👤 Hezzy Shmueli

The protease BACE1 is a major drug target for Alzheimer's disease, but chronic BACE1 inhibition is associated with non-progressive cognitive worsening that may be caused by modulation of unknown physiological BACE1 substrates. To identify in vivo-relevant BACE1 substrates, we applied pharmacoproteomics to non-human-primate cerebrospinal fluid (CSF) after acute treatment with BACE inhibitors. Besides SEZ6, the strongest, dose-dependent reduction was observed for the pro-inflammatory cytokine receptor gp130/IL6ST, which we establish as an in vivo BACE1 substrate. Gp130 was also reduced in human CSF from a clinical trial with a BACE inhibitor and in plasma of BACE1-deficient mice. Mechanistically, we demonstrate that BACE1 directly cleaves gp130, thereby attenuating membrane-bound gp130 and increasing soluble gp130 abundance and controlling gp130 function in neuronal IL-6 signaling and neuronal survival upon growth-factor withdrawal. BACE1 is a new modulator of gp130 function. The BACE1-cleaved, soluble gp130 may serve as a pharmacodynamic BACE1 activity marker to reduce the occurrence of side effects of chronic BACE1 inhibition in humans. Show less

Peripartum cardiomyopathy (PPCM) is a rare but potentially devastating complication of pregnancy. Although the pathophysiology of PPCM is not fully understood, there are known risk factors for developing PPCM, which are maternal and gestation related. In the first wave of the coronavirus disease 2019 (COVID-19) pandemic, we witnessed an elevated incidence of PPCM among COVID-19 survivors. To present a single-center case series of three patients diagnosed with peripartum cardiomyopathy after recovered from COVID-19 during the index pregnancy. In this single center case study, all patients diagnosed with PPCM at our institute during the examined time frame were included. Electronic medical records were studied. Three patients previously diagnosed with asymptomatic or mildly symptomatic COVID-19 disease during pregnancy presented with PPCM before or shortly after delivery. Patients underwent testing to rule out residual COVID-19 myocarditis, were treated pharmacologically and with wearable defibrillators as needed, and were examined in follow-up 1-9 months after delivery. Residual endothelial damage due to COVID-19 disease, even if originally mild in presentation, could predispose pregnant patients to PPCM and should be considered as a risk factor when assessing patients with new onset symptoms of heart failure. Further research is needed to confirm this hypothesis and fully determine the underlying pathophysiology. These preliminary findings warrant a high index of suspicion for PPCM in COVID-19 recoverers. Show less