The effect of vitamin D supplementation and nutritional intake on skeletal maturity and bone health in socio-economically deprived children.

PURPOSE: 1. To determine the effect of vitamin D supplementation on bone age (BA), a marker of skeletal maturity, and Bone Health Index (BHI), a surrogate marker of bone density. 2. To characterise the differences in nutritional intake and anthropometry between children with advanced vs. delayed BA. METHODS: The current study is a post hoc analysis of radiographs obtained as part of a randomised controlled trial. In this double-blind, placebo-controlled trial, deprived Afghan children (n = 3046) aged 1-11 months were randomised to receive six doses of oral placebo or vitamin D3 (100,000 IU) every 3 months for 18 months. Dietary intake was assessed through semi-quantitative food frequency questionnaires at two time points. Anthropometric measurements were undertaken at baseline and 18 months. Serum 25OHD was measured at five time points on a random subset of 632 children. Knee and wrist radiographs were obtained from a random subset (n = 641), of which 565 wrist radiographs were digitised for post-hoc analysis of BA and BHI using BoneXpert version 3.1. RESULTS: Nearly 93% (522, male = 291) of the images were analysable. The placebo (n = 258) and vitamin D (n = 264) groups were comparable at baseline. The mean (± SD) age of the cohort was 2 (± 0.3) years. At study completion, there was no difference in mean 25-hydroxy vitamin D concentrations [47 (95% CI 41, 56) vs. 55 (95% CI 45, 57) nmol/L, p = 0.2], mean (± SD) BA SDS [- 1.04 (1.36) vs. - 1.14 (1.26) years, p = 0.3] or mean (± SD) BHI SDS [- 0.30 (0.86) vs. - 0.31 (0.80), p = 0.8] between the placebo and vitamin D groups, respectively. Children with advanced skeletal maturity (BA SDS ≥ 0) when compared to children with delayed skeletal maturity (BA SDS < 0), had consumed more calories [mean (± SD) calories 805 (± 346) vs 723 (± 327) kcal/day, respectively, p < 0.05], were significantly less stunted (height SDS - 1.43 vs. - 2.32, p < 0.001) and underweight (weight SDS - 0.82 vs. - 1.45, p < 0.001), with greater growth velocity (11.57 vs 10.47 cm/ year, p < 0.05). CONCLUSION: Deprived children have significant delay in skeletal maturation but no substantial impairment in bone health as assessed by BHI. BA delay was influenced by total calorie intake, but not bolus vitamin D supplementation.

Neuronal Aquaporin 1 Inhibits Amyloidogenesis by Suppressing the Interaction Between Beta-Secretase and Amyloid Precursor Protein.

The accumulation of amyloid-ß (Aß) is a characteristic event in the pathogenesis of Alzheimer's disease (AD). Aquaporin 1 (AQP1) is a membrane water channel protein belonging to the AQP family. AQP1 levels are elevated in the cerebral cortex during the early stages of AD, but the role of AQP1 in AD pathogenesis is unclear. We first determined the expression and distribution of AQP1 in brain tissue samples of AD patients and two AD mouse models (3xTg-AD and 5xFAD). AQP1 accumulation was observed in vulnerable neurons in the cerebral cortex of AD patients, and in neurons affected by the Aß or tau pathology in the 3xTg-AD and 5xFAD mice. AQP1 levels increased in neurons as aging progressed in the AD mouse models. Stress stimuli increased AQP1 in primary cortical neurons. In response to cellular stress, AQP1 appeared to translocate to endocytic compartments of ß- and γ-secretase activities. Ectopic expression of AQP1 in human neuroblastoma cells overexpressing amyloid precussir protein (APP) with the Swedish mutations reduced ß-secretase (BACE1)-mediated cleavage of APP and reduced Aß production without altering the nonamyloidogenic pathway. Conversely, knockdown of AQP1 enhanced BACE1 activity and Aß production. Immunoprecipitation experiments showed that AQP1 decreased the association of BACE1 with APP. Analysis of a human database showed that the amount of Aß decreases as the expression of AQP1 increases. These results suggest that the upregulation of AQP1 is an adaptive response of neurons to stress that reduces Aß production by inhibiting the binding between BACE1 and APP.

Metabolic bone disease of prematurity: causes, recognition, prevention, treatment and long-term consequences.

Metabolic bone disease of prematurity (MBDP) is characterised by skeletal demineralisation, and in severe cases it can result in fragility fractures of long bones and ribs during routine handling. MBDP arises from prenatal and postnatal factors. Infants who are born preterm are deprived of fetal mineral accumulation, 80% of which occurs in the third trimester. Postnatally, it is difficult to maintain a comparable intake of minerals, and medications, such as corticosteroids and diuretic therapy, lead to bone resorption. With improvements in neonatal care and nutrition, the incidence of MBDP in preterm infants appears to have decreased, although the recent practice of administering phosphate supplements alone will result in secondary hyperparathyroidism and associated bone loss, worsening MBDP. Postnatal immobilisation and loss of placental supply of oestrogen also contribute to skeletal demineralisation. There is no single diagnostic or screening test for MBDP, with pitfalls existing for most radiological and biochemical investigations. By reviewing the pathophysiology of calcium and phosphate homeostasis, one can establish that plasma parathyroid hormone is important in determining the aetiology of MBDP - primarily calcipaenia or phosphopaenia. This will then direct treatment with the appropriate supplements while considering optimal physiological calcium to phosphate ratios.

Duplex Ratio Tests as Diagnostic Biomarkers in Malignant Melanoma.

Chromosomal instability is a well-described feature of malignant tumors. Melanomas have typical patterns of chromosomal instability compared with benign nevi, which have minimal DNA copy number change. A few malignant melanomas and their benign counterparts, nevi, prove difficult to diagnose on histopathologic analysis alone, which is currently the gold standard. Quantitative PCR-based assays called duplex ratio tests (DRTs) have been developed by our laboratory for application using DNA from FFPE samples of melanomas and nevi. The reproducibility and accuracy of the DRTs were demonstrated and appropriate correction factors for DNA quality calculated for each assay, based on the results of 108 diploid samples. As a panel, seven DRTs were able to differentiate unambiguous cases of melanoma and nevi with a sensitivity of 87% (95% CI, 83%-91%) and a specificity of 88% (95% CI, 84%-92%) in a series of 145 melanomas and 123 nevi. The DRT scores for 20 nonmetastasizing primary melanomas and 20 metastasizing primary melanomas revealed that DRTs had a marginal benefit as prognostic markers. DRTs have early potential to act as molecular biomarkers of melanoma on FFPE specimens pending validation, and DRTs may have applicability as prognostic markers in melanoma or other tumor types if new DRTs to relevant loci are developed.

Postnatal TLR2 activation impairs learning and memory in adulthood.

Neuroinflammation in the central nervous system is detrimental for learning and memory, as evident form epidemiological studies linking developmental defects and maternal exposure to harmful pathogens. Postnatal infections can also induce neuroinflammatory responses with long-term consequences. These inflammatory responses can lead to motor deficits and/or behavioral disabilities. Toll like receptors (TLRs) are a family of innate immune receptors best known as sensors of microbial-associated molecular patterns, and are the first responders to infection. TLR2 forms heterodimers with either TLR1 or TLR6, is activated in response to gram-positive bacterial infections, and is expressed in the brain during embryonic development. We hypothesized that early postnatal TLR2-mediated neuroinflammation would adversely affect cognitive behavior in the adult. Our data indicate that postnatal TLR2 activation affects learning and memory in adult mice in a heterodimer-dependent manner. TLR2/6 activation improved motor function and fear learning, while TLR2/1 activation impaired spatial learning and enhanced fear learning. Moreover, developmental TLR2 deficiency significantly impairs spatial learning and enhances fear learning, stressing the involvement of the TLR2 pathway in learning and memory. Analysis of the transcriptional effects of TLR2 activation reveals both common and unique transcriptional programs following heterodimer-specific TLR2 activation. These results imply that adult cognitive behavior could be influenced in part, by activation or alterations in the TLR2 pathway at birth.

Tellurium compound AS101 ameliorates experimental autoimmune encephalomyelitis by VLA-4 inhibition and suppression of monocyte and T cell infiltration into the CNS.

Multiple sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system (CNS) involving demyelinating and neurodegenerative processes. Several of the major pathological CNS alterations and behavioral deficits of MS are recapitulated in the experimental autoimmune encephalitis (EAE) mouse model in which the disease process is induced by administration of myelin peptides. Development of EAE requires infiltration of inflammatory cytokine-generating monocytes and macrophages, and auto-reactive T cells, into the CNS. Very late antigen-4 (VLA-4, α4ß1) is an integrin molecule that plays a role in inflammatory responses by facilitating the migration of leukocytes across the blood-brain barrier during inflammatory disease, and antibodies against VLA-4 exhibit therapeutic efficacy in mouse and monkey MS models. Here, we report that the tellurium compound AS101 (ammonium trichloro (dioxoethylene-o,o') tellurate) ameliorates EAE by inhibiting monocyte and T cell infiltration into the CNS. CD49d is an alpha subunit of the VLA-4 (α4ß1) integrin. During the peak stage of EAE, AS101 treatment effectively ameliorated the disease process by reducing the number of CD49d(+) inflammatory monocyte/macrophage cells in the spinal cord. AS101 treatment markedly reduced the pro-inflammatory cytokine levels, while increasing anti-inflammatory cytokine levels. In contrast, AS101 treatment did not affect the peripheral populations of CD11b(+) monocytes and macrophages. AS101 treatment reduced the infiltration of CD4(+) and CD49(+)/VLA4 T cells. In addition, treatment of T cells from MS patients with AS101 resulted in apoptosis, while such treatment did not affect T cells from healthy donors. These results suggest that AS101 reduces accumulation of leukocytes in the CNS by inhibiting the activity of the VLA-4 integrin and provide a rationale for the potential use of Tellurium IV compounds for the treatment of MS.

Chronic mild sleep restriction accentuates contextual memory impairments, and accumulations of cortical Aß and pTau in a mouse model of Alzheimer's disease.

Age-associated dysregulation of sleep can be worsened by Alzheimer's disease (AD). AD and sleep restriction both impair cognition, yet it is unknown if mild chronic sleep restriction modifies the proteopathic processes involved in AD. The goal of this work was to test the hypothesis that sleep restriction worsens memory impairments, and amyloid ß-peptide (Aß) and pTau accumulations in the brain in a mouse model of AD, with a focus on a role for circulating glucocorticoids (GC). Male 3xTgAD mice were subjected to sleep restriction (SR) for 6h/day for 6 weeks using the modified multiple platform technique, and behavioral (Morris water maze, fear conditioning, open field) and biochemical (immunoblot) outcomes were compared to mice undergoing daily cage transfers (large cage control; LCC) as well as control mice that remained in their home cage (control; CTL). At one week, both LCC and SR mice displayed significant elevations in plasma corticosterone compared to CTL (p<0.002). By four weeks, SR mice displayed a two-fold increase in circulating corticosterone levels compared to CTL. Behavioral data indicated deficits in contextual and cued memory in SR mice that were not present for LCC or CTL (p<0.04). Both Aß and pTau levels increased in the cortex of SR mice compared to CTL and LCC; however these changes were not noted in the hippocampus. Significant positive correlations between cortical Aß and pTau levels and circulating corticosterone indicate a potential role for GCs in mediating behavioral and biochemical changes observed after sleep restriction in a mouse model of AD.

CD28-inducible transcription factor DEC1 is required for efficient autoreactive CD4+ T cell response.

During the initial hours after activation, CD4(+) T cells experience profound changes in gene expression. Co-stimulation via the CD28 receptor is required for efficient activation of naive T cells. However, the transcriptional consequences of CD28 co-stimulation are not completely understood. We performed expression microarray analysis to elucidate the effects of CD28 signals on the transcriptome of activated T cells. We show that the transcription factor DEC1 is highly induced in a CD28-dependent manner upon T cell activation, is involved in essential CD4(+) effector T cell functions, and participates in the transcriptional regulation of several T cell activation pathways, including a large group of CD28-regulated genes. Antigen-specific, DEC1-deficient CD4(+) T cells have cell-intrinsic defects in survival and proliferation. Furthermore, we found that DEC1 is required for the development of experimental autoimmune encephalomyelitis because of its critical role in the production of the proinflammatory cytokines GM-CSF, IFN-γ, and IL-2. Thus, we identify DEC1 as a critical transcriptional mediator in the activation of naive CD4(+) T cells that is required for the development of a T cell-mediated autoimmune disease.

Neuron-specific expression of tomosyn1 in the mouse hippocampal dentate gyrus impairs spatial learning and memory.

Tomosyn, a syntaxin-binding protein, is known to inhibit vesicle priming and synaptic transmission via interference with the formation of SNARE complexes. Using a lentiviral vector, we specifically overexpressed tomosyn1 in hippocampal dentate gyrus neurons in adult mice. Mice were then subjected to spatial learning and memory tasks and electrophysiological measurements from hippocampal slices. Tomosyn1-overexpression significantly impaired hippocampus-dependent spatial memory while tested in the Morris water maze. Further, tomosyn1-overexpressing mice utilize swimming strategies of lesser cognitive ability in the Morris water maze compared with control mice. Electrophysiological measurements at mossy fiber-CA3 synapses revealed impaired paired-pulse facilitation in the mossy fiber of tomosyn1-overexpressing mice. This study provides evidence for novel roles for tomosyn1 in hippocampus-dependent spatial learning and memory, potentially via decreased synaptic transmission in mossy fiber-CA3 synapses. Moreover, it provides new insight regarding the role of the hippocampal dentate gyrus and mossy fiber-CA3 synapses in swimming strategy preference, and in learning and memory.

3,6'-dithiothalidomide improves experimental stroke outcome by suppressing neuroinflammation.

Tumor necrosis factor-α (TNF) plays a prominent role in the brain damage and functional deficits that result from ischemic stroke. It was recently reported that the thalidomide analog 3,6'-dithiothalidomide (3,6'-DT) can selectively inhibit the synthesis of TNF in cultured cells. We therefore tested the therapeutic potential of 3,6'-DT in a mouse model of focal ischemic stroke. Administration of 3,6'-DT immediately prior to a stroke or within 3 hr after the stroke reduced infarct volume, neuronal death, and neurological deficits, whereas thalidomide was effective only when administered prior to stroke. Neuroprotection was accompanied by decreased inflammation; 3,6'-DT-treated mice exhibited reduced expression of TNF, interleukin-1ß, and inducible nitric oxide synthase; reduced numbers of activated microglia/macrophages, astrocytes, and neutrophils; and reduced expression of intercellular adhesion molecule-1 in the ischemic brain tissue. 3,6'-DT treatment attenuated stroke-induced disruption of the blood-brain barrier by a mechanism that appears to involve suppression of matrix metalloproteinase-9 and preservation of occludin. Treatment with 3,6'-DT did not reduce ischemic brain damage in mice lacking TNF receptors, consistent with a critical role for suppression of TNF production and TNF signaling in the therapeutic action of 3,6'-DT. These findings suggest that anti-inflammatory mechanisms underlie the therapeutic actions of 3,6-DT in an animal model of stroke.

A ketone ester diet exhibits anxiolytic and cognition-sparing properties, and lessens amyloid and tau pathologies in a mouse model of Alzheimer's disease.

Alzheimer's disease (AD) involves progressive accumulation of amyloid ß-peptide (Aß) and neurofibrillary pathologies, and glucose hypometabolism in brain regions critical for memory. The 3xTgAD mouse model was used to test the hypothesis that a ketone ester-based diet can ameliorate AD pathogenesis. Beginning at a presymptomatic age, 2 groups of male 3xTgAD mice were fed a diet containing a physiological enantiomeric precursor of ketone bodies (KET) or an isocaloric carbohydrate diet. The results of behavioral tests performed at 4 and 7 months after diet initiation revealed that KET-fed mice exhibited significantly less anxiety in 2 different tests. 3xTgAD mice on the KET diet also exhibited significant, albeit relatively subtle, improvements in performance on learning and memory tests. Immunohistochemical analyses revealed that KET-fed mice exhibited decreased Aß deposition in the subiculum, CA1 and CA3 regions of the hippocampus, and the amygdala. KET-fed mice exhibited reduced levels of hyperphosphorylated tau deposition in the same regions of the hippocampus, amygdala, and cortex. Thus, a novel ketone ester can ameliorate proteopathic and behavioral deficits in a mouse AD model.

Effects of cerium oxide nanoparticles on the growth of keratinocytes, fibroblasts and vascular endothelial cells in cutaneous wound healing.

Rapid and effective wound healing requires a coordinated cellular response involving fibroblasts, keratinocytes and vascular endothelial cells (VECs). Impaired wound healing can result in multiple adverse health outcomes and, although antibiotics can forestall infection, treatments that accelerate wound healing are lacking. We now report that topical application of water soluble cerium oxide nanoparticles (Nanoceria) accelerates the healing of full-thickness dermal wounds in mice by a mechanism that involves enhancement of the proliferation and migration of fibroblasts, keratinocytes and VECs. The Nanoceria penetrated into the wound tissue and reduced oxidative damage to cellular membranes and proteins, suggesting a therapeutic potential for topical treatment of wounds with antioxidant nanoparticles.

Evidence for a developmental role for TLR4 in learning and memory.

Toll-like receptors (TLRs) play essential roles in innate immunity and increasing evidence indicates that these receptors are expressed in neurons, astrocytes and microglia in the brain where they mediate responses to infection, stress and injury. Very little is known about the roles of TLRs in cognition. To test the hypothesis that TLR4 has a role in hippocampus-dependent spatial learning and memory, we used mice deficient for TLR4 and mice receiving chronic TLR4 antagonist infusion to the lateral ventricles in the brain. We found that developmental TLR4 deficiency enhances spatial reference memory acquisition and memory retention, impairs contextual fear-learning and enhances motor functions, traits that were correlated with CREB up-regulation in the hippocampus. TLR4 antagonist infusion into the cerebral ventricles of adult mice did not affect cognitive behavior, but instead affected anxiety responses. Our findings indicate a developmental role for TLR4 in shaping spatial reference memory, and fear learning and memory. Moreover, we show that central TLR4 inhibition using a TLR4 antagonist has no discernible physiological role in regulating spatial and contextual hippocampus-dependent cognitive behavior.

Exendin-4 ameliorates motor neuron degeneration in cellular and animal models of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by a progressive loss of lower motor neurons in the spinal cord. The incretin hormone, glucagon-like peptide-1 (GLP-1), facilitates insulin signaling, and the long acting GLP-1 receptor agonist exendin-4 (Ex-4) is currently used as an anti-diabetic drug. GLP-1 receptors are widely expressed in the brain and spinal cord, and our prior studies have shown that Ex-4 is neuroprotective in several neurodegenerative disease rodent models, including stroke, Parkinson's disease and Alzheimer's disease. Here we hypothesized that Ex-4 may provide neuroprotective activity in ALS, and hence characterized Ex-4 actions in both cell culture (NSC-19 neuroblastoma cells) and in vivo (SOD1 G93A mutant mice) models of ALS. Ex-4 proved to be neurotrophic in NSC-19 cells, elevating choline acetyltransferase (ChAT) activity, as well as neuroprotective, protecting cells from hydrogen peroxide-induced oxidative stress and staurosporine-induced apoptosis. Additionally, in both wild-type SOD1 and mutant SOD1 (G37R) stably transfected NSC-19 cell lines, Ex-4 protected against trophic factor withdrawal-induced toxicity. To assess in vivo translation, SOD1 mutant mice were administered vehicle or Ex-4 at 6-weeks of age onwards to end-stage disease via subcutaneous osmotic pump to provide steady-state infusion. ALS mice treated with Ex-4 showed improved glucose tolerance and normalization of behavior, as assessed by running wheel, compared to control ALS mice. Furthermore, Ex-4 treatment attenuated neuronal cell death in the lumbar spinal cord; immunohistochemical analysis demonstrated the rescue of neuronal markers, such as ChAT, associated with motor neurons. Together, our results suggest that GLP-1 receptor agonists warrant further evaluation to assess whether their neuroprotective potential is of therapeutic relevance in ALS.

Aberrant heart rate and brainstem brain-derived neurotrophic factor (BDNF) signaling in a mouse model of Huntington's disease.

Huntington's disease (HD) is associated with profound autonomic dysfunction including dysregulation of cardiovascular control often preceding cognitive or motor symptoms. Brain-derived neurotrophic factor (BDNF) levels are decreased in the brains of HD patients and HD mouse models, and restoring BDNF levels prevents neuronal loss and extends survival in HD mice. We reasoned that heart rate changes in HD may be associated with altered BDNF signaling in cardiovascular control nuclei in the brainstem. Here we show that heart rate is elevated in HD (N171-82Q) mice at presymptomatic and early disease stages, and heart rate responses to restraint stress are attenuated. BDNF levels were significantly reduced in brainstem regions containing cardiovascular nuclei in HD mice and human HD patients. Central administration of BDNF restored the heart rate to control levels. Our findings establish a link between diminished BDNF expression in brainstem cardiovascular nuclei and abnormal heart rates in HD mice, and suggest a novel therapeutic target for correcting cardiovascular dysfunction in HD.

3xTgAD mice exhibit altered behavior and elevated Aß after chronic mild social stress.

Chronic stress may be a risk factor for developing Alzheimer's disease (AD), but most studies of the effects of stress in models of AD utilize acute adverse stressors of questionable clinical relevance. The goal of this work was to determine how chronic psychosocial stress affects behavioral and pathological outcomes in an animal model of AD, and to elucidate underlying mechanisms. A triple-transgenic mouse model of AD (3xTgAD mice) and nontransgenic control mice were used to test for an affect of chronic mild social stress on blood glucose, plasma glucocorticoids, plasma insulin, anxiety, and hippocampal amyloid ß-particle (Aß), phosphorylated tau (ptau), and brain-derived neurotrophic factor (BDNF) levels. Despite the fact that both control and 3xTgAD mice experienced rises in corticosterone during episodes of mild social stress, at the end of the 6-week stress period 3xTgAD mice displayed increased anxiety, elevated levels of Aß oligomers and intraneuronal Aß, and decreased brain-derived neurotrophic factor levels, whereas control mice did not. Findings suggest 3xTgAD mice are more vulnerable than control mice to chronic psychosocial stress, and that such chronic stress exacerbates Aß accumulation and impairs neurotrophic signaling.

Molecular changes in brain aging and Alzheimer's disease are mirrored in experimentally silenced cortical neuron networks.

Activity-dependent modulation of neuronal gene expression promotes neuronal survival and plasticity, and neuronal network activity is perturbed in aging and Alzheimer's disease (AD). Here we show that cerebral cortical neurons respond to chronic suppression of excitability by downregulating the expression of genes and their encoded proteins involved in inhibitory transmission (GABAergic and somatostatin) and Ca(2+) signaling; alterations in pathways involved in lipid metabolism and energy management are also features of silenced neuronal networks. A molecular fingerprint strikingly similar to that of diminished network activity occurs in the human brain during aging and in AD, and opposite changes occur in response to activation of N-methyl-D-aspartate (NMDA) and brain-derived neurotrophic factor (BDNF) receptors in cultured cortical neurons and in mice in response to an enriched environment or electroconvulsive shock. Our findings suggest that reduced inhibitory neurotransmission during aging and in AD may be the result of compensatory responses that, paradoxically, render the neurons vulnerable to Ca(2+)-mediated degeneration.

The homocysteine-inducible endoplasmic reticulum (ER) stress protein Herp counteracts mutant α-synuclein-induced ER stress via the homeostatic regulation of ER-resident calcium release channel proteins.

Endoplasmic reticulum (ER) stress has been implicated as an initiator or contributing factor in neurodegenerative diseases. The mechanisms that lead to ER stress and whereby ER stress contributes to the degenerative cascades remain unclear but their understanding is critical to devising effective therapies. Here we show that knockdown of Herp (Homocysteine-inducible ER stress protein), an ER stress-inducible protein with an ubiquitin-like (UBL) domain, aggravates ER stress-mediated cell death induced by mutant α-synuclein (αSyn) that causes an inherited form of Parkinson's disease (PD). Functionally, Herp plays a role in maintaining ER homeostasis by facilitating proteasome-mediated degradation of ER-resident Ca(2+) release channels. Deletion of the UBL domain or pharmacological inhibition of proteasomes abolishes the Herp-mediated stabilization of ER Ca(2+) homeostasis. Furthermore, knockdown or pharmacological inhibition of ER Ca(2+) release channels ameliorates ER stress, suggesting that impaired homeostatic regulation of Ca(2+) channels promotes a protracted ER stress with the consequent activation of ER stress-associated apoptotic pathways. Interestingly, sustained upregulation of ER stress markers and aberrant accumulation of ER Ca(2+) release channels were detected in transgenic mutant A53T-αSyn mice. Collectively, these data establish a causative link between impaired ER Ca(2+) homeostasis and chronic ER stress in the degenerative cascades induced by mutant αSyn and suggest that Herp is essential for the resolution of ER stress through maintenance of ER Ca(2+) homeostasis. Our findings suggest a therapeutic potential in PD for agents that increase Herp levels or its ER Ca(2+)-stabilizing action.

Ceruloplasmin deficiency results in an anxiety phenotype involving deficits in hippocampal iron, serotonin, and BDNF.

Ceruloplasmin (Cp) is a ferroxidase involved in iron metabolism by converting Fe(2+) to Fe(3+), and by regulating cellular iron efflux. In the ceruloplasmin knockout (CpKO) mouse, the deregulation of iron metabolism results in moderate liver and spleen hemosiderosis, but the impact of Cp deficiency on brain neurochemistry and behavior in this animal model is unknown. We found that in contrast to peripheral tissues, iron levels in the hippocampus are significantly reduced in CpKO mice. Although it does not cause any discernable deficits in motor function or learning and memory, Cp deficiency results in heightened anxiety-like behavior in the open field and elevated plus maze tests. This anxiety phenotype is associated with elevated levels of plasma corticosterone. Previous studies provided evidence that anxiety disorders and long-standing stress are associated with reductions in levels of serotonin (5HT) and brain-derived neurotrophic factor (BDNF) in the hippocampus. We found that levels of 5HT and norepinephrine (NE), and the expression of BDNF and its receptor trkB, are significantly reduced in the hippocampus of CpKO mice. Thus, Cp deficiency causes an anxiety phenotype by a mechanism that involves decreased levels of iron, 5HT, NE, and BDNF in the hippocampus.