Publications by authors named "Natasza A Kurpios"

17 Publications

  • Page 1 of 1

The asymmetric Pitx2 gene regulates gut muscular-lacteal development and protects against fatty liver disease.

Cell Rep 2021 Nov;37(8):110030

Department of Molecular Medicine, College of Veterinary Medicine, Cornell, Ithaca, NY 14853, USA. Electronic address:

Intestinal lacteals are essential lymphatic channels for absorption and transport of dietary lipids and drive the pathogenesis of debilitating metabolic diseases. However, organ-specific mechanisms linking lymphatic dysfunction to disease etiology remain largely unknown. In this study, we uncover an intestinal lymphatic program that is linked to the left-right (LR) asymmetric transcription factor Pitx2. We show that deletion of the asymmetric Pitx2 enhancer ASE alters normal lacteal development through the lacteal-associated contractile smooth muscle lineage. ASE deletion leads to abnormal muscle morphogenesis induced by oxidative stress, resulting in impaired lacteal extension and defective lymphatic system-dependent lipid transport. Surprisingly, activation of lymphatic system-independent trafficking directs dietary lipids from the gut directly to the liver, causing diet-induced fatty liver disease. Our study reveals the molecular mechanism linking gut lymphatic function to the earliest symmetry-breaking Pitx2 and highlights the important relationship between intestinal lymphangiogenesis and the gut-liver axis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.celrep.2021.110030DOI Listing
November 2021

Multiomic analysis defines the first microRNA atlas across all small intestinal epithelial lineages and reveals novel markers of almost all major cell types.

Am J Physiol Gastrointest Liver Physiol 2021 12 13;321(6):G668-G681. Epub 2021 Oct 13.

Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York.

MicroRNA-mediated regulation is critical for the proper development and function of the small intestinal (SI) epithelium. However, it is not known which microRNAs are expressed in each of the cell types of the SI epithelium. To bridge this important knowledge gap, we performed comprehensive microRNA profiling in all major cell types of the mouse SI epithelium. We used flow cytometry and fluorescence-activated cell sorting with multiple reporter mouse models to isolate intestinal stem cells, enterocytes, goblet cells, Paneth cells, enteroendocrine cells, tuft cells, and secretory progenitors. We then subjected these cell populations to small RNA-sequencing. The resulting atlas revealed highly enriched microRNA markers for almost every major cell type (https://sethupathy-lab.shinyapps.io/SI_miRNA/). Several of these lineage-enriched microRNAs (LEMs) were observed to be embedded in annotated host genes. We used chromatin-run-on sequencing to determine which of these LEMs are likely cotranscribed with their host genes. We then performed single-cell RNA-sequencing to define the cell type specificity of the host genes and embedded LEMs. We observed that the two most enriched microRNAs in secretory progenitors are miR-1224 and miR-672, the latter of which we found is deleted in hominin species. Finally, using several in vivo models, we established that miR-152 is a Paneth cell-specific microRNA. In this study, first, microRNA atlas (and searchable web server) across all major small intestinal epithelial cell types is presented. We have demonstrated microRNAs that uniquely mark several lineages, including enteroendocrine and tuft. Identification of a key marker of mouse secretory progenitor cells, miR-672, which we show is deleted in humans. We have used several in vivo models to establish miR-152 as a specific marker of Paneth cells, which are highly understudied in terms of microRNAs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/ajpgi.00222.2021DOI Listing
December 2021

Enteroendocrine Progenitor Cell-Enriched miR-7 Regulates Intestinal Epithelial Proliferation in an Xiap-Dependent Manner.

Cell Mol Gastroenterol Hepatol 2020 19;9(3):447-464. Epub 2019 Nov 19.

Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York. Electronic address:

Background & Aims: The enteroendocrine cell (EEC) lineage is important for intestinal homeostasis. It was recently shown that EEC progenitors contribute to intestinal epithelial growth and renewal, but the underlying mechanisms remain poorly understood. MicroRNAs are under-explored along the entire EEC lineage trajectory, and comparatively little is known about their contributions to intestinal homeostasis.

Methods: We leverage unbiased sequencing and eight different mouse models and sorting methods to identify microRNAs enriched along the EEC lineage trajectory. We further characterize the functional role of EEC progenitor-enriched miRNA, miR-7, by in vivo dietary study as well as ex vivo enteroid in mice.

Results: First, we demonstrate that miR-7 is highly enriched across the entire EEC lineage trajectory and is the most enriched miRNA in EEC progenitors relative to Lgr5+ intestinal stem cells. Next, we show in vivo that in EEC progenitors miR-7 is dramatically suppressed under dietary conditions that favor crypt division and suppress EEC abundance. We then demonstrate by functional assays in mouse enteroids that miR-7 exerts robust control of growth, as determined by budding (proxy for crypt division), EdU and PH3 staining, and likely regulates EEC abundance also. Finally, we show by single-cell RNA sequencing analysis that miR-7 regulates Xiap in progenitor/stem cells and we demonstrate in enteroids that the effects of miR-7 on mouse enteroid growth depend in part on Xiap and Egfr signaling.

Conclusions: This study demonstrates for the first time that EEC progenitor cell-enriched miR-7 is altered by dietary perturbations and that it regulates growth in enteroids via intact Xiap and Egfr signaling.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcmgh.2019.11.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7021555PMC
May 2021

Coronary Arteries Shake Up Developmental Dogma.

Dev Cell 2018 12;47(6):680-681

Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. Electronic address:

The leading cause of death worldwide is disease of the coronary arteries, the vessels that nourish the heart muscle. However, mechanisms that control their development and possible regeneration remain unknown. Recent work is challenging current dogma of coronary artery origins and illuminating key programs that govern coronary artery formation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.devcel.2018.11.044DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8273883PMC
December 2018

Midgut Laterality Is Driven by Hyaluronan on the Right.

Dev Cell 2018 09 30;46(5):533-551.e5. Epub 2018 Aug 30.

Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. Electronic address:

For many years, biologists have focused on the role of Pitx2, expressed on the left side of developing embryos, in governing organ laterality. Here, we identify a different pathway during left-right asymmetry initiated by the right side of the embryo. Surprisingly, this conserved mechanism is orchestrated by the extracellular glycosaminoglycan, hyaluronan (HA) and is independent of Pitx2 on the left. Whereas HA is normally synthesized bilaterally as a simple polysaccharide, we show that covalent modification of HA by the enzyme Tsg6 on the right triggers distinct cell behavior necessary to drive the conserved midgut rotation and to pattern gut vasculature. HA disruption in chicken and Tsg6 mice results in failure to initiate midgut rotation and perturbs vascular development predisposing to midgut volvulus. Our study leads us to revise the current symmetry-breaking paradigm in vertebrates and demonstrates how enzymatic modification of HA matrices can execute the blueprint of organ laterality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.devcel.2018.08.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6207194PMC
September 2018

Transcriptional regulation of cell shape during organ morphogenesis.

J Cell Biol 2018 09 30;217(9):2987-3005. Epub 2018 Jul 30.

Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY

The emerging field of transcriptional regulation of cell shape changes aims to address the critical question of how gene expression programs produce a change in cell shape. Together with cell growth, division, and death, changes in cell shape are essential for organ morphogenesis. Whereas most studies of cell shape focus on posttranslational events involved in protein organization and distribution, cell shape changes can be genetically programmed. This review highlights the essential role of transcriptional regulation of cell shape during morphogenesis of the heart, lungs, gastrointestinal tract, and kidneys. We emphasize the evolutionary conservation of these processes across different model organisms and discuss perspectives on open questions and research avenues that may provide mechanistic insights toward understanding birth defects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1083/jcb.201612115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6122985PMC
September 2018

Morphogenesis: Eternal truth or ephemeral beauty.

Dev Dyn 2016 Mar 30;245(3):189. Epub 2016 Jan 30.

College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/dvdy.24381DOI Listing
March 2016

Chromatin Architecture of the Pitx2 Locus Requires CTCF- and Pitx2-Dependent Asymmetry that Mirrors Embryonic Gut Laterality.

Cell Rep 2015 Oct 24;13(2):337-49. Epub 2015 Sep 24.

Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. Electronic address:

Expression of Pitx2 on the left side of the embryo patterns left-right (LR) organs including the dorsal mesentery (DM), whose asymmetric cell behavior directs gut looping. Despite the importance of organ laterality, chromatin-level regulation of Pitx2 remains undefined. Here, we show that genes immediately neighboring Pitx2 in chicken and mouse, including a long noncoding RNA (Pitx2 locus-asymmetric regulated RNA or Playrr), are expressed on the right side and repressed by Pitx2. CRISPR/Cas9 genome editing of Playrr, 3D fluorescent in situ hybridization (FISH), and variations of chromatin conformation capture (3C) demonstrate that mutual antagonism between Pitx2 and Playrr is coordinated by asymmetric chromatin interactions dependent on Pitx2 and CTCF. We demonstrate that transcriptional and morphological asymmetries driving gut looping are mirrored by chromatin architectural asymmetries at the Pitx2 locus. We propose a model whereby Pitx2 auto-regulation directs chromatin topology to coordinate LR transcription of this locus essential for LR organogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.celrep.2015.08.075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4617833PMC
October 2015

The left-right Pitx2 pathway drives organ-specific arterial and lymphatic development in the intestine.

Dev Cell 2014 Dec 4;31(6):690-706. Epub 2014 Dec 4.

Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. Electronic address:

The dorsal mesentery (DM) is the major conduit for blood and lymphatic vessels in the gut. The mechanisms underlying their morphogenesis are challenging to study and remain unknown. Here we show that arteriogenesis in the DM begins during gut rotation and proceeds strictly on the left side, dependent on the Pitx2 target gene Cxcl12. Although competent Cxcr4-positive angioblasts are present on the right, they fail to form vessels and progressively emigrate. Surprisingly, gut lymphatics also initiate in the left DM and arise only after-and dependent on-arteriogenesis, implicating arteries as drivers of gut lymphangiogenesis. Our data begin to unravel the origin of two distinct vascular systems and demonstrate how early left-right molecular asymmetries are translated into organ-specific vascular patterns. We propose a dual origin of gut lymphangiogenesis in which prior arterial growth is required to initiate local lymphatics that only subsequently connect to the vascular system.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.devcel.2014.11.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4326534PMC
December 2014

Integration of left-right Pitx2 transcription and Wnt signaling drives asymmetric gut morphogenesis via Daam2.

Dev Cell 2013 Sep;26(6):629-44

Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.

A critical aspect of gut morphogenesis is initiation of a leftward tilt, and failure to do so leads to gut malrotation and volvulus. The direction of tilt is specified by asymmetric cell behaviors within the dorsal mesentery (DM), which suspends the gut tube, and is downstream of Pitx2, the key transcription factor responsible for the transfer of left-right (L-R) information from early gastrulation to morphogenesis. Although Pitx2 is a master regulator of L-R organ development, its cellular targets that drive asymmetric morphogenesis are not known. Using laser microdissection and targeted gene misexpression in the chicken DM, we show that Pitx2-specific effectors mediate Wnt signaling to activate the formin Daam2, a key Wnt effector and itself a Pitx2 target, linking actin dynamics to cadherin-based junctions to ultimately generate asymmetric cell behaviors. Our work highlights how integration of two conserved cascades may be the ultimate force through which Pitx2 sculpts L-R organs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.devcel.2013.07.019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3965270PMC
September 2013

Single unpurified breast tumor-initiating cells from multiple mouse models efficiently elicit tumors in immune-competent hosts.

PLoS One 2013 26;8(3):e58151. Epub 2013 Mar 26.

Centre for Functional Genomics, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.

The tumor-initiating cell (TIC) frequency of bulk tumor cell populations is one of the criteria used to distinguish malignancies that follow the cancer stem cell model from those that do not. However, tumor-initiating cell frequencies may be influenced by experimental conditions and the extent to which tumors have progressed, parameters that are not always addressed in studies of these cells. We employed limiting dilution cell transplantation of minimally manipulated tumor cells from mammary tumors of several transgenic mouse models to determine their tumor-initiating cell frequency. We determined whether the tumors that formed following tumor cell transplantation phenocopied the primary tumors from which they were isolated and whether they could be serially transplanted. Finally we investigated whether propagating primary tumor cells in different tissue culture conditions affected their resident tumor-initiating cell frequency. We found that tumor-initiating cells comprised between 15% and 50% of the bulk tumor cell population in multiple independent mammary tumors from three different transgenic mouse models of breast cancer. Culture of primary mammary tumor cells in chemically-defined, serum-free medium as non-adherent tumorspheres preserved TIC frequency to levels similar to that of the primary tumors from which they were established. By contrast, propagating the primary tumor cells in serum-containing medium as adherent populations resulted in a several thousand-fold reduction in their tumor-initiating cell fraction. Our findings suggest that experimental conditions, including the sensitivity of the transplantation assay, can dramatically affect estimates of tumor initiating cell frequency. Moreover, conditional on cell culture conditions, the tumor-initiating cell fraction of bulk mouse mammary tumor cell preparations can either be maintained at high or low frequency in vitro thus permitting comparative studies of tumorigenic and non-tumorigenic cancer cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0058151PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3608640PMC
September 2013

On the growth and form of the gut.

Nature 2011 Aug 3;476(7358):57-62. Epub 2011 Aug 3.

School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.

The developing vertebrate gut tube forms a reproducible looped pattern as it grows into the body cavity. Here we use developmental experiments to eliminate alternative models and show that gut looping morphogenesis is driven by the homogeneous and isotropic forces that arise from the relative growth between the gut tube and the anchoring dorsal mesenteric sheet, tissues that grow at different rates. A simple physical mimic, using a differentially strained composite of a pliable rubber tube and a soft latex sheet is consistent with this mechanism and produces similar patterns. We devise a mathematical theory and a computational model for the number, size and shape of intestinal loops based solely on the measurable geometry, elasticity and relative growth of the tissues. The predictions of our theory are quantitatively consistent with observations of intestinal loops at different stages of development in the chick embryo. Our model also accounts for the qualitative and quantitative variation in the distinct gut looping patterns seen in a variety of species including quail, finch and mouse, illuminating how the simple macroscopic mechanics of differential growth drives the morphology of the developing gut.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nature10277DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3335276PMC
August 2011

The Pea3 Ets transcription factor regulates differentiation of multipotent progenitor cells during mammary gland development.

Dev Biol 2009 Jan 18;325(1):106-21. Epub 2008 Oct 18.

Department of Biochemistry and Biomedical Sciences, Centre for Functional Genomics, McMaster University, Hamilton, Ontario, Canada.

The Pea3 Ets transcription factor is overexpressed in breast tumors suggesting that it plays a role in mammary oncogenesis. However, the normal biological function of Pea3 in the mammary gland is not known. Here we report that Pea3 was expressed in the epithelium of the mouse mammary anlagen commensurate with their genesis, and at later times in the nipple and mammary ducts of female embryos. In adult mice Pea3 transcripts peaked at the onset of puberty and early pregnancy, times of active epithelial cell proliferation and differentiation. Pea3 was expressed in all progenitor cap cells and rare body cells of terminal end buds, and in the myoepithelial cells of ducts and alveoli. Analyses of the mammary glands of Pea3-null mice during puberty revealed an increased number of terminal end buds and an increased fraction of proliferating progenitor cells within these structures compared to their wild type littermates. Tissue transplant experiments demonstrated that these phenotypes were intrinsic to the Pea3-null mammary epithelium. During pregnancy, mammary glands isolated from Pea3-null females had impaired alveolar development as revealed by a decreased fraction of alveolar structures. We performed in vitro colony forming assays of mammary epithelial cells and discovered that loss of Pea3 altered the distribution of specific multipotent progenitor cells. Double-immunofluorescence confirmed that multipotential progenitors co-expressing markers of the myoepithelial and luminal epithelial lineage were amplified in the mammary glands of Pea3-null mice by comparison to their wild type counterparts. We propose that Pea3 functions in multipotential progenitors to regulate their lineage-specific differentiation potential.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ydbio.2008.09.033DOI Listing
January 2009

The chirality of gut rotation derives from left-right asymmetric changes in the architecture of the dorsal mesentery.

Dev Cell 2008 Jul;15(1):134-45

Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.

We have investigated the structural basis by which the counterclockwise direction of the amniote gut is established. The chirality of midgut looping is determined by left-right asymmetries in the cellular architecture of the dorsal mesentery, the structure that connects the primitive gut tube to the body wall. The mesenchymal cells of the dorsal mesentery are more condensed on the left side than on the right and, additionally, the overlying epithelium on the left side exhibits a columnar morphology, in contrast to a cuboidal morphology on the right. These properties are instructed by a set of transcription factors: Pitx2 and Isl1 specifically expressed on the left side, and Tbx18 expressed on the right, regulated downstream of the secreted protein Nodal which is present exclusively on the left side. The resultant differences in cellular organization cause the mesentery to assume a trapezoidal shape, tilting the primitive gut tube leftward.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.devcel.2008.05.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2528248PMC
July 2008

The direction of gut looping is established by changes in the extracellular matrix and in cell:cell adhesion.

Proc Natl Acad Sci U S A 2008 Jun 23;105(25):8499-506. Epub 2008 Jun 23.

Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.

The counterclockwise coiling of the intestines is initiated by a leftward tilt of the primitive gut tube, imparted by left-right asymmetries in the architecture of the dorsal mesentery. In silico analysis suggests that this is achieved by synergistic changes in its epithelium and mesenchyme. Within the mesenchymal compartment, cells are more densely packed on the left than on the right. In silico results indicate that this property can result from asymmetries in both extracellular matrix (ECM) and cell:cell adhesion. We find that the dorsal mesentery ECM is indeed left-right asymmetric and moreover that the adhesion molecule N-cadherin is expressed exclusively on the left side. These asymmetries are regulated by the asymmetrically expressed transcription factors Pitx2 and Isl1. Functional studies demonstrate that N-cadherin acts upstream of the changes in the ECM and is both necessary and sufficient to explain the asymmetric packing of the mesenchymal cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.0803578105DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2438376PMC
June 2008

Targeted disruption of beta1-integrin in a transgenic mouse model of human breast cancer reveals an essential role in mammary tumor induction.

Cancer Cell 2004 Aug;6(2):159-70

Department of Medical Sciences, McMaster University, Hamilton, Ontario, L8S 4K1, Canada.

Despite evidence demonstrating the role of beta1-integrin in the regulation of cancer cell proliferation in vitro, the importance of this cell adhesion receptor during the initiation and progression of epithelial tumors in vivo remains unclear. Here we have used the Cre/LoxP1 recombination system to disrupt beta1-integrin function in the mammary epithelium of a transgenic mouse model of human breast cancer. Using this approach, we show that beta1-integrin expression is critical for the initiation of mammary tumorigenesis in vivo, and for maintaining the proliferative capacity of late-stage tumor cells. These observations provide a direct demonstration that beta1-integrin plays a critical role in both the initiation and maintenance of mammary tumor growth in vivo.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ccr.2004.06.025DOI Listing
August 2004

Function of PEA3 Ets transcription factors in mammary gland development and oncogenesis.

J Mammary Gland Biol Neoplasia 2003 Apr;8(2):177-90

Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada.

The Ets gene families of mice and man currently comprise 27 genes that encode sequence-specific transcription factors. Ets proteins share an approximately 85 amino acid structurally conserved ETS DNA binding domain. Genetic analyses in model organisms suggest roles for Ets proteins in embryonic development and various adult physiological processes. Chromosomal translocations involving several ETS genes are associated with Ewing's sarcomas and leukemias, whereas the overexpression of some ETS genes is linked with numerous malignancies, including breast cancer. Indeed PEA3, ETS-1, PDEF, and ELF-3 transcripts have all been reported to be elevated in human breast tumors. Some of the ETS genes that are overexpressed in human breast tumors are also overexpressed in mouse models of this disease. Notably, pea3, as well as its close paralogs er81 and erm, which comprise the pea3 subfamily of ets genes, are coordinately overexpressed in mouse mammary tumors. Genetic analyses in mice reveal required roles for one or more of the PEA3 subfamily Ets proteins in the initiation and progression of mouse mammary tumors. The pea3 subfamily genes are normally expressed in the primitive epithelium of mouse mammary buds during embryogenesis, and these three genes are expressed in epithelial progenitor cells during postnatal mammary gland development. Loss-of-function mutations in the mouse pea3 gene results in increased numbers of terminal end buds and an increased fraction of proliferating cells in these structures, suggesting a role for PEA3 in progenitor cell renewal or terminal differentiation. Taken together these observations suggest that the PEA3 subfamily proteins play key regulatory roles in both mammary gland development and oncogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1023/a:1025948823955DOI Listing
April 2003
-->