Metabolic Bypass Rescues Aberrant S-nitrosylation-Induced TCA Cycle Inhibition and Synapse Loss in Alzheimer's Disease Human Neurons.

In Alzheimer's disease (AD), dysfunctional mitochondrial metabolism is associated with synaptic loss, the major pathological correlate of cognitive decline. Mechanistic insight for this relationship, however, is still lacking. Here, comparing isogenic wild-type and AD mutant human induced pluripotent stem cell (hiPSC)-derived cerebrocortical neurons (hiN), evidence is found for compromised mitochondrial energy in AD using the Seahorse platform to analyze glycolysis and oxidative phosphorylation (OXPHOS). Isotope-labeled metabolic flux experiments revealed a major block in activity in the tricarboxylic acid (TCA) cycle at the α-ketoglutarate dehydrogenase (αKGDH)/succinyl coenzyme-A synthetase step, metabolizing α-ketoglutarate to succinate. Associated with this block, aberrant protein S-nitrosylation of αKGDH subunits inhibited their enzyme function. This aberrant S-nitrosylation is documented not only in AD-hiN but also in postmortem human AD brains versus controls, as assessed by two separate unbiased mass spectrometry platforms using both SNOTRAP identification of S-nitrosothiols and chemoselective-enrichment of S-nitrosoproteins. Treatment with dimethyl succinate, a cell-permeable derivative of a TCA substrate downstream to the block, resulted in partial rescue of mitochondrial bioenergetic function as well as reversal of synapse loss in AD-hiN. These findings have therapeutic implications that rescue of mitochondrial energy metabolism can ameliorate synaptic loss in hiPSC-based models of AD.

Trends and Racial/Ethnic Disparities in the Rates of Pre-eclampsia by HIV Status in the US.

BACKGROUND: Preeclampsia and HIV account for a significant proportion of the global burden of disease and pose severe maternal-fetal risks. There is a dearth of literature regarding racial/ethnic disparities in preeclampsia associated with HIV/AIDS in the US. METHODS: We retrospectively analyzed data from the National Inpatient Sample (NIS) database from 2002 to 2015 on a cohort of hospitalized pregnant women with or without preeclampsia and HIV. Joinpoint regression models were used to identify trends in the rates of preeclampsia among pregnant women living with or without HIV, stratified by race/ethnicity over the study period. We also assessed the association between preeclampsia and various socio-demographic factors. RESULTS: We analyzed over 60 million pregnancy-related hospitalizations, of which 3665 had diagnoses of preeclampsia and HIV, corresponding to a rate of 0.61 per 10,000. There was an increasing trend in the diagnosis of preeclampsia among hospitalized, pregnant women without HIV across each racial/ethnic category. The highest prevalence of preeclampsia was among non-Hispanic (NH) Blacks, regardless of HIV status. CONCLUSION: The increase in rates of pre-eclampsia between 2002 and 2015 was mostly noted among pregnant women without HIV. Regardless of HIV status, NH-Blacks experienced the highest discharge prevalence of preeclampsia.