[Association between insomnia and type 2 diabetes: A two-sample Mendelian rando-mization study].

OBJECTIVE: To explore the robust relationship between insomnia and type 2 diabetes mellitus by two-sample Mendelian randomization analysis to overcome confounding factors and reverse causality in observational studies. METHODS: We identified strong, independent single nucleotide polymorphisms (SNPs) of insomnia from the most up to date genome wide association studies (GWAS) within European ancestors and applied them as instrumental variable to GWAS of type 2 diabetes mellitus. After excluding SNPs that were significantly associated with smoking, physical activity, alcohol consumption, educational attainment, obesity, or type 2 diabetes mellitus, we assessed the impact of insomnia on type 2 diabetes mellitus using inverse variance weighting (IVW) method. Weighted median and MR-Egger regression analysis were also conducted to test the robustness of the association. We calculated the F statistic of the selected SNPs to test the applicability of instrumental variable and F statistic over than ten indicated that there was little possibility of bias of weak instrumental variables. We further examined the existence of pleiotropy by testing whether the intercept term in MR-Egger regression was significantly different from zero. In addition, the leave-one-out method was used for sensitivity analysis to verify the stability and reliability of the results. RESULTS: We selected 248 SNPs independently associated with insomnia at the genome-wide level (P<5×10-8) as a preliminary candidate set of instrumental variables. After clumping based on the reference panel from 1000 Genome Project and removing the potential pleiotropic SNPs, a total of 167 SNPs associated with insomnia were included as final instrumental variables. The F statistic of this study was 39. 74, which was in line with the relevance assumption of Mendelian randomization. IVW method showed insomnia was associated with higher risk of type 2 diabetes mellitus that po-pulation with insomnia were 1. 14 times more likely to develop type 2 diabetes mellitus than those without insomnia (95% CI: 1.09-1.21, P<0.001). The weighted median estimator (WME) method and MR-Egger regression showed similar causal effect of insomnia on type 2 diabetes mellitus. And MR-Egger regression also showed that the effect was less likely to be triggered by pleiotropy. Sensitivity analyses produced directionally similar estimates. CONCLUSION: Insomnia is a risk factor of type 2 diabetes mellitus, which has positively effects on type 2 diabetes mellitus. Our study provides further rationale for indivi-duals at risk for diabetes to keep healthy lifestyle.

Per- and polyfluoroalkyl substances target and alter human prostate stem-progenitor cells.

Per- and polyfluorinated alkyl substances (PFAS) are a large family of widely used synthetic chemicals that are environmentally and biologically persistent and present in most individuals. Chronic PFAS exposure have been linked to increased prostate cancer risk in occupational settings, however, underlying mechanisms have not been interrogated. Herein we examined exposure of normal human prostate stem-progenitor cells (SPCs) to 10 nM PFOA or PFOS using serial passage of prostasphere cultures. Exposure to either PFAS for 3-4 weeks increased spheroid numbers and size indicative of elevated stem cell self-renewal and progenitor cell proliferation. Transcriptome analysis using single-cell RNA sequencing (scRNA-seq) showed 1) SPC expression of PPARs and RXRs able to mediate PFAS effects, 2) the emergence of a new cell cluster of aberrantly differentiated luminal progenitor cells upon PFOS/PFOA exposure, and 3) enrichment of cancer-associated signaling pathways. Metabolomic analysis of PFAS-exposed prostaspheres revealed increased glycolytic pathways including the Warburg effect as well as strong enrichment of serine and glycine metabolism which may promote a pre-malignant SPC fate. Finally, growth of in vivo xenografts of tumorigenic RWPE-2 human prostate cells, shown to contain cancer stem-like cells, was markedly enhanced by daily PFOS feeding to nude mice hosts. Together, these findings are the first to identify human prostate SPCs as direct PFAS targets with resultant reprogrammed transcriptomes and metabolomes that augment a preneoplastic state and may contribute to an elevated prostate cancer risk with chronic exposures.

Stem cells from a malignant rat prostate cell line generate prostate cancers in vivo: a model for prostate cancer stem cell propagated tumor growth.

Cancer stem cells (CSCs) are resistant to conventional cancer therapies, permitting the repopulation of new tumor growth and driving disease progression. Models for testing prostate CSC-propagated tumor growth are presently limited yet necessary for therapeutic advancement. Utilizing the congenic nontumorigenic NRP152 and tumorigenic NRP154 rat prostate epithelial cell lines, the present study investigated the self-renewal, differentiation, and regenerative abilities of prostate stem/progenitor cells and developed a CSC-based PCa model. NRP154 cells expressed reduced levels of tumor suppressor caveolin-1 and increased p-Src as compared to NRP152 cells. Gene knockdown of caveolin-1 in NRP152 cells upregulated p-Src, implicating their role as potential oncogenic mediators in NRP154 cells. A FACS-based Hoechst exclusion assay revealed a side population of stem-like cells (0.1%) in both NRP152 and NRP154 cell lines. Using a 3D Matrigel culture system, stem cells from both cell lines established prostaspheres at a 0.1% efficiency through asymmetric self-renewal and rapid proliferation of daughter progenitor cells. Spheres derived from both cell lines contained CD117+ and CD133+ stem cell subpopulations and basal progenitor cell subpopulations (p63+ and CK5+) but were negative for luminal cell CK8 markers at day 7. While some NRP152 sphere cells were androgen receptor (AR) positive at this timepoint, NRP154 cells were AR- up to 30 days of 3D culture. The regenerative capacity of the stem/progenitor cells was demonstrated by in vivo tissue recombination with urogenital sinus mesenchyme (UGM) and renal grafting in nude mice. While stem/progenitor cells from NRP152 spheroids generated normal prostate structures, CSCs and progeny cells from NRP154 tumoroids generated tumor tissues that were characterized by immunohistochemistry. Atypical hyperplasia and prostatic intraepithelial neoplasia (PIN) lesions progressed to adenocarcinoma with kidney invasion over 4 months. This provides clear evidence that prostate CSCs can repopulate new tumor growth outside the prostate gland that rapidly progresses to poorly differentiated adenocarcinoma with invasive capabilities. The dual in vitro/in vivo CSC model system presented herein provides a novel platform for screening therapeutic agents that target prostate CSCs for effective combined treatment protocols for local and advanced disease stages.

Morphometric Analysis of Rat Prostate Development: Roles of MEK/ERK and Rho Signaling Pathways in Prostatic Morphogenesis.

The molecular mechanisms underlying prostate development can provide clues for prostate cancer research. It has been demonstrated that MEK/ERK signaling downstream of androgen-targeted FGF10 signaling directly induces prostatic branching during development, while Rho/Rho-kinase can regulate prostate cell proliferation. MEK/ERK and Rho/Rho kinase regulate myosin light chain kinase (MLCK), and MLCK regulates myosin light chain phosphorylation (MLC-P), which is critical for cell fate, including cell proliferation, differentiation, and apoptosis. However, the roles and crosstalk of the MEK/ERK and Rho/Rho kinase signaling pathways in prostatic morphogenesis have not been examined. In the present study, we used numerical and image analysis to characterize lobe-specific rat prostatic branching during postnatal organ culture and investigated the roles of FGF10-MEK/ERK and Rho/Rho kinase signaling pathways in prostatic morphogenesis. Prostates exhibited distinctive lobe-specific growth and branching patterns in the ventral (VP) and lateral (LP) lobes, while exogenous FGF10 treatment shifted LP branching towards a VP branching pattern. Treatment with inhibitors of MEK1/2, Rho, Rho kinase, or MLCK significantly inhibited VP growth and blocked branching morphogenesis, further supporting critical roles for MEK/ERK and Rho/Rho kinase signaling pathways in prostatic growth and branching during development. We propose that MLCK-regulated MLC-P may be a central downstream target of both signaling pathways in regulating prostate morphogenesis.

Keratin Profiling by Single-Cell RNA-Sequencing Identifies Human Prostate Stem Cell Lineage Hierarchy and Cancer Stem-Like Cells.

Single prostate stem cells can generate stem and progenitor cells to form prostaspheres in 3D culture. Using a prostasphere-based label retention assay, we recently identified keratin 13 (KRT13)-enriched prostate stem cells at single-cell resolution, distinguishing them from daughter progenitors. Herein, we characterized the epithelial cell lineage hierarchy in prostaspheres using single-cell RNA-seq analysis. Keratin profiling revealed three clusters of label-retaining prostate stem cells; cluster I represents quiescent stem cells (PSCA, CD36, SPINK1, and KRT13/23/80/78/4 enriched), while clusters II and III represent active stem and bipotent progenitor cells (KRT16/17/6 enriched). Gene set enrichment analysis revealed enrichment of stem and cancer-related pathways in cluster I. In non-label-retaining daughter progenitor cells, three clusters were identified; cluster IV represents basal progenitors (KRT5/14/6/16 enriched), while clusters V and VI represent early and late-stage luminal progenitors, respectively (KRT8/18/10 enriched). Furthermore, MetaCore analysis showed enrichment of the "cytoskeleton remodeling-keratin filaments" pathway in cancer stem-like cells from human prostate cancer specimens. Along with common keratins (KRT13/23/80/78/4) in normal stem cells, unique keratins (KRT10/19/6C/16) were enriched in cancer stem-like cells. Clarification of these keratin profiles in human prostate stem cell lineage hierarchy and cancer stem-like cells can facilitate the identification and therapeutic targeting of prostate cancer stem-like cells.