Pablo Martín-Vasallo | Universidad de La Laguna (original) (raw)

Papers by Pablo Martín-Vasallo

Antioxidants

An excess of oxidative stress (OS) may affect several physiological processes fundamental to repr... more An excess of oxidative stress (OS) may affect several physiological processes fundamental to reproduction. SIRT1, SIRT6 and SIRT7 are involved in protection stress systems caused by OS, and they can be activated by antioxidants such as celastrol or melatonin. In this study, we evaluate SIRT1, SIRT6 and SIRT7 gene expression in cultured human granulosa-lutein (hGL) cells in response to OS inductors (glucose or peroxynitrite) and/or antioxidants. Our results show that celastrol and melatonin improve cell survival in the presence and absence of OS inductors. In addition, melatonin induced SIRT1, SIRT6 and SIRT7 gene expression while celastrol only induced SIRT7 gene expression. This response was not altered by the addition of OS inductors. Our previous data for cultured hGL cells showed a dual role of celastrol as a free radical scavenger and as a protective agent by regulating gene expression. This study shows a direct effect of celastrol on SIRT7 gene expression. Melatonin may protec...

Biology of the Cell, 1994

Antioxidants, 2021

Annals of the Rheumatic Diseases, 2001

Background An altered chondrocytes phenotipic expression of biglycan and decorin is an early even... more Background An altered chondrocytes phenotipic expression of biglycan and decorin is an early event in osteoarthritis (OA). Changes in extracellular matrix sodium concentration ([Na+]) occurs in OA. Previous results suggested that chondrocytes are sensitive to changes in their extracellular [Na+] environment and respond with variations in the matrix synthesis. Objectives Here we have studied the influence of extracellular [Na+] on the metabolism of small proteoglycans, biglycan and decorin, in a human chondrocyte-like cell line, C20/A4. Methods Extracellular deposition of biglycan and decorin was analysed in C20A4 cells cultured: 1) inmunohistochemically using specific antibodies against biglycan and decorin and secondary IFTC conjugated antibodies; and 2) in SDS-PAGE electrophoresis and blotting using the corresponding antibodies. Results Fluorescence inmunohistochemically shows specific extracellular expression of biglycan and decorin in chondrocytes cultured in estandard [Na+] (15...

Regulation of oxidative stress (OS) is important to prevent damage to female reproductive physiol... more Regulation of oxidative stress (OS) is important to prevent damage to female reproductive physiology. While normal OS levels may have a regulatory role, high OS levels may negatively affect vital processes such as folliculogenesis or embryogenesis. The aim of this work was to study OS induced by glucose, a reactive oxygen species generator, or peroxynitrite, a reactive nitrogen species generator, in cultured human granulosa-lutein (hGL) cells from oocyte donors, analyzing expression of genes involved in oocyte maturation (FSHR, PAPP, and CYP19A1) and OS damage response (ALDH3A2). We also evaluated the effect of celastrol as an antioxidant. Our results showed that although both glucose and peroxynitrite produce OS increments in hGL cells, only peroxynitrite treatment increases ALDH3A2 and PAPP gene expression levels and decreases FSHR gene expression levels. Celastrol pre-treatment prevents this effect of peroxynitrite. Interestingly, when celastrol alone was added, we observed a red...

Abstract: Membrane transport systems participate in fundamental activities such as cell cycle con... more Abstract: Membrane transport systems participate in fundamental activities such as cell cycle control, proliferation, survival, volume regulation, pH maintenance and regulation of extracellular matrix synthesis. Multiple isoforms of Na +, K +-ATPase are expressed in primary chondrocytes. Some of these isoforms have previously been reported to be expressed exclusively in electrically excitable cells (i.e., cardiomyocytes and neurons). Studying the distribution of Na +, K +-ATPase isoforms in chondrocytes makes it possible to document the diversity of isozyme pairing and to clarify issues concerning Na +, K +-ATPase isoform abundance and the physiological relevance of their expression. In this study, we investigated the expression of Na +, K +-ATPase in a human chondrocyte cell line (C-20/A4) using a combination of immunological and biochemical techniques. A panel of well-characterized antibodies revealed abundant expression of the α1, β1 and β2 isoforms. Western blot analysis of plas...

© 2008 Avila et al; licensee BioMed Central Ltd. This is an Open Access article distributed under... more © 2008 Avila et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License

Osteoblasts play a critical role in bone formation and mineralization, a process that depends on ... more Osteoblasts play a critical role in bone formation and mineralization, a process that depends on optimal calcium and phosphate homeostasis. Transcellular transport of free calcium [Ca2+], uptake of inorganic phosphate (P(i)) and numerous other transport systems in osteoblasts depend on a low intracellular Na+:K+ ratio furnished by (Na++K+)-stimulated adenosine triphosphatase (Na+,K+-ATPase), an enzyme embedded in the plasma membrane. In this study, we have examined, for the first time, the expression of the catalytic α and regulatory β subunit isoforms of Na+,K+-ATPase in primary human bone derived osteoblasts using isoform specific monoclonal and polyclonal antibodies. Immunofluorescence was used to detect the α1, β1 and β2 isoforms of Na+,K+-ATPase in dispersed osteoblasts. Laser scanning confocal microscopy also revealed an abundance of Na+,K+-ATPase isoforms in subcellular compartments. The existence of α1, β1 and β2 suggests that at least two major isozyme combinations of Na+,K...

International Journal of Molecular Sciences

Several origins have been proposed for cancer-associated fibroblasts (CAFs), including resident C... more Several origins have been proposed for cancer-associated fibroblasts (CAFs), including resident CD34+ stromal cells/telocytes (CD34+SCs/TCs). The characteristics and arrangement of mammary CD34+SCs/TCs are well known and invasive lobular carcinoma of the breast (ILC) is one of the few malignant epithelial tumours with stromal cells that can express CD34 or αSMA, which could facilitate tracking these cells. Our objective is to assess whether tissue-resident CD34+SCs/TCs participate in the origin of CAFs in ILCs. For this purpose, using conventional and immunohistochemical procedures, we studied stromal cells in ILCs (n:42) and in normal breasts (n:6, also using electron microscopy). The results showed (a) the presence of anti-CD34+ or anti-αSMA+ stromal cells in varying proportion (from very rare in one of the markers to balanced) around nests/strands of neoplastic cells, (b) a similar arrangement and location of stromal cells in ILC to CD34+SCs/TCs in the normal breast, (c) both typ...

Revue du Rhumatisme

Resume Les chondrocytes sont les principales cellules de la matrice extracellulaire du cartilage ... more Resume Les chondrocytes sont les principales cellules de la matrice extracellulaire du cartilage articulaire et leur phenotype hautement differencie est caracteristique des fonctions physiologiques uniques de ce tissu conjonctif de soutien specialise. La membrane plasmique des chondrocytes articulaires contient un large ensemble diversifie de proteines membranaires auxiliaires, appele membranome, qui determine le phenotype de la surface de ces cellules. Cible cle des agents pharmacologiques, le membranome exerce des fonctions importantes pour le chondrocyte. Il regroupe des canaux, des transporteurs, des enzymes, des recepteurs et des proteines d’ancrage pour les proteines intracellulaires, du cytosquelette et de la matrice extracellulaire et les autres complexes macromoleculaires. Le « channelome » du chondrocyte est un sous-compartiment du membranome, il comprend un ensemble complet de canaux ioniques et de porines exprimes dans ces cellules. Plusieurs de ces proteines multifonctionnelles exercent des roles caches et servent de canaux, de recepteurs et participent a la signalisation d’assemblages moleculaires de plus grande taille. Le but de cette revue est de resumer les connaissances actuelles sur les aspects fondamentaux du « channelome » du chondrocyte, d’aborder ses fonctions dans la biologie du cartilage et de mettre en evidence son eventuel role dans la pathogenese de l’arthrose. Des contraintes mecaniques excessives et inappropriees, un micro-environnement inflammatoire, un epissage alternatif des composants du canal ou une accumulation de cristaux elementaires de calcium phosphate peuvent perturber le fonctionnement du « channelome » du chondrocyte. Des alterations de la signalisation du Ca2+ peuvent entrainer une alteration de la synthese des macromolecules de la MEC et une aggravation des reponses cataboliques des chondrocytes, lesquelles representent un aspect important et relativement inexplore du mecanisme complexe de developpement de l’arthrose.

Ultrastructural Pathology

Extracellular vesicles (EVs) are a heterogeneous population involved in intercellular communicati... more Extracellular vesicles (EVs) are a heterogeneous population involved in intercellular communication. Little attention has been paid to a peculiar EV type with the appearance of a multivesicular body: extracellular multivesicular body (EMVB), also termed matrix vesicle cluster/multivesicular cargo. The aim of this work is to assess the ultrastructural characteristics, participation, and tissue location of EMVBs in inflammation/repair and tumors (with physiopathological processes involving intense intercellular communication), for which representative specimens were used. The results showed several forms of EMVBs: a) mature EMVBs, made up of clusters of vesicles surrounded by a plasma membrane, b) pre-EMVBs, with protruding grouped vesicles under the cell membrane, and c) post-EMVBs, releasing their vesicles. In tissues with inflammation/repair, EMVBs were observed in vessel lumens, interstitial spaces of vessel walls (between endothelial cells, pericytes, and smooth muscle cells) and between inflammatory and stromal cells. In tumors, such as basal cell carcinoma, craniopharyngioma, syringocystoadenoma, fibrous histiocytoma, alveolar rhabdomyosarcoma, lymphomas, neuroblastoma, astrocytomas, meningiomas, and hydatiform mole, EMVBs were present in tumor gland lumens and between tumor cells. In conclusion, in numerous physiopathological processes, we contribute EMVB ultrastructural characteristics (including different forms of mature, pre- and post-EMVBs, suggesting a more efficient EV transport), location and relationship with different types of cells. Further studies are required to assess the role of EMVBs in these physiopathological conditions.

In the Na+/K+-ATPase system, the alpha subunit has been implicated in the ion pumping process and... more In the Na+/K+-ATPase system, the alpha subunit has been implicated in the ion pumping process and the s subunit has no known role in ion transport. Two different isoforms of the s subunit (s1 and s2) have been described in mammals (3). The s2 isoform is an adhesion molecule on glial cells (AMOG), specifically involved in neuron-astrocyte adhesion (1). The s2 isoform has no obvious adhesion function in other cell types, and no adhesion function whatsoever has been reported for the s1 isoform. In order to understand further the localization and functional implications, we have generated a series of isoform-specific antibodies against the human Na+/K+-ATPase s1 and s2 isoforms. Polyclonal rabbit antisera were raised against truncated s-isoform molecules. These proteins were made in E. coli with pET expression vectors (5). Immunohistochemical preparations of 15-days-old whole rat embryos and on nerve cell cultures obtained from those, showed an specific staining pattern, particularly enhanced in the apical membrane of ear semicircular ducts and choroid plexus.

International Journal of Molecular Sciences, Dec 31, 2019

Sirtuins are a family of deacetylases that modify structural proteins, metabolic enzymes, and his... more Sirtuins are a family of deacetylases that modify structural proteins, metabolic enzymes, and histones to change cellular protein localization and function. In mammals, there are seven sirtuins involved in processes like oxidative stress or metabolic homeostasis associated with aging, degeneration or cancer. We studied gene expression of sirtuins by qRT-PCR in human mural granulosa-lutein cells (hGL) from IVF patients in different infertility diagnostic groups and in oocyte donors (OD; control group). Study 1: sirtuins genes’ expression levels and correlations with age and IVF parameters in women with no ovarian factor. We found significantly higher expression levels of SIRT1, SIRT2 and SIRT5 in patients ≥40 years old than in OD and in women between 27 and 39 years old with tubal or male factor, and no ovarian factor (NOF). Only SIRT2, SIRT5 and SIRT7 expression correlated with age. Study 2: sirtuin genes’ expression in women poor responders (PR), endometriosis (EM) and polycystic ovarian syndrome. Compared to NOF controls, we found higher SIRT2 gene expression in all diagnostic groups while SIRT3, SIRT5, SIRT6 and SIRT7 expression were higher only in PR. Related to clinical parameters SIRT1, SIRT6 and SIRT7 correlate positively with FSH and LH doses administered in EM patients. The number of mature oocytes retrieved in PR is positively correlated with the expression levels of SIRT3, SIRT4 and SIRT5. These data suggest that cellular physiopathology in PR’s follicle may be associated with cumulative DNA damage, indicating that further studies are necessary.

Joint, bone, spine : revue du rhumatisme, Jan 13, 2018

Chondrocytes are the main cells in the extracellular matrix of articular cartilage and possess a ... more Chondrocytes are the main cells in the extracellular matrix of articular cartilage and possess a highly differentiated phenotype that is the hallmark of the unique physiological functions of this specialised load-bearing connective tissue. The plasma membrane of articular chondrocytes contains a rich and diverse complement of membrane proteins, known as the membranome, which defines the cell surface phenotype of the cells. The membranome is a key target of pharmacological agents and is important for chondrocyte function. It includes channels, transporters, enzymes, receptors, and anchors for intracellular, cytoskeletal and extracellular matrix proteins and other macromolecular complexes. The chondrocyte channelome, is a sub-compartment of the membranome and includes a complete set of ion channels and porins expressed in these cells. Many of these are multi-functional proteins with "moonlighting" roles, serving as channels, receptors and signalling components of larger mole...

The aim of the present study was to assess the presence of beta1- and beta2-isoforms of the beta-... more The aim of the present study was to assess the presence of beta1- and beta2-isoforms of the beta-subunit of Na,K-ATPase in the rat renal cortex. This has been accomplished by immunohistochemistry and Western blotting using isoform-specific antisera. Western blot of brain extract, used as positive control, revealed the bands corresponding to beta1- and beta2-glycosylated peptides, with a molecular weight (MW) of approximately 50-60 that, after exhaustive treatment with N-endoglycosidase-F, migrated to the MW corresponding to the core peptides (approximately 35). In the renal cortex, Western blot revealed the bands corresponding to beta1. After deglycosylation of the samples, the bands hybridizing with the anti-beta1-antibodies moved to the MW corresponding to a partially deglycosylated form and the core peptide. Bands with a MW of approximately 50-60 hybridized with anti-beta2, although digestion with endoglycosidase failed to move the band towards a lower MW. Immunohistochemistry revealed the presence of beta1- but not beta2-isoform. Northern blot for total mRNA showed strong signals for beta1 in renal cortex, the mRNA for the beta2-isoform being undetectable. In conclusion, only mRNA and glycopeptide of the beta1-isoform seem to be present in renal cortex of adult control rats.

Bioelectricity

Background: Although the chondrocyte is a nonexcitable cell, there is strong interest in gaining ... more Background: Although the chondrocyte is a nonexcitable cell, there is strong interest in gaining detailed knowledge of its ion pumps, channels, exchangers, and transporters. In combination, these transport mechanisms set the resting potential, regulate cell volume, and strongly modulate responses of the chondrocyte to endocrine agents and physicochemical alterations in the surrounding extracellular microenvironment. Materials and Methods: Mathematical modeling was used to assess the functional roles of energy-requiring active transport, the Na + /K + pump, in chondrocytes. Results: Our findings illustrate plausible physiological roles for the Na + /K + pump in regulating the resting membrane potential and suggest ways in which specific molecular components of pump can respond to the unique electrochemical environment of the chondrocyte. Conclusion: This analysis provides a basis for linking chondrocyte electrophysiology to metabolism and yields insights into novel ways of manipulating or regulating responsiveness to external stimuli both under baseline conditions and in chronic diseases such as osteoarthritis.

Experimental cell …, 2008

Juvenile neuronal ceroid lipofuscinosis (JNCL, Batten disease) is the most common progressive neu... more Juvenile neuronal ceroid lipofuscinosis (JNCL, Batten disease) is the most common progressive neurodegenerative disorder of childhood. CLN3, the transmembrane protein underlying JNCL, is proposed to participate in multiple cellular events including membrane trafficking and cytoskeletal functions. We demonstrate here that CLN3 interacts with the plasma membrane-associated cytoskeletal and endocytic fodrin and the associated Na(+), K(+) ATPase. The ion pumping activity of Na(+), K(+) ATPase was unchanged in Cln3(-/-) mouse primary neurons. However, the immunostaining pattern of fodrin appeared abnormal in JNCL fibroblasts and Cln3(-/-) mouse brains suggesting disturbances in the fodrin cytoskeleton. Furthermore, the basal subcellular distribution as well as ouabain-induced endocytosis of neuron-specific Na(+), K(+) ATPase were remarkably affected in Cln3(-/-) mouse primary neurons. These data suggest that CLN3 is involved in the regulation of plasma membrane fodrin cytoskeleton and co...

Cells

Glioblastoma (GBM) is the most malignant tumor in the brain. In addition to the vascular pattern ... more Glioblastoma (GBM) is the most malignant tumor in the brain. In addition to the vascular pattern with thin-walled vessels and findings of sprouting angiogenesis, GBM presents a bizarre microvasculature (BM) formed by vascular clusters, vascular garlands, and glomeruloid bodies. The mechanisms in BM morphogenesis are not well known. Our objective was to assess the role of pericyte/endothelial proliferation and intussusceptive angiogenic mechanisms in the formation of the BM. For this purpose, we studied specimens of 66 GBM cases using immunochemistry and confocal microscopy. In the BM, the results showed (a) transitional forms between the BM patterns, mostly with prominent pericytes covering all the abluminal endothelial cell (EC) surface of the vessels, (b) a proliferation index high in the prominent pericytes and low in ECs (47.85 times higher in pericytes than in ECs), (c) intravascular pillars (hallmark of intussusceptive angiogenesis) formed by transcapillary interendothelial br...