Project description:Kupffer cells (KCs) are tissue-resident macrophages which colonize the liver early during embryogenesis. KCs start to acquire a tissue-specific transcriptional signature immediately after colonizing the liver, mature together with the tissue, and adapt to the tissue?s functions. Throughout development and adulthood, KCs have distinct core functions that are essential for liver and organismal homeostasis, such as supporting fetal erythropoiesis as well as postnatal erythrocyte recycling and liver metabolism. However, whether perturbations of macrophage core functions during development contribute to or cause disease at postnatal stages is poorly understood. Here, we utilize a mouse model of maternal obesity to perturb KC functions during gestation. We show that offspring exposed to maternal obesity develop fatty liver disease, driven by aberrant developmental programming of KCs that persists into adulthood. Programmed KCs mediate lipid uptake by hepatocytes through apolipoprotein secretion. KC depletion in neonates born to obese mothers, followed by replenishment with exogenous monocytes, rescues the fatty liver disease. The transcriptional programming of KCs and the fatty liver disease phenotype are also rescued by genetic depletion of hypoxia-inducible factor alpha (Hif1?) in macrophages during gestation. These results establish developmental perturbation of KC functions as a cause for the development of fatty liver disease in adult life and, thereby, place fetal-derived macrophages as intergenerational messengers within the concept of developmental origins of health and diseases.
Project description:Despite their importance in lung health and disease, it remains unknown how human alveolar macrophages develop early in life. In this study we identified the fetal progenitor of human alveolar macrophages. We used microarray to define the gene signatures of human CD14+ blood monocytes (adult AM precursors), CD116+CD64+ fetal liver monocytes, and CD116+CD64- fetal AM precursors.
Project description:Microarray profiling of unstimulated human fetal and adult bone marrow classical monocytes Classical monocytes were sort purified, RNA isolated, and amplified. 4 of each sample was collected and used
Project description:Non-specific protective effects against reinfection have been described following infection with Candida albicans. Here we show that mice defective in functional T and B lymphocytes were protected against reinfection with C. albicans in a monocyte-dependent manner. C. albicans and beta glucans induced functional programming of monocytes, leading to enhanced cytokine production in vivo and in vitro. The training required the beta glucan receptor dectin 1 and the non-canonical Raf 1 pathway. Monocyte training by beta-glucans was mediated by epigenetic mechanisms through genome-wide changes in histone trimethylation at H3K4. Pathway analysis showed specific induction of epigenetic changes in genes of innate immunity. The functional programming of monocytes, reminiscent of similar properties of NK cells, has been termed M-bM-^@M-^\trained immunityM-bM-^@M-^] and may be employed for the design of improved vaccination strategies. Chromatin-IP at day7 followed by highthroughput sequencing to look at the differences in H3K4me3 and H3K27me3 binding in Monocytes either cultured in RPMI only versus those trained for 24hrs with beta glucan. Additionally expression analysis was performed by doing strandspecific RNAseq also for both unstimulated and beta glucan trained monocytes for correlating the histone modification changes with the expression changes. Biological replicates were generated from independent samples for H3K4me3 and RNAseq. Additional H3K4me3 ChIP-seq assays were performed for day0 untreated, 24hrs control and beta glucan trained monocytes. H3K4me3 ChIP-seq was also performed for Mouse macrophages both saline(control) and low dose Candida treated.
Project description:Antenatal hypoxia has critial impacts on fetal heart development. The molecular mechanism of the antenaltal hypoxia effect on the heart development is still unknown. We performed DNA methylome and transcriptome analyses of antenatal hypoxia induced rat fetal and adult offspring hearts to understand the hypoxia-mediated epigenomic programming in the heart development. Heart tissue from fetal (E21) and adult rat (5 months old) were collected. mRNA and genomic DNA methylation profiles of the heart tissue were generated by RNAseq and reduced representation bisulfite seuqencing (RRBS) techniques. We found 323 and 112 differential expressed genes between control and hypoxia groups in the fetal and adult hearts, respectively. Meanwhile, 2828 and 2193 differential methylated regions were identified in the fetal and adult hearts. Furthermore, opposite gobal DNA methylation pattern changes in transcription start site regions (TSS ± 1kb) were observed between fetal and adult hearts. Combining transcriptome, data indicates a significant difference in the responding genes and pathways between fetal and adult hearts in responding to the antenatal hypoxia. Our study provides an initial framework and new insights into fetal hypoxia-mediated epigenetic programming of pro-inflammatory phenotype in the heart development, linking antenatal stress, and developmental programming of heart vulnerability to disease later in life.