An esculentin-1 homolog from a dark-spotted frog (Pelophylax nigromaculatus) possesses antibacterial and immunoregulatory properties.

BACKGROUND: Esculentin-1, initially discovered in the skin secretions of pool frogs (Pelophylax lessonae), has demonstrated broad-spectrum antimicrobial activity; however, its immunomodulatory properties have received little attention. RESULTS: In the present study, esculentin-1 cDNA was identified by analysing the skin transcriptome of the dark-spotted frog (Pelophylax nigromaculatus). Esculentin-1 from this species (esculentin-1PN) encompasses a signal peptide, an acidic spacer peptide, and a mature peptide. Sequence alignments with other amphibian esculentins-1 demonstrated conservation of the peptide, and phylogenetic tree analysis revealed its closest genetic affinity to esculentin-1P, derived from the Fukien gold-striped pond frog (Pelophylax fukienensis). Esculentin-1PN transcripts were observed in various tissues, with the skin exhibiting the highest mRNA levels. Synthetic esculentin-1PN demonstrated antibacterial activity against various pathogens, and esculentin-1PN exhibited bactericidal activity by disrupting cell membrane integrity and hydrolyzing genomic DNA. Esculentin-1PN did not stimulate chemotaxis in RAW264.7, a murine leukemic monocyte/macrophage cell line. However, it amplified the respiratory burst and augmented the pro-inflammatory cytokine gene (TNF-α and IL-1ß) expression in RAW264.7 cells. CONCLUSIONS: This novel finding highlights the immunomodulatory activity of esculentin-1PN on immune cells.

The vesicular transporter STX11 governs ATGL-mediated hepatic lipolysis and lipophagy.

Hepatic lipid accumulation is closely associated with nonalcoholic fatty liver disease (NAFLD). Adipose-triglyceride-lipase (ATGL) regulates triglyceride hydrolysis and maintains energy homeostasis in hepatocytes. Identifying key factors in the regulation of ATGL will help tackle hepatic lipid accumulation and related metabolic diseases. Herein, we demonstrate that syntaxin11 (STX11), a member of the SNARE family, generally expressed in immune cells, mediates lipid metabolism by binding to ATGL and inhibiting lipid droplet degradation and lipid autophagy in hepatocytes. Our data show that the C-terminal of STX11 and the patatin domain-containing segment of ATGL have direct physical interactions. Thus, STX11 overexpression prevents spatial translocation of ATGL onto LDs by recruitment of ATGL to the ER. Conversely, STX11 deficiency in hepatocytes promotes lipid hydrolysis, and the ATGL-SIRT1 signaling pathway enhances lipophagy. Overall, this study uncovered that the regulation of lipolysis and lipophagy is achieved by STX11 through the attenuation of ATGL action in hepatocytes.

DECR1 directly activates HSL to promote lipolysis in cervical cancer cells.

Fatty acids have a high turnover rate in cancer cells to supply energy for tumor growth and proliferation. Lipolysis is particularly important for the regulation of fatty acid homeostasis and in the maintenance of cancer cells. In the current study, we explored how 2,4-Dienoyl-CoA reductase (DECR1), a short-chain dehydrogenase/reductase associated with mitochondrial and cytoplasmic compartments, promotes cancer cell growth. We report that DECR1 overexpression significantly reduced the triglyceride (TAG) content in HeLa cells; conversely, DECR1 silencing increased intracellular TAG content. Subsequently, our experiments demonstrate that DECR1 promotes lipolysis via effects on hormone sensitive lipase (HSL). The direct interaction of DECR1 with HSL increases HSL phosphorylation and activity, facilitating the translocation of HSL to lipid droplets. The ensuing enhancement of lipolysis thus increases the release of free fatty acids. Downstream effects include the promotion of cervical cancer cell migration and growth, associated with the enhanced levels of p62 protein. In summary, high levels of DECR1 serves to enhance lipolysis and the release of fatty acid energy stores to support cervical cancer cell growth.

First Report of blaNDM-1 Bearing IncX3 Plasmid in Clinically Isolated ST11 Klebsiella pneumoniae from Pakistan.

The New Delhi Metallo-ß-lactamase (NDM) is among the most threatening forms of carbapenemases produced by K. pneumoniae, well-known to cause severe worldwide infections. The molecular epidemiology of blaNDM-1-harboring K. pneumoniae is not well elucidated in Pakistan. Herein, we aim to determine the antibiotics-resistance profile, genes type, molecular type, and plasmid analysis of 125 clinically isolated K. pneumoniae strains from urine samples during July 2018 to January 2019 in Pakistan. A total of 34 (27.2%) K. pneumoniae isolates were carbapenemases producers, and 23 (18.4%) harbored the blaNDM-1 gene. The other carbapenemases encoding genes, i.e., blaIMP-1 (7.2%), blaVIM-1 (3.2%), and blaOXA-48 (2.4%) were also detected. The Multi Locus Sequence Typing (MLST) results revealed that all blaNDM-1-harboring isolates were ST11. The other sequence types detected were ST1, ST37, and ST105. The cluster analysis of Xbal Pulsed Field Gel Electrophoresis (PFGE) revealed variation amongst the clusters of the identical sequence type isolates. The blaNDM-1 gene in all of the isolates was located on a 45-kb IncX3 plasmid, successfully transconjugated. For the first time, blaNDM-1-bearing IncX3 plasmids were identified from Pakistan, and this might be a new primary vehicle for disseminating blaNDM-1 in Enterobacteriaceae as it has a high rate of transferability.

Dynamic cyclic behaviors of lipid droplets monitored by two-photon fluorescence probe with high photostability.

Lipid droplets (LDs) are organelles featuring in intracellular storage of neutral lipids, which are involved with many biological processes. Monitoring the dynamical cyclic behaviors of cellular LDs poses great importance for early disease diagnosis. Herein, two coumarin-based LDs-specific fluorescence probes exhibited "turn-on" and two-photon fluorescence triggered by breaking their aggregation states. By virtue of establishing oil/water emulsions model to simulate LDs, the behaviors of "turn-on" fluorescence were elucidated, which benefited for the enhancement of selectivity of the probes to LDs. Then, we highlight a LDs-specific coumarin-based two-photon probe (L1) with high photo-stability to monitor the dynamic cyclic behaviors of LDs in cells, unraveling the changes of LDs quantity during lipophagy and the reproduction of LDs to prevent lipotoxicity. We believe the probe offers a convenient way to investigate the biology of LDs.

Toxicological effects, mechanisms, and implied toxicity thresholds in the roots of Vicia faba L. seedlings grown in copper-contaminated soil.

Copper (Cu) contamination has become a global concern because of industrial, agricultural, and other anthropogenic activities. In the present experiments, the toxicological effects, mechanisms, and potential toxicity thresholds were investigated in the roots of Vicia faba L. seedlings that were cultivated in Cu-amended soils (0, 6.25, 12.5, 25, 50, 100, 200, 400, and 600 mg kg(-1)) for 20 days, based on an analysis of the soil physicochemical properties, native Cu, available Cu, and root-enriched Cu contents. The superoxide dismutase (SOD), ascorbate peroxidase (APX), and guaiacol peroxidase (POD) isozymes and activities, as well as glutathione (GSH) and heat shock protein 70 (HSP70), changed like biphasic dose-response curves, cooperating to control the redox homeostasis. The APX and POD enzymes exhibited enhanced activities and became H2O2 scavengers primarily when the catalase (CAT) activities tended to decrease. Endoprotease (EP) isozymes and activities might be enhanced to degrade carbonylated proteins and alleviate metabolic disturbance in the roots. Additionally, HSP70 may not be suitable as a biomarker for relatively higher soil Cu concentrations and relatively longer exposure times for the roots. As a result, the isozymes and activities of SOD, CAT, and EP, as well as GSH, can be adopted as the most sensitive biomarkers. The toxicity threshold is estimated as 0.76-1.21 mg kg(-1) of available Cu in the soils or 25.04-36.65 µg Cu g(-1) dry weights (DW) in the roots.