scholarly journals Mitochondria functionality and sperm quality

Reproduction ◽  
2013 ◽  
Vol 146 (5) ◽  
pp. R163-R174 ◽  
Author(s):  
Alexandra Amaral ◽  
Bárbara Lourenço ◽  
Mónica Marques ◽  
João Ramalho-Santos

Although mitochondria are best known for being the eukaryotic cell powerhouses, these organelles participate in various cellular functions besides ATP production, such as calcium homoeostasis, generation of reactive oxygen species (ROS), the intrinsic apoptotic pathway and steroid hormone biosynthesis. The aim of this review was to discuss the putative roles of mitochondria in mammalian sperm function and how they may relate to sperm quality and fertilisation ability, particularly in humans. Although paternal mitochondria are degraded inside the zygote, sperm mitochondrial functionality seems to be critical for fertilisation. Indeed, changes in mitochondrial integrity/functionality, namely defects in mitochondrial ultrastructure or in the mitochondrial genome, transcriptome or proteome, as well as low mitochondrial membrane potential or altered oxygen consumption, have been correlated with loss of sperm function (particularly with decreased motility). Results from genetically engineered mouse models also confirmed this trend. On the other hand, increasing evidence suggests that mitochondria derived ATP is not crucial for sperm motility and that glycolysis may be the main ATP supplier for this particular aspect of sperm function. However, there are contradictory data in the literature regarding sperm bioenergetics. The relevance of sperm mitochondria may thus be associated with their role in other physiological features, particularly with the production of ROS, which in controlled levels are needed for proper sperm function. Sperm mitochondria may also serve as intracellular Ca2+stores, although their role in signalling is still unclear.

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 92
Author(s):  
Rosanna Chianese ◽  
Riccardo Pierantoni

Besides ATP production, mitochondria are key organelles in several cellular functions, such as steroid hormone biosynthesis, calcium homoeostasis, intrinsic apoptotic pathway, and the generation of reactive oxygen species (ROS). Despite the loss of the majority of the cytoplasm occurring during spermiogenesis, mammalian sperm preserves a number of mitochondria that rearrange in a tubular structure at the level of the sperm flagellum midpiece. Although sperm mitochondria are destroyed inside the zygote, the integrity and the functionality of these organelles seem to be critical for fertilization and embryo development. The aim of this review was to discuss the impact of mitochondria-produced ROS at multiple levels in sperm: the genome, proteome, lipidome, epigenome. How diet, aging and environmental pollution may affect sperm quality and offspring health—by exacerbating oxidative stress—will be also described.


Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 100 ◽  
Author(s):  
Marc Llavanera ◽  
Ariadna Delgado-Bermúdez ◽  
Samuel Olives ◽  
Yentel Mateo-Otero ◽  
Sandra Recuero ◽  
...  

Glutathione S-transferases (GSTs) are essential sperm antioxidant enzymes involved in cell protection against oxidative stress and toxic chemicals, preserving sperm function and fertilising ability. Artificial insemination (AI) in pigs is commonly carried out through the use of liquid-stored semen at 17 °C, which not only reduces sperm metabolic activity but also sperm quality and AI-farrowing rates within the 72 h of storage. While one may reasonably suggest that such enzymes are implicated in the physiology and maintenance of mammalian sperm function during liquid-storage, no previous studies conducted on any species have addressed this hypothesis. Therefore, the objective of the present work was to characterise the presence and function of sperm GSTs in mammalian sperm, using the pig as a model. In this regard, inhibition of such enzymes by ethacrynic acid (EA) during semen storage at 17 °C was performed to evaluate the effects of GSTs in liquid-preserved boar sperm by flow cytometry, immunofluorescence, and immunoblotting analysis. The results of this study have shown, for the first time in mammalian species, that the inhibition of GSTs reduces sperm quality and functionality parameters during their storage at 17 °C. These findings highlight the key role of such enzymes, especially preserving mitochondrial function and maintaining plasma membrane stability. In addition, this study has identified and localised GSTM3 in the tail and equatorial subdomain of the head of boar sperm. Finally, this study has set grounds for future investigations testing supplementation of semen extenders with GSTs, as this may improve fertility outcomes of swine AIs.


Reproduction ◽  
2016 ◽  
Vol 151 (1) ◽  
pp. R1-R13 ◽  
Author(s):  
R S Tavares ◽  
S Escada-Rebelo ◽  
M Correia ◽  
P C Mota ◽  
J Ramalho-Santos

Exposure to toxicants present in the environment, especially the so-called endocrine-disrupting chemicals (EDCs), has been associated with decreased sperm quality and increased anomalies in male reproductive organs over the past decades. Both human and animal populations are continuously exposed to ubiquitous synthetic and natural-occurring EDCs through diet, dermal contact and/or inhalation, therefore potentially compromising male reproductive health. Although the effects of EDC are likely induced via multiple genomic-based pathways, their non-genomic effects may also be relevant. Furthermore, spermatozoa are transcriptionally inactive cells that can come in direct contact with EDCs in reproductive fluids and secretions and are therefore a good model to address non-genomic effects. This review thus focuses on the non-genomic effects of several important EDCs relevant to mammalian exposure. Notably, EDCs were found to interfere with pre-existing pathways inducing a panoply of deleterious effects to sperm function that included altered intracellular Ca2+oscillations, induction of oxidative stress, mitochondrial dysfunction, increased DNA damage and decreased sperm motility and viability, among others, potentially jeopardizing male fertility. Although many studies have used non-environmentally relevant concentrations of only one compound for mechanistic studies, it is important to remember that mammals are not exposed to one, but rather to a multitude of environmental EDCs, and synergistic effects may occur. Furthermore, some effects have been detected with single compounds at environmentally relevant concentrations.


2019 ◽  
Author(s):  
Shahan Mamoor

Differential gene expression analysis of multiple datasets, in mice and in men revealed that transcripts of the olfactomedin-like family are differentially expressed in metastases, both in patients with breast cancer and in genetically engineered mouse models of breast cancer. The expression of olfactomedin-like genes was perturbed in metastases to the bone, brain and the lung, suggesting that these molecules function in the metastatic process rather than having tissue-specific associations with the site of dissemination. The olfactomedin-like family may play a role in the progression of breast cancer from frank tumor to colonization of distant organ sites.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1960
Author(s):  
K. Tanuj Sapra ◽  
Ohad Medalia

The cytoskeleton of the eukaryotic cell provides a structural and functional scaffold enabling biochemical and cellular functions. While actin and microtubules form the main framework of the cell, intermediate filament networks provide unique mechanical properties that increase the resilience of both the cytoplasm and the nucleus, thereby maintaining cellular function while under mechanical pressure. Intermediate filaments (IFs) are imperative to a plethora of regulatory and signaling functions in mechanotransduction. Mutations in all types of IF proteins are known to affect the architectural integrity and function of cellular processes, leading to debilitating diseases. The basic building block of all IFs are elongated α-helical coiled-coils that assemble hierarchically into complex meshworks. A remarkable mechanical feature of IFs is the capability of coiled-coils to metamorphize into β-sheets under stress, making them one of the strongest and most resilient mechanical entities in nature. Here, we discuss structural and mechanical aspects of IFs with a focus on nuclear lamins and vimentin.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii295-iii295
Author(s):  
Annette Wu ◽  
Tak Mak ◽  
Jerome Fortin

Abstract Diffuse midline gliomas (DMGs) are aggressive childhood brain tumors with a dismal prognosis. Most of these tumors carry K27M mutations in histone H3-encoding genes, particularly H3F3A and HIST1H3B. In addition, activating mutations in ACVR1 and PIK3CA co-occur in a subset of DMGs. To understand how these lesions drive the development of DMGs, we generated genetically engineered mouse models in which Acvr1G328V, Hist1h3bK27M, and Pik3caH1047R are targeted to the OLIG2-expressing cell lineage. Animals carrying Acvr1G328V and Pik3caH1047R, with (“AHPO”) or without (“APO”) Hist1h3bK27M, developed high-grade diffuse gliomas involving midline and forebrain regions. Neither Acvr1G328V nor Pik3caH1047R drove tumorigenesis by themselves, but Acvr1G328V was sufficient to cause oligodendroglial differentiation arrest, pointing to a role in the earliest stages of gliomas formation. Transcriptomic analyses of AHPO and APO tumors indicated a predominantly proneural and oligodendrocyte precursor-like gene expression signature, consistent with the corresponding human pathology. Genes encoding transcription factors (TFs) with dual roles in controlling glial and neuronal differentiation were upregulated in tumors. Some of these genes were mildly induced by Acvr1G328V alone. Functional experiments using CRISPR/Cas9-mediated gene editing in patient-derived cell lines confirmed a role for some of these TFs in controlling DMG cell fitness. Overall, our results suggest that Pik3caH1047R consolidates Acvr1G328V-induced glial differentiation arrest to drive DMG development and progression.


2016 ◽  
Vol 113 (42) ◽  
pp. E6409-E6417 ◽  
Author(s):  
David G. McFadden ◽  
Katerina Politi ◽  
Arjun Bhutkar ◽  
Frances K. Chen ◽  
Xiaoling Song ◽  
...  

Genetically engineered mouse models (GEMMs) of cancer are increasingly being used to assess putative driver mutations identified by large-scale sequencing of human cancer genomes. To accurately interpret experiments that introduce additional mutations, an understanding of the somatic genetic profile and evolution of GEMM tumors is necessary. Here, we performed whole-exome sequencing of tumors from three GEMMs of lung adenocarcinoma driven by mutant epidermal growth factor receptor (EGFR), mutant Kirsten rat sarcoma viral oncogene homolog (Kras), or overexpression of MYC proto-oncogene. Tumors from EGFR- and Kras-driven models exhibited, respectively, 0.02 and 0.07 nonsynonymous mutations per megabase, a dramatically lower average mutational frequency than observed in human lung adenocarcinomas. Tumors from models driven by strong cancer drivers (mutant EGFR and Kras) harbored few mutations in known cancer genes, whereas tumors driven by MYC, a weaker initiating oncogene in the murine lung, acquired recurrent clonal oncogenic Kras mutations. In addition, although EGFR- and Kras-driven models both exhibited recurrent whole-chromosome DNA copy number alterations, the specific chromosomes altered by gain or loss were different in each model. These data demonstrate that GEMM tumors exhibit relatively simple somatic genotypes compared with human cancers of a similar type, making these autochthonous model systems useful for additive engineering approaches to assess the potential of novel mutations on tumorigenesis, cancer progression, and drug sensitivity.


2021 ◽  
pp. 112757
Author(s):  
Reihaneh Alsadat Mahmoudian ◽  
Moein Farshchian ◽  
Mohammad Reza Abbaszadegan

Sign in / Sign up

Export Citation Format

Share Document