Two kinds of fats cells had been contaminated within the laboratory: one derived from human stem cells remoted from subcutaneous tissue and the opposite differentiated from stem cells taken from visceral adipose tissue.
Experiments present that visceral fats — the fats across the liver, intestines, and different organs, which is a danger issue for heart problems, diabetes, and hypertension — contributes extra to heart problems, diabetes, and hypertension.[{” attribute=””>COVID-19 than subcutaneous fat (under the skin, as in “love handles”). The experiments were conducted in Brazil by researchers at the State University of Campinas (UNICAMP) and the University of São Paulo (USP).
In order to arrive at this conclusion, Marcelo Mori, a professor at the Institute of Biology at UNICAMP and one of the study's leaders, infected in the lab two different types of fat cells: one obtained from human stem cells isolated from subcutaneous tissue and the other differentiated from stem cells taken from visceral fatty tissue.
“It was possible to observe that visceral adipocytes are more susceptible to infection by SARS-CoV-2 . Viral load increased far more in this fat cell type than in subcutaneous adipocytes. We believe this was due mainly to higher levels of the protein ACE-2 [ to which the virus binds to invade cells ] on the floor of the cell,” Mori informed Agência FAPESP.
As well as, the researchers found that when visceral adipocytes grew to become contaminated, they produced a higher quantity of pro-inflammatory cytokines, which alert the immune system to a risk that should be fought.
An article in regards to the research was not too long ago revealed within the Scientific Journal
“We wanted to see if there was a similar association in the context of COVID-19,” Mori said. “And in fact, our model suggests that the more visceral adipose tissue there is in obese individuals, the more the virus can replicate, and this amplifies the inflammatory process.”
In subcutaneous adipocytes, on the other hand, the group observed a decrease in lipolysis, the breakdown of fats and other lipids by hydrolysis to release fatty acids, which can be used as a source of energy during physical activity or fasting periods.
“Our hypothesis is that this represents an antiviral cellular response,” Mori said. “There are studies showing that inhibition of lipolysis lowers the replicative capacity of SARS-CoV-2, which can be explained by the fact that the virus needs lipids to produce its envelope, as well as energy from cells to make copies of its genetic material.” Reduced lipolysis in subcutaneous adipose tissue, therefore, could be positive for the patient and bad news for the virus.
Contrasting responses
Visceral adipocytes were exposed to different strains of SARS-CoV-2: the ancestral lineage originally from Wuhan, China, and isolated from one of the first Brazilians diagnosed with COVID-19; and the gamma variant (P.1.), which emerged in late 2020 in Manaus, the capital of Amazonas state in Brazil. The difference in susceptibility compared to subcutaneous adipocytes was observed only in response to the ancestral virus.
“We concluded that the Manaus variant is less effective at infecting visceral fat cells than the ancestral strain,” Mori said. “A proteomic analysis [ of all the proteins produced by the cells ] confirmed that the Wuhan pressure led to a lower in a number of proteins concerned within the mobile response to interferon [ an immune system mechanism to combat viruses ], whereas the gamma variable led to a rise. In different phrases, the Manaus pressure made the adipocytes produce extra proteins that enhance the antiviral response. “
Latest analysis signifies a downward pattern within the variety of extreme instances of COVID-19 as a result of new variants amongst folks with weight problems. However this may be affected by different elements, akin to a earlier vaccination or harm. Or, these people could have taken additional care as a result of they knew they belonged to a high-risk group,” Morey defined.
To attempt to deepen their understanding of all of those processes, the group is planning extra experiments involving adipocytes cultured with delta and Omicron variants.
One other plan for future analysis is to analyze attainable medium- to long-term metabolic results of SARS-CoV-2 an infection. “We wish to know if the an infection adjustments the chance of growing diabetes or heart problems, for instance,” Morey mentioned. “A technique to do that might be to investigate samples from sufferers who contracted COVID-19 and subsequently had bariatric surgical procedure, to see if morphological and practical adjustments occurred within the visceral adipose tissue because of the an infection.”
Reference: “SARS-CoV-2 infects adipose tissue within the fats depot – and in a viral lineage-dependent method” By Tatiana Dandolini Sacon, Felipe Mossovich-Neto, Raisa Guimarães Ludwig, Victor Corasola Caregari, Ana Beatriz dos Anjos Souza and Amanda Stefan Cruz dos Passos , Mateus Cavalheiro Martini, Priscilla Pascual Barbosa, Gabriela Fabiano de Souza, Stephanie Bremon Moraro, Julia Furato, Marien Ribeiro Amorim, Rafael Elias Marquez, Flavio Protasio Veras, Esther Barreto, Thiago Tomazini Gonçalves, Isadorina Carolina Could Kawagusi Onodera, Ronaldo Braganca Martins Jr. , Paulo Henrique Cavalcante de Araújo, Sabrina Setembri Patah, Rosa Maria Mendes Viana, Danilo Machado de Melo, Aleksandar Todorovic Fabro, Eurico Arico, Fernando Queiroz Cunha, Thiago Matar Cunha, Bradley Joseph Smith, Henrique Marquez Souza, Thiago L. Nettle, Gabriel Palermo Ruiz, Gerson S. Nabibe, Teresa Cristina Minto Fontes Cal, Mariana Boroni, Marco Aurelio Ra Mérez Vignolo, Alessandro S Farias, Pedro Manuel M. Kiyomi Osako, Louise Osorio Liria and Marcelo A. Mori, September 29, 2022, Out there right here. Nature Communications
DOI: 10.1038/s41467-022-33218-8