Histological Injury Research Articles

Angiotensin-(1-7) alleviates acute lung injury by activating the Mas receptor in neutrophil.

Acute lung injury (ALI) is a major cause of mortality and morbidity in the clinic. None of the current pharmacological interventions has achieved a detectable benefit. The renin-angiotensin system (RAS) is a complex humoral system essentially involved in the regulation of ALI. In the RAS family, angiotensin (Ang)-(1-7) was found to provide protection by counteracting the effects of Ang II in various cardiopulmonary disease models. The downstream receptor of Ang-(1-7) is the G protein-coupled receptor (GPCR) Mas. We hypothesize that the Ang-(1-7)-Mas pathway would protect patients from ALI. To establish a 2-hit ALI model, the mice underwent intratracheal instillation of hydrochloric acid followed by ventilator-induced lung injury (VILI). ALI was evaluated based on lung edema, histology, myeloperoxidase activity, and proinflammatory cytokine production. The effects of the infusion or inhalation of Ang-(1-7) and Mas receptor blocker A779 were examined. The human neutrophils were isolated, and Mas receptor expression was examined. The neutrophil responses to platelet-activating factor (PAF) stimulation were tested by measuring the formation of reactive oxygen species (ROS), neutrophil adhesion, and chemotaxis. Next, in the mouse model, the neutrophils were depleted using an anti-ly6G antibody. The infusion or inhalation of Ang-(1-7) protected mice from ALI as evidenced by decreases in lung edema, the histological lung injury score, myeloperoxidase activity, and proinflammatory cytokine production. Such effects were largely blocked by the Mas receptor blocker A779. Mas receptor expression in the neutrophils was identified at both the messenger ribonucleic acid and protein levels. Ang-(1-7) prevented neutrophil responses to PAF stimulation, including the formation of ROS, neutrophil adhesion, and chemotaxis, while A779 alleviated these effects. The importance of neutrophils in ALI was further confirmed by neutrophil depletion using the anti-ly6G antibody; however, A779 partially reversed the protective role of neutrophil depletion in ALI, indicating the critical role of Ang-(1-7)-Mas signaling in other pulmonary cells. Ang-(1-7)/Mas receptor attenuates the key features of ALI by regulating neutrophil activation. Our study provides new evidence of their role in the pathogenesis of ALI and may lead to the development of a promising therapeutic strategy.

Local Delivery of Azithromycin Nanoformulation Attenuated Acute Lung Injury in Mice.

Humanity has suffered from the coronavirus disease 2019 (COVID-19) pandemic over the past two years, which has left behind millions of deaths. Azithromycin (AZ), an antibiotic used for the treatment of several bacterial infections, has shown antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as against the dengue, Zika, Ebola, and influenza viruses. Additionally, AZ has shown beneficial effects in non-infective diseases such as cystic fibrosis and bronchiectasis. However, the systemic use of AZ in several diseases showed low efficacy and potential cardiac toxicity. The application of nanotechnology to formulate a lung delivery system of AZ could prove to be one of the solutions to overcome these drawbacks. Therefore, we aimed to evaluate the attenuation of acute lung injury in mice via the local delivery of an AZ nanoformulation. The hot emulsification-ultrasonication method was used to prepare nanostructured lipid carrier of AZ (AZ-NLC) pulmonary delivery systems. The developed formulation was evaluated and characterized in vitro and in vivo. The efficacy of the prepared formulation was tested in the bleomycin (BLM) -mice model for acute lung injury. AZ-NLC was given by the intratracheal (IT) route for 6 days at a dose of about one-eighth oral dose of AZ suspension. Samples of lung tissues were taken at the end of the experiment for immunological and histological assessments. AZ-NLC showed an average particle size of 453 nm, polydispersity index of 0.228 ± 0.07, zeta potential of -30 ± 0.21 mV, and a sustained release pattern after the initial 50% drug release within the first 2 h. BLM successfully induced a marked increase in pro-inflammatory markers and also induced histological changes in pulmonary tissues. All these alterations were significantly reversed by the concomitant administration of AZ-NLC (IT). Pulmonary delivery of AZ-NLC offered delivery of the drug locally to lung tissues. Its attenuation of lung tissue inflammation and histological injury induced by bleomycin was likely through the downregulation of the p53 gene and the modulation of Bcl-2 expression. This novel strategy could eventually improve the effectiveness and diminish the adverse drug reactions of AZ. Lung delivery could be a promising treatment for acute lung injury regardless of its cause. However, further work is needed to explore the stability of the formulation, its pharmacokinetics, and its safety.

Short-chain fatty acids ameliorate necrotizing enterocolitis-like intestinal injury through enhancing Notch1-mediated single immunoglobulin interleukin-1-related receptor, toll-interacting protein, and A20 induction.

Single immunoglobulin interleukin-1-related receptor (SIGIRR), toll-interacting protein (TOLLIP), and A20 are major inhibitors of toll-like receptor (TLR) signaling induced postnatally in the neonatal intestine. Short-chain fatty acids (SCFAs), fermentation products of indigestible carbohydrates produced by symbiotic bacteria, inhibit intestinal inflammation. Herein, we investigated the mechanisms by which SCFAs regulate SIGIRR, A20, and TOLLIP expression and mitigate experimental necrotizing enterocolitis (NEC). Butyrate induced NOTCH activation by repressing sirtuin 1 (SIRT1)-mediated deacetylation of the Notch intracellular domain (NICD) in human intestinal epithelial cells (HIECs). Overexpression of NICD induced SIGIRR, A20, and TOLLIP expression. Chromatin immunoprecipitation revealed that butyrate-induced NICD binds to the SIGIRR, A20, and TOLLIP gene promoters. Notch1-shRNA suppressed butyrate-induced SIGIRR/A20 upregulation in mouse enteroids and HIEC. Flagellin (TLR5 agonist)-induced inflammation in HIEC was inhibited by butyrate in a SIGIRR-dependent manner. Neonatal mice fed butyrate had increased NICD, A20, SIGIRR, and TOLLIP expression in the ileal epithelium. Butyrate inhibited experimental NEC-induced intestinal apoptosis, cytokine expression, and histological injury. Our data suggest that SCFAs can regulate the expression of the major negative regulators of TLR signaling in the neonatal intestine through Notch1 and ameliorate experimental NEC. Enteral SCFAs supplementation in preterm infants provides a promising bacteria-free, therapeutic option for NEC.NEW & NOTEWORTHY Short-chain fatty acids (SCFAs), such as propionate and butyrate, metabolites produced by symbiotic gut bacteria are known to be anti-inflammatory, but the mechanisms by which they protect against NEC are not fully understood. In this study, we reveal that SCFAs regulate intestinal inflammation by inducing the key TLR and IL1R inhibitors, SIGIRR and A20, through activation of the pluripotent transcriptional factor NOTCH1. Butyrate-mediated SIGIRR and A20 induction represses experimental NEC in the neonatal intestine.

Activation of TREK-1 (K2P2.1) potassium channels protects against influenza A-induced lung injury.

Influenza-A virus (IAV) infects yearly an estimated one billion people worldwide, resulting in 300,000-650,000 deaths. Preventive vaccination programs and antiviral medications represent the mainstay of therapy, but with unacceptably high morbidity and mortality rates, new targeted therapeutic approaches are urgently needed. Since inflammatory processes are commonly associated with measurable changes in the cell membrane potential (Em), we investigated whether Em hyperpolarization via TREK-1 (K2P2.1) K+ channel activation can protect against influenza-A virus (IAV)-induced pneumonia. We infected mice with IAV, which after 5 days caused 10-15% weight loss and a decrease in spontaneous activity, representing a clinically relevant infection. We then started a 3-day intratracheal treatment course with the novel TREK-1 activating compounds BL1249 or ML335. We confirmed TREK-1 activation with both compounds in untreated and IAV-infected primary human alveolar epithelial cells (HAECs) using high-throughput fluorescent imaging plate reader (FLIPR) assays. In mice, TREK-1 activation with BL1249 and ML335 counteracted IAV-induced histological lung injury and decrease in lung compliance and improved BAL fluid total protein levels, cell counts, and inflammatory IL-6, IP-10/CXCL-10, MIP-1α, and TNF-α levels. To determine whether these anti-inflammatory effects were mediated by activation of alveolar epithelial TREK-1 channels, we studied the effects of BL1249 and ML335 in IAV-infected HAEC, and found that TREK-1 activation decreased IAV-induced inflammatory IL-6, IP-10/CXCL10, and CCL-2 secretion. Dissection of TREK-1 downstream signaling pathways and construction of protein-protein interaction (PPI) networks revealed NF-κB1 and retinoic acid-inducible gene-1 (RIG-1) cascades as the most likely targets for TREK-1 protection. Therefore, TREK-1 activation may represent a novel therapeutic approach against IAV-induced lung injury.

This Month in Anesthesiology

This Month in Anesthesiology

A macrophage-endothelial immunoregulatory axis ameliorates septic acute kidney injury

The most common cause of acute kidney injury (AKI) in critically ill patients is sepsis. Kidney macrophages consist of both F4/80hi and CD11bhi cells. The role of macrophage subpopulations in septic AKI pathogenesis remains unclear. As F4/80hi macrophages are reported to contribute to immunomodulation following injury, we hypothesized that selective depletion of F4/80hi macrophages would worsen septic AKI. F4/80hi macrophages were depleted via diphtheria toxin injection in CD11cCre(+)/CX3CR1dtr/wt (F4/80 MKO mice) compared to CD11cCre(-)/CX3CR1dtr/wt (F4/80 MWT) mice. F4/80 MWT and F4/80 MKO mice were subjected to sham or cecal ligation and puncture to induce sepsis. Compared to F4/80 MWT mice, F4/80 MKO mice displayed worsened septic AKI at 24 hours as measured by serum creatinine and histologic injury scoring. Kidneys from F4/80 MKO mice elaborated higher kidney interleukin-6 levels. Mechanistically, single cell RNA sequencing identified a macrophage-endothelial cell immunoregulatory axis that underlies interleukin-6 expression. F4/80hi macrophages expressed interleukin-1 receptor antagonist and limited interleukin-6 expression in endothelial cells. In turn, anti-interleukin-6 therapy ameliorated septic AKI in F4/80 MKO mice. Thus, F4/80hi macrophages express interleukin-1 receptor antagonist and constrain interleukin-6 generation from endothelial cells to limit septic AKI, representing a targetable cellular crosstalk in septic AKI. These findings are particularly relevant owing to the efficacy of anti-interleukin-6 therapies during COVID-19 infection, a disease associated with high rates of AKI and endothelial dysfunction.

The impact of dietary fibers on Clostridioides difficile infection in a mouse model.

Diets rich in fiber may provide health benefits and regulate the gut microbiome, which affects the immune system. However, the role of dietary fiber in Clostridioides difficile infection (CDI) is controversial. Here, we investigated the use of fermentable fibers, such as inulin or pectin, to replace the insoluble fiber cellulose to explore how dietary fiber affects C. difficile-induced colitis in mice through intestinal microecology and metabolomics. Using C. difficile VPI 10463, we generated a mouse model of antibiotic-induced CDI. We evaluated disease outcomes and the microbial community among mice fed two fermentable fibers (inulin or pectin) versus the insoluble fiber cellulose. We analyzed and compared the gut microbiota, intestinal epithelium, cytokine levels, immune responses, and metabolites between the groups. Severe histological injury and elevated cytokine levels were observed in colon tissues after infection. Different diets showed different effects, and pectin administration protected intestinal epithelial permeability. Pectin also steadily increased the diversity of the microbiome and decreased the levels of C. difficile-induced markers of inflammation in serum and colonic tissues. The pectin group showed a higher abundance of Lachnospiraceae and a lower abundance of the conditionally pathogenic Enterobacteriaceae than the cellulose group with infection. The concentration of short-chain fatty acids in the cecal contents was also higher in the pectin group than in the cellulose group. Pectin exerted its effects through the aryl hydrocarbon receptor (AhR) pathway, which was confirmed by using the AhR agonist FICZ and the inhibitor CH2223191. Our results show that pectin alters the microbiome and metabolic function and triggers a protective immune response.

Paeonol protects against acute pancreatitis by Nrf2 and NF-κB pathways in mice.

Paeonol (PAE) is an active ingredient with anti-inflammatory and antioxidant properties. This study was designed to investigate the effect of PAE on acute pancreatitis (AP). AP was induced by the intraperitoneal injection of 20% l-arginine (4 g/kg) for 6 h. Mice were pretreated with PAE (25, 50 or 100 mg/kg) intragastrically for 5 days. The histological damage and alterations of biochemical indicators, inflammatory cytokines and oxidative stress factors in AP mice were detected. The Nrf2 and NF-κB pathways were examined to illustrate the potential mechanism. In AP model, we found that PAE attenuated histological injury of pancreatic tissues, reduced the serum levels of α-amylase and increased Ca2+ contents in a dose-dependent manner. The white blood cell content, and IL-1β, IL-6 and TNF-α levels in the serum of AP mice were reduced by PAE. Furthermore, PAE caused a reduction of MPO and MDA levels, accompanied by an increase in SOD activity in the pancreas of AP mice. We also demonstrated that the alterations of Nrf2 and NF-κB pathways in AP mice were reversed by PAE. PAE attenuates inflammation and oxidative stress in the development of AP by the regulation of Nrf2 and NF-κB pathways.

Tetrabromobisphenol a exacerbates the overall radioactive hazard to zebrafish (Danio rerio)

The major health risks of dual exposure to two hazardous factors of plastics and radioactive contamination are obscure. In the present study, we systematically evaluated the combinational toxic effects of tetrabromobisphenol A (TBBPA), one of the most influential plastic ingredients, mainly from electronic wastes, and γ-irradiation in zebrafish for the first time. TBBPA (0.25 μg/mL for embryos and larvae, 300 μg/L for adults) contamination aggravated the radiation (6 Gy for embryos and larvae, 20 Gy for adults)-induced early dysplasia and aberrant angiogenesis of embryos, further impaired the locomotor vitality of irradiated larvae, and worsened the radioactive multiorganic histologic injury, neurobehavioural disturbances and dysgenesis of zebrafish adults as well as the inter-generational neurotoxicity in offspring. TBBPA exaggerated the radiative toxic effects not only by enhancing the inflammatory and apoptotic response but also by further unbalancing the endocrine system and disrupting the underlying gene expression profiles. In conclusion, TBBPA exacerbates radiation-induced injury in zebrafish, including embryos, larvae, adults and even the next generation. Our findings provide new insights into the toxicology of TBBPA and γ-irradiation, shedding light on the severity of cocontamination of MP components and radioactive substances and thereby inspiring novel remediation and rehabilitation strategies for radiation-injured aqueous organisms and radiotherapy patients.

Nicorandil mitigates amiodarone-induced pulmonary toxicity and fibrosis in association with the inhibition of lung TGF-β1/PI3K/Akt1-p/mTOR axis in rats.

The long-term side effect of the antiarrhythmic drug, amiodarone (AMIO), such as lung toxicity, remains a critical clinical issue. The previous knowledge denotes diverse antioxidant, anti-inflammatory, and antifibrotic properties of the anti-anginal drug, nicorandil (NI). Therefore, we aimed to investigate the possible protective effect of NI on pulmonary tissue remodelling following AMIO-induced lung toxicity. The included rats were assigned into four equal groups (n=8): (1) control, (2) control group that received NI 10mg kg-1 day-1 , (3) model group that received AMIO in a dose of 60 mg kg-1 day-1 , and (4) treated group (AMIO-NI) that were treated with AMIO plus NI as shown above. Drug administration continued for 10 weeks. AMIO resulted in deteriorated (p < 0.001) pulmonary functions accompanied by respiratory acidosis. AMIO showed an obvious histological injury score with intense collagen deposition, disturbed nitric oxide synthase enzymes (NOS/iNOS), and increased alpha smooth muscle actin expression. Furthermore, AMIO upregulated the transforming growth factor (TGF-β1)/phosphoinositide-3 kinase (PI3K)-Akt1-p/mammalian target of rapamycin (mTOR) axis, which determined the possible mechanism of AMIO on pulmonary remodelling. NI treatment significantly (p < 0.001) prevented the AMIO-induced lung toxicity, as well as inhibited the TGF-β1/PI3K/Akt1-p/mTOR axis in the lung tissue of rats. The results were confirmed by an in-vitro study. CONCLUSION: The current results revealed that NI was effective in preserving the lung structure and functions. Amelioration of the oxidative stress and modulation of TGF-β1/PI3K/Akt1-p/mTOR have been achieved. This study suggests NI administration as a preventive therapy from the serious pulmonary fibrosis side effect of AMIO.

Phosphorylation of S6RP in peritubular capillaries of kidney grafts and circulating HLA donor-specific antibodies.

Antibody-mediated rejection (ABMR) caused by donor-specific HLA-antibodies (DSA) is a mediator of allograft loss after kidney transplantation (KT). DSA can activate microvascular endothelium damage through the mTOR pathway. In this study we assessed the mTOR pathway activation by DSA in KT with ABMR (ABMR + DSA+) compared to controls (ABMR-DSA-), biopsies with ABMR changes without DSA (ABMR + DSA-) and DSA without ABMR changes (ABMR-DSA+), and the potential modulation by mTOR inhibitors (mTORi). We evaluated 97 biopsies: 31 ABMR + DSA+, 33 controls ABMR-DSA-, 16 ABMR + DSA-, and 17 ABMR-DSA+ cases. Regarding immunosuppression of full ABMR + DSA+ and controls, 21 biopsies were performed under mTORi treatment (11 of them ABMR + DSA+ cases) and 43 without mTORi (20 of them ABMR + DSA+) so as to explore its effect on the mTOR pathway. Biopsies were stained for C4d, Ki67, and phosphorylated (p) S6RP, ERK, and mTOR by immunohistochemistry. Labeling was graded according to peritubular capillary staining. ABMR biopsies showed significantly higher C4d, p-S6RP, and Ki67 staining in peritubular capillaries (PTC) compared to controls, and light differences in p-ERK or p-mTOR. mTORi treatment did not modify p-S6RP, p-mTOR, and p-ERK staining. Diffuse p-S6RP in PTC in the biopsies significantly associated with circulating HLA-DSA independently of graft rejection, and with worse death-censored graft survival. These findings suggest that activation of endothelium through the mTOR pathway evidence different mechanisms of damage in ABMR + DSA+ and ABMR + DSA- despite similar histological injury.

Inhibition of glutamine transporter ASCT2 mitigates bleomycin-induced pulmonary fibrosis in mice

BackgroundIdiopathic pulmonary fibrosis (IPF) represents a fatal pulmonary disease. Its mechanisms remain unclear and effective therapies are urgently needed. Glutaminolysis is involved in IPF pathology, but little is known about the role of ASCT2 responsible for cellular uptake of glutamine in IPF. We investigated the role of ASCT2 and its therapeutic implication in IPF through knockdown of ASCT2 in mice. MethodsMouse IPF model was established through a single intratracheal administration of bleomycin, and lentivirus-coated ASCT2 siRNA was administrated into mice via caudal vein for knockdown of ASCT2. Mouse blood and lung tissues were collected for biochemical, histological, and molecular examinations. ResultsASCT2 siRNA significantly lowered ASCT2 expression in mouse lung tissues. Knockdown of ASCT2 reduced pulmonary levels of glutamic acid, α-ketoglutarate, glutathione and ATP, mitigated pulmonary histological injury, and reduced serum concentrations of pulmonary injury parameters including SP-A, SP-D, KL-6 and CCL18 in IPF mice. Moreover, serum levels of fibrotic parameters HA, LN, PC-III and IV-C were lowered by ASCT2 depletion. Collagen production and pulmonary hydroxyproline levels were also decreased by ASCT2 siRNA in IPF mice, which was concomitant with downregulation of α-smooth muscle actin, collagen type Iα1 and transforming growth factor-β receptor II. Furthermore, ASCT2 deficiency downregulated the mRNA and protein expression of inflammatory cytokines IL-1β and TNF-α as well as macrophage marker F4/80 in lung tissues of IPF mice. ConclusionsInhibition of ASCT2 effectively mitigated pulmonary injury, fibrosis and inflammation in mice with bleomycin-induced IPF. ASCT2 could be a novel therapeutic target for treatment of IPF.

The Effects of Chronic Lead Exposure on Testicular Development of Japanese Quail (Coturnix japonica): Histopathological Damages, Oxidative Stress, Steroidogenesis Disturbance, and Hypothalamus-Pituitary-Testis Axis Disruption.

Lead (Pb) becomes a global public health concern for its high toxicology. Birds are sensitive to environmental pollution and Pb contamination exerts multiple negative influences on bird life. Pb also impacts on avian reproductive system. Thus, in this study, we attempted to determine toxicological effects and possible mechanistic pathways of Pb on avian testicular development by using the model species-Japanese quail (Coturnix japonica). Male quail chicks of 1-week-old were exposed to 0, 50, 500, and 1000ppm Pb concentrations in drinking water for 5weeks when reaching sexual maturation. The results showed that high Pb doses (500 and 1000ppm) induced testis atrophy and cloacal gland shrinkage. Microstructural damages of both hypothalamus and testis indicated the disruption of the hypothalamus-pituitary-gonadal (HPG) axis by Pb exposure. The decrease of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and testosterone (T) may also imply HPG axis disruption. Moreover, excess testicular oxidative damages featured by increasing reactive oxygen species (ROS) and malondialdehyde (MDA) and decreasing catalase (CAT), glutathione (GSH), superoxide dismutase (SOD), glutathione-S-transferase (GST), and total antioxidant capacity (T-AOC) indicated increasing risks of reproductive dysfunction by Pb. Furthermore, increasing apoptosis and upregulation of gene expression associated with cell death suggested testicular abnormal development. In addition, molecular signaling involved with steroidogenesis in the testis was disturbed by Pb treatment. The study showed that Pb could impair testicular development and reproductive function by morphological and histological injury, hormone suppression, oxidative stress, cell death, and HPG axis disruption.

Systematic comparison with autoimmune liver disease identifies specific histological features of immune checkpoint inhibitor-related adverse events

BackgroundImmune checkpoint inhibitors (ICIs) have become a mainstay of cancer treatment. Their immune-boosting quality has one major drawback, their proclivity to induce a broad array of immune-related adverse events (irAEs)...

Effects of contralateral nephrectomy timing and ischemic conditions on kidney fibrosis after unilateral kidney ischemia-reperfusion injury

Acute kidney injury (AKI) is an important cause of chronic kidney disease (CKD), but the underlying mechanisms are unclear. Animal models are tools for studying the AKI-CKD progression. Kidney ischemia-reperfusion injury (IRI) models, especially the unilateral IRI (uIRI) model with delayed contralateral kidney resection, are commonly used to induce fibrotic progression to CKD after AKI. However, in previous studies, we found that details of the operation had a significant impact on the long-term outcomes of the kidney in this uIRI model. In this study, we investigated the effects of resection timing of the contralateral intact kidney, core body temperatures during ischemia, and time length of kidney ischemia on kidney function, histological injury and kidney fibrosis after AKI, using a mouse uIRI model with delayed contralateral nephrectomy. The results showed that all these parameters significantly affected the AKI-CKD transition. The post-AKI fibrosis worsened and the survival rate declined with a longer interval between contralateral nephrectomy and uIRI, higher ischemic body temperature, or longer ischemic duration when the other two variables were fixed. In conclusion, in the uIRI model with delayed contralateral nephrectomy, kidney fibrosis after AKI is influenced by many factors. Strictly controlling the experimental conditions is very important for the stability and consistency of the model.

MG132 protects against lung injury following brain death in rats.

Brain death (BD) results in injury to organs and induces lung donor dysfunction. Since the 20S proteasome abnormality is associated with a variety of diseases, the present study investigated whether it was involved in lung injury following BD in rats, and the effects of the proteasome inhibitor MG132 on lung injury was also assessed. Rats were assigned to a BD group or a control sham group. The BD group of rats were sacrificed at different time points after BD. Administration of MG132 was performed intraperitoneally 30 min before BD. Arterial blood was drawn to measure the oxygenation index [partial artery pressure of oxygen (PaO2)/fractional concentration of inspired oxygen (FiO2)]. The right lung was used for staining with hematoxylin and eosin, immunohistochemistry, immunofluorescence, western blotting and RT-qPCR analysis. The left lung was used to measure the wet and dry weights. Rat alveolar macrophages (NR8383) were treated with MG132 and hypoxia/reoxygenation (H/R) and used for western blotting and flow cytometry. The PaO2/FiO2 ratio decreased after BD; the wet/dry weight ratio, histological lung injury score and protein expression of 20S proteasome β1 and inducible nitric oxide synthase (iNOS) gradually increased in rats after BD. Colocalization in the immunofluorescence between 20S proteasome β1 and iNOS was observed. MG132 treatment increased the PaO2/FiO2 ratio and decreased the wet/dry weight ratio, histological lung injury score and protein expression of 20S proteasome β1 and iNOS in rats after BD. MG132 was revealed to increase NR8383 apoptosis after H/R and to upregulate the protein expression levels of p-JNK and cleaved-caspase 3. Overall, the proteasome inhibitor MG132 could effectively reduce lung injury, which may be associated with its ability to inhibit the expression of the proteasome and promote the apoptosis of alveolar macrophages.

Pre-clinical Investigation of Protective Effect of Nutraceutical D-Glucosamine on TNBS-induced Colitis

The level of precursors involved in the biosynthesis of glycosaminoglycan (GAG), glucosamine synthase, and N-acetyl glucosamine (NAG), are significantly reduced in inflammatory bowel disease (IBD). This results in deficient GAG content in mucosa, which eventually disrupts the gut wall integrity, provoking abnormal immunological responses. This is characterized by colossal liberation of inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukins (IL), and reactive oxygen species provoking colonic inflammation. D-glucosamine (D-GLU) is reported to suppress oxidative stress, and pro-inflammatory cytokines and acts as a starting material for biosynthesis of NAG. The potential of D-GLU and its combination with mesalamine (5-ASA) was investigated in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-instigated IBD in Wistar rats. Standard and test drugs were given orally for five days to separate groups of rats. Colonic inflammation was evaluated by disease activity score rate (DASR), colon/body weight ratio, colon length, diameter, colon pH, histological injury and score. Inflammatory biomarkers IL-1β, TNF-α, along with reduced glutathione (GSH), and malondialdehyde (MDA) were assessed. Combination of D-GLU +5-ASA significantly ameliorated severity of colonic inflammation by lowering DASR (P < 0.001) and colon/body weight ratio (P < 0.001), restored the colonic architecture and suppressed the histopathological score (P < 0.001), along with the absence of major adverse reactions. The combination suppressed the levels of inflammatory markers (P < 0.001) and MDA (P < 0.001) while enhancing GSH level (P < 0.001). In comparison to individual 5-ASA and D-GLU, combination of drugs significantly diminished colitis severity through their combined anti-inflammatory and antioxidant effects by acting on multiple targets simultaneously. The combination holds remarkable potential in the management of IBD.

Classical prescription Huanglian Decoction relieves ulcerative colitis via maintaining intestinal barrier integrity and modulating gut microbiota

Background: Ulcerative colitis (UC) has affected an increasing number of people globally, with still limited clinical success. Huanglian Decoction (HLD) is a famous classical prescription documented for alleviating gastrointestinal disorders with unexplored therapeutic effects and mechanisms.Purpose: This study aimed to investigate the therapeutic effect and underlying mechanism of HLD in dextran sodium sulfate (DSS)-induced colitis mice.Methods: The efficacy and safety of HLD were evaluated in a well-established DSS-induced colitis mice model. Disease progression was monitored via clinical symptoms, histopathological examination, biochemical assays, and epithelial barrier function evaluation.Results: HLD alleviated DSS-induced colitis symptoms, reversed colon length reduction, reduced histological injury, downregulated the level of pro-inflammatory cytokines, maintained the tight distribution of ZO-1/occludin-1 and the normal level of β-catenin, concurrent with apoptosis reduction in the colonic epithelium. After HLD treatment, the DSS-induced gut dysbiosis was modulated, and the gut microbiota achieved a new equilibrium state.Conclusion: This study demonstrates that HLD may present a potential remedy for UC treatment, providing evidence for further developing Chinese classical prescriptions.

Antarctic krill (Euphausia superba) oil modulatory effects on ethanol-induced acute injury of the gastric mucosa in rats.

Antarctic krill oil (KO) prepared using supercritical carbon dioxide extraction and characterized using gas chromatography-mass spectrometry was used to investigate its preventive effect on ethanol-induced gastric tissue damage in a rat model in vivo. KO characterization showed that 74.96% of the unsaturated fatty acids consist of oleic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Rats pre-treated with KO (100, 200, and 500 mg/kg) showed mitigated oxidative stress through enhanced antioxidant enzyme superoxide dismutase (SOD) and reducing enzymes malondialdehyde (MDA) and myeloperoxidase (MPO) in gastric mucosal injury induced by ethanol. Additionally, the secretion of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β), the expression of the IκBα/NF-κB signaling pathway, and nitric oxide (NO) production was suppressed. The results also demonstrated a significant decrease in histological injury and hemorrhage scores in a dose-dependent manner in the KO range. Therefore, KO has potential as a food supplement to alleviate ethanol-induced acute gastric mucosal injury.

Soluble Protein Hydrolysate Ameliorates Gastrointestinal Inflammation and Injury in 2,4,6-Trinitrobenzene Sulfonic Acid-Induced Colitis in Mice

Inflammatory bowel diseases (IBD) are chronic, recurring gastrointestinal diseases that severely impair health and quality of life. Although therapeutic options have significantly expanded in recent years, there is no effective therapy for a complete and permanent cure for IBD. Well tolerated dietary interventions to improve gastrointestinal health in IBD would be a welcome advance especially with anticipated favorable tolerability and affordability. Soluble protein hydrolysate (SPH) is produced by the enzymatic hydrolysis of commercial food industry salmon offcuts (consisting of the head, backbone and skin) and contains a multitude of bioactive peptides including those with anti-oxidant properties. This study aimed to investigate whether SPH ameliorates gastrointestinal injury in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced mouse colitis model. Mice were randomly assigned to four groups: Control (no colitis), Colitis, Colitis/CP (with control peptide treatment), and Colitis/SPH (with SPH treatment). Colitis was induced by cutaneous sensitization with 1% TNBS on day −8 followed by 2.5% TNBS enema challenge on day 0. Control peptides and SPH were provided to the mice in the Colitis/CP or Colitis/SPH group respectively by drinking water at the final concentration of 2% w/v daily from day −10 to day 4. Then, the colon was harvested on day 4 and examined macro- and microscopically. Relevant measures included disease activity index (DAI), colon histology injury, immune cells infiltration, pro- and anti-inflammatory cytokines and anti-oxidative gene expression. It was found that SPH treatment decreased the DAI score and colon tissue injury when compared to the colitis-only and CP groups. The protective mechanisms of SPH were associated with reduced infiltration of CD4+ T, CD8+ T and B220+ B lymphocytes but not macrophages, downregulated pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-6), and upregulated anti-inflammatory cytokines (transforming growth factor-β1 and interleukin-10) in the colon tissue. Moreover, the upregulation of anti-oxidative genes, including ferritin heavy chain 1, heme oxygenase 1, NAD(P)H quinone oxidoreductase 1, and superoxide dismutase 1, in the colons of colitis/SPH group was observed compared with the control peptide treatment group. In conclusion, the protective mechanism of SPH is associated with anti-inflammatory and anti-oxidative effects as demonstrated herein in an established mice model of colitis. Clinical studies with SPH as a potential functional food for the prevention or as an adjuvant therapy in IBD may add an effective and targeted diet-based approach to IBD management in the future.