Development of NR0B2 as a therapeutic target for the re-education of tumor associated myeloid cells.

Immune checkpoint blockade (ICB) has had limited utility in several solid tumors such as breast cancer, a major cause of cancer-related mortality in women. Therefore, there is considerable interest in alternate strategies to promote an anti-cancer immune response. A paper co-published in this issue describes how NR0B2, a protein involved in cholesterol homeostasis, functions within myeloid immune cells to modulate the inflammasome and reduce the expansion of immune-suppressive regulatory T cells (Treg). Here, we develop NR0B2 as a potential therapeutic target. NR0B2 in tumors is associated with improved survival for several cancer types including breast. Importantly, NR0B2 expression is also prognostic of ICB success. Within breast tumors, NR0B2 expression is inversely associated with FOXP3, a marker of Tregs. While a described agonist (DSHN) had some efficacy, it required high doses and long treatment times. Therefore, we designed and screened several derivatives. A methyl ester derivative (DSHN-OMe) emerged as superior in terms of (1) cellular uptake, (2) ability to regulate expected expression of genes, (3) suppression of Treg expansion using in vitro co-culture systems, and (4) efficacy against the growth of primary and metastatic tumors. This work identifies NR0B2 as a target to re-educate myeloid immune cells and a novel ligand with significant anti-tumor efficacy in preclinical models.

NR0B2 re-educates myeloid immune cells to reduce regulatory T cell expansion and progression of breast and other solid tumors.

Although survival from breast cancer has dramatically increased, many will develop recurrent, metastatic disease. Unfortunately, survival for this stage of disease remains very low. Activating the immune system has incredible promise since it has the potential to be curative. However, immune checkpoint blockade (ICB) which works through T cells has been largely disappointing for metastatic breast cancer. One reason for this is a suppressive myeloid immune compartment that is unaffected by ICB. Cholesterol metabolism and proteins involved in cholesterol homeostasis play important regulatory roles in myeloid cells. Here, we demonstrate that NR0B2, a nuclear receptor involved in negative feedback of cholesterol metabolism, works in several myeloid cell types to impair subsequent expansion of regulatory T cells (Tregs); Tregs being a subset known to be highly immune suppressive and associated with poor therapeutic response. Within myeloid cells, NR0B2 serves to decrease many aspects of the inflammasome, ultimately resulting in decreased IL1ß; IL1ß driving Treg expansion. Importantly, mice lacking NR0B2 exhibit accelerated tumor growth. Thus, NR0B2 represents an important node in myeloid cells dictating ensuing Treg expansion and tumor growth, thereby representing a novel therapeutic target to re-educate these cells, having impact across different solid tumor types. Indeed, a paper co-published in this issue demonstrates the therapeutic utility of targeting NR0B2.

An integrated single-nucleus and spatial transcriptomics atlas reveals the molecular landscape of the human hippocampus.

The hippocampus contains many unique cell types, which serve the structure's specialized functions, including learning, memory and cognition. These cells have distinct spatial topography, morphology, physiology, and connectivity, highlighting the need for transcriptome-wide profiling strategies that retain cytoarchitectural organization. Here, we generated spatially-resolved transcriptomics (SRT) and single-nucleus RNA-sequencing (snRNA-seq) data from adjacent tissue sections of the anterior human hippocampus across ten adult neurotypical donors. We defined molecular profiles for hippocampal cell types and spatial domains. Using non-negative matrix factorization and transfer learning, we integrated these data to define gene expression patterns within the snRNA-seq data and infer the expression of these patterns in the SRT data. With this approach, we leveraged existing rodent datasets that feature information on circuit connectivity and neural activity induction to make predictions about axonal projection targets and likelihood of ensemble recruitment in spatially-defined cellular populations of the human hippocampus. Finally, we integrated genome-wide association studies with transcriptomic data to identify enrichment of genetic components for neurodevelopmental, neuropsychiatric, and neurodegenerative disorders across cell types, spatial domains, and gene expression patterns of the human hippocampus. To make this comprehensive molecular atlas accessible to the scientific community, both raw and processed data are freely available, including through interactive web applications.

Cholesterol Metabolite 27-Hydroxycholesterol Enhances the Secretion of Cancer Promoting Extracellular Vesicles by a Mitochondrial ROS-Induced Impairment of Lysosomal Function.

Extracellular vesicles (EVs) serve as crucial mediators of cell-to-cell communication in normal physiology as well as in diseased states, and have been largely studied in regard to their role in cancer progression. However, the mechanisms by which their biogenesis and secretion are regulated by metabolic or endocrine factors remain unknown. Here, we delineate a mechanism by which EV secretion is regulated by a cholesterol metabolite, 27-Hydroxycholesterol (27HC), where treatment of myeloid immune cells (RAW 264.7 and J774A.1) with 27HC impairs lysosomal homeostasis, leading to shunting of multivesicular bodies (MVBs) away from lysosomal degradation, towards secretion as EVs. This impairment of lysosomal function is caused by mitochondrial dysfunction and subsequent increase in reactive oxygen species (ROS). Interestingly, cotreatment with a mitochondria-targeted antioxidant rescued the lysosomal impairment and attenuated the 27HC-mediated increase in EV secretion. Overall, our findings establish how a cholesterol metabolite regulates EV secretion and paves the way for the development of strategies to regulate cancer progression by controlling EV secretion.

Comparative effectiveness research trial for antidepressant incomplete and non-responders with treatment resistant depression (ASCERTAIN-TRD) a randomized clinical trial.

Further research is needed to help improve both the standard of care and the outcome for patients with treatment-resistant depression. A particularly critical evidence gap exists with respect to whether pharmacological or non-pharmacological augmentation is superior to antidepressant switch, or vice-versa. The objective of this study was to compare the effectiveness of augmentation with aripiprazole or repetitive transcranial magnetic stimulation versus switching to the antidepressant venlafaxine XR (or duloxetine for those not eligible to receive venlafaxine) for treatment-resistant depression. In this multi-site, 8-week, randomized, open-label study, 278 subjects (196 females and 82 males, mean age 45.6 years (SD 15.3)) with treatment-resistant depression were assigned in a 1:1:1 fashion to treatment with either of these three interventions; 235 subjects completed the study. 260 randomized subjects with at least one post-baseline Montgomery-Asberg Depression Rating (MADRS) assessment were included in the analysis. Repetitive transcranial magnetic stimulation (score change (standard error (se)) = -17.39 (1.3) (p = 0.015) but not aripiprazole augmentation (score change (se) = -14.9 (1.1) (p = 0.069) was superior to switch (score change (se) = -13.22 (1.1)) on the MADRS. Aripiprazole (mean change (se) = -37.79 (2.9) (p = 0.003) but not repetitive transcranial magnetic stimulation augmentation (mean change (se) = -42.96 (3.6) (p = 0.031) was superior to switch (mean change (se) = -34.45 (3.0)) on the symptoms of depression questionnaire. Repetitive transcranial magnetic stimulation augmentation was shown to be more effective than switching antidepressants in treatment-resistant depression on the study primary measure. In light of these findings, clinicians should consider repetitive transcranial magnetic stimulation augmentation early-on for treatment-resistant depression.Trial registration: ClinicalTrials.gov, NCT02977299.

Transcriptomic analysis of the human habenula in schizophrenia.

Importance: Habenula (Hb) pathophysiology is involved in many neuropsychiatric disorders, including schizophrenia. Deep brain stimulation and pharmacological targeting of the Hb are emerging as promising therapeutic treatments. However, little is known about the cell type-specific transcriptomic organization of the human Hb or how it is altered in schizophrenia. Objective: To define the molecular neuroanatomy of the human habenula and identify transcriptomic changes in individuals with schizophrenia compared to neurotypical controls. Design Setting and Participants: This study utilized Hb-enriched postmortem human brain tissue. Single nucleus RNA-sequencing (snRNA-seq) and single molecule fluorescent in situ hybridization (smFISH) experiments were conducted to identify molecularly defined Hb cell types and map their spatial location (n=3-7 donors). Bulk RNA-sequencing and cell type deconvolution were used to investigate transcriptomic changes in Hb-enriched tissue from 35 individuals with schizophrenia and 33 neurotypical controls. Gene expression changes associated with schizophrenia in the Hb were compared to those previously identified in the dorsolateral prefrontal cortex (DLPFC), hippocampus, and caudate. Main Outcomes and Measures: Semi-supervised snRNA-seq cell type clustering. Transcript visualization and quantification of smFISH probes. Bulk RNA-seq cell type deconvolution using reference snRNA-seq data. Schizophrenia-associated gene differential expression analysis adjusting for Hb and thalamus fractions, RNA degradation-associated quality surrogate variables, and other covariates. Cross-brain region schizophrenia-associated gene expression comparison. Results: snRNA-seq identified 17 cell type clusters across 16,437 nuclei, including 3 medial and 7 lateral Hb populations. Cell types were conserved with those identified in a rodent model. smFISH for cell type marker genes validated snRNA-seq Hb cell types and depicted the spatial organization of subpopulations. Bulk RNA-seq analyses yielded 45 schizophrenia-associated differentially expressed genes (FDR < 0.05), with 32 (71%) unique to Hb-enriched tissue. Conclusions: These results identify topographically organized cell types with distinct molecular signatures in the human Hb. They further demonstrate unique transcriptomic changes in the epithalamus associated with schizophrenia, thereby providing molecular insights into the role of Hb in neuropsychiatric disorders.

Greater Emotional and Psychological Well-being Are Associated With Reduced Employee Self-report Illness-Related Absenteeism: A Multi-Industry, Cross-sectional Study Conducted During COVID-19 Pandemic.

OBJECTIVE: The purpose of this study is to determine the relationship that emotional, psychological, and social well-being has with self-reported illness-related absenteeism. METHODS: This study examines the relationship between three dimensions of well-being (emotional, psychological, and social) and self-report illness-related absenteeism among 133 workers spanning multiple industries across 16 different companies. This secondary, cross-sectional data were analyzed using multiple linear regression. RESULTS: As hypothesized, emotional well-being and psychological well-being were found to be negatively associated with absenteeism, with emotional well-being being the stronger predictor. Contrary to our hypothesis, we found that social well-being was not associated with absenteeism among workers. CONCLUSIONS: Employee emotional well-being and psychological well-being are associated with self-reported illness-related absenteeism. Future work should explore causal relationships between these constructs.

Gut microbiome responds to alteration in female sex hormone status and exacerbates metabolic dysfunction.

Women are at significantly greater risk of metabolic dysfunction after menopause, which subsequently leads to numerous chronic illnesses. The gut microbiome is associated with obesity and metabolic dysfunction, but its interaction with female sex hormone status and the resulting impact on host metabolism remains unclear. Herein, we characterized inflammatory and metabolic phenotypes as well as the gut microbiome associated with ovariectomy and high-fat diet feeding, compared to gonadal intact and low-fat diet controls. We then performed fecal microbiota transplantation (FMT) using gnotobiotic mice to identify the impact of ovariectomy-associated gut microbiome on inflammatory and metabolic outcomes. We demonstrated that ovariectomy led to greater gastrointestinal permeability and inflammation of the gut and metabolic organs, and that a high-fat diet exacerbated these phenotypes. Ovariectomy also led to alteration of the gut microbiome, including greater fecal ß-glucuronidase activity. However, differential changes in the gut microbiome only occurred when fed a low-fat diet, not the high-fat diet. Gnotobiotic mice that received the gut microbiome from ovariectomized mice fed the low-fat diet had greater weight gain and hepatic gene expression related to metabolic dysfunction and inflammation than those that received intact sham control-associated microbiome. These results indicate that the gut microbiome responds to alterations in female sex hormone status and contributes to metabolic dysfunction. Identifying and developing gut microbiome-targeted modulators to regulate sex hormones may be useful therapeutically in remediating menopause-related diseases.

Metabolic tagging of extracellular vesicles and development of enhanced extracellular vesicle based cancer vaccines.

As key mediators of cellular communication, extracellular vesicles (EVs) have been actively explored for diagnostic and therapeutic applications. However, effective methods to functionalize EVs and modulate the interaction between EVs and recipient cells are still lacking. Here we report a facile and universal metabolic tagging technology that can install unique chemical tags (e.g., azido groups) onto EVs. The surface chemical tags enable conjugation of molecules via efficient click chemistry, for the tracking and targeted modulation of EVs. In the context of tumor EV vaccines, we show that the conjugation of toll-like receptor 9 agonists onto EVs enables timely activation of dendritic cells and generation of superior antitumor CD8+ T cell response. These lead to 80% tumor-free survival against E.G7 lymphoma and 33% tumor-free survival against B16F10 melanoma. Our study yields a universal technology to generate chemically tagged EVs from parent cells, modulate EV-cell interactions, and develop potent EV vaccines.

Natural climate solutions provide robust carbon mitigation capacity under future climate change scenarios.

Natural climate solutions (NCS) are recognized as an important tool for governments to reduce greenhouse gas emissions and remove atmospheric carbon dioxide. Using California as a globally relevant reference, we evaluate the magnitude of biological climate mitigation potential from NCS starting in 2020 under four climate change scenarios. By mid-century NCS implementation leads to a large increase in net carbon stored, flipping the state from a net source to a net sink in two scenarios. Forest and conservation land management strategies make up 85% of all NCS emissions reductions by 2050, with agricultural strategies accounting for the remaining 15%. The most severe climate change impacts on ecosystem carbon materialize in the latter half of the century with three scenarios resulting in California ecosystems becoming a net source of carbon emissions under a baseline trajectory. However, NCS provide a strong attenuating effect, reducing land carbon emissions 41-54% by 2100 with total costs of deployment of 752-777 million USD annually through 2050. Rapid implementation of a portfolio of NCS interventions provides long-term investment in protecting ecosystem carbon in the face of climate change driven disturbances. This open-source, spatially-explicit framework can help evaluate risks to NCS carbon storage stability, implementation costs, and overall mitigation potential for NCS at jurisdictional scales.

Ecological Momentary Assessment of Midlife Adults' Daily Stress: Protocol for the Stress Reports in Variable Environments (STRIVE) App Study.

BACKGROUND: Daily stressors are associated with cognitive decline and increased risk of heart disease, depression, and other debilitating chronic illnesses in midlife adults. Daily stressors tend to occur at home or at work and are more frequent in urban versus rural settings. Conversely, spending time in natural environments such as parks or forests, or even viewing nature-themed images in a lab setting, is associated with lower levels of perceived stress and is hypothesized to be a strong stress "buffer," reducing perceived stress even after leaving the natural setting. However, many studies of daily stress have not captured environmental contexts and relied on end-of-day recall instead of in-the-moment data capture. With new technology, these limitations can be addressed to enhance knowledge of the daily stress experience. OBJECTIVE: We propose to use our novel custom-built Stress Reports in Variable Environments (STRIVE) ecological momentary assessment mobile phone app to measure the experience of daily stress of midlife adults in free-living conditions. Using our app to capture data in real time will allow us to determine (1) where and when daily stress occurs for midlife adults, (2) whether midlife adults' daily stressors are linked to certain elements of the built and natural environment, and (3) how ecological momentary assessment measurement of daily stress is similar to and different from a modified version of the popular Daily Inventory of Stressful Events measurement tool that captures end-of-day stress reports (used in the Midlife in the United States [MIDUS] survey). METHODS: We will enroll a total of 150 midlife adults living in greater Indianapolis, Indiana, in this study on a rolling basis for 3-week periods. As those in underrepresented minority groups and low-income areas have previously been found to experience greater levels of stress, we will use stratified sampling to ensure that half of our study sample is composed of underrepresented minorities (eg, Black, American Indian, Hispanic, or Native Pacific Islanders) and approximately one-third of our sample falls within low-, middle-, and high-income brackets. RESULTS: This project is funded by the National Institute on Aging from December 2022 to November 2024. Participant enrollment began in August 2023 and is expected to finish in July 2024. Data will be spatiotemporally analyzed to determine where and when stress occurs for midlife adults. Pictures of stressful environments will be qualitatively analyzed to determine the common elements of stressful environments. Data collected by the STRIVE app will be compared with retrospective Daily Inventory of Stressful Events data. CONCLUSIONS: Completing this study will expand our understanding of midlife adults' experience of stress in free-living conditions and pave the way for data-driven individual and community-based intervention designs to promote health and well-being in midlife adults. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/51845.

Re-education of myeloid immune cells to reduce regulatory T cell expansion and impede breast cancer progression.

Immune checkpoint blockade (ICB) has revolutionized cancer therapy but has had limited utility in several solid tumors such as breast cancer, a major cause of cancer-related mortality in women. Therefore, there is considerable interest in alternate strategies to promote an anti-cancer immune response. We demonstrate that NR0B2, a protein involved in cholesterol homeostasis, functions within myeloid immune cells to modulate the NLRP3 inflammasome and reduce the expansion of immune-suppressive regulatory T cells (Treg). Loss of NR0B2 increased mammary tumor growth and metastasis. Small molecule agonists, including one developed here, reduced Treg expansion, reduced metastatic growth and improved the efficacy of ICB. This work identifies NR0B2 as a target to re-educate myeloid immune cells providing proof-of-principle that this cholesterol-homeostasis axis may have utility in enhancing ICB.

Macrophage-to-endothelial cell crosstalk by the cholesterol metabolite 27HC promotes atherosclerosis in male mice.

Hypercholesterolemia and vascular inflammation are key interconnected contributors to the pathogenesis of atherosclerosis. How hypercholesterolemia initiates vascular inflammation is poorly understood. Here we show in male mice that hypercholesterolemia-driven endothelial activation, monocyte recruitment and atherosclerotic lesion formation are promoted by a crosstalk between macrophages and endothelial cells mediated by the cholesterol metabolite 27-hydroxycholesterol (27HC). The pro-atherogenic actions of macrophage-derived 27HC require endothelial estrogen receptor alpha (ERα) and disassociation of the cytoplasmic scaffolding protein septin 11 from ERα, leading to extranuclear ERα- and septin 11-dependent activation of NF-κB. Furthermore, pharmacologic inhibition of cyp27a1, which generates 27HC, affords atheroprotection by reducing endothelial activation and monocyte recruitment. These findings demonstrate cell-to-cell communication by 27HC, and identify a major causal linkage between the hypercholesterolemia and vascular inflammation that partner to promote atherosclerosis. Interventions interrupting this linkage may provide the means to blunt vascular inflammation without impairing host defense to combat the risk of atherosclerotic cardiovascular disease that remains despite lipid-lowering therapies.

Plasma Membrane Channel TRPM4 Mediates Immunogenic Therapy-Induced Necrosis.

Several emerging therapies kill cancer cells primarily by inducing necrosis. As necrosis activates immune cells, potentially, uncovering the molecular drivers of anticancer therapy-induced necrosis could reveal approaches for enhancing immunotherapy efficacy. To identify necrosis-associated genes, we performed a genome-wide CRISPR-Cas9 screen with negative selection against necrosis-inducing preclinical agents BHPI and conducted follow-on experiments with ErSO. The screen identified transient receptor potential melastatin member 4 (TRPM4), a calcium-activated, ATP-inhibited, sodium-selective plasma membrane channel. Cancer cells selected for resistance to BHPI and ErSO exhibited robust TRPM4 downregulation, and TRPM4 reexpression restored sensitivity to ErSO. Notably, TRPM4 knockout (TKO) abolished ErSO-induced regression of breast tumors in mice. Supporting a broad role for TRPM4 in necrosis, knockout of TRPM4 reversed cell death induced by four additional diverse necrosis-inducing cancer therapies. ErSO induced anticipatory unfolded protein response (a-UPR) hyperactivation, long-term necrotic cell death, and release of damage-associated molecular patterns that activated macrophages and increased monocyte migration, all of which was abolished by TKO. Furthermore, loss of TRPM4 suppressed the ErSO-induced increase in cell volume and depletion of ATP. These data suggest that ErSO triggers initial activation of the a-UPR but that it is TRPM4-mediated sodium influx and cell swelling, resulting in osmotic stress, which sustains and propagates lethal a-UPR hyperactivation. Thus, TRPM4 plays a pivotal role in sustaining lethal a-UPR hyperactivation that mediates the anticancer activity of diverse necrosis-inducing therapies. SIGNIFICANCE: A genome-wide CRISPR screen reveals a pivotal role for TRPM4 in cell death and immune activation following treatment with diverse necrosis-inducing anticancer therapies, which could facilitate development of necrosis-based cancer immunotherapies.

Btbd11 supports cell-type-specific synaptic function.

Synapses in the brain exhibit cell-type-specific differences in basal synaptic transmission and plasticity. Here, we evaluated cell-type-specific specializations in the composition of glutamatergic synapses, identifying Btbd11 as an inhibitory interneuron-specific, synapse-enriched protein. Btbd11 is highly conserved across species and binds to core postsynaptic proteins, including Psd-95. Intriguingly, we show that Btbd11 can undergo liquid-liquid phase separation when expressed with Psd-95, supporting the idea that the glutamatergic postsynaptic density in synapses in inhibitory interneurons exists in a phase-separated state. Knockout of Btbd11 decreased glutamatergic signaling onto parvalbumin-positive interneurons. Further, both in vitro and in vivo, Btbd11 knockout disrupts network activity. At the behavioral level, Btbd11 knockout from interneurons alters exploratory behavior, measures of anxiety, and sensitizes mice to pharmacologically induced hyperactivity following NMDA receptor antagonist challenge. Our findings identify a cell-type-specific mechanism that supports glutamatergic synapse function in inhibitory interneurons-with implications for circuit function and animal behavior.

Activity-regulated gene expression across cell types of the mouse hippocampus.

Activity-regulated gene (ARG) expression patterns in the hippocampus (HPC) regulate synaptic plasticity, learning, and memory, and are linked to both risk and treatment responses for many neuropsychiatric disorders. The HPC contains discrete classes of neurons with specialized functions, but cell type-specific activity-regulated transcriptional programs are not well characterized. Here, we used single-nucleus RNA-sequencing (snRNA-seq) in a mouse model of acute electroconvulsive seizures (ECS) to identify cell type-specific molecular signatures associated with induced activity in HPC neurons. We used unsupervised clustering and a priori marker genes to computationally annotate 15,990 high-quality HPC neuronal nuclei from N = 4 mice across all major HPC subregions and neuron types. Activity-induced transcriptomic responses were divergent across neuron populations, with dentate granule cells being particularly responsive to activity. Differential expression analysis identified both upregulated and downregulated cell type-specific gene sets in neurons following ECS. Within these gene sets, we identified enrichment of pathways associated with varying biological processes such as synapse organization, cellular signaling, and transcriptional regulation. Finally, we used matrix factorization to reveal continuous gene expression patterns differentially associated with cell type, ECS, and biological processes. This work provides a rich resource for interrogating activity-regulated transcriptional responses in HPC neurons at single-nuclei resolution in the context of ECS, which can provide biological insight into the roles of defined neuronal subtypes in HPC function.

A comparison of candidate banker plants for management of pests in lettuce.

Agricultural systems are often lacking in resources for natural enemies. Providing alternative prey can help natural enemies persist through periods of low pest abundance, although this approach has been rarely commercially implemented in open field crops. In this study, we tested the potential of eight plant species to provide alternative prey to natural enemies in lettuce fields over a 2-yr period. Results showed that the tested plants would not act as sources of the lettuce aphid Nasonovia ribisnigri Mosley (Hemiptera: Aphididae), the primary lettuce pest. Of the banker plants tested, barley contained high numbers of non-lettuce aphids and appeared to provide reliable habitat for hoverfly larvae. However, lettuce aphids were present on lettuce early in the season, and may have dwarfed any effects of nonlettuce aphids on natural enemy populations. Numbers of hoverfly larvae were also high in lettuce, but did not appear to track numbers of non-lettuce aphids on banker plants. In contrast, numbers of lacewing larvae were highest on plants containing high numbers of non-lettuce aphids, and predatory hemipterans appeared to be associated with numbers of thrips on banker plants. Although barley showed promise as a source of alternative aphids, it did not appear to improve pest control in the adjacent crop.

Corrigendum: Functional MRI study of feedback-based reinforcement learning in depression.

[This corrects the article DOI: 10.3389/fninf.2022.1028121.].

G0S2 promotes antiestrogenic and pro-migratory responses in ER+ and ER- breast cancer cells.

G0/G1 switch gene 2 (G0S2) is known to inhibit lipolysis by inhibiting adipose triglyceride lipase (ATGL). In this report, we dissect the role of G0S2 in ER+ versus ER- breast cancer. Overexpression of G0S2 in ER- cells increased cell proliferation, while G0S2 overexpression in ER+ cells decreased cell proliferation. Transcriptome analysis revealed that G0S2 mediated distinct but overlapping transcriptional responses in ER- and ER+ cells. G0S2 reduced genes associated with an epithelial phenotype, especially in ER- cells, including CDH1, ELF3, STEAP4 and TACSTD2, suggesting promotion of the epithelial-mesenchymal transition (EMT). G0S2 also repressed estrogen signaling and estrogen receptor target gene signatures, especially in ER+ cells, including TFF1 and TFF3. In addition, G0S2 overexpression increased cell migration in ER- cells and increased estrogen deprivation sensitivity in ER+ cells. Interestingly, two genes downstream of ATGL in fat utilization and very important in steroid hormone biosynthesis, HMGCS1 and HMGCS2, were downregulated in G0S2 overexpressing ER+ cells. In addition, HSD17B11, a gene that converts estradiol to its less estrogenic derivative, estrone, was highly upregulated in G0S2 overexpressing ER+ cells, suggesting G0S2 overexpression has a negative effect on estradiol production and maintenance. High expression of G0S2 and HSD17B11 was associated with improved relapse-free survival in breast cancer patients while high expression of HMGSC1 was associated with poor survival. Finally, we deleted G0S2 in breast cancer-prone MMTV-PyMT mice. Our data indicates a complex role for G0S2 in breast cancer, dependent on ER status, that may be partially mediated by suppression of the estrogen signaling pathway.

Blimp-1/PRDM1 and Hr3/RORß specify the blue-sensitive photoreceptor subtype in Drosophila by repressing the hippo pathway.

During terminal differentiation of the mammalian retina, transcription factors control binary cell fate decisions that generate functionally distinct subtypes of photoreceptor neurons. For instance, Otx2 and RORß activate the expression of the transcriptional repressor Blimp-1/PRDM1 that represses bipolar interneuron fate and promotes rod photoreceptor fate. Moreover, Otx2 and Crx promote expression of the nuclear receptor Nrl that promotes rod photoreceptor fate and represses cone photoreceptor fate. Mutations in these four transcription factors cause severe eye diseases such as retinitis pigmentosa. Here, we show that a post-mitotic binary fate decision in Drosophila color photoreceptor subtype specification requires ecdysone signaling and involves orthologs of these transcription factors: Drosophila Blimp-1/PRDM1 and Hr3/RORß promote blue-sensitive (Rh5) photoreceptor fate and repress green-sensitive (Rh6) photoreceptor fate through the transcriptional repression of warts/LATS, the nexus of the phylogenetically conserved Hippo tumor suppressor pathway. Moreover, we identify a novel interaction between Blimp-1 and warts, whereby Blimp-1 represses a warts intronic enhancer in blue-sensitive photoreceptors and thereby gives rise to specific expression of warts in green-sensitive photoreceptors. Together, these results reveal that conserved transcriptional regulators play key roles in terminal cell fate decisions in both the Drosophila and the mammalian retina, and the mechanistic insights further deepen our understanding of how Hippo pathway signaling is repurposed to control photoreceptor fates for Drosophila color vision.