Intestinal mucosal lesion in low-flow states. I. A morphological, hemodynamic, and metabolic reappraisal

Sevoflurane alleviates intestinal ischemia-reperfusion injury in aged mice

Sevoflurane is a widely used inhalation anesthetic during the perioperative period. Recent studies have suggested that sevoflurane has an enteroprotective effect, but its mechanism is unclear. To explore the mechanism of sevoflurane in intestinal ischemia‒reperfusion injury, an intestinal ischemia‒reperfusion injury mouse model was established. First, intestinal ischemia‒reperfusion injury was compared between aged and young mice. The results showed that intestinal ischemia‒reperfusion injury caused pathological intestinal injury and disrupted the intestinal mucosal barrier. The aged mice had more severe intestinal ischemia‒reperfusion injury than the young mice and therefore had a lower survival rate. The aged mice subsequently received sevoflurane via inhalation. Sevoflurane alleviated the pathological injury to the intestinal mucosa and repaired the function of the intestinal mucosal barrier in aged mice, thus increasing the level of intestinal mucosal hypoxia-inducible factor-1α and improving the survival rate of aged mice. However, preoperative administration of the hypoxia-inducible factor-1α inhibitor BAY87-2243 could counteract the enteroprotective effect of sevoflurane and lower the expression level of heme oxygenase-1, a downstream antioxidant enzyme of hypoxia-inducible factor-1α. Our findings suggest that sevoflurane alleviates intestinal ischemia‒reperfusion injury in aged mice by repairing the intestinal mucosal barrier through the activation of hypoxia-inducible factor-1α/heme oxygenase-1, providing a new target for the treatment of intestinal ischemia‒reperfusion injury in aged mice.

Impact of sodium butyrate on stroke-related intestinal injury in diabetic mice: Interference with Caspase-1/GSDMD pyroptosis pathway and preservation of intestinal barrier

Diabetic stroke-associated acute intestinal injury is characterized by high mortality, disability, and poor prognosis due to the lack of effective therapies. Our prior research demonstrated that administration of 300 mg/kg sodium butyrate (NaB) can improve neurological outcomes post-diabetic stroke. Nonetheless, whether the effect of NaB is related to intestinal regulation, along with its underlying mechanisms, remains uncertain. This study aims to investigate the effects and mechanistic pathways of NaB on diabetic stroke-associated acute intestinal injury. A middle cerebral artery occlusion/reperfusion model was established in mice with streptozotocin-induced diabetes. The results demonstrated that NaB alleviated colonic injury 24 h after reperfusion in diabetic stroke. Pyroptosis-related protein levels in colonic tissues were significantly elevated following diabetic stroke but were markedly reduced with NaB treatment. NaB also improved gut barrier integrity and reduced inflammation, promoting epithelial barrier self-repair. In the NaB combined with lipopolysaccharide group, lipopolysaccharide administration induced a significant inflammatory response in the colonic tissue. Conversely, treatment with NaB and VX-765 (an inhibitor for Caspase-1) led to a notable alleviation in intestinal inflammation. These findings suggest that NaB mitigates colonic injury and enhances barrier function following diabetic stroke, potentially through the Caspase-1/Gasdermin D pyroptosis pathway. This study may provide a novel strategy and direction for intestinal rehabilitation in diabetic stroke patients.

Intestinal alterations of mucosal barrier integrity, motility and enteric nerve in cynomolgus monkey model of Parkinson's disease

The most prevalent non-motor symptoms in individuals with Parkinson's disease (PD) such as constipation and bloating that significantly impact patients' quality of life. However, the pathophysiological mechanisms underlying these symptoms remain unclear. PD model with typical and stable symptoms was induced by individualized dosing of MPTP with Kurlan score increased to 10 or above and remained steady for three months or more. TH-positive neurons in the injured substantia nigra (SN) of the brain of PD monkeys showed up to 83.95 % reduction. Histopathological examination indicated severe damage to both enteric nerve and TH neurons, along with significant disruption of mucosal structure, intestinal barrier integrity and motility in PD monkeys across all four intestinal segments, including the duodenum, ileum, transverse colon, and rectum. The association between dopaminergic neuronal deficits in SN and these above mentioned intestinal disorders, that might be attributed to the abnormal regulation of gastrointestinal function due to the breakdown of the integrity of the nigrostriatal dopaminergic nervous system. Therefore, the abnormal alterations found in gut of PD monkeys and its triggered possible secondary pathophysiological cascade reactions might be a potential mechanism underlying the presence of constipation and other intestinal symptoms observed in PD patients. These findings in this study provide a valuable scientific basis for investigating the pathogenesis of gastrointestinal symptoms in PD patients and potential therapeutic approaches. (The graphical abstract is by Figdraw).

Dual-modality ultrasound/photoacoustic tomography for mapping tissue oxygen saturation distribution in intestinal strangulation

The strangulation of intestinal obstruction (IO) presents challenges in the assessment of disease progression and surgical decision-making. Intraoperatively, an accurate evaluation of the status of the IO is critical for determining the extent of surgical resection. Dual-modality ultrasound/photoacoustic tomography (US/PAT) imaging has the potential to provide spatially resolved tissue oxygen saturation (SO₂), serving as a valuable marker for IO diagnosis. In this study, US/PAT was utilized for imaging rat models of IO, with the data used for reconstruction, statistical analysis, and distribution evaluation. Results showed that SO₂ decreased with increasing strangulation severity. Notably, the kurtosis and skewness of the SO₂ distribution outperformed SO₂ itself in diagnosis, as they more effectively capture the heterogeneity of SO₂ distribution. Kurtosis reflects distribution concentration, while skewness measures asymmetry, both achieving areas under the receiver operating characteristic curve (AUROC) of 0.969. In conclusion, US/PAT offers a rapid and convenient method for assessing strangulation in IO.

Protective Effect of Obeticholic Acid on Sepsis-Induced Liver Dysfunction via Regulating Bile Acid Homeostasis

Background/Objectives: Abnormal bile acid (BA) pool may play an important role in inducing liver damage in sepsis. Farnesoid X receptor (FXR) is a main negative feedback regulator of BA metabolism. This study aims to explore the protective effect and mechanism of the FXR agonist obeticholic acid (OCA) on liver dysfunction when sepsis occurs. Methods: A rat model of sepsis was induced by cecal ligation and puncture (CLP) for 24 h. Systematic inflammation, tissue injury, hepatic FXR, and BA transporter expression were investigated in the CLP rats and sham-operated control rats with and without OCA pre-treatment (10 mg/kg, gavage) at 2 h before operation. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was performed to access BA composition in the rats' serum and livers. The injury and inflammatory effects of the elevated unconjugated BAs found in the CLP rats was further verified in a hepatic cell line BRL-3A in vitro. Results: Hepatic FXR was repressed in CLP rats, whereas OCA upregulated liver FXR and hepatic BA transporter expression, reduced total serum BA concentration, ameliorated the elevation of serum levels of IL-1β and IL-6, and improved liver and ileal tissue injuries. OCA administration reduced the elevated unconjugated BAs in both serum and liver, and effectively inhibited increases in cholic acid (CA), deoxycholic acid (DCA), and 7-ketoDCA concentrations in CLP rat livers. These BA fractions promoted the release of aspartate aminotransferase (AST) from BRL-3A cells and increased IL-6, CXCL2, and monocyte chemoattractant protein-1 (MCP-1) expression in the cells, along with enhanced transcription factor nuclear factor-κB activation. Conclusions: Liver inflammation and dysfunction during sepsis is attributable to significant changes in bile acid composition in the blood and liver. FXR activation reduces systemic inflammation and liver dysfunction by regulating bile acid homeostasis, especially inflammatory unconjugated bile acid components.

Chlorpyrifos Inhibits Intestinal Stem Cell Proliferation and Differentiation at the Acceptable Daily Intake and Disrupts Immune Responses at High Doses

The acceptable daily intake (ADI) and maximum residue limits in food for chlorpyrifos (CPF), a widely used organophosphorus pesticide, may damage the intestine. Here, we evaluated damage to the intestine by CPF at the ADI (0.01 mg/kg bodyweight/day) and at 10 times the ADI (10ADI; 0.1 mg/kg bodyweight/day) in mice after 8 weeks of exposure and evaluated the resulting immune response to an enterotoxigenic Escherichia coli (ETEC) infection. CPF at the ADI dose significantly disrupted the intestinal integrity and intestinal stem cell functionality, which may be associated with reduced indole-3-propionic acid levels. However, mice in the 10ADI group exhibited only elevated pro-inflammatory cell and cytokine levels. During ETEC infection, intestinal mucosal immunity was activated by the 10ADI dose, as indicated by increased regulatory T cells and IL-10 levels, which were associated with decreased fecal butyric acid content. Our study demonstrated that the effects of pesticide residues appear to be dose-specific, bringing attention to the health risk at the ADI level.

Effects of Resveratrol on Intestinal Flora and Metabolism in Rats With Non-Steroidal Anti-Inflammatory Drug-Induced Intestinal Injury Under Plateau Hypoxia Environment

The plateau hypoxic environment is a main habitat for human beings, which can result in dysbiosis of the intestinal flora. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used anti-inflammatory drugs that can cause intestinal damage with long-term administration. Moreover, the administration of these drugs in the hypoxic plateau environment may exacerbate intestinal damage. This study aimed to investigate the therapeutic effect of resveratrol (RSV) on the intestinal injury induced by NSAIDs in rats under plateau hypoxia. Aspirin was used as the inducer to induce intestinal injury in rats. Rats were divided into seven groups: Ck (vehicle group), HCk (high-altitude control group), PAsp (plain aspirin-treated group), HAsp (High-altitude aspirin-treated group), RSVL (low-dose resveratrol-treated group), RSVM (medium-dose resveratrol-treated group), and RSVH (high-dose resveratrol-treated group). The body weight of the rats was recorded every 7 days during the experiment. On the last day of the experiment, jejunal tissues of the rats were collected for hematoxylin and eosin staining (H&E), and feces of the rats were collected for analysis of intestinal flora and metabolite analysis. The results demonstrated that RSV inhibited weight loss and intestinal damage initiated by aspirin administration in a hypoxic plateau environment. Moreover, it markedly elevated the expression levels of interleukin (IL)-10 and superoxide dismutase (SOD) while substantially reducing the expression levels of TNF-α, IL-1β, and myeloperoxidase (MPO). Furthermore, 16SrRNA gene sequence analysis showed that both aspirin and RSV altered the composition and structure of rat gut microbiomes. Metabolomics results showed that RSV altered the intestinal metabolites of aspirin-induced intestinal injury in rats, reducing the content of 2-hydroxy-3- (4-hydroxyphenyl) protonic acid and 3- [(1-carboxyvinyl) oxy] benzoate and increasing the content of coumaryl, 3-amino-4 hydroxybenzoate, and L-carnitine. Resveratrol can alleviate NSAID (Aspirin)-induced intestinal damage in the hypoxic environment of the plateau by regulating intestinal flora and metabolites, with the best effect in the RSVM group (50 mg/kg).

Improving Intestinal Barrier Function in Sepsis by Partially Hydrolysed Guar Gum via the Suppression of the NF-κB/MLCK Pathway

Partially hydrolyzed guar gum (PHGG) protects against intestinal barrier dysfunction and can ameliorate some intestinal diseases. However, whether PHGG has a role in protecting intestinal barrier function (IBF) during sepsis remains unclear. This study aimed to investigate the role and probable mechanism of PHGG in the intestinal mucosa in sepsis. A rat sepsis model was constructed using cecal ligation and puncture (CLP). FITC-dextran 4 (FD-4) flux, serum inflammatory mediator levels, tight junction (TJ) levels, jejunum mucosa pathology, and epithelial intercellular junction ultrastructure were monitored to evaluate the effect of PHGG on IBF. Caco-2 monolayers were used to study the impact and mechanism of PHGG on lipopolysaccharide (LPS)-induced barrier dysfunction in vitro. The expression of zonula occludens protein-1 and occludin and the location of P65 were studied by immunofluorescence. Nuclear factor kappa B (NF-κB) and myosin light chain kinase 3 (MLCK) pathway-related protein expression was verified by quantitative reverse transcriptase polymerase chain reaction or western blotting. The results indicated that the jejunal mucosa structure was destroyed, the villi were disrupted and shortened, and neutrophil infiltration was evident in the septic rats. Compared to Sham group, spetic rats had increased Chiu's score, serum inflammatory mediator levels, and FD-4 flux but decreased TJ and gap junction density. In addition, the expression of MLCK, p-MLC, and TJ proteins and the expression of P65 in the nucleus were increased in septic rats. Furthermore, compared to those in the Control group, LPS-treated Caco-2 cells showed lower cell viability and transepithelial electrical resistance, while had higher FD-4 flux and the expression of MLCK, p-MLC, TJ proteins and P65 in the nucleus. PHGG pretreatment reversed the above effects induced by CLP or LPS treatment. Moreover, SN50, an NF-κB inhibitor, attenuated the above effects of LPS on Caco-2 cells. Overall, PHGG reduced inflammation, increased TJ protein expression and localization, and relieved damage to the TJ structure and intestinal permeability through suppression of the NF-κB/MLCK pathway. This study provides new insights into the role of PHGG in sepsis therapy.

Octreotide attenuates intestinal ischemia/reperfusion mischief in rats through modulation of Nrf2/PRX2/ASK1/JNK signaling pathway

Intestinal ischemia/reperfusion (IIR) is a substantial cause of mortality and morbidity worldwide. Octreotide (OCT) has been proven to be effective against various organ insults. However, the exact mechanism by which it exerts protective effect against IIR is still obscure. Thus, the aim was to unveil the potential role of octreotide in an IIR model and decipher its mechanism of action. The rats were allocated into sham-operated, IIR, and OCT groups. Histopathological changes were performed to assess the intestinal injury. Immunohistochemical analysis was used to estimate the NF-κB, Bcl2, caspase-3, IL-17, LC3B, and beclin-1. The mRNA of TNF-α and IL-17 were examined using real time PCR. The levels of p-Nrf2, PRX2, p-JNK, ASK1, and LC3 were assessed using western blot technique. The levels of total antioxidant capacity and SOD were measured using appropriate kits. Furthermore, the protein expressions of Bax, caspase-3, ASK1, and Nrf2 were assessed using proper ELISA kits. Additionally, the comet assay was determined to investigate the effect on apoptosis. At the molecular level, OCT administration upregulated TAC and SOD levels, demonstrating its antioxidant effect. The anti-apoptotic effect was signified by the upregulation of Bcl2 and downregulation of Bax and caspase-3, which was confirmed by comet assay. Furthermore, OCT decreased the levels of TNF-α, NF-κB, and IL-17, confirming its anti-inflammatory effect. OCT pre-treatment triggered autophagy, as evidenced by the upregulation of beclin-1 and LC3B. These effects were accomplished by increasing p-Nrf2 and PRX2 and decreasing ASK1 and p-JNK. Consequently, this impeded the necrosis of intestinal cells and improved the intestinal histoarchitecture abnormalities. Ultimately, OCT successfully ameliorated IIR injury via modulating the Nrf2/PRX2/ASK1/JNK signaling trajectory, leading to autophagic, antioxidant, anti-apoptotic, and anti-inflammatory effects.

Apigenin Alleviates Intestinal Ischemia/Reperfusion Injury via Upregulating Nrf2-Mediated Tight Junction Integrity

Epithelial barrier dysfunction, critically involved in intestinal ischemia/reperfusion (I/R) injury, is significantly regulated by Nrf2-mediated oxidative stress. Apigenin, a flavonoid commonly found in fruits and vegetables with diverse biological properties, has an unclear impact on intestinal I/R injury. We hypothesize that apigenin improves intestinal barrier dysfunction by activating Nrf2 signaling. Thirty rats were randomly divided into five groups to establish an I/R model using superior mesenteric artery occlusion. Hypoxia and re-oxygenation (H/R) model was developed utilizing Caco-2 and IEC-6 cells, which were exposed to hypoxic conditions followed by re-oxygenation. Apigenin protected against intestinal mucosal damage by suppressing inflammatory cytokines release (TNF-α, IL-1β, IL-6, MPO, p < 0.01), ameliorating oxidative stress (MDA, SOD, GSH, GSH-Px, p < 0.01), and improving barrier dysfunction (DAO and TEER, p < 0.01) both in vivo and in vitro, without causing significant changes in the corresponding normal controls (p > 0.05). Apigenin up-regulated the protein expression of Nrf2, HO-1, and tight junction (TJ) proteins (p < 0.01). Furthermore, the knockdown of Nrf2 significantly abrogated apigenin-enhanced the TJ expression. Apigenin pretreatment alleviates intestinal I/R-induced barrier damage through Nrf2 activation and TJ upregulation, offering new strategies for preventing or treating I/R-associated intestinal diseases.

Mucosal Immunity: Lessons from the Lower Respiratory and Small Intestinal Epithelia

Mucosal epithelia represent a diverse group of tissues that function as a barrier against the external environment and exert a wide variety of tissue-specific secondary functions. This review focuses on the lower respiratory tract and small intestinal epithelia, which serve as two distinct sites within the body with respect to their physiological functions. This review provides an overview of their physiology, including both physiological and mechanical defense systems, and their immune responses, which allow both tissues to tolerate commensal organisms while mounting a response against potential pathogens. By highlighting the commonalities and differences across the two tissue types, opportunities to learn from these tissues emerge, which can inform the development of novel therapeutic strategies that harness the unique properties of mucosal epithelia.

Crude Polygalae Radix after boiling with licorice decoction alleviates intestinal mucosal barrier injury of rats by regulating TLR4/NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Polygala tenuifolia Willd. (pharmacologically termed Polygalae Radix, PR), a nootropic botanical in traditional Chinese medicine, demonstrates anxiolytic and cognitive-enhancing properties with two millennia of documented therapeutic applications. Long-term or large-dose use of crude Polygalae Radix (CPR) causes intestinal injury, which could be reduced by use of Glycyrrhiza uralensis Fisch. (licorice) decoction-boiled Polygalae Radix. However, the effects of boiling CPR with licorice decoction on reducing intestinal mucosal barrier injury have not been studied.

AIM OF THE STUDY

Our research mainly focused on the alleviating effects and underlying mechanism of CPR after boiling with licorice decoction on intestinal mucosal barrier injury in rats.

METHODS AND MATERIALS

SD rats were orally administered CPR and licorice decoction-boiled PR (LPR) extracts respectively for 15 consecutive days. Subsequently, levels of pro-inflammatory cytokines and immunoglobulins were measured, and histopathological changes in intestinal tissues were examined. The mRNA expression levels of pro-inflammatory cytokines were evaluated by qRT-PCR. The expression difference of TLR4/NF-κB signaling pathway key protein and tight junction (TJ) protein were evaluated using Western blotting and immunohistochemistry.

RESULTS

Processing PR with licorice decoction significantly ameliorated the downregulation of intestinal TJ proteins (occludin, claudin-1, and ZO-1) and elevated serum lipopolysaccharide levels induced by CPR. It alleviated the suppression of intestinal immunoglobulin A, serum immunoglobulin A and immunoglobulin G levels caused by CPR while mitigating intestinal mucosal injury and inflammatory responses. Additionally, processing PR with licorice decoction inhibited CPR-triggered upregulation of TLR4, NF-κB p65, p-NF-κB p65, and p-κBα proteins expression, while preventing IκBα downregulation in intestinal tissues. Furthermore, it significantly suppressed the upregulation of interleukin (IL)-6, IL-8, and tumor necrosis factor-α (TNF-α) mRNA expression while concurrently inhibiting the secretion levels of these pro-inflammatory cytokines in small intestine.

CONCLUSION

Our experimental data suggest that licorice decoction boiling effectively prevents CPR-induced reductions in TJ proteins and immunoglobulins expression, alleviates intestinal mucosal barrier injuries, and mediates these effects through suppression of TLR4/NF-κB signaling pathway activation and subsequent production of IL-6, IL-8, and TNF-α.

MTX-induced gastrointestinal reactions in RA: Prevotella enrichment, gut dysbiosis, and PI3K/Akt/Ras/AMPK pathways

OBJECTIVES

To investigate the role of gut microbiota in methotrexate (MTX)-induced gastrointestinal reactions (MRGR) in patients with rheumatoid arthritis (RA).

METHODS

As a prospective, single-center, convenience sampling study, stool samples were obtained from 28 RA patients (male: female = 10:18) at Lanzhou University Second Hospital who were undergoing MTX treatment for analysis of their gut microbiota using 16S rRNA gene sequencing. Clinical disease activity (CDAI) and MRGR were assessed after two months of MTX therapy. All data collection periods exceeded one year. Intestinal germ-free mice, generated through antibiotic treatment, received fecal microbiota transplantation (FMT) from the patients, followed by varying doses of MTX to observe MRGR. Intestinal transcriptomics and markers related to intestinal barrier function were subsequently examined.

RESULTS

Females (84.6%) and high disease activity (CDAI scores, 39.6 ± 11.2 vs 26.3 ± 9.2) were prone to have MRGR in RA patients. Patients with MRGR (PT-GR) showed lower gut microbial diversity versus non-MRGR (PT-noGR). Prevotella abundance, positively correlated with CDAI and MRGR (p < 0.05), was elevated in PT-GR. Administering 10 mg/kg MTX to mice caused intestinal damage. FMT-GR-MTX mice exhibited weight loss (95.2%), morphological deterioration (86.4%), and reduced tight junction proteins (Claudin-1:72.4%; ZO-1:81.2%). Transcriptomics linked upregulated Gβγ/CREB/Atp4b to PI3K/Akt/Ras pathways and downregulated PFK2/PP2 to AMPK signaling in MRGR.

CONCLUSION

Our study identified notable gut microbiota alterations in RA patients prone to MRGR, with changes in intestinal gene expression and reduced intestinal barrier function potentially contributing to MRGR. These findings suggest potential strategies to mitigate MRGR in RA patients undergoing MTX treatment. Key Points • The RA-related MRGR is correlated with the intestinal microbiota. • Females, low gut diversity, and Prevotella enrichment are MRGR risks in RA. • Upregulated DEGs in MRGR linked to PI3K/Akt, Ras pathways. • Downregulated DEGs in MRGR focus on the AMPK pathway.

Role of Bifidobacterium animalis subsp. lactis BB-12 in mice with acute pancreatitis

Acute pancreatitis (AP) is a prevalent acute gastrointestinal disease, which may be prevented and alleviated by probiotics. Bifidobacterium animalis subsp. lactis BB-12 (BB-12) is a widely studied probiotic strain; however, its specific effects in this context remain unexplored. In this study, we aimed to investigate the prophylactic and therapeutic effects of BB-12 in AP. Our findings revealed that BB-12 administration via gavage significantly reduced pathological pancreatic damage and serum amylase activity. Microbiome analysis showed that BB-12 treatment significantly increased the relative abundance of Ligilactobacillus and decreased that of Bilophila in the gut microbiota of mice with AP. Transcriptome analysis revealed that BB-12 mitigated the AP-induced dysregulation of several pathways, specifically attenuating the upregulation of the pancreatic secretion and ascorbate and aldarate metabolism pathways while reversing the downregulation of the ribosome, oxidative phosphorylation, and thermogenesis pathways. Spearman's correlation analysis revealed a positive correlation between the abundances of Bilophila and ASF356 and serum amylase activity. Furthermore, the abundances of Bilophila and ASF356 were significantly correlated with BB-12-regulated pancreatic genes and were predominantly enriched in the ribosome pathway. In conclusion, BB-12 pretreatment alleviated AP, likely by regulating the abundance of intestinal Lactobacillus, Bilophila, and ASF356, as well as the pancreatic secretion, ascorbate and aldarate metabolism, oxidative phosphorylation, ribosome, and thermogenesis pathways.

Paricalcitol alleviates intestinal ischemia-reperfusion injury via inhibition of the ATF4-CHOP pathway

Introduction

Intestinal ischemia reperfusion (I/R) injury is a severe condition characterized by inflammation, oxidative stress, and compromised intestinal barrier function, which can lead to death. This study investigated the effects of paricalcitol, a synthetic vitamin D receptor (VDR) agonist, on intestinal I/R injury, focusing on the activating transcription factor 4 (ATF4)-C/EBP homologous protein (CHOP) signaling pathway and the modulation of endoplasmic reticulum stress (ERS).

Methods

This study consists of both in vivo and in vitro experiments. In vivo experiment, a mouse model of intestinal I/R injury was established by clamping the superior mesenteric artery, and followed by 24 or 72 h of reperfusion. 6-week-old male C57BL/6 J mice were randomly assigned to six groups: sham, I/R 24h, I/R 72 h, and their respective paricalcitol-treated counterparts. VDR knockout mice and wild-type mice were assigned to WT, VDR-KO, WT + I/R and VDR-KO + I/R groups. The paricalcitol-treated groups received oral gavage of paricalcitol (0.3 μg/kg) once daily for 5 days before I/R. In vitro, IEC-6 cells were incubated in a microaerophilic system (5% CO2, 1% O2, 94% N2) for 6 h to induce hypoxia. The cells were then transferred to complete medium with or without paricalcitol (200 nM) and cultured under normoxic conditions for 24 h to establish the hypoxia/re-oxygenation (H/R) model and investigate the protective effects of paricalcitol on H/R-induced injury in cells. We further utilized VDR- and ATF4-silenced cells to examine how paricalcitol regulates the expression of VDR, ATF4, and CHOP.

Results

We demonstrated that protective paricalcitol treatment reduces ERS and apoptosis by activating VDR and inhibiting the ATF4-CHOP pathway, thereby alleviating intestinal I/R injury in vivo and H/R injury in vitro. Furthermore, experiments with VDR knockout mice demonstrated that the absence of VDR exacerbated I/R injury, underscoring the protective role of VDR in intestinal epithelial cells.

Discussion

These findings suggest that the protective effects of paricalcitol may offer a promising therapeutic strategy for managing intestinal I/R injury.

Pathogenesis and therapeutic effect of sitagliptin in experimental diabetic model of COVID-19

This study evaluates the pathogenesis of COVID-19 and the therapeutic efficacy of sitagliptin in diabetic and obese mice. Using a novel double-transgenic mouse model (db/db and K18-hACE2), the findings demonstrates that SARS-CoV-2 infection (Delta variant) causes severe multi-organ damage, glucose metabolism abnormalities, insulin resistance, and pancreatic islet cell damage in diabetic mice. Infected diabetic mice displayed higher mortality, inflammation (elevated TNF-α, IL-6, IL-1β), and fibrinolytic activity (PAI-1), alongside dysregulated diabetes-related hormones (GLP-1, leptin, ghrelin, resistin) compared to non-diabetic controls. Sitagliptin treatment reduced organ injury, hyperglycemia, inflammation, and fibrinolytic activity while improving insulin resistance and glucose metabolism. This was evidenced by decreased fasting blood glucose levels, improved insulin sensitivity, and elevated insulin and GLP-1 levels. These findings suggest sitagliptin is a promising therapeutic strategy to mitigate the severity of COVID-19 in experimental diabetes by modulating inflammation and improving metabolic syndrome. Further mechanistic investigations revealed that the level of hACE2 expression, along with the activation of NF-κB and IRS-1, play critical roles in the development of SARS-CoV-2-induced diabetes, the exacerbation of pre-existing diabetes, and the therapeutic efficacy of sitagliptin.

Nonocclusive Mesenteric Ischemia: A Review for Interventional Radiologists

Nonocclusive mesenteric ischemia (NOMI) is a condition characterized by segmental or discontinuous mesenteric ischemia and intestinal necrosis without an organic obstruction in the mesenteric vessels. Diagnosis is challenging, and early intervention is crucial for improving patient outcomes. Various factors such as background factors, symptoms, biomarkers, and imaging techniques contribute to the diagnosis. Ensuring an early diagnosis and prompt treatment is of paramount importance. Although studies reported on the effectiveness of intra-arterial vasodilator infusion therapy as an endovascular treatment, its future role remains uncertain. Therefore, this review primarily aimed to provide a comprehensive summary of the advancements in the current state of NOMI management, with a specific emphasis on the implementation of endovascular therapy.

Protective Effects of a Polyherbal Mixture on Intestinal Injury via the NF-κB Signaling Pathway and Gut Microbiota Modulation in Hyperuricemic Mice

This study investigated the protective effects of a polyherbal tea (PHT) on intestinal injury in hyperuricemia (HUA) mice and the underlying mechanisms. PHT was orally administered to mice for 49 days, while potassium oxonate and hypoxanthine were administered 7 days after PHT administration and continued for 42 days to cause HUA. Treatment with PHT significantly reduced serum uric acid and blood urea nitrogen levels in HUA mice. It also inhibited liver xanthine oxidase activity and promoted intestinal uric acid excretion through the upregulation of transporters GLUT9 and ABCG2. Intestinal barrier integrity was reinforced, as evidenced by the restoration of the villous structure, reduction in edema, and upregulation of tight junction proteins (occludin, ZO-1) and mucin (MUC2). Moreover, PHT suppressed serum LPS levels and inhibited the NF-κB pathway, leading to a reduction in TNF-α and IL-6 levels in the gut. Gut microbiota analysis revealed PHT reversed dysbiosis, enriching beneficial bacteria like Duncaniella sp. and Heminiphilus faecis. By UPLC-MS analysis, 154 compounds of PHT persisted in the gut, suggesting that these compounds are likely to modulate both intestinal barrier function and gut microbiota. These findings suggest that this PHT may have potential as a functional food for the prevention of hyperuricemia.

Clostridium butyricum ameliorates indomethacin-induced enteropathy by promoting MUC2 secretion via suppressing the Notch pathway

Nonsteroidal anti-inflammatory drug (NSAID) enteropathy is a serious clinical complication with no effective treatments available. Modulating the intestinal microbiota through dietary and nutritional targets is a promising strategy for preventing NSAID enteropathy. This study aimed to investigate the protective effect and underlying mechanisms of the probiotic Clostridium butyricum (CB) on indomethacin (IND)-induced enteropathy. C57BL/6J mice received CB treatment for 14 days along with concurrent IND gavage for the final 7 days. Caco2 cells were stimulated with IND to evaluate the effect of CB supernatant (CBS) on the intestinal barrier function, and LS174T cells were used to validate the modulatory action of CBS on the Notch signaling pathway. Our findings revealed that CB treatment prevented anorexia and weight loss, reduced the severity of enteropathy, and decreased the inflammatory response of the small intestine. CB also increased the expression of tight junction proteins and reduced permeability in mice and Caco2 cells. Additionally, CB suppressed apoptosis and promoted proliferation in the small intestine. Further research found that CB increased the number of goblet cells and MUC2 secretion. Mechanistically, CB may promote MUC2 secretion by suppressing the Notch signaling pathway, consistent with the results of intervention in LS174T cells with CBS. In conclusion, CB might prevent NSAID enteropathy by increasing MUC2 secretion through the inhibition of the Notch pathway. Our study identified the potential efficacy of CB as a preventive strategy against NSAID enteropathy and showed promising prospects for CB as a food supplement.

Macrophage Membrane Coated Manganese Dioxide Nanoparticles Loaded with Rapamycin Alleviate Intestinal Ischemia-Reperfusion Injury by Reducing Oxidative Stress and Enhancing Autophagy

Background

Intestinal ischemia-reperfusion (I/R) injury is a common and severe clinical issue. With high morbidity and mortality, it burdens patients and the healthcare system. Despite the efforts in medical research, current treatment options are unsatisfactory, urging novel therapeutic strategies. Oxidative stress and dysregulated autophagy play pivotal roles in the pathogenesis of I/R injury, damaging intestinal tissues and disrupting normal functions. The aim of this study is to fabricate macrophage membrane-coated manganese dioxide nanospheres loaded with rapamycin [Ma@(MnO₂+RAPA)] for alleviating intestinal I/R injury.

Methods

We engineered honeycomb MnO2 nanospheres coated with a macrophage membrane to act as a drug delivery system, encapsulating RAPA. In vitro OGD/R model in IEC-6 cells and in vivo mouse I/R injury models were used. Targeting ability was evaluated through in-vivo imaging system. Effects on cell viability, reactive oxygen species (ROS) levels, oxygen generation, inflammatory factors, apoptosis, autophagy, and biocompatibility were detected by methods such as MTT assay, fluorescence microscopy, ELISA kit, TUNEL assay, Western blotting and histological analysis.

Results

In this study, Ma@(MnO₂+RAPA) efficiently deliver RAPA to damaged tissues and exhibited good ROS-responsive release. Our data showed that Ma@(MnO₂+RAPA) reduced ROS, increased O₂, inhibited inflammation, and promoted autophagy while reducing apoptosis in IEC-6 cells. In a mouse I/R model, Ma@(MnO₂+RAPA) significantly reduced Chiu's score, improved tight conjunction proteins, decreased apoptosis, reduced levels of inflammatory cytokines and oxidative stress. RAPA released from the Ma@(MnO₂+RAPA), enhanced the expression of autophagy-regulated proteins p62, Beclin-1, and LC3II. The biocompatibility and safety of Ma@(MnO₂+RAPA) were confirmed through histological analysis and biochemical detection in mice.

Conclusion

Our results demonstrated that Ma@(MnO₂+RAPA) alleviated intestinal I/R injury by reducing oxidative stress, promoting autophagy, and inhibiting inflammation. This study offers a potential therapeutic strategy for the treatment of intestinal ischemia-reperfusion injury.

EFFECT OF ARTESUNATE TREATMENT ON INTESTINAL INJURY AFTER CARDIOPULMONARY RESUSCITATION IN SWINE

ABSTRACT

Introduction: Intestinal injury is often caused by systemic ischemia-reperfusion injury early after cardiac arrest (CA) and resuscitation. Artesunate (Art) has been confirmed to protect vital organs against diverse of regional I/R injury. This study aimed to investigate the effect of Art on intestinal injury after CA and cardiopulmonary resuscitation (CPR) in swine. Methods: Twenty-two swine were randomly divided into three groups: sham (n = 6), CA/CPR (n = 8), and CA/CPR + Art (n = 8). The CA/CPR swine model was established by inducing 9 min of untreated ventricular fibrillation (VF) followed by 6 min of CPR. Five minutes after resuscitation, 4.8 mg/kg of Art was intravenously administered for 2 h in the CA/CPR + Art group. Intestinal fatty acid-binding protein and diamine oxidase concentrations were compared among the three groups before CA and at 1, 2, 4, and 24 h after resuscitation. At 24 h after resuscitation, intestinal zonula occluden-1 (ZO-1), occludin, apoptosis, caspase-3/gasdermin E (GSDME)-mediated pyroptosis proteins concentrations, and proinflammatory cytokine concentrations were examined to evaluate intestinal injury. Results: During CPR, spontaneous circulation was achieved in seven and six swine in the CA/CPR and CA/CPR + Art groups, respectively. Serum intestinal fatty acid-binding protein and diamine oxidase concentrations were significantly higher and intestinal tissue ZO-1 and occludin concentrations were significantly lower in the CA/CPR and CA/CPR + Art groups than in the sham group. However, Art treatment resulted in markedly improved levels of intestinal injury biomarkers compared with those in the CA/CPR group. Additionally, intestinal apoptosis and concentrations of caspase-3/GSDME-mediated pyroptosis proteins and proinflammatory cytokines were significantly higher in the CA/CPR and CA/CPR + Art groups than in the sham group. However, these variables were significantly lower in the CA/CPR + Art group than in the CA/CPR group. Conclusions: Art treatment effectively alleviates postresuscitation intestinal injury, possibly by inhibiting the caspase-3/GSDME-mediated pyroptosis pathway in a swine CA and CPR model.

Sodium Butyrate Inhibits Necroptosis by Regulating MLKL via E2F1 in Intestinal Epithelial Cells of Liver Cirrhosis

Background and Aims

Necroptosis is critical for regulating intestinal epithelial cells (IECs). Butyric acid (BA), produced during intestinal microbial metabolism, protects the intestinal epithelial barrier. However, whether necroptosis occurs in IECs during liver cirrhosis and whether sodium butyrate (NaB) can regulate necroptosis have not yet been reported. In this study, we aimed to investigate whether IECs undergo necroptosis in cirrhosis and whether NaB can regulate necroptosis and the related regulatory mechanisms.

Methods

Serum levels of RIPK3, MLKL, and Zonulin, as well as fecal BA levels, were measured and correlated in 48 patients with liver cirrhosis and 20 healthy controls. A rat model of liver cirrhosis was established, and NaB was administered. The expressions of MLKL, p-MLKL, and tight junction proteins were measured. We conducted an in vitro investigation of the effect of NaB on necroptosis in the HT29 cell line.

Results

Serum levels of RIPK3, MLKL, and Zonulin in the liver cirrhosis group were higher, while fecal BA levels were lower than those in the control group. Zonulin levels were positively correlated with RIPK3 and MLKL levels, while fecal BA levels were negatively correlated with serum MLKL levels, but not with RIPK3 levels. NaB reduced the mRNA and protein expression of MLKL but had no effect on RIPK1 and RIPK3 in vitro. Rescue experiments demonstrated that NaB inhibited necroptosis through E2F1-mediated regulation of MLKL.

Conclusions

NaB alleviates intestinal mucosal injury and reduces necroptosis in IECs in liver cirrhosis. It also inhibits the necroptosis of IECs and protects the intestinal barrier by reducing E2F1 expression and downregulating MLKL expression levels. These results can be employed to develop a novel strategy for treating complications arising from liver cirrhosis.

Modulation of the Oxidative Stress and ICAM-1/TLR4/NF-Κβ Levels by Metformin in Intestinal Ischemia/Reperfusion Injury in Rats

Metformin, a biguanide drug, is used for its antihyperglycemic effects. The purpose of the present study was to investigate the effects of metformin on the experimental model of intestinal ischemia-reperfusion (I/R) injury. Ischemia was induced by superior mesenteric artery occlusion followed by reperfusion. Metformin was administered orally by gavage at doses of 50, 100 or 200 mg/kg for one week before the surgery. Rats were divided to five groups (n = 8 for each): Sham control group; I/R control group; Metformin50 treated I/R group; Metformin100 treated I/R group; and Metformin200 treated I/R group. Tissue levels of malondialdehyde (MDA), glutathione (GSH), myeloperoxidase (MPO) activity, intercellular adhesion molecule-1 (ICAM-1), toll-like receptor 4 (TLR4), and nuclear factor-κB (NF-κB) as well as histological analysis were evaluated. Metformin treatment decreased the levels of MDA in 100 and 200 mg/kg doses besides lowering the MPO activity and ICAM-1 levels in all doses. Metformin also reduced NF-κB levels at dose of 200 mg/kg and improved histopathological scores at doses of 100 and 200 mg/kg. The treatment with metformin can prevent I/R-induced intestinal injury through down-regulating ICAM-1 and NF-κB levels, reducing oxidative stress, and lowering neutrophil accumulation. We propose that metformin could be a therapeutic agent in intestinal I/R.

The role of serum vaspin level in the early diagnosis of mesenteric ischemia induced in experimental animal model

PURPOSE

Acute mesenteric ischaemia (AMI) is one of the abdominal surgical emergencies with high mortality and morbidity and early diagnosis and treatment are of vital importance. We aimed to evaluate the usefulness of serum vaspin level as a potential biomarker for early diagnosis of AMI in an experimental animal model.

MATERIALS AND METHODS

Sixty female Wistar-Albino rats were divided into 6 groups. Ischaemia groups (1, 3, 5) underwent SMA dissection and ligation, while control groups (2, 4, 6) did not. Blood and intestinal tissue samples were collected at 30 min, 2 h, and 6 h. Vaspin (ng/ml), TAS (Total antioxidant capacity, μmol Trolox equiv./L), TOS (Total oxidant capacity, μmol H2O2 equiv./L), ALT (Alanine Aminotransferase, U/L), AST (Aspartate Aminotransferase, U/L) and OSI (TOS/TAS) ratio of these biochemical values were studied.

RESULTS

Vaspin levels were compared at 30 min, 2 h, and 6 h in ischaemia and control groups. No significant difference was found at 30 min and 2 h (p > 0.05), but a significant increase was observed at 6 h (p < 0.05). There was a statistically significant difference between the Vaspin (ng/ml) measurements of the ischaemia groups at three different times (p < 0.05). The highest Vaspin (ng/ml) value was obtained at the 6th hour and the lowest at the 30th minute.

CONCLUSION

In our study, a statistically significant increase in vaspin levels was detected with increasing ischaemia duration and necrosis. These findings suggest that vaspin may be a potential biomarker in the early diagnosis of AMI.

Chaihuang Qingyi Huoxue granule ameliorates severe acute pancreatitis by modulating gut microbiota and repairing the intestinal mucosal barrier

Background

During severe acute pancreatitis (SAP), damage to the intestinal mucosal barrier and translocation of intestinal pathogenic bacteria are key mechanisms that accelerate the disease progression of SAP. Chaihuang Qingyi Huoxue Granule (CH) is a herbal formula used in the clinical treatment of SAP. This study aims to investigate the role of CH in regulating gut microbiota and intestinal mucosal barrier in SAP rats.

Methods

Sodium taurocholate (3.5%) was retrogradely perfused into the biliopancreatic duct to establish the model of SAP in rats. CH (4.4 g/kg) was administered by gavage. Serum amylase, lipase, and endotoxin levels were measured. Hematoxylin-eosin (HE) staining was used to observe morphological changes in the pancreas and colon. The expression of zona occludens-1 (ZO-1) and occludin in the colon was examined by immunohistochemistry (IHC) and western blot. 16S rDNA gene sequencing was used to analyze the gut microbiota of the rats. The content of short-chain fatty acids (SCFAs) in the intestinal contents of the rats was determined by gas chromatography-mass spectrometry (GC-MS).

Results

CH reduced serum amylase, lipase, and endotoxin levels in SAP rats, alleviated pathological damage in the pancreas and colon, and restored the expression of ZO-1 and occludin. Moreover, CH alleviated gut microbiota dysbiosis in SAP rats, with restored gut microbiota diversity and structure. At the phylum level, the relative abundance of Firmicutes and Bacteroidetes increased, while that of Proteobacteria decreased. At the genus level, the abundance of Ruminococcus 1, Parabacteroides, Prevotellaceae UCG-001, Lachnospiraceae NK4A136 group, and Lactobacillus increased, while that of Escherichia-Shigella, Enterococcus, and Enterobacter decreased. In addition, CH increased the levels of SCFAs in the intestinal contents of SAP rats.

Conclusion

CH ameliorates SAP by maintaining the homeostasis and diversity of the gut microbiota, increasing the levels of SCFAs, and repairing the intestinal mucosal barrier.

Enteric-Coated Aspirin Induces Small Intestinal Injury via the Nrf2/Gpx4 Pathway: A Promising Model for Chronic Enteropathy

Background

Aspirin is widely used to prevent and treat cardiovascular diseases. The most common side effect is gastrointestinal damage. In recent years, aspirin-associated enteropathy has received increasing attention. This study aimed to establish a chronic model of aspirin-associated enteropathy, investigate the effect of enteric-coated aspirin on the intestinal flora, and explore the specific molecular mechanism of small intestinal damage.

Methods

C57BL/6J mice were given aspirin for 45 days to induce chronic small intestinal injury. The intestinal mucosal injury was observed macroscopically and microscopically. Intestinal mucus levels were assessed by PAS staining. The intestinal permeability was measured by FD4. The oxidative stress levels of the small intestine were detected by immunofluorescence and immunohistochemistry. The mRNA and protein levels of inflammatory factors, tight junctions, and antioxidant defense-related genes were measured by qRT-PCR and Western Blot. The MPO activity, SOD activity and MDA content in serum were measured. The mitochondrial morphology and paracellular space were observed under transmission electron microscopy. The fecal samples were analyzed by high-throughput sequencing of 16S rRNA V3-V4 amplicons.

Results

Aspirin induced weight loss, reduced food intake and increased faecal occult blood in mice. Aspirin led to a shortened small intestine, macroscopic and microscopic damage to the intestinal mucosa, and local inflammation. Aspirin disrupted the intestinal barriers and increased the permeability of the small intestine. Aspirin destroyed mitochondrial structure and damaged antioxidant capacity, and aspirin may induce oxidative stress through Nrf2/Gpx4 signaling pathway. Intestinal flora analysis showed that aspirin could induce changes in the abundance of Akkermansia and Lactobacillus.

Conclusion

Long-term administration of enteric-coated aspirin successfully established a chronic small intestinal injury model in mice. It increased oxidative stress in the small intestine by disrupting mitochondrial structure and impairing antioxidant capacity. This damaged the intestinal mucosal barrier, increased intestinal permeability, and triggered gut microbial dysbiosis and inflammation.

Transcriptomic analysis of key genes and signaling pathways in sepsis-associated intestinal mucosal barrier damage

OBJECTIVES

The aim is to analyze differentially expressed genes (DEGs) in mice with sepsis-related intestinal mucosal barrier damage and to explore the diagnostic and protective mechanisms of this condition at the transcriptome level.

METHODS

Small intestinal tissues from healthy male C57BL/6J mice subjected to Cecal ligation and puncture (CLP) and sham operation were collected. High-throughput sequencing was performed using the paired-end sequencing mode of the Illumina HiSeq platform. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted on the differentially expressed genes (DEGs). A protein-protein interaction (PPI) network was constructed using the STRING database, and hub genes were identified with Cytoscape. These hub genes were then validated using quantitative real-time polymerase chain reaction (RT-qPCR).

RESULTS

A total of 239 DEGs were identified, with 49 upregulated and 130 downregulated genes. KEGG enrichment analysis showed that these DEGs were primarily involved in cytokine-cytokine receptor interaction, Th1 and Th2 cell differentiation, viral protein interactions with cytokines and their receptors, and the IL-17 signaling pathway. The top 10 hub genes were selected using the cytoHubba plugin. Experimental validation confirmed that the expression levels of TBX21, CSF3, IL-6, CXCR3, and CXCL9 matched the sequencing results.

CONCLUSION

TBX21, CSF3, IL-6,CXCR3, and CXCL9 may be potential biological markers for the diagnosis and treatment the sepsis-associated intestinal mucosal barrier.

Dachaihu decoction alleviates septic intestinal epithelial barrier disruption via PI3K/AKT pathway based on transcriptomics and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Dachaihu decoction (DCH) is a famous and ancient TCM formula, extensively utilized for over 1800 years in treating gastrointestinal and inflammatory conditions. Our previous study showed that DCH ameliorated intestinal damage and modulated the gut microflora in septic rats. However, the material basis for these effects and the underlying mechanism of action remains ill-defined. We aimed to explore the pharmaceutical ingredients of DCH and its mechanism in mitigating sepsis-induced intestinal epithelial barrier disruption (IEBD).

MATERIALS AND METHODS

Ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) was used to identify DCH composition. A septic rat model and Caco-2 cells were employed to investigate DCH's effects on IEBD. Transcriptomics and network pharmacology were used to predict potential mechanisms, which were further validated by molecular docking and dynamics simulations. The Modified Murine Sepsis Score (mMSS) and histological assessments were performed. Serum fluorescence intensity of FD4 and the expression of Occludin were evaluated to assess intestinal barrier integrity. And p-PI3K P85, PI3K P85, p-AKT, AKT, Bax and Bcl-2 were determined by Western blot. Cell viability was determined using CCK-8 assay, IL-6 and TNF-α by ELISA and quantitative Real-time PCR (RT-qPCR). The integrity and permeability of single layer of Caco-2 cells were assessed via transepithelial resistance (TEER), alkaline phosphatase (ALP) activity and FD4 permeability.

RESULTS

UHPLC-HRMS identified 180 compounds in DCH. DCH significantly reduced mMSS, improved pathological conditions in the ileum, decreased FD4 serum fluorescence, and enhanced Occludin expression. Transcriptomic and network pharmacology analyses identified the PI3K/AKT pathway as a critical mechanism of action. Molecular docking and dynamics simulations confirmed strong binding of DCH components to PIK3R1. DCH upregulated p-PI3K and p-AKT in ileum tissue of septic rats. DCH improved cell viability, decreased IL-6 and TNF-α, promoted cell survival and Occludin level, and upregulated p-PI3K and p-AKT in LPS-stimulated Caco-2 cells. DCH also maintained TEER, ALP activity and decreased FD4 permeability and these effects were reversed by PI3K inhibitor, LY294002. DCH also downregulated Bax expression and increased Bcl-2 levels in both septic rats and LPS-stimulated Caco-2 cells.

CONCLUSION

DCH ameliorates sepsis-induced IEBD via PI3K/AKT pathway activation, offering a novel therapeutic perspective for sepsis-related intestinal dysfunction.

Continuous renal replacement therapy with cytokine-adsorbing hemofilter to control resuscitative endovascular balloon occlusion of the aorta-related ischemia-reperfusion injury in a swine hemorrhagic shock model

PURPOSE

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is beneficial for uncontrollable torso bleeding; however, prolonged REBOA causes ischemia-reperfusion injury. The purpose of this study is to examine the hypothesis that continuous renal replacement therapy (CRRT) with a cytokine-adsorbing hemofilter would improve mortality due to hemorrhagic shock with REBOA-reperfusion injury by controlling metabolic acidosis, hyperkalemia, and hypercytokinemia.

METHODS

Hemorrhagic shock with 40% blood loss was induced by phlebotomy in eight female swine. CRRT was performed on four swine after 90 min of REBOA, and the remaining four swine (control group) underwent the same procedures except for CRRT. We evaluated the survival time and trends of pH, HCO3-, potassium, lactate, circulatory inflammatory cytokines, and histopathology of the intestine for 180 min after REBOA deflation.

RESULTS

Two swine in the CRRT group and one in the control group survived; no significant difference were observed in survival rates between the groups (p = 0.45). Furthermore, no significant differences in the transition of biomarkers and histopathological grades were observed between the groups. The CRRT group showed a tendency of increasing pH and HCO3-, decreasing lactate, lower elevation of potassium and cytokine levels (interleukin 6, CRRT: 1008.5 [770.4-1246.6], control; 1636.7 [1636.7-1636.7] pg/mL at t = 270), and lower intestine histopathological grade (jejunum, CRRT; 1.5 [1.3-1.8], control; 4.0 [4.0-4.0], ileum, CRRT; 1.5 [1.3-1.8], control; 4.0 [4.0-4.0] at t = 270) than the control group.

CONCLUSIONS

CRRT may mitigate acute-REBOA-related ischemia-reperfusion injury by controlling biomarkers. Further research is required to evaluate the impact on long-term mortality.

Geraniol modulates inflammatory and antioxidant pathways to mitigate intestinal ischemia-reperfusion injury in male rats

Intestinal ischemia-reperfusion injury (IIR/I) significantly increases morbidity and mortality. This study examines the therapeutic effects of geraniol (GNL), which is noted for its anti-inflammatory and antioxidant properties, on intestinal I/R injury in rats. Forty-nine male Wistar-Albino rats were divided into seven groups. After 30 min of ischemia and subsequent reperfusion for either 1 or 6 h, intestinal and hepatic tissues were analyzed. Biochemical assessments measured malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), myeloperoxidase (MPO), and nitric oxide (NO) activities. Inflammatory and apoptotic markers were evaluated using qRT-PCR and ELISA, and apoptotic cell rates were determined by flow cytometry. GNL treatment significantly protected intestinal and hepatic tissues, enhancing antioxidant enzyme activity and normalizing MDA and NO activities. It demonstrated notable anti-inflammatory effects at 100 and 200 mg/kg doses, reducing TNF-α, IL-1β, and IL-6 levels while decreasing tissue MPO content. GNL also increased Bcl-2 levels and decreased Bax levels, indicating anti-apoptotic effects. Serum activities of ALT, AST, and creatine kinase were lower in GNL-treated rats, and flow cytometry showed a reduction in apoptotic cells. GNL effectively mitigated oxidative stress and histopathological damage from intestinal I/R injury by reducing pro-apoptotic markers and increasing anti-apoptotic markers, highlighting its protective effects.

Lactobacillus acidophilus alleviate Salmonella enterica Serovar Typhimurium-induced murine inflammatory/oxidative responses via the p62-Keap1-Nrf2 signaling pathway and cecal microbiota

Background

Salmonella enterica Serovar Typhimurium (S. Typhimurium) infection can cause inflammation and oxidative stress in the body, leading to gastroenteritis, fever and other diseases in humans and animals. More and more studies have emphasized the broad prospects of probiotics in improving inflammation and oxidative stress, but the ability and mechanism of Lactobacillus acidophilus (LA) to alleviate the inflammatory/oxidative reaction caused by pathogens are still unclear.

Methods and results

In this study, we treated the mice with LA for 14 days, infected them with S. Typhimurium for 24 h, and sacrificed the mice to collect samples. We found that the early intervention of LA alleviated the pathological injury and reversed the down-regulation of the duodenal and hepatic tight junction protein mRNA levels caused by S. Typhimurium infection. Compared with S. Typhimurium group, LA early intervention increased the expression of antioxidant enzymes, but decreased the levels of serum malondialdehyde (MDA), interleukin-8 and tumor necrosis factor-α (TNF-α). Additionally, LA early intervention significantly increased Nrf2 mRNA expression in the liver and decreased Keap1 mRNA expression in the duodenum compared to the S. Typhimurium group. Furthermore, early LA treatment reduced the abundance of Bacteroides acidificiens, increased the abundance of Akkermansia, and alleviated the decrease in SCFAs levels in the cecum of S. Typhimurium-infected mice. Spearman correlation analysis showed that there was a certain correlation between cecal flora and serum indicators and short chain fatty acids.

Conclusion

Taken together, the results indicate that LA early intervention may alleviates S. Typhimurium-induced inflammation and oxidative responses in mice by activating the p62-Keap1-Nrf2 signaling pathway and regulating the gut microbial community.

Significance and impact of the study

Exploring the ability of LA to resist animal oxidative stress and microflora regulation caused by pathogenic microbes, so as to provide more options for developing healthy disease-resistant feed additives.

Ganoderic Acid A Alleviates Severe Acute Pancreatitis by Modulating Gut Homeostasis and Inhibiting TLR4-NLRP3 Signaling

Background Severe acute pancreatitis (SAP) manifests as a critical state marked by acute abdominal symptoms, often associated with intestinal barrier dysfunction, exacerbating SAP retroactively. Ganoderic acid A (GAA) demonstrates anti-inflammatory properties in various inflammatory disorders. Nonetheless, its potential therapeutic impact on SAP and the underlying mechanisms remain unexplored. Methods In both wild-type and TLR4-/- mice, experimental SAP was induced using caerulein plus lipopolysaccharide. Caerulein injections were administered intraperitoneally following 7 days of intragastric GAA administration. Additionally, the potential mechanisms by which GAA ameliorates SAP were further investigated using fecal microbiota transplantation and TLR4-overexpressing IEC-6 cells. Results We observed that GAA treatment significantly ameliorated serum levels of amylase, lipase, and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) in SAP mice. Pretreatment with GAA mitigated pathological injuries and reduced M1 macrophage and neutrophil infiltration in pancreatic or ileal tissues. Additionally, GAA treatment down-regulated TLR4-MAPK/NF-κB signaling and NLRP3 inflammasome activation in the pancreatic and ileal tissues of SAP mice. The results further revealed that the gavage of GAA decreased bacterial translocation (Escherichia coli and EUB338), repaired intestinal barrier dysfunction (ZO-1, occludin, DAO, and FITC), increased lysozyme and MUC2 expression, and raised the levels of short-chain fatty acids. Analysis of the gut microbiome showed that the beneficial effects of GAA treatment were associated with improvements in pancreatitis-associated gut microbiota dysbiosis, characterized by notable increases in α-diversity and the abundance of probiotics such as Akkermansia, GCA-900066575, and Parvibacter. Fecal transplantation experiments further confirmed that GAA exerts protective effects by modulating intestinal flora. The protective role of GAA in intestinal and pancreatic injuries is mediated by the inhibition of TLR4 signaling, as further evidenced in TLR4-deficient mice and TLR4-overexpressed IEC-6 cells. The results of docking indicated that GAA interacts with TLR4 via a hydrophobic interaction. Conclusions The study demonstrates that GAA significantly alleviates SAP through its anti-inflammatory and antioxidant capacities, as well as by restoring intestinal homeostasis, thereby providing insights into novel treatments for SAP.

The efficacy and active compounds of Chaihuang Qingyi Huoxue granule to Ameliorate intestinal mucosal barrier injury in rats with severe acute pancreatitis by suppressing the HMGB1/TLR4/NF-κB signaling pathway

Intestinal mucosal barrier injury represents a critical complication of severe acute pancreatitis (SAP) without effective treatment. This study investigated the efficacy, underlying mechanism, and responsible active compounds of the traditional Chinese medicinal prescription Chaihuang Qingyi Huoxue granule (CHQY) in treating SAP-induced intestinal mucosal barrier injury. SAP was established in Sprague-Dawley rats via intra-pancreaticobiliary duct infusion of sodium taurocholate, followed by oral CHQY administration (3.15 g/kg every 6 h for 12 and 24 h). Blood and tissues were harvested to assess the severity of pancreatitis, intestinal mucosal barrier integrity, and extent of inflammatory injury. Intestine-absorbing compounds were identified using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). Our results showed that CHQY treatment effectively mitigated SAP-induced intestinal mucosal injury, as evidenced by improved intestinal epithelial structure, decreased serum levels of intestinal injury markers (d-lactic acid, diamine oxidase, I-FABP, and Zonulin), restored expression of the tight junction protein ZO-1, and reduced serum endotoxin levels. Furthermore, CHQY administration suppressed the expression of proinflammatory mediator HMGB1, its receptor TLR4, and downstream NF-κB signaling in the intestine, leading to downregulated intestinal IL-1β expression and reduced circulating TNF-α and IL-6. UHPLC-HRMS analysis identified 15 intestine-absorbing compounds in CHQY, of which paeoniflorin sulfite and chrysin-7-O-glucuronide independently inhibited TNF-α-induced tight junction loss in IEC-6 cells and mitigated intestinal mucosal barrier injury in SAP rats through suppressing NF-κB signaling. In summary, CHQY ameliorates SAP-induced intestinal mucosal barrier injury by downregulating the proinflammatory HMGB1/TLR4/NF-κB signaling, with efficacy partially attributed to its active compounds paeoniflorin sulfite and chrysin-7-O-glucuronide.

Evaluation of the protective role of resveratrol on LPS-induced septic intestinal barrier function via TLR4/MyD88/NF-κB signaling pathways

The intestinal barrier function is a critical defense mechanism in the human body, serving as both the primary target and initiating organ in cases of sepsis. Preserving the integrity of this barrier is essential for preventing complications and diseases, including sepsis and mortality. Despite this importance, the impact of resveratrol on intestinal barrier function remains unclear. Thus, this study aims to explore the potential beneficial effects of resveratrol on maintaining intestinal barrier function. Fifteen male Sprague Dawley rats, weighing between 180 g and 220 g, were randomly assigned to one of three groups: the control group (Con), the lipopolysaccharide (LPS) group, and the resveratrol (RSV) group. The resveratrol group received an intravenous administration of resveratrol at a dosage of 8 mg/kg, 10 min prior to lipopolysaccharide treatment. Each group comprised five rats. Various techniques including enzyme-linked immunosorbent assay (ELISA), hematoxylin and eosin staining (HE), periodic acid Schiff (PAS) staining, transmission electron microscopy (TEM), Western blot analysis (WB), and quantitative real-time polymerase chain reaction (qRT-PCR) were utilized to assess differences in inflammatory cytokine expression, histopathological changes, apoptosis, tight junction (TJ) protein, and the TLR4/MyD88/NF-кB signaling pathways. Resveratrol exhibited anti-inflammatory effects by decreasing levels of interleukin (IL)-1β, interleukin(IL)-6, and tumor necrosis factor (TNF)-α, while increasing interleukin (IL)-10. Additionally, in rats treated with resveratrol, there was a reduction in the expression of apoptosis-associated proteins Bax and Caspase-3. Resveratrol also significantly increased the expression of intestinal tight junction proteins (TJ), and decreased the levels of intestinal fatty acid binding protein (I-FABP) and D-lactic acid (D-LA). Furthermore, the expression of proteins in the related signaling pathways TLR4, MyD88, and NF-κB was decreased. Resveratrol has been shown to reduce the expression of intestinal apoptotic proteins, enhance the expression of intestinal tight junction proteins, and inhibit the inflammatory response mediated by the TLR4/MyD88/NF-κB signaling pathway, thereby alleviating LPS-induced septic intestinal injury.

The phenotype of necrotizing enterocolitis correlates with distinct changes of intestinal junctional proteins

Necrotizing enterocolitis (NEC) is a major cause of mortality in preterm infants. Its pathophysiology remains poorly understood but intestinal epithelial barrier dysfunction contributes to the disease. We characterized junctional proteins in intestinal specimens from preterm infants. Samples from 27 patients with NEC and 20 patients with focal intestinal perforation (FIP) from the center of the specimens (affected) or the macroscopically healthy resection margins whenever available (non-affected) were collected. NEC patients displayed higher mortality and more commonly occurrence of impaired glucose homeostasis, patent ductus arteriosus, anemia and antibiotic treatment compared to FIP patients. Discrimination between NEC and FIP was not possible in affected areas based on H.E. staining using a newly developed scoring system. Immunofluorescence revealed reduced Claudin-3 in affected NEC samples and decreased Claudin-4 in affected FIP and all NEC samples. E-cadherin and Desmoglein-2 were reduced in a subgroup of the affected NEC samples. Plakophilin-2 was decreased in intestine affected by FIP and unaffected intestine in patients with NEC. In affected areas of NEC, Plakophilin-2 was completely lost. Plakoglobin reduction in affected NEC samples correlated with poor survival. This study provides novel insights into changes of junctional proteins in NEC, suggesting Claudin-3 and Plakophilin-2 as diagnostic markers to differentiate FIP from NEC and reduced Plakoglobin as a prognostic marker.

Intestinal oxygen utilisation and cellular adaptation during intestinal ischaemia-reperfusion injury

The gastrointestinal tract can be deranged by ailments including sepsis, trauma and haemorrhage. Ischaemic injury provokes a common constellation of microscopic and macroscopic changes that, together with the paradoxical exacerbation of cellular dysfunction and death following restoration of blood flow, are collectively known as ischaemia-reperfusion injury (IRI). Although much of the gastrointestinal tract is normally hypoxemic, intestinal IRI results when there is inadequate oxygen availability due to poor supply (pathological hypoxia) or abnormal tissue oxygen use and metabolism (dysoxia). Intestinal oxygen uptake usually remains constant over a wide range of blood flows and pressures, with cellular function being substantively compromised when ischaemia leads to a >50% decline in intestinal oxygen consumption. Restoration of perfusion and oxygenation provokes additional injury, resulting in mucosal damage and disruption of intestinal barrier function. The primary cellular mechanism for sensing hypoxia and for activating a cascade of cellular responses to mitigate the injury is a family of heterodimer proteins called hypoxia-inducible factors (HIFs). The HIF system is connected to numerous biochemical and immunologic pathways induced by IRI and the concentration of those proteins increases during hypoxia and dysoxia. Activation of the HIF system leads to augmented transcription of specific genes in various types of affected cells, but may also augment apoptotic and inflammatory processes, thus aggravating gut injury. KEY POINTS: During intestinal ischaemia, mitochondrial oxygen uptake is reduced when cellular oxygen partial pressure decreases to below the threshold required to maintain normal oxidative metabolism. Upon reperfusion, intestinal hypoxia may persist because microcirculatory flow remains impaired and/or because available oxygen is consumed by enzymes, intestinal cells and neutrophils.

Shielding the Gut: Ghrelin and Ferrostatin-1's Protective Role Against Sepsis-Induced Intestinal Ferroptosis

Objective: This study investigates the therapeutic efficacy of ghrelin in alleviating sepsis-induced intestinal damage, focusing on its potential to inhibit ferroptosis and protect intestinal barrier integrity. Methods: This study evaluates the therapeutic efficacy of intraperitoneal ghrelin (80 μg/kg) and Ferrostatin-1 (5 mg/kg) using a cecal ligation and puncture (CLP) model in C57BL/6 mice to determine their potential in alleviating sepsis-induced intestinal damage. The investigation focuses on the impacts of ghrelin and Ferrostatin-1 on bacterial load, intestinal morphology, systemic inflammation, oxidative stress, and ferroptosis markers. Our comprehensive methodology encompasses histopathological evaluations, cytokine profiling, oxidative stress assays, and detailed analyses of ferroptosis indicators to thoroughly assess the interventions' efficacy. Results: Treatment with ghrelin significantly reduced bacterial proliferation, mitigated intestinal damage, and decreased systemic inflammation. Comparable outcomes were observed with Fer-1 treatment. Both interventions restored intestinal barrier functions, modulated inflammatory responses, and attenuated oxidative stress, indicating a suppression of the ferroptosis pathway. Conclusion: Ghrelin exhibits a protective role in sepsis-induced intestinal injury, likely through the inhibition of ferroptosis. This mechanism underscores ghrelin's therapeutic potential in sepsis management, suggesting avenues for further clinical exploration.

Zinc pretreatment for protection against intestinal ischemia-reperfusion injury

BACKGROUND

Intestinal ischemia-reperfusion (I/R) injury (II/RI) is a critical condition that results in oxidative stress, inflammation, and damage to multiple organs. Zinc, an essential trace element, offers protective benefits in several tissues during I/R injury, but its effects on intestinal II/RI remain unclear.

AIM

To investigate the effects of zinc pretreatment on II/RI and associated multiorgan damage.

METHODS

C57BL/6 mice were pretreated with zinc sulfate (ZnSO4, 10 mg/kg) daily for three days before I/R injury was induced via superior mesenteric artery occlusion (SMAO) and abdominal aortic occlusion (AAO) models. Tissue and serum samples were collected to evaluate intestinal, liver, and kidney damage using Chiu's score, Suzuki score, and histopathological analysis. Caco-2 cells and intestinal organoids were used for in vitro hypoxia-reoxygenation injury models to measure reactive oxygen species (ROS) and superoxide dismutase (SOD) levels.

RESULTS

Zinc pretreatment significantly reduced intestinal damage in the SMAO and AAO models (P < 0.001). The serum levels of liver enzymes (alanine aminotransferase, aspartate aminotransferase) and kidney markers (creatinine and urea) were lower in the zinc-treated mice than in the control mice, indicating reduced hepatic and renal injury. In vitro, zinc decreased ROS levels and increased SOD activity in Caco-2 cells subject to hypoxia-reoxygenation injury. Intestinal organoids pretreated with zinc exhibited enhanced resilience to hypoxic injury compared to controls.

CONCLUSION

Zinc pretreatment mitigates II/RI and reduces associated multiorgan damage. These findings suggest that zinc has potential clinical applications in protecting against I/R injuries.

Bifidobacterium longum Metabolite Indole-3-Carboxaldehyde Blocks HDAC3 and Inhibits Macrophage NLRP3 Inflammasome Activation in Intestinal Ischemia/Reperfusion Injury

Indole-3-carboxaldehyde (3-IAld), a tryptophan metabolite derived from gut microbiota, has been reported to protect the intestine against radiation injury. This study aimed to clarify the role of Bifidobacterium longum (B. longum) and its metabolite indole-3-carboxaldehyde (3-IAld) in the pathophysiology of intestinal ischemia/reperfusion (II/R) injury. Superior mesenteric artery occlusion and reperfusion were performed to establish II/R mice, and pathological injury in II/R mice was evaluated. II/R mice showed impaired gut microbiota diversity and reduced abundance of B. longum in the intestines. Transplantation of B. longum mitigated II/R injury by protecting the integrity of the intestinal barrier and reducing inflammatory response. The 3-IAld level increased after transplantation of B. longum, and 3-IAld treatment inhibited the inflammatory response of bone marrow-derived macrophages (BMDM). Histone deacetylase 3 (HDAC3) was a target of 3-IAld, and HDAC3 was translocated to mitochondria to promote mitochondrial fatty acid oxidation (FAO) during macrophage inflammasome formation. HDAC3 overexpression promoted the formation of macrophage inflammasomes in intestinal tissues. Overall, this study confirmed the beneficial effects of B. longum in combating II/R injury through HDAC3-mediated control of mitochondrial FAO and macrophage inflammasome formation via 3-IAld.

Pharmacodynamic Evaluation of Phage Therapy in Ameliorating ETEC-Induced Diarrhea in Mice Models

Enterotoxigenic Escherichia coli (ETEC) is a major pathogen causing diarrhea in humans and animals, with increasing antimicrobial resistance posing a growing challenge in recent years. Lytic bacteriophages (phages) offer a targeted and environmentally sustainable approach to combating bacterial infections, particularly in eliminating drug-resistant strains. In this study, ETEC strains were utilized as indicators, and a stable, high-efficiency phage, designated vB_EcoM_JE01 (JE01), was isolated from pig farm manure. The genome of JE01 was a dsDNA molecule, measuring 168.9 kb, and a transmission electron microscope revealed its characteristic T4-like Myoviridae morphology. JE01 effectively lysed multi-drug-resistant ETEC isolates. Stability assays demonstrated that JE01 retained its activity across a temperature range of 20 °C to 50 °C and a pH range of 3-11, showing resilience to ultraviolet radiation and chloroform exposure. Furthermore, JE01 effectively suppressed ETEC adhesion to porcine intestinal epithelial cells (IPEC-J2), mitigating the inflammatory response triggered by ETEC. To investigate the in vivo antibacterial efficacy of phage JE01 preparations, a diarrhea model was established using germ-free mice infected with a drug-resistant ETEC strain. The findings indicated that 12 h post-ETEC inoculation, intragastric administration of phage JE01 significantly reduced mortality, alleviated gastrointestinal lesions, decreased ETEC colonization in the jejunum, and suppressed the expression of the cytokines IL-6 and IL-8. These results demonstrate a therapeutic benefit of JE01 in treating ETEC-induced diarrhea in mice. Additionally, a fluorescent phage incorporating red fluorescent protein (RFP) was engineered, and the pharmacokinetics of phage therapy were preliminarily assessed through intestinal fluorescence imaging in mice. The results showed that the phage localized to ETEC in the jejunum rapidly, within 45 min. Moreover, the pharmacokinetics of the phage were markedly slowed in the presence of its bacterial target in the gut, suggesting sustained bacteriolytic activity in the ETEC-infected intestine. In conclusion, this study establishes a foundation for the development of phage-based therapies against ETEC.

Jianpi Huoxue Decoction Ameliorates Alcohol-associated Liver Disease by Improving Intestinal Barrier Function in Rats

OBJECTIVE

Jianpi huoxue decoction (JHD), a Chinese herbal formula, is commonly used for treating alcohol-associated liver disease (ALD). This study aimed to investigate the mechanism by which JHD affects intestinal barrier function in ALD rats.

METHODS

The Sprague-Dawley rats were randomly divided into three groups: control group, model group and JHD group. They were pair-fed a modified Lieber-DeCarli liquid diet containing alcohol (model group, n=10; JHD group, n=10) or isocaloric maltose dextrin (control group, n=10) for 6 weeks. After 3 weeks of feeding, the mice in the JHD group were given JHD (10 mL/kg/day) by gavage for 3 weeks, and those in the control and model groups received equal amounts of double-distilled water for the same period of time. Afterwards, all the rats were given lipopolysaccharide (LPS) by gavage and sacrificed 3.5 h later. LPS levels were measured in the portal blood to evaluate gut leakage. Transmission electron microscopy (TEM) was used to observe ultrastructural changes in the intestinal tract. Adherens junction (AJ) and tight junction (TJ) proteins were detected by Western blotting, immunofluorescence or immunohistochemistry.

RESULTS

JHD ameliorated Lieber-DeCarli liquid diet-induced hepatic steatosis, inflammation and LPS expression. It improved pathological changes in the liver and alleviated intestinal ultrastructure injury. Moreover, it significantly enhanced the integrity of tight junctions by increasing the expression of zonula occludens-1 (ZO-1) and occludin. It suppressed the activation of myosin light chain (MLC) phosphorylation.

CONCLUSION

JHD improves intestinal barrier function and reduces gut leakiness in ALD rats.

Jianghua Kucha black tea containing theacrine attenuates depression-like behavior in CUMS mice by regulating gut microbiota-brain neurochemicals and cytokines

Theacrine and theaflavins are known for their potential to mitigate depression and cognitive impairment. Jianghua Kucha black tea (JH) contains both compounds, yet its antidepressant properties are seldom documented. This study evaluated the effects of JH on depression in chronic unpredictable mild stress (CUMS) mice and explored the underlying mechanisms through integrative analyses of gut microbiota and fecal metabolomics. JH was found to significantly alleviate CUMS-induced depression-like behavior by improving body weight, food intake, 1% sucrose preference, immobility time, and numbers of crossings and standings compared to Zhuyeqi black tea (ZYQ), which contains theaflavins. JH notably altered the gut microbiota composition, enriching genera such as Turicibacter, Faecalibaculum, Akkermansia, and Desulfovibrio, while inhibiting genera norank_f__Muribaculaceae and Lactobacillus. Additionally, JH modified the fecal metabolite profile, characterized by increased levels of several secondary bile acids (BAs) and decreased levels of several purine intermediate metabolites. Furthermore, JH upregulated levels of monoamine neurotransmitters (5-HT and DA) and brain-derived neurotrophic factor (BDNF), while downregulating pro-inflammatory cytokines IL-6 and TNF-α in brain tissue. These findings suggested that JH could mitigate CUMS-induced depression-like behavior, potentially by modulating gut microbiota composition and function, as well as brain neurochemicals and cytokines.

Fucoidan ameliorates rotenone-induced Parkinsonism in mice by regulating the microbiota-gut-brain axis

Microbiota-gut-brain axis, the bidirectional relationship between the gut microbiota and the brain, has been increasingly appreciated in the pathogenesis of Parkinson's disease (PD). Fucoidan, a sulphate-rich polysaccharide, has been shown to be neuroprotective by reducing oxidative stress in PD models. However, the role of microbiota-gut-brain axis in the neuroprotective activity of fucoidan has not been revealed. In this study, the therapeutic effects of fucoidan and involvement of microbiota-gut-brain axis in rotenone (ROT)-induced PD were investigated. The results showed that fucoidan gavage attenuated neuroinflammation, dopamine neuronal damage and motor dysfunction in ROT-induced PD mice. In addition, fucoidan treatment ameliorated gut dysfunction, intestinal inflammation and disruption of the intestinal barrier in PD mice. Fucoidan also affected the composition of gut microbiota in PD mice, indicated particularly by decreased abundance of Akkermansia muciniphila and Lactobacillus johnsonii and increased abundance of Lactobacillus murinus. Mechanistic studies showed that fecal microbiota transplantation (FMT) from the fucoidan-treated mice and probiotic Lactobacillus murinus supplement are as potent as fucoidan treatment in attenuating peripheral and central inflammation and ameliorating dopamine neuronal damage, which might be attributed to the downregulation of LPS/TLR4/NF-κB signaling pathway. Our study suggests that fucoidan might be potential candidates for the treatment of PD.

Large animal models enhance the study of crypt-mediated epithelial recovery from prolonged intestinal ischemia reperfusion injury

Intestinal ischemia and reperfusion injury (IRI) is a deadly and common condition. Death is associated with sepsis due to insufficient epithelial repair, requiring stem cell-driven regeneration, typically beginning 48 h after injury. Animal models are critical to advancing this field. To effectively study epithelial healing, models must survive clinically relevant intestinal ischemic injury extending to the crypt. Although mouse models are indispensable to intestinal research, their application for studying epithelial repair following severe IRI may be limited. Ischemic injury was induced in mouse and porcine jejunum for up to 3 h, with up to 72 h of reperfusion. Histologic damage was scored by Chiu-Park grade, and animal survival was assessed. Findings were compared between species. A mouse IRI literature review was performed to evaluate the purported degree of injury, duration of recovery, and reported survival rates. In mice and pigs, 3 h of ischemia induced severe, reliable injury extending into the crypt. However, at 48 h, mouse survival was only 23.5% compared with 100% survival in pigs. In literature, ischemia was induced for >1 h in only 4 of 102 mouse studies and none to 3 h. Recovery was attempted for 48 h in only six reports. Forty-seven studies reported intestinal crypt injury. Of those that featured histologic intestinal crypt damage, survival rates at 48 h ranged from 10 to 50% (median 30%). Mouse models are not ideal for studying intestinal stem cell-mediated recovery from severe IRI. Alternative large animal models, like pigs, are recommended.NEW & NOTEWORTHY Additional research is needed to improve recovery from severe intestinal ischemia. The selection of the ideal animal model is critical to facilitating this work. Based on our experimentation and literature review, porcine models, with increased translatability and an improved ability to survive both prolonged ischemia and the recovery period, appear to be the most appropriate choice for future studies.

Regulatory role of AMPK/Nrf2 signaling pathway in sevoflurane-enhanced intestinal protection against ischemia-reperfusion injury

Intestinal ischemia-reperfusion (I/R) injury is common in clinical settings and is associated with high mortality. Sevoflurane, a widely used anesthetic, has long recognized for its protective effects against intestinal I/R injury, though the underlying mechanisms remain largely uncharacterized. In this study, using both in vivo and in vitro models, we uncovered a novel role of sevoflurane in preventing ferroptotic cell death during intestinal I/R injury. Sevoflurane treatment activated transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) and upregulated its target genes involved in iron sequestration (FTL) and glutathione biosynthesis (SLC7A11 and GCLM). These changes reduced intracellular ferrous iron levels and alleviated iron-dependent oxidative stress and lipid peroxidation, a hallmark of ferroptosis. Importantly, through large-scale kinome screening, we revealed that sevoflurane-induced Nrf2 activation was mediated by AMP-activated protein kinase (AMPK). Sevoflurane treatment activated AMPK, which subsequently phosphorylated Nrf2 and prevented its degradation. Stabilized Nrf2 then entered nucleus, where it promoted the transcription of downstream targets. We concluded that sevoflurane exerts anti-ferroptoic function in intestinal I/R through the AMPK/Nrf2 signaling pathway. These results expand our knowledge about the pathogenesis of intestinal I/R injury, and provide novel insights for optimizing clinical treatments and developing novel therapeutic strategies.

Matrine regulates autophagy in ileal epithelial cells in a porcine circovirus type 2-infected murine model

Introduction

Porcine circovirus type 2 (PCV2) is an important pathogen that causes diarrhea in nursery and fattening pigs, resulting in huge economic losses for commercial pig farms. Protective efficacy of vaccines is compromised by mutations in pathogens. There is an urgent need to articulate the mechanism by which PCV2 destroys the host's intestinal mucosal barrier and to find effective therapeutic drugs. Increasing attention has been paid to the natural antiviral compounds extracted from traditional Chinese medicines. In the present study, we investigated the role of Matrine in mitigating PCV2-induced intestinal damage and enhancing autophagy as a potential therapeutic strategy in mice.

Methods

A total of 40 female, specific-pathogen-free-grade Kunming mice were randomly divided into four groups with 10 mice in each group: control, PCV2 infection, Matrine treatment (40 mg/kg Matrine), and Ribavirin treatment (40 mg/kg Ribavirin). Except for the control group, all mice were injected intraperitoneally with 0.5 mL 105.4 50% tissue culture infectious dose (TCID50)/mL PCV2.

Results

While attenuating PCV2-induced downregulation of ZO-1 and occludin and restoring intestinal barrier function in a PCV2 Kunming mouse model, treatment with Matrine (40 mg/kg) attenuated ultrastructural damage and improved intestinal morphology. Mechanistically, Matrine reversed PCV2-induced autophagosome accumulation by inhibiting signal transducer and activator of transcription 3 (STAT3) phosphorylation and upregulating Beclin1 protein expression, thus resisting viral hijacking of enterocyte autophagy.

Discussion

Our findings demonstrate that Matrine may be a novel, potential antiviral agent against PCV2 by activating intestine cellular autophagy, which provides a new strategy for host-directed drug discovery.

Celecoxib and rofecoxib have different effects on small intestinal ischemia/reperfusion injury in rats

Introduction

Intestinal ischemia/reperfusion (I/R) injury is associated with high mortality and there is an unmet need for novel therapies. The intestinal expression of cyclooxygenase-2 (COX-2) increases rapidly after mesenteric I/R, but it is still a question of debate whether selective COX-2 inhibitors can mitigate I/R-induced gut injury. Here we aimed to compare the effect of celecoxib and rofecoxib, two selective COX-2 inhibitors, on intestinal I/R-induced injury in rats.

Methods

Wistar rats were treated with celecoxib (10 and 100 mg/kg), rofecoxib (5 and 50 mg/kg), or vehicle for 8 days via gavage and then were subjected to sham operation or mesenteric I/R. Small intestinal inflammation and tissue damage were assessed by histology and quantification of inflammatory and tight junction proteins. The intestinal activity of COX enzymes was determined by a COX activity assay.

Results

The higher dose of celecoxib reduced the I/R-associated increase in inflammatory mediators (myeloperoxidase, pentraxin 3, COX-2, interleukin-1β) and loss of tight junction proteins (claudin-1, occludin), whereas the lower dose of celecoxib was only marginally effective. However, even high-dose celecoxib failed to prevent the histological injury of the mucosa. In contrast to celecoxib, rofecoxib did not affect intestinal inflammation and injury at any of the tested doses. Neither celecoxib nor rofecoxib affected the I/R-induced changes of HO-1 and PPAR-γ, known off-targets of COX-inhibitors, but celecoxib increased the I/R-induced elevation of Bax/Bcl-2, a marker of apoptosis, whereas rofecoxib reduced the elevation of phospho-Akt. Importantly, high-dose celecoxib, but not rofecoxib, has already reduced intestinal COX-1 activity.

Conclusion

Our study provides evidence for the higher anti-inflammatory efficacy of celecoxib compared to rofecoxib in mesenteric I/R injury, which is likely due to its lower selectivity for COX-2. However, even high-dose celecoxib was unable to reduce the mucosal damage. Our results suggest that selective COX-2 inhibitors have only limited therapeutic value in intestinal I/R injury.

Short cycles of remote ischemic preconditioning had no effect on tensile strength in small intestinal anastomoses: an experimental animal study

PURPOSE

This study aimed to investigate the effect of remote ischemic preconditioning (RIPC) on the healing of small intestinal anastomoses, evaluated by tensile strength and histologic wound healing on postoperative day 5.

METHODS

A total of 22 female pigs were randomized 1:1 into either an intervention or control group. The intervention group received 5 cycles of 3-minute ischemia followed by 3-minute reperfusion on the right forelimb. Two end-to-end anastomoses, a distal and a proximal, were created in the small intestine 30 and 60 min after RIPC, respectively. On postoperative day 5, the anastomoses were harvested and underwent a maximal anastomotic tensile strength (MATS) test (MATS 1-3) followed by histologic analyses.

RESULTS

MATS 1, when a tear became visible in the serosa, was significantly increased in the proximal anastomoses of the RIPC group compared with the control group (4.91 N vs 3.83 N; P = .005). No other significant differences were found when comparing these 2 groups.

CONCLUSION

Our study showed no convincing results of RIPC on intestinal anastomotic healing to recommend its use in a general clinical setting. Further animal studies on RIPC's effect after relative or absolute intestinal ischemia may be recommended.

Transcriptomic analysis provides insights into the mechanisms underlying the resistance of Penaeus vannamei to Enterocytozoon hepatopenaei (EHP)

The Penaeus vannamei aquaculture industry is facing a significant challenge in the form of hepatopancreatic microsporidiosis (HPM) caused by Enterocytozoon hepatopenaei (EHP), resulting in substantial economic losses. However, the extent of knowledge regarding the mechanisms by which shrimp resist EHP is limited. We screened resistant and susceptible shrimp and found that resistant shrimp had lower EHP load and less tissue damage. To gain insight into the molecular mechanisms underlying the EHP resistance of shrimp, a comparison was conducted at the transcriptional level between the resistant and susceptible families. Transcriptomic analysis of shrimp hepatopancreas revealed significant differences between the resistant and susceptible families. Compared to the susceptible family, the immune system of the resistant family was activated. The resistant family showed up-regulation in the expression of cathepsin L, C-type lectin, penaeidin, chitinase genes, and metabolism of xenobiotics by cytochrome P450-related genes. Additionally, the resistant shrimp exhibited a higher capacity for amino acid uptake. The observed differences in the resistant and susceptible family transcriptome may contribute to the shrimp's resistance to EHP.

Flowmetry and spectrophotometry for the assessment of intestinal viability in horses with naturally occurring strangulating small intestinal lesions

BACKGROUND

Ancillary diagnostic methods to enhance the accuracy of viability assessment have not been established for use in clinical practice.

OBJECTIVES

To assess intestinal microperfusion measured by Laser Doppler Flowmetry and Spectrophotometry (LDFS) in naturally occurring small intestinal strangulations of different origins and to compare this between viable and non-viable segments.

STUDY DESIGN

Prospective clinical trial.

METHODS

Forty horses undergoing colic surgery for naturally occurring small intestinal strangulations were included. Tissue oxygen saturation (tSO2), haemoglobin (tHB) and blood flow (tBF) were determined by LDFS before and after release of the strangulation. Intestinal biopsies were taken in cases that underwent intestinal resection or intraoperative euthanasia and assessed using a semi-quantitative mucosal injury score (MIS). The LDFS measurements were compared between the different categories of strangulation causes and histopathological injury using parametric and non-parametric tests (p < 0.05).

RESULTS

Strangulations by pedunculated lipomas had lower tBF (13.9 ± 18 arbitrary units [AU]) than epiploic foramen entrapments (65.2 ± 61 AU; CI -1.697 to -0.2498; p = 0.005). Segments with MIS > 5 showed lower tBF during strangulation than segments with MIS < 4 (mean difference 61.1 AU; CI -1.119 to -0.07361; p = 0.03). This did not differ significantly following release of strangulation. Furthermore, there was a positive correlation between the inflammatory cell count and tBF during strangulation (r 0.34; CI 0.01 to 0.60; p = 0.04). The tSO2 and tHB did not differ between the different categories of lesions or injury.

MAIN LIMITATIONS

No biopsies could be taken from the intestinal segments that did not undergo resection. The duration of strangulation could not reliably be ascertained.

CONCLUSIONS

Blood flow measurements in naturally occurring strangulating lesions show a varying degree of ischaemia in different causes of strangulation. Intestinal blood flow measurements prior to release of the strangulation could potentially contribute to the identification of mucosal injury, yet a high individual variability and other contributing factors need to be considered.