MicroRNA-145 plays a role in mitochondrial dysfunction in alveolar epithelial cells in lipopolysaccharide-induced acute respiratory distress syndrome

O-GlcNAcylation attenuates ischemia-reperfusion-induced pulmonary epithelial cell ferroptosis via the Nrf2/G6PDH pathway

BACKGROUND

Lung ischemia-reperfusion (I/R) injury is a common clinical pathology associated with high mortality. The pathophysiology of lung I/R injury involves ferroptosis and elevated protein O-GlcNAcylation levels, while the effect of O-GlcNAcylation on lung I/R injury remains unclear. This research aimed to explore the effect of O-GlcNAcylation on reducing ferroptosis in pulmonary epithelial cells caused by I/R.

RESULTS

First, we identified O-GlcNAc transferase 1 (Ogt1) as a differentially expressed gene in lung epithelial cells of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) patients, using single-cell sequencing, and Gene Ontology analysis (GO analysis) revealed the enrichment of the ferroptosis process. We found a time-dependent dynamic alteration in lung O-GlcNAcylation during I/R injury. Proteomics analysis identified the differentially expressed proteins enriched in ferroptosis and multiple redox-related pathways based on KEGG annotation. Thus, we generated Ogt1-conditional knockout mice and found that Ogt1 deficiency aggravated ferroptosis, as evidenced by lipid reactive oxygen species (lipid ROS), malondialdehyde (MDA), Fe2+, as well as alterations in critical protein expression glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11). Consistently, we found that elevated O-GlcNAcylation inhibited ferroptosis sensitivity in hypoxia/reoxygenation (H/R) injury-induced TC-1 cells via O-GlcNAcylated NF-E2-related factor-2 (Nrf2). Furthermore, both the chromatin immunoprecipitation (ChIP) assay and the dual-luciferase reporter assay indicated that Nrf2 could bind with translation start site (TSS) of glucose-6-phosphate dehydrogenase (G6PDH) and promote its transcriptional activity. As an important rate-limiting enzyme in the pentose phosphate pathway (PPP), elevated G6PDH provided a mass of nicotinamide adenine dinucleotide phosphate (NADPH) to improve the redox state of glutathione (GSH) and eventually led to ferroptosis resistance. Rescue experiments proved that Nrf2 knockdown or Nrf2-T334A (O-GlcNAcylation site) mutation abolished the protective effect of ferroptosis resistance.

CONCLUSIONS

In summary, we revealed that O-GlcNAcylation could protect against I/R lung injury by reducing ferroptosis sensitivity via the Nrf2/G6PDH pathway. Our work will provide a new basis for clinical therapeutic strategies for pulmonary ischemia-reperfusion-induced acute lung injury.

Patient care during interfacility transport: a narrative review of managing diverse disease states

BACKGROUND

When critically ill patients require specialized treatment that exceeds the capability of the index hospitals, patients are frequently transferred to a tertiary or quaternary hospital for a higher level of care. Therefore, appropriate and efficient care for patients during the process of transport between two hospitals (interfacility transfer) is an essential part of patient care. While medical adverse events may occur during the interfacility transfer process, there have not been evidence-based guidelines regarding the equipment or the practice for patient care during transport.

METHODS

We conducted searches from the PubMed, Cumulative Index of Nursing and Allied Health (CINAHL), and Scopus databases up to June 2022. Two reviewers independently screened the titles and abstracts for eligibility. Studies that were not in the English language and did not involve critically ill patients were excluded.

RESULTS

The search identified 75 articles, and we included 48 studies for our narrative review. Most studies were observational studies.

CONCLUSION

The review provided the current evidence-based management of diverse disease states during the interfacility transfer process, such as proning positioning for respiratory failure, extracorporeal membrane oxygenation (ECMO), obstetric emergencies, and hypertensive emergencies (aortic dissection and spontaneous intracranial hemorrhage).