key: cord-0995114-mi0sq1wb
authors: Santos e Silva, Juan Carlo; Vasconcelos, Amanda Pereira; Yonehara Noma, Isabella Harumi; Noronha, Natália Yumi; Aquino, Rodrigo; Giddaluru, Jeevan; Durão, Luiz; Costa-Martins, André Guilherme; Schuch, Viviane; Moraes-Vieira, Pedro M.; Nakaya, Helder I.
title: Gene Signatures of Autopsy Lungs from Obese Patients with COVID-19
date: 2021-05-26
journal: Clin Nutr ESPEN
DOI: 10.1016/j.clnesp.2021.05.004
sha: 4ce68938963a5ca5d781e48dadbed5664edac89c
doc_id: 995114
cord_uid: mi0sq1wb

Background & aims Obesity is associated with low grade systemic inflammation and insulin resistance. Although metabolic and immunological changes may contribute to the increased risk for COVID-19 mortality in obese, little is known about the impact of obesity in the lungs of patients with COVID-19. Methods We analyzed gene expression profiles of autopsy lungs of a cohort of 14 COVID-19 patients and 4 control individuals. Patients were divided into 3 groups according to their comorbidities: hypertension, type 2 diabetes (T2D) and obesity. We then identified the molecular alterations associated with these comorbidities in COVID-19 patients. Results Patients with only hypertension showed higher levels of inflammatory genes and B-cell related genes when compared to those with T2D and obesity. However, the levels of IFN-gamma, IL22, and CD274 (a ligand that binds to receptor PD1) were higher in COVID-19 patients with T2D and obesity. Several metabolic- and immune-associated genes such as G6PD, LCK and IL10 were significantly induced in the lungs of the obese group. Conclusion Our findings suggest that SARS-CoV-2 infection in the lungs may exacerbate the immune response and chronic condition in obese COVID-19 patients.

and obesity. We then identified the molecular alterations associated with these comorbidities in COVID-19 patients.

Results: Patients with only hypertension showed higher levels of inflammatory genes and B-cell related genes when compared to those with T2D and obesity.

However, the levels of IFN-gamma, IL22, and CD274 (a ligand that binds to receptor PD1) were higher in COVID-19 patients with T2D and obesity. Several metabolic-and immune-associated genes such as G6PD, LCK and IL10 were significantly induced in the lungs of the obese group.

Chronic inflammation and dysfunction of immune response emerge as consequences of obesity, and lead to increase in the susceptibility to pulmonary diseases [1] . Although obesity is a key comorbidity associated with severe COVID-19 [2] , little is known about its impact in the lungs of COVID-19 patients.

Here, we analyzed the transcriptional profile of autopsy lungs from obese and non-obese patients with COVID-19. The expression of several immune-, metabolic-and obesity-related genes was altered in obese patients compared to control individuals. We developed an online database to display all of the results. Our work highlights the impact of nutrition on the immune response to SARS-CoV-2 in the lungs.

Publicly available data from 18 individuals were downloaded using the GEOquery R package (GEO accession number: GSE151764) [3] . The primary cause of death in all 18 individuals was respiratory failure, and sometimes multiorgan failure [3] . Laboratory results of COVID-19 patients showed high levels of circulating markers of inflammation: IL-6 (mean) = 5,774 ng/l, C-reactive protein (mean) 216,36 mg/l [3] . Levels of circulating markers of glucose metabolism were not measured. The complete clinicopathological data of the 18 patients, including information about therapy, cause of death, thromboembolic events in the lungs, and disseminated intravascular coagulation can be found in Table S1 (which was adapted from [3] ).

We summed the count expression of genes from technical replicates and performed differential expression analysis using the edgeR package. The cutoff for identifying the differentially expressed genes (DEGs) were |log 2 fold-change| > 0.5849 and FDR < 0.05. We also correlated body mass index (BMI), SARS-CoV-2 viral load (in log 10 ) and age of COVID-19 patients with gene expression.

We then used the significant Pearson correlations (P < 0.05) to create a network using Cytoscape. The online database was created in python using streamlit, pandas and altair libraries for data manipulation and visualization.

Recently, Nienhold et al [3] Hypertension+T2D+Obesity group compared to controls. The size of the nodes is proportional to their degree.

Obesity is a key comorbidity associated with severe COVID-19 [2] . Here, we revealed significant alterations in gene expression in the lungs of obese patients that died from COVID-19 complications [3] . Type-I interferon and interleukin-1 up-regulates the expression of EGR2 in primary human monocytes [5] .

Together with the fact that leptin dysregulation in the lungs is associated with abnormal ventilation, excessive remodeling, and immune dysregulation seen in pulmonary diseases [6] , we think that leptin may play a key role in COVID-19 physiopathology in obese individuals.

Our findings also suggest that neutrophils may migrate less to the lungs of obese COVID-19 patients, compared to non-obese ones. This was supported by the fact that the expression of CXCR2 (a chemokine that mediates neutrophil migration to sites of inflammation), and FCGR3A and FCGR3B genes was negatively correlated with BMI. FCGR3A and FCGR3B are the two subunits of CD16 surface molecule, which is found in neutrophils, as well as in natural killer cells, monocytes, and macrophages. There is increase evidence that neutrophils and Neutrophil Extracellular Traps play an important role in the lungs of COVID-19 patients [7] . Nienhold et al [3] have estimated the number of J o u r n a l P r e -p r o o f neutrophils per lung tissue section by immunohistochemical stains for CD15 and MPO. We found that in 83% of lung tissue sections of obese patients, few or no neutrophils were found, whereas in non-obese patients, the number of tissue sections with few or no neutrophils was around 60%.

Since obesity is associated with an increased risk of developing T2D and hypertension, we must also consider its impact as the driver of the signatures in the present data. However, our correlation analysis was performed taking into account these comorbidities. Also, our online database provides the scientific papers which are related to the genes and to the comorbidities shown in this work.

We recognize the study limitations, which mainly consist in a reduced number of samples and genes, absence of obese people in the healthy control group, and the presence of confounding factors [3] , such as smoker status and the drug therapy taken by the COVID-19 patients before death. Indeed, these limitations prevent us to determine others key factors that may interfere to the observed phenomena. However, our results present novel insights about the mechanism and severity of COVID-19 in obese individuals.

The lungs of obese patients with COVID-19 display an altered metabolic and immunological gene profile that may explain the association between obesity and the increased risk for the severe COVID-19.

J o u r n a l P r e -p r o o f

142058/2020-3 to IHYN)

to PMMV); and CAPES (grant number 88882.180020/2018-01 to NYN)

Insulin resistance exacerbates lung inflammation in obese patients via PI3K/Akt signaling pathway

High Prevalence of Obesity in Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) Requiring Invasive Mechanical Ventilation

Two distinct immunopathological profiles in autopsy lungs of COVID-19

Novel Role of Lck in Leptin-Induced Inflammation and Implications for Renal Aging

Leptin up-regulates TLR2 in human monocytes

The Thousand Faces of Leptin in the Lung

Excessive Neutrophils and Neutrophil Extracellular

We are thankful to the participants of the Systems Biology course (02.2020) and the members of Computational Systems Biology Laboratories (CSBL) for the discussions that refined this work, including Allan Rodrigo for his help with the online database.