Multiscale modeling uncovers 7q11.23 copy number variation–dependent changes in ribosomal biogenesis and neuronal maturation and excitability

• Text
• PDF

Abstract

Copy number variation (CNV) at 7q11.23 causes Williams-Beuren syndrome (WBS) and 7q microduplication syndrome (7Dup), neurodevelopmental disorders (NDDs) featuring intellectual disability accompanied by symmetrically opposite neurocognitive features. Although significant progress has been made in understanding the molecular mechanisms underlying 7q11.23-related pathophysiology, the propagation of CNV dosage across gene expression layers and their interplay remains elusive. Here we uncovered 7q11.23 dosage–dependent symmetrically opposite dynamics in neuronal differentiation and intrinsic excitability. By integrating transcriptomics, translatomics, and proteomics of patient-derived and isogenic induced neurons, we found that genes related to neuronal transmission follow 7q11.23 dosage and are transcriptionally controlled, while translational factors and ribosomal genes are posttranscriptionally buffered. Consistently, we found phosphorylated RPS6 (p-RPS6) downregulated in WBS and upregulated in 7Dup. Surprisingly, p-4EBP was changed in the opposite direction, reflecting dosage-specific changes in total 4EBP levels. This highlights different dosage-sensitive dyregulations of the mTOR pathway as well as distinct roles of p-RPS6 and p-4EBP during neurogenesis. Our work demonstrates the importance of multiscale disease modeling across molecular and functional layers, uncovers the pathophysiological relevance of ribosomal biogenesis in a paradigmatic pair of NDDs, and uncouples the roles of p-RPS6 and p-4EBP as mechanistically actionable relays in NDDs.

Authors

Marija Mihailovich, Pierre-Luc Germain, Reinald Shyti, Davide Pozzi, Roberta Noberini, Yansheng Liu, Davide Aprile, Erika Tenderini, Flavia Troglio, Sebastiano Trattaro, Sonia Fabris, Ummi Ciptasari, Marco Tullio Rigoli, Nicolò Caporale, Giuseppe D’Agostino, Filippo Mirabella, Alessandro Vitriolo, Daniele Capocefalo, Adrianos Skaros, Agnese Virginia Franchini, Sara Ricciardi, Ida Biunno, Antonino Neri, Nael Nadif Kasri, Tiziana Bonaldi, Rudolf Aebersold, Michela Matteoli, Giuseppe Testa

Alkynyl nicotinamides show antileukemic activity in drug-resistant acute myeloid leukemia

• Text
• PDF

Abstract

Activating mutations of FLT3 contribute to deregulated hematopoietic stem and progenitor cell (HSC/Ps) growth and survival in patients with acute myeloid leukemia (AML), leading to poor overall survival. AML patients treated with investigational drugs targeting mutant FLT3, including Quizartinib and Crenolanib, develop resistance to these drugs. Development of resistance is largely due to acquisition of cooccurring mutations and activation of additional survival pathways, as well as emergence of additional FLT3 mutations. Despite the high prevalence of FLT3 mutations and their clinical significance in AML, there are few targeted therapeutic options available. We have identified 2 novel nicotinamide-based FLT3 inhibitors (HSN608 and HSN748) that target FLT3 mutations at subnanomolar concentrations and are potently effective against drug-resistant secondary mutations of FLT3. These compounds show antileukemic activity against FLT3ITD in drug-resistant AML, relapsed/refractory AML, and in AML bearing a combination of epigenetic mutations of TET2 along with FLT3ITD. We demonstrate that HSN748 outperformed the FDA-approved FLT3 inhibitor Gilteritinib in terms of inhibitory activity against FLT3ITD in vivo.

Authors

Baskar Ramdas, Neetu Dayal, Ruchi Pandey, Elizabeth Larocque, Rahul Kanumuri, Santhosh Kumar Pasupuleti, Sheng Liu, Chrysi Kanellopoulou, Elizabeth Fei Yin Chu, Rodrigo Mohallem, Saniya Virani, Gaurav Chopra, Uma K. Aryal, Rena Lapidus, Jun Wan, Ashkan Emadi, Laura S. Haneline, Frederick W. Holtsberg, M. Javad Aman, Herman O. Sintim, Reuben Kapur

Generation of allogenic and xenogeneic functional muscle stem cells for intramuscular transplantation

• Text
• PDF

Abstract

Satellite cells, the stem cells of skeletal muscle tissue, hold a remarkable regeneration capacity and therapeutic potential in regenerative medicine. However, low satellite cell yield from autologous or donor-derived muscles hinders the adoption of satellite cell transplantation for the treatment of muscle diseases, including Duchenne muscular dystrophy (DMD). To address this limitation, here we investigated whether satellite cells can be derived in allogeneic or xenogeneic animal hosts. First, injection of CRISPR/Cas9-corrected mouse DMD-induced pluripotent stem cells (iPSCs) into mouse blastocysts carrying an ablation system of host satellite cells gave rise to intraspecies chimeras exclusively carrying iPSC-derived satellite cells. Furthermore, injection of genetically corrected DMD-iPSCs into rat blastocysts resulted in the formation of interspecies rat-mouse chimeras harboring mouse satellite cells. Remarkably, iPSC-derived satellite cells or derivative myoblasts produced in intraspecies or interspecies chimeras restored dystrophin expression in DMD mice following intramuscular transplantation, and contributed to the satellite cell pool. Collectively, this study demonstrates the feasibility of producing therapeutically competent stem cells across divergent animal species, raising the possibility of generating human muscle stem cells in large animals for regenerative medicine purposes.

Authors

Ajda Lenardič, Seraina A. Domenig, Joel Zvick, Nicola Bundschuh, Monika Tarnowska-Sengül, Regula Furrer, Falko J. Noé, Christine Ling Li Trautmann, Adhideb Ghosh, Giada Bacchin, Pjeter Gjonlleshaj, Xhem Qabrati, Evi Masschelein, Katrien De Bock, Christoph Handschin, Ori Bar-Nur

ZMYND8 protects breast cancer stem cells against oxidative stress and ferroptosis through activation of NRF2

• Text
• PDF

Abstract

Breast cancer stem cells (BCSCs) mitigate oxidative stress to maintain their viability and plasticity. However, the regulatory mechanism of oxidative stress in BCSCs remains unclear. We recently found that the histone reader ZMYND8 was upregulated in BCSCs. Here, we showed that ZMYND8 reduced ROS and iron to inhibit ferroptosis in aldehyde dehydrogenase (ALDH)high BCSCs, leading to BCSC expansion and tumor initiation in mice. The underlying mechanism involved a twofold posttranslational regulation of nuclear factor erythroid 2–related factor 2 (NRF2). ZMYND8 increased stability of NRF2 protein through KEAP1 silencing. On the other hand, ZMYND8 interacted with and recruited NRF2 to the promoters of antioxidant genes to enhance gene transcription in mammospheres. NRF2 phenocopied ZMYND8 to enhance BCSC stemness and tumor initiation by inhibiting ROS and ferroptosis. Loss of NRF2 counteracted ZMYND8’s effects on antioxidant genes and ROS in mammospheres. Interestingly, ZMYND8 expression was directly controlled by NRF2 in mammospheres. Collectively, these findings uncover a positive feedback loop that amplifies the antioxidant defense mechanism sustaining BCSC survival and stemness.

Authors

Maowu Luo, Lei Bao, Yuanyuan Xue, Ming Zhu, Ashwani Kumar, Chao Xing, Jennifer E Wang, Yingfei Wang, Weibo Luo

Human pluripotent stem cell modeling of alveolar type 2 cell dysfunction caused by ABCA3 mutations

• Text
• PDF

Abstract

Mutations in ATP-binding cassette A3 (ABCA3), a phospholipid transporter critical for surfactant homeostasis in pulmonary alveolar type II epithelial cells (AEC2s), are the most common genetic causes of childhood interstitial lung disease (chILD). Treatments for patients with pathological variants of ABCA3 mutations are limited, in part due to a lack of understanding of disease pathogenesis resulting from an inability to access primary AEC2s from affected children. Here, we report the generation of AEC2s from affected patient induced pluripotent stem cells (iPSCs) carrying homozygous versions of multiple ABCA3 mutations. We generated syngeneic CRISPR/Cas9 gene-corrected and uncorrected iPSCs and ABCA3-mutant knockin ABCA3:GFP fusion reporter lines for in vitro disease modeling. We observed an expected decreased capacity for surfactant secretion in ABCA3-mutant iPSC-derived AEC2s (iAEC2s), but we also found an unexpected epithelial-intrinsic aberrant phenotype in mutant iAEC2s, presenting as diminished progenitor potential, increased NFκB signaling, and the production of pro-inflammatory cytokines. The ABCA3:GFP fusion reporter permitted mutant-specific, quantifiable characterization of lamellar body size and ABCA3 protein trafficking, functional features that are perturbed depending on ABCA3 mutation type. Our disease model provides a platform for understanding ABCA3 mutation–mediated mechanisms of alveolar epithelial cell dysfunction that may trigger chILD pathogenesis.

Authors

Yuliang L. Sun, Erin E. Hennessey, Hillary Heins, Ping Yang, Carlos Villacorta-Martin, Julian Kwan, Krithi Gopalan, Marianne James, Andrew Emili, F. Sessions Cole, Jennifer A. Wambach, Darrell N. Kotton

Metagenome analyses identify human endogenous retrovirus–K113 (HML-2) subtype in glioblastoma. Reply.

• Text
• PDF

Abstract

Authors

Vaidya Govindarajan, Jay Chandar, Avindra Nath, Ashish H. Shah

DNA methylation mediated Rbpjk suppression protects against fracture nonunion caused by systemic inflammation

• Text
• PDF

Abstract

Challenging skeletal repairs are frequently seen in patients experiencing systemic inflammation. To tackle the complexity and heterogeneity of skeletal repair process, we performed single-cell RNA sequencing and revealed that progenitor cell was one of the major lineages responsive to elevated inflammation and this response adversely affected progenitor differentiation by upregulation of Rbpjk in fracture nonunion. We then validated the interplay between inflammation (via Ikk2ca) and Rbpjk specifically in progenitors by using genetic animal models. Focusing on epigenetic regulation, we identified Rbpjk as a direct target of Dnmt3b. Mechanistically, inflammation decreased Dnmt3b expression in progenitor cells, consequently leading to Rbpjk upregulation via hypomethylation within its promoter region. We also showed that Dnmt3b loss-of-function mice phenotypically recapitulated the fracture repair defects observed in Ikk2ca mice, whereas Dnmt3b transgenic mice alleviated fracture repair defects induced by Ikk2ca. Moreover, Rbpjk ablation restored fracture repair in both Ikk2ca mice and Dnmt3b loss-of-function mice. Altogether, this work elucidates a common mechanism involving NFkB/Dnmt3b/Rbpjk axis within the context of inflamed bone regeneration. Building upon this mechanistic insight, we applied local treatment with epigenetically modified progenitor cells in RA mice and showed a functional restoration of bone regeneration under inflammatory condition through an increase in progenitor differentiation potential.

Authors

Ding Xiao, Liang Fang, Zhongting Liu, Yonghua He, Jun Ying, Haocheng Qin, Aiwu Lu, Meng Shi, Tiandao Li, Bo Zhang, Jianjun Guan, Cuicui Wang, Yousef Abu-Amer, Jie Shen

FXYD3 functionally demarcates an ancestral breast cancer stem cell subpopulation with features of drug-tolerant persisters

• Text
• PDF

Abstract

The heterogeneity of cancer stem cells (CSCs) within tumors presents a challenge in therapeutic targeting. To decipher the cellular plasticity that fuels phenotypic heterogeneity, we undertook single-cell transcriptomics analysis in triple-negative breast cancer (TNBC) to identify subpopulations in CSCs. We found a subpopulation of CSCs with ancestral features that is marked by FXYD domain–containing ion transport regulator 3 (FXYD3), a component of the Na+/K+ pump. Accordingly, FXYD3+ CSCs evolve and proliferate, while displaying traits of alveolar progenitors that are normally induced during pregnancy. Clinically, FXYD3+ CSCs were persistent during neoadjuvant chemotherapy, hence linking them to drug-tolerant persisters (DTPs) and identifying them as crucial therapeutic targets. Importantly, FXYD3+ CSCs were sensitive to senolytic Na+/K+ pump inhibitors, such as cardiac glycosides. Together, our data indicate that FXYD3+ CSCs with ancestral features are drivers of plasticity and chemoresistance in TNBC. Targeting the Na+/K+ pump could be an effective strategy to eliminate CSCs with ancestral and DTP features that could improve TNBC prognosis.

Authors

Mengjiao Li, Tatsunori Nishimura, Yasuto Takeuchi, Tsunaki Hongu, Yuming Wang, Daisuke Shiokawa, Kang Wang, Haruka Hirose, Asako Sasahara, Masao Yano, Satoko Ishikawa, Masafumi Inokuchi, Tetsuo Ota, Masahiko Tanabe, Kei-ichiro Tada, Tetsu Akiyama, Xi Cheng, Chia-Chi Liu, Toshinari Yamashita, Sumio Sugano, Yutaro Uchida, Tomoki Chiba, Hiroshi Asahara, Masahiro Nakagawa, Shinya Sato, Yohei Miyagi, Teppei Shimamura, Luis Augusto E. Nagai, Akinori Kanai, Manami Katoh, Seitaro Nomura, Ryuichiro Nakato, Yutaka Suzuki, Arinobu Tojo, Dominic C. Voon, Seishi Ogawa, Koji Okamoto, Theodoros Foukakis, Noriko Gotoh

Intracytoplasmic sperm injection induces transgenerational abnormalities in mice

• Text
• PDF

Abstract

In vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are 2 major assisted reproductive techniques (ARTs) used widely to treat infertility. Recently, spermatogonial transplantation emerged as a new ART to restore fertility to young patients with cancer after cancer therapy. To examine the influence of germ cell manipulation on behavior of offspring, we produced F1 offspring by a combination of two ARTs, spermatogonial transplantation and ICSI. When these animals were compared with F1 offspring produced by ICSI using fresh wild-type sperm, not only spermatogonial transplantation–ICSI mice but also ICSI-only control mice exhibited behavioral abnormalities, which persisted in the F2 generation. Furthermore, although these F1 offspring appeared normal, F2 offspring produced by IVF using F1 sperm and wild-type oocytes showed various types of congenital abnormalities, including anophthalmia, hydrocephalus, and missing limbs. Therefore, ARTs can induce morphological and functional defects in mice, some of which become evident only after germline transmission.

Authors

Mito Kanatsu-Shinohara, Yusuke Shiromoto, Narumi Ogonuki, Kimiko Inoue, Satoko Hattori, Kento Miura, Naomi Watanabe, Ayumi Hasegawa, Keiji Mochida, Takuya Yamamoto, Tsuyoshi Miyakawa, Atsuo Ogura, Takashi Shinohara

Activation of mTOR signaling in adult lung microvascular progenitor cells accelerates lung aging

• Text
• PDF

Abstract

Reactivation and dysregulation of the mTOR signaling pathway is a hallmark of aging and chronic lung disease, however the impact on microvascular progenitor cells (MVPC), capillary angiostasis and tissue homeostasis is unknown. While the existence of an adult lung vascular progenitor has long been hypothesized, these studies show that Abcg2 enriches for a population of angiogenic tissue resident MVPC present in both adult mouse and human lungs using functional, lineage and transcriptomic analyses. These studies link human and mouse MVPC specific mTORC1 activation to decreased stemness, angiogenic potential, disruption of p53 and Wnt pathways, with consequent loss of alveolar-capillary structure and function. Following mTOR activation these MVPC adapt a unique transcriptome signature and emerge as a venous subpopulation in the angiodiverse microvascular endothelial subclusters. Thus, our findings support a significant role for mTOR in the maintenance of MVPC function, microvascular niche homeostasis as well as a cell-based mechanism driving loss of tissue structure underlying lung aging and the development of emphysema.

Authors

Emma C. Mason, Swapna Menon, Benjamin R. Schneider, Christa F. Gaskill, Maggie M. Dawson, Camille M. Moore, Laura Craig Armstrong, Okyong J. Cho, Bradley W. Richmond, Jonathan A. Kropski, James D. West, Patrick Geraghty, Brigitte N. Gomperts, Kevin C. Ess, Fabienne Gally, Susan M. Majka