The direct p53 target gene, FLJ11259/DRAM, is a member of a novel family of transmembrane proteins

The tumor suppressor p53 regulates diverse biological processes primarily via activation of downstream target genes. Even though many p53 target genes have been described, the precise mechanisms of p53 biological actions are uncertain. In previous work we identified by microarray analysis a candidate p53 target gene, FLJ11259/DRAM. In this report we have identified three uncharacterized human proteins with sequence homology to FLJ11259, suggesting that FLJ11259 is a member of a novel family of proteins with six transmembrane domains. Several lines of investigation confirm FLJ11259 is a direct p53 target gene. p53 siRNA prevented cisplatin-mediated up-regulation of FLJ11259 in NT2/D1 cells. Likewise in HCT116 p53+/+ cells and MCF10A cells, FLJ11259 is induced by cisplatin treatment but to a much lesser extent in isogenic p53-suppressed cells. A functional p53 response element was identified 22.3 kb upstream of the first coding exon of FLJ11259 and is shown to be active in reporter assays. In addition, chromatin immunoprecipitation assays indicate that p53 binds directly to this element in vivo and that binding is enhanced following cisplatin treatment. Confocal microscopy showed that an FLJ-GFP fusion protein localizes mainly in a punctate pattern in the cytoplasm. Overexpression studies in Cos-7, Saos2, and NT2/D1 cells suggest that FLJ11259 is associated with increased clonal survival. In summary, we have identified FLJ11259/DRAM as a p53-inducible member of a novel family of transmembrane proteins. FLJ11259/DRAM may be an important modulator of p53 responses in diverse tumor types.     

Muscle-bone properties after prolonged voluntary wheel running in a mouse model of dominant severe osteogenesis imperfecta

Objective:The objective of the current study is to assess the effect of a seven-week voluntary wheel running intervention on muscles and bones properties in a mouse model mimicking dominant severe osteogenesis imperfecta (OI).Methods:Female wild-type (WT) and OI (Col1a1^Jrt/+) mice either performed voluntarily wheel-running exercise for 7-weeks or remained sedentary. Running distance and speed, forelimb grip strength, isolated muscle force and fatigability as well as bone morphology and mechanical properties were assessed.Results:We demonstrate that female WT and OI mice voluntarily performed exercise, although OI mice exercised less than WT littermates. The exercise regimen increased soleus muscle masses in WT and OI but increased relative grip strength in WT mice only. Specific muscle force and fatigability were similar between WT and OI mice and did not improve with exercise. Furthermore, the exercise regimen did not improve the femoral architectural and biomechanical properties in OI mice.Conclusion:Our study suggests that voluntary wheel running is not appropriate to assess the effects of exercise in a mouse model of OI. Findings from exercising OI mice model studies may not necessarily be transferable to humans.     

Dereplication of natural products from complex extracts by regression analysis and molecular networking: case study of redox-active compounds from <Emphasis Type="Italic">Viola alba</Emphasis> subsp. <Emphasis Type="Italic">dehnhardtii</Emphasis>

Introduction

In natural product research, bioassay-guided fractionation was previously widely employed but is now judged to be inadequate in terms of time and cost, particularly if only known compounds are ultimately isolated. The development of metabolomics, along with improvements in analytical tools, allows comprehensive metabolite profiling. This enables dereplication to target unknown active compounds early in the purification workflow.

Objectives

Starting from an ethanolic extract of violet leaves, this study aims to predict redox active compounds within a complex matrix through an untargeted metabolomics approach and correlation analysis.

Methods

Rapid fractionation of crude extracts was carried out followed by multivariate data analysis (MVA) of liquid chromatography–high resolution mass spectrometry (LC–HRMS) profiles. In parallel, redox active properties were evaluated by the capacity of the molecules to reduce 2,2-diphenyl-1-picrylhydrazyl (DPPH^·) and superoxide (O₂ ^·?) radicals using UV–Vis and electron spin resonance spectroscopies (ESR), respectively. A spectral similarity network (molecular networking) was used to highlight clusters involved in the observed redox activities.

Results

Dereplication on Viola alba subsp. dehnhardtii highlighted a reproducible pool of redox active molecules. Polyphenols, particularly O-glycosylated coumarins and C-glycosylated flavonoids, were identified and de novo dereplicated through molecular networking. Confirmatory analyses were undertaken by thin layer chromatography (TLC)–DPPH–MS assays and nuclear magnetic resonance (NMR) spectra of the most active compounds.

Conclusion

Our dereplication strategy allowed the screening of leaf extracts to highlight new biologically active metabolites in few steps with a limited amount of crude material and reduced time-consuming manipulations. This approach could be applied to any kind of natural extract for the study of various biological activities.

     

<Emphasis Type="Italic">Neolebouria blatta</Emphasis> n. sp. (Digenea: Opecoelidae) from <Emphasis Type="Italic">Pristipomoides argyrogrammicus</Emphasis> (Valenciennes) and <Emphasis Type="Italic">Etelis carbunculus</Emphasis> Cuvier (Perciformes: Lutjanidae) off New Caledonia

Neolebouria blatta n. sp. is described from Pristipomoides argyrogrammicus (Valenciennes) and Etelis carbunculus Cuvier in waters off New Caledonia. It differs from all other species of Neolebouria Gibson, 1976 but one, N. georgenascimentoi Bray, 2002, in the extension of the cirrus-sac to the ovary or nearly so. It differs from N. georgenascimentoi in its continuous, rather than interrupted, vitelline distribution. N. blatta belongs to a small group of similar Neolebouria species reported in deep-water lutjanids, which includes N. longisacculus (Yamaguti, 1970) n. comb., N. rooseveltiae (Yamaguti, 1970) n. comb. and N. ulaula (Yamaguti, 1970).     

Monogeneans of the grouper Epinephelus tauvina (Perciformes, Serranidae) off Moorea, French Polynesia, with a description of Pseudorhabdosynochus pai n. sp. (Monogenea: Diplectanidae)

Specimens of the greasy grouper Epinephelus tauvina (Forssk?l), caught off Moorea, French Polynesia, harboured four species of gill monogeneans. The diplectanid Pseudorhabdosynochus pai n. sp. is characterised by an extremely big male quadriloculate organ (inner length 77 μm, cone length 15, tube length 47), the largest of all members of the genus, and a sclerotised vagina with a very complex structure, including three secondary chambers instead of one as in most species. Pseudorhabdosynochus sp. is a species of the ‘cupatus group’; this species is not formally described but various measurements are provided. The ancyrocephalid Haliotrema sp. and the capsalid Benedenia sp. were rare; they are both mentioned but not described. The diplectanid fauna of E. tauvina corresponds to the pattern already found in a clade of grouper species, the members of which often harbour both a species of the ‘cupatus group’ and another species of Pseudorhabdosynochus Yamaguti, 1958.

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Résumé  Des spécimens du mérou Epinephelus tauvina (Forssk?l) pêchés à Moorea, Polynésie Fran?aise, hébergeaient quatre espèces de monogènes sur les branchies. Le Diplectanidae Pseudorhabdosynochus pai n. sp. est caractérisé par un organe tétraloculé male de très grande taille (longueur interne 77 μm, longueur du c?ne 15, longueur du tube 47), le plus grand de toutes les espèces du genre, et un vagin sclérifié à structure très complexe, comprenant trois chambres secondaires, au lieu d’une comme c’est le cas chez la plupart des autres espèces. Pseudorhabdosynochus sp. est une espèce du ‘groupe cupatus’ qui n’est pas formellement décrite, mais des mesures sont indiquées. Un Ancyrocephalidae, Haliotrema sp., et un Capsalidae, Benedenia sp., étaient rares, et sont mentionnés mais non décrits. La faune des Diplectanidae de E. tauvina correspond au patron déjà trouvé dans un clade d’espèces de mérous, dont les membres hébergent souvent à la fois une espèce du ‘groupe cupatus’ et une autre espèce de Pseudorhabdosynochus Yamaguti, 1958.

     

Structural insights into the cause of human RSPH4A primary ciliary dyskinesia

Cilia and flagella are evolutionarily conserved eukaryotic organelles involved in cell motility and signaling. In humans, mutations in Radial Spoke Head Component 4A (RSPH4A) can lead to primary ciliary dyskinesia (PCD), a life-shortening disease characterized by chronic respiratory tract infections, abnormal organ positioning, and infertility. Despite its importance for human health, the location of RSPH4A in human cilia has not been resolved, and the structural basis of RSPH4A^–/– PCD remains elusive. Here, we present the native three-dimensional structure of RSPH4A^–/– human respiratory cilia using samples collected noninvasively from a PCD patient. Using cryo–electron tomography (cryo-ET) and subtomogram averaging, we compared the structures of control and RSPH4A^–/– cilia, revealing primary defects in two of the three radial spokes (RSs) within the axonemal repeat and secondary (heterogeneous) defects in the central pair complex. Similar to RSPH1^–/– cilia, the radial spoke heads of RS1 and RS2, but not RS3, were missing in RSPH4A^–/– cilia. However, RSPH4A^–/– cilia also exhibited defects within the arch domains adjacent to the RS1 and RS2 heads, which were not observed with RSPH1 loss. Our results provide insight into the underlying structural basis for RSPH4A^–/– PCD and highlight the benefits of applying cryo-ET directly to patient samples for molecular structure determination.