GENE DNAH11: ANALISI DI MUTAZIONE IN PAZIENTI AFFETTI DA DISCINESIA CILIARE PRIMARIA CON ULTRASTRUTTURA CILIARE NORMALE

La Discinesia Ciliare Primaria è una malattia genetica rara dovuta ad alterazioni della struttura e/o della funzione delle ciglia della mucosa respiratoria che determinano un deficit del trasporto mucociliare e la comparsa di diversi quadri di patologia a carico delle vie aeree e del parenchima polmonare. L’eterogeneità clinica, strutturale e genetica rendono complicata la diagnosi di DCP. La frequenza del battito ciliare, il pattern motorio delle ciglia e la misurazione dell’ossido nitrico nasale possono essere utilizzate ma solo la valutazione della ciliogenesi in colture cellulari sembra essere decisiva per la diagnosi di casi con DCP “atipica” cioè con ultrastruttura ciliare normale. L’identificazione di mutazioni geniche associate alla malattia potrebbe permettere di superare gli attuali limiti diagnostici. Sono stati studiati pazienti con diagnosi clinica di DCP, bassi livelli di ossido nitrico nasale, ultrastruttura normale, allo scopo di stabilire se questi casi atipici di DCP possano essere associati a mutazioni nel gene DNAH11. I risultati ottenuti confermano il coinvolgimento del gene DNAH11 in pazienti con DCP atipica la cui diagnosi è spesso difficoltosa per la presenza di una ultrastruttura ciliare normale

Exploring metallodrug-protein interactions by mass spectrometry: comparisons between platinum coordination complexes and an organometallic ruthenium compound

Electrospray ionisation mass spectrometry was used to analyse the reactions of metal compounds with mixtures of selected proteins. Three representative medicinally relevant compounds, cisplatin, transplatin and the organometallic ruthenium compound RAPTA-C, were reacted with a pool of three proteins, ubiquitin, cytochrome c and superoxide dismutase, and the reaction products were analysed using high-resolution mass spectrometry. Highly informative electrospray ionisation mass spectra were acquired following careful optimisation of the experimental conditions. The formation of metal-protein adducts was clearly observed for the three proteins. In addition, valuable information was obtained on the nature of the protein-bound metallofragments, on their distribution among the three different proteins and on the binding kinetics. The platinum compounds were less reactive and considerably less selective in protein binding than RAPTA-C, which showed a high affinity towards ubiquitin and cytochrome c, but not superoxide dismutase. In addition, competition studies between cisplatin and RAPTA-C showed that the two metallodrugs have affinities for the same amino acid residues on protein bindin

A Novel Missense Mutation of the NSD1 Gene Associated with Overgrowth in Three Generations of an Italian Family: Case Report, Differential Diagnosis, and Review of Mutations of NSD1 Gene in Familial Sotos Syndrome

Sotos syndrome (SoS) is characterized by overgrowth of prenatal onset, learning disability, and characteristic facial appearance; it is usually due to haploinsufficiency of NSD1 gene at chromosome 5q35. An Italian child was born at 37 weeks of gestation (weight 2,910 g, 25th-50th centiles; length 50 cm, 75th centile; head circumference 36 cm, 97th centile) showing cryptorchidism on the right side, hypertelorism, dolichocephaly, broad and prominent forehead, and narrow jaw; the pregnancy was worsened by maternal preeclampsia and gestational diabetes, and his mother had a previous history of four early miscarriages. The patient showed neonatal jaundice, hypotonia, feeding difficulties, frequent vomiting, and gastroesophageal reflux. After the age of 6 months, his weight, length, and head circumference were above the 97th centile; psychomotor development was delayed. At the age of 9 years, the patient showed also joint laxity and scoliosis. DNA sequence analysis of NSD1 gene detected a novel heterozygous mutation (c.521T>A, p.Val174Asp) in exon 2. The same mutant allele was also found in the mother and in the maternal grandfather of the proband; both the mother and the maternal grandfather of the proband showed isolated overgrowth with height above the 97th centile in absence of other features of SoS. At present 23 familial cases of SoS have been described (two cases with mutation in exon 2 of NSD1 gene); no familial cases of SoS with mutation of NSD1 gene and isolated overgrowth have been reported. Probably, point mutations of NSD1 gene, and particularly mutations between exon 20 and exon 23, are not likely to affect reproductive fitness. Epigenetic mechanisms and intrauterine environment may influence phenotypes, therefore genetic tests are not useful to predict the phenotype but they are indispensable for the diagnosis of SoS. This is the first Italian familial case of SoS with genetic confirmation and the third report in which a missense mutation of NSD1 gene is found in three generations of the same family

Discovery of novel mutations in the dihydropyrimidine dehydrogenase gene associated with toxicity of fluoropyrimidines and viewpoint on preemptive pharmacogenetic screening in patients

Background: Dihydropyrimidine dehydrogenase (DPD) is the initial and rate-limiting enzyme of the metabolic pathway of 5-fluorouracil (5-FU) and other fluoropyrimidines to inactive compounds. For this reason, severe, life-threatening toxicities may occur in patients with deficient DPD activity when administered standard doses of 5-FU and its prodrugs. Materials and methods: We selected three patients with colorectal adenocarcinoma who displayed unexpected severe adverse reactions after treatment with 5-FU and capecitabine. To investigate the possible involvement of deficient variants of the DPD gene (DPYD), a denaturing HPLC (dHPLC) approach followed by target exon sequencing of DPYD was performed on DNA extracted from peripheral blood. Results: Three novel non-synonymous mutations of DPYD, c.2509-2510insC, c.1801G>C, and c.680G>A, were detected in these subjects. Due to the absence of other deficient variants of DPYD and the compatibility of adverse reactions with fluoropyrimidine treatment, the novel variants were associated with a poor-metabolizer phenotype. Conclusions: Stratification of patients on the basis of their genotype may help prevent toxicity, and the large body of evidence about the pathogenesis of fluoropyrimidine-induced adverse reactions strongly encourages the adoption of best practice recommendations to appropriately address this important clinical issue. This approach is of utmost importance within a preventive, prognostic, and personalized approach to patient care in the oncology setting

Safety and efficacy of burosumab in improving phosphate metabolism, bone health, and quality of life in adolescents with X-linked hypophosphatemic rickets

Background and objective: X-linked hypophosphatemic rickets (XLH) is due to loss-of-function mutations in the phosphate-regulating endopeptidase homologue on the X chromosome (PHEX) that lead to increased fibroblast growth factor 23 (FGF23) production. FGF23 excess causes renal phosphate wasting and insufficient 1,25-dihydroxyvitamin D (1,25(OH)2D) synthesis with reduced intestinal phosphate absorption, ultimately resulting in chronic hypophosphatemia. Children with XLH show typical skeletal lesions of rickets, deformities of the lower limbs, stunted growth with disproportionate short stature, bone pain, and physical dysfunctions. Burosumab, a fully human IgG1 monoclonal antibody that binds to FGF23 to inhibit its activity, is more effective to improve the biochemical and clinical signs of XLH than conventional treatment with phosphate supplements and vitamin D active metabolites. Data on adolescents with XLH during the transition period to young adulthood are few. In this prospective case series, we aimed to assess safety and efficacy of burosumab in adolescents with XLH who discontinued long-term conventional therapy. Methods: Five Caucasian adolescents (4 males, 1 female; mean age 15.4 ± 1.5 years) with XLH were recruited and switched from conventional treatment to burosumab (0.8–1.2 mg/kg, s. c. QW2). Burosumab was continued for 12–48 months and, once discontinued, patients were followed-up for 6–12 months. In all patients, serum calcium, phosphate, alkaline phosphatase (ALP), parathyroid hormone (PTH), and 1,25(OH)2D levels, and renal tubular reabsorption of phosphate (TmP/GFR) values were assessed at entry and during burosumab. Intact FGF23 plasma levels were measured at entry. Patient-reported outcomes (PROs) were assessed at entry and every 3–6 months to evaluate the impact of low extremity pain, stiffness, and difficulties performing daily activities. Results: At entry, all patients showed hypophosphatemia, increased intact FGF23 levels, reduced TmP/GFR, insufficient 1,25(OH)2D levels, and in four out of five increased ALP levels. Two patients had radiological signs of rickets. During burosumab, all patients showed a significant increase in serum phosphate and 1,25(OH)2D levels, and in TmP/GFR values (P < 0.05 - P < 0.0001). Serum ALP levels significantly declined (P < 0.05) to normal values. No changes of serum calcium and PTH levels (P[dbnd]NS) were found during burosumab. PROs significantly improved (P < 0.02 - P < 0.0001) in all patients. Four patients discontinued burosumab when they turned 18 or 19, whereas one continued the treatment since he was still younger than 18 during the study period. Four patients who suspended burosumab showed a rapid decline in serum phosphate and 1,25(OH)2D levels and in TmP/GFR values; serum ALP levels increased, and PROs progressively worsened with a significant reduction in quality of life. These consequences were not observed in the patient who continued burosumab treatment. Discussion: Our data showed that conventional treatment improved only in part the signs and symptoms of XLH. Burosumab was well tolerated and was effective in improving phosphate metabolism, bone health, and PROs. All the benefits of burosumab were lost after its discontinuation. These results suggested that continuing burosumab is required to achieve and maintain the clinical benefits of the treatment during the transition to young adulthood in patients with XLH

Inorganic nanoparticles interactions with dendritic cells

Stimulation of the immune system may be of help for several diseases including cancer, for which the proposed vaccination strategies include the use of nanomaterials and dendritic cells (DCs) as adjuvants. Silica and gold nanoparticles (SiO2NPs and AuNPs) are easy to produce and are endowed with high biocompatibility, tunable physicochemical properties and high adsorption power, which can lead to the formation of a protein corona. We have evaluated the interactions between human DCs and these types of NPs either alone or covered with a corona from cancer cell lysates. AuNPs and SiO2NPs were prepared [1-2] and exposed to lysates from two different cancer cell lines. Some SiO2NPs were made fluorescent with rhodamine. The NPs and the protein corona were characterized by physico-chemical methods. DCs were generated in vitro from human monocytes [3], incubated up to 48 h with NPs at different concentrations and analyzed by phase contrast, fluorescence and electron microscopy, flow cytometry and mixed lymphocyte reaction. When incubated with immature DCs, pure NPs were internalized and localized within vesicles and lysosomes. They did not cause cytotoxic nor stimulatory effects. The amount absorbed depended on NP concentration and did not increase appreciably between 4 and 24 h of incubation. Silica and gold NPs bound different pools of biomolecules from the same lysates. All lysate coated NPs promoted DC-mediated CD4+ cell proliferation. Lysate coated AuNPs also promoted DC maturation and DC-mediated CD8+ cell proliferation. The results indicate that NPs are well tolerated by DCs and can represent a simple, cost-effective and versatile method to deliver antigens to DCs in view of cancer immunotherapy

Case report: Early-onset osteoporosis in a patient carrying a novel heterozygous variant of the WNT1 gene

Article presents a case study of a 35 year-old Caucasian woman who experienced multiple vertebral fractures two months after her second pregnancy. The results suggest a potential role of heterozygous WNT1 variants in the pathogenesis of early-onset osteoporosis. The authors suggest that teriparatide is one of the most appropriate available therapies for such cases

The neurogenic potential of astrocytes is regulated by inflammatory signals

Although the adult brain contains neural stem cells (NSCs) that generate new neurons throughout life, these astrocyte-like populations are restricted to two discrete niches. Despite their terminally differentiated phenotype, adult parenchymal astrocytes can re-acquire NSC-like characteristics following injury, and as such, these 'reactive' astrocytes offer an alternative source of cells for central nervous system (CNS) repair following injury or disease. At present, the mechanisms that regulate the potential of different types of astrocytes are poorly understood. We used in vitro and ex vivo astrocytes to identify candidate pathways important for regulation of astrocyte potential. Using in vitro neural progenitor cell (NPC)-derived astrocytes, we found that exposure of more lineage-restricted astrocytes to either tumor necrosis factor alpha (TNF-α) (via nuclear factor-κB (NFκB)) or the bone morphogenetic protein (BMP) inhibitor, noggin, led to re-acquisition of NPC properties accompanied by transcriptomic and epigenetic changes consistent with a more neurogenic, NPC-like state. Comparative analyses of microarray data from in vitro-derived and ex vivo postnatal parenchymal astrocytes identified several common pathways and upstream regulators associated with inflammation (including transforming growth factor (TGF)-β1 and peroxisome proliferator-activated receptor gamma (PPARγ)) and cell cycle control (including TP53) as candidate regulators of astrocyte phenotype and potential. We propose that inflammatory signalling may control the normal, progressive restriction in potential of differentiating astrocytes as well as under reactive conditions and represent future targets for therapies to harness the latent neurogenic capacity of parenchymal astrocytes