Protective effect of intestinal ischemic preconditioning on ischemia reperfusion-caused lung injury in rats

Advancements in the study of acute lung injury resulting from intestinal ischemia/reperfusion

Intestinal ischemia/reperfusion is a prevalent pathological process that can result in intestinal dysfunction, bacterial translocation, energy metabolism disturbances, and subsequent harm to distal tissues and organs via the circulatory system. Acute lung injury frequently arises as a complication of intestinal ischemia/reperfusion, exhibiting early onset and a grim prognosis. Without appropriate preventative measures and efficacious interventions, this condition may progress to acute respiratory distress syndrome and elevate mortality rates. Nonetheless, the precise mechanisms and efficacious treatments remain elusive. This paper synthesizes recent research models and pertinent injury evaluation criteria within the realm of acute lung injury induced by intestinal ischemia/reperfusion. The objective is to investigate the roles of pathophysiological mechanisms like oxidative stress, inflammatory response, apoptosis, ferroptosis, and pyroptosis; and to assess the strengths and limitations of current therapeutic approaches for acute lung injury stemming from intestinal ischemia/reperfusion. The goal is to elucidate potential targets for enhancing recovery rates, identify suitable treatment modalities, and offer insights for translating fundamental research into clinical applications.

Corilagin alleviates intestinal ischemia/reperfusion injury by relieving oxidative stress and apoptosis via AMPK/Sirt1-autophagy pathway

Intestinal ischemia/reperfusion (II/R) injury is a common pathological process with high clinical morbidity and mortality. Autophagy plays an important role in the pathological development of II/R. Corilagin (CA) is a natural ellagitannin with various pharmacological effects such as autophagy regulation, antioxidant, and antiapoptosis. However, whether CA alleviates II/R injury is still unclear. In this study, we had found that CA significantly attenuated II/R induced intestinal tissue pathological damage, oxidative stress, and cell apoptosis in rats. Further studies showed that CA significantly promoted AMPK phosphorylation and sirt1 expression, and thus activated autophagy by upregulating protein expression of autophagy-related proteins Beclin1 and LC3II and promoting SQSTM1/P62 degradation both in vivo and in vitro. Inhibition of AMPK phosphorylation by its inhibitor compound C(CC) significantly abolished CA-mediated autophagy activation and the relievable effects on oxidative stress and apoptosis in vitro, suggesting the excellent protective activity of CA against II/R injury via AMPK/Sirt1-autophagy pathway. These findings confirmed the potent effects of CA against II/R injury, and provided novel insights into the mechanisms of the compound as a potential candidate for the treatment of II/R.

Mitochondrial DNA Release Contributes to Intestinal Ischemia/Reperfusion Injury

Mitochondria release many damage-associated molecular patterns (DAMPs) when cells are damaged or stressed, with mitochondrial DNA (mtDNA) being. MtDNA activates innate immune responses and induces inflammation through the TLR-9, NLRP3 inflammasome, and cGAS-STING signaling pathways. Released inflammatory factors cause damage to intestinal barrier function. Many bacteria and endotoxins migrate to the circulatory system and lymphatic system, leading to systemic inflammatory response syndrome (SIRS) and even damaging the function of multiple organs throughout the body. This process may ultimately lead to multiple organ dysfunction syndrome (MODS). Recent studies have shown that various factors, such as the release of mtDNA and the massive infiltration of inflammatory factors, can cause intestinal ischemia/reperfusion (I/R) injury. This destroys intestinal barrier function, induces an inflammatory storm, leads to SIRS, increases the vulnerability of organs, and develops into MODS. Mitophagy eliminates dysfunctional mitochondria to maintain cellular homeostasis. This review discusses mtDNA release during the pathogenesis of intestinal I/R and summarizes methods for the prevention or treatment of intestinal I/R. We also discuss the effects of inflammation and increased intestinal barrier permeability on drugs.

Non-Invasive Remote Ischemic Preconditioning May Protect the Gastric Mucosa Against Ischemia-Reperfusion-Induced Injury Through Involvement of Glucocorticoids

Remote ischemic preconditioning (RIPC) is one of the most effective approaches to attenuate tissue injury caused by severe ischemia-reperfusion (I/R). Experimental studies have demonstrated that RIPC is capable of producing a protective effect not only on heart, but also on brain, lungs, kidneys, liver, intestine, and stomach. We previously demonstrated that glucocorticoids participate in protective effect of local gastric ischemic preconditioning against I/R-induced gastric injury. In the present study we investigated whether RIPC may protect the gastric mucosa against I/R-induced injury through involvement of glucocorticoids. Anesthetized fasted Sprague Dawley male rats were exposed to prolonged gastric I/R (30 min occlusion of celiac artery followed by 3 h of reperfusion) alone or with preliminary brief RIPC (10 min non-invasive occlusion of right hind limb blood flow followed by reperfusion for 30 min). First, we investigated the effect of RIPC on I/R-induced injury by itself. Then to study the role of glucocorticoids similar experiments were carried out: 1) in rats pretreated with the inhibitor of glucocorticoid synthesis, metyrapone (30 mg/kg, i.p), and in control animals; 2) in adrenalectomized rats without or with corticosterone replacement (4 mg/kg, s.c.) and in sham-operated animals; 3) in rats pretreated with glucocorticoid receptor antagonist RU-38486 (20 mg/kg, s.c.) and in control animals. I/R induced corticosterone rise and resulted in the gastric erosion formation. RIPC significantly reduced the erosion area in control animals. Metyrapone injected shortly before RIPC caused a decrease in plasma corticosterone levels and prevented the gastroprotective effect of RIPC and, moreover, further aggravated the deleterious effect of I/R. Adrenalectomy performed 1 week before experiment created long-lasting corticosterone deficiency and had no effect on the gastroprotective effect of RIPC. Nevertheless, corticosterone replacement which mimics the corticosterone rise, similar to RIPS, significantly reduced erosion areas of gastric mucosa in adrenalectomized rats supporting the role of glucocorticoids in gastroprotection. RU-38486, which occupied glucocorticoid receptors, similar to metyrapone prevented the gastroprotective effect of RIPC and, moreover, further aggravated the deleterious effect of I/R. The results of the present study demonstrate for the first time that RIPC may protect the gastric mucosa against I/R-induced injury through involvement of glucocorticoids.

Intestinal ischemic reperfusion injury: Recommended rats model and comprehensive review for protective strategies

Intestinal ischemic reperfusion injury (IIRI) is a life-threatening condition with high morbidity and mortality in the clinic. IIRI was induced by intestinal ischemic diseases such as, small bowel transplantation, aortic aneurysm surgery, and strangulated hernias. Although related mechanisms have not been fully elucidated, during the last decade, researches have demonstrated that many factors are crucial in the pathological process, including oxidative stress (OS), epithelial barrier function disorder, and so on. Rats model, as the most applied animal IIRI model, provides specific targets for researches and therapeutic strategies. Moreover, various treatment strategies such as, anti-oxidative stress, anti-apoptosis, and anti-inflammation, have shown promising effects in alleviating IIRI. However, current researches cannot solve the clinical problems of IIRI, and specific treatment strategies are still needed to be exploited. This review focuses on a recommended experimental IIRI rat model and understanding of the involved mechanisms such as, OS, gut bacteria translocation, apoptosis, and necroptosis, aim at providing novel ideas for therapeutic strategies of IIRI.

Cinnamaldehyde protects against rat intestinal ischemia/reperfusion injuries by synergistic inhibition of NF-κB and p53

Our preliminary study shows that cinnamaldehyde (CA) could protect against intestinal ischemia/reperfusion (I/R) injuries, in which p53 and NF-κB p65 play a synergistic role. In this study, we conducted in vivo and in vitro experiments to verify this proposal. SD rats were pretreated with CA (10 or 40 mg · kg⁻¹ · d⁻¹, ig) for 3 days, then subjected to 1 h mesenteric ischemia followed by 2 h reperfusion. CA pretreatment dose-dependently ameliorated morphological damage and reduced inflammation evidenced by decreased TNF-α, IL-1β, and IL-6 levels and MPO activity in I/R-treated intestinal tissues. CA pretreatment also attenuated oxidative stress through restoring SOD, GSH, LDH, and MDA levels in I/R-treated intestinal tissues. Furthermore, CA pretreatment significantly reduced the expression of inflammation/apoptosis-related NF-κB p65, IKKβ, IK-α, and NF-κB p50, and downregulated apoptotic protein expression including p53, Bax, caspase-9 and caspase-3, and restoring Bcl-2, in I/R-treated intestinal tissues. We pretreated IEC-6 cells in vitro with CA for 24 h, followed by 4 h hypoxia and 3 h reoxygenation (H/R) incubation. Pretreatment with CA (3.125, 6.25, and 12.5 μmol · L⁻¹) significantly reversed H/R-induced reduction of IEC-6 cell viability. CA pretreatment significantly suppressed oxidative stress, NF-κB activation and apoptosis in H/R-treated IEC-6 cells. Moreover, CA pretreatment significantly reversed mitochondrial dysfunction in H/R-treated IEC-6 cells. CA pretreatment inhibited the nuclear translocation of p53 and NF-κB p65 in H/R-treated IEC-6 cells. Double knockdown or overexpression of p53 and NF-κB p65 caused a synergistic reduction or elevation of p53 compared with knockdown or overexpression of p53 or NF-κB p65 alone. In H/R-treated IEC-6 cells with double knockdown or overexpression of NF-κB p65 and p53, CA pretreatment caused neither further decrease nor increase of NF-κB p65 or p53 expression, suggesting that CA-induced synergistic inhibition on both NF-κB and p53 played a key role in ameliorating intestinal I/R injuries. Finally, we used immunoprecipitation assay to demonstrate an interaction between p53 and NF-κB p65, showing the basis for CA-induced synergistic inhibition. Our results provide valuable information for further studies.

Ischaemic preconditioning and pharmacological preconditioning with dexmedetomidine in an equine model of small intestinal ischaemia-reperfusion

Small intestinal strangulation associated with ischaemia-reperfusion injury (IRI) is common in horses. In laboratory animals IRI can be ameliorated by ischaemic preconditioning (IPC) and pharmacological preconditioning (PPC) with dexmedetomidine. The aim of this study was to determine the effect of PPC with dexmedetomidine or IPC in an equine model of small intestinal ischaemia-reperfusion (IR). In a randomized controlled experimental trial, 15 horses were assigned to three groups: control (C), IPC, and PPC with dexmedetomidine (DEX). All horses were placed under general anaesthesia and 90% jejunal ischaemia was induced for 90 minutes, followed 30 minutes of reperfusion. In group IPC, three short bouts of ischaemia and reperfusion were implemented, and group DEX received a continuous rate infusion of dexmedetomidine prior to the main ischaemia. Jejunal biopsies were collected before ischaemia (P), and at the end of ischaemia (I) and reperfusion (R). Mucosal injury was assessed by the Chiu-Score, inflammatory cells were stained by cytosolic calprotectin. The degree of apoptosis and cell necrosis was assessed by cleaved-caspase-3 and TUNEL. Parametric data were analyzed by two-way ANOVA for repeated measurements followed by Dunnetts t-test. Non parametric data were compared between groups at the different time points by a Kruskal-Wallis-Test and a Wilcoxon-2-Sample-test. The mucosal injury score increased during I in all groups. After reperfusion, IRI further progressed in group C, but not in IPC and DEX. In all groups the number of cleaved caspase-3 and TUNEL positive cells increased from P to I. The number of TUNEL positive cells were lower in group DEX compared to group C after I and R. Infiltration with calprotectin positive cells was less pronounced in group DEX compared to group C, whereas in group IPC more calprotectin positive cells were seen. In conclusion, IPC and DEX exert protective effects in experimental small intestinal ischaemia in horses.

Intestinal and Limb Ischemic Preconditioning Provides a Combined Protective Effect in the Late Phase, But not in the Early Phase, Against Intestinal Injury Induced by Intestinal Ischemia-Reperfusion in Rats

Intestinal ischemia/reperfusion (I/R) injury is associated with high morbidity and mortality. This study aimed to compare the protective efficacy of intestinal ischemic preconditioning (IIPC) and limb ischemic preconditioning (LIPC) against intestinal I/R injury and investigate their combined protective effect and the underlying mechanism. Male Sprague-Dawley rats were pretreated with IIPC, LIPC, or IIPC plus LIPC (combined), and intestinal I/R or sham operation was performed. The animals were sacrificed at 2 and 24 h after reperfusion and then blood and tissue samples were harvested for further analyses. In additional groups of animals, a 7-day survival study was conducted. The results showed that ischemic preconditioning (IPC) improved the survival rate and attenuated intestinal edema, injury, and apoptosis. IPC decreased the levels of tumor necrosis factor-α, interleukin -6, malondialdehyde and myeloperoxidase, and increased the activity of superoxide dismutase in serum and intestine after the I/R event. IPC downregulated the expression of Toll-like receptor-4 (TLR4) and nuclear factor-kappa B (NF-κB). The effect of combined pretreatment was better than that of single pretreatment in the late phase (24 h), but not in the early phase (2 h). The study demonstrated that IPC could significantly attenuate intestinal injury induced by intestinal I/R via inhibiting inflammation, oxidative stress, and apoptosis. IIPC and LIPC conferred no synergy in protecting I/R-induced intestinal injury in the early phase, but combined preconditioning had clearly stronger protection in the late phase, which was associated with the inhibition of the activated TLR4/NF-κB signaling pathway. It suggested that LIPC or combined preconditioning could potentially be applied in the clinical settings of surgical patient care.

The role of ischemic preconditioning in the expression of apoptosis-related genes in a rat model of intestinal ischemia-reperfusion injury

Purpose:

To analyze the effects of ischemic preconditioning (IPC) in the expression of apoptosis-related genes in rat small intestine subjected to ischemia and reperfusion.

Methods:

Thirty anesthetized rats underwent laparotomy and were drive into five groups: control (CG); ischemia (IG); ischemia and reperfusion (IRG); IPC and ischemia (IG+IPC); IPC and ischemia and reperfusion (I/RG+IPC). Intestinal ischemia was performed by clamping the superior mesenteric artery for 60 minutes, whereas reperfusion lasted for 120 minutes. IPC was carried out by one cycle of 5 minutes of ischemia followed by 10 minutes of reperfusion prior to the prolonged 60-minutes-ischemia and 120-minutes-reperfusion. Thereafter, the rats were euthanized and samples of small intestine were processed for histology and gene expression.

Results:

Histology of myenteric plexus showed a higher presence of neurons presenting pyknotic nuclei and condensed chromatin in the IG and IRG. IG+IPC and I/RG+IPC groups exhibited neurons with preserved volume and nuclei, along with significant up-regulation of the anti-apoptotic protein Bcl2l1 and down-regulation of pro-apoptotic genes. Moreover, Bax/Bcl2 ratio was lower in the groups subjected to IPC, indicating a protective effect of IPC against apoptosis.

Conclusion:

Ischemic preconditioning protect rat small intestine against ischemia/reperfusion injury, reducing morphologic lesions and apoptosis.

Ischemia Injury: A New Method Accelerates Bone Healing in a Rat Tibia Fracture Model

To find a simple and noninvasive method to promote fracture healing, we are trying to explore whether repetitive brief ischemia would promote bone healing. 88 rats divided into 6 groups were used to make right tibia closed fracture caused by the heavy weight collision method. Healthy side groups received homemade tourniquet placed on left and affected side group placed on right thigh 10 min inflated/10 min deflated 3 times every 24 hours or 48 hours after tibia fractured. Rats in control groups received homemade tourniquet uninflated placed on right thigh 1 hour every 24 hours or 48 hours. X-rays were checked at 1, 2, and 4 weeks. Micro-CT inspected the bone healing at 2 and 4 weeks. Serum cytokines, such as bone morphogenetic protein-2 (BMP-2), vascular endothelial growth factor (VEGF), diethanolamine enzyme activity unit of alkaline phosphatase (ALP) and transforming growth factor-β1 (TGF-β1), interleukin 10 (IL-10) and interleukin 6 (IL-6), were checked at 1, 2, and 4 weeks. Local histology was evaluated at 2 weeks. HE dye and BMP-2, VEGF, TGF-β, and ALP immunohistochemical stains were made. Callus areas of posterior-anterior and lateral views were calculated and repetitive brief ischemia increased the callus areas ratio at 1 and 2 weeks. Besides, from micro-CT results, repetitive brief ischemia increased the bone volume (BV) at 2 and 4 weeks and also increased the total bone tissue volume (TV) at 2 weeks and BV/TV at 4 weeks. The serum cytokines, such as BMP-2, VEGF, diethanolamine enzyme activity unit of ALP and TGF-β1, have increased by repetitive brief ischemia at 1, 2 weeks. It is opposite of affected side group that the level of serum IL-10 increased and IL-6 decreased in healthy side group at 1, 2 weeks. Repetitive brief ischemia increased the callus area at 2 weeks and boosted the synthesis of BMP-2, VEGF, TGF-β, and ALP in the fracture region at 2 weeks from tissue stains. Repetitive brief ischemia promotes bone healing no matter on the affected side or the healthy side limb.

The role of ischemic preconditioning in gene expression related to inflammation in a rat model of intestinal ischemia-reperfusion injury

PURPOSE

To investigate the gene expression related to inflammation on mice subjected to intestinal ischemia and reperfusion (I/R) and treated with ischemic preconditioning (IPC).

METHODS

Thirty rats (EPM-Wistar), distributed in five groups of six animals each, were underwent anesthesia and laparotomy. The ischemia time was standardized in 60 minutes and the reperfusion time 120 minutes. IPC was standardized in 5 minutes of ischemia followed by 10 minutes of reperfusion accomplished before I/R. The control group was submitted only to anesthesia and laparotomy. The other groups were submitted to ischemia, I/R, ischemia + IPC and I/R + IPC. It was collected a small intestine sample to analyses by Quantitative Polymerase Chain Reaction in real Time (RT-qPCR) and histological analyses. It was studied 27 genes.

RESULTS

The groups that received IPC presented downregulation of genes, observed in of genes in IPC+ischemia group and IPC+I/R group. Data analysis by clusters showed upregulation in I/R group, however in IPC groups occurred downregulation of genes related to inflammation.

CONCLUSION

The ischemia/reperfusion promoted upregulation of genes related to inflammation, while ischemic preconditioning promoted downregulation of these genes.

Knockdown of TNF‑α alleviates acute lung injury in rats with intestinal ischemia and reperfusion injury by upregulating IL‑10 expression

Intestinal ischemia and reperfusion (II/R) injury often triggers severe injury in remote organs, with the lungs being considered the main target. Excessive elevation of proinflammatory cytokines is a major contributor in the occurrence and development of II/R-induced acute lung injury (ALI). Therefore, the present study aimed to investigate whether blocking tumor necrosis factor-α (TNF-α) expression could protect the lungs from injury following II/R, and to explore the possible underlying mechanism involving interleukin-10 (IL-10). Briefly, II/R was induced in rats by 40 min occlusion of the superior mesenteric artery and celiac artery, followed by 8, 16 or 24 h of reperfusion. Subsequently, lentiviral vectors containing TNF-α short hairpin (sh)RNA were injected into the right lung tissues, in order to induce TNF-α knockdown. The severity of ALI was determined according to lung injury scores and lung edema (lung wet/dry weight ratio). The expression levels of TNF-α were analyzed by quantitative polymerase chain reaction (qPCR), western blotting and immunofluorescence (IF) staining. IL-10 expression, in response to TNF-α knockdown, was detected in lung tissues by qPCR and IF. The results detected marked inflammatory responses, and increased levels of lung wet/dry weight ratio and TNF-α expression, in the lungs of II/R rats. Conversely, treatment with TNF-α shRNA significantly alleviated the severity of ALI and upregulated the expression levels of IL-10 in lung tissues. These findings suggested that TNF-α RNA interference may exert a protective effect on II/R-induced ALI via the upregulation of IL-10. Therefore, TNF-α knockdown may be considered a potential strategy for the prevention or treatment of ALI induced by II/R in future clinical trials.

The expression of endothelial and inducible nitric oxide synthase and apoptosis in intestinal ischemia and reperfusion injury under the action of ischemic preconditioning and pentoxifylline

PURPOSE

To investigate the expression of nitric oxide synthase (NOS) and apoptosis associated with ischemic preconditioning (IPC) and pentoxifylline (PTX) in intestinal ischemia (I) and reperfusion (R) injury.

METHODS

Thirty male rats were assigned to 5 groups: (CG), no clamping of the superior mesenteric artery (90 minutes); (IR-SS) saline + ischemia (30 minutes) + reperfusion (60 minutes); (IR-PTX) PTX + ischemia (30 minutes) + reperfusion (60 minutes); (IPC-IR-SS) 5 minutes of ischemia + 5 minutes of reperfusion (IPC) + saline + I(30 minutes)+R(60 minutes); and (IPC-IR-PTX) IPC + PTX + I(30 minutes)+ R(60 minutes).

RESULTS

The application of IPC and PTX showed a significantly lower immunohistochemistry reaction for active caspase-3 (P<0.05) compared to IR+SS. The number of cells immunoreactive to BCL-2 was higher in the IR-PTX group (P>0.05). The NOS-2 expression (qRTPCR) in the IR-PTX group (P<0.05) was higher than the values for the IPC+IR-SS and IPC-IR-PTX groups. The NOS-3 expression was significantly upper in the IPC-IR-PTX group than in the CG (P<0.05), the IR-SS (P<0.05) and the IR-PTX (P<0.05) groups.

CONCLUSIONS

The BCL-2 and active caspase-3 showed beneficial effects on PTX and IPC. The expression of NOS-2 and NOS-3 in the IPC and IPC-PTX groups showed no synergistic effect.

Magnolol pretreatment attenuates heat stress-induced IEC-6 cell injury

OBJECTIVE

Heat stress (HS) is an important environmental stressor that adversely influences livestock during the summer. The aim of this study was to investigate whether magnolol protects against HS-induced intestinal epithelial cell injury.

MATERIALS AND METHODS

An intestinal epithelial cell line (IEC-6) was subjected to HS at 42 °C, with and without magnolol pretreatment. Cell injury was detected by monitoring lactate dehydrogenase (LDH) release. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay was used to assess cell proliferation and viability, including identifying effective concentrations of magnolol. Flow cytometry confirmed G1-phase cell-cycle arrest and its alleviation by magnolol. Active DNA synthesis was measured by incorporation of nucleic acid 5-ethynyl-2'-deoxyuridine (EdU). G1-phase cell-cycle-related gene expression was assessed by real-time reverse transcription polymerase chain reaction (RT-PCR) and levels of G1-phase-related proteins by Western blotting.

RESULTS

HS induced IEC-6 cell injury and decreased cell viability, as demonstrated by data from LDH and MTS assays, respectively. Based on a number of criteria, IEC-6 cells subjected to HS were arrested in the G1 phase of the cell cycle. Magnolol pretreatment decreased HS-induced cell injury through relief of this cell-cycle arrest.

CONCLUSIONS

Magnolol pretreatment attenuates HS-induced injury in IEC-6 cells. Magnolol is potentially promising as a protective strategy for HS in livestock.

Selenium Deficiency Facilitates Inflammation Following S. aureus Infection by Regulating TLR2-Related Pathways in the Mouse Mammary Gland

Selenium (Se) is an essential micronutrient affecting various aspects of health. Se deficiency has been associated with inflammation and immune responses. Mastitis poses a serious problem for humans and animals in the postpartum period. Staphylococcus aureus (S. aureus) is the most common infectious bacterial pathogen associated with mastitis. The present study sought to determine the effects and underlying mechanism of dietary Se on S. aureus-induced inflammation using a model of mouse mastitis. ELISA and Western blotting were performed to detect protein levels. Quantitative PCR (qPCR) was performed to detect messenger RNA (mRNA) levels. The histopathological changes indicated that Se deficiency resulted in increased inflammatory lesions in S. aureus mastitis, whereas Se deficiency did not induce inflammatory lesions in the mammary gland. Myeloperoxidase (MPO) activity was increased in Se-deficient mice with S. aureus mastitis. Analysis of cytokine mRNA and protein showed that Se deficiency leads to increased TNF-α, IL-1β, and IL-6 production in S. aureus mastitis. In addition, Se deficiency enhanced the mRNA and protein expressions of toll-like receptor 2 (TLR2), which were originally upregulated by S. aureus in the mammary gland tissues and human embryonic kidney 293 (HEK293)-mTLR2 cells. When Se-deficient mice were infected with S. aureus, the phosphorylation of IκB, nuclear factor-κB (NF-κB), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 was greatly increased. The results indicate that Se deficiency could intensify the inflammatory reaction in S. aureus mastitis. This work contributes to the exploration of new methods of preventing or treating of S. aureus mastitis and other infectious diseases.

Intestinal ischemic preconditioning reduces liver ischemia reperfusion injury in rats

The aim of the current study was to investigate whether intestinal ischemic preconditioning (IP) reduces damage to the liver during hepatic ischemia reperfusion (IR). Sprague Dawley rats were used to model liver IR injury, and were divided into the sham operation group (SO), IR group and IP group. The results indicated that IR significantly increased Bax, caspase 3 and NF-κBp65 expression levels, with reduced expression of Bcl-2 compared with the IP group. Compared with the IR group, the levels of AST, ALT, MPO, MDA, TNF-α and IL-1 were significantly reduced in the IP group. Immunohistochemistry for Bcl-2 and Bax indicated that Bcl-2 expression in the IP group was significantly increased compared with the IR group. In addition, IP reduced Bax expression compared with the IR group. The average liver injury was worsened in the IR group and improved in the IP group, as indicated by the morphological evaluation of liver tissues. The present study suggested that IP may alleviates apoptosis, reduce the release of pro-inflammatory cytokines, ameloriate reductions in liver function and reduce liver tissue injury. To conclude, IP provided protection against hepatic IR injury.

Cardio-Pulmonary-Renal Interactions: A Multidisciplinary Approach

Over the past decade, science has greatly advanced our understanding of interdependent feedback mechanisms involving the heart, lung, and kidney. Organ injury is the consequence of maladaptive neurohormonal activation, oxidative stress, abnormal immune cell signaling, and a host of other mechanisms that precipitate adverse functional and structural changes. The presentation of interorgan crosstalk may include an acute, chronic, or acute on chronic timeframe. We review the current, state-of-the-art understanding of cardio-pulmonary-renal interactions and their related pathophysiology, perpetuating nature, and cycles of increased susceptibility and reciprocal progression. To this end, we present a multidisciplinary approach to frame the diverse spectrum of published observations on the topic. Assessment of organ functional reserve and use of biomarkers are valuable clinical strategies to screen and detect disease, assist in diagnosis, assess prognosis, and predict recovery or progression to chronic disease.

Ischemic preconditioning ameliorates intestinal injury induced by ischemia-reperfusion in rats

AIM: To evaluate preventative effects of ischemic preconditioning (IP) in a rat model of intestinal injury induced by ischemia-reperfusion (IR).

METHODS: Male Sprague-Dawley rats (250-300 g) were fasted for 24 h with free access to water prior to the operation. Eighteen rats were randomly divided into three experimental groups: S group (n = 6), rats were subjected to isolation of the superior mesenteric artery (SMA) for 40 min, then the abdomen was closed; IR group (n = 6), rats were subjected to clamping the SMA 40 min, and the abdomen was closed followed by a 4-h reperfusion; IP group (n = 6) rats underwent three cycles of 5 min ischemia and 5 min reperfusion, then clamping of the SMA for 40 min, then the abdomen was closed and a 4-h reperfusion followed. All animals were euthanized by barbiturate overdose (150 mg/kg pentobarbital sodium, i.v.) for tissue collection, and the SMA was isolated via median abdominal incision. Intestinal histologic injury was observed. Malondialdehyde (MDA), myeloperoxidase (MPO) and tumor necrosis factor (TNF)-α concentrations in intestinal tissue were measured. Intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 expression, as well as nuclear factor (NF)-κB activity and expression in intestinal tissue were also determined.

RESULTS: Compared with the IR group, IP reduced IR-induced histologic injury of the intestine in rats (2.00 ± 0.71 vs 3.60 ± 0.84, P < 0.05). IP significantly inhibited the increase in MDA content (5.6 ± 0.15 μmol/L vs 6.84 ± 0.18 μmol/L, P < 0.01), MPO activity (0.13 ± 0.01 U/L vs 0.24 ± 0.01 U/L, P < 0.01), and TNF-α levels (7.79 ± 2.35 pg/mL vs 10.87 ± 2.48 pg/mL, P < 0.05) in the intestinal tissue of rats. IP also markedly ameliorated the increase in ICAM-1 (204.67 ± 53.27 vs 353.33 ± 45.19, P < 0.05) and VCAM-1 (256.67 ± 58.59 vs 377.33 ± 41.42, P < 0.05) protein expression in the intestinal tissues. Additionally, IP remarkably decreased NF-κB activity (0.48 ± 0.16 vs 0.76 ± 0.22, P < 0.05) and protein expression (320.23 ± 38.16 vs 520.76 ± 40.53, P < 0.01) in rat intestinal tissue.

CONCLUSION: IP may protect against IR-induced intestinal injury by attenuation of the neutrophil-endothelial adhesion cascade via reducing ICAM-1 and VCAM-1 expression and TNF-α-induced NF-κB signaling pathway activity.