Quantitative Reverse transcription-PCR Assay Research Articles

Pathological roles of antimicrobial peptides and pro-inflammatory factors secreted from the cervical epithelium in Gardnerella vaginalis-abundant vaginal flora in pregnancy

Bacterial vaginosis due to Gardnerella vaginalis (GV) is one of the main causes of preterm birth. Antimicrobial function of the cervical glands prevents ascending pathogen infection. This study investigated the effect of GV on the cervical gland cells. We examined the correlation between GV and neutrophil elastase in the cervical mucous obtained from pregnant women’s clinical samples. Culture supernatants (sup) of GV and Lactobacillus crispatus (LC) were added to human immortalized cervical gland cells (EndoCx). Quantitative reverse transcription PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to examine the effects on the production of antimicrobial peptides (AMPs), secretory leukocyte peptidase inhibitor (SLPI), and Elafin. mRNA microarray analysis revealed the expression profile of GV-exposed EndoCx. Moreover, the antimicrobial activity of Elafin against LC and GV was investigated. In the clinical samples, neutrophil elastase was increased in the GV-positive cervical mucous. In an in vitro assay, RT-qPCR and ELISA showed that GV-sup enhanced the secretion of Elafin, but not SLPI, from EndoCx, whereas LC-sup did not. mRNA microarray assay and ELISA results demonstrated that GV-sup enhanced the proinflammatory pathway and interleukin (IL)− 8 secretion from EndoCx as well as cell adhesion and tight junction pathways. Moreover, GV-sup directly enhanced Elafin and IL-8 secretion from the cervical gland cells. In the GV-abundant vaginal flora, IL-8 level increased the neutrophil elastase activity and Elafin inhibited the elastase activity to protect from tissue damage and infection. Thus, the balance of IL-8-induced neutrophil and Elafin-induced antiprotease activities may be crucial in preterm labor.

Development of a multienzyme isothermal rapid amplification and lateral flow dipstick combination assay for bovine coronavirus detection.

Bovine coronavirus (BCoV) is a major cause of infectious disease in cattle, causing huge economic losses to the beef and dairy industries worldwide. BCoV can infect humans and multiple other species of animals. A rapid, reliable, and simple test is needed to detect BCoV infection in suspected farms. In this study, we developed a novel multienzyme isothermal rapid amplification (MIRA) and lateral flow dipstick (LFD) combination assay, targeting a highly conserved region of the viral nucleocapsid (N) gene for BCoV detection. The MIRA-LFD assay was highly specific and sensitive, comparable to a published reverse transcription quantitative PCR (RT-qPCR) assay for BCoV detection. Compared with the published RT-qPCR assay, the κ value of the MIRA-LFD assay in the detection of 192 cattle clinical samples was 0.982. The MIRA-LFD assay did not require sophisticated instruments and the results could be observed with eyes. Our results showed that the MIRA-LFD assay was a useful diagnostic tool for rapid on-site detection of BCoV.

AEBP1 Contributes to Breast Cancer Progression by Facilitating Cell Proliferation, Migration, Invasion, and Blocking Apoptosis.

The aberrant expression of adipocyte enhancer binding protein 1 (AEBP1) has been observed in many cancers and it seems to be involved in the tumorigenesis, progression, and metastasis in numerous tumor types. However, the contribution of AEBP1 in breast cancer (BCa) remains inexplicable. Information related to the diagnostic significance and expression of AEBP1 in BCa was obtained from the public dataset Kaplan-Meier Plotter (http://kmplot.com/analysis/) and the dataset UALCAN (https://ualcan.path.uab.edu/index.html). The MTT (methyl thiazolyl tetrazolium) assay, colony formation assay, Transwell® assay, and FACS (fluorescence-activated cell sorting) assay were used to detect the proliferation, invasive and apoptotic ability of cells before and after treatment. In addition, we constructed an AEBP1 overexpression vector and silenced AEBP1, combined with Real-Time Quantitative Reverse Transcription PCR (qRT-PCR), western blot, immunohistochemistry and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling) assay to investigate the prognostic significance, biological functions and potential mechanisms of AEBP1 in BCa. Higher expression of AEBP1 mRNA (message RNA) was observed in BCa patients with later-stage, who obtained poorer overall survival. Meanwhile, compared with adjacent noncancerous tissues, AEBP1 protein expression was dramatically upregulated in the BCa ones. Furthermore, overexpressed AEBP1 enhanced cell proliferation, migration, invasion, and blocked cell apoptosis in BCa cells. Moreover, the research certificated that AEBP1 upregulated the expression of MMP (matrix metalloproteinase)-2, 9, vimentin, N-cadherin (neural-cadherin), phosphorylation of ERK (extracellular signal-regulated kinase), Smad2/3 (Abbreviated from Sma for nematode and Mad for Drosophila) and AKT (V-akt murine thymoma viral oncogene homolog), while down-regulated the expression of E-cadherin (epithelial cadherin) and PTEN (phosphatase and tensin homolog deleted on chromosome 10). To inhibit cell apoptosis, enforced expression of AEBP1 effectively blocked the cleavage of caspase 9 and p53 (protein 53) and promoted the expression of anti-apoptotic protein Bcl-2 (B-cell lymphoma-2). Finally, AEBP1 accelerated subcutaneously transplanted tumor growth in nude mice by increasing the expression of the cell proliferation biomarker ki67, the phosphorylation of AKT, and blocked apoptosis in vivo. In summary, these data suggested the important role of AEBP1 in the BCa progression, which could be used as a potential biomarker for prognostic hallmark and a novel therapeutic strategy.

Development of RT-qPCR for quantification of human enterovirus D68 in vitro

The common cold is the most frequent viral infectious disease of the upper respiratory tract with different intensities based on the serotype and the characteristics of the virus. Numerous human rhinoviruses have been identified and classified. Human rhinovirus 87 (HRV87), also known as enterovirus D68 (EV-D68), is one of the common viruses causing respiratory infections. In this study, a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay was developed, optimized, and validated for the detection of EV-D68. Method development also covers specificity, sensitivity, efficiency, and inter-and-intra-assay variations. Overall, this one-step qPCR assay will permit quantitative assessments of human enterovirus D68 RNA.•Enterovirus D68 is a reemerging viral agent causing respiratory infection.•RT-qPCR assay developed for detection of human enterovirus D68.•In this article validation to secure reproducibility is done according to MIQE guidelines.

Characterization of the RpoN regulon reveals the regulation of motility, T6SS2 and metabolism in Vibrio parahaemolyticus.

Vibrio parahaemolyticus is a foodborne pathogen that can colonize the small intestine of the host and cause diarrhea. The alternative sigma factor RpoN plays a vital role in regulating motility, carbon utilization and affects host colonization in V. parahaemolyticus RIMD2210633. In this study, transcriptome and phenotypic analysis further expanded our understanding of the RpoN regulon in V. parahaemolyticus. A deletion mutant of rpoN (ΔrpoN) was subjected to RNA-seq for systemic identification of the RpoN-controlled genes. Compared with the wild-type (WT), 399 genes were differentially expressed in the ΔrpoN strain. Moreover, 264 genes were down-regulated in the ΔrpoN strain, including those associated with nitrogen utilization (VP0118), glutamine synthetase (VP0121), formate dehydrogenase (VP1511 and VP1513-VP1515), quorum sensing (opaR and luxZ), polar flagellar systems, and type VI secretion system 2 (T6SS2). Quantitative real-time reverse transcription PCR (qRT-PCR) and electrophoretic mobility shift assay (EMSA) further confirmed that RpoN could directly bind to the promoters of these genes associated with polar flagellar systems (flgB and fliE), lateral flagellar systems (flgB2 and lafA), T6SS2 (hcp2 and VPA1044) and glutamine synthetase (VP0121), and then positively regulate the expression of these systems. A RpoN-binding motif was identified in V. parahaemolyticus using the MEME suite and verified by the EMSA. Besides, the deletion of rpoN caused a significant decrease in hemolytic activity, adhesion, and cytotoxicity. Our results provide new cues to better understand the regulatory networks of RpoN protein to motility, T6SS2, and metabolism in V. parahaemolyticus.

Mechanism for inhibition of cytotoxicity of Shiga toxin by luteolin

Enterohemorrhagic or Shiga toxin-producing Escherichia coli is a food-poisoning bacterium that grows in the intestine to produce Shiga toxin (Stx). In this study, the effects of 20 polyphenols on the cytotoxicity of Stx1 and Stx2 in Vero cells were investigated. Among these, epigallocatechin gallate, butein, isorhapontigenin, hesperetin, morin, luteolin, resveratrol, and rhapontigenin showed inhibitory effects on the cytotoxicity of Stxs at 0.4 mmol/L. Furthermore, Vero cells pre-treated with these polyphenols were resistant to Stx at 0.4 mmol/L. However, luteolin showed the most potent inhibitory and cytoprotective effect against Stxs at 0.08 mmol/L or more. This inhibitory mechanism of luteolin was determined using a cell-free protein synthesis system and quantitative reverse transcription PCR assay to detect depurination of 28S rRNA in Vero cells. Luteolin did not inhibit the cell-free protein synthesis by Stxs, suggesting that the enzymatic activity of the Stx A subunit was not inhibited by luteolin. The depurination of 28S rRNA by Stxs was also investigated in Vero cells. The 28S rRNA depurination by Stxs was suppressed in Vero cells treated with Stxs which had been pretreated with luteolin. These results suggest that luteolin inhibits the incorporation of Stxs into Vero cells. This is the first report to show that luteolin inhibits the cytotoxicity of both Stx1 and Stx2 by inhibiting the incorporation of Stxs into Vero cells.

Effect of integrin α7 on cell proliferation, invasion, apoptosis and the PI3K/AKT pathway, and its association with clinicopathological features in endometrial cancer.

Targeting integrin α7 (ITGA7) suppresses malignant progression of several types of cancer, including tongue squamous cell carcinoma, hepatocellular carcinoma and non-small cell lung cancer, while the effect of its knockdown on cell function and its association with clinicopathological features in endometrial cancer (EC) is unclear. The present study aimed to investigate this issue. ITGA7 was knocked down by short-interfering (si)RNA in Ishikawa and RL95-2 cells followed by western blotting and reverse transcription-quantitative PCR assays. Subsequently, cell proliferation, apoptosis, invasion and expression levels of PI3K, phosphorylated (p-) PI3K, AKT and p-AKT were determined using Cell Counting Kit-8, TUNEL, Transwell assays and western blotting. Moreover, ITGA7 in tumor and adjacent tissues from 50 patients with endometrial cancer was detected using immunohistochemical assay. ITGA7 expression was increased in EC cell lines (HEC-1A, RL95-2, Ishikawa and KLE) compared with telomerase-immortalized human endometrial stromal cells (THESCs). In both Ishikawa and RL95-2 cells, three ITGA7 siRNAs all demonstrated good efficiency on ITGA7 knockdown, amongst which the one with the highest efficiency was selected for the following experiments. ITGA7 knockdown reduced cell proliferation and invasion, while inducing apoptosis; moreover, it suppressed p-PI3K/PI3K and p-AKT/AKT ratios. In patients with EC, ITGA7 expression was increased in tumor tissues compared with adjacent tissues, and its lower tumor expression was associated with myometrial invasion (<1/2), non-lymphovascular invasion and decreased FIGO stage. In conclusion, ITGA7 knockdown repressed proliferation, invasion and the PI3K/AKT pathway while inducing apoptosis in EC cell lines, and its insufficiency was associated with less advanced tumor features in EC patients. These results indicated that ITGA7 may be a potential target for the treatment of EC.

Exon-Skipping for a Pathogenic COL6A1 Variant in Ullrich Congenital Muscular Dystrophy.

Single nucleotide variants that alter splice sites or splicing regulatory elements can lead to the skipping of exons, retention of introns, or insertion of pseudo-exons (PE) into the mature mRNA transcripts. When translated, these changes can disrupt the function of the synthesized protein. Splice-switching antisense oligonucleotides (ASOs) are synthetic, modified nucleic acids that can correct these aberrant splicing events. They are currently in active clinical development for a number of conditions and have been approved by regulatory agencies for the treatment of neuromuscular disorders such as Duchenne muscular dystrophy and spinal muscular atrophy. We have previously reported that splice-switching ASOs effectively skip a pathogenic PE that causes Ullrich congenital muscular dystrophy (UCMD). This erroneous PE insertion is caused by a deep-intronic variant located within intron 11 of COL6A1 (c.930+189 C>T). Here, we describe the detailed protocols and workflow that our labs have used to assess the efficacy of ASOs to skip this PE in vitro. The protocols include designing ASOs; isolating, culturing, and transfecting fibroblasts; extracting RNA and protein; and validating splicing correction at the mRNA and protein levels using quantitative reverse transcription PCR (qRT-PCR) and western blot assays, respectively.

Capacidad pro-apoptótica in vitro de Valeriana rígida y Valeriana decussata sobre una línea celular de cáncer de mama.

Cancer represents a worldwide public health problem, with high incidence and mortality rates in developed and undeveloped countries. Cur-rently, therapeutic alternatives of natural origin are being evaluated with the purpose of establishing more efficient and less invasive treatments. Apoptosis is the type of programmed death cancer cells undergo during treatment with anti-neoplastic drugs. Therefore, the aim of this research was to evaluate in vitro the pro-apoptotic and cytotoxic capacity of valerian extracts on a breast cancer cell line (MCF-7). In this study, MCF7 cells were cultured and treated with different concentrations of the extracts of the root, leaves and stems of Valeriana rígida and Valeriana decussata. Cell viability was assessed by the MTT assay. Quantitative reverse transcription PCR assays were used for the determi-nation of gene expression of anti- and proapoptotic proteins (Bax, Bcl-2, p53). Different concentrations of the extracts (10–8 to 10–1 mg/mL) decreased cell viability (proliferation) in a concentration-dependent manner. These extracts induced gene expression of Bax and Bcl-2 proteins but not of p53. The expres-sion of Bax was higher than that of Bcl-2, causing an elevated Bax/Bcl-2 ratio (proapoptotic condition). In conclusion, it was determined that Valeriana de-cussata and Valeriana rígida extracts have a viability (proliferation) reducing effect on the MCF-7 breast cancer cell line, probably mediated by altering the ratio of Bax and Bcl-2 proteins linked to apoptosis.

Morning SARS-CoV-2 Testing Yields Better Detection of Infection Due to Higher Viral Loads in Saliva and Nasal Swabs upon Waking.

Optimizing specimen collection methods to achieve the most reliable SARS-CoV-2 detection for a given diagnostic sensitivity would improve testing and minimize COVID-19 outbreaks. From September 2020 to April 2021, we performed a household-transmission study in which participants self-collected specimens every morning and evening throughout acute SARS-CoV-2 infection. Seventy mildly symptomatic participants collected saliva, and of those, 29 also collected nasal swab specimens. Viral load was quantified in 1,194 saliva and 661 nasal swab specimens using a high-analytical-sensitivity reverse transcription-quantitative PCR (RT-qPCR) assay. Viral loads in both saliva and nasal swab specimens were significantly higher in morning-collected specimens than in evening-collected specimens after symptom onset. This aspect of the biology of SARS-CoV-2 infection has implications for diagnostic testing. We infer that morning collection would have resulted in significantly improved detection and that this advantage would be most pronounced for tests with low to moderate analytical sensitivity. Collecting specimens for COVID-19 testing in the morning offers a simple and low-cost improvement to clinical diagnostic sensitivity of low- to moderate-analytical-sensitivity tests. IMPORTANCE Our findings suggest that collecting saliva and nasal swab specimens in the morning immediately after waking yields higher SARS-CoV-2 viral loads than collection later in the day. The higher viral loads from morning specimen collection are predicted to significantly improve detection of SARS-CoV-2 in symptomatic individuals, particularly when using moderate- to low-analytical-sensitivity COVID-19 diagnostic tests, such as rapid antigen tests.

HpaP divergently regulates the expression of hrp genes in Xanthomonas oryzae pathovars oryzae and oryzicola.

The bacterial pathogens Xanthomonas oryzae pathovars oryzae (Xoo) and oryzicola (Xoc) cause leaf blight and leaf streak diseases on rice, respectively. Pathogenesis is largely defined by the virulence genes harboured in the pathogen genome. Recently, we demonstrated that the protein HpaP of the crucifer pathogen Xanthomonas campestris pv. campestris is an enzyme with both ATPase and phosphatase activities, and is involved in regulating the synthesis of virulence factors and the induction of the hypersensitive response (HR). In this study, we investigated the role of HpaP homologues in Xoo and Xoc. We showed that HpaP is required for full virulence of Xoo and Xoc. Deletion of hpaP in Xoo and Xoc led to a reduction in virulence and alteration in the production of virulence factors, including extracellular polysaccharide and cell motility. Comparative transcriptomics and reverse transcription-quantitative PCR assays revealed that in XVM2 medium, a mimic medium of the plant environment, the expression levels of hrp genes (for HR and pathogenicity) were enhanced in the Xoo hpaP deletion mutant compared to the wild type. By contrast, in the same growth conditions, hrp gene expression was decreased in the Xoc hpaP deletion mutant compared to the wild type. However, an opposite expression pattern was observed when the pathogens grew in planta, where the expression of hrp genes was reduced in the Xoo hpaP mutant but increased in the Xoc hpaP mutant. These findings indicate that HpaP plays a divergent role in Xoo and Xoc, which may lead to the different infection strategies employed by these two pathogens.

CRISPR/Cas9-targeted mutagenesis of a representative member of a novel PR10/Bet v1-like protein subfamily significantly reduces rice plant height and defense against Meloidogyne graminicola

Plant PR10/Bet v1-like proteins are involved in defense against microbial pathogens, however, whether they participate in host defense against plant-parasitic animals including nematodes remains unknown. Here, according to the phylogeny, sequence-similarity, and secondary structure analyses, we found that the rice OsBet v1 protein and its homologs constitute a new subfamily of PR10/Bet v1-like protein. Reverse transcription-quantitative PCR assay showed that OsBet v1 was highly expressed in rice roots and induced by Meloidogyne graminicola infection. Using a transient expression assay in rice protoplasts, we demonstrated that OsBet v1 was localized in the cytoplasm and nucleus. Furthermore, CRISPR/Cas9-targeted mutagenesis of OsBet v1 significantly increased rice susceptibility to M. graminicola, but reduced rice plant height. In addition, the expression levels of two peroxidase genes (peroxidase 5 and peroxidase 56) were significantly down-regulated in OsBet v1 knockout mutants compared with those in wild-type rice plants. Taken together, this study identified a new PR10/Bet v1-like protein subfamily in plant and revealed the involvement of OsBet v1, a representative member of the subfamily, in rice growth and defense against M. graminicola. This provides a new insight into the role of plant PR10/Bet v1-like proteins in plant–nematode interactions.

Aberrant expression of polo-like kinase 4 in renal cell carcinoma: Association with clinicopathological characteristics and long-term survival.

Polo-like kinase 4 (PLK4) promotes tumorigenesis and is associated with the prognosis of several solid tumors, while its clinical role in patients with renal cell carcinoma (RCC) remains unidentified. The present study aimed to analyze the association of PLK4 with clinicopathological characteristics and long-term prognosis in patients with RCC. The present study detected PLK4 protein and mRNA expression using immunohistochemical and reverse transcription-quantitative PCR assays in 120 patients with RCC. Disease-free survival (DFS) and overall survival (OS) time were calculated based on a median follow-up duration of 6.9 years (range, 1.2-9.9 years). PLK4 protein expression was elevated in tumor tissues compared with adjacent tissues (P<0.001). Upregulation of PLK4 protein was associated with increased T stage (P=0.023), N stage (P=0.014) and TNM stage (P=0.007). Additionally, elevated tumor PLK4 protein expression exhibited an associating trend (without statistical significance) with reduced DFS rate (P=0.066) and was associated with decreased OS rate (P=0.036). However, univariate Cox's regression analysis indicated that high PLK4 protein expression (compared with low PLK4 protein expression) was associated with reduced OS rate (P=0.040) but not with PFS rate (P=0.070). Following adjustment by multivariate Cox's regression analysis, PLK4 protein expression was associated with neither DFS nor OS rate (both P>0.050). Additionally, PLK4 mRNA expression was further detected in some patients (for which fresh specimens frozen in liquid nitrogen were available) to validate the aforementioned observations, and the expression was elevated in tumor tissues compared with adjacent tissues. Furthermore, increased PLK4 mRNA expression was associated with tumor size ≥7 cm, high TNM stage and reduced DFS rate (all P<0.050). PLK4 possesses a certain clinical utility in monitoring the clinical stage of patients with RCC, while its prognostic value requires further validation.

Expression and Purification of Recombinant SARS-CoV-2 Accessory Protein ORF7a and Functional Analysis of Its Role in Up-Regulating Cytokine Production

The severity of coronavirus disease 2019 is closely linked to dysregulated immune responses. The search for viral proteins associated with immune regulation in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical to reveal the pathogenicity of the virus. In this study, accessory proteins ORF7a (referred to as ORF7a-1 and ORF7a-2, respectively) from two SARS-related coronaviruses, severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2, were produced through the denaturing and refolding of inclusion body proteins. The recombinant protein was incubated with alveolar epithelial cells, and the transcription and expression levels of major cytokines were determined by reverse transcription-quantitative PCR and enzyme-linked immunosorbent assay. SARS-related coronavirus ORF7a can up-regulate the transcription and expression of interleukin-6, C-C motif chemokine ligand 8, interferon α, and interferon β. The results also indicated that the two highly conserved ORF7a had certain differences in promoting the transcription and expression of cytokines. The study showed that ORF7a is a virus-encoded immune regulator by alveolar epithelial cells that plays an important role in the pathogenicity of SARS-related coronaviruses.

Knockdown of ARL5B Induces Mitochondrial-mediated Apoptosis and Inhibits Glycolysis in Breast Cancer Cells by Activating MDA5 Signaling.

Mitochondria are essential for energy metabolism in the tumor microenvironment and the survival of cancer cells. ADP-ribosylation factor-like GTPase 5b (ARL5B) has been found to be associated with mitochondrial dysfunction and breast cancer (BC) progression, but the underlying mechanism needs to be further understood. We investigated the effects of ARL5B on the apoptosis and glycolysis of breast cancer cells and its underlying mechanisms. Quantitative reverse transcription-PCR (qRT-PCR) and western blot assays were used to detect the expression of ARL5B in breast cancer tissues and cells. An ARL5B loss-of-function assay was performed to verify its role in BC development. ARL5B was upregulated in breast cancer tissues and cell lines. ARL5B knockdown induced apoptosis and activated the mitochondrial pathway in breast cancer cells. Interestingly, the inhibition of ARL5B repressed the aerobic glycolysis of breast cancer cells. The role of ARL5B in breast cancer cells was exerted by mediating the activation of viral RNA sensor MDA5-evoked signaling. Silencing ARL5B triggered MDA5 signaling by upregulating the key proteins involved in the MDA5 pathway. Importantly, MDA5 silencing reversed the effects of ARL5B knockdown on mitochondrial-mediated apoptosis and glycolysis, whereas poly (I:C), as a ligand for MDA5, further enhanced ARL5B knockdown- facilitated mitochondrial apoptosis and the inhibition of glycolysis. The knockdown of ARL5B activated MDA5 signaling and thus led to the enhanced mitochondrial- mediated apoptosis and glycolysis inhibition in breast cancer cells. Our study suggested that ARL5B might be a potential therapy target for BC.

Human placental mesenchymal stem cells regulate inflammation via the NF‑κB signaling pathway

Emerging evidence has indicated that mesenchymal stem cells (MSCs) are involved in the modulation of inflammation. Human placenta-derived (HPL)-MSCs exist in sufficient quantities and play a role in immune regulation. However, the exact roles of HPL-MSCs in inflammation and the specific underlying mechanisms are not well defined. In the present study, HPL-MSCs were obtained from human fetal placentas, and further purified using a commercial kit. Using ELISA, reverse transcription-quantitative PCR, western blot, NO detection and other assays, the present study revealed that HPL-MSCs may improve lipopolysaccharide-induced macrophage inflammation by regulating macrophage polarization. Further mechanistic studies demonstrated that HPL-MSCs attenuated the NF-κB signaling pathway by regulating the expression of toll-like receptor 4 and the phosphorylation of IκBα and p65, which resulted in a reduction in the levels of inflammation. The present study indicated that HPL-MSCs may act as a novel target for the treatment of inflammation-related diseases.

A high-throughput screening RT-qPCR assay for quantifying surrogate markers of immunity from PBMCs.

Immunoassays that quantitate cytokines and other surrogate markers of immunity from peripheral blood mononuclear cells (PBMCs), such as flow cytometry or Enzyme-Linked Immunosorbent Spot (ELIspot), allow highly sensitive measurements of immune effector function. However, those assays consume relatively high numbers of cells and expensive reagents, precluding comprehensive analyses and high-throughput screening (HTS). To address this issue, we developed a sensitive and specific reverse transcription-quantitative PCR (RT-qPCR)-based HTS assay, specifically designed to quantify surrogate markers of immunity from very low numbers of PBMCs. We systematically evaluated the volumes and concentrations of critical reagents within the RT-qPCR protocol, miniaturizing the assay and ultimately reducing the cost by almost 90% compared to current standard practice. We assessed the suitability of this cost-optimized RT-qPCR protocol as an HTS tool and determined the assay exceeds HTS uniformity and signal variance testing standards. Furthermore, we demonstrate this technique can effectively delineate a hierarchy of responses from as little as 50,000 PBMCs stimulated with CD4+ or CD8+ T cell peptide epitopes. Finally, we establish that this HTS-optimized protocol has single-cell analytical sensitivity and a diagnostic sensitivity equivalent to detecting 1:10,000 responding cells (i.e., 100 Spot Forming Cells/106 PBMCs by ELIspot) with over 90% accuracy. We anticipate this assay will have widespread applicability in preclinical and clinical studies, especially when samples are limited, and cost is an important consideration.

Development of a sensitive real-time quantitative RT-PCR assay for the detection of pear chlorotic leaf spot-associated virus

Pear chlorotic leaf spot associated virus (PCLSaV) belongs to the genus Emaravirus and possesses a genome composed of five negative-sense single-stranded RNA (-ssRNA) segments. This study developed a SYBR green-based reverse transcription quantitative PCR (RT-qPCR) assay for the detection of PCLSaV infecting pear trees. A set of two primers q5-F2/q5-R2 designed based on the viral RNA5 sequences showed high specificity and feasibility for PCLSaV detection. The standard curve was established. RT-qPCR assays showed that PCLSaV content was greatly higher in diseased branch and symptomatic leaf samples than that in un-diseased branch and asymptomatic leaf samples. The RT-qPCR was reliability in the detection of the virus in field and in-vitro cultured pear samples. This technique would be useful for the supervision of the viral disease and the certification of pear planting materials.

Down-regulation of KLF9 ameliorates LPS-caused acute lung injury and inflammation in mice via reducing GSDMD expression

Acute lung injury (ALI) is considered as a severe respiratory disease with aggravated inflammatory responses. Krüppel-like factor 9 (KLF9), a member of KLF family, has been reported to be involved in inflammatory disorders. However, the effect of KLF9 in ALI has not been elucidated. Here the present study was to clarify the role of KLF9 and its mechanism in ALI. The ALI in vitro model was established with lipopolysaccharide (LPS)-treated RAW264.7 cells. Mice were injected with LPS to conduct an ALI in vivo model. The expression of KLF9 and gasdermin D (GSDMD) was examined using quantitative reverse transcription-PCR, haematoxylin-eosin/immunohistochemistry staining and western blot assays. Enzyme-linked immunosorbent assay was employed to detect the levels of inflammatory cytokines. JASPAR database was used to predict the recognition motif of KLF9, and the relationship between KLF9 and GSDMD was determined by luciferase reporter assay and chromatin immunoprecipitation analysis. The number of neutrophils in bronchoalveolar lavage fluid as well as the wet/dry weight ratio was caculated. The results showed that The expression of KLF9 in lung was significantly increased in LPS-stimulated mice. Moreover, KLF9 knockout relieved the lung injury in ALI mice. GSDMD is one of targets genes of the transcription factor KLF9. KLF9 knockout induced a decreased expression of GSDMD in LPS-treated mice. Furthermore, in RAW264.7 cells after LPS administration, KLF9 knockdown reduced the levels of inflammatory factors and suppressed the expression of GSDMD. In summarise, these findings exhibited that KLF9 knockout could mitigate the lung injury and inflammatory responses in ALI mice by directly regulating GSDMD.

High Expression of circ_0001821 Promoted Colorectal Cancer Progression Through miR-600/ISOC1 Axis

It has been reported that circRNAs play an important regulatory role in the progression of colorectal cancer (CRC). However, the molecular role of circ_0001821 in CRC development is unclear. In this study, we aimed to investigate the regulatory role and molecular mechanisms of circ_0001821 in CRC. Reverse transcription-quantitative PCR and western blot assays were used to detect the expression of circ_0001821, miR-600 and isochorismatase domain containing 1 (ISOC1) in CRC tissues as well as its cell lines. Colony formation assay and EDU assay were used to detect the proliferative capacity of cells. Transwell assay was used to assess cell migration and invasion ability. Flow cytometry was used to analyze cell apoptosis. ELISA was used to measure the glycolytic capacity of cells. Dual-luciferase reporter assay and RNA pull-down assay were used to analyze the relationships between circ_0001821, miR-600 and ISOC1. Animal experimentation was used to validate the functional study of circ_0001821 in vivo. Immunohistochemistry (IHC) of Ki67 staining analysis was conducted to assess tumor growth. Circ_0001821 and ISOC1 were significantly increased in CRC tissues and its cell lines, and miR-600 was significantly decreased in CRC tissues and its cell lines. Silencing circ_0001821 inhibited cell proliferation, migration, invasion and glycolytic capacity, while inducing apoptosis. And it could inhibit tumor growth in vivo. Circ_0001821 could act as a sponge for miR-600 to regulate CRC processes. ISOC1 was identified as a downstream regulator of miR-600, also miR-600 could regulate the expression of ISOC1. In addition, circ_0001821 could regulate ISOC1 expression changes through miR-600. Mechanistically, either miR-600 inhibitor or overexpression of ISOC1 could reverse the effects of knockdown of circ_0001821 on cell biological properties. Circ_0001821 regulated the developmental process of CRC through miR-600/ISOC1 axis.