Miguel Fornes | Universidad Nacional de Cuyo (original) (raw)

Papers by Miguel Fornes

Food & Function, 2022

Organosulfur compounds could confer sunflower oil a beneficial effect and be considered as value-... more Organosulfur compounds could confer sunflower oil a beneficial effect and be considered as value-added nutraceuticals.

Developmental Biology, Oct 1, 1999

We previously demonstrated that mouse sperm capacitation is accompanied by a time-dependent incre... more We previously demonstrated that mouse sperm capacitation is accompanied by a time-dependent increase in protein tyrosine phosphorylation that is dependent on the presence of BSA, Ca 2؉ , and NaHCO 3 , all three of which are also required for this maturational event. We also demonstrated that activation of protein kinase A (PK-A) is upstream of this capacitation-associated increase in protein tyrosine phosphorylation. BSA is hypothesized to modulate capacitation through the removal of cholesterol from the sperm plasma membrane. In this report, we demonstrate that incubation of mouse sperm medium containing BSA results in a release of cholesterol from the sperm plasma membrane to the medium; release of this sterol does not occur in medium devoid of BSA. We next determined whether cholesterol release leads to changes in protein tyrosine phosphorylation. Blocking the action of BSA by adding exogenous cholesterol-SO 4 ؊ to the BSA-containing medium inhibits the increase in protein tyrosine phosphorylation as well as capacitation. This inhibitory effect is overcome by (1) the addition of increasing concentrations of BSA at a given concentration of cholesterol-SO 4 ؊ and (2) the addition of dibutyryl cAMP plus IBMX. High-density lipoprotein (HDL), another cholesterol binding protein, also supports the capacitation-associated increase in protein tyrosine phosphorylation through a cAMP-dependent pathway, whereas proteins that do not interact with cholesterol have no effect. HDL also supports sperm capacitation, as assessed by fertilization in vitro. Finally, we previously demonstrated that HCO 3 ؊ is necessary for the capacitation-associated increase in protein tyrosine phosphorylation and demonstrate here, by examining the effectiveness of HCO 3 ؊ or BSA addition to sperm on protein tyrosine phosphorylation, that the HCO 3 ؊ effect is downstream of the site of BSA action. Taken together, these data demonstrate that cholesterol release is associated with the activation of a transmembrane signal transduction pathway involving PK-A and protein tyrosine phosphorylation, leading to functional maturation of the sperm.

Este manual se desarrolla desde una escritura simple y amena , tomando lo básico de cada tópico p... more Este manual se desarrolla desde una escritura simple y amena , tomando lo básico de cada tópico para dar pie a algunos de los muchos interrogantes en el campo de la biología celular y molecular aplicada al espermatozoide de mamíferos, en particular, a los estudiados por los autores del presente manual.Fil: Castellon, Enrique. Universidad de Chile; ChileFil: Cesari, Andreina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Fornes, Miguel Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin

Pharmaceutics, Jan 3, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Protein expression in SHRs cortex kidney. Representative blot of WT-1, VDR, Hsp70 and AT1 protein... more Protein expression in SHRs cortex kidney. Representative blot of WT-1, VDR, Hsp70 and AT1 protein expression in SHRs cortex kidney. Housekeeping gene β-actin protein expression is shown in the line here below. (TIF 26384 kb)

La ingesta elevada de grasas de origen animal (“saturadas”) conlleva a un incremento de colestero... more La ingesta elevada de grasas de origen animal (“saturadas”) conlleva a un incremento de colesterol en sangre (hipercolesterolemia, HC), y es un factor de riesgo para el desarrollo de enfermedades cardiovasculares.

Free Radical Biology and Medicine, 2017

Obesity is a low-grade chronic inflammatory disease resulting from adipose tissue inflammation. M... more Obesity is a low-grade chronic inflammatory disease resulting from adipose tissue inflammation. Metabolic syndrome (MS) is the most serious consequence of obesity. Although many organs are affected in the MS, its impact on lung biochemistry is less known. Herein we aimed at determining the impact of MS on redox/inflammatory status and potential consequences in the lung using a previously developed mouse model of MS. To achieve this goal, 6 week-old male C57BL / 6J mice were fed for 16 weeks with a low fat- (LFD) or a high fat-diet (HFD, chicken fat) and water supplemented with 10% fructose (F). Thus, the experimental design included 2 groups: LFD (control) HFD+F (MS). Compared to control, the lung parenchyma of MS mice showed increased neutrophils content, MPO activity, oxidative stress (NOX-2, carbonyls, TBARS and nitrotyrosine) and inflammation markers (iNOS, ICAM-1, TNF-α and IL-6). In addition and compared to LFD, the lung parenchyma of HFD+F mice had a lower total antioxidant c...

Free Radical Biology and Medicine, 2018

mitochondria. While it is now clear that recovery respiration is essential for tumour formation, ... more mitochondria. While it is now clear that recovery respiration is essential for tumour formation, its functional link to the process is unclear. It includes gradual increase in mtDNA level of homoplasmic host polymorphism, followed by binding of mtDNA-processing enzymes to its regulatory domain, replication and transcription of mtDNA, increased expression of components of respiratory complexes, resulting in full restoration of respiration. We found that pyrimidine biosynthesis, supported by the respiration-linked enzyme dihydroorotate dehydrogenase (DHODH), is critically required to overcome cell cycle arrest. We further confirmed that efficient de novo pyrimidine synthesis, necessary for tumour cell proliferation, is the key event for triggering tumour growth. Moreover, respiration recovery, which is necessary for tumour formation, is associated with efficient de novo pyrimidine synthesis. In conclusion, we propose that DHODH is a critical link between de novo pyrimidine synthesis and respiration, and that it is a promising target for broad-spectrum cancer therapy.

Inflammation, 2019

Chicken fat and fructose are added into food-processing to reduce costs and enhance acceptability... more Chicken fat and fructose are added into food-processing to reduce costs and enhance acceptability; however, these additives turn food into unhealthy and hypercaloric meals. Herein we have hypothesized that chronic feeding with chicken fat and fructose, together or by separate, can cause pulmonary redox and inflammatory changes. These changes are particularly related to neutrophils and myeloperoxidase, with consequent changes in the organ histophysiology. To test this hypothesis, we fed mice for 16 weeks with either control food (low-fat diet, LFD) or control food supplemented with 22% chicken fat and with or without 10% fructose in the drinking water. At the end of the feeding regimen, we measured redox and inflammatory changes in the lung with particular emphasis on neutrophil accumulation/activation and molecular-histological markers of fibrosis. Our results suggest that a diet supplemented with chicken fat and fructose causes additive effects on pulmonary oxidative stress, inflammation, and a pro-fibrotic status. Neutrophilic inflammation may play a critical role in pulmonary pathology associated with metabolic syndrome.

Revista Jornadas de Investigación (2020);año 11, n° 11, Oct 1, 2020

Evaluar la utilidad de las mediciones bioquímicas de rutina como herramientas para valorar hiperc... more Evaluar la utilidad de las mediciones bioquímicas de rutina como herramientas para valorar hipercolesterolemia en conejos neozelandeses alimentados con dieta alta en grasa saturada (DAG)

Molecular Reproduction and Development, May 1, 1994

Recently, a new head-to-head sperm association was described in the rat during epididymal transit... more Recently, a new head-to-head sperm association was described in the rat during epididymal transit. This association was called a rosette and a filamentous and PAS-positive material was also described joining the sperm heads. The beginning of rosette formation in the epididymis and the linking material between heads have remained unclear. Epididymides of adult rats were fixed by vascular perfusion and thin sections of the principal regions were studied by transmission electron microscopy (TEM). The first evidence of rosette formation was observed in the distal corpus. Rosettes were isolated from the distal corpus and processed for immunogold and immunofluorescence microscopy to detect an epididymal glycoprotein called DE. This glycoprotein is secreted by the corpus epididymis and appears to be involved in sperm maturation. Colloidal gold marks and fluorescence were observed in the linking material between the sperm heads. The results presented here show that rosettes begin to appear following the sites of DE secretion and permit us to postulate that DE is involved in rosette formation and constitutes another example of gamete-epididymal interaction.

American Journal of Physiology-renal Physiology, Jun 15, 2012

Vitamin D slows the progression of chronic kidney disease. Furthermore, activators of vitamin D r... more Vitamin D slows the progression of chronic kidney disease. Furthermore, activators of vitamin D receptors (VDR) have suppressant effects on the renin-angiotensin system, as well as anti-inflammatory and antifibrotic actions. This study aimed to evaluate the cytoprotective effects of paricalcitol, a VDR activator, at the mitochondrial level using an obstructive nephropathy model [unilateral ureteral obstruction (UUO)]. Rats subjected to UUO and controls were treated daily with vehicle or paricalcitol. The control group underwent a sham surgery. The treatment was done for 15 days (30 ng/kg). The following were determined: biochemical parameters; fibrosis; apoptosis; mitochondrial morphology; VDR, AT1 receptor, and NADPH oxidase 4 expression; and NADPH oxidase activity (in total and in mitochondrial fractions from the renal cortex). VDR activation prevented fibrosis (20 Ϯ 5 vs. 60 Ϯ 10%) and the number of TUNEL-positive apoptotic cells (10 Ϯ 3 vs. 25 Ϯ 4) in UUO. Biochemical, histological, and molecular studies suggest mitochondrial injury. Electron microscopy revealed in UUO electronically luminous material in the nucleus. Some mitochondria were increased in size and contained dilated crests and larger than normal spaces in their interiors. These changes were not present with paricalcitol treatment. Additionally, high AT1-receptor mRNA and NADPH activity was reverted in mitochondrial fractions from obstructed paricalcitol-treated animals (0.58 Ϯ 0.06 vs. 0.95 Ϯ 0.05 relative densitometry units and 9,000 Ϯ 800 vs. 15,000 Ϯ 1,000 relative fluorescence units•g protein Ϫ1 •min Ϫ1 , respectively). These changes were consistent with an improvement in VDR expression (0.75 Ϯ 0.05 vs. 0.35 Ϯ 0.04 relative densitometry units). These results suggest that paricalcitol confers a protective effect and reveal, as well, a possible AT1 receptor-dependent protective effect that occurs at the mitochondrial level.

Developmental Biology, Dec 1, 1997

The molecular basis of mammalian sperm capacitation, defined as those biochemical and functional ... more The molecular basis of mammalian sperm capacitation, defined as those biochemical and functional changes that render the sperm competent to fertilize the egg, is poorly understood. This extratesticular maturational process is accompanied by the activation of a unique signal transduction pathway involving the cAMP-dependent up-regulation of protein tyrosine phosphorylation presumably through the activation of protein kinase A (PK-A). We demonstrate in this report that capacitation of cauda epididymal mouse sperm in vitro was accompanied by a time-dependent increase in PK-A activity. This increase in PK-A activity did not occur in a medium that does not support capacitation. While PK-A catalytic and RI/RII regulatory subunits, as well as PK-A enzyme activity, were found in both the Triton X-100-soluble and-insoluble fractions of the sperm, the increase in PK-A activity accompanying capacitation was associated with enzyme activity found in the soluble fraction. Moreover, the regulatory and catalytic subunits of PK-A were observed by indirect immunofluorescence to be present throughout the head, midpiece, and principal piece of the sperm. Thus, PK-A appears to be functional in multiple compartments of this highly differentiated cell. A fraction of the Triton X-100-insoluble PK-A is presumably tethered by AKAP82, the major protein of the fibrous sheath of the sperm flagellum which anchors and compartmentalizes PK-A to the cytoskeleton via the RII subunit of PK-A. Using various recombinant truncated AKAP82 constructs in a gel overlay assay, the RII subunit-binding domain of this protein was mapped to a 57-amino-acid residue region at its N-terminus. Computer analysis revealed a 14-amino-acid region that resembled the RII-binding domains of other A Kinase Anchor Proteins. A synthetic peptide corresponding to this domain inhibited AKAP82-RII binding in a gel overlay assay, providing further support that AKAP82 is an anchoring protein for the subcellular localization of PK-A in the mouse sperm fibrous sheath. This work, along with previous findings that cAMP is a key intermediary second messenger in regulating protein tyrosine phosphorylation and capacitation, further supports the importance of PK-A in these processes and necessitates a further understanding of the contribution of both the soluble and insoluble forms of PK-A, as well as AKAP82, to sperm function.

International Journal of Andrology, Feb 11, 2023

BackgroundRabbits are sensitive to dietary cholesterol and rapidly develop hypercholesterolemia, ... more BackgroundRabbits are sensitive to dietary cholesterol and rapidly develop hypercholesterolemia, leading to prominent subfertility. Sterol regulatory element‐binding protein isoform 2 drives the intracellular cholesterol pathway in many tissues, including the testicles. Its abnormal regulation could be the mainly responsible for the failure of suppressing cholesterol synthesis in a cholesterol‐enriched environment, ultimately leading to testicular and seminal alterations. However, extra‐virgin olive oil consumption has beneficial properties that promote lowering of cholesterol levels, including the recovery of seminal parameters altered under a high‐fat diet.ObjectivesOur goal was to investigate the effects of high‐fat diet supplementation with extra‐virgin olive oil at the molecular level on rabbit testes, by analyzing sterol regulatory element‐binding protein isoform 2 protein and its corresponding downstream effectors.Materials and methodsDuring 12 months, male rabbits were fed a control diet, high‐fat diet, or 6‐month high‐fat diet followed by 6‐month high‐fat diet plus extra‐virgin olive oil. Serum lipids, testosterone levels, bodyweight, and seminal parameters were tested. The mRNA and protein levels of sterol regulatory element‐binding protein isoform 2, 3‐hydroxy‐3‐methyl‐glutaryl‐coenzyme A reductase, and low‐density lipoprotein receptor were determined by semi‐quantitative polymerase chain reaction and Western blotting techniques. The expression pattern of sterol regulatory element‐binding protein isoform 2 protein in the rabbit testicles was studied by indirect immunofluorescence. In addition, testicular cholesterol was detected and quantified by filipin staining and gas chromatography.ResultsThe data showed that the addition of extra‐virgin olive oil to high‐fat diet reduced testicular cholesterol levels and recovered the expression of sterol regulatory element‐binding protein isoform 2, 3‐hydroxy‐3‐methyl‐glutaryl‐coenzyme A reductase, and low‐density lipoprotein receptor initially altered by the high‐fat diet.Discussion and conclusionsThe combination of high‐fat diet with extra‐virgin olive oil encourages testicular recovery by modifying the expression of the enzymes related to intracellular cholesterol management.

Theriogenology wild, 2023

Male reproductive cycles in lizards can be continuous or seasonal depending on the environmental ... more Male reproductive cycles in lizards can be continuous or seasonal depending on the environmental conditions and female availability. The aim of this study is to investigate whether adult males of the psammophilus lizard Liolaemus cuyanus present seasonal changes of reproductive traits throughout the reproductive cycle. In order to carry out this task, sampling of specimens (N = 27) was carried out monthly from October to March in Valle de Matagusanos, Ullúm, San Juan, Argentina (31°06′46.08′’ S, 68°38′03.84′’ W; altitude: 945 m), a semi-arid zone. The animals captured in different months were grouped based on reproductive criteria according to three relevant periods: pre-reproductive (PrR), reproductive (R) and post-reproductive (PsR). In order to identify and characterize these periods, several male reproductive traits were obtained, like morphometric parameters (body mass, snout-vent length, testes and abdominal fat body mass), tubular surface and estimation of the interstitial tissue coverage, combined with histological and cell seminiferous tubule observations (germ cells types, histological and ultrastructural details) and presence of sperm in the cauda epididymis. During the PrR period, which occurred during spring, well-developed testes with free tubular sperm cells were present, but these were less frequent than during the R period. On the other hand, luminal sperm cells were evident at the seminiferous tubules from the beginning of the R period, in conjunction with the maximum testes mass and seminiferous tubular surfaces. This was also coincident with a higher abundance of sperm cells in the cauda epididymal lumen. At the end of this period, the initial regression of the seminiferous epithelium was corroborated by organelle regression which was observed in the ultrastructure of spermatogenic cells. At the beginning of the PsR period, before autumn, a marked decrease in male reproductive traits above described was detected. Instead, an increase in abdominal fat body mass could be observed indicating the onset of the lethargy period. The results obtained suggest that this population of L. cuyanus has a seasonal reproductive cycle, with its reproductive activity occurring during the spring-summer months (PrR-R periods) and finishing in late summer (PsR).

The relationship between obesity/hypercholesterolemia and reduced male fertility has been reporte... more The relationship between obesity/hypercholesterolemia and reduced male fertility has been reported clinically and in experimental models. The effect of high cholesterol intake and its impact in different tissue/organs has also been described in several models. The deleterious impact on reproductive tissues has been studied in rabbits and other species. Changes in lipid content in testis cells and epididymal cells were reported in normal or genetically reprogrammed animals. Recent work using the hypercholesterolemic rabbit (HCR) (breed: New Zealand) model previously developed to study atherosclerosis has demonstrated that increased fat in a nutritionally complete diet alters the cholesterol content and distribution in the rabbit sperm membrane. The high dietary fat level has serious consequences on sperm-specific functions that depend on membrane integrity/dynamics. At least two of the proposed pathways involved in regulating sperm capacitation and acrosomal reaction (AR) via cholesterol were compromised in the results; daily virgin olive oil supplementation together with a fat diet provided to male rabbits can restore the hypercholesterolemic (HC) response to basal level with a significant improvement of semen and sperm quality. We also concluded that the cellular events implicated must be further investigated to make greater progress not only in diagnosis and treatment but also in prevention. In these previous works, the sperm morphology of ejaculated sperm was altered. The final appearance of the sperm cell is due to complex mechanisms that take place in the seminiferous tubules. Recent work in the lab was aimed to study the Golgi apparatus / acrosome ? acroplaxome development, structures involved in the acquisition of the sperm head shape. Under HC the Golgi / acrosome development during spermiogenesis was altered promoting several sperm head and flagella implantation malformations. Interestingly, olive oil addition to normal diet avoids semen/sperm and testicular alterations in adult male rabbits.Fil: Fornes, Miguel Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Saez Lancellotti, Tania Emilce Estefania. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Simón, Layla Yamila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Funes, Abi Karenina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin

Microscopy and Microanalysis, Aug 1, 2000

Head-to-head sperm association was described in some species as a normal phenomenon during epidid... more Head-to-head sperm association was described in some species as a normal phenomenon during epididyma transit (Phillips and Bedford, 1987). Recently, a new sperm head association (SHA) was characterized in the rat (Fornés & Burgos 1990; 1994).At this moment, the study of SHA was extended to mouse sperm. SHA is a type of cell-cell interaction clearly observed when an a drop of epididymal fluid, obtained by a puncture of epididymal duct, is placed in a culture medium (HMB media: Modified Ringers medium).This preparation can be observed under contrast phase microscope (optiphot-2, Nikkon) with or without fixative (2% paraformaldehyde and 2% glutaraldehyde in 0.01 M PBS buffer, pH 7,2). The mass of spermatozoa begin to move but not as a single sperm. They move as a clump of sperm and without fixative the sperm motility alone disaggregate the SHA.