👤 Yamile Bocanegra

To have maximal benefit, Alzheimer's disease-modifying treatments might need to be started before the onset of clinical symptoms. Mutations of the PSEN1 gene are inherited as fully penetrant, autosomal-dominant traits, which almost always result in the clinical onset of Alzheimer's disease before the age of 65 years. We aimed to evaluate the efficacy, including possible delayed emergence of cognitive impairment, and safety of crenezumab, an anti-amyloid monoclonal antibody, in cognitively unimpaired carriers of the PSEN1 This 5-8-year common-close, double-blind, placebo-controlled, single-centre trial screened kindred members aged 30-60 years from the main health-care site in Medellín, Colombia. Participants who were cognitively unimpaired and carried the PSEN1 619 Colombian API registrants were prescreened, 315 were assessed for eligibility, and 252 were enrolled (crenezumab-carrier, n=85; placebo-carrier, n=84; placebo-non-carrier, n=83; 160 [63%] women and 92 [37%] men) between Dec 20, 2013, and Feb 27, 2017. 237 (94%) completed the trial, with final data collection on March 22, 2022. The annualised rate of change in the API ADAD composite was -1·10 (SE 0·29) in the crenezumab group and -1·43 (0·29) in the placebo group (between-group difference 0·33 [95% CI -0·48 to 1·13]; p=0·43). The annualised rate of change in FCSRT-CI was -0·03 (0·00) in the crenezumab group and -0·04 (0·00) in the placebo group (between-group difference 0·01 [0·00 to 0·02]; p=0·16). All participants had at least one adverse event; serious adverse events occurred in 23 (27%) of 84 in the crenezumab group and 21 (25%) of 84 in the placebo group. No fatalities occurred. Crenezumab therapy administered for 5-8 years did not result in significant benefits on our primary clinical outcomes in cognitively unimpaired participants predisposed to developing ADAD dementia; secondary and exploratory outcomes also showed no significant effect on removal of amyloid plaques or other clinical or biomarker outcomes. Together with the results of other anti-amyloid β trials, robust fibrillar amyloid removal appears necessary for clinical efficacy in people with elevated brain amyloid. This study will further inform the biomarker, cognitive, and clinical trajectory of preclinical ADAD, the risk of clinical progression in amyloid-positive and amyloid-negative mutation carriers, and the size and design of future secondary and primary prevention trials. US National Institute on Aging (NIA), Banner Alzheimer's Institute, Genentech, F Hoffmann-La Roche. Show less

Silicon included in a restructured meat (RM) matrix (Si-RM) as a functional ingredient has been demonstrated to be a potential bioactive antidiabetic compound. However, the jejunal and hepatic molecular mechanisms by which Si-RM exerts its cholesterol-lowering effects remain unclear. Male Wistar rats fed an RM included in a high-saturated-fat high-cholesterol diet (HSFHCD) combined with a low dose of streptozotocin plus nicotinamide injection were used as late-stage type 2 diabetes mellitus (T2DM) model. Si-RM was included into the HSFHCD as a functional food. An early-stage TD2M group fed a high-saturated-fat diet (HSFD) was taken as reference. Si-RM inhibited the hepatic and intestinal microsomal triglyceride transfer protein (MTP) reducing the apoB-containing lipoprotein assembly and cholesterol absorption. Upregulation of liver X receptor (LXRα/β) by Si-RM turned in a higher low-density lipoprotein receptor (LDLr) and ATP-binding cassette transporters (ABCG5/8, ABCA1) promoting jejunal cholesterol efflux and transintestinal cholesterol excretion (TICE), and facilitating partially reverse cholesterol transport (RCT). Si-RM decreased the jejunal absorptive area and improved mucosal barrier integrity. Consequently, plasma triglycerides and cholesterol levels decreased, as well as the formation of atherogenic lipoprotein particles. Si-RM mitigated the dyslipidemia associated with late-stage T2DM by Improving cholesterol homeostasis. Silicon could be used as an effective nutritional approach in diabetic dyslipidemia management. Show less

The birth of widely available genomic databases at the turn of the millennium led to the identification of many previously unknown myosin genes and identification of novel classes of myosin, including MYO19. Further sequence analysis has revealed the unique evolutionary history of class XIX myosins. MYO19 is found in species ranging from vertebrates to some unicellular organisms, while it has been lost from some lineages containing traditional experimental model organisms. Unique sequences in the motor domain suggest class-specific mechanochemistry that may relate to its cellular function as a mitochondria-associated motor. Work over the past 10 years has demonstrated that MYO19 is an actin-activated ATPase capable of actin-based transport, and investigation of some of the conserved differences within the motor domain indicate their importance in MYO19 motor activity. The cargo-binding MyMOMA tail domain contains two distinct mechanisms of interaction with mitochondrial outer membrane components, and perturbation of MYO19 expression leads to alterations in mitochondrial movement and dynamics that impact cell function. This chapter summarizes the current state of the field and highlights potential new directions of inquiry. Show less

MYO19 interacts with mitochondria through a C-terminal membrane association domain (MyMOMA). Specific mechanisms for localization of MYO19 to mitochondria are poorly understood. Using promiscuous biotinylation data in combination with existing affinity-capture databases, we have identified a number of putative MYO19-interacting proteins. We chose to explore the interaction between MYO19 and the mitochondrial GTPase Miro2 by expressing mchr-Miro2 in combination with GFP-tagged fragments of the MyMOMA domain and assaying for recruitment of MYO19-GFP to mitochondria. Coexpression of MYO19 Show less