| Objective To study the m RNA relative expression of NLRC4(the NOD-like receptor family CARD domain-containing protein 4),NLRP12(the NOD-like receptor family pyrin domaincontaining protein 12),Caspase-1(Cysteinyl aspartate specific proteinase 1)and ASC(apoptosis-associated speck-like protein containing a CARD)in the peripheral blood of all subjects in the acute and chronic phases and healthy people.Analyze its significance,and further explore the immunological mechanism of NLRC4 and NLRP12 in the process of human anti-brucella infection.Methods The patients with brucellosis who were screened and diagnosed in the Inner Mongolia Center for Disease Control and Prevention were collected.According to international clinical staging standards,20 patients in the acute phase and 20 patients in the chronic phase were collected.At the same time,20 healthy people were collected as the control group at the Physical Examination Center of the Affiliated Hospital of Inner Mongolia Medical University,which with the same age composition and gender composition as the case group.We collected the fasting venous blood of these 60 subjects,and used real-time fluorescent quantitative nucleic acid amplification detection system(Q-PCR)to measure the relative expression levels of NLRC4,NLRP12,Caspase-1,and ASC proteins in the whole blood.After separating the serum,enzyme-linked immunosorbent assay(ELISA)was used to determine the expression levels of the downstream inflammatory cytokines interleukin 1β(IL-1β),interleukin 18(IL-18)and interferon gamma(IFN-γ).Use IBM SPSS Statistics 22.0statistical software to analyze all the data,to analyze the differences in the expression levels of the above-mentioned proteins,and the correlation between the expression levels of the protein and the expression levels of inflammatory cytokines.Resμlts(1)The expression level of Caspase-1 in the acute phase case group was 1.32(0.81,1.66),the expression level in the chronic phase case group was 1.60(1.17,2.64),and the expression level in the control group was 1.00(1.00,1.00).After statistical testing,the expression level of the chronic phase case group was higher than that of the acute phase case group and the control group(P<0.05),which was statistically significant.There was no significant difference in expression between the acute phase case group and the control group(P >0.05),the expression level of Caspase-1 in the acute phase case group has an upward trend compared with the control group.The expression level of ASC in the acute phase case group was 0.86(0.55,1.09),the expression level in the chronic phase case group was 0.89(0.52,1.26),and the expression level in the control group was 1.00(1.00,1.00).After statistical testing,the expression level of the acute phase case group was lower than that of the control group(P<0.05),and the difference was statistically significant.However,there was no significant difference in the expression level between the acute phase case group and the chronic phase case group,and the chronic phase case group and the control group(P>0.05).The expression level in the chronic phase case group is higher than that in the acute phase case group.The expression level of NLRC4 in the acute phase case group was 0.89(0.58,1.58),the expression level in the chronic phase case group was 0.93(0.44,1.38),and the expression level in the control group was 1.01(1.00,1.02).After statistical testing,there was no significant difference in expression levels between the three groups of study subjects(P>0.05).The expression level of NLRP12 gene in the acute phase case group was 2.95(0.70,4.28),the expression level in the chronic phase case group was 1.48(1.03,3.10),and the expression level in the control group was 1.01(1.00,1.01).After statistical testing,the expression level in the acute phase case group was significantly higher than that in the control group(P<0.05),and the expression level in the chronic phase case group was also higher than that in the control group(P<0.05),the difference was statistically significant,while there was no significant difference between the acute phase case group and the chronic phase case group(P>0.05).The protein expression level of the chronic phase case group had a downward trend compared with the acute phase case group.(2)The expression level of the inflammatory cytokine IL-1β in the acute phase case group was 7.05(0.56,7.57),the expression level in the chronic phase was 1.47(0.29,6.33),and the expression level in the control group was 1.03(0.35,2.83).After statistical testing,there was no difference in expression between the three groups(P>0.05).The expression in the acute phase case group and the chronic phase case group had an upward trend.The expression level of IL-18 in the acute phase case group was 2665.81(1446.15,6038.80),the expression level in the chronic phase was 1066.90(787.20,1656.71),and the expression level in the control group was1333.25(1063.73,1889.29).After statistical testing,the expression level in the acute phase was higher than that in the chronic phase case group and the control group(P<0.05),while there was no significant difference in expression between the chronic phase case group and the control group(P>0.05).The expression trend of the chronic phase case group was lower than that of the acute phase case group,which was the same as that of the control group.The expression level of IFN-γ in the acute phase case group was 4.39(0.00,17.35),the expression level in the chronic phase was 0.14(0.00,1.18),and the expression level in the control group was 0.00.After statistical testing,the expression level in the acute phase case group was higher than that in the chronic phase case group and control group,and the expression level in the chronic phase case group was higher than that in the control group(P<0.05).The chronic phase case group compared with the acute phase case group,the expression trend decreased.(3)The correlation between the components of the inflammasome(Caspase-1,ASC,NLRC4,NLRP12)and the inflammatory cytokines(IL-1β,IL-18,IFN-γ)was carried out by Sprearman correlation analysis method.There is a negative weak correlation between Caspase-1 and NLRC4,and between ASC and IL-18.There are weak positive and weak correlations between ASC and NLRC4,and between NLRP12 and IFN-γ.There is no obvious correlation among the other indicators.Conclusion NLRC4 is not effectively activated in the early and late stages of Brucella infection in humans and the specific mechanism of regulating the expression of this protein needs further research.Caspase-1 related inflammasomes are inhibited in the early stages of Brucella infection in humans,and gradually activated in the later stages,inducing the secretion of a series of inflammatory factors,and causing immune responses that promote bacterial clearance and inflammation formation.Which members of the Nod-like receptor family(NLRs)are involved in the composition of Caspase-1 related inflammasomes also need further research.NLRP12 may inhibit the expression of NLRC4 and ASC in the early stage of brucella infection in humans,and further hinder the effective activation of Caspase-1to play its role in negatively regulating the immune response.This may be an immune escape mechanism of Brucella in the early stage of human infection. |
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