Spinal muscular atrophy (SMA) is a devastating childhood disease primarily affecting lower motoneurons in the spinal cord. SMA is caused by the loss of functional survival of motoneuron (SMN) protein, leading to structural and functional alterations of the cytoskeleton in motoneurons and other cells. Loss of SMN results in impairments of microtubule architecture, but the underlying mechanisms are not completely understood. In this study, we mechanistically analyzed the effects of SMN deficiency on microtubules, demonstrating a reduced stability together with a reduction in alpha tubulin detyrosination. This was caused by increased levels of microtubule-associated protein 1B and tubulin tyrosine ligase, resulting in mitochondrial mislocalization in SMA. Our findings suggest that altered tubulin post-translational modifications and microtubule-associated proteins are involved in the pathomechanisms of SMA, such as an impaired axonal transport of mitochondria.

Exercise studies in neuromuscular diseases like spinal muscular atrophy (SMA), a devastating disease caused by survival of motor neuron 1 (SMN1) gene mutations, are drawing attention due to its beneficial effects. In this study, we presented a constructed arm cycling exercise protocol and evaluated the benefits on SMA patients. Five SMA type II patients performed 12 weeks of supervised arm cycling exercise. The physical functions were evaluated together with the SMN2 copy numbers, SMN protein levels, insulin-like growth factor 1(IGF1) and binding protein 3 (IGFBP3) levels. The active cycling distance and duration of patients significantly improved. Significant changes could not have detected either SMN or IGF1 and IGFBP3 levels in response to exercise. The findings demonstrated that the patients tolerated the exercise protocol and gained a benefit from arm cycling but benefits could not be associated with SMN2 copy number, SMN protein level, IGF1, or IGFBP3 levels.

The Golgi complex is a highly dynamic and tightly regulated cellular organelle with essential roles in the processing as well as the sorting of proteins and lipids. Its structure undergoes rapid disassembly and reassembly during normal physiological processes, including cell division, migration, polarization, differentiation, and cell death. Golgi dispersal or fragmentation also occurs in pathological conditions, such as neurodegenerative diseases, infectious diseases, congenital disorders of glycosylation diseases, and cancer. In this review, current knowledge about both structural organization and morphological alterations in the Golgi in physiological and pathological conditions is summarized together with the methodologies that help to reveal its structure.