Inhibition of autophagy, lysosome and VCP function impairs stress granule assembly

Stress granules (SGs) are mRNA-protein aggregates induced during stress, which accumulate in many neurodegenerative diseases. Previously, the autophagy-lysosome pathway and valosin-containing protein (VCP), key players of the protein quality control (PQC), were shown to regulate SG degradation. This is consistent with the idea that PQC may survey and/or assist SG dynamics. However, despite these observations, it is currently unknown whether the PQC actively participates in SG assembly. Here, we describe that inhibition of autophagy, lysosomes and VCP causes defective SG formation after induction. Silencing the VCP co-factors UFD1L and PLAA, which degrade defective ribosomal products (DRIPs) and 60S ribosomes, also impaired SG assembly. Intriguingly, DRIPs and 60S, which are released from disassembling polysomes and are normally excluded from SGs, were significantly retained within SGs in cells with impaired autophagy, lysosome or VCP function. Our results suggest that deregulated autophagy, lysosomal or VCP activities, which occur in several neurodegenerative (VCP-associated) diseases, may alter SG morphology and composition.

Zebrafish Collagen Type I: Molecular and Biochemical Characterization of the Major Structural Protein in Bone and Skin

Over the last years the zebrafish imposed itself as a powerful model to study skeletal diseases, but a limit to its use is the poor characterization of collagen type I, the most abundant protein in bone and skin. In tetrapods collagen type I is a trimer mainly composed of two α1 chains and one α2 chain, encoded by COL1A1 and COL1A2 genes, respectively. In contrast, in zebrafish three type I collagen genes exist, col1a1a, col1a1b and col1a2 coding for α1(I), α3(I) and α2(I) chains. During embryonic and larval development the three collagen type I genes showed a similar spatio-temporal expression pattern, indicating their co-regulation and interdependence at these stages. In both embryonic and adult tissues, the presence of the three α(I) chains was demonstrated, although in embryos α1(I) was present in two distinct glycosylated states, suggesting a developmental-specific collagen composition. Even though in adult bone, skin and scales equal amounts of α1(I), α3(I) and α2(I) chains are present, the presented data suggest a tissue-specific stoichiometry and/or post-translational modification status for collagen type I. In conclusion, this data will be useful to properly interpret results and insights gained from zebrafish models of skeletal diseases.

The HSPB8-BAG3 chaperone complex is upregulated in astrocytes in the human brain affected by protein aggregation diseases

AIMS

HSPB8 is a small heat shock protein that forms a complex with the co-chaperone BAG3. Overexpression of the HSPB8-BAG3 complex in cells stimulates autophagy and facilitates the clearance of mutated aggregation-prone proteins, whose accumulation is a hallmark of many neurodegenerative disorders. HSPB8-BAG3 could thus play a protective role in protein aggregation diseases and might be specifically upregulated in response to aggregate-prone protein-mediated toxicity. Here we analysed HSPB8-BAG3 expression levels in post-mortem human brain tissue from patients suffering of the following protein conformation disorders: Alzheimer's disease, Parkinson's disease, Huntington's disease and spinocerebellar ataxia type 3 (SCA3).

METHODS

Western blotting and immunohistochemistry techniques were used to analyse HSPB8 and BAG3 expression levels in fibroblasts from SCA3 patients and post-mortem brain tissues, respectively.

RESULTS

In all diseases investigated, we observed a strong upregulation of HSPB8 and a moderate upregulation of BAG3 specifically in astrocytes in the cerebral areas affected by neuronal damage and degeneration. Intriguingly, no significant change in the HSPB8-BAG3 expression levels was observed within neurones, irrespective of their localization or of the presence of proteinaceous aggregates.

CONCLUSIONS

We propose that the upregulation of HSPB8 and BAG3 may enhance the ability of astrocytes to clear aggregated proteins released from neurones and cellular debris, maintain the local tissue homeostasis and/or participate in the cytoskeletal remodelling that astrocytes undergo during astrogliosis.

Strain-dependent high-level expression of a transgene for manganese superoxide dismutase is associated with growth retardation and decreased fertility

Manganese superoxide dismutase (MnSOD) is essential in protecting mitochondria against the damaging effects of superoxide radicals (O(2)(*-)), and increased expression of MnSOD protects cells and transgenic animals from various forms of oxidative stress. In addition, increased levels of MnSOD have been shown to slow down cell growth and induce differentiation. To study the effects of high MnSOD levels in vivo, we generated a series of transgenic mice using a mouse genomic sequence under control of the endogenous promoter. Four transgenic lines produced by pronuclear DNA injection exhibited up to 2-fold elevated MnSOD levels in brain and heart. However, using an embryonic stem cell approach, a line having 10-fold elevated MnSOD levels in the brain and 6- to 7-fold elevated levels in the heart and kidney was generated. Surprisingly, the genetic background of this transgenic line influenced the expression level of the transgene, with DBA/2 (D2) and C57BL/6 (B6) mice exhibiting low- and high-level transgene expression, respectively. This difference was the result of an increased transcription rate of the transgene. High-level MnSOD expression in B6 animals was associated with small size, male infertility, and decreased female fertility. These features are absent on the D2 background and indicate that high levels of MnSOD activity may interfere with normal growth and fertility.

Modulation of glutamate receptors in response to the novel antipsychotic olanzapine in rats

BACKGROUND

A disturbance in glutamate neurotransmission has been hypothesized in schizophrenia. Hence, the beneficial effects of pharmacological treatment may be related to adaptive changes taking place in this neurotransmitter system.

METHODS

In this study, we investigated the modulation of ionotropic and metabotropic glutamate receptors in the rat brain following acute or chronic exposure to the novel antipsychotic olanzapine.

RESULTS

In accordance with the clear distinction between classical and atypical drugs, olanzapine did not alter glutamate receptor expression in striatum. Chronic, not acute, exposure to olanzapine was capable of up-regulating hippocampal mRNA levels for GluR-B and GluR-C, two alpha-amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid (AMPA)-forming subunits. This effect could be relevant for the improvement of schizophrenic alterations, which are thought to depend on dysfunction of the glutamatergic transmission within the hippocampal formation. We also found that the expression of group II glutamate metabotropic receptors was up-regulated in the frontal cortex after chronic exposure to clozapine, and to a lesser extent olanzapine, but not with haloperidol.

CONCLUSIONS

The adaptive mechanisms taking place in glutamatergic transmission might prove useful in ameliorating some of the dysfunction observed in the brain of schizophrenic patients.

Effect of atmospheric nitric oxide (NO) on measurements of exhaled NO in asthmatic children

The measurement of exhaled nitric oxide concentrations [NO] may provide a simple, noninvasive means for measuring airway inflammation. However, several measurement conditions may influence exhaled NO levels, and ambient NO may be one of these. We measured exhaled NO levels in 47 stable asthmatic children age 5 to 17 years and in 47 healthy children, gender and age matched. Exhaled [NO] in expired air was measured by a tidal breathing method with a chemiluminescence analyzer, sampling at the expiratory side of the mouthpiece. NO steady-state levels were recorded. In order to keep the soft palate closed and avoid nasal contamination, the breathing circuit had a restrictor providing an expiratory pressure of 3-4 cm H2O at the mouthpiece. To evaluate the effect of [NO] in ambient air, measurements were randomly performed by breathing ambient air or NO-free air from a closed circuit. Breathing NO-free air, exhaled [NO] in asthmatics (mean +/- SEM) was 23.7 +/- 1.4 ppb, significantly higher (P < 0.001) than in healthy controls (8.7 +/- 0.4 ppb). Exhaled NO concentrations measured during ambient air breathing were higher (49 +/- 4.6 ppb, P < 0.001) than when breathing NO-free air (23.7 +/- 1.4 ppb) and were significantly correlated (r = 0.89, P < 0.001) with atmospheric concentrations of NO (range 3-430 ppb). These findings show that 1) exhaled [NO] values of asthmatic children are significantly higher than in healthy controls, and 2) atmospheric NO levels critically influence the measurement of exhaled [NO]. Therefore, using a tidal breathing method the inhalation of NO-free air during the test is recommended.

Home oxygen therapy in infants with bronchopulmonary dysplasia: a prospective study

We followed the clinical course of 21 infants with bronchopulmonary dysplasia enrolled in a prospective home O2 therapy programme during a 4-year-period. Mean gestational age was 28.5 weeks (range, 25-36 weeks) and mean birth weight 1093 g (range 630-2750 g). Infants were regularly monitored to maintain pulse oximeter O2 saturation over 94%-95%. The source of O2 was liquid oxygen and was delivered by nasal cannula. During the follow up oxygenation was assessed by SatO2 measurement, cardiac function by Doppler echocardiography and respiratory function by the occlusion technique. All patients had an ophthalmological follow up. The mean age of the infants at discharge was 3.7 months (range 1.7-8.6) and mean weight 2830 g (range 2150-3780 g). At discharge 8 infants had right ventricular hypertrophy (RVH) and four of them had pulmonary hypertension. Mean duration of home O2 therapy was 97 days (range 15-320 days) and the mean age of discontinuation of O2 was 6.9 months (range 3-14.7 months). The cardiological follow up was benign: the ECG signs of RVH disappeared by 12 months of age in six out of eight infants and the right ventricular pulmonary pressure, as measured by the Doppler method, normalised in the four patients in whom it was detected. No relationship was found between respiratory mechanics and the duration of O2 therapy. Weight gain was poor with mean growth at the 3rd percentile for females and just below the 3rd percentile for males. Twelve of the 21 infants required 25 rehospitalizations. No one presented deterioration of retinopathy of prematurity that was present in 16 infants at discharge; at 12 months retinopathy was resolved in 14 infants. A total of 2025 hospital days were saved, representing a significant financial saving.

CONCLUSION

Home O2 therapy permits the safe early discharge of O2-dependent BPD infants and it reduces significantly the length of time spent in hospital which represents a considerable financial saving.

Novel approach to the molecular diagnosis of Marfan syndrome: application to sporadic cases and in prenatal diagnosis

Marfan syndrome is an autosomal dominant disorder affecting the skeletal, ocular, and cardiovascular systems. Defects in the gene that encodes fibrillin-1 (FBN1), the main structural component of the elastin-associated microfibrils, are responsible for the disorder. Molecular diagnosis in families with Marfan syndrome can be undertaken by using intragenic FBN1 gene markers to identify and track the disease allele. However, in sporadic cases, which constitute up to 30% of the total, DNA-based diagnosis cannot be performed using linked markers but rather requires the identification of the specific FBN1 gene mutation. Due to the size and complexity of the FBN1 gene, identification of a causative Marfan syndrome mutation is not a trivial undertaking. Herein, we describe a comprehensive approach to the molecular diagnosis of Marfan syndrome that relies on the direct analysis of the FBN1 gene at the cDNA level and detects both coding sequence mutations and those leading to exon-skipping, which are often missed by analysis at the genomic DNA level. The ability to consistently determine the specific FBN1 gene mutation responsible for a particular case of Marfan syndrome allows both prenatal and pre-implantation diagnosis, even in sporadic instances of the disease.

ANAPHYLAXIS AND PREGNANCY: A SYSTEMATIC REVIEW AND CALL FOR PUBLIC HEALTH ACTIONS

BACKGROUND

Although rare, anaphylaxis during pregnancy implies a risk to both mothers and newborns.

OBJECTIVE

This systematic review is intended to identify key issues in the diagnosis and management of this condition in order to support prevention strategies and decrease the risk of death related to anaphylaxis during pregnancy.

METHODS

We searched MEDLINE, Cochrane, Lilacs, Scielo and Science Direct databases for manuscripts concerning terms "anaphylaxis during pregnancy" without language restrictions. We screened studies, extracted data, and assessed risk of bias independently in duplicate.

RESULTS

We selected 12 articles. Frequency of anaphylaxis during pregnancy is estimated between 1.5 to 3.8 per 100 000 maternities. Only one study provided anaphylaxis mortality data in pregnant women, and the rate of anaphylaxis-related maternal mortality is estimated at 0.05 per 100 000 live births. No standard definition of anaphylaxis severity has been utilized. Forty-nine percent to 74% of anaphylaxis cases were described during caesarean sections. Beta-lactam antibiotics (58%), latex (25%) and anaesthetic agents (17%) were the main culprits. In 17% of papers, causative agents were proven by allergy testing. Seventy two percent of articles proposed the same management and treatment for a clinical episode of anaphylaxis during pregnancy as in non-pregnant patients, and, use of epinephrine in the patient's care during anaphylaxis in pregnancy.

CONCLUSION

Few studies address anaphylaxis during pregnancy, and the majority have been produced by non-allergy specialists. Collaboration between different specialists involved in the care of pregnant women should be established in order to support preventive strategies and reduce avoidable deaths.

Nucleoli and Promyelocytic Leukemia Protein (PML) bodies are phase separated nuclear protein quality control compartments for misfolded proteins

We uncovered a role for nucleoli and PML-bodies as phase-separated protein quality control organelles that compartmentalize protein quality control factors and misfolded proteins for their efficient clearance. Failure to dispose misfolded proteins converts nucleoli and PML-bodies into a solid state that immobilizes ubiquitin, limiting its recycling for genome integrity maintenance.

Long-term effects of somatostatin analogues in rat GH-secreting pituitary tumor cell lines

PURPOSE

First-generation somatostatin analogs, octreotide (OCT) and lanreotide, are the cornerstone for the medical treatment of growth hormone (GH)-secreting pituitary tumors. A new multireceptor analog, such as pasireotide (PAS), showed better activity than OCT in long-term treatment of patients with acromegaly, but modulation of intracellular key processes is still unclear in vitro. In this study, we evaluated the antitumor activity of OCT and PAS in two GH-secreting pituitary tumor cell lines, GH3 and GH4C1, after a long-term incubation.

METHODS

The effects of PAS and OCT on the cell viability, cell cycle, apoptosis, GH secretion, and tumor-induced angiogenesis have been evaluated through a colorimetric method (MTS Assay), DNA flow cytometry with propidium iodide, and Annexin V-FITC/propidium iodide staining, ELISA assay and zebrafish platform, respectively.

RESULTS

PAS showed a more potent antitumor activity compared to OCT in GH3 cell line exerted through inhibition of cell viability, perturbation of cell cycle progression, and induction of apoptosis after 6 days of incubation. A concomitant decrease in GH secretion has been observed after 2 days of incubation only with PAS. No effect on tumor-induced angiogenesis has been reported after treatment with OCT or PAS in zebrafish/tumor xenograft model.

CONCLUSION

Long-term incubation with PAS showed a more potent antitumor activity than that reported after OCT in GH3 cells, mainly modulated by a cell cycle perturbation and a relevant induction in apoptosis.

A localized salt-dependent aquagenic urticaria successfully treated with omalizumab

We present the first case of a localized salt-dependent aquagenic urticaria confirmed by a challenge test. A good therapeutic response was achieved after only the first dose of omalizumab.

Adult Outcomes of Childhood Wheezing Phenotypes Are Associated with Early-Life Factors

Introduction: While the phenotypic diversity of childhood wheezing is well described, the subsequent life course of such phenotypes and their adult outcomes remain poorly understood. We hypothesized that different childhood wheezing phenotypes have varying longitudinal outcomes at age 26. We sought to identify factors associated with wheezing persistence, clinical remission, and new onset in adulthood. Methods: Participants were seen at birth and at 1, 2, 4, 10, 18, and 26 years in the Isle of Wight Birth Cohort (n = 1456). Information was collected prospectively on wheeze prevalence and phenotypic characteristics at each assessment. Wheeze phenotypes at 10 years were defined as participants wheezing (CW10) or not wheezing at 10 (CNW10). Multivariable regression analyses were undertaken to identify factors associated with wheezing persistence/remission in CW10 and wheeze development in CNW10 at age 26 years. Results: Childhood wheezing phenotypes showed different subsequent outcomes and associated risk factors. Adult wheeze developed in 17.8% of CNW10. Factors independently associated with adult wheeze development in CNW10 included eczema at age 4 years, family history of rhinitis, and parental smoking at birth. Conversely, 56.1% of CW10 had remission of wheeze by 26 years. Factors predicting adult wheezing remission in CW10 included absence of both atopy at age 4 years and family history of rhinitis. Conclusion: Early-life factors influence adult outcomes for childhood wheezing phenotypes, both with respect to later development of adult wheezing in asymptomatic participants and of wheeze remission in childhood wheezers. This suggests potential areas that could be targeted by early-life interventions to alleviate adult disease burden.