Muscle Strength and Biochemical Markers as Predictors of Depression in Hemodialysis Patients: A Cross-Sectional Study.

Patients with chronic renal failure, many of which treated with hemodialysis, present a high prevalence of impaired muscle strength which suggest that muscle mass parameters may be used as markers for changes in muscle in these patients. Measurement of handgrip strength (HGS) is a common, simple, and quick measure of muscle function an indicator of overall muscle strength which has been associated with physical activity and several anthropometric traits. Intercellular adhesion molecule-1 (ICAM-1) and insulin-like growth factor-1 (IGF-1) are biochemical markers associated with inflammatory processes which are a common consequence of dialysis. Additionally, hemodialysis patients frequently present signs of malnutrition and depression. This cross-sectional study aimed to evaluate if muscle and biochemical markers could be used to predict the risk of depression in hemodialysis patients. Several anthropometric parameters, nutrient intake, depression state and the serum levels of ICAM-1 and IGF-1 were determined and Pearson's correlation coefficient and/or Spearman's correlation coefficient were used to test the correlation between them. Our results do not show a correlation between HGF, IGF-1 and ICAM-1 with the depression status of the patients, but mid-arm muscle circumference (MAMC) was statistically and positively correlated with depression. Additionally, ICAM-1 levels were negatively correlated with HGS, MAMC, and IGF-1. Overall, the results of the present study suggest that HGS may be used as an indicator of cardiovascular diseases and MAMC may be a good predictor of the level of depression in hemodialysis patients, although further studies are required.

Knowledge Assessment During the Medication Process Use by Older Patients on Clinical Routine: A Pilot Study.

Objectives: The consumption of medicines has been increasing over the last decades. The lack of medication knowledge (MK) may affect the process of medication use and, consequently, may lead to negative health outcomes. This study carried out a pilot study using a new tool to assess MK in older patients in a daily clinical practice. Materials and Methods: An exploratory cross-sectional study was conducted, including older patients (≥65 years), taking two or more medicines, followed in a regional clinic. Data were collected during a structured interview, which included an algorithm for assessing MK regarding the identification of the medicines and its use and storage conditions. Health literacy and treatment adherence were also assessed. Results: The study enrolled 49 patients, mainly between 65 and 75 years (n: 33; 67.3%) and polymedicated (n: 40; 81.6%), taking a mean of 6.9 ± 2.8 medicines per day. A lack of MK (score <50%) was observed in 15 (30.6%) participant patients. "Drug strength" and "storage conditions" were the items which presented the lowest score. MK was positively correlated with higher scores for health literacy and treatment adherence. Younger patients (age <65 years old) also had a higher MK score. Conclusion: This study showed that the applied tool could evaluate the MK of the participants and identified specific gaps regarding MK within the process of medicine use. Further studies, with more participants, will allow the confirmation of these findings and will stimulate the development of specific strategies to improve MK, thus contributing to better health outcomes.

Central and peripheral mechanisms of pain in fibromyalgia: scoping review protocol.

Fibromyalgia is characterised by widespread musculoskeletal pain, which may present with fatigue, depression, anxiety, sleep and cognitive disturbances. It is the second most prevalent rheumatic disease. An accurate diagnosis is challenging, since its symptoms may resemble diverse conditions such as carpal tunnel syndrome, Raynaud syndrome, Sjögren syndrome, amongst others. Neuropathic pain and autonomic dysfunction in fibromyalgia suggest the involvement of the nervous system. Ion channels, neurotransmitters and neuromodulators may play a role. Small fibre neuropathy (SFN) may also cause chronic widespread pain. SFN may occur in 50% of fibromyalgia patients, but its role in the disease is unknown. Despite several efforts to synthesise the evidence on the mechanisms for pain in fibromyalgia, there are few studies applying an integrative perspective of neurochemical, immunological, and neuroanatomical characteristics, and their relevance to the disease. This protocol aims to clarify the mechanisms of the central and peripheral nervous system associated with pain in fibromyalgia. We will retrieve published studies from Web of Science, MEDLINE, Scopus, EBSCOhost, Ovid and Google Scholar. All clinical studies or experimental models of fibromyalgia reporting imaging, neurophysiological, anatomical, structural, neurochemical, or immunological characteristics of the central or peripheral nervous systems associated with pain will be included. Exclusion criteria will eliminate studies evaluating pain without a standardised measure, studies written in languages different from Spanish or English that could not be appropriately translated, and studies whose full-text files could not be retrieved after all efforts made. A narrative synthesis will be performed.

The effect of almond intake on cardiometabolic risk factors, inflammatory markers, and liver enzymes: A systematic review and meta-analysis.

Almond intake may be correlated with improvements in several cardiometabolic parameters, but its effects are controversial in the published literature, and it needs to be comprehensively summarized. We conducted a systematic search in several international electronic databases, including MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov until April 2021 to identify randomized controlled trials that examined the effects of almond consumption on cardiometabolic risk factors, inflammatory markers, and liver enzymes. Data were pooled using the random-effects model method and presented as standardized mean differences (SMDs) with 95% confidence intervals (CIs). Twenty-six eligible trials were analyzed (n = 1750 participants). Almond intake significantly decreased diastolic blood pressure, total cholesterol, triglyceride, low-density lipoprotein (LDL), non-high-density lipoprotein (HDL), and very LDL (p < 0.05). The effects of almond intake on systolic blood pressure, fasting blood glucose, insulin, hemoglobin A1c, homeostatic model assessment of insulin resistance, C-peptide, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, C-reactive protein (CRP), hs-CRP (high sensitivity C-reactive protein), interleukin 6, tumor necrosis factor-α, ICAM (Intercellular Adhesion Molecule), VCAM (Vascular Cell Adhesion Molecule), homocysteine, HDL, ox-LDL, ApoA1, ApoB, and lipoprotien-a were not statistically significant (p > .05). The current body of evidence supports the ingestion of almonds for their beneficial lipid-lowering and antihypertensive effects. However, the effects of almonds on antiinflammatory markers, glycemic control, and hepatic enzymes should be further evaluated via performing more extensive randomized trials.

Adherence to literature search reporting guidelines in leading rheumatology journals' systematic reviews: umbrella review protocol.

Literature searches are important components of systematic reviews. They are not only informative of the retrieval process, but they also set the data to be analyzed and influence additional components of systematic reviews. Despite the available guidelines, several studies have shown that the quality of reporting in systematic reviews is deficient in several medical fields. Systematic reviews may not comply completely with those guidelines despite explicitly stating they do. This protocol intends to answer to what extent systematic reviews published in rheumatology journals have complied with the PRISMA's search strategy guidelines published in 2009. The objective of the study is to analyze the compliance with the PRISMA (2009) search strategy guidelines among systematic reviews published in leading rheumatology journals. Inclusion criteria for this umbrella review protocol are systematic reviews (with or without meta-analyses) that mention having followed the PRISMA statement (2009) in their methods section, and published in journals listed in the Rheumatology category of the Journal of Citations Report 2020. Exclusion criteria are articles published before 2009; retraction letters, notes, expressions of concern; systematic reviews using PRISMA 2020. Databases to be consulted are Web of Science, PubMed and Scopus, from inception to present. Data summaries will be presented in graphs, figures, tables and network maps. A narrative synthesis will be described. This protocol complies with guidelines such as PRISMA 2020, PRISMA-A, PRISMA-P, PRISMA-S, PRESS, and JBI Manual for evidence synthesis, as long as it is suitable for umbrella review protocols. Articles in any language will be considered.

The effect of Conjugated Linoleic Acid intake on oxidative stress parameters and antioxidant enzymes: A systematic review and meta-analysis of randomized clinical trials.

Conjugated Linoleic Acid (CLA) are thought to pose beneficial effects on inflammatory responses and oxidative stress (OS). Thus, the present systematic review and meta-analysis of randomized controlled trials (RCTs) aimed to assess the net effects of CLA supplementation on various OS parameters and antioxidant enzymes. PubMed/MEDLINE, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases were searched for publications on CLA supplementation effects on OS parameters up to March 2021. The data extracted from eligible studies were expressed as standardized mean difference with 95% confidence intervals and then combined into meta-analysis using the random-effects model. Overall, 11 RCTs (enrolling 586 participants) met the inclusion criteria and were included in meta-analysis; however, since those trials evaluated different OS parameters, meta-analysis was carried out considering different sets for each parameter separately. According to our results, CLA supplementation significantly increases 8-iso-PGF2α urinary concentration (SMD: 2; 95% CI: 0.74, 3.27; I2 = 87.7%). On contrary, the intervention does not seem to change 15-keto-dihydro-PGF2α urinary concentration, nor the serum levels of CAT, SOD, GPx and MDA. Taken all together, CLA supplementation does not appear to have substantial effects on OS markers in general; albeit due to relatively small sample size and high level of heterogeneity between studies, the obtained findings should be interpreted with caution. Further large well-designed RCTs, investigating the impact of CLA and including various groups of patients, are still needed.

Proteome dataset of sea bass (Dicentrarchus labrax) skin-scales exposed to fluoxetine and estradiol.

Contamination of aquatic ecosystems with anthropogenic pollutants, including pharmaceutical drugs, is a major concern worldwide. Aquatic organisms such as fish are particularly at risk of exposure to pollutants. The surface of fish is the first point of contact with pollutants, but few studies have considered the impact of pollutants on the skin-scale barrier. The present proteome data are the basis of the findings discussed in the associated research article "Proteomics of sea bass skin-scales exposed to the emerging pollutant fluoxetine compared to estradiol" [1]. Juvenile sea bass were exposed by intraperitoneal injections to: a) the antidepressant fluoxetine (FLX), a widely prescribed psychotropic drug and an emerging pollutant; b) the natural estrogen 17ß-estradiol (E2) and c) the vehicle, coconut oil (control). The scale proteome of fish exposed to these compounds for 5 days was analysed using quantitative label-free proteomics technology SWATH-MS (sequential windowed data-independent acquisition of the total high-resolution-mass spectra). The proteome data generated was submitted to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD020983. LC-MS data from pooled protein extracts from the scales of all experimental groups was acquired using information-dependent acquisition (IDA) and 1,254 proteins were identified by searching against the sea bass genome database. 715 proteins were quantified by SWATH acquisition, and 213 proteins had modified levels (p < 0.05) between the E2- or FLX-exposed fish compared to the control. The main biological processes and KEGG pathways affected by E2 or FLX treatments were identified using Cytoscape/ClueGO enrichment analyses.

Effects of Vitamin D Supplementation on Bone Health and Bone-related Parameters in HIV-infected Patients: A Systematic Review and Meta-analysis.

PURPOSE: There is growing evidence that bone health is decreased in individuals with HIV infection. Vitamin D deficiency is also highly prevalent among HIV-infected patients. The literature was systematically reviewed to determine whether bone health and bone-related parameters may improve with vitamin D supplementation in HIV-infected individuals. METHODS: Four databases were systematically searched for randomized clinical trials of vitamin D supplementation in HIV infection, published from January 1990 to September 2021. No language or publication restrictions were applied. Standardized mean differences (SMD) with 95% CIs are reported. A random-effects model was used to perform meta-analysis. FINDINGS: Ten studies met the inclusion criteria (N = 733 participants at study completion). The mean ages of the patients in the included trials ranged from 10 to 49 years. The meta-analysis indicated that with vitamin D supplementation, serum 25-hydroxy vitamin D (25[OH]D) level was significantly increased (SMD, 1.86; 95% CI, 1.02 to 2.70; I2 = 94.4%), but there were no significant effects on levels of serum 1,25-dihydroxy vitamin D (1,25-[OH]2D) (SMD, 0.29; 95% CI, -0.07 to 0.64; I2 = 67.4%), total bone mineral density (SMD, 0.07; 95% CI, -0.23 to 0.37; I2 = 00.0%), spine bone mineral density (SMD, 0.15; 95% CI, -0.19 to 0.49; I2 = 17.3%), and parathyroid hormone level (SMD, -0.18; 95% CI, -0.37 to 0.02; I2 = 1.2%) in HIV-infected patients. IMPLICATIONS: This study showed that vitamin D supplementation can improve serum 25(OH)D in HIV-infected patients. The effects of vitamin D supplementation on other bone health-related parameters such as bone mineral density and parathyroid hormone in HIV-infected patients need to be further investigated in larger-scale, well-designed randomized, controlled trials.

Effect of omega-3 fatty acids supplementation on adipokines: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Although a large body of literature reported the beneficial effects of omega-3 fatty acids (omega-3 FAs) consumption on adipokines levels, but recent findings from clinical trials are not univocal. The aim of this systematic review and meta-analysis was to evaluate the effect of omega-3 FAs supplements on adipokines. METHODS: We searched Medline, Web of Science, Scopus, Embase, and Cochrane Library from inception to August 2020 without any particular language limitations. Outcomes were summarized as standardized mean difference (SMD) with 95% confidence intervals (CIs) estimated from Hedge's g and random effects modeling. RESULTS: Fifty-two trials involving 4,568 participants were included. Omega-3 FAs intake was associated with a significant increase in plasma adiponectin levels (n = 43; 3,434 participants; SMD: 0.21, 95% CI: 0.04, 0.37; p = 0.01; I2= 80.14%). This meta-analysis indicates that supplementing participants with omega-3 fatty acids more than 2000 mg daily and more than 10 weeks resulted in a significant and more favorable improvement in plasma adiponectin levels. However, omega-3 FAs intake had no significant effect on leptin levels (SMD: -0.02, 95% CI: -0.20, 0.17, I2= 54.13%). CONCLUSION: The evidence supports a beneficial effect of omega-3 FAs intake on serum adiponectin levels but does not appear to impact on leptin concentrations. Larger well-designed RCTs are still required to evaluate the effect of omega-3 FAs on leptin in specific diseases.

The effect of chromium intake on oxidative stress parameters: A systematic review and meta-analysis.

BACKGROUND: Trivalent chromium is a trace element thought to have a beneficial effect on oxidative stress (OS) parameters and inflammation. This review aimed to investigate the dose-response of chromium and summarize the effects of chromium supplementation on OS parameters in the literature. METHODS: MEDLINE, Scopus, Web of Science and Cochrane CENTRAL databases were searched for RCTs published from inception to January 2021 evaluating the effect of chromium supplementation on OS parameters, namely MDA, TBARS, SOD, TAS, CAT, GPx, and GSH. A random-effects model was used to pool data and calculated standard mean difference and 95 % confidence intervals. Quantified heterogeneity among studies was assessed through Cochrane's I2 values. RESULTS: Nine studies enrolling 550 participants met the inclusion criteria. The obtained results indicate that chromium supplementation significantly increases TAC (SMD: 0.46; 95 % CI: 0.08, 0.84; I2 = 00.0 % n = 2) and significantly decreases MDA levels (SMD: -0.46; 95 % CI: -0.86, -0.07; I2 = 52.4 % n = 5). Supplementation did not significantly change CAT, GPx, GSH, SOD, TAS, and TBARS. CONCLUSION: Chromium supplementation may improve OS parameters, however, due to high heterogeneity observed in the included studies, these findings should be interpreted with caution. Large RCTs on various patient groups evaluating the impact of chromium supplementation are needed to allow an adequate generalization of the benefits of chromium on human health.

Effect of saffron supplementation on liver enzymes: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIMS: Possible protective effects of saffron (Crocus sativus L) have been reported in several randomized clinical trials (RCTs). Current systematic review was performed to summarize the efficacy of saffron intake on liver enzymes. METHODS: An electronic database search was conducted on PubMed/Medline, Scopus, Web of Science, and Cochrane for RCTs comparing effect of saffron and placebo on liver enzymes from inception to July 2021. There was no restriction in language of included studies and we calculated the standardized mean difference (SMD) and 95% Confidence Intervals (CI) for each variable. Random-effect model was used to calculate effect size. RESULTS: Eight studies (n = 463 participants) were included in the systematic review. The saffron intake was associated with a statistically significant decrease in aspartate aminotransferase (AST) (SMD: -0.18; 95% CI: -0.34, -0.02; I2 = 0%) in comparison to placebo intake. Our results also indicated that saffron consumption did not have a significant effect on alanine aminotransferase (ALT) (SMD: -0.14; 95% CI: -0.36, 0.09; I2 = 47.0%) and alkaline phosphatase (ALP) levels (SMD: 0.14; 95% CI: -0.18, 0.46; I2 = 42.9%) compared to placebo. CONCLUSIONS: Saffron intake showed beneficial impacts on circulating AST levels. However, larger well-designed RCTs are still needed to clarify the effect of saffron intake on these and other liver enzymes.

Sumac fruit supplementation improve glycemic parameters in patients with metabolic syndrome and related disorders: A systematic review and meta-analysis.

BACKGROUND: Metabolic syndrome (MetS) is the one of the main causes of mortality worldwide. Several randomized controlled trials (RCTs) have revealed the beneficial effects of sumac (Rhus coriaria) on cardiometabolic risk factors. However, the entirety of the evidence has yet to be summarized in a systematic review. OBJECTIVE: The aim of this systematic review and meta-analysis was to evaluate the effects of sumac on several cardiometabolic risk factors in patients with MetS and related disorders. METHODS: We reviewed Medline, Scopus, Web of Science and Cochrane CENTRAL for RCTs published from inception to December 2020 evaluating the impact of sumac in adults with MetS or related disorders. Outcome measures included anthropometric measures, glycemic indices, blood lipids, blood pressure and liver enzymes. Pooled effect sizes were reported as standard mean differences (SMDs) and 95% confidence intervals (CIs). Trials were pooled using a random effects model. RESULTS: Nine studies enrolling 526 participants met the inclusion criteria for this meta-analysis. Our results indicate that sumac intake significantly decrease fasting blood sugar (FBS) (SMD: -0.28; 95% CI: -0.54, -0.02; I2 = 00.0%), insulin (SMD: -0.67; 95% CI: -0.99, -0.36; I2 = 03.7%), and insulin resistance (measured through the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)) (SMD: -0.79; 95% CI: -1.24, -0.34; I2 = 50.1%). Sumac intake did not have a significant impact on weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist to hip ratio (WHR), HbA1c, total cholesterol (TC), triglycerides (TG), high density lipoproteins (HDL), low density lipoprotein (LDL), systolic blood pressure (SBP), diastolic blood pressure (DBP), aspartate transaminase (AST) and alanine transaminase (ALT). CONCLUSION: Sumac, as an adjuvant therapy, may decrease serum levels of FBS, insulin and HOMA-IR. However, due to high heterogeneity in the included studies, these findings must be interpreted with great caution. Larger, well-designed placebo-controlled clinical trials are still needed to further evaluate the capacity of sumac as a complementary treatment to control MetS risk factors.

Estradiol and genistein effects on the sea bass (Dicentrarchus labrax) scales: Transcriptome dataset.

Fish scales are mineralized structures that play important roles in protection and mineral homeostasis. This tissue expresses multiple estrogen receptor subtypes and can be targeted by estrogens or estrogenic endocrine-disrupting compounds, but their effects are poorly explored. The transcriptome data here presented support the findings reported in the research article "Genistein and estradiol have common and specific impacts on the sea bass (Dicentrarchus labrax) skin-scale barrier" [1]. Juvenile sea bass were exposed to estradiol and the phytoestrogen genistein for 1 and 5 days, by intraperitoneal injections, and the effects on scale transcript expression were analysed by RNA-seq using an Illumina Hi-seq 1500. The raw reads of the 30 libraries produced have been deposited in the NCBI-SRA database with the project accession number SRP102504. Mapping of RNA-seq reads against the sea bass reference genome using the Cufflinks/TopHat package identified 371 genes that had significant (FDR<0.05) differential expression with the estradiol or genistein treatments in relation to the control scales at each exposure time, 254 of which presented more than a 2-fold change in expression. The identity of the differentially expressed genes was obtained using both automatic and manual annotations against multiple public sequence databases and they were grouped according to their patterns of expression using hierarchical clustering and heat-maps. The biological processes and KEGG pathways most significantly affected by the estradiol and/or genistein treatments were identified using Cytoscape/ClueGO enrichment analyses.

Genistein and estradiol have common and specific impacts on the sea bass (Dicentrarchus labrax) skin-scale barrier.

Teleost fish scales play important roles in animal protection and homeostasis. They can be targeted by endogenous estrogens and by environmental estrogenic endocrine disruptors. The phytoestrogen genistein is ubiquitous in the environment and in aquaculture feeds and is a disruptor of estrogenic processes in vertebrates. To test genistein disrupting actions in teleost fish we used a minimally invasive approach by analysing scales plucked from the skin of sea bass (Dicentrarchus labrax). Genistein transactivated all three fish nuclear estrogen receptors and was most potent with the Esr2, had the highest efficacy with Esr1, but reached, in all cases, transactivation levels lower than those of estradiol. RNA-seq revealed 254 responsive genes in the sea bass scales transcriptome with an FDR < 0.05 and more than 2-fold change in expression, 1 or 5 days after acute exposure to estradiol or to genistein. 65 genes were specifically responsive to estradiol and 106 by genistein while 83 genes were responsive to both compounds. Estradiol specifically regulated genes of protein/matrix turnover and genistein affected sterol biosynthesis and regeneration, while innate immune responses were affected by both compounds. This comprehensive study revealed the impact on the fish scale transcriptome of estradiol and genistein, providing a solid background to further develop fish scales as a practical screening tool for endocrine disrupting chemicals in teleosts.

Duplicated membrane estrogen receptors in the European sea bass (Dicentrarchus labrax): Phylogeny, expression and regulation throughout the reproductive cycle.

The numerous estrogen functions reported across vertebrates have been classically explained by their binding to specific transcription factors, the nuclear estrogen receptors (ERs). Rapid non-genomic estrogenic responses have also been recently identified in vertebrates including fish, which can be mediated by membrane receptors such as the G protein-coupled estrogen receptor (Gper). In this study, two genes for Gper, namely gpera and gperb, were identified in the genome of a teleost fish, the European sea bass. Phylogenetic analysis indicated they were most likely retained after the 3R teleost-specific whole genome duplication and raises questions about their function in male and female sea bass. Gpera expression was mainly restricted to brain and pituitary in both sexes while gperb had a widespread tissue distribution with higher expression levels in gill filaments, kidney and head kidney. Both receptors were detected in the hypothalamus and pituitary of both sexes and significant changes in gpers expression were observed throughout the annual reproductive season. In female pituitaries, gpera showed an overall increase in expression throughout the reproductive season while gperb levels remained constant. In the hypothalamus, gpera had a higher expression during vitellogenesis and decreased in fish entering the ovary maturation and ovulation stage, while gperb expression increased at the final atresia stage. In males, gpers expression was constant in the hypothalamus and pituitary throughout the reproductive cycle apart from the mid- to late testicular development stage transition when a significant up-regulation of gpera occurred in the pituitary. The differential sex, seasonal and subtype-specific expression patterns detected for the two novel gper genes in sea bass suggests they may have acquired different and/or complementary roles in mediating estrogens actions in fish, namely on the neuroendocrine control of reproduction.

In vitro screening for estrogenic endocrine disrupting compounds using Mozambique tilapia and sea bass scales.

A wide range of estrogenic endocrine disruptors (EDCs) are accumulating in the environment and may disrupt the physiology of aquatic organisms. The effects of EDCs on fish have mainly been assessed using reproductive endpoints and in vivo animal experiments. We used a simple non-invasive assay to evaluate the impact of estrogens and EDCs on sea bass (Dicentrarchus labrax) and tilapia (Oreochromis mossambicus) scales. These were exposed to estradiol (E2), two phytoestrogens and six anthropogenic estrogenic/anti-estrogenic EDCs and activities of enzymes related to mineralized tissue turnover (TRAP, tartrate-resistant acid phosphatase and ALP, alkaline phosphatase) were measured. Semi-quantitative RT-PCR detected the expression of both membrane and nuclear estrogen receptors in the scales of both species, confirming scales as a target for E2 and EDCs through different mechanisms. Changes in TRAP or ALP activities after 30minute and 24h exposure were detected in sea bass and tilapia scales treated with E2 and three EDCs, although compound-, time- and dose-specific responses were observed for the two species. These results support again that the mineralized tissue turnover of fish is regulated by estrogens and reveals that the scales are a mineralized estrogen-responsive tissue that may be affected by some EDCs. The significance of these effects for whole animal physiology needs to be further explored. The in vitro fish scale bioassay is a promising non-invasive screening tool for E2 and EDCs effects, although the low sensitivity of TRAP/ALP quantification limits their utility and indicates that alternative endpoints are required.

Tissue responsiveness to estradiol and genistein in the sea bass liver and scale.

As in mammals, estrogens in fish are essential for reproduction but also important regulators of mineral homeostasis. Fish scales are a non-conventional target tissue responsive to estradiol and constitute a good model to study mineralized tissues effects and mechanisms of action of estrogenic compounds, including phytoestrogens. The responsiveness to estradiol and the phytoestrogen genistein, was compared between the scales and the liver, a classical estrogenic target, in sea bass (Dicentrarchus labrax). Injection with estradiol and genistein significantly increased circulating vitellogenin (for both compounds) and mineral levels (estradiol only) and genistein also significantly increased scale enzymatic activities suggesting it increased mineral turnover. The repertoire, abundance and estrogenic regulation of nuclear estrogen receptors (ESR1, 2a and 2b) and membrane G-protein receptors (GPER and GPER-like) were different between liver and scales, which presumably explains the tissue-specific changes detected in estrogen-responsive gene expression. In scales changes in gene expression mainly consisted of small rapid increases, while in liver strong, sustained increases/decreases in gene expression occurred. Similar but not overlapping gene expression changes were observed in response to both estradiol and genistein. This study demonstrates for the first time the expression of membrane estrogen receptors in scales and that estrogens and phytoestrogens, to which fish may be exposed in the wild or in aquaculture, both affect liver and mineralized tissues in a tissue-specific manner.

Cellular morphology and markers of cartilage and bone in the marine teleost Sparus auratus.

Modifications have been characterised in terms of cellular organisation and the extracellular matrix (ECM) during bone ontogeny in the sea bream (Sparus auratus). During endochondral development, the agglomeration of matrix-secreting cells gives rise to chondrones; these chondrones frequently contain proliferating-cell-nuclear-antigen-positive cells, which subsequently become large collagen-II-positive cells with the characteristics of chondrocytes. Moreover, the matrix:cell ratio within the perichondrium increases, accompanied by a modification in ECM composition. Mineralisation of cartilage ECM is marked by a rapid fall in cell number, the switching off of collagen II transcription and the switching on of collagen X transcription, followed by collagen I transcription and bone mineralisation. The formation of dermal structures initiated upon the condensation of mesenchyme cells defines the future location of the dermal bone. Subsequent cellular differentiation gives rise to cells on the bone surface; these cells are positive for collagen I and osteonectin transcripts. The fish skeleton, with the exception of vertebrae, tends to comprise flattened bones that are covered by a monolayer of cells, the periosteum. A third type of tissue, present in gills, consists of chondrocyte-like cells embedded in a mineralised matrix resembling chondroid bone in mammals. The results suggest that the cellular organisation and ontogeny of endochondral and dermal bone in the sea bream are similar to those described in other vertebrates.

Isolation and characterization of piscine osteonectin and downregulation of its expression by PTH-related protein.

UNLABELLED: The skeleton is the main source of osteonectin mRNA in adults of the seawater teleost sea bream Sparus auratus. It is expressed by cells forming the basement membrane of calcifying tissue indicating that, as in mammals, it may play a role in osteoblast differentiation. PTHrP induced downregulation of osteonectin mRNA in vitro in scales, a mineralizing tissue with bone-like metabolism. This indicates a means to redirect calcium to activities such as vitellogenesis when this ion is in high demand. INTRODUCTION: Osteonectin is a unique matricellular calcium-binding glycoprotein and a major noncollagenous constituent of higher eukaryote bone. In terrestrial vertebrates, it has been associated with development, remodeling, cell turnover, and tissue repair, all processes involving substantial changes in extracellular matrix (ECM) structure. In skeleton biology, osteonectin has been described as a positive factor in the mineralization process as well as in osteoblastic cell lineage differentiation and is downregulated by the hypercalcemic hormone PTH. In this study, we report the cloning and characterization of bream S. auratus osteonectin cDNA and its tissue and cellular distribution. Its high expression by fish scales provides a unique in vitro bioassay with which to study regulation of osteonectin gene expression by the recently isolated piscine PTH-related peptide (PTHrP). MATERIALS AND METHODS: An intervertebral tissue cDNA library from S. auratus was the source of the full-length cDNA clone for osteonectin. Expression studies were performed by semiquantitative RT-PCR, Northern blot, and in situ hybridization analysis. Moreover, an in vitro bioassay with S. auratus scales was specifically developed for measuring the effect of PTHrP on osteonectin expression. RESULTS AND CONCLUSIONS: Phylogenetic analysis showed that S. auratus osteonectin is highly homologous with previously reported osteonectins, supporting the idea of a conserved function for this protein in the ECM. Its expression pattern in adult tissues from S. auratus was markedly biased toward skeletal structures of both dermal or endochondral origin. More specifically, the localization of the osteonectin mRNA in the basement membrane that separates the epithelia from the underlying mineralized connective tissue supports a role for this protein in calcified matrix turnover. Furthermore, the recently identified piscine hypercalcemic factor PTHrP downregulates osteonectin expression in scales, suggesting a catabolic action for this hormone on these structures.