Cryptdin-2 predicts intestinal injury during heatstroke in mice

The pathogenesis and management of heatstroke and heatstroke-induced lung injury

In the past two decades, record-breaking heat waves have caused an increasing number of heat-related deaths, including heatstroke, globally. Heatstroke is a life-threatening systemic condition characterized by a core body temperature >40°C and the subsequent development of multiple organ dysfunction syndrome. Lung injury is a well-documented complication of heatstroke and is usually the secondary cause of patient death. In recent years, extensive research has been conducted to investigate the underlying causes of heatstroke and heatstroke-induced lung injury. This review aims to consolidate and present the current understanding of the key pathogenic mechanisms involved in heatstroke and heatstroke-induced lung injury. In addition, systemic factors such as heat cytotoxicity, systemic inflammation, oxidative stress, endothelial cell dysfunction, and other factors are involved in the pathogenesis of lung injury in heatstroke. Furthermore, we also established current management strategies for heatstroke and heatstroke-induced lung injury. However, further investigation is required to fully understand the detailed pathogenesis of heatstroke so that potentially effective means of treating and preventing heatstroke and heatstroke-induced lung injury can be developed and studied.

Effect of supplementation with Lactobacillus rhamnosus GG powder on intestinal and liver damage in broiler chickens challenged by lipopolysaccharide

This study explores the effect of dietary along with Lactobacillus rhamnosus GG (LGG) powder on intestinal and liver damage in broiler chickens challenged by lipopolysaccharide (LPS). A total of 100 healthy 1-day-old Ross 308 broiler chickens were selected and randomly divided into two treatments: the control group and the LGG treatment group. There were five replicates for each group, with 10 chickens per replicate. The chickens in the control group were fed a basal diet, while LGG treatment was supplemented with 1,000 mg/kg LGG along with the basal diet. The experiment lasted 29 days, and the trial included two phases. During the first 27 days, the animals were weighed on the 14th and 27th days to calculate growth performance. Then, on day 29, 2 animals from each replicate were intraperitoneally injected with 1 mg/kg BW LPS, and another 2 animals were treated with an equal volume of saline. The chickens were slaughtered 3 h later for sampling and further analysis. (1) LGG addition to the diet did not affect growth performance, including average daily gain (ADG), average daily feed intake (ADFI), and feed-to-weight ratio (F/G) of broiler chickens; (2) LPS stimulation decreased villus height (VH), and caused oxidative stress and increased the amount of diamine oxidase (DAO) in plasma, and the relative expression of intestinal inflammation genes (interleukin-8 [IL-8], interleukin 1β [IL-1β], inducible nitric oxide synthase [iNOS], and tumor necrosis factor-α [TNF-α]) and the relative expression of liver injury genes (b-cell lymphoma 2 [BCL2], heat shock protein70 [HSP70], and matrix metallopeptidase 13 [MMP13]). (3) Supplementation of LGG increased VH and the relative expression of intestinal barrier genes (mucins 2 [Mucin2] and occludin [Occludin]) and decreased the amount of DAO in plasma and the relative expression of intestinal inflammatory factors (IL-8, iNOS, and IL-1β). LGG supplementation also increased the expression of liver injury-related genes (MMP13 and MMP9). In conclusion, LGG enhanced intestinal barrier function, improved intestinal morphology, and alleviated the intestines' inflammatory response in LPS-stimulated broiler chicken, and it has a slightly protective effect on liver damage.

Intestinal alkaline phosphatase improves intestinal permeability and alleviates multiple organ dysfunction caused by heatstroke

Objective

Heatstroke (HS) is a severe acute disease related to gastrointestinal barrier dysfunction, systemic inflammation and multiple organ injury. Many of the functions of Intestinal alkaline phosphatase (IAP) have been linked to gut homeostasis, gut barrier function and inflammation. However, the protective effect of IAP on heatstroke is not fully elucidated. This study aims to explore the protective effect of IAP on heatstroke by maintaining intestinal barrier and improving permeability.

Methods

Male C57BL/6 mice were placed in a controlled climate chamber (ambient temperature: 40.0 ± 0.5 °C; humidity: 60 ± 5 %) until the maximum core temperature (Tc, max) reached 42.7 °C (the received criterion of HS). Then heat exposed mice (n = 195) were divided into three groups: 0.2 mL of 0.9 % physiological saline (HS) or vehicle (HS + Vehicle) or 300 IU IAP (HS + IAP) by gavage at 0, 24, and 48 h after onset. Control group mice (Con) (n = 65) were not exposed to heat and were gavaged with 0.9 % physiological saline of the same volume at the same time.

Results

IAP treatment significantly reduced the levels of endotoxin, FD4, and D-lactate in the blood of heatstroke mice, reduced intestinal permeability and maintained the integrity of the intestinal barrier by increasing the expression of tight junction proteins. Meanwhile, IAP treatment alleviated liver and kidney damage caused by heatstroke, reduced serum levels of inflammatory cytokines, and thus improved survival rate of mice after heatstroke.

Conclusion

This study indicates that IAP can improve the intestinal barrier function and intestinal permeability by increasing intestinal tight junctions, reduce systemic inflammation and multiple organ injury and improving the survival rate of heatstroke. Therefore, we consider IAP may be added to enteral nutrition formulas as a potential means for diseases characterized by intestinal permeability disorders, including heatstroke.

Mechanisms and regulation of defensins in host defense

As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.

Agrobacterium sp. ZX09 β-Glucan Attenuates Enterotoxigenic Escherichia coli-Induced Disruption of Intestinal Epithelium in Weaned Pigs

To explore the protective effect of dietary β-glucan (BGL) supplementation on intestinal epithelium exposure to enterotoxigenic Escherichia coli (ETEC), thirty-two weaned pigs were assigned to four groups. Pigs were fed with a basal diet or basal diet containing 500 mg/kg BGL, and were orally infused with ETEC or culture medium. Results showed BGL supplementation had no influence on growth performance in weaned pigs. However, BGL supplementation increased the absorption of D-xylose, and significantly decreased the serum concentrations of D-lactate and diamine oxidase (DAO) in the ETEC-challenged pigs (p < 0.05). Interestingly, BGL significantly increased the abundance of the zonula occludens-1-(ZO-1) in the jejunal epithelium upon ETEC challenge (p < 0.05). BGL supplementation also increased the number of S-phase cells and the number of sIgA-positive cells, but significantly decreased the number of total apoptotic cells in the jejunal epithelium upon ETEC challenge (p < 0.05). Moreover, BGL significantly increased the duodenal catalase (CAT) activity and the ileal total superoxide dismutase (T-SOD) activity in the ETEC-challenged pigs (p < 0.05). Importantly, BGL significantly decreased the expression levels of critical inflammation related proteins such as the tumor necrosis factor-α (TNF-α), interlukin-6 (IL-6), myeloid differentiation factor 88 (MyD88), and nuclear factor-κB (NF-κB) in the jejunal and ileal mucosa upon ETEC challenge (p < 0.05). BGL also elevated the propanoic acid content and the abundance of Lactobacillus and Bacillus in the colon upon ETEC challenge (p < 0.05). These results suggested BGL could alleviate the ETEC-induced intestinal epithelium injury, which may be associated with suppressed inflammation and improved intestinal immunity and antioxidant capacity, as well as the improved intestinal macrobiotic.

The Chinese Herbal Formula Huoxiang Zhengqi Dropping Pills Prevents Acute Intestinal Injury Induced by Heatstroke by Increasing the Expression of Claudin-3 in Rats

Intestinal injury has been regarded as an important causative factor for systemic inflammation during heatstroke, and maintaining intestinal integrity has been a potential target for the prevention of HS. Huoxiang Zhengqi Dropping Pills (HZPD) is a modern preparation of Huoxiang Zhengqi and widely used to prevent HS. The present study aims to explore the protective effect of HZDP on intestinal injury during heatstroke and analyze its potential pharmacodynamic basis. Male rats in the control and HS groups were given normal saline, and those in the HZDP groups were given HZDP (0.23, 0.46, and 0.92 g/kg) before induction of HS. Serum contents of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), intestinal fatty acid-binding protein (iFABP), and diamine oxidase (DAO) were determined using ELISA. Histopathology of intestinal injury was observed following H&E staining. The expression of claudin-3 was determined using western blot, immunohistochemistry, and immunofluorescence techniques. Moreover, network pharmacological tools were used to analyze the potential pharmacodynamic basis and the mechanism of HZDP. Treatment with HZDP significantly prolonged the time to reach Tc. Compared with the control group, the contents of TNF-α, IL-6, iFABP, and DAO in HS rats increased markedly. HZDP treatments reduced these levels significantly, and the effects in the middle dose group (0.46 g/kg) were most obvious. HZDP also attenuated intestinal injury and significantly reversed the decrease in claudin-3 expression. Bioinformatics analysis suggested that 35 active ingredients and 128 target genes of HZDP were screened from TCMSP and 93 target genes intersected with heatstroke target genes, which were considered potential therapeutic targets. TNF-α and IL-6 were the main inflammatory target genes of HZDP correlated with HS. These results indicated that HZDP effectively protected intestinal barrier function and prevented acute intestinal injury by increasing the expression of claudin-3 in rats, eventually improving heat resistance.

Electroacupuncture in Treatment of Acute Gastrointestinal Injury in Patients with Severe Traumatic Brain Injury: A Multicenter Randomized Controlled Trial

OBJECTIVE

To evaluate whether electroacupuncture (EA) would improve gastrointestinal function and clinical prognosis in patients with severe traumatic brain injury (TBI) complicocted by acute gastrointestinal injury (AGI).

METHODS

This multicenter, single-blind trial included patients with TBI and AGI admitted to 5 Chinese hospitals from September 2018 to December 2019. A total of 500 patients were randomized to the control or acupuncture groups using a random number table, 250 cases in each group. Patients in the control group received conventional treatment, including mannitol, nutritional support, epilepsy and infection prevention, and maintenance of water, electrolytes, and acid-base balance. While patients in the acupuncture group received EA intervention at bilateral Zusanli (ST 36), Shangjuxu (ST 37), Xiajuxu (ST 39), Tianshu (ST 25), and Zhongwan (RN 12) acupoints in addition to the conventional treatment, 30 min per time, twice daily, for 7 d. The primary endpoint was 28-d mortality. The secondary endpoints were serum levels of D-lactic acid (D-lac), diamine oxidase (DAO), lipopolysaccharide (LPS), motilin (MTL) and gastrin (GAS), intra-abdominal pressure (IAP), bowel sounds, abdominal circumference, AGI grade, scores of gastrointestinal failure (GIF), Glasgow Coma Scale (GCS), Acute Physiology and Chronic Health Evaluation (APACHE II), Sequential Organ Failure Assessment (SOFA), and Multiple Organ Dysfunction Syndrome (MODS), mechanical ventilation time, intense care unit (ICU) stay, and the incidence of hospital-acquired pneumonia.

RESULTS

The 28-d mortality in the acupuncture group was lower than that in the control group (22.80% vs. 33.20%, P<0.05). Compared with the control group, the acupuncture group at 7 d showed lower GIF, APACHE II, SOFA, MODS scores, D-lac, DAO, LPS, IAP, and abdominal circumference and higher GCS score, MTL, GAS, and bowel sound frequency (all P<0.05). In addition, the above indices showed simillar changes at 7 d compared with days 1 and 3 (all P<0.05) in the EA group.

CONCLUSION

Early EA can improve gastrointestinal function and clinical prognosis in patients with severe TBI complicated by AGI. (Registration No. ChiCTR2000032276).

Intestinal Microbiota and Serum Metabolic Profile Responded to Two Nutritional Different Diets in Mice

There is an interaction and bidirectional selection between dietary intake and gut microbiota due to the different efficiency of nutrients in the gut. The nutritional composition of germ-free (GF) diets differs significantly from specific pathogen-free (SPF) diets. There is, however, no data revealing how SPF animals from the same microbial background respond to them and if they affect the host. We examined the growth of SPF mice on the GF diet and found that it reduced body weight, intestinal length and intestinal morphology. Interestingly, the GF diet increased the level of pro-inflammatory bacteria in the gut of SPF mice, including Proteobacteria, Burkholderiaceae, Alloprevotella and Parasutterella. Furthermore, GF diets caused significant increases in malondialdehyde (MDA), IL-1β, IL-6, and D-lactate levels in the serum of SPF mice and significantly altered their serum metabolic profile, especially amino acid metabolism. In conclusion, GF diets are not suitable for the growth and development of SPF mice. These findings, based on the role of gut microbiota in diet selection, provide new insights into the scientific and rational use of experimental animal diets.

Prognostic value of plasma exosomal levels of histone H3 protein in patients with heat stroke

Heat stroke (HS) is a condition that can lead to multiple organ dysfunction syndrome and death; however, there is no reliable method for stratifying mortality risk in HS. The abundance of exosomes in the circulation and their contents may be used as potential biomarkers of HS. The present study aimed to examine whether histone H3 levels in plasma exosomes could be used to determine HS prognosis. Blood samples were collected from patients with HS (36 survivors and 8 non-survivors) at admission to the intensive care unit and 4 days after admission. Blood samples were additionally collected from 15 healthy volunteers. Plasma exosomes were isolated using high-speed differential centrifugation. Correlation between histone H3 level and organ function and disease severity was examined. The results suggested differential expression and enrichment of histone H3 in the plasma exosomes of patients with HS (survivors, 249.3±04.6; non-survivors, 500.4±216.8; healthy controls, 161.1±52.49 pg/100 µg; P<0.05). The increased expression of histone H3 was associated with increased disease severity and duration. Plasma exosomal levels of histone H3 were significantly correlated with both organ dysfunction and disease severity (P<0.0001) and were significantly different between non-survivors and survivors (area under the receiver operating characteristic curve, 0.9668). A cutoff value of 307 pg/100 µg demonstrated optimized sensitivity (95%) and specificity (91.67%) for predicting mortality risk, suggesting that histone H3 levels in plasma exosomes may be a reliable biomarker for HS prognosis.

Clinical Characteristics and Risk Factors Associated With Acute Kidney Injury Inpatient With Exertional Heatstroke: An Over 10-Year Intensive Care Survey

Background: Exertional heat stroke (EHS) is a life-threatening injury that can lead to acute kidney injury (AKI). The clinical characteristics of and risk factors for EHS complicated with AKI have been poorly documented.

Methods: A retrospective study with EHS admitted to the intensive care unit (ICU) from January 2008 to June 2019 was performed. Data including baseline clinical information at admission, main organ dysfunction, 90-day mortality and total cost of hospitalization were collected.

Results: A total of 187 patients were finally included, of which 82 (43.9%) had AKI. AKI patients had more severe organ injury and higher total hospitalization costs than non-AKI patients. Multivariate logistic analysis showed that lymphocyte, neutrophil, D-dimer and myoglobin (MB) ≥ 1,000 ng/ml were independent risk factors for AKI caused by EHS. In addition, SOFA score [hazard ratio (HR) 4.1, 95% confidence interval (95% CI) 1.6–10.8, P = 0.004] and GCS score (HR 3.2, 95% CI 1.2–8.4 P = 0.017) were the risk factor for 90-day mortality in patients with EHS complicated with AKI, with an area under the curve (AUC) of 0.920 (95% CI 0.842–0.998, P < 0.001) and 0.851 (95% CI 0.739–0.962, P < 0.001), respectively. Survival analysis showed that the 90-day mortality in AKI patients was significantly high (P < 0.0001) and the mortality rate of patients with AKI stage 2 was the highest than other stages.

Conclusions: EHS complicated with AKI is associated with higher hospitalization costs and poorly clinical outcomes. MB ≥1,000 ng/ml, Inflammation, coagulation were associated with the occurrence and development of AKI. Early treatment strategies based reducing the SOFA and GCS score may be pivotal for improving the prognosis of EHS.

The influence on oxidative stress markers, inflammatory factors and intestinal injury-related molecules in Wahui pigeon induced by lipopolysaccharide

Introduction

The intestinal structure is the foundation for various activities and functions in poultry. An important question concerns the changes in the intestinal status under endotoxin stimulation. This study aimed to investigate the mechanism of intestinal injury induced by lipopolysaccharide (LPS) in Wahui pigeons.

Methods

Thirty-six 28-day-old healthy Wahui pigeons were randomly divided into two groups. The experimental group was injected with LPS (100 μg/kg) once per day for five days, and the control group was treated with the same amount of sterile saline. Blood and the ileum were collected from pigeons on the first, third, and fifth days of the experiment and used for oxidative stress assessment, inflammatory factor detection, histopathological examination, and positive cell localization. In addition, intestinal injury indices and mRNA expression levels (tight junction proteins, inflammatory cytokines, and factors related to autophagy and apoptosis) were evaluated.

Results

Villi in the ileum were shorter in the LPS group than in the control group, and D-lactic acid levels in the serum were significantly increased. Glutathione and catalase levels significantly decreased, but the malondialdehyde content in the serum increased. TNF-α and IL-10 were detected at higher levels in the serum, with stronger positive signals and higher mRNA expression levels, in the LPS group than in the control group. In addition, the levels of TLR4, MyD88, NF-κB, and HMGB1 in the inflammatory signaling pathway were also upregulated. Finally, the mRNA expression of Claudin3, Occludin, and ZO-1 was significantly decreased; however, that of Beclin1 and Atg5 was increased in the LPS group.

Conclusion

Ileal pathological changes and oxidative stress were caused by LPS challenge; it is proposed that this triggering regulates the inflammatory response, causing excessive autophagy and apoptosis, promoting intestinal permeability, and leading to intestinal injury in Wahui pigeons.

Streptococcus thermophilus Attenuates Inflammation in Septic Mice Mediated by Gut Microbiota

Sepsis is a life-threatening organ dysfunction condition caused by a dysregulated host response to infection and lack of effective treatment method. Supplementation of probiotics has emerged as a potential biotherapy for inflammatory diseases in recent years, but its role in protecting viscera against the damage caused by sepsis and the underlying mechanism is poorly understood. Streptococcus thermophilus 19 is one of the most well-studied probiotics, which is selected in this study among seven strains isolated from homemade yogurt due to its optimal ability of suppressing the inflammation response in vitro. It showed significant decrease in the expression of TNF-α, IL-1β, and IL-6 in the co-culture of S. thermophilus 19 and LPS-treated mouse macrophage. The effect of S. thermophilus 19 in mice and the response of mice gut microbiota were subsequently investigated. In LPS-induced septic mouse model, S. thermophilus 19 was highly resistant to LPS and exhibited significantly decreased expressions of inflammatory factors compared to LPS-treated mice. A MiSeq-based 16S rDNA sequence analysis revealed that the decrease of gut microbial diversity in mice intraperitoneally injected with 1 mg/ml LPS were mitigated by the administration of S. thermophilus 19. Fusobacterium significantly decreased during the development of sepsis and rose again after supplement strain 19, while Flavonifractor showed the opposite trend, which demonstrated these two genera were the key bacteria that may function in the mice gut microbiota for alleviation of LPS-induced inflammation reaction. To conclude, S. thermophilus 19 may be a potential candidate for novel biotherapeutic interventions against inflammation caused by sepsis.

Betulinic Acid Ameliorates the T-2 Toxin-Triggered Intestinal Impairment in Mice by Inhibiting Inflammation and Mucosal Barrier Dysfunction through the NF-κB Signaling Pathway

T-2 toxin, a trichothecene mycotoxin produced by Fusarium, is widely distributed in crops and animal feed and frequently induces intestinal damage. Betulinic acid (BA), a plant-derived pentacyclic lupane-type triterpene, possesses potential immunomodulatory, antioxidant and anti-inflammatory biological properties. The current study aimed to explore the protective effect and molecular mechanisms of BA on intestinal mucosal impairment provoked by acute exposure to T-2 toxin. Mice were intragastrically administered BA (0.25, 0.5, or 1 mg/kg) daily for 2 weeks and then injected intraperitoneally with T-2 toxin (4 mg/kg) once to induce an intestinal impairment. BA pretreatment inhibited the loss of antioxidant capacity in the intestine of T-2 toxin-treated mice by elevating the levels of CAT, GSH-PX and GSH and reducing the accumulation of MDA. In addition, BA pretreatment alleviated the T-2 toxin-triggered intestinal immune barrier dysregulation by increasing the SIgA level in the intestine at dosages of 0.5 and 1 mg/kg, increasing IgG and IgM levels in serum at dosages of 0.5 and 1 mg/kg and restoring the intestinal C3 and C4 levels at a dosage of 1 mg/kg. BA administration at a dosage of 1 mg/kg also improved the intestinal chemical barrier by decreasing the serum level of DAO. Moreover, BA pretreatment improved the intestinal physical barrier via boosting the expression of ZO-1 and Occludin mRNAs and restoring the morphology of intestinal villi that was altered by T-2 toxin. Furthermore, treatment with 1 mg/kg BA downregulated the expression of p-NF-κB and p-IκB-α proteins in the intestine, while all doses of BA suppressed the pro-inflammatory cytokines expression of IL-1β, IL-6 and TNF-α mRNAs and increased the anti-inflammatory cytokine expression of IL-10 mRNA in the intestine of T-2 toxin-exposed mice. BA was proposed to exert a protective effect on intestinal mucosal disruption in T-2 toxin-stimulated mice by enhancing the intestinal antioxidant capacity, inhibiting the secretion of inflammatory cytokines and repairing intestinal mucosal barrier functions, which may be associated with BA-mediated inhibition of the NF-κB signaling pathway activation.

Resistant Maltodextrin Alleviates Dextran Sulfate Sodium-Induced Intestinal Inflammatory Injury by Increasing Butyric Acid to Inhibit Proinflammatory Cytokine Levels

Inflammatory bowel disease (IBD), one kind of intestinal chronic inflammatory disease, is characterized by colonic epithelial barrier injury, overproduction of proinflammatory cytokines, and fewer short-chain fatty acids (SCFAs). The present study is aimed at testing the hypothesis that resistant maltodextrin (RM), a soluble dietary fiber produced by starch debranching, alleviated dextran sulfate sodium- (DSS-) induced colitis in mice. Female C57BL/6 mice with or without oral administration of 50 mg/kg RM for 19 days were challenged with 3% DSS in drinking water to induce colitis (from day 14 to day 19). Although RM could not reverse DSS-induced weight loss or colon shortening, it reduced inflammatory cell infiltration and epithelial damage in colon tissue, as well as the transfer of intestinal permeability indicators including serum diamine oxidase (DAO) and D-lactic acid (D-LA). ELISA analysis indicated that RM significantly suppressed the increase of Th1 cytokines induced by DSS in the colon such as tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). The levels of proinflammatory cytokines interleukin-1β (IL-1β), IL-17, and IL-8 in the DSS group were significantly higher than those in the control group and RM group, but no significant difference was observed in the RM-DSS group compared with the RM group. Interestingly, IL-10 levels of the DSS group were significantly higher than those of the other groups. With respect to SCFAs, DSS administration significantly decreased the concentration of faecal butyric acid while the RM-DSS group showed a tendency to increase (P = 0.08). In general, RM alleviated dextran sulfate sodium-induced intestinal inflammation through increasing the level of butyric acid and subsequently inhibiting the expression of proinflammatory cytokines.

Icariin Alleviates Bisphenol A Induced Disruption of Intestinal Epithelial Barrier by Maintaining Redox Homeostasis In Vivo and In Vitro

Bisphenol A (BPA), a globally prevalent environmental contaminant, has been shown to have the potential to disrupt intestinal barrier function. This study explored the mechanisms of BPA-induced intestinal barrier dysfunction. In addition, the protective effect of the natural product icariin (ICA) on BPA-induced intestinal barrier dysfunction was evaluated. BPA relieved oxidative stress (reactive oxygen species (ROS), reactive nitrogen species (RNS), malondialdehyde (MDA), and hydrogen peroxide (H₂O₂)), suppressed antioxidant enzyme (superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and total antioxidant capacity (T-AOC)) activity, and increased gene expression and protein content of p38 mitogen-activated protein kinase (MAPK), giving rise to the dysfunctional gut in mice. ICA therapy effectively eased intestinal barrier dysfunction caused by BPA in vivo and in vitro. Treatment with p38 MAPK inhibitor (SB203580) significantly rescued the MODE-K cell barrier function disrupted by BPA challenge. However, treatment with p38 MAPK activator (anisomycin) did not attenuate the MODE-K cell barrier function impaired by BPA challenge. Overall, our data suggested that BPA disrupted intestinal barrier function in a p38 MAPK-dependent manner. Furthermore, we demonstrated that ICA regulated the redox equilibrium of intestinal epithelial cells by inhibiting the expression of p38 MAPK, thereby alleviating BPA-induced disruption of intestinal barrier function. These findings contributed to a better understanding of the mechanisms of BPA-induced intestinal barrier dysfunction and provided new insights into the prevention and treatment of BPA-induced intestinal diseases.

Fecal microbiota transplantation from patients with autoimmune encephalitis modulates Th17 response and relevant behaviors in mice

The significance of the microbiota-gut-brain axis has been increasingly recognized as a major modulator of autoimmunity. Here, we aim to characterize the gut microbiota of a large cohort of treatment-naïve anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis patients relative to that of healthy controls (HCs). Relative to HCs, anti-NMDAR encephalitis patients had a decreased microbiome alpha-diversity index, marked disturbances of gut microbial composition and intestinal permeability damage. Disturbed microbiota in anti-NMDAR encephalitis patients might be linked with different clinical characteristics. Imputed KEGG analysis revealed perturbations of functional modules in the gut microbiomes of anti-NMDAR encephalitis. Compared to HCs, microbiota-depleted mice receiving fecal microbiota transplantation (FMT) from anti-NMDAR encephalitis patients had hypersensitivity and cognitive impairment. Furthermore, anti-NMDAR encephalitis FMT mice showed altered T cells in the spleen and small intestine lamina propria with an increased Th17 cells. Overall, this study first suggests that the anti-NMDAR encephalitis microbiome itself can influence neurologic, Th17 response and behavioral function. The gut microbiota is a potential therapeutic target for anti-NMDAR encephalitis.

Coagulopathy signature precedes and predicts severity of end-organ heat stroke pathology in a mouse model

BACKGROUND

Immune challenge is known to increase heat stroke risk, although the mechanism of this increased risk is unclear.

OBJECTIVES

We sought to understand the effect of immune challenge on heat stroke pathology.

PATIENTS/METHODS

Using a mouse model of classic heat stroke, we examined the impact of prior viral or bacterial infection on hematological aspects of recovery. Mice were exposed to heat either 48 or 72 hours following polyinosinic:polycytidylic acid (poly I:C) or lipopolysaccharide injection, time points when symptoms of illness (fever, lethargy, anorexia) were minimized or completely absent.

RESULTS

Employing multivariate supervised machine learning to identify patterns of molecular and cellular markers associated with heat stroke, we found that prior viral infection simulated with poly I:C injection resulted in heat stroke presenting with high levels of factors indicating coagulopathy. Despite a decreased number of platelets in the blood, platelets are large and non-uniform in size, suggesting younger, more active platelets. Levels of D-dimer and soluble thrombomodulin were increased in more severe heat stroke, and in cases of the highest level of organ damage markers D-dimer levels dropped, indicating potential fibrinolysis-resistant thrombosis. Genes corresponding to immune response, coagulation, hypoxia, and vessel repair were up-regulated in kidneys of heat-challenged animals; these correlated with both viral treatment and distal organ damage while appearing before discernible tissue damage to the kidney itself.

CONCLUSIONS

Heat stroke-induced coagulopathy may be a driving mechanistic force in heat stroke pathology, especially when exacerbated by prior infection. Coagulation markers may serve as accessible biomarkers for heat stroke severity and therapeutic strategies.

Protective effect and mechanism of mesenchymal stem cells on heat stroke induced intestinal injury

Heat stroke (HS) is considered to be a severe systemic inflammatory reaction disease that is caused by high fever. The mortality of HS is high worldwide due to the lack of effective treatments. Presently, mesenchymal stem cells (MSCs) have been demonstrated to serve roles in inflammation and immune regulation. Therefore, the current study aimed to investigate the protective effect and mechanism of MSCs against the HS-induced inflammatory response and organ dysfunction. A rat model of HS was induced by a high-temperature environment and treated with MSCs via tail veins. The levels of molecular markers of organ function, inflammatory factors and chemokines were examined at days 1, 7, 14 and 28. Histological staining was performed on the intestines of rats and control groups, and the Chiu's scores of the two groups were compared. The results revealed that MSCs injection significantly reduced the mortality and inhibited the circulatory inflammatory response. Additionally, main organ function, such as in the liver and kidney, were significantly improved following MSCs infusion in HS rats. Furthermore, MSCs treatment significantly improved edema, necrosis and villus exfoliation of intestinal mucosa, and reduced the inflammatory response of intestinal tissue. These results indicated that MSC infusion had therapeutic effects on HS of rats by regulating the circulatory and intestinal inflammatory response. Moreover, MSCs may be able to protect organ function and promote tissue repair in HS. The results of the current study indicated that MSCs may be used as a potential method to treat HS and the resulting organ dysfunction.

Radiotherapy Induces Intestinal Barrier Dysfunction by Inhibiting Autophagy

Radiation enteritis is a common complication of abdominal irradiation (IR) therapy. However, the molecular mechanism of radiation enteritis accompanied by impaired intestinal barrier function is not clear. The aim of this study was to investigate the important role of autophagy in radiation-induced intestinal barrier function impairment. IR increased the abundance of autophagy-related genes in the colonic mucosa of mice. An autophagy activator (rapamycin) inhibited the oxidative stress (reactive oxygen species, reactive nitrogen species, malondialdehyde, and hydrogen peroxide) and inflammatory response (interleukin-1β, -6, -8, and tumor necrosis factor-α) in the colon samples. Antioxidant indices (superoxide dismutase, glutathione peroxidase, catalase, and total antioxidant capacity) in serum and colonic mucosa were significantly increased in the rapamycin group. Rapamycin can improve the activity of mitochondrial respiratory chain complexes I-V in colon mucosa. In addition, rapamycin reduced the gene expression and enzyme activity of caspase in the colonic mucosa. Levels of endotoxin, diamine peroxidase, d-lactic acid, and zonulin in serum and colonic mucosa were significantly reduced in the rapamycin group. Moreover, rapamycin significantly elevated the gene abundance of zonula occludens-1, occludin, claudin-1, and claudin-4. In contrast, completely opposite results were obtained for the autophagy inhibitor 3-methyladenine as compared to those of rapamycin. These results revealed that inhibition of autophagy is an important mechanism of intestinal barrier function damage caused by radiation. Collectively, these findings increase our understanding of the pathogenesis of radiation-induced intestinal barrier dysfunction.

Protective effects of rolipram on endotoxic cardiac dysfunction via inhibition of the inflammatory response in cardiac fibroblasts

BACKGROUND

Cardiac fibroblasts, regarded as the immunomodulatory hub of the heart, have been thought to play an important role during sepsis-induced cardiomyopathy (SIC). However, the detailed molecular mechanism and targeted therapies for SIC are still lacking. Therefore, we sought to investigate the likely protective effects of rolipram, an anti-inflammatory drug, on lipopolysaccharide (LPS)-stimulated inflammatory responses in cardiac fibroblasts and on cardiac dysfunction in endotoxic mice.

METHOD

Cardiac fibroblasts were isolated and stimulated with 1 μg/ml LPS for 6 h, and 10 μmol/l rolipram was administered for 1 h before LPS stimulation. mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in fibroblasts and their protein concentrations in supernatant were measured with real-time PCR (rt-PCR) and enzyme-linked immunosorbent assay, respectively. The expression of dual specificity phosphatase 1 (DUSP1), an endogenous negative regulator that inactivates MAPK-mediated inflammatory pathways, was also measured by rt-PCR and western blotting. DUSP1-targeted small interfering RNA (siRNA) was used to examine the specific role of DUSP1. To evaluate the role of rolipram in vivo, an endotoxic mouse model was established by intraperitoneal injection of 15 mg/kg LPS, and 10 mg/kg rolipram was intraperitoneally injected 1 h before LPS injection. mRNA and protein levels of inflammatory cytokines and DUSP1 in heart, inflammatory cell infiltration and cardiac function were all examined at 6 h after LPS injection.

RESULTS

The results showed that LPS could increase the expression and secretion of inflammatory cytokines and decrease the transcription and expression of DUSP1 in cardiac fibroblasts. However, rolipram pretreatment significantly reversed the LPS-induced downregulation of DUSP1 and inhibited LPS-induced upregulation and secretion of TNF-α and IL-6 but not IL-1β. Moreover, DUSP1-targeted siRNA experiments indicated that the protective effect of rolipram on inflammatory response was specific dependent on DUSP1 expression. Moreover, rolipram could further reduce inflammatory cell infiltration scores as shown by pathological analysis and increase the ejection fraction (EF) detected with echocardiography in the hearts of endotoxic mice.

CONCLUSIONS

Rolipram could improve endotoxin-induced cardiac dysfunction by upregulating DUSP1 expression to inhibit the inflammatory response in cardiac fibroblasts, which may be a potential treatment for SIC.