Publications by authors named "Luna Laera"

7 Publications

  • Page 1 of 1

Differential Expression of ADP/ATP Carriers as a Biomarker of Metabolic Remodeling and Survival in Kidney Cancers.

Biomolecules 2020 Dec 30;11(1). Epub 2020 Dec 30.

Department of Biosciences, Biotechnologies, Biopharmaceutics, University "Aldo Moro" of Bari, Via E. Orabona, 4, 70125 Bari, Italy.

ADP/ATP carriers (AACs) are mitochondrial transport proteins playing a strategic role in maintaining the respiratory chain activity, fueling the cell with ATP, and also regulating mitochondrial apoptosis. To understand if AACs might represent a new molecular target for cancer treatment, we evaluated AAC expression levels in cancer/normal tissue pairs available on the Tissue Cancer Genome Atlas database (TCGA), observing that AACs are dysregulated in most of the available samples. It was observed that at least two AACs showed a significant differential expression in all the available kidney cancer/normal tissue pairs. Thus, we investigated AAC expression in the corresponding kidney non-cancer (HK2)/cancer (RCC-Shaw and CaKi-1) cell lines, grown in complete medium or serum starvation, for investigating how metabolic alteration induced by different growth conditions might influence AAC expression and resistance to mitochondrial apoptosis initiators, such as "staurosporine" or the AAC highly selective inhibitor "carboxyatractyloside". Our analyses showed that AAC2 and AAC3 transcripts are more expressed than AAC1 in all the investigated kidney cell lines grown in complete medium, whereas serum starvation causes an increase of at least two AAC transcripts in kidney cancer cell lines compared to non-cancer cells. However, the total AAC protein content is decreased in the investigated cancer cell lines, above all in the serum-free medium. The observed decrease in AAC protein content might be responsible for the decrease of OXPHOS activity and for the observed lowered sensitivity to mitochondrial apoptosis induced by staurosporine or carboxyatractyloside. Notably, the cumulative probability of the survival of kidney cancer patients seriously decreases with the decrease of AAC1 expression in KIRC and KIRP tissues making AAC1 a possible new biomarker of metabolic remodeling and survival in kidney cancers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/biom11010038DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7824283PMC
December 2020

Mitochondrial Membranes of Human SH-SY5Y Neuroblastoma Cells Express Serotonin 5-HT Receptor.

Int J Mol Sci 2020 Dec 17;21(24). Epub 2020 Dec 17.

Biofordrug srl, via Dante 99, 70019 Triggiano (Bari), Italy.

Mitochondria in neurons contribute to energy supply, the regulation of synaptic transmission, Ca homeostasis, neuronal excitability, and stress adaptation. In recent years, several studies have highlighted that the neurotransmitter serotonin (5-HT) plays an important role in mitochondrial biogenesis in cortical neurons, and regulates mitochondrial activity and cellular function in cardiomyocytes. 5-HT exerts its diverse actions by binding to cell surface receptors that are classified into seven distinct families (5-HT1 to 5-HT7). Recently, it was shown that 5-HT3 and 5-HT4 receptors are located on the mitochondrial membrane and participate in the regulation of mitochondrial function. Furthermore, it was observed that activation of brain 5-HT7 receptors rescued mitochondrial dysfunction in female mice from two models of Rett syndrome, a rare neurodevelopmental disorder characterized by severe behavioral and physiological symptoms. Our Western blot analyses performed on cell-lysate and purified mitochondria isolated from neuronal cell line SH-SY5Y showed that 5-HT7 receptors are also expressed into mitochondria. Maximal binding capacity (Bmax) obtained by Scatchard analysis on purified mitochondrial membranes was 0.081 pmol/mg of 5-HT7 receptor protein. Lastly, we evaluated the effect of selective 5-HT7 receptor agonist LP-211 and antagonist (inverse agonist) SB-269970 on mitochondrial respiratory chain (MRC) cytochrome c oxidase activity on mitochondria from SH-SY5Y cells. Our findings provide the first evidence that 5-HT7 receptor is also expressed in mitochondria.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms21249629DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7766962PMC
December 2020

FAD/NADH Dependent Oxidoreductases: From Different Amino Acid Sequences to Similar Protein Shapes for Playing an Ancient Function.

J Clin Med 2019 Dec 2;8(12). Epub 2019 Dec 2.

Laboratory of Biochemistry; Molecular and Structural Biology; Department of Biosciences, Biotechnologies, Biopharmaceutics; University of Bari; Via E. Orabona 4; 70125 Bari, Italy.

Flavoprotein oxidoreductases are members of a large protein family of specialized dehydrogenases, which include type II NADH dehydrogenase, pyridine nucleotide-disulphide oxidoreductases, ferredoxin-NAD+ reductases, NADH oxidases, and NADH peroxidases, playing a crucial role in the metabolism of several prokaryotes and eukaryotes. Although several studies have been performed on single members or protein subgroups of flavoprotein oxidoreductases, a comprehensive analysis on structure-function relationships among the different members and subgroups of this great dehydrogenase family is still missing. Here, we present a structural comparative analysis showing that the investigated flavoprotein oxidoreductases have a highly similar overall structure, although the investigated dehydrogenases are quite different in functional annotations and global amino acid composition. The different functional annotation is ascribed to their participation in species-specific metabolic pathways based on the same biochemical reaction, i.e., the oxidation of specific cofactors, like NADH and FADH. Notably, the performed comparative analysis sheds light on conserved sequence features that reflect very similar oxidation mechanisms, conserved among flavoprotein oxidoreductases belonging to phylogenetically distant species, as the bacterial type II NADH dehydrogenases and the mammalian apoptosis-inducing factor protein, until now retained as unique protein entities in or , respectively. Furthermore, the presented computational analyses will allow consideration of FAD/NADH oxidoreductases as a possible target of new small molecules to be used as modulators of mitochondrial respiration for patients affected by rare diseases or cancer showing mitochondrial dysfunction, or antibiotics for treating bacterial/fungal/protista infections.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/jcm8122117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6947548PMC
December 2019

CRAT missense variants cause abnormal carnitine acetyltransferase function in an early-onset case of Leigh syndrome.

Hum Mutat 2020 01 23;41(1):110-114. Epub 2019 Sep 23.

Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, Bari, Italy.

Leigh syndrome, or subacute necrotizing encephalomyelopathy, is one of the most severe pediatric disorders of the mitochondrial energy metabolism. By performing whole-exome sequencing in a girl affected by Leigh syndrome and her parents, we identified two heterozygous missense variants (p.Tyr110Cys and p.Val569Met) in the carnitine acetyltransferase (CRAT) gene, encoding an enzyme involved in the control of mitochondrial short-chain acyl-CoA concentrations. Biochemical assays revealed carnitine acetyltransferase deficiency in the proband-derived fibroblasts. Functional analyses of recombinant-purified CRAT proteins demonstrated that both missense variants, located in the acyl-group binding site of the enzyme, severely impair its catalytic function toward acetyl-CoA, and the p.Val569Met variant also toward propionyl-CoA and octanoyl-CoA. Although a single recessive variant in CRAT has been recently associated with neurodegeneration with brain iron accumulation (NBIA), this study reports the first kinetic analysis of naturally occurring CRAT variants and demonstrates the genetic basis of carnitine acetyltransferase deficiency in a case of mitochondrial encephalopathy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/humu.23901DOI Listing
January 2020

6-Thioguanine and Its Analogs Promote Apoptosis of Castration-Resistant Prostate Cancer Cells in a BRCA2-Dependent Manner.

Cancers (Basel) 2019 Jul 5;11(7). Epub 2019 Jul 5.

Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Via Amendola 122/O, 70126 Bari, Italy.

: Mutations in the oncosuppressor gene () predispose to aggressive forms of prostate cancer which show poor response to taxane-based therapy, the standard treatment for castration-resistant, aggressive prostate cancer. Herein, we addressed the question whether changes in BRCA2 expression, a potential surrogate marker for BRCA2 activity, may affect the response of castration-resistant prostate cancer cells to 6-thioguanine (6-TG), a thiopurine used in the treatment of haematological malignancies. : Yeast, normal prostate cells and castration-resistant prostate cancer cells were treated with 6-TG or its analogues, in presence or absence of paclitaxel, or with olaparib, a poly-(ADP-ribose) polymerase (PARP) inhibitor currently in clinical trials for treatment of metastatic castration-resistant prostate cancer, and cell proliferation, apoptosis and androgen receptor (AR) levels were measured. : 6-TG inhibited cell proliferation in yeast, normal and castration-resistant prostate cancer cells but promoted apoptosis only in cancer cells. Suppression of BRCA2 expression by siRNA or shRNA increased the sensitivity to 6-TG- and olaparib-induced apoptosis but did not affect cancer cell response to taxane. Intriguingly, 6-TG reduced AR expression levels independently on BRCA2 expression. Instead, olaparib decreased AR levels only in BRCA2-knockdown prostate cancer cells. Notably, overexpression of BRCA2 resulted in resistance of castration-resistant prostate cancer cells to 6-TG-, taxane- and olaparib-based treatment but promoted sensitivity to apoptosis induced by 2-amino-6-bromopurine and 2,6-dithiopurine, two 6-TG analogues. : Our results provide a pre-clinical rationale for the use of 6-TG in the treatment of BRCA2-deficient castration-resistant prostate cancers, and of certain 6-TG analogues for treatment of BRCA2-proficient prostate cancers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers11070945DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6678799PMC
July 2019

SLC25A10 biallelic mutations in intractable epileptic encephalopathy with complex I deficiency.

Hum Mol Genet 2018 02;27(3):499-504

Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, 70125 Bari, Italy.

Mitochondrial diseases are a plethora of inherited neuromuscular disorders sharing defects in mitochondrial respiration, but largely different from one another for genetic basis and pathogenic mechanism. Whole exome sequencing was performed in a familiar trio (trio-WES) with a child affected by severe epileptic encephalopathy associated with respiratory complex I deficiency and mitochondrial DNA depletion in skeletal muscle. By trio-WES we identified biallelic mutations in SLC25A10, a nuclear gene encoding a member of the mitochondrial carrier family. Genetic and functional analyses conducted on patient fibroblasts showed that SLC25A10 mutations are associated with reduction in RNA quantity and aberrant RNA splicing, and to absence of SLC25A10 protein and its transporting function. The yeast SLC25A10 ortholog knockout strain showed defects in mitochondrial respiration and mitochondrial DNA content, similarly to what observed in the patient skeletal muscle, and growth susceptibility to oxidative stress. Albeit patient fibroblasts were depleted in the main antioxidant molecules NADPH and glutathione, transport assays demonstrated that SLC25A10 is unable to transport glutathione. Here, we report the first recessive mutations of SLC25A10 associated to an inherited severe mitochondrial neurodegenerative disorder. We propose that SLC25A10 loss-of-function causes pathological disarrangements in respiratory-demanding conditions and oxidative stress vulnerability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/hmg/ddx419DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5886107PMC
February 2018

The transcription factors or are required for RTG pathway activation and evasion from yeast acetic acid-induced programmed cell death in raffinose.

Microb Cell 2016 Dec 2;3(12):621-631. Epub 2016 Dec 2.

National Research Council of Italy, Institute of Biomembranes and Bioenergetics, Bari, Italy.

Yeast grown on glucose undergoes programmed cell death (PCD) induced by acetic acid (AA-PCD), but evades PCD when grown in raffinose. This is due to concomitant relief of carbon catabolite repression (CCR) and activation of mitochondrial retrograde signaling, a mitochondria-to-nucleus communication pathway causing up-regulation of various nuclear target genes, such as , encoding peroxisomal citrate synthase, dependent on the positive regulator in response to mitochondrial dysfunction. CCR down-regulates genes mainly involved in mitochondrial respiratory metabolism. In this work, we investigated the relationships between the RTG and CCR pathways in the modulation of AA-PCD sensitivity under glucose repression or de-repression conditions. Yeast single and double mutants lacking and/or certain factors regulating carbon source utilization, including , , , , and , have been analyzed for their survival and expression after acetic acid treatment. and were identified as positive regulators of -dependent gene transcription. and interact with and with each other in inducing cell resistance to AA-PCD in raffinose and controlling the nature of cell death. In the absence of and , AA-PCD evasion is acquired through activation of an alternative factor/pathway repressed by suggesting that may play a function in promoting necrotic cell death in repressing conditions when RTG pathway is inactive. Moreover, our data show that simultaneous mitochondrial retrograde pathway activation and -dependent relief of CCR have a key role in central carbon metabolism reprogramming which modulates the yeast acetic acid-stress response.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.15698/mic2016.12.549DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5348981PMC
December 2016