Biological Connection of Psychological Stress and Polytrauma under Intensive Care: The Role of Oxytocin and Hydrogen Sulfide

FGF2 Functions in H2S's Attenuating Effect on Brain Injury Induced by Deep Hypothermic Circulatory Arrest in Rats

Deep hypothermic circulatory arrest (DHCA) can protect the brain during cardiac and aortic surgery by cooling the body, but meanwhile, temporary or permanent brain injury may arise. H2S protects neurons and the central nervous system, especially from secondary neuronal injury. We aim to unveil part of the mechanism of H2S's attenuating effect on brain injury induced by DHCA by exploring crucial target genes, and further promote the clinical application of H2S in DHCA. Nine SD rats were utilized to provide histological and microarray samples, and further the differential expression analysis. Then we conducted GO and KEGG pathway enrichment analyses on candidate genes. The protein-protein interaction (PPI) networks were performed by STRING and GeneMANIA. Crucial target genes' expression was validated by qRT-PCR and western blot. Histological study proved DHCA's damaging effect and H2S's repairing effect on brain. Next, we got 477 candidate genes by analyzing differentially expressed genes. The candidate genes were enriched in 303 GO terms and 28 KEGG pathways. Then nine genes were selected as crucial target genes. The function prediction by GeneMANIA suggested their close relation to immunity. FGF2 was identified as the crucial gene. FGF2 plays a vital role in the pathway when H2S attenuates brain injury after DHCA. Our research provides more information for understanding the mechanism of H2S attenuating brain injury after DHCA. We infer the process might probably be closely associated with immunity.

MiR-1909-5p targeting GPX4 affects the progression of aortic dissection by modulating nicotine-induced ferroptosis

OBJECTIVE

Aortic dissection (AD) is a prevalent and acute clinical catastrophe characterized by abrupt manifestation, swift progression, and elevated fatality rates. Despite smoking being a significant risk factor for AD, the precise pathological process remains elusive. This investigation endeavors to explore the mechanisms by which smoking accelerates AD through ferroptosis induction.

METHODOLOGY

In this novel study, we detected considerable endothelial cell death by ferroptosis within the aortic inner lining of both human AD patients with a smoking history and murine AD models induced by β-aminopropionitrile, angiotensin II, and nicotine. Utilizing bioinformatic approaches, we identified microRNAs regulating the expression of the ferroptosis inhibitor Glutathione peroxidase 4 (GPX4). Nicotine's impact on ferroptosis was further assessed in human umbilical vein endothelial cells (HUVECs) through modulation of miR-1909-5p. Additionally, the therapeutic potential of miR-1909-5p antagomir was evaluated in vivo in nicotine-exposed AD mice.

FINDINGS

Our results indicate a predominance of ferroptosis over apoptosis, pyroptosis, and necroptosis in the aortas of AD patients who smoke. Nicotine exposure instigated ferroptosis in HUVECs, where the miR-1909-5p/GPX4 axis was implicated. Modulation of miR-1909-5p in these cells revealed its regulatory role over GPX4 levels and subsequent endothelial ferroptosis. In vivo, miR-1909-5p suppression reduced ferroptosis and mitigated AD progression in the murine model.

CONCLUSIONS

Our data underscore the involvement of the miR-1909-5p/GPX4 axis in the pathogenesis of nicotine-induced endothelial ferroptosis in AD.

Oxytocin and oxygen: the evolution of a solution to the ‘stress of life’

Oxytocin (OT) and the OT receptor occupy essential roles in our current understanding of mammalian evolution, survival, sociality and reproduction. This narrative review examines the hypothesis that many functions attributed to OT can be traced back to conditions on early Earth, including challenges associated with managing life in the presence of oxygen and other basic elements, including sulfur. OT regulates oxidative stress and inflammation especially through effects on the mitochondria. A related nonapeptide, vasopressin, as well as molecules in the hypothalamic–pituitary–adrenal axis, including the corticotropin-releasing hormone family of molecules, have a broad set of functions that interact with OT. Interactions among these molecules have roles in the causes and consequence of social behaviour and the management of threat, fear and stress. Here, we discuss emerging evidence suggesting that unique properties of the OT system allowed vertebrates, and especially mammals, to manage over-reactivity to the ‘side effects’ of oxygen, including inflammation, oxidation and free radicals, while also supporting high levels of sociality and a perception of safety.

This article is part of the theme issue ‘Interplays between oxytocin and other neuromodulators in shaping complex social behaviours’.