GSE158401
Differential sex-dependent regulation of the alveolar macrophage miRNome of SP-A2 and co-ex (SP-A1/SP-A2) and sex differences attenuation after 18h of ozone exposure
BACKGROUND: Human SP-A1 and SP-A2, encoded by SFTPA1 and SFTPA2 and their genetic variants differentially impact alveolar macrophage (AM) functions and regulation, including the miRNome.  We investigated whether miRNome differences previously observed between AM from SP-A2 and SP-A1/SP-A2 mice are due to continued qualitative differences or a delayed response of mice carrying a single gene.    METHODS: Human transgenic (hTG) mice, carrying SP-A2 or both SP-A genes and SP-A-KO mice were exposed to filtered air (FA) or O3. AM miRNA levels, target gene expression and pathways determined 18 h after O3 exposure.    RESULTS: We found: (a) Differences in miRNome due to sex, SP-A genotype, and exposure; (b) miRNome of both sexes was largely downregulated by O3 ; co-ex had fewer changed (=2X) miRNAs than either group.  (c) the number and direction of expression of genes with significant changes in males and females in co-ex is almost the opposite of those in SP-A2; (iv) The same pathways were found in the studied groups; (e) O3 exposure attenuated sex differences; a higher number of genotype-dependent and genotype-independent miRNAs was common in both sexes after O3 exposure.    CONCLUSION: Qualitative differences between SP-A2 and co-ex persist 18 h post-O3, and O3 attenuates sex differences. Overall design: Twelve week old, humanized transgenic (hTG) mice carrying a single SP-A2 (1A0) variant, or both SP-A1/SP-A2 (6A2/1A0, co-ex) gene variants, as well as SP-A knockout (KO) mice, were used in this study.  The hTG mice were generated on the C57BL/6J SP-A (KO) background . The animals were exposed to FA or O3 in parallel.  A group of 4 animals/sex/condition (FA, O3, except for SP-A2 (1A0) and co-ex male, 3 animals/condition) for miRNA analysis  were exposed to FA or O3 for 3 h, and alveolar macrophages (AM) were isolated after 18 h of recovery as described . Total RNA extraction from AM cells, library construction, and sequencing were performed.  The differentially expressed miRNAs between FA and O3-exposed males and females were identified by using the edgeR and the TCC v1.14.0 R package with false discovery rate (FDR) adjusted P-value of 0.1 as a significance cutoff.