Vahkal Brett, Altosaar Illimar, Ariana Ardeshir, Jabbour Josie, Pantieras Falia, Daniel Redaet, Tremblay Éric, Sad Subash, Beaulieu Jean-François, Côté Marceline, Ferretti Emanuela
Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.
Centre for Infection, Immunity and Inflammation (CI3), University of Ottawa, Ottawa, ON, Canada.
Pediatr Res. 2024 Nov 28. doi: 10.1038/s41390-024-03757-5.
Human milk contains extracellular vesicles (EVs) that carry bioactive molecules such as microRNA, to the newborn intestine. The downstream effects of EV cargo on signaling and immune modulation may shield neonates against inflammatory diseases, including necrotizing enterocolitis. Premature infants are especially at risk, while human milk-feeding may offer protection. The effect of gestational-age specific term and preterm EVs from transitional human milk was characterized on human intestinal epithelial cells (HIECs and Caco-2), primary macrophages, and THP-1 monocytes. We hypothesized that term and preterm EVs differentially influence immune-related cytokines and cell death. We found that preterm EVs were enriched in CD14 surface marker, while both term and preterm EVs increased epidermal growth factor secretion. Following inflammatory stimuli, only term EVs inhibited secretion of IL-6 in HIECs, and reduced expression of pro-inflammatory cytokine IL-1β in macrophages. Term and preterm EVs inhibited secretion of IL-1β and reduced inflammasome related cell death. We proposed that human milk EVs regulate immune-related signaling via their conserved microRNA cargo, which could promote tolerance and a homeostatic immune response. These findings provide basis for further studies into potential therapeutic supplementation with EVs in vulnerable newborn populations by considering functional, gestational age-specific effects. IMPACT: This study reveals distinct functional differences between term and preterm transitional human milk extracellular vesicles (EVs) highlighting the importance of gestational age in their bioactivity. Term EVs uniquely inhibited IL-6 secretion, IL-1β expression, and apoptosis following inflammatory stimuli. Both term and preterm human milk EVs reduced IL-1β secretion and inflammasome-induced cell death. Conserved human milk extracellular vesicle microRNA cargo could be a mediator of the anti-inflammatory effects, particularly targeting cytokine production, the inflammasome, and programmed cell death. These findings underscore the importance of considering gestational age in future research exploring the therapeutic potential of human milk extracellular vesicles to prevent or treat intestinal inflammatory diseases in neonates.
母乳中含有细胞外囊泡（EVs），这些囊泡会将诸如微小RNA等生物活性分子携带至新生儿肠道。EVs所载物质对信号传导和免疫调节的下游效应可能会保护新生儿抵御包括坏死性小肠结肠炎在内的炎性疾病。早产儿尤其面临风险，而母乳喂养可能会提供保护作用。本研究对过渡乳中特定胎龄足月儿和早产儿的EVs对人肠上皮细胞（HIECs和Caco-2）、原代巨噬细胞及THP-1单核细胞的作用进行了表征。我们假设足月儿和早产儿的EVs对免疫相关细胞因子和细胞死亡有不同影响。我们发现早产儿的EVs富含CD14表面标志物，而足月儿和早产儿的EVs均能增加表皮生长因子的分泌。在炎性刺激后，只有足月儿的EVs能抑制HIECs中IL-6的分泌，并降低巨噬细胞中促炎细胞因子IL-1β的表达。足月儿和早产儿的EVs均能抑制IL-1β的分泌，并减少炎性小体相关的细胞死亡。我们提出，母乳中的EVs通过其保守的微小RNA所载物质调节免疫相关信号传导，这可能会促进耐受性和稳态免疫反应。这些发现为进一步研究通过考虑功能、特定胎龄效应，对脆弱新生儿群体进行EVs潜在治疗性补充提供了基础。影响：本研究揭示了足月儿和早产儿过渡乳细胞外囊泡（EVs）之间明显的功能差异，突出了胎龄在其生物活性中的重要性。足月儿的EVs在炎性刺激后能独特地抑制IL-6分泌、IL-1β表达及细胞凋亡。足月儿和早产儿的母乳EVs均能减少IL-1β分泌和炎性小体诱导的细胞死亡。保守的母乳细胞外囊泡微小RNA所载物质可能是抗炎作用的介质，尤其针对细胞因子产生、炎性小体及程序性细胞死亡。这些发现强调了在未来研究中考虑胎龄的重要性，该研究旨在探索母乳细胞外囊泡预防或治疗新生儿肠道炎性疾病的治疗潜力。
