MedNexus
2021年 · 第04卷第01期
MedNexus
Single-nucleotide polymorphisms (SNPs) are the third generation of genetic markers, having been refined from the first generation of restriction fragment length polymorphisms and the second generation of microsatellite polymorphisms. SNPs represent a focal point of current studies of Staphylococcus aureus. On one hand, this review aims to summarize common methodologies for detecting SNPs. These methods have typically included DNA genome sequencing methods and PCR-based detection methods. Alternative methods, such as mass spectrometry, denaturing high-performance liquid chromatography, SNaPshot, and SNP array have also been employed for SNP analysis. On the other hand, we enumerate a series of applications of SNP analysis in investigations of Staphylococcus aureus. SNP analysis can be applied to investigate epidemiological outbreaks and transmission of Staphylococcus aureus infections, the transmission and evolution of antimicrobial resistance genes in Staphylococcus aureus isolates, interactions of Staphylococcus aureus with other bacteria, and the links between Staphylococcus aureus in humans and livestock.
Liver cancer stem cells (CSCs) are the culprits of hepatocellular carcinoma metastasis and recurrence. Only by eliminating tumor stem cells can malignant tumors be fundamentally cured. This study aimed to identify the role and underlying mechanism of aberrant Collagen Type XIV Alpha 1 Chain (COL14A1) overexpression in liver CSCs, and improve understanding of the molecular basis of hepatocellular carcinoma metastasis and recurrence.
First, quantitative real-time polymerase chain reaction was used to confirm aberrant high-expression of COL14A1 in liver CSCs. Next, interference experiments were performed to determine the key role of COL14A1. To explore the mechanism of COL14A1 overexpression in liver CSCs, putative microRNA (miRNAs) targeting COL14A1 were analyzed using the miRTarBase database. Next, quantitative real-time polymerase chain reaction, western blotting, and luciferase reporter assays were performed to verify the interaction between miR-7108-3p and COL14A1. Lastly, key target proteins of the COL14A1-extracellular-regulated signal kinase (ERK) signaling pathway were identified through western blotting analysis. This study was approved by the Ethics Committee of Shanghai Fourth People’s Hospital, Tongji University School of Medicine, China (approval No. 2019tjdx17) on February 21, 2019.
COL14A1 is abnormally highly expressed in liver CSCs, which is necessary for liver CSCs to maintain their self-renewal capability. Mechanistically, COL14A1 is post-transcriptionally regulated by miR-7108-3p in a negative manner. Low expression of miR-7108-3p increased translation of COL14A1, which subsequently activated ERK signaling, ultimately maintaining the self-renewal and stem cell-like properties of liver CSCs.
COL14A1, which is negatively regulated by miR-7108-3p, was found to play a crucial role in maintaining the self-renewal and stem cell-like properties of liver CSCs through activation of ERK signaling.
Pseudomonas aeruginosa (P. aeruginosa) contains a hierarchy of quorum sensing (QS) network, consisting of the las, rhl and pqs systems, which play a key role in coordinating the expression of virulence factors. PA2146 was found to be associated with P. aeruginosa pathogenicity in macrophage and host Immune response. The aim of this study was to investigate the effects of PA2146 on the virulence of P. aeruginosa and explore its mechanism.
PA2146 gene knockout strain and complement strain of P. aeruginosa PAO1 were constructed. The biomass of biofilm was detected by crystal violet staining; the virulence factors were measured, including pyocyanin, rhamnolipid, LasA elastase, LasB elastase and hemolytic activity; RNA-seq and label-free relative quantitative proteomics analyses were carried out to test the influence of PA2146 on transcriptomics and proteomics. This study was approved by the Institutional Review Board of the Third Xiangya Hospital, Central South University, China (approval No. 2019-S021).
PA2146-deficient strains showed reduced biofilm formation and increased pyocyanin, rhamnolipid, LasA elastase, LasB elastase, and hemolytic activity, as well as increased motility, compared with the wild-type strain. RNA-seq and label-free relative quantitative proteomics analyses revealed that PA2146 repressed the transcription of several genes that are integral to the pqs system and to pyocyanin biosynthesis, and increased the expression of MexEF-OprN efflux pump components at the gene and protein level.
PA2146 gene was found to inhibit the pqs system. PA2146 may affect quorum sensing by directly inhibiting the pqs system or by enhancing the expression of MexEF-OprN efflux pump components, thereby promoting efflux of 2-heptyl-4(1H)-quinolone, a Pseudomonas quinolone signal precursor, and thus affecting P. aeruginosa virulence.
To identify potential early diagnostic markers for hepatitis B progression to primary liver carcinoma using routine immunological tests based on 6 cytokine combinations.
Eight hundred and ninety-nine patients with hepatitis B progressing to early primary liver carcinoma admitted to and treated at Changhai Hospital, Naval Military Medical University, Shanghai, China between March 2015 and June 2017 were included in this observational study, including 666 patients with HBsAg+, HBeAb+, HBcAb+ liver carcinoma and 233 patients with HBsAg+, HBeAg+, HBcAb+ liver carcinoma. Receiver operating characteristic (ROC) curves were used to evaluate the efficiency of the different cytokine in the diagnosis of hepatocellular carcinoma in patients with hepatitis B. This study was approved by the Institutional Review Board of Changhai Hospital, Naval Military Medical University, China (approval No. CHEC2020-080) on June 6, 2020.
Changed levels of interleukin (IL)-1β, IL-2R, IL-8, and tumor necrosis factor (TNF)-α were statistically significant (P < 0.05). The area under the ROC curve, sensitivity, specificity, positive predictive value, negative predictive value, and Youden index for the diagnosis of primary liver carcinoma using the combination of IL-1β, IL-2R, IL-8, and TNF-α were 0.938, 79.2%, 96.7%, 96%, 82.0%, 0.759, respectively. The serum alpha-fetoprotein level in patients with primary liver carcinoma was positively correlated with IL-2R (r=0.3502, P < 0.001), IL-8 (r=0.1558, P=0.0273), and TNF-α (r=0.2544, P < 0.001) levels. The equation fitted to the results was logit(P)=0.086+ 0.01 × IL-2R-0.001 × IL-8-0.033 × TNF-α-0.041 × IL-1β.
Our study establishes a novel, potentially valuable diagnostic model based on four cytokines related to the early stages of liver carcinoma.
To investigate and analyze changes of T lymphocyte and other lymphocyte subsets in the peripheral blood of patients with coronavirus disease 2019 (COVID-19), with the goal of improving clinical understanding and the value of research applications.
General data of 66 confirmed COVID-19 patients admitted to the Fifth Medical Center of Beijing PLA General Hospital from January 2 to March 23, 2020 were collected in this retrospective case-control observational study, and they were divided into mild (n=26), mid-grade (n=19), and severe/critical disease groups (n=21) according to disease severity. Neutrophils, lymphocytes, neutrophil/lymphocyte ratios, CD4 absolute counts, CD8 absolute counts, and CD4/CD8 expression ratios of peripheral whole blood among the three patient groups were compared. The study protocol was approved by the Ethics Committee of the Fifth Medical Center, General Hospital of Chinese PLA (approval No. 2020-69-D) on May 5, 2020.
Among the 66 COVID-19 patients examined, 38 were male and 28 were female, with an average age of 53 ± 17 years. Among patients, 26 cases were mild, 19 cases were mid-grade, and 21 cases were severe/critical. Neutrophils, neutrophil/lymphocyte ratios, and CD4+/CD8+ ratios of the severe/critical group were significantly higher compared with mild and mid-grade groups (P < 0.01); however, there was no obvious difference between mid-grade and mild groups (P > 0.05). Lymphocytes, CD4 absolute counts, and CD8+ absolute counts of the severe/critical group were significantly lower compared with mild and mid-grade groups (P < 0.01); however, there was no significant difference between mid-grade and mild groups (P > 0.05).
Counts of lymphocytes and T lymphocytes in severe/critically ill patients were decreased, which is of great significance for the identification of severe and critical COVID-19 patients.
Hepatic phosphorylase kinase (PhK) plays an important role in glycogen metabolism by activating phosphorylase. Patients with PhK deficiency may get glycogen storage disease (GSD) type-IXa, an X-linked liver glycogenosis disease. To inform genetic counseling in a family with two affected GSD brothers, we performed a genetic analysis. The GSD in the older brother was confirmed by histological examination of a liver biopsy, which showed glycogen accumulation in liver cells. A liver biopsy was not available from the younger brother. The two patients and their parents were analyzed by whole exome sequencing. A pathogenic mutation in a gene encoding a regulatory subunit of PhK, PHKA2 located on chromosome Xp22, was identified as c.G3373A (p.E1125K) and confirmed by Sanger sequencing. The proband’s maternal grandparents and the brothers and sisters of the proband’s maternal grandfather were physically examined and genetically tested by Sanger sequencing. Pedigree analysis showed that the mother was a carrier and that the two patients inherited the mutation from their undiagnosed maternal grandfather. Moreover, among the maternal grandfather and four granduncles, three of them possessed the same mutation and four suffered from fatty liver. This is the first report of this mutation causing X-linked liver glycogenosis in a Chinese family and shows that GSD IXa is a mild form of glycogenosis in terms of clinical symptoms, indicating that GSD may be undiagnosed or underestimated. Nevertheless, to provide appropriate intervention and genetic counseling, early identification of the genetic cause is imperative. This study was approved by the Ethics Committee of First Affiliated Hospital, Hunan University of Chinese Medicine (approval No. HN-LL-ZFKY-2018-001-01) on January 12, 2018.
本期目次
