The gene ANXA11, which is known to be mutated in amyotrophic lateral sclerosis (ALS), contributes to the neurodegenerative disease in two distinct ways, according to a new study appearing in Science Translational Medicine this week. Mutations in ANXA11, which encodes a Ca2+-dependent phospholipid-binding protein, were recently identified in people with both familial and sporadic ALS through whole-exome sequencing, but its physiological and pathophysiological roles in ALS remain unknown. To investigate, scientists from Hanyang University analyzed the exome sequences of 500 Korean patients with sporadic ALS and identified nine ANXA11 variants in 13 patients. Certain of these variants were found to induce alterations in intracellular calcium homeostasis and delay stress granule disassembly, both of which are increasingly recognized as critical components of ALS pathology, the researchers write. In light of these separate disease-associated mechanisms, "multitarget therapeutic strategies may be the ideal comprehensive approach for more effective ALS management," the study's authors write.
Amid growing evidence linking autism spectrum disorder (ASD) with dysbiosis in the gut microbiome, scientists from Peking University have discovered enzyme deficiencies in autistic children that appear to affect the breakdown of toxins in the intestines. As reported in Science Advances, the investigators used a novel strategy for metagenomic analysis that pairs ASD samples with control samples of similar metabolic background. They also performed shotgun-based metagenome sequencing of fecal samples from ASD individuals and healthy controls in order to identify apparent deficiencies in deoxidation and toxicant-degradation pathways in ASD microbiome. With this approach, they identify significant deficiencies in ASD children in detoxifying enzymes and pathways, which show a strong correlation with biomarkers of mitochondrial dysfunction. Given that toxin exposure has been shown to be one of the main etiological factors of ASD, impairment of the intestinal microbiome's ability to clear toxins suggests a "previously unknown mechanism to explain why patients with ASD are more vulnerable to toxicant exposure and how the intestinal microbiome contributes to the pathogenesis of ASD," the researchers write. The findings may also aid in the development of future therapeutic strategies based on restoring microbial detoxification capabilities in ASD patients.