Lacticaseibacillus rhamnosus modulates the inflammatory response and the subsequent lung damage in a murine model of acute lung inflammation

Objective: The present study investigated the anti-inflammatory effect of the probiotic Lacticaseibacillus rhamnosus (Lr) on lung inflammation induced by Lipopolysaccharide (LPS) of Escherichia coli in C57BL/6 mice. Methods: C57BL/6 mice were divided into four groups: control, LPS, Lr (1 day) + LPS, and Lr (14 days) + LPS. Total and differential cells from Bronchoalveolar Lavage Fluid (BALF) were counted in a Neubauer 40X chamber, and pro-and anti-inflammatory cytokines (IL-1β, IL-6, CXCL-1, TNF-α, TGF-β, and IL-10) were measured by ELISA assay. The analysis of whole leukocytes in blood was performed using the automated system Sysmex 800i. Morphometry of pulmonary tissue evaluated alveolar hemorrhage, alveolar collapse, and inflammatory cells. Pulmonary vascular permeability was assessed by Evans blue dye extravasation, and bronchoconstriction was evaluated in a tissue bath station. The transcription factor NF-kB was evaluated by ELISA, and its gene expression and TLR-2, TLR-4, MMP-9, MMP-12, and TIMP by PCR. Results: The probiotic Lr had a protective effect against the inflammatory responses induced by LPS. Lr significantly reduced pro-inflammatory cells in the airways, lung parenchyma, and blood leukocytes. Furthermore, Lr reduced the production of pro-inflammatory cytokines and chemokines in BALF and the expression of TLRs, MMPs, and NF-kB in lung tissue and maintained the expression of TIMP in treated animals promoting a protective effect on lung tissue. Conclusions: The results of the study indicate that pre-treatment with the probiotic Lr may be a promising way to mitigate lung inflammation in endotoxemia

Estudo do efeito anti-inflamatório do probiótico lactobacillus rhamnosus na inflamação pulmonar aguda induzida por lipopolissacarídeo de Escherichia coli em camundongos C57Bl/6

OBJECTIVE: To study the anti-inflammatory effect of probiotic Lactobacillus rhamnosus (Lr) on cellular infiltrate and secretion of inflammatory mediators in an experimental model of acute LPS-induced pulmonary inflammation in C57Bl/6 mice. METHODS: Male C57Bl/6 mice were divided into 4 experimental groups (n = 7 mice for experimental group) described below: control (animals received intranasal saline solution instillation), LPS (mice received intranasal instillation of LPS), Lr / 1day + LPS (mice received Lr gastric oro at the same time as intranasally LPS), Lr / 14 days + LPS (mice received Lr gastric oro 1 time daily for 14 days prior to intranasal LPS instillation), Lr / 1day(mice received Lr gastric oro), Lr / 14 days (mice received Lr gastric oro 1 time daily for 14 days). All mice were euthanized 24 hours after LPS administration. Cellular infiltrate in the lung was assessed from the number of cells in the bronchoalveolar lavage (BAL) and changes in lung tissue were quantified from pulmonary morphometry. Inflammatory mediators in BAL and NF-κB in the lung were measured by ELISA. mRNA expression for toll like receptor (TLR) -2 and -4 receptors, MMP-9 and MMP-12 metaloproteases, and NF-κB transcription factor was evaluated by PCR. RESULTS: Lr attenuated cell migration and modulated secretion of pro- and anti-inflammatory mediators. Moreover, Lr reduced mRNA of TLR2 and -4, MMP-9, MMP-12 and NF-κB. CONCLUSION: The protective effect of Lr targets modulation of inflammatory markers and inhibition of NF-κB, both directly related to acute lung inflammation.OBJETIVO: Estudar o efeito antiinflamatório do probiótico Lactobacillus rhamnosus (Lr) sobre o infiltrado celular e a secreção de mediadores inflamatórios em um modelo experimental de inflamação pulmonar aguda induzida por lipopolissacarídeo (LPS) em camundongos C57Bl/6. MÉTODOS: Camundongos C57Bl/6 machos com idade de 6-8 semanas foram divididos em 6 grupos experimentais (n= 7 animais para grupo experimental) descritos a seguir: controle (animais receberam instilação intranasal de solução salina), LPS (animais receberam instilação intranasal de LPS), Lr/1dia + LPS (animais receberam Lr via oro gástrica e concomitantemente o LPS por via intranasal), Lr/14 dias + LPS (animais receberam Lr 1 vez ao dia via oro gástrica, durante 14 dias antes da instilação intranasal de LPS), Lr/1dia (animais receberam Lr por via oro gástrica), Lr/14 dias (animais receberam Lr 1 vez ao dia via oro gástrica, durante 14 dias). Todos os animais foram eutanasiados 24 horas após administração de LPS. O infiltrado celular no pulmão foi avaliado a partir do número de células no lavado broncoalveolar (LBA) e as alterações no tecido pulmonar foram quantificadas a partir da morfometria pulmonar. Os mediadores inflamatórios no LBA e o NF-κB no pulmão foram mensurados pela técnica de ELISA. A expressão de RNAm pulmonar para os receptores do tipo toll-like (TLR) -2 e -4, para as metaloproteases MMP-9 e MMP-12, e para o fator de transcrição NF-kB foi avaliada por PCR. RESULTADOS: O Lr atenuou a migração celular e modulou a secreção dos mediadores pró- e anti-inflamatórios, além de reduzir a expressão gênica dos TLR2 e -4, assim como das MMP-9 e MMP-12, e do NF-κB. CONCLUSÃO: O efeito protetor do Lr tem como alvos a exacerbação da resposta imune inata, o desequilíbrio entre mediadores pró- e anti-inflamatórios, a atividade das proteases, o fator de transcrição NF-kB, e a lesão pulmonar.Dados abertos - Sucupira - Teses e dissertações (2019

Prevalence evolution of SARS-CoV-2 infection in the city of São Paulo, 2020–2021

OBJECTIVE To estimate the evolution of the prevalence of SARS-CoV-2 virus infection among residents aged 18 years or over in the municipality of São Paulo. METHODS This is a population-based household survey conducted every 15 days, between June and September 2020, and January and February 2021. In total, the study comprised 11 phases. The presence of antibodies against SARS-CoV-2 was identified in venous blood using a lateral flow test, Wondfo Biotech. In the last phase, the researchers combined it with an immunoenzymatic test, Euroimmun. The participants also answered a semi-structured questionnaire on sociodemographic and economic factors, and on social distancing measures. Prevalence estimates and the 95% confidence interval were estimated according to regions, Human Development Index, sex, age group, ethnicity, education, income, and variables associated with risk or prevention of infection. To compare the frequencies among the categories of each variable, the chi-square test with Rao-Scott correction was used, considering a significance level of 5%. RESULTS In total, 23,397 individuals were interviewed and had their samples collected. The estimated prevalence of antibodies against SARS-CoV-2 ranged from 9.7% (95%CI: 7.9–11.8%) to 25.0% (95%CI: 21.7–28.7). The prevalence of individuals with antibodies against the virus was higher among black and brown people, people with lower schooling and income, and among residents of regions with lower Human Development Index. The lowest prevalences were associated with recommended measures of disease protection. The proportion of asymptomatic infection was 45.1%. CONCLUSION The estimated prevalence of the infection was lower than the cumulative incidence variation, except for the last phase of the study. The differences in prevalence estimates observed among subpopulations showed social inequality as a risk of infection. The lower prevalence observed among those who could follow prevention measures reinforce the need to maintain social distancing measures as a way to prevent SARS-CoV-2 infection