A Novel Electrochemiluminescent Immunoassay Based on Target Transformation Assisted with Catalyzed Hairpin Assembly Amplification for the Ultrasensitive Bioassay

In this work, we constructed a novel electrochemiluminescent (ECL) strategy based on sandwich immunoassay-induced target transformation assisted with catalyzed hairpin assembly (CHA) amplification for ultrasensitive bioassay with cysteine-rich protein 61 (CCN1) as a model. First, the target CCN1 could be equally transformed into the specific oligonucleotide (initiator I) labeled on the detection antibody based on the specific sandwich immunoassay. In addition, the initiator I triggered an efficient nonenzymatic CHA amplification in the presence of ferrocene-labeled hairpin 1 (Fc-H1) and hairpin 2 (H2) to produce massive hybrids (Fc-H1-H2) containing a sticky end labeled with ferrocene. Finally, Fc-H1-H2 could be immobilized on the capture probe single-stranded DNA (ssDNA)-modified electrode through the hybridization between the sticky end of Fc-H1-H2 and ssDNA, and a significantly quenched ECL signal could be obtained due to the efficient quench effect between ferrocene and the ECL indicator, ruthenium(II) tris(4,4'-dicarboxylicacid-2,2'-bipyridyl) [Ru(dcbpy)₃²⁺], immobilized on the surface of the electrode, which was related to the concentration of target CCN1. As expected, the proposed ECL biosensor exhibited a relatively low detection limit of 3.9 fg/mL in a linear range from 10 fg/mL to 100 ng/mL. This ECL strategy inspired the clinical examination of the biomarker CCN1, providing potential application in early diagnosis and malignant monitoring of cancer.

Tumor matrix stiffness promotes metastatic cancer cell interaction with the endothelium

Tumor progression alters the composition and physical properties of the extracellular matrix. Particularly, increased matrix stiffness has profound effects on tumor growth and metastasis. While endothelial cells are key players in cancer progression, the influence of tumor stiffness on the endothelium and the impact on metastasis is unknown. Through quantitative mass spectrometry, we find that the matricellular protein CCN1/CYR61 is highly regulated by stiffness in endothelial cells. We show that stiffness-induced CCN1 activates β-catenin nuclear translocation and signaling and that this contributes to upregulate N-cadherin levels on the surface of the endothelium, in vitro This facilitates N-cadherin-dependent cancer cell-endothelium interaction. Using intravital imaging, we show that knockout of Ccn1 in endothelial cells inhibits melanoma cancer cell binding to the blood vessels, a critical step in cancer cell transit through the vasculature to metastasize. Targeting stiffness-induced changes in the vasculature, such as CCN1, is therefore a potential yet unappreciated mechanism to impair metastasis.

Validity of Klotho, CYR61 and YKL-40 as ideal predictive biomarkers for acute kidney injury: review study

CONTEXT AND OBJECTIVE:

Acute kidney injury (AKI) is still a headache for clinicians and scientists as a possible reason for increased death among intensive care unit (ICU) patients after invasive cardiac surgery. Furthermore, the diagnostic process for AKI using conventional biomarkers is not sufficient to ensure early warning of this condition because of the morbid influence of non-renal factors that definitively delay the time for the prognosis. These imposed limitations have led to significant amounts of research targeted towards identifying novel biomarkers for AKI with a sustained degree of sensitivity and specificity. Here, we reviewed previous studies conducted on the Klotho, CYR61 and YKL-40 biomarkers in relation to AKI.

DESIGN AND SETTING:

Review of the literature conducted in the Institute of Clinical Chemistry & Biochemistry, Ljubljana University Medical Center, Slovenia.

METHODS:

The literature was searched in PubMed and the Cochrane Library. From the database of this specialty, we selected 17 references that matched our context for detailed analysis and further investigation.

RESULTS:

The studies reviewed showed notable differences in their results relating to the diagnostic impact of Klotho, CYR61 and YKL-40 on early prediction of AKI.

CONCLUSIONS:

The results regarding the Klotho, CYR61 and YKL-40 biomarkers showed markedly equivocal performance in the previous studies and did not fulfill the expectations that these factors would form valid possible biomarkers for AKI.

NUR77 inhibits the expression of TIMP2 and increases the migration and invasion of HTR-8/SVneo cells induced by CYR61

OBJECTIVE

To investigate the function and mechanism of CYR61 on the migration and invasion of the trophoblast cell line, HTR-8/SVneo cells.

STUDY DESIGN

The mRNA and protein levels of NUR77 in the placentas of normal and preeclampsia (PE) women were evaluated using real-time PCR and Western blot, respectively. Paraffin-embedded tissues were processed for localization of NUR77 protein in placental villus by immunohistochemistry. HTR-8/SVneo cells were cultured in the presence of CYR61, Ad-NUR77 or a small interfering RNA for NUR77 (Ad-sinur77). The expression of NUR77 in the HTR-8/SVneo cells was detected and the effects of CYR61 on the migration and invasion of HTR-8/SVneo cells were assessed in wound-healing and transwell experiments, respectively. Gelatin zymography was used to measure the MMP2 release in HTR-8/SVneo cells.

RESULTS

NUR77 is significantly decreased in the placenta of women with PE compared with the levels during a normal pregnancy. CYR61 can significantly increase the expression of NUR77 in HTR-8/SVneo cells. CYR61, as well as NUR77, can promote HTR-8/SVneo cells migration and invasion, which can be blocked by Ad-sinur77. Both CYR61 and Ad-nur77 reduced the mRNA expression of TIMP2 in HTR-8/SVneo cells.

CONCLUSIONS

CYR61 may promote HTR-8/SVneo cells migration and invasion through the upregulation of NUR77, leading to the increase of MMP2 release and the downregulation of TIMP2 expression.