Protective Effects of Danmu Extract Syrup on Acute Lung Injury Induced by Lipopolysaccharide in Mice through Endothelial Barrier Repair

OBJECTIVE

To investigate the effects of Danmu Extract Syrup (DMS) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and explore the mechanism.

METHODS

Seventy-two male Balb/C mice were randomly divided into 6 groups according to a random number table (n=12), including control (normal saline), LPS (5 mg/kg), LPS+DMS 2.5 mL/kg, LPS+DMS 5 mL/kg, LPS+DMS 10 mL/kg, and LPS+Dexamethasone (DXM, 5 mg/kg) groups. After pretreatment with DMS and DXM, the ALI mice model was induced by LPS, and the bronchoalveolar lavage fluid (BALF) were collected to determine protein concentration, cell counts and inflammatory cytokines. The lung tissues of mice were stained with hematoxylin-eosin, and the wet/dry weight ratio (W/D) of lung tissue was calculated. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1 β in BALF of mice were detected by enzyme linked immunosorbent assay. The expression levels of Claudin-5, vascular endothelial (VE)-cadherin, vascular endothelial growth factor (VEGF), phospho-protein kinase B (p-Akt) and Akt were detected by Western blot analysis.

RESULTS

DMS pre-treatment significantly ameliorated lung histopathological changes. Compared with the LPS group, the W/D ratio and protein contents in BALF were obviously reduced after DMS pretreatment (P<0.05 or P<0.01). The number of cells in BALF and myeloperoxidase (MPO) activity decreased significantly after DMS pretreatment (P<0.05 or P<0.01). DMS pre-treatment decreased the levels of TNF-α, IL-6 and IL-1 β (P<0.01). Meanwhile, DMS activated the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway and reversed the expressions of Claudin-5, VE-cadherin and VEGF (P<0.01).

CONCLUSIONS

DMS attenuated LPS-induced ALI in mice through repairing endothelial barrier. It might be a potential therapeutic drug for LPS-induced lung injury.

Strictosamide alleviates acute lung injury via regulating T helper 17 cells, regulatory T cells, and gut microbiota

BACKGROUND

Nauclea officinalis (Pierre ex Pit.) Merr. & Chun (Rubiaceae) is widely used to treat respiratory diseases in China. Strictosamide is its main active component and has significant anti-inflammatory activity. However, the effects and molecular mechanisms of strictosamide in the treatment of acute lung injury (ALI) remain largely unknown.

PURPOSE

This study aimed to examine the regulatory effects of strictosamide on T helper 17 cells (Th17 cells)/Regulatory T cells (Treg cells) and gut microbiota in ALI-affected mice.

MATERIALS AND METHODS

The ALI model was induced using lipopolysaccharide (LPS) intraperitoneal injection. Hematoxylin-eosin (H&E) staining, the number of inflammatory cells in broncho-alveolar lavage fluid (BALF), the Wet/Dry (W/D) ratio, and myeloperoxidase (MPO) activity were utilized as evaluation indices for the therapeutic efficacy of strictosamide on ALI. Flow cytometry (FCM), enzyme-linked immune sorbent assay (ELISA), quantitative reverse transcription polymerase chain reaction (qRT-PCR), and western blotting were used to determine the regulation of strictosamide on the Th17/Treg cells and the STAT3/STAT5 signaling pathway. The analysis of gut microbiota was conducted using 16S rDNA sequencing. The verification of the relationship between the gut microbiome and immune function was conducted using Spearman analysis.

RESULTS

Strictosamide attenuated inflammation on ALI induced by LPS, which reduced the levels of Th17-related factors interleukin (IL)-6 and IL-17 and increased Treg-related factors IL-10 and transforming growth factor (TGF)-β. In the spleens and whole blood, strictosamide reduced the proportion of Th17 cells and increased the proportion of Treg cells. Furthermore, strictosamide increased Forkhead/winged helix transcription factor 3 (Foxp3) and p-STAT5 protein expression while inhibiting Retinoid-related orphan nuclear receptors-γt (RORγt) and p-STAT3 expression. Moreover, strictosamide reshaped the diversity and structure of the gut microbiota, and influence the associations between immune parameters and gut microbiota in ALI mice.

CONCLUSIONS

In summary, the results of the current investigation showed that strictosamide has a therapeutic impact on LPS-induced ALI. The mechanism of action of this effect may be associated with the modulation of Th17 and Treg cells differentiation via the SATA signaling pathway, as well as the impact of the gut microbiota.

[Analysis of liver pathological characteristics and exploration of noninvasive markers of liver fibrosis in children with chronic hepatitis B]

Objective: To analyze and summarize the characteristics of liver pathology and their relation to clinical markers and further explore noninvasive markers of liver fibrosis in children with chronic hepatitis B. Methods: Data of 80 hospitalized children with chronic hepatitis B who underwent liver biopsy without antiviral treatment from 2011 to 2020 were retrospectively analyzed. Inflammation and liver fibrosis characteristics were analyzed in children of different ages and genders. Variables with good correlation with liver fibrosis stage were selected to establish a non-invasive diagnostic score of liver fibrosis in children. Measurement data was used to compare the t-test or rank sum test. Mantel-Haenszel χ (2) test was used for bidirectional ordered grouping data. Spearman's rank correlation test was used for rank correlation analysis. Receiver operating characteristic curve (ROC) was used to evaluate the diagnostic value of the newly established diagnostic score in children with liver fibrosis. Results: The median age of the children was 6.4 years. HBV DNA level was high (P50 = 7.6 log(10) IU/ml), and serum alanine aminotransferase (ALT) in P50 was 171 U/L (< ULN: 5 cases, ULN-2ULN: 10 cases, > 2 ULN: 65 cases). Pathological analysis showed that the incidence of liver tissue inflammation was 97.5%, and the proportion of patients with G≥2 was 42.5%, while S≥2 was 36.3%. The incidence rate of liver fibrosis and liver cirrhosis was 81.3%, and 1.3%, respectively. The changes in liver tissue inflammation and fibrosis were gradually aggravated with the increase of age, and the proportion of high-grade inflammation and liver fibrosis in male children was higher than that in female children. Serum levels of glutamyl transpeptidase (GGT), γ-glutamyltransferase/platelet ratio (GPR) and HBeAg had a good correlation with fibrosis stage (r(s) = 0.397, 0.389, and - 0.311) in children with chronic hepatitis B. The combination of GGT, GPR and HBeAg can establish a non-invasive diagnostic score for evaluating liver fibrosis in children. When the score is less than 1.5, it can be diagnosed as S0, and 1.5 ≤ score < 3.5, it can be diagnosed as S1; 3.5 ≤ score < 5.5, the diagnosis of fibrosis is S2; score≥ 5.5, the diagnosis of fibrosis is S≥3. The sensitivity and specificity were 80%, 83%, 86%, and 53%, 55%, 67%, respectively. Conclusion: The incidence of liver tissue inflammation in children with chronic hepatitis B with elevated and fluctuating transaminase levels is high, and the pathological changes of liver tissue aggravate with the age of the children. GGT, GPR and HBeAg have a good correlation with liver fibrosis in children with chronic hepatitis B. Therefore, combining the above-mentioned markers to establish a new noninvasive diagnostic score has certain diagnostic value for liver fibrosis stage S0-S3 in children with chronic hepatitis B.

A common variant of the endothelial nitric oxide synthase (Glu298-->Asp) is a major risk factor for coronary artery disease in the UK

BACKGROUND

Endothelium-derived nitric oxide (NO) is synthesised from L-arginine by endothelial nitric oxide synthase (eNOS) encoded by the NOS 3 gene on chromosome 7. Because reduced NO synthesis has been implicated in the development of coronary atherosclerosis, which has a heritable component, we hypothesised that polymorphisms of NOS 3 might be associated with increased susceptibility to this disorder.

METHODS AND RESULTS

Single-strand conformation polymorphism analysis of NOS 3 identified a G-->T polymorphism in exon 7 of the gene which encodes a Glu-->Asp amino acid substitution at residue 298 of eNOS. We investigated the relationship between this Glu(298)-->Asp variant and atherosclerotic coronary artery disease (CAD) using 2 independent case-controlled studies. In the first study (CHAOS), cases consisted of 298 unrelated patients with positive coronary angiograms and controls were 138 unrelated healthy individuals ascertained through a population health screen. In the second study (CHAOS II), the cases were 249 patients with recent myocardial infarction (MI), and a further 183 unrelated controls. There was an excess of homozygotes for the Asp298 variant among patients with angiographic CAD, and among patients with recent MI when compared with their respective controls (35.9% versus 10.2%, P<0.0001 in CHAOS, and 18.1% versus 8.7%, P<0.02 in CHAOS II). In comparison to Glu(298) homozygotes, homozygosity for Asp(298) was associated with an odds ratio of 4.2 (95% CI, 2.3 to 7.9) for angiographic CAD and 2.5 (95% CI, 1.3 to 4.2) for MI.

CONCLUSIONS

Homozygosity for a common NOS 3 polymorphism (894 G-->T) which encodes a Glu298-->Asp amino acid substitution in eNOS is a risk factor for angiographic CAD and recent MI in this population.