Owing to its high protein secretion capacity, simple nutritional requirements, and GRAS (generally regarded as safe) status, Bacillus licheniformis is widely used as a host for the industrial ...production of enzymes, antibiotics, and peptides. However, as compared with its close relative Bacillus subtilis, little is known about the physiology and stress responses of B. licheniformis. To explore its temperature-stress metabolome, B. licheniformis strains ATCC 14580 and B186, with respective optimal growth temperatures of 42℃ and 50℃, were cultured at 42℃, 50℃, and 60℃ and their corresponding metabolic profiles were determined by gas chromatography/mass spectrometry and multivariate statistical analyses. It was found that with increased growth temperatures, the two B. licheniformis strains displayed elevated cellular levels of proline, glutamate, lysine, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, and octadecanoic acid, and decreased levels of glutamine and octadecenoic acid. Regulation of amino acid and fatty acid metabolism is likely to be associated with the evolution of protective biochemical mechanisms of B. licheniformis. Our results will help to optimize the industrial use of B. licheniformis and other important Bacillus species.
Use of thermotolerant strains offers the advantage of conducting production process at elevated temperatures, thereby improving the catalytic efficiency and reducing the energy consumption and the ...production costs. In the present study, thermotolerance gene groES from the thermophilic strain Bacillus licheniformis B186 was implanted into B. subtilis WB600 to improve its thermotolerance. The engineered strain WB600-pHY-groES displayed reduced doubling time as well as increased specific growth rates and cell viability compared with the control. Our results suggested that introducing heat shock proteins (HSPs) from thermophiles into B. subtilis could be an effective approach to enhance its thermotolerance, thus facilitating the development of multichaperone expression systems for constructing more thermotolerant commercial B. subtilis strains. To the best of our knowledge, this is the first report on improving the thermotolerance of B. subtilis by overexpression of HSPs.
Abstract
Listeria monocytogenes (LM) is a zoonotic pathogen that widely adapts to various environments. Recent studies have found that noncoding RNAs (ncRNAs) play regulatory roles in LM responses to ...environmental stress. To understand the role of ncRNA rli87 in the response regulation, a rli87 deletion strain LM-Δrli87 was constructed by homologous recombination and tested for stress responses to high temperature, low temperature, high osmotic pressure, alcohol, acidity, alkaline and oxidative environments, along with LM EGD-e strain (control). The results showed that compared with LM EGD-e, LM-Δrli87 grew faster (P < 0.05) at low temperature (30 °C), high temperature (42 °C), and in alkaline condition (pH = 9), similarly (P > 0.05) in acidic and high osmatic pressure (10% NaCl) conditions. When cultured in medium containing 3.8% ethanol, the growth was not significantly different between the two strains (P > 0.05). When cultured at pH 9, they had similar growth rates in the first 5 h (P > 0.05), but the rates were significantly different after 6 h (P < 0.05). The expression of rsbV, rsbW, hpt, clpP, and ctsR was upregulated in LM-∆rli87 compared with LM EGD-e at pH 9, indicating that the rli87 gene regulated the expression of the five genes in alkaline environment. Our results suggest that the rli87 gene has an important regulatory role in LM's response to temperature (30 and 42 °C), alkaline stresses.
Impact of rli87 gene deletion on response of Listeria monocytogenes to environmental stress.
Graphical Abstract Figure.
Impact of rli87 gene deletion on response of Listeria monocytogenes to environmental stress.
BackgroundFor advanced gastric cancer (GC) patients who fail first-line treatment, chemotherapy alone is of limited benefit. Ramucirumab combined with paclitaxel and apatinib combined with docetaxel ...provided clinical benefit in previous studies, but the feasibility of apatinib combined with other chemotherapy agents remains unknown. The aim of the present study was to evaluate the efficacy and safety of apatinib combined with chemotherapy as a second-line treatment for advanced GC. MethodsPatients aged 18-75 years with histologically or cytologically confirmed advanced or metastatic GC or gastroesophageal junction adenocarcinoma that had progressed with first-line treatment were recruited and received apatinib 250 or 500 mg oral apatinib and chemotherapy regimens, including docetaxel, paclitaxel, tegafur, oxaliplatin, and capecitabine. Each treatment cycle was 28 days (4 weeks). During post-discontinuation follow-up, all patients were followed for survival every 8 weeks (+0 to 7 days) until disease progression, death, or study completion. Overall survival (OS) was the primary endpoint. Secondary endpoints were overall response rate (ORR), disease control rate (DCR), and progression-free survival (PFS). Adverse events (AEs) were also noted. Tumor response and progression were assessed according to RECIST 1.1. AEs were graded following the National Cancer Institute common terminology criteria for AEs (NCI-CTCAE 4.0). ResultsBetween August 31, 2016 and February 17, 2020, a total of 32 patients were enrolled in the present study, and 29 were evaluable. At the time of data cut-off, median follow-up was 7.00 months (IQR, 4.60-12.23 months). The ORR and DCR were 18.52% and 92.59%, respectively. The median PFS was 3.06 months, and the median OS was 6.93 months. In the population receipt of apatinib plus docetaxel, the median OS was 6.51 months. AEs were observed in 22 patients. Leukopenia was the most common AE (24.1%), followed by hypertension (24.1%) and neutropenia (17.2%). Patients did not develop any AEs that were grade 4 or higher. ConclusionsThe combination of apatinib and chemotherapy demonstrated clinical activity and acceptable toxicity as a second-line treatment for advanced GC, and may provide new second-line treatment options for advanced GC patients.
AMPK-related kinase 5 (ARK5) is a member of the human AMP-activated protein kinase (AMPK) family, which is associated with increased tumor survival and drug resistance in many cancers. However, the ...function of ARK5 in pancreatic carcinoma (PC) is unclear. Our study investigated the role of ARK5 in the chemo-resistance of PC and its underlying mechanism. PC cell lines that displayed high expression levels of ARK5 had low sensitivity to gemcitabine (GEM). Suppression of ARK5 increased sensitivity to GEM in PC cell lines. Western blotting and immunofluorescence showed that suppression of ARK5 upregulated expression of E-cadherin and downregulated vimentin expression. Suppression of ARK5 also inhibited the epithelial-mesenchymal transition (EMT) efficiency associated with GEM in PC cell lines and upregulation of ARK5 expression enhanced GEM resistance in PC cell lines by inducing Twist-mediated EMT. In addition, we found that suppression of ARK5 increased GEM sensitivity in PC cell lines under hypoxic conditions. ARK5 increases GEM resistance in PC cell lines via EMT, and suppression of ARK5 increases sensitivity to GEM under both normoxic and hypoxic conditions.
In forested ecosystems,complex forest canopies may redistribute and chemically modify the composition of rain water; this field within the study of ecological hydrology has recently attracted a ...considerable amount of attention.Throughfall is a major part of the rainfall penetrating the forest canopy and redistributes rainfall,and throughfall patterns can affect the distribution of soil water as well as the cycling and use of nutrients. Furthermore,spatial variability in the amount of throughfall can affect the concentration and deposition of solutes and the spatial distribution of nutrients in a forested landscape. Therefore,changes in throughfall beneath the canopy have very important effects on water balance,hydrological processes,and nutrient cycling within forest ecosystems. Many studies have analyzed the effects of the forest canopy on the interception and redistribution of rainfall,and the regularity of throughfall in different forest types; these studies provide a clearer understanding of the hydrological processes involved in rainfall interception and redistribution.However,few studies have addressed the horizontal spatial distribution of throughfall under a forest canopy. An examination of the spatial distribution of throughfall would provide important data to aid comprehension of the eco-hydrological processes and nutrient cycling within a forest. The goal of the present study was to determine the spatial heterogeneity of throughfallunder a forest canopy and to explore the ecological mechanisms of the effects of canopy structure in a Larix gmelinii forest on throughfall. Several factors,such as distance( of the sampling site to the trunk),canopy thickness,and leaf area index( LAI),can all influence the spatial distribution of throughfall. Throughfall was measured under a Larix gmelinii forest canopy at three locations-beneath the canopy itself,beneath the canopy edge,and in canopy gaps-during 19 rainfall events,using 38 rain gauges during the period of development of a stable canopy( Jul.-Aug. 2013). The spatial heterogeneity of both forest canopy structure( LAI and canopy thickness) and throughfall were analyzed using statistical methods. The spatial variability of throughfall in the Larix gmelinii forest analyzed here was estimated for different rainfall events. The results indicate that throughfall under a Larix gmelinii forest canopy was 148. 33 mm during the observation period,and accounts for 80.62% of the rainfall in an open field. The throughfall ratio increased with increasing amounts of rainfall,and the relationship between these could be described with a power function( P0.01). The coefficient of variance of throughfall decreased with increasing rainfall amounts,and the relationship between these could be described with a logarithmic function( P 0. 01). Structural characteristics of the canopy were found to be the most important factors controlling the spatial variability of throughfall,and the throughfall amount was significantly negatively correlated with the degree of complexity within the canopy structure( P 0. 01). The influence of distance was most important,and was significantly positively correlated with the throughfall ratio( r2= 0. 580,P 0. 01). Canopy thickness and LAI were significantly negatively correlated with the throughfall ratio( P0.01),but exhibited poor fitting results. When considering the ecological mechanism of throughfall,canopy thickness was the most important canopy structure / factor that affects the spatial redistribution of throughfall in a Larix gmelinii forest.
Wnt signaling plays essential role in mesenchymal stem cell (MSC) differentiation. Activation of Wnt signaling suppresses adipogenesis, but promotes osteogenesis in MSC. Adenomatous polyposis coli ...(APC) is a negative regulator of β-catenin and Wnt signaling activity. The mutation of APC gene leads to the activation of Wnt signaling and is responsible for tumorigenesis in APC(min) mouse; however, very few studies focused on its metabolic abnormalities. The present study reports a widespread metabolic disorder phenotype in APC(min) mice. The old APC(min) mice have decreased body weight and impaired adipogenesis, but severe hyperlipidemia, which mimic the phenotypes of Familial Adenomatous Polyposis (FAP), an inherited disease also caused by APC gene mutation in human. We found that the expression of lipid metabolism and free fat acids (FA) use genes in the white adipose tissue (WAT) of the APC(min) mice is much lower than those of control. The changed gene expression pattern may lead to the disability of circulatory lipid transportation and storage at WAT. Moreover, the APC(min) mice could not maintain the core body temperature in cold condition. PET-CT determination revealed that the BAT of APC(min) mice has significantly impaired ability to take up (18)FDG from the blood. Morphological studies identified that the brown adipocytes of APC(min) mice were filled with lipid droplets but fewer mitochondria. These results matched with the findings of impaired BAT function in APC(min) mice. Collectively, our study explores a new mechanism that explains abnormal metabolism in APC(min) mice and provides insights into studying the metabolic disorders of FAP patients.
Transcriptional coactivator with PDZ-binding motif (TAZ) is a key transcriptional mediator of Hippo signaling that has been recently reported to mediate Wnt-activated transcription and serve as a ...component to suppress canonical Wnt/β-catenin activity. The Bromodomain and Extra-terminal domain (BET) family of proteins can recognize the acetylated lysine chain on histones and plays a critical role in transcriptional regulation. However, the mechanisms underlying transcriptional repression by the BET bromodomain are poorly understood. Here, we found that BET bromodomain inhibition upregulated TAZ protein and its transcriptional output, independent of its well-established role as a mediator of Hippo and Wnt signaling. Additionally, JQ1, a synthetic BET inhibitor, suppressed Wnt/β-catenin activity by upregulating TAZ. Although JQ1 upregulated TAZ, which is known to promote cell proliferation, it drastically suppressed the growth of colon cancer cells by inducing cell cycle arrest. Collectively, our study identified an unexpected transcriptional repression function of the BET bromodomain and a novel mechanism for TAZ upregulation.
•BET bromodomain has an unexpected non-transcriptional regulatory function to suppress TAZ.•Inhibition of BET bromodomain upregulates TAZ in a manner independent of canonical Hippo and Wnt signaling.•Inhibition of BET bromodomain suppresses the proliferation of colon cancer cells via inducing cell cycle arrest.
G protein-coupled receptor 40 (GPR40) has become an attractive target for the treatment of diabetes since it was shown clinically to promote glucose-stimulated insulin secretion. Herein, we report ...our efforts to develop highly selective and potent GPR40 agonists with a dual mechanism of action, promoting both glucose-dependent insulin and incretin secretion. Employing strategies to increase polarity and the ratio of sp3/sp2 character of the chemotype, we identified BMS-986118 (compound 4), which showed potent and selective GPR40 agonist activity in vitro. In vivo, compound 4 demonstrated insulinotropic efficacy and GLP-1 secretory effects resulting in improved glucose control in acute animal models.
The solubility of bicalutamide, megestrol acetate, prednisolone, beclomethasone dipropionate, and clarithromycin in subcritical water (SBCW) at the temperature range from 383.15 to 443.15 K and ...constant pressure of 5.5 MPa were measured using a modified solvent–antisolvent method combined with SBCW technology. The chemical structures of these five kinds of solutes were stable after processed in SBCW at up to 443.15 K, which was demonstrated by Fourier transformed infrared analysis. The solubility of selected solutes increased exponentially as the temperature of the SBCW increased from 383.15 to 443.15 K. The obtained solubility data were correlated using a modified Apelblat model and the results of the predicted solubility show good agreement with the experimental value.
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