The constitutively active androgen receptor (AR) splice variant 7 (AR-V7) plays an important role in the progression of castration-resistant prostate cancer (CRPC). Although biomarker studies established the role of AR-V7 in resistance to AR-targeting therapies, how AR-V7 mediates genomic functions in CRPC remains largely unknown. Using a ChIP-exo approach, we show AR-V7 binds to distinct genomic regions and recognizes a full-length androgen-responsive element in CRPC cells and patient tissues. Remarkably, we find dramatic differences in AR-V7 cistromes across diverse CRPC cells and patient tissues, regulating different target gene sets involved in CRPC progression. Surprisingly, we discover that HoxB13 is universally required for and colocalizes with AR-V7 binding to open chromatin across CRPC genomes. HoxB13 pioneers AR-V7 binding through direct physical interaction, and collaborates with AR-V7 to up-regulate target oncogenes. Transcriptional coregulation by HoxB13 and AR-V7 was further supported by their coexpression in tumors and circulating tumor cells from CRPC patients. Importantly, HoxB13 silencing significantly decreases CRPC growth through inhibition of AR-V7 oncogenic function. These results identify HoxB13 as a pivotal upstream regulator of AR-V7-driven transcriptomes that are often cell context-dependent in CRPC, suggesting that HoxB13 may serve as a therapeutic target for AR-V7-driven prostate tumors.

We present scMAGeCK, a computational framework to identify genomic elements associated with multiple expression-based phenotypes in CRISPR/Cas9 functional screening that uses single-cell RNA-seq as readout. scMAGeCK outperforms existing methods, identifies genes and enhancers with known and novel functions in cell proliferation, and enables an unbiased construction of genotype-phenotype network. Single-cell CRISPR screening on mouse embryonic stem cells identifies key genes associated with different pluripotency states. Applying scMAGeCK on multiple datasets, we identify key factors that improve the power of single-cell CRISPR screening. Collectively, scMAGeCK is a novel tool to study genotype-phenotype relationships at a single-cell level.

Preeclampsia is a serious pathologic complication during pregnancy, and its pathogenesis remains poorly understood. Recent studies have demonstrated that autoantibodies against angiotensin II type 1A receptor (AT1-AA) are present in women with preeclampsia. However, their role in the development of hypertension in preeclamptic patients has never been previously investigated. The present study was designed to determine whether AT1-AA isolated from the sera of preeclamptic patients causes vascular constriction and, if so, to further investigate the cellular receptors that mediate their vasoactivity. Blood samples were collected from 49 pregnant women (preeclampsia = 31, control = 18) and AT1-AA was detected using enzyme-linked immunosorbent assay. Vasoconstrictive effect of purified IgG from the sera of either preeclamptic patients or normal pregnant women was determined in isolated rat thoracic aorta, arteriae cerebri media and coronary artery. Compared with normal pregnant women, frequency of AT1-AA positive samples was markedly increased in preeclamptic patients (80.7 vs. 5.6%, P < 0.01). In isolated thoracic aortic rings, middle cerebral artery and coronary artery segments, AT1-AA induced vasoconstriction in a concentration-dependent fashion (P < 0.01). The vasoconstrictive effect of AT1-AA was completely blocked by losartan, an AT1-receptor antagonist. These data demonstrate that the AT1-AA causes significant vascular constriction in large conduit vessel as well as small resistant vessels though activation of the AT1 receptor. These results suggest that overproduction of AT1-AA is a novel risk factor in pregnant women and may play a causative role in the development of hypertension and vascular injury in preeclamptic patients.

Aims/Introduction The aim of the present study was to identify candidate differentially expressed genes ( DEG s) and pathways using bioinformatics analysis, and to improve our understanding of the cause and potential molecular events of diabetic nephropathy. Materials and Methods Two cohort profile datasets ( GSE 30528 and GSE 33744) were integrated and used for deep analysis. We sorted DEG s and analyzed differential pathway enrichment. DEG ‐associated ingenuity pathway analysis was carried out. The screened gene expression feature was verified in the db / db mouse kidney cortex. Then, rat mesangial cells cultured with high‐concentration glucose were used for verification. The target genes of transcriptional factor E26 transformation‐specific‐1 (ETS1) were predicted with online tools and validated using chromatin immunoprecipitation assay quantitative polymerase chain reaction . Results The two GSE datasets identified 89 shared DEG s; 51 were upregulated; and 38 were downregulated. Most of the DEG s were significantly enriched in cell adhesion, the plasma membrane, the extracellular matrix and the extracellular region. Quantitative reverse transcription polymerase chain reaction analysis validated the upregulated expression of Itgb2 , Cd44 , Sell , Fn1 , Tgfbi and Il7r , and the downregulated expression of Igfbp2 and Cd55 in the db / db mouse kidney cortex. Chromatin immunoprecipitation assay quantitative polymerase chain reaction showed that Itgb2 was the target gene of transcription factor Ets1. ETS 1 knockdown in rat mesangial cells decreased integrin subunit beta 2 expression. Conclusion We found that EST 1 functioned as an important transcription factor in diabetic nephropathy development through the promotion of integrin subunit beta 2 expression. EST 1 might be a drug target for diabetic nephropathy treatment.