Blood is a fluid connective tissue of human body, where it plays vital functions for the nutrition, defense and well-being of the organism. When circulating in peripheral districts, it is exposed to ...some physical stresses coming from outside the human body, as electromagnetic fields (EMFs) which can cross the skin. Such fields may interact with biomolecules possibly inducing non thermal-mediated biological effects at the cellular level. In this study, the occurrence of biochemical/biological modifications in human peripheral blood lympho-monocytes exposed in a reverberation chamber for times ranging from 1 to 20 h to EMFs at 1.8 GHz frequency and 200 V/m electric field strength was investigated. Morphological analysis of adherent cells unveiled, in some of these, appearance of an enlarged and deformed shape after EMFs exposure. Raman spectra of the nuclear compartment of cells exposed to EMFs revealed the onset of biochemical modifications, mainly consisting in the reduction of the DNA backbone-linked vibrational modes. Respirometric measurements of mitochondrial activity in intact lympho-monocytes resulted in increase of the resting oxygen consumption rate after 20 h of exposure, which was coupled to a significant increase of the FoF1-ATP synthase-related oxygen consumption. Notably, at lower time-intervals of EMFs exposure (i.e. 5 and 12 h) a large increase of the proton leak-related respiration was observed which, however, recovered at control levels after 20 h exposure. Confocal microscopy analysis of the mitochondrial membrane potential supported the respiratory activities whereas no significant variations in the mitochondrial mass/morphology was observed in EMFs-exposed lympho-monocytes. Finally, altered redox homeostasis was shown in EMFs-exposed lympho-monocytes, which progressed differently in nucleated cellular subsets. This results suggest the occurrence of adaptive mechanisms put in action, likely via redox signaling, to compensate for early impairments of the oxidative phosphorylation system caused by exposure to EMFs. Overall the data presented warn for health safety of people involved in long-term exposure to electromagnetic fields, although further studies are required to pinpoint the leukocyte cellular subset(s) selectively targeted by the EMFs action and the mechanisms by which it is achieved.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Adult haematopoietic stem/progenitor cells (HSPCs) constitute the lifespan reserve for the generation of all the cellular lineages in the blood. Although massive progress in identifying the cluster ...of master genes controlling self‐renewal and multipotency has been achieved in the past decade, some aspects of the physiology of HSPCs still need to be clarified. In particular, there is growing interest in the metabolic profile of HSPCs in view of their emerging role as determinants of cell fate. Indeed, stem cells and progenitors have distinct metabolic profiles, and the transition from stem to progenitor cell corresponds to a critical metabolic change, from glycolysis to oxidative phosphorylation. In this review, we summarize evidence, reported in the literature and provided by our group, highlighting the peculiar ability of HSPCs to adapt their mitochondrial oxidative/bioenergetic metabolism to survive in the hypoxic microenvironment of the endoblastic niche and to exploit redox signalling in controlling the balance between quiescence versus active cycling and differentiation. Especial prominence is given to the interplay between hypoxia inducible factor‐1, globins and NADPH oxidases in managing the mitochondrial dioxygen‐related metabolism and biogenesis in HSPCs under different ambient conditions. A mechanistic model is proposed whereby ‘mitochondrial differentiation’ is a prerequisite in uncommitted stem cells, paving the way for growth/differentiation factor‐dependent processes. Advancing the understanding of stem cell metabolism will, hopefully, help to (i) improve efforts to maintain, expand and manipulate HSPCs ex vivo and realize their potential therapeutic benefits in regenerative medicine; (ii) reprogramme somatic cells to generate stem cells; and (iii) eliminate, selectively, malignant stem cells.
Linked Articles
This article is part of a themed section on Emerging Therapeutic Aspects in Oncology. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.169.issue‐8
Cells infected by the hepatitis C virus (HCV) are characterized by endoplasmic reticulum stress, deregulation of the calcium homeostasis and unbalance of the oxido-reduction state. In this context, ...mitochondrial dysfunction proved to be involved and is thought to contribute to the outcome of the HCV-related disease. Here, we propose a temporal sequence of events in the HCV-infected cell whereby the primary alteration consists of a release of Ca2+ from the endoplasmic reticulum, followed by uptake into mitochondria. This causes successive mitochondrial alterations comprising generation of reactive oxygen and nitrogen species and impairment of the oxidative phosphorylation. A progressive adaptive response results in an enhancement of the glycolytic metabolism sustained by up-regulation of the hypoxia inducible factor. Pathogenetic implications of the model are discussed.
The mechanisms of liver injury in chronic hepatitis C virus (HCV) infection are poorly understood though HCV induces a state of hepatic oxidative stress that is more pronounced than that present in ...many other inflammatory diseases. This mini-review will focus on recent findings revealing an unexpected role of mitochondria in providing a central role in the innate immunity and in addition will illustrate the application of stably transfected human-derived cell lines, inducibly expressing the entire HCV open reading frame for in vitro studies on mitochondria. Results obtained by a comparative analysis of the respiratory chain complexes activities along with mitochondrial morpho-functional confocal microscopy imaging show a detrimental effect of HCV proteins on the cell oxidative metabolism with specific inhibition of complex I activity, decrease of mtΔ
Ψ, increased production of reactive oxygen species. A possible de-regulation of calcium recycling between the endoplasmic reticulum and the mitochondrial network is discussed to provide new insights in the pathogenesis of hepatitis C.
Various genes have been identified for monogenic disorders resembling Parkinson's disease. The products of some of these genes are associated with mitochondria and have been implicated in cellular ...protection against oxidative damage. In the present study we analysed fibroblasts from a patient carrying the homozygous mutation p.W437X in the PTEN-induced kinase 1 (PINK1), which manifested a very early onset parkinsonism.
Patient's fibroblasts did not show variation in the mtDNA copy number or in the expression of the oxidative phosphorylation complexes. Sequence analysis of the patient's mtDNA presented two new missense mutations in the ND5 (m.12397A>G, p.T21A) and ND6 (m. 14319T>C, p.N119D) genes coding for two subunits of complex I. The two mutations were homoplasmic in both the patient and the patient's mother. Patient's fibroblasts resulted in enhanced constitutive production of the superoxide anion radical that was abrogated by inhibitor of the complex I. Moreover enzyme kinetic analysis of the NADH:ubiquinone oxidoreductase showed changes in the substrates affinity.
To our knowledge, this is the first report showing co-segregation of a Parkinson's disease related nuclear gene mutation with mtDNA mutation(s). Our observation might shed light on the clinical heterogeneity of the hereditary cases of Parkinson's disease, highlighting the hitherto unappreciated impact of coexisting mtDNA mutations in determining the development and the clinical course of the disease.
IntroductionHepatocellular carcinoma (HCC) represents the sixth leading cancer and the third most common cause of death from cancer. Many different aetiological factors are involved in the ...development of HCC, which may be modulated by both estrogens and androgens hormones during its initiation, progression and metastasis. The misuse of anabolic androgenic steroids (AAS) is associated with serious adverse effects to the liver, including cellular adenomas and adenocarcinomas, and is considered a factor risk of developing hepatic sex hormone related tumours. The purpose of this study was to investigate the role of Nandrolone, one of the most commonly used AAS, in regulating proliferation and differentiation of HCC.Material and methodsHuman HCC cell line HepG2 was treated with Nandrolone, a synthetic androgen ligand, for 48 hs and its viability and proliferation was assessed by MTS and cell cycle analysis, respectively. The expression of protein involved in cell cycle regulation and differentiation markers were analysed by western blot and real time PCR. Measurement of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were performed using Seahorse XF96 extracellular flux analyzer. Respiratory chain complex activities were assayed spectrophotometrically. Stemness surface markers expression was detected by FACSCalibur flow cytometer.Results and discussionsNandrolone treatment caused cell growth inhibition associated to a downregulation of cyclin D1 and an upregulation of the cyclin-dependent kinase inhibitors p21Waf1/Cip1 leading to cell cycle arrest in the G2 phase. Moreover, a significant overall impairment of mitochondrial functions, resulting in a reduced OCR and impairment of OXPHOS complexes activities were also observed, thus suggesting a role in the control of the metabolic reprogramming. Finally, a significant increase of the stemness markers was detected following Nandrolone treatment, also confirmed in additional human stem cell types and in an in vivo mouse model.ConclusionNandrolone shows a strong anti-proliferative effect in differentiated tumour cells, promoting cancer cells stemness through cellular metabolic reprogramming. These results could have important public health implications in order to improve the primary prevention such as revising altered lifestyles, like AAS abuse.
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