- Zaragoza, Aragon, Spain
Eva Latorre
University of Zaragoza, Biochemistry, Faculty Member
- University of Exeter, Exeter Medical School, Post-DocUniversity of Zaragoza, Pharmacology and Physiology, Graduate Studentadd
Intestinal serotonergic system is a key modulator of intestinal homeostasis; however, its regulation is still unclear. Toll-like receptor 9 (TLR9), an innate immune receptor, detects different external agents in the intestine, preserving... more
Intestinal serotonergic system is a key modulator of intestinal homeostasis; however, its regulation is still unclear. Toll-like receptor 9 (TLR9), an innate immune receptor, detects different external agents in the intestine, preserving intestinal integrity. Since little is known about TLR9 role in the intestine, our aim was to address the potential regulation between TLR9 and intestinal serotonergic system. Caco-2/TC7 cell line and intestinal tract of Tlr9−/− mice were used in this study. Serotonin uptake studies were performed, and molecular expression of different serotonergic components was analyzed by western blot and real-time PCR. Our results show that TLR9 activation inhibits serotonin transporter activity and expression, involving p38/MAPK and ERK/MAPK intracellular pathways, and reciprocally, serotonin increases TLR9 expression. Supporting this interaction, serotonin transporter, serotonin receptors and serotonin producer enzymes were found altered in intestinal tract of ...
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During the last decades, the management of patients with chronic intestinal diseases has experienced remarkable progress from both diagnostic and therapeutic point of view [...]
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Synthesis and characterisation of resveralogues. (PDF 3019Â kb)
The effect of ERK inhibition on splicing factor expression. (TIFF 143Â kb)
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The effect of manipulation of the ERK pathway with chemical inhibitors and agonists on cellular senescence. (TIFF 193Â kb)
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Level of necrosis and apoptosis following treatment with resveratrol analogues. (TIFF 230Â kb)
Changes in biochemical and molecular markers of cellular senescence following chronic or repeated treatment with resveratrol. (TIFF 154Â kb)
Model equations, Data Fit/Cost Function, Change in Error, Parameters/Constraints, Optimization, Sensitivity Analysis
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Background:The serotonergic system is a key component of physiological brain function and is essential for proper neurological activity. Numerous neuropsychiatric disorders are associated with deregulation of the serotonergic system.... more
Background:The serotonergic system is a key component of physiological brain function and is essential for proper neurological activity. Numerous neuropsychiatric disorders are associated with deregulation of the serotonergic system. Accordingly, many pharmacological treatments are focused on modulation of this system. While providing a promising line of therapeutic moderation, these approaches may be complicated due to the presence of alternative splicing events for key genes in this pathway. Alternative splicing is a co-transcriptional process by which different mRNA transcripts can be produced from the same gene. These different isoforms may have diverse activities and functions, and their relative balance is often critical for the maintenance of homeostasis. Alternative splicing greatly increases the production of proteins, augmenting cell plasticity, and provides an important control point for regulation of gene expression.Aim:The objective of this narrative review is to discus...
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Cellular plasticity is a key facet of cellular homeostasis requiring correct temporal and spatial patterns of alternative splicing. Splicing factors, which orchestrate this process, demonstrate age-related dysregulation of expression;... more
Cellular plasticity is a key facet of cellular homeostasis requiring correct temporal and spatial patterns of alternative splicing. Splicing factors, which orchestrate this process, demonstrate age-related dysregulation of expression; they are emerging as potential influences on aging and longevity. The upstream drivers of these alterations are still unclear but may involve aberrant cellular signaling. We compared the phosphorylation status of proteins in multiple signaling pathways in early and late passage human primary fibroblasts. We then assessed the impact of chemical inhibition or targeted knockdown of direct downstream targets of the ERK and AKT pathways on splicing factor expression, cellular senescence, and proliferation kinetics in senescent primary human fibroblasts. Components of the ERK and AKT signaling pathways demonstrated altered activation during cellular aging. Inhibition of AKT and ERK pathways led to up-regulation of splicing factor expression, reduction in sen...
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Serotonin (5-HT) is a chief modulator of intestinal activity. The effects of 5-HT depend on its extracellular availability, which is mainly controlled by serotonin transporter (SERT), expressed in enterocytes. On the other hand, innate... more
Serotonin (5-HT) is a chief modulator of intestinal activity. The effects of 5-HT depend on its extracellular availability, which is mainly controlled by serotonin transporter (SERT), expressed in enterocytes. On the other hand, innate immunity, mediated by Toll-like receptors (TLRs) and nucleotide oligomerization domain (NOD)-like receptors (NLRs), is known to control intestinal microbiota and maintain intestinal homeostasis. The dysregulation of the intestinal serotonergic system and innate immunity has been observed in inflammatory bowel diseases (IBD), the incidence of which has severely increased all over the world. The aim of the present study, therefore, was to analyze the effect of NOD2 on intestinal SERT activity and expression, as well as to study the crosstalk of NOD2 with TLR2 and TLR4. Intestinal epithelial cell line Caco-2/TC7 was used to analyze SERT activity and SERT, NOD2, TLR2 and TLR4 molecular expression by real-time PCR and western blotting. Moreover, intestinal...
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Cellular senescence is a key driver of ageing, influenced by age-related changes to the regulation of alternative splicing. Hydrogen sulfide (HS) has similarly been described to influence senescence, but the pathways by which it... more
Cellular senescence is a key driver of ageing, influenced by age-related changes to the regulation of alternative splicing. Hydrogen sulfide (HS) has similarly been described to influence senescence, but the pathways by which it accomplishes this are unclear.We assessed the effects of the slow release HS donor Na-GYY4137 (100 µg/ml), and three novel mitochondria-targeted HS donors AP39, AP123 and RT01 (10 ng/ml) on splicing factor expression, cell proliferation, apoptosis, DNA replication, DNA damage, telomere length and senescence-related secretory complex (SASP) expression in senescent primary human endothelial cells.All HS donors produced up to a 50% drop in senescent cell load assessed at the biochemical and molecular level. Some changes were noted in the composition of senescence-related secretory complex (SASP); IL8 levels increased by 24% but proliferation was not re-established in the culture as a whole. Telomere length, apoptotic index and the extent of DNA damage were unaf...
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Coronary heart disease (CHD) is a leading cause of morbidity in the over 65s; over 40% of all deaths are due to this condition. The association between increasing age and CHD is well-documented; the accumulation of senescent cells in... more
Coronary heart disease (CHD) is a leading cause of morbidity in the over 65s; over 40% of all deaths are due to this condition. The association between increasing age and CHD is well-documented; the accumulation of senescent cells in cardiac and vascular tissues may represent one factor underpinning this observation. We aimed to identify senescence-related expression changes in primary human senescent cardiomyocytes and endothelial cells and to relate transcript expression in peripheral blood leucocytes to prevalent and incident CHD in the InCHIANTI study of aging. We quantified splicing factor expression and splicing patterns of candidate transcripts in proliferative and senescent later passage endothelial cells and cardiomyocytes using qRTPCR. Senescence-associated isoforms also expressed in peripheral blood leucocytes were then examined for associations with CHD status in 134 pairs of age, sex and BMI-matched CHD cases and controls. Splicing factor expression was dysregulated in ...
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Serotonin (5-HT) is an essential gastrointestinal modulator whose effects regulate the intestinal physiology. 5-HT effects depend on extracellular 5-HT bioavailability, which is controlled by the serotonin transporter (SERT) expressed in... more
Serotonin (5-HT) is an essential gastrointestinal modulator whose effects regulate the intestinal physiology. 5-HT effects depend on extracellular 5-HT bioavailability, which is controlled by the serotonin transporter (SERT) expressed in both the apical and basolateral membranes of enterocytes. SERT is a critical target for regulating 5-HT levels and consequently, modulating the intestinal physiology. The deregulation of innate immune receptors has been extensively studied in inflammatory bowel diseases (IBD), where an exacerbated defense response to commensal microbiota is observed. Interestingly, many innate immune receptors seem to affect the serotonergic system, demonstrating a new way in which microbiota could modulate the intestinal physiology. Therefore, our aim was to analyze the effects of NOD1 activation on SERT function, as well as NOD1's interaction with other immune receptors such as TLR2 and TLR4. Our results showed that NOD1 activation inhibits SERT activity and e...
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Techniques to analyze human telomeres are imperative in studying the molecular mechanism of aging and related diseases. Two important aspects of telomeres are their length in DNA base pairs (bps) and their biophysical nanometer... more
Techniques to analyze human telomeres are imperative in studying the molecular mechanism of aging and related diseases. Two important aspects of telomeres are their length in DNA base pairs (bps) and their biophysical nanometer dimensions. However, there are currently no techniques that can simultaneously measure these quantities in individual cell nuclei. Here, we develop and evaluate a telomere "dual" gold nanoparticle-fluorescent probe simultaneously compatible with both X-ray fluorescence (XRF) and super resolution microscopy. We used silver enhancement to independently visualize the spatial locations of gold nanoparticles inside the nuclei, comparing to a standard QFISH (quantitative fluorescence in situ hybridization) probe, and showed good specificity at ∼90%. For sensitivity, we calculated telomere length based on a DNA/gold binding ratio using XRF and compared to quantitative polymerase chain reaction (qPCR) measurements. The sensitivity was low (∼10%), probably b...
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Altered expression of mRNA splicing factors occurs with ageing in vivo and is thought to be an ageing mechanism. The accumulation of senescent cells also occurs in vivo with advancing age and causes much degenerative age-related... more
Altered expression of mRNA splicing factors occurs with ageing in vivo and is thought to be an ageing mechanism. The accumulation of senescent cells also occurs in vivo with advancing age and causes much degenerative age-related pathology. However, the relationship between these two processes is opaque. Accordingly we developed a novel panel of small molecules based on resveratrol, previously suggested to alter mRNA splicing, to determine whether altered splicing factor expression had potential to influence features of replicative senescence. Treatment with resveralogues was associated with altered splicing factor expression and rescue of multiple features of senescence. This rescue was independent of cell cycle traverse and also independent of SIRT1, SASP modulation or senolysis. Under growth permissive conditions, cells demonstrating restored splicing factor expression also demonstrated increased telomere length, re-entered cell cycle and resumed proliferation. These phenomena wer...
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Background Inflammatory bowel diseases are consequence of an intestinal homeostasis breakdown in which innate immune dysregulation is implicated. Toll-like receptor (TLR)2 and TLR4 are immune recognition receptors expressed in the... more
Background Inflammatory bowel diseases are consequence of an intestinal homeostasis breakdown in which innate immune dysregulation is implicated. Toll-like receptor (TLR)2 and TLR4 are immune recognition receptors expressed in the intestinal epithelium, the first physical-physiological barrier for microorganisms, to inform the host of the presence of Gram-positive and Gram-negative organisms. Interleukin (IL)-10 is an essential anti-inflammatory cytokine that contributes to maintenance of intestinal homeostasis. Aim Our main aim was to investigate intestinal IL-10 synthesis and release, and whether TLR2 and TLR4 are determinants of IL-10 expression in the intestinal tract. Methods We used Caco-2 cell line as an enterocyte-like cell model, and also ileum and colon from mice deficient in TLR2, TLR4 or TLR2/4 to test the involvement of TLR signaling. Results Intestinal epithelial cells are able to synthesize and release IL-10 and their expression is increased after TLR2 or TLR4 activat...
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Serotonin is a neuromodulator mainly synthesized by intestinal enterochromaffin cells that regulate overall intestinal physiology. The serotonin transporter (SERT) determines the final serotonin availability and has been described as... more
Serotonin is a neuromodulator mainly synthesized by intestinal enterochromaffin cells that regulate overall intestinal physiology. The serotonin transporter (SERT) determines the final serotonin availability and has been described as altered in inflammatory bowel diseases. IL-10 is an anti-inflammatory cytokine that is involved in intestinal inflammatory processes and also contributes to intestinal mucosa homeostasis. The regulation of SERT by pro-inflammatory factors is well known; however, the effect of IL-10 on the intestinal serotoninergic system mediated by SERT remains unknown. Therefore, the aim of the present study is to determine whether IL-10 affects SERT activity and expression in enterocyte-like Caco-2 cells. Treatment with IL-10 was assessed and SERT activity was determined by 5-HT uptake. SERT mRNA and protein expression was analyzed using quantitative RT-PCR and western blotting. The results showed that IL-10 induced a dual effect on SERT after 6h of treatment. On one hand, IL-10, at a low concentration, inhibited SERT activity, and this effect might be explained by a non-competitive inhibition of SERT. On the other hand, IL-10, at a high concentration, increased SERT activity and molecular expression in the membrane of the cells. This effect was mediated by the IL-10 receptor and triggered by the PI3K intracellular pathway. Our results demonstrate that IL-10 modulates SERT activity and expression, depending on its extracellular conditions. This study may contribute to understand serotoninergic responses in intestinal pathophysiology.
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TLR2 is a microbiota recognition receptor that has been described to contribute to intestinal homeostasis and to ameliorate inflammatory intestinal injury. In this context, serotonin (5-HT) has shown to be an essential intestinal... more
TLR2 is a microbiota recognition receptor that has been described to contribute to intestinal homeostasis and to ameliorate inflammatory intestinal injury. In this context, serotonin (5-HT) has shown to be an essential intestinal physiological neuromodulator that is also involved in intestinal inflammatory diseases. Since the interaction between TLR2 activation and the intestinal serotoninergic system remains non-investigated, our main aim was to analyze the effect of TLR2 on intestinal serotonin transporter (SERT) activity and expression and the intracellular pathways involved. Caco-2/TC7 cells were used to analyze SERT and TLR2 molecular expression and SERT activity by measuring 5-HT uptake. The results showed that apical TLR2 activation inhibits SERT activity in Caco-2/TC7 cells mainly by reducing SERT protein level either in the plasma membrane, after short-term TLR2 activation or in both the plasma membrane and cell lysate, after long-term activation. cAMP/PKA pathway appears t...
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Disruption of the microbiota–gut–brain axis results in a wide range of pathologies that are affected, from the brain to the intestine. Gut hormones released by enteroendocrine cells to the gastrointestinal (GI) tract are important... more
Disruption of the microbiota–gut–brain axis results in a wide range of pathologies that are affected, from the brain to the intestine. Gut hormones released by enteroendocrine cells to the gastrointestinal (GI) tract are important signaling molecules within this axis. In the search for the language that allows microbiota to communicate with the gut and the brain, serotonin seems to be the most important mediator. In recent years, serotonin has emerged as a key neurotransmitter in the gut–brain axis because it largely contributes to both GI and brain physiology. In addition, intestinal microbiota are crucial in serotonin signaling, which gives more relevance to the role of the serotonin as an important mediator in microbiota–host interactions. Despite the numerous investigations focused on the gut–brain axis and the pathologies associated, little is known regarding how serotonin can mediate in the microbiota–gut–brain axis. In this review, we will mainly discuss serotonergic system m...
Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder whose aetiology is still unknown. Most hypotheses point out the gut-brain axis as a key factor for IBS. The axis is composed of different anatomic and functional... more
Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder whose aetiology is still unknown. Most hypotheses point out the gut-brain axis as a key factor for IBS. The axis is composed of different anatomic and functional structures intercommunicated through neurotransmitters. However, the implications of key neurotransmitters such as norepinephrine, serotonin, glutamate, GABA or acetylcholine in IBS are poorly studied. The aim of this review is to evaluate the current evidence about neurotransmitter dysfunction in IBS and explore the potential therapeutic approaches. IBS patients with altered colorectal motility show augmented norepinephrine and acetylcholine levels in plasma and an increased sensitivity of central serotonin receptors. A decrease of colonic mucosal serotonin transporter and a downregulation of α2 adrenoceptors are also correlated with visceral hypersensitivity and an increase of 5-hydroxyindole acetic acid levels, enhanced expression of high affinity c...
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Milk contains active molecules with important functional properties as the defensive proteins; among them are the whey protein lactoferrin and proteins of the milk fat globule membrane (MFGM) present in buttermilk. The aim of this study... more
Milk contains active molecules with important functional properties as the defensive proteins; among them are the whey protein lactoferrin and proteins of the milk fat globule membrane (MFGM) present in buttermilk. The aim of this study has been to investigate the effect of lactoferrin, whey and buttermilk as modulators of intestinal innate immunity and oxidative stress on intestinal epithelial cells, to evaluate its potential use for the development of functional foods. Innate immune Toll-like receptors (TLR2, TLR4, and TLR9) mRNA expression, lipid peroxidation (MDA+4-HDA) and protein carbonyl levels were analyzed in enterocyte-like Caco-2/TC7 cells treated for 24 hours with different concentrations of lactoferrin, whey or buttermilk. None of the substances analyzed caused oxidative damage; however, whey significantly decreased the levels of lipid peroxidation. Furthermore, both lactoferrin and whey were able to reduce the oxidative stress induced by lipopolysaccharide. Respect to ...
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Alternative splicing is a co-transcriptional process, which allows for the production of multiple transcripts from a single gene and is emerging as an important control point for gene expression. Alternatively expressed isoforms often... more
Alternative splicing is a co-transcriptional process, which allows for the production of multiple transcripts from a single gene and is emerging as an important control point for gene expression. Alternatively expressed isoforms often have antagonistic function and differential temporal or spatial expression patterns, yielding enormous plasticity and adaptability to cells and increasing their ability to respond to environmental challenge. The regulation of alternative splicing is critical for numerous cellular functions in both pathological and physiological conditions, and deregulated alternative splicing is a key feature of common chronic diseases. Isoform choice is controlled by a battery of splicing regulatory proteins, which include the serine arginine rich (SRSF) proteins and the heterogeneous ribonucleoprotein (hnRNP) classes of genes. These important splicing regulators have been implicated in age-related disease, and in the ageing process itself. This review will outline th...
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The accumulation of senescent cells in tissues is causally linked to the development of several age-related diseases; the removal of senescent glial cells in animal models prevents Tau accumulation and cognitive decline. Senescent cells... more
The accumulation of senescent cells in tissues is causally linked to the development of several age-related diseases; the removal of senescent glial cells in animal models prevents Tau accumulation and cognitive decline. Senescent cells can arise through several distinct mechanisms; one such mechanism is dysregulation of alternative splicing. In this study, we characterised the senescent cell phenotype in primary human astrocytes in terms of SA-β-Gal staining and SASP secretion, and then assessed splicing factor expression and candidate gene splicing patterns. Finally, we assessed associations between expression of dysregulated isoforms and premature cognitive decline in 197 samples from the InCHIANTI study of ageing, where expression was present in both blood and brain. We demonstrate here that senescent astrocytes secrete a modified SASP characterised by increased IL8, MMP3, MMP10, and TIMP2 but decreased IL10 levels. We identified significant changes in splicing factor expression...
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Cellular senescence is a key driver of ageing, influenced by age-related changes to the regulation of alternative splicing. Hydrogen sulfide (H2S) has similarly been described to influence senescence, but the pathways by which it... more
Cellular senescence is a key driver of ageing, influenced by age-related changes to the regulation of alternative splicing. Hydrogen sulfide (H2S) has similarly been described to influence senescence, but the pathways by which it accomplishes this are unclear.We assessed the effects of the slow release H2S donor Na-GYY4137 (100 µg/ml), and three novel mitochondria-targeted H2S donors AP39, AP123 and RT01 (10 ng/ml) on splicing factor expression, cell proliferation, apoptosis, DNA replication, DNA damage, telomere length and senescence-related secretory complex (SASP) expression in senescent primary human endothelial cells.All H2S donors produced up to a 50% drop in senescent cell load assessed at the biochemical and molecular level. Some changes were noted in the composition of senescence-related secretory complex (SASP); IL8 levels increased by 24% but proliferation was not re-established in the culture as a whole. Telomere length, apoptotic index and the extent of DNA damage were unaffected. Differential effects on splicing factor expression were observed depending on the intracellular targeting of the H2S donors. Na-GYY4137 produced a general 1.9 - 3.2-fold upregulation of splicing factor expression, whereas the mitochondria-targeted donors produced a specific 2.5 and 3.1-fold upregulation of SRSF2 and HNRNPD splicing factors only. Knockdown of SRSF2 or HNRNPD genes in treated cells rendered the cells non-responsive to H2S, and increased levels of senescence by up to 25% in untreated cells.Our data suggest that SRSF2 and HNRNPD may be implicated in endothelial cell senescence, and can be targeted by exogenous H2S. These molecules may have potential as moderators of splicing factor expression and senescence phenotypes.
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Coronary heart disease (CHD) is a leading cause of morbidity in the over 65s; over 40% of all deaths are due to this condition. The association between increasing age and CHD is well-documented; the accumulation of senescent cells in... more
Coronary heart disease (CHD) is a leading cause of morbidity in the over 65s; over 40% of all deaths are due to this condition. The association between increasing age and CHD is well-documented; the accumulation of senescent cells in cardiac and vascular tissues may represent one factor underpinning this observation. We aimed to identify senescence-related expression changes in primary human senescent cardiomyocytes and endothelial cells and to relate transcript expression in peripheral blood leucocytes to prevalent and incident CHD in the InCHIANTI study of aging. We quantified splicing factor expression and splicing patterns of candidate transcripts in proliferative and senescent later passage endothelial cells and cardiomyocytes using qRTPCR. Senescence-associated isoforms also expressed in peripheral blood leucocytes were then examined for associations with CHD status in 134 pairs of age, sex and BMI-matched CHD cases and controls. Splicing factor expression was dysregulated in senescent cardiomyocytes, as previously reported for endothelial cells, as was the expression of alternatively-expressed cardiac and vascular candidate genes in both cell types. We found nominal associations between the expression of VEGFA156b and FNI-EIIIIA isoforms in peripheral blood mRNA and CHD status. Dysregulated splicing factor expression is a key feature of senescent cardiomyocytes and endothelial cells. Altered splicing of key cardiac or endothelial genes may contribute to the risk of CHD in the human population
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Background/Aims: Serotonin (5-HT) is a chief modulator of intestinal activity. The effects of 5-HT depend on its extracellular availability, which is mainly controlled by serotonin transporter (SERT), expressed in enterocytes. On the... more
Background/Aims: Serotonin (5-HT) is a chief modulator of intestinal activity. The effects of 5-HT depend on its extracellular availability, which is mainly controlled by serotonin transporter (SERT), expressed in enterocytes. On the other hand, innate immunity, mediated by Toll-like receptors (TLRs) and nucleotide oligomerization domain (NOD)-like receptors (NLRs), is known to control intestinal microbiota and maintain intestinal homeostasis. The dysregulation of the intestinal serotonergic system and innate immunity has been observed in inflammatory bowel diseases (IBD), the incidence of which has severely increased all over the world. The aim of the present study, therefore, was to analyze the effect of NOD2 on intestinal SERT activity and expression, as well as to study the crosstalk of NOD2 with TLR2 and TLR4. Methods: Intestinal epithelial cell line Caco-2/TC7 was used to analyze SERT activity and SERT, NOD2, TLR2 and TLR4 molecular expression by real-time PCR and western blotting. Moreover, intestinal tract (ileum and colon) from mice deficient in TLR2, TLR4 or TLR2/4 receptors was used to test the interdependence of NOD2 with these TLR receptors. Results: NOD2 activation inhibits SERT activity in Caco-2/TC7 cells, mainly due to the decrement of SERT molecular expression, with RIP2/RICK being the intracellular pathway involved in this effect. This inhibitory effect on SERT would yield an increment of extracellular 5-HT availability. In this sense, 5-HT strongly inhibits NOD2 expression. In addition, NOD2 showed greater interdependence with TLR2 than with TLR4. Indeed, NOD2 expression significantly increased in both cells treated with TLR2 agonists and the intestinal tract of Tlr2-/- mice. Conclusions: It may be inferred from our data that NOD2 could play a role in intestinal pathophysiology not only through its inherent innate immune role but also due to its interaction with other receptors as TLR2 and the modulation of the intestinal serotonergic system decreasing SERT activity and expression.
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Serotonin (5-HT) is an essential gastrointestinal modulator whose effects regulate the intestinal physiology. 5-HT effects depend on extracellular 5-HT bioavailability, which is controlled by the serotonin transporter (SERT) expressed in... more
Serotonin (5-HT) is an essential gastrointestinal modulator whose effects regulate the intestinal physiology. 5-HT effects depend on extracellular 5-HT bioavailability, which is controlled by the serotonin transporter (SERT) expressed in both the apical and basolateral membranes of enterocytes. SERT is a critical target for regulating 5-HT levels and consequently, modulating the intestinal physiology. The deregulation of innate immune receptors has been extensively studied in inflammatory bowel diseases (IBD), where an exacerbated defense response to commensal microbiota is observed. Interestingly, many innate immune receptors seem to affect the serotonergic system, demonstrating a new way in which microbiota could modulate the intestinal physiology. Therefore, our aim was to analyze the effects of NOD1 activation on SERT function, as well as NOD1's interaction with other immune receptors such as TLR2 and TLR4. Our results showed that NOD1 activation inhibits SERT activity and expression in Caco-2/TC7 cells through the extracellular signal-regulated kinase (ERK) signaling pathway. A negative feedback between 5-HT and NOD1 expression was also described. The results showed that TLR2 and TLR4 activation seems to regulate NOD1 expression in Caco-2/TC7 cells. To assess the extend of cross-talk between NOD1 and TLRs, NOD1 expression was measured in the intestinal tract (ileum and colon) of wild type mice and mice with individual knockouts of TLR2, and TLR4 as well as double knockout TLR2/TLR4 mice. Hence, we demonstrate that NOD1 acts on the serotonergic system decreasing SERT activity and molecular expression. Additionally, NOD1 expression seems to be modulated by 5-HT and other immune receptors as TLR2 and TLR4. This study could clarify the relation between both the intestinal serotonergic system and innate immune system, and their implications in intestinal inflammation
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Background Altered expression of mRNA splicing factors occurs with ageing in vivo and is thought to be an ageing mechanism. The accumulation of senescent cells also occurs in vivo with advancing age and causes much degenerative... more
Background
Altered expression of mRNA splicing factors occurs with ageing in vivo and is thought to be an ageing mechanism. The accumulation of senescent cells also occurs in vivo with advancing age and causes much degenerative age-related pathology. However, the relationship between these two processes is opaque. Accordingly we developed a novel panel of small molecules based on resveratrol, previously suggested to alter mRNA splicing, to determine whether altered splicing factor expression had potential to influence features of replicative senescence.
Results
Treatment with resveralogues was associated with altered splicing factor expression and rescue of multiple features of senescence. This rescue was independent of cell cycle traverse and also independent of SIRT1, SASP modulation or senolysis. Under growth permissive conditions, cells demonstrating restored splicing factor expression also demonstrated increased telomere length, re-entered cell cycle and resumed proliferation. These phenomena were also influenced by ERK antagonists and agonists.
Conclusions
This is the first demonstration that moderation of splicing factor levels is associated with reversal of cellular senescence in human primary fibroblasts. Small molecule modulators of such targets may therefore represent promising novel anti-degenerative therapies.
Altered expression of mRNA splicing factors occurs with ageing in vivo and is thought to be an ageing mechanism. The accumulation of senescent cells also occurs in vivo with advancing age and causes much degenerative age-related pathology. However, the relationship between these two processes is opaque. Accordingly we developed a novel panel of small molecules based on resveratrol, previously suggested to alter mRNA splicing, to determine whether altered splicing factor expression had potential to influence features of replicative senescence.
Results
Treatment with resveralogues was associated with altered splicing factor expression and rescue of multiple features of senescence. This rescue was independent of cell cycle traverse and also independent of SIRT1, SASP modulation or senolysis. Under growth permissive conditions, cells demonstrating restored splicing factor expression also demonstrated increased telomere length, re-entered cell cycle and resumed proliferation. These phenomena were also influenced by ERK antagonists and agonists.
Conclusions
This is the first demonstration that moderation of splicing factor levels is associated with reversal of cellular senescence in human primary fibroblasts. Small molecule modulators of such targets may therefore represent promising novel anti-degenerative therapies.
Research Interests:
Techniques to analyze human telomeres are imperative in studying the molecular mechanism of aging and related diseases. Two important aspects of telomeres are their length in DNA base pairs (bps) and their biophysical nanometer... more
Techniques to analyze human telomeres are imperative in studying the molecular mechanism of aging and related diseases. Two important aspects of telomeres are their length in DNA base pairs (bps) and their biophysical nanometer dimensions. However, there are currently no techniques that can simultaneously measure these quantities in individual cell nuclei. Here, we develop and evaluate a telomere "dual" gold nanoparticle-fluorescent probe simultaneously compatible with both X-ray fluorescence (XRF) and super resolution microscopy. We used silver enhancement to independently visualize the spatial locations of gold nanoparticles inside the nuclei, comparing to a standard QFISH (quantitative fluorescence in situ hybridization) probe, and showed good specificity at ∼90%. For sensitivity, we calculated telomere length based on a DNA/gold binding ratio using XRF and compared to quantitative polymerase chain reaction (qPCR) measurements. The sensitivity was low (∼10%), probably because of steric interference prohibiting the relatively large 10 nm gold nanoparticles access to DNA space. We then measured the biophysical characteristics of individual telomeres using super resolution microscopy. Telomeres that have an average length of ∼10 kbps, have diameters ranging between ∼60-300 nm. Further, we treated cells with a telomere-shortening drug and showed there was a small but significant difference in telomere diameter in drug-treated vs control cells. We discuss our results in relation to the current debate surrounding telomere compaction
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Aims: Cognitive impairment causes functional impairment and declining quality of life in the elderly. Occupational therapy (OT) could help to prevent or slow cognitive decline. However, little is known of how OT parameters could influence... more
Aims: Cognitive impairment causes functional impairment and
declining quality of life in the elderly. Occupational therapy (OT)
could help to prevent or slow cognitive decline. However, little is
known of how OT parameters could influence cognitive impairment.
Methods: We conducted an observational study over the
course of 1 year, on 94 long-term care residents, analyzing cognitive
impairment. The cohort was split into three groups, each
being provided with different amounts of OT (non-OT, 2 h OT a
week, and 10 h OT a week). The OT program consisted of cognitive
andmemory training, reality orientation, psychomotor activities,
and crafts. Results: Our results show that OT is effective in
slowing cognitive decline and its effectiveness seems to be proportional
to the hours of OT received. The 10 h OT group showed
significantly reduced Mini-Mental State Examination score compared
with the non-OT group (p < 0.01). OT also appears to be
useful in people with previous cognitive impairment. Conclusions:
The study adds to the growing literature of OT interventions for
older adults and our findings support the concept that OT could
be effective in slowing cognitive impairment in the elderly.
declining quality of life in the elderly. Occupational therapy (OT)
could help to prevent or slow cognitive decline. However, little is
known of how OT parameters could influence cognitive impairment.
Methods: We conducted an observational study over the
course of 1 year, on 94 long-term care residents, analyzing cognitive
impairment. The cohort was split into three groups, each
being provided with different amounts of OT (non-OT, 2 h OT a
week, and 10 h OT a week). The OT program consisted of cognitive
andmemory training, reality orientation, psychomotor activities,
and crafts. Results: Our results show that OT is effective in
slowing cognitive decline and its effectiveness seems to be proportional
to the hours of OT received. The 10 h OT group showed
significantly reduced Mini-Mental State Examination score compared
with the non-OT group (p < 0.01). OT also appears to be
useful in people with previous cognitive impairment. Conclusions:
The study adds to the growing literature of OT interventions for
older adults and our findings support the concept that OT could
be effective in slowing cognitive impairment in the elderly.
Research Interests:
Listeria monocytogenes is a Gram-positive bacterium that can cause a serious infection. Intestinal microorganisms have been demonstrated to contribute to intestinal physiology not only through immunological responses but also by... more
Listeria monocytogenes is a Gram-positive bacterium that can cause a serious infection. Intestinal microorganisms have been demonstrated to contribute to intestinal physiology not only through immunological responses but also by modulating the intestinal serotonergic system. Serotonin (5-HT) is a neuromodulator that is synthesized in the intestinal epithelium and regulates the whole intestinal physiology. The serotonin transporter (SERT), located in enterocytes, controls intestinal 5-HT availability and therefore serotonin's effects. Infections caused by L. monocytogenes are well described as being due to the invasion of intestinal epithelial cells; however , the effect of L. monocytogenes on the intestinal epithelium remains unknown. The main aim of this work, therefore, was to study the effect of L. monocytogenes on SERT. Caco2/TC7 cell line was used as an enterocyte-like in vitro model, and SERT functional and molecular expression assays were performed. Our results demonstrate that living L. monocytogenes inhibits serotonin uptake by reducing SERT expression at the brush border membrane. However, neither inactivated L. monocytogenes nor soluble metabolites were able to affect SERT. The results also demonstrate that L. monocytogenes yields TLR2 and TLR10 transcriptional changes in intestinal epithelial cells and suggest that TLR10 is potentially involved in the inhibitory effect observed on SERT. Therefore, L. monocytogenes, through TLR10-mediated SERT inhibition , may induce increased intestinal serotonin availability and potentially contributing to intestinal physiological changes and the initiation of the inflammatory response.
Research Interests:
TLR2 is a microbiota recognition receptor that has been described to contribute to intestinal homeostasis and to ameliorate inflammatory intestinal injury. In this context, serotonin (5-HT) has shown to be an essential intestinal... more
TLR2 is a microbiota recognition receptor that has been described to contribute to intestinal homeostasis and to ameliorate inflammatory intestinal injury. In this context, serotonin (5-HT) has shown to be an essential intestinal physiological neuromodulator that is also involved in intestinal inflammatory diseases. Since the interaction between TLR2 activation and the intestinal serotoninergic system remains non-investigated, our main aim was to analyze the effect of TLR2 on intestinal serotonin transporter (SERT) activity and expression and the intracellular pathways involved. Caco-2/TC7 cells were used to analyze SERT and TLR2 molecular expression and SERT activity by measuring 5-HT uptake. The results showed that apical TLR2 activation inhibits SERT activity in Caco-2/TC7 cells mainly by reducing SERT protein level either in the plasma membrane, after short-term TLR2 activation or in both the plasma membrane and cell lysate, after long-term activation. cAMP/PKA pathway appears to mediate short-term inhibitory effect of TLR2 on SERT; however, p38 MAPK pathway has been shown to be involved in both short-and long-term TLR2 effect. Reciprocally, 5-HT long-term treatment yielded TLR2 down regulation in Caco-2/TC7 cells. Finally, results from in vivo showed an augmented intestinal SERT expression in mice Tlr2-/-, thus confirming our inhibitory effect of TLR2 on intestinal SERT in vitro. The present work infers that TLR2 may act in intestinal pathophysiology, not only by its inherent innate immune role, but also by regulating the intestinal serotoninergic system.
Research Interests:
En la homeostasis general del organismo el epitelio intestinal desarrolla numerosas funciones reguladas finamente por los sistemas nervioso y endocrino. Así, el epitelio intestinal que se encuentra en contacto continuo con toxinas y... more
En la homeostasis general del organismo el epitelio intestinal desarrolla numerosas funciones reguladas finamente por los sistemas nervioso y endocrino. Así, el epitelio intestinal que se encuentra en contacto continuo con toxinas y microorganismos, muchos de los cuales potencialmente patógenos, desarrolla una importante función en la defensa inmunológica. La serotonina (5-HT), como parte del sistema serotoninérgico regulador de funciones intestinales, juega también un importante papel como mediador de información entre el epitelio y el sistema inmune, actuando como una molécula neuromoduladora en la fisiología intestinal. Estudios recientes muestran una alteración del sistema serotoninérgico en las enfermedades inflamatorias intestinales (IBDs); un aumento de los niveles de 5-HT y de sus células productoras, junto con una disminución de la actividad y la expresión del transportador de serotonina (SERT). Además, 5-HT también se ha descrito como una molécula potencialmente proinflama...
Background / Purpose: Toll-like receptors (TLRs) play a critical role in maintaining mucosal integrity via innate immune mechanisms. However, the involvement of TLRs in oxidative stress in intestinal epithelial cells remains unknown. Main... more
Background / Purpose: Toll-like receptors (TLRs) play a critical role in maintaining mucosal integrity via innate immune mechanisms. However, the involvement of TLRs in oxidative stress in intestinal epithelial cells remains unknown. Main conclusion: Our study demonstrates that the activation of TLR2, TLR3 and TLR4 increases oxidative stress, and affects the activity of antioxidant enzymes in intestinal epithelial cells.
The intestine is a complex organ with different functions accurately coordinated in part by the serotoninergic system. The serotonin availability in the intestine has been shown to be essential for serotoninergic actions, and it is... more
The intestine is a complex organ with different functions accurately coordinated in part by the serotoninergic system. The serotonin availability in the intestine has been shown to be essential for serotoninergic actions, and it is regulated by the serotonin transporter (SERT). The alteration of SERT activity has been shown to be involved in intestinal diseases related with inflammatory processes and motility deregulation. The intestinal lumen is colonized by a wide microbial population (microbiota) which contributes to intestinal homeostasis. The equilibrium between host and microbiota is in part carried out by host specific receptors that recognize the microbiota, named pathogen-recognition receptors (PRRs). The imbalance in the host-microbiota information is one of the factors of intestinal inflammation, and it seems in part be mediated by PRRs deregulation. The relation between PRRs and the serotoninergic system, and the consequences of PRRs activity alteration on intestinal reg...