Levosimendan Ameliorates Cardiopulmonary Function but Not Inflammatory Response in a Dual Model of Experimental ARDS

Novel insights into the whole-blood DNA methylome of asthma in ethnically diverse children and youth

BACKGROUND

The epigenetic mechanisms of asthma remain largely understudied in African Americans and Hispanics/Latinos, two populations disproportionately affected by asthma. We aimed to identify markers, regions and processes with differential patterns of DNA methylation (DNAm) in whole blood by asthma status in ethnically diverse children and youth, and to assess their functional consequences.

METHODS

DNAm levels were profiled with the Infinium MethylationEPIC or HumanMethylation450 BeadChip arrays among 1226 African Americans or Hispanics/Latinos and assessed for differential methylation per asthma status at the CpG and region (differentially methylated region (DMR)) level. Novel associations were validated in blood and/or nasal epithelium from ethnically diverse children and youth. The functional and biological implications of the markers identified were investigated by combining epigenomics with transcriptomics from study participants.

RESULTS

128 CpGs and 196 DMRs were differentially methylated after multiple testing corrections, including 92.3% and 92.8% novel associations, respectively. 41 CpGs were replicated in other Hispanics/Latinos, prioritising cg17647904 (NCOR2) and cg16412914 (AXIN1) as asthma DNAm markers. Significant DNAm markers were enriched in previous associations for asthma, fractional exhaled nitric oxide, bacterial infections, immune regulation or eosinophilia. Functional annotation highlighted epigenetically regulated gene networks involved in corticosteroid response, host defence and immune regulation. Several implicated genes are targets for approved or experimental drugs, including TNNC1 and NDUFA12. Many differentially methylated loci previously associated with asthma were validated in our study.

CONCLUSIONS

We report novel whole-blood DNAm markers for asthma underlying key processes of the disease pathophysiology and confirm the transferability of previous asthma DNAm associations to ethnically diverse populations.

Resveratrol influences pulmonary mechanics and inflammatory response in a porcine ARDS model

AIMS

Influencing the inflammatory response represents an important branch in ARDS research. The naturally occurring polyphenol derivative resveratrol has already been confirmed to have strong anti-inflammatory effects on the cardiac and metabolic system. In the present study, we investigated the propagated anti-inflammatory effects of intravenous resveratrol in a porcine ARDS model.

MAIN METHODS

20 domestic pigs (30 ± 2 kg; approval G20-1-135), divided into three groups: 1. resveratrol high dose (HD; n = 8), single bolus of 20 mg/kg over 15 min. 2. resveratrol low dose (LD; n = 8), single bolus of 10 mg/kg over 15 min. 3. Vehicle (n = 4), with the carrier solution DMSO over 15 min administered after ARDS induction. ARDS induction: using BAL/oleic acid and a subsequent test period of 8 h. Measurement parameters: Hemodynamics/spirometry data were collected continuously, BGA/laboratory parameters repetitively. Post-mortem: analysis of pulmonary inflammatory markers.

STATISTICS

Two-way analysis of variance (repeated measurement) and Student-Newman-Keuls method.

KEY FINDINGS

Resveratrol HD significantly reduced the expression of TNF-alpha in lung tissue compared to the LD group (p < 0.05). A significantly increased functional residual capacity (FRC) could be demonstrated for the HD group at the end of the test (p < 0.05 for HD vs. LD/vehicle). Further, resveratrol HD reduced statistically the EVLWI compared to LD/vehicle (p < 0.05 at T4/T8).

SIGNIFICANCE

In this study, resveratrol HD ameliorated pulmonary mechanics as reported for the FRC and EVLWI. Further, the proposed anti-inflammatory effects of resveratrol, a significant reduction in the expression of TNF-alpha was observed in the HD group.

Comparison of two porcine acute lung injury models: a post-hoc analysis

Background

Acute respiratory distress syndrome (ARDS) is a common disease in intensive care medicine. Despite intensive research, mortality rates are high, not even in COVID-19 ARDS. Thereby, pigs offer some advantages to study the characteristics of ARDS. Many different ARDS models exist. Most of the articles published focused on histopathological and microscopic lung alterations to identify the most suitable animal ARDS model. “Macroscopic” observations and descriptions are often missing. Therefore, we performed a post-hoc comparison of two common ARDS models for pigs: lipopolysaccharide (LPS) vs. a double-hit model (bronchoalveolar lavage + oleic acid infusion). We investigated hemodynamic, spirometric and laboratory changes as another main clinical part of ARDS.

Results

The groups were compared by two-way analysis of variance (ANOVA) with a post-hoc Student–Newman–Keuls test. A p value lower than 0.05 was accepted as significant. All animals (n = 8 double-hit ARDS; n = 8 LPS ARDS) survived the observation period of 8 h. ARDS induction with reduced oxygen indices was successful performed in both models (76 ± 35/225 ± 54/212 ± 79 vs. 367 ± 64; T0/T4/T8 vs. BLH for double-hit; 238 ± 57/144 ± 59 vs. 509 ± 41; T4/T8 vs. BLH for LPS; p < 0.05). ARDS induced with LPS leads to more hemodynamic (mean arterial pulmonary pressure 35 ± 3/30 ± 3 vs. 28 ± 4/23 ± 4; T4/T8 LPS vs. double-hit; p < 0.05; doses of norepinephrine 1.18 ± 1.05 vs. 0.11 ± 0.16; LPS vs. double-hit for T8; p < 0.05) and inflammatory (pulmonary IL-6 expression: 2.41e−04 ± 1.08e−04 vs. 1.45e−05 ± 7.26e−06; LPS vs. double-hit; p < 0.05) alterations. ARDS induced by double-hit requires a more invasive ventilator strategy to maintain a sufficient oxygenation (PEEP at T4: 8 ± 3 vs. 6 ± 2; double-hit vs. LPS; p < 0.05).

Conclusions

Both animal ARDS models are feasible and are similar to human presentation of ARDS. If your respiratory research focus on hemodynamic/inflammation variables, the LPS-induced ARDS is a feasible model. Studying different ventilator strategies, the double-hit ARDS model offers a suitable approach.