The histone demethylase JMJD2A/KDM4A facilitates prostate cancer development, yet how JMJD2A function is regulated has remained elusive. Here, we demonstrate that SET7/9-mediated methylation on 6 lysine residues modulated JMJD2A. Joint mutation of these lysine residues suppressed JMJD2A’s ability to stimulate the MMP1 matrix metallopeptidase promoter upon recruitment by the ETV1 transcription factor. Mutation of just 3 methylation sites (K505, K506, and K507) to arginine residues (3xR mutation) was sufficient to maximally reduce JMJD2A transcriptional activity and also decreased its binding to ETV1. Introduction of the 3xR mutation into DU145 prostate cancer cells reduced in vitro growth and invasion and also severely compromised tumorigenesis. Consistently, the 3xR genotype caused transcriptome changes related to cell proliferation and invasion pathways, including downregulation of MMP1 and the NPM3 nucleophosmin/nucleoplasmin gene. NPM3 downregulation phenocopied and its overexpression rescued, to a large degree, the 3xR mutation in DU145 cells, suggesting that NPM3 was a seminal downstream effector of methylated JMJD2A. Moreover, we found that NPM3 was overexpressed in prostate cancer and might be indicative of disease aggressiveness. SET7/9-mediated lysine methylation of JMJD2A may aggravate prostate tumorigenesis in a manner dependent on NPM3, implying that the SET7/9→JMJD2A→NPM3 axis could be targeted for therapy.
Ruicai Gu, Tae-Dong Kim, Hoogeun Song, Yuan Sui, Sook Shin, Sangphil Oh, Ralf Janknecht
MTORC1 integrates signaling from the immune microenvironment to regulate T cell activation, differentiation, and function. TSC2 in the tuberous sclerosis complex tightly regulates mTORC1 activation. CD8+ T cells lacking TSC2 have constitutively enhanced mTORC1 activity and generate robust effector T cells; however sustained mTORC1 activation prevents generation of long-lived memory CD8+ T cells. Here we show manipulating TSC2 at Ser1365 potently regulates activated but not basal mTORC1 signaling in CD8+ T cells. Unlike non-stimulated TSC2 knockout cells, CD8+ T cells expressing a phospho-silencing mutant TSC2-S1365A (SA) retain normal basal mTORC1 activity. PKC and T-cell Receptor (TCR) stimulation induces TSC2 S1365 phosphorylation and preventing this with the SA mutation markedly increases mTORC1 activation and T-cell effector function. Consequently, SA CD8+ T cells display greater effector responses while retaining their capacity to become long-lived memory T cells. SA CD8+ T cells also display enhanced effector function under hypoxic and acidic conditions. In murine and human solid-tumor models, CD8+ SA T cells used as adoptive cell therapy display greater anti-tumor immunity than WT CD8+ T cells. These findings reveal an upstream mechanism to regulate mTORC1 activity in T cells. The TSC2-SA mutation enhances both T cell effector function and long-term persistence/memory formation, supporting an approach to engineer better CAR-T cells for treating cancer.
Chirag H. Patel, Yi Dong, Navid Koleini, Xiaoxu Wang, Brittany L. Dunkerly-Eyring, Jiayu Wen, Mark J. Ranek, Laura M. Bartle, Daniel B. Henderson, Jason G. Sagert, David A. Kass, Jonathan D. Powell
Factor inhibiting HIF (FIH) is an asparagine hydroxylase that acts on hypoxia inducible factors (HIFs) to control cellular adaptation to hypoxia. FIH is expressed in several tumor types, but its impact in tumor progression remains largely unexplored. We observed that FIH was expressed on human lung cancer tissue. Deletion of FIH in mouse and human lung cancer cells resulted in an increased glycolytic metabolism, consistent with increased HIF activity. FIH-deficient lung cancer cells exhibited decreased proliferation. Analysis of RNA-seq data confirmed changes in the cell cycle and survival, and revealed molecular pathways that were dysregulated in the absence of FIH including the upregulation of angiomotin (Amot), a key component of the Hippo tumor suppressor pathway. We show that FIH-deficient tumors were characterized by higher immune infiltration of NK and T cells compared to FIH competent tumor cells. In vivo studies demonstrated that FIH deletion resulted in reduced tumor growth and metastatic capacity. Moreover, high FIH expression correlated with poor overall survival in non-small cell lung cancer (NSCLC). Together, our data unravel FIH as a therapeutic target for the treatment of lung cancer.
Ana García-del Río, Endika Prieto-Fernández, Leire Egia-Mendikute, Asier Antoñana-Vildosola, Borja Jimenez-Lasheras, So Young Lee, Adrián Barreira-Manrique, Samanta Romina Zanetti, Ander de Blas, Paloma Velasco-Beltrán, Alexandre Bosch, Ana M. Aransay, Asis Palazon
Epithelial Na+ channels (ENaCs) control extracellular fluid volume by facilitating Na+ absorption across transporting epithelia. In vitro studies showed that Cys-palmitoylation of the γ ENaC subunit is a major regulator of channel activity. We tested whether γ subunit palmitoylation sites are necessary for channel function in vivo by generating mice lacking the palmitoylated cysteines (γC33A,C41A) using CRISPR-Cas9 technology. ENaCs in dissected kidney tubules from γC33A,C41A mice had reduced open probability compared to wild type (WT) littermates maintained on either standard or Na+-deficient diets. Male mutant mice also had higher aldosterone levels than WT littermates following Na+ restriction. However, γC33A,C41A mice did not have reduced amiloride-sensitive Na+ currents in the distal colon or benzamil-induced natriuresis compared to WT mice. We identified a second, larger conductance cation channel in the distal nephron with biophysical properties distinct from ENaC. The activity of this channel was higher in Na+-restricted γC33A,C41A versus WT mice and was blocked by benzamil, providing a possible compensatory mechanism for reduced prototypic ENaC function. We conclude that γ subunit palmitoylation sites are required for prototypic ENaC activity in vivo, but are not necessary for amiloride/benzamil-sensitive Na+ transport in the distal nephron or colon.
Andrew J. Nickerson, Stephanie M. Mutchler, Shaohu Sheng, Natalie A. Cox, Evan C. Ray, Ossama B. Kashlan, Marcelo D. Carattino, Allison L. Marciszyn, Aaliyah Winfrey, Sebastien Gingras, Annet Kirabo, Rebecca P. Hughey, Thomas R. Kleyman
Superficial erythematous cutaneous vascular malformations are assumed to be blood vascular in origin, but cutaneous lymphatic malformations can contain blood and appear red. Management may be different and so an accurate diagnosis is important. Cutaneous malformations were investigated through 2D-histology and 3D-whole-mount-histology. Two lesions were clinically considered as port-wine birthmark, and another three lesions as erythematous telangiectasias. The aims were: i) to prove that cutaneous erythematous malformations including telangiectasia can represent a lymphatic phenotype, ii) to determine if lesions represent expanded but otherwise normal or malformed lymphatics, and iii) to determine if the presence of erythrocytes explained the red colour. Microscopy revealed all lesions as lymphatic structures. Port-wine birthmarks proved to be cystic lesions, with non-uniform lymphatic marker expression, and a disconnected lymphatic network suggesting a lymphatic malformation. Erythematous telangiectasias represented expanded but non-malformed lymphatics. Blood within lymphatics appeared to explain the colour. Blood-lymphatic-shunts could be detected in the erythematous telangiectasia. In conclusion, erythematous cutaneous capillary lesions may be lymphatic in origin but clinically indistinguishable from blood vascular malformations. Biopsy is advised for correct phenotyping and management. Erythrocytes are the likely explanation for colour accessing lymphatics through lympho-venous-shunts.
René Hägerling, Malou Van Zanten, Rose Yinghan Behncke, Sascha Ulferts, Nils R. Hansmeier, Bruno Märkl, Christian Witzel, Bernard Ho, Vaughan Keeley, Katie Riches, Sahar Mansour, Kristiana Gordon, Pia Ostergaard, Peter S. Mortimer
The identity and origin of the stem/progenitor cells for adult joint cartilage repair remain unknown, impeding therapeutic development. Simulating the common therapeutic modality for cartilage repair in humans, i.e., full-thickness microfracture joint surgery, we combined the mouse full-thickness injury model with lineage tracing and identified a distinct skeletal progenitor cell type enabling long-term (beyond 7 days after injury) articular cartilage repair in vivo. Deriving from a population with active Prg4 expression in adulthood while lacking aggrecan expression, these progenitors proliferate, differentiate to express aggrecan and type II collagen, and predominate in long-term articular cartilage wounds, where they represent the principal repair progenitors in situ under native repair conditions without cellular transplantation. They originate outside the adult bone marrow or superficial zone articular cartilage. These findings have implications for skeletal biology and regenerative medicine for joint injury repair.
Mei Massengale, Justin L. Massengale, Catherine R. Benson, Ninib Barywano, Toshihiko Oki, Matthew L. Steinhauser, Alissa Wang, Deepak Balani, Luke S. Oh, Mark A. Randolph, Thomas J. Gill III, Henry M. Kronenberg, David T. Scadden
Diabetic cardiomyopathy, an increasingly global epidemic and a major cause of heart failure with preserved ejection fraction (HFpEF), is associated with hyperglycemia, insulin resistance, and intra-cardiomyocyte calcium mishandling. Here we identify that, in db/db mice with type 2 diabetes induced HFpEF, abnormal remodeling of cardiomyocyte transverse-tubule microdomains occurs with downregulation of the membrane scaffolding protein cardiac bridging integrator 1 (cBIN1). Transduction of cBIN1 by AAV9 gene therapy can restore transverse-tubule microdomains to normalize intracellular distribution of calcium handling proteins and, surprisingly, glucose transporter 4 (GLUT4). Cardiac proteomics revealed that AAV9-cBIN1 normalizes components of calcium handling and GLUT4 translocation machineries. Functional studies further identified that AAV9-cBIN1 normalizes insulin-dependent glucose uptake in diabetic cardiomyocytes. Phenotypically, AAV9-cBIN1 rescues cardiac lusitropy, improves exercise intolerance, and ameliorates hyperglycemia in diabetic mice. Restoration of transverse-tubule microdomains can improve cardiac function in the setting of diabetic cardiomyopathy, and also improve systemic glycemic control.
Jing Li, Bradley Richmond, Ahmad A. Cluntun, Ryan Bia, Maureen A. Walsh, Kikuyo Shaw, J. David Symons, Sarah Franklin, Jared Rutter, Katsuhiko Funai, Robin M. Shaw, TingTing Hong
Type 2 diabetes (T2D) is associated with compromised identity of insulin-producing pancreatic islet β cells, characterized by inappropriate production of other islet cell–enriched hormones. Here, we examined how hormone misexpression was influenced by the MAFA and MAFB transcription factors, closely related proteins that maintain islet cell function. Mice specifically lacking MafA in β cells demonstrated broad, population-wide changes in hormone gene expression with an overall gene signature closely resembling islet gastrin+ (Gast+) cells generated under conditions of chronic hyperglycemia and obesity. A human β cell line deficient in MAFB, but not one lacking MAFA, also produced a GAST+ gene expression pattern. In addition, GAST was detected in human T2D β cells with low levels of MAFB. Moreover, evidence is provided that human MAFB can directly repress GAST gene transcription. These results support a potentially novel, species-specific role for MafA and MAFB in maintaining adult mouse and human β cell identity, respectively. Here, we discuss the possibility that induction of Gast/GAST and other non–β cell hormones, by reduction in the levels of these transcription factors, represents a dysfunctional β cell signature.
Jeeyeon Cha, Xin Tong, Emily M. Walker, Tehila Dahan, Veronica A. Cochrane, Sudipta Ashe, Ronan Russell, Anna B. Osipovich, Alex M. Mawla, Min Guo, Jin-hua Liu, Zachary A. Loyd, Mark O. Huising, Mark A. Magnuson, Matthias Hebrok, Yuval Dor, Roland Stein
Patients with triple negative breast cancer remain at risk for metastatic disease despite treatment. The acquisition of chemoresistance is a major cause of tumor relapse and death, but the mechanisms are far from understood. We have demonstrated that breast cancer cells (BCCs) can engulf mesenchymal stem/stromal cells (MSCs), leading to enhanced dissemination. Here, we show that clinical samples of primary invasive carcinoma and chemoresistant breast cancer metastasis contain a unique hybrid cancer cell population co-expressing pan-cytokeratin and the MSC marker fibroblast activation protein-alpha. We show that hybrid cells form in primary tumors and that they promote breast cancer metastasis and chemoresistance. Using single cell microfluidics and in vivo models, we found that within the hybrid cell population are polyploid senescent cells that contribute to metastatic dissemination. Our data reveal that WNT5A plays a crucial role in supporting the chemoresistance properties of hybrid cells. Furthermore, we identify that WNT5A mediates hybrid cell formation through a phagocytosis-like mechanism that requires BCC-derived Interleukin 6 and MSC-derived C-C Motif Chemokine Ligand 2. These findings reveal hybrid cell formation as a novel mechanism of chemoresistance and suggest that interrupting this mechanism may be a potential strategy to overcome breast cancer drug resistance.
Giuseppina Augimeri, Maria E. Gonzalez, Alessandro Paolì, Ahmad Eido, Yehyun Choi, Boris Burman, Sabra Djomehri, Santhosh Kumar Karthikeyan, Sooryanarayana Varambally, Johanna M. Buschhaus, Yu-Chih Chen, Loredana Mauro, Daniela Bonofiglio, Alexey I. Nesvizhskii, Gary D. Luker, Sebastiano Andò, Euisik Yoon, Celina G. Kleer
Inadequate adaption to mechanical forces, including blood pressure, contributes to development of arterial aneurysms. Recent studies have pointed to a mechano-protective role of YAP and TAZ in vascular smooth muscle cells (SMCs). Here, we identified reduced expression of YAP1 in human aortic aneurysms. Vascular SMC-specific knockouts (KOs) of YAP/TAZ were thus generated using the novel integrin α8 (Itga8)-Cre mouse model (i8-YT-KO). i8-YT-KO mice spontaneously developed aneurysms in the abdominal aorta within two weeks of knockout induction and in smaller arteries at later times. The vascular specificity of the Itga8-Cre circumvented gastrointestinal effects. Aortic aneurysms were characterized by elastin disarray, SMC apoptosis, and accumulation of proteoglycans and immune cell populations. RNA-sequencing, proteomics, and myography demonstrated decreased contractile differentiation of SMCs and impaired vascular contractility. This associated with partial loss of myocardin expression, reduced blood pressure, and edema. Mediators in the inflammatory cGAS-STING pathway, were increased. A sizeable increase of SOX9, along with several direct target genes, including aggrecan (Acan), contributed to proteoglycan accumulation. This was the earliest detectable change, occurring three days after knockout induction and before the pro-inflammatory transition. In conclusion, Itga8-Cre deletion of YAP and TAZ represents a rapid and spontaneous aneurysm model that recapitulates features of human abdominal aortic aneurysms.
Marycarmen Arévalo Martínez, Olivia Ritsvall, Joakim A. Bastrup, Selvi Celik, Gabriel Jakobsson, Fatima Daoud, Christopher Winqvist, Anders Aspberg, Catarina Rippe, Lars Maegdefessel, Alexandru Schiopu, Thomas A. Jepps, Johan Holmberg, Karl Swärd, Sebastian Albinsson
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