Lipid Metabolism
lipid metabolism
Metabolic Remodelling in the Developing Forebrain in Health and Disease
Little is known about the critical metabolic changes that neural cells have to undergo during development and how temporary shifts in this program can influence brain circuitries and behavior. Motivated by the identification of autism-associated mutations in SLC7A5, a transporter for metabolically essential large neutral amino acids (LNAAs), we utilized metabolomic profiling to investigate the metabolic states of the cerebral cortex across various developmental stages. Our findings reveal significant metabolic restructuring occurring in the forebrain throughout development, with specific groups of metabolites exhibiting stage-specific changes. Through the manipulation of Slc7a5 expression in neural cells, we discovered an interconnected relationship between the metabolism of LNAAs and lipids within the cortex. Neuronal deletion of Slc7a5 influences the postnatal metabolic state, resulting in a shift in lipid metabolism and a cell-type-specific modification in neuronal activity patterns. This ultimately gives rise to enduring circuit dysfunction.
Cholesterol and matrisome pathways dysregulated in Alzheimer’s disease brain astrocytes and microglia
The impact of apolipoprotein E ε4 (APOE4), the strongest genetic risk factor for Alzheimer’s disease (AD), on human brain cellular function remains unclear. Here, we investigated the effects of APOE4 on brain cell types derived from population and isogenic human induced pluripotent stem cells, post-mortem brain, and APOE targeted replacement mice. Population and isogenic models demonstrate that APOE4 local haplotype, rather than a single risk allele, contributes to risk. Global transcriptomic analyses reveal human-specific, APOE4-driven lipid metabolic dysregulation in astrocytes and microglia. APOE4 enhances de novo cholesterol synthesis despite elevated intracellular cholesterol due to lysosomal cholesterol sequestration in astrocytes. Further, matrisome dysregulation is associated with upregulated chemotaxis, glial activation, and lipid biosynthesis in astrocytes co-cultured with neurons, which recapitulates altered astrocyte matrisome signaling in human brain. Thus, APOE4 initiates glia-specific cell and non-cell autonomous dysregulation that may contribute to increased AD risk." https://doi.org/10.1016/j.cell.2022.05.017
Pro-regenerative functions of microglia in demyelinating diseases
Our goal is to understand why myelin repair fails in multiple sclerosis and to develop regenerative medicines for the nervous system. A central obstacle for progress in this area has been the complex biology underlying the response to CNS injury. Acute CNS damage is followed by a multicellular response that encompasses different cell types and spans different scales. Currently, we do not understand which factors determines lesion recovery. Failure of inflammation to resolve is a key underlying reason of poor regeneration, and one focus is therefore on the biology of microglia during de- and remyelination, and their cross talk to other cells, in particular oligodendrocytes and the progenitor cells. In addition, we are exploring the link between lipid metabolism and inflammation, and its role in the regulation of regeneration. I will report about our recent progress in our understanding of how microglia promote regeneration in the CNS.
Phospholipid regulation in cognitive impairment and vascular dementia
An imbalance in lipid metabolism in neurodegeneration is still poorly understood. Phospholipids (PLs) have multifactorial participation in vascular dementia as Alzheimer, post-stroke dementia, CADASIL between others. Which include the hyperactivation of phospholipases, mitochondrial stress, peroxisomal dysfunction and irregular fatty acid composition triggering proinflammation in a very early stage of cognitive impairment. The reestablishment of physiological conditions of cholesterol, sphingolipids, phospholipids and others are an interesting therapeutic target to reduce the progression of AD. We propose the positive effect of BACE1 silencing produces a balance of phospholipid profile in desaturase enzymes-depending mode to reduce the inflammation response, and recover the cognitive function in an Alzheimer´s animal and brain stroke models. Pointing out there is a great need for new well-designed research focused in preventing phospholipids imbalance, and their consequent energy metabolism impairment, pro-inflammation and enzymatic over-processing, which would help to prevent unhealthy aging and AD progression.
Neurocircuits in control of integrative physiology
This open colloquia session is part of the special workshop entitled "Obesity at the Interface of Neuroscience and Physiology II". Abstract: Proopiomelanocortin (POMC)- and agouti related peptide (AgRP)-expressing neurons in the arcuate nucleus of the hypothalamus (ARH) are critical regulators of food intake and energy homeostasis. They rapidly integrate the energy state of the organism through sensing fuel availability via hormones, nutrient components and even rapidly upon sensory food perception. Importantly, they not only regulate feeding responses, but numerous autonomic responses including glucose and lipid metabolism, inflammation and blood pressure. More recently, we could demonstrate that sensory food cue-dependent regulation of POMC neurons primes the hepatic endoplasmic reticulum (ER) stress response to prime liver metabolism for the postpramndial state. The presentation will focus on the regulation of these neurons in control of integrative physiology, the identification of distinct neuronal circuitries targeted by these cells and finally on the broad range implications resulting from dysregulation of these circuits as a consequence of altered maternal metabolism.
Dysregulated lipid metabolism and neuroinflammation following high-fat diet in the TDP-43Q331K-low transgenic mouse model of ALS-FTD
FENS Forum 2024