Presentation_1_Interferon-induced transmembrane protein 3 in the hippocampus: a potential novel target for the therapeutic effects of recombinant human brain natriuretic peptide on sepsis-associated encephalopathy.pdf

ObjectiveThis study aims to explore whether interferon-induced transmembrane protein 3 (IFITM3) is involved in recombinant human brain natriuretic peptide (rhBNP)-mediated effects on sepsis-induced cognitive dysfunction in mice.MethodsThe cellular localization and expression level of IFITM3 in the hippocampus were detected. The IFITM3 overexpression was achieved using an intracranial stereotactic system to inject an adeno-associated virus into the hippocampal CA1 region of mice. Field experiments, an elevated plus maze, and conditioned fear memory tests assessed the cognitive impairment in rhBNP-treated septic mice. Finally, in the hippocampus of septic mice, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining and Immunoblot were used to detect changes in the protein expression of cleaved Caspase-8 and cleaved Caspase-3 in apoptosis-related pathways, and toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) p65 in inflammatory pathways.ResultsFourteen days after cecal ligation and puncture (CLP) surgery, IFITM3 localized in the plasma membrane and cytoplasm of the astrocytes in the hippocampus of septic mice, partially attached to the perivascular and neuronal surfaces, but not expressed in the microglia. The expression of IFITM3 was increased in the astrocytes and neurons in the hippocampus of septic mice, which was selectively inhibited by the administration of rhBNP. Overexpression of IFITM3 resulted in elevated anxiety levels and long-term learning and memory dysfunction, completely abolished the therapeutic effect of rhBNP on cognitive impairment in septic mice, and induced an increase in the number of neuronal apoptosis in the hippocampal CA1 region. The expression levels of cleaved Caspase-3 and cleaved Caspase-8 proteins were significantly increased in the hippocampus, but the expression levels of TLR4 and NF-κB p65 were not increased.ConclusionThe activation of IFITM3 may be a potential new target for treating sepsis-associated encephalopathy (SAE), and it may be one of the key anti-apoptotic mechanisms in rhBNP exerting its therapeutic effect, providing new insight into the clinical treatment of SAE patients.</p

Chitosan oligosaccharide ameliorates acute lung injury induced by blast injury through the DDAH1/ADMA pathway

<div><p>Objective</p><p>To investigate the protective effect of chitosan oligosaccharide (COS) on acute lung injury (ALI) caused by blast injury, and explore possible molecular mechanisms.</p><p>Methods</p><p>A mouse model of blast injury-induced ALI was established using a self-made explosive device. Thirty mice were randomly assigned to control, ALI and ALI + COS groups. An eight-channel physiological monitor was used to determine the mouse physiological index. Enzyme linked immunosorbent assay was used to measure serum inflammatory factors. Hematoxylin-eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, immunofluorescence staining, real time-polymerase chain reaction and western blot assay were used to detect inflammatory reactions, oxidative stress and apoptosis.</p><p>Results</p><p>Mice were sacrificed 24 hours after successful model induction. Compared with the ALI group, the heart rate, respiration and PCO₂ were significantly lower, but the PO₂, TCO₂ and HCO₃^- were significantly higher in the ALI + COS group. Compared to ALI alone, COS treatment of ALI caused a significant decrease in the wet/dry lung weight ratio, indicating a reduction in lung edema, inflammatory cell infiltration, levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-4, IL-6 and nuclear factor kappa B mRNA and protein expression were reduced and IL-10 mRNA and protein expression was increased (<i>P</i> < 0.05). COS significantly inhibited reactive oxygen species, MDA5 and IREα mRNA and protein expressions, cell apoptosis and Bax and Caspase-3 mRNA and protein expressions, and significantly increased superoxide dismutase-1 mRNA expression, and Bcl-2 and Caspase-8 mRNA and protein expression (all <i>P</i><0.05). COS significantly increased dimethylarginine dimethylaminohydrolase 1 (DDAH1) protein expression, and reduced ADMA and p38 protein expression (<i>P</i>< 0.05).</p><p>Conclusion</p><p>Blast injury causes inflammation, oxidative stress and apoptosis in the lung tissues of mice. COS has protective effects on blast injury-induced ALI, possibly by promoting DDAH1 expression and inhibiting ADMA and mitogen-activated protein kinase pathways.</p></div

COS effects on inflammatory factor expression in the lung.

<p>The expression of TNF-α, IL-1β, IL-4, IL-6 and IL-10 in serum were determined using ELISA kit. The expression of inflammatory factors was detected using real time-PCR and western blot. *<i>P</i> < 0.05, vs. control group; ^#<i>P</i> < 0.05, vs. ALI group. COS: chitosan oligosaccharide; ALI: acute lung injury; TNF: tumor necrosis factor; IL: interleukin.</p

COS effects on the wet/dry weight ratio and pathological changes in the lung of mice.

<p>*<i>P</i> < 0.05, vs. control group; ^#P < 0.05, vs. ALI group. COS: chitosan oligosaccharide; ALI: acute lung injury.</p

COS effects on mouse weight, heart rate, respiratory rate and blood gas analysis.

<p>The MPA2000 eight-channel physiological monitor was used to record pulmonary function. Lung function parameters were calculated by esophageal pressure, airway pressure and gas flow. After left femoral artery catheterization, connecting heart function analyzer and blood pressure sensor, mouse heart rate was continuously monitored. *<i>P</i> < 0.05, vs. control group; ^#<i>P</i> < 0.05, vs. the ALI group. COS: chitosan oligosaccharide; ALI: acute lung injury.</p

COS effects on oxidative stress in the lung.

<p>Oxidative stress in the lung was determined using immunofluorescence staining, real time-PCR and western blot. *<i>P</i> < 0.05, vs. control group; ^#<i>P</i> < 0.05, vs. ALI group. COS: chitosan oligosaccharide; ALI: acute lung injury.</p

COS effects on pathway protein expression in the lung.

<p>Pathway protein expression in the lung was measured using immunofluorescence staining, real time-PCR and western blot. *<i>P</i> < 0.05, vs. control group; ^#<i>P</i> < 0.05, vs. ALI group. COS: chitosan oligosaccharide; ALI: acute lung injury.</p