Small extracellular vesicles (SEVs) are functional messengers of certain cellular niches to permit non-contact cell communications. Whether niche-specific SEVs fulfill this role in cancer is unclear. Here, we used seven cell-type specific mouse Cre lines to conditionally knockout Vps33b in Cdh5+ or Tie2+ endothelial cells (ECs), Lepr+ bone marrow perivascular cells, Osx+ osteo-progenitor cells (OPCs), Pf4+ megakaryocytes and Tcf21+ spleen stromal cells. We then examined the effects of reduced SEV secretion on progression of MLL-AF9 induced acute myeloid leukemia (AML) as well as normal hematopoiesis. Blocking SEV secretion from ECs, but not perivascular cells, megakaryocytes or spleen stromal cells, markedly delayed the leukemia progression. Notably, reducing SEV production from ECs had no effect on normal hematopoiesis. Protein analysis showed that EC-derived SEVs contained a high level of ANGPTL2, which accelerated leukemia progression via binding to LILRB2 receptor. Moreover, ANGPTL2-SEVs released from ECs were governed by VPS33B. Importantly, ANGPTL2-SEVs were also required for primary human AML cell maintenance. These findings demonstrate a role of niche-specific SEVs in cancer development and suggest that targeting ANGPTL2-SEVs from ECs might be a potential strategy to interfere certain types of AML.
Dan Huang, Guohuan Sun, Xiaoxin Hao, Xiaoxiao He, Zhaofeng Zheng, Chiqi Chen, Zhuo Yu, Li Xie, Shihui Ma, Ligen Liu, Bo O. Zhou, Hui Cheng, Junke Zheng, Tao Cheng
Zeb1, a zinc finger E-box binding homeobox epithelial-mesenchymal (EMT) transcription factor, confers properties of ‘stemness’, such as self-renewal, in cancer. Yet little is known about the function of Zeb1 in adult stem cells. Here, we used the hematopoietic system, as a well-established paradigm of stem cell biology, to evaluate Zeb1 mediated regulation of adult stem cells. We employed a conditional genetic approach using the Mx1-Cre system to specifically knockout (KO) Zeb1 in adult hematopoietic stem cells (HSCs) and their downstream progeny. Acute genetic deletion of Zeb1 led to rapid onset thymic atrophy and apoptosis driven loss of thymocytes and T cells. A profound cell-autonomous self-renewal defect and multi-lineage differentiation block was observed in Zeb1 KO HSCs. Loss of Zeb1 in HSCs activated transcriptional programs of deregulated HSC maintenance and multi-lineage differentiation genes, and of cell polarity, consisting of cytoskeleton, lipid metabolism/lipid membrane and cell adhesion related genes. Notably, Epithelial cell adhesion molecule (EpCAM) expression was prodigiously upregulated in Zeb1 KO HSCs, which correlated with enhanced cell survival, diminished mitochondrial metabolism, ribosome biogenesis, and differentiation capacity and an activated transcriptomic signature associated with acute myeloid leukemia (AML) signaling. ZEB1 expression was downregulated in AML patients and Zeb1 KO in the malignant counterparts of HSCs - leukemic stem cells (LSCs) - accelerated MLL-AF9 and Meis1a/Hoxa9-driven AML progression, implicating Zeb1 as a tumor suppressor in AML LSCs. Thus, Zeb1 acts as a transcriptional regulator in hematopoiesis, critically co-ordinating HSC self-renewal, apoptotic and multi-lineage differentiation fates required to suppress leukemic potential in AML.
Alhomidi Almotiri, Hamed Ahmad A. Alzahrani, Juan Bautista Menendez-Gonzalez, Ali Abdelfattah, Badi Alotaibi, Lubaid Saleh, Adelle Greene, Mia R. F. Georgiou, Alex Gibbs, Amani Salem Alsayari, Sarab Taha, Leigh-Anne Thomas, Dhruv Shah, Sarah Edkins, Peter J. Giles, Marc P. Stemmler, Simone Brabletz, Thomas Brabletz, Ashleigh S. Boyd, Florian A. Siebzehnrubl, Neil P. Rodrigues
Glioblastoma multiforme (GBM) heterogeneity causes a greater number of deaths than any other brain tumor, despite the availability of alkylating chemotherapy. GBM stem-like cells (GSCs) contribute to GBM complexity and chemoresistance, but it remains challenging to identify and target GSCs or factors that control their activity. Here, we identified a specific GSC subset and show that activity of these cells is positively regulated by stabilization of methyl CpG binding domain 3 (MBD3) protein. MBD3 binds to CK1A and to BTRCP E3 ubiquitin ligase, triggering MBD3 degradation, suggesting that modulating this circuit could antagonize GBM recurrence. Accordingly, xenograft mice treated with the CK1A activator pyrvinium pamoate (Pyr-Pam) showed enhanced MBD3 degradation in cells expressing high levels of O6-methylguanine-DNA methyltransferase (MGMT) and in GSCs, overcoming temozolomide chemoresistance. Pyr-Pam blocked recruitment of MBD3 and the repressive nucleosome remodeling and deacetylase (NuRD) complex to neurogenesis-associated gene loci and increased acetyl–histone H3 activity and GSC differentiation. We conclude that CK1A/BTRCP/MBD3/NuRD signaling modulates GSC activation and malignancy, and that targeting this signaling could suppress GSC proliferation and GBM recurrence.
Byoung-San Moon, Mingyang Cai, Grace Lee, Tong Zhao, Xiaofeng Song, Steven L. Giannotta, Frank J. Attenello, Min Yu, Wange Lu
Heterotopic ossification (HO) is pathological bone formation characterized by ossification within muscle, tendons, or other soft tissues. However, the cells of origin and mechanisms involved in the pathogenesis of HO remain elusive. Here we show that deletion of Suppressor of fused (Sufu) in Cathepsin K-Cre-expressing (Ctsk-Cre-expressing) cells resulted in spontaneous and progressive ligament, tendon, and periarticular ossification. Lineage tracing studies and cell functional analysis demonstrated that Ctsk-Cre could label a subpopulation of tendon-derived progenitor cells (TDPCs) marked by tendon marker Scleraxis (Scx). Ctsk+Scx+ TDPCs are enriched for tendon stem cell markers and show the highest self-renewal capacity and differentiation potential. Sufu deficiency caused enhanced chondrogenic and osteogenic differentiation of Ctsk-Cre-expressing tendon-derived cells via upregulating Hedgehog (Hh) signaling. Furthermore, pharmacological intervention of hedgehog signaling using JQ1 suppressed the development of HO. Thus, our results display that Cathepsin K-Cre labels a subpopulation of TDPCs contributing to HO and their cell fate changes are driven by activation of Hh signaling.
Heng Feng, Wenhui Xing, Yujiao Han, Jun Sun, Mingxiang Kong, Bo Gao, Yang Yang, Zi Yin, Xiao Chen, Yun Zhao, Qing Bi, Weiguo Zou
Cells sense extracellular environment and mechanical stimuli and translate these signals into intracellular responses through mechanotransduction and alters cell maintenance, proliferation, and differentiation. Here we use a mouse model of trauma induced heterotopic ossification (HO) to examine how cell-extrinsic forces impact MPC fate. After injury, single cell (sc) RNA sequencing of the injury site reveals an early increase in MPC genes associated with pathways of cell adhesion and ECM-receptor interactions, and MPC trajectories to cartilage and bone. Immunostaining uncovers active mechanotransduction after injury with increased focal adhesion kinase signaling and nuclear translocation of transcriptional co-activator TAZ, inhibition of which mitigates HO. Similarly, joint immobilization decreases mechanotransductive signaling, and completely inhibits HO. Joint immobilization decreases collagen alignment and increases adipogenesis. Further, scRNA sequencing of the HO site after injury with or without immobilization identifies gene signatures in mobile MPCs correlating with osteogenesis, while signatures from immobile MPCs with adipogenesis. scATAC-seq in these same MPCs confirm that in mobile MPCs, chromatin regions around osteogenic genes are open, while in immobile MPCs, regions around adipogenic genes are open. Together these data suggest that joint immobilization after injury results in decreased ECM alignment, altered MPC mechanotransduction, and changes in genomic architecture favoring adipogenesis over osteogenesis, resulting in decreased formation of HO.
Amanda K. Huber, Nicole Patel, Chase A. Pagani, Simone Marini, Karthik Padmanabhan, Daniel L. Matera, Mohamed Said, Charles Hwang, Ginny Ching-Yun Hsu, Andrea A. Poli, Amy L. Strong, Noelle D. Visser, Joseph A. Greenstein, Reagan Nelson, Shuli Li, Michael T. Longaker, Yi Tang, Stephen J. Weiss, Brendon M. Baker, Aaron W. James, Benjamin Levi
Acute myeloid leukemia (AML) disrupts the generation of normal blood cells, predisposing patients to hemorrhage, anemia, and infections. Differentiation and proliferation of residual normal hematopoietic stem and progenitor cells (HSPCs) are impeded in AML-infiltrated bone marrow (BM). The underlying mechanisms and interactions of residual hematopoietic stem cells (HSCs) within the leukemic niche are poorly understood, especially in the human context. To mimic AML infiltration and dissect the cellular crosstalk in human BM, we established humanized ex vivo and in vivo niche models comprising AML cells, normal HSPCs, and mesenchymal stromal cells (MSCs). Both models replicated the suppression of phenotypically defined HSPC differentiation without affecting their viability. As occurs in AML patients, the majority of HSPCs were quiescent and showed enrichment of functional HSCs. HSPC suppression was largely dependent on secreted factors produced by transcriptionally remodeled MSCs. Secretome analysis and functional validation revealed MSC-derived stanniocalcin 1 (STC1) and its transcriptional regulator HIF-1α as limiting factors for HSPC proliferation. Abrogation of either STC1 or HIF-1α alleviated HSPC suppression by AML. This study provides a humanized model to study the crosstalk among HSPCs, leukemia, and their MSC niche, and a molecular mechanism whereby AML impairs normal hematopoiesis by remodeling the mesenchymal niche.
Alexander Waclawiczek, Ashley Hamilton, Kevin Rouault-Pierre, Ander Abarrategi, Manuel Garcia Albornoz, Farideh Miraki-Moud, Nourdine Bah, John Gribben, Jude Fitzgibbon, David Taussig, Dominique Bonnet
Inherited bone marrow failure syndromes (IBMFSs) are a heterogeneous group of disorders characterized by defective hematopoiesis, impaired stem cell function, and cancer susceptibility. Diagnosis of IBMFS presents a major challenge due to the large variety of associated phenotypes, and novel, clinically relevant biomarkers are urgently needed. Our study identified nuclear interaction partner of ALK (NIPA) as an IBMFS gene, as it is significantly downregulated in a distinct subset of myelodysplastic syndrome–type (MDS-type) refractory cytopenia in children. Mechanistically, we showed that NIPA is major player in the Fanconi anemia (FA) pathway, which binds FANCD2 and regulates its nuclear abundance, making it essential for a functional DNA repair/FA/BRCA pathway. In a knockout mouse model, Nipa deficiency led to major cell-intrinsic defects, including a premature aging phenotype, with accumulation of DNA damage in hematopoietic stem cells (HSCs). Induction of replication stress triggered a reduction in and functional decline of murine HSCs, resulting in complete bone marrow failure and death of the knockout mice with 100% penetrance. Taken together, the results of our study add NIPA to the short list of FA-associated proteins, thereby highlighting its potential as a diagnostic marker and/or possible target in diseases characterized by hematopoietic failure.
Stefanie Kreutmair, Miriam Erlacher, Geoffroy Andrieux, Rouzanna Istvanffy, Alina Mueller-Rudorf, Melissa Zwick, Tamina Rückert, Milena Pantic, Teresa Poggio, Khalid Shoumariyeh, Tony A. Mueller, Hiroyuki Kawaguchi, Marie Follo, Cathrin Klingeberg, Marcin Wlodarski, Irith Baumann, Dietmar Pfeifer, Michal Kulinski, Martina Rudelius, Simone Lemeer, Bernhard Kuster, Christine Dierks, Christian Peschel, Nina Cabezas-Wallscheid, Jesus Duque-Afonso, Robert Zeiser, Michael L. Cleary, Detlev Schindler, Annette Schmitt-Graeff, Melanie Boerries, Charlotte M. Niemeyer, Robert A.J. Oostendorp, Justus Duyster, Anna Lena Illert
Sensory nerve was recently identified as being involved in regulation of bone mass accrual. We previously discovered that PGE2 secreted by osteoblastic cells could activate sensory nerve EP4 receptor to promote bone formation by inhibiting sympathetic activity. However, the fundamental units of bone formation are active osteoblasts, which originate from skeletal stem cells. Here, we found that after sensory denervation, knockout of the EP4 receptor in sensory nerves, or knockout of cyclooxygenase-2 (COX2) in osteoblasts could significantly promote adipogenesis and inhibit osteogenesis in adult mice. Furthermore, injection of SW033291 (a small molecule that locally increases PGE2 level) or propranolol (a beta-blocker) significantly promoted osteogenesis and inhibited adipogenesis. This effect of SW033291, but not propranolol, was abolished in conditional EP4 knockout mice under normal conditions or in the bone repair process. We conclude that the PGE2-EP4 sensory nerve axis could regulate skeletal stem cell differentiation in bone marrow of adult mice.
Bo Hu, Xiao Lv, Hao Chen, Peng Xue, Bo Gao, Xiao Wang, Gehua Zhen, Janet L. Crane, Dayu Pan, Shen Liu, Shuangfei Ni, Panfeng Wu, Weiping Su, Xiaonan Liu, Zemin Ling, Mi Yang, Ruoxian Deng, Yusheng Li, Lei Wang, Ying Zhang, Mei Wan, Zengwu Shao, Huajiang Chen, Wen Yuan, Xu Cao
Glioblastoma (GBM) contains a subpopulation of cells, GBM stem cells (GSCs), that maintain the bulk tumor and represent a key therapeutic target. Norrin is a Wnt ligand that binds the Frizzled4 (FZD4) receptor to activate canonical Wnt signaling. While Norrin, encoded by NDP, has a well- described role in vascular development, its function in human tumorigenesis is largely unexplored. Here, we show that NDP expression is enriched in neurological cancers, including GBM, and its levels positively correlated with survival in a GBM subtype defined by low expression of ASCL1, a proneural factor. We investigated the function of Norrin and FZD4 in GSCs and found that it mediated opposing tumor-promoting and -suppressive effects on ASCL1lo and ASCL1hi GSCs. Consistent with a potential tumor suppressive effect of Norrin suggested by the tumour outcome data, we found that Norrin signaling through FZD4 inhibited growth in ASCL1lo GSCs. In contrast, in ASCL1hi GSCs Norrin promoted Notch signaling, independently of WNT, to promote tumor progression. Forced ASCL1 expression reversed the tumor suppressive effects of Norrin in ASCL1lo GSCs. Our results identify Norrin as a modulator of human brain cancer progression and reveal an unanticipated Notch mediated function of Norrin in regulating cancer stem cell biology.
Ahmed El-Sehemy, Hayden J. Selvadurai, Arturo Ortin-Martinez, Neno T. Pokrajac, Yasin Mamatjan, Nobuhiko Tachibana, Katherine J. Rowland, Lilian Lee, Nicole I. Park, Kenneth D. Aldape, Peter Dirks, Valerie A. Wallace
Lamin A is a component of the inner nuclear membrane that, together with epigenetic factors, organizes the genome in higher order structures required for transcriptional control. Mutations in the Lamin A/C gene cause several diseases, belonging to the class of laminopathies, including muscular dystrophies. Nevertheless, molecular mechanisms involved in the pathogenesis of Lamin A-dependent dystrophies are still largely unknown. Polycomb group of proteins (PcG) are epigenetic repressors and Lamin A interactors, primarily involved in the maintenance of cell identity. Using a murine model of Emery-Dreifuss Muscular Dystrophy (EDMD), we showed here that Lamin A loss deregulated PcG positioning in muscle satellite stem cells leading to de-repression of non-muscle specific genes and p16INK4a, a senescence driver encoded in the Cdkn2a locus. This aberrant transcriptional programme caused impairment in self-renewal, loss of cell identity and premature exhaustion of quiescent satellite cell pool. Genetic ablation of Cdkn2a locus restored muscle stem cell properties in Lamin A/C null dystrophic mice. Our findings established a direct link between Lamin A and PcG epigenetic silencing and indicated that Lamin A-dependent muscular dystrophy can be ascribed to intrinsic epigenetic dysfunctions of muscle stem cells.
Andrea Bianchi, Chiara Mozzetta, Gloria Pegoli, Federica Lucini, Sara Valsoni, Valentina Rosti, Cristiano Petrini, Alice Cortesi, Francesco Gregoretti, Laura Antonelli, Gennaro Oliva, Marco De Bardi, Roberto Rizzi, Beatrice Bodega, Diego Pasini, Francesco Ferrari, Claudia Bearzi, Chiara Lanzuolo