Severe cases of COVID-19 are associated with extensive lung damage and the presence of infected multinucleated syncytial pneumocytes. The viral and cellular mechanisms regulating the formation of these syncytia are not well understood. Here, we show that SARS-CoV-2-infected cells express the Spike protein (S) at their surface and fuse with ACE2-positive neighboring cells. Expression of S without any other viral proteins triggers syncytia formation. Interferon-induced transmembrane proteins (IFITMs), a family of restriction factors that block the entry of many viruses, inhibit S-mediated fusion, with IFITM1 being more active than IFITM2 and IFITM3. On the contrary, the TMPRSS2 serine protease, which is known to enhance infectivity of cell-free virions, processes both S and ACE2 and increases syncytia formation by accelerating the fusion process. TMPRSS2 thwarts the antiviral effect of IFITMs. Our results show that SARS-CoV-2 pathological effects are modulated by cellular proteins that either inhibit or facilitate syncytia formation.
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http://dx.doi.org/10.15252/embj.2020106267 | DOI Listing |
Biophys J
January 2025
Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel. Electronic address:
Migrasomes, the vesicle-like membrane micro-structures, arise on the retraction fibers (RFs), the branched nano-tubules pulled out of cell plasma membranes during cell migration and shaped by membrane tension. Migrasomes form in two steps: a local RF bulging is followed by a protein-dependent stabilization of the emerging spherical bulge. Here we addressed theoretically and experimentally the previously unexplored mechanism of bulging of membrane tubular systems.
View Article and Find Full Text PDFPoult Sci
December 2024
State Key Laboratory of Swine and Poultry Breeding Industry, Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, and Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China. Electronic address:
For commercial laying hens, the continuous high-intensity ovulation process leads to a significant accumulation of reactive oxygen species (ROS) in the granulosa cells, inducing oxidative stress, which accelerates ovarian aging and shortens the peak laying period. The molecular mechanisms underlying this process remain poorly understood. Therefore, we modeled the processes of oxidative stress and antioxidant in chicken granulosa cells.
View Article and Find Full Text PDFJ Med Virol
January 2025
Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, State Key Laboratory of Advanced Medical Materials and Devices, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.
Multinucleated cells are present in lung tissues of patients infected by SARS-CoV-2. Although the spike protein can cause the fusion of infected cells and ACE2-expressing cells to form syncytia and induce damage, how host cell responses to this damage and the role of DNA damage response (DDR) signals in cell fusion are still unclear. Therefore, we investigated the effect of SARS-CoV-2 spike protein on the fusion of homologous and heterologous cells expressing ACE2 in vitro models, focusing on the protein levels of ATR and ATM, the major kinases responding to DNA damage, and their substrates CHK1 and CHK2.
View Article and Find Full Text PDFSci Rep
December 2024
Laboratory of Molecular and Cellular Immunology, Institute of Molecular Biology NAS RA, 7 Hasratyan Str., Yerevan, 0014, Armenia.
Antiphospholipid syndrome (APS) is associated with recurrent pregnancy morbidity, yet the underlying mechanisms remain elusive. We performed multifaceted characterization of the biological and transcriptomic signatures of mouse placenta and uterine natural killer (uNK) cells in APS. Histological analysis of APS placentas unveiled placental abnormalities, including disturbed angiogenesis, occasional necrotic areas, fibrin deposition, and nucleated red blood cell enrichment.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Chemistry and Biochemistry, Charles E. Schmidt College of Science, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL, 33431, USA.
We present novel fluorescent cholesteryl probes (CNDs) with a modular design based on the solvatochromic 1,8-phthalimide scaffold. We have explored how different modules-linkers and head groups-affect the ability of these probes to integrate into lipid membranes and how they distribute intracellularly in mouse astrocytes and fibroblasts targeting lysosomes and lipid droplets. Each compound was assessed for its solvatochromic behavior in organic solvents and model membranes.
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