Kupffer cell diversity maintains liver function in alcohol-associated liver disease.

BACKGROUND AND AIMS: Liver macrophages are heterogeneous and play an important role in alcohol-associated liver disease (ALD) but there is limited understanding of the functions of specific macrophage subsets in the disease. We used a Western diet alcohol (WDA) mouse model of ALD to examine the hepatic myeloid cell compartment by single cell RNAseq and targeted KC ablation to understand the diversity and function of liver macrophages in ALD. APPROACH AND RESULTS: In the WDA liver, KCs and infiltrating monocytes/macrophages each represented about 50% of the myeloid pool. Five major KC clusters all expressed genes associated with receptor-mediated endocytosis and lipid metabolism, but most were predicted to be noninflammatory and antifibrotic with 1 minor KC cluster having a proinflammatory and extracellular matrix degradation gene signature. Infiltrating monocyte/macrophage clusters, in contrast, were predicted to be proinflammatory and profibrotic. In vivo, diphtheria toxin-based selective KC ablation during alcohol exposure resulted in a liver failure phenotype with increases in PT/INR and bilirubin, loss of differentiated hepatocyte gene expression, and an increase in expression of hepatocyte progenitor markers such as EpCAM, CK7, and Igf2bp3. Gene set enrichment analysis of whole-liver RNAseq from the KC-ablated WDA mice showed a similar pattern as seen in human alcoholic hepatitis. CONCLUSIONS: In this ALD model, KCs are anti-inflammatory and are critical for the maintenance of hepatocyte differentiation. Infiltrating monocytes/macrophages are largely proinflammatory and contribute more to liver fibrosis. Future targeting of specific macrophage subsets may provide new approaches to the treatment of liver failure and fibrosis in ALD.

Hippo signaling cofactor, WWTR1, at the crossroads of human trophoblast progenitor self-renewal and differentiation.

Healthy progression of human pregnancy relies on cytotrophoblast (CTB) progenitor self-renewal and its differentiation toward multinucleated syncytiotrophoblasts (STBs) and invasive extravillous trophoblasts (EVTs). However, the underlying molecular mechanisms that fine-tune CTB self-renewal or direct its differentiation toward STBs or EVTs during human placentation are poorly defined. Here, we show that Hippo signaling cofactor WW domain containing transcription regulator 1 (WWTR1) is a master regulator of trophoblast fate choice during human placentation. Using human trophoblast stem cells (human TSCs), primary CTBs, and human placental explants, we demonstrate that WWTR1 promotes self-renewal in human CTBs and is essential for their differentiation to EVTs. In contrast, WWTR1 prevents induction of the STB fate in undifferentiated CTBs. Our single-cell RNA sequencing analyses in first-trimester human placenta, along with mechanistic analyses in human TSCs revealed that WWTR1 fine-tunes trophoblast fate by directly regulating WNT signaling components. Importantly, our analyses of placentae from pathological pregnancies show that extreme preterm births (gestational time ≤28 wk) are often associated with loss of WWTR1 expression in CTBs. In summary, our findings establish the critical importance of WWTR1 at the crossroads of human trophoblast progenitor self-renewal versus differentiation. It plays positive instructive roles in promoting CTB self-renewal and EVT differentiation and safeguards undifferentiated CTBs from attaining the STB fate.

Loss of the repressor REST affects progesterone receptor function and promotes uterine leiomyoma pathogenesis.

Uterine leiomyomas (UL) are benign tumors that arise in the myometrial layer of the uterus. The standard treatment option for UL is hysterectomy, although hormonal therapies, such as selective progesterone receptor modulators, are often used as temporary treatment options to reduce symptoms or to slow the growth of tumors. However, since the pathogenesis of UL is poorly understood and most hormonal therapies are not based on UL-specific, divergent hormone signaling pathways, hallmarks that predict long-term efficacy and safety of pharmacotherapies remain largely undefined. In a previous study, we reported that aberrant expression of repressor element 1 silencing transcription factor/neuron-restrictive silencing factor (REST/NRSF) target genes activate UL growth due to the near ubiquitous loss of REST. Here, we show that ablation of the Rest gene in mouse uterus leads to UL phenotype and gene-expression patterns analogous to UL, including altered estrogen and progesterone signaling pathways. We demonstrate that many of the genes dysregulated in UL harbor cis-regulatory elements bound by REST and progesterone receptor (PGR) adjacent to each other. Crucially, we identify an interaction between REST and PGR in healthy myometrium and present a putative mechanism for the dysregulation of progesterone-responsive genes in UL ensuing in the loss of REST. Using three Rest conditional knockout mouse lines, we provide a comprehensive picture of the impact loss of REST has in UL pathogenesis and in altering the response of UL to steroid hormones.

Sera of Individuals Chronically Infected with Hepatitis B Virus (HBV) Contain Diverse RNA Types Produced by HBV Replication or Derived from Integrated HBV DNA.

This study aimed to better characterize the repertoire of serum hepatitis B virus (HBV) RNAs during chronic HBV infection in humans, which remains understudied. Using reverse transcription-PCR (RT-PCR), real-time quantitative PCR (RT-qPCR), RNA-sequencing, and immunoprecipitation, we found that (i) >50% of serum samples bore different amounts of HBV replication-derived RNAs (rd-RNAs); (ii) a few samples contained RNAs transcribed from integrated HBV DNA, including 5'-HBV-human-3' RNAs (integrant-derived RNAs [id-RNAs]) and 5'-human-HBV-3' transcripts, as a minority of serum HBV RNAs; (iii) spliced HBV RNAs were abundant in <50% of analyzed samples; (iv) most serum rd-RNAs were polyadenylated via conventional HBV polyadenylation signal; (v) pregenomic RNA (pgRNA) was the major component of the pool of serum RNAs; (vi) the area of HBV positions 1531 to 1739 had very high RNA read coverage and thus should be used as a target for detecting serum HBV RNAs; (vii) the vast majority of rd-RNAs and pgRNA were associated with HBV virions but not with unenveloped capsids, exosomes, classic microvesicles, or apoptotic vesicles and bodies; (viii) considerable rd-RNAs presence in the circulating immune complexes was found in a few samples; and (ix) serum relaxed circular DNA (rcDNA) and rd-RNAs should be quantified simultaneously to evaluate HBV replication status and efficacy of anti-HBV therapy with nucleos(t)ide analogs. In summary, sera contain various HBV RNA types of different origin, which are likely secreted via different mechanisms. In addition, since we previously showed that id-RNAs were abundant or predominant HBV RNAs in many of liver and hepatocellular carcinoma tissues as compared to rd-RNAs, there is likely a mechanism favoring the egress of replication-derived RNAs. IMPORTANCE The presence of integrant-derived RNAs (id-RNAs) and 5'-human-HBV-3' transcripts derived from integrated hepatitis B virus (HBV) DNA in sera was demonstrated for the first time. Thus, sera of individuals chronically infected with HBV contained both replication-derived and integrant-transcribed HBV RNAs. The majority of serum HBV RNAs were the transcripts produced by HBV genome replication, which were associated with HBV virions and not with other types of extracellular vesicles. These and other above-mentioned findings advanced our understanding of the HBV life cycle. In addition, the study suggested a promising target area on the HBV genome to increase sensitivity of the detection of serum HBV RNAs and supported the idea that simultaneous detection of replication-derived RNAs (rd-RNAs) and relaxed circular DNA (rcDNA) in serum provides more adequate evaluation of (i) the HBV genome replication status and (ii) the durability and efficiency of the therapy with anti-HBV nucleos(t)ide analogs, which could be useful for improvement of the diagnostics and treatment of HBV-infected individuals.

Identifying novel mechanisms of per- and polyfluoroalkyl substance-induced hepatotoxicity using FRG humanized mice.

Per- and polyfluoroalkyl substances (PFAS) such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) and perfluoro-2-methyl-3-oxahexanoic acid (GenX), the new replacement PFAS, are major environmental contaminants. In rodents, these PFAS induce several adverse effects on the liver, including increased proliferation, hepatomegaly, steatosis, hypercholesterolemia, nonalcoholic fatty liver disease and liver cancers. Activation of peroxisome proliferator receptor alpha by PFAS is considered the primary mechanism of action in rodent hepatocyte-induced proliferation. However, the human relevance of this mechanism is uncertain. We investigated human-relevant mechanisms of PFAS-induced adverse hepatic effects using FRG liver-chimeric humanized mice with livers repopulated with functional human hepatocytes. Male FRG humanized mice were treated with 0.067 mg/L of PFOA, 0.145 mg/L of PFOS, or 1 mg/L of GenX in drinking water for 28 days. PFOS caused a significant decrease in total serum cholesterol and LDL/VLDL, whereas GenX caused a significant elevation in LDL/VLDL with no change in total cholesterol and HDL. All three PFAS induced significant hepatocyte proliferation. RNA-sequencing with alignment to the human genome showed a total of 240, 162, and 619 differentially expressed genes after PFOA, PFOS, and GenX exposure, respectively. Upstream regulator analysis revealed that all three PFAS induced activation of p53 and inhibition of androgen receptor and NR1D1, a transcriptional repressor important in circadian rhythm. Further biochemical studies confirmed NR1D1 inhibition and in silico modeling indicated potential interaction of all three PFAS with the DNA-binding domain of NR1D1. In conclusion, our studies using FRG humanized mice have revealed new human-relevant molecular mechanisms of PFAS including their previously unknown effect on circadian rhythm.

Doublecortin-like kinase 1 is a therapeutic target in squamous cell carcinoma.

Doublecortin like kinase 1 (DCLK1) plays a crucial role in several cancers including colon and pancreatic adenocarcinomas. However, its role in squamous cell carcinoma (SCC) remains unknown. To this end, we examined DCLK1 expression in head and neck SCC (HNSCC) and anal SCC (ASCC). We found that DCLK1 is elevated in patient SCC tissue, which correlated with cancer progression and poorer overall survival. Furthermore, DCLK1 expression is significantly elevated in human papilloma virus negative HNSCC, which are typically aggressive with poor responses to therapy. To understand the role of DCLK1 in tumorigenesis, we used specific shRNA to suppress DCLK1 expression. This significantly reduced tumor growth, spheroid formation, and migration of HNSCC cancer cells. To further the translational relevance of our studies, we sought to identify a selective DCLK1 inhibitor. Current attempts to target DCLK1 using pharmacologic approaches have relied on nonspecific suppression of DCLK1 kinase activity. Here, we demonstrate that DiFiD (3,5-bis [2,4-difluorobenzylidene]-4-piperidone) binds to DCLK1 with high selectivity. Moreover, DiFiD mediated suppression of DCLK1 led to G2/M arrest and apoptosis and significantly suppressed tumor growth of HNSCC xenografts and ASCC patient derived xenografts, supporting that DCLK1 is critical for SCC growth.

Progressive loss of hepatocyte nuclear factor 4 alpha activity in chronic liver diseases in humans.

BACKGROUND AND AIMS: Hepatocyte nuclear factor 4 alpha (HNF4α) is indispensable for hepatocyte differentiation and critical for maintaining liver health. Here, we demonstrate that loss of HNF4α activity is a crucial step in the pathogenesis of chronic liver diseases (CLDs) that lead to development of HCC. APPROACH AND RESULTS: We developed an HNF4α target gene signature, which can accurately determine HNF4α activity, and performed an exhaustive in silico analysis using hierarchical and K-means clustering, survival, and rank-order analysis of 30 independent data sets containing over 3500 individual samples. The association of changes in HNF4α activity to CLD progression of various etiologies, including HCV- and HBV-induced liver cirrhosis (LC), NAFLD/NASH, and HCC, was determined. Results revealed a step-wise reduction in HNF4α activity with each progressive stage of pathogenesis. Cluster analysis of LC gene expression data sets using the HNF4α signature showed that loss of HNF4α activity was associated with progression of Child-Pugh class, faster decompensation, incidence of HCC, and lower survival with and without HCC. A moderate decrease in HNF4α activity was observed in NAFLD from normal liver, but a further significant decline was observed in patients from NAFLD to NASH. In HCC, loss of HNF4α activity was associated with advanced disease, increased inflammatory changes, portal vein thrombosis, and substantially lower survival. CONCLUSIONS: In conclusion, these data indicate that loss of HNF4α function is a common event in the pathogenesis of CLDs leading to HCC and is important from both diagnostic and therapeutic standpoints.

The START domain mediates Arabidopsis GLABRA2 dimerization and turnover independently of homeodomain DNA binding.

Class IV homeodomain leucine-zipper transcription factors (HD-Zip IV TFs) are key regulators of epidermal differentiation that are characterized by a DNA-binding HD in conjunction with a lipid-binding domain termed steroidogenic acute regulatory-related lipid transfer (START). Previous work established that the START domain of GLABRA2 (GL2), a HD-Zip IV member from Arabidopsis (Arabidopsis thaliana), is required for TF activity. Here, we addressed the functions and possible interactions of START and the HD in DNA binding, dimerization, and protein turnover. Deletion analysis of the HD and missense mutations of a conserved lysine (K146) resulted in phenotypic defects in leaf trichomes, root hairs, and seed mucilage, similar to those observed for START domain mutants, despite nuclear localization of the respective proteins. In vitro and in vivo experiments demonstrated that while HD mutations impair binding to target DNA, the START domain is dispensable for DNA binding. Vice versa, protein interaction assays revealed impaired GL2 dimerization for multiple alleles of START mutants, but not HD mutants. Using in vivo cycloheximide chase experiments, we provided evidence for the role of START, but not HD, in maintaining protein stability. This work advances our mechanistic understanding of HD-Zip TFs as multidomain regulators of epidermal development in plants.

Atypical protein kinase C iota (PKCλ/ι) ensures mammalian development by establishing the maternal-fetal exchange interface.

In utero mammalian development relies on the establishment of the maternal-fetal exchange interface, which ensures transportation of nutrients and gases between the mother and the fetus. This exchange interface is established via development of multinucleated syncytiotrophoblast cells (SynTs) during placentation. In mice, SynTs develop via differentiation of the trophoblast stem cell-like progenitor cells (TSPCs) of the placenta primordium, and in humans, SynTs are developed via differentiation of villous cytotrophoblast (CTB) progenitors. Despite the critical need in pregnancy progression, conserved signaling mechanisms that ensure SynT development are poorly understood. Herein, we show that atypical protein kinase C iota (PKCλ/ι) plays an essential role in establishing the SynT differentiation program in trophoblast progenitors. Loss of PKCλ/ι in the mouse TSPCs abrogates SynT development, leading to embryonic death at approximately embryonic day 9.0 (E9.0). We also show that PKCλ/ι-mediated priming of trophoblast progenitors for SynT differentiation is a conserved event during human placentation. PKCλ/ι is selectively expressed in the first-trimester CTBs of a developing human placenta. Furthermore, loss of PKCλ/ι in CTB-derived human trophoblast stem cells (human TSCs) impairs their SynT differentiation potential both in vitro and after transplantation in immunocompromised mice. Our mechanistic analyses indicate that PKCλ/ι signaling maintains expression of GCM1, GATA2, and PPARγ, which are key transcription factors to instigate SynT differentiation programs in both mouse and human trophoblast progenitors. Our study uncovers a conserved molecular mechanism, in which PKCλ/ι signaling regulates establishment of the maternal-fetal exchange surface by promoting trophoblast progenitor-to-SynT transition during placentation.

TEAD4 ensures postimplantation development by promoting trophoblast self-renewal: An implication in early human pregnancy loss.

Early pregnancy loss affects ∼15% of all implantation-confirmed human conceptions. However, evolutionarily conserved molecular mechanisms that regulate self-renewal of trophoblast progenitors and their association with early pregnancy loss are poorly understood. Here, we provide evidence that transcription factor TEAD4 ensures survival of postimplantation mouse and human embryos by controlling self-renewal and stemness of trophoblast progenitors within the placenta primordium. In an early postimplantation mouse embryo, TEAD4 is selectively expressed in trophoblast stem cell-like progenitor cells (TSPCs), and loss of Tead4 in postimplantation mouse TSPCs impairs their self-renewal, leading to embryonic lethality before embryonic day 9.0, a developmental stage equivalent to the first trimester of human gestation. Both TEAD4 and its cofactor, yes-associated protein 1 (YAP1), are specifically expressed in cytotrophoblast (CTB) progenitors of a first-trimester human placenta. We also show that a subset of unexplained recurrent pregnancy losses (idiopathic RPLs) is associated with impaired TEAD4 expression in CTB progenitors. Furthermore, by establishing idiopathic RPL patient-specific human trophoblast stem cells (RPL-TSCs), we show that loss of TEAD4 is associated with defective self-renewal in RPL-TSCs and rescue of TEAD4 expression restores their self-renewal ability. Unbiased genomics studies revealed that TEAD4 directly regulates expression of key cell cycle genes in both mouse and human TSCs and establishes a conserved transcriptional program. Our findings show that TEAD4, an effector of the Hippo signaling pathway, is essential for the establishment of pregnancy in a postimplantation mammalian embryo and indicate that impairment of the Hippo signaling pathway could be a molecular cause for early human pregnancy loss.

A negative reciprocal regulatory axis between cyclin D1 and HNF4α modulates cell cycle progression and metabolism in the liver.

Hepatocyte nuclear factor 4α (HNF4α) is a master regulator of liver function and a tumor suppressor in hepatocellular carcinoma (HCC). In this study, we explore the reciprocal negative regulation of HNF4α and cyclin D1, a key cell cycle protein in the liver. Transcriptomic analysis of cultured hepatocyte and HCC cells found that cyclin D1 knockdown induced the expression of a large network of HNF4α-regulated genes. Chromatin immunoprecipitation-sequencing (ChIP-seq) demonstrated that cyclin D1 inhibits the binding of HNF4α to thousands of targets in the liver, thereby diminishing the expression of associated genes that regulate diverse metabolic activities. Conversely, acute HNF4α deletion in the liver induces cyclin D1 and hepatocyte cell cycle progression; concurrent cyclin D1 ablation blocked this proliferation, suggesting that HNF4α maintains proliferative quiescence in the liver, at least, in part, via repression of cyclin D1. Acute cyclin D1 deletion in the regenerating liver markedly inhibited hepatocyte proliferation after partial hepatectomy, confirming its pivotal role in cell cycle progression in this in vivo model, and enhanced the expression of HNF4α target proteins. Hepatocyte cyclin D1 gene ablation caused markedly increased postprandial liver glycogen levels (in a HNF4α-dependent fashion), indicating that the cyclin D1-HNF4α axis regulates glucose metabolism in response to feeding. In AML12 hepatocytes, cyclin D1 depletion led to increased glucose uptake, which was negated if HNF4α was depleted simultaneously, and markedly elevated glycogen synthesis. To summarize, mutual repression by cyclin D1 and HNF4α coordinately controls the cell cycle machinery and metabolism in the liver.

LH/hCG Regulation of Circular RNA in Mural Granulosa Cells during the Periovulatory Period in Mice.

Ovarian follicles undergo a series of dynamic changes following the ovulatory surge of luteinizing hormone including cumulus expansion, oocyte maturation, ovulation, and luteinization. Post-transcriptional gene regulatory events are critical for mediating LH follicular responses, and among all RNA isoforms, circular RNA (circRNA) is one of the most abundant forms present in cells, yet they remain the least studied. Functionally, circRNA can act as miRNA sponges, protein sponges/decoys, and regulators of transcription and translation. In the context of ovarian follicular development, the identity and roles of circRNA are relatively unknown. In the present study, high throughput RNA sequencing of granulosa cells immediately prior to and 4-h after the LH/hCG surge identified 42,381 circRNA originating from 7712 genes. A total of 54 circRNA were identified as differentially expressed between 0-h and 4-h time points (Fold Change ± 1.5, FDR ≤ 0.1), among them 42 circRNA were upregulated and 12 circRNA were downregulated. All differentially expressed circRNA between the 0-h and 4-h groups were subjected to circinteractome analysis and identified networks of circRNA-protein and circRNA-miRNA were further subjected to "micro-RNA target filter analysis" in Ingenuity Pathway Analyses, which resulted in the identification of miRNA targeted mRNAs. A comparison of these circRNA target mRNAs with LH-induced mRNAs identified Runx2, Egfr, Areg, Sult1el, Cyp19a1, Cyp11a1, and Hsd17b1 as targets of circKif2, circVcan, circMast4, and circMIIt10. These newly identified LH/hCG-induced circRNA, their target miRNA and protein networks provide new insights into the complex interactions associated with periovulatory follicular development.

Loss of REST in breast cancer promotes tumor progression through estrogen sensitization, MMP24 and CEMIP overexpression.

BACKGROUND: Breast cancer is the most common malignancy in women, and is both pathologically and genetically heterogeneous, making early detection and treatment difficult. A subset of breast cancers express normal levels of REST (repressor element 1 silencing transcription factor) mRNA but lack functional REST protein. Loss of REST function is seen in ~ 20% of breast cancers and is associated with a more aggressive phenotype and poor prognosis. Despite the frequent loss of REST, little is known about the role of REST in the molecular pathogenesis of breast cancer. METHODS: TCGA data was analyzed for the expression of REST target genes in breast cancer patient samples. We then utilized gene knockdown in MCF-7 cells in the presence or absence of steroid hormones estrogen and/ progesterone followed by RNA sequencing, as well as chromatin immunoprecipitation and PCR in an attempt to understand the tumor suppressor role of REST in breast cancer. RESULTS: We show that REST directly regulates CEMIP (cell migration-inducing and hyaluronan-binding protein, KIAA1199) and MMP24 (matrix metallopeptidase 24), genes known to have roles in invasion and metastasis. REST knockdown in breast cancer cells leads to significant upregulation of CEMIP and MMP24. In addition, we found REST binds to RE-1 sites (repressor element-1) within the genes and influences their transcription. Furthermore, we found that the estrogen receptor (ESR1) signaling pathway is activated in the absence of REST, regardless of hormone treatment. CONCLUSIONS: We demonstrate a critical role for the loss of REST in aggressive breast cancer pathogenesis and provide evidence for REST as an important diagnostic marker for personalized treatment plans.

Forkhead box F1 induces columnar phenotype and epithelial-to-mesenchymal transition in esophageal squamous cells to initiate Barrett's like metaplasia.

Multiple genome-wide association studies (GWAS) have linked Forkhead Box F1 (FOXF1) to Barrett's esophagus (BE). Understanding whether FOXF1 is involved in initiation of Barrett's metaplasia could allow FOXF1 to be used for risk stratification and for therapy. Two-dimensional cell cultures and three-dimensional organoid cultures and well-annotated human biopsies were used to determine the role of FOXF1 in BE pathogenesis. Multiple established esophageal squamous and BE cell lines were tested in gain- and loss-of-function studies. Initiation of a BE-like metaplastic change was evaluated by measuring characteristic cytokeratins and global gene expression profiling and by culturing organoids. Epithelial-mesenchymal transition (EMT) was evaluated by immunostaining for E-cadherin, vimentin and Snail, and by cell motility assay. Columnar esophageal epithelium of BE patients exhibited higher expression of FOXF1 compared to normal squamous esophageal epithelium of GERD patients (P < 0.001). Acidic bile salts induced nuclear FOXF1 in esophageal squamous cells. FOXF1 overexpression in normal esophageal squamous cells: (a) increased columnar cytokeratins and decreased squamous cytokeratins, (b) converted squamous organoids to glandular organoids, and (c) switched global gene profiles to resemble that of human BE epithelium (P = 2.1685e - 06 for upregulated genes and P = 8.3378e - 09 for downregulated genes). FOXF1 inhibition in BE cell lines led to loss of BE differentiation markers, CK7, and mucin 2. Also, FOXF1 induced EMT and promoted cell motility in normal esophageal squamous epithelial cells. FOXF1-induced genes mapped to pathways such as Cancer, Cellular Assembly and Organization, DNA Replication, Recombination, and Repair. In conclusion, FOXF1 promotes a BE-like columnar phenotype and cell motility in esophageal squamous epithelial cells, which may have a critical role in BE development. FOXF1 should be studied further as a biomarker for BE and as a target for BE treatment.

A Western diet with alcohol in drinking water recapitulates features of alcohol-associated liver disease in mice.

BACKGROUND: Mouse models of alcohol-associated liver disease vary greatly in their ease of implementation and the pathology they produce. Effects range from steatosis and mild inflammation with the Lieber-DeCarli liquid diet to severe inflammation, fibrosis, and pyroptosis seen with the Tsukamoto-French intragastric feeding model. Implementation of all of these models is limited by the labor-intensive nature of the protocols and the specialized skills necessary for successful intragastric feeding. We thus sought to develop a new model to reproduce features of alcohol-induced inflammation and fibrosis with minimal operational requirements. METHODS: Over a 16-week period, mice were fed ad libitum with a pelleted high-fat Western diet (WD; 40% calories from fat) and alcohol added to the drinking water. We found the optimal alcohol consumption to be that at which the alcohol concentration was 20% for 4 days and 10% for 3 days per week. Control mice received WD pellets with water alone. RESULTS: Alcohol consumption was 18 to 20 g/kg/day in males and 20 to 22 g/kg/day in females. Mice in the alcohol groups developed elevated serum transaminase levels after 12 weeks in males and 10 weeks in females. At 16 weeks, both males and females developed liver inflammation, steatosis, and pericellular fibrosis. Control mice on WD without alcohol had mild steatosis only. Alcohol-fed mice showed reduced HNF4α mRNA and protein expression. HNF4α is a master regulator of hepatocyte differentiation, down-regulation of which is a known driver of hepatocellular failure in alcoholic hepatitis. CONCLUSION: A simple-to-administer, 16-week WD alcohol model recapitulates the inflammatory, fibrotic, and gene expression aspects of human alcohol-associated steatohepatitis.

Genomic, Clinical, and Behavioral Characterization of 15q11.2 BP1-BP2 Deletion (Burnside-Butler) Syndrome in Five Families.

The 15q11.2 BP1-BP2 deletion (Burnside-Butler) syndrome is emerging as the most common cytogenetic finding in patients with neurodevelopmental or autism spectrum disorders (ASD) presenting for microarray genetic testing. Clinical findings in Burnside-Butler syndrome include developmental and motor delays, congenital abnormalities, learning and behavioral problems, and abnormal brain findings. To better define symptom presentation, we performed comprehensive cognitive and behavioral testing, collected medical and family histories, and conducted clinical genetic evaluations. The 15q11.2 BP1-BP2 region includes the TUBGCP5, CYFIP1, NIPA1, and NIPA2 genes. To determine if additional genomic variation outside of the 15q11.2 region influences expression of symptoms in Burnside-Butler syndrome, whole-exome sequencing was performed on the parents and affected children for the first time in five families with at least one parent and child with the 15q1l.2 BP1-BP2 deletion. In total, there were 453 genes with possibly damaging variants identified across all of the affected children. Of these, 99 genes had exclusively de novo variants and 107 had variants inherited exclusively from the parent without the deletion. There were three genes (APBB1, GOLGA2, and MEOX1) with de novo variants that encode proteins evidenced to interact with CYFIP1. In addition, one other gene of interest (FAT3) had variants inherited from the parent without the deletion and encoded a protein interacting with CYFIP1. The affected individuals commonly displayed a neurodevelopmental phenotype including ASD, speech delay, abnormal reflexes, and coordination issues along with craniofacial findings and orthopedic-related connective tissue problems. Of the 453 genes with variants, 35 were associated with ASD. On average, each affected child had variants in 6 distinct ASD-associated genes (x¯ = 6.33, sd = 3.01). In addition, 32 genes with variants were included on clinical testing panels from Clinical Laboratory Improvement Amendments (CLIA) approved and accredited commercial laboratories reflecting other observed phenotypes. Notably, the dataset analyzed in this study was small and reported results will require validation in larger samples as well as functional follow-up. Regardless, we anticipate that results from our study will inform future research into the genetic factors influencing diverse symptoms in patients with Burnside-Butler syndrome, an emerging disorder with a neurodevelopmental behavioral phenotype.

The Histone Demethylase KDM3A, Increased in Human Pancreatic Tumors, Regulates Expression of DCLK1 and Promotes Tumorigenesis in Mice.

BACKGROUND & AIMS: The histone lysine demethylase 3A (KDM3A) demethylates H3K9me1 and H3K9Me2 to increase gene transcription and is upregulated in tumors, including pancreatic tumors. We investigated its activities in pancreatic cancer cell lines and its regulation of the gene encoding doublecortin calmodulin-like kinase 1 (DCLK1), a marker of cancer stem cells. METHODS: We knocked down KDM3A in MiaPaCa-2 and S2-007 pancreatic cancer cell lines and overexpressed KDM3A in HPNE cells (human noncancerous pancreatic ductal cell line); we evaluated cell migration, invasion, and spheroid formation under hypoxic and normoxic conditions. Nude mice were given orthotopic injections of S2-007 cells, with or without (control) knockdown of KDM3A, and HPNE cells, with or without (control) overexpression of KDM3A; tumor growth was assessed. We analyzed pancreatic tumor tissues from mice and pancreatic cancer cell lines by immunohistochemistry and immunoblotting. We performed RNA-sequencing analysis of MiaPaCa-2 and S2-007 cells with knockdown of KDM3A and evaluated localization of DCLK1 and KDM3A by immunofluorescence. We analyzed the cancer genome atlas for levels of KDM3A and DCLK1 messenger RNA in human pancreatic ductal adenocarcinoma (PDAC) tissues and association with patient survival time. RESULTS: Levels of KDM3A were increased in human pancreatic tumor tissues and cell lines, compared with adjacent nontumor pancreatic tissues, such as islet and acinar cells. Knockdown of KDM3A in S2-007 cells significantly reduced colony formation, invasion, migration, and spheroid formation, compared with control cells, and slowed growth of orthotopic tumors in mice. We identified KDM3A-binding sites in the DCLK1 promoter; S2-007 cells with knockdown of KDM3A had reduced levels of DCLK1. HPNE cells that overexpressed KDM3A formed foci and spheres in culture and formed tumors and metastases in mice, whereas control HPNE cells did not. Hypoxia induced sphere formation and increased levels of KDM3A in S2-007 cells and in HPNE cells that overexpressed DCLK1, but not control HPNE cells. Levels of KDM3A and DCLK1 messenger RNA were higher in human PDAC than nontumor pancreatic tissues and correlated with shorter survival times of patients. CONCLUSIONS: We found human PDAC samples and pancreatic cancer cell lines to overexpress KDM3A. KDM3A increases expression of DCLK1, and levels of both proteins are increased in human PDAC samples. Knockdown of KDM3A in pancreatic cancer cell lines reduced their invasive and sphere-forming activities in culture and formation of orthotopic tumors in mice. Hypoxia increased expression of KDM3A in pancreatic cancer cells. Strategies to disrupt this pathway might be developed for treatment of pancreatic cancer.

Genetic redundancy of GATA factors in the extraembryonic trophoblast lineage ensures the progression of preimplantation and postimplantation mammalian development.

GATA transcription factors are implicated in establishing cell fate during mammalian development. In early mammalian embryos, GATA3 is selectively expressed in the extraembryonic trophoblast lineage and regulates gene expression to promote trophoblast fate. However, trophoblast-specific GATA3 function is dispensable for early mammalian development. Here, using dual conditional knockout mice, we show that genetic redundancy of Gata3 with paralog Gata2 in trophoblast progenitors ensures the successful progression of both pre- and postimplantation mammalian development. Stage-specific gene deletion in trophoblasts reveals that loss of both GATA genes, but not either alone, leads to embryonic lethality prior to the onset of their expression within the embryo proper. Using ChIP-seq and RNA-seq analyses, we define the global targets of GATA2/GATA3 and show that they directly regulate a large number of common genes to orchestrate stem versus differentiated trophoblast fate. In trophoblast progenitors, GATA factors directly regulate BMP4, Nodal and Wnt signaling components that promote embryonic-extraembryonic signaling cross-talk, which is essential for the development of the embryo proper. Our study provides genetic evidence that impairment of trophoblast-specific GATA2/GATA3 function could lead to early pregnancy failure.

Hepatocyte Nuclear Factor 4 Alpha Activation Is Essential for Termination of Liver Regeneration in Mice.

Hepatocyte nuclear factor 4 alpha (HNF4α) is critical for hepatic differentiation. Recent studies have highlighted its role in inhibition of hepatocyte proliferation and tumor suppression. However, the role of HNF4α in liver regeneration (LR) is not known. We hypothesized that hepatocytes modulate HNF4α activity when navigating between differentiated and proliferative states during LR. Western blotting analysis revealed a rapid decline in nuclear and cytoplasmic HNF4α protein levels, accompanied with decreased target gene expression, within 1 hour after two-thirds partial hepatectomy (post-PH) in C57BL/6J mice. HNF4α protein expression did not recover to pre-PH levels until day 3. Hepatocyte-specific deletion of HNF4α (HNF4α-KO [knockout]) in mice resulted in 100% mortality post-PH, despite increased proliferative marker expression throughout regeneration. Sustained loss of HNF4α target gene expression throughout regeneration indicated that HNF4α-KO mice were unable to compensate for loss of HNF4α transcriptional activity. Deletion of HNF4α resulted in sustained proliferation accompanied by c-Myc and cyclin D1 overexpression and a complete deficiency of hepatocyte function after PH. Interestingly, overexpression of degradation-resistant HNF4α in hepatocytes delayed, but did not prevent, initiation of regeneration after PH. Finally, adeno-associated virus serotype 8 (AAV8)-mediated reexpression of HNF4α in hepatocytes of HNF4α-KO mice post-PH restored HNF4α protein levels, induced target gene expression, and improved survival of HNF4α-KO mice post-PH. Conclusion: In conclusion, these data indicate that HNF4α reexpression following initial decrease is critical for hepatocytes to exit from cell cycle and resume function during the termination phase of LR. These results indicate the role of HNF4α in LR and have implications for therapy of liver failure.

Neuronal cytoskeletal gene dysregulation and mechanical hypersensitivity in a rat model of Rett syndrome.

Children with Rett syndrome show abnormal cutaneous sensitivity. The precise nature of sensory abnormalities and underlying molecular mechanisms remain largely unknown. Rats with methyl-CpG binding protein 2 (MeCP2) mutation, characteristic of Rett syndrome, show hypersensitivity to pressure and cold, but hyposensitivity to heat. They also show cutaneous hyperinnervation by nonpeptidergic sensory axons, which include subpopulations encoding noxious mechanical and cold stimuli, whereas peptidergic thermosensory innervation is reduced. MeCP2 knockdown confined to dorsal root ganglion sensory neurons replicated this phenotype in vivo, and cultured MeCP2-deficient ganglion neurons showed augmented axonogenesis. Transcriptome analysis revealed dysregulation of genes associated with cytoskeletal dynamics, particularly those controlling actin polymerization and focal-adhesion formation necessary for axon growth and mechanosensory transduction. Down-regulation of these genes by topoisomerase inhibition prevented abnormal axon sprouting. We identified eight key affected genes controlling actin signaling and adhesion formation, including members of the Arhgap, Tiam, and cadherin families. Simultaneous virally mediated knockdown of these genes in Rett rats prevented sensory hyperinnervation and reversed mechanical hypersensitivity, indicating a causal role in abnormal outgrowth and sensitivity. Thus, MeCP2 regulates ganglion neuronal genes controlling cytoskeletal dynamics, which in turn determines axon outgrowth and mechanosensory function and may contribute to altered pain sensitivity in Rett syndrome.