scholarly journals A(a)LS: Ammonia-induced amyotrophic lateral sclerosis

Author(s):  
Bhavin K Parekh

Amyotrophic lateral sclerosis (ALS) is a dreadful, devastating and incurable motor neuron disease. Aetiologically, it is a multigenic, multifactorial and multiorgan disease. Despite intense research, ALS pathology remains unexplained. After the literature review, this paper posits a new integrative explanation. This framework proposes that ammonia neurotoxicity is a main player in ALS pathogenesis. According to this explanation, a combination of impaired ammonia removal— mainly because of impaired hepatic urea cycle dysfunction—and increased ammoniagenesis— mainly because of impaired glycolytic metabolism in fast twitch skeletal muscle—causes chronic hyperammonia in ALS. In the absence of neuroprotective calcium binding proteins (calbindin, calreticulin and parvalbumin), elevated ammonia—a neurotoxin—damages motor neurons. Ammonia-induced motor neuron damage occurs through multiple mechanisms such as macroautophagy-endolysosomal impairment, ER-stress, CDK5 activation, oxidative/nitrosative stress and neuroinflammation. Furthermore, the regional pattern of calcium binding proteins’ loss, owing to either ER stress and/or impaired oxidative metabolism, determines clinical viabilities of ALS. Most importantly, this new framework can be generalised to explain other neurodegenerative disorders such as Huntington’s disease.

2015 ◽  
Author(s):  
Bhavin K Parekh

Amyotrophic lateral sclerosis (ALS) is a dreadful, devastating and incurable motor neuron disease. Aetiologically, it is a multigenic, multifactorial and multiorgan disease. Despite intense research, ALS pathology remains unexplained. After the literature review, this paper posits a new integrative explanation. This framework proposes that ammonia neurotoxicity is a main player in ALS pathogenesis. According to this explanation, a combination of impaired ammonia removal— mainly because of impaired hepatic urea cycle dysfunction—and increased ammoniagenesis— mainly because of impaired glycolytic metabolism in fast twitch skeletal muscle—causes chronic hyperammonia in ALS. In the absence of neuroprotective calcium binding proteins (calbindin, calreticulin and parvalbumin), elevated ammonia—a neurotoxin—damages motor neurons. Ammonia-induced motor neuron damage occurs through multiple mechanisms such as macroautophagy-endolysosomal impairment, ER-stress, CDK5 activation, oxidative/nitrosative stress and neuroinflammation. Furthermore, the regional pattern of calcium binding proteins’ loss, owing to either ER stress and/or impaired oxidative metabolism, determines clinical viabilities of ALS. Most importantly, this new framework can be generalised to explain other neurodegenerative disorders such as Huntington’s disease.


F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 119 ◽  
Author(s):  
Bhavin Parekh

Amyotrophic lateral sclerosis (ALS) is a dreadful, devastating and incurable motor neuron disease. Aetiologically, it is a multigenic, multifactorial and multiorgan disease. Despite intense research, ALS pathology remains unexplained. Following extensive literature review, this paper posits a new integrative explanation. This framework proposes that ammonia neurotoxicity is a main player in ALS pathogenesis. According to this explanation, a combination of impaired ammonia removal— mainly because of impaired hepatic urea cycle dysfunction—and increased ammoniagenesis— mainly because of impaired glycolytic metabolism in fast twitch skeletal muscle—causes chronic hyperammonia in ALS. In the absence of neuroprotective calcium binding proteins (calbindin, calreticulin and parvalbumin), elevated ammonia—a neurotoxin—damages motor neurons. Ammonia-induced motor neuron damage occurs through multiple mechanisms such as macroautophagy-endolysosomal impairment, endoplasmic reticulum (ER) stress, CDK5 activation, oxidative/nitrosative stress, neuronal hyperexcitability and neuroinflammation. Furthermore, the regional pattern of calcium binding proteins’ loss, owing to either ER stress and/or impaired oxidative metabolism, determines clinical variability of ALS. Most importantly, this new framework can be generalised to explain other neurodegenerative disorders such as Huntington’s disease and Parkinsonism.


1994 ◽  
Vol 36 (6) ◽  
pp. 846-858 ◽  
Author(s):  
Maria E. Alexianu ◽  
Bao-Kuang Ho ◽  
A. Habib Mohamed ◽  
Vincenzo La Bella ◽  
R. Glenn Smith ◽  
...  

Contact ◽  
2021 ◽  
Vol 4 ◽  
pp. 251525642110225
Author(s):  
Nica Borgese ◽  
Francesca Navone ◽  
Nobuyuki Nukina ◽  
Tomoyuki Yamanaka

Nearly twenty years ago a mutation in the VAPB gene, resulting in a proline to serine substitution (p.P56S), was identified as the cause of a rare, slowly progressing, familial form of the motor neuron degenerative disease Amyotrophic Lateral Sclerosis (ALS). Since then, progress in unravelling the mechanistic basis of this mutation has proceeded in parallel with research on the VAP proteins and on their role in establishing membrane contact sites between the ER and other organelles. Analysis of the literature on cellular and animal models reviewed here supports the conclusion that P56S-VAPB, which is aggregation-prone, non-functional and unstable, is expressed at levels that are insufficient to support toxic gain-of-function or dominant negative effects within motor neurons. Instead, insufficient levels of the product of the single wild-type allele appear to be required for pathological effects, and may be the main driver of the disease. In light of the multiple interactions of the VAP proteins, we address the consequences of specific VAPB depletion and highlight various affected processes that could contribute to motor neuron degeneration. In the future, distinction of specific roles of each of the two VAP paralogues should help to further elucidate the basis of p.P56S familial ALS, as well as of other more common forms of the disease.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1449
Author(s):  
Cyril Quessada ◽  
Alexandra Bouscary ◽  
Frédérique René ◽  
Cristiana Valle ◽  
Alberto Ferri ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive and selective loss of motor neurons, amyotrophy and skeletal muscle paralysis usually leading to death due to respiratory failure. While generally considered an intrinsic motor neuron disease, data obtained in recent years, including our own, suggest that motor neuron protection is not sufficient to counter the disease. The dismantling of the neuromuscular junction is closely linked to chronic energy deficit found throughout the body. Metabolic (hypermetabolism and dyslipidemia) and mitochondrial alterations described in patients and murine models of ALS are associated with the development and progression of disease pathology and they appear long before motor neurons die. It is clear that these metabolic changes participate in the pathology of the disease. In this review, we summarize these changes seen throughout the course of the disease, and the subsequent impact of glucose–fatty acid oxidation imbalance on disease progression. We also highlight studies that show that correcting this loss of metabolic flexibility should now be considered a major goal for the treatment of ALS.


2019 ◽  
Vol 27 (4) ◽  
pp. 1369-1382 ◽  
Author(s):  
Honglin Tan ◽  
Mina Chen ◽  
Dejiang Pang ◽  
Xiaoqiang Xia ◽  
Chongyangzi Du ◽  
...  

Abstract Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive loss of motor neurons. Improving neuronal survival in ALS remains a significant challenge. Previously, we identified Lanthionine synthetase C-like protein 1 (LanCL1) as a neuronal antioxidant defense gene, the genetic deletion of which causes apoptotic neurodegeneration in the brain. Here, we report in vivo data using the transgenic SOD1G93A mouse model of ALS indicating that CNS-specific expression of LanCL1 transgene extends lifespan, delays disease onset, decelerates symptomatic progression, and improves motor performance of SOD1G93A mice. Conversely, CNS-specific deletion of LanCL1 leads to neurodegenerative phenotypes, including motor neuron loss, neuroinflammation, and oxidative damage. Analysis reveals that LanCL1 is a positive regulator of AKT activity, and LanCL1 overexpression restores the impaired AKT activity in ALS model mice. These findings indicate that LanCL1 regulates neuronal survival through an alternative mechanism, and suggest a new therapeutic target in ALS.


2011 ◽  
Vol 3 (1) ◽  
pp. 4 ◽  
Author(s):  
Aline Furtado Bastos ◽  
Marco Orsini ◽  
Dionis Machado ◽  
Mariana Pimentel Mello ◽  
Sergio Nader ◽  
...  

The Amyotrophic lateral sclerosis (ALS) is the most common form of motor neuron disease in the adulthood, and it is characterized by rapid and progressive compromise of the upper and lower motor neurons. The majority of the cases of ALS are classified as sporadic and, until now, a specific cause for these cases still is unknown. To present the different hypotheses on the etiology of ALS. It was carried out a search in the databases: Bireme, Scielo and Pubmed, in the period of 1987 to 2011, using the following keywords: Amyotrophic lateral sclerosis, motor neuron disease, etiology, causes and epidemiology and its similar in Portuguese and Spanish. It did not have consensus as regards the etiology of ALS. Researches demonstrates evidences as regards intoxication by heavy metals, environmental and occupational causes, genetic mutations (superoxide dismutase 1), certain viral infections and the accomplishment of vigorous physical activity for the development of the disease. There is still no consensus regarding the involved factors in the etiology of ALS. In this way, new research about these etiologies are necessary, for a better approach of the patients, promoting preventive programs for the disease and improving the quality of life of the patients.


2016 ◽  
Vol 74 (10) ◽  
pp. 849-854
Author(s):  
Paulo Victor Sgobbi de Souza ◽  
Wladimir Bocca Vieira de Rezende Pinto ◽  
Flávio Moura Rezende Filho ◽  
Acary Souza Bulle Oliveira

ABSTRACT Motor neuron disease is one of the major groups of neurodegenerative diseases, mainly represented by amyotrophic lateral sclerosis. Despite wide genetic and biochemical data regarding its pathophysiological mechanisms, motor neuron disease develops under a complex network of mechanisms not restricted to the unique functions of the alpha motor neurons but which actually involve diverse functions of glial cell interaction. This review aims to expose some of the leading roles of glial cells in the physiological mechanisms of neuron-glial cell interactions and the mechanisms related to motor neuron survival linked to glial cell functions.


Sign in / Sign up

Export Citation Format

Share Document