High-throughput screening reveals novel mutations in spinal muscular atrophy patients

Cytoskeletal protein SPTA1 mediating the decrease in erectile function induced by high-fat diet via Hippo signaling pathway

BACKGROUND

The mechanism of high-fat diet (HFD)-induced decrease in erectile function has not been elucidated, and in previous studies, spectrin alpha, erythrocytic 1 (SPTA1) is a cytoskeletal protein that regulates cellular function, which belongs to a family of proteins that can affect cell and tissue growth and development by regulating YAP, an effector on the Hippo signaling pathway, but its particular role has not been elucidated.

OBJECTIVE

To explore the role of SPTA1 in the abnormality of erectile function induced by HFD.

METHODS

We analyzed the penile tissues of mice on normal diet and HFD by transcriptomics and screened for differentially expressed genes, further identified closely related target genes in rat penile tissues, and verified target gene expression in in vitro construction of high-glucose (HG)-treated corpus cavernosum endothelial cells (CCECs) and corpus cavernosum smooth muscle cells (CCSMCs) models. The distribution of target genes in various cell populations in penile tissues was retrieved by single-cell sequencing Male Health Atlas database. Moreover, interfering with target genes was further applied to explore the mechanisms involved in erectile function decline.

RESULTS

Transcriptomic analysis screened out down-regulated differential gene SPTA1; Western blot and immunohistochemistry results showed that SPTA1 expression significantly decreased in the penile tissues of Sprague-Dawley (SD) rats in the HFD group. Immunofluorescence staining showed a positive expression of CD31 and VWF in CCECs and a positive expression of α-SMA in CCSMCs. The expression level of SPTA1 protein significantly decreased in the HG group of CCECs and CCSMCs. The expression of SPTA1 mRNA significantly decreased in CCSMCs while significantly increased in CCECs. SPTA1 may have various expression patterns and biological functions in different cell populations. Real-time quantitative PCR results showed that the siSPTA1 transfected in CCSMCs had a significant interference effect compared with the control siNC. Transfection of siSPTA1 into CCSMCs resulted in the significant down-regulation of mRNA and protein expression of eNOS, and significant up-regulation of YAP, Caspase-1, GSDMD, GSDMD-N IL-18, and IL-1β protein expression levels. The expression level of CCSMCs contractile-type protein α-SMA was significantly down-regulated.

CONCLUSIONS

The down-regulation of SPTA1 in SD rats fed with HFD may induce cell pyroptosis and lead to the decrease of erectile function by activating the Hippo pathway; these findings may provide new therapeutic targets for improving erectile function.

Stress granules in the spinal muscular atrophy and amyotrophic lateral sclerosis: The correlation and promising therapy

Increasing genetic and biochemical evidence has broadened our view of the pathomechanisms that lead to Spinal muscular atrophy (SMA) and Amyotrophic lateral sclerosis (ALS), two fatal neurodegenerative diseases with similar symptoms and causes. Stress granules are dynamic cytosolic storage hubs for mRNAs in response to stress exposures, that are evolutionarily conserved cytoplasmic RNA granules in somatic cells. A lot of previous studies have shown that the impaired stress granules are crucial events in SMA/ALS pathogenesis. In this review, we described the key stress granules related RNA binding proteins (SMN, TDP-43, and FUS) involved in SMA/ALS, summarized the reported mutations in these RNA binding proteins involved in SMA/ALS pathogenesis, and discussed the mechanisms through which stress granules dynamics participate in the diseases. Meanwhile, we described the applications and limitation of current therapies targeting SMA/ALS. We futher proposed the promising targets on stress granules in the future therapeutic interventions of SMA/ALS.