IntroductionDeregulated or excessive host immune responses contribute to the pathogenesis of sepsis. Toll-like receptor (TLR) signaling pathways and their negative regulators play a pivotal role in the modulation of host immune responses and the development of sepsis. The objective of this study was to investigate the association of variants in the TLR signaling pathway genes and their negative regulator genes with susceptibility to sepsis in the Chinese Han population.MethodsPatients with severe sepsis (n = 378) and healthy control subjects (n = 390) were enrolled. Five genes, namely TLR2, TLR4, TLR9, MyD88 and TOLLIP, were investigated for their association with sepsis susceptibility by a tag single nucleotide polymorphism (SNP) strategy. Twelve tag SNPs were selected based on the data of Chinese Han in Beijing from the HapMap project and genotyped by direct sequencing. The mRNA expression levels of TOLLIP were determined using real-time quantitative Polymerase Chain Reaction (PCR) assays, and concentrations of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA).ResultsOur results showed that the minor C-allele of rs5743867 in TOLLIP was significantly associated with the decreased risk of sepsis (Padj = 0.00062, odds ratio (OR)adj = 0.71, 95% confidence interval (CI) 0.59 to 0.86) after adjustment for covariates in multiple logistic regression analysis. A 3-SNP haplotype block harboring the associated SNP rs5743867 also displayed strong association with omnibus test P value of 0.00049. Haplotype GTC showed a protective role against sepsis (Padj = 0.0012), while haplotype GCT showed an increased risk for sepsis (Padj = 0.00092). After exposure to lipopolysaccharide (LPS), TOLLIP mRNA expression levels in peripheral blood mononuclear cells (PBMCs) from homozygotes for the rs5743867C allele were significantly higher than in heterozygotes and homozygotes for the rs5743867T allele (P = 0.013 and P = 0.01, respectively). Moreover, the concentrations of TNF-α and IL-6 in culture supernatants were significantly lower in the subjects of rs5743867CC genotype than in CT and TT genotype subjects (P = 0.016 and P = 0.003 for TNF-α; P = 0.01 and P = 0.002 for IL-6, respectively).ConclusionsOur findings indicated that the variants in TOLLIP were significantly associated with sepsis susceptibility in the Chinese Han population.

ShuFengJieDu capsule (SFJDC), a traditional Chinese medicine (TCM) that contains eight medicinal herbs, has been extensively utilized for the treatment of acute lung injury (ALI) and respiratory infections for more than 30 years in China. SFJDC has also been listed in the official guidelines of the China Food and Drug Administration (CFDA) due to its stable clinical manifestations. However, the underlying mechanism of SFJDC during ALI repair remains unclear. In the present study, we explored the protective and therapeutic mechanisms of SFJDC in a rat model by performing qualitative and label-free quantitative proteomics studies. After establishing lipopolysaccharide (LPS)-induced ALI rat models, we profiled macrophage cells isolated from freshly resected rat lung tissues derived from ALI models and ALI rat lung tissue sections using a high performance liquid chromatography-mass spectrometry (HPLC-MS/MS) shotgun proteomics approach to identify changes in the expression levels of proteins of interest. On the basis of our proteomics results and the results of a protein dysregulation analysis of ALI rat lung tissues and rat lung macrophages, AKT1 was selected as a putative key factor that may play an important role in mediating the effects of SFJDC treatment during ALI progression. Follow-up validation studies demonstrated that AKT1 expression effectively regulates various ALI-related molecules, and Gene Ontology analysis indicated that SFJDC-treated ALI rat macrophages were influenced by AKT1-based networks. Gain- and loss-of-function analyses following lentivirus-AKT1 or lentivirus-si-AKT1 infection in macrophages also indicated that AKT1 was essential for the development of ALI due to its ability to regulate oxidative stress, apoptosis, or inflammatory responses. In summary, SFJDC effectively modulated anti-inflammatory and immunomodulation activity during ALI, potentially due to AKT1 regulation during ALI progression. New insights into SFJDC mechanisms may facilitate the development of novel pharmaceutical strategies to control the expression of inflammatory factors.

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