Trigger 10 - Revision, Consolidation and Application of Knowledge Flashcards
Would measuring epigenetic changes in saliva give a good representation of what is happening in other organs?
No, while saliva-based liquid biopsy is cost-effective and non-invasive, it may not provide a comprehensive representation of epigenetic changes in specific organs due to variations in epigenetic modifications among different tissues and cell types.
How would you analyze the data obtained from measuring DNA methylation levels?
The DNA methylation pattern of specific genomic regions is examined, typically using techniques like Illumina DNA methylation arrays. Hypermethylation of certain genes can indicate disease states, such as hypermethylated oestrogen receptor genes for cardiovascular disease.
The technique used to measure DNA methylation levels is ______________.
Illumina DNA methylation arrays are commonly used to measure DNA methylation levels, allowing for highly multiplexed measurements of DNA methylation at individual CpG islands.
Which of the following is NOT a type of epigenetic modification?
A) DNA Methylation
B) Histone Acetylation
C) RNA Splicing
D) Chromatin Remodeling
C) RNA Splicing
True or False:
Statement: A change in mRNA expression always leads to a corresponding change in protein levels/activity.
False. Post-transcriptional and post-translational regulations can affect protein levels/activity independently of mRNA expression changes.
How could genetic risk scores be used to determine who would benefit most from lifestyle interventions?
Genetic risk scores can categorize individuals based on their genetic predisposition to certain diseases, allowing for targeted lifestyle interventions for those at higher risk, potentially optimizing the effectiveness of interventions.
What drugs are available to target epigenetic changes?
Methylation inhibiting drugs such as 5-Azacytidine and Guadecitabine, as well as histone deacetylase (HDAC) inhibitors like valproic acid, are among the drugs used to target epigenetic changes
True or False:
Statement: Epigenetic information availability does not raise ethical concerns related to privacy and discrimination.
False. Epigenetic information availability raises significant ethical concerns regarding privacy, discrimination by insurance companies or employers, and informed consent.
What is the gold standard technique for quantifying genome-wide DNA modification levels?
Whole genome bisulfite sequencing is considered the gold standard technique for quantifying genome-wide DNA modification levels, providing single-base resolution information about DNA methylation patterns.
How does chromatin remodeling influence gene expression regulation?
Chromatin remodeling involves altering the positioning and accessibility of nucleosomes, thereby regulating gene expression by controlling the accessibility of DNA to transcription factors and regulatory proteins.
Which of the following is NOT a type of epigenetic modification?
A) DNA Methylation
B) Histone Methylation
C) mRNA Splicing
D) Chromatin Remodeling
C) mRNA Splicing
True or False:
Statement: CRISPR-based gene editing allows for the precise modification of gene expression patterns by introducing specific sequence alterations.
True. CRISPR-based gene editing can precisely modify gene expression patterns by directing the Cas nuclease to specific DNA sequences.
What is the role of RNA interference (RNAi) in gene expression regulation?
RNA interference involves the post-transcriptional silencing of specific genes by introducing small interfering RNA (siRNA) or microRNAs (miRNAs) to target and degrade complementary mRNA molecules.
True or False:
Statement: Workplace discrimination based on epigenetic information is not a concern as it does not provide accurate predictions of life expectancy or chronic illness.
False. Workplace discrimination based on epigenetic information, such as predictions of life expectancy or chronic illness, is a significant ethical concern.
How does alternative splicing contribute to gene expression regulation?
Alternative splicing allows for the inclusion/exclusion of different exons during pre-mRNA processing, leading to the production of multiple mRNA isoforms from a single gene, thereby regulating gene expression by generating different protein variants or isoforms.
True or False:
Statement: The spatial organization of chromatin within the nucleus has no impact on gene expression regulation.
False. The spatial organization of chromatin within the nucleus can affect gene expression by facilitating interactions between regulatory elements and target genes.
What is the significance of post-translational modifications in regulating protein activity?
Post-translational modifications, such as phosphorylation, acetylation, ubiquitination, and glycosylation, can alter protein activity, stability, and localization, thereby regulating various cellular processes and pathways.
Which of the following techniques allows for the precise editing of gene expression patterns at the genomic level?
A) RNA Interference
B) Small Molecule Inhibitors
C) Chromatin Remodeling
D) CRISPR-based Gene Editing
D) CRISPR-based Gene Editing
How does RNA interference (RNAi) differ from CRISPR-based gene editing in terms of gene regulation mechanisms?
RNA interference (RNAi) involves the post-transcriptional silencing of specific genes by degrading complementary mRNA molecules using small interfering RNA (siRNA) or microRNAs (miRNAs), whereas CRISPR-based gene editing allows for the precise modification of gene expression patterns by introducing specific sequence alterations at the genomic level.
True or False:
Statement: Epigenetic changes, such as DNA methylation, only occur in somatic cells and do not impact germline cells.
False. Epigenetic changes, including DNA methylation, can occur in both somatic and germline cells, potentially influencing gene expression in subsequent generations.
What is the role of histone modification in gene expression regulation?
Histone modification involves post-translational modifications to histone proteins, such as methylation, acetylation, phosphorylation, and ubiquitination, which can either activate or repress gene transcription by altering chromatin structure and accessibility to transcription factors.
True or False:
Statement: Genetic risk scores are solely based on environmental factors and lifestyle choices.
False. Genetic risk scores are calculated based on genetic variants associated with certain traits or diseases, in addition to considering environmental factors and lifestyle choices.
How does methylation of promoter regions influence gene expression?
Methylation of promoter regions can lead to gene silencing by blocking the binding of transcription factors and recruiting proteins involved in gene repression, thereby reducing or preventing gene transcription.
Which of the following is NOT a method used to measure DNA methylation levels?
A) Methylated DNA Immunoprecipitation Sequencing (MeDIP-seq)
B) CRISPR-based Gene Editing
C) Reduced Representation Bisulfite Sequencing
D) Whole Genome Bisulfite Sequencing
B) CRISPR-based Gene Editing
True or False:
Statement: Histone modification refers only to changes in the amino acid sequence of histone proteins.
False. Histone modification includes various post-translational modifications to histone proteins, such as methylation, acetylation, phosphorylation, and ubiquitination.
How does the technique of reduced representation bisulfite sequencing (RRBS) work in quantifying DNA methylation levels?
Reduced representation bisulfite sequencing (RRBS) selectively sequences regions of the genome that are enriched for CpG sites, allowing for the quantification of DNA methylation levels at specific genomic loci with reduced sequencing costs compared to whole-genome bisulfite sequencing.
Which of the following techniques allows for the quantification of DNA modification levels at many or all cytosines in the genome?
A) Chromatin Immunoprecipitation Sequencing (ChIP-seq)
B) Methylated DNA Immunoprecipitation Sequencing (MeDIP-seq)
C) Reduced Representation Bisulfite Sequencing (RRBS)
D) Whole Genome Bisulfite Sequencing (WGBS)
D) Whole Genome Bisulfite Sequencing (WGBS)
How does the technique of methylated DNA immunoprecipitation sequencing (MeDIP-seq) work in quantifying DNA methylation levels?
MeDIP-seq involves immunoprecipitation of methylated DNA fragments using specific antibodies, followed by sequencing to determine the locations of methylated regions in the genome, providing information about DNA methylation patterns.
True or False:
Statement: DNA methylation occurs exclusively at cytosine residues in CpG dinucleotides.
False. While DNA methylation predominantly occurs at cytosine residues in CpG dinucleotides, it can also occur at non-CpG sites, albeit at lower frequencies, particularly in certain cell types such as embryonic stem cells.
How do DNA methyltransferase inhibitors, such as 5-Azacytidine, function in modulating DNA methylation levels?
DNA methyltransferase inhibitors interfere with the activity of DNA methyltransferase enzymes, preventing the addition of methyl groups to cytosine residues, thereby leading to DNA demethylation and alterations in gene expression patterns.
What is hypoxia signaling?
Hypoxia signaling involves the activation of Hypoxia-Inducible Factors (HIFs) under low oxygen conditions, leading to the transcriptional regulation of genes involved in various physiological responses.
How does hypoxia response affect cellular physiology?
Hypoxia response leads to increased vascularization, enhanced ventilation and cardiac output, metabolic shift from aerobic to anaerobic, and promotion of improved oxygen carrying capacity.
In hypoxic conditions, the enzymatic activity of PHD is inhibited, preventing HIF-a hydroxylation and ubiquitin-mediated proteasome degradation, thus stabilizing HIF-a proteins and allowing them to translocate to the nucleus and induce the expression of downstream genes containing ______________.
Hypoxia-responsive elements (HREs).
True or False:
Statement: Increased cardiac output is one of the major physiological effects of hypoxia response.
True
What is a major physiological effect of hypoxia response?
A) Decreased ventilation
B) Reduced vascularization
C) Increase in blood oxygen carrying capacity
D) Shift from anaerobic to aerobic metabolism
C) Increase in blood oxygen carrying capacity
How can animal models be used to study human diseases?
Animal models are used for studying human diseases through techniques such as cell transplantation, transgenesis, and injection, allowing researchers to simulate disease conditions and study disease mechanisms in vivo.
What are the advantages and disadvantages of in vivo model systems?
In vivo models allow the study of entire organ systems, provide control over experimental conditions, and enable longitudinal studies, but may not always replicate human symptoms accurately and raise ethical concerns.
In vitro models are more ethically suitable compared to in vivo models, but they only represent the response of specific cells or tissues used in the experiment, thus limiting the ______________.
Generalizability of results.
True or False:
Statement: In vitro models are cheaper and quicker than in vivo models, but their findings may need confirmation using in vivo models.
True
Which of the following is NOT a method used to model human diseases in animals?
A) Cell transplantation
B) Transgenesis
C) In vitro culture
D) Injection
C) In vitro culture
What hurdles are associated with oxygen availability in islet transplantation, and how does cotransplantation with MSCs address these hurdles?
Islet transplantation faces challenges such as poor islet graft revascularization and hypoxia, leading to islet death. Cotransplantation with MSCs can increase oxygenation, induce revascularization, and enhance islet function.
Cotransplantation of MSCs with islets can lead to enhanced mitochondrial function and improved islet function by increasing glucose-stimulated oxygen consumption rate and reducing ______________.
Hypoxia-related islet death.
True or False:
Statement: Hypertension can increase the risk of dementia by causing brain damage due to oxidative stress and DNA damage.
True
How can hypertension affect oxygen distribution in the brain and promote the development of dementia?
A) By reducing blood perfusion to capillaries
B) By increasing neurogenesis
C) By decreasing white matter hyperintensities
D) By promoting endothelial function
A) By reducing blood perfusion to capillaries
How does hypoxia contribute to the development of sarcopenia?
Hypoxia disrupts mitochondrial function, induces oxidative stress, and inhibits the mTOR pathway, leading to muscle atrophy and sarcopenia.
Hypoxia-induced inhibition of the mTOR pathway can lead to reduced muscle protein synthesis (MPS), contributing to ______________.
Muscle atrophy.
True or False:
Statement: Hyperbaric oxygen therapy is used in clinical settings to treat sarcopenia by enhancing muscle strength and function.
False. Hyperbaric oxygen therapy is not commonly used to treat sarcopenia.
What is a potential therapeutic strategy for addressing sarcopenia associated with hypoxia?
A) Hyperbaric oxygen therapy
B) Stem cell transplantation
C) Gene therapy
D) Chemotherapy
B) Stem cell transplantation
What is hypoxia?
Hypoxia is a condition characterized by a deficiency in the amount of oxygen reaching the tissues, leading to cellular stress and adaptive responses.
How do Hypoxia-Inducible Factors (HIFs) mediate cellular responses to hypoxic conditions?
HIFs are transcription factors that, under hypoxic conditions, stabilize and translocate to the nucleus, where they bind to hypoxia-responsive elements (HREs) on target genes, regulating their expression and promoting adaptive responses to hypoxia.
In normoxic conditions, HIF-a proteins undergo rapid ubiquitination and degradation by the proteasome through hydroxylation of prolyl residues mediated by ______________.
Prolyl hydroxylase enzymes (PHDs).
True or False:
Statement: HIF-a proteins contain an oxygen-dependent degradation domain utilized by the proline hydroxylase family (PHDs) and von Hippel-Lindau protein (pVHL) for ubiquitin-mediated proteasomal degradation under normoxic conditions.
True
What is the primary function of HIFs under hypoxic conditions?
A) Promoting ubiquitination of target proteins
B) Inducing mitochondrial biogenesis
C) Regulating gene expression to adapt to low oxygen levels
D) Inhibiting angiogenesis
C) Regulating gene expression to adapt to low oxygen levels
What is in vitro modeling?
In vitro modeling involves studying biological processes or disease mechanisms using isolated cells or tissues cultured outside their natural environment, typically in laboratory settings.
