scholarly journals Selective effects of protein 4.1N deficiency on neuroendocrine and reproductive systems

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hua Wang ◽  
Marilyn Parra ◽  
John G. Conboy ◽  
Christopher D. Hillyer ◽  
Narla Mohandas ◽  
...  
Keyword(s):  
Cell Body ◽  
Secretory Granules ◽  
Weight Ratio ◽  
Neuronal Cell ◽  
Neuronal Cell Body ◽  
Corpora Lutea ◽  
Reproductive Systems ◽  
Pituitary Glands ◽  
Selective Effects

Abstract Protein 4.1N, a member of the protein 4.1 family, is highly expressed in the brain. But its function remains to be fully defined. Using 4.1N−/− mice, we explored the function of 4.1N in vivo. We show that 4.1N−/− mice were born at a significantly reduced Mendelian ratio and exhibited high mortality between 3 to 5 weeks of age. Live 4.1N−/− mice were smaller than 4.1N+/+ mice. Notably, while there were no significant differences in organ/body weight ratio for most of the organs, the testis/body and ovary/body ratio were dramatically decreased in 4.1N−/− mice, demonstrating selective effects of 4.1N deficiency on the development of the reproductive systems. Histopathology of the reproductive organs showed atrophy of both testis and ovary. Specifically, in the testis there is a lack of spermatogenesis, lack of leydig cells and lack of mature sperm. Similarly, in the ovary there is a lack of follicular development and lack of corpora lutea formation, as well as lack of secretory changes in the endometrium. Examination of pituitary glands revealed that the secretory granules were significantly decreased in pituitary glands of 4.1N−/− compared to 4.1N+/+. Moreover, while GnRH was expressed in both neuronal cell body and axons in the hypothalamus of 4.1N+/+ mice, it was only expressed in the cell body but not the axons of 4.1N-/- mice. Our findings uncover a novel role for 4.1N in the axis of hypothalamus-pituitary gland-reproductive system.

The adrenal paraneurone: tubulin organization

1984 ◽  
Vol 62 (5) ◽  
pp. 502-511 ◽  
Author(s):  
M. F. Bader ◽  
F. Bernier-Valentin ◽  
B. Rousset ◽  
D. Aunis
Keyword(s):  
Cell Body ◽  
Intracellular Transport ◽  
Cultured Cells ◽  
Specific Binding ◽  
Secretory Granules ◽  
Immunofluorescent Staining ◽  
Chromaffin Granules ◽  
Two Dimensional Gel Electrophoresis ◽  
Granule Membrane

When chromaffin cells from the bovine adrenal medulla are maintained in culture, they develop neuritelike processes which end with growth-cone-like structures. Chromaffin granules were found to migrate from the cell body to the neurite endings. Thus, the intracellular transport of secretory granules, existing in vivo, seems to occur in an exaggerated way in the cultured cells. These cells offer an excellent model for studying the mechanism of transport, particularly the role of microtubules. By immunofluorescent staining, we observed that tubulin antibodies decorate a complex network visible along the neurites. Colchicine treatment induced the disappearance of this network followed by a return of granules in the cell body and a retraction of neurites. To test the presence of tubulin in the chromaffin granule membrane, we used two-dimensional gel electrophoresis and a radioimmunoassay. Our results indicate that tubulin is not a significant component of chromaffin granules. However, binding experiments show that granule membranes are able to bind tubulin through high affinity binding sites. These results show that microtubules appear involved in neurite formation and probably in granule transport. Tubulin is not an integral constituent of the granule membrane, but is present as a result of a reversible specific binding. This insertion of tubulin into the membrane might represent a step in the association between microtubules and secretory granules.

Separation of a process from the neuronal cell body using a thin aluminum foil separator

1998 ◽  
Vol 2 (4) ◽  
pp. 352-356 ◽  
Author(s):  
Kosuke Noda ◽  
Keita Jimbo ◽  
Kazuo Suzuki ◽  
Kentaro Yoda
Keyword(s):  
Cell Body ◽  
Neuronal Cell ◽  
Aluminum Foil ◽  
Neuronal Cell Body ◽  
Thin Aluminum ◽  
Thin Aluminum Foil

scholarly journals Differences in splicing defects between the grey and white matter in myotonic dystrophy type 1

2019 ◽  
Author(s):  
Masamitsu Nishi ◽  
Takashi Kimura ◽  
Mitsuru Furuta ◽  
Koichi Suenaga ◽  
Tsuyoshi Matsumura ◽  
...  
Keyword(s):  
White Matter ◽  
Myotonic Dystrophy ◽  
Cell Body ◽  
Neuronal Cell ◽  
Neuronal Cell Body ◽  
Myotonic Dystrophy Type 1 ◽  
Myotonic Dystrophy Type ◽  
And Control ◽  
The Brain

AbstractMyotonic dystrophy type 1 (DM1) is a multi-system disorder caused by CTG repeats in the myotonic dystrophy protein kinase (DMPK) gene. This leads to sequestration of the splicing factor, muscleblind-like 2 (MBNL2), and aberrant splicing, mainly in the central nervous system. We investigated the splicing patterns of MBNL1/2 and genes controlled by MBNL2 in several regions of the brain and between the grey matter (GM) and white matter (WM) in DM1 patients using RT-PCR. Compared with the control, the percentage of spliced-in parameter (PSI) for most of the examined exons were significantly altered in most of the brain regions of DM1 patients, except for the cerebellum. The splicing of many genes was differently regulated between the GM and WM in both DM1 and control. The level of change in PSI between DM1 and control was higher in the GM than in the WM. The differences in alternative splicing between the GM and WM may be related to the effect of DM1 on the WM of the brain. We hypothesize that in DM1, aberrantly spliced isoforms in the neuronal cell body of the GM may not be transported to the axon. This might affect the WM as a consequence of Wallerian degeneration secondary to cell body damage. Our findings may have implications for analysis of the pathological mechanisms and exploring potential therapeutic targets.

scholarly journals Reconstitution of Herpes Simplex Virus Microtubule-Dependent Trafficking In Vitro

2006 ◽  
Vol 80 (9) ◽  
pp. 4264-4275 ◽  
Author(s):  
Grace E. Lee ◽  
John W. Murray ◽  
Allan W. Wolkoff ◽  
Duncan W. Wilson
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Fluorescent Protein ◽  
Neuronal Cell ◽  
Time Lapse ◽  
Neuronal Cell Body ◽  
Anterograde Transport ◽  
Simplex Virus

ABSTRACT Microtubule-mediated anterograde transport of herpes simplex virus (HSV) from the neuronal cell body to the axon terminal is crucial for the spread and transmission of the virus. It is therefore of central importance to identify the cellular and viral factors responsible for this trafficking event. In previous studies, we isolated HSV-containing cytoplasmic organelles from infected cells and showed that they represent the first and only destination for HSV capsids after they emerge from the nucleus. In the present study, we tested whether these cytoplasmic compartments were capable of microtubule-dependent traffic. Organelles containing green fluorescent protein-labeled HSV capsids were isolated and found to be able to bind rhodamine-labeled microtubules polymerized in vitro. Following the addition of ATP, the HSV-associated organelles trafficked along the microtubules, as visualized by time lapse microscopy in an imaging microchamber. The velocity and processivity of trafficking resembled those seen for neurotropic herpesvirus traffic in living axons. The use of motor-specific inhibitors indicated that traffic was predominantly kinesin mediated, consistent with the reconstitution of anterograde traffic. Immunocytochemical studies revealed that the majority of HSV-containing organelles attached to the microtubules contained the trans-Golgi network marker TGN46. This simple, minimal reconstitution of microtubule-mediated anterograde traffic should facilitate and complement molecular analysis of HSV egress in vivo.

scholarly journals Dual Role of Herpes Simplex Virus 1 pUS9 in Virus Anterograde Axonal Transport and Final Assembly in Growth Cones in Distal Axons

2015 ◽  
Vol 90 (5) ◽  
pp. 2653-2663 ◽  
Author(s):  
Monica Miranda-Saksena ◽  
Ross A. Boadle ◽  
Russell J. Diefenbach ◽  
Anthony L. Cunningham
Keyword(s):  
Axonal Transport ◽  
Cell Body ◽  
Virus Assembly ◽  
Neuronal Cell ◽  
Growth Cones ◽  
Neuronal Cell Body ◽  
Anterograde Axonal Transport ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACTThe herpes simplex virus type 1 (HSV-1) envelope protein pUS9 plays an important role in virus anterograde axonal transport and spread from neuronal axons. In this study, we used both confocal microscopy and transmission electron microscopy (TEM) to examine the role of pUS9 in the anterograde transport and assembly of HSV-1 in the distal axon of human and rat dorsal root ganglion (DRG) neurons using US9 deletion (US9−), repair (US9R), and wild-type (strain F, 17, and KOS) viruses. Using confocal microscopy and single and trichamber culture systems, we observed a reduction but not complete block in the anterograde axonal transport of capsids to distal axons as well as a marked (∼90%) reduction in virus spread from axons to Vero cells with the US9 deletion viruses. Axonal transport of glycoproteins (gC, gD, and gE) was unaffected. Using TEM, there was a marked reduction or absence of enveloped capsids, in varicosities and growth cones, in KOS strain and US9 deletion viruses, respectively. Capsids (40 to 75%) in varicosities and growth cones infected with strain 17, F, and US9 repair viruses were fully enveloped compared to less than 5% of capsids found in distal axons infected with the KOS strain virus (which also lacks pUS9) and still lower (<2%) with the US9 deletion viruses. Hence, there was a secondary defect in virus assembly in distal axons in the absence of pUS9 despite the presence of key envelope proteins. Overall, our study supports a dual role for pUS9, first in anterograde axonal transport and second in virus assembly in growth cones in distal axons.IMPORTANCEHSV-1 has evolved mechanisms for its efficient transport along sensory axons and subsequent spread from axons to epithelial cells after reactivation. In this study, we show that deletion of the envelope protein pUS9 leads to defects in virus transport along axons (partial defect) and in virus assembly and egress from growth cones (marked defect). Virus assembly and exit in the neuronal cell body are not impaired in the absence of pUS9. Thus, our findings indicate that pUS9 contributes to the overall HSV-1 anterograde axonal transport, including a major role in virus assembly at the axon terminus, which is not essential in the neuronal cell body. Overall, our data suggest that the process of virus assembly at the growth cones differs from that in the neuronal cell body and that HSV-1 has evolved different mechanisms for virus assembly and exit from different cellular compartments.

scholarly journals The transport properties of axonal microtubules establish their polarity orientation.

1993 ◽  
Vol 120 (6) ◽  
pp. 1427-1437 ◽  
Author(s):  
P W Baas ◽  
F J Ahmad
Keyword(s):  
Transport Properties ◽  
Cell Body ◽  
Sympathetic Neurons ◽  
Neuronal Cell ◽  
Axon Growth ◽  
Progressive Increase ◽  
Neuronal Cell Body ◽  
Drug Concentrations ◽  
Efficient Mechanisms ◽  
Uniform Polarity

It is well established that axonal microtubules (MTs) are uniformly oriented with their plus ends distal to the neuronal cell body (Heidemann, S. R., J. M. Landers, and M. A. Hamborg. 1981. J. Cell Biol. 91:661-665). However, the mechanisms by which these MTs achieve their uniform polarity orientation are unknown. Current models for axon growth differ with regard to the contributions of MT assembly and transport to the organization and elaboration of the axonal MT array. Do the transport properties or assembly properties of axonal MTs determine their polarity orientation? To distinguish between these possibilities, we wished to study the initiation and outgrowth of axons under conditions that would arrest MT assembly while maintaining substantial levels of preexisting polymer in the cell body that could still be transported into the axon. We found that we could accomplish this by culturing rat sympathetic neurons in the presence of nanomolar levels of vinblastine. In concentrations of the drug up to and including 100 nM, the neurons actively extend axons. The vinblastine-axons are shorter than control axons, but clearly contain MTs. To quantify the effects of the drug on MT mass, we compared the levels of polymer throughout the cell bodies and axons of neurons cultured overnight in the presence of 0, 16, and 50 nM vinblastine with the levels of MT polymer in freshly plated neurons before axon outgrowth. Without drug, the total levels of polymer increase by roughly twofold. At 16 nM vinblastine, the levels of polymer are roughly equal to the levels in freshly plated neurons, while at 50 nM, the levels of polymer are reduced by about half this amount. Thus, 16 nM vinblastine acts as a "kinetic stabilizer" of MTs, while 50 nM results in some net MT disassembly. At both drug concentrations, there is a progressive increase in the levels of MT polymer in the axons as they grow, and a corresponding depletion of polymer from the cell body. These results indicate that highly efficient mechanisms exist in the neuron to transport preassembled MTs from the cell body into the axon. These mechanisms are active even at the expense of the cell body, and even under conditions that promote some MT disassembly in the neuron. MT polarity analyses indicate that the MTs within the vinblastine-axons, like those in control axons, are uniformly plus-end-distal.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Mitochondria as Crucial Players in Demyelinated Axons: Lessons from Neuropathology and Experimental Demyelination

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Graham R. Campbell ◽  
Don J. Mahad
Keyword(s):  
Energy Demand ◽  
Structural Integrity ◽  
Harmful Effect ◽  
Neuronal Cell ◽  
Neuronal Cell Body ◽  
Energy Demands ◽  
The Central Nervous System ◽  
Experimental Demyelination

Mitochondria are the most efficient producers of energy in the form of ATP. Energy demands of axons, placed at relatively great distances from the neuronal cell body, are met by mitochondria, which when functionally compromised, produce reactive oxygen species (ROS) in excess. Axons are made metabolically efficient by myelination, which enables saltatory conduction. The importance of mitochondria for maintaining the structural integrity of myelinated axons is illustrated by neuroaxonal degeneration in primary mitochondrial disorders. When demyelinated, the compartmentalisation of ion channels along axons is disrupted. The redistribution of electrogenic machinery is thought to increase the energy demand of demyelinated axons. We review related studies that focus on mitochondria within unmyelinated, demyelinated and dysmyelinated axons in the central nervous system. Based on neuropathological observations we propose the increase in mitochondrial presence within demyelinated axons as an adaptive process to the increased energy need. An increased presence of mitochondria would also increase the capacity to produce deleterious agents such as ROS when functionally compromised. Given the lack of direct evidence of a beneficial or harmful effect of mitochondrial changes, the precise role of increased mitochondrial presence within axons due to demyelination needs to be further explored in experimental demyelinationin-vivoandin-vitro.

Sign in / Sign up

Export Citation Format

Share Document