RÉSUMÉ
The cerebellum is involved in higher order cognitive function and is susceptible to age-related atrophy. However, limited evidence has directly examined the cerebellum's role in cognitive aging. To interrogate potential substrates of the relationship between cerebellar structure and memory in aging, here we target the Purkinje cells (PCs). The sole output neurons of the cerebellum, PC loss and/or degeneration underlie a variety of behavioral abnormalities. Using a rat model of normal cognitive aging, we immunostained sections through the cerebellum for the PC-specific protein, calbindin-D28k. Although morphometric quantification revealed no significant difference in total PC number as a function of age or cognitive status, regional cell number was a more robust correlate of memory performance in the young cerebellum than in aged animals. Parallel biochemical analysis of PC-specific protein levels in whole cerebellum additionally revealed that calbindin-D28k and Purkinje cell protein-2 (pcp-2) levels were lower selectively in aged rats with spatial memory impairment compared to both young animals and aged rats with intact memory. These results suggest that cognitive aging is associated with cerebellum vulnerability, potentially reflecting disruption of the cerebellum-medial temporal lobe network.
Sujet(s)
Cellules de Purkinje , Protéine G liant le calcium S100 , Rats , Animaux , Cellules de Purkinje/métabolisme , Calbindine-1/métabolisme , Protéine G liant le calcium S100/composition chimique , Protéine G liant le calcium S100/métabolisme , Cervelet , Neurones/métabolismeRÉSUMÉ
Engineered nanomaterials induce hazardous effects at the cellular and molecular levels. We investigated different mechanisms underlying the neurotoxic potential of zinc oxide nanoparticles (ZnONPs) on cerebellar tissue and clarified the ameliorative role of Quercetin supplementation. Forty adult male albino rats were divided into control group (I), ZnONPs-exposed group (II), and ZnONPs and Quercetin group (III). Oxidative stress biomarkers (MDA & TOS), antioxidant biomarkers (SOD, GSH, GR, and TAC), serum interleukins (IL-1ß, IL-6, IL-8), and tumor necrosis factor alpha (TNF-α) were measured. Serum micro-RNA (miRNA): miRNA-21-5p, miRNA-122-5p, miRNA-125b-5p, and miRNA-155-3p expression levels were quantified by real-time quantitative polymerase-chain reaction (RT-QPCR). Cerebellar tissue sections were stained with Hematoxylin & Eosin and Silver stains and examined microscopically. Expression levels of Calbindin D28k, GFAP, and BAX proteins in cerebellar tissue were detected by immunohistochemistry. Quercetin supplementation lowered oxidative stress biomarkers levels and ameliorated the antioxidant parameters that were decreased by ZnONPs. No significant differences in GR activity were detected between the study groups. ZnONPs significantly increased serum IL-1ß, IL-6, IL-8, and TNF-α which were improved with Quercetin. Serum miRNA-21-5p, miRNA-122-5p, miRNA-125b-5p, and miRNA-155-p expression levels showed significant increase in ZnONPs group, while no significant difference was observed between Quercetin-treated group and control group. ZnONPs markedly impaired cerebellar tissue structure with decreased levels of calbindin D28k, increased BAX and GFAP expression. Quercetin supplementation ameliorated cerebellar tissue apoptosis, gliosis and improved calbindin levels. In conclusion: Quercetin supplementation ameliorated cerebellar neurotoxicity induced by ZnONPs at cellular and molecular basis by different studied mechanisms.Abbreviations: NPs: Nanoparticles, ROS: reactive oxygen species, ZnONPs: Zinc oxide nanoparticles, AgNPs: silver nanoparticles, BBB: blood-brain barrier, ncRNAs: Non-coding RNAs, miRNA: Micro RNA, DMSO: Dimethyl sulfoxide, LPO: lipid peroxidation, MDA: malondialdehyde, TBA: thiobarbituric acid, TOS: total oxidative status, ELISA: enzyme-linked immunosorbent assay, H2O2: hydrogen peroxide, SOD: superoxide dismutase, GR: glutathione reductase, TAC: total antioxidant capacity, IL-1: interleukin-1, TNF: tumor necrosis factor alpha, cDNA: complementary DNA, RT-QPCR: Real-time quantitative polymerase-chain reaction, ABC: Avidin biotin complex technique, DAB: 3', 3-diaminobenzidine, SPSS: Statistical Package for Social Sciences, ANOVA: One way analysis of variance, Tukey's HSD: Tukey's Honestly Significant Difference, GFAP: glial fiberillar acitic protein, iNOS: Inducible nitric oxide synthase, NO: nitric oxide, HO-1: heme oxygenase-1, Nrf2: nuclear factor erythroid 2-related factor 2, NF-B: nuclear factor-B, SCI: spinal cord injury, CB: Calbindin.
Sujet(s)
Nanoparticules métalliques , microARN , Neuroprotecteurs , Oxyde de zinc , Rats , Mâle , Animaux , Antioxydants/pharmacologie , Antioxydants/usage thérapeutique , Quercétine/pharmacologie , Quercétine/usage thérapeutique , Oxyde de zinc/pharmacologie , Oxyde de zinc/usage thérapeutique , Oxyde de zinc/métabolisme , Neuroprotecteurs/pharmacologie , Neuroprotecteurs/usage thérapeutique , Facteur de nécrose tumorale alpha/métabolisme , Protéine Bax/métabolisme , Calbindine-1/métabolisme , Peroxyde d'hydrogène/métabolisme , Interleukine-6/métabolisme , Interleukine-8/métabolisme , Argent/métabolisme , Superoxide dismutase/métabolisme , Cervelet/métabolisme , microARN/génétique , Marqueurs biologiquesRÉSUMÉ
BACKGROUND: Recent clinical and experimental studies have highlighted the involvement of Ventral Tegmental Area (VTA) dopamine (DA) neurons for the early pathogenesis of Alzheimer's Disease (AD). We have previously described a progressive and selective degeneration of these neurons in the Tg2576 mouse model of AD, long before amyloid-beta plaque formation. The degenerative process in DA neurons is associated with an autophagy flux impairment, whose rescue can prevent neuronal loss. Impairments in autophagy can be the basis for accumulation of damaged mitochondria, leading to disturbance in calcium (Ca2+) homeostasis, and to functional and structural deterioration of DA neurons. METHODS: In Tg2576 mice, we performed amperometric recordings of DA levels and analysis of dopaminergic fibers in the Nucleus Accumbens - a major component of the ventral striatum precociously affected in AD patients - together with retrograde tracing, to identify the most vulnerable DA neuron subpopulations in the VTA. Then, we focused on these neurons to analyze mitochondrial integrity and Apoptosis-inducing factor (AIF) localization by electron and confocal microscopy, respectively. Stereological cell count was also used to evaluate degeneration of DA neuron subpopulations containing the Ca2+-binding proteins Calbindin-D28K and Calretinin. The expression levels for these proteins were analyzed by western blot and confocal microscopy. Lastly, using electrophysiology and microfluorometry we analyzed VTA DA neuron intrinsic properties and cytosolic free Ca2+ levels. RESULTS: We found a progressive degeneration of mesolimbic DA neurons projecting to the ventral striatum, located in the paranigral nucleus and parabrachial pigmented subnucleus of the VTA. At the onset of degeneration (3 months of age), the vulnerable DA neurons in the Tg2576 accumulate damaged mitochondria, while AIF translocates from the mitochondria to the nucleus. Although we describe an age-dependent loss of the DA neurons expressing Calbindin-D28K or Calretinin, we observed that the remaining cells upregulate the levels of Ca2+-binding proteins, and the free cytosolic levels of Ca2+ in these neurons are significantly decreased. Coherently, TUNEL-stained Tg2576 DA neurons express lower levels of Calbindin-D28K when compared with non-apoptotic cells. CONCLUSION: Overall, our results suggest that the overexpression of Ca2+-binding proteins in VTA DA neurons might be an attempt of cells to survive by increasing their ability to buffer free Ca2+. Exploring strategies to overexpress Ca2+-binding proteins could be fundamental to reduce neuronal suffering and improve cognitive and non-cognitive functions in AD.
Sujet(s)
Maladie d'Alzheimer , Aire tegmentale ventrale , Souris , Animaux , Aire tegmentale ventrale/métabolisme , Aire tegmentale ventrale/anatomopathologie , Neurones dopaminergiques/métabolisme , Dopamine/métabolisme , Calbindine-2/métabolisme , Maladie d'Alzheimer/métabolisme , Régulation positive , Protéines de transport/métabolisme , Calbindine-1/métabolismeRÉSUMÉ
Generalization is a fundamental cognitive ability of organisms to deal with the uncertainty in real-world situations. Excessive fear generalization and impaired reward generalization are closely related to many psychiatric disorders. However, the neural circuit mechanism for reward generalization and its role in anxiety-like behaviours remain elusive. Here, we found a robust activation of calbindin 1-neurons (Calb 1) in the posterior basolateral amygdala (pBLA), simultaneous with reward generalization to an ambiguous cue after reward conditioning in mice. We identify the infralimbic medial prefrontal cortex (IL) to the pBLACalb1 (Calb 1 neurons in the pBLA) pathway as being involved in reward generalization for the ambiguity. Activating IL-pBLA inputs strengthens reward generalization and reduces chronic unpredictable mild stress-induced anxiety- and depression-like behaviours in a manner dependent on pBLACalb1 neuron activation. These findings suggest that the IL-pBLACalb1 circuit could be a target to promote stress resilience via reward generalization and consequently ameliorate anxiety- and depression-like behaviours.
Sujet(s)
Anxiété , Groupe nucléaire basolatéral , Calbindine-1 , Dépression , Neurones , Cortex préfrontal , Animaux , Anxiété/génétique , Anxiété/métabolisme , Groupe nucléaire basolatéral/métabolisme , Calbindine-1/génétique , Calbindine-1/métabolisme , Dépression/génétique , Dépression/métabolisme , Souris , Neurones/métabolisme , Neurones/physiologie , Cortex préfrontal/métabolisme , Cortex préfrontal/physiologieRÉSUMÉ
In response to many stresses, such as oncogene activation or DNA damage, cells can enter cellular senescence, a state of proliferation arrest accompanied by a senescence-associated secretory phenotype (SASP). Cellular senescence plays a key role in many physiopathological contexts, including cancer, aging and aging-associated diseases, therefore, it is critical to understand how senescence is regulated. Calcium ions (Ca2+) recently emerged as pivotal regulators of cellular senescence. However, how Ca2+ levels are controlled during this process is barely known. Here, we report that intracellular Ca2+ contents increase in response to many senescence inducers in immortalized human mammary epithelial cells (HMECs) and that expression of calbindin 1 (CALB1), a Ca2+-binding protein, is upregulated in this context, through the Ca2+-dependent calcineurin/NFAT pathway. We further show that overexpression of CALB1 buffers the rise in intracellular Ca2+ levels observed in senescent cells. Finally, we suggest that increased expression of Ca2+-binding proteins calbindins is a frequent mark of senescent cells. This work thus supports that, together with Ca2+channels, Ca2+-binding proteins modulate Ca2+ levels and flux during cellular senescence. This opens potential avenues of research to better understand the role of Ca2+ and of Ca2+-binding proteins in regulating cellular senescence.
Sujet(s)
Vieillissement , Calbindine-1 , Calcium , Vieillissement de la cellule , Calbindine-1/métabolisme , Calcium/métabolisme , Altération de l'ADN , Cellules épithéliales/métabolisme , HumainsRÉSUMÉ
Herein, we aimed to use double-labeling immunofluorescence to describe the expression pattern of Calbindin-D28K (CaBP28K) in the mouse cochlea from late embryonic (E) stages to the adulthood. CaBP28K was expressed in the inner hair cells (IHCs) and the greater epithelial ridge (GER) at E17. In addition, its expression was observed in the interdental cells. On postnatal day 1 (P1), CaBP28K immunoreactivity was observed in the IHCs and outer hair cells (OHCs) and was also specifically expressed in the nucleus and the cytoplasm of spiral ganglion neurons (SGNs). At P8, CaBP28K labeling disappeared from the interdental cells, and the CaBP28K-positive domain within the GER shifted from the entire cytoplasm to only the apical and basal regions. At P14, CaBP28K immunoreactivity was lost from the GER; however, its expression in the IHCs and OHCs, as well as the SGNs, persisted into adulthood. The identification of CaBP28K in the hair cells (HCs) and cuticular plates, as well as SGNs, was confirmed by its colocalization with several markers for Sox2, Myosin VIIa, Phalloidin, and Tuj1. We also detected colocalization with calmodulin in the cytoplasm of both HCs and SGNs. Western blot revealed an increase in CaBP28K postnatal expression in the mouse cochlea.
Sujet(s)
Calbindine-1/génétique , Cochlée/croissance et développement , Neurones , Ganglion spiral , Animaux , Calbindine-1/analyse , Calbindine-1/métabolisme , Technique d'immunofluorescence , Immunohistochimie , Souris , Neurones/métabolismeRÉSUMÉ
Renshaw cells (RCs) are one of the most studied spinal interneurons; however, their roles in motor control remain enigmatic in part due to the lack of experimental models to interfere with RC function, specifically in adults. To overcome this limitation, we leveraged the distinct temporal regulation of Calbindin (Calb1) expression in RCs to create genetic models for timed RC manipulation. We used a Calb1 allele expressing a destabilized Cre (dgCre) theoretically active only upon trimethoprim (TMP) administration. TMP timing and dose influenced RC targeting efficiency, which was highest within the first three postnatal weeks, but specificity was low with many other spinal neurons also targeted. In addition, dgCre showed TMP-independent activity resulting in spontaneous recombination events that accumulated with age. Combining Calb1-dgCre with Parvalbumin (Pvalb) or Engrailed1 (En1) Flpo alleles in dual conditional systems increased cellular and timing specificity. Under optimal conditions, Calb1-dgCre/Pvalb-Flpo mice targeted 90% of RCs and few dorsal horn neurons; Calb1-dgCre/En1-Flpo mice showed higher specificity, but only a maximum of 70% of RCs targeted. Both models targeted neurons throughout the brain. Restricted spinal expression was obtained by injecting intraspinally AAVs carrying dual conditional genes. These results describe the first models to genetically target RCs bypassing development.
Sujet(s)
Allèles , Calbindine-1/métabolisme , Protéines à homéodomaine/métabolisme , Integrases/génétique , Parvalbumines/métabolisme , Cellules de Renshaw/métabolisme , Animaux , Marqueurs biologiques , Technique d'immunofluorescence , Ciblage de gène , Immunohistochimie , Integrases/métabolisme , Souris , Souris transgéniques , Liaison aux protéinesRÉSUMÉ
Alzheimer's disease is a progressive, devastating, and irreversible brain disorder that, day by day, destroys memory skills and social behavior. Despite this, the number of known genes suitable for discriminating between AD patients is insufficient. Among the genes potentially involved in the development of AD, there are the chitinase-like proteins (CLPs) CHI3L1, CHI3L2, and CHID1. The genes of the first two have been extensively investigated while, on the contrary, little information is available on CHID1. In this manuscript, we conducted transcriptome meta-analysis on an extensive sample of brains of healthy control subjects (n = 1849) (NDHC) and brains of AD patients (n = 1170) in order to demonstrate CHID1 involvement. Our analysis revealed an inverse correlation between the brain CHID1 expression levels and the age of NDHC subjects. Significant differences were highlighted comparing CHID1 expression of NDHC subjects and AD patients. Exclusive in AD patients, the CHID1 expression levels were correlated positively to calcium-binding adapter molecule 1 (IBA1) levels. Furthermore, both in NDHC and in AD patient's brains, the CHID1 expression levels were directly correlated with calbindin 1 (CALB1) and neurogranin (NRGN). According to brain regions, correlation differences were shown between the expression levels of CHID1 in prefrontal, frontal, occipital, cerebellum, temporal, and limbic system. Sex-related differences were only highlighted in NDHC. CHID1 represents a new chitinase potentially involved in the principal processes underlying Alzheimer's disease.
Sujet(s)
Maladie d'Alzheimer/génétique , Encéphale/métabolisme , Calbindine-1/génétique , Protéines de liaison au calcium/génétique , Protéines de transport/génétique , Protéines des microfilaments/génétique , Neurogranine/génétique , Sujet âgé , Sujet âgé de 80 ans ou plus , Maladie d'Alzheimer/métabolisme , Maladie d'Alzheimer/anatomopathologie , Encéphale/anatomopathologie , Cartographie cérébrale , Calbindine-1/métabolisme , Protéines de liaison au calcium/métabolisme , Protéines de transport/métabolisme , Études cas-témoins , Biologie informatique , Femelle , Analyse de profil d'expression de gènes , Régulation de l'expression des gènes , Humains , Mâle , Protéines des microfilaments/métabolisme , Adulte d'âge moyen , Neurogranine/métabolisme , Transduction du signal , TranscriptomeRÉSUMÉ
Proprioceptive neurons (PNs) are essential for the proper execution of all our movements by providing muscle sensory feedback to the central motor network. Here, using deep single cell RNAseq of adult PNs coupled with virus and genetic tracings, we molecularly identify three main types of PNs (Ia, Ib and II) and find that they segregate into eight distinct subgroups. Our data unveil a highly sophisticated organization of PNs into discrete sensory input channels with distinct spatial distribution, innervation patterns and molecular profiles. Altogether, these features contribute to finely regulate proprioception during complex motor behavior. Moreover, while Ib- and II-PN subtypes are specified around birth, Ia-PN subtypes diversify later in life along with increased motor activity. We also show Ia-PNs plasticity following exercise training, suggesting Ia-PNs are important players in adaptive proprioceptive function in adult mice.
Sujet(s)
Rétroaction sensorielle/physiologie , Ganglions sensitifs des nerfs spinaux/métabolisme , Motoneurones/métabolisme , Proprioception/physiologie , Cellules réceptrices sensorielles/métabolisme , Animaux , Calbindine-1/génétique , Calbindine-1/métabolisme , Protéines de liaison au calcium/génétique , Protéines de liaison au calcium/métabolisme , Protéines corépressives/génétique , Protéines corépressives/métabolisme , Sous-unité alpha 2 du facteur CBF/génétique , Sous-unité alpha 2 du facteur CBF/métabolisme , Sous-unité alpha 3 du facteur CBF/génétique , Sous-unité alpha 3 du facteur CBF/métabolisme , Ganglions sensitifs des nerfs spinaux/cytologie , Expression des gènes , Protéines à domaine LIM/génétique , Protéines à domaine LIM/métabolisme , Lectines de type C/génétique , Lectines de type C/métabolisme , Mâle , Souris , Souris de lignée C57BL , Souris transgéniques , Motoneurones/classification , Motoneurones/cytologie , Protéines de tissu nerveux/génétique , Protéines de tissu nerveux/métabolisme , Conditionnement physique d'animal , Cellules réceptrices sensorielles/classification , Cellules réceptrices sensorielles/cytologie , Analyse sur cellule unique , Moelle spinale/cytologie , Moelle spinale/métabolismeRÉSUMÉ
Cochlear development is a complex process with precise spatiotemporal patterns. A detailed understanding of this process is important for studies of congenital hearing loss and regenerative medicine. However, much of our understanding of cochlear development is based on rodent models. Animal models that bridge the gap between humans and rodents are needed. In this study, we investigated the development of hearing organs in a small New World monkey species, the common marmoset (Callithrix jacchus). We describe the general stages of cochlear development in comparison with those of humans and mice. Moreover, we examined more than 25 proteins involved in cochlear development and found that expression patterns were generally conserved between rodents and primates. However, several proteins involved in supporting cell processes and neuronal development exhibited interspecific expression differences. Human fetal samples for studies of primate-specific cochlear development are extremely rare, especially for late developmental stages. Our results support the use of the common marmoset as an effective alternative for analyses of primate cochlear development.
Sujet(s)
Callithrix/génétique , Cochlée/métabolisme , Régulation de l'expression des gènes au cours du développement , Modèles animaux , Organogenèse/génétique , Animaux , Aquaporine-4/génétique , Aquaporine-4/métabolisme , Calbindine-1/génétique , Calbindine-1/métabolisme , Callithrix/embryologie , Callithrix/croissance et développement , Callithrix/métabolisme , Cochlée/anatomie et histologie , Cochlée/cytologie , Cochlée/croissance et développement , Séquence conservée , Inhibiteur p27 de kinase cycline-dépendante/génétique , Inhibiteur p27 de kinase cycline-dépendante/métabolisme , Embryon de mammifère , Facteur de transcription GATA-3/génétique , Facteur de transcription GATA-3/métabolisme , Humains , Protéines à homéodomaine LIM/génétique , Protéines à homéodomaine LIM/métabolisme , Souris , Myosine-VIIa/génétique , Myosine-VIIa/métabolisme , Parvalbumines/génétique , Parvalbumines/métabolisme , Périphérines/génétique , Périphérines/métabolisme , Facteurs de transcription SOX-B1/génétique , Facteurs de transcription SOX-B1/métabolisme , Spécificité d'espèce , Transporteurs de sulfate/génétique , Transporteurs de sulfate/métabolisme , Facteur de transcription Brn-3C/génétique , Facteur de transcription Brn-3C/métabolisme , Tubuline/génétique , Tubuline/métabolismeRÉSUMÉ
Neuropathic pain (NP) is a common complication that negatively affects the lives of patients with spinal cord injury (SCI). The disruption in the balance of excitatory and inhibitory neurons in the spinal cord dorsal horn contributes to the development of SCI and induces NP. The calcium-binding protein (CaBP) calbindin-D 28K (CaBP-28K) is highly expressed in excitatory interneurons, and the CaBP parvalbumin (PV) is present in inhibitory neurons in the dorsal horn. To better define the changes in the CaBPs contributing to the development of SCI-induced NP, we examined the changes in CaBP-28K and PV staining density in the lumbar (L4-6) lamina I and II, and their relationship with NP after mild spinal cord contusion injury in mice. We additionally examined the effects of alternate thermal stimulation (ATS). Compared with sham mice, injured animals developed mechanical allodynia in response to light mechanical stimuli and exhibited mechanical hyporesponsiveness to noxious mechanical stimuli. The decreased response latency to heat stimuli and increased response latency to cold stimuli at 7 days post injury suggested that the injured mice developed heat hyperalgesia and cold hypoalgesia, respectively. Temperature preference tests showed significant warm allodynia after injury. Animals that underwent ATS (15-18 and 35-40°C; +5 minutes/stimulation/day; 5 days/week) displayed significant amelioration of heat hyperalgesia, cold hypoalgesia, and warm allodynia after 2 weeks of ATS. In contrast, mechanical sensitivity was not influenced by ATS. Analysis of the CaBP-28K positive signal in L4-6 lamina I and II indicated an increase in staining density after SCI, which was associated with an increase in the number of CaBP-28K-stained L4-6 dorsal root ganglion (DRG) neurons. ATS decreased the CaBP-28K staining density in L4-6 spinal cord and DRG in injured animals, and was significantly and strongly correlated with ATS alleviation of pain behavior. The expression of PV showed no changes in lamina I and II after ATS in SCI animals. Thus, ATS partially decreases the pain behavior after SCI by modulating the changes in CaBP-associated excitatory-inhibitory neurons.
Sujet(s)
Calbindine-1/métabolisme , Ganglions sensitifs des nerfs spinaux/métabolisme , Chauffage/méthodes , Hyperalgésie/métabolisme , Hyperalgésie/thérapie , Corne dorsale de la moelle spinale/métabolisme , Traumatismes de la moelle épinière/métabolisme , Traumatismes de la moelle épinière/thérapie , Animaux , Comportement animal , Modèles animaux de maladie humaine , Femelle , Souris , Souris de lignée C57BL , Névralgie/métabolisme , Neurones/métabolisme , Parvalbumines/métabolisme , Résultat thérapeutiqueRÉSUMÉ
Alzheimer's disease (AD) represents one of the main forms of dementia that afflicts our society. The expression of several genes has been associated with disease development. Despite this, the number of genes known to be capable of discriminating between AD patients according to sex remains deficient. In our study, we performed a transcriptomes meta-analysis on a large court of brains of healthy control subjects (n = 2139) (NDHC) and brains of AD patients (n = 1170). Our aim was to verify the brain expression levels of CHI3L2 and its correlation with genes associated with microglia-mediated neuroinflammation (IBA1), alteration of the blood-brain barrier (PECAM1), and neuronal damage (CALB1). We showed that the CHI3L2, IBA1, PECAM1, and CALB1 expression levels were modulated in the brains of patients with AD compared to NDHC subjects. Furthermore, both in NDHC and in AD patient's brains, the CHI3L2 expression levels were directly correlated with IBA1 and PECAM1 and inversely with CALB1. Additionally, the expression levels of CHI3L2, PECAM1, and CALB1 but not of IBA1 were sex-depended. By stratifying the samples according to age and sex, correlation differences emerged between the expression levels of CHI3L2, IBA1, PECAM1, and CALB1 and the age of NDHC subjects and AD patients. CHI3L2 represents a promising gene potentially involved in the key processes underlying Alzheimer's disease. Its expression in the brains of sex-conditioned AD patients opens up new possible sex therapeutic strategies aimed at controlling imbalance in disease progression.
Sujet(s)
Maladie d'Alzheimer/métabolisme , Transcriptome , Sujet âgé , Sujet âgé de 80 ans ou plus , Maladie d'Alzheimer/génétique , Maladie d'Alzheimer/anatomopathologie , Encéphale/métabolisme , Calbindine-1/génétique , Calbindine-1/métabolisme , Protéines de liaison au calcium/génétique , Protéines de liaison au calcium/métabolisme , Chitinase/génétique , Chitinase/métabolisme , Bases de données génétiques , Femelle , Humains , Mâle , Protéines des microfilaments/génétique , Protéines des microfilaments/métabolisme , Antigènes CD31/génétique , Antigènes CD31/métabolismeRÉSUMÉ
Certain neuronal populations, including basal forebrain cholinergic neurons (BFCN) and noradrenergic neurons of the locus coeruleus (LC), are selectively vulnerable to pathology and loss early in the course of aging and Alzheimer's disease (AD). Human BFCN show substantial loss of the calcium-binding protein (CBP), calbindin-D28K (CB), during normal aging, which is associated with formation of neurofibrillary tangles and BFCN loss in AD. Here we determined if, similar to the BFCN, LC neurons contain CB or the other 2 ubiquitous CBPs parvalbumin and calretinin, and whether these proteins display an age-related loss from LC neurons. Immunostaining for CBP and tyrosine hydroxylase, a marker of catecholaminergic neurons, was used in sections from the LC of young and aged human brains. Parvalbumin and calretinin immunoreactivities were completely absent from human LC neurons. A subpopulation of LC neurons (~10%) contained CB immunoreactivity. Quantitative analysis revealed no age-related loss of CB from LC neurons. Thus, unlike the BFCN, age-related loss of CB does not figure prominently in the selective vulnerability of LC neurons to degeneration in AD.
Sujet(s)
Neurones adrénergiques/métabolisme , Neurones adrénergiques/anatomopathologie , Vieillissement/métabolisme , Vieillissement/anatomopathologie , Calbindine-1/métabolisme , Calbindine-2/métabolisme , Neurones cholinergiques/métabolisme , Neurones cholinergiques/anatomopathologie , Locus ceruleus/cytologie , Locus ceruleus/métabolisme , Parvalbumines/métabolisme , Adulte , Sujet âgé , Maladie d'Alzheimer/métabolisme , Maladie d'Alzheimer/anatomopathologie , Femelle , Humains , Mâle , Adulte d'âge moyen , Enchevêtrements neurofibrillaires/métabolisme , Enchevêtrements neurofibrillaires/anatomopathologie , Jeune adulteRÉSUMÉ
The mammalian vestibular epithelia exhibit a remarkably stereotyped organization featuring cellular characteristics under planar cell polarity (PCP) control. PCP mechanisms are responsible for the organization of hair cell morphologic polarization vectors, and are thought to be responsible for the postsynaptic expression of the calcium-binding protein calretinin that defines the utricular striola and cristae central zone. However, recent analyses revealed that subtle differences in the topographic expression of oncomodulin, another calcium-binding protein, reflects heterogeneous factors driving the subtle variations in expression. Calbindin represents a third calcium-binding protein that has been previously described to be expressed in both hair cells and afferent calyces in proximity to the utricular striola and crista central zone. The objective of the present investigation was to determine calbindin's topographic pattern of expression to further elucidate the extent to which PCP mechanisms might exert control over the organization of vestibular neuroepithelia. The findings revealed that calbindin exhibited an expression pattern strikingly similar to oncomodulin. However, within calyces of the central zone calbindin was colocalized with calretinin. These results indicate that organizational features of vestibular epithelia are governed by a suite of factors that include PCP mechanisms as well others yet to be defined.
Sujet(s)
Calbindine-1/biosynthèse , Calbindine-2/biosynthèse , Protéines de liaison au calcium/métabolisme , Cellules ciliées auditives/métabolisme , Cellules neuroépithéliales/métabolisme , Labyrinthe vestibulaire/métabolisme , Animaux , Calbindine-1/métabolisme , Calbindine-2/métabolisme , Polarité de la cellule/physiologie , Cellules ciliées auditives/cytologie , Souris de lignée C57BL , Cellules neuroépithéliales/cytologie , Labyrinthe vestibulaire/cytologieRÉSUMÉ
CalbindinD28K (Calb1) may protect human lens epithelial cells (HLECs) from apoptosis, which is a process resulting in individual cell death. The protective effects of Calb1 may be attributed to buffering high concentrations of Ca2+. The present study investigated the mechanisms through which Calb1 protects SRA01/04 cells (a human lens epithelial cell line) against apoptosis induced by ultraviolet B (UVB) exposure. Cells transfected with a lentivirus overexpressing Calb1 and control cells were treated with 40 µW/cm2 irradiation for 15 min and then cultured for 24 h. The changes in intracellular Ca2+ were detected by colorimetry, and the protein expression levels of Bad, Bcl2 and caspase12 were measured by western blot analysis. The intracellular Ca2+ concentration of control HLECs increased significantly following UVB irradiation, whereas in Calb1overexpressing cells, the Ca2+ levels remained steady. In the control cells, the expression of Bad and caspase12 was upregulated, and that of Bcl2 was downregulated. Notably, during UVB radiationinduced apoptosis, the overexpression of Calb1 inhibited cell death, resulting in the decreased expression of Bad and caspase12, and in the upregulated expression of Bcl2. These results suggested that Calb1 inhibited the upregulation of genes involved in apoptosis. The siRNAmediated knockdown of Calb1 resulted in increased rates of UVB radiationinduced apoptosis, the increased expression of Bad and caspase12, and the decreased expression of Bcl2, further demonstrating that Calb1 may mediate UVB radiationmediated apoptosis by regulating Ca2+. On the whole, the findings of the present study indicate that UVB exposure can lead to an imbalance in the intracellular Ca2+ homeostasis in HLECs and that Calb1 protein exerts a negative effect on the expression of proapoptotic genes in HLECs. Calb1 may thus inhibit the UVB radiationinduced apoptosis of HLECs by regulating Ca2+.
Sujet(s)
Apoptose/physiologie , Calbindine-1/métabolisme , Cellules épithéliales/métabolisme , Rayons ultraviolets/effets indésirables , Apoptose/effets des radiations , Calcium/métabolisme , Caspase-12/métabolisme , Lignée cellulaire , Cellules épithéliales/effets des radiations , Homéostasie/physiologie , Homéostasie/effets des radiations , Humains , Protéines proto-oncogènes c-bcl-2/métabolisme , Régulation positive/physiologie , Régulation positive/effets des radiations , Protéine Bad/métabolismeRÉSUMÉ
Mitochondrial dysfunction is critically involved in Parkinson's disease, characterized by loss of dopaminergic neurons (DaNs) in the substantia nigra (SNc), whereas DaNs in the neighboring ventral tegmental area (VTA) are much less affected. In contrast to VTA, SNc DaNs engage calcium channels to generate action potentials, which lead to oxidant stress by yet unknown pathways. To determine the molecular mechanisms linking calcium load with selective cell death in the presence of mitochondrial deficiency, we analyzed the mitochondrial redox state and the mitochondrial membrane potential in mice of both sexes with genetically induced, severe mitochondrial dysfunction in DaNs (MitoPark mice), at the same time expressing a redox-sensitive GFP targeted to the mitochondrial matrix. Despite mitochondrial insufficiency in all DaNs, exclusively SNc neurons showed an oxidized redox-system, i.e., a low reduced/oxidized glutathione (GSH-GSSG) ratio. This was mimicked by cyanide, but not by rotenone or antimycin A, making the involvement of reactive oxygen species rather unlikely. Surprisingly, a high mitochondrial inner membrane potential was maintained in MitoPark SNc DaNs. Antagonizing calcium influx into the cell and into mitochondria, respectively, rescued the disturbed redox ratio and induced further hyperpolarization of the inner mitochondrial membrane. Our data therefore show that the constant calcium load in SNc DaNs is counterbalanced by a high mitochondrial inner membrane potential, even under conditions of severe mitochondrial dysfunction, but triggers a detrimental imbalance in the mitochondrial redox system, which will lead to neuron death. Our findings thus reveal a new mechanism, redox imbalance, which underlies the differential vulnerability of DaNs to mitochondrial defects.SIGNIFICANCE STATEMENT Parkinson's disease is characterized by the preferential degeneration of dopaminergic neurons (DaNs) of the substantia nigra pars compacta (SNc), resulting in the characteristic hypokinesia in patients. Ubiquitous pathological triggers cannot be responsible for the selective neuron loss. Here we show that mitochondrial impairment together with elevated calcium burden destabilize the mitochondrial antioxidant defense only in SNc DaNs, and thus promote the increased vulnerability of this neuron population.
Sujet(s)
Antioxydants/métabolisme , Calcium/toxicité , Neurones dopaminergiques/métabolisme , Neurones dopaminergiques/anatomopathologie , Maladies mitochondriales/métabolisme , Maladies mitochondriales/anatomopathologie , Substantia nigra/métabolisme , Substantia nigra/anatomopathologie , Animaux , Calbindine-1/métabolisme , Mort cellulaire , Cyanures/toxicité , Femelle , Mâle , Potentiel de membrane mitochondriale , Souris , Membranes mitochondriales/métabolisme , Oxydoréduction , Stress oxydatif , Aire tegmentale ventrale/métabolisme , Aire tegmentale ventrale/anatomopathologieRÉSUMÉ
The basolateral amygdala (BLA) and ventral hippocampal CA1 (vCA1) are cellularly and functionally diverse along their anterior-posterior and superficial-deep axes. Here, we find that anterior BLA (aBLA) and posterior BLA (pBLA) innervate deep-layer calbindin1-negative (Calb1-) and superficial-layer calbindin1-positive neurons (Calb1+) in vCA1, respectively. Photostimulation of pBLA-vCA1 inputs has an anxiolytic effect in mice, promoting approach behaviours during conflict exploratory tasks. By contrast, stimulating aBLA-vCA1 inputs induces anxiety-like behaviour resulting in fewer approaches. During conflict stages of the elevated plus maze task vCA1Calb1+ neurons are preferentially activated at the open-to-closed arm transition, and photostimulation of vCA1Calb1+ neurons at decision-making zones promotes approach with fewer retreats. In the APP/PS1 mouse model of Alzheimer's disease, which shows anxiety-like behaviour, photostimulating the pBLA-vCA1Calb1+ circuit ameliorates the anxiety in a Calb1-dependent manner. These findings suggest the pBLA-vCA1Calb1+ circuit from heterogeneous BLA-vCA1 connections drives approach behaviour to reduce anxiety-like behaviour.
Sujet(s)
Anxiolytiques/pharmacologie , Groupe nucléaire basolatéral/métabolisme , Région CA1 de l'hippocampe/métabolisme , Calbindine-1/métabolisme , Comportement de choix/physiologie , Maladie d'Alzheimer/métabolisme , Animaux , Anxiété , Comportement animal , Calbindine-1/génétique , Prise de décision , Mâle , Apprentissage du labyrinthe/physiologie , Souris , Souris de lignée C57BL , Souris knockout , Neurones/physiologie , ProtéomiqueRÉSUMÉ
Calcineurin inhibitors (CNIs) are immunosuppressive drugs used to prevent graft rejection after organ transplant. Common side effects include renal magnesium wasting and hypomagnesemia, which may contribute to new-onset diabetes mellitus, and hypercalciuria, which may contribute to post-transplant osteoporosis. Previous work suggested that CNIs reduce the abundance of key divalent cation transport proteins, expressed along the distal convoluted tubule, causing renal magnesium and calcium wasting. It has not been clear, however, whether these effects are specific for the distal convoluted tubule, and whether these represent off-target toxic drug effects, or result from inhibition of calcineurin. The CNI tacrolimus can inhibit calcineurin only when it binds with the immunophilin, FKBP12; we previously generated mice in which FKBP12 could be deleted along the nephron, to test whether calcineurin inhibition is involved, these mice are normal at baseline. Here, we confirmed that tacrolimus-treated control mice developed hypomagnesemia and urinary calcium wasting, with decreased protein and mRNA abundance of key magnesium and calcium transport proteins (NCX-1 and Calbindin-D28k ). However, qPCR also showed decreased mRNA expression of NCX-1 and Calbindin-D28k , and TRPM6. In contrast, KS-FKBP12-/- mice treated with tacrolimus were completely protected from these effects. These results indicate that tacrolimus affects calcium and magnesium transport along the distal convoluted tubule and strongly suggests that inhibition of the phosphatase, calcineurin, is directly involved.
Sujet(s)
Inhibiteurs de la calcineurine/pharmacologie , Calcium/métabolisme , Hypercalciurie/induit chimiquement , Tubules contournés distaux/effets des médicaments et des substances chimiques , Magnésium/métabolisme , Protéine 1A de liaison au tacrolimus/génétique , Tacrolimus/pharmacologie , Troubles de l'équilibre hydroélectrolytique/induit chimiquement , Animaux , Calbindine-1/effets des médicaments et des substances chimiques , Calbindine-1/génétique , Calbindine-1/métabolisme , Inhibiteurs de la calcineurine/effets indésirables , Calcium/urine , Expression des gènes , Hypercalciurie/métabolisme , Hypercalciurie/urine , Tubules contournés distaux/métabolisme , Magnésium/urine , Souris , Souris knockout , ARN messager/effets des médicaments et des substances chimiques , ARN messager/métabolisme , Échangeur sodium-calcium/effets des médicaments et des substances chimiques , Échangeur sodium-calcium/génétique , Échangeur sodium-calcium/métabolisme , Canaux cationiques TRPM/effets des médicaments et des substances chimiques , Canaux cationiques TRPM/génétique , Canaux cationiques TRPM/métabolisme , Tacrolimus/effets indésirables , Protéine 1A de liaison au tacrolimus/métabolisme , Troubles de l'équilibre hydroélectrolytique/métabolisme , Troubles de l'équilibre hydroélectrolytique/urineRÉSUMÉ
For precisely regulating intracellular Ca2+ signals in a time- and space-dependent manner, cells make use of various components of the "Ca2+ signaling toolkit," including Ca2+ entry and Ca2+ extrusion systems. A class of cytosolic Ca2+-binding proteins termed Ca2+ buffers serves as modulators of such, mostly short-lived Ca2+ signals. Prototypical Ca2+ buffers include parvalbumins (α and ß isoforms), calbindin-D9k, calbindin-D28k, and calretinin. Although initially considered to function as pure Ca2+ buffers, that is, as intracellular Ca2+ signal modulators controlling the shape (amplitude, decay, spread) of Ca2+ signals, evidence has accumulated that calbindin-D28k and calretinin have additional Ca2+ sensor functions. These other functions are brought about by direct interactions with target proteins, thereby modulating their targets' function/activity. Dysregulation of Ca2+ buffer expression is associated with several neurologic/neurodevelopmental disorders including autism spectrum disorder (ASD) and schizophrenia. In some cases, the presence of these proteins is presumed to confer a neuroprotective effect, as evidenced in animal models of Parkinson's or Alzheimer's disease.
Sujet(s)
Signalisation calcique , Calcium/métabolisme , Cytosol/métabolisme , Régulation de l'expression des gènes , Transduction du signal , Maladie d'Alzheimer/métabolisme , Animaux , Trouble du spectre autistique/métabolisme , Substances tampon , Calbindine-1/métabolisme , Calbindine-2/métabolisme , Protéines de liaison au calcium/métabolisme , Régulation négative , Humains , Mitochondries/métabolisme , Maladie de Parkinson/métabolisme , Parvalbumines/métabolisme , Domaines protéiques , Protéine G liant le calcium S100/métabolisme , Schizophrénie/métabolismeRÉSUMÉ
BACKGROUND: In studies on cardiac arrest (CA)/resuscitation (R) injury, Purkinje cell degeneration was described, however, with inconsistent data concerning severity and time point of manifestation. Moreover, CA/R studies paid only limited attention to inhibitory stellate interneurons. To this aim, the hypothesis that cerebellar could be relatively resilient toward CA/R because of diverse cellular defense mechanisms including interaction with stellate cells was tested. METHODS: We examined rats with survival times of 6, 24, and 48 h, and 7 and 21 days in comparison with sham- and nonoperated animals. Thereby, we focused on the immunohistochemical expression of cfos, MnSOD, Bcl2, caspase 3, parvalbumin, calbindin D28 k, MAP2, IBA1, and GFAP, especially in the particular sensitivity to CA/R cerebellar lobule IX. Hippocampal CA1 degeneration was demonstrated by expression patterns of MAP2 and NeuN in combination with IBA1 and GFAP. RESULTS/CONCLUSIONS: Comparative analysis of hippocampal CA1 pyramidal cells and cerebellar Purkinje cells confirmed a relative resil-ience of Purkinje cells to CA/R. We found only a notable degeneration of Purkinje cell neuronal fiber network, which, however, not necessarily led to neuronal cell death. To induce significant Purkinje cell loss, a stronger ischemic trigger seems to be needed. As possible Purkinje cell-protecting mechanisms, we would propose: (1) activation of inhibitory stellate cells, shown by cfos, MnSOD, and Bcl2 expression, balancing out ischemia-induced excitation and inhibition of Purkinje cells; (2) translocation of the calcium-buffering system, shown by parvalbumin and calbindin D28 k expression, protecting Purkinje cells from detrimental calcium overload; (3) activation of the neuron-astrocyte cross talk, protecting Purkinje cells from over-excitation by removing potassium and neurotransmitters from the extracellular space; (4) activation of the effective and long-lasting MnSOD defense system; and (5) of the anti-apoptotic protein Bcl2 in Purkinje cells itself. Moreover, the results emphasize the limited comparability of animal CA/R studies because of the heterogeneity of the used experimental regimes.