The Effect of Copper on Endometrial Receptivity and Induction of Apoptosis on Decidualized Human Endometrial Stromal Cells.

Intrauterine devices (IUDs) have been widely used to prevent pregnancies with great efficacy during decades. It has been demonstrated that IUD alters the endometrial gene expression, but there is no scientific data about how copper, a metal commonly used in these devices, by itself, is able to influence the processes of endometrial receptivity and apoptosis in decidualized human endometrial stromal cells. Five endometrial samples were obtained from fertile women and processed by a standard protocol to obtain human endometrial stromal cells for in vitro studies. Stromal cells were cultured in vitro and decidualized for 8 days. At day 6, copper was added to the treatment group or camptothecin as positive control for apoptosis until day 8. Five endometrial samples were used in each group. The aim of this study was to analyze the effect of copper in apoptosis and necrosis by flow cytometry, to visualize the apoptotic microtubule network during apoptosis by immunofluorescence, and finally to determine the gene expression profile of a panel of 192 genes related to endometrial receptivity and immune system by quantitative reverse transcription PCR (RT-qPCR). Copper, compared to the decidualized group, induced changes in the gene expression by an order of magnitude in 49 genes (42 up- and 9 downregulated). This alteration in the decidualization gene signature by copper includes 19 genes involved in the endometriosis pathology and others related to other gynecological disorders such as preeclampsia and infertility. Our results indicate that copper does not increase the apoptosis level induced by the decidualization treatment. However, copper alters the gene expression of some biomarkers of endometrial receptivity and immune response.

Dynamic Reorganization of the Cytoskeleton during Apoptosis: The Two Coffins Hypothesis.

During apoptosis, cells undergo characteristic morphological changes in which the cytoskeleton plays an active role. The cytoskeleton rearrangements have been mainly attributed to actinomyosin ring contraction, while microtubule and intermediate filaments are depolymerized at early stages of apoptosis. However, recent results have shown that microtubules are reorganized during the execution phase of apoptosis forming an apoptotic microtubule network (AMN). Evidence suggests that AMN is required to maintain plasma membrane integrity and cell morphology during the execution phase of apoptosis. The new "two coffins" hypothesis proposes that both AMN and apoptotic cells can adopt two morphological patterns, round or irregular, which result from different cytoskeleton kinetic reorganization during the execution phase of apoptosis induced by genotoxic agents. In addition, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocyte responses. These findings suggest that knowing the type of apoptosis may be important to predict how fast apoptotic cells undergo secondary necrosis and the subsequent immune response. From a pathological point of view, round-shaped apoptosis can be seen as a physiological and controlled type of apoptosis, while irregular-shaped apoptosis can be considered as a pathological type of cell death closer to necrosis.

Coenzyme Q10 partially restores pathological alterations in a macrophage model of Gaucher disease.

BACKGROUND: Gaucher disease (GD) is caused by mutations in the GBA1 gene which encodes lysosomal ß-glucocerebrosidase (GCase). In GD, partial or complete loss of GCase activity causes the accumulation of the glycolipids glucosylceramide (GlcCer) and glucosylsphingosine in the lysosomes of macrophages. In this manuscript, we investigated the effects of glycolipids accumulation on lysosomal and mitochondrial function, inflammasome activation and efferocytosis capacity in a THP-1 macrophage model of Gaucher disease. In addition, the beneficial effects of coenzyme Q10 (CoQ) supplementation on cellular alterations were evaluated. Chemically-induced Gaucher macrophages were developed by differentiateing THP-1 monocytes to macrophages by treatment with phorbol 12-myristate 13-acetate (PMA) and then inhibiting intracellular GCase with conduritol B-epoxide (CBE), a specific irreversible inhibitor of GCase activity, and supplementing the medium with exogenous GlcCer. This cell model accumulated up to 16-fold more GlcCer compared with control THP-1 cells. RESULTS: Chemically-induced Gaucher macrophages showed impaired autophagy flux associated with mitochondrial dysfunction and increased oxidative stress, inflammasome activation and impaired efferocytosis. All abnormalities were partially restored by supplementation with CoQ. CONCLUSION: These data suggest that targeting mitochondria function and oxidative stress by CoQ can ameliorate the pathological phenotype of Gaucher cells. Chemically-induced Gaucher macrophages provide cellular models that can be used to investigate disease pathogenesis and explore new therapeutics for GD.

Two coffins and a funeral: early or late caspase activation determines two types of apoptosis induced by DNA damaging agents.

Cell cytoskeleton makes profound changes during apoptosis including the organization of an Apoptotic Microtubule Network (AMN). AMN forms a cortical structure which plays an important role in preserving plasma membrane integrity during apoptosis. Here, we examined the cytoskeleton rearrangements during apoptosis induced by camptothecin (CPT), a topoisomerase I inhibitor, in human H460 and porcine LLCPK-1α cells. Using fixed and living cell imaging, we showed that CPT induced two dose- and cell cycle-dependent types of apoptosis characterized by different cytoskeleton reorganizations, time-dependent caspase activation and final apoptotic cell morphology. In the one referred as "slow" (~h) or round-shaped, apoptosis was characterized by a slow contraction of the actinomyosin ring and late caspase activation. In "slow" apoptosis the γ-tubulin complexes were not disorganized and microtubules were not depolymerized at early stages. In contrast, "fast" (~min) or irregular-shaped apoptosis was characterized by early caspase activation followed by full contraction of the actinomyosin ring. In fast apoptosis γ-tubulin complexes were disorganized and microtubules were initially depolymerized. However, after actinomyosin contraction, microtubules were reformed adopting a cortical but irregular disposition near plasma membrane. In addition to distinctive cytoskeleton reorganization kinetics, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocytes response. Our results suggest that the knowledge and modulation of the type of apoptosis promoted by genotoxic agents may be important for deciding a better therapeutic option and predicting the immune response in cancer treatment.

The Connections Among Autophagy, Inflammasome and Mitochondria.

BACKGROUND: The molecular crosstalk between inflammation and autophagy is an emerging field of research that is essential for the understanding of multicellular organism homeostasis and how these processes influence a variety of pathological conditions. OBJECTIVE: In this review, we briefly describe the relationship between autophagy and inflammasome activation. The central role that mitochondria play in both cellular processes is also discussed. CONCLUSION: Inflammasome and autophagy often modulate each other by common inhibitory mechanisms that are controlled by different input pathways. Thus, inflammasome components coordinate autophagy and autophagy regulates inflammasome activation, making the balance between both processes a fundamental player in cellular homeostasis.

AMPK Regulation of Cell Growth, Apoptosis, Autophagy, and Bioenergetics.

In eukaryotic cells, AMP-activated protein kinase (AMPK) generally promotes catabolic pathways that produce ATP and at the same time inhibits anabolic pathways involved in different processes that consume ATP. As an energy sensor, AMPK is involved in the main cellular functions implicated in cell fate, such as cell growth and autophagy.Recently, AMPK has been connected with apoptosis regulation, although the molecular mechanism by which AMPK induces and/or inhibits cell death is not clear.This chapter reviews the essential role of AMPK in signaling pathways that respond to cellular stress and damage, highlighting the complex and reciprocal regulation between AMPK and their targets and effectors. The therapeutic implications of the role of AMPK in different pathologies such as diabetes, cancer, or mitochondrial dysfunctions are still controversial, and it is necessary to further investigate the molecular mechanisms underlying AMPK activation.

Amitriptyline induces mitophagy that precedes apoptosis in human HepG2 cells.

Systemic treatments for hepatocellular carcinoma (HCC) have been largely unsuccessful. This study investigated the antitumoral activity of Amitriptyline, a tricyclic antidepressant, in hepatoma cells. Amitriptyline-induced toxicity involved early mitophagy activation that subsequently switched to apoptosis. Amitriptyline induced mitochondria dysfunction and oxidative stress in HepG2 cells. Amitriptyline specifically inhibited mitochondrial complex III activity that is associated with decreased mitochondrial membrane potential (∆Ψm) and increased reactive oxygen species (ROS) production. Transmission electron microscopy (TEM) studies revealed structurally abnormal mitochondria that were engulfed by double-membrane structures resembling autophagosomes. Consistent with mitophagy activation, fluorescence microscopy analysis showed mitochondrial Parkin recruitment and colocalization of mitochondria with autophagosome protein markers. Pharmacological or genetic inhibition of autophagy exacerbated the deleterious effects of Amitriptyline on hepatoma cells and led to increased apoptosis. These results suggest that mitophagy acts as an initial adaptive mechanism of cell survival. However persistent mitochondrial damage induced extensive and lethal mitophagy, autophagy stress and autophagolysome permeabilization leading eventually to cell death by apoptosis. Amitriptyline also induced cell death in hepatoma cells lines with mutated p53 and non-sense p53 mutation. Our results support the hypothesis that Amitriptyline-induced mitochondrial dysfunction can be a useful therapeutic strategy for HCC treatment, especially in tumors showing p53 mutations and/or resistant to genotoxic treatments.

AMPK As A Target in Rare Diseases.

The AMP-activated protein kinase (AMPK) has emerged as an important sensor of signals that control cellular energy balance in all eukaryotes. AMPK is also involved in fatty acid oxidation, glucose transport, antioxidant defense, mitochondrial biogenesis and the modulation of inflammatory processes. The numerous roles of AMPK in cell physiological and pathological states justified the notable increase in the number of publications in previous years, with almost 1500 scientific articles relative to this kinase in 2014. Due to its role in maintaining energy balance, a dysfunction in AMPK signalling pathway may result in perturbations at the systemic level that contribute to the development of many disease conditions. Among them, more than 7000 poorly-known rare diseases are particularly of social and scientific interest because they are usually chronically debilitating or even lifethreatening and lack effective and safe treatment. Several authors have demonstrated AMPK alterations and the beneficial effect of treatments with drugs regulating AMPK activity in some of these low prevalence pathologies. Among these rare diseases in which AMPK can play an important pathological role are mitochondrial disorders, muscular dystrophies, cardiovascular diseases, neurodegenerative pathologies, or even some types of cancer for the importance of AMPK as a suppressor of cell proliferation. This review focuses on current knowledge about the pathophysiological roles of AMPK and future approaches as therapeutic targeting in rare diseases.

Mitochondrial Dynamics in Mitochondrial Diseases.

Mitochondria are very versatile organelles in continuous fusion and fission processes in response to various cellular signals. Mitochondrial dynamics, including mitochondrial fission/fusion, movements and turnover, are essential for the mitochondrial network quality control. Alterations in mitochondrial dynamics can cause neuropathies such as Charcot-Marie-Tooth disease in which mitochondrial fusion and transport are impaired, or dominant optic atrophy which is caused by a reduced mitochondrial fusion. On the other hand, mitochondrial dysfunction in primary mitochondrial diseases promotes reactive oxygen species production that impairs its own function and dynamics, causing a continuous vicious cycle that aggravates the pathological phenotype. Mitochondrial dynamics provides a new way to understand the pathophysiology of mitochondrial disorders and other diseases related to mitochondria dysfunction such as diabetes, heart failure, or Hungtinton's disease. The knowledge about mitochondrial dynamics also offers new therapeutics targets in mitochondrial diseases.

Mitochondrial Dysfunction in Lysosomal Storage Disorders.

Lysosomal storage diseases (LSDs) describe a heterogeneous group of rare inherited metabolic disorders that result from the absence or loss of function of lysosomal hydrolases or transporters, resulting in the progressive accumulation of undigested material in lysosomes. The accumulation of substances affects the function of lysosomes and other organelles, resulting in secondary alterations such as impairment of autophagy, mitochondrial dysfunction, inflammation and apoptosis. LSDs frequently involve the central nervous system (CNS), where neuronal dysfunction or loss results in progressive neurodegeneration and premature death. Many LSDs exhibit signs of mitochondrial dysfunction, which include mitochondrial morphological changes, decreased mitochondrial membrane potential (ΔΨm), diminished ATP production and increased generation of reactive oxygen species (ROS). Furthermore, reduced autophagic flux may lead to the persistence of dysfunctional mitochondria. Gaucher disease (GD), the LSD with the highest prevalence, is caused by mutations in the GBA1 gene that results in defective and insufficient activity of the enzyme ß-glucocerebrosidase (GCase). Decreased catalytic activity and/or instability of GCase leads to accumulation of glucosylceramide (GlcCer) and glucosylsphingosine (GlcSph) in the lysosomes of macrophage cells and visceral organs. Mitochondrial dysfunction has been reported to occur in numerous cellular and mouse models of GD. The aim of this manuscript is to review the current knowledge and implications of mitochondrial dysfunction in LSDs.

Targeting autophagy and mitophagy for mitochondrial diseases treatment.

INTRODUCTION: Mitochondrial diseases are a group of rare genetic diseases with complex and heterogeneous origins which manifest a great variety of phenotypes. Disruption of the oxidative phosphorylation system is the main cause of pathogenicity in mitochondrial diseases since it causes accumulation of reactive oxygen species (ROS) and ATP depletion. AREAS COVERED: Current evidences support the main protective role of autophagy and mitophagy in mitochondrial diseases and other diseases associated with mitochondrial dysfunction. EXPERT OPINION: The use of autophagy and/or mitophagy inducers may allow a novel strategy for improving mitochondrial function for both mitochondrial diseases and other diseases with altered mitochondrial metabolism. However, a deeper investigation of the molecular mechanisms behind mitophagy and mitochondrial biogenesis is needed in order to safely modulate these processes. In the coming years, we will also see an increase in awareness of mitochondrial dynamics modulation that will allow the therapeutic use of new drugs for improving mitochondrial function in a great variety of mitochondrial disorders.

Emerging roles of apoptotic microtubules during the execution phase of apoptosis.

Apoptosis is a genetically programmed energy-dependent process of cell demise, characterized by specific morphological and biochemical events in which the activation of caspases has an essential role. During apoptosis the cytoskeleton participates actively in characteristic morphological rearrangements of the dying cell. This reorganisation has been assigned mainly to actinomyosin ring contraction, while microtubule and intermediate filaments are depolymerized at early stages of apoptosis. However, recent reports have showed that microtubules are reformed during the execution phase of apoptosis organizing an apoptotic microtubule network (AMN). AMN is organized behind plasma membrane, forming a cortical structure. Apoptotic microtubules repolymerization takes place in many cell types and under different apoptotic inducers. It has been hypothesized that AMN is critical for maintaining plasma membrane integrity and cell morphology during the execution phase of apoptosis. AMN disorganization leads apoptotic cells to secondary necrosis and the release of potential toxic molecules which can damage neighbor cells and promotes inflammation. Therefore, AMN formation during physiological apoptosis or in pathological apoptosis induced by anti-cancer treatments is essential for tissue homeostasis and the prevention of additional cell damage and inflammation.

Pharmacological Chaperones and Coenzyme Q10 Treatment Improves Mutant ß-Glucocerebrosidase Activity and Mitochondrial Function in Neuronopathic Forms of Gaucher Disease.

Gaucher disease (GD) is caused by mutations in the GBA1 gene, which encodes lysosomal ß-glucocerebrosidase. Homozygosity for the L444P mutation in GBA1 is associated with high risk of neurological manifestations which are not improved by enzyme replacement therapy. Alternatively, pharmacological chaperones (PCs) capable of restoring the correct folding and trafficking of the mutant enzyme represent promising alternative therapies.Here, we report on how the L444P mutation affects mitochondrial function in primary fibroblast derived from GD patients. Mitochondrial dysfunction was associated with reduced mitochondrial membrane potential, increased reactive oxygen species (ROS), mitophagy activation and impaired autophagic flux.Both abnormalities, mitochondrial dysfunction and deficient ß-glucocerebrosidase activity, were partially restored by supplementation with coenzyme Q10 (CoQ) or a L-idonojirimycin derivative, N-[N'-(4-adamantan-1-ylcarboxamidobutyl)thiocarbamoyl]-1,6-anhydro-L-idonojirimycin (NAdBT-AIJ), and more markedly by the combination of both treatments. These data suggest that targeting both mitochondria function by CoQ and protein misfolding by PCs can be promising therapies in neurological forms of GD.

Stabilization Of Apoptotic Cells: Generation Of Zombie Cells.

Apoptosis is characterized by degradation of cell components but plasma membrane remains intact. Apoptotic microtubule network (AMN) is organized during apoptosis forming a cortical structure beneath plasma membrane that maintains plasma membrane integrity. Apoptotic cells are also characterized by high reactive oxygen species (ROS) production that can be potentially harmful for the cell. The aim of this study was to develop a method that allows stabilizing apoptotic cells for diagnostic and therapeutic applications. We were able by using a cocktail composed of taxol (a microtubule stabilizer), Zn2+ (a caspase inhibitor) and coenzyme Q10 (a lipid antioxidant) to stabilize H460 apoptotic cells in cell cultures for at least 72hours preventing secondary necrosis. Stabilized apoptotic cells maintain many apoptotic cells characteristics such as the presence of apoptotic microtubules, plasma membrane integrity, low intracellular calcium levels, plasma membrane potential, PS externalization and ability of being phagocytosed. Stabilized apoptotic cells can be considered as dying cells in which the cellular cortex and plasma membrane are maintained intact or alive. In a metaphorical sense, we can consider them as "living dead" or "zombie cells". Stabilization of apoptotic cells can be used for reliable detection and quantification of apoptosis in cultured cells and may allow a safer administration of apoptotic cells in clinical applications. Furthermore, it opens new avenues in the functional reconstruction of apoptotic cells for longer preservation.

Coenzyme q10 therapy.

For a number of years, coenzyme Q10 (CoQ10) was known for its key role in mitochondrial bioenergetics; later studies demonstrated its presence in other subcellular fractions and in blood plasma, and extensively investigated its antioxidant role. These 2 functions constitute the basis for supporting the clinical use of CoQ10. Also, at the inner mitochondrial membrane level, CoQ10 is recognized as an obligatory cofactor for the function of uncoupling proteins and a modulator of the mitochondrial transition pore. Furthermore, recent data indicate that CoQ10 affects the expression of genes involved in human cell signaling, metabolism and transport, and some of the effects of CoQ10 supplementation may be due to this property. CoQ10 deficiencies are due to autosomal recessive mutations, mitochondrial diseases, aging-related oxidative stress and carcinogenesis processes, and also statin treatment. Many neurodegenerative disorders, diabetes, cancer, and muscular and cardiovascular diseases have been associated with low CoQ10 levels as well as different ataxias and encephalomyopathies. CoQ10 treatment does not cause serious adverse effects in humans and new formulations have been developed that increase CoQ10 absorption and tissue distribution. Oral administration of CoQ10 is a frequent antioxidant strategy in many diseases that may provide a significant symptomatic benefit.

Apoptotic cells subjected to cold/warming exposure disorganize apoptotic microtubule network and undergo secondary necrosis.

Apoptotic microtubule network (AMN) is organized during apoptosis, forming a cortical structure beneath the plasma membrane which plays a critical role in preserving cell morphology and plasma membrane integrity. The aim of this study was to examine the effect of cold/warming exposure on apoptotic microtubules and plasma membrane integrity during the execution phase of apoptosis. We demonstrated in camptothecin-induced apoptotic H460 cells that cold/warming exposure disorganized apoptotic microtubules and allowed the access of active caspases to the cellular cortex and the cleavage of essential proteins in the preservation of plasma membrane permeability. Cleavage of cellular cortex and plasma membrane proteins, such as α-spectrin, paxilin, focal adhesion kinase and calcium ATPase pump (PMCA-4) involved in cell calcium extrusion resulted in increased plasma permeability and calcium overload leading apoptotic cells to secondary necrosis. The essential role of caspase-mediated cleavage in this process was demonstrated because the addition of the pan-caspase inhibitor z-VAD during cold/warming exposure that induces AMN depolymerization avoided the cleavage of cortical and plasma membrane proteins and prevented apoptotic cells to undergo secondary necrosis. Likewise, apoptotic microtubules stabilization by taxol during cold/warming exposure also prevented cellular cortex and plasma membrane protein cleavage and secondary necrosis. Furthermore, microtubules stabilization or caspase inhibition during cold/warming exposure was also critical for proper phosphatidylserine externalization and apoptotic cell clearance by macrophages. These results indicate that cold/warming exposure of apoptotic cells induces secondary necrosis which can be prevented by both, microtubule stabilization or caspase inhibition.

Clinical applications of coenzyme Q10.

Coenzyme Q10 (CoQ10) or ubiquinone was known for its key role in mitochondrial bioenergetics as electron and proton carrier; later studies demonstrated its presence in other cellular membranes and in blood plasma, and extensively investigated its antioxidant role. These two functions constitute the basis for supporting the clinical indication of CoQ10. Furthermore, recent data indicate that CoQ10 affects expression of genes involved in human cell signalling, metabolism and transport and some of the effects of CoQ10 supplementation may be due to this property. CoQ10 deficiencies are due to autosomal recessive mutations, mitochondrial diseases, ageing-related oxidative stress and carcinogenesis processes, and also a secondary effect of statin treatment. Many neurodegenerative disorders, diabetes, cancer, fibromyalgia, muscular and cardiovascular diseases have been associated with low CoQ10 levels. CoQ10 treatment does not cause serious adverse effects in humans and new formulations have been developed that increase CoQ10 absorption and tissue distribution. Oral CoQ10 treatment is a frequent mitochondrial energizer and antioxidant strategy in many diseases that may provide a significant symptomatic benefit.

Screening of effective pharmacological treatments for MELAS syndrome using yeasts, fibroblasts and cybrid models of the disease.

BACKGROUND AND PURPOSE: MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) is a mitochondrial disease most usually caused by point mutations in tRNA genes encoded by mitochondrial DNA (mtDNA). Approximately 80% of cases of MELAS syndrome are associated with a m.3243A > G mutation in the MT-TL1 gene, which encodes the mitochondrial tRNALeu (UUR). Currently, no effective treatments are available for this chronic progressive disorder. Treatment strategies in MELAS and other mitochondrial diseases consist of several drugs that diminish the deleterious effects of the abnormal respiratory chain function, reduce the presence of toxic agents or correct deficiencies in essential cofactors. EXPERIMENTAL APPROACH: We evaluated the effectiveness of some common pharmacological agents that have been utilized in the treatment of MELAS, in yeast, fibroblast and cybrid models of the disease. The yeast model harbouring the A14G mutation in the mitochondrial tRNALeu(UUR) gene, which is equivalent to the A3243G mutation in humans, was used in the initial screening. Next, the most effective drugs that were able to rescue the respiratory deficiency in MELAS yeast mutants were tested in fibroblasts and cybrid models of MELAS disease. KEY RESULTS: According to our results, supplementation with riboflavin or coenzyme Q(10) effectively reversed the respiratory defect in MELAS yeast and improved the pathologic alterations in MELAS fibroblast and cybrid cell models. CONCLUSIONS AND IMPLICATIONS: Our results indicate that cell models have great potential for screening and validating the effects of novel drug candidates for MELAS treatment and presumably also for other diseases with mitochondrial impairment.