A hidden threshold in motor neuron gene networks revealed by modulation of miR-218 dose
Amin, ND;Senturk, G;Costaguta, G;Driscoll, S;O'Leary, B;Bonanomi, D;Pfaff, SL;
PMID: 34450025 | DOI: 10.1016/j.neuron.2021.07.028
Disruption of homeostatic microRNA (miRNA) expression levels is known to cause human neuropathology. However, the gene regulatory and phenotypic effects of altering a miRNA's in vivo abundance (rather than its binary gain or loss) are not well understood. By genetic combination, we generated an allelic series of mice expressing varying levels of miR-218, a motor neuron-selective gene regulator associated with motor neuron disease. Titration of miR-218 cellular dose unexpectedly revealed complex, non-ratiometric target mRNA dose responses and distinct gene network outputs. A non-linearly responsive regulon exhibited a steep miR-218 dose-dependent threshold in repression that, when crossed, resulted in severe motor neuron synaptic failure and death. This work demonstrates that a miRNA can govern distinct gene network outputs at different expression levels and that miRNA-dependent phenotypes emerge at particular dose ranges because of hidden regulatory inflection points of their underlying gene networks.
Interactions between cancer cells and immune cells drive transitions to mesenchymal-like states in glioblastoma
Hara, T;Chanoch-Myers, R;Mathewson, ND;Myskiw, C;Atta, L;Bussema, L;Eichhorn, SW;Greenwald, AC;Kinker, GS;Rodman, C;Gonzalez Castro, LN;Wakimoto, H;Rozenblatt-Rosen, O;Zhuang, X;Fan, J;Hunter, T;Verma, IM;Wucherpfennig, KW;Regev, A;Suvà, ML;Tirosh, I;
PMID: 34087162 | DOI: 10.1016/j.ccell.2021.05.002
The mesenchymal subtype of glioblastoma is thought to be determined by both cancer cell-intrinsic alterations and extrinsic cellular interactions, but remains poorly understood. Here, we dissect glioblastoma-to-microenvironment interactions by single-cell RNA sequencing analysis of human tumors and model systems, combined with functional experiments. We demonstrate that macrophages induce a transition of glioblastoma cells into mesenchymal-like (MES-like) states. This effect is mediated, both in vitro and in vivo, by macrophage-derived oncostatin M (OSM) that interacts with its receptors (OSMR or LIFR) in complex with GP130 on glioblastoma cells and activates STAT3. We show that MES-like glioblastoma states are also associated with increased expression of a mesenchymal program in macrophages and with increased cytotoxicity of T cells, highlighting extensive alterations of the immune microenvironment with potential therapeutic implications.
Bridging scales: From cell biology to physiology using in situ single-cell technologies
Nagle, MP;Tam, GS;Maltz, E;Hemminger, Z;Wollman, R;
PMID: 34015260 | DOI: 10.1016/j.cels.2021.03.002
Biological organization crosses multiple spatial scales: from molecular, cellular, to tissues and organs. The proliferation of molecular profiling technologies enables increasingly detailed cataloging of the components at each scale. However, the scarcity of spatial profiling has made it challenging to bridge across these scales. Emerging technologies based on highly multiplexed in situ profiling are paving the way to study the spatial organization of cells and tissues in greater detail. These new technologies provide the data needed to cross the scale from cell biology to physiology and identify the fundamental principles that govern tissue organization. Here, we provide an overview of these key technologies and discuss the current and future insights these powerful techniques enable.
Novel Tyrosine Kinase Targets in Urothelial Carcinoma
International journal of molecular sciences
Torres-Jiménez, J;Albarrán-Fernández, V;Pozas, J;Román-Gil, MS;Esteban-Villarrubia, J;Carrato, A;Rosero, A;Grande, E;Alonso-Gordoa, T;Molina-Cerrillo, J;
PMID: 33451055 | DOI: 10.3390/ijms22020747
Urothelial carcinoma represents one of the most prevalent types of cancer worldwide, and its incidence is expected to grow. Although the treatment of the advanced disease was based on chemotherapy for decades, the developments of different therapies, such as immune checkpoint inhibitors, antibody drug conjugates and tyrosine kinase inhibitors, are revolutionizing the therapeutic landscape of this tumor. This development coincides with the increasing knowledge of the pathogenesis and genetic alterations in urothelial carcinoma, from the non-muscle invasive setting to the metastatic one. The purpose of this article is to provide a comprehensive review of the different tyrosine kinase targets and their roles in the therapeutic scene of urothelial carcinoma.
Coordination between Transport and Local Translation in Neurons
Broix, L;Turchetto, S;Nguyen, L;
| DOI: 10.1016/j.tcb.2021.01.001
The axonal microtubules (MTs) support long-distance transport of cargoes that are dispatched to distinct cellular subcompartments. Among them, mRNAs are directly transported in membraneless ribonucleoprotein (RNP) granules that, together with ribosomes, can also hitchhike on fast-moving membrane-bound organelles for accurate transport along MTs. These organelles serve as platforms for mRNA translation, thus generating axonal foci of newly synthesized proteins. Local translation along axons not only supports MT network integrity but also modulates the processivity and function of molecular motors to allow proper trafficking of cargoes along MTs. Thus, identifying the mechanisms that coordinate axonal transport with local protein synthesis will shed new light on the processes underlying axon development and maintenance, whose deregulation often contribute to neurological disorders.
Kim, S;Yoon, J;Lee, K;Kim, Y;
| DOI: 10.1016/j.xpro.2022.102007
Human mitochondrial genome is transcribed bidirectionally, generating long complementary RNAs that can form double-stranded RNAs (mt-dsRNAs). When released to the cytosol, these mt-dsRNAs can activate antiviral signaling. Here, we present a detailed protocol for the analysis of mt-dsRNA expression. The protocol provides three approaches that can complement one another in examining mt-dsRNAs. While the described protocol is optimized for human cells, this approach can be adapted for use in other animal cell lines and tissue samples. For complete details on the use and execution of this protocol, please refer to Kim et al. (2022).1
International journal of molecular sciences
Abou Nader, N;Zamberlam, G;Boyer, A;
PMID: 36430866 | DOI: 10.3390/ijms232214388
The cortex of the adrenal gland is organized into concentric zones that produce distinct steroid hormones essential for body homeostasis in mammals. Mechanisms leading to the development, zonation and maintenance of the adrenal cortex are complex and have been studied since the 1800s. However, the advent of genetic manipulation and transgenic mouse models over the past 30 years has revolutionized our understanding of these mechanisms. This review lists and details the distinct Cre recombinase mouse strains available to study the adrenal cortex, and the remarkable progress total and conditional knockout mouse models have enabled us to make in our understanding of the molecular mechanisms regulating the development and maintenance of the adrenal cortex.
Byrnes, SJ;Angelovich, TA;Busman-Sahay, K;Cochrane, CR;Roche, M;Estes, JD;Churchill, MJ;
PMID: 36146803 | DOI: 10.3390/v14091997
Human Immunodeficiency virus (HIV)-associated neurocognitive disorders are a major burden for people living with HIV whose viremia is stably suppressed with antiretroviral therapy. The pathogenesis of disease is likely multifaceted, with contributions from viral reservoirs including the brain, chronic and systemic inflammation, and traditional risk factors including drug use. Elucidating the effects of each element on disease pathogenesis is near impossible in human clinical or ex vivo studies, facilitating the need for robust and accurate non-human primate models. In this review, we describe the major non-human primate models of neuroHIV infection, their use to study the acute, chronic, and virally suppressed infection of the brain, and novel therapies targeting brain reservoirs and inflammation.
Methods in molecular biology (Clifton, N.J.)
Annese, T;Errede, M;De Giorgis, M;Lorusso, L;Tamma, R;Ribatti, D;
PMID: 36161411 | DOI: 10.1007/978-1-0716-2703-7_8
Vascular co-option is a non-angiogenic mechanism whereby tumor growth and progression move on by hijacking the pre-existing and nonmalignant blood vessels and is employed by various tumors to grow and metastasize.The histopathological identification of co-opted blood vessels is complex, and no specific markers were defined, but it is critical to develop new and possibly more effective therapeutic strategies. Here, in glioblastoma, we show that the co-opted blood vessels can be identified, by double immunohistochemical staining, as weak CD31+ vessels with reduced P-gp expression and proliferation and surrounded by highly proliferating and P-gp- or S100A10-expressing tumor cells. Results can be quantified by the Aperio Colocalization algorithm, which is a valid and robust method to handle and investigate large data sets.
Methods in molecular biology (Clifton, N.J.)
Centa, JL;Hastings, ML;
PMID: 35895256 | DOI: 10.1007/978-1-0716-2521-7_2
Targeting of pre-mRNA splicing has yielded a rich variety of strategies for altering gene expression as a treatment for disease. The search for therapeutics that can modulate splicing has been dominated by antisense oligonucleotides (ASOs) and small molecule compounds, with each platform achieving remarkably effective results in the clinic. The success of RNA-targeting drugs has led to the exploration of new strategies to expand the repertoire of this type of therapeutic. Here, we discuss some of the more common causes of faulty gene expression and provide examples of approaches that have been developed to target and correct these defects for therapeutic value.
Harbauer, AB;Hees, JT;Wanderoy, S;Segura, I;Gibbs, W;Cheng, Y;Ordonez, M;Cai, Z;Cartoni, R;Ashrafi, G;Wang, C;Perocchi, F;He, Z;Schwarz, TL;
PMID: 35216662 | DOI: 10.1016/j.neuron.2022.01.035
PTEN-induced kinase 1 (PINK1) is a short-lived protein required for the removal of damaged mitochondria through Parkin translocation and mitophagy. Because the short half-life of PINK1 limits its ability to be trafficked into neurites, local translation is required for this mitophagy pathway to be active far from the soma. The Pink1 transcript is associated and cotransported with neuronal mitochondria. In concert with translation, the mitochondrial outer membrane proteins synaptojanin 2 binding protein (SYNJ2BP) and synaptojanin 2 (SYNJ2) are required for tethering Pink1 mRNA to mitochondria via an RNA-binding domain in SYNJ2. This neuron-specific adaptation for the local translation of PINK1 provides distal mitochondria with a continuous supply of PINK1 for the activation of mitophagy.
Development (Cambridge, England)
Toothaker, JM;Olaloye, O;McCourt, BT;McCourt, CC;Silva, TN;Case, RM;Liu, P;Yimlamai, D;Tseng, G;Konnikova, L;
PMID: 35050308 | DOI: 10.1242/dev.200013
Maintenance of healthy pregnancy is reliant on successful balance between the fetal and maternal immune systems. Although maternal mechanisms responsible have been well studied, those used by the fetal immune system remain poorly understood. Using suspension mass cytometry and various imaging modalities, we report a complex immune system within the mid-gestation (17-23 weeks) human placental villi (PV). Consistent with recent reports in other fetal organs, T cells with memory phenotypes, though rare in abundance, were detected within the PV tissue and vasculature. Moreover, we determined T cells isolated from PV samples may be more proliferative than adult T cells at baseline after T cell receptor (TCR) stimulation. Collectively, we identified multiple subtypes of fetal immune cells within the PV and specifically highlight the enhanced proliferative capacity of fetal PV T cells.
