Muscular laminopathies: role of prelamin A in early steps of muscle differentiation

Lamin A is a nuclear envelope constituent involved in a group of human disorders, collectively referred to as laminopathies, which include Emery-Dreifuss muscular dystrophy. Because increasing evidence suggests a role of lamin A precursor in nuclear functions, we investigated the processing of prelamin A along muscle differentiation. Both protein levels and cellular localization of prelamin A appears to be modulated during C2C12 mouse myoblasts activation. Similar changes also occur in the expression of two lamin A-binding proteins: emerin and LAP2α. Furthermore prelamin A forms a complex with LAP2α in differentiating myoblasts. Prelamin A accumulation in cycling myoblasts by expressing unprocessable mutants affects LAP2α and PCNA amount and increases caveolin 3 mRNA and protein levels, whilst accumulation of prelamin A in differentiated muscle cells following treatment with a farnesyl transferase inhibitor inhibits caveolin 3 expression. These data provide evidence for a critical role of lamin A precursor in the early steps of muscle cell differentiation. In fact the post-translational processing of prelamin A affects caveolin 3 expression and influences the myoblast differentiation process. Thus, altered lamin A processing could affect myoblast differentiation and/or muscle regeneration and might contribute to the myopathic phenotype.     

Safety and efficacy of lactoferrin versus ferrous sulphate in curing iron deficiency and iron deficiency anaemia in hereditary thrombophilia pregnant women: an interventional study

Objective Evaluate the safety and efficacy of bovine lactoferrin (bLf) versus the ferrous sulphate standard intervention in curing iron deficiency (ID) and ID anaemia (IDA) in pregnant women affected by hereditary thrombophilia (HT). Design Interventional study. Setting Secondary-level hospital for complicated pregnancies in Rome, Italy. Population 295 HT pregnant women (≥18 years) suffering from ID/IDA. Methods Women were enrolled in Arm A or B in accordance with their personal choice. In Arm A, 156 women received oral administration of 100 mg of bLf twice a day; in Arm B, 139 women received 520 mg of ferrous sulphate once a day. Therapies lasted until delivery. Main outcome measures Red blood cells, haemoglobin, total serum iron, serum ferritin (haematological parameters) were assayed before and every 30 days during therapy until delivery. Serum IL-6, key factor in inflammatory and iron homeostasis disorders, was detected at enrolment and after therapy at delivery. Possible maternal, foetal, and neonatal adverse effects were assessed. Results Haematological parameters were significantly higher in Arm A than in Arm B pregnant women (P ≤ 0.0001). Serum IL-6 significantly decreased in bLf-treated women and increased in ferrous sulphate-treated women. BLf did not exert any adverse effect. Adverse effects in 16.5 % of ferrous sulphate-treated women were recorded. Arm A women experienced no miscarriage compared to five miscarriages in Arm B women. Conclusions Differently from ferrous sulphate, bLf is safe and effective in curing ID/IDA associated with a consistent decrease of serum IL-6. The absence of miscarriage among bLf-treated women provided an unexpected benefit. Trial registration: ClinicalTrials.gov Identifier NCT01221844.     

Lactoferrin differently modulates the inflammatory response in epithelial models mimicking human inflammatory and infectious diseases

Conflicting data are reported on pro- or anti-inflammatory activity of bovine lactoferrin (bLf) in different cell models as phagocytes or epithelial cell lines infected by bacteria. Here we evaluated the bLf effect on epithelial models mimicking two human pathologies characterized by inflammation and infection with specific bacterial species. Primary bronchial epithelium from a cystic fibrosis (CF) patient and differentiated intestinal epithelial cells were infected with Pseudomonas aeruginosa LESB58 isolated from a CF patient and Adherent-Invasive Escherichia coli LF82 isolated from a Crohn’s disease patient. Surprisingly, bLf significantly reduced the intracellular bacterial survival, but differently modulated the inflammatory response. These data lead us to hypothesize that bLf differentially acts depending on the epithelial model and infecting pathogen. To verify this hypothesis, we explored whether bLf could modulate ferroportin (Fpn), the only known cellular iron exporter from cells, that, by lowering the intracellular iron level, determines a non permissive environment for intracellular pathogens. Here, for the first time, we describe the bLf ability to up-regulate Fpn protein in infected epithelial models. Our data suggest that the mechanism underlying the bLf modulating activity on inflammatory response in epithelial cells is complex and the bLf involvement in modulating cellular iron homeostasis should be taken into account.     

Wilms’ Tumor Gene 1 (WT1) Silencing Inhibits Proliferation of Malignant Peripheral Nerve Sheath Tumor sNF96.2 Cell Line

Wilms’ tumor gene 1 (WT1) plays complex roles in tumorigenesis, acting as tumor suppressor gene or an oncogene depending on the cellular context. WT1 expression has been variably reported in both benign and malignant peripheral nerve sheath tumors (MPNSTs) by means of immunohistochemistry. The aim of the present study was to characterize its potential pathogenetic role in these relatively uncommon malignant tumors. Firstly, immunohistochemical analyses in MPNST sNF96.2 cell line showed strong WT1 staining in nuclear and perinuclear areas of neoplastic cells. Thus, we investigated the effects of silencing WT1 by RNA interference. Through Western Blot analysis and proliferation assay we found that WT1 knockdown leads to the reduction of cell growth in a time- and dose-dependent manner. siWT1 inhibited proliferation of sNF96.2 cell lines likely by influencing cell cycle progression through a decrease in the protein levels of cyclin D1 and inhibition of Akt phosphorylation compared to the control cells. These results indicate that WT1 knockdown attenuates the biological behavior of MPNST cells by decreasing Akt activity, demonstrating that WT1 is involved in the development and progression of MPNSTs. Thus, WT1 is suggested to serve as a potential therapeutic target for MPNSTs.     

Hyperferritinaemia in Dengue Virus Infected Patients Is Associated with Immune Activation and Coagulation Disturbances

Background

During a dengue outbreak on the Caribbean island Aruba, highly elevated levels of ferritin were detected in dengue virus infected patients. Ferritin is an acute-phase reactant and hyperferritinaemia is a hallmark of diseases caused by extensive immune activation, such as haemophagocytic lymphohistiocytosis. The aim of this study was to investigate whether hyperferritinaemia in dengue patients was associated with clinical markers of extensive immune activation and coagulation disturbances.

Methodology/Principal Findings

Levels of ferritin, standard laboratory markers, sIL-2R, IL-18 and coagulation and fibrinolytic markers were determined in samples from patients with uncomplicated dengue in Aruba. Levels of ferritin were significantly increased in dengue patients compared to patients with other febrile illnesses. Moreover, levels of ferritin associated significantly with the occurrence of viraemia. Hyperferritinaemia was also significantly associated with thrombocytopenia, elevated liver enzymes and coagulation disturbances. The results were validated in a cohort of dengue virus infected patients in Brazil. In this cohort levels of ferritin and cytokine profiles were determined. Increased levels of ferritin in dengue virus infected patients in Brazil were associated with disease severity and a pro-inflammatory cytokine profile.

Conclusions/Significance

Altogether, we provide evidence that ferritin can be used as a clinical marker to discriminate between dengue and other febrile illnesses. The occurrence of hyperferritinaemia in dengue virus infected patients is indicative for highly active disease resulting in immune activation and coagulation disturbances. Therefore, we recommend that patients with hyperferritinaemia are monitored carefully.     

Identification and initial characterization of an autocrine pheromone receptor in the protozoan ciliate Euplotes raikovi

The polypeptide pheromone Er-1, purified from the ciliate Euplotes raikovi of mating type I and genotype mat-1/mat-1, was iodinated with 125I-Bolton-Hunter reagent to a sp act of 0.45-0.73 mu Ci/microgram of protein. This preparation of 125I-Er-1 bound specifically to high affinity binding sites on the same cells of mating type I. Binding of 125I-Er-1 occurred with an apparent Kd of 4.63 +/- 0.12 X 10(-9) M in cells in early stationary phase. It was estimated that these cells carry a total number of approximately 5 X 10(7) sites/cell, with a site density that falls in the range of 1,600-1,700/microns 2 of cell surface. Unlabeled Er-1, other homologous pheromones such as Er-2 and Er-10, antibodies specific for Er-1, and human IL-2 were shown to act as effective inhibitors of specific binding of 125I-Er-1 to mating type I cells. The "autocrine" nature of the identified specific high affinity binding sites for Er-1 was further substantiated by cross-linking experiments. These experiments revealed that mating type-I cell membranes contain one protein entity of Mr = 28,000 that is capable of reacting specifically with the homodimeric native form of Er-1.     

The frontal organ of a triclad flatworm,Dugesia lugubris

Summary In an examination of the ultrastructure of the anteromedian portion of the head of Dugesia lugubris we demonstrated a frontal glandulo-muscular organ which consists of a voluminous glandular complex with three types of secretory cells and a well-developed musculature derived from the sub-epidermal fibers. The presence of neurosecretory cells, free nerve endings and single axons with sensitive cilia at the apex is characteristic. The last of these ultrastructural observations, together with functional tests, lead us to believe that the frontal organ possesses a marked chemosensitivity. The nature and structure of this organ are compared with the glandulo-muscular organ described in other Tricladida paludicola, thus contributing toward their much-debated classification.     

Disorders of Nuclear-Mitochondrial Intergenomic Signalling

In addition to sporadic or maternally-inherited mutations of the mitochondrial genome, abnormalities of mtDNA can be transmitted as mendelian traits. The latter are believed to be caused by mutations in still unknown nuclear genes, which deleteriously interact with the mitochondrial genome. Two groups of mtDNA-related mendelian disorders are known: those associated with mtDNA large-scale rearrangements and those characterized by severe reduction of the mtDNA copy number. The most frequent presentation of the first group of disorders is an adult-onset encephalomyopathy, defined clinically by the syndrome of progressive external ophthalmoplegia plus, genetically by autosomal dominant transmission of the trait, and molecularly by the presence of multiple deletions of mtDNA. The second group of disorders comprises early-onset, organ-specific syndromes, associated with mtDNA depletion, that are presumably transmitted as autosomal recessive traits. Linkage analysis and search for candidate genes are two complementary strategies to clarify the molecular basis of these disorders of the nuclear-mitochondrial intergenomic signalling.