Ubc9 overexpression and SUMO1 deficiency blunt inflammation after intestinal ischemia/reperfusion

Pdia3 deficiency exacerbates intestinal injury by disrupting goblet and Paneth cell function during ischemia/reperfusion

Intestinal ischemia/reperfusion (I/R) injury is a severe medical condition associated with high mortality rates due to its disruption of intestinal homeostasis and impairment of mucosal defenses. The intestinal epithelium, particularly goblet and Paneth cells, plays a critical role in maintaining gut barrier integrity. Protein disulfide isomerase A3 (PDIA3) is involved in protein folding within intestinal epithelial cells (IECs) and has been linked to the stress response during I/R injury. This study aims to explore the role of PDIA3 in preserving intestinal integrity and immune function during I/R injury. Our study employed both human and mouse models to investigate PDIA3's expression and function. The correlation between PDIA3 expression and disease severity was analyzed using statistical tests, including Pearson's correlation coefficient. An intestinal I/R model was established in intestinal epithelium-specific conditional knockout mice lacking the Pdia3 gene. Single-cell RNA sequencing, immunohistochemistry, and transcriptomic analysis were used to assess PDIA3 expression in various intestinal cell types and to evaluate its role in epithelial differentiation and immune responses. PDIA3 was found to be highly expressed in healthy IECs, especially in goblet and Paneth cells. Its expression was reduced in patients with mesenteric artery ischemia and Pdia3-deficient mice, leading to severe intestinal damage, including impaired goblet and Paneth cell function, reduced antimicrobial peptide production, and altered gut microbiota. Treatment with recombinant defensin α1, an antimicrobial peptide secreted by Paneth cells, significantly alleviated the adverse effects of Pdia3 deficiency, restoring gut microbiota balance and reducing inflammation in the intestinal I/R injury mice. Taken together, our findings suggest that Pdia3 plays a vital role in maintaining intestinal barrier function and immune defense. Its deficiency exacerbates I/R-induced intestinal damage by impairing epithelial differentiation, mucus production, and antimicrobial peptide secretion. Targeting Pdia3 and associated pathways offers promising therapeutic strategies for mitigating I/R injury and restoring intestinal homeostasis.

SUMO2 rescues neuronal and glial cells from the toxicity of P301L Tau mutant

Introduction

Abnormal intracellular accumulation of Tau aggregates is a hallmark of Alzheimer's disease (AD) and other Tauopathies, such as Frontotemporal dementia (FTD). Tau deposits primarily affect neurons, but evidence indicates that glial cells may also be affected and contribute distinctively to disease progression. Cells can respond to toxic insults by orchestrating global changes in posttranslational modifications of their proteome. Previous studies suggest that SUMOylation, a posttranslational modification consisting of conjugation of SUMO (Small ubiquitin-like modifier) to target proteins, was decreased in the hippocampus of AD patients and in animal model of AD compared with controls. This decrease in SUMOylation was correlated with increased Tau pathology and cognitive decline. Other studies have reported increased levels of SUMO in AD brains. The goal of our study was to evaluate whether SUMO conjugation modifies the neurodegenerative disease pathology associated with the aggregation-prone mutant TauP301L, in neurons and in glial cells.

Methods

We used viral approaches to express mutant TauP301L and SUMO2 in the hippocampus of wild-type mice. We assessed Tau distribution by immunostaining and Tau aggregation by insolubility assays followed by western blotting. We assessed neuronal toxicity and performed cell count and shape descriptor analyses on astrocytes and microglial cells.

Results

We found that mutant TauP301L, when expressed exclusively in neurons, is toxic not only to neurons but also to glial cells, and that SUMO2 counteracts TauP301L toxicity in neurons as well as in glia.

Discussion

Our results uncover an endogenous neuroprotective mechanism, whereby SUMO2 conjugation reduces Tau neuropathology and protects against toxic effects of Tau in glial cells.

Vagal stimulation ameliorates murine colitis by regulating SUMOylation

Inflammatory bowel diseases (IBDs) are chronic debilitating conditions without cure, the etiologies of which are unknown, that shorten the lifespans of 7 million patients worldwide by nearly 10%. Here, we found that decreased autonomic parasympathetic tone resulted in increased IBD susceptibility and mortality in mouse models of disease. Conversely, vagal stimulation restored neuromodulation and ameliorated colitis by inhibiting the posttranslational modification SUMOylation through a mechanism independent of the canonical interleukin-10/α7 nicotinic cholinergic vagal pathway. Colonic biopsies from patients with IBDs and mouse models showed an increase in small ubiquitin-like modifier (SUMO)2 and SUMO3 during active disease. In global genetic knockout mouse models, the deletion of Sumo3 protected against development of colitis and delayed onset of disease, whereas deletion of Sumo1 halted the progression of colitis. Bone marrow transplants from Sumo1-knockout (KO) but not Sumo3-KO mice into wild-type mice conferred protection against development of colitis. Electric stimulation of the cervical vagus nerve before the induction of colitis inhibited SUMOylation and delayed the onset of colitis in Sumo1-KO mice and resulted in milder symptoms in Sumo3-KO mice. Treatment with TAK-981, a first-in-class inhibitor of the SUMO-activating enzyme, ameliorated disease in three murine models of IBD and reduced intestinal permeability and bacterial translocation in a severe model of the disease, suggesting the potential to reduce progression to sepsis. These results reveal a pathway of vagal neuromodulation that reprograms endogenous stress-adaptive responses through inhibition of SUMOylation and suggest SUMOylation as a therapeutic target for IBD.

Dexmedetomidine alleviates intestinal ischemia/reperfusion injury by modulating intestinal neuron autophagy and mitochondrial homeostasis via Nupr1 regulation

Intestinal ischemia/reperfusion injury (I/R) is a common yet challenging-to-treat condition, presenting a significant clinical challenge. This study aims to investigate the protective mechanisms of Dexmedetomidine (Dex) against I/R injury, with a particular focus on its role in regulating autophagy activity in intestinal neurons and maintaining mitochondrial homeostasis. Experimental findings demonstrate that Dex can mitigate intestinal damage induced by I/R through the modulation of autophagy activity and mitochondrial function in intestinal neurons by suppressing the expression of Nupr1. This discovery sheds light on a new molecular mechanism underlying the potential efficacy of Dex in treating intestinal I/R injury, offering valuable insights for clinical therapy.

SUMOylation at the crossroads of gut health: insights into physiology and pathology

SUMOylation, a post-translational modification involving the covalent attachment of small ubiquitin-like modifier (SUMO) proteins to target substrates, plays a pivotal role at the intersection of gut health and disease, influencing various aspects of intestinal physiology and pathology. This review provides a comprehensive examination of SUMOylation's diverse roles within the gut microenvironment. We examine its critical roles in maintaining epithelial barrier integrity, regulating immune responses, and mediating host-microbe interactions, thereby highlighting the complex molecular mechanisms that underpin gut homeostasis. Furthermore, we explore the impact of SUMOylation dysregulation in various intestinal disorders, including inflammatory bowel diseases and colorectal cancer, highlighting its implications as a potential diagnostic biomarker and therapeutic target. By integrating current research findings, this review offers valuable insights into the dynamic interplay between SUMOylation and gut health, paving the way for novel therapeutic strategies aimed at restoring intestinal equilibrium and combating associated pathologies.

E3 ligase TRIM65 alleviates intestinal ischemia/reperfusion injury through inhibition of TOX4-mediated apoptosis

Intestinal ischemia-reperfusion (II/R) injury is an urgent clinical disease with high incidence and mortality, and impaired intestinal barrier function caused by excessive apoptosis of intestinal cells is an important cause of its serious consequences. Tripartite motif-containing protein 65 (TRIM65) is an E3 ubiquitin ligase that is recently reported to suppress the inflammatory response and apoptosis. However, the biological function and regulation of TRIM65 in II/R injury are totally unknown. We found that TRIM65 was significantly decreased in hypoxia-reoxygenation (H/R) induced intestinal epithelial cells and II/R-induced intestine tissue. TRIM65 knockout mice markedly aggravated intestinal apoptosis and II/R injury. To explore the molecular mechanism of TRIM65 in exacerbating II/R-induced intestinal apoptosis and damage, thymocyte selection-associated high mobility group box factor 4 (TOX4) was screened out as a novel substrate of TRIM65 using the yeast two-hybrid system. TRIM65 binds directly to the N-terminal of TOX4 through its coiled-coil and SPRY structural domains. Immunofluorescence confocal microscopy showed that they can co-localize both in the cytoplasm and nucleus. Furthermore, TRIM65 mediated the K48 ubiquitination and degradation of TOX4 depending on its E3 ubiquitin ligase activity. In addition, TRIM65 inhibits H/R-induced intestinal epithelial apoptosis via TOX4. In summary, our results indicated that TRIM65 promotes ubiquitination and degradation of TOX4 to inhibit apoptosis in II/R. These findings provide a promising target for the clinical treatment of II/R injury.

Bioinformatic Analysis of lncRNA Mediated CeRNA Network in Intestinal Ischemia/Reperfusion Injury

INTRODUCTION

Recently, accumulating studies have reported the roles of competitive endogenous RNA (ceRNA) networks in ischemia/reperfusion (I/R) injury in several organs, including the liver, kidney, heart, brain, and intestine. However, the functions and mechanisms of long noncoding RNAs (lncRNAs)-which serve as ceRNA networks in intestinal I/R injury-remain elusive.

METHODS

RNA expression data were retrieved from the National Center for Biotechnology Information-Gene Expression Omnibus database. Differentially expressed microRNAs (miRNAs) (miDEGs) were explored between the sham and intestinal I/R injury samples. Next, targeted lncRNAs and messenger RNAs in the database were matched based on miDEGs. Hub ceRNA networks were constructed and visualized via Cytoscape. Intersection analysis was performed to screen mDEGs between two datasets. Finally, the vital nodes of the ceRNA networks were validated by quantitative PCR.

RESULTS

A total of 189 miDEGs were identified. Forty miRNAs were found to be associated with 240 predicted target genes from miRWalk 3.0. The ceRNA network was constructed with 10 miRNAs, including the 1700020114Rik/mmu-miR-7a-5p/Klf4 axis. Furthermore, the expression of lncRNA 1700020114Rik (P < 0.05) and messenger RNA Klf4 (P < 0.01) was markedly decreased in mouse models of intestinal I/R injury, whereas the expression level of mmu-miR-7a-5p was significantly increased (P < 0.05).

CONCLUSIONS

The results provide novel insights into the molecular mechanism of ceRNA networks in intestinal I/R injury and highlight the potential of the 170002700020114Rik/mmu-miR-7a-5p/Klf4 axis in the prevention and treatment of intestinal I/R injury.

SUMOylation in peripheral tissues under low perfusion-related pathological states

SUMOylation is described as a posttranslational protein modification (PTM) that is involved in the pathophysiological processes underlying several conditions related to ischemia- and reperfusion-induced damage. Increasing evidence suggests that, under low oxygen levels, SUMOylation might be part of an endogenous mechanism, which is triggered by injury to protect cells within the central nervous system. However, the role of ischemia-induced SUMOylation in the periphery is still unclear. This article summarizes the results of recent studies regarding SUMOylation profiles in several diseases characterized by impaired blood flow to the cardiorenal, gastrointestinal, and respiratory systems. Our review shows that although ischemic injury per se does not always increase SUMOylation levels, as seen in strokes, it seems that in most cases the positive modulation of protein SUMOylation after peripheral ischemia might be a protective mechanism. This complex relationship warrants further investigation, as the role of SUMOylation during hypoxic conditions differs from organ to organ and is still not fully elucidated.

NRIP1 aggravates lung injury caused by Pseudomonas aeruginosa in mice by increasing PIAS1 ubiquitination

Recently, evidence has shown that nuclear receptor interacting protein 1 (NRIP1) is involved in acute lung injury (ALI) progression, but the specific mechanism remains unclear. Pseudomonas aeruginosa (PA)-treated TC-1 cells were transfected with pcDNA-NRIP1 or si-NRIP1, and we found that overexpression of NRIP1 inhibited cell viability and promoted cell apoptosis and secretion of inflammatory factors, and transfection of si-NRIP1 reversed these effects. Furthermore, online bioinformatics analysis and co-immunoprecipitation assay results indicated that NRIP1 could bind to Ubiquitin Conjugating Enzyme E2I (UBE2I), and promoted UBE2I expression. Next, the PA-treated TC-1 cells were transfected with si-NRIP1 alone or together with pcDNA-UBE2I, and we observed that transfection with si-NRIP1 inhibited UBE2I expression, promoted cell viability, and reduced cell apoptosis and inflammatory factor secretion, which could be reversed by UBE2I overexpression. Moreover, UBE2I could bind to protein inhibitor of activated signal transducer and activators of transcription 1 (PIAS1). Overexpression of NRIP1 promoted UBE2I expression and inhibited PIAS1 expression, and NRIP1 promoted PIAS1 ubiquitination and degradation by UBE2I. The PA-treated TC-1 cells were transfected with si-UBE2I alone or together with si-PIAS1, and the results indicated that transfection of si-UBE2I had the same effect as transfection of si-NRIP1. Finally, our in vivo findings indicated that the expression of NRIP1 and UBE2I was decreased, and PIAS1 expression was increased, in the lung tissues of mice with NRIP1 knocked-down, and the inflammatory infiltration in the lung tissue was reduced. In conclusion, our study demonstrates that NRIP1 aggravates PA-induced lung injury in mice by promoting PIAS1 ubiquitination.

JAK2/STAT3 inhibition attenuates intestinal ischemia-reperfusion injury via promoting autophagy: in vitro and in vivo study

BACKGROUND

Intestinal ischemia-reperfusion (I/R) causes severe injury to the intestine, leading to systemic inflammation and multiple organ failure. Autophagy is a stress-response mechanism that can protect against I/R injury by removing damaged organelles and toxic protein aggregates. Recent evidence has identified JAK-STAT signaling pathway as a new regulator of autophagy process, however, their regulatory relationship in intestinal I/R remains unknown.

METHODS AND RESULTS

We systematically analyzed intestinal transcriptome data and found that JAK-STAT pathway was largely activated in response to I/R with most significant upregulation observed for JAK2 and STAT3. ChIP-Seq and luciferase assays in an in vitro oxygen-glucose deprivation and reoxygenation model revealed that activated JAK2/STAT3 signaling directly inhibited the transcription of autophagy regulator Beclin-1, leading to the suppression of autophagy and the activation of intestinal cell death. These findings were further confirmed in an in vivo mouse model, in which, intestinal I/R injury was associated with the activation of JAK2/STAT3 pathway and the deactivation of Beclin-1-mediated autophagy, while inhibiting JAK2/STAT3 with AG490 reactivated autophagy and improved survival after intestinal I/R injury.

CONCLUSIONS

JAK2/STAT3 signaling suppresses autophagy process during intestinal I/R, while inhibiting JAK-STAT can be protective against intestinal I/R injury by activating autophagy. These findings expand our knowledge on intestinal I/R injury and provide therapeutic targets for clinical treatment.

Rg3 promotes the SUMOylation of SERCA2a and corrects cardiac dysfunction in heart failure

SUMOylation of sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) has been shown to play a critical role in the abnormal Ca2+ cycle of heart failure. Ginsenoside Rg3 (Rg3), the main active constituent of Panax ginseng, exerts a wide range of pharmacological effects in cardiovascular diseases. However, the effect of Rg3 on abnormal Ca2+ homeostasis in heart failure has not been reported. In this study, we showed a novel role of Rg3 in the abnormal Ca2+ cycle in cardiomyocytes of mice with heart failure. Among mice undergoing transverse aortic constriction, animals that received Rg3 showed improvements in cardiac function and Ca2+ homeostasis, accompanied by increases in the SUMOylation level and SERCA2a activity. In an isoproterenol (ISO)-induced cell hypertrophy model, Rg3 reduced the ISO-induced Ca2+ overload in HL-1 cells. Gene knockout of SUMO1 in mice inhibited the cardioprotective effect of Rg3, and SUMO1 knockout mice that received Rg3 did not exhibit improved Ca2+ homeostasis in cardiomyocytes. Additionally, mutation of the SUMOylation sites of SERCA2a blocked the positive effect of Rg3 on the ISO-induced abnormal Ca2+ cycle in HL-1 cells, and was accompanied by an abnormal endoplasmic reticulum stress response and generation of ROS. Our data demonstrated that Rg3 has a positive effect on the abnormal Ca2+ cycle in the cardiomyocytes of mice with heart failure. SUMO1 is an important factor that mediates the protective effect of Rg3. Our findings suggest that drug intervention by regulating the SUMOylation of SERCA2a can provide a novel therapeutic strategy for the treatment of heart failure.

Tofacitinib protects intestinal epithelial cells against oxygen-glucose deprivation/reoxygenation injury by inhibiting the JAK/STAT3 signaling pathway

The present study aimed to investigate the role and potential mechanism of action of tofacitinib (Tofa) in intestinal ischemia/reperfusion (I/R) injury. The normal rat small intestine epithelial cell line, IEC-6, was used to establish an I/R injury model by inducing oxygen-glucose deprivation/reoxygenation (OGD/R). Cells were divided into the following five groups: Control, OGD/R, OGD/R with 50, 100 and 200 nM Tofa. Following Tofa administration, cell viability was measured using Cell Counting Kit-8 assay and a lactate dehydrogenase detection kit. The expression levels of cell apoptosis-related proteins, Bcl-2, cleaved-caspase-3 and cleaved-caspase-9 were detected using western blot analysis. Additionally, the levels of oxidative stress-related markers, such as reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD), and inflammatory cytokines, TNF-α, IL-6 and IL-1β were assessed using the colorimetric method. Western blot analysis was also used to measure the expression levels of the Janus kinase (JAK)/STAT3 signaling pathway-related proteins, including phosphorylated (p)-JAK1, p-JAK3 and p-STAT3. Subsequently, colivelin, an agonist of the JAK/STAT3 pathway, was used to investigate whether the effects of Tofa on intestinal I/R injury were mediated by this signaling pathway. The results showed that Tofa dose-dependently elevated cell viability compared with that in the OGD/R group. By contrast, Tofa attenuated cell apoptosis, which was coupled with upregulated Bcl-2 expression, downregulated cleaved-caspase-3 and downregulated cleaved-caspase-9 levels, in OGD/R-induced IEC-6 cells. Furthermore, the contents of ROS and MDA were significantly increased following exposure to OGD/R, which were accompanied by the decreased activity of SOD. These effects were reversed following cell treatment with Tofa. Consistently, Tofa intervention reduced the secretion levels of TNF-α, IL-6 and IL-1β in a dose-dependent manner. Additionally, Tofa markedly downregulated the phosphorylation levels of JAK1, JAK3 and STAT3 in OGD/R-induced IEC-6 cells. However, treatment with colivelin markedly reversed the inhibitory effects of Tofa on cell viability, cell apoptosis, oxidative stress and inflammation. Overall, the findings of the present study suggested that Tofa could protect against intestinal I/R injury by inhibiting the JAK/STAT3 signaling pathway, which may hold promise as a therapeutic agent for intestinal I/R injury.

SUMOylation as a Therapeutic Target for Myocardial Infarction

Myocardial infarction is a prevalent and life-threatening cardiovascular disease. The main goal of existing interventional therapies is to restore coronary reperfusion while few are designed to ameliorate the pathology of heart diseases via targeting the post-translational modifications of those critical proteins. Small ubiquitin-like modifier (SUMO) proteins are recently discovered to form a new type of protein post-translational modifications (PTM), known as SUMOylation. SUMOylation and deSUMOylation are dynamically balanced in the maintenance of various biological processes including cell division, DNA repair, epigenetic transcriptional regulation, and cellular metabolism. Importantly, SUMOylation plays a critical role in the regulation of cardiac functions and the pathology of cardiovascular diseases, especially in heart failure and myocardial infarction. This review summarizes the current understanding on the effects of SUMOylation and SUMOylated proteins in the pathophysiology of myocardial infarction and identifies the potential treatments against myocardial injury via targeting SUMO. Ultimately, this review recommends SUMOylation as a key therapeutic target for treating cardiovascular diseases.

SUMO paralogue-specific functions revealed through systematic analysis of human knockout cell lines and gene expression data

The small ubiquitin-related modifiers (SUMOs) regulate nearly every aspect of cellular function, from gene expression in the nucleus to ion transport at the plasma membrane. In humans, the SUMO pathway has five SUMO paralogues with sequence homologies that range from 45% to 97%. SUMO1 and SUMO2 are the most distantly related paralogues and also the best studied. To what extent SUMO1, SUMO2, and the other paralogues impart unique and nonredundant effects on cellular functions, however, has not been systematically examined and is therefore not fully understood. For instance, knockout studies in mice have revealed conflicting requirements for the paralogues during development and studies in cell culture have relied largely on transient paralogue overexpression or knockdown. To address the existing gap in understanding, we first analyzed SUMO paralogue gene expression levels in normal human tissues and found unique patterns of SUMO1–3 expression across 30 tissue types, suggesting paralogue-specific functions in adult human tissues. To systematically identify and characterize unique and nonredundant functions of the SUMO paralogues in human cells, we next used CRISPR-Cas9 to knock out SUMO1 and SUMO2 expression in osteosarcoma (U2OS) cells. Analysis of these knockout cell lines revealed essential functions for SUMO1 and SUMO2 in regulating cellular morphology, promyelocytic leukemia (PML) nuclear body structure, responses to proteotoxic and genotoxic stress, and control of gene expression. Collectively, our findings reveal nonredundant regulatory roles for SUMO1 and SUMO2 in controlling essential cellular processes and provide a basis for more precise SUMO-targeting therapies.

SUMOylation Connects Cell Stress Responses and Inflammatory Control: Lessons From the Gut as a Model Organ

Conjugation with the small ubiquitin-like modifier (SUMO) constitutes a key post-translational modification regulating the stability, activity, and subcellular localization of its target proteins. However, the vast numbers of identified SUMO substrates obscure a clear view on the function of SUMOylation in health and disease. This article presents a comprehensive review on the physiological relevance of SUMOylation by discussing how global SUMOylation levels—rather than specific protein SUMOylation—shapes the immune response. In particular, we highlight the growing body of work on SUMOylation in intestinal pathologies, because of the unique metabolic, infectious, and inflammatory challenges of this organ. Recent studies show that global SUMOylation can help restrain detrimental inflammation while maintaining immune defenses and tissue integrity. These results warrant further efforts to develop new therapeutic tools and strategies to control SUMOylation in infectious and inflammatory disorders.

STING-dependent induction of lipid peroxidation mediates intestinal ischemia-reperfusion injury

Stimulator of interferon genes (STING) is essential for the type I interferon response against DNA pathogens. Recent evidence has indicated that STING also plays a critical role in various diseases such as systemic lupus erythematous, nonalcoholic fatty liver disease, and cancer. However, the exact function and mechanism of STING in ischemia/reperfusion (I/R) injury, especially in the intestine, remains unknown. In the current study, we evaluated the contribution of STING to the intestinal I/R progression. The data indicate a robust STING activation, specifically in the reperfusion period, with the evidence of interferon response and NF-κB pathway activation. The intestinal I/R injury and distant organ damage was absent in STING^-/- mice. Mechanically, this detrimental effect relies on excess level of lipid peroxidation, which was proved by the level of 4-hydroxynonenal (4-HNE) and the malondialdehyde (MDA). Additionally, bone marrow derived macrophage (BMDM) was stimulated with mtDNA or STING agonist showed a dose- and time-dependent lipid peroxidation and cell death, which could be reverse by STING^-/- or pretreatment of lipid peroxidation inhibitor. Liproxstatin-1 could also ameliorate injury I/R induced multiple-organ damage. Similar results were also identified in the GSE96733 database, which indicated that STING activation was associated with the disbalance of lipid peroxidation and antioxidant system. Collectively, our results indicate a novel role for STING activation in the regulation of lipid peroxidation is closely associated with intestinal I/R injury, and that anti-lipid peroxidation is a unique and effective mechanistic approach for intestinal I/R injury and STING activation associated damage prevention and treatment.

Molecular Mechanisms Underlying Intestinal Ischemia/Reperfusion Injury: Bioinformatics Analysis and In Vivo Validation

Background

Intestinal ischemia/reperfusion (I/R) injury is a serious clinical complication. This study aimed to explore the hub genes and pathways of intestinal I/R injury.

Material/Methods

GSE96733 from the GEO website was extracted to analyze the differentially expressed genes (DEGs) of intestinal I/R injured and sham-operated mice at 3 h and 6 h after surgery. The DAVID and STRING databases were used to construct functional enrichment analyses of DEGs and the protein–protein interaction (PPI) network. In Cytoscape software, cytoHubba was used to identify hub genes, and MCODE was used for module analysis. Testing by qRT-PCR detected the expression of hub genes in intestinal I/R injury. Western blot analysis detected the key proteins involved with the important pathways of intestinal I/R injury.

Results

IL-6, IL-10, CXCL1, CXCL2, and IL-1β were identified as critical upregulated genes, while IRF7, IFIT3, IFIT1, Herc6, and Oasl2 were identified as hub genes among the downregulated genes. The qRT-PCR testing showed the expression of critical upregulated genes was significantly increased in intestinal I/R injury (P<0.05), while the expression of hub downregulated genes was notably reduced (P<0.05). The proteins of CXCL1 and CXCR2 were upregulated following intestinal I/R injury (P<0.05) and the CXCL1/CXCR2 axis was involved with intestinal I/R injury.

Conclusions

The results of the present study identified IL-6, IL-10, CXCL1, CXCL2, IL-1β, IRF7, IFIT3, IFIT1, Herc6, and Oasl2 as hub genes in intestinal I/R injury and identified the involvement of the CXCL1/CXCR2 axis in intestinal I/R injury.

Sumoylation in liver disease

Small ubiquitin-like modifiers (SUMO) are highly conserved post-translational modification proteins that are present in eukaryotic cells. They are extensively expressed in diverse tissues, including the heart, liver, kidney, and lungs. SUMOylation, a crucial post-translational modification, exhibits a strong effect on DNA repair, transcriptional regulation, protein stability and cell cycle progression. Increasing evidence has demonstrated that SUMOylation is closely related to the development of liver disease. Therefore, the effects of SUMOylation in liver diseases, such as Hepatocellular carcinoma (HCC), viral hepatitis, non-alcoholic fatty liver disease (NAFLD), cirrhosis and primary biliary cirrhosis (PBC) were reviewed in this study. Specifically, SUMO1 was found to promote the invasion and metastasis of HCC and may promote hypoxia-mediated P65 nuclear transport while accelerating the progression of HCC. In addition, SUMO1-modified centrosomal P4.1-associated protein (CAPA) was observed to be overexpressed in Hepatitis B virus (HBV)-related HCC in response to TNF-α stimulation. Furthermore, SUMOylated CAPA was found to induce HBX-triggered NF-κB activation. Considering the diversity and significance of SUMOylation, targeting of the SUMOylation pathway may serve as an effective approach in the treatment of liver diseases.

Zinc-Induced SUMOylation of Dynamin-Related Protein 1 Protects the Heart against Ischemia-Reperfusion Injury

Background

Zinc plays a role in mitophagy and protects cardiomyocytes from ischemia/reperfusion injury. This study is aimed at investigating whether SUMOylation of Drp1 is involved in the protection of zinc ion on cardiac I/R injury.

Methods

Mouse hearts were subjected to 30 minutes of regional ischemia followed by 2 hours of reperfusion (ischemia/reoxygenation (I/R)). Infarct size and apoptosis were assessed. HL-1 cells were subjected to 24 hours of hypoxia and 6 hours of reoxygenation (hypoxia/reoxygenation (H/R)). Zinc was given 5 min before reperfusion for 30 min. SENP2 overexpression plasmid (Flag-SENP2), Drp1 mutation plasmid (Myc-Drp1 4KR), and SUMO1 siRNA were transfected into HL-1 cells for 48 h before hypoxia. Effects of zinc on SUMO family members were analyzed by Western blotting. SUMOylation of Drp1, apoptosis and the collapse of mitochondrial membrane potential (ΔΨm), and mitophagy were evaluated.

Results

Compared with the control, SUMO1 modification level of proteins in the H/R decreased, while this effect was reversed by zinc. In the setting of H/R, zinc attenuated myocardial apoptosis, which was reversed by SUMO1 siRNA. Similar effects were observed in SUMO1 KO mice exposed to H/R. In addition, the dynamin-related protein 1 (Drp1) is a target protein of SUMO1. The SUMOylation of Drp1 induced by zinc regulated mitophagy and contributed to the protective effect of zinc on H/R injury.

Conclusions

SUMOylation of Drp1 played an essential role in zinc-induced cardio protection against I/R injury. Our findings provide a promising therapeutic approach for acute myocardial I/R injury.