Photobiomodulation reduces the cytokine storm syndrome associated with Covid-19 in the zebrafish model

Although the exact mechanism of the pathogenesis of COVID-19 is not fully understood, oxidative stress and the release of pro-inflammatory cytokines have been highlighted as playing a vital role in the pathogenesis of the disease. In this sense, alternative treatments are needed to reduce the inflammation caused by COVID-19. Therefore, this study aimed to investigate the potential effect of red PBM as an attractive therapy to downregulate the cytokine storm caused by COVID-19 from a zebrafish model. RT-PCR analyses and protein-protein interaction prediction among SARS-CoV-2 and Danio rerio proteins showed that rSpike was responsible for generating systemic inflammatory processes with significantly increased pro-inflammatory (il1b, il6, tnfa, and nfkbiab), oxidative stress (romo1) and energy metabolism (slc2a1a, coa1) mRNA markers, with a pattern like those observed in COVID-19 cases in humans. On the other hand, PBM treatment decreased the mRNA levels of these pro-inflammatory and oxidative stress markers compared with rSpike in various tissues, promoting an anti-inflammatory response. Conversely, PBM promotes cellular and tissue repair of injured tissues and significantly increases the survival rate of rSpike-inoculated individuals. Additionally, metabolomics analysis showed that the most impacted metabolic pathways between PBM and the rSpike-treated groups were related to steroid metabolism, immune system, and lipids metabolism. Together, our findings suggest that the inflammatory process is an incisive feature of COVID-19, and red PBM can be used as a novel therapeutic agent for COVID-19 by regulating the inflammatory response. Nevertheless, the need for more clinical trials remains, and there is a significant gap to overcome before clinical trials.publishedVersio

SPREADING EUTROPHICATION AND CHANGING CO2 FLUXES IN THE TROPICAL COASTAL OCEAN: A FEW LESSONS FROM RIO DE JANEIRO

International audienceIn Brazil and in many other tropical countries, large urban cities and populations are still growing on the coast and coverage in terms of sewage treatments is far from desirable. Cultural eutrophication is not solely a threat for the coastal ocean; it is now acting as one of its major biogeochemical and ecological driver. Along the littoral of the state of Rio de Janeiro, semi-enclosed marine bays and lagoons show clear spatial and temporal pattern of increasing concentrations of chlorophyll a (Chl a), organic carbon, and nutrients in their waters and sediments in urbanized regions. Acting as a buffer, the nearshore ecosystems have turned highly eutrophic and their autotrophic metabolism has been enhanced creating strong carbon dioxide (CO2) sinks. We compile here data of CO2fluxes recently gathered in four coastal marine ecosystems in the state of Rio de Janeiro: the Guanabara Bay and the Araruama, Saquarema and Jacarepagua lagoons. We observed intense CO2 sources in restricted areas at the vicinity of sewage loads, where microbial degradation of organic matter predominates, and large CO2 sinks in confined and nearshore brackish, marine and hypersaline waters, where phytoplankton blooms occur. We also report a correlation across the four ecosystems between the partial pressure of CO2 in waters and the Chl a concentration. Chl a satellite data all along the Brazilian coast suggest that the CO2 sink induced by eutrophication probably occurs in many coastal ecosystems including bays, lagoon and shelf waters, and could contribute to an additional blue carbon. Part of the additional organic carbon is stored in sediments, and part is exported offshore. However, this additional blue carbon has dramatic environment impacts as it would evolve toward the formation of marine dead zones, and could contribute to a production of methane (CH4) a more powerful greenhouse gas. We emphasize an urgent need for multidisciplinary research to promote simultaneously the storage of atmospheric carbon, and the preservation of biodiversity and socio-economic goods in the eutrophic tropical coastal ocean.&#x0D; Keywords: tropical coastal ecosystems, cultural eutrophication, phytoplankton blooms, marine dead zones, blue carbon</jats:p