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Spontaneous apoptosis of neutrophils plays a key role in maintaining immune homeostasis and resolving inflammation. However, the mechanism triggering this apoptosis remains obscure. In the present study, we performed a global metabolomics analysis of neutrophils undergoing spontaneous apoptosis by using hydrophilic interaction chromatography ultra-high-performance liquid chromatography-tandem quadrupole/time-of-flight mass spectrometry and found 23 metabolites and 42 related pathways that were altered in these cells. Among them, glutathione, which is known to be involved in apoptosis, was particularly interesting. We found that L -pyroglutamic acid, glutamate, and their glutathione-mediated embolic pathways were all changed. Our findings confirmed the glutathione levels decreased in apoptotic neutrophils. Exogenous glutathione and LPS treatment delayed neutrophil apoptosis and decreased the levels of pro-apoptotic protein caspase-3. γ-glutamylcyclotransferase, 5-oxoprolinase, and ChaC1, which participated in glutathione degradation, were all activated. At the same time, the down-regulation of ATP production suggested the activity of glutathione biosynthesis may be attenuated even if glutamate-cysteine ligase and glutathione synthase, which are two ATP-dependent enzymes participating in glutathione biosynthesis, were enhanced. To our knowledge, this is the first report highlighting a global metabolomics analysis using hydrophilic interaction chromatography ultra-high-performance liquid chromatography-tandem quadrupole/time-of-flight mass spectrometry and the potential involvement of glutathione depletion in spontaneous apoptosis of neutrophils demonstrating that LPS could delay this process.

Solute carrier family 20 member 1 (SLC20A1) is a sodium/inorganic phosphate symporter, which has been identified as a prognostic marker in several types of cancer, including pancreatic cancer. However, to the best of our knowledge, the association between SLC20A1 expression and cancer stem cell (CSC) markers, such as aldehyde dehydrogenase 1 (ALDH1), in pancreatic ductal adenocarcinoma (PDAC), and the role of SLC20A1 in PDAC CSCs remains unclear. In the present study, a genomic dataset of primary pancreatic cancer (The Cancer Genome Atlas, Pan-Cancer Atlas) was downloaded and analyzed. Kaplan-Meier analysis and multivariate Cox regression analysis were performed to evaluate the overall survival, disease-specific survival (DSS), disease-free interval (DFI) and progression-free interval (PFI). Subsequently, SLC20A1 small interfering RNA (siRNA) knockdown (KD) was induced in the PANC-1 and MIA-PaCa-2 PDAC cell lines, and in sorted high ALDH1 activity (ALDH1high) cells, after which, cell viability, in vitro tumor sphere formation, cell death and caspase-3 activity were examined. The results revealed that patients with high expression of SLC20A1 (SLC20A1high) at tumor stage I had a poor prognosis compared with patients with low expression of SLC20A1 (SLC20A1low) in terms of DSS, DFI and PFI. In addition, patients with high expression of SLC20A1 and ALDH1A3 (SLC20A1highALDH1A3high) exhibited poorer clinical outcomes than patients with high expression of SLC20A1 and low expression of ALDH1A3 (SLC20A1highALDH1A3low), low expression of SLC20A1 and high expression of ALDH1A3 (SLC20A1lowALDH1A3high) and SLC20A1lowALDH1A3low. SLC20A1 siRNA KD in ALDH1high cells isolated from PANC-1 and MIA-PaCa-2 cell lines resulted in suppression of in vitro tumorsphere formation, and enhancement of cell death and caspase-3 activity. These results suggested that SLC20A1 was involved in cell survival via the suppression of caspase-3-dependent apoptosis, and contributed to cancer progression and poor clinical outcomes in PDAC. In conclusion, SLC20A1 may be used as a prognostic marker and novel therapeutic target of ALDH1-positive pancreatic CSCs. [ABSTRACT FROM AUTHOR]

The mitochondrial toxin rotenone exerts cytotoxicity via overproduction of reactive oxygen species (ROS) and depolarization of the mitochondrial membrane. We investigated the effects of rotenone (12.5, 25, 50, 100 nmol/L) on mitochondrial biogenesis and the potential roles of ROS production in SH-SY5Y cells. Mitochondrial biogenesis was assessed by counting the number of mitochondria, determining protein expression of peroxisome proliferator-activated receptor γ coactivator α (PGC1-α) and its regulator, SIRT1, and oxygen consumption. ROS production and levels of reduced glutathione (GSH) and oxidized glutathione(GSSG) were also determined. Compared with controls, rotenone (12.5 nmol/L) significantly increased the quantity of mitochondria and amount of oxygen consumption, whereas rotenone at >12.5 nmol/L decreased the quantity of mitochondria and amount of oxygen consumption. GSH contents and GSH/GSSG were also significantly enhanced by rotenone at 12.5 nmol/L and decreased by rotenone at >12.5 nmol/L. Except for ROS production and SIRT1 protein expression, all concentration–response relationships showed a typical inverted-U shape. ROS production was continually increased in cells treated with rotenone. These data indicate that low concentrations of rotenone can induce mitohormesis, which may be attributed to ROS production.

Recent evidence indicates the existence of subpopulations of myeloid-derived suppressor cells (MDSCs) with distinct phenotypes and functions. Here, we characterized the role of MDSC subpopulations in the pathogenesis of autoimmune arthritis in a collagen-induced arthritis (CIA) mouse model. The splenic CD11b+Gr-1+ MDSC population expanded in CIA mice, and these cells could be subdivided into polymorphonuclear (PMN) and mononuclear (MO) MDSC subpopulations based on Ly6C and Ly6G expression. During CIA, the proportion of splenic MO-MDSCs was increased in association with the severity of joint inflammation, while PMN-MDSCs were decreased. MO-MDSCs expressed higher levels of surface CD40 and CD86 protein, but lower levels of Il10, Tgfb1, Ccr5, and Cxcr2 mRNA. PMN-MDSCs exhibited a more potent capacity to suppress polyclonal T-cell proliferation in vitro, compared with MO-MDSCs. Moreover, the adoptive transfer of PMN-MDSCs, but not MO-MDSCs, decreased joint inflammation, accompanied by reduced levels of serum cytokine secretion and the frequencies of Th1 and Th17 cells in draining lymph nodes. These results suggest that there could be a shift from potently suppressive PMN-MDSCs to poorly suppressive MO-MDSCs during the development of experimental arthritis, which might reflect the failure of expanded MDSCs to suppress autoimmune arthritis. [ABSTRACT FROM AUTHOR]

Highlights: [•] OECCM could protect ASTs against H2O2 induced injury. [•] Its mechanism might be related to against ROS generation, inhibit Ca2+ overloading and stabilize mitochondrial function. [•] OECCM is a promising clinical treatment for neuronal injury. [ABSTRACT FROM AUTHOR]

Background/aim: CD58 is an immune adhesion molecule on the cellular surface. It was previously found that a high expression of CD58 predicted a poor prognosis of patients with lower-grade gliomas. Therefore, the aim of this paper was to investigate the association between CD58 and breast cancer., Materials and Methods: CD58 gene expression data downloaded from cBioPortal was compared between the different subtypes of breast cancer. Clinical prognosis was examined using Kaplan-Meier analysis and multivariable Cox regression analysis. The association between CD58 expression and immune cell infiltration was estimated using the TIMER 2.0 web platform. Finally, the tumour sphere formation of aldehyde dehydrogenase 1 (ALDH1) high basal-like breast cancer stem cells in which CD58 was knocked down using siRNA was measured., Results: CD58 mRNA was mainly enriched in claudin-low and basal-like subtypes. The high expression of CD58 predicted a good prognosis in patients with luminal A and luminal B breast cancer. This prediction may be due to the association of immune cell infiltration with CD58. Notably, patients with luminal A breast cancer with a high expression of CD58 in association with ALDH1A3 exhibited a good prognosis; however, this did not apply to patients with basal-like breast cancer. The in vitro experiments revealed that knockdown of CD58 inhibited the tumour sphere formation ability of ALDH1 high basal-like cancer cells., Conclusion: CD58 may function as a potential prognostic biomarker and therapeutic target in ALDH-positive basal-like cancer stem cells., (Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Objective To study the expression of Notch signaling pathway-related microRNAs in T cells of collagen-induced arthritis (CIA) mice. Methods First, the mice model was established with bovine collagen type II and immune adjuvant DBA/1 J mice. Next, peripheral blood mononuclear cells (PBMCs) were isolated and CD4 + T and CD8 + T cells were sorted from the peripheral blood, spleen, lymph node in CIA mice by using flow cytometry. Finally, real-time quantitative PCR was used to detect the expression levels of Notch signaling pathway-related microRNAs in PBMCs and T cells. Results The levels of miR-200b-3p, miR-30c-5p, miR-30b-5p and miR-23b-3p in the PBMCs of CIA mice were significantly decreased; miR-200b-3p, miR-30c-5p and miR-30b-5p in peripheral blood, spleen, lymph node CD4 + T cells and CD8 + T cells of CIA mice was not significantly different from that of normal controls; but the expression level of miR-23b-3p in peripheral blood and spleen CD4 + T cells of CIA mice was significantly lower than that of normal control mice. Conclusion miR-23b-3p may be involved in the immunoregulation of Notch signaling to T cells of CIA mice.

Objective: To investigate the effects of lipopolysaccharide (LPS) and phytohaemagglutinin (PHA) on the level of microRNAs in mouse peripheral blood mononuclear cells (PBMCs)., Methods: The mouse PBMCs were cultured in vitro and stimulated with 100 ng/mL LPS for 1 hour or 2 hours and 2.5 μg/mL phytohaemagglutinin (PHA) for 2 hours or 4 hours, respectively. The levels of miR-9, miR-122-3p, miR-181d and miR-342-3p in both PBMCs and culture supernatants were determined by real-time quantitative PCR (qRT-PCR)., Results: The levels of miR-9, miR-122-3p, miR-181d and miR-342-3p in PBMCs and culture supernatants had no significant difference between blank control and LPS stimulation group, nor did between LPS stimulation 2 hours group and 1 hour group. The levels of miR-9, miR-122-3p and miR-342-3p in PBMCs and culture supernatant had no significant difference between blank control and PHA stimulation group, nor did between PHA stimulation 4 hours group and 2 hours group. However, compared with blank control, the expression of miR-181d significantly increased after PHA stimulation, while the time of stimulation did not affect the miR-181d level significantly., Conclusion: The stimulation of PHA could promote the expression and secretion of miR-181d in mouse PBMCs.