Cold shock treatment alleviates chilling injury in peach fruit by regulating antioxidant capacity and membrane lipid metabolism

Objectives The work intended to reveal the effect of cold shock (CS) treatment on chilling injury (CI), antioxidant capacity, and membrane fatty acid of peach fruit. Materials and methods Peaches were soaked in ice water (0 °C) for 10 min and stored at 5 °C for 28 days for determination, except CI, and then stored for 3 days at 20 °C, only CI was measured. The electrolyte leakage (EL) was measured by conductivity meter. The activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase) and key enzymes of membrane lipid metabolism (phospholipase D, lipase, and lipoxygenase) as well as reactive oxygen species (ROS; O2·– and H2O2) were measured with a spectrophotometer. An ELISA kit and gas chromatography were used to determine membrane lipids and membrane fatty acids. The relative gene expression was measured by real-time polymerase chain reaction analysis. Results The results showed that CS treatment effectively delayed CI, suppressed the increase of EL and malondialdehyde content. Meanwhile, CS-treated fruit exhibited lower level of ROS and higher activities of antioxidant enzymes. Furthermore, CS treatment inhibited the activities as well as the relative gene expression of key enzymes in membrane lipid metabolism. CS-treated fruits maintained higher membrane fatty acid unsaturation and lower phosphatidic acid content. Conclusions These results indicated that CS treatment effectively alleviated CI and maintained the integrity of cell membranes by inducing antioxidant-related enzyme activity and maintaining a higher ratio of unsaturated fatty acids to saturated fatty acids.

A 4-Gene Signature of CDKN1, FDXR, SESN1 and PCNA Radiation Biomarkers for Prediction of Patient Radiosensitivity

The quest for the discovery and validation of radiosensitivity biomarkers is ongoing and while conventional bioassays are well established as biomarkers, molecular advances have unveiled new emerging biomarkers. Herein, we present the validation of a new 4-gene signature panel of CDKN1, FDXR, SESN1 and PCNA previously reported to be radiation-responsive genes, using the conventional G2 chromosomal radiosensitivity assay. Radiation-induced G2 chromosomal radiosensitivity at 0.05 Gy and 0.5 Gy IR is presented for a healthy control (n = 45) and a prostate cancer (n = 14) donor cohort. For the prostate cancer cohort, data from two sampling time points (baseline and Androgen Deprivation Therapy (ADT)) is provided, and a significant difference (p > 0.001) between 0.05 Gy and 0.5 Gy was evident for all donor cohorts. Selected donor samples from each cohort also exposed to 0.05 Gy and 0.5 Gy IR were analysed for relative gene expression of the 4-gene signature. In the healthy donor cohort, there was a significant difference in gene expression between IR dose for CDKN1, FXDR and SESN1 but not PCNA and no significant difference found between all prostate cancer donors, unless they were classified as radiation-induced G2 chromosomal radiosensitive. Interestingly, ADT had an effect on radiation response for some donors highlighting intra-individual heterogeneity of prostate cancer donors.

Oocyte Morphometric Assessment and Gene Expression Profiling of Oocytes and Cumulus Cells as Biomarkers of Oocyte Competence in Sheep

Oocyte quality is crucial for subsequent embryo development and so it is a major challenge in assisted reproductive technologies. The aim of the present work was to evaluate the morphometric parameters of oocytes (experiment 1) and the relative gene expression of oocytes and cumulus cells (CCs) (experiment 2) as biomarkers of oocyte quality after individually culturing them (one oocyte or embryo/drop). In experiment 1, individually matured oocytes were measured and classified into small, intermediate, and large oocytes after a cluster analysis, based on total diameter (with zona pellucida, ZP), oocyte diameter (without ZP), and ZP thickness. These oocytes were individually fertilized in vitro and cultured. The embryo development was evaluated up to the blastocyst stage. According to the total diameter, oocyte diameter, and ZP thickness, the blastocyst rate decreased in the small oocytes group (3.1 ± 3.1, 14.1 ± 9.4, and 26.7 ± 3.9, respectively) compared to the intermediate (29.4 ± 5.2, 30.5 ± 10.1, and 28.6 ± 9.6, respectively) and large oocytes groups (54.2 ± 13.5, 44.4 ± 3.9, and 67.6 ± 12.4, respectively). In addition, the probability of reaching the blastocyst stage was positively related to the total diameter (p < 0.001), oocyte diameter (p < 0.05), and ZP thickness (p < 0.001). Furthermore, the relative gene expression of BAX, BCL2, GDF9, and GJA1 was lower in oocytes classified as large. In experiment 2, the mRNA transcript relative abundance pattern of genes in CCs was evaluated according to oocyte total diameter and developmental stage reached. CCs from oocytes classified as large and oocytes capable of developing to the blastocyst stage had a lower relative expression of BAX, STAR, and PTGS2, while a higher expression of HAS2 and SDC2 transcript was observed for those oocytes. In conclusion, oocyte morphometric parameters and gene expression analysis in oocytes and CCs provide methods for the identification of the most competent oocytes for assisted reproductive technologies in sheep.

Increased gene expression and copy number of mutated blaKPC lead to high-level ceftazidime/avibactam resistance in Klebsiella pneumoniae

Background Resistance to ceftazidime-avibactam was reported, and it is important to investigate the mechanisms of ceftazidime/avibactam resistance in K. pneumoniae with mutations in blaKPC. Results We report the mutated blaKPC is not the only mechanism related to CZA resistance, and investigate the role of outer porin defects, efflux pump, and relative gene expression and copy number of blaKPC and ompk35/36. Four ceftazidime/avibactam-sensitive isolates detected wild type blaKPC-2, while 4 ceftazidime/avibactam-resistant isolates detected mutated blaKPC (blaKPC-51, blaKPC-52, and blaKPC-33). Compared with other ceftazidime/avibactam-resistant isolates with the minimal inhibitory concentration of ceftazidime/avibactam ranging 128–256 mg/L, the relative gene expression and copy number of blaKPC was increased in the isolate which carried blaKPC-51 and also showed the highest minimal inhibitory concentration of ceftazidime/avibactam at 2048 mg/L. The truncated Ompk35 contributes rare to ceftazidime/avibactam resistance in our isolates. No significant difference in minimal inhibitory concentration of ceftazidime/avibactam was observed after the addition of PABN. Conclusions Increased gene expression and copy number of mutated blaKPC can cause high-level ceftazidime/avibactam resistance.

Influence of Angiopoietin Treatment with Hypoxia and Normoxia on Human Intervertebral Disc Progenitor Cell’s Proliferation, Metabolic Activity, and Phenotype

Increasing evidence implicates intervertebral disc (IVD) degeneration as a major contributor to low back pain. In addition to a series of pathogenic processes, degenerated IVDs become vascularized in contrast to healthy IVDs. In this context, angiopoietin (Ang) plays a crucial role and is involved in cytokine recruitment, and anabolic and catabolic reactions within the extracellular matrix (ECM). Over the last decade, a progenitor cell population has been described in the nucleus pulposus (NP) of the IVD to be positive for the Tie2 marker (also known as Ang-1 receptor). In this study, we investigated the influence of Ang-1 and Ang-2 on human NP cell (Tie2+, Tie2- or mixed) populations isolated from trauma patients during 7 days in normoxia (21% O2) or hypoxia (≤ 5% O2). At the end of the process, the proliferation and metabolic activity of the NP cells were analyzed. Additionally, the relative gene expression of NP-related markers was evaluated. NP cells showed a higher proliferation depending on the Ang treatment. Moreover, the study revealed higher NP cell metabolism when cultured in hypoxia. Additionally, the relative gene expression followed, with an increase linked to the oxygen level and Ang concentration. Our study comparing different NP cell populations may be the start of new approaches for the treatment of IVD degeneration.

The Spatial Distribution Characteristics of Typical Pathogens and Nitrogen and Phosphorus in the Sediments of Shahe Reservoir and their Relationships

Using samples collected in Shahe Reservoir in the upper North Canal in China, this research analyzes the structure of a microorganism group in sediment and the gene expression levels of two typical pathogenic bacteria (Escherichia coli and Enterococcus), and their relationship with environmental factors including total nitrogen (TN) and total phosphorus (TP). The study of samples collected from the surface (0–20 cm) and sediment cores shows that the absolute gene expression level of E. coli in in horizontal distribution in the sediment is higher than the relative gene expression level in the downstream of the reservoir and contaminated area. In vertical distribution, the absolute gene expression level of the two pathogenic bacteria in the sediment tends to decrease with increasing depth, although the relative gene expression level has its highest value at 10–30 cm depth. The relative gene expression level of the two pathogenic bacteria is much greater in the sediment of Shahe Reservoir with the structure of horizontal groups including Clortridium sensu stricto, unclassified Anaeroineaceae, and Povalibacter, while Anaeroineaceae is much more abundant in the group structure of the vertical distribution. Pearson correlation analysis suggests positive correlation in horizontal distribution for E. coli and TN and TP (P < 0.05) and for Enterococcus and TP (P < 0.05). The results clearly show that the amount of pathogenic bacteria in the sediment in Shahe Reservoir is most likely due to water eutrophication.

Embryo-to-embryo variability in RNAi knockdown efficiency of dKDM5/lid in Drosophila melanogaster

We used the maternal-Gal4 shRNA system to knock down expression of dKDM5/lid in Drosophila melanogaster embryos, and analyzed the efficacy of the knockdown by qRT-PCR. Although average relative expression of lid was significantly lower in knockdown conditions compared to the driver-only control, we observed a wide and overlapping range of relative gene expression between individual control and knockdown embryos.

Ingestion of Bifidobacterium longum changes miRNA levels in the brains of mice

The purpose of this research is to investigate the relationship between the microbiota of the gastrointestinal (GI) system and relative gene expression of miRNAs and mRNAs in the brain. C57BL/6 mice and Balb/c mice are fed Bifidobacterium longum, a well-characterized probiotic bacterial species shown to change behavior and improve sociability of Balb/c mice. After feeding, RNA was extracted from whole brains and PCR arrays were utilized to determine changes in the gene expression of brain-specific miRNAs. The results of these PCR arrays reveal that the relative gene expression of mmu-mir-652-3p is sensitive to B. longum probiotic treatment in C57BL/6 mice. qPCR was performed to measure expression of Dab1, an mRNA target of this miRNA. Dab1 expression is also dependent on B. longum. The goal of this study is to further understand the relationship between the gut microbiota and its impacts on neurological gene expression and brain function.