The Role of Protein SUMOylation in the Pathogenesis of Atherosclerosis

Unravelling the molecular interplay: SUMOylation, PML nuclear bodies and vascular cell activity in health and disease

In the seemingly well-researched field of vascular research, there are still many underestimated factors and molecular mechanisms. In recent years, SUMOylation has become increasingly important. SUMOylation is a post-translational modification in which small ubiquitin-related modifiers (SUMO) are covalently attached to target proteins. Sites where these SUMO modification processes take place in the cell nucleus are PML nuclear bodies (PML-NBs) - multiprotein complexes with their essential main component and organizer, the PML protein. PML and SUMO, either alone or as partners, influence a variety of cellular processes, including regulation of transcription, senescence, DNA damage response and defence against microorganisms, and are involved in innate immunity and inflammatory responses. They also play an important role in maintaining homeostasis in the vascular system and in pathological processes leading to the development and progression of cardiovascular diseases. This review summarizes information about the function of SUMO(ylation) and PML(-NBs) in the human vasculature from angiogenesis to disease and highlights their clinical potential as drug targets.

The complex landscape of intracellular signalling in protein modification under hyperglycaemic stress leading to metabolic disorders

Hyperglycaemia is a life-threatening risk factor that occurs in both chronic and acute phases and has been linked to causing injury to many organs. Protein modification was triggered by hyperglycaemic stress, which resulted in pathogenic alterations such as impaired cellular function and tissue damage. Dysregulation in cellular function increases the condition associated with metabolic disorders, including cardiovascular diseases, nephropathy, retinopathy, and neuropathy. Hyperglycaemic stress also increases the proliferation of cancer cells. The major areas of experimental biomedical research have focused on the underlying mechanisms involved in the cellular signalling systems involved in diabetes-associated chronic hyperglycaemia. Reactive oxygen species and oxidative stress generated by hyperglycaemia modify many intracellular signalling pathways that result in insulin resistance and β-cell function degradation. The dysregulation of post translational modification in β cells is clinically associated with the development of diabetes mellitus and its associated diseases. This review will discuss the effect of hyperglycaemic stress on protein modification and the cellular signalling involved in it. The focus will be on the significant molecular changes associated with severe metabolic disorders.

Potential diagnostic markers shared between non-alcoholic fatty liver disease and atherosclerosis determined by machine learning and bioinformatic analysis

Background

Evidence indicates that chronic non-alcoholic fatty liver disease (NAFLD) can increase the risk of atherosclerosis (AS), but the underlying mechanism remains unclear.

Objective

This study is intended for confirming key genes shared between NAFLD and AS, and their clinical diagnostic value to establish a foundation for searching novel therapeutic targets.

Methods

We downloaded the Gene Expression Omnibus (GEO) datasets, GSE48452 and GSE89632 for NAFLD and GSE100927, GSE40231 and GSE28829 for AS. The progression of NAFLD co-expression gene modules were recognized via weighted gene co-expression network analysis (WGCNA). We screened for differentially expressed genes (DEGs) associated with AS and identified common genes associated with NAFLD and AS using Venn diagrams. We investigated the most significant core genes between NAFLD and AS using machine learning algorithms. We then constructed a diagnostic model by creating a nomogram and evaluating its performance using ROC curves. Furthermore, the CIBERSORT algorithm was utilized to explore the immune cell infiltration between the two diseases, and evaluate the relationship between diagnostic genes and immune cells.

Results

The WGCNA findings associated 1,129 key genes with NAFLD, and the difference analysis results identified 625 DEGs in AS, and 47 genes that were common to both diseases. We screened the core RPS6KA1 and SERPINA3 genes associated with NAFLD and AS using three machine learning algorithms. A nomogram and ROC curves demonstrated that these genes had great clinical meaning. We found differential expression of RPS6KA1 in patients with steatosis and NASH, and of SERPINA3 only in those with NASH compared with normal individuals. Immune infiltration findings revealed that macrophage and mast cell infiltration play important roles in the development of NAFLD and AS. Notably, SERPINA3 correlated negatively, whereas RPS6KA1 correlated positively with macrophages and mast cells.

Conclusion

We identified RPS6KA1 and SERPINA3 as potential diagnostic markers for NAFLD and AS. The most promising marker for a diagnosis of NAFLD and AS might be RPS6KA1, whereas SERPINA3 is the most closely related gene for NASH and AS. We believe that further exploration of these core genes will reveal the etiology and a pathological relationship between NAFLD and AS.

Protective effect of SERCA2a-SUMOylation by SUMO-1 on diabetes-induced atherosclerosis and aortic vascular injury

Diabetes is a major risk factor for cardiovascular disease. However, the exact mechanism by which diabetes contributes to vascular damage is not fully understood. The aim of this study was to investigate the role of SUMO-1 mediated SERCA2a SUMOylation in the development of atherosclerotic vascular injury associated with diabetes mellitus. ApoE-/- mice were treated with streptozotocin (STZ) injection combined with high-fat feeding to simulate diabetic atherosclerosis and vascular injury. Human aortic vascular smooth muscle cells (HAVSMCs) were treated with high glucose (HG, 33.3 mM) and palmitic acid (PA, 200 µM) for 24 h to mimic a model of diabetes-induced vascular injury in vitro. Aortic vascular function, phenotypic conversion, migration, proliferation, intracellular Ca2+ concentration, the levels of small ubiquitin-like modifier type 1 (SUMO1), SERCA2a and SUMOylated SERCA2a were detected. Diabetes-induced atherosclerotic mice presented obvious atherosclerotic plaques and vascular injury, companied by significantly lower levels of SUMO1 and SERCA2a in aorta. HG and PA treatment in HAVSMCs reduced the expressions of SUMO1, SERCA2a and SUMOylated SERCA2a, facilitated the HAVSMCs phenotypic transformation, proliferation and migration, attenuated the Ca2+ transport, and increased the resting intracellular Ca2+ concentration. We also confirmed that SUMO1 directly bound to SERCA2a in HAVSMCs. Overexpression of SUMO1 restored the function and phenotypic contractile ability of HAVSMCs by upregulating SERCA2a SUMOylation, thereby alleviating HG and PA-induced vascular injury. These observations suggest an essential role of SUMO1 to protect diabetes-induced atherosclerosis and aortic vascular injury by the regulation of SERCA2a-SUMOylation and calcium homeostasis.

Deficiency of protein inhibitor of activated STAT3 exacerbates atherosclerosis by modulating VSMC phenotypic switching

BACKGROUND AND AIMS

Phenotypic switching of vascular smooth muscle cells (VSMCs) plays an essential role in the development of atherosclerosis. Protein inhibitor of activated STAT (Pias) regulates VSMCs phenotype via acting as sumo E3 ligase to promote protein sumoylation. Our previous study indicated that Pias3 expression decreased in atherosclerotic lesions. Therefore, this study aimed to explore the role of Pias3 on VSMCs phenotype switching during atherosclerosis.

METHODS

ApoE-/- and ApoE-/-Pias3-/- double-deficient mice were fed with high-fat/high-cholesterol diet to induce atherosclerosis. Aorta tissues and primary VSMCs were collected to assess plaque formation and VSMCs phenotype. In vitro, Pias3 was overexpressed in A7r5, a VSMCs cell line, by transfection with Pias3 plasmid. Real-time quantitative PCR, immunoblotting, immunoprecipitation, were used to analyze the effect of Pias3 on VSMCs phenotypic switching.

RESULTS

Pias3 deficiency significantly exacerbated atherosclerotic plaque formation and promoted VSMCs phenotypic switching to a synthetic state within lesion. In vitro, overexpressing Pias3 in VSMCs increased the expression of contractile markers (myosin heavy chain 11, calponin 1), while it decreased the level of synthetic marker (vimentin). Additionally, Pias3 overexpression blocked PDGF-BB-induced VSMCs proliferation and migration. Immunoprecipitation and mass spectrometry results showed that Pias3 enhanced sumoylation and ubiquitination of vimentin, and shortened its half-life. Moreover, the ubiquitination level of vimentin was impaired by 2-D08, a sumoylation inhibitor. This suggests that Pias3 might accelerate the ubiquitination-degradation of vimentin by promoting its sumoylation.

CONCLUSIONS

These results indicate that Pias3 might ameliorate atherosclerosis progression by suppressing VSMCs phenotypic switching and reducing vimentin protein stability.

Proteomics Studies Suggest That Nitric Oxide Donor Furoxans Inhibit In Vitro Vascular Smooth Muscle Cell Proliferation by Nitric Oxide-Independent Mechanisms

Physiologically, smooth muscle cells (SMC) and nitric oxide (NO) produced by endothelial cells strictly cooperate to maintain vasal homeostasis. In atherosclerosis, where this equilibrium is altered, molecules providing exogenous NO and able to inhibit SMC proliferation may represent valuable antiatherosclerotic agents. Searching for dual antiproliferative and NO-donor molecules, we found that furoxans significantly decreased SMC proliferation in vitro, albeit with different potencies. We therefore assessed whether this property is dependent on their thiol-induced ring opening. Indeed, while furazans (analogues unable to release NO) are not effective, furoxans' inhibitory potency parallels with the electron-attractor capacity of the group in 3 of the ring, making this effect tunable. To demonstrate whether their specific block on G1-S phase could be NO-dependent, we supplemented SMCs with furoxans and inhibitors of GMP- and/or of the polyamine pathway, which regulate NO-induced SMC proliferation, but they failed in preventing the antiproliferative effect. To find the real mechanism of this property, our proteomics studies revealed that eleven cellular proteins (with SUMO1 being central) and networks involved in cell homeostasis/proliferation are modulated by furoxans, probably by interaction with adducts generated after degradation. Altogether, thanks to their dual effect and pharmacological flexibility, furoxans may be evaluated in the future as antiatherosclerotic molecules.

Possible molecular mechanisms underlying the development of atherosclerosis in cancer survivors

Cancer survivors undergone treatment face an increased risk of developing atherosclerotic cardiovascular disease (CVD), yet the underlying mechanisms remain elusive. Recent studies have revealed that chemotherapy can drive senescent cancer cells to acquire a proliferative phenotype known as senescence-associated stemness (SAS). These SAS cells exhibit enhanced growth and resistance to cancer treatment, thereby contributing to disease progression. Endothelial cell (EC) senescence has been implicated in atherosclerosis and cancer, including among cancer survivors. Treatment modalities for cancer can induce EC senescence, leading to the development of SAS phenotype and subsequent atherosclerosis in cancer survivors. Consequently, targeting senescent ECs displaying the SAS phenotype hold promise as a therapeutic approach for managing atherosclerotic CVD in this population. This review aims to provide a mechanistic understanding of SAS induction in ECs and its contribution to atherosclerosis among cancer survivors. We delve into the mechanisms underlying EC senescence in response to disturbed flow and ionizing radiation, which play pivotal role in atherosclerosis and cancer. Key pathways, including p90RSK/TERF2IP, TGFβR1/SMAD, and BH4 signaling are explored as potential targets for cancer treatment. By comprehending the similarities and distinctions between different types of senescence and the associated pathways, we can pave the way for targeted interventions aim at enhancing the cardiovascular health of this vulnerable population. The insights gained from this review may facilitate the development of novel therapeutic strategies for managing atherosclerotic CVD in cancer survivors.

The role of SUMOylation in the neurovascular dysfunction after acquired brain injury

Acquired brain injury (ABI) is the most common disease of the nervous system, involving complex pathological processes, which often leads to a series of nervous system disorders. The structural destruction and dysfunction of the Neurovascular Unit (NVU) are prominent features of ABI. Therefore, understanding the molecular mechanism underlying NVU destruction and its reconstruction is the key to the treatment of ABI. SUMOylation is a protein post-translational modification (PTM), which can degrade and stabilize the substrate dynamically, thus playing an important role in regulating protein expression and biological signal transduction. Understanding the regulatory mechanism of SUMOylation can clarify the molecular mechanism of the occurrence and development of neurovascular dysfunction after ABI and is expected to provide a theoretical basis for the development of potential treatment strategies. This article reviews the role of SUMOylation in vascular events related to ABI, including NVU dysfunction and vascular remodeling, and puts forward therapeutic prospects.

SUMOylation targeting mitophagy in cardiovascular diseases

Small ubiquitin-like modifier (SUMO) plays a key regulatory role in cardiovascular diseases, such as cardiac hypertrophy, hypertension, atherosclerosis, and cardiac ischemia-reperfusion injury. As a multifunctional posttranslational modification molecule in eukaryotic cells, SUMOylation is essentially associated with the regulation of mitochondrial dynamics, especially mitophagy, which is involved in the progression and development of cardiovascular diseases. SUMOylation targeting mitochondrial-associated proteins is admittedly considered to regulate mitophagy activation and mitochondrial functions and dynamics, including mitochondrial fusion and fission. SUMOylation triggers mitochondrial fusion to promote mitochondrial dysfunction by modifying Fis1, OPA1, MFN1/2, and DRP1. The interaction between SUMO and DRP1 induces SUMOylation and inhibits lysosomal degradation of DRP1, which is further involved in the regulation of mitochondrial fission. Both SUMOylation and deSUMOylation contribute to the initiation and activation of mitophagy by regulating the conjugation of MFN1/2 SERCA2a, HIF1α, and PINK1. SUMOylation mediated by the SUMO molecule has attracted much attention due to its dual roles in the development of cardiovascular diseases. In this review, we systemically summarize the current understanding underlying the expression, regulation, and structure of SUMO molecules; explore the biochemical functions of SUMOylation in the initiation and activation of mitophagy; discuss the biological roles and mechanisms of SUMOylation in cardiovascular diseases; and further provide a wider explanation of SUMOylation and deSUMOylation research to provide a possible therapeutic strategy for cardiovascular diseases. Considering the precise functions and exact mechanisms of SUMOylation in mitochondrial dysfunction and mitophagy will provide evidence for future experimental research and may serve as an effective approach in the development of novel therapeutic strategies for cardiovascular diseases. Regulation and effect of SUMOylation in cardiovascular diseases via mitophagy. SUMOylation is involved in multiple cardiovascular diseases, including cardiac hypertrophy, hypertension, atherosclerosis, and cardiac ischemia-reperfusion injury. Since it is expressed in multiple cells associated with cardiovascular disease, SUMOylation can be regulated by numerous ligases, including the SENP family proteins PIAS1, PIASy/4, UBC9, and MAPL. SUMOylation regulates the activation and degradation of PINK1, SERCA2a, PPARγ, ERK5, and DRP1 to mediate mitochondrial dynamics, especially mitophagy activation. Mitophagy activation regulated by SUMOylation further promotes or inhibits ventricular diastolic dysfunction, perfusion injury, ventricular remodelling and ventricular noncompaction, which contribute to the development of cardiovascular diseases.

The role of p53 in the alternation of vascular functions

Ageing is a risk factor for many degenerative diseases. Cardiovascular diseases (CVDs) are usually big burdens for elderly, caregivers and the health system. During the aging process, normal functions of vascular cells and tissue progressively lost and eventually develop vascular diseases. Endothelial dysfunction, reduced bioavailability of endothelium-derived nitric oxide are usual phenomena observed in patients with cardiovascular diseases. Myriad of studies have been done to investigate to delay the vascular dysfunction or improve the vascular function to prolong the aging process. Tumor suppressor gene p53, also a transcription factor, act as a gatekeeper to regulate a number of genes to maintain normal cell function including but not limited to cell proliferation, cell apoptosis. p53 also crosstalk with other key transcription factors like hypoxia-inducible factor 1 alpha that contribute to the progression of cardiovascular diseases. Therefore, in recent three decades, p53 has drawn scientists’ attention on its effects in vascular function. Though the role of tumor suppressor gene p53 is still not clear in vascular function, it is found to play regulatory roles and may involve in vascular remodeling, atherosclerosis or pulmonary hypertension. p53 may have a divergent role in endothelial and vascular muscle cells in those conditions. In this review, we describe the different effects of p53 in cardiovascular physiology. Further studies on the effects of endothelial cell-specific p53 deficiency on atherosclerotic plaque formation in common animal models are required before the therapeutic potential can be realized.

Bidirectional regulation between AP-1 and SUMO genes modulates inflammatory signalling during Salmonella infection

Post-translational modifications (PTMs), such as SUMOylation, are known to modulate fundamental processes of a cell. Infectious agents such as Salmonella Typhimurium (STm) that causes gastroenteritis, utilizes PTM mechanism SUMOylation to highjack host cell. STm suppresses host SUMO-pathway genes Ubc9 and PIAS1 to perturb SUMOylation for an efficient infection. In the present study, the regulation of SUMO-pathway genes during STm infection was investigated. A direct binding of c-Fos, a component of AP-1 (Activator Protein-1), to promoters of both UBC9 and PIAS1 was observed. Experimental perturbation of c-Fos led to changes in expression of both Ubc9 and PIAS1. STm infection of fibroblasts with SUMOylation deficient c-Fos (c-FOS-KOSUMO-def-FOS) resulted in uncontrolled activation of target genes, resulting in massive immune activation. Infection of c-FOS-KOSUMO-def-FOS cells favored STm replication, indicating misdirected immune mechanisms. Finally, chromatin Immuno-precipitation assays confirmed a context dependent differential binding and release of AP-1 to/from target genes due to its Phosphorylation and SUMOylation respectively. Overall, our data point towards existence of a bidirectional cross-talk between c-Fos and the SUMO pathway and highlighting its importance in AP-1 function relevant to STm infection and beyond.

Association of Cardiovascular Health Through Young Adulthood With Genome-Wide DNA Methylation Patterns in Midlife: The CARDIA Study

BACKGROUND

Cardiovascular health (CVH) from young adulthood is strongly associated with an individual's future risk of cardiovascular disease (CVD) and total mortality. Defining epigenomic biomarkers of lifelong CVH exposure and understanding their roles in CVD development may help develop preventive and therapeutic strategies for CVD.

METHODS

In 1085 CARDIA study (Coronary Artery Risk Development in Young Adults) participants, we defined a clinical cumulative CVH score that combines body mass index, blood pressure, total cholesterol, and fasting glucose measured longitudinally from young adulthood through middle age over 20 years (mean age, 25-45). Blood DNA methylation at >840 000 methylation markers was measured twice over 5 years (mean age, 40 and 45). Epigenome-wide association analyses on the cumulative CVH score were performed in CARDIA and compared in the FHS (Framingham Heart Study). We used penalized regression to build a methylation-based risk score to evaluate the risk of incident coronary artery calcification and clinical CVD events.

RESULTS

We identified 45 methylation markers associated with cumulative CVH at false discovery rate <0.01 (P=4.7E-7-5.8E-17) in CARDIA and replicated in FHS. These associations were more pronounced with methylation measured at an older age. CPT1A, ABCG1, and SREBF1 appeared as the most prominent genes. The 45 methylation markers were mostly located in transcriptionally active chromatin and involved lipid metabolism, insulin secretion, and cytokine production pathways. Three methylation markers located in genes SARS1, SOCS3, and LINC-PINT statistically mediated 20.4% of the total effect between CVH and risk of incident coronary artery calcification. The methylation risk score added information and significantly (P=0.004) improved the discrimination capacity of coronary artery calcification status versus CVH score alone and showed association with risk of incident coronary artery calcification 5 to 10 years later independent of cumulative CVH score (odds ratio, 1.87; P=9.66E-09). The methylation risk score was also associated with incident clinical CVD in FHS (hazard ratio, 1.28; P=1.22E-05).

CONCLUSIONS

Cumulative CVH from young adulthood contributes to midlife epigenetic programming over time. Our findings demonstrate the role of epigenetic markers in response to CVH changes and highlight the potential of epigenomic markers for precision CVD prevention, and earlier detection of subclinical CVD, as well.

Role of Posttranslational Modifications of Proteins in Cardiovascular Disease

Cardiovascular disease (CVD) has become a leading cause of mortality and morbidity globally, making it an urgent concern. Although some studies have been performed on CVD, its molecular mechanism remains largely unknown for all types of CVD. However, recent in vivo and in vitro studies have successfully identified the important roles of posttranslational modifications (PTMs) in various diseases, including CVD. Protein modification, also known as PTMs, refers to the chemical modification of specific amino acid residues after protein biosynthesis, which is a key process that can influence the activity or expression level of proteins. Studies on PTMs have contributed directly to improving the therapeutic strategies for CVD. In this review, we examined recent progress on PTMs and highlighted their importance in both physiological and pathological conditions of the cardiovascular system. Overall, the findings of this review contribute to the understanding of PTMs and their potential roles in the treatment of CVD.

Signalling mechanisms and cellular functions of SUMO

Sumoylation is an essential post-translational modification that is catalysed by a small number of modifying enzymes but regulates thousands of target proteins in a dynamic manner. Small ubiquitin-like modifiers (SUMOs) can be attached to target proteins as one or more monomers or in the form of polymers of different types. Non-covalent readers recognize SUMO-modified proteins via SUMO interaction motifs. SUMO simultaneously modifies groups of functionally related proteins to regulate predominantly nuclear processes, including gene expression, the DNA damage response, RNA processing, cell cycle progression and proteostasis. Recent progress has increased our understanding of the cellular and pathophysiological roles of SUMO modifications, extending their functions to the regulation of immunity, pluripotency and nuclear body assembly in response to oxidative stress, which partly occurs through the recently characterized mechanism of liquid-liquid phase separation. Such progress in understanding the roles and regulation of sumoylation opens new avenues for the targeting of SUMO to treat disease, and indeed the first drug blocking sumoylation is currently under investigation in clinical trials as a possible anticancer agent.

Construction and validation of a two-gene signature based on SUMOylation regulatory genes in non-small cell lung cancer patients

BACKGROUND

Post-translational modification plays an important role in the occurrence and development of various tumors. However, few researches were focusing on the SUMOylation regulatory genes as tumor biomarkers to predict the survival for specific patients. Here, we constructed and validated a two-gene signature to predict the overall survival (OS) of non-small cell lung cancer (NSCLC) patients.

METHODS

The datasets analyzed in this study were downloaded from TCGA and GEO databases. The least absolute shrinkage and selection operator (LASSO) Cox regression was used to construct the two-gene signature. Gene set enrichment analysis (GSEA) and Gene Ontology (GO) was used to identify hub pathways associated with risk genes. The CCK-8 assay, cell cycle analysis, and transwell assay was used to validate the function of risk genes in NSCLC cell lines.

RESULTS

Firstly, most of the SUMOylation regulatory genes were highly expressed in various tumors through the R package 'limma' in the TCGA database. Secondly, our study found that the two gene signature constructed by LASSO regression analysis, as an independent prognostic factor, could predict the OS in both the TCGA training cohort and GEO validation cohorts (GSE68465, GSE37745, and GSE30219). Furthermore, functional enrichment analysis suggests that high-risk patients defined by the risk score system were associated with the malignant phenomenon, such as DNA replication, cell cycle regulation, p53 signaling pathway. Finally, the results of the CCK-8 assay, cell cycle analysis, and transwell assay demonstrated that the two risk genes, SAE1 and UBA2, could promote proliferation and migration in non-small cell lung cancer cells.

CONCLUSIONS

The two-gene signature constructed in our study could predict the OS and may provide valuable clinical guidance for the treatment of NSCLC patients.

Small-molecule inhibitors targeting small ubiquitin-like modifier pathway for the treatment of cancers and other diseases

SUMOylation is a key post-translational modification that involves the covalent attachment of small ubiquitin-like modifier (SUMO) to the lysine residues of target proteins. The well-balanced SUMOylation is essential for normal cellular behaviors, while disturbance of SUMOylation is associated with various cancers and other diseases. Herein, we summarize the structures and biological functions of proteins involved in the SUMOylation process, their dysregulation in human diseases, and the discovery of small-molecular inhibitors targeting this pathway. In addition, we highlight the emerging trends in this field.

Shared Molecular Mechanisms between Atherosclerosis and Periodontitis by Analyzing the Transcriptomic Alterations of Peripheral Blood Monocytes

OBJECTIVE

This study investigated the nature of shared transcriptomic alterations in PBMs from periodontitis and atherosclerosis to unravel molecular mechanisms underpinning their association.

METHODS

Gene expression data from PBMs from patients with periodontitis and those with atherosclerosis were each downloaded from the GEO database. Differentially expressed genes (DEGs) in periodontitis and atherosclerosis were identified through differential gene expression analysis. The disease-related known genes related to periodontitis and atherosclerosis each were downloaded from the DisGeNET database. A Venn diagram was constructed to identify crosstalk genes from four categories: DEGs expressed in periodontitis, periodontitis-related known genes, DEGs expressed in atherosclerosis, and atherosclerosis-related known genes. A weighted gene coexpression network analysis (WGCNA) was performed to identify significant coexpression modules, and then, coexpressed gene interaction networks belonging to each significant module were constructed to identify the core crosstalk genes.

RESULTS

Functional enrichment analysis of significant modules obtained by WGCNA analysis showed that several pathways might play the critical crosstalk role in linking both diseases, including bacterial invasion of epithelial cells, platelet activation, and Mitogen-Activated Protein Kinases (MAPK) signaling. By constructing the gene interaction network of significant modules, the core crosstalk genes in each module were identified and included: for GSE23746 dataset, RASGRP2 in the blue module and VAMP7 and SNX3 in the green module, as well as HMGB1 and SUMO1 in the turquoise module were identified; for GSE61490 dataset, SEC61G, PSMB2, SELPLG, and FIBP in the turquoise module were identified.

CONCLUSION

Exploration of available transcriptomic datasets revealed core crosstalk genes (RASGRP2, VAMP7, SNX3, HMGB1, SUMO1, SEC61G, PSMB2, SELPLG, and FIBP) and significant pathways (bacterial invasion of epithelial cells, platelet activation, and MAPK signaling) as top candidate molecular linkage mechanisms between atherosclerosis and periodontitis.

The Function of SUMOylation and Its Critical Roles in Cardiovascular Diseases and Potential Clinical Implications

Cardiovascular disease (CVD) is a common disease caused by many factors, including atherosclerosis, congenital heart disease, heart failure, and ischemic cardiomyopathy. CVD has been regarded as one of the most common diseases and has a severe impact on the life quality of patients. The main features of CVD include high morbidity and mortality, which seriously threaten human health. SUMO proteins covalently conjugate lysine residues with a large number of substrate proteins, and SUMOylation regulates the function of target proteins and participates in cellular activities. Under certain pathological conditions, SUMOylation of proteins related to cardiovascular development and function are greatly changed. Numerous studies have suggested that SUMOylation of substrates plays critical roles in normal cardiovascular development and function. We reviewed the research progress of SUMOylation in cardiovascular development and function, and the regulation of protein SUMOylation may be applied as a potential therapeutic strategy for CVD treatment.

Promyelocytic leukemia protein: an atherosclerosis suppressor protein?

As many as 70% of cells in atherosclerotic plaque are vascular smooth muscle cell (VSMC) in origin, and pathways and proteins which regulate VSMC migration, proliferation, and phenotype modulation represent novel targets for rational drug design to reduce atherosclerotic vascular disease. In this volume of Clinical Science, Karle et al. demonstrate that tumor suppressor, promyelocytic leukemia protein (PML) plays an important role in regulation of VSMC phenotype and response to inflammatory stimuli (Clin Sci (2021) 135(7), 887-905; DOI: 10.1042/CS20201399). This important work demonstrates that PML, previously unrecognized as a participant in development of atherosclerosis, may represent a novel target for anti-atherosclerotic therapeutic modalities.

Epigenetic reprogramming mechanisms of immunity during influenza A virus infection

This paper reviews epigenetic mechanisms by which influenza viruses affect cellular gene activity to control their life cycles, aiming to provide new insights into the complexity of functional interactions between viral and cellular factors, as well as to introduce novel targets for therapeutic intervention and vaccine development against influenza infections.

Promyelocytic leukemia protein promotes the phenotypic switch of smooth muscle cells in atherosclerotic plaques of human coronary arteries

Promyelocytic leukemia protein (PML) is a constitutive component of PML nuclear bodies (PML-NBs), which function as stress-regulated SUMOylation factories. Since PML can also act as a regulator of the inflammatory and fibroproliferative responses characteristic of atherosclerosis, we investigated whether PML is implicated in this disease. Immunoblotting, ELISA and immunohistochemistry showed a stronger expression of PML in segments of human atherosclerotic coronary arteries and sections compared with non-atherosclerotic ones. In particular, PML was concentrated in PML-NBs from α-smooth muscle actin (α-SMA)-immunoreactive cells in plaque areas. To identify possible functional consequences of PML-accumulation in this cell type, differentiated human coronary artery smooth muscle cells (dHCASMCs) were transfected with a vector containing the intact PML-gene. These PML-transfected dHCASMCs showed higher levels of small ubiquitin-like modifier (SUMO)-1-dependent SUMOylated proteins, but lower levels of markers for smooth muscle cell (SMC) differentiation and revealed more proliferation and migration activities than dHCASMCs transfected with the vector lacking a specific gene insert or with the vector containing a mutated PML-gene coding for a PML-form without SUMOylation activity. When dHCASMCs were incubated with different cytokines, higher PML-levels were observed only after interferon γ (IFN-γ) stimulation, while the expression of differentiation markers was lower. However, these phenotypic changes were not observed in dHCASMCs treated with small interfering RNA (siRNA) suppressing PML-expression prior to IFN-γ stimulation. Taken together, our results imply that PML is a previously unknown functional factor in the molecular cascades associated with the pathogenesis of atherosclerosis and is positioned in vascular SMCs (VSMCs) between upstream IFN-γ activation and downstream SUMOylation.

The Role of Posttranslational Modification and Mitochondrial Quality Control in Cardiovascular Diseases

Cardiovascular disease (CVD) is the leading cause of death in the world. The mechanism behind CVDs has been studied for decades; however, the pathogenesis is still controversial. Mitochondrial homeostasis plays an essential role in maintaining the normal function of the cardiovascular system. The alterations of any protein function in mitochondria may induce abnormal mitochondrial quality control and unexpected mitochondrial dysfunction, leading to CVDs. Posttranslational modifications (PTMs) affect protein function by reversibly changing their conformation. This review summarizes how common and novel PTMs influence the development of CVDs by regulating mitochondrial quality control. It provides not only ideas for future research on the mechanism of some types of CVDs but also ideas for CVD treatments with therapeutic potential.

SENP3 regulates high glucose-induced endothelial dysfunction via ROS dependent signaling

BACKGROUND

The current study aimed to explore the role of SENP3 in endothelial cell dysfunction in a high-glucose setting.

METHODS

The gene and protein expressions of SENP3 in high-glucose cultured HAECs were examined using quantitative PCR and western blotting. The effects of SENP3 on HAEC viability, apoptosis, migration, and endothelial-monocyte adhesion were evaluated in vitro by knockdown. Moreover, a mouse streptozotocin-induced type I diabetes model was established for SENP3 expression assessment. In addition, the effects of SENP3 on ROS-related signaling pathways were investigated in high-glucose cultured HAECs.

RESULTS

Significantly increased levels of SENP3 mRNA and protein were found in high-glucose cultured HAECs in a time-dependent manner. SENP3 knockdown reversed high glucose-induced HAEC viability, apoptosis, and migration reduction. SENP3 knockdown attenuated the high glucose-induced intercellular adhesion of THP-1 monocytic cells and HAECs via downregulation of ICAM-1 and VCAM-1 expression. Increased levels of SENP3, ICAM-1, and VCAM-1 expression were observed in the aorta tissue of mice with type I diabetes. Downregulation of SENP3 expression was observed in HAECs cultured with high glucose levels using the free radical scavenger N-acetyl-L-cysteine or NOX4 siRNA.

CONCLUSIONS

SENP3 was involved in high glucose-induced endothelial dysfunction, and ROS-dependent signaling served as the mechanism.

HOPS and p53: thick as thieves in life and death

The oncosuppressor protein p53 plays a major role in transcriptionally controlling the expression of a number of genes, which in turn regulates many functions in response to DNA damage, oncogene triggering, oxidative, and additional cell stresses. A developing area of interest in p53 is the studies related to its cytoplasmic function(s). Many investigations revealed the significant role of p53 in the cytoplasm, acting in a transcriptional-independent manner in important processes related to cell homeostasis such as; apoptosis, autophagy, metabolism control, drug, and oxidative stress response. The studies on cytoplasmic p53 have shown intricate mechanisms by which posttranslational modifications allow p53 to perform its cytoplasmic functions. A number of ubiquitins, deubiquitins, and small ubiquitin-like proteins, have a pivotal role in controlling cytoplasmic stability and localization. Recently, HOPS/TMUB1 a novel small ubiquitin-like protein has been described as a vital molecule stabilizing p53 half-life, directing it to the mitochondria and favoring p53-mediated apoptosis. Furthermore, HOPS/TMUB1 competing with importin-α lessens p53 nuclear localization, thereby increasing cytoplasmic concentration. HOPS/TMUB1 as p53 modifiers could be attractive candidates to elucidate apoptosis or other important transcriptional-independent functions which are key in cancer research in order to develop new therapeutic approaches.

SUMO proteins in the cardiovascular system: friend or foe?

Post-translational modifications (PTMs) are crucial for the adaptation of various signalling pathways to ensure cellular homeostasis and proper adaptation to stress. PTM is a covalent addition of a small chemical functional group such as a phosphate group (phosphorylation), methyl group (methylation), or acetyl group (acetylation); lipids like hydrophobic isoprene polymers (isoprenylation); sugars such as a glycosyl group (glycosylation); or even small peptides such as ubiquitin (ubiquitination), SUMO (SUMOylation), NEDD8 (neddylation), etc. SUMO modification changes the function and/or fate of the protein especially under stress conditions, and the consequences of this conjugation can be appreciated from development to diverse disease processes. The impact of SUMOylation in disease has not been monotonous, rather SUMO is found playing a role on both sides of the coin either facilitating or impeding disease progression. Several recent studies have implicated SUMO proteins as key regulators in various cardiovascular disorders. The focus of this review is thus to summarize the current knowledge on the role of the SUMO family in the pathophysiology of cardiovascular diseases.

Not So Slim Anymore-Evidence for the Role of SUMO in the Regulation of Lipid Metabolism

One of the basic building blocks of all life forms are lipids—biomolecules that dissolve in nonpolar organic solvents but not in water. Lipids have numerous structural, metabolic, and regulative functions in health and disease; thus, complex networks of enzymes coordinate the different compositions and functions of lipids with the physiology of the organism. One type of control on the activity of those enzymes is the conjugation of the Small Ubiquitin-like Modifier (SUMO) that in recent years has been identified as a critical regulator of many biological processes. In this review, I summarize the current knowledge about the role of SUMO in the regulation of lipid metabolism. In particular, I discuss (i) the role of SUMO in lipid metabolism of fungi and invertebrates; (ii) the function of SUMO as a regulator of lipid metabolism in mammals with emphasis on the two most well-characterized cases of SUMO regulation of lipid homeostasis. These include the effect of SUMO on the activity of two groups of master regulators of lipid metabolism—the Sterol Regulatory Element Binding Protein (SERBP) proteins and the family of nuclear receptors—and (iii) the role of SUMO as a regulator of lipid metabolism in arteriosclerosis, nonalcoholic fatty liver, cholestasis, and other lipid-related human diseases.