 are associated with other diseases. In various cancers, G3BP1 is a cancer-promoting factor, which can promote the proliferation, invasion and metastasis of cancer cells. Moreover, compared with normal tissues, G3BP1 expression is higher in tumor tissues, indicating that it can be used as an indicator for cancer diagnosis. In this review, the structure of G3BP1 and the regulation of G3BP1 in multiple dimensions are described. In addition, the effects and potential mechanisms of G3BP1 on various carcinomas, viral infections, nervous system diseases and cardiovascular diseases are elucidated, which may provide a direction for clinical applications of G3BP1 in the future.

Pathophysiology of stress granules: An emerging link to diseases (Review)

Under unfavorable environmental conditions, eukaryotic cells may form stress granules (SGs) in the cytosol to protect against injury and promote cell survival. The initiation, mRNA and protein composition, distribution and degradation of SGs are subject to multiple intracellular post-translational modifications and signaling pathways to cope with stress damage. Despite accumulated comprehensive knowledge of their composition and dynamics, the function of SGs remains poorly understood. When the stress persists, aberrant and/or persistent intracellular SGs and aggregation of SGs-related proteins may lead to various diseases. In the present article, the research progress regarding the generation, modification and function of SGs was reviewed. The regulatory effects and influencing factors of SGs in the development of tumors, cardiovascular diseases, viral infections and neurodegenerative diseases were also summarized, which may provide novel insight for preventing and treating SG-related diseases.

Knockdown of long noncoding RNA GAS5 reduces vascular smooth muscle cell apoptosis by inactivating EZH2-mediated RIG-I signaling pathway in abdominal aortic aneurysm

Background

Abdominal aortic aneurysm (AAA), an irreversible cardiovascular disease prevalent in the artery, causes the increase of the aneurysm diameter over time, and is a fatal phenomenon inducing sidewall rupture. Long noncoding RNAs (lncRNAs) serve as promising biomarkers for AAA. In the present study, we sought to define the role of lncRNA growth-arrest-specific transcript 5 (GAS5) in growth of smooth muscle cells (SMC) and progression of AAA.

Methods

Initially, we established angiotensin II (Ang II)-induced AAA mouse models and Ang II-treated vascular SMC model. RT-qPCR and Western blot analysis were adopted to determine expression of GAS5 and zeste homolog 2 (EZH2). After ectopic expression and depletion experiments in Ang II-treated mice and vascular SMCs, cell apoptosis was detected in SMCs using flow cytometry and in mice using TUNEL staining. The binding of GAS5 and EZH2 was evaluated using RNA binding protein immunoprecipitation (RIP) and Co-IP assays.

Results

Increased GAS5 and RIG-I but decreased EZH2 were found in aortic tissues of AAA mice. EZH2 overexpression inhibited AAA formation and suppressed SMC apoptosis. Functionally, EZH2 blocked the RIG-I signaling pathway and consequently inhibited SMC apoptosis. GAS5 regulated EZH2 transcription in a negative manner in SMCs. Knockdown of GAS5 attenuated SMC apoptosis, which was reversed by EZH2 inhibition or RIG-I overexpression.

Conclusions

The current study demonstrated that GAS5 induced SMC apoptosis and subsequent AAA onset by activating EZH2-mediated RIG-I signaling pathway, highlighting GAS5 as a novel biomarker for AAA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03023-w.

Research Progress on the Structure and Function of G3BP

Ras-GTPase-activating protein (SH3 domain)-binding protein (G3BP) is an RNA binding protein. G3BP is a key component of stress granules (SGs) and can interact with many host proteins to regulate the expression of SGs. As an antiviral factor, G3BP can interact with viral proteins to regulate the assembly of SGs and thus exert antiviral effects. However, many viruses can also use G3BP as a proximal factor and recruit translation initiation factors to promote viral proliferation. G3BP regulates mRNA translation and attenuation to regulate gene expression; therefore, it is closely related to diseases, such as cancer, embryonic death, arteriosclerosis, and neurodevelopmental disorders. This review discusses the important discoveries and developments related G3BP in the biological field over the past 20 years, which includes the formation of SGs, interaction with viruses, stability of RNA, and disease progression.

Hereditary Disorders of Cardiovascular Calcification

Arterial calcification is a common phenomenon in the elderly, in patients with atherosclerosis or renal failure and in diabetes. However, when present in very young individuals, it is likely to be associated with an underlying hereditary disorder of arterial calcification. Here, we present an overview of the few monogenic disorders presenting with early-onset cardiovascular calcification. These disorders can be classified according to the function of the respective disease gene into (1) disorders caused by an altered purine and phosphate/pyrophosphate metabolism, (2) interferonopathies, and (3) Gaucher disease. The finding of arterial calcification in early life should alert the clinician and prompt further genetic work-up to define the underlying genetic defect, to establish the correct diagnosis, and to enable appropriate therapy.

Omics research in vascular calcification

Vascular calcification (VC), the pathological process of hydroxyapatite mineral deposition in the vascular system, is closely associated with aging, atherosclerotic plaque formation, cardiovascular disease (CVD) and diabetes mellitus (DM). Studies have shown that VC is related to cellular phenotypic changes, extracellular vesicles, disordered calcium and phosphate homeostasis, and an imbalance between inducers and inhibitors of VC. Unfortunately, there is currently no effective preventive or targeted treatment for pathologic condition. The rapid evolution of omics technology (genomics, epigenomics, transcriptomics, proteomics and metabolomics) has provided a novel approach for elucidation of pathophysiologic mechanisms in general and those associated with VC specifically. Here, we review articles published over the last twenty years and focus on the current state, challenges, limitations and future of omics in VC research and clinical practice. Highlighting potential targets based on omics technology will improve our understanding of this pathologic condition and assist in the development of potential treatment options for VC related disease.

Omics research in vascular calcification

Vascular calcification (VC), the pathological process of hydroxyapatite mineral deposition in the vascular system, is closely associated with aging, atherosclerotic plaque formation, cardiovascular disease (CVD) and diabetes mellitus (DM). Studies have shown that VC is related to cellular phenotypic changes, extracellular vesicles, disordered calcium phosphate homeostasis and an imbalance between inducers and inhibitors of VC. Unfortunately, there is currently no effective preventive or targeted treatment for this disorder. Recently, the evolution of omics technology (genomics, epigenomics, transcriptomics, proteomics and metabolomics) has paved the way for elucidation of complex biochemical processes and, as such, may provide new insight on VC. Accordingly, we conducted a review of articles published over the last twenty years and herein focus on current and future potential of omics technology in clarifying mechanisms of this disease process. Identification of new biomarkers will provide additional tools in characterizing this pathology and will further assist in the development of potential therapeutic targets.

PTH/PTHrP Receptor Signaling Restricts Arterial Fibrosis in Diabetic LDLR-/- Mice by Inhibiting Myocardin-Related Transcription Factor Relays

RATIONALE

The PTH1R (PTH [parathyroid hormone]/PTHrP [PTH-related protein] receptor) is expressed in vascular smooth muscle (VSM) and increased VSM PTH1R signaling mitigates diet-induced arteriosclerosis in LDLR-/- mice.

OBJECTIVE

To study the impact of VSM PTH1R deficiency, we generated mice SM22-Cre:PTH1R(fl/fl);LDLR-/- mice (PTH1R-VKO) and Cre-negative controls.

METHODS AND RESULTS

Immunofluorescence and Western blot confirmed PTH1R expression in arterial VSM that was reduced by Cre-mediated knockout. PTH1R-VKO cohorts exhibited increased aortic collagen accumulation in vivo, and VSM cultures from PTH1R-VKO mice elaborated more collagen (2.5-fold; P=0.01) with elevated Col3a1 and Col1a1 expression. To better understand these profibrotic responses, we performed mass spectrometry on nuclear proteins extracted from Cre-negative controls and PTH1R-VKO VSM. PTH1R deficiency reduced Gata6 but upregulated the MADS (MCM1, Agamous, Deficiens, and Srf DNA-binding domain)-box transcriptional co-regulator, Mkl-1 (megakaryoblastic leukemia [translocation] 1). Co-transfection assays (Col3a1 promoter-luciferase reporter) confirmed PTH1R-mediated inhibition and Mkl-1-mediated activation of Col3a1 transcription. Regulation mapped to a conserved hybrid CT(A/T)6GG MADS-box cognate in the Col3a1 promoter. Mutations of C/G in this motif markedly reduced Col3a1 transcriptional regulation by PTH1R and Mkl-1. Upregulation of Col3a1 and Col1a1 in PTH1R-VKO VSM was inhibited by small interfering RNA targeting Mkl1 and by treatment with the Mkl-1 antagonist CCG1423 or the Rock (Rho-associated coiled-coil containing protein kinase)-2 inhibitor KD025. Chromatin precipitation demonstrated that VSM PTH1R deficiency increased Mkl-1 binding to Col3a1 and Col1a1, but not TNF, promoters. Proteomic studies of plasma extracellular vesicles and VSM from PTH1R-VKO mice identified C1r (complement component 1, r) and C1s (complement component 1, s), complement proteins involved in vascular collagen metabolism, as potential biomarkers. VSM C1r protein and C1r message were increased with PTH1R deficiency, mediated by Mkl-1-dependent transcription and inhibited by CCG1423 or KD025.

CONCLUSIONS

PTH1R signaling restricts collagen production in the VSM lineage, in part, via Mkl-1 regulatory circuits that control collagen gene transcription. Strategies that maintain homeostatic VSM PTH1R signaling, as reflected in extracellular vesicle biomarkers of VSM PTH1R/Mkl-1 action, may help mitigate arteriosclerosis and vascular fibrosis.

Foot-and-Mouth Disease Virus 3A Protein Causes Upregulation of Autophagy-Related Protein LRRC25 To Inhibit the G3BP1-Mediated RIG-Like Helicase-Signaling Pathway

We show that foot-and-mouth disease virus (FMDV) 3A inhibits retinoic acid-inducible gene I (RIG-I)-like helicase signaling by degrading G3BP1 protein. Furthermore, FMDV 3A reduces G3BP1 by upregulating the expression of autophagy-related protein LRRC25. Additionally, other picornavirus 3A proteins, such as Seneca Valley virus (SVV) 3A, enterovirus 71 (EV71) 3A, and encephalomyocarditis virus (EMCV) 3A, also degrade G3BP1 by upregulating LRRC25 expression. This study will help us improve the design of current vaccines and aid the development of novel control strategies to combat FMD.

Foot-and-mouth disease virus (FMDV) is one of the most notorious pathogens in the global livestock industry. To establish an infection, FMDV needs to counteract host antiviral responses. Several studies have shown how FMDV suppresses the type I interferon (IFN) response; however, whether FMDV modulates the integrated autophagy and innate immunity remains largely unknown. Here, the porcine Ras-GAP SH3-binding protein 1 (G3BP1) was shown to promote the retinoic acid-inducible gene I (RIG-I)-like helicase (RLH) signaling by upregulating the expression of RIG-I and melanoma differentiation-associated gene 5 (MDA5). FMDV nonstructural protein 3A interacted with G3BP1 to inhibit G3BP1 expression and G3BP1-mediated RLH signaling by upregulating the expression of autophagy-related protein LRRC25. In addition, 3A proteins of other picornaviruses, including Seneca Valley virus (SVV) 3A, enterovirus 71 (EV71) 3A, and encephalomyocarditis virus (EMCV) 3A, also showed similar actions. Taking the data together, we elucidated, for the first time, a novel mechanism by which FMDV has evolved to inhibit IFN signaling and counteract host innate antiviral responses by autophagy.

IMPORTANCE We show that foot-and-mouth disease virus (FMDV) 3A inhibits retinoic acid-inducible gene I (RIG-I)-like helicase signaling by degrading G3BP1 protein. Furthermore, FMDV 3A reduces G3BP1 by upregulating the expression of autophagy-related protein LRRC25. Additionally, other picornavirus 3A proteins, such as Seneca Valley virus (SVV) 3A, enterovirus 71 (EV71) 3A, and encephalomyocarditis virus (EMCV) 3A, also degrade G3BP1 by upregulating LRRC25 expression. This study will help us improve the design of current vaccines and aid the development of novel control strategies to combat FMD.

The Epigenetic Landscape of Vascular Calcification: An Integrative Perspective

Vascular calcification (VC) is an important complication among patients of advanced age, those with chronic kidney disease, and those with diabetes mellitus. The pathophysiology of VC encompasses passive occurrence of physico-chemical calcium deposition, active cellular secretion of osteoid matrix upon exposure to metabolically noxious stimuli, or a variable combination of both processes. Epigenetic alterations have been shown to participate in this complex environment, through mechanisms including DNA methylation, non-coding RNAs, histone modifications, and chromatin changes. Despite such importance, existing reviews fail to provide a comprehensive view of all relevant reports addressing epigenetic processes in VC, and cross-talk between different epigenetic machineries is rarely examined. We conducted a systematic review based on PUBMED and MEDLINE databases up to 30 September 2019, to identify clinical, translational, and experimental reports addressing epigenetic processes in VC; we retrieved 66 original studies, among which 60.6% looked into the pathogenic role of non-coding RNA, followed by DNA methylation (12.1%), histone modification (9.1%), and chromatin changes (4.5%). Nine (13.6%) reports examined the discrepancy of epigenetic signatures between subjects or tissues with and without VC, supporting their applicability as biomarkers. Assisted by bioinformatic analyses blending in each epigenetic component, we discovered prominent interactions between microRNAs, DNA methylation, and histone modification regarding potential influences on VC risk.

Interactive and Multifactorial Mechanisms of Calcific Vascular and Valvular Disease

Calcific vascular and valvular disease (CVVD) is widespread and has major health consequences. Although coronary artery calcification has long been associated with hyperlipidemia and increased mortality, recent evidence suggests that its progression is increased in association with cholesterol-lowering HMG-CoA reductase inhibitors ('statins') and long-term, high-intensity exercise. A nationwide trial showed no cardiovascular benefit of vitamin D supplements. Controversy remains as to whether calcium deposits in plaque promote or prevent plaque rupture. CVVD appears to occur through mechanisms similar to those of intramembranous, endochondral, and osteophytic skeletal bone formation. New evidence implicates autotaxin, endothelial-mesenchymal transformation, and microRNA and long non-coding RNA (lncRNA) as novel regulatory factors. New therapeutic options are being developed.

The stress granule protein G3BP1 binds viral dsRNA and RIG-I to enhance interferon-β response

RIG-I senses viral RNA in the cytosol and initiates host innate immune response by triggering the production of type 1 interferon. A recent RNAi knockdown screen yielded close to hundred host genes whose products affected viral RNA-induced IFN-β production and highlighted the complexity of the antiviral response. The stress granule protein G3BP1, known to arrest mRNA translation, was identified as a regulator of RIG-I-induced IFN-β production. How G3BP1 functions in RIG-I signaling is not known, however. Here, we overexpress G3BP1 with RIG-I in HEK293T cells and found that G3BP1 significantly enhances RIG-I-induced ifn-b mRNA synthesis. More importantly, we demonstrate that G3BP1 binds RIG-I and that this interaction involves the C-terminal RGG domain of G3BP1. Confocal microscopy studies also show G3BP1 co-localization with RIG-I and with infecting vesicular stomatitis virus in Cos-7 cells. Interestingly, immunoprecipitation studies using biotin-labeled viral dsRNA or poly(I·C) and cell lysate-derived or in vitro translated G3BP1 indicated that G3BP1 could directly bind these substrates and again via its RGG domain. Computational modeling further revealed a juxtaposed interaction between G3BP1 RGG and RIG-I RNA-binding domains. Together, our data reveal G3BP1 as a critical component of RIG-I signaling and possibly acting as a co-sensor to promote RIG-I recognition of pathogenic RNA.

Urine proteome changes associated with autonomic regulation of heart rate in cosmonauts

Background

The strategy of adaptation of the human body in microgravity is largely associated with the plasticity of cardiovascular system regulatory mechanisms. During long-term space flights the changes in the stroke volume of the heart are observed, the heart rate decreases, the phase structure of cardiac cycle is readjusted The purpose of this work was to clarify urine proteome changes associated with the initial condition of the heart rate autonomic regulation mechanisms in cosmonauts who have participated in long space missions. Urine proteome of each cosmonaut was analyzed before and after space flight, depending on the initial parameters characterizing the regulatory mechanisms of the cardiovascular system.

Results

The proteins cadherin-13, mucin-1, alpha-1 of collagen subunit type VI (COL6A1), hemisentin-1, semenogelin-2, SH3 domain-binding protein, transthyretin and serine proteases inhibitors realize a homeostatic role in individuals with different initial type of the cardiovascular system regulation. The role of significantly changed urine proteins in the cardiovascular homeostasis maintenance is associated with complex processes of atherogenesis, neoangiogenesis, activation of calcium channels, changes in cell adhesion and transmembrane properties, changes in extracellular matrix, participation in protection from oxidative stress and leveling the effects of hypoxia. Therefore, the concentrations of these proteins significantly differ between groups with dominant parasympathetic and sympathetic influences.

Conclusion

The space flight induced urine proteome changes are significantly different in the groups identified by heart rate autonomic regulation peculiarities before space flight. All these proteins regulate the associated biological processes which affect the stiffness of the vascular wall, blood pressure level, the severity of atherosclerotic changes, the rate and degree of age-related involution of elastin and fibulin, age-related increase in collagen stiffness, genetically determined features of elastin fibers. The increased vascular rigidity (including the aorta) and of myocardium may be regarded as a universal response to various extreme factors. Significant differences in the semi-quantitative analysis of signal proteins between groups with different types of autonomic regulation are explained by a common goal: to ensure optimal adaptation regardless of age and of the genetically determined type of responses to the extreme environmental factors effects.

Electronic supplementary material

The online version of this article (10.1186/s12918-019-0688-9) contains supplementary material, which is available to authorized users.

Inhibiting Arginine Methylation as a Tool to Investigate Cross-Talk with Methylation and Acetylation Post-Translational Modifications in a Glioblastoma Cell Line

Glioblastomas (GBM) are the most common grade 4 brain tumours; patients have very poor prognosis with an average survival of 15 months after diagnosis. Novel research lines have begun to explore aberrant protein arginine methylation (ArgMe) as a possible therapeutic target in GBM and ArgMe inhibitors are currently in clinical trials. Enzymes known as protein arginine methyltransferases (PRMT1-9) can lead to mono- or di-ArgMe, and in the latter case symmetric or asymmetric dimethylation (SDMA and ADMA, respectively). Using the most common GBM cell line, we have profiled the expression of PRMTs, used ArgMe inhibitors as tools to investigate post-translational modifications cross-talk and measured the effect of ArgMe inhibitors on cell viability. We have identified novel SDMA events upon inhibition of ADMA in GBM cells and spheroids. We have observed cross-talk between ADMA and lysine acetylation in GBM cells and platelets. Treatment of GBM cells with furamidine, a PRMT1 inhibitor, reduces cell viability in 2D and 3D models. These data provide new molecular understanding of a disease with unmet clinical needs.

Rasputin a decade on and more promiscuous than ever? A review of G3BPs

Ras-GTPase-activating protein (SH3 domain)-binding proteins (G3BPs, also known as Rasputin) are a family of RNA binding proteins that regulate gene expression in response to environmental stresses by controlling mRNA stability and translation. G3BPs appear to facilitate this activity through their role in stress granules for which they are considered a core component, however, it should be noted that not all stress granules contain G3BPs and this appears to be contextual depending on the environmental stress and the cell type. Although the role of G3BPs in stress granules appears to be one of its major roles, data also strongly suggests that they interact with mRNAs outside of stress granules to regulate gene expression. G3BPs have been implicated in several diseases including cancer progression, invasion, and metastasis as well as virus survival. There is now a body of evidence that suggests targeting of G3BPs could be explored as a form of cancer therapeutic. This review discusses the important discoveries and advancements made in the field of G3BPs biology over the last two decades including their roles in RNA stability, translational control of cellular transcripts, stress granule formation, cancer progression and its interactions with viruses during infection. An emerging theme for G3BPs is their ability to regulate gene expression in response to environmental stimuli, disease progression and virus infection making it an intriguing target for disease therapies.

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Triage of many cellular mRNA occurs via stress granules in a G3BP-dependant manner.

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G3BPs control intra cellular responses to viral infection.

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Transcript stability, degradation and translation are controlled by G3BPs.

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G3BPs can control cancer progression.