PPP2R2A inhibition contributes to preeclampsia by regulating the proliferation, apoptosis, and angiogenesis modulation potential of mesenchymal stem cells.

BACKGROUND: The precise mechanisms underlying preeclampsia (PE) pathogenesis remain unclear. Mesenchymal stem cells (MSCs) are involved in the pathology of PE. The aim of our study was to identify the effects of protein phosphatase 2 regulatory subunit B α (PPP2R2A) on MSCs and ascertain its latent role in the progression of PE. METHODS: Reverse-transcription quantitative polymerase chain reaction and western blot analyses were performed to determine the expression of PPP2R2A in decidual tissue and decidual (d)MSCs from healthy pregnant women and patients with PE as well as the expression levels of Bax and Bcl-2 in dMSCs. The levels of p-PI3K, PI3K, p-AKT, and AKT were determined using western blotting. Cell growth, apoptosis, and migration were analyzed using MTT, flow cytometry, and Transwell assays, respectively. Human umbilical vein endothelial cell (HUVEC) tube formation ability was assayed using a HUVEC capillary-like tube formation assay. RESULTS: PPP2R2A was downregulated in decidual tissues and dMSCs of patients with PE when compared with that in healthy pregnant women. Moreover, upregulation of PPP2R2A enhanced cell proliferation, reduced apoptotic dMSC, inhibited Bax expression, and increased Bcl-2 levels. Conditioned medium from PPP2R2A-overexpressing dMSCs promoted HTR-8/SVneo cell migration and angiogenesis of HUVEC. Furthermore, the PPP2R2A plasmid suppressed PI3K/AKT pathway activation in dMSCs. However, these effects were partially reversed by LY2940002 treatment. CONCLUSION: PPP2R2A inhibition contributes to PE by regulating the proliferation, apoptosis, and angiogenesis of MSCs, providing a new therapeutic target for PE diagnosis and treatment.

A microfluidic chip using Au@SiO2 array-based highly SERS-active substrates for ultrasensitive detection of dual cervical cancer-related biomarkers.

In this work, a microfluidic chip using Au@SiO2 array-based highly active SERS substrates was developed for quantitative detection of squamous cell carcinoma antigen (SCCA) and carcinoembryonic antigen (CEA) associated with cervical cancer. The chip consisted of six functional units with pump-free design, enabling parallel detection of multiple samples in an automatic manner without external pumps and improving the portability. Ag nanocubes (AgNCs) were labeled with Raman reporters and coupled with antibodies (labeling) to prepare SERS tags, while the Au nanoparticle-modified SiO2 microsphere (Au@SiO2) array was conjugated with antibodies (coating) to generate the highly SERS-active capturing substrate. In the presence of target biomarkers, they were captured by SERS tags and capturing substrate, resulting in the formation of "sandwich" structures which were trapped in the detection chamber. As the immune reaction proceeded, a large number of "hot spots" were generated by the proximity of the Au@SiO2 array substrate and AgNCs, greatly amplifying SERS signals. With this chip, the limits of detection of the SCCA and CEA levels in human serum were estimated to be as low as 0.45 pg mL-1 and 0.36 pg mL-1, respectively. Furthermore, the good selectivity and reproducibility of this chip were confirmed. Finally, clinical serum samples were analyzed by this chip, and the outcomes were consistent with those of enzyme-linked immunosorbent assay (ELISA). Thus, the proposed microfluidic chip can be potentially applied for the clinical diagnosis of cervical cancer.

Highly sensitive and simultaneous detection of ctDNAs related to non-small cell lung cancer in serum using a catalytic hairpin assembly strategy in a SERS microfluidic chip.

Circulating tumor DNA (ctDNA) is an ideal biomarker for cancer diagnosis based on liquid biopsy, so there is an urgent need for developing an efficient, rapid, and ultrasensitive detection method to meet clinical needs. In this paper, a novel surface-enhanced Raman scattering (SERS) microfluidic chip combined with a catalytic hairpin assembly (CHA) was proposed to detect two non-small cell lung cancer (NSCLC)-related ctDNA (TP53 and PIK3CA-Q546K) simultaneously. The chip consists of six channels for parallel detection. In the reaction region, the CHA reaction between HP1 of the SERS probe and HP2 of the capture substrate was triggered by ctDNAs to form HP1-HP2 duplexes. As the reaction proceeds, more and more SERS probes are captured on the substrate. The gathered reaction products continuously form a lot of hot spots, which greatly enhance the SERS signal. This reaction was completed within 5 minutes. Through this method, the detection limits of TP53 and PIK3CA-Q546K in human serum were as low as 2.26 aM and 2.34 aM, respectively. The microfluidic chip also exhibited high specificity, reproducibility and stability. The clinical feasibility of the SERS microfluidic chip was verified by analyzing the serum samples of healthy subjects and NSCLC patients. The reliability of the experimental results was verified by the qRT-PCR test. The constructed SERS-based analytical micro-platform has great potential in dynamic monitoring of cancer staging and could be used as a clinical tool for early cancer screening.

A pump-free and high-throughput microfluidic chip for highly sensitive SERS assay of gastric cancer-related circulating tumor DNA via a cascade signal amplification strategy.

Circulating tumour DNA (ctDNA) has emerged as an ideal biomarker for the early diagnosis and prognosis of gastric cancer (GC). In this work, a pump-free, high-throughput microfluidic chip coupled with catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR) as the signal cascade amplification strategy (CHA-HCR) was developed for surface-enhanced Raman scattering (SERS) assays of PIK3CA E542K and TP53 (two GC-related ctDNAs). The chip consisted of six parallel functional units, enabling the simultaneous analysis of multiple samples. The pump-free design and hydrophilic treatment with polyethylene glycol (PEG) realized the automatic flow of reaction solutions in microchannels, eliminating the dependence on external heavy-duty pumps and significantly improving portability. In the reaction region of the chip, products generated by target-triggered CHA initiated the HCR, forming long nicked double-stranded DNA (dsDNA) on the Au nanobowl (AuNB) array surface, to which numerous SERS probes (Raman reporters and hairpin DNA-modified Cu2O octahedra) were attached. This CHA-HCR strategy generated numerous active "hot spots" around the Cu2O octahedra and AuNB surface, significantly enhancing the SERS signal intensity. Using this chip, an ultralow limit of detection (LOD) for PIK3CA E542K (1.26 aM) and TP53 (2.04 aM) was achieved, and the whole process was completed within 13 min. Finally, a tumour-bearing mouse model was established, and ctDNA levels in mouse serum at different stages were determined. To verify the experimental accuracy, the gold-standard qRT-PCR assay was utilized, and the results showed a high degree of consistency. Thus, this rapid, sensitive and cost-effective SERS microfluidic chip has potential as an ideal detection platform for ctDNA monitoring.

FCRB U-Net: A novel fully connected residual block U-Net for fetal cerebellum ultrasound image segmentation.

In this paper, we propose a novel U-Net with fully connected residual blocks (FCRB U-Net) for the fetal cerebellum Ultrasound image segmentation task. FCRB U-Net, an improved convolutional neural network (CNN) based on U-Net, replaces the double convolution operation in the original model with the fully connected residual block and embeds an effective channel attention module to enhance the extraction of valid features. Moreover, in the decoding stage, a feature reuse module is employed to form a fully connected decoder to make full use of deep features. FCRB U-Net can effectively alleviate the problem of the loss of feature information during the convolution process and improve segmentation accuracy. Experimental results demonstrate that the proposed approach is effective and promising in the field of fetal cerebellar segmentation in actual Ultrasound images. The average IoU value and mean Dice index reach 86.72% and 90.45%, respectively, which are 3.07% and 5.25% higher than that of the basic U-Net.

Pump-free microfluidic chip based laryngeal squamous cell carcinoma-related microRNAs detection through the combination of surface-enhanced Raman scattering techniques and catalytic hairpin assembly amplification.

MicroRNA (miRNA), as one of the ideal target biomarker analytes, plays an essential role in biological processes; thus, the development of rapidly sensitive detection methods is imperative. Herein, we proposed a pump-free surface-enhanced Raman scatting (SERS) microfluidic chip for the rapid and ultrasensitive detection of miR-106b and miR-196b, laryngeal squamous cell carcinoma (LSCC)-related miRNAs. Ag-Au core-shell nanorods (Ag-AuNRs) were applied to prepare SERS tags by modifying Raman reporters and hairpin DNAs. The capture probes were synthesized by labeling hairpin DNAs onto the magnetic beads (MBs) surface. In the presence of targets, the catalytic hairpin assembly (CHA) reactions between SERS tags and capture probes could be triggered, causing the aggregation of Ag-AuNRs. The tiny magnets installed under the rectangular chamber could magnetically gather the CHA products, leading to the further aggregation of Ag-AuNRs. Thus, this strategy could achieve the double aggregation of Ag-AuNRs, resulting in the significant amplification of the SERS signal. The proposed strategy achieved simultaneous and sensitive detection of miR-106b and miR-196b, with limits of detection low to aM level. The whole detection process could be completed within 5 min. Moreover, this microfluidic chip exhibited excellent reproducibility, stability, and specificity. The high accuracy of this SERS microfluidic chip was proved by practical analysis in LSCC patients' serum. The results demonstrated that SERS could be a promising alternative clinical diagnosis tool and exhibited potential application for the dynamic monitoring of cancer staging.