Kidney single cell sequencing results from 10-day unilateral ureteral obstruction mice

Renal fibrosis is a common consequence of various progressive nephropathies, including obstructive nephropathy, and ultimately leads to kidney failure. Infiltration of inflammatory cells is a prominent feature of renal injury after draining blockages from the kidney, and correlates closely with the development of renal fibrosis. However, the underlying molecular mechanism behind the promotion of renal fibrosis by inflammatory cells remains unclear. Herein, we showed that unilateral ureteral obstruction (UUO) induced Gasdermin D (GSDMD) activation in neutrophils, abundant neutrophil extracellular traps (NETs) formation and macrophage-to-myofibroblast transition (MMT) characterized by α-smooth muscle actin (α-SMA) expression in macrophages. Gsdmd deletion significantly reduced infiltration of inflammatory cells in the kidneys and inhibited NETs formation, MMT and thereby renal fibrosis. Chimera studies confirmed that Gsdmd deletion in bone marrow-derived cells, instead of renal parenchymal cells, provided protection against renal fibrosis. Further, specific deletion of Gsdmd in neutrophils instead of macrophages protected the kidney from undergoing fibrosis after UUO. Single-cell RNA sequencing identified robust crosstalk between neutrophils and macrophages. In vitro, GSDMD-dependent NETs triggered p65 translocation to the nucleus, which boosted the production of inflammatory cytokines and α-SMA expression in macrophages by activating TGF-β1/Smad pathway. In addition, we demonstrated that caspase-11, that could cleave GSDMD, was required for NETs formation and renal fibrosis after UUO. Collectively, our findings demonstrate that caspase-11/GSDMD-dependent NETs promote renal fibrosis by facilitating inflammation and MMT, therefore highlighting the role and mechanisms of NETs in renal fibrosis. Harvested cells at the required densities were combined with gel beads containing the barcoded information along with a mixture of cells and enzymes. Oil surfactant droplets in a microfluidic double-cross system were used for encapsulation to generate Gel Beads-In-Emulsions (GEMs). GEMs were passed through a reservoir and collected while the gel beads were lysed to release the barcode sequence. The cDNA fragment was then reverse transcribed before the sample was labeled. The gel beads and the oil droplets are ruptured and PCR amplification was performed using the generated cDNA as a template. The products of all GEMs were mixed and a standard sequencing library is constructed. The cDNA was first enzymatically digested into fragments of about 200300 base pairs (bp), together with the library building process of traditional secondgeneration sequencing such as sequencing junction and primers. Finally, the DNA library was generated by PCR amplification