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 Ca 2C stores, although their role in signalling is still unclear.
The inositolphosphosphingolipid phospholipase C (Isc1p) of Saccharomyces cerevisiae belongs to the family of neutral sphingomyelinases that generates the bioactive sphingolipid ceramide. In this work the role of Isc1p in oxidative stress resistance and chronological lifespan was investigated. Loss of Isc1p resulted in a higher sensitivity to hydrogen peroxide that was associated with an increase in oxidative stress markers, namely intracellular oxidation, protein carbonylation, and lipid peroxidation. Microarray analysis showed that Isc1p deficiency up-regulated the iron regulon leading to increased levels of iron, which is known to catalyze the production of the highly reactive hydroxyl radicals via the Fenton reaction. In agreement, iron chelation suppressed hydrogen peroxide sensitivity of isc1⌬ mutants. Cells lacking Isc1p also displayed a shortened chronological lifespan associated with oxidative stress markers and aging of parental cells was correlated with a decrease in Isc1p activity. The analysis of DNA fragmentation and caspase-like activity showed that Isc1p deficiency increased apoptotic cell death associated with oxidative stress and aging. Furthermore, deletion of Yca1p metacaspase suppressed the oxidative stress sensitivity and premature aging phenotypes of isc1⌬ mutants. These results indicate that Isc1p plays an important role in the regulation of cellular redox homeostasis, through modulation of iron levels, and of apoptosis.
STUDY QUESTION What recommendations can be provided on the approach to and use of time-lapse technology (TLT) in an IVF laboratory? SUMMARY ANSWER The present ESHRE document provides 11 recommendations on how to introduce TLT in the IVF laboratory. WHAT IS KNOWN ALREADY Studies have been published on the use of TLT in clinical embryology. However, a systematic assessment of how to approach and introduce this technology is currently missing. STUDY DESIGN, SIZE, DURATION A working group of members of the Steering Committee of the ESHRE Special Interest Group in Embryology and selected ESHRE members was formed in order to write recommendations on the practical aspects of TLT for the IVF laboratory. PARTICIPANTS/MATERIALS, SETTING, METHODS The working group included 11 members of different nationalities with internationally recognized experience in clinical embryology and basic science embryology, in addition to TLT. This document is developed according to the manual for development of ESHRE recommendations for good practice. Where possible, the statements are supported by studies retrieved from a PUBMED literature search on ‘time-lapse’ and ART. MAIN RESULTS AND THE ROLE OF CHANCE A clear clinical benefit of the use of TLT, i.e. an increase in IVF success rates, remains to be proven. Meanwhile, TLT systems are being introduced in IVF laboratories. The working group listed 11 recommendations on what to do before introducing TLT in the lab. These statements include an assessment of the pros and cons of acquiring a TLT system, selection of relevant morphokinetic parameters, selection of an appropriate TLT system with technical and customer support, development of an internal checklist and education of staff. All these aspects are explained further here, based on the current literature and expert opinion. LIMITATIONS, REASONS FOR CAUTION Owing to the limited evidence available, recommendations are mostly based on clinical and technical expertise. The paper provides technical advice, but leaves any decision on whether or not to use TLT to the individual centres. WIDER IMPLICATIONS OF THE FINDINGS This document is expected to have a significant impact on future developments of clinical embryology, considering the increasing role and impact of TLT. STUDY FUNDING/COMPETING INTEREST(S) The meetings of the working group were funded by ESHRE. S.A. declares participation in the Nordic Embryology Academic Team with meetings sponsored by Gedeon Richter. T.E. declares to have organized workshops for Esco and receiving consulting fees from Ferring and Gynemed and speakers’ fees from Esco and honorarium from Merck and MSD. T.F. received consulting fees from Vitrolife and Laboratoires Genévrier, speakers’ fees from Merck Serono, Gedeon Richter, MSD and Ferring and research grants from Gedeon Richter and MSD. M.M. received sponsorship from Merck. M.M.E. received speakers’ fees from Merck, Ferring and MSD. R.S. received a research grant from ESHRE. G.C. received speakers’ fees from IBSA and Excemed. The other authors declare that they have no conflict of interest. TRIAL REGISTRATION NUMBER N/A. DISCLAIMER This Good Practice Recommendations (GPR) document represents the views of ESHRE, which are the result of consensus between the relevant ESHRE stakeholders and are based on the scientific evidence available at the time of preparation. ESHRE’s GPRs should be used for information and educational purposes. They should not be interpreted as setting a standard of care or be deemed inclusive of all proper methods of care nor exclusive of other methods of care reasonably directed to obtaining the same results. They do not replace the need for application of clinical judgment to each individual presentation, nor variations based on locality and facility type. Furthermore, ESHRE GPRs do not constitute or imply the endorsement, or favouring of any of the included technologies by ESHRE. †ESHRE Pages content is not externally peer reviewed. The manuscript has been approved by the Executive Committee of ESHRE.
The Pep4p vacuolar proteinase contributes to the turnover of oxidized proteins but PEP4 overexpression is not sufficient to increase chronological lifespan in Saccharomyces cerevisiae Turnover of damaged molecules is considered to play a key role in housekeeping of cells exposed to oxidative stress, and during the progress of ageing. In this work, global changes in the transcriptome were analysed during recovery of yeast cells after H 2 O 2 stress. Regarding induced genes, those associated with protein fate were the most significantly over-represented. In addition to genes encoding subunits of the 20S proteasome, genes related to vacuolar proteolysis (PEP4 and LAP4), protein sorting into the vacuole, and vacuolar fusion were found to be induced. The upregulation of PEP4 gene expression was associated with an increase in Pep4p activity. The induction of genes related to proteolysis was correlated with an increased protein turnover after H 2 O 2 -induced oxidation. Furthermore, protein degradation and the removal of oxidized proteins decreased in Pep4p-deficient cells. Pep4p activity also increased during chronological ageing, and cells lacking Pep4p displayed a shortened lifespan associated with higher levels of carbonylated proteins. PEP4 overexpression prevented the accumulation of oxidized proteins, but did not increase lifespan. These results indicate that Pep4p is important for protein turnover after oxidative damage; however, increased removal of oxidized proteins is not sufficient to enhance lifespan.
BackgroundBevacizumab has become standard of care as first-line treatment of metastatic colorectal cancer (mCRC), after proving increased response rates and improvement in survival outcomes. Hypertension (HTN) is a common complication of the treatment with bevacizumab and, owing to its close relation with antiangiogenic mechanism, may represent a clinical biomarker to predict the efficacy of the treatment. The aim of this study was to retrospectively evaluate if HTN grades 2 to 3 were correlated with response to treatment with bevacizumab in first line, as well as with improved progression-free survival (PFS) and overall survival (OS), in a series of patients with mCRC.MethodsRetrospective evaluation of clinical records of patients with histologically proven mCRC, treated with bevacizumab as first-line treatment, between January 2008 and December 2013.Results79 patients were evaluated. 51.9% of patients developed HTN G2-G3 during chemotherapy-bevacizumab treatment. In the group of patients who developed bevacizumab-related HTN, 73.2% showed response to treatment (complete response (CR)+ partial response (PR)) and 97.6% achieved disease control (CR, PR or stable disease) compared to 18.4% of patients with response and 63.2% with disease control in the group that did not (OR 12.08; 95% CI 4.13 to 35.29; p<0.001 responders vs non-responders; OR 20.8; 95% CI 2.56 to 168.91; p 0.005 controlled vs non controlled disease). The median OS was 28 months (22.7–33.3). Significant statistical difference was obtained in PFS between the two groups (p<0.001). In the group that developed bevacizumab-related HTN, the median OS was 33 months (25.7–40.3), and in the group that did not, it was 21 months (16.5–25.5) with no significant statistical difference between the two groups (p 0.114).ConclusionsIn this subset of patients, HTN G2-3 was predictive of response to treatment with bevacizumab and of PFS but not of OS.
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