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Biology subjects

Fisch, K. M.

Publications and source records attributed to Fisch, K. M..

7 recordsLinked to original sources

Ovarian Tumor FAK Inhibition Releases Omega-3 Fatty Acids Stimulating GATA6 Peritoneal Macrophage CXCL13 Production Enhancing Immunotherapy

High grade serous ovarian cancer (HGSOC) is the most lethal gynecologic malignancy in the USA due to chemo- and immuno-therapy resistance. We show that focal adhesion kinase (FAK) inhibition with ifebemtinib or tumor genetic FAK knockout (KO) in syngeneic ovarian tumor models stimulated resident large peritoneal macrophages to express CXCL13 chemokine and promoted B cell infiltration. Macrophage GATA6 inactivation prevented CXCL13 expression and enhanced FAK-KO tumor growth. Combining ifebemtinib with pegylated doxorubicin chemotherapy and anti-TIGIT immune checkpoint antibody extended survival with tumor-associated tertiary lymphoid structure formation. Mechanistically, FAK-KO heat-treated conditioned media contained exosomes enriched with omega-3 fatty acids which stimulated macrophage CXCL13 production. Ifebemtinib-treated tumors, FAK-KO exosomes, and purified eicosapentaenoic acid enhanced murine and human HGSOC-associated tumor macrophage reprogramming and CXCL13 expression. Overall, our studies define a tumor to macrophage signaling linkage via omega-3 exosome lipids supporting B cell recruitment, survival, immunotherapy enhancement, and actionable via small molecule FAK inhibition. eTOC BlurbHigh-grade serous ovarian cancer remains difficult to treat due to therapy resistance. Chen et. al. reveal that tumor FAK inhibition educates macrophages to express CXCL13 associated with B cell infiltration - highlighting a new therapeutic pathway linking FAK inhibition, omega-3 fatty acid containing exosomes, and macrophage mediated anti-tumor activation. Bullet pointsO_LIGenetic or small molecule FAK inhibition enhances ovarian tumor B cell infiltration C_LIO_LITumor FAK inhibition stimulates GATA6+ macrophages to make CXCL13 C_LIO_LIFAKi, pegylated doxorubicin and anti-TIGIT promote tertiary lymphoid structures C_LIO_LIOmega-3 fatty acids stimulate human HGSOC ascites macrophages to make CXCL13 C_LI

cancer biology↗

VGLL1 contributes to both the transcriptome and epigenome of the developing trophoblast compartment

The trophectoderm (TE), the first lineage specified during mammalian development, initiates implantation and gives rise to placental trophoblasts. While animal models have elucidated key conserved signaling pathways involved in early TE specification, including BMP, WNT, and HIPPO, species-specific differences during early development emphasize the need for human-specific models. We previously identified VGLL1, a coactivator of TEAD transcription factors, as a human-specific placental marker. In this study, we employed a pluripotent stem cell (PSC)-based model of TE induction by BMP4 to investigate chromatin remodeling and transcriptional dynamics during TE formation. BMP4-induced chromatin accessibility changes promoted a trophoblast gene expression program, while mesoderm lineage markers were only transiently expressed upon canonical WNT activation. We found that VGLL1 was expressed downstream of key TE transcription factors (GATA2/3, TFAP2A/C) but was essential for establishment of full trophoblast identity by up-regulating EGFR and reinforcing GATA3 expression through positive feedback. Notably, VGLL1 enhanced canonical WNT signaling via direct regulation of WNT receptors and effectors. We also identified KDM6B, a histone demethylase that removes H3K27me3 repressive marks, as a direct VGLL1 target. KDM6B facilitated activation of bivalent promoters associated with TE markers, linking epigenetic regulation to lineage identity. Our findings establish a mechanistic framework positioning VGLL1 as a central regulator that integrates HIPPO, BMP, and WNT signaling pathways to drive establishment of human TE. Statement of SignificanceEarly development of the human placenta is essential for pregnancy success, yet the mechanisms that guide placental lineage specification remain poorly defined. Using human stem cells, we show how signaling pathways and chromatin remodeling programs work together to direct formation of the trophectoderm, the earliest placental cell type. We identify VGLL1 as a key regulator linking multiple signaling networks to gene expression and epigenetic control. Our findings reveal a species-specific mechanism of placental initiation with broad implications for understanding reproductive disorders, pregnancy loss, and advancing stem cell-based models to study and potentially treat human placental disease.

developmental biology↗

Cell-associated Transcriptional Alterations in the Retinal of Alzheimer's Disease

Current approaches for studying pathologic changes in the retina associated with Alzheimers Disease (AD) remain heterogeneous, limiting the use of retinal amyloid-beta as a viable biomarker for AD. Transcriptomic profiling of the retina has provided cell-specific insight into AD progression in the brain yet is lacking in the retina. In this study, we implemented a non-biased approach through next generation sequencing to profile frozen archived retinal tissues from autopsy/pathologically confirmed AD and non-diagnosed cases (NonAD). A total of 37,211 nuclei were isolated from frozen retinal tissue punches originating from AD, and 31,326 were isolated from non-diagnosed cases. Gene expression patterns specific to the retinal region and major retinal cell types were represented in both tissue groups. AD-associated genes were differentially expressed in AD retinal glial cells, including microglia. A greater percentage of microglial nuclei from AD retinal nuclei expressed TYRO protein tyrosine kinase-binding protein (TYROBP) compared to nonAD retinal nuclei. However, compared to microglia from single retinal cell datasets from elderly non-diseased individuals, TYROBP expression is highly expressed in the single cell data set, indicating TYROBP transcripts reside within the cytoplasm. However, other AD-associated genes were differentially expressed in AD nuclei such as DOCK2, PICALM, and PLCG2 compared to non-diseased single-cell microglia, implicating a role of these genes in the AD retina. To summarize, we extracted a high number of nuclei from frozen retinal tissue that retain specific gene markers for cell classification and highlighted candidate AD-associated genes in retinal microglia that may be viable in future AD retinal studies.

neuroscience↗

NASA GeneLab RNA-Seq Consensus Pipeline: Standardized Processing of Short-Read RNA-Seq Data

With the development of transcriptomic technologies, we are able to quantify precise changes in gene expression profiles from astronauts and other organisms exposed to spaceflight. Members of NASA GeneLab and GeneLab-associated analysis working groups (AWGs) have developed a consensus pipeline for analyzing short-read RNA-sequencing data from spaceflight-associated experiments. The pipeline includes quality control, read trimming, mapping, and gene quantification steps, culminating in the detection of differentially expressed genes. This data analysis pipeline and the results of its execution using data submitted to GeneLab are now all publicly available through the GeneLab database. We present here the full details and rationale for the construction of this pipeline in order to promote transparency, reproducibility and reusability of pipeline data, to provide a template for data processing of future spaceflight-relevant datasets, and to encourage cross-analysis of data from other databases with the data available in GeneLab.

bioinformatics↗

AGE IS ASSOCIATED WITH INCREASED EXPRESSION OF PATTERN RECOGNITION RECEPTOR GENES AND ACE2, THE RECEPTOR FOR SARS-COV-2: IMPLICATIONS FOR THE EPIDEMIOLOGY OF COVID-19 DISEASE

Older aged adults and those with pre-existing conditions are at highest risk for severe COVID-19 associated outcomes. Using a large dataset of genome-wide RNA-seq profiles derived from human dermal fibroblasts (GSE113957) we investigated whether age affects the expression of pattern recognition receptor (PRR) genes and ACE2, the receptor for SARS-CoV-2. Older age was associated with increased expression of PRR genes, ACE2 and four genes that encode proteins that have been shown to interact with SAR2-CoV-2 proteins. Assessment of PRR expression might provide a strategy for stratifying the risk of severe COVID-19 disease at both the individual and population levels.

molecular biology↗

FAK activity sustains intrinsic and acquired ovarian cancer resistance to platinum chemotherapy

Gene copy number changes, cancer stem cell (CSC) increases, and platinum chemotherapy resistance contribute to poor prognosis in patients with recurrent high grade serous ovarian cancer (HGSOC). CSC phenotypes involving Wnt-{beta}-catenin and aldehyde dehydrogenase activities, platinum resistance, and tumor initiating frequency are here associated with spontaneous genetic gains, including genes encoding KRAS, MYC and FAK, in a new murine model of ovarian cancer (KMF). Noncanonical FAK signaling was sufficient to sustain human and KMF tumorsphere proliferation, CSC survival, and platinum resistance. Increased FAK tyrosine phosphorylation occurred in HGSOC patient tumors surviving neo-adjuvant platinum and paclitaxel chemotherapy and platinum resistant tumorspheres acquired FAK dependence for growth. Importantly, combining a pharmacologic FAK inhibitor with platinum overcame chemoresistance and triggered apoptosis in vitro and in vivo. Knockout, rescue, genomic and transcriptomic analyses collectively identified more than 400 genes regulated along a FAK/{beta}-catenin/Myc axis impacting stemness and DNA repair in HGSOC, with 66 genes gained in a majority of Cancer Genome Atlas samples. Together, these results support combinatorial testing of FAK inhibitors for the treatment of recurrent ovarian cancer.\n\nGraphical Summary\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=125 SRC=\"FIGDIR/small/594184_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (52K):\norg.highwire.dtl.DTLVardef@20c737org.highwire.dtl.DTLVardef@1f714faorg.highwire.dtl.DTLVardef@823560org.highwire.dtl.DTLVardef@7e6219_HPS_FORMAT_FIGEXP M_FIG C_FIG Key PointsO_LIHigh grade serous ovarian carcinoma tumors contain PTK2 (FAK) 8q24.3 gains associated with prognostic differences.\nC_LIO_LIKMF, a new murine ovarian cancer model with K-Ras, Myc, and FAK gene gains and intrinsic platinum resistance.\nC_LIO_LIFAK activation in tumors surviving platinum chemotherapy promotes cancer stem cell survival.\nC_LIO_LIFAK facilitates a {beta}-catenin-Myc signaling axis controlling gene expression supporting platinum resistance.\nC_LIO_LIFAK activity is essential for KMF tumor growth and is a targetable cellular adaptation of platinum resistance.\nC_LI

cancer biology↗

Perturbed functional networks in Alzheimers Disease reveal opposing roles for TGIF and EGR3

While Alzheimers disease (AD) is the most prevalent cause of dementia, complex combinations of the underlying pathologies have led to evolved concepts in clinical and neuropathological criteria in the past decade. Pathological AD can be decomposed into subsets of individuals with significantly different antemortem cognitive decline rates. Using transcriptome as a proxy for functional state, we preselected 414 expression profiles of clinically and neuropathologically confirmed AD subjects and age matched non-demented controls sampled from a large community based neuropathological study. By combining brain tissue specific protein interactome with gene network, we identify functionally distinct composite clusters of genes which reveal extensive changes in expression levels in AD. The average global expression for clusters corresponding to synaptic transmission, metabolism, cell cycle, survival and immune response were downregulated while the upregulated cluster had a large set of uncharacterized pathways and processes that may constitute an AD specific phenotypic signature. We identified four master regulators across all clusters of differentially expressed genes by enrichment analysis including TGIF1 and EGR3. These transcription factors have previously not been associated with AD and were validated in brain tissue samples from an independent AD cohort. We identify TGIF1, a transcriptional repressor as being neuroprotective in AD by activating co-repressors regulating genes critical for DNA repair, maintaining homeostasis and arresting cell cycle. In addition, we show that loss of EGR3 regulation, mediates synaptic deficits by targeting the synaptic vesicle cycle. Collectively, our results highlight the utility of integrating protein interactions with gene perturbations to generate a comprehensive framework for characterizing the alterations in molecular network as applied to AD.

bioinformatics↗