scholarly journals SOD1A4Vaggregation alters ubiquitin homeostasis in a cell model of ALS

2017 ◽  
Author(s):  
Natalie E. Farrawell ◽  
Isabella Lambert-Smith ◽  
Kristen Mitchell ◽  
Jessie McKenna ◽  
Luke McAlary ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Primary Motor Cortex ◽  
Cell Model ◽  
Ubiquitin Proteasome System ◽  
Mitochondrial Morphology ◽  
Mutant Sod1 ◽  
A Cell ◽  
Selective Death ◽  
Misfolded Sod1 ◽  
And Function

AbstractAmyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease involving the selective death of upper and lower motor neurons in the primary motor cortex and spinal cord. A hallmark of ALS pathology is the accumulation of ubiquitinated protein inclusions within motor neurons. Previous studies suggest the sequestration of ubiquitin (Ub) into inclusions reduces the availability of free Ub, which is essential for cellular function and survival. However, the dynamics of the Ub landscape in ALS have not yet been described. Here we show that Ub homeostasis is altered in a SOD1 cell model of ALS. Utilising fluorescently tagged Ub, we followed the distribution of Ub in living cells expressing SOD1 and show that Ub is present at the earliest stages of SOD1 aggregation. We also report that cells containing aggregates of mutant SOD1 have greater ubiquitin-proteasome system (UPS) dysfunction as measured by the accumulation of the fluorescent proteasome reporter tdTomatoCL1. Furthermore, SOD1 aggregation is associated with the redistribution of Ub and depletion of the free Ub pool. Ubiquitomics analysis indicates that mutant SOD1 is associated with a shift of Ub to a pool of supersaturated proteins including those associated with oxidative phosphorylation and metabolism, corresponding with altered mitochondrial morphology and function. Taken together, these results suggest misfolded SOD1 contributes to UPS dysfunction and that Ub homeostasis is an important target for monitoring pathological changes in ALS.

scholarly journals Early upregulation of cytosolic phospholipase A2α in motor neurons is induced by misfolded SOD1 in a mouse model of amyotrophic lateral sclerosis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Yafa Fetfet Malada Edelstein ◽  
Yulia Solomonov ◽  
Nurit Hadad ◽  
Leenor Alfahel ◽  
Adrian Israelson ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Amyotrophic Lateral Sclerosis ◽  
Transgenic Mice ◽  
Motor Neurons ◽  
Dependent Manner ◽  
Mutant Sod1 ◽  
Over Expression ◽  
Cytosolic Phospholipase ◽  
Misfolded Sod1 ◽  
Lateral Sclerosis

Abstract Background Amyotrophic lateral sclerosis (ALS) is a fatal multifactorial neurodegenerative disease characterized by the selective death of motor neurons. Cytosolic phospholipase A2 alpha (cPLA2α) upregulation and activation in the spinal cord of ALS patients has been reported. We have previously shown that cPLA2α upregulation in the spinal cord of mutant SOD1 transgenic mice (SOD1G93A) was detected long before the development of the disease, and inhibition of cPLA2α upregulation delayed the disease’s onset. The aim of the present study was to determine the mechanism for cPLA2α upregulation. Methods Immunofluorescence analysis and western blot analysis of misfolded SOD1, cPLA2α and inflammatory markers were performed in the spinal cord sections of SOD1G93A transgenic mice and in primary motor neurons. Over expression of mutant SOD1 was performed by induction or transfection in primary motor neurons and in differentiated NSC34 motor neuron like cells. Results Misfolded SOD1 was detected in the spinal cord of 3 weeks old mutant SOD1G93A mice before cPLA2α upregulation. Elevated expression of both misfolded SOD1 and cPLA2α was specifically detected in the motor neurons at 6 weeks with a high correlation between them. Elevated TNFα levels were detected in the spinal cord lysates of 6 weeks old mutant SOD1G93A mice. Elevated TNFα was specifically detected in the motor neurons and its expression was highly correlated with cPLA2α expression at 6 weeks. Induction of mutant SOD1 in primary motor neurons induced cPLA2α and TNFα upregulation. Over expression of mutant SOD1 in NSC34 cells caused cPLA2α upregulation which was prevented by antibodies against TNFα. The addition of TNFα to NSC34 cells caused cPLA2α upregulation in a dose dependent manner. Conclusions Motor neurons expressing elevated cPLA2α and TNFα are in an inflammatory state as early as at 6 weeks old mutant SOD1G93A mice long before the development of the disease. Accumulated misfolded SOD1 in the motor neurons induced cPLA2α upregulation via induction of TNFα.

scholarly journals Novel chemical inhibitor against SOD1 misfolding and aggregation protects neuron-loss and ameliorates disease symptoms in ALS mouse model

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Tae-Gyun Woo ◽  
Min-Ho Yoon ◽  
So-mi Kang ◽  
Soyoung Park ◽  
Jung-Hyun Cho ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Neuroblastoma Cell ◽  
Neuroblastoma Cell Line ◽  
Human Neuroblastoma Cell ◽  
Human Neuroblastoma ◽  
Mutant Sod1 ◽  
Chemical Screening ◽  
Model Mouse ◽  
Extended Lifespan ◽  
Selective Death

AbstractAmyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by selective death of motor neurons. Mutations in Cu, Zn-superoxide dismutase (SOD1) causing the gain of its toxic property are the major culprit of familial ALS (fALS). The abnormal SOD1 aggregation in the motor neurons has been suggested as the major pathological hallmark of ALS patients. However, the development of pharmacological interventions against SOD1 still needs further investigation. In this study, using ELISA-based chemical screening with wild and mutant SOD1 proteins, we screened a new small molecule, PRG-A01, which could block the misfolding/aggregation of SOD1 or TDP-43. The drug rescued the cell death induced by mutant SOD1 in human neuroblastoma cell line. Administration of PRG-A01 into the ALS model mouse resulted in significant improvement of muscle strength, motor neuron viability and mobility with extended lifespan. These results suggest that SOD1 misfolding/aggregation is a potent therapeutic target for SOD1 related ALS.

scholarly journals AAV2/9-mediated overexpression of MIF inhibits SOD1 misfolding, delays disease onset, and extends survival in mouse models of ALS

2019 ◽  
Vol 116 (29) ◽  
pp. 14755-14760 ◽  
Author(s):  
Marcel F. Leyton-Jaimes ◽  
Joy Kahn ◽  
Adrian Israelson
Keyword(s):  
Spinal Cord ◽  
Motor Neurons ◽  
Therapeutic Potential ◽  
Disease Onset ◽  
Mutant Sod1 ◽  
Protein Levels ◽  
Specific Accumulation ◽  
Intracellular Organelles ◽  
Misfolded Sod1

Mutations in superoxide dismutase (SOD1) cause amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by the loss of upper and lower motor neurons. Transgenic mice that overexpress mutant SOD1 develop paralysis and accumulate misfolded SOD1 onto the cytoplasmic faces of intracellular organelles, including mitochondria and endoplasmic reticulum (ER). Recently, macrophage migration inhibitory factor (MIF) was shown to directly inhibit mutant SOD1 misfolding and binding to intracellular membranes. In addition, complete elimination of endogenous MIF accelerated disease onset and late disease progression, as well as shortened the lifespan of mutant SOD1 mice with higher amounts of misfolded SOD1 detected within the spinal cord. Based on these findings, we used adeno-associated viral (AAV) vectors to overexpress MIF in the spinal cord of mutant SOD1G93A and loxSOD1G37R mice. Our data show that MIF mRNA and protein levels were increased in the spinal cords of AAV2/9-MIF–injected mice. Furthermore, mutant SOD1G93A and loxSOD1G37R mice injected with AAV2/9-MIF demonstrated a significant delay in disease onset and prolonged survival compared with their AAV2/9-GFP–injected or noninjected littermates. Moreover, these mice accumulated reduced amounts of misfolded SOD1 in their spinal cords, with no observed effect on glial overactivation as a result of MIF up-regulation. Our findings indicate that MIF plays a significant role in SOD1 folding and misfolding mechanisms and strengthen the hypothesis that MIF acts as a chaperone for misfolded SOD1 in vivo and may have further implications regarding the therapeutic potential role of up-regulation of MIF in modulating the specific accumulation of misfolded SOD1.

scholarly journals Dscam2 suppresses synaptic strength through a PI3K-dependent endosomal pathway

2020 ◽  
Vol 219 (6) ◽  
Author(s):  
G. Lorenzo Odierna ◽  
Sarah K. Kerwin ◽  
Lucy E. Harris ◽  
Grace Ji-eun Shin ◽  
Nickolas A. Lavidis ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Neuronal Development ◽  
Surface Protein ◽  
Synaptic Strength ◽  
Protein Isoforms ◽  
Synaptic Physiology ◽  
Transmission Electron ◽  
Alternative Protein ◽  
A Cell ◽  
And Function

Dscam2 is a cell surface protein required for neuronal development in Drosophila; it can promote neural wiring through homophilic recognition that leads to either adhesion or repulsion between neurites. Here, we report that Dscam2 also plays a post-developmental role in suppressing synaptic strength. This function is dependent on one of two distinct extracellular isoforms of the protein and is autonomous to motor neurons. We link the PI3K enhancer, Centaurin gamma 1A, to the Dscam2-dependent regulation of synaptic strength and show that changes in phosphoinositide levels correlate with changes in endosomal compartments that have previously been associated with synaptic strength. Using transmission electron microscopy, we find an increase in synaptic vesicles at Dscam2 mutant active zones, providing a rationale for the increase in synaptic strength. Our study provides the first evidence that Dscam2 can regulate synaptic physiology and highlights how diverse roles of alternative protein isoforms can contribute to unique aspects of brain development and function.

INVERSE UNCERTAINTY QUANTIFICATION OF A CELL MODEL USING A GAUSSIAN PROCESS METAMODEL

2020 ◽  
Vol 10 (4) ◽  
pp. 333-349
Author(s):  
Kevin de Vries ◽  
Anna Nikishova ◽  
Benjamin Czaja ◽  
Gábor Závodszky ◽  
Alfons G. Hoekstra
Keyword(s):  
Gaussian Process ◽  
Uncertainty Quantification ◽  
Cell Model ◽  
A Cell

Preincubation with Sn-complexes causes intensive intracellular retention of 99mTc in thyroid cells in vitro

2012 ◽  
Vol 51 (05) ◽  
pp. 179-185 ◽  
Author(s):  
M. Wendisch ◽  
D. Aurich ◽  
R. Runge ◽  
R. Freudenberg ◽  
J. Kotzerke ◽  
...  
Keyword(s):  
Cell Model ◽  
Low Energy ◽  
Thyroid Cells ◽  
Low Energy Electrons ◽  
A Cell ◽  
Vitro Model ◽  
Uptake Studies ◽  
Radiobiological Effects ◽  
Radioactivity Retention

SummaryTechnetium radiopharmaceuticals are well established in nuclear medicine. Besides its well-known gamma radiation, 99mTc emits an average of five Auger and internal conversion electrons per decay. The biological toxicity of these low-energy, high-LET (linear energy transfer) emissions is a controversial subject. One aim of this study was to estimate in a cell model how much 99mTc can be present in exposed cells and which radiobiological effects could be estimated in 99mTc-overloaded cells. Methods: Sodium iodine symporter (NIS)- positive thyroid cells were used. 99mTc-uptake studies were performed after preincubation with a non-radioactive (cold) stannous pyro - phosphate kit solution or as a standard 99mTc pyrophosphate kit preparation or with pure pertechnetate solution. Survival curves were analyzed from colony-forming assays. Results: Preincubation with stannous complexes causes irreversible intracellular radioactivity retention of 99mTc and is followed by further pertechnetate influx to an unexpectedly high 99mTc level. The uptake of 99mTc pertechnetate in NIS-positive cells can be modified using stannous pyrophosphate from 3–5% to >80%. The maximum possible cellular uptake of 99mTc was 90 Bq/cell. Compared with nearly pure extracellular irradiation from routine 99mTc complexes, cell survival was reduced by 3–4 orders of magnitude after preincubation with stannous pyrophosphate. Conclusions: Intra cellular 99mTc retention is related to reduced survival, which is most likely mediated by the emission of low-energy electrons. Our findings show that the described experiments constitute a simple and useful in vitro model for radiobiological investigations in a cell model.

CD38 as an immunomodulator in cancer

2020 ◽  
Vol 16 (34) ◽  
pp. 2853-2861
Author(s):  
Yanli Li ◽  
Rui Yang ◽  
Limo Chen ◽  
Sufang Wu
Keyword(s):  
Multiple Myeloma ◽  
Cell Activation ◽  
Human Tissues ◽  
Transmembrane Glycoprotein ◽  
Cell Activation Marker ◽  
Research Findings ◽  
A Cell ◽  
And Function ◽  
Human Molecule

CD38 is a transmembrane glycoprotein that is widely expressed in a variety of human tissues and cells, especially those in the immune system. CD38 protein was previously considered as a cell activation marker, and today monoclonal antibodies targeting CD38 have witnessed great achievements in multiple myeloma and promoted researchers to conduct research on other tumors. In this review, we provide a wide-ranging review of the biology and function of the human molecule outside the field of myeloma. We focus mainly on current research findings to summarize and update the findings gathered from diverse areas of study. Based on these findings, we attempt to extend the role of CD38 in the context of therapy of solid tumors and expand the role of the molecule from a simple marker to an immunomodulator.

Sign in / Sign up

Export Citation Format

Share Document