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Archer, A.

Publications and source records attributed to Archer, A..

3 recordsLinked to original sources

Estrogen receptor activation remodels TEAD1 gene expression to alleviate nonalcoholic fatty liver disease

IntroductionThe occurrence of obesity-related hepatic malignancies differs between sexes, suggesting the involvement of sex hormones. Female sex hormones maintain cell homeostasis through estrogen receptor (ER) signaling and protect from developing nonalcoholic fatty liver disease (NAFLD) in mice and humans. RationaleTo understand recovery from high-fat diet (HFD)-induced liver disease in males upon estrogen treatment, we comprehensively characterized molecular changes in the liver upon selective activation of estrogen receptors (ERs) to identify novel therapeutic targets downstream of estrogen signaling. MethodsTo dissect hepatic ER isoform-driven responses, we integrated liver transcriptomes from female and male HFD mice treated with or without four different estrogen agonists, along with multiomics data, including bulk, single-cell and spatial transcriptomics, chromatin profiling, machine learning models and advanced microscopy. Patient cohorts and primary human hepatocyte spheroids datasets were included. ResultsOnly males developed liver steatosis. We found that selective activation of either ER or ER{beta} reduced HFD-induced hepatic steatosis in male mice. Systemic ER activation restored HFD-induced aberrant gene expression of cellular processes across liver cell types, including hepatocytes. Profiling of marked histones revealed that ER activation modulated promoter and enhancer sites and identified 68 estrogen-sensitive enhancer-gene pairs. Most of these genes were similarly deregulated in human nonalcoholic fatty liver disease (NAFLD) patients, including the transcription factor TEAD1. TEAD1 expression increased in NAFLD patients, and inhibiting TEAD ameliorated steatosis in spheroids by suppressing lipogenic pathways. ConclusionsSystemic activation of ER or ER{beta} modulates molecular pathways in the liver to counteract NAFLD. Our study identified TEAD1 as a key ER-sensitive gene and suggested that its inhibition poses a therapeutic strategy to combat NAFLD without the undesired side effects elicited by estrogen signaling. Clinical research relevanceWe identified drug targets downstream of estrogen signaling, including TEAD1, and demonstrate that TEAD inhibition improves steatosis by suppressing lipogenic pathways. Basic research relevanceThe targeted activation of nuclear ERs recovers high-fat diet-induced molecular and physiological liver phenotypes by remodeling core pathways beyond lipid metabolism. ER-responsive enhancers regulate central metabolic genes of clinical significance in NAFLD patients, highlighting the potential impact of this research on understanding liver cell plasticity. HIGHLIGHTSO_LIsteatosis in livers of high-fat diet (HFD) male mice was effectively reduced by selective activation of estrogen receptors (ER and ER{beta}) with four different agonists. C_LIO_LIER agonist treatments successfully reversed HFD-induced changes in gene regulation and expression, revealing new treatment targets involving previously unconnected molecular pathways. C_LIO_LIestrogen-sensitive enhancers regulated important genes, including TEAD1, emerging as pivotal NAFLD regulators significantly impacting metabolic processes. C_LIO_LIhigh TEAD1 gene expression in NAFLD patients correlated with disease severity, underscoring its clinical significance in disease progression. C_LIO_LIinhibiting TEAD with small molecules alleviated steatosis by suppressing lipogenic pathways, resembling some of the same beneficial effects as estrogen treatment. C_LI

genomics↗

Linking the Salmonella enterica 1,2-propanediol utilization bacterial microcompartment shell to the enzymatic core via the shell protein PduB

Bacterial microcompartments (MCPs) are protein-based organelles that house the enzymatic machinery for metabolism of niche carbon sources, allowing enteric pathogens to outcompete native microbiota during host colonization. While much progress has been made toward understanding MCP biogenesis, questions still remain regarding the mechanism by which core MCP enzymes are enveloped within the MCP protein shell. Here we explore the hypothesis that the shell protein PduB is responsible for linking the shell of the 1,2-propanediol utilization (Pdu) MCP from Salmonella enterica serovar Typhimurium LT2 to its enzymatic core. Using fluorescent reporters, we demonstrate that all members of the Pdu enzymatic core are encapsulated in Pdu MCPs. We also demonstrate that PduB is the sole protein responsible for linking the entire Pdu enzyme core to the MCP shell. Using MCP purifications, transmission electron microscopy, and fluorescence microscopy we find that shell assembly can be decoupled from the enzymatic core, as apparently empty MCPs are formed in Salmonella strains lacking PduB. Mutagenesis studies also reveal that PduB is incorporated into the Pdu MCP shell via a conserved, lysine-mediated hydrogen bonding mechanism. Finally, growth assays and systems-level pathway modeling reveal that unencapsulated pathway performance is strongly impacted by enzyme concentration, highlighting the importance of minimizing polar effects when conducting these functional assays. Together, these results provide insight into the mechanism of enzyme encapsulation within Pdu MCPs and demonstrate that the process of enzyme encapsulation and shell assembly are separate processes in this system, a finding that will aid future efforts to understand MCP biogenesis. ImportanceMCPs are unique, genetically encoded organelles used by many bacteria to survive in resource-limited environments. There is significant interest in understanding the biogenesis and function of these organelles, both as potential antibiotic targets in enteric pathogens and also as useful tools for overcoming metabolic engineering bottlenecks. However, the mechanism by which these organelles are formed natively is still not completely understood. Here we provide evidence of a potential mechanism inS. enterica by which a single protein, PduB, links the MCP shell and metabolic core. This finding is critical for those seeking to disrupt MCPs during pathogenic infections or for those seeking to harness MCPs as nanobioreactors in industrial settings.

synthetic biology↗

High-fat diet impacts the colon and its transcriptome in a sex-dependent manner that is modifiable by estrogens

Epidemiological studies highlight a strong association between obesity and colorectal cancer (CRC), especially in men. Estrogen, on the other hand, is associated with protection against both the metabolic syndrome and CRC. The colon is the first organ to respond to a high-fat diet (HFD), and estrogen receptor beta (ER{beta}) in the intestine appears to prevent CRC. How estrogen impacts the colon under HFD condition has, however, not been investigated. Estrogen can act through three different receptors (ER, ER{beta}, GPER1) which all may impact metabolism. In an effort to dissect this, we fed mice a control diet or a high-fat diet (HFD) for 13 weeks and administered receptor-selective estrogenic ligands for the last three weeks. We recorded corresponding physiological impact on fat distribution, fasting glucose, colon crypt proliferation and immune cell infiltration, and the colon transcriptome response. We identify clear sex-differences at the transcriptome level, both at base line and after HFD and ligand treatments. An unexpected observation was the significant sex-differences and impact by HFD and estrogens on circadian clock gene expression, such as Npas2 and Arntl (Bmal1), in the colon. Both sexes also exhibited an increased infiltration of F4/80+ macrophages as a result of HFD. In males, but not females, this was accompanied by changes in colonic epithelial cell proliferation. ER-selective PPT treatment had significant systemic effects, reducing body weight in both sexes, whereas ER{beta}-selective DPN treatment did not impact body weight, but reduced infiltration of F4/80+ macrophages in colon of both sexes and attenuated HFD-induced proliferation of male colon crypts. Both ER and ER{beta} activation contributed to circadian clock gene regulations. We detail for the first time how HFD and estrogens modulate the colon transcriptome and physiology in a sex and ER-specific manner.

cell biology↗