scholarly journals Mitochondrial DNA Copy Number in Cleavage Stage Human Embryos—Impact on Infertility Outcome

2022 ◽  
Vol 44 (1) ◽  
pp. 273-287
Author(s):  
Amira Podolak ◽  
Joanna Liss ◽  
Jolanta Kiewisz ◽  
Sebastian Pukszta ◽  
Celina Cybulska ◽  
...  

A retrospective case control study was undertaken at the molecular biology department of a private center for reproductive medicine in order to determine whether any correlation exists between mitochondrial DNA (mtDNA) content of cleavage-stage preimplantation embryos and their developmental potential. A total of 69 couples underwent IVF treatment (averaged women age: 36.5, SD 4.9) and produced a total of 314 embryos. A single blastomere was biopsied from each embryo at the cleavage stage (day-3 post-fertilization) subjected to low-pass next generation sequencing (NGS), for the purpose of detecting aneuploidy. For each sample, the number of mtDNA reads obtained after analysis using NGS was divided by the number of reads attributable to the nuclear genome. The mtDNA copy number amount was found to be higher in aneuploid embryos than in those that were euploid (mean mtDNA ratio ± SD: 6.3 ± 7.5 versus 7.1 ± 5.8, p < 0.004; U Mann–Whitney test), whereas no statistically significant differences in mtDNA content were seen in relation to embryo morphology (6.6 ± 4.8 vs. 8.5 ± 13.6, p 0.09), sex (6.6 ± 4.1 vs. 6.2 ± 6.8, p 0.16), maternal age (6.9 ± 7.8 vs. 6.7 ± 4.5, p 0.14) or its ability to implant (7.4 ± 6.6 vs. 5.1 ± 4.6, p 0.18). The mtDNA content cannot serve as a useful biomarker at this point in development. However, further studies investigating both quantitative and qualitative aspects of mtDNA are still required to fully evaluate the relationship between mitochondrial DNA and human reproduction.

2011 ◽  
Vol 23 (1) ◽  
pp. 230
Author(s):  
P. Pawlak ◽  
E. Pers-Kamczyc ◽  
D. Lechniak-Cieslak

In many domestic species (pig, cow, sheep), oocytes from prepubertal females show impaired quality when compared with those from adult animals. Incomplete cytoplasmic maturation is thought to be the main factor responsible for reduced developmental competence of embryos derived from prepubertal oocytes. The status of ooplasm maturation is also reflected by the copy number of mitochondrial DNA (mtDNA). Because replication of mtDNA ceases when oocytes reach their final size and occurs again at the blastocyst stage, the mtDNA copy number is a proved marker of oocyte quality in the pig (El Shourbagy et al. 2006 Reproduction 131, 233–245). The number of mtDNA copies in the grown oocyte is crucial to sustain the first embryonic divisions. To increase the rate of good-quality blastocysts, oocytes of domestic animals have been evaluated by the brilliant cresyl blue test (BCB). According to El Shourbagy et al. (2006), more competent BCB+ oocytes possess higher copy number of mtDNA (on average 222 446) than do their BCB– counterparts (115 352). However, there are no published data on the variation in mtDNA copy number in oocytes derived from ovaries of prepubertal (NCL) and cyclic (CL) gilts. Ovaries of NCL and CL gilts were collected in a local slaughterhouse. Cumulus–oocyte complexes (COC) were aspirated from nonatretic follicles 2 to 6 mm in diameter and evaluated morphologically. Only COC with a proper morphology were subjected to the BCB test. A group of non-BCB-treated COC served as control. Four groups of COC were collected: BCB+ (CL, NCL) and control (CL, NCL). Follicular cells attached to oocytes were removed by pipetting, and completely denuded gametes were individually frozen in liquid nitrogen. Analysis of the mtDNA copy number included isolation of the total DNA followed by amplification of the Cytochrome b (CYTB) gene by real-time PCR (one copy per one mitochondrial genome). Differences in mtDNA copy number among experimental groups were evaluated by Student’s t-test. To date, 30 BCB+ oocytes have been analysed individually (15 CL and 15 NCL). The analysed parameter varied in a wide range from 79 852 to 522 712 copies in CL oocytes and from 52 270 to 287 852 copies in NCL oocytes. Oocytes from cyclic gilts contained significantly more mtDNA copies (on average 267 524) than did gametes of prepubertal females (179 339; P < 0.05). The data on the mtDNA copy number in the control oocytes are currently under investigation. The preliminary results indicate that impaired oocytes quality of prepubertal gilts may be also attributed to the reduced copy number of mtDNA. This project was sponsored by MSHE Poland (grant no. 451/N-COST/2009/0).


2018 ◽  
Author(s):  
Reena Debray ◽  
Noah Snyder-Mackler ◽  
Jordan Kohn ◽  
Mark Wilson ◽  
Luis Barreiro ◽  
...  

AbstractIn many social mammals, social adversity predicts compromised health and reduced fitness. These effects are thought to be driven in part by chronic social stress, but their molecular underpinnings are not well understood. Recent work suggests that chronic stress can affect mitochondrial copy number, heteroplasmy rates, and function. Here, we tested the first two possibilities, for the first time in nonhuman primates. We manipulated dominance rank in captive female rhesus macaques (n=45), where low rank induces chronic social stress, and measured mitochondrial DNA copy number and heteroplasmy in five peripheral blood mononuclear cell types from each study subject. We found no effect of dominance rank on either mtDNA copy number or heteroplasmy rates. However, grooming rates, a measure of affiliative social behavior predicted by high social status, was positively associated with mtDNA copy number in B cells, cytotoxic T cells, and monocytes. Our results suggest that social interactions can influence mtDNA regulation in immune cells. Further, they indicate the importance of considering both affiliative and competitive interactions in investigating this relationship.


2015 ◽  
Author(s):  
Ed Reznik ◽  
Martin Miller ◽  
Yasin Senbabaoglu ◽  
Nadeem Riaz ◽  
William Lee ◽  
...  

In cancer, mitochondrial dysfunction, through mutations, deletions, and changes in copy number of mitochondrial DNA (mtDNA), contributes to the malignant transformation and progression of tumors. Here, we report the first large-scale survey of mtDNA copy number variation across 21 distinct solid tumor types, examining over 13,000 tissue samples profiled with next-generation sequencing methods. We find a tendency for cancers, especially of the bladder and kidney, to be significantly depleted of mtDNA, relative to matched normal tissue. We show that mtDNA copy number is correlated to the expression of mitochondrially-localized metabolic pathways, suggesting that mtDNA copy number variation reflect gross changes in mitochondrial metabolic activity. Finally, we identify a subset of tumor-type-specific somatic alterations, including IDH1 and NF1 mutations in gliomas, whose incidence is strongly correlated to mtDNA copy number. Our findings suggest that modulation of mtDNA copy number may play a role in the pathology of cancer.


2021 ◽  
Vol 4 (4) ◽  
pp. 88
Author(s):  
Casey C. Read ◽  
Sadikshya Bhandari ◽  
Sarah E. Moorey

To sustain energy-demanding developmental processes, oocytes must accumulate adequate stores of metabolic substrates and mitochondrial numbers prior to the initiation of maturation. In the past, researchers have utilized pooled samples to study oocyte metabolism, and studies that related multiple metabolic outcomes in single oocytes, such as ATP concentration and mitochondrial DNA copy number, were not possible. Such scenarios decreased sensitivity to intraoocyte metabolic relationships and made it difficult to obtain adequate sample numbers during studies with limited oocyte availability. Therefore, we developed and validated procedures to measure both mitochondrial DNA (mtDNA) copy number and ATP quantity in single oocytes. Validation of our procedures revealed that we could successfully divide oocyte lysates into quarters and measure consistent results from each of the aliquots for both ATP and mtDNA copy number. Coefficient of variation between the values retrieved for mtDNA copy number and ATP quantity quadruplicates were 4.72 ± 0.98 and 1.61 ± 1.19, respectively. We then utilized our methodology to concurrently measure mtDNA copy number and ATP quantity in germinal vesicle (GV) and metaphase two (MII) stage oocytes. Our methods revealed a significant increase in ATP levels (GV = 628.02 ± 199.53 pg, MII = 1326.24 ± 199.86 pg, p < 0.001) and mtDNA copy number (GV = 490,799.4 ± 544,745.9 copies, MII = 1,087,126.9 ± 902,202.8 copies, p = 0.035) in MII compared to GV stage oocytes. This finding is consistent with published literature and provides further validation of the accuracy of our methods. The ability to produce consistent readings and expected results from aliquots of the lysate from a single oocyte reveals the sensitivity and feasibility of using this method.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jee-Yon Lee ◽  
Duk-Chul Lee ◽  
Jee-Aee Im ◽  
Ji-Won Lee

Aims. Visceral obesity is associated with an increased risk of cardiometabolic diseases and it is important to identify the underlying mechanisms. There is growing evidence that mitochondrial dysfunction is associated with metabolic disturbances related to visceral obesity. In addition, maintaining mitochondrial DNA (mtDNA) copy number is important for preserving mitochondrial function. Therefore, we investigated the relationship between mtDNA copy number and visceral fat in healthy young adults.Methods. A total of 94 healthy young subjects were studied. Biomarkers of metabolic risk factors were assessed along with body composition by computed tomography. mtDNA copy number was measured in peripheral leukocytes using real-time polymerase chain reaction (PCR) methods.Results. The mtDNA copy number correlated with BMI (r=-0.22,P=0.04), waist circumference (r=-0.23,P=0.03), visceral fat area (r=-0.28,P=-0.01), HDL-cholesterol levels (r=0.25,P=0.02), and hs-CRP (r=0.32,P=0.02) after adjusting for age and sex. Both stepwise and nonstepwise multiple regression analyses confirmed that visceral fat area was independently associated with mtDNA copy number (β=-0.33,P<0.01,β=0.32, andP=0.03, resp.).Conclusions. An independent association between mtDNA content and visceral adiposity was identified. These data suggest that mtDNA copy number is a potential predictive marker for metabolic disturbances. Further studies are required to understand the causality and clinical significance of our findings.


2019 ◽  
Vol 15 (1) ◽  
pp. 20180643 ◽  
Author(s):  
Reena Debray ◽  
Noah Snyder-Mackler ◽  
Jordan N. Kohn ◽  
Mark E. Wilson ◽  
Luis B. Barreiro ◽  
...  

In many social mammals, social adversity predicts compromised health and reduced fitness. These effects are thought to be driven in part by chronic social stress, but their molecular underpinnings are not well understood. Recent work suggests that chronic stress can affect mitochondrial copy number, heteroplasmy rates and function. Here, we tested the first two possibilities for the first time in non-human primates. We manipulated dominance rank in captive female rhesus macaques ( n = 45), where low rank induces chronic social stress, and measured mitochondrial DNA (mtDNA) copy number and heteroplasmy in five peripheral blood mononuclear cell types from each study subject. We found no effect of dominance rank on either mtDNA copy number or heteroplasmy rates. However, grooming rate, a measure of affiliative social behaviour predicted by high social status, was positively associated with mtDNA copy number in B cells, cytotoxic T cells and monocytes. Our results suggest that social interactions can influence mtDNA regulation in immune cells. Further, they indicate the importance of considering both affiliative and competitive interactions in investigating this relationship.


Blood ◽  
2008 ◽  
Vol 112 (10) ◽  
pp. 4247-4249 ◽  
Author(s):  
Qing Lan ◽  
Unhee Lim ◽  
Chin-San Liu ◽  
Stephanie J. Weinstein ◽  
Stephen Chanock ◽  
...  

Abstract Mitochondrial DNA (mtDNA) copy number is increased in patients with chronic lymphocytic leukemia (CLL), in Burkitt lymphoma and Epstein-Barr virus–transformed lymphoblastoid cell lines, and in T cells activated via the T-cell receptor. We hypothesized that having a higher mtDNA copy number in peripheral white blood cell DNA from healthy subjects would be associated with future risk of non-Hodgkin lymphoma (NHL). We analyzed mtDNA copy number in 104 incident male NHL cases and 104 matched controls within the prospective Alpha-Tocopherol, Beta-Carotene (ATBC) Cancer Prevention cohort. There was a dose-response relationship between tertiles of mtDNA copy number and risk of NHL (odds ratio [OR], 95% confidence interval [CI]: 1.0; 1.4 [0.7-2.8]; and 2.4 [1.0-5.5], respectively; Ptrend = .046). The effect was most pronounced for the CLL/small lymphocytic lymphoma (SLL) subtype (OR: 1.0; 3.2 [0.7-15.7]; 14.1 [1.9-103.2]; Ptrend = .009). These results suggest that mtDNA copy number could be associated with the risk of NHL, particularly CLL/SLL.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Ed Reznik ◽  
Martin L Miller ◽  
Yasin Şenbabaoğlu ◽  
Nadeem Riaz ◽  
Judy Sarungbam ◽  
...  

Mutations, deletions, and changes in copy number of mitochondrial DNA (mtDNA), are observed throughout cancers. Here, we survey mtDNA copy number variation across 22 tumor types profiled by The Cancer Genome Atlas project. We observe a tendency for some cancers, especially of the bladder, breast, and kidney, to be depleted of mtDNA, relative to matched normal tissue. Analysis of genetic context reveals an association between incidence of several somatic alterations, including IDH1 mutations in gliomas, and mtDNA content. In some but not all cancer types, mtDNA content is correlated with the expression of respiratory genes, and anti-correlated to the expression of immune response and cell-cycle genes. In tandem with immunohistochemical evidence, we find that some tumors may compensate for mtDNA depletion to sustain levels of respiratory proteins. Our results highlight the extent of mtDNA copy number variation in tumors and point to related therapeutic opportunities.


2021 ◽  
Vol 22 (12) ◽  
pp. 6634
Author(s):  
Hisanori Fukunaga

Mitochondrial dysfunction is known to contribute to mitochondrial diseases, as well as to a variety of aging-based pathologies. Mitochondria have their own genomes (mitochondrial DNA (mtDNA)) and the abnormalities, such as point mutations, deletions, and copy number variations, are involved in mitochondrial dysfunction. In recent years, several epidemiological studies and animal experiments have supported the Developmental Origin of Health and Disease (DOHaD) theory, which states that the environment during fetal life influences the predisposition to disease and the risk of morbidity in adulthood. Mitochondria play a central role in energy production, as well as in various cellular functions, such as apoptosis, lipid metabolism, and calcium metabolism. In terms of the DOHaD theory, mtDNA copy number may be a mediator of health and disease. This paper summarizes the results of recent epidemiological studies on the relationship between environmental factors and mtDNA copy number during pregnancy from the perspective of DOHaD theory. The results of these studies suggest a hypothesis that mtDNA copy number may reflect environmental influences during fetal life and possibly serve as a surrogate marker of health risks in adulthood.


Author(s):  
Baptiste Sourty ◽  
Laure-Marie Dardaud ◽  
Céline Bris ◽  
Desquiret-Dumas Valérie ◽  
Blandine Boisselier ◽  
...  

Abstract Background Glioblastoma (GBM) is the most common and aggressive form of glioma. GBM frequently displays chromosome (chr) 7 gain, chr 10 loss and/or EGFR amplification (chr7+/chr10-/EGFRamp). Overall survival (OS) is 15 months after treatment. In young adults, IDH1/2 mutations are associated with longer survival. In children, histone H3 mutations portend a dismal prognosis. Novel reliable prognostic markers are needed in GBM. We assessed the prognostic value of mitochondrial DNA (mtDNA) copy number in adult GBM. Methods mtDNA copy number was assessed using real-time quantitative PCR in 232 primary GBM. Methylation of POLG and TFAM genes, involved in mtDNA replication, was assessed by bisulfite-pyrosequencing in 44 and 51 cases, respectively. Results Median age at diagnosis was 56.6 years-old and median OS, 13.3 months. 153/232 GBM (66 %) displayed chr7+/chr10-/EGFRamp, 23 (9.9 %) IDH1/2 mutation, 3 (1.3 %) H3 mutation and 53 (22.8 %) no key genetic alterations. GBM were divided into two groups, “Low” (n = 116) and “High” (n = 116), according to the median mtDNA/nuclear DNA ratio (237.7). There was no significant difference in OS between the two groups. By dividing the whole cohort according to the median age at diagnosis, OS was longer in the “High” vs “Low” subgroup (27.3 vs 15 months, p = 0.0203) in young adult GBM (n = 117) and longer in the “Low” vs “High” subgroup (14.5 vs 10.2 months, p = 0.0116) in older adult GBM (n = 115). POLG was highly methylated, whereas TFAM remained unmethylated. Conclusion mtDNA copy number may be a novel prognostic biomarker in GBM, its impact depending on age.


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