Premature ovarian ageing following heterozygous loss of Senataxin

2020 ◽  
Author(s):  
G N Subramanian ◽  
M Lavin ◽  
H A Homer
Keyword(s):  
Dna Damage ◽  
Neurodegenerative Disorder ◽  
Dna Helicase ◽  
Dna Integrity ◽  
Ovarian Activity ◽  
Homozygous Mutation ◽  
Female Mice ◽  
Mating Trial ◽  
High Prevalence

Abstract Premature loss of ovarian activity before 40 years of age is known as primary ovarian insufficiency (POI) and occurs in ∼1% of women. A more subtle decline in ovarian activity, known as premature ovarian ageing (POA), occurs in ∼10% of women. Despite the high prevalence of POA, very little is known regarding its genetic causation. Senataxin (SETX) is an RNA/DNA helicase involved in repair of oxidative stress-induced DNA damage. Homozygous mutation of SETX leads to the neurodegenerative disorder, ataxia oculomotor apraxia type 2 (AOA2). There have been reports of POI in AOA2 females suggesting a link between SETX and ovarian ageing. Here, we studied female mice lacking either one (Setx+/−) or both (Setx−/−) copies of SETX over a 12- to 14-month period. We find that DNA damage is increased in oocytes from 8-month-old Setx+/− and Setx−/− females compared with Setx+/+ oocytes leading to a marked reduction in all classes of ovarian follicles at least 4 months earlier than typically occurs in female mice. Furthermore, during a 12-month long mating trial, Setx+/− and Setx−/− females produced significantly fewer pups than Setx+/+ females from 7 months of age onwards. These data show that SETX is critical for preventing POA in mice, likely by preserving DNA integrity in oocytes. Intriguingly, heterozygous Setx loss causes an equally severe impact on ovarian ageing as homozygous Setx loss. Because heterozygous SETX disruption is less likely to produce systemic effects, SETX compromise could underpin some cases of insidious POA.

scholarly journals Senataxin: A New Guardian of the Female Germline Important for Delaying Ovarian Aging

2021 ◽  
Vol 12 ◽  
Author(s):  
Hayden A. Homer
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Ovarian Reserve ◽  
Ovarian Function ◽  
Dna Helicase ◽  
Dna Integrity ◽  
Low Grade ◽  
Critical Determinant ◽  
Oocyte Growth ◽  
Ovarian Aging

Early decline in ovarian function known as premature ovarian aging (POA) occurs in around 10% of women and is characterized by a markedly reduced ovarian reserve. Premature ovarian insufficiency (POI) affects ~1% of women and refers to the severe end of the POA spectrum in which, accelerated ovarian aging leads to menopause before 40 years of age. Ovarian reserve refers to the total number of follicle-enclosed oocytes within both ovaries. Oocyte DNA integrity is a critical determinant of ovarian reserve since damage to DNA of oocytes within primordial-stage follicles triggers follicular apoptosis leading to accelerated follicle depletion. Despite the high prevalence of POA, very little is known regarding its genetic causation. Another little-investigated aspect of oocyte DNA damage involves low-grade damage that escapes apoptosis at the primordial follicle stage and persists throughout oocyte growth and later follicle development. Senataxin (SETX) is an RNA/DNA helicase involved in repair of oxidative stress-induced DNA damage and is well-known for its roles in preventing neurodegenerative disease. Recent findings uncover an important role for SETX in protecting oocyte DNA integrity against aging-induced increases in oxidative stress. Significantly, this newly identified SETX-mediated regulation of oocyte DNA integrity is critical for preventing POA and early-onset female infertility by preventing premature depletion of the ovarian follicular pool and reducing the burden of low-grade DNA damage both in primordial and fully-grown oocytes.

scholarly journals High prevalence of previously unknown heart failure and left ventricular dysfunction in patients with type 2 diabetes

Diabetologia ◽  
2012 ◽  
Vol 55 (8) ◽  
pp. 2154-2162 ◽  
Author(s):  
L. J. M. Boonman-de Winter ◽  
F. H. Rutten ◽  
M. J. M. Cramer ◽  
M. J. Landman ◽  
A. H. Liem ◽  
...  
Keyword(s):  
Heart Failure ◽  
Type 2 Diabetes ◽  
Left Ventricular Dysfunction ◽  
Ventricular Dysfunction ◽  
Left Ventricular ◽  
High Prevalence

scholarly journals Polyphosphate Reverses the Toxicity of the Quasi-Enzyme Bleomycin on Alveolar Endothelial Lung Cells In Vitro

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 750
Author(s):  
Werner E. G. Müller ◽  
Meik Neufurth ◽  
Shunfeng Wang ◽  
Heinz C. Schröder ◽  
Xiaohong Wang
Keyword(s):  
Dna Damage ◽  
Human Lung ◽  
Dna Integrity ◽  
Lung Cells ◽  
Antitumor Antibiotic ◽  
Cell Toxicity ◽  
Inorganic Polyphosphate ◽  
Human Lung Cells ◽  
Anti Cancer

The anti-cancer antitumor antibiotic bleomycin(s) (BLM) induces athyminic sites in DNA after its activation, a process that results in strand splitting. Here, using A549 human lung cells or BEAS-2B cells lunc cells, we show that the cell toxicity of BLM can be suppressed by addition of inorganic polyphosphate (polyP), a physiological polymer that accumulates and is released from platelets. BLM at a concentration of 20 µg ml−1 causes a decrease in cell viability (by ~70%), accompanied by an increased DNA damage and chromatin expansion (by amazingly 6-fold). Importantly, the BLM-caused effects on cell growth and DNA integrity are substantially suppressed by polyP. In parallel, the enlargement of the nuclei/chromatin in BLM-treated cells (diameter, 20–25 µm) is normalized to ~12 µm after co-incubation of the cells with BLM and polyP. A sequential application of the drugs (BLM for 3 days, followed by an exposure to polyP) does not cause this normalization. During co-incubation of BLM with polyP the gene for the BLM hydrolase is upregulated. It is concluded that by upregulating this enzyme polyP prevents the toxic side effects of BLM. These data might also contribute to an application of BLM in COVID-19 patients, since polyP inhibits binding of SARS-CoV-2 to cellular ACE2.

404 Sleep-Disordered Breathing In Native Hawaiians/Pacific Islanders With Associated Comorbidities And Adherence To Therapy

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A160-A161
Author(s):  
Darin Ryujin ◽  
Krishna Sundar ◽  
Allyson Gilles
Keyword(s):  
Sleep Disordered Breathing ◽  
Demographic Data ◽  
Ethnic Origin ◽  
Pacific Islanders ◽  
Native Hawaiians ◽  
University Of Utah ◽  
High Prevalence ◽  
Artery Disease ◽  
Disordered Breathing

Abstract Introduction Sleep-disordered breathing in Native Hawaiians and Pacific Islanders (NHPIs), its relationship to type 2 diabetes mellitus (DM), chronic renal, and heart disease, is not well known. NHPIs comprise only 1.3% of Utah’s population, but have the highest rates of DM and deaths due to diabetic kidney disease in Utah. This study assessed the nature of sleep-disordered breathing, its association with demographic variables, and comorbidities, and adherence patterns to positive airway pressure (PAP) therapy. Methods University of Utah sleep clinics patient databases from 2014 were evaluated to identify NHPIs using first/last names. Electronic medical records were reviewed to confirm patient ethnic origin, demographic data, and comorbidities. The most recent PAP downloads were obtained. Results Of 106 NHPIs were identified, data available for 104 patients (71 males, 33 females) was analyzed. Mean age of males was 47 + 13 years and females 48±13 years. Prevalence rates of obesity were 13% (female 9%, male 15%) with BMI≥30, 33% (female 24%, male 23%) with BMI≥35, and 49% (female 58%, Male 23%) with BMI≥40). Majority of patients had severe OSA (61% males with AHI≥30; 39% females with ≥ 30), with overall mean AHI of 47±38. A high prevalence of comorbidities was noted: 61% hypertension (male 58%; female 67%), diabetes 54% (male 48%, female 67%), renal disease 20% (male 21%, female 18%), coronary artery disease 13% (male 14%, female 9%), and congestive heart failure 13% (male 15%, female 9%). Prevalence of lung disease was low 13% (male 9%, female 18%). Conclusion NHPIs evaluated for sleep-disordered breathing have high rates of obesity, severe OSA, and concerning comorbidities. PAP adherence in this group was poor compared to overall adherence for patients seen in University of Utah sleep clinics (~70%). Further research is required to assess the relationships between OSA, associated comorbidities, and disease outcomes. Addressing low rates of PAP adherence in this population may afford opportunities to improve health outcomes. Support (if any) n/a

scholarly journals Interactions and Localization of Escherichia coli Error-Prone DNA Polymerase IV after DNA Damage

2015 ◽  
Vol 197 (17) ◽  
pp. 2792-2809 ◽  
Author(s):  
Sarita Mallik ◽  
Ellen M. Popodi ◽  
Andrew J. Hanson ◽  
Patricia L. Foster
Keyword(s):  
Dna Damage ◽  
Dna Polymerase ◽  
Dna Helicase ◽  
Dna Lesions ◽  
Replication Forks ◽  
Content Type ◽  
Pol Iv ◽  
Dna Polymerase Iv ◽  
Stalled Replication Forks

ABSTRACTEscherichia coli's DNA polymerase IV (Pol IV/DinB), a member of the Y family of error-prone polymerases, is induced during the SOS response to DNA damage and is responsible for translesion bypass and adaptive (stress-induced) mutation. In this study, the localization of Pol IV after DNA damage was followed using fluorescent fusions. After exposure ofE. colito DNA-damaging agents, fluorescently tagged Pol IV localized to the nucleoid as foci. Stepwise photobleaching indicated ∼60% of the foci consisted of three Pol IV molecules, while ∼40% consisted of six Pol IV molecules. Fluorescently tagged Rep, a replication accessory DNA helicase, was recruited to the Pol IV foci after DNA damage, suggesting that thein vitrointeraction between Rep and Pol IV reported previously also occursin vivo. Fluorescently tagged RecA also formed foci after DNA damage, and Pol IV localized to them. To investigate if Pol IV localizes to double-strand breaks (DSBs), an I-SceI endonuclease-mediated DSB was introduced close to a fluorescently labeled LacO array on the chromosome. After DSB induction, Pol IV localized to the DSB site in ∼70% of SOS-induced cells. RecA also formed foci at the DSB sites, and Pol IV localized to the RecA foci. These results suggest that Pol IV interacts with RecAin vivoand is recruited to sites of DSBs to aid in the restoration of DNA replication.IMPORTANCEDNA polymerase IV (Pol IV/DinB) is an error-prone DNA polymerase capable of bypassing DNA lesions and aiding in the restart of stalled replication forks. In this work, we demonstratein vivolocalization of fluorescently tagged Pol IV to the nucleoid after DNA damage and to DNA double-strand breaks. We show colocalization of Pol IV with two proteins: Rep DNA helicase, which participates in replication, and RecA, which catalyzes recombinational repair of stalled replication forks. Time course experiments suggest that Pol IV recruits Rep and that RecA recruits Pol IV. These findings providein vivoevidence that Pol IV aids in maintaining genomic stability not only by bypassing DNA lesions but also by participating in the restoration of stalled replication forks.

scholarly journals Effects of plant extracts on antioxidant status and oxidant-induced stress in Caco-2 cells

2007 ◽  
Vol 97 (2) ◽  
pp. 321-328 ◽  
Author(s):  
S. Aisling Aherne ◽  
Joseph P. Kerry ◽  
Nora M. O'Brien
Keyword(s):  
Dna Damage ◽  
Plant Extract ◽  
Plant Extracts ◽  
Antioxidant Status ◽  
Cell Injury ◽  
Membrane Integrity ◽  
Neutral Red ◽  
Dna Integrity ◽  
Cell Membrane Integrity ◽  
Wide Range

Experimental evidence suggests that most herbs and spices possess a wide range of biological and pharmacological activities that may protect tissues against O2-induced damage. The objectives of the present study were: first, to determine the effects of plant extracts on the viability, membrane integrity, antioxidant status and DNA integrity of Caco-2 cells and second, to investigate the cytoprotective and genoprotective effects of these plant extracts against oxidative stress in Caco-2 cells. The plant extracts examined were rosemary (Rosmarinus officinalis L.), oregano (Origanum vulgare L.), sage (Salvia officinalis L.) and echinacea (Echinacea purpurea L.). Cell membrane integrity was assessed by the lactate dehydrogenase release assay. Viability was determined by the neutral red uptake assay (NRUA) and the concentration of compound that resulted in 50 % cell death (IC50) was calculated. Antioxidant status of the cells was assessed by measuring GSH content, catalase activity and superoxide dismutase activity. To examine their cytoprotective and genoprotective effects, Caco-2 cells were pre-treated with each plant extract for 24 h followed by exposure to H2O2. DNA damage was assessed by the comet assay and cell injury was determined by the NRUA. Rosemary was the most toxic (IC50 123 μg/ml) and echinacea the least toxic (IC50 1421 μg/ml). Sage was the only plant extract to affect the antioxidant status of the cells by increasing GSH content. Sage, oregano and rosemary protected against H2O2-induced DNA damage (olive tail moment and percentage tail DNA), whereas protection against H2O2-induced cytotoxicity was afforded by sage only.

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