Research progress of microfluidics-based food safety detection.

High demands for food safety detection and analysis have been advocated with people's increasing living standards. Even though numerous analytical testing techniques have been proposed, their widespread adoption is still constrained by the high limit of detection, narrow detection ranges, and high implementation costs. Due to their advantages, such as reduced sample and reagent consumption, high sensitivity, automation, low cost, and portability, using microfluidic devices for food safety monitoring has generated significant interest. This review provides a comprehensive overview of the latest microfluidic detection platforms (published in recent 4 years) and their applications in food safety, aiming to provide references for developing efficient research strategies for food contaminant detection and facilitating the transition of these platforms from laboratory research to practical field use.

A portable CRISPR-Cas12a triggered photothermal biosensor for sensitive and visual detection of Staphylococcus aureus and Listeria monocytogenes.

The detection of foodborne pathogens is crucial for ensuring the maintenance of food safety. In the present study, a portable CRISPR-Cas12a triggered photothermal biosensor integrating branch hybrid chain reaction (bHCR) and DNA metallization strategy for sensitive and visual detection of foodborne pathogens was proposed. The sheared probes were utilized to block the locker probes, which enabled preventing the assembly of bHCR in the absence of target bacteria, while target bacteria can activate the cleavage of sheared probes through CRISPR-Cas12a. Therefore, the locker probes functioned as initiating chains, triggering the formation of the branching double-stranded DNA consisting of H1, H2, and H3. The silver particles, which were in situ deposited on the DNA structure, functioned as a signal factor for conducting photothermal detection. Staphylococcus aureus and Listeria monocytogenes were selected as the foodborne pathogens to verify the analytical performance of this CRISPR-Cas12a triggered photothermal sensor platform. The sensor exhibited a sensitive detection with a low detection limit of 1 CFU/mL, while the concentration ranged from 100 to 108 CFU/mL. Furthermore, this method could efficiently detect target bacteria in multiple food samples. The findings demonstrate that this strategy can serve as a valuable reference for the development of a portable platform enabling quantitative analysis, visualization, and highly sensitive detection of foodborne bacteria.

BMI1 induces ubiquitination and protein degradation of Nod-like receptor family CARD domain containing 5 and suppresses human leukocyte antigen class I expression to induce immune escape in non-small cell lung cancer.

The Nod-like receptor (NLR) family CARD domain containing 5 (NLRC5) has been reported as an activator of human leukocyte antigen (HLA) class I that is responsible for immune activity in cancer treatment. This work focuses on the role of BMI1 proto-oncogene (BMI1) in the NLRC5-HLA class I axis and in immune escape in non-small cell lung cancer (NSCLC). First, immunoblot analysis and/or reverse transcription-quantitative polymerase chain reaction were performed, which identified decreased NLRC5 and HLA class I levels in NSCLC tissues and cell lines. NSCLCs were co-cultured with activated CD8+ T cells. Overexpression of NLRC5 in NSCLC cells elevated the expression of HLA class I and increased the activity of T cells and IL-2 production, and it reduced the PD-1/PD-L1 levels. The ubiquitination and immunoprecipitation assays confirmed that BMI1 bound to NLRC5 to induce is ubiquitination and protein degradation. Downregulation of BMI1 in NSCLC cells elevated NLRC5 and HLA class I levels, and consequently promoted T cell activation and decreased PD-1/PD-L1 levels in the co-culture system. However, overexpression of BMI1 in cells led to inverse trends. In summary, this study demonstrates that BMI1 induces ubiquitination and protein degradation of NLRC5 and suppresses HLA class I expression, which potentially helps immune escape in NSCLC.

Association between genetic polymorphisms of inflammatory response genes and the risk of ovarian cancer.

BACKGROUND/PURPOSE: Inflammation plays an important role in promoting ovarian tumorigenesis and cancer progression. However, the relationship between polymorphisms in inflammatory response genes and risk of ovarian cancer remains poorly understood. In this study, we investigated the association of PPARG Pro12Ala, IL6-174G/C, E-selectin S128R, NFKB1-94 ins/del, NFKBIA-826C/T, and ICAM-1 K469E polymorphisms with ovarian cancer risk in a Chinese population. METHODS: Genotyping of the polymorphisms was performed on 687 cases and 687 controls employing the PCR-RFLP technique, and the logistic regression model was used to measure the risk association. RESULTS: A significantly increased risk association was observed for the heterozygous genotypes of PPARG [odds ratio (OR) = 1.52, 95% confidence interval (CI) = 1.01-2.29] and E-selectin (OR = 1.77, 95% CI = 1.07-2.93) polymorphisms, as well as the homozygous ins/ins genotype of NFKB1 polymorphism (OR = 1.39, 95% CI = 1.00-1.92). By contrast, ICAM-1 KE genotype was associated with a decreased ovarian cancer risk (OR = 0.77, 95% CI = 0.60-0.98). In addition, the NFKB1 del/del + NFKBIA TT combination was also found to be associated with a decreased ovarian cancer risk, with OR = 0.12 (95% CI = 0.01-0.95). The associations of the NFKB1 and ICAM-1 polymorphisms replicated the findings of previous reports, assuring the reliability of the results obtained. CONCLUSION: NFKB1 and ICAM-1 polymorphisms could serve as useful ovarian cancer risk prediction biomarkers for the Chinese population, while the utility of PPARG and E-selectin polymorphisms as biomarkers requires further confirmation in independent ovarian cancer cohorts.

Expression of Septin4 in Schistosoma japonicum-infected mouse livers after praziquantel treatment.

BACKGROUND: Septin4 (SEPT4) exists widely in human tissues and is related to mechanical stability, actin dynamics, membrane trafficking, viral replication and apoptosis. Data from many studies have suggested that SEPT4 plays a significant role in liver fibrosis. SEPT4 is down-regulated in the model of CCl4 and BDL treated liver fibrosis. However, it is up-regulated and peaked at 12 weeks post-infection (p.i.), and then decreased subsequently in Schistosoma japonicum (S. japonicum) egg-induced liver fibrosis. The aim of this study was to observe the dynamic alteration of SEPT4 after the treatment of praziquantel (PZQ) in ICR mice infected with S. japonicum. METHODS: Expression of SEPT4 was determined by western blot, immunofluorescence and qRT-PCR. And pro-inflammatory cytokines IL-6 and TNF-α were detected by qRT-PCR. The number of eggs, the diameter of egg granulomas and fibrosis-associated genes were also measured. RESULTS: Our results showed that the granulomatous inflammation was reduced, whereafter the expression of SEPT4 on hepatic stellate cells (HSCs) was decreased after PZQ anti-schistosome therapy. And the variation tendency of SEPT4 had positive correlation with the inflammatory response in the area of S. japonicum egg granulomas. CONCLUSIONS: Based on these findings, the inhibition of the expression of the SEPT4 by PZQ might be due to alleviation of the inflammatory response at the chronic and advanced stage of S. japonicum infection.

Schistosoma japonicum soluble egg antigens induce apoptosis and inhibit activation of hepatic stellate cells: a possible molecular mechanism.

Hepatic stellate cells play a key role in the development of hepatic fibrosis. Activated hepatic stellate cells can be reversed to a quiescent-like state or apoptosis can be induced to reverse fibrosis. Some studies have recently shown that Schistosoma mansoni eggs could suppress the activation of hepatic stellate cells and that soluble egg antigens from schistosome eggs could promote immunocyte apoptosis. Hence, in this study, we attempt to assess the direct effects of Schistosoma japonicum soluble egg antigens on hepatic stellate cell apoptosis, and to explore the mechanism by which the apoptosis of activated hepatic stellate cells can be induced by soluble egg antigens, as well as the mechanism by which hepatic stellate cell activation is inhibited by soluble egg antigens. Here, it was shown that S. japonicum-infected mouse livers had increased apoptosis phenomena and a variability of peroxisome proliferator-activated receptor γ expression. Soluble egg antigens induce morphological changes in the hepatic stellate cell LX-2 cell line, inhibit cell proliferation and induce cell-cycle arrest at the G1 phase. Soluble egg antigens also induce apoptosis in hepatic stellate cells through the TNF-related apoptosis-inducing ligand/death receptor 5 and caspase-dependent pathways. Additionally, soluble egg antigens could inhibit the activation of hepatic stellate cells through peroxisome proliferator-activated receptor γ and the transforming growth factor ß signalling pathways. Therefore, our study provides new insights into the anti-fibrotic effects of S. japonicum soluble egg antigens on hepatic stellate cell apoptosis and the underlying mechanism by which the liver fibrosis could be attenuated by soluble egg antigens.

Expression of Septin4 in human hepatic stellate cells LX-2 stimulated by LPS.

Septin4, a member of polymerizing GTP-binding proteins family, is reported to be involved in cytoskeletal organization in mitosis, apoptosis, fibrosis, and other cellular processes. Since various Septin4 expression patterns were reported in different diseases, this study aimed to investigate Septin4 expression in human LX-2 cell line stimulated by lipopolysaccharides (LPS) and attempted to clarify the relationship between Septin4 and hepatic inflammatory injury and fibrosis. In this subject, human stellate cell line LX-2 was stimulated by LPS. The expression of Septin4 was analyzed by Western blot and quantitative real-time PCR. To observe the relationship among Toll-like receptor 4 (TLR4), TGF-ß, and Septin4, proteins from the anti-TLR4 antibody blocked cells, as well as the TGF-ß-induced cells, were analyzed by the method of Western blot. As the results, LPS could induce the alteration of α-smooth muscle actin and Septin4 expression in LX-2 cells. Septin4 expression was regulated by LPS stimulation through TLR4 and TGF-ß pathway. These results therefore suggest that Septin4 may be involved in the process of activation of hepatic stellate cells by LPS stimulation. Further work would focus on the function of Septin4 in hepatic inflammatory injury and fibrosis.