Mitochondria play a pivotal role in cellular energy-generating processes and are considered master regulators of cell life and death fate. Mitochondrial function integrates signalling networks in ...several metabolic pathways controlling neurogenesis and neuroplasticity. Indeed, dysfunctional mitochondria and mitochondrial-dependent activation of intracellular stress cascades are critical initiating events in many human neurodegenerative or neurodevelopmental diseases including Down syndrome (DS). It is well established that trisomy of human chromosome 21 can cause DS. DS is associated with neurodevelopmental delay, intellectual disability and early neurodegeneration. Recently, molecular mechanisms responsible for mitochondrial damage and energy deficits have been identified and characterized in several DS-derived human cells and animal models of DS. Therefore, therapeutic strategies targeting mitochondria could have great potential for new treatment regimens in DS. The purpose of this review is to highlight recent studies concerning mitochondrial impairment in DS, focusing on alterations of the molecular pathways controlling mitochondrial function. We will also discuss the effects and molecular mechanisms of naturally occurring and chemically synthetized drugs that exert neuroprotective effects through modulation of mitochondrial function and attenuation of oxidative stress. These compounds might represent novel therapeutic tools for the modulation of energy deficits in DS.
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•Mitochondrial dysfunctions and oxidative stress are hallmarks in Down syndrome.•The molecular basis of mitochondrial dysfunctions in DS are discussed.•Many mitochondrial alterations in DS are shared with those found in DS-associated diseases.•Drugs targeting mitochondria may be therapeutic challenge for DS handling.
Alzheimer's disease (AD), a chronic and progressive neurodegenerative disease, is characterized by memory and cognitive impairment and by the accumulation in the brain of abnormal proteins, more ...precisely beta-amyloid (β-amyloid or Aβ) and Tau proteins. Studies aimed at researching pharmacological treatments against AD have focused precisely on molecules capable, in one way or another, of preventing/eliminating the accumulations of the aforementioned proteins. Unfortunately, more than 100 years after the discovery of the disease, there is still no effective therapy in modifying the biology behind AD and nipping the disease in the bud. This state of affairs has made neuroscientists suspicious, so much so that for several years the idea has gained ground that AD is not a direct neuropathological consequence taking place downstream of the deposition of the two toxic proteins, but rather a multifactorial disease, including mitochondrial dysfunction as an early event in the pathogenesis of AD, occurring even before clinical symptoms. This is the reason why the search for pharmacological agents capable of normalizing the functioning of these subcellular organelles of vital importance for nerve cells is certainly to be considered a promising approach to the design of effective neuroprotective drugs aimed at preserving this organelle to arrest or delay the progression of the disease. Here, our intent is to provide an updated overview of the mitochondrial alterations related to this disorder and of the therapeutic strategies (both natural and synthetic) targeting mitochondrial dysfunction.
Functional and structural damages to mitochondria have been critically associated with the pathogenesis of Down syndrome (DS), a human multifactorial disease caused by trisomy of chromosome 21 and ...associated with neurodevelopmental delay, intellectual disability and early neurodegeneration. Recently, we demonstrated in neural progenitor cells (NPCs) isolated from the hippocampus of Ts65Dn mice -a widely used model of DS - a severe impairment of mitochondrial bioenergetics and biogenesis and reduced NPC proliferation. Here we further investigated the origin of mitochondrial dysfunction in DS and explored a possible mechanistic link among alteration of mitochondrial dynamics, mitochondrial dysfunctions and defective neurogenesis in DS. We first analyzed mitochondrial network and structure by both confocal and transmission electron microscopy as well as by evaluating the levels of key proteins involved in the fission and fusion machinery. We found a fragmentation of mitochondria due to an increase in mitochondrial fission associated with an up-regulation of dynamin-related protein 1 (Drp1), and a decrease in mitochondrial fusion associated with a down-regulation of mitofusin 2 (Mnf2) and increased proteolysis of optic atrophy 1 (Opa1). Next, using the well-known neuroprotective agent mitochondrial division inhibitor 1 (Mdivi-1), we assessed whether the inhibition of mitochondrial fission might reverse alteration of mitochondrial dynamics and mitochondrial dysfunctions in DS neural progenitors cells. We demonstrate here for the first time, that Mdivi-1 restores mitochondrial network organization, mitochondrial energy production and ultimately improves proliferation and neuronal differentiation of NPCs. This research paves the way for the discovery of new therapeutic tools in managing some DS-associated clinical manifestations.
•Mitochondrial network is impaired in neural progenitors cells (NPCs) from Ts65Dn model of DS.•Drp1-dependent mitochondrial fragmentation occurs during Ts65Dn NPCs proliferation.•Mitochondrial division inhibitor 1 (Mdivi-1) restores mitochondrial dynamics in Ts65Dn NPCs.•Mdivi-1 counteracts mitochondrial dysfunctions and in turn promotes in vitro neurogenesis.
The use of DTG-containing two-drug regimens is one of the most promising solutions to the need to ease the management of HIV treatment without harming its efficacy and safety. We report long- term ...results in patients switched, while virologically suppressed, to the combination of dolutegravir (DTG) plus lamivudine (3TC). This is a prospective, clinical, uncontrolled cohort enrolling ART-experienced people living with HIV (PLWH) with HIV-RNA < 50 copies/ml for 6 months or longer, negative hepatitis B virus surface antigen, and without known M184V/I mutations. Kaplan-Meiers curves are used to describe persistency of virological suppression on therapy and a Cox regression model to evaluate baseline characteristics and the risk of stopping therapy. 218 individuals switched their regimen since 2015. The mean estimated follow-up was of 64.3 months (95% CI 61.3-67.3) for approximately 1000 patient/years. After 5 years of follow-up, 77.1% were still on the DTG-3TC combination. No virologic failure was detected throughout the whole study period, and only 15 subjects presented single isolated viral blips above 50 copies/ml. Most patients stopped therapy because of reasons unrelated to study drugs (lost to follow-up; patients' decision; moved to other Centers), but due to the unselected nature of the casuistry; 11 subjects died in the 5 years of follow-up mostly because of pre-existing co-morbidities (6 neoplastic diseases and 2 end-stage liver disease). The median baseline CD4 count was 669 cells/mcl (IQR 483-927). After 5 years it raised to 899 cells/mcl (IQR 646-1160) (P < 0.001) without a significant change of CD8 counts that lowered from 767 cells/mcl (IQR 532-1034) to 683 cells/mcl (IQR 538-988). Consequently, the CD4/CD8 ratio varied from 0.93 (IQR 0.60-1.30) to 1.15 (IQR 0.77-1.45) (P < 0.0001). A non-significant (P = 0.320) increment of mean creatinine, 0.06 mg/dl in magnitude, was observed over the whole follow-up. These long-term results over 5 years reinforce the durability and good tolerability of DTG-3TC. Our results continue to support the recommended switch use of this 2DR as a well-accepted treatment option for ART-experienced PLWH.
3-bromopyruvate (3-BP) is an anti-tumour drug effective on hepatocellular carcinoma and other tumour cell types, which affects both glycolytic and mitochondrial targets, depleting cellular ATP pool. ...Here we tested 3-BP on human prostate cancer cells showing, differently from other tumour types, efficient ATP production and functional mitochondrial metabolism. We found that 3-BP rapidly induced cultured androgen-insensitive (PC-3) and androgen-responsive (LNCaP) prostate cancer cell death at low concentrations (IC
50
values of 50 and 70 μM, respectively) with a multimodal mechanism of action. In particular, 3-BP-treated PC-3 cells showed a selective, strong reduction of glyceraldeide 3-phosphate dehydrogenase activity, due to the direct interaction of the drug with the enzyme. Moreover, 3-BP strongly impaired both glutamate/malate- and succinate-dependent mitochondrial respiration, membrane potential generation and ATP synthesis, concomitant with the inhibition of respiratory chain complex I, II and ATP synthase activities. The drastic reduction of cellular ATP levels and depletion of GSH pool, associated with significant increase in cell oxidative stress, were found after 3-BP treatment of PC-3 cells. Interestingly, the activity of both glyoxalase I and II, devoted to the elimination of the cytotoxic methylglyoxal, was strongly inhibited by 3-BP. Both N-acetylcysteine and aminoguanidine, GSH precursor and methylglyoxal scavenger, respectively, prevented 3-BP-induced PC-3 cell death, showing that impaired cell antioxidant and detoxifying capacities are crucial events leading to cell death. The provided information on the multi-target cytotoxic action of 3-BP, finally leading to PC-3 cell necrosis, might be useful for future development of 3-BP as a therapeutic option for prostate cancer treatment.
Impaired energy metabolism may play a role in the pathogenesis of neurodevelopmental disorders including fragile X syndrome (FXS). We checked brain energy status and some aspects of cell ...bioenergetics, namely the activity of key glycolytic enzymes, glycerol-3-phosphate shuttle and mitochondrial respiratory chain (MRC) complexes, in the cerebral cortex of the
knockout (KO) mouse model of FXS. We found that, despite a hyperactivation of MRC complexes, adenosine triphosphate (ATP) production via mitochondrial oxidative phosphorylation (OXPHOS) is compromised, resulting in brain energy impairment in juvenile and late-adult
KO mice. Thus, an altered mitochondrial energy metabolism may contribute to neurological impairment in FXS.
Mitochondria and l‐lactate metabolism Passarella, Salvatore; de Bari, Lidia; Valenti, Daniela ...
FEBS letters,
October 29, 2008, Letnik:
582, Številka:
25-26
Journal Article
Recenzirano
Odprti dostop
We review here the novel insights arisen from investigations on l‐lactate metabolism in mammalian, plant and yeast mitochondria. The presence of l‐lactate dehydrogenases inside mitochondria, where ...l‐lactate enters in a carrier‐mediated fashion, suggests that mitochondria play an important role in l‐lactate metabolism. Functional studies have demonstrated the occurrence of several l‐lactate carriers. Moreover, immunological investigations have proven the existence of monocarboxylate translocator isoforms in mitochondria.
Mitochondria are complex and multifaceted organelles that constitute a dynamic network of signaling platforms playing a pivotal role in cellular energy-generating processes ...
Increasing evidence reveals a large dependency of epithelial cancer cells on oxidative phosphorylation (OXPHOS) for energy production. In this study we tested the potential of ...epigallocatechin-3-gallate (EGCG), a natural polyphenol known to target mitochondria, in inducing OXPHOS impairment and cell energy deficit in human epitheliod (REN cells) and biphasic (MSTO-211H cells) malignant pleural mesothelioma (MMe), a rare but highly aggressive tumor with high unmet need for treatment. Due to EGCG instability that causes H2O2 formation in culture medium, the drug was added to MMe cells in the presence of exogenous superoxide dismutase and catalase, already proved to stabilize the EGCG molecule and prevent EGCG-dependent reactive oxygen species formation. We show that under these experimental conditions, EGCG causes the selective arrest of MMe cell growth with respect to normal mesothelial cells and the induction of mitochondria-mediated apoptosis, as revealed by early mitochondrial ultrastructure modification, swelling and cytochrome c release. We disclose a novel mechanism by which EGCG induces apoptosis through the impairment of mitochondrial respiratory chain complexes, particularly of complex I, II and ATP synthase. This induces a strong reduction in ATP production by OXPHOS, that is not adequately counterbalanced by glycolytic shift, resulting in cell energy deficit, cell cycle arrest and apoptosis. The EGCG-dependent negative modulation of mitochondrial energy metabolism, selective for cancer cells, gives an important input for the development of novel pharmacological strategies for MMe.
•Stabilized EGCG induces a selective growth arrest in human malignant mesothelioma cells.•EGCG induces a strong reduction in ATP production by OXPHOS impairment in MMe cells.•EGCG induces cell cycle arrest and mitochondrial-mediated apoptosis in MMe cells.•The negative modulation of OXPHOS could give an input for novel therapeutic strategies for MMe.
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