scholarly journals Age-Dependent Decline in Neuron Growth Potential and Mitochondria Functions in Cortical Neurons

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1625
Author(s):  
Theresa C. Sutherland ◽  
Arthur Sefiani ◽  
Darijana Horvat ◽  
Taylor E. Huntington ◽  
Yuanjiu Lei ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Traumatic Injury ◽  
Axon Growth ◽  
Neurite Growth ◽  
Growth Potential ◽  
Mitochondrial Functions ◽  
Cord Injury ◽  
Age Dependent ◽  
Mitochondria Functions ◽  
The Impact

The age of incidence of spinal cord injury (SCI) and the average age of people living with SCI is continuously increasing. However, SCI is extensively modeled in young adult animals, hampering translation of research to clinical applications. While there has been significant progress in manipulating axon growth after injury, the impact of aging is still unknown. Mitochondria are essential to successful neurite and axon growth, while aging is associated with a decline in mitochondrial functions. Using isolation and culture of adult cortical neurons, we analyzed mitochondrial changes in 2-, 6-, 12- and 18-month-old mice. We observed reduced neurite growth in older neurons. Older neurons also showed dysfunctional respiration, reduced membrane potential, and altered mitochondrial membrane transport proteins; however, mitochondrial DNA (mtDNA) abundance and cellular ATP were increased. Taken together, these data suggest that dysfunctional mitochondria in older neurons may be associated with the age-dependent reduction in neurite growth. Both normal aging and traumatic injury are associated with mitochondrial dysfunction, posing a challenge for an aging SCI population as the two elements can combine to worsen injury outcomes. The results of this study highlight this as an area of great interest in CNS trauma.

scholarly journals The Age-Dependent Decline in Neuron Growth Potential in the CNS is Associated with an Age-Related Dysfunction of Neuronal Mitochondria

2021 ◽  
Author(s):  
Theresa C. Sutherland ◽  
Arthur Sefiani ◽  
Darijana Horvat ◽  
Taylor E. Huntington ◽  
Yuanjiu Lei ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Traumatic Injury ◽  
Axon Growth ◽  
Neurite Growth ◽  
Growth Potential ◽  
Age Related ◽  
Mitochondrial Functions ◽  
Cord Injury ◽  
Age Dependent ◽  
Neuron Growth

The age of incidence of Spinal Cord Injury (SCI) and the average age of people living with SCI is continuously increasing. In contrast, SCI is extensively modelled in young adult animals, hampering translation of research to clinical application. While there has been significant progress in manipulating axon growth after injury, how it is impacted by aging impacts this is still unknown. Aging is associated with a decline in mitochondrial functions, whereas mitochondria are essential to successful neurite and axon growth. Using isolation and culture of adult cortical neurons, we have analyzed mitochondrial changes in 2-, 6-, 12- and 18-month mice. We observed reduced neurite growth in older neurons. Older neurons also showed dysfunctional respiration, reduced membrane potential, and altered mitochondrial membrane transport proteins; however mitochondrial DNA (mtDNA) abundance and cellular ATP were increased. Taken together, these data suggest dysfunctional mitochondria in older neurons are involved in the age-dependent reduction in neuron growth. Both normal aging and traumatic injury are associated with mitochondrial dysfunction, posing a challenge for an aging SCI population as the two elements can compound one another to worsen injury outcomes. The results of this study highlight this as an area of great interest in CNS trauma.

scholarly journals Exosome-Mediated siRNA pool Inhibits Axonal Growth Inhibitor in Cortical Neurons of Spinal Cord Injury in Rats

2020 ◽  
Author(s):  
Qi Liao ◽  
Jiang-Hua Ming ◽  
Ge-Liang Hu
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cell Proliferation ◽  
Cortical Neurons ◽  
Axon Growth ◽  
Axonal Growth ◽  
Growth Inhibitor ◽  
Protective Role ◽  
Primary Cortical Neurons ◽  
Cord Injury

Abstract Background: As exosomes have been confirmed as a reservoir of siRNAs involved in certain diseases, the current study aims to investigate whether exosomal-siRNA could exert a protective role in spinal cord injury (SCI). Methods and Results: Exosomes in our experiment were isolated from lysosomal membrane-associated protein 2b (Lamp2b) overexpression HEK 293T cells, and purity of exosomes was characterized by the expression of CD9, CD47, and CD63 via western blot. Furthermore, the siRNA pool contains four siRNAs including siRNA-NgR, siRNA-LINGO-1, siRNA-Troy, and siRNA-PTEN was loaded to the exosomes, which indicated a significant role for the siRNA pool in reducing the expression of axon growth inhibitory factors. Upon the completion of loading into exosomes (exo-siRNA pool), the exo-siRNA pool was injected into primary cortical neurons of the SCI model in rats before cell proliferation and Rho expression were determined With the results revealed that purified addition could be applied to future experiments. The exo-siRNA pooled transfection caused downregulation of axon growth suppressors in primary cortical neurons including Nogo receptors (NgR), leucine-rich repeats and immunoglobulin domain-containing protein 1 (LINGO-1), Troy, and phosphatase and tenson homolog (PTEN). Cell proliferation and Rho expression of primary cortical neurons inhibited the expression of axonal growth inhibitors in rats with SCI by transfecting exogenous Sirna. Conclusion: This study confirmed that exosomes derived from Lamp2b overexpression HEK 293T cells facilitated both the recovery of functions and the survival of neurons when being loaded with the siRNA pool.

scholarly journals Bone Marrow Mesenchymal Stem Cell-Derived Exosome-Educated Macrophages Promote Functional Healing After Spinal Cord Injury

2021 ◽  
Vol 15 ◽  
Author(s):  
Chengjun Li ◽  
Tian Qin ◽  
Jinyun Zhao ◽  
Rundong He ◽  
Haicheng Wen ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Bone Marrow ◽  
Spinal Cord Injury ◽  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Cortical Neurons ◽  
Axon Growth ◽  
Sensory Function ◽  
Functional Assay ◽  
Cord Injury

The spinal cord injury is a site of severe central nervous system (CNS) trauma and disease without an effective treatment strategy. Neurovascular injuries occur spontaneously following spinal cord injury (SCI), leading to irreversible loss of motor and sensory function. Bone marrow mesenchymal stem cell (BMSC)–derived exosome-educated macrophages (EEM) have great characteristics as therapeutic candidates for SCI treatment. It remains unknown whether EEM could promote functional healing after SCI. The effect of EEM on neurovascular regeneration after SCI needs to be further explored. We generated M2-like macrophages using exosomes isolated from BMSCs, which were known as EEM, and directly used these EEM for SCI treatment. We aimed to investigate the effects of EEM using a spinal cord contusive injury mouse model in vivo combined with an in vitro cell functional assay and compared the results to those of a normal spinal cord without any biological intervention, or PBS treatment or macrophage alone (MQ). Neurological function measurements and histochemical tests were performed to evaluate the effect of EEM on angiogenesis and axon regrowth. In the current study, we found that treatment with EEM effectively promoted the angiogenic activity of HUVECs and axonal growth in cortical neurons. Furthermore, exogenous administration of EEM directly into the injured spinal cord could promote neurological functional healing by modulating angiogenesis and axon growth. EEM treatment could provide a novel strategy to promote healing after SCI and various other neurovascular injury disorders.

scholarly journals Ligand-Induced GPR110 Activation Facilitates Axon Growth after Injury

2021 ◽  
Vol 22 (7) ◽  
pp. 3386
Author(s):  
Heungsun Kwon ◽  
Karl Kevala ◽  
Hu Xin ◽  
Samarjit Patnaik ◽  
Juan Marugan ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Neurite Outgrowth ◽  
Nerve Injury ◽  
Cortical Neurons ◽  
Axon Growth ◽  
Neurite Growth ◽  
Nerve Crush ◽  
Developing Neurons

Recovery from axonal injury is extremely difficult, especially for adult neurons. Here, we demonstrate that the activation of G-protein coupled receptor 110 (GPR110, ADGRF1) is a mechanism to stimulate axon growth after injury. N-docosahexaenoylethanolamine (synaptamide), an endogenous ligand of GPR110 that promotes neurite outgrowth and synaptogenesis in developing neurons, and a synthetic GPR110 ligand stimulated neurite growth in axotomized cortical neurons and in retinal explant cultures. Intravitreal injection of GPR110 ligands following optic nerve crush injury promoted axon extension in adult wild-type, but not in gpr110 knockout, mice. In vitro axotomy or in vivo optic nerve injury rapidly induced the neuronal expression of gpr110. Activating the developmental mechanism of neurite outgrowth by specifically targeting GPR110 that is upregulated upon injury may provide a novel strategy for stimulating axon growth after nerve injury in adults.

Alteraciones sistémicas y metabólicas producidas por lesión medular

2019 ◽  
Vol 1 (1) ◽  
pp. 59-75
Author(s):  
Gabriel Guízar Sahagún
Keyword(s):  
Spinal Cord ◽  
Daily Living ◽  
Autonomic Function ◽  
Clinical Presentation ◽  
Scientific Literature ◽  
International Standards ◽  
Therapeutic Approaches ◽  
Cord Injury ◽  
Life Threatening ◽  
The Impact

Besides the well-known loss of motor and sensory capabilities, people with spinal cord injury (SCI) experience a broad range of systemic and metabolic abnormalities including, among others, dysfunction of cardiovascular, respiratory, gastrointestinal, urinary, and endocrine systems. These alterations are a significant challenge for patients with SCI because such disorders severely interfere with their daily living and can be potentially life-threatening. Most of these disorders are associated with impairment of regulation of the autonomic nervous system, arising from disruption of connections between higher brain centers and the spinal cord caudal to the injured zone. Thus, the higher and more complete the lesion, the greater the autonomic dysfunction and the severity of complications.This article summarizes the medical scientific literature on key systemic and metabolic alterations derived of SCI. It provides information primarily focused on the pathophysiology and clinical presentation of these disorders, as well as some guides to prevent and alleviate such complications. Due to the impact of these alterations, this topic must be a priority and diffuse to those involved with the care of people with SCI, including the patient himself/herself. We consider that any collaborative effort should be supported, like the development of international standards, to evaluate autonomic function after SCI, as well as the development of novel therapeutic approaches.

scholarly journals The Role of Lipids, Lipid Metabolism and Ectopic Lipid Accumulation in Axon Growth, Regeneration and Repair after CNS Injury and Disease

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1078
Author(s):  
Debasish Roy ◽  
Andrea Tedeschi
Keyword(s):  
Nervous System ◽  
Lipid Metabolism ◽  
Lipid Accumulation ◽  
Axon Regeneration ◽  
Axon Growth ◽  
The Body ◽  
Cns Repair ◽  
Cord Injury ◽  
Cns Trauma

Axons in the adult mammalian nervous system can extend over formidable distances, up to one meter or more in humans. During development, axonal and dendritic growth requires continuous addition of new membrane. Of the three major kinds of membrane lipids, phospholipids are the most abundant in all cell membranes, including neurons. Not only immature axons, but also severed axons in the adult require large amounts of lipids for axon regeneration to occur. Lipids also serve as energy storage, signaling molecules and they contribute to tissue physiology, as demonstrated by a variety of metabolic disorders in which harmful amounts of lipids accumulate in various tissues through the body. Detrimental changes in lipid metabolism and excess accumulation of lipids contribute to a lack of axon regeneration, poor neurological outcome and complications after a variety of central nervous system (CNS) trauma including brain and spinal cord injury. Recent evidence indicates that rewiring lipid metabolism can be manipulated for therapeutic gain, as it favors conditions for axon regeneration and CNS repair. Here, we review the role of lipids, lipid metabolism and ectopic lipid accumulation in axon growth, regeneration and CNS repair. In addition, we outline molecular and pharmacological strategies to fine-tune lipid composition and energy metabolism in neurons and non-neuronal cells that can be exploited to improve neurological recovery after CNS trauma and disease.

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