scholarly journals Airborne particulate matters induce thrombopoiesis from megakaryocytes through regulating mitochondrial oxidative phosphorylation

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Xiaoting Jin ◽  
Hongyan Yu ◽  
Baoqiang Wang ◽  
Zhendong Sun ◽  
Ze Zhang ◽  
...  

Abstract Background Although airborne fine particulate matter (PM) pollution has been demonstrated as an independent risk factor for pulmonary and cardiovascular diseases, their currently-available toxicological data is still far from sufficient to explain the cause-and-effect. Platelets can regulate a variety of physiological and pathological processes, and the epidemiological study has indicated a positive association between PM exposure and the increased number of circulative platelets. As one of the target organs for PM pollution, the lung has been found to be involved in the storage of platelet progenitor cells (i.e. megakaryocytes) and thrombopoiesis. Whether PM exposure influences thrombopoiesis or not is thus explored in the present study by investigating the differentiation of megakaryocytes upon PM treatment. Results The results showed that PM exposure promoted the thrombopoiesis in an exposure concentration-dependent manner. PM exposure induced the megakaryocytic maturation and development by causing cell morphological changes, occurrence of DNA ploidy, and alteration in the expressions of biomarkers for platelet formation. The proteomics assay demonstrated that the main metabolic pathway regulating PM-incurred alteration of megakaryocytic maturation and thrombopoiesis was the mitochondrial oxidative phosphorylation (OXPHOS) process. Furthermore, airborne PM sample promoted-thrombopoiesis from megakaryocytes was related to particle size, but independent of sampling filters. Conclusion The findings for the first time unveil the potential perturbation of haze exposure in thrombopoiesis from megakaryocytes by regulating mitochondrial OXPHOS. The substantial evidence on haze particle-incurred hematotoxicity obtained herein provided new insights for assessing the hazardous health risks from PM pollution.

Crustaceana ◽  
2021 ◽  
Vol 94 (7) ◽  
pp. 855-863
Author(s):  
Ming Zhao ◽  
Fengying Zhang ◽  
Wei Wang ◽  
Zhiqiang Liu ◽  
Lingbo Ma

Abstract The mud crab Scylla paramamosain is one of the economically important aquaculture species in China. The larval development of the mud crab is characterized by two significant morphological changes, from the 5th zoea (Z5) to the megalopa (M) stage and from the M to the first juvenile crab (C1) stage. In this study, we found that methyl farnesoate (MF) could prohibit the Z5 to M metamorphosis in a concentration-dependent manner, and that a concentration of 10 μM MF could completely prohibit the Z5 metamorphosis. Farnesoic acid (FA) could also prohibit the Z5 metamorphosis, but its effects seemed to be concentration-independent. In addition, MF could delay rather than prohibit the M to C1 metamorphosis, while FA had no effect on the M to C1 metamorphosis at all. To summarize, it is hypothesized that either absence of MF and FA, or at least very low levels of these substances, might be necessary for a successful Z5 to M metamorphosis.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Larisa Emelyanova ◽  
Sirisha Gudlawar ◽  
Farhan Rizvi ◽  
Ekhson Holmuhamedov ◽  
Monika Thakur ◽  
...  

Introduction: Dronedarone (DR), a new antiarrhythmic drug, was recently shown to worsen heart failure (HF) and mortality in patients with atrial fibrillation and left ventricular dysfunction. However, the mechanism underlying the adverse effect is not known. Since, myocardium depends on mitochondrial oxidative phosphorylation (OXPHOS), we hypothesized that DR impairs mitochondrial function, which could further compropmise energetic reserves predisposing to worsening of HF and death in patients with HF. Methods: Mitochondria isolated from rat heart (2 month old, SD) were treated with DR (1, 5, 10, 20, 50 μM), and the effect on oxygen consumption rate (OCR) in State 3 (St 3, ADP stimulated), State 4 (St 4o, oligomycin) and following FCCP addition were determined using Seahorse XF24 Analyzer in the presence of glutamate/malate (complex I substrates) and succinate/rotenone (complex II substrate). Results: DR dose dependently reduced St 3 respiration both in the presence of complex I (Fig). In the presence of glutamate/malate, DR inhibited OCR by 16%, 20%, 25%, 39% and 100% at 1, 5, 10, 20, 50 μM, respectively, when compared to untreated control. At 20 μM, DR uncoupled mitochondria and increased St 4o respiration. DR at 50 μM was toxic with complete inhibition of OCR and loss of membrane potential. Similar results were observed when succinate/rotenone were used to assess complex II activity. Conclusion: DR has dose-dependent inhibitory effect on mitochondrial respiration, inhibiting OXPHOS at low concentration (1-10 μM), uncoupling at higher (20 μM) and toxic effect at 50 μM. Impairment of mitochondrial energetics could explain DR results reported in HF patients in clinical trials.


2020 ◽  
Vol 117 (7) ◽  
pp. 3397-3404 ◽  
Author(s):  
Zhaoming Liu ◽  
Zhisen Zhang ◽  
Zheming Wang ◽  
Biao Jin ◽  
Dongsheng Li ◽  
...  

Organisms use inorganic ions and macromolecules to regulate crystallization from amorphous precursors, endowing natural biominerals with complex morphologies and enhanced properties. The mechanisms by which modifiers enable these shape-preserving transformations are poorly understood. We used in situ liquid-phase transmission electron microscopy to follow the evolution from amorphous calcium carbonate to calcite in the presence of additives. A combination of contrast analysis and infrared spectroscopy shows that Mg ions, which are widely present in seawater and biological fluids, alter the transformation pathway in a concentration-dependent manner. The ions bring excess (structural) water into the amorphous bulk so that a direct transformation is triggered by dehydration in the absence of morphological changes. Molecular dynamics simulations suggest Mg-incorporated water induces structural fluctuations, allowing transformation without the need to nucleate a separate crystal. Thus, the obtained calcite retains the original morphology of the amorphous state, biomimetically achieving the morphological control of crystals seen in biominerals.


2009 ◽  
Vol 297 (5) ◽  
pp. F1168-F1173 ◽  
Author(s):  
Guillermo B. Silva ◽  
Jeffrey L. Garvin

Absorption of NaCl by the thick ascending limb (TAL) involves active transport and therefore depends on oxidative phosphorylation. Extracellular ATP has pleiotropic effects, including both stimulation and inhibition of transport and inhibition of oxidative phosphorylation. However, it is unclear whether ATP alters TAL transport and how this occurs. We hypothesized that ATP inhibits TAL Na absorption by reducing Na entry. We measured oxygen consumption in TAL suspensions. ATP reduced oxygen consumption in a concentration-dependent manner. The purinergic (P2) receptor antagonist suramin (300 μM) blocked the effect of ATP on TAL oxygen consumption (147 ± 15 vs. 146 ± 16 nmol O2·min−1·mg protein−1). In contrast, the adenosine receptor antagonist theophylline did not block the effect of ATP on oxygen consumption. When Na-K-2Cl cotransport and Na/H exchange were blocked with furosemide (100 μM) plus dimethyl amiloride (100 μM), ATP did not inhibit TAL oxygen consumption (from 78 ± 13 to 98 ± 5 nmol O2·min−1·mg protein−1). The Na ionophore nystatin (200 U/ml) increased TAL oxygen consumption to a similar extent in both ATP- and vehicle-treated samples (368 ± 41 vs. 397 ± 47 nmol O2·min−1·mg protein−1). The nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (3 mM) blocked the ATP effects on TAL oxygen consumption (157 ± 10 vs. 165 ± 15 nmol O2·min−1·mg protein−1). The P2X-selective receptor antagonist NF023 blocked the effect of ATP on oxygen consumption, whereas the P2X-selective agonist β-γ-Me-ATP reduced oxygen consumption in a concentration-dependent manner. We conclude that ATP inhibits Na transport-related oxygen consumption in TALs by reducing Na entry and P2X receptors and nitric oxide mediate this effect.


2011 ◽  
Vol 301 (3) ◽  
pp. H803-H812 ◽  
Author(s):  
Anne R. Diers ◽  
Katarzyna A. Broniowska ◽  
Victor M. Darley-Usmar ◽  
Neil Hogg

S-nitrosation of thiols in key proteins in cell signaling pathways is thought to be an important contributor to nitric oxide (NO)-dependent control of vascular (patho)physiology. Multiple metabolic enzymes are targets of both NO and S-nitrosation, including those involved in glycolysis and oxidative phosphorylation. Thus it is important to understand how these metabolic pathways are integrated by NO-dependent mechanisms. Here, we compared the effects of NO and S-nitrosation on both glycolysis and oxidative phosphorylation in bovine aortic endothelial cells using extracellular flux technology to determine common and unique points of regulation. The compound S-nitroso-l-cysteine (l-CysNO) was used to initiate intracellular S-nitrosation since it is transported into cells and results in stable S-nitrosation in vitro. Its effects were compared with the NO donor DetaNONOate (DetaNO). DetaNO treatment caused only a decrease in the reserve respiratory capacity; however, l-CysNO impaired both this parameter and basal respiration in a concentration-dependent manner. In addition, DetaNO stimulated extracellular acidification rate (ECAR), a surrogate marker of glycolysis, whereas l-CysNO stimulated ECAR at low concentrations and inhibited it at higher concentrations. Moreover, a temporal relationship between NO- and S-nitrosation-mediated effects on metabolism was identified, whereby NO caused a rapid impairment in mitochondrial function, which was eventually overwhelmed by S-nitrosation-dependent processes. Taken together, these results suggest that severe pharmacological nitrosative stress may differentially regulate metabolic pathways through both intracellular S-nitrosation and NO-dependent mechanisms. Moreover, these data provide insight into the role of NO and related compounds in vascular (patho)physiology.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Ping Hsiao ◽  
Chun-Shu Yu ◽  
Chien-Chih Yu ◽  
Jai-Sing Yang ◽  
Jo-Hua Chiang ◽  
...  

Bufalin was obtained from the skin and parotid venom glands of toad and has been shown to induce cytotoxic effects in various types of cancer cell lines, but there is no report to show that whether bufalin affects human skin cancer cells. The aim of this investigation was to study the effects of bufalin on human malignant melanoma A375.S2 cells and to elucidate possible mechanisms involved in induction of apoptosis. A375.S2 cells were treated with different concentrations of bufalin for a specific time period and investigated for effects on apoptotic analyses. Our results indicated that cells after exposure to bufalin significantly decreased cell viability, and induced cell morphological changes and chromatin condensation in a concentration-dependent manner. Flow cytometric assays indicated that bufalin promoted ROS productions, loss of mitochondrial membrane potential (ΔΨm), intracellular Ca2+release, and nitric oxide (NO) formations in A375.S2 cells. Additionally, the apoptotic induction of bufalin on A375.S2 cells resulted from mitochondrial dysfunction-related responses (disruption of theΔΨmand releases of cytochromec, AIF, and Endo G), and activations of caspase-3, caspase-8 and caspase-9 expressions. Based on those observations, we suggest that bufalin-triggered apoptosis in A375.S2 cells is correlated with extrinsic- and mitochondria-mediated multiple signal pathways.


1989 ◽  
Vol 109 (2) ◽  
pp. 863-875 ◽  
Author(s):  
S K Akiyama ◽  
S S Yamada ◽  
W T Chen ◽  
K M Yamada

We have developed two rat mAbs that recognize different subunits of the human fibroblast fibronectin receptor complex and have used them to probe the function of this cell surface heterodimer. mAb 13 recognizes the integrin class 1 beta polypeptide and mAb 16 recognizes the fibronectin receptor alpha polypeptide. We tested these mAbs for their inhibitory activities in cell adhesion, spreading, migration, and matrix assembly assays using WI38 human lung fibroblasts. mAb 13 inhibited the initial attachment as well as the spreading of WI38 cells on fibronectin and laminin substrates but not on vitronectin. Laminin-mediated adhesion was particularly sensitive to mAb 13. In contrast, mAb 16 inhibited initial cell attachment to fibronectin substrates but had no effect on attachment to either laminin or vitronectin substrates. When coated on plastic, both mAbs promoted WI38 cell spreading. However, mAb 13 (but not mAb 16) inhibited the radial outgrowth of cells from an explant on fibronectin substrates. mAb 16 also did not inhibit the motility of individual fibroblasts on fibronectin in low density culture and, in fact, substantially accelerated migration rates. In assays of the assembly of an extracellular fibronectin matrix by WI38 fibroblasts, both mAbs produced substantial inhibition in a concentration-dependent manner. The inhibition of matrix assembly resulted from impaired retention of fibronectin on the cell surface. Treatment of cells with mAb 16 also resulted in a striking redistribution of cell surface fibronectin receptors from a streak-like pattern to a relatively diffuse distribution. Concomitant morphological changes included decreases in thick microfilament bundle formation and reduced adhesive contacts of the streak-like and focal contact type. Our results indicate that the fibroblast fibronectin receptor (a) functions in initial fibroblast attachment and in certain types of adhesive contact, but not in the later steps of cell spreading; (b) is not required for fibroblast motility but instead retards migration; and (c) is critically involved in fibronectin retention and matrix assembly. These findings suggest a central role for the fibronectin receptor in regulating cell adhesion and migration.


2016 ◽  
Author(s):  
Mina Popovic ◽  
Brett A Neilan ◽  
Francesco Pomati

Perfluorinated compounds have raised concern due to their potential association with detrimental postnatal outcomes in animals and humans. We tested the effects of perfluorooctane sulfonate (PFOS) on a human pluripotent teratocarcinoma (known as NCCIT) cells as an in vitro prototype for developmental toxicity in mammals. NCCIT contains stem-cells able to differentiate into endoderm, mesoderm and ectoderm. We tested our cell model using a teratogenic compound, retinoic acid (RA), a cytotoxin, nocodazole (ND), and PFOS. We assayed cells proliferation, morphology and expression of stem cell and germ layer marker genes. PFOS reduced NCCIT cell proliferation in a concentration-dependent manner and induced morphological changes in cell cultures that resembled ectodermal phenotypes. A tendency towards a differentiated state in NCCIT was confirmed by real-time gene expression. PFOS triggered up-regulation of the gene nestin, indicative of ectodermal lineage differentiation, and interfered with the expression of the pluripotency stem-cell marker TERT. PFOS produced effects on both cells proliferation and differentiation, although not as severe as those observed for RA and ND, at levels that fall within the range of concentrations found in animal and human plasma. We discuss our findings in the context of possible interference of PFOS with the processes governing the early development of mammalian tissues.


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