| Autor: |
Tellez Freitas CM; Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, United States of America., Burrell HR; Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, United States of America., Valdoz JC; Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, United States of America., Hamblin GJ; Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, United States of America., Raymond CM; Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, United States of America., Cox TD; Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, United States of America., Johnson DK; Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, United States of America., Andersen JL; Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, United States of America., Weber KS; Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, United States of America., Bridgewater LC; Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, United States of America. laura_bridgewater@byu.edu. |
| Abstrakt: |
We previously identified a nuclear variant of bone morphogenetic protein 2 (BMP2), named nBMP2, that is translated from an alternative start codon. Decreased nuclear localization of nBMP2 in the nBmp2NLS tm mouse model leads to muscular, neurological, and immune phenotypes-all of which are consistent with aberrant intracellular calcium (Ca 2+ ) response. Ca 2+ response in these mice, however, has yet to be measured directly. Because a prior study suggested impairment of macrophage function in nBmp2NLS tm mutant mice, bone marrow derived (BMD) macrophages and splenic macrophages were isolated from wild type and nBmp2NLS tm mutant mice. Immunocytochemistry revealed that nuclei of both BMD and splenic macrophages from wild type mice contain nBMP2, while the protein is decreased in nuclei of nBmp2NLS tm mutant macrophages. Live-cell Ca 2+ imaging and engulfment assays revealed that Ca 2+ response and phagocytosis in response to bacterial supernatant are similar in BMD macrophages isolated from naïve (uninfected) nBmp2NLS tm mutant mice and wild type mice, but are deficient in splenic macrophages isolated from mutant mice after secondary systemic infection with Staphylococcus aureus, suggesting progressive impairment as macrophages respond to infection. This direct evidence of impaired Ca 2+ handling in nBMP2 mutant macrophages supports the hypothesis that nBMP2 plays a role in Ca 2+ response. |
