JMJD6 Dysfunction Due to Iron Deficiency in Preeclampsia Disrupts Fibronectin Homeostasis Resulting in Diminished Trophoblast Migration

The mechanisms contributing to excessive fibronectin in preeclampsia, a pregnancy-related disorder, remain unknown. Herein, we investigated the role of JMJD6, an O2- and Fe2+-dependent enzyme, in mediating placental fibronectin processing and function. MALDI-TOF identified fibronectin as a novel target of JMJD6-mediated lysyl hydroxylation, preceding fibronectin glycosylation, deposition, and degradation. In preeclamptic placentae, fibronectin accumulated primarily in lysosomes of the mesenchyme. Using primary placental mesenchymal cells (pMSCs), we found that fibronectin fibril formation and turnover were markedly impeded in preeclamptic pMSCs, partly due to impaired lysosomal degradation. JMJD6 knockdown in control pMSCs recapitulated the preeclamptic FN phenotype. Importantly, preeclamptic pMSCs had less total and labile Fe2+ and Hinokitiol treatment rescued fibronectin assembly and promoted lysosomal degradation. Time-lapse imaging demonstrated that defective ECM deposition by preeclamptic pMSCs impeded HTR-8/SVneo cell migration, which was rescued upon Hinokitiol exposure. Our findings reveal new Fe2+-dependent mechanisms controlling fibronectin homeostasis/function in the placenta that go awry in preeclampsia.

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Identification of astroglia-like cardiac nexus glia that are critical regulators of cardiac development and function

PLoS Biology ◽

10.1371/journal.pbio.3001444 ◽

2021 ◽

Vol 19 (11) ◽

pp. e3001444

Author(s):

Nina L. Kikel-Coury ◽

Jacob P. Brandt ◽

Isabel A. Correia ◽

Michael R. O’Dea ◽

Dana F. DeSantis ◽

...

Keyword(s):

Heart Rate ◽

Nervous System ◽

Cardiac Development ◽

Time Lapse ◽

Zebrafish Model ◽

Single Cell Sequencing ◽

Parasympathetic System ◽

And Function ◽

Time Lapse Imaging

Glial cells are essential for functionality of the nervous system. Growing evidence underscores the importance of astrocytes; however, analogous astroglia in peripheral organs are poorly understood. Using confocal time-lapse imaging, fate mapping, and mutant genesis in a zebrafish model, we identify a neural crest–derived glial cell, termed nexus glia, which utilizes Meteorin signaling via Jak/Stat3 to drive differentiation and regulate heart rate and rhythm. Nexus glia are labeled with gfap, glast, and glutamine synthetase, markers that typically denote astroglia cells. Further, analysis of single-cell sequencing datasets of human and murine hearts across ages reveals astrocyte-like cells, which we confirm through a multispecies approach. We show that cardiac nexus glia at the outflow tract are critical regulators of both the sympathetic and parasympathetic system. These data establish the crucial role of glia on cardiac homeostasis and provide a description of nexus glia in the PNS.

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Assemblies of DivIVA Mark Sites for Hyphal Branching and Can Establish New Zones of Cell Wall Growth in Streptomyces coelicolor

Journal of Bacteriology ◽

10.1128/jb.00839-08 ◽

2008 ◽

Vol 190 (22) ◽

pp. 7579-7583 ◽

Cited By ~ 91

Author(s):

Antje Marie Hempel ◽

Sheng-bing Wang ◽

Michal Letek ◽

José A. Gil ◽

Klas Flärdh

Keyword(s):

Cell Wall ◽

Streptomyces Coelicolor ◽

Time Lapse ◽

Cell Wall Assembly ◽

Peptidoglycan Synthesis ◽

Wall Growth ◽

Lateral Branches ◽

Wall Assembly ◽

Time Lapse Imaging

ABSTRACT Time-lapse imaging of Streptomyces hyphae revealed foci of the essential protein DivIVA at sites where lateral branches will emerge. Overexpression experiments showed that DivIVA foci can trigger establishment of new zones of cell wall assembly, suggesting a key role of DivIVA in directing peptidoglycan synthesis and cell shape in Streptomyces.

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EB1 binding provides a diffusion trap mechanism regulating STIM1 localization and Ca2+ signaling

10.1101/224162 ◽

2017 ◽

Author(s):

Chi-Lun Chang ◽

Yu-Ju Chen ◽

Jen Liou

Keyword(s):

Endoplasmic Reticulum ◽

Plasma Membrane ◽

Live Cell Imaging ◽

Cell Imaging ◽

Time Lapse ◽

Cellular Functions ◽

Binding Ability ◽

Spatiotemporal Regulation ◽

Time Lapse Imaging

AbstractThe endoplasmic reticulum (ER) Ca2+ sensor STIM1 forms oligomers and translocates to ER-plasma membrane (PM) junctions to activate store-operated Ca2+ entry (SOCE) following ER Ca2+ depletion. STIM1 also directly interacts with end binding protein 1 (EB1) at microtubule (MT) plus-ends and resembles comet-like structures during time-lapse imaging. Nevertheless, the role of STIM1-EB1 interaction in regulating SOCE remains unresolved. Using live-cell imaging combined with pharmacological perturbation and a reconstitution approach, we revealed that EB1 binding constitutes a diffusion trap mechanism restricting STIM1 targeting to ER-PM junctions. We further showed that STIM1 oligomers retain EB1 binding ability in ER Ca2+-depleted cells. EB1 binding delayed the translocation of STIM1 oligomers to ER-PM junctions and recaptured STIM1 to prevent excess SOCE and ER Ca2+ overload. Thus, the counterbalance of EB1 binding and PM targeting of STIM1 shapes the kinetics and amplitude of local SOCE in regions with growing MTs, and contributes to precise spatiotemporal regulation of Ca2+ signaling crucial for cellular functions and homeostasis.SummarySTIM1 activates store-operated Ca2+ entry (SOCE) by translocating to endoplasmic reticulum-plasma membrane junctions. Chang et al. revealed that STIM1 localization and SOCE are regulated by a diffusion trap mechanism mediated by STIM1 binding to EB1 at growing microtubule ends.

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Abstract 536: Lysosome Insufficiency in Atherosclerosis Prone DBA/2 Mouse Macrophages Associated With Impaired Autolysosome Formation and Lipid Drop Clearance

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.35.suppl_1.536 ◽

2015 ◽

Vol 35 (suppl_1) ◽

Author(s):

Peggy Robinet ◽

Jonathan D Smith

Keyword(s):

Cathepsin L ◽

Foam Cells ◽

Lysosomal Degradation ◽

Over Expression ◽

Protein Levels ◽

Lysosome Biogenesis ◽

Mouse Macrophages ◽

Macrophage Foam Cells ◽

And Function

In a previous study, we identified autolysosome formation as the limiting step for turnover of cholesterol esters in lipid droplets of macrophage foam cells from the atherosclerosis sensitive DBA/2 strain compared to the atherosclerosis resistant AKR mouse strain. As autophagosome formation was similar in these two strains, we wanted to evaluate the role of lysosome biogenesis and function on autolysosome formation in AKR and DBA/2 cells. The transcription factor TFEB is a key regulator for lysosome biogenesis and function that positively regulates the expression of lysosomal enzymes and structural proteins, and controls lysosomes number. For all our studies, we cultured AKR and DBA/2 macrophages with or without acetylated LDL (AcLDL) for 24h. First, we analyzed TFEB protein expression by western blot. Upon loading, TFEB was increased in AKR (48%, p<0.01) but not DBA/2 cells leading to a 45% higher TFEB level in AKR vs. DBA/2 foam cells (p<0.05), suggesting that lysosome number and function may be impaired in DBA/2 foam cells. To assess lysosome function and number, cells were labeled with Lysotracker red DND-99 (LyT) and analyzed by flow cytometry. We found that AcLDL loading did not affect LyT intensity. However, in both unloaded and loaded conditions, DBA/2 cells exhibited a 30 to 50% lower LyT intensity suggesting that they have intrinsically decreased lysosome number/function. Lysosomal degradation capacity was assayed by incubation with DQ-ovalbumin and we observed a 27% decrease in lysosome function in DBA/2 vs. AKR foam cells (p<0.01). In addition, upon loading, the mature form of cathepsin L was increased in AKR (43%, p<0.05) but not DBA/2 cells. Together these data suggest an impairment of lysosomal degradation capacity in DBA/2 foam cells. Finally, we investigated the role of TPC2, a lysosomal membrane protein which over expression has been previously linked to a defect in autolysosome formation. We found that upon AcLDL loading TPC2 protein levels were increased by 35% in DBA/2 cells, which are defective in autolysosome formation, while they were unchanged in AKR cells. In conclusion, we found that DBA/2 vs. AKR foam cells express more TPC2 and have fewer and/or dysfunctional lysosomes that may explain the autolysosome formation defect in these cells.

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Fijiyama: a registration tool for 3D multimodal time-lapse imaging

Bioinformatics ◽

10.1093/bioinformatics/btaa846 ◽

2020 ◽

Cited By ~ 1

Author(s):

Romain Fernandez ◽

Cédric Moisy

Keyword(s):

Time Series Data ◽

Time Lapse ◽

Supplementary Information ◽

Series Data ◽

3D Registration ◽

Extensive Documentation ◽

Intractable Problems ◽

Mri Scans ◽

And Function ◽

Time Lapse Imaging

Abstract Summary The increasing interest of animal and plant research communities for biomedical 3D imaging devices results in the emergence of new topics. The anatomy, structure and function of tissues can be observed non-destructively in time-lapse multimodal imaging experiments by combining the outputs of imaging devices such as X-ray CT and MRI scans. However, living samples cannot remain in these devices for a long period. Manual positioning and natural growth of the living samples induce variations in the shape, position and orientation in the acquired images that require a preprocessing step of 3D registration prior to analyses. This registration step becomes more complex when combining observations from devices that highlight various tissue structures. Identifying image invariants over modalities is challenging and can result in intractable problems. Fijiyama, a Fiji plugin built upon biomedical registration algorithms, is aimed at non-specialists to facilitate automatic alignment of 3D images acquired either at successive times and/or with different imaging systems. Its versatility was assessed on four case studies combining multimodal and time series data, spanning from micro to macro scales. Availability and implementation Fijiyama is an open source software (GPL license) implemented in Java. The plugin is available through the official Fiji release. An extensive documentation is available at the official page: https://imagej.github.io/Fijiyama Supplementary information Supplementary data are available at Bioinformatics online.

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Dendritic Spines: The Locus of Structural and Functional Plasticity

Physiological Reviews ◽

10.1152/physrev.00012.2013 ◽

2014 ◽

Vol 94 (1) ◽

pp. 141-188 ◽

Cited By ~ 250

Author(s):

Carlo Sala ◽

Menahem Segal

Keyword(s):

Dendritic Spines ◽

Synapse Formation ◽

Complex Structure ◽

Time Lapse ◽

Spiny Neurons ◽

Synaptic Interactions ◽

Health And Disease ◽

Spine Structure ◽

And Function ◽

Time Lapse Imaging

The introduction of high-resolution time lapse imaging and molecular biological tools has changed dramatically the rate of progress towards the understanding of the complex structure-function relations in synapses of central spiny neurons. Standing issues, including the sequence of molecular and structural processes leading to formation, morphological change, and longevity of dendritic spines, as well as the functions of dendritic spines in neurological/psychiatric diseases are being addressed in a growing number of recent studies. There are still unsettled issues with respect to spine formation and plasticity: Are spines formed first, followed by synapse formation, or are synapses formed first, followed by emergence of a spine? What are the immediate and long-lasting changes in spine properties following exposure to plasticity-producing stimulation? Is spine volume/shape indicative of its function? These and other issues are addressed in this review, which highlights the complexity of molecular pathways involved in regulation of spine structure and function, and which contributes to the understanding of central synaptic interactions in health and disease.

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Long Non-Coding RNA 554 Promotes Cardiac Fibrosis via TGF-β1 Pathway in Mice Following Myocardial Infarction

Frontiers in Pharmacology ◽

10.3389/fphar.2020.585680 ◽

2020 ◽

Vol 11 ◽

Author(s):

Bihui Luo ◽

Zhiyu He ◽

Shijun Huang ◽

Jinping Wang ◽

Dunzheng Han ◽

...

Keyword(s):

Myocardial Infarction ◽

Cardiac Fibrosis ◽

Cardiac Fibroblasts ◽

Non Coding Rna ◽

Novel Target ◽

And Function ◽

Tgf Β1

Rationale: Cardiac fibrosis is observed in nearly every form of myocardial disease. Long non-coding RNAs (lncRNAs) have been shown to play an important role in cardiac fibrosis, but the detailed molecular mechanism remains unknown.Object: We aimed at characterizing lncRNA 554 expression in murine cardiac fibroblasts (CFs) after myocardial infarction (MI) to identify CF-enriched lncRNA and investigate its function and contribution to cardiac fibrosis and function.Methods and Results: In this study, we identified lncRNA NONMMUT022554 (lncRNA 554) as a regulator of MI-induced cardiac fibrosis. We found that lncRNA 554 was significantly up-regulated in the mouse hearts following MI. Further study showed that lncRNA 554 was predominantly expressed in cardiac fibroblasts, indicating a potential role of lncRNA 554 in cardiac fibrosis. In vitro knockdown of lncRNA 554 by siRNA suppressed fibroblasts migration and expression of extracellular matrix (ECM); while overexpression of lncRNA 554 promoted expression of ECM genes. Consistently, lentivirus mediated in vivo knockdown of lncRNA 554 could inhibit cardiac fibrosis and improve cardiac function in mouse model of MI. More importantly, TGF-β1 inhibitor (TEW-7197) could reverse the pro-fibrotic function of lncRNA 554 in CFs. This suggests that the effects of lncRNA 554 on cardiac fibrosis is TGF-β1 dependent.Conclusion: Collectively, our study illustrated the role of lncRNA 554 in cardiac fibrosis, suggested that lncRNA 554 might be a novel target for cardiac fibrosis.

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A nanobody-based toolset to monitor and modify the mitochondrial GTPase Miro1

10.1101/2021.12.10.472061 ◽

2021 ◽

Author(s):

Funmilayo O Fagbadebo ◽

Philipp D Kaiser ◽

Katharina Zittlau ◽

Natascha Bartlick ◽

Teresa R Wagner ◽

...

Keyword(s):

Time Lapse ◽

Model Systems ◽

Live Cells ◽

Mitochondrial Outer Membrane ◽

Potential Biomarker ◽

Time Lapse Imaging ◽

Lateral Sclerosis ◽

Neuronal Disorders ◽

Research Tools

The mitochondrial outer membrane (MOM)-anchored GTPase Miro1, is a central player in mitochondrial transport and homeostasis. The dysregulation of Miro1 in amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD) suggests that Miro1 may be a potential biomarker or drug target in neuronal disorders. However, the molecular functionality of Miro1 under (patho-) physiological conditions is poorly known. For a more comprehensive understanding of the molecular functions of Miro1, we have developed Miro1-specific nanobodies (Nbs) as novel research tools. We identified seven Nbs that bind either the N- or C-terminal GTPase domain of Miro1 and demonstrate their application as research tools for proteomic and imaging approaches. To visualize the dynamics of Miro1 in real time, we selected intracellularly functional Nbs, which we reformatted into chromobodies (Cbs) for time-lapse imaging of Miro1. By genetic fusion to an Fbox domain, these Nbs were further converted into Miro1-specific degrons and applied for targeted degradation of Miro1 in live cells. In summary, this study presents a collection of novel Nbs that serve as a toolkit for advanced biochemical and intracellular studies and modulations of Miro1, thereby contributing to the understanding of the functional role of Miro1 in disease-derived model systems.

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Achieving functional neuronal dendrite structure through sequential stochastic growth and retraction

10.1101/2020.07.09.195446 ◽

2020 ◽

Cited By ~ 1

Author(s):

André Ferreira Castro ◽

Lothar Baltruschat ◽

Tomke Stürner ◽

Amirhoushang Bahrami ◽

Peter Jedlicka ◽

...

Keyword(s):

Body Wall ◽

Time Lapse ◽

Membrane Curvature ◽

Class I ◽

List Type ◽

Larval Body ◽

And Function ◽

Dendritic Branches ◽

Time Lapse Imaging

AbstractClass I ventral posterior dendritic arborisation (c1vpda) proprioceptive sensory neurons respond to contractions in the Drosophila larval body wall during crawling. Their dendritic branches run along the direction of contraction, possibly a functional requirement to maximise membrane curvature during crawling contractions. Although the molecular machinery of dendritic patterning in c1vpda has been extensively studied, the process leading to the precise elaboration of their comb-like shapes remains elusive. Here, to link dendrite shape with its proprioceptive role, we performed long-term, non-invasive, in vivo time-lapse imaging of c1vpda embryonic and larval morphogenesis to reveal a sequence of differentiation stages. We combined computer models and dendritic branch dynamics tracking to propose that distinct sequential phases of targeted growth and stochastic retraction achieve efficient dendritic trees both in terms of wire and function. Our study shows how dendrite growth balances structure–function requirements, shedding new light on general principles of self-organisation in functionally specialised dendrites.In briefAn optimal wire and function trade-off emerges from noisy growth and stochastic retraction during Drosophila class I ventral posterior dendritic arborisation (c1vpda) dendrite development.HighlightsC1vpda dendrite outgrowth follows wire constraints.Stochastic retraction of functionally suboptimal branches in a subsequent growth phase.C1vpda growth rules favour branches running parallel to larval body wall contraction.Comprehensive growth model reproduces c1vpda development in silico.

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Dual function of perivascular fibroblasts in vascular stabilization in zebrafish

PLoS Genetics ◽

10.1371/journal.pgen.1008800 ◽

2020 ◽

Vol 16 (10) ◽

pp. e1008800

Author(s):

Arsheen M. Rajan ◽

Roger C. Ma ◽

Katrinka M. Kocha ◽

Dan J. Zhang ◽

Peng Huang

Keyword(s):

Blood Vessels ◽

Time Lapse ◽

Cell Types ◽

Dual Function ◽

Dual Roles ◽

Vascular Integrity ◽

Genetic Ablation ◽

Mural Cells ◽

And Function ◽

Time Lapse Imaging

Blood vessels are vital to sustain life in all vertebrates. While it is known that mural cells (pericytes and smooth muscle cells) regulate vascular integrity, the contribution of other cell types to vascular stabilization has been largely unexplored. Using zebrafish, we identified sclerotome-derived perivascular fibroblasts as a novel population of blood vessel associated cells. In contrast to pericytes, perivascular fibroblasts emerge early during development, express the extracellular matrix (ECM) genes col1a2 and col5a1, and display distinct morphology and distribution. Time-lapse imaging reveals that perivascular fibroblasts serve as pericyte precursors. Genetic ablation of perivascular fibroblasts markedly reduces collagen deposition around endothelial cells, resulting in dysmorphic blood vessels with variable diameters. Strikingly, col5a1 mutants show spontaneous hemorrhage, and the penetrance of the phenotype is strongly enhanced by the additional loss of col1a2. Together, our work reveals dual roles of perivascular fibroblasts in vascular stabilization where they establish the ECM around nascent vessels and function as pericyte progenitors.

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