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Journal of Immunology Research 2021We recently showed that both nontypeable (NTHi) and its surface plasminogen- (Plg-) binding proteins interact with lipoprotein(a) (Lp(a)) in a lysine-dependent manner....
We recently showed that both nontypeable (NTHi) and its surface plasminogen- (Plg-) binding proteins interact with lipoprotein(a) (Lp(a)) in a lysine-dependent manner. Because Lp(a) can be taken up by macrophages, we postulated that it serves as an opsonin to enhance phagocytosis of NTHi by macrophages. Based on colony-forming unit (CFU) counts, Lp(a) was found to increase U937 macrophage-mediated phagocytosis of NTHi49247 and NTHi49766 by 34% and 43%, respectively, after 120 min. In contrast, Lp(a) did not enhance phagocytosis of BL21 or JM109, which were unable to bind to Lp(a). As with U937 macrophages, Lp(a) was capable of increasing phagocytosis of NTHi49247 by peripheral blood mononuclear cell-derived macrophages. Opsonic phagocytosis by Lp(a) was inhibited by the addition of recombinant kringle IV type 10 (rKIV), a lysine-binding competitor; moreover, Lp(a) did not increase phagocytosis of NTHi by U937 macrophages that were pretreated with a monoclonal antibody against the scavenger receptor CD36. Taken together, our observation suggests that Lp(a) might serve as a lysine-binding opsonin to assist macrophages in rapid recognition and phagocytosis of NTHi.
Topics: CD36 Antigens; Cell Line; Cell Line, Tumor; Escherichia coli; Haemophilus Infections; Haemophilus influenzae; Humans; Leukocytes, Mononuclear; Lipoprotein(a); Macrophages; Opsonin Proteins; Phagocytosis; U937 Cells
PubMed: 34765679
DOI: 10.1155/2021/2185568 -
Bioscience Reports Jun 2021Acute leukemia is a hematological malignant tumor. Long non-coding RNA urothelial cancer-associated 1 (UCA1) is involved in the chemo-resistance of diverse cancers, but...
Acute leukemia is a hematological malignant tumor. Long non-coding RNA urothelial cancer-associated 1 (UCA1) is involved in the chemo-resistance of diverse cancers, but it is unclear whether UCA1 is associated with the sensitivity of acute leukemia cells to daunorubicin (DNR). DNR (100 nM) was selected for functional analysis. The viability, cell cycle progression, apoptosis, and invasion of treated acute leukemia cells (HL-60 and U-937) were evaluated by cell counting kit-8 (CCK-8) assay, flow cytometry assay, or transwell assay. Protein levels were detected with Western blot analysis. Expression patterns of UCA1 and miR-613 were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between UCA1 and microRNA-613 (miR-613) was verified by dual-luciferase reporter assay. We observed that UCA1 expression was elevated in HL-60 and U-937cells. DNR constrained viability, cell cycle progression, invasion, and facilitated apoptosis of HL-60 and U-937 cells in a dose-dependent manner, but these impacts mediated by DNR were reverted after UCA1 overexpression. MiR-613 was down-regulated in HL-60 and U-937 cells, and UCA1 was verified as a miR-613 sponge. MiR-613 inhibitor reversed DNR treatment-mediated effects on viability, cell cycle progression, apoptosis, and invasion of HL-60 and U-937 cells, but these impacts mediated by miR-613 inhibitor were counteracted after UCA1 inhibition. Notably, the inactivation of the PI3K/AKT pathway caused by DNR treatment was reversed after miR-613 inhibitor introduction, but this influence mediated by miR-613 inhibitor was offset after UCA1 knockdown. In conclusion, UCA1 up-regulation facilitated the resistance of acute leukemia cells to DNR via the PI3K/AKT pathway by sponging miR-613.
Topics: Antibiotics, Antineoplastic; Apoptosis; Cell Cycle; Cell Movement; Cell Proliferation; Daunorubicin; Drug Resistance, Neoplasm; Gene Expression Regulation, Leukemic; HL-60 Cells; Humans; Leukemia; MicroRNAs; Neoplasm Invasiveness; Phosphatidylinositol 3-Kinase; Proto-Oncogene Proteins c-akt; RNA, Long Noncoding; Signal Transduction; U937 Cells
PubMed: 33969374
DOI: 10.1042/BSR20201389 -
Scientific Reports Jul 2020Loss of estrogens at menopause is a major cause of osteoporosis and increased fracture risk. Estrogens protect against bone loss by decreasing osteoclast number through...
Loss of estrogens at menopause is a major cause of osteoporosis and increased fracture risk. Estrogens protect against bone loss by decreasing osteoclast number through direct actions on cells of the myeloid lineage. Here, we investigated the molecular mechanism of this effect. We report that 17β-estradiol (E) decreased osteoclast number by promoting the apoptosis of early osteoclast progenitors, but not mature osteoclasts. This effect was abrogated in cells lacking Bak/Bax-two pro-apoptotic members of the Bcl-2 family of proteins required for mitochondrial apoptotic death. FasL has been previously implicated in the pro-apoptotic actions of E. However, we show herein that FasL-deficient mice lose bone mass following ovariectomy indistinguishably from FasL-intact controls, indicating that FasL is not a major contributor to the anti-osteoclastogenic actions of estrogens. Instead, using microarray analysis we have elucidated that ERα-mediated estrogen signaling in osteoclast progenitors decreases "oxidative phosphorylation" and the expression of mitochondria complex I genes. Additionally, E decreased the activity of complex I and oxygen consumption rate. Similar to E, the complex I inhibitor Rotenone decreased osteoclastogenesis by promoting osteoclast progenitor apoptosis via Bak/Bax. These findings demonstrate that estrogens decrease osteoclast number by attenuating respiration, and thereby, promoting mitochondrial apoptotic death of early osteoclast progenitors.
Topics: Adenosine Triphosphate; Animals; Apoptosis; Biomarkers; Bone Density; Bone and Bones; Cell Count; Cell Differentiation; Cells, Cultured; Estrogens; Female; Gene Expression Regulation; Mice; Mice, Knockout; Mitochondria; Monocyte-Macrophage Precursor Cells; Osteoclasts; Osteogenesis; Oxidative Phosphorylation; Signal Transduction
PubMed: 32686739
DOI: 10.1038/s41598-020-68890-7 -
Pharmacological Research Jul 2019Poly(ADP-ribose) polymerase (PARP) is involved in the pathogenesis of cell dysfunction, inflammation and organ failure during septic shock. The goal of the current study...
The PARP inhibitor olaparib exerts beneficial effects in mice subjected to cecal ligature and puncture and in cells subjected to oxidative stress without impairing DNA integrity: A potential opportunity for repurposing a clinically used oncological drug for the experimental therapy of sepsis.
Poly(ADP-ribose) polymerase (PARP) is involved in the pathogenesis of cell dysfunction, inflammation and organ failure during septic shock. The goal of the current study was to investigate the efficacy and safety of the clinically approved PARP inhibitor olaparib in experimental models of oxidative stress in vitro and in sepsis in vivo. In mice subjected to cecal ligation and puncture (CLP) organ injury markers, circulating and splenic immune cell distributions, circulating mediators, DNA integrity and survival was measured. In U937 cells subjected to oxidative stress, cellular bioenergetics, viability and DNA integrity were measured. Olaparib was used to inhibit PARP. The results show that in adult male mice subjected to CLP, olaparib (1-10 mg/kg i.p.) improved multiorgan dysfunction. Olaparib treatment reduced the degree of bacterial CFUs. Olaparib attenuated the increases in the levels of several circulating mediators in the plasma. In the spleen, the number of CD4+ and CD8+ lymphocytes were reduced in response to CLP; this reduction was inhibited by olaparib treatment. Treg but not Th17 lymphocytes increased in response to CLP; these cell populations were reduced in sepsis when the animals received olaparib. The Th17/Treg ratio was lower in CLP-olaparib group than in the CLP control group. Analysis of miRNA expression identified a multitude of changes in spleen and circulating white blood cell miRNA levels after CLP; olaparib treatment selectively modulated these responses. Olaparib extended the survival rate of mice subjected to CLP. In contrast to males, in female mice olaparib did not have significant protective effects in CLP. In aged mice olaparib exerted beneficial effects that were less pronounced than the effects obtained in young adult males. In in vitro experiments in U937 cells subjected to oxidative stress, olaparib (1-100 μM) inhibited PARP activity, protected against the loss of cell viability, preserved NAD levels and improved cellular bioenergetics. In none of the in vivo or in vitro experiments did we observe any adverse effects of olaparib on nuclear or mitochondrial DNA integrity. In conclusion, olaparib improves organ function and extends survival in septic shock. Repurposing and eventual clinical introduction of this clinically approved PARP inhibitor may be warranted for the experimental therapy of septic shock.
Topics: Animals; Anti-Inflammatory Agents; Cecum; Cytokines; DNA; Drug Repositioning; Female; Humans; Ligation; Liver; Lung; Lymphocyte Count; Male; Mice, Inbred C57BL; Oxidative Stress; Phthalazines; Piperazines; Poly(ADP-ribose) Polymerase Inhibitors; Punctures; Sepsis; Spleen; U937 Cells
PubMed: 31071432
DOI: 10.1016/j.phrs.2019.104263 -
Medical Science Monitor : International... Oct 2019BACKGROUND Acute myeloid leukemia (AML) is associated with a high relapse rate and poor prognosis. This study aimed to use weighted gene coexpression network analysis...
Weighted Gene Coexpression Network Analysis Identifies Cysteine-Rich Intestinal Protein 1 (CRIP1) as a Prognostic Gene Associated with Relapse in Patients with Acute Myeloid Leukemia.
BACKGROUND Acute myeloid leukemia (AML) is associated with a high relapse rate and poor prognosis. This study aimed to use weighted gene coexpression network analysis (WGCNA) of gene coexpression networks to identify candidate prognostic biomarker genes in patients with AML and to investigate the expression of these genes in the human U937 cell line in vitro. MATERIAL AND METHODS RNA-seq data were retrieved from the Cancer Genome Atlas (TCGA) and included bone marrow samples and survival data of patients with AML (N=151), patients who did not relapse after treatment (N=119), and patients with relapse (N=40). Differentially expressed genes were identified, WGCNA was used to detect functional modules, and survival analysis was performed. The Cell Counting Kit-8 (CCK-8) assay investigated the proliferation of U937 cells transfected with short hairpin RNAs (shRNAs), shCRIP1, shHIST1H1C, and shHIST1H1E. RNA-seq analysis identified gene expression following CRIP1 knockdown. RESULTS Eighty-two genes were associated with both relapse and prognosis in patients with AML. There were two prognosis-related gene modules in the coexpression network. In the coexpression network, the histone cluster 1 H1 family member gene, HIST1H1C had the maximum relapse fold change, HIST1H1E had the lowest survival p-value, and the cysteine-rich intestinal protein 1 (CRIP1) gene had the most edge numbers and was significantly associated with poor prognosis (P=0.0165786). RNA-seq data showed that there was a significant difference in gene expression after CRIP1 knockdown in U937 cells. CONCLUSIONS WGCNA of gene coexpression networks identified CRIP1 as a potential prognostic biomarker gene in patients with AML.
Topics: Carrier Proteins; Cell Proliferation; China; Computational Biology; Databases, Genetic; Female; Gene Expression Profiling; Gene Regulatory Networks; Humans; LIM Domain Proteins; Leukemia, Myeloid, Acute; Male; Prognosis; RNA, Long Noncoding; RNA, Small Interfering; Recurrence; U937 Cells
PubMed: 31577790
DOI: 10.12659/MSM.918092 -
International Immunopharmacology Jun 2024Patients with diabetes are particularly susceptible to Legionella pneumophila (LP) infection, but the exact pathogenesis of LP infection in diabetic patients is still...
BACKGROUND
Patients with diabetes are particularly susceptible to Legionella pneumophila (LP) infection, but the exact pathogenesis of LP infection in diabetic patients is still not fully understood. Herein, we investigated the effect of diabetes on immune function during LP infection in vitro and in vivo.
METHODS
The time course of LP infection in macrophages under normal and high-glucose (HG) conditions was examined in vitro. Western blot was used to determine nucleotide-binding oligomerization domain 1 (NOD1), kinase 1/2 (ERK1/2), mitogen-activated protein kinase p38 (MAPK p38), and c-Jun N-terminal kinases (JNK). Enzyme-linked immunosorbent assay (ELISA) was used to assess the secretion of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Cell Counting Kit-8 (CCK8) assay assessed U937 cell viability after treating cells with different concentrations of high sugar medium and ML130 (NOD1 inhibitor). For the in vivo study, normal and streptozocin-induced diabetic guinea pigs were infected with LP for 6, 24, and 72 h, after which NOD1, MAPK-related signals, TNF-α, and IL-6 expression in lung tissues were assessed using immunohistochemistry, western blot, and RT-PCR.
RESULTS
HG attenuated the upregulation of NOD1 expression and reduced TNF-α and IL-6 secretion caused by LP compared with LP-infected cells exposed to normal glucose levels (all p < 0.05). In diabetic guinea pigs, HG inhibited the upregulation of NOD1 expression in lung tissues and the activation of p38, ERK1/2, and cJNK caused by LP infection compared to control pigs (all p < 0.05).
CONCLUSION
HG attenuates the response of macrophages to LP infection by inhibiting NOD1 upregulation and the activation of MAPK signaling.
Topics: Nod1 Signaling Adaptor Protein; Animals; Humans; Macrophages; Legionella pneumophila; Glucose; Guinea Pigs; Male; Interleukin-6; Legionnaires' Disease; Diabetes Mellitus, Experimental; MAP Kinase Signaling System; U937 Cells; Tumor Necrosis Factor-alpha; Mice
PubMed: 38749333
DOI: 10.1016/j.intimp.2024.112254 -
Zhonghua Xue Ye Xue Za Zhi = Zhonghua... May 2023To investigate the effect of the AML1-ETO (AE) fusion gene on the biological function of U937 leukemia cells by establishing a leukemia cell model that induces AE...
To investigate the effect of the AML1-ETO (AE) fusion gene on the biological function of U937 leukemia cells by establishing a leukemia cell model that induces AE fusion gene expression. The doxycycline (Dox) -dependent expression of the AE fusion gene in the U937 cell line (U937-AE) were established using a lentivirus vector system. The Cell Counting Kit 8 methods, including the PI and sidanilide induction, were used to detect cell proliferation, cell cycle-induced differentiation assays, respectively. The effect of the AE fusion gene on the biological function of U937-AE cells was preliminarily explored using transcriptome sequencing and metabonomic sequencing. ①The Dox-dependent Tet-on regulatory system was successfully constructed to regulate the stable AE fusion gene expression in U937-AE cells. ②Cell proliferation slowed down and the cell proliferation rate with AE expression (3.47±0.07) was lower than AE non-expression (3.86 ± 0.05) after inducing the AE fusion gene expression for 24 h (<0.05). The proportion of cells in the G(0)/G(1) phase in the cell cycle increased, with AE expression [ (63.45±3.10) %) ] was higher than AE non-expression [ (41.36± 9.56) %] (<0.05). The proportion of cells expressing CD13 and CD14 decreased with the expression of AE. The AE negative group is significantly higher than the AE positive group (<0.05). ③The enrichment analysis of the transcriptome sequencing gene set revealed significantly enriched quiescence, nuclear factor kappa-light-chain-enhancer of activated B cells, interferon-α/γ, and other inflammatory response and immune regulation signals after AE expression. ④Disorder of fatty acid metabolism of U937-AE cells occurred under the influence of AE. The concentration of the medium and short-chain fatty acid acylcarnitine metabolites decreased in cells with AE expressing, propionyl L-carnitine, wherein those with AE expression (0.46±0.13) were lower than those with AE non-expression (1.00±0.27) (<0.05). The metabolite concentration of some long-chain fatty acid acylcarnitine increased in cells with AE expressing tetradecanoyl carnitine, wherein those with AE expression (1.26±0.01) were higher than those with AE non-expression (1.00±0.05) (<0.05) . This study successfully established a leukemia cell model that can induce AE expression. The AE expression blocked the cell cycle and inhibited cell differentiation. The gene sets related to the inflammatory reactions was significantly enriched in U937-AE cells that express AE, and fatty acid metabolism was disordered.
Topics: Humans; U937 Cells; RUNX1 Translocation Partner 1 Protein; Leukemia; Core Binding Factor Alpha 2 Subunit; Oncogene Proteins, Fusion; Leukemia, Myeloid, Acute
PubMed: 37550185
DOI: 10.3760/cma.j.issn.0253-2727.2023.05.003