Clusterin: a multifaceted protein in the brain.
Ontology highlight
ABSTRACT:
SUBMITTER: Moon HJ
PROVIDER: S-EPMC8284263 | biostudies-literature | 2021 Jul
REPOSITORIES: biostudies-literature
Publications
Clusterin: a multifaceted protein in the brain.
Moon Hee-Jung HJ Herring Sarah K SK Zhao Liqin L
Neural regeneration research 20210701 7
Similar Datasets
Project description:Clusterin (CLU), or apolipoprotein J (ApoJ), is the third most predominant genetic risk factor associated with late-onset Alzheimer's disease (LOAD). In this study, we use multiple rodent and human brain tissue and neural cell models to demonstrate that CLU is expressed as multiple isoforms that have distinct cellular or subcellular localizations in the brain. Of particular significance, we identify a non-glycosylated 45 kDa CLU isoform (mitoCLU) that is localized to the mitochondrial matrix and expressed in both rodent and human neurons and astrocytes. In addition, we show that rodent mitoCLU is translated from a non-canonical CUG (Leu) start site in Exon 3, a site that coincides with an AUG (Met) in human CLU. Last, we reveal that mitoCLU is present at the gene and protein level in the currently available CLU-/- mouse model. Collectively, these data provide foundational knowledge that is integral in elucidating the relationship between CLU and the development of LOAD.
| S-EPMC6860991 | biostudies-literature
Project description:Progress in the preclinical and clinical development of neuroprotective and antiepileptogenic treatments for traumatic brain injury (TBI) necessitates the discovery of prognostic biomarkers for post-injury outcome. Our previous mRNA-seq data revealed a 1.8-2.5 fold increase in clusterin mRNA expression in lesioned brain areas in rats with lateral fluid-percussion injury (FPI)-induced TBI. On this basis, we hypothesized that TBI leads to increases in the brain levels of clusterin protein, and consequently, increased plasma clusterin levels. For evaluation, we induced TBI in adult male Sprague-Dawley rats (n = 80) by lateral FPI. We validated our mRNA-seq findings with RT-qPCR, confirming increased clusterin mRNA levels in the perilesional cortex (FC 3.3, p < 0.01) and ipsilateral thalamus (FC 2.4, p < 0.05) at 3 months post-TBI. Immunohistochemistry revealed a marked increase in extracellular clusterin protein expression in the perilesional cortex and ipsilateral hippocampus (7d to 1 month post-TBI), and ipsilateral thalamus (14d to 12 months post-TBI). In the thalamus, punctate immunoreactivity was most intense around activated microglia and mitochondria. Enzyme-linked immunoassays indicated that an acute 15% reduction, rather than an increase in plasma clusterin levels differentiated animals with TBI from sham-operated controls (AUC 0.851, p < 0.05). Our findings suggest that plasma clusterin is a candidate biomarker for acute TBI diagnosis.
| S-EPMC6934775 | biostudies-literature
Project description:concepts play a central role in human behaviour and constitute a critical component of the human conceptual system. Here, we investigate the neural basis of four types of abstract concepts, examining their similarities and differences through neuroimaging meta-analyses. We examine numerical and emotional concepts, and two higher-order abstract processes, morality judgements and theory of mind. Three main findings emerge. First, representation of abstract concepts is more widespread than is often assumed. Second, representations of different types of abstract concepts differ in important respects. Each of the domains examined here was associated with some unique areas. Third, some areas were commonly activated across domains and included inferior parietal, posterior cingulate and medial prefrontal cortex. We interpret these regions in terms of their role in episodic recall, event representation and social-emotional processing. We suggest that different types of abstract concepts can be represented and grounded through differing contributions from event-based, interoceptive, introspective and sensory-motor representations. The results underscore the richness and diversity of abstract concepts, argue against single-mechanism accounts for representation of all types of abstract concepts and suggest mechanisms for their direct and indirect grounding.This article is part of the theme issue 'Varieties of abstract concepts: development, use and representation in the brain'.
| S-EPMC6015833 | biostudies-literature
Project description:BackgroundThe multifunctional glycoprotein clusterin has been associated with late-onset Alzheimer's disease (AD). Further investigation to define the role of clusterin in AD phenotypes would be aided by the development of techniques to quantify level, potential post-translational modifications, and isoforms of clusterin. We have developed a quantitative technique based on multiple reaction monitoring (MRM) mass spectrometry to measure clusterin in human postmortem brain tissues.ResultsA stable isotope-labeled concatenated peptide (QconCAT) bearing selected peptides from clusterin was expressed with an in vitro translation system and purified. This clusterin QconCAT was validated for use as an internal standard for clusterin quantification using MRM mass spectrometry. Measurements were performed on the human postmortem frontal and temporal cortex from control and severe AD cases. During brain tissues processing, 1% SDS was used in the homogenization buffer to preserve potential post-translational modifications of clusterin. However, MRM quantifications in the brain did not suggest phosphorylation of Thr(393), Ser(394), and Ser(396) residues reported for clusterin in serum. MRM quantifications in the frontal cortex demonstrated significantly higher (P < 0.01) level of clusterin in severe AD group (39.1 ± 9.1 pmol/mg tissue protein) in comparison to control group (25.4 ± 4.4 pmol/mg tissue protein). In the temporal cortex, the clusterin levels were not significantly different, 29.0 ± 7.9 pmol/mg tissue protein and 28.0 ± 8.4 pmol/mg tissue protein in control and severe AD groups, respectively.ConclusionsThe proposed protocol is a universal quantitative technique to assess expression level of clusterin. It is expected that application of this protocol to quantification of various clusterin isoforms and potential post-translational modifications will be helpful in addressing the role of clusterin in AD.
| S-EPMC3470951 | biostudies-literature
Project description:Physical exercise is generally beneficial to all aspects of human and animal health, slowing cognitive ageing and neurodegeneration1. The cognitive benefits of physical exercise are tied to an increased plasticity and reduced inflammation within the hippocampus2-4, yet little is known about the factors and mechanisms that mediate these effects. Here we show that 'runner plasma', collected from voluntarily running mice and infused into sedentary mice, reduces baseline neuroinflammatory gene expression and experimentally induced brain inflammation. Plasma proteomic analysis revealed a concerted increase in complement cascade inhibitors including clusterin (CLU). Intravenously injected CLU binds to brain endothelial cells and reduces neuroinflammatory gene expression in a mouse model of acute brain inflammation and a mouse model of Alzheimer's disease. Patients with cognitive impairment who participated in structured exercise for 6 months had higher plasma levels of CLU. These findings demonstrate the existence of anti-inflammatory exercise factors that are transferrable, target the cerebrovasculature and benefit the brain, and are present in humans who engage in exercise.
| S-EPMC9721468 | biostudies-literature
Project description:Genome-wide association studies have pointed to clusterin (apolipoprotein J) as being linked to the occurrence of Alzheimer's disease (AD); studies have identified the protein as a possible biomarker. The association between clusterin and senile plaques in AD brain is well known, and clusterin levels in AD brain are 40% higher than that in control subjects. The present study investigates, immunohistochemically, the association between clusterin and Aβ peptides in AD and control cortex. A unique and specific association between clusterin and Aβ40 was observed in plaques in the cerebral cortex from AD subjects in that only plaques that contained Aβ40 showed clusterin immunoreactivity, while the many plaques with Aβ42 alone lacked clusterin labeling. Cerebrovascular Aβ in AD brain generally lacked Aβ42 but was positively labeled by both the Aβ40 and the clusterin antibodies. In control subjects, however, Aβ40 was absent from plaques, although very occasional plaques were found to be labeled by both the Aβ42 and the clusterin antibodies. Overall, in AD, but not aged control brain, clusterin was associated specifically with the Aβ40 form of Aβ in the brain. The lack of clusterin in association with Aβ42 may be a significant feature in neuronal loss and neurodegeneration in the disease state.
| S-EPMC8029492 | biostudies-literature
Project description:Early diagnosis of late-onset Alzheimer's disease (AD) by peripheral biomarkers remains a challenge; many have been proposed, but none have been evaluated in a prospective manner. CLUSTERIN (CLU), a chaperone protein expressed in the brain and found in relatively high concentrations in plasma, is a promising candidate. CLU contributes to the elimination of β-amyloid (Aβ), which is associated to neurofibrillary tangles and to the genetic risk for AD. We performed a longitudinal measurement of CLU in the brain and the plasma in 3xTgAD mice. Assessment of CLU was also conducted in 12-month-old TgF344-AD rats. In humans, brain CLU was measured in non-demented and in AD subjects. The plasma CLU was longitudinally measured in four cohorts defined as healthy controls that remained stable, healthy controls that presented a cognitive decline between the two measures, mild cognitive impairment (MCI) that presented a cognitive decline between the two measures and AD. A validation cohort composed of 19 MCI was used and plasma CLU was measured before and after conversion in AD. Increases in CLU were measured in the hippocampus of 3xTgAD and TgF344-AD animals in the absence of plasmatic changes. CLU is heterogeneously expressed in the hippocampus in non-demented individuals and increased in AD. In the plasma, two CLU levels were measured: low in controls and MCI, and high in AD. To validate that the elevation in CLU is associated with conversion to AD, a replication study showed, in a second group MCI patients converting to AD in the follow-up that CLU levels increased in 16/19 individuals. The increase in brain CLU occurs in AD models as in humans, and seems to precede plasma variations, which could make it an AD therapeutic target. Plasma CLU seems to be a promising marker of cognitive decline, and its association with AD may be a useful complementary diagnostic tool.
| S-EPMC11835443 | biostudies-literature
Project description:Isthmin (ISM) is a secreted protein family with two members, namely ISM1 and ISM2, both containing a TSR1 domain followed by an AMOP domain. Its broad expression pattern suggests diverse functions in developmental and physiological processes. Over the past few years, multiple studies have focused on the functional analysis of the ISM protein family in several events, including angiogenesis, metabolism, organ homeostasis, immunity, craniofacial development, and cancer. Even though ISM was identified two decades ago, we are still short of understanding the roles of the ISM protein family in embryonic development and other pathological processes. To address the role of ISM, functional studies have begun but unresolved issues remain. To elucidate the regulatory mechanism of ISM, it is crucial to determine its interactions with other ligands and receptors that lead to the activation of downstream signalling pathways. This review provides a perspective on the gene organization and evolution of the ISM family, their links with developmental and physiological functions, and key questions for the future.
| S-EPMC9818725 | biostudies-literature
Project description: Not available
| S-EPMC5565473 | biostudies-literature
Project description:We discovered “runner” plasma, collected from voluntarily running mice, infused into sedentary mice recapitulates the cellular and functional benefits of exercise on the adult brain. Importantly, runner plasma reduces baseline neuroinflammatory gene expression and experimentally induced brain inflammation. Plasma proteomic analysis revealed a striking increase in complement cascade inhibitors including clusterin (CLU), which is facilitating the anti-inflammatory effects of runner plasma. Intravenously injected CLU strongly binds to brain endothelial cells reducing their inflammatory gene expression in an acute model of brain inflammation and in Alzheimer’s disease model mice. These findings demonstrate the existence of anti-inflammatory “exercise factors” that are transferrable, target the cerebrovasculature and benefit the brain.
2021-09-01 | GSE164401 | GEO