scholarly journals Spinal motor neuron loss occurs through a p53-and-p21-independent mechanism in the Smn mouse model of spinal muscular atrophy

2021 ◽  
Vol 337 ◽  
pp. 113587
Author(s):  
Emily J. Reedich ◽  
Martin Kalski ◽  
Nicholas Armijo ◽  
Gregory A. Cox ◽  
Christine J. DiDonato
Author(s):  
V. Manochithra ◽  
G. Sumithra

Spinal muscular atrophy (SMA) describes a group of disorders associated with spinal motor neuron loss. In this review we provide an update regarding the most common form of SMA, proximal or 5q SMA, and discuss the contemporary approach to diagnosis and treatment. Electromyography and muscle biopsy features of denervation were once the basis for diagnosis, but molecular testing for homozygous deletion or mutation of the SMN1 gene allows efficient and specific diagnosis. In combination with loss of SMN1, patients retain variable numbers of copies of a second similar gene, SMN2, which produce reduced levels of the survival motor neuron (SMN) protein that are insufficient for normal motor neuron function. Despite the fact that the understanding of how ubiquitous reduction of SMN protein leads to motor neuron loss remains incomplete, several promising therapeutics are now being tested in early phase clinical trials. This proposed model investigates the symptoms and scans readings from the initial MRI scan images of babies with mutation progress and SMN proteins formation benchmark values for this particular disorder SMA and further this segmented parameters are acquitted into the K-means clustering technique that predict the report with the disorder symptoms with MSE (mean square error) values that helps the babies in future to take prevention measures to overcome this problem.


2017 ◽  
Vol 26 (17) ◽  
pp. 3409-3420 ◽  
Author(s):  
Samantha L. Sison ◽  
Teresa N. Patitucci ◽  
Emily R. Seminary ◽  
Eric Villalon ◽  
Christian L. Lorson ◽  
...  

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Beth B Murinson ◽  
Norman J Haughey ◽  
Nicholas J Maragakis

2019 ◽  
Author(s):  
AM Rossor ◽  
JN Sleigh ◽  
M Groves ◽  
F Muntoni ◽  
MM Reilly ◽  
...  

AbstractBICD2 is a key component of the dynein/dynactin motor complex. Autosomal dominant mutations in BICD2 cause Spinal Muscular Atrophy Lower Extremity Predominant 2 (SMALED2), a developmental disease of motor neurons. In this study we sought to examine the motor neuron phenotype of conditional Bicd2−/− mice. Bicd2−/− mice show a significant reduction in the number of motor axons of the L4 ventral root compared to wild type mice. Muscle-specific knockout of Bicd2, but not motor neuron-specific Bicd2 loss, results in a reduction in L4 ventral axons comparable to global Bicd2−/− mice. Rab6, a small GTPase required for the sorting of secretory vesicles from the TGN to the plasma membrane is a major binding partner of BICD2. We therefore examined the secretory pathway in SMALED2 patient fibroblasts and demonstrated impaired flow of constitutive secretory cargoes. Together, these data indicate that BICD2 loss from muscles is a major driver of non-cell autonomous pathology with important implications for future therapeutic approaches to SMALED2.SummaryMissense mutations in the cargo adaptor protein BICD2 cause SMALED2, a developmental disease of motor neurons. In this study, the authors show that BICD2 mutations cause motor neuron loss by a non-cell autonomous mechanism determining a disabling impairment of muscle function.


2021 ◽  
Vol 22 (16) ◽  
pp. 8494
Author(s):  
Anton J. Blatnik ◽  
Vicki L. McGovern ◽  
Arthur H. M. Burghes

Proximal spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder characterized by motor neuron loss and subsequent atrophy of skeletal muscle. SMA is caused by deficiency of the essential survival motor neuron (SMN) protein, canonically responsible for the assembly of the spliceosomal small nuclear ribonucleoproteins (snRNPs). Therapeutics aimed at increasing SMN protein levels are efficacious in treating SMA. However, it remains unknown how deficiency of SMN results in motor neuron loss, resulting in many reported cellular functions of SMN and pathways affected in SMA. Herein is a perspective detailing what genetics and biochemistry have told us about SMA and SMN, from identifying the SMA determinant region of the genome, to the development of therapeutics. Furthermore, we will discuss how genetics and biochemistry have been used to understand SMN function and how we can determine which of these are critical to SMA moving forward.


Author(s):  
Alexander M. Rossor ◽  
James N. Sleigh ◽  
Michael Groves ◽  
Francesco Muntoni ◽  
Mary M. Reilly ◽  
...  

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