Chronic stress can trigger several pathologies including mood disorders for which no clear diagnostic molecular markers have been established yet. Attractive biomarker sources are extracellular vesicles (EVs). Evs are released by cells in health and disease and contain genetic material, proteins and lipids characteristic of the cell state.
View Article and Find Full Text PDFThe Developmental Origins of Health and Disease hypothesis sustains that exposure to different stressors during prenatal development prepares the offspring for the challenges to be encountered after birth. We studied the gestational period as a particularly vulnerable window where different stressors can have strong implications for fetal programming of the offspring's life-long metabolic status via alterations of specific placentally expressed nutrient transporters. To study this mechanism, we used a murine prenatal stress model, human preeclampsia, early miscarriage, and healthy placental tissue samples, in addition to in vitro models of placental cells.
View Article and Find Full Text PDFTwo PIEZO mechanosensitive cation channels, PIEZO1 and PIEZO2, have been identified in mammals, where they are involved in numerous sensory processes. While structurally similar, PIEZO channels are expressed in distinct tissues and exhibit unique properties. How different PIEZOs transduce force, how their transduction mechanism varies, and how their unique properties match the functional needs of the tissues they are expressed in remain all-important unanswered questions.
View Article and Find Full Text PDFThe nervous system monitors the environment to maintain homeostasis, which can be affected by stressful conditions. Using mammalian models of chronic stress, we previously observed altered brain levels of GPM6A, a protein involved in neuronal morphology. However, GPM6A's role in systemic stress responses remains unresolved.
View Article and Find Full Text PDFPrenatal stress (PS) is a major risk factor for the development of emotional disorders in adulthood that may be mediated by an altered hypothalamic-pituitary-adrenal axis response to stress. Although the early onset of stress-related disorders is recognized as a major public health problem, to date, there are relatively few studies that have examined the incidence of early-life stressors in younger individuals. In this study, we assessed PS impact on the stress-coping response of juvenile offspring in behavioral tests and in the induced molecular changes in the hippocampus.
View Article and Find Full Text PDFPathogens phagocytosis and the uptake of apoptotic cells (efferocytosis) are essential macrophages tasks, classically considered as mutually exclusive. Macrophages have been observed to polarize into either pro-inflammatory/microbicidal or anti-inflammatory/efferocytic phenotypes. However, macrophage functions have shown to be more complex.
View Article and Find Full Text PDFPrenatal stress (PS) induces molecular changes that alter neural connectivity, increasing the risk for neuropsychiatric disorders. Here we analyzed -in the hippocampus of adult rats exposed to PS- the epigenetic signature mediating the PS-induced neuroplasticity changes. Furthermore, using cultured hippocampal neurons, we investigated the effects on neuroplasticity of an epigenetic modulator.
View Article and Find Full Text PDFNeurosci Biobehav Rev
October 2020
Prenatal stress (PS) impacts early postnatal behavioural and cognitive development. This process of 'fetal programming' is mediated by the effects of the prenatal experience on the developing hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS). We derive a multi-scale multi-species approach to devising preclinical and clinical studies to identify early non-invasively available pre- and postnatal biomarkers of PS.
View Article and Find Full Text PDFMembrane neuronal glycoprotein M6a is highly expressed in the brain and contributes to neural plasticity promoting neurite growth and spine and synapse formation. We have previously showed that chronic stressors alter hippocampal M6a mRNA levels in rodents and tree shrews. We now show that M6a glycoprotein can be detected in mouse blood.
View Article and Find Full Text PDFClostridium perfringens epsilon toxin (ETX), the most potent toxin produced by this bacteria, plays a key role in the pathogenesis of enterotoxaemia in ruminants, causing brain edema and encephalomalacia. Studies of animals suffering from ETX intoxication describe severe neurological disorders that are thought to be the result of vasogenic brain edemas and indirect neuronal toxicity, killing oligodendrocytes but not astrocytes, microglia, or neurons in vitro. In this study, by means of intravenous and intracerebroventricular delivery of sub-lethal concentrations of ETX, the histological and ultrastructural changes of the brain were studied in rats and mice.
View Article and Find Full Text PDFPrevious studies from our laboratory have shown that male adult offspring of stressed mothers exhibited higher levels of ionotropic and metabotropic glutamate receptors than control rats. These offspring also showed long-lasting astroglial hypertrophy and a reduced dendritic arborization with synaptic loss. Since metabolism of glutamate is dependent on interactions between neurons and surrounding astroglia, our results suggest that glutamate neurotransmitter pathways might be impaired in the brain of prenatally stressed rats.
View Article and Find Full Text PDFPrenatal stress (PS) strongly impacts fetal brain development and function in adulthood. In normal aging and Alzheimer's disease, there is hypothalamic-pituitary-adrenal axis dysfunction and loss of cholinergic neurons and neuronal nicotinic acetylcholine receptors (nAChRs). This study investigated whether prenatal restraint stress affects nAChR expression in the brain of adult offspring.
View Article and Find Full Text PDFReproductive biotechnologies such as in vitro fertilization (IVF) and somatic cell nuclear transfer (SCNT) enable improved reproductive efficiency of animals. However, the birth rate of in vitro-derived embryos still lags behind that of their in vivo counterparts. Thus, it is critical to develop an accurate evaluation and prediction system of embryo competence, both for commercial purposes and for scientific research.
View Article and Find Full Text PDFWe have previously demonstrated that prenatal stress (PS) exerts an impairment of midbrain dopaminergic (DA) system metabolism especially after puberty, suggesting a particular sensitivity of DA development to variations in gonadal hormonal peaks. Furthermore we demonstrated that PS alters the long term androgens profile of the rat male offspring from prepubertal to adult stages. In this work we evaluated the sexual hormones activational effects on the DA system by analysing PS effects on the dopaminergic D2-like (D2R) and on the gonadal hormones receptor levels on cortical and hippocampal areas of prepubertal and adult male offspring.
View Article and Find Full Text PDFPrenatal stress (PS) exerts strong impact on fetal brain development and on adult offspring brain functions. Previous work demonstrated that chronic stress alters the mRNA expression of GPM6A, a neuronal glycoprotein involved in filopodium extension. In this work, we analyzed the effect of PS on gpm6a expression and the epigenetic mechanisms involved.
View Article and Find Full Text PDFSeveral studies have demonstrated that the presence of stressors during pregnancy induces adverse effects on the neuroendocrine system of the offspring later in life. In the present work, we investigated the effects of early programming on the male reproductive system, employing a prenatal stress (PS) paradigm. This study found that when pregnant dams were placed in a plastic restrainer three times a day during the last week of pregnancy, the offspring showed reduced anogenital distance and delayed testicular descent.
View Article and Find Full Text PDFBackground: Members of the proteolipid protein family, including the four-transmembrane glycoprotein M6a, are involved in neuronal plasticity in mammals. Results from our group previously demonstrated that M6, the only proteolipid protein expressed in Drosophila, localizes to the cell membrane in follicle cells. M6 loss triggers female sterility, which suggests a role for M6 in follicular cell remodeling.
View Article and Find Full Text PDFWe had previously shown that the transmembrane glycoprotein M6a, a member of the proteolipid protein (PLP) family, regulates neurite/filopodium outgrowth, hence, M6a might be involved in neuronal remodeling and differentiation. In this work we focused on M6, the only PLP family member present in Drosophila, and ortholog to M6a. Unexpectedly, we found that decreased expression of M6 leads to female sterility.
View Article and Find Full Text PDFM6a is a neuronal membrane glycoprotein whose expression diminishes during chronic stress. M6a overexpression in rat primary hippocampal neurons induces the formation of filopodial protrusions that could be spine precursors. As the filopodium and spine motility has been associated with synaptogenesis, we analysed the motility of M6a-induced protrusions by time-lapse imaging.
View Article and Find Full Text PDFChronic stress causes morphological alterations in the hippocampus of rodents and tree shrews, including atrophy of CA3 dendrites and loss of synapses. The molecular mechanisms underlying these structural changes remain largely unknown. We have previously identified M6a as a stress responsive gene and shown that M6a is involved in filopodium/spine outgrowth and, likely, synapse formation.
View Article and Find Full Text PDFPolysialic acid (PSA) attached to NCAM is involved in cell-cell interactions participating in structural and functional plasticity of neuronal circuits. Two polysialyltransferases, ST8SiaII/STX and ST8SiaIV/PST, polysialylate NCAM. We previously suggested that ST8SiaII/STX is the key enzyme for polysialylation in hippocampus.
View Article and Find Full Text PDFRetinal ganglion cells send visual and circadian information to the brain regarding the environmental light-dark cycles. We investigated the capability of retinal ganglion cells of synthesizing melatonin, a highly reliable circadian marker that regulates retinal physiology, as well as the capacity of these cells to function as autonomous circadian oscillators. Chick retinal ganglion cells presented higher levels of melatonin assessed by radioimmunoassay during both the subjective day in constant darkness and the light phase of a light-dark cycle.
View Article and Find Full Text PDFPolysialyltransferases ST8SiaII/STX and ST8SiaIV/PST add polysialic acid (PSA) to the neural cell adhesion molecule (NCAM). Surface-located PSA is involved in cell-cell interactions participating in structural and functional plasticity of neuronal circuits. This study was undertaken to investigate the polysialyltransferase regulation pattern during hippocampal development.
View Article and Find Full Text PDFAs retinal ganglion cells (RGCs) develop, the amount of membrane glycoprotein Thy-1 increases, consequently, the RGC binding to Thy-1 antibody enlarges. This phenomenon sustained Thy-1 panning purification of two sets: loose bound cells (LBCs); and tight bound cells (TBCs). Thy-1, neurofilament and growth associated protein-43 characterized both sets as RGCs, but the expression of RA4 antigen and gangliotetraosylgangliosides distinguished LBCs as immature and TBCs as mature.
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