Astaxanthin (Asta), a photo-protective red pigment of the carotenoid family, is known for its mul... more Astaxanthin (Asta), a photo-protective red pigment of the carotenoid family, is known for its multiple beneficial properties. In this study, the effects of Asta on isolated human sperm were evaluated. Capacitation involves a series of transformations to let sperm acquire the correct features for potential oocyte fertilization, including the generation of a controlled amount of reactive oxygen species (ROS), cholesterol depletion of the sperm outer membrane, and protein tyrosine phosphorylation (Tyr-P) process in the head region. Volunteers, with normal spermiogram values, were divided in two separate groups on the basis of their ability to generate the correct content of endogenous ROS. Both patient group (PG) and control group (CG) were analysed for Tyr-phosphorylation (Tyr-P) pattern and percentages of acrosome-reacted cells (ARC) and non-viable cells (NVC), in the presence or absence of Asta. In addition, the involvement of ROS on membrane reorganization and the presence of Lyn, a Src family kinase associated with lipid rafts, were investigated. Results show that Lyn is present in the membranes of human sperm, mainly confined in midpiece in resting conditions. Following capacitation, Lyn translocated to the head concomitantly with raft relocation, thus allowing the Tyr-P of head proteins. Asta succeeded to trigger Lyn translocation in PG sperm thus bypassing the impaired ROS-related mechanism for rafts and Lyn translocation. In this study, we showed an interdependence between ROS generation and lipid rafts and Lyn relocation leading the cells to undergo the successive acrosome reaction (AR). Asta, by ameliorating PG sperm functioning, may be utilised to decrease male idiopathic infertility.
Primary hyperparathyroidism (PHPT) is often found on routine blood tests, at a relatively asympto... more Primary hyperparathyroidism (PHPT) is often found on routine blood tests, at a relatively asymptomatic stage. However many studies suggest different systemic effects related to PHPT, which could be enhanced by an abnormal cortisol release due to chronic stress of hyperparathyroidism. Being PHPT frequently found in the 6th to 7th decade of life, a careful and multifaceted approach should be taken. We report the case of an elderly patient with symptomatic PHPT and incidental pulmonary embolism. He was treated with hydration, zoledronic acid, cinacalcet and high-dose unfractionated heparin. Parathyroid surgery was successfully performed, but patient's conditions suddenly worsened because of a transient thyrotoxicosis, probably induced by a previous exposure to iodine load and/or thyroid surgical manipulation. A short-term treatment with beta-blockers was introduced for symptomatic relief. The patient also presented a transient hypercortisolism with elevated ACTH, likely due to stre...
A wide variety of sperm preparation protocols are currently available for assisted conception. Th... more A wide variety of sperm preparation protocols are currently available for assisted conception. They include density gradient separation and washing methods. Both aim at isolating and capacitating as much motile sperm as possible for subsequent oocyte fertilization. The aim of this study was to examine the effects of four commercial sperm washing buffers on sperm viability and capacitation. Semen samples from 48 healthy donors (normal values of sperm count, motility, morphology, and volume) were analyzed. After separation (density gradient 40/80%), sperm were incubated in various buffers then analysed for reactive oxygen species (ROS) production, viability, tyrosine phosphorylation (Tyr-P), cholera toxin B subunit (CTB) labeling, and the acrosome reaction (AR). The buffers affected ROS generation in various ways resulting either in rapid cell degeneration (when the amount of ROS was too high for cell survival) or the inability of the cells to maintain correct functioning (when ROS were too few). Only when the correct ROS generation curve was maintained, suitable membrane reorganization, evidenced by CTB labeling was achieved, leading to the highest percentages of both Tyr-P- and acrosome-reacted-cells. Distinguishing each particular pathological state of the sperm sample would be helpful to select the preferred buffer treatment since both ROS production and membrane reorganization can be significantly altered by commercial buffers.
This study examined the possible involvement of carbonic anhydrase activation in response to an e... more This study examined the possible involvement of carbonic anhydrase activation in response to an endometriosis-related increase in oxidative stress. Peripheral blood samples obtained from 27 healthy controls and 30 endometriosis patients, classified as having endometriosis by histological examination of surgical specimens, were analysed by multiple immunoassay and carbonic anhydrase activity assay. Red blood cells (RBC) were analysed for glutathionylated protein (GSSP) content in the membrane, total glutathione (GSH) in the cytosol and carbonic anhydrase concentration and activity. In association with a membrane increase of GSSP and a cytosolic decrease of GSH content in endometriosis patients, carbonic anhydrase significantly increased (P < 0.0001) both monomerization and activity compared with controls. This oxidation-induced activation of carbonic anhydrase was positively and significantly correlated with the GSH content of RBC (r = 0.9735, P < 0.001) and with the amount of the 30-kDa monomer of carbonic anhydrase (r = 0.9750, P < 0.001). Because carbonic anhydrase activation is implied in many physiological and biochemical processes linked to pathologies such as glaucoma, hypertension, obesity and infections, carbonic anhydrase activity should be closely monitored in endometriosis. These data open promising working perspectives for diagnosis and treatment of endometriosis and hopefully of other oxidative stress-related diseases. Endometriosis is a chronic disease associated with infertility and local inflammatory response, which is thought to spread rapidly throughout the body as a systemic subclinical inflammation. One of the causes in the pathogenesis/evolution of endometriosis is oxidative stress, which occurs when reactive oxygen species are produced faster than the endogenous antioxidant defence systems can neutralize them. Once produced, reactive oxygen species can alter the morphological and functional properties of endothelial cells, including permeability and adhesion molecule expression, thus contributing to ongoing inflammation. Due to their main cellular functions--delivery of O2 from lung to tissue and removal of CO2 from tissue to lung--red blood cells (RBC) are exposed to oxidative stress. Carbon dioxide in tissue capillaries diffuses into red cells, where it is rapidly hydrated by the action of cytosolic carbonic anhydrase. Analysis of the oxidation status of endometriotic RBC membranes showed a high content of glutathionylated proteins, indicating pre-existing oxidation-related alterations. The increase in glutathionylated proteins was correlated to increased carbonic anhydrase activity in endometriotic RBC compared with healthy controls. Carbonic anhydrase is a family of metalloenzymes involved in many physiological processes such as acid-base homeostasis, respiration, carbon dioxide and ion transport, and bone resorption, and in the regulation of ureagenesis, gluconeogenesis, lipogenesis and tumourigenesis. Due to the potential implication of carbonic anhydrase activation in many pathologies, such as glaucoma, hypertension, obesity and infections, carbonic anhydrase activity should be closely monitored in endometriosis to prevent possible complications and/or worsening of related conditions.
Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein ... more Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein tyrosine (Tyr) residues are two main cellular changes involved in sperm capacitation. This study examined the relationship between tyrosine-phosphorylation (Tyr-P) and endogenous ROS production during sperm capacitation, and correlated them with both sperm motility and functionality expressed as acrosome-reacted cells. Immediate ROS generation was observed to peak after a 45-min incubation, followed by a rapid decrease in ROS content and successive regeneration of the ROS peak in 3 h and later. These two peaks were directly correlated with both the Tyr-P process involving sperm heads and tails, and the acrosome reaction (69 ± 8% and 65 ± 4%, respectively). The period of low-ROS content resulted in low Tyr-P patterns, located exclusively in the cell midpiece, and drastic reduction in acrosome-reacted cells. Ascorbic acid addition inhibited both Tyr-P patterns and acrosome reactions, whereas NADPH induced high ROS generation, with Tyr-P patterns located only on sperm tails, and prevented the acrosome reaction. Sperm hyperactivation was insensitive to ROS content. This is an important parameter for evaluation of sperm capacitation, which is achieved only when both ROS generation reaches a peak and Tyr-P involves the sperm head.
Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein ... more Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein tyrosine residues (Tyr) are two closely related changes involved in sperm capacitation. This study investigated the effect of altered endogenous ROS production on Tyr-phosphorylation (Tyr-P), acrosome reaction (AR) and cell viability during sperm capacitation. The possible origin of the altered ROS production was also evaluated by apocynin (APO) or oligomycin (Oligo) addition. A total of 63 samples of purified sperm were analysed for ROS production by enhanced chemiluminescence, Tyr-P pattern by immunocytochemistry, and AR and viability by fluorochrome fluorescein isothiocyanate (FITC)-labelled peanut (Arachis hypogaea) agglutinin and propidium iodide positivity, respectively. Samples were divided into four categories depending on the ability of sperm to produce ROS, expressed as Relative Luminescence Units (RLU), in capacitating conditions: low ROS production (LRP), range about 0.0-0.05 RLU; normal (NRP), 0.05-0.1 RLU; high (HRP), 0.1-0.4 RLU; very high (VHRP) 0.4-2.0 RLU. In NRP sperm heads, capacitation induced Tyr-P in 87.9 ± 4.3%, and the AR occurred in 62.5 ± 5.4% of cells; in LRP, HRP and VHRP Tyr-P labelling rarely spread over the head, acrosome-reacted cells only accounted for a small number of sperm, and the non-viable cells (NVC) were increased. The addition of APO, but not Oligo, drastically decreased ROS production in analysed samples. This study proposes the optimal threshold for endogenous ROS production for correct sperm viability and functioning, and indicates the direct involvement of APO-sensitive NADPH oxidase in ROS production.
Astaxanthin (Asta), a photo-protective red pigment of the carotenoid family, is known for its mul... more Astaxanthin (Asta), a photo-protective red pigment of the carotenoid family, is known for its multiple beneficial properties. In this study, the effects of Asta on isolated human sperm were evaluated. Capacitation involves a series of transformations to let sperm acquire the correct features for potential oocyte fertilization, including the generation of a controlled amount of reactive oxygen species (ROS), cholesterol depletion of the sperm outer membrane, and protein tyrosine phosphorylation (Tyr-P) process in the head region. Volunteers, with normal spermiogram values, were divided in two separate groups on the basis of their ability to generate the correct content of endogenous ROS. Both patient group (PG) and control group (CG) were analysed for Tyr-phosphorylation (Tyr-P) pattern and percentages of acrosome-reacted cells (ARC) and non-viable cells (NVC), in the presence or absence of Asta. In addition, the involvement of ROS on membrane reorganization and the presence of Lyn, a Src family kinase associated with lipid rafts, were investigated. Results show that Lyn is present in the membranes of human sperm, mainly confined in midpiece in resting conditions. Following capacitation, Lyn translocated to the head concomitantly with raft relocation, thus allowing the Tyr-P of head proteins. Asta succeeded to trigger Lyn translocation in PG sperm thus bypassing the impaired ROS-related mechanism for rafts and Lyn translocation. In this study, we showed an interdependence between ROS generation and lipid rafts and Lyn relocation leading the cells to undergo the successive acrosome reaction (AR). Asta, by ameliorating PG sperm functioning, may be utilised to decrease male idiopathic infertility.
Primary hyperparathyroidism (PHPT) is often found on routine blood tests, at a relatively asympto... more Primary hyperparathyroidism (PHPT) is often found on routine blood tests, at a relatively asymptomatic stage. However many studies suggest different systemic effects related to PHPT, which could be enhanced by an abnormal cortisol release due to chronic stress of hyperparathyroidism. Being PHPT frequently found in the 6th to 7th decade of life, a careful and multifaceted approach should be taken. We report the case of an elderly patient with symptomatic PHPT and incidental pulmonary embolism. He was treated with hydration, zoledronic acid, cinacalcet and high-dose unfractionated heparin. Parathyroid surgery was successfully performed, but patient's conditions suddenly worsened because of a transient thyrotoxicosis, probably induced by a previous exposure to iodine load and/or thyroid surgical manipulation. A short-term treatment with beta-blockers was introduced for symptomatic relief. The patient also presented a transient hypercortisolism with elevated ACTH, likely due to stre...
A wide variety of sperm preparation protocols are currently available for assisted conception. Th... more A wide variety of sperm preparation protocols are currently available for assisted conception. They include density gradient separation and washing methods. Both aim at isolating and capacitating as much motile sperm as possible for subsequent oocyte fertilization. The aim of this study was to examine the effects of four commercial sperm washing buffers on sperm viability and capacitation. Semen samples from 48 healthy donors (normal values of sperm count, motility, morphology, and volume) were analyzed. After separation (density gradient 40/80%), sperm were incubated in various buffers then analysed for reactive oxygen species (ROS) production, viability, tyrosine phosphorylation (Tyr-P), cholera toxin B subunit (CTB) labeling, and the acrosome reaction (AR). The buffers affected ROS generation in various ways resulting either in rapid cell degeneration (when the amount of ROS was too high for cell survival) or the inability of the cells to maintain correct functioning (when ROS were too few). Only when the correct ROS generation curve was maintained, suitable membrane reorganization, evidenced by CTB labeling was achieved, leading to the highest percentages of both Tyr-P- and acrosome-reacted-cells. Distinguishing each particular pathological state of the sperm sample would be helpful to select the preferred buffer treatment since both ROS production and membrane reorganization can be significantly altered by commercial buffers.
This study examined the possible involvement of carbonic anhydrase activation in response to an e... more This study examined the possible involvement of carbonic anhydrase activation in response to an endometriosis-related increase in oxidative stress. Peripheral blood samples obtained from 27 healthy controls and 30 endometriosis patients, classified as having endometriosis by histological examination of surgical specimens, were analysed by multiple immunoassay and carbonic anhydrase activity assay. Red blood cells (RBC) were analysed for glutathionylated protein (GSSP) content in the membrane, total glutathione (GSH) in the cytosol and carbonic anhydrase concentration and activity. In association with a membrane increase of GSSP and a cytosolic decrease of GSH content in endometriosis patients, carbonic anhydrase significantly increased (P < 0.0001) both monomerization and activity compared with controls. This oxidation-induced activation of carbonic anhydrase was positively and significantly correlated with the GSH content of RBC (r = 0.9735, P < 0.001) and with the amount of the 30-kDa monomer of carbonic anhydrase (r = 0.9750, P < 0.001). Because carbonic anhydrase activation is implied in many physiological and biochemical processes linked to pathologies such as glaucoma, hypertension, obesity and infections, carbonic anhydrase activity should be closely monitored in endometriosis. These data open promising working perspectives for diagnosis and treatment of endometriosis and hopefully of other oxidative stress-related diseases. Endometriosis is a chronic disease associated with infertility and local inflammatory response, which is thought to spread rapidly throughout the body as a systemic subclinical inflammation. One of the causes in the pathogenesis/evolution of endometriosis is oxidative stress, which occurs when reactive oxygen species are produced faster than the endogenous antioxidant defence systems can neutralize them. Once produced, reactive oxygen species can alter the morphological and functional properties of endothelial cells, including permeability and adhesion molecule expression, thus contributing to ongoing inflammation. Due to their main cellular functions--delivery of O2 from lung to tissue and removal of CO2 from tissue to lung--red blood cells (RBC) are exposed to oxidative stress. Carbon dioxide in tissue capillaries diffuses into red cells, where it is rapidly hydrated by the action of cytosolic carbonic anhydrase. Analysis of the oxidation status of endometriotic RBC membranes showed a high content of glutathionylated proteins, indicating pre-existing oxidation-related alterations. The increase in glutathionylated proteins was correlated to increased carbonic anhydrase activity in endometriotic RBC compared with healthy controls. Carbonic anhydrase is a family of metalloenzymes involved in many physiological processes such as acid-base homeostasis, respiration, carbon dioxide and ion transport, and bone resorption, and in the regulation of ureagenesis, gluconeogenesis, lipogenesis and tumourigenesis. Due to the potential implication of carbonic anhydrase activation in many pathologies, such as glaucoma, hypertension, obesity and infections, carbonic anhydrase activity should be closely monitored in endometriosis to prevent possible complications and/or worsening of related conditions.
Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein ... more Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein tyrosine (Tyr) residues are two main cellular changes involved in sperm capacitation. This study examined the relationship between tyrosine-phosphorylation (Tyr-P) and endogenous ROS production during sperm capacitation, and correlated them with both sperm motility and functionality expressed as acrosome-reacted cells. Immediate ROS generation was observed to peak after a 45-min incubation, followed by a rapid decrease in ROS content and successive regeneration of the ROS peak in 3 h and later. These two peaks were directly correlated with both the Tyr-P process involving sperm heads and tails, and the acrosome reaction (69 ± 8% and 65 ± 4%, respectively). The period of low-ROS content resulted in low Tyr-P patterns, located exclusively in the cell midpiece, and drastic reduction in acrosome-reacted cells. Ascorbic acid addition inhibited both Tyr-P patterns and acrosome reactions, whereas NADPH induced high ROS generation, with Tyr-P patterns located only on sperm tails, and prevented the acrosome reaction. Sperm hyperactivation was insensitive to ROS content. This is an important parameter for evaluation of sperm capacitation, which is achieved only when both ROS generation reaches a peak and Tyr-P involves the sperm head.
Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein ... more Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein tyrosine residues (Tyr) are two closely related changes involved in sperm capacitation. This study investigated the effect of altered endogenous ROS production on Tyr-phosphorylation (Tyr-P), acrosome reaction (AR) and cell viability during sperm capacitation. The possible origin of the altered ROS production was also evaluated by apocynin (APO) or oligomycin (Oligo) addition. A total of 63 samples of purified sperm were analysed for ROS production by enhanced chemiluminescence, Tyr-P pattern by immunocytochemistry, and AR and viability by fluorochrome fluorescein isothiocyanate (FITC)-labelled peanut (Arachis hypogaea) agglutinin and propidium iodide positivity, respectively. Samples were divided into four categories depending on the ability of sperm to produce ROS, expressed as Relative Luminescence Units (RLU), in capacitating conditions: low ROS production (LRP), range about 0.0-0.05 RLU; normal (NRP), 0.05-0.1 RLU; high (HRP), 0.1-0.4 RLU; very high (VHRP) 0.4-2.0 RLU. In NRP sperm heads, capacitation induced Tyr-P in 87.9 ± 4.3%, and the AR occurred in 62.5 ± 5.4% of cells; in LRP, HRP and VHRP Tyr-P labelling rarely spread over the head, acrosome-reacted cells only accounted for a small number of sperm, and the non-viable cells (NVC) were increased. The addition of APO, but not Oligo, drastically decreased ROS production in analysed samples. This study proposes the optimal threshold for endogenous ROS production for correct sperm viability and functioning, and indicates the direct involvement of APO-sensitive NADPH oxidase in ROS production.
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Papers by Gabriella Donà