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Nanomaterials (Basel, Switzerland) Oct 2020Barium ferrite nanoparticles (BaFeNPs) were investigated as vehicles for Ra radionuclide in targeted α-therapy. BaFe nanoparticles were labeled using a hydrothermal Ba...
Barium ferrite nanoparticles (BaFeNPs) were investigated as vehicles for Ra radionuclide in targeted α-therapy. BaFe nanoparticles were labeled using a hydrothermal Ba cations replacement by Ra with yield reaching 61.3 ± 1.8%. Radiolabeled nanoparticles were functionalized with 3-phosphonopropionic acid (CEPA) linker followed by covalent conjugation to trastuzumab (Herceptin). Thermogravimetric analysis and radiometric method with the use of [I]-labeled trastuzumab revealed that on average 19-21 molecules of trastuzumab are attached to the surface of one BaFe-CEPA nanoparticle. The hydrodynamic diameter of BaFe-CEPA-trastuzumab conjugate is 99.9 ± 3.0 nm in water and increases to 218.3 ± 3.7 nm in PBS buffer, and the zeta potential varies from +27.2 ± 0.7 mV in water to -8.8 ± 0.7 in PBS buffer. The [Ra]BaFe-CEPA-trastuzumab radiobioconjugate almost quantitatively retained Ra (>98%) and about 96% of Bi and 94% of Pb over 30 days. The obtained radiobioconjugate exhibited high affinity, cell internalization and cytotoxicity towards the human ovarian adenocarcinoma SKOV-3 cells overexpressing HER2 receptor. Confocal studies indicated that [Ra]BaFe-CEPA-trastuzumab was located in peri-nuclear space. High cytotoxicity of the [Ra]BaFe-CEPA-trastuzumab bioconjugate was confirmed by radiotoxicity studies on SKOV-3 cell monolayers and 3D-spheroids. In addition, the magnetic properties of the radiobioconjugate should allow for its use in guide drug delivery driven by magnetic field gradient.
PubMed: 33092037
DOI: 10.3390/nano10102067 -
Cells May 2024Eukaryotic cells tether the nucleoskeleton to the cytoskeleton via a conserved molecular bridge, called the LINC complex. The core of the LINC complex comprises...
Eukaryotic cells tether the nucleoskeleton to the cytoskeleton via a conserved molecular bridge, called the LINC complex. The core of the LINC complex comprises SUN-domain and KASH-domain proteins that directly associate within the nuclear envelope lumen. Intra- and inter-chain disulphide bonds, along with KASH-domain protein interactions, both contribute to the tertiary and quaternary structure of vertebrate SUN-domain proteins. The significance of these bonds and the role of PDIs (protein disulphide isomerases) in LINC complex biology remains unclear. Reducing and non-reducing SDS-PAGE analyses revealed a prevalence of SUN2 homodimers in non-tumorigenic breast epithelia MCF10A cells, but not in the invasive triple-negative breast cancer MDA-MB-231 cell line. Furthermore, super-resolution microscopy revealed SUN2 staining alterations in MCF10A, but not in MDA-MB-231 nuclei, upon reducing agent exposure. While PDIA1 levels were similar in both cell lines, pharmacological inhibition of PDI activity in MDA-MB-231 cells led to SUN-domain protein down-regulation, as well as Nesprin-2 displacement from the nucleus. This inhibition also caused changes in perinuclear cytoskeletal architecture and lamin downregulation, and increased the invasiveness of PDI-inhibited MDA-MB-231 cells in space-restrictive in vitro environments, compared to untreated cells. These results emphasise the key roles of PDIs in regulating LINC complex biology, cellular architecture, biomechanics, and invasion.
Topics: Humans; Cell Line, Tumor; Neoplasm Invasiveness; Protein Disulfide-Isomerases; Female; Down-Regulation; Breast Neoplasms; Membrane Proteins; Nuclear Proteins; Nuclear Envelope; Triple Negative Breast Neoplasms; Intracellular Signaling Peptides and Proteins
PubMed: 38891038
DOI: 10.3390/cells13110906 -
Viruses Feb 2024Two novel members of the subfamily , family were identified in Brazil. Overall, their genomes have the typical organization 3'-' observed in mono-segmented...
Two novel members of the subfamily , family were identified in Brazil. Overall, their genomes have the typical organization 3'-' observed in mono-segmented plant-infecting rhabdoviruses. In aristolochia-associated cytorhabdovirus (AaCV), found in the liana aristolochia ( Hook), an additional short orphan ORF encoding a transmembrane helix was detected between and . The AaCV genome and inferred encoded proteins share the highest identity values, consistently < 60%, with their counterparts of the yerba mate chlorosis-associated virus (). The second virus, false jalap virus (FaJV), was detected in the herbaceous plant false jalap ( L.) and represents together with tomato betanucleorhabdovirus 2, originally found in tomato plants in Slovenia, a tentative new species of the genus . FaJV particles accumulate in the perinuclear space, and electron-lucent viroplasms were observed in the nuclei of the infected cells. Notably, distinct from typical rhabdoviruses, most virions of AaCV were observed to be non-enclosed within membrane-bounded cavities. Instead, they were frequently seen in close association with surfaces of mitochondria or peroxisomes. Unlike FaJV, AaCV was successfully graft-transmitted to healthy plants of three species of the genus Aristolochia, while mechanical and seed transmission proved unsuccessful for both viruses. Data suggest that these viruses belong to two new tentative species within the subfamily .
Topics: Aristolochia; Mirabilis; Genome, Viral; Rhabdoviridae; Plants; Phylogeny; Plant Diseases
PubMed: 38543688
DOI: 10.3390/v16030322 -
International Journal of Nanomedicine 2019We recently reported on long-term comprehensive biocompatibility and biodistribution study of fluorescent nanodiamond particles (NV)-Z-average 800nm (FNDP-(NV)) in rats....
BACKGROUND
We recently reported on long-term comprehensive biocompatibility and biodistribution study of fluorescent nanodiamond particles (NV)-Z-average 800nm (FNDP-(NV)) in rats. FNDP-(NV) primary deposition was found in the liver, yet liver function tests remained normal.
PURPOSE
The present study aimed to gain preliminary insights on discrete localization of FNDP-(NV) in liver cells of the hepatic lobule unit and venous micro-vasculature. Kinetics of FDNP-(NV) uptake into liver cells surrogates in culture was conducted along with cell cytokinesis as markers of cells' viability.
METHODS
Preserved liver specimens from a pilot consisting of two animals which were stained for cytoskeletal elements (fluorescein-isothiocyanate-phalloidin) were examined for distribution of FNDP-(NV) by fluorescent microscopy (FM) and Confocal-FM (CFM) using near infra-red fluorescence (NIR). Hepatocellular carcinoma cells (HepG-2) and human umbilical vein endothelial cells (HUVEC) were cultured with FNDP-(NV) and assayed for particle uptake and location using spectrophotometric technology and microscopy.
RESULTS
HepG-2 and HUVEC displayed rapid (<30 mins) onset and concentration-dependent FNDP-(NV) internalization and formation of peri-nuclear corona. FM/CFM of liver sections revealed FNDP-(NV) presence throughout the hepatic lobules structures marked by spatial distribution, venous microvascular spaces and parenchyma and non-parenchyma cells.
CONCLUSION
The robust presence of FNDP-(NV) throughout the hepatic lobules including those internalized within parenchyma cells and agglomerates in the liver venous micro-circulation were not associated with macro or micro histopathological signs nor vascular lesions. Cells cultures indicated normal cytokinesis in cells containing FNDP-(NV) agglomerates. Liver parenchyma cells and the liver microcirculation remain agnostic to presence of FNDP-(NV) in the sinusoids or internalized in the hepatic cells.
Topics: Animals; Biocompatible Materials; Hep G2 Cells; Hepatocytes; Human Umbilical Vein Endothelial Cells; Humans; Imaging, Three-Dimensional; Kinetics; Liver; Microscopy, Fluorescence; Nanodiamonds; Particle Size; Rats, Sprague-Dawley; Tissue Distribution
PubMed: 31496697
DOI: 10.2147/IJN.S209663 -
PLoS Pathogens Jan 2024Nuclear egress is an essential process in herpesvirus replication whereby nascent capsids translocate from the nucleus to the cytoplasm. This initial step of nuclear...
Nuclear egress is an essential process in herpesvirus replication whereby nascent capsids translocate from the nucleus to the cytoplasm. This initial step of nuclear egress-budding at the inner nuclear membrane-is coordinated by the nuclear egress complex (NEC). Composed of the viral proteins UL31 and UL34, NEC deforms the membrane around the capsid as the latter buds into the perinuclear space. NEC oligomerization into a hexagonal membrane-bound lattice is essential for budding because NEC mutants designed to perturb lattice interfaces reduce its budding ability. Previously, we identified an NEC suppressor mutation capable of restoring budding to a mutant with a weakened hexagonal lattice. Using an established in-vitro budding assay and HSV-1 infected cell experiments, we show that the suppressor mutation can restore budding to a broad range of budding-deficient NEC mutants thereby acting as a universal suppressor. Cryogenic electron tomography of the suppressor NEC mutant lattice revealed a hexagonal lattice reminiscent of wild-type NEC lattice instead of an alternative lattice. Further investigation using x-ray crystallography showed that the suppressor mutation promoted the formation of new contacts between the NEC hexamers that, ostensibly, stabilized the hexagonal lattice. This stabilization strategy is powerful enough to override the otherwise deleterious effects of mutations that destabilize the NEC lattice by different mechanisms, resulting in a functional NEC hexagonal lattice and restoration of membrane budding.
Topics: Herpesvirus 1, Human; Suppression, Genetic; Cell Nucleus; Nuclear Envelope; Herpesviridae; Virus Release
PubMed: 38227586
DOI: 10.1371/journal.ppat.1011936