Sulphide donors affect the expression of mucin and sulphide detoxification genes in the mucosal organs of Atlantic salmon (Salmo salar)

Hydrogen sulphide (H2S) is a gas that affects mucosal functions in mammals. However, its detrimental effects are less understood in fish despite being known to cause mass mortality. Here we used explant models to demonstrate the transcriptional responses of Atlantic salmon (Salmo salar) mucosa to the sulphide donor sodium hydrosulphide (NaHS). The study focused on two groups of genes: those encoding for sulphide detoxification and those for mucins. Moreover, we performed pharmacological studies by exposing the organ explants to mucus-interfering compounds and consequently exposed them to a sulphide donor. Exposure to NaHS significantly affected the expression of sulphide:quinone oxidoreductase (sqor1, sqor2) and mucin-encoding genes (muc5ac, muc5b). The general profile indicated that NaHS upregulated the expression of sulphide detoxification genes while a significant downregulation was observed with mucins. These expression profiles were seen in both organ explant models. Pharmacological stimulation and inhibition of mucus production used acetylcholine (ACh) and niflumic acid (NFA), respectively. This led to a significant regulation of the two groups of marker genes in the gills and olfactory rosette explants. Treatment of the mucosal organ explants with the mucus-interfering compounds showed that low dose NFA triggered more substantial changes while a dose-dependent response could not be established with ACh. Pharmacological interference demonstrated that mucins played a crucial role in mucosal protection against H2S toxicity. These results offer insights into how a sulphide donor interfered with mucosal responses of Atlantic salmon and are expected to contribute to our understanding of the least explored H2S-fish interactions—particularly at the mucosa.Sulphide donors affect the expression of mucin and sulphide detoxification genes in the mucosal organs of Atlantic salmon (Salmo salar)publishedVersio

Differential sensitivity of mucosal organs to transient exposure to hydrogen sulphide in post-smolt Atlantic salmon (Salmo salar)

Mortality related to hydrogen sulphide (H2S) has recently become a serious concern in Atlantic salmon (Salmo salar) farming, particularly in saline recirculating aquaculture systems (RASs), where the risk of H2S formation is high. H2S has a distinct odour of rotten eggs, and its production is associated with the anaerobic bacterial decomposition of protein and other sulphur-containing organic matter. Significant advances have been made in elucidating its formation in RAS, but the biological consequences of this toxicant in salmon remain elusive. We report the physiological consequences of transient exposure of post-smolt Atlantic salmon to H2S. The fish were exposed to one of three levels of H2S for 1 h: 0 µM (unexposed), 0.6 µM (low exposure), and 1.2 µM (high exposure). Fish were allowed to recover for 24 h and then sampled for gene expression, histology, and metabolomics analyses. Molecular profiling was performed on a subset of genes with known functions in sulphide detoxification, mucins, immunity, and stress responses, which focused on the gills, olfactory organ, skin, and distal gut. With the exception of interleukin 10, all genes studied were significantly affected in the skin, where high H2S triggered significant upregulation. Stress-related genes were mostly affected in the gills, where the high H2S level also induced significant upregulation. Downregulation of the marker genes was identified in the olfactory organ especially in the low-dose group. The distal gut was less sensitive to H2S, regardless of the dose. Histological health scoring of the four mucosal organs revealed no substantial structural alterations and only sporadic cases of mild-moderate unspecific tissue damage. High-throughput metabolomics revealed that transient H2S exposure had a substantial mucosal impact rather than a systemic impact, as shown by changes in skin mucus metabolome. Functional annotation indicated that 10 metabolomic pathways were significantly affected in the skin mucus, including tRNA charging, the superpathway of branched-chain amino acid biosynthesis, and glucosilinate biosynthesis from phenylalanine. The physiological alterations following transient exposure to H2S showed that the mucosal organs exhibited distinct response profiles, where transcriptional impacts were more pronounced in the skin and gills. The results contribute to a better understanding of the biological functions of exogenous H2S in teleost fish, as well as the development of mitigation strategies for salmon-production facilities and the risk of H2S exposure.Differential sensitivity of mucosal organs to transient exposure to hydrogen sulphide in post-smolt Atlantic salmon (Salmo salar)publishedVersio

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Self-Healing Hydrogel Scaffolds through PET-RAFT Polymerization in Cellular Environment

Photo electron/energy transfer-reversible addition–fragmentation chain transfer (PET-RAFT) has emerged as a powerful reversible-deactivation radical polymerization technique, enabling oxygen-tolerant polymerizations with exquisite spatiotemporal control through irradiation with visible light. In contrast to traditional free radical photo-polymerization, which often requires the use of DNA-damaging UV irradiation, PET-RAFT offers a more cytocompatible alternative for the preparation of polymeric materials in cell culture environments. Herein, we report the use of PET-RAFT for the fabrication of self-healing hydrogels using commercially available monomers, reaching high monomer conversions and cell encapsulation efficiencies. Our hydrogels showed the expected rheological and mechanical properties for the systems considered, together with excellent cytocompatibility and spatiotemporal control over the polymerization process. Moreover, hydrogels prepared through this method could be cut and healed again by simply adding further monomer and irradiating the system with visible light, even in the presence of mammalian cells. This study demonstrates for the first time the potential of PET-RAFT polymerization as a viable methodology for the synthesis of self-healing hydrogel scaffolds for cell encapsulation

Sulphide donors affect the expression of mucin and sulphide detoxification genes in the mucosal organs of Atlantic salmon (Salmo salar)

Hydrogen sulphide (H2S) is a gas that affects mucosal functions in mammals. However, its detrimental effects are less understood in fish despite being known to cause mass mortality. Here we used explant models to demonstrate the transcriptional responses of Atlantic salmon (Salmo salar) mucosa to the sulphide donor sodium hydrosulphide (NaHS). The study focused on two groups of genes: those encoding for sulphide detoxification and those for mucins. Moreover, we performed pharmacological studies by exposing the organ explants to mucus-interfering compounds and consequently exposed them to a sulphide donor. Exposure to NaHS significantly affected the expression of sulphide:quinone oxidoreductase (sqor1, sqor2) and mucin-encoding genes (muc5ac, muc5b). The general profile indicated that NaHS upregulated the expression of sulphide detoxification genes while a significant downregulation was observed with mucins. These expression profiles were seen in both organ explant models. Pharmacological stimulation and inhibition of mucus production used acetylcholine (ACh) and niflumic acid (NFA), respectively. This led to a significant regulation of the two groups of marker genes in the gills and olfactory rosette explants. Treatment of the mucosal organ explants with the mucus-interfering compounds showed that low dose NFA triggered more substantial changes while a dose-dependent response could not be established with ACh. Pharmacological interference demonstrated that mucins played a crucial role in mucosal protection against H2S toxicity. These results offer insights into how a sulphide donor interfered with mucosal responses of Atlantic salmon and are expected to contribute to our understanding of the least explored H2S-fish interactions—particularly at the mucosa

Effectiveness of silver nitrate compared to talc slurry as pleural sclerosing agent in rabbits. Influence of concomitant intrapleural lidocaine

Não está ainda definido, qual o agente ideal para a produção de uma pleurodese efetiva. O talco é o agente mais freqüentemente utilizado apesar de suas manifestações colaterais. Outra possibilidade é o nitrato de prata, largamente usado no passado. OBJETIVOS: Determinar a influência da injeção intrapleural de lidocaina na produção de pleurodese com nitrato de prata, definir o efeito da lidocaina na maturação das fibras colágenas e confirmar que a pleurodese produzida pelo nitrato de prata é mais potente que a conseqüente à injeção intrapleural de talco. MÉTODOS: Foram estudados três grupos de 8 coelhos. Dois receberam nitrato de prata a 0,5%; em um deles, foi injetado previamente 0,5 ml de lidocaina a 2%. O terceiro grupo recebeu 2 ml de talco (400 mg/kg). Os animais foram sacrificados após 28 dias da injeção intrapleural e as cavidades pleurais examinadas macroscopicamente, analisando-se a presença de fusão entre os folhetos pleurais e microscopicamente avaliando-se a inflamação e a fibrose. Quantificou-se o total de colágeno na pleura e a distribuição de fibras finas e grossas, utilizando-se a coloração de pricrosirius. RESULTADOS: Nos dois grupos em que se injetou nitrato de prata (s/ lidocaina: 3.5 + 0.3 e com lidocaina: 3.2 + 0.3), a pleurodese macroscópica (scala 0 - 4) foi significantemente (p = 0.001) melhor do que a pleurodese resultante do talco (1.6 + 0.2). A média da fibrose pleural induzida pelo nitrato de prata (3.5 + 0.2) foi significantemente (p = 0.004) mais acentuada do que a produzida por talco (1.9 + 0.1). A instilação prévia de lidocaina determinou tendência a diminuir a quantidade de fibrose (3.1 + 0.4). A média (10³mm²) do colágeno pleural foi significantemente (p = 0.009) maior nos coelhos que receberam nitrato de prata (116.9 + 22.7) do que naqueles que receberam talco (10.7 + 3.4). A injeção de lidocaina reduziu discretamente o colágeno (80.1 + 30.3). A distribuição das fibras colágenas não foi diferente entre os grupos estudados. CONCLUSÃO: Este modelo animal confirma que, o nitrato de prata injetado no espaço pleural mais efetivo do que o talco na produção de pleurodese. A injeção intrapleural de lidocaina determina uma tendência a reduzir a quantidade de colágeno, mas não muda a efetividade da sínfise pleural ou modifica a maturação do colágeno.The ideal agent for producing pleurodesis has not been identified. Talc, the most commonly used, poses several problems. Another possibility is silver nitrate, which was widely used in the past. PURPOSE: To determine the influence of the intrapleural instillation of lidocaine in producing a pleurodesis with silver nitrate, to define the effect of lidocaine in the maturation of the collagen fibers, and to confirm that the pleurodesis after silver nitrate is stronger than after talc. METHODS: We studied three groups of 8 rabbits. Two groups received 0.5% silver nitrate; in one we had previously injected 0.5 ml of 2% lidocaine. The third group received 400 mg/kg talc (2 ml). The animals were sacrificed 28 days after the injection, and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of inflammation and fibrosis. The total amount of pleural collagen and the distribution of thick and thin collagen fibers were quantified. Collagen was identified using picrosirius red stain. RESULTS: In the two groups that received silver nitrate (without lidocaine: 3.5 + 03 and with lidocaine: 3.2 + 0.3), the macroscopic pleurodesis (scale 0 -- 4) was significantly (p = 0.001) better than that resulting from talc (1.6 + 0.2). The mean degree of pleural fibrosis induced by silver nitrate (3.5 + 0.2) was significantly (p = 0.004) higher than that induced by talc (1.9 + 0.1). The previous instillation of lidocaine resulted in a tendency for decreased amounts of fibrosis (3.1 + 0.4). The mean amount (10³mm²) of pleural collagen was significantly (p = 0.009) greater in the rabbits that received silver nitrate (116.9 + 22.7) than in those that received talc (10.7 + 3.4). The injection of lidocaine slightly reduced the collagen (80.1 + 30.3). The distribution of collagen fibers did not differ among the groups. CONCLUSION: This rabbit model clearly confirms that intrapleural silver nitrate is more effective than talc for producing pleurodesis. The previous intrapleural instillation of lidocaine results in a decreasing trend in the amount of collagen, but does not change the effectiveness of the pleural fusion or modify the process of collagen maturation

Mucosal and systemic physiological changes underscore the welfare risks of environmental hydrogen sulphide in post-smolt Atlantic salmon (Salmo salar)

publishedVersio

Circulating circRNA as biomarkers for dilated cardiomyopathy etiology

Dilated cardiomyopathy (DCM) is the third most common cause of heart failure. The multidisciplinary nature of testing ¿ involving genetics, imaging, or cardiovascular techniques ¿ makes its diagnosis challenging. Novel and reliable biomarkers are needed for early identifcation and tailored personalized management. Peripheral circular RNAs (circRNAs), a leading research topic, remain mostly unexplored in DCM. We aimed to assess whether peripheral circRNAs are expressed diferentially among etiology-based DCM. The study was based on a case¿control multicentric study. We enrolled 130 subjects: healthy controls (n=20), idiopathic DCM (n=30), ischemic DCM (n=20), and familial DCM patients which included pathogen variants of (i) LMNA gene (n=30) and (ii) BCL2-associated athanogene 3 (BAG3) gene (n=30). Diferentially expressed circRNAs were analyzed in plasma samples by quantitative RT-PCR and cor¿ related to relevant systolic and diastolic parameters. The patho¿ physiological implications were explored through bioinformatics tools. Four circRNAs were overexpressed compared to controls: hsa_circ_0003258, hsa_circ_0051238, and hsa_circ_0051239 in LMNA-related DCM and hsa_circ_0089762 in the ischemic DCM cohort. The obtained areas under the curve confrm the discriminative capacity of circRNAs. The circRNAs correlated with some diastolic and systolic echocardiographic parameters with notable diagnostic potential in DCM. Circulating circRNAs may be helpful for the etiology-based diagnosis of DCM as a non-invasive biomarker

Circulating circRNA as biomarkers for dilated cardiomyopathy etiology

Dilated cardiomyopathy (DCM) is the third most common cause of heart failure. The multidisciplinary nature of testing - involving genetics, imaging, or cardiovascular techniques - makes its diagnosis challenging. Novel and reliable biomarkers are needed for early identification and tailored personalized management. Peripheral circular RNAs (circRNAs), a leading research topic, remain mostly unexplored in DCM. We aimed to assess whether peripheral circRNAs are expressed differentially among etiology-based DCM. The study was based on a case-control multicentric study. We enrolled 130 subjects: healthy controls (n = 20), idiopathic DCM (n = 30), ischemic DCM (n = 20), and familial DCM patients which included pathogen variants of (i) LMNA gene (n = 30) and (ii) BCL2-associated athanogene 3 (BAG3) gene (n = 30). Differentially expressed circRNAs were analyzed in plasma samples by quantitative RT-PCR and correlated to relevant systolic and diastolic parameters. The pathophysiological implications were explored through bioinformatics tools. Four circRNAs were overexpressed compared to controls: hsa_circ_0003258, hsa_circ_0051238, and hsa_circ_0051239 in LMNA-related DCM and hsa_circ_0089762 in the ischemic DCM cohort. The obtained areas under the curve confirm the discriminative capacity of circRNAs. The circRNAs correlated with some diastolic and systolic echocardiographic parameters with notable diagnostic potential in DCM. Circulating circRNAs may be helpful for the etiology-based diagnosis of DCM as a non-invasive biomarker. Key messages The limitations of cardiac diagnostic imaging and the absence of a robust biomarker reveal the need for a diagnostic tool for dilated cardiomyopathy (DCM). The circular RNA (circRNA) expression pattern is paramount for categorizing the DCM etiologies. Our peripheral circRNAs fingerprint discriminates between various among etiology-based DCM and correlates with some echocardiographic parameters. We provide a potential non-invasive biomarker for the etiology-based diagnosis of LMNA-related DCM and ischemic DCM.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by grants in the framework of the European Regional Development Fund (ERDF) Integrated Territorial Initiative (ITI PI0048-2017 and ITI0033_2019), a clinical research grant from the Spanish Society of Cardiology for Basic Research in cardiology (PI0012_2019), COST (European Cooperation in Science and Technology) Action EUCardioRNA CA17129, and the Portuguese Foundation for Science and Technology (FCT) under the framework of the research grant PTDC-MED-GEN-29389-2017

Induction of Short-Term Sensitization by an Aversive Chemical Stimulus in Zebrafish Larvae

Larval zebrafish possess a number of molecular and genetic advantages for rigorous biological analyses of learning and memory. These advantages have motivated the search for novel forms of memory in these animals that can be exploited for understanding the cellular and molecular bases of vertebrate memory formation and consolidation. Here, we report a new form of behavioral sensitization in zebrafish larvae that is elicited by an aversive chemical stimulus [allyl isothiocyanate (AITC)] and that persists for ≥30 min. This form of sensitization is expressed as enhanced locomotion and thigmotaxis, as well as elevated heart rate. To characterize the neural basis of this nonassociative memory, we used transgenic zebrafish expressing the fluorescent calcium indicator GCaMP6 (Chen et al., 2013); because of the transparency of larval zebrafish, we could optically monitor neural activity in the brain of intact transgenic zebrafish before and after the induction of sensitization. We found a distinct brain area, previously linked to locomotion, that exhibited persistently enhanced neural activity following washout of AITC; this enhanced neural activity correlated with the behavioral sensitization. These results establish a novel form of memory in larval zebrafish and begin to unravel the neural basis of this memory