Circadian transcriptional profile of tissues with and without neutrophil depletion

We previously reported that neutrophils infiltrate most tissues in a circadian fashion, as they clear out from the circulation (Casanova-Acebes et al., 2018). In our current study we hypothesized that neutrophils are relevant contributors to the matrix of barrier tissues and that then their elimination should leave a temporal footprint in the circadian pattern of expression of matrix-associated genes. To answer this question, we generated a circadian transcriptional dataset from the bone marrow, lung, liver, intestine and skin in wild type and neutrophil-depleted animals. The anlysis of the circadian patern of matrix related genes obtained from this datasets indicates that their temporal expression patterns in the analysed tissues is disrupted following neutrophil depletion. This results directly implicate neutrophils in the circadian biology of the matrix organization in various tissues. Overall design: For the circadian transcriptional analysis of lung, bone marrow, liver and intestine (Neutropenia model: Antibody depletion) we used an anti-Ly6G (characteristics: depleted) or an anti- IgG isotype control (characteristics: WT) antibodies. Tissues were harvested at ZT1-5-9-13-17-21 (characteristics: ZT) from 3 mice per group. For the circadian transcriptional analysis of the skin we used the Mrp8CRE; iDTR mouse model (neutropenia model: DT depletion) in which administration of diphtheria toxin induces neutropenia in CRE+ mice (genotype: Mrp8CRE; iDTR ) but not in wild type mice (C57BL/6 WT). In addition, a mouse model in which the intrinsic circadian clock is disrupted specifically in neutrophils by floxing out the Anrtl gene (genotype: Mrp8CRE; Bmal1-flox) was included in the Skin dataset. Skin was harvested at ZT1-3-4-5-7-9-10-12-13-15-16-18-19-21-22-24 (characteristics: ZT) from one mouse per group.