The impact of the Hsp67Bc gene product on Drosophila melanogaster longevity, fecundity, and acute heat stress tolerance

Drosophila melanogaster Hsp67Bc is a heat- and cold-inducible small heat shock protein that participates in the prevention of aggregation of misfolded proteins and in macroautophagy regulation. Overexpression of the Hsp67Bc gene has been shown to enhance macroautophagy in Drosophila S2 cells, and the deletion of this gene leads to the formation of a slightly increased number of autophagic vacuoles in the fruit f ly brain neurons. Recently, we found that Hsp67Bc-null D. melanogaster f lies have poor tolerance to cold stress (0 °C) of various durations. In the present work, we investigated how the Hsp67Bc gene deletion affects the f itness of fruit f lies under normal conditions and their tolerance to elevated temperatures at different developmental stages. Larvae and pupae were not adversely affected by the Hsp67Bc gene deletion, and adult Hsp67Bc-null f lies showed an extended lifespan in comparison with the control at normal (24–25 °C) and elevated temperature (29 °C), and after acute heat stress (37 °C, 2 h). At the same time, the fecundity of the mutant females was lower by 6–13 % in all tested environments, except for permanent maintenance at 29 °C, where the mean numbers of eggs laid by the mutant and control f lies were equal. We explain this phenomenon by a reduced number of ovarioles in Hsp67Bc-null females and enhanced macroautophagy in their germaria, which promotes the death of forming egg chambers. In addition, short heat stress (37 °C, 2 h), which increased the control line’s longevity (an effect common for a wide range of organisms), had a negative impact on the lifespan of Hsp67Bc-null f lies. Therefore, Hsp67Bc-null D. melanogaster have an extended lifespan under normal and elevated temperature conditions, and reduced fecundity and thermal stress tolerance

Supporting data and methods for the characterization of iron oxide nanoparticles conjugated with pH-(low)-insertion peptide, testing their cytotoxicity and analyses of biodistribution in SCID mice bearing MDA-MB231 tumor

The method of Fe3O4 magnetic nanoparticle synthesis by co-precipitation, modification by 3-aminopropylsilane and conjugation with pH-(low)-insertion peptide (pHLIP) is reported. The characterization of nanoparticles by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, elemental and thermogravimetric analyses as well as dynamic light scattering and z-potential measurements is provided. The effect of nanoparticles on the viability of mouse and human peripheral blood mononuclear cells is tested by flow cytometry. The experimental details of nanoparticle administration to tumor-bearing mice, magnetic resonance imaging scanning as well as subsequent tumor sample collection and their processing for transmission electron microscopy, inductively coupled plasma atomic emission spectroscopy, histological and immunohistochemical analyses are described. Biodistribution of the nanoparticles in mice and blood serum analysis data for experimental animals are given. The data are useful for an experiment workflow design and for the development of theranostic systems based on magnetic nanoparticles. © 2020 The AuthorsRussian Foundation for Basic Research, RFBR: 18-015-00319_aMinistry of Education and Science of the Russian Federation, Minobrnauka: RFMEFI62117X0015This work was supported by the Russian Foundation for Basic Research [grant number 18-015-00319_a ]. The ICP-AES measurements were carried out using the core facilities of TPU's “Physical and chemical methods of analysis” (project VIU-RSCBS-142/2019). The research involving PBMC experiments was carried out within the framework of the state assignment theme (No. AAAA-A18-118031490008-7) of the Siberian State Medical University. The research into nanoparticle characterization by IR spectroscopy, elemental analysis (CHN) and TGA was carried out within the framework of the state assignment theme (No. АААА-А19-119011790130-3) in the Joint-Use Center for Spectroscopy and Analysis of Organic Compounds, Postovsky Institute of Organic Synthesis UB RAS. Dynamic light scattering (DLS) and zeta potential (z P ) characterization were carried out within the framework of the state assignment theme No. АААА-А18-118020290129-5 in the Miheev Institute of Metal Physics UB RAS. The experiments with animals and MRI were carried out at the Center for Genetic Resources of Laboratory Animals at the Institute of Cytology and Genetics SB RAS, supported by the Ministry of Education and Science of Russia (Unique identifier of the project RFMEFI62117X0015 ). TEM analysis was carried out at the Multiple-access Center for Microscopy of Biological Subjects, Institute of Cytology and Genetics SB RAS