Apoptosis, Induced by Human α-Synuclein in Yeast, Can Occur Independent of Functional Mitochondria

Human α-synuclein expression in baker’s yeast reportedly induces mitochondria-dependent apoptosis. Surprisingly, we find that, under de-repressing conditions of the inducible MET25/GAL1 promoters, yeast cells expressing chromosomally-integrated copies of the human α-synuclein gene are not killed, but spontaneously form respiration-deficient rho-minus (ρ−) petites. Although yeast cells can undergo cell death (apoptosis) from loss of mitochondrial function, they can also survive without functional mitochondria. Such cells are referred to as ρ0 or ρ− petites. This study reports that minimal expression of human α-synuclein in yeast, from MET25/GAL1 promoter, gives rise to ρ− petites. Interestingly, the full expression of α-synuclein, from the same promoters, in α-synuclein-triggered ρ− petites and also in ρ0 petites (produced by treating ρ+ cells with the mutagen ethidium bromide) initiates apoptosis. The percentages of petites increase with increasing α-synuclein gene copy-number. ρ− petites expressing α-synuclein from fully-induced MET25/GAL1 promoters exhibit increased ROS levels, loss of mitochondrial membrane potential, and nuclear DNA fragmentation, with increasing copies of α-synuclein. Our results indicate that, for the first time in yeast, α-synuclein-triggered apoptosis can occur independently of functional mitochondria. The observation that α-synuclein naturally forms petites and that they can undergo apoptosis may have important implications in understanding the pathogenesis of Parkinson’s disease.

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Sperm of patients with severe asthenozoospermia show biochemical, molecular and genomic alterations

Reproduction ◽

10.1530/rep-16-0342 ◽

2016 ◽

Vol 152 (6) ◽

pp. 695-704 ◽

Cited By ~ 22

Author(s):

Oriana Bonanno ◽

Giulietta Romeo ◽

Paola Asero ◽

Franca Maria Pezzino ◽

Roberto Castiglione ◽

...

Keyword(s):

Copy Number ◽

Mitochondrial Membrane ◽

Nuclear Dna ◽

Pathological Condition ◽

Ros Production ◽

Oxygen Species ◽

Mtdna Copy Number ◽

Sperm Abnormalities ◽

Fertilizing Ability ◽

Nuclear Dna Fragmentation

The multifactorial pathological condition, that is, severe low sperm motility is a frequent cause of infertility. However, mechanisms underlying the development of this condition are not completely understood. Single abnormalities have been reported in sperm of patients with asthenozoospermia. In this study, we characterized, in 22 normozoospermic men and in 37 patients with asthenozoospermia, biochemical, molecular and genomic abnormalities that frequently occur in sperm of patients with asthenozoospermia. We evaluated a panel of sperm biomarkers that may affect the motility and fertilizing ability of sperm of patients with severe asthenozoospermia. Since reactive oxygen species (ROS) production is involved in the pathogenesis of such sperm abnormalities, we determined the association between ROS production and sperm abnormalities. High percentage of patients with severe asthenozoospermia showed increased basal and stimulated ROS production. Moreover, these patients showed increased mitochondrial DNA (mtDNA) copy number but decreased mtDNA integrity and they were associated with elevated ROS levels. Furthermore, mitochondrial membrane potential was also significantly decreased and again associated with high ROS production in these patients. However, the rate of nuclear DNA fragmentation was increased only in less than one-fifth of these patients. An important cohort of these patients showed multiple identical biochemical, molecular and genomic abnormalities, which are typical manifestations of oxidative stress. The most frequent association was found in patients with high ROS levels, increased mtDNA copy number and decreased integrity, and low MMP. A smaller cohort of the aforementioned patients also showed nDNA fragmentation. Therefore, patients with asthezoospermia likely present reduced fertilizing potential because of such composed abnormalities.

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Assessment of HER-2/neu, с-MYC and CCNE1 gene copy number variations and protein expression in endometrial carcinomas

Experimental Oncology ◽

10.32471/exp-oncology.2312-8852.vol-41-no-2.12973 ◽

2019 ◽

Vol 41 (2) ◽

Author(s):

L.G. Buchynska ◽

◽

O.V. Brieieva* ◽

N.P. Iurchenko ◽

◽

...

Keyword(s):

Protein Expression ◽

Copy Number ◽

Gene Copy Number ◽

Copy Number Variations ◽

Gene Copy ◽

Her 2 ◽

Endometrial Carcinomas

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Faculty Opinions recommendation of Diet and the evolution of human amylase gene copy number variation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1092307.546722 ◽

2007 ◽

Author(s):

Magnus Ingelman-Sundberg

Keyword(s):

Copy Number Variation ◽

Copy Number ◽

Gene Copy Number ◽

Gene Copy ◽

Amylase Gene ◽

Gene Copy Number Variation ◽

Number Variation

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Faculty Opinions recommendation of RNA polymerase I activators count and adjust ribosomal RNA gene copy number.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734776122.793556076 ◽

2019 ◽

Author(s):

Angela Taddei

Keyword(s):

Rna Polymerase ◽

Ribosomal Rna ◽

Copy Number ◽

Gene Copy Number ◽

Rna Polymerase I ◽

Gene Copy ◽

Ribosomal Rna Gene ◽

Polymerase I

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Estimating Copy-Number Proportions: The Comeback of Sanger Sequencing

Genes ◽

10.3390/genes12020283 ◽

2021 ◽

Vol 12 (2) ◽

pp. 283

Author(s):

Eyal Seroussi

Keyword(s):

Copy Number ◽

Sanger Sequencing ◽

Cytosine Methylation ◽

Direct Sequencing ◽

Information Source ◽

Gene Copy Number ◽

Cost Effective ◽

Gene Copy ◽

Base Editing ◽

Recent Developments

Determination of the relative copy numbers of mixed molecular species in nucleic acid samples is often the objective of biological experiments, including Single-Nucleotide Polymorphism (SNP), indel and gene copy-number characterization, and quantification of CRISPR-Cas9 base editing, cytosine methylation, and RNA editing. Standard dye-terminator chromatograms are a widely accessible, cost-effective information source from which copy-number proportions can be inferred. However, the rate of incorporation of dye terminators is dependent on the dye type, the adjacent sequence string, and the secondary structure of the sequenced strand. These variable rates complicate inferences and have driven scientists to resort to complex and costly quantification methods. Because these complex methods introduce their own biases, researchers are rethinking whether rectifying distortions in sequencing trace files and using direct sequencing for quantification will enable comparable accurate assessment. Indeed, recent developments in software tools (e.g., TIDE, ICE, EditR, BEEP and BEAT) indicate that quantification based on direct Sanger sequencing is gaining in scientific acceptance. This commentary reviews the common obstacles in quantification and the latest insights and developments relevant to estimating copy-number proportions based on direct Sanger sequencing, concluding that bidirectional sequencing and sophisticated base calling are the keys to identifying and avoiding sequence distortions.

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Nongenotoxic ABCB1 activator tetraphenylphosphonium can contribute to doxorubicin resistance in MX-1 breast cancer cell line

Scientific Reports ◽

10.1038/s41598-021-86120-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Raimonda Kubiliute ◽

Indre Januskeviciene ◽

Ruta Urbanaviciute ◽

Kristina Daniunaite ◽

Monika Drobniene ◽

...

Keyword(s):

Breast Cancer ◽

Cell Line ◽

Protein Level ◽

Copy Number ◽

Gene Copy Number ◽

Gene Copy ◽

Common Mechanism ◽

Dna Hypomethylation ◽

Mesenchymal Transition ◽

Molecular Features

AbstractHyperactivation of ABC transporter ABCB1 and induction of epithelial–mesenchymal transition (EMT) are the most common mechanism of acquired cancer chemoresistance. This study describes possible mechanisms, that might contribute to upregulation of ABCB1 and synergistically boost the acquisition of doxorubicin (DOX) resistance in breast cancer MX-1 cell line. DOX resistance in MX-1 cell line was induced by a stepwise increase of drug concentration or by pretreatment of cells with an ABCB1 transporter activator tetraphenylphosphonium (TPP+) followed by DOX exposure. Transcriptome analysis of derived cells was performed by human gene expression microarrays and by quantitative PCR. Genetic and epigenetic mechanisms of ABCB1 regulation were evaluated by pyrosequencing and gene copy number variation analysis. Gradual activation of canonical EMT transcription factors with later activation of ABCB1 at the transcript level was observed in DOX-only treated cells, while TPP+ exposure induced considerable activation of ABCB1 at both, mRNA and protein level. The changes in ABCB1 mRNA and protein level were related to the promoter DNA hypomethylation and the increase in gene copy number. ABCB1-active cells were highly resistant to DOX and showed morphological and molecular features of EMT. The study suggests that nongenotoxic ABCB1 inducer can possibly accelerate development of DOX resistance.

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