Intestinal Intestinal Ischemia-reperfusion Injury Research Articles

Effects of butyrate on intestinal ischemia-reperfusion injury via the HMGB1-TLR4-MyD88 signaling pathway.

This study combined bioinformatics and experimental verification in a mouse model of intestinal ischemia-reperfusion injury (IRI) to explore the protection mechanism exerted by butyrate against IRI. GeneCards, Bioinformatics Analysis Tool for Molecular Mechanisms of Traditional Chinese Medicine and GSE190581 were used to explore the relationship between butyrate and IRI and aging. Protein-protein interaction networks involving butyrate and IRI were constructed via the STRING database, with hub gene analysis performed through Cytoscape. Functional enrichment analysis was conducted on intersection genes. A mouse model of IRI was established, followed by direct arterial injection of butyrate. The experiment comprised five groups: normal, sham, model, vehicle, low-dose butyrate, and high-dose butyrate. Intestinal tissue observation was done via transmission electron microscopy (TEM), histological examination via hematoxylin and eosin (H&E) staining, tight junction proteins detection via immunohistochemistry, and Western blot analysis of hub genes. Drug-target interactions were evaluated through molecular docking. Butyrate protected against IRI by targeting 458 genes, including HMGB1 and TLR4. Toll-like receptor pathway was implicated. Butyrate improved intestinal IRI by reducing mucosal damage, increasing tight junction proteins, and lowering levels of HMGB1, TLR4, and MyD88. Molecular docking showed strong binding energies between butyrate and HMGB1 (-3.7 kcal/mol) and TLR4 (-3.8 kcal/mol). According to bioinformatics predictions, butyrate mitigates IRI via multiple-target and multiple-channel mechanisms. The extent of IRI can be reduced by butyrate through the inhibition of the HMGB1-TLR4-MyD88 signaling pathway, which is related to senescence.

Attenuation of intestinal ischemia-reperfusion-injury by anesthetics: a potentially protective effect of anesthetic management in experimental studies.

Intestinal ischemia-reperfusion injury (IRI) is a potentially severe clinical syndrome after major surgical procedures. In addition to causing intestinal mucosa injury, intestinal IRI further damages distant organs, causing the severity of the condition in patients. So far, effective therapy for intestinal IRI is still absent, and the survival rate of the patients is low. Previous experimental studies have shown that some anesthetics can alleviate intestinal IRI and protect organs while exerting their pharmacological effects, indicating that reasonable perioperative anesthesia management may provide potential benefits for patients to avoid intestinal IRI. These meaningful findings drive scholars to investigate the mechanism of anesthetics in treating intestinal IRI in-depth to discuss the possible new clinical uses. In the present mini-review, we will introduce the protective effects of different anesthetics in intestinal IRI to help us enrich our knowledge in this area.

Microfluidic intestinal organoid-on-a-chip uncovers therapeutic targets by recapitulating oxygen dynamics of intestinal IR injury.

Increasing evidence demonstrates that mammals have different reactions to hypoxia with varied oxygen dynamic patterns. It takes ∼24h for tri-gas incubator to achieve steady cell hypoxia, which fails to recapitulate ultrafast oxygen dynamics of intestinal ischemia/reperfusion (IR) injury. Inspired from the structure of native intestinal villi, we engineered an intestinal organoid chip embedded with engineered artificial microvessels based on co-axial microfluidic technology by using pH-responsive ZIF-8/sodium alginate scaffold. The chip was featured on: (i) eight times the oxygen exchange efficiency compared with the conventional device, tri-gas incubator, (ii) implantation of intestinal organoid reproducing all types of intestinal epithelial cells, and (iii) bio-responsiveness to hypoxia and reoxygenation (HR) by presenting metabolism disorder, inflammatory reaction, and cell apoptosis. Strikingly, it was found for the first time that Olfactomedin 4 (Olfm4) was the most significantly down-regulated gene under a rapid HR condition by sequencing the RNA from the organoids. Mechanistically, OLFM4 played protective functions on HR-induced cell inflammation and tissue damage by inhibiting the NF-kappa B signaling activation, thus it could be used as a therapeutic target. Altogether, this study overcomes the issue of mismatched oxygen dynamics between in vitro and in vivo, and sets an example of next-generation multisystem-interactive organoid chip for finding precise therapeutic targets of IR injury.

Intravenous Polyethylene Glycol Alleviates Intestinal Ischemia-Reperfusion Injury in a Rodent Model

Intestinal ischemia-reperfusion injury (IRI) is a common clinical entity, and its outcome is unpredictable due to the triad of inflammation, increased permeability and bacterial translocation. Polyethylene glycol (PEG) is a polyether compound that is extensively used in pharmacology as an excipient in various products. More recently, this class of products have shown to have potent anti-inflammatory, anti-apoptotic, immunosuppressive and cell-membrane-stabilizing properties. However, its effects on the outcome after intestinal IRI have not yet been investigated. We hypothesized that PEG administration would reduce the effects of intestinal IRI in rodents. In a previously described rat model of severe IRI (45 min of ischemia followed by 60 min of reperfusion), we evaluated the effect of IV PEG administration at different doses (50 and 100 mg/kg) before and after the onset of ischemia. In comparison to control animals, PEG administration stabilized the endothelial glycocalyx, leading to reduced reperfusion edema, bacterial translocation and inflammatory reaction as well as improved 7-day survival. These effects were seen both in a pretreatment and in a treatment setting. The fact that this product is readily available and safe should encourage further clinical investigations in settings of intestinal IRI, organ preservation and transplantation.

Protective Effect of Oxygen and Isoflurane in Rodent Model of Intestinal Ischemia-Reperfusion Injury.

Animal research in intestinal ischemia-reperfusion injury (IRI) is mainly performed in rodent models. Previously, intraperitoneal (I.P.) injections with ketamine-xylazine mixtures were used. Nowadays, volatile anesthetics (isoflurane) are more common. However, the impact of the anesthetic method on intestinal IRI has not been investigated. We aim to analyze the different anesthetic methods and their influence on the extent of intestinal IRI in a rat model. Male Sprague-Dawley rats were used to investigate the effect of I.P. anesthesia on 60 min of intestinal ischemia and 60 min of reperfusion in comparison to hyperoxygenation (100% O2) and volatile isoflurane anesthesia. In comparison to I.P. anesthesia with room air (21% O2), supplying 100% O2 improved 7-day survival by cardiovascular stabilization, reducing lactic acidosis and preventing vascular leakage. However, this had no effect on the intestinal epithelial damage, permeability, and inflammatory response observed after intestinal IRI. In contrast to I.P. + 100% O2, isoflurane anesthesia reduced intestinal IRI by preventing ongoing low-flow reperfusion hypotension, limiting intestinal epithelial damage and permeability, and by having anti-inflammatory effects. When translating the aforementioned results of this study to clinical situations, such as intestinal ischemia or transplantation, the potential protective effects of hyperoxygenation and volatile anesthetics require further research.

Carbon monoxide-releasing molecule 2 inhibits inflammation associated with intestinal ischemia-reperfusion injury in a rat model of hemorrhagic shock.

Intestinal ischemia-reperfusion injury (IRI) occurs in multiple clinical settings and contributes to systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). Due to the innate inflammatory immune nature, T cells play a crucial role in the pathogenesis of IRI, which includes not only CD4+T cells, but also CD8+and γδ T cells. Carbon monoxide (CO) plays an important role in regulating CD4+T cell responses and has been proven to be a novel therapeutic target in a variety of inflammatory disease models. This study aimed to assess whether pretreatment with carbon monoxide-releasing molecule-2 (CORM-2) could ameliorate inflammation by regulating differentiation of CD4+T cells in intestinal mucosa of rats undergoing hemorrhagic shock. A hemorrhagic shock model was established to study intestinal IRI. Morphological changes were investigated using light microscopes. Fluorescein isothiocyanate-dextran (FITC-dextran) was used as an indicator of intestinal paracellular permeability. Transcription factors involved in differentiation of CD4+T cells in intestinal mucosa were detected by immunofluorescence, and the expression levels of related cytokines were determined by Western blotting. The results of hematoxylin-eosin (H-E) staining and FITC-dextran intestinal paracellular permeability assay revealed that CORM-2 maintained the integrity of intestinal mucosal barrier and inhibited the changes of intestinal mucosal permeability. In addition, activation of T helper type 1 (Th1) and T helper type 17 (Th17) cells, and the increased expression levels of proinflammatory cytokines, such as interleukin-17 (IL-17) and interferon-gamma (IFN-γ), were observed in intestinal IRI process. In contrast, pretreatment with CORM-2 weakened changes of the abovementioned observations, in which inhibited activation of Th1 and Th17 cells. However, CORM-2 did not influence differentiation of regulatory T (Treg) cells in intestinal IRI progress. Notably, CORM-2 significantly upregulated the expression level of interleukin-10 (IL-10) protein and downregulated the expression levels of IL-17 and IFN-γ proteins in ileal tissues of rats. CORM-2 possessed anti-inflammatory effects in the progress of intestinal IRI by inhibiting activation of Th1 and Th17 cells in rats undergoing hemorrhagic shock.

Transplanted hair follicle mesenchymal stem cells alleviated small intestinal ischemia–reperfusion injury via intrinsic and paracrine mechanisms in a rat model

Background: Small intestinal ischemia-reperfusion (IR) injury is a common intestinal disease with high morbidity and mortality. Mesenchymal stem cells (MSCs) have been increasingly used in various intestinal diseases. This study aimed to evaluate the therapeutic effect of hair follicle MSCs (HFMSCs) on small intestinal IR injury. Methods: We divided Sprague–Dawley rats into three groups: the sham group, IR group and IR + HFMSCs group. A small intestinal IR injury rat model was established by clamping of the superior mesenteric artery (SMA) for 30 min and reperfusion for 2 h. HFMSCs were cultured in vitro and injected into the rats through the tail vein. Seven days after treatment, the intrinsic homing and differentiation characteristics of the HFMSCs were observed by immunofluorescence and immunohistochemical staining, and the paracrine mechanism of HFMSCs was assessed by Western blotting and enzyme-linked immunosorbent assay (ELISA). Results: A small intestinal IR injury model was successfully established. HFMSCs could home to damaged sites, express proliferating cell nuclear antigen (PCNA) and intestinal stem cell (ISC) markers, and promote small intestinal ISC marker expression. The expression levels of angiopoietin-1 (ANG1), vascular endothelial growth factor (VEGF) and insulin growth factor-1 (IGF1) in the IR + HFMSCs group were higher than those in the IR group. HFMSCs could prevent IR-induced apoptosis by increasing B-cell lymphoma-2 (Bcl-2) expression and decreasing Bcl-2 homologous antagonist/killer (Bax) expression. Oxidative stress level detection showed that the malondialdehyde (MDA) content was decreased, while the superoxide dismutase (SOD) content was increased in the IR + HFMSCs group compared to the IR group. An elevated diamine oxidase (DAO) level reflected the potential protective effect of HFMSCs on the intestinal mucosal barrier. Conclusion: HFMSCs are beneficial to alleviate small intestinal IR injury through intrinsic homing to the small intestine and by differentiating into ISCs, via a paracrine mechanism to promote angiogenesis, reduce apoptosis, regulate the oxidative stress response, and protect intestinal mucosal function potentially. Therefore, this study suggests that HFMSCs serve as a new option for the treatment of small intestinal IR injury.

Adaptive mechanisms in no flow vs. low flow ischemia in equine jejunum epithelium: Different paths to the same destination.

Intestinal ischemia reperfusion injury (IRI) is a frequent complication of equine colic. Several mechanisms may be involved in adaptation of the intestinal epithelium to IRI and might infer therapeutic potential, including hypoxia-inducible factor (HIF) 1α, AMP-activated protein kinase (AMPK), nuclear factor-erythroid 2-related factor 2 (NRF2), and induction of autophagy. However, the mechanisms supporting adaptation and thus cellular survival are not completely understood yet. We investigated the activation of specific adaptation mechanisms in both no and low flow ischemia and reperfusion simulated in equine jejunum epithelium in vivo. We found an activation of HIF1α in no and low flow ischemia as indicated by increased levels of HIF1α target genes and phosphorylation of AMPKα tended to increase during ischemia. Furthermore, the protein expression of the autophagy marker LC3B in combination with decreased expression of nuclear-encoded mitochondrial genes indicates an increased rate of mitophagy in equine intestinal IRI, possibly preventing damage by mitochondria-derived reactive oxygen species (ROS). Interestingly, ROS levels were increased only shortly after the onset of low flow ischemia, which may be explained by an increased antioxidative defense, although NFR2 was not activated in this setup. In conclusion, we could demonstrate that a variety of adaptation mechanisms manipulating different aspects of cellular homeostasis are activated in IRI irrespective of the ischemia model, and that mitophagy might be an important factor for epithelial survival following small intestinal ischemia in horses that should be investigated further.

Role and Potential Mechanism of Heme Oxygenase-1 in Intestinal Ischemia-Reperfusion Injury.

Intestinal ischemia-reperfusion (IR) injury is a complex, multifactorial, and pathophysiological condition with high morbidity and mortality, leading to serious difficulties in treatment, especially in humans. Heme oxygenase (HO) is the rate-limiting enzyme involved in heme catabolism. HO-1 (an inducible form) confers cytoprotection by inhibiting inflammation and oxidation. Furthermore, nuclear factor-erythroid 2-related factor 2 (Nrf2) positively regulates HO-1 transcription, whereas BTB and CNC homolog 1 (Bach1) competes with Nrf2 and represses its transcription. We investigated the role and potential mechanism of action of HO-1 in intestinal IR injury. Intestinal ischemia was induced for 45 min followed by 4 h of reperfusion in wild-type, Bach1-deficient, and Nrf2-deficient mice, and a carbon monoxide (CO)-releasing molecule (CORM)-3 was administered. An increase in inflammatory marker levels, nuclear factor-κB (NF-κB) activation, and morphological impairments were observed in the IR-induced intestines of wild-type mice. These inflammatory changes were significantly attenuated in Bach1-deficient mice or those treated with CORM-3, and significantly exacerbated in Nrf2-deficient mice. Treatment with an HO-1 inhibitor reversed this attenuation in IR-induced Bach1-deficient mice. Bach1 deficiency and treatment with CORM-3 resulted in the downregulation of NF-κB activation and suppression of adhesion molecules. Together, Bach1, Nrf2, and CO are valuable therapeutic targets for intestinal IR injury.

Inhibition of Prolyl Oligopeptidase Prevents Consequences of Reperfusion following Intestinal Ischemia.

Background: Intestinal ischemia/reperfusion injury (IRI) remains a clinical event that contributes to high morbidity and mortality rates. Intestinal epithelium is exposed to histological and vascular changes following tissue ischemia. Prolyl endopeptidase (PREP), involved in inflammatory responses, could be targeted for recovery from the permanent consequences following intestinal ischemia. Our aim was to investigate the role of PREP inhibitor KYP-2047 in tissue damage, angiogenesis, and endothelial barrier permeability after intestinal IRI in mice. Methods: KYP-2047 treatments were performed 5 min prior to intestinal damage. Intestinal IRI was induced in mice by clamping the superior mesenteric artery and the celiac trunk for 30 min, followed by 1 h of reperfusion. Results: PREP inhibition by KYP-2047 treatment reduced intestinal IR-induced histological damage and neutrophil accumulation, limiting inflammation through decrease of NF-ĸB nuclear translocation and fibrotic processes. KYP-2047 treatment restored barrier permeability and structural alteration following intestinal IRI, attenuating neovascular processes compromised by ischemia/reperfusion. Additionally, loss of epithelial cells during intestinal ischemia occurring by apoptosis was limited by KYP-2047 treatment, which showed strong effects counteracting apoptosis and DNA damage. Conclusions: These findings provide the first evidence that PREP inhibition through KYP-2047 inhibitor use could be a validate strategy for resolving alterations of intestinal epithelium the pathophysiology of intestinal disease.

The protective effect of α7-nACh receptor and its interaction with 5-HT1B/1D receptors in acute intestinal ischemia-reperfusion injury in rats.

Over the past decades, great attention has been given to the nervous system modulating effects on the immune response in inflammation-associated injuries, such as acute intestinal ischemia-reperfusion (IR). Recently, we proved the anti-inflammatory and antioxidant effects of 5-hydroxytryptamine (5-HT)1B/1D receptors in intestinal IR injury in rats. Also, the alpha7 nicotinic acetylcholine (α7-nACh) receptor has anti-inflammatory effects in different inflammation-associated injuries. Starting from these premises, we aimed to examine the function of the α7-nACh receptors and the functional interactions between the anti-inflammatory and antioxidant effects of α7-nACh and 5-HT1B/1D receptors in acute intestinal IR injury. To confirm the expression and localization of α7-nACh receptors on the ileum nerves, an immunofluorescence-based method was applied. Then, intestinal IR injury was induced by 30-min occlusion of superior mesenteric artery and reperfusion for 2h in rats. Acute systemic administration of α7-nACh receptor agonist PNU-282987 and antagonist methyllycaconitine, and 5-HT1B/1D receptors agonist (sumatriptan) and antagonist (GR127, 935) were used in the model of intestinal IR injury. Finally, biochemical and histological parameters were assessed. Α7-nACh receptors were expressed by 9% on the ileum nerves. Likewise, activation of the α7-nACh receptor showed anti-inflammatory and antioxidant effects in intestinal IR injury but not as well as 5-HT1B/1D receptors. Interestingly, 5-HT1B/1D receptors via attenuation of glutamate (Glu) release indirectly activated the α7-nACh receptor and its protective effects against inflammation and oxidative stress. The protective effect of the α7-nACh receptor on intestinal IR injury was activated indirectly through the 5-HT1B/1D receptors' modulatory impact on Glu release.

Endothelial RIPK3 Regulation and its Effects on Vascular Permeability Following Intestinal Ischemia‐Reperfusion Injury

The cytoplasmic protein receptor-interacting serine/threonine-protein kinase 3 (RIPK3) is primarily known for promoting necroptosis, but more recent findings suggest that RIPK3 has additional functions separate from necroptosis. Our lab recently demonstrated that in the absence of the chromatin-remodeling enzyme CHD4, RIPK3 is elevated in hypoxic cultured embryonic endothelial cells (ECs) and that elevated RIPK3 causes vessel fragility in midgestation mouse embryos. Our current study investigates the regulation of endothelial RIPK3 following intestinal ischemia-reperfusion injury (IRI) in mice and its effects on vascular permeability and damage following IRI. To assess RIPK3 regulation following IRI, first-order branches of the superior mesenteric artery were clamped for 1 hr to induce ischemia, and clamps were removed subsequently for 24 hr reperfusion (C57BL/6J mice; 10-12 weeks old). Unclamped vessels and downstream gut tissue from the same animal were used as sham controls. RIPK3 and VE-Cadherin expression (mean fluorescence intensity; MFI) were quantified in 1st and 2nd order mesenteric arteries using immunostaining of en face vessel preparations. RIPK3 was significantly elevated (P=0.0216) at 1 hr ischemia and following 24 hr IR injury (P=0.0295) compared to sham controls (7-8 vessels/group, n=4 mice). Junctional VE-Cadherin showed increased expression (not significant) following 1 hr ischemia. Although no changes were observed following 24 hr IRI, VE-Cadherin expression at mesenteric arterial endothelial junctions were discontinuous and unstable suggesting a potential barrier dysfunction associated with IRI. To assess the role of RIPK3 on vascular permeability, we used Ripk3fl/fl;Cdh5(PAC)-CreERT2 mice (Ripk3 endothelial cell knockout=RIPK3ECKO) compared to littermate controls, and vascular permeability was assessed using the Evans blue assay following 24 hr intestinal IRI. Gut vascular permeability was increased following IRI in both RIPK3ECKO (n=4 mice)and littermate controls (n=3 mice), however permeability was also significantly increased (P=0.02) in sham gut regions and the livers (P=0.04) of RIPK3ECKO mice unlike in controls. Collectively, these data suggest that deletion of endothelial RIPK3 increases vascular damage downstream of injury sites and points toward a protective role for RIPK3 in the vasculature following IRI. Future studies evaluating mechanisms of RIPK3 protective effects in endothelial cells following IRI will provide insight into therapeutic targets for vessel recovery from IRI.

The effect of pre- and post-remote ischemic conditioning reduces the injury associated with intestinal ischemia/reperfusion.

Midgut volvulus is associated with intestinal ischemia/reperfusion (IR) injury and can progress to severe intestinal damage. Remote ischemic conditioning (RIC) reduces IR-induced injury in distant organs. The aim of this study was to investigate whether RIC protects the intestine from IR injury. We investigated intestinal IR injury in 3weeks old SD rats. Animals underwent: (i) sham laparotomy, (ii) intestinal IR injury, (iii) intestinal IR + RIC during ischemia, or (iv) intestinal IR + RIC after reperfusion. Intestinal IR injury was achieved by 45min occlusion of superior mesenteric artery followed by de-occlusion. RIC was administered via four cycles of 5min of hind limb ischemia followed by 5min reperfusion. Animals were sacrificed 24h after surgery and the ileum was harvested for evaluation. Intestinal injury was present after IR. However, this injury was reduced in both IR + RIC groups. Expression of inflammatory cytokine IL6 was lower in IR + RIC groups compared to IR alone. Carbonyl protein was also significantly lower in IR + RIC compared to IR, indicating lower oxidative stress in both IR + RIC groups. Remote ischemic conditioning attenuated intestinal injury, inflammation, and oxidative stress in experimental intestinal ischemia/reperfusion injury. Remote ischemic conditioning may be useful in children with midgut volvulus to reduce the intestinal injury. Experimental study. Animal experiment.

Gut-lymph-lung pathway mediates sepsis-induced acute lung injury.

This review attempts to unveil the possible mechanisms underlying how gut lymph affects lung and further gives rise to acute respiratory distress syndrome, as well as potential interventional targets under the condition of ischemia-reperfusion injury. We searched electronic databases including PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Google Scholar, Web of Science, and Embase to identify relevant literatures published up to December 2019. We enrolled the literatures including the Mesh Terms of “gut lymph or intestinal lymph and acute lung injury or acute respiratory distress syndrome.” Gut is considered to be the origin of systemic inflammation and the engine of multiple organ distress syndrome in the field of critical care medicine, whereas gut lymph plays a pivotal role in initiation of ischemia-reperfusion injury-induced acute respiratory distress syndrome. In fact, in the having been established pathologic model of sepsis leading to multiple organ dysfunction named by Gut Lymph theory, a variety of literatures showed the position and role of changes in gut lymph components in the initiation of systemic inflammatory response, which allows us to screen out potential intervention targets to pave the way for future clinic and basic research.

Sulforaphane Elicits Protective Effects in Intestinal Ischemia Reperfusion Injury.

Intestinal ischemia reperfusion injury (IRI) is an inherent, unavoidable event of intestinal transplantation, contributing to allograft failure and rejection. The inflammatory state elicited by intestinal IRI is characterized by heightened leukocyte recruitment to the gut, which is amplified by a cross-talk with platelets at the endothelial border. Sulforaphane (SFN), a naturally occurring isothiocyanate, exhibits anti-inflammatory characteristics and has been shown to reduce platelet activation and block leukocyte adhesion. Thus, the aim of this study was to investigate protective effects and mechanism of action of SFN in a murine model of intestinal IRI. Intestinal IRI was induced by superior mesenteric artery occlusion for 30 min, followed by reperfusion for 2 h, 8 h or 24 h. To investigate cellular interactions, leukocytes were in vivo stained with rhodamine and platelets were harvested from donor animals and ex vivo stained. Mice (C57BL/6J) were divided into three groups: (1) control, (2) SFN treatment 24 h prior to reperfusion and (3) SFN treatment 24 h prior to platelet donation. Leukocyte and platelet recruitment was analyzed via intravital microscopy. Tissue was analyzed for morphological alterations in intestinal mucosa, barrier permeability, and leukocyte infiltration. Leukocyte rolling and adhesion was significantly reduced 2 h and 8 h after reperfusion. Mice receiving SFN treated platelets exhibited significantly decreased leukocyte and platelet recruitment. SFN showed protection for intestinal tissue with less damage observed in histopathological and ultrastructural evaluation. In summary, the data presented provide evidence for SFN as a potential therapeutic strategy against intestinal IRI.

The Potential Role of Protein Tyrosine Phosphatase, Receptor Type C (CD45) in the Intestinal Ischemia-Reperfusion Injury.

This study was designed to identify several key genes and their functions in preventing or ameliorating intestinal ischemia-reperfusion (IR) injury, which could provide rationale for further exploring the regulatory mechanisms or clinical treatment for intestinal IR injury. The microarray GSE37013 of human intestinal IR injury was downloaded from Gene Expression Omnibus database. The differentially expressed genes (DEGs) with changes of reperfusion time were screened using Short Time-series Expression Miner, followed by function enrichment analysis, protein-protein interaction (PPI) network, and module construction. Subsequently, the key DEGs were identified with VEEN analysis based on the significant results of function enrichment analysis and PPI module. Finally, the gene-drug interactions were predicted using DGIdb 2.0. The DEGs of intestinal IR injury were significantly divided into three clusters with changes of reperfusion time. The genes in the three clusters were mainly enriched in transmembrane transport, defense responses, and cellular component assembly related pathways, respectively. There were 121 nodes and 281 interactions in PPI network, including one significant submodule. Protein tyrosine phosphatase, receptor type C (PTPRC) was a hub code both in PPI network and in submodule. A total of eight key DEGs were identified but only PTPRC was predicted to be interacted with eight drugs, such as infliximab. Totally, eight key genes associated with intestinal IR were identified; PTPRC especially was the most prominent potential drug target. These findings provided several potential therapeutic targets or potential breakthrough area in the study of intestinal IR injury.

The olfactomedin-4 positive neutrophil has a role in murine intestinal ischemia/reperfusion injury.

Olfactomedin-4 (OLFM4) identifies a subset of neutrophils conserved in both mouse and man, associated with worse outcomes in several inflammatory conditions. We investigated the role of OLFM4-positive neutrophils in murine intestinal ischemia/reperfusion (IR) injury. Wild-type (WT) C57Bl/6 and OLFM4 null mice were subjected to intestinal IR injury and then monitored for survival or tissues harvested for further analyses. In vivo intestinal barrier function was determined via functional assay of permeability to FITC-dextran. OLFM4 null mice had a significant 7-d survival benefit and less intestinal barrier dysfunction compared with WT. Early after IR, WT mice had worse mucosal damage on histologic examination. Experiments involving adoptive transfer of bone marrow demonstrated that the mortality phenotype associated with OLFM4-positive neutrophils was transferrable to OLFM4 null mice. After IR injury, WT mice also had increased intestinal tissue activation of NFκB and expression of iNOS, 2 signaling pathways previously demonstrated to be involved in intestinal IR injury. In combination, these experiments show that OLFM4-positive neutrophils are centrally involved in the pathologic pathway leading to intestinal damage and mortality after IR injury. This may provide a therapeutic target for mitigation of intestinal IR injury in a variety of common clinical situations.-Levinsky, N. C., Mallela, J., Opoka, A., Harmon, K., Lewis, H. V., Zingarelli, B., Wong, H. R., Alder, M. N. The olfactomedin-4 positive neutrophil has a role in murine intestinal ischemia/reperfusion injury.

The protective effects of urapidil on lung tissue after intestinal ischemia-reperfusion injury

Abstract Objective The effects of urapidil in intestinal ischemia-reperfusion (IR) model were investigated using histopathological and biochemical methods. Materials and methods Forty Wistar albino rats were subjected to sham operation (Group 1), IR (Group 2), IR+dimethyl sulfoxide (Group 3), IR+urapidil 0.5 mg/kg (Group 4), and IR+urapidil 5 mg/kg (Group 5). Levels of MDA, TAS, TOS, SOD, MPO, NF-κB, caspase-3, and LC3B were measured. Results and discussion The groups 2 and 3 had significantly higher TOS and MPO levels than the sham group had (p < 0.001), whereas the TAS and SOD levels were significantly lower in Group 2 than in the sham group. In treatment groups, TAS and SOD levels increased, whereas TOS, MPO, and MDA levels decreased compared to Group 2. Caspase-3 and LC3B immunopositivities were seen at severe levels in Group 2 and 3. However, Group 4 and 5 were found to have lower levels of immunopositivity. Immunopositivity was observed in interstitial areas, peribronchial region, and bronchial epithelial cells. A moderate level of NF-κB immunopositivity was seen in Group 2 and 3. Conclusion Our results show that urapidil is one of the antioxidant agents and protects lung tissue from oxidant effects of intestinal IR injury.

The effects of hydrogen-rich saline solution on intestinal anastomosis performed after intestinal ischemia reperfusion injury

AimWe investigated the effects of hydrogen-rich saline solution (HRSS) on intestinal anastomosis performed after intestinal ischemia reperfusion injury (IRI). Materials and methodsThirty Wistar albino female rats were randomly divided into five groups. Only laparotomy was performed in the Sham group. In the other four groups, an intestinal IRI was performed for 45 min by clamping the superior mesenteric artery. After intestinal IRI, anastomosis was performed by cutting the intestine from the proximal 15 cm of the ileocecal valve at the first and 24th hours. HRSS was given intraperitoneally 5 ml/kg before reperfusion and for four more days in the HRSS1 and HRSS24groups, while no treatment was given to the I/R1 and I/R24 groups. After 5 days, all groups underwent relaparotomy. The anastomotic bursting pressures were measured in all groups, except the Sham group. The tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), myeloperoxidase (MPO) and malondialdehyde (MDA) levels were measured in the tissues taken from the anastomosis line. The tissue sections were evaluated histopathologically and the apoptosis index was determined by applying the TUNEL method. The results were analyzed one-way analysis of variance (ANOVA) and Pearson's chi-squared test. ResultsAlthough the MPO, MDA, IL-6 and TNF-α tissue values were not statistically significant among the groups, the degree of tissue damage and apoptosis levels were lower and the anastomotic bursting pressures values were higher in the HRSS1 and HRSS24 groups compared to the I/R1 and I/R24 groups. ConclusionHRSS is effective in reducing the intestinal damage caused by an IRI: HRSS has the potential to reduce the detrimental effects of intestinal anastomosis performed after an intestinal IRI.

Dexmedetomidine Rescues Enteric Glial Cells from Oxidative Stress-Induced Intestinal Ischemia-Reperfusion Injury Through Promoting Mitochondrial Translocation of Telomerase Reverse Transcriptase

Background: Intestinal ischemia-reperfusion injury (IRI) is a devastating complication in the perioperative period leading to systemic inflammation and multiple organ dysfunction. We aimed to determine whether dexmedetomidine protects against oxidative stress injury induced by mitochondrial translocation of telomerase reverse transcriptase (TERT) in enteric glial cells (EGCs) of a rat model after intestinal IRI and the mechanisms involved in this protection. Methods: After the rat model with intestinal IRI was established, the rats were treated with high/low dose of dexmedetomidine. The positive rate of TERT protein was detected by immunohistochemistry. The distribution and levels of TERT were measured by immunofluorescence. The levels of apoptosis-related proteins and oxidative stress injury-related factors (ROS, MDA, and GSH) were also measured. Mitochondrial membrane permeability and potential were detected using Calcein cobalt and Rhodamine 123 staining respectively. The oxidative injury of mtDNA was detected by real-time fluorescence quantitative PCR. Cell Counting Kit-8 (CCK-8) assay and flow cytometry were applied to detection of EGC viability and apoptosis. Results: Relative to normal rats, rats with intestinal IRI displayed with reduced TERT mitochondrial translocation and EGC viability, as well as elevated mitochondrial damage, oxidative stress, and EGC apoptosis. Dexmedetomidine treatment could alleviate intestinal IRI by promoting mitochondrial translocation of TERT, reducing mitochondrial damage and oxidative stress. The regulatory mechanism functioned in a dose-dependent manner. Conclusion: Dexmedetomidine restores mitochondrial translocation of TERT, thus reducing oxidative stress and mitochondrial damage in EGCs after intestinal IRI. Funding: The study was supported by a grant from the National Natural Science Foundation of China (No. 81660096). Declaration of Interest: The authors have no competing interests to declare. Ethical Approval: Our study was approved by the Institutional Review Board of the First Affiliated Hospital of Nanchang University. All animal experiments and procedures were performed in accordance with the Guide for the Care and Use of Laboratory Animals published by the National Institutes of Health.