Seminal extracellular vesicles alter porcine in vitro fertilization outcome by modulating sperm metabolism

Porcine seminal plasma (SP) is loaded with a heterogeneous population of extracellular vesicles (sEVs) that modulate several reproductive-related processes. This study investigated the effect of two sEV subsets, small (S-sEVs) and large (L-sEVs), on porcine in vitro fertilization (IVF). The sEVs were isolated from nine SP pools (five ejaculates/pool) using a size-exclusion chromatography-based procedure and characterized for quantity (total protein), morphology (cryogenic electron microscopy), size distribution (dynamic light scattering), purity and EV-protein markers (flow cytometry; albumin, CD81, HSP90β). The characterization confirmed the existence of two subsets of high purity (low albumin content) sEVs that differed in size (S- and L-sEVs). In vitro fertilization was performed with in vitro matured oocytes and frozen-thawed spermatozoa and the IVF medium was supplemented during gamete coincubation (1 h at 38.5 °C, 5 % CO2 in a humidified atmosphere) with three different concentrations of each sEV subset: 0 (control, without sEVs), 0.1, and 0.2 mg/mL. The first experiment showed that sEVs, regardless of subset and concentration, decreased penetration rates and total IVF efficiency (P < 0.0001). In a subsequent experiment, it was shown that sEVs, regardless of subset and concentration, impaired the ability of spermatozoa to bind to the zona pellucida of oocytes (P < 0.0001). The following experiment showed that sEVs, regardless of the subset, bound to frozen-thawed sperm but not to in vitro matured oocytes, indicating that sEVs would affect sperm functionality but not oocyte functionality. The lack of effect on oocytes was confirmed by incubating sEVs with oocytes prior to IVF, achieving sperm-zona pellucida binding results similar to those of control. In the last experiment, conducted under IVF conditions, sperm functionality was analyzed in terms of tyrosine phosphorylation, acrosome integrity and metabolism. The sEVs, regardless of the subset, did not affect sperm tyrosine phosphorylation or acrosome integrity, but did influence sperm metabolism by decreasing sperm ATP production under capacitating conditions. In conclusion, this study demonstrated that the presence of sEVs on IVF medium impairs IVF outcomes, most likely by altering sperm metabolism.

Extracellular cAMP and MRP4 activity influence in vitro capacitation and fertilizing ability of pig spermatozoa

cAMP has been reported to be an essential driver of sperm capacitation. In bovine sperm cAMP efflux through multidrug resistance-associated protein 4 (MRP4) has been suggested to maintain intracellular cAMP homeostasis and generate extracellular signaling able to regulate capacitation. The aim of this work was to determine whether extracellular cAMP may influence in vitro pig sperm capacitation and acquisition of fertilizing ability and to evaluate the role of MRP4. In vitro sperm capacitation and gamete coincubation were performed in Brackett and Oliphant's medium (BO) in presence of caffeine (Ctr+) or in BO without caffeine (Ctr-) supplemented with 0, 8, 9, 10 mM cAMP. Despite the percentage of capacitated sperm, assayed by immunolocalization of tyrosine-phosphorylated proteins, was significantly lower in Ctr- compared to Ctr+, it increased supplementing 10 mM cAMP to Ctr- reaching values similar to Ctr+. The absence of caffeine during gamete coincubation reduced the fertilization rate compared to Ctr+, while 10 mM cAMP supplementation to Ctr- increased the fertilization rate reaching values similar to Ctr + . The presence of MRP4 in pig spermatozoa was detected for the first time by western blot and immunohistochemistry assays. To evaluate MRP4 role on pig sperm capacitation, in vitro capacitation and gamete coincubation were performed in Ctr + in presence of MK571, a MRP4 selective inhibitor. MK571 reduced the percentage of capacitated cells and the fertilization rate, while cAMP addition fully reversed MRP4 blockade consequences. Present findings suggest that, under our in vitro conditions, extracellular cAMP and MRP4 activity influence pig sperm capacitating events.

Cell bioenergetics and ATP production of boar spermatozoa

Cellular metabolism is an important feature of spermatozoa that deserves more insights to be fully understood, in particular in porcine semen physiology. The present study aims to characterize the balance between glycolytic and oxidative metabolism in boar sperm cells. Agilent Seahorse technology was used to assess both oxygen consumption rate (OCR), as an oxidative metabolism index, and extracellular acidification rate (ECAR), as a glycolytic index. Different metabolic parameters were studied on freshly ejaculated sperm cells (identified as day zero sample, d0) and after one day of storage at 17 °C in Androhep extender (d1). Mitochondrial ATP production rate (MitoATP) was higher than the glycolytic ATP production rate (glycoATP) at both d0 and d1 while at d1 the amount of ATP production decreased, in particular, due to OXPHOS reduction. Conversely, glycoATP was not significantly different between d0 and d1. Interestingly, OCR profile showed no different bioenergetic parameters (i.e. ATP turnover, basal or maximal respiration, and spare respiration) between d0 and d1, thus indicating that sperm cell metabolism was reversibly decreased by preservation conditions. Other metabolic parameters showed the same trend, irrespective of the storage time: under stressed conditions (oligomycin plus FCCP), spermatozoa showed an increase in mitochondrial respiration while the metabolic potential of glycolysis did not undergo variations when compared to baseline metabolism. The rate of oxidation of fuel substrates - glucose, fatty acids, and glutamine - showed that sperm reliance on glucose oxidation to maintain baseline respiration was higher than fatty acids or glutamine. Interestingly spermatozoa demonstrated to have a low "capacity" parameter, which indicates that they cannot use only a single fuel substrate to produce energy. This feature of sperm metabolism to be unable to increase oxidation of a particular fuel to compensate for inhibition of alternative fuel pathway(s) was demonstrated by the negative value of "flexibility". Our results showed that ATP production in boar sperm cells relied on mitochondrial oxidative metabolism in freshly ejaculated cells, while, under liquid storage conditions, their oxidative metabolism decreased while the glycolysis remained constant. These results open new fields of research in the preservation techniques of boar sperm cells.

Study of mitochondrial function in thawed bull spermatozoa using selective electron transfer chain inhibitors

Bull spermatozoa depend equally on glycolysis and oxidative phosphorylation for the maintenance of the energy necessary for their proper functioning. The aim of the present work was to delineate the mitochondrial activity of bull spermatozoa after incubation with specific inhibitors of the different mitochondrial complexes and evaluate their ROS production. Thawed bull sperm cells (30 × 106 mL-1 in Tyrode's extender) were incubated 1 and 3h at 37 °C with rotenone 5 μM (ROT), complex I inhibitor; dimethyl-malonate 10 mM (DMM), complex II inhibitor; carbonyl cyanide m-chlorophenyl hydrazine 5 μM (CCCP), uncoupling agent; antimycin A 1 μg/mL (ANTI), complex III inhibitor; oligomycin 5 μM (OLIGO), ATP synthase inhibitor, and 0.5% DMSO, vehicle (CTR). Sperm motility and kinematics were assessed by Hamilton Thorn IVOS 12.0. Mitochondrial membrane potential, mitochondrial O2•- production and H2O2 intracellular content were evaluated by BD FACSCalibur flow cytometer, and sperm viability (SYBR-14/PI) and mitochondrial activity (JC-1/SYBR-14/PI) were assessed by epifluorescence microscopy. A multivariate analysis was performed on the results. In addition, sperm kinematic features, registered for each motile spermatozoon, were studied by cluster analysis. The incubation during 1 or 3 h in presence of the inhibitors of mitochondrial functionality only had a minor effect on motility parameters, decreasing the proportion of the SP1 (fast progressive) subpopulation after 3 h of incubation with ROT, ANTI or OLIGO. The percentage of live spermatozoa with active mitochondria was reduced under the effect of ANTI and CCCP both at 1 and 3 h. In conclusion, mitochondrial function is somehow impaired in frozen thawed bull sperm as not all live cells showed active mitochondria. These results support the findings that bull spermatozoa can alternatively rely on oxidative phosphorylation or glycolysis for energy obtainment and that their mitochondria are less affected by ETC inhibitors.

The sperm mitochondria: clues and challenges

Sperm cells rely on different substrates to fulfil thei energy demand for different functions and diverse moments of their life. Species specific mechanism involve both energy substrate transport and their utilization: hexose transporters, a protein family of facilitative passive transporters of glucose and other hexose, have been identified in spermatozoa of different species and, within the species, their localization has been identified and, in some cases, linked to specific glycilitic enzyme presence. The catabolism of hexose sources for energy purposes has been studied in various species, and recent advances has been made in the knowledge of metabolic strategies of sperm cells. In particular, the importance of aerobic metabolism has been defined and described in horse, boar and even mouse spermatozoa; bull sperm cells demonstrate to have a good adaptability and capacity to switch between glycolysis and oxidative phosphorylation; finally, dog sperm cells have been demonstrated to have a great plasticity in energy metabolism management, being also able to activate the anabolic pathway of glycogen syntesis. In conclusion, the study of energy management and mitochondrial function in spermatozoa of different specie furnishes important base knowledge to define new media for preservation as well as newbases for reproductive biotechnologies.

The Proteome of Large or Small Extracellular Vesicles in Pig Seminal Plasma Differs, Defining Sources and Biological Functions

Seminal plasma contains many morphologically heterogeneous extracellular vesicles (sEVs). These are sequentially released by cells of the testis, epididymis, and accessory sex glands and involved in male and female reproductive processes. This study aimed to define in depth sEV subsets isolated by ultrafiltration and size exclusion chromatography, decode their proteomic profiles using liquid chromatography-tandem mass spectrometry, and quantify identified proteins using sequential window acquisition of all theoretical mass spectra. The sEV subsets were defined as large (L-EVs) or small (S-EVs) by their protein concentration, morphology, size distribution, and EV-specific protein markers and purity. Liquid chromatography-tandem mass spectrometry identified a total of 1034 proteins, 737 of them quantified by SWATH in S-EVs, L-EVs, and non-EVs-enriched samples (18-20 size exclusion chromatography-eluted fractions). The differential expression analysis revealed 197 differentially abundant proteins between both EV subsets, S-EVs and L-EVs, and 37 and 199 between S-EVs and L-EVs versus non-EVs-enriched samples, respectively. The gene ontology enrichment analysis of differentially abundant proteins suggested, based on the type of protein detected, that S-EVs could be mainly released through an apocrine blebbing pathway and be involved in modulating the immune environment of the female reproductive tract as well as during sperm-oocyte interaction. In contrast, L-EVs could be released by fusion of multivesicular bodies with the plasma membrane becoming involved in sperm physiological processes, such as capacitation and avoidance of oxidative stress. In conclusion, this study provides a procedure capable of isolating subsets of EVs from pig seminal plasma with a high degree of purity and shows differences in the proteomic profile between EV subsets, indicating different sources and biological functions for the sEVs.

Effects of cryopreservation on the mitochondrial bioenergetics of bovine sperm

This study evaluated the bioenergetic map of mitochondria metabolism in cryopreserved bovine sperm. The detected oligomycin-sensitive basal respiration supported ATP production; frozen-thawed spermatozoa were found to have a coupling efficiency higher than 0.80. Cell respiration, however, was not stimulated by the protonophoric action of FCCP, as its titration with 1, 2, 4 and 6 μM did not stimulate the uncoupling activity on oxidative phosphorylation as highlighted by unresponsive oxygen consumption. The unusual effect on the stimulation of maximal respiration was not related to fibronectin- or PDL-coated plates used for cellular metabolism analysis. Conversely, irradiation of frozen-thawed bovine sperm with the red light improved mitochondrial parameters. In effect, the maximal respiration of red-light-stimulated sperm in PDL-coated plates was higher than the non-irradiated. In spite of this, red-light irradiation had no impact on membrane integrity and mitochondrial activity evaluated by epifluorescence microscopy.

HTA supporting clinical practice: the case of surgical repair of thoracoabdominal aortic aneurysms

Background

Thoracoabdominal aortic aneurysms (TAAAs) are defined as those aortic aneurysms involving renovisceral arteries. They account for around 10% of aortic aneurysms, and their treatment is burdened by considerable mortality and morbidity. Open surgical repair has been practised as the standard of care since the 1950s. In 2001 endovascular repair was introduced to reduce treatment invasiveness, and the technology is still evolving. The potential benefits of endovascular repair over open surgery should be carefully weighed in a multidimensional framework.

Methods

We applied the Health Technology Assessment (HTA) framework (EUnetHTA core model with 9 dimensions) to conduct a report comparing the two technologies. A multidisciplinary working group was established. We derived and pooled: i) secondary data derived from systematic literature reviews, and ii) original data from IRCCS San Raffaele Hospital, Milan, a national referral centre for TAAA (qualitative and economic data).

Results

Endovascular repair resulted superior to the traditional open surgery in terms of efficacy and safety, as justified by the meta-analysis we performed. Despite the higher costs, a significant impact on budget and slightly lower cost-effectiveness, the endovascular protheses’ adoption could provide conspicuous benefits in terms of social and ethical dimensions without affecting long-term organisational and legal aspects.

Conclusions

The multi-criteria decision analysis carried out from a hospital point of view shows that there is no significant difference (final score endovascular repair 0.68 vs open surgery 0.63) between the two procedures considering all the dimensions. Still, the endovascular repair is slightly superior to the open surgery in terms of safety, effectiveness, social, ethical, legal, and organisational impact. From the policy maker’s point of view, technologies with a score superior to 0.6 are equally valuable, and the final decision should be left to the clinicians.

Key messages

• Further research is needed to compare endovascular prostheses and open surgery’s long-term population benefits, balancing clinical, economic, organisational and patient-related outcomes.

• HTA methodology offers substantial support to compare in-use technologies, informing clinicians’ and decision-makers’ choices to strengthen healthcare provision equity and preparedness.

Use of specific mitochondrial complex inhibitors to investigate mitochondrial involvement on horse sperm motility and ROS production

Equine spermatozoa highly rely on oxidative phosphorylation for their energy management. The present work aimed to characterize the role of mitochondria on horse sperm motility and ROS production by incubating spermatozoa with specific inhibitors of the different mitochondrial complexes. Equine spermatozoa were incubated 1 h and 3 h at 37 °C with: complex I inhibitor rotenone (5 μM, ROT), complex II inhibitor dimethyl-malonate (10 mM, DMM), complex III inhibitor antimycin A (1.8 μM, ANTI), the uncoupling agent carbonyl cyanide m-chlorophenyl hydrazine (5 μM, CCCP), ATP synthase inhibitor oligomycin (5 μM, OLIGO), and 2 μL vehicle DMSO (control, CTL). Samples were analyzed for sperm motility and for mitochondrial membrane potential (MMP), mitochondrial integrity, mitochondrial O₂^•- production, and cytoplasmic H₂O₂. A multivariate analysis was performed on the data. CCCP caused a pronounced MMP reduction at both time points while ROT and ANTI showed the same effect at 3 h. All treatments at 3 h incubation significantly reduced the percentage of sperm with early changes in membrane permeability with active mitochondria. The H₂O₂ production of live cells was low at 1 h incubation in all treatments; after 3 h a slight decrease in the percentage of low-H₂O₂ producing cells was recorded. All treatments, except DMM, induced a significant decline in sperm motility and kinematics and modified the pattern of sperm subpopulations. The effect of DMM was evident only after 3 h, increasing the percentage of slow sperm subpopulation. In conclusion, the disruption of mitochondrial integrity induces an increase of mitochondrial ROS production that could be detrimental for cell function and survivior.

Assessment of sperm mitochondrial activity by flow cytometry and fluorescent microscopy: a comparative study of mitochondrial fluorescent probes in bovine spermatozoa

CONTEXT

While conventional semen analysis is a simple, time-saving, and economical means to evaluate sperm quality, it leaves biochemical and metabolic characteristics of spermatozoa aside. To address this issue, the use of fluorescent probes assessing functional sperm parameters, such as JC-1, DiOC6 (3) and MitoTracker, has increased over the last decades. Apparently contradictory observations have nevertheless fostered an ongoing debate on their sensitivity and ability to evaluate the mitochondrial membrane potential (MMP) of sperm cells, thus warranting a re-examination of these probes.

AIMS

The present study aims to elucidate the suitability and sensitivity of each probe to evaluate the MMP of bovine spermatozoa by flow cytometry.

METHODS

Cryopreserved spermatozoa from ten bulls were thawed, stained with JC-1/SYTOXRed, DiOC6 (3)/propidium iodide (PI) or MitoTracker Deep Red (MTDR)/PI, and evaluated with flow cytometry and fluorescence microscopy.

KEY RESULTS

DiOC6 (3), JC-1 and MTDR can be simultaneously co-stained with a viability marker. The results of the present study support the ability of DiOC6 (3)/PI and JC-1/SYTOXRed, but not that of MTDR/PI, to monitor the MMP of spermatozoa.

CONCLUSIONS

JC-1/SYTOXRed assessed by flow cytometry was found to be the most sensitive and robust fluorescent probe to assess MMP. Moreover, DiOC6 (3)/PI could be a suitable alternative when the flow cytometer is not equipped with a red laser and/or an adequate optical filter.

IMPLICATIONS

Both DiOC6 (3) and JC-1, but not MTDR, could be used as probes to assess the mitochondrial membrane potential of bovine spermatozoa.

Impact of glyphosate and its formulation Roundup® on stallion spermatozoa

The growing and widespread use of glyphosate-based herbicides (GBHs) has raised an intense public debate about the impact of environmental contamination on animal and human health, including male fertility. The aim of this study was to deepen the impact of glyphosate (Gly) and GBHs on mammalian sperm investigating the effect of in vitro exposure of stallion spermatozoa to Gly and to its commercial formulation Roundup® (R). Spermatozoa were incubated at 37 °C with different Gly or R concentrations (from 0.5 to 720 μg/mL Gly or R at the same Gly-equivalent concentrations). After 1 h of incubation motility, viability, acrosome integrity, mitochondrial activity and ROS production were assessed. Gly, at all the concentrations tested, did not induce any detrimental impact on the sperm quality parameters evaluated. Conversely, R starting from 360 μg/mL (Gly-equivalent dose) significantly (P < 0.05) decreased total and progressive motility, viability, acrosome integrity, mitochondrial activity and the percentage of live spermatozoa with intact mitochondria not producing ROS. Our results indicate that the commercial formulation R is more toxic than its active molecule Gly and that the negative impact on stallion sperm motility might be likely due to a detrimental effect mainly at membrane and mitochondrial level and, at least in part, to redox unbalance. Moreover, based on the data obtained, it can be hypothesized a species-specificity in sperm sensitivity to Gly and GBHs as horse spermatozoa were negatively influenced at higher concentrations of R compared to those reported in literature to be toxic for human and swine male germ cells.

Role of exogenous antioxidants on the performance and function of pig sperm after preservation in liquid and frozen states: A systematic review

In situations where an excessive generation of reactive oxygen species overwhelms antioxidant capacity, a harmful effect on sperm function is exerted. Antioxidants are molecules capable of minimizing this detrimental effect, which is important in pig sperm due to the high content of polyunsaturated fatty acids in their plasma membrane. The present systematic review aims at evaluating whether supplementing semen extenders (for liquid storage at 17 °C) or freezing and/or thawing media (for cryopreservation) with antioxidants influences sperm quality and functionality parameters, and in vitro/in vivo fertility outcomes. We defined inclusion and exclusion criteria in a PICOS table according to PRISMA guidelines, and conducted a literature search through MEDLINE-PubMed in November 2020. After systematic selection, 75 studies were included: 47 focused on cryopreservation and 28 on liquid storage at 17 °C. More than 70% of the studies included in this review showed that adding semen extenders for liquid storage and/or freezing/thawing media for cryopreservation with antioxidants enhances sperm quality and functionality parameters. In addition, this supplementation improves in vivo/in vitro fertility outcomes, supporting the hypothesis that the beneficial effect observed upon sperm quality has a positive impact on reproduction outcomes.

The role of endogenous antioxidants in male animal fertility

Mammalian semen is a physiological fluid composed of a cellular fraction (spermatozoa), and a liquid fraction (seminal plasma). Once delivered to the female genital tract, spermatozoa should be able to capacitate; a process which involves a plethora of biochemical and physiological changes required to fertilize the oocyte. Sperm production (spermatogenesis) occurs in the testes, whereby pluripotent spermatogonia differentiate to form the most morphologically specialized cells in the body. Further maturation of spermatozoa occurs in the epididymis, where they are stored prior to ejaculation. During this whole process, spermatozoa are exposed to different environments and cellular processes which may expose them to substantial levels of oxidative stress. To avoid damage associated with the unchecked production of reactive oxygen species (ROS), both spermatozoa, and the parts of the male genital tract in which they reside, are furnished with a suite of antioxidant molecules which are able to provide protection to these cells, thereby increasing their chance of being able to fertilize the oocyte and deliver an intact paternal genome to the future offspring. However, there are a host of reasons why these antioxidant systems may fail, including nutritional deficiencies, genetics, and disease states, and in these situations, a reduction or abolition of fertilizing capacity may result. This review paper focuses on the endogenous antioxidant defences available to spermatozoa during spermatogenesis and sperm maturation, the site of their production and their physiological role. Furthermore, we revised the causes and effects of antioxidant deficiencies (congenital or acquired during the animal's adulthood) on reproductive function in different animal species.

The inhibition of spermatic cystine/glutamate antiporter xCT (SLC7A11) influences the ability of cryopreserved stallion sperm to bind to heterologous zonae pellucidae

Sperm are redox-regulated cells, and deregulation of their redox status is considered to affect male fertility and to reduce their fertilizing ability following biotechnological procedures, such as cryopreservation. Cystine (CysS), after incorporation in sperm via SLC7A11 antiporter, has been demonstrated to increase intracellular GSH content, the most important non enzymatic antioxidant. This study was aimed at investigating the role of SLC7A11 antiporter on frozen-thawed stallion sperm ability to respond to in vitro capacitating environment after post-thaw incubation with CysS and/or Sulfasalazine (SS), a specific inhibitor of SLC7A11 antiporter. Viability, motility, immunolocalization of tyrosine phosphorylated proteins and the ability to bind to heterologous zonae pellucidae were evaluated. Thawed sperm from seven stallions (2 ejaculates/stallion) was washed and resuspended in Tyrodes media; each thawed ejaculate was divided in Control (CTR) and 3 samples supplemented with: 0.5 mM Cystine (CysS), 500 μM Sulfasalazine (SS) and 0.5 mM CysS + 500 μM SS (CysS + SS). After 1 h of incubation at 37 °C, samples were washed twice, resuspended in capacitating BWW medium and incubated at 38 °C under 5% CO₂. After 30 and 60 min, sperm motility, viability and tyrosine phosphorylated protein immunolocalization, used as capacitation status index, were evaluated. After 30 min of capacitation, 4 × 10⁵ sperm were co-incubated with denuded pig oocytes in capacitation medium for 30 min for the heterologous binding assay. None of the sperm parameters studied (motility, viability and tyrosine phosphorylation) showed any difference respective to control. The number of sperm bound per oocyte (mean ± SEM) tended to increase in CysS group (44.0 ± 12.3) respect CTR (40.8 ± 10.8) while decreased in SS group (32.4 ± 7.8) (p < 0.01). Moreover, CysS + SS group showed a lower binding rate (32.0 ± 10.0) compared to CysS (p < 0.001). Our results suggest that CysS supplementation of thawed stallion sperm can influence their ability to bind to heterologous zona pellucidae as the inhibition of CysS incorporation by SLC7A11 reduced the number of sperm bound per oocyte. This effect does not seem to be ascribed to a modification of sperm motility, membrane integrity and tyrosine phosphorylation.

Preventive and responsive plans to COVID-19 epidemic in a leading teaching hospital in Milan, Italy

Issue

Following the SARS-Cov-2 outbreak in Wuhan, China, the first case of COVID-19 was reported in Codogno, Lombardy, Italy, on 20 February 2020. The ongoing epidemic has exposed the health care system to a severe stress. San Raffaele Hospital (OSR) in Milan, Italy - a leader in the emergency management, may provide a benchmarking experience useful for other countries.

Description of the Problem

OSR has established a task force including the health care director, the Infections Prevention and Control Committee (IPCC) and the head of ward and outpatients' facilities management area in order to assess the situation and to define a multi-step strategy. The management process has been divided in two steps. Firstly, a preventive phase was devised, in a preparedness perspective, to avoid the spread of the infection to the Healthcare Professionals (HCP). Secondly, a reorganizational phase was implemented to guarantee assistance to infected patients, especially the critical ones.

Results

Before the outbreak, the IPCC updated OSR's procedures, based on the WHO's, national and regional guidance, planned a lectures series and an online survey to train healthcare professionals and proposed to stack Personal Protective Equipment (PPE) to face the expected shortage. The Head of the facilities management area defined separate pathways in the Emergency Department in order to isolate patients with respiratory symptoms, set up a new ward, with 26 beds and dedicated personnel, as well as two Intensive Care Units, with 13 beds, Some wards were merged and more healthcare workers were moved to the COVID-19 units.

Lessons

The coordination between task force members has been crucial for translating the multi-step strategy in a quick reorganization of the whole hospital. Despite early preparations, we could not anticipate the evolution of the outbreak and its logistic impact, especially on the PPE procurement.

Key messages

A major Hospital was proved to be capable to respond to the changing healthcare requests. Organizational flexibility is crucial for proper emergency management.

Glyphosate and its formulation Roundup impair pig oocyte maturation

Glyphosate, formulated as glyphosate-based herbicides (GBHs) including the best-known formulation Roundup, is the world's most widely used herbicide. During the last years, the growing and widespread use of GBHs has raised a great concern about the impact of environmental contamination on animal and human health including potential effect on reproductive systems. Using an in vitro model of pig oocyte maturation, we examined the biological impact of both glyphosate and Roundup on female gamete evaluating nuclear maturation, cytoplasmic maturation and developmental competence of oocytes, steroidogenic activity of cumulus cells as well as intracellular levels of glutathione (GSH) and ROS of oocytes. Our results indicate that although exposure to glyphosate and Roundup during in vitro maturation does not affect nuclear maturation and embryo cleavage, it does impair oocyte developmental competence in terms of blastocyst rate and cellularity. Moreover, Roundup at the same glyphosate-equivalent concentrations was shown to be more toxic than pure glyphosate, altering steroidogenesis and increasing oocyte ROS levels, thus confirming that Roundup adjuvants enhance glyphosate toxic effects and/or are biologically active in their side-effect and therefore should be considered and tested as active ingredients.

Effects of Roundup and its main component, glyphosate, upon mammalian sperm function and survival

The wide use of glyphosate-based herbicides (GBHs) has become a matter of concern due to its potential harmful effects on human health, including men fertility. This study sought to investigate, using the pig as a model, the impact of pure glyphosate and its most known commercial formulation, Roundup, on sperm function and survival. With this purpose, fresh commercial semen doses were incubated with different concentrations (0-360 µg/mL) of glyphosate (GLY; exp. 1) or Roundup, at the equivalent GLY concentration (exp. 2), at 38 °C for 3 h. Glyphosate at 360 µg/mL significantly (P < 0.05) decreased sperm motility, viability, mitochondrial activity and acrosome integrity but had no detrimental effect at lower doses. On the other hand, Roundup did significantly (P < 0.05) reduce sperm motility at ≥ 5 µg/mL GLY-equivalent concentration; mitochondrial activity at ≥ 25 µg/mL GLY-equivalent concentration; and sperm viability and acrosome integrity at ≥ 100 µg/mL GLY-equivalent concentration as early as 1 h of incubation. In a similar fashion, GLY and Roundup did not inflict any detrimental effect on sperm DNA integrity. Taken together, these data indicate that, while both glyphosate and Roundup exert a negative impact on male gametes, Roundup is more toxic than its main component, glyphosate.

Different approaches for assessing sperm function

Different approaches can be used to assess sperm function in different conditions, i.e. sperm storage, freezing-thawing or activation by induction of capacitation and acrosome reaction. In this review we will focus on the assays routinely performed in our laboratories, giving a literature support to critically analyse different approaches. In fact, researchers usually tend to look for the "one shot" parameter that could explain itself a specific process; it is our conviction that a multiparametric approach is still more valid, as some changes in sperm function are very complex and could be explained only by operating in different ways. Sperm motility, the most evident sperm characteristic, should be assessed by computer-aided sperm analysers that permit an objective evaluation of the motility and its kinematic parameters. Commercial and open source instruments are available and could be profitably used together with specific statistical approaches. The use of microscopy, and particularly fluorescent microscopy, could be a very useful tool to assess different parameters in sperm cells both by fluorophores that give indication of a determined function, and by immunolocalization of proteins, that permits the discover of new features or to explain particular sperm functions. The same substrates could be used also in flow cytometry: the difference is that it permits to study wider sperm populations (and their sub-population distribution). Flow cytometry is undergoing a very wide use in spermatology and technical and experimental rigor is needed to obtain reliable results. Metabolic assessment of sperm features, particularly energetic supply, ATP formation and other enzyme activities, could represent a very important challenge to acquire new information and complete/integrate those derived from other techniques. Finally, functional assays such as oocyte binding and in vitro fertilization, represent a very strong tool to assess sperm function in vitro, as they could evidence the functional intactness of some pathways.

Improvement of in vitro fertilization by a tannin rich vegetal extract addition to frozen thawed boar sperm

Boar spermatozoa are very susceptible to cryopreservation injuries and, for this reason, pig remains one of the few species in which fresh semen is still preferred to thawed one for routine artificial insemination (AI). The present work evaluated the effect of supplementing boar sperm thawing medium with Silvafeed SP (SSP), a mixture of Chestnut and Quebracho wood extracts (60/40 w/w) rich in polyphenols (92.4% tannin content) on in vitro fertilization (IVF) and on the following sperm parameters: sperm motility (assessed by CASA), viability, acrosome integrity, mitochondrial function and lipid peroxidation (assessed by flow cytometry) and capacitation status (immunolocalization of tyrosine phosphorylated proteins). Thawed spermatozoa were incubated 1 h at 37°C in BTS without (CTR) or with (5, 10, 20 µg/mL) SSP. After incubation sperm suspension was divided in three aliquots: one was used for IVF trials, one for sperm analysis, and the last one was capacitated for 1 h at 39°C 5% CO2 in IVF medium. Sperm motility parameters, viability, acrosome integrity, mitochondrial functionality, lipid peroxidation and tyrosine phosphorylated protein immunolocalization, used as capacitation parameter, were not influenced by SSP. However, oocytes inseminated with thawed spermatozoa pretreated with all the different SSP concentrations presented a significant (P < 0.01) increase in penetration rate compared to CTR. In addition, 5 µg/mL SSP exerted a positive effect (P<0.05) on the total efficiency of fertilization. These results encourage the use of SSP in the thawing medium since post-thawing fertility is a limit for the large-scale use of boar frozen semen.

Sperm function and mitochondrial activity: An insight on boar sperm metabolism

In this study boar sperm mitochondrial activity was studied and deepened in order to delineate the main metabolic strategies used by boar sperm to obtain energy and to link them to sperm function. Boar spermatozoa were collected, diluted at 30 × 10⁶ spz/mL and incubated for 1 h with: Rotenone (ROT), complex I inhibitor, Dimethyl-malonate (DMM), complex II inhibitor, antimycin A (ANTI), complex III inhibitor, oligomycin (OLIGO), ATP synthase inhibitor, Carbonyl cyanide m-chlorophenyl hydrazone (CCCP), uncoupling agent, 2-deoxy-glucose (2DG), glucose agonist, and Dimethyl sulphoxide (DMSO) as control vehicle. Viability and mitochondrial membrane potential (Sybr14/PI/JC1 staining) and sperm motility (using CASA system) were assayed after incubation. ROT, ANTI, OLIGO and CCCP significantly reduced total and progressive motility as well as cell velocities; ANTI and CCCP depressed mitochondrial membrane potential but did not affect cell viability. Cluster analysis of kinematic parameters showed some interesting features of sperm subpopulations: ANTI and CCCP caused a shift in sperm subpopulation towards "slow non progressive" cells, OLIGO and ROT caused a shift towards "average" and "slow non progressive" cells, while DMM and 2DG increased the "fast progressive" cells subpopulation. Sperm mitochondrial respiration and substrate oxidation, assayed polographically and spectrofluorimetrically, respectively pointed out a high ATP turnover and a low spare respiratory capacity, mainly linked to the NADH-O₂ oxidase activity. Therefore, boar spermatozoa heavily rely on mitochondrial oxidative phosphorylation, and especially on Complex I activity, to produce ATP and fuel motility.

Step by step procedure for stereological counts of catecholamine neurons in the mouse brainstem

This work represents a detailed methodological description of automated stereology dedicated to all brainstem catecholamine nuclei. Each tyrosine-hydroxylase-containing nucleus was analyzed to count the following features: i) nuclear volume; ii) neuron number per nucleus; iii) neuron area per each nucleus.A number of reports described catecholamine-containing neurons within brainstem of a variety of animal species. In a recently published work, we reported a simultaneous quantitative analysis of tyrosine hydroxylase-positive neurons in the whole brainstem. Here we report the detailed step by step stereological procedure which allowed to perform a morphometric assessment of each catecholamine nucleus. This protocol provides the method chance to analyze simultaneously various morphological features in the same experimental setting to avoid variability when single nuclei are analyzed in different experiments. This improves the reliability of comparisons between brainstem catecholamine nuclei within the reticular formation to increase our insight about the key functional roles played by these cells in the mammalian brain. In fact, despite being a discrete number of neurons scattered in a small brain area, these cells provide remarkable axonal collateralization which allows the modulation of neuronal activity in the entire CNS. The step by step description of brainstem stereology provided here is reported in order to share these methods and enhance quantitative studies about these fascinating nuclei. At the same time we aim to provide a tool to be used routinely when analyzing the morphology and physiology of brainstem catecholamine cells.

Resveratrol and Epigallocatechin-3-gallate addition to thawed boar sperm improves in vitro fertilization

Thawing is one of the most delicate process after semen cryopreservation as spermatozoa pass from a dormant metabolic stage to a sudden awakening in cellular metabolism. The rapid oxygen utilization leads to an overproduction of reactive oxygen species that can damage sperm cells, thus causing a significant decrease of fertilizing potential of frozen-thawed spermatozoa. Resveratrol (Res) is a natural grape-derived phytoalexin and Epigallocatechin-3-gallate (EGCG) is the major polyphenol in green tea (Camellia sinensis); both molecules are known to possess high levels of antioxidant activity. The objective of the present study was to assess the effect of different concentrations of Res (0.5, 1 or 2 mM; Experiment 1) or EGCG (25, 50 or 100 μM; Experiment 2) supplementation to thawing boar semen extender on sperm quality parameters (viability and acrosome integrity) and in vitro fertilization (IVF). Semen after thawing and dilution with three volumes of Beltsville Thawing Solution (BTS), was immediately divided in control group without antioxidants addition (CTR) and either Res or EGCG groups. Sperm viability and acrosome integrity were evaluated in CTR, Res or EGCG groups after 1 h of incubation at 37 °C. The addition of different doses of Res or EGCG to thawing extender for 1 h did not induce any effect on boar sperm viability and acrosome integrity. However, both Res and EGCG treated samples exhibited a significantly higher penetration rate compared with CTR when used for IVF. In particular the treatment with all the EGCG concentrations increased the penetration rate (P < 0.01) while only Res 2 mM induced a significant increase of this parameter (P < 0.01). In addition, EGCG 25 and 50 μM supplementation significantly increased total fertilization efficiency as compared to control (EGCG 25 μM: 40.3 ± 8.2 vs 26.8 ± 9.5, P < 0.05; EGCG 50 μM: 40.4 ± 7.8 vs 26.8 ± 9.5, P < 0.01). The same effect was observed with Res 2 mM (51.0 ± 7.6 vs 29.6 ± 11.3, P < 0.01). In conclusion, our results indicate that the addition of different doses of the two antioxidants to thawed spermatozoa for one hour, even if does not exert any effect on sperm viability and acrosome integrity, efficiently improves in vitro penetration rate. Moreover, both molecules (EGCG 25 and 50 μM and Res 2 mM) significantly increases the total efficiency of fertilization.

Epigallocatechin-3-gallate (EGCG) and green tea polyphenols do not improve stallion semen parameters during cooling at 4°C

Stallion semen storage for artificial insemination is mainly based on liquid cooled storage. In many stallions this technique maintains sperm quality for an extended period of time (24-72 hr) at 7°C. While this technique is commonly used in the horse industry, there can be a decline in fertility in some stallions, due to an inability of their sperm to tolerate the cool storage process. The aim of the present work was to evaluate the effect of two natural antioxidants (epigallocatechin-3-gallate (EGCG) at 20, 60 and 120 μm and green tea polyphenols, and p at .001, .01 and .1 mg/ml) on some sperm parameters (sperm motility, viability/acrosome integrity and DNA quality) in extended semen immediately after its collection (T0) and after 2, 6, 24 and 48 hr of cool storage. Two ejaculates from three trotter stallions were analysed after 48 hr of storage at 4°C. No beneficial effect on the analysed parameters was observed: the two antioxidants were not able to improve sperm quality after 48 hr of storage. These results are in agreement with previous findings on the effect of different antioxidants reported by other researches, who have demonstrated that stallion semen keeps good antioxidant capacity after dilution for 24 hr. In conclusion, the positive effect exerted by antioxidant molecules in other species is not confirmed in the equine one.

Beta-mercaptoethanol supplementation of in vitro maturation medium does not influence nuclear and cytoplasmic maturation of equine oocytes

In vitro embryo production in the horse is still not as efficient as in other species. Oxidative stress negatively affects oocyte and embryo culture. To attenuate/minimize the oxidative stress, antioxidants such as low-molecular thiol compounds can be added to culture media. Beta-mercaptoethanol (BME) has been shown to improve maturation and embryo development in different species. The aim of this study was to investigate whether the addition to maturation medium of BME at common (0.1 mM) and high (0.7 mM) concentration could improve oocyte maturation also in the horse. Equine oocytes recovered from slaughterhouse ovaries were used. Meiotic configuration after in vitro maturation (IVM) and early embryo production after intracytoplasmic sperm injection (ICSI) were considered as criteria for assessing nuclear and cytoplasmic maturation, respectively. A total of 1,076 oocytes were analysed over two experiments: 848 (control n = 293, BME 0.1 n = 270, BME 0.7 n = 285) were stained with Hoechst 33342 and examined for nuclear stage after 26 hr of IVM, and 228 MII oocytes were fertilized by ICSI (control n = 83, BME 0.1 n = 65, BME 0.7 n = 80). Cleavage rates were determined after 60 hr of culture. Unlike results obtained in other species, the addition of BME did not influence maturation rates (51.9% control vs 55.6% BME 0.1 mM and 55.1% BME 0.7 mM), nor cleavage rates after ICSI (38.6% vs 38.5% and 41.3%, respectively). In conclusion, the addition of BME at 0.1 and 0.7 mM to the maturation medium, in our culture conditions, has no effect on nuclear and cytoplasmic maturation of equine oocytes.

Validation of an electrophoretic method to detect albuminuria in cats

Objectives The aims of this study were to validate a semi-automated high-resolution electrophoretic technique to quantify urinary albumin in healthy and diseased cats, and to evaluate its diagnostic performance in cases of proteinuria and renal diseases. Methods Urine samples were collected from 88 cats (healthy; chronic kidney disease [CKD]; lower urinary tract disease [LUTD]; non-urinary tract diseases [OTHER]). Urine samples were routinely analysed and high-resolution electrophoresis (HRE) was performed. Within-assay and between-assay variability, linearity, accuracy, recovery and the lowest detectable and quantifiable bands were calculated. Receiver operating curve (ROC) analysis was also performed. Results All coefficients of variation were <10%, percentage recovery was between 97% and 109% with a high linearity (r = 0.99). HRE allowed the visualisation of a faint band of albumin and a diffused band between alpha and beta zones in healthy cats, while profiles from diseased cats were variable. Albumin (mg/dl) and urine albumin:creatinine ratio (UAC) were significantly ( P <0.05) different between healthy and diseased cats. After ROC analysis, UAC values of 0.035 and 0.074 had a high sensitivity and high specificity, respectively, to classify proteinuria and identify borderline proteinuric cats. Moreover, a UAC of 0.017 had a high sensitivity in distinguishing between healthy and diseased cats. However, UAC was not able to distinguish between renal (CKD) and non-renal diseases (LUTD/OTHER), probably owing to the pathophysiology of CKD in cats, which is characterised by low-grade proteinuria and less glomerular involvement than in dogs. Conclusions and relevance HRE is an accurate and precise method that could be used to measure albuminuria in cats. UAC was useful to correctly classify proteinuria and to discriminate between healthy and diseased cats. HRE might also provide additional information on urine proteins with a profile of all proteins (albumin and globulins) to aid clinicians in the diagnosis of diseases characterised by proteinuria.

Embelin supplementation of in vitro maturation medium does not influence nuclear and cytoplasmic maturation of pig oocytes

Oxidative stress caused from in vitro culture contributes to inadequate oocyte maturation which leads to a poor embryo development. Therefore, it is important to protect oocytes and embryos against oxidative stress. This study was aimed at evaluating the effect of Embelin (2,5-dihydroxy-3-undecyl-1,4-benzoquinone), an antioxidant with various pharmacologic activities, on nuclear and cytoplasmic maturation of pig oocytes as well as on steroidogenesis of cumulus cells (CCs). Another objective was to determine the influence of Embelin on developmental competence of pig oocytes as well as the expression levels of three key genes (Nanog, Sox2 and Oct4) involved in the control of pluripotency in parthenogenetically activated embryos. Embelin (0, 10, 20 and 40 μM) was added during in vitro maturation of cumulus oocyte complexes; media of both the first and the second day of culture were collected and assayed for progesterone and estradiol-17β. At the end of the maturation period, the oocytes were fixed (to determine nuclear maturation) or partenogenically activated to evaluate cytoplasmic maturation and genes expression. Embelin did not exert any effect on the proportion of MII oocytes, steroidogenesis of CCs, percentage of embryos that developed to blastocyst stage and the number of blastomeres/blastocyst. Moreover, no significant differences of Oct4, Nanog and Sox2 transcripts were detected in blastocyst stage embryos. In conclusion, Embelin did not influence the reproductive parameters assessed, confirming that it is not possible to predict whether the beneficial effect exerted by an antioxidant in a particular tissue could be present also in another one.

Storage of sexed boar spermatozoa: Limits and perspectives

Despite the great potential application of sex-sorted spermatozoa in swine, the technology is not practiced in the pig industry because of technical factors and species-specific issues. The susceptibility of boar spermatozoa to stresses induced by the sorting procedure, the relative slowness of the sex-sorting process together with the high sperm numbers required for routine artificial insemination in pig are some of the main factors limiting the commercial application of this technology in pigs. This review briefly describes the damage to spermatozoa during sex sorting, focusing on an additional limiting factor: increased susceptibility of sexed boar spermatozoa to injuries induced by liquid storage and cryopreservation that, in turn, impairs sperm quality leading to unsatisfactory results in vivo. Strategies to extend the lifespan of sex-sorted boar spermatozoa and to improve their fertilizing ability after liquid storage or cryopreservation need to be implemented before this technology can be used in pig farms. In this regard, encapsulation in barium alginate membranes could be a promising technique to optimize the in vivo use of sexed boar spermatozoa, by protecting, targeting, and controlling the release of sperm into the female genital tract.

Sex-sorted canine sperm cryopreservation: limits and procedural considerations

The aim of this study was to define a protocol to store dog sperm before and after sorting to obtain an insemination dose sufficient to allow the conception by artificial insemination. Experiment 1 and 2 were performed to evaluate the more appropriate extender for preserving at room temperature dog sperm before and after sorting. Four extenders were tested: (1) Tris-fructose-citrate (TFC), (2) Tris-glucose-citrate (TGC), (3) modified Tyrode's albumin lactate pyruvate medium (mTALP), and (4) third fraction of the ejaculate (after centrifugation at 5000× g for 10 minutes; III FRAC). Experiment 3 and 4 were performed to evaluate the ability of dog semen to withstand sex sorting and freezing/thawing. Modified Tyrode's albumin lactate pyruvate medium was the best extender for canine sperm storage at room temperature (20 °C-25 °C) before (total motility: TFC, 8.3 ± 1.7; TGC, 50.0 ± 11.5; mTALP, 70.0 ± 0.1; III FRAC, 25.0 ± 1 0.4; P < 0.05) and after sorting (total motility: TFC, 7.3 ± 1.5; TGC, 10.3 ± 1.5; mTALP, 33.3 ± 6.7; III FRAC, 8.7 ± 5.8; P < 0.05), even if at 24-hour sorted sperm quality was impaired in all extenders tested herein. Sperm quality decreased after sorting (total motility: control, 92.5 ± 0.9; sorted, 52.9 ± 6.0; P < 0.05) and, especially, after freezing/thawing (total motility: frozen control, 25.7 ± 4.1; frozen sorted, 2.4 ± 1.2; P < 0.05). In conclusion, mTALP is an appropriate medium for canine sperm storage before and soon after sorting (hours), but a long storage period of sexed sperm at room temperature is not adequate. Cryopreservation greatly impaired sperm quality, and further studies are needed to optimize the freezing protocol for sexed dog sperm.