Protein kinetics of superoxide dismutase-1 in familial and sporadic amyotrophic lateral sclerosis.

OBJECTIVE: Accumulation of misfolded superoxide dismutase-1 (SOD1) is a pathological hallmark of SOD1-related amyotrophic lateral sclerosis (ALS) and is observed in sporadic ALS where its role in pathogenesis is controversial. Understanding in vivo protein kinetics may clarify how SOD1 influences neurodegeneration and inform optimal dosing for therapies that lower SOD1 transcripts. METHODS: We employed stable isotope labeling paired with mass spectrometry to evaluate in vivo protein kinetics and concentration of soluble SOD1 in cerebrospinal fluid (CSF) of SOD1 mutation carriers, sporadic ALS participants and controls. A deaminated SOD1 peptide, SDGPVKV, that correlates with protein stability was also measured. RESULTS: In participants with heterozygous SOD1A5V mutations, known to cause rapidly progressive ALS, mutant SOD1 protein exhibited ~twofold faster turnover and ~ 16-fold lower concentration compared to wild-type SOD1 protein. SDGPVKV levels were increased in SOD1A5V carriers relative to controls. Thus, SOD1 mutations impact protein kinetics and stability. We applied this approach to sporadic ALS participants and found that SOD1 turnover, concentration, and SDGPVKV levels are not significantly different compared to controls. INTERPRETATION: These results highlight the ability of stable isotope labeling approaches and peptide deamidation to discern the influence of disease mutations on protein kinetics and stability and support implementation of this method to optimize clinical trial design of gene and molecular therapies for neurological disorders. TRIAL REGISTRATION: Clinicaltrials.gov: NCT03449212.

Assessment of the Psychosocial Impact of Pancreatic Cancer Surveillance in High-Risk Individuals.

OBJECTIVES: Pancreatic cancer (PC) surveillance of high-risk individuals (HRIs) downstages PC and improves survival. However, it remains less clear whether PC surveillance has a positive psychosocial impact on HRIs. Herein, we aimed to define the attitudes and beliefs of HRIs undergoing PC surveillance, and the immediate and sustained psychosocial impact of PC surveillance in HRIs. METHODS: 100 HRIs undergoing PC surveillance by endoscopic ultrasound (EUS) completed three surveys addressing different components of the psychosocial impact of PC surveillance. Logistic regression analyses were performed to identify predictive factors relating to these components. RESULTS: Most HRIs reported increased perceived benefits of PC surveillance, self-efficacy, and perceived severity of PC. HRIs reported few negative emotions prior to surveillance and frequent positive emotions after surveillance. Compared to prior to surveillance, there was a 53.5% decrease in the level of distress reported by HRIs after surveillance, which was sustained for 4-6 weeks post-surveillance. Family history of PC and lower self-reported mental health were identified as predictors for increased perceived susceptibility to PC (p < 0.01) and greater change in distress pre- to post-surveillance (p < 0.01), respectively. CONCLUSIONS: Our findings suggest that PC surveillance can lead to sustained psychosocial benefits in HRIs.