Neurodegeneration correlates with Alzheimer's disease (AD) symptoms, but the molecular identities of pathogenic amyloid β-protein (Aβ) oligomers and their targets, leading to neurodegeneration, remain unclear. Amylospheroids (ASPD) are AD patient-derived 10-to 15-nm spherical Aβ oligomers that cause selective degeneration of mature neurons. Here, we show that the ASPD target is neuronspecific Na + /K + -ATPase α3 subunit (NAKα3). ASPD-binding to NAKα3 impaired NAKα3-specific activity, activated N-type voltage-gated calcium channels, and caused mitochondrial calcium dyshomeostasis, tau abnormalities, and neurodegeneration. NMR and molecular modeling studies suggested that spherical ASPD contain N-terminal-Aβ-derived "thorns" responsible for target binding, which are distinct from low molecular-weight oligomers and dodecamers. The fourth extracellular loop (Ex4) region of NAKα3 encompassing Asn 879 and Trp 880 is essential for ASPD-NAKα3 interaction, because tetrapeptides mimicking this Ex4 region bound to the ASPD surface and blocked ASPD neurotoxicity. Our findings open up new possibilities for knowledge-based design of peptidomimetics that inhibit neurodegeneration in AD by blocking aberrant ASPD-NAKα3 interaction.NMR | computational modeling | abnormal protein-protein interaction in synapse | hyperexcitotoxicity | protein-protein interaction inhibitors

Background The presence of chronic kidney disease is a significant independent risk factor for poor prognosis in patients with chronic heart failure (CHF). However, the mechanisms and mediators underlying this interaction are poorly understood. In this study, we tested our hypothesis that chronic cardiac volume overload leads to de novo renal dysfunction by co-activating the sympathetic nervous system (SNS) and the renin-angiotensin system (RAS) in the kidney. We also examined the therapeutic potential of renal denervation and RAS inhibition to suppress renal injury in CHF. Methods and Results Sprague-Dawley rats underwent aortic regurgitation (AR) and were treated for 6 months with either vehicle, olmesartan [an angiotensin II (AngII) receptor blocker], or hydralazine. At 6 months, albuminuria and glomerular podocyte injury were significantly increased in AR rats. These changes were associated with increased urinary angiotensinogen excretion, kidney AngII and norepinephrine (NE) levels, as well as enhanced angiotensinogen and angiotensin type 1a receptor gene expression, and oxidative stress in renal cortical tissues. AR rats with renal denervation had decreased albuminuria and glomerular podocyte injury, which were associated with reduced kidney NE, angiotensinogen, AngII and oxidative stress. Renal denervation combined with olmesartan prevented podocyte injury and albuminuria induced by AR. Conclusions In this chronic cardiac volume overload animal model, activation of the SNS augments kidney RAS and oxidative stress, which act as crucial cardio-renal mediators. Renal denervation and olmesartan prevent the onset and progression of renal injury, providing new insight into the treatment of cardio-renal syndrome.

http://hyper.ahajournals.org/ Downloaded from Watanabe et al S(P)RR During Pregnancy 1251invasion and migration. 16,17 Clinically during pregnancy, it is well-known that even women with no complication exhibit BP changes with gestational age; the BP is typically at its lowest between 24 and 26 gestational weeks, increasing thereafter until the end of the pregnancy. 18 In addition, the circulating RAS is involved in the development of hypertensive disorders, including preeclampsia, during pregnancy. 1,16,19 However, no evidence suggests that the tissue RAS contributes to BP changes during pregnancy.On the basis of these background findings, the present study was conducted to examine whether the tissue RAS contributed to BP changes during pregnancy and the incidence of preeclampsia. To this end, we assessed the relationship between plasma s(P)RR concentrations and BP levels during pregnancy in a prospective cohort study. Methods Study ParticipantsIn this prospective cohort study, Japanese pregnant women whose first visit to the National Center for Child Health and Development hospital was at <16 weeks and 0 days of gestation were enrolled between January and December 2010. At recruitment, written informed consent was obtained from all participants. The study protocol was approved by the ethics committee of the National Center for Child Health and Development (Tokyo, Japan).The expected due date was confirmed by ultrasound in all participants. Inclusion criteria were systolic BP <140 mm Hg and diastolic BP <90 mm Hg at the time of enrollment (<16 weeks of gestation) and the absence of preexisting hypertensive disorders and renal disease. The study initially enrolled 477 pregnant women who met the criteria; however, 40 pregnant women were excluded because of early abortion (n=8) or the inability to follow-up because of relocation (n=32), resulting in a total of 437 study participants.Plasma samples were obtained at 3 prenatal visits throughout the pregnancy and at time of delivery. The first sample was obtained before 16 weeks 0 days gestation (early pregnancy), the second between 16 weeks 0 days and 27 weeks 6 days gestation (mid-pregnancy), and the third after 28 weeks 0 days gestation (late pregnancy) at routine blood testing during prenatal visits. The fourth blood sample was obtained at time of delivery. We determined s(P)RR concentrations for first, second, and third trimester using the blood samples obtained in early, middle, and late pregnancy, respectively. We then analyzed s(P) RR concentrations in early pregnancy in association with BP values measured at 16 to 20, 20 to 24, 24 to 28, 28 to 32, 32 to 36, and 36 to 40 weeks of gestation (6 periods). Similarly, s(P)RR concentrations in mid-pregnancy were analyzed in association with BP levels measured at 28 to 32, 32 to 36, and 36 to 40 weeks gestation (3 periods) and s(P)RR concentrations in late pregnancy with BP levels measured at 36 to 40 weeks gestation (1 period). Finally, s(P)RR at delivery was used for analysis of the association between s(P)RR conce...