Characteristics of obstructive sleep apnea related to insulin resistance.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with multiple comorbidities, including diabetes. Its development is preceded by alterations in the initial phase of carbohydrate metabolism characterized by insulin resistance. This study aims to evaluate the role of intermittent hypoxia and sleep fragmentation characteristic of OSA on the risk of insulin resistance among apneic patients without diabetes. METHODOLOGY: 92 consecutive patients with OSA without evidence of diabetes were recruited. Overnight video polysomnography was performed and, the following morning, fasting blood glucose, insulin and glycosylated hemoglobin were determined. Insulin resistance was measured using the HOMA-IR index. RESULTS: Insulin resistance was present in 52.2% of OSA patients. In these subjects, insulin resistance was independently associated to the apnea index during REM sleep (adjusted odds ratio [aOR] 1.09; 95% CI, 1.03 to 1.16; p = 0.004), desaturation index (aOR 1.08; 95% CI: 1.04 to 1.13; p = 0.027), and sleep time with oxygen saturation below 90% (aOR 1.04; 95% CI 1.00 to 1.08; p = 0.049). Furthermore, the HOMA-IR level was also directly related to the desaturation index (standardized regression coefficient [B] = 0.514, p < 0.001) and to the apnea index during REM sleep (B = 0.344, p = 0.002). CONCLUSIONS: Intermittent hypoxia and disturbances in REM sleep emerge as main contributors to insulin resistance in OSA patients yet to experience diabetes onset.

Relationship between Body Posture Assessed by Dynamic Baropodometry and Dental Occlusion in Patients with and without Dental Pathology.

Body biomechanics and dental occlusion are related, but this interaction is not fully elucidated. The aim of this study was to investigate the association between body posture and occlusion in patients with and without dental pathology. A cross-sectional study was carried out with 29 patients divided into a control group and a group with pathology (malocclusions). Body posture was evaluated by dynamic baropodometry, analyzing parameters such as the line of gait and the anteroposterior and lateral position of the center of pressure (CoP). Occlusion was classified radiographically according to the sagittal skeletal relationship. Results showed significant differences in mean position phase line between groups (p = 0.01-0.02), with means of 115.85 ± 16.98 mm vs. 95.74 ± 24.47 mm (left side) and 109.03 ± 18.03 mm vs. 91.23 ± 20.80 mm (right side) for controls and pathologies, respectively. The effect size was large (Cohen's d 0.97 and 0.92). There were no differences in the anteroposterior (p = 0.38) or lateral (p = 0.78) position of the CoP. In gait analysis, significant differences were observed in left (548.89 ± 127.50 N vs. 360.15 ± 125.78 N, p < 0.001) and right (535.71 ± 131.57 N vs. 342.70 ± 108.40 N, p < 0.001) maximum heel strength between groups. The results suggest an association between body posture and occlusion, although further studies are needed to confirm this relationship. An integrated postural and occlusal approach could optimize the diagnosis and treatment of dental patients.

Feeding frequency and dietary protein/carbohydrate ratio affect feed intake and appetite regulation-related genes expression in gilthead seabream (Sparus aurata).

To evaluate the effects of feeding frequency (FF) and dietary protein/carbohydrate (P/CH) ratios on appetite regulation of gilthead seabream, two practical diets were formulated to include high protein and low carbohydrate (P50/CH10 diet) or low protein and high carbohydrate (P40/CH20 diet) content and each diet was fed to triplicate groups of fish until visual satiation each meal at a FF of 1, 2, or 3 meals per day. Feed intake and feed conversion ratio were higher in fish fed 2 or 3 meals than 1 meal per day and in fish fed the P40/CH20 than the P50/CH10 diet. The specific growth rate was only affected by FF, being higher in fish fed 2 or 3 meals per day than 1 meal per day. Expression of the cocaine-amphetamine-related transcript, corticotropin-releasing hormone, ghrelin receptor-a (ghsr-a), leptin, and neuropeptide y in the brain, cholecystokinin (cck) in the intestine, and leptin and ghrelin in the stomach was not affected by FF or dietary P/CH ratio. This is the first time that ghrelin cells were immune-located in the stomach of gilthead seabream. Fish fed 3 meals per day presented lower cck expression in the brain than those fed twice per day and higher hepatic ghsr-b expression than those fed once per day. Fish fed P40/CH20 diet presented higher hepatic leptin expression than those fed P50/CH10 diet. In conclusion, present results indicate that feeding a P40/CH20 diet at 3 meals a day seems to decrease the satiation feeling of gilthead seabream compared to fish fed higher P/CH ratio diets or fed 1 or 2 meals a day.

Polyphosphate Activates von Willebrand Factor Interaction with Glycoprotein Ib in the Absence of Factor VIII In Vitro.

Polyphosphate (polyP), a phosphate polymer released by activated platelets, may modulate various stages of hemostasis by binding to blood proteins. In this context, we previously reported that polyP binds to the von Willebrand factor (VWF). One of the most significant functions of VWF is to bind to and protect the blood circulating Factor VIII (FVIII). Therefore, here, we study the role of polyP in the VWF-FVIII complex in vitro and suggest its biological significance. Surface plasmon resonance and electrophoretic mobility assays indicated that polyP binds dynamically to VWF only in the absence of FVIII. Using the VWF Ristocetin Cofactor assay, the most accepted method for studying VWF in platelet adhesion, we found that polyP activates this role of VWF only at low levels of FVIII, such as in plasmas with chemically depleted FVIII and plasmas from severe hemophilia A patients. Moreover, we demonstrated that FVIII competes with polyP in the activation of VWF. Finally, polyP also increases the binding of VWF to platelets in samples from patients with type 2 and type 3 von Willebrand disease. We propose that polyP may be used in designing new therapies to activate VWF when FVIII cannot be used.

Myomaker and Myomixer Characterization in Gilthead Sea Bream under Different Myogenesis Conditions.

Skeletal muscle is formed by multinucleated myofibers originated by waves of hyperplasia and hypertrophy during myogenesis. Tissue damage triggers a regeneration process including new myogenesis and muscular remodeling. During myogenesis, the fusion of myoblasts is a key step that requires different genes' expression, including the fusogens myomaker and myomixer. The present work aimed to characterize these proteins in gilthead sea bream and their possible role in in vitro myogenesis, at different fish ages and during muscle regeneration after induced tissue injury. Myomaker is a transmembrane protein highly conserved among vertebrates, whereas Myomixer is a micropeptide that is moderately conserved. myomaker expression is restricted to skeletal muscle, while the expression of myomixer is more ubiquitous. In primary myocytes culture, myomaker and myomixer expression peaked at day 6 and day 8, respectively. During regeneration, the expression of both fusogens and all the myogenic regulatory factors showed a peak after 16 days post-injury. Moreover, myomaker and myomixer were present at different ages, but in fingerlings there were significantly higher transcript levels than in juveniles or adult fish. Overall, Myomaker and Myomixer are valuable markers of muscle growth that together with other regulatory molecules can provide a deeper understanding of myogenesis regulation in fish.

Photoperiod Manipulation Affects Transcriptional Profile of Genes Related to Lipid Metabolism and Apoptosis in Zebrafish (Danio rerio) Larvae: Potential Roles of Gut Microbiota.

Gut microbiota plays a fundamental role in maintaining host's health by controlling a wide range of physiological processes. Administration of probiotics and manipulation of photoperiod have been suggested as modulators of microbial composition and are currently undergoing an extensive research in aquaculture as a way to improve health and quality of harvested fish. However, our understanding regarding their effects on physiological processes is still limited. In the present study we investigated whether manipulation of photoperiod and/or probiotic administration was able to alter microbial composition in zebrafish larvae at hatching stage. Our findings show that probiotic does not elicit effects while photoperiod manipulation has a significant impact on microbiota composition. Moreover, we successfully predicted lipid biosynthesis and apoptosis to be modulated by microbial communities undergoing continuous darkness. Interestingly, expression levels of caspase 3 gene (casp3) and lipid-related genes (hnf4a, npc1l1, pparγ, srebf1, agpat4 and fitm2) were found to be significantly overexpressed in dark-exposed larvae, suggesting an increase in the occurrence of apoptotic processes and a lipid metabolism impairment, respectively (p < 0.05). Our results provide the evidence that microbial communities in zebrafish at early life stages are not modulated by a short administration of probiotics and highlight the significant effect that dark photoperiod elicits on zebrafish microbiota and potentially on health.

Gilthead seabream (Sparus aurata) in vitro adipogenesis and its endocrine regulation by leptin, ghrelin, and insulin.

Leptin, ghrelin, and insulin influence lipid metabolism and thus can directly affect adipose tissue characteristics, modulating the organoleptic quality of aquaculture fish. The present study explored gilthead seabream (Sparus aurata) cultured preadipocytes development, and the regulation of adipogenesis by those three hormones. Preadipocytes presented a fibroblast-like phenotype during the proliferation phase that changed to round-shaped with an enlarged cytoplasm filled with lipid droplets after complete differentiation, confirming the characteristics of mature adipocytes. peroxisome proliferator-activated receptor-γ (pparγ) expression was higher at the beginning of the culture, while fatty acid synthase and 3-hydroxyacyl-CoA dehydrogenase gradually increased with cell maturation. The expression of lipoprotein lipase-like, lysosomal acid lipase (lipa), fatty acid translocase/cluster of differentiation-36 (cd36), and leptin receptor (lepr) were not affected during cell culture development; and undetectable expression levels were observed for leptin. Concerning regulation, leptin inhibited lipid accumulation significantly reducing pparγ and cd36 gene expression, both in early differentiating and mature adipocytes, while ghrelin decreased the expression of pparγ in the early differentiating phase but did not reduce intracellular lipid content significantly. Additional insulin past the onset of adipogenesis did not affect lipid accumulation either. In conclusion, at present culture conditions leptin has an anti-adipogenic function in differentiating preadipocytes of gilthead seabream and continues exerting this role in mature adipocytes, while ghrelin and insulin do not seem to influence adipogenesis progression. A better understanding of leptin, ghrelin, and insulin impact on the adipogenic process could help in the prevention of fat accumulation, improving aquaculture fish production and quality.

Short-Term Responses to Fatty Acids on Lipid Metabolism and Adipogenesis in Rainbow Trout (Oncorhynchus mykiss).

Fish are rich in n-3 long-chain polyunsaturated fatty acids (LC-PUFA) such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Due to the increasing use of vegetable oils (VO), their proportion in diets has lowered, affecting lipid metabolism and fillet composition. Rainbow trout cultured preadipocytes were treated with representative FA found in fish oils (EPA and DHA) or VO (linoleic, LA and alpha-linolenic, ALA acids), while EPA and LA were also orally administered, to evaluate their effects on adipogenesis and lipid metabolism. In vitro, all FA increased lipid internalization, with ALA producing the highest effect, together with upregulating the FA transporter fatp1. In vivo, EPA or LA increased peroxisome proliferator-activated receptors ppara and pparb transcripts abundance in adipose tissue, suggesting elevated ß-oxidation, contrary to the results obtained in liver. Furthermore, the increased expression of FA synthase (fas) and the FA translocase/cluster of differentiation (cd36) in adipose tissue indicated an enhanced uptake of lipids and lipogenesis de novo, whereas stable or low hepatic expression of genes involved in lipid transport and turnover was found. Thus, fish showed a similar tissue metabolic response to the short-term availability of EPA or LA in vivo, while in vitro VO-derived FA demonstrated greater potential inducing fat accumulation.

Genistein Induces Adipogenic and Autophagic Effects in Rainbow Trout (Oncorhynchus mykiss) Adipose Tissue: In Vitro and In Vivo Models.

Soybeans are one of the most used alternative dietary ingredients in aquafeeds. However, they contain phytoestrogens like genistein (GE), which can have an impact on fish metabolism and health. This study aimed to investigate the in vitro and in vivo effects of GE on lipid metabolism, apoptosis, and autophagy in rainbow trout (Oncorhynchus mykiss). Primary cultured preadipocytes were incubated with GE at different concentrations, 10 or 100 µM, and 1 µM 17ß-estradiol (E2). Furthermore, juveniles received an intraperitoneal injection of GE at 5 or 50 µg/g body weight, or E2 at 5 µg/g. In vitro, GE 100 µM increased lipid accumulation and reduced cell viability, apparently involving an autophagic process, indicated by the higher LC3-II protein levels, and higher lc3b and cathepsin d transcript levels achieved after GE 10 µM. In vivo, GE 50 µg/g upregulated the gene expression of fatty acid synthase (fas) and glyceraldehyde-3-phosphate dehydrogenase in adipose tissue, suggesting enhanced lipogenesis, whereas it increased hormone-sensitive lipase in liver, indicating a lipolytic response. Besides, autophagy-related genes increased in the tissues analyzed mainly after GE 50 µg/g treatment. Overall, these findings suggest that an elevated GE administration could lead to impaired adipocyte viability and lipid metabolism dysregulation in rainbow trout.

Germinal Matrix-Intraventricular Hemorrhage of the Preterm Newborn and Preclinical Models: Inflammatory Considerations.

The germinal matrix-intraventricular hemorrhage (GM-IVH) is one of the most important complications of the preterm newborn. Since these children are born at a critical time in brain development, they can develop short and long term neurological, sensory, cognitive and motor disabilities depending on the severity of the GM-IVH. In addition, hemorrhage triggers a microglia-mediated inflammatory response that damages the tissue adjacent to the injury. Nevertheless, a neuroprotective and neuroreparative role of the microglia has also been described, suggesting that neonatal microglia may have unique functions. While the implication of the inflammatory process in GM-IVH is well established, the difficulty to access a very delicate population has lead to the development of animal models that resemble the pathological features of GM-IVH. Genetically modified models and lesions induced by local administration of glycerol, collagenase or blood have been used to study associated inflammatory mechanisms as well as therapeutic targets. In the present study we review the GM-IVH complications, with special interest in inflammatory response and the role of microglia, both in patients and animal models, and we analyze specific proteins and cytokines that are currently under study as feasible predictors of GM-IVH evolution and prognosis.

Gene expression analyses in malformed skeletal structures of gilthead sea bream (Sparus aurata).

The incidence of skeletal anomalies in reared fish has been translated for years in important economic losses for the aquaculture industry. In the present study, we have analysed the gene expression of extracellular matrix components and transcription factors involved in bone development in gilthead sea bream presenting different skeletal anomalies: lordosis (LD), lordosis-scoliosis-kyphosis (LSK) or opercular, dental or jaw malformations in comparison with control (CT) specimens. Results showed a possible link between the presence of LD and LSK and the significant downregulation of genes involved in osteoblasts' maturation and matrix mineralization (collagen type 1-alpha, osteopontin, osteocalcin, matrix Gla protein and tissue non-specific alkaline phosphatase), as well as in bone resorption (cathepsin K and matrix metalloproteinase 9) compared to CT animals. Contrarily, the key osteogenic transcription factor runx2 was upregulated in the malformed vertebra suggesting impaired determination of mesenchymal stem cells towards the osteoblastic lineage. Despite the gene expression patterns of the other malformed structures were not affected in comparison with CT fish, the results of the present study may contribute in the long term to identify potential candidate gene profiles associated with column deformities that may help reducing the incidence of appearance of skeletal anomalies in this important aquaculture species.

Effects of ß2-adrenoceptor agonists on gilthead sea bream (Sparus aurata) cultured muscle cells.

ß2-adrenoceptors are a subtype of G-protein coupled receptors whose activation leads to increased protein synthesis and decreased degradation in mammalian skeletal muscle, causing hypertrophy. In this study, we compared the effects of the classical ß2-agonist noradrenaline (NA) with two representatives of a new generation of agonists (formoterol, FOR and salmeterol, SALM) on growth and metabolism of primary cultured muscle cells of gilthead sea bream. Activation of signaling pathways, cell development and expression of relevant genes were analyzed in day 4 myocytes. The three agonists increased either cAMP levels or PKA phosphorylation, plus TOR phosphorylation, and the proportion of proliferating cell nuclear antigen (PCNA)-positive cells, in parallel with pcna mRNA levels. Thus, demonstrating that these cells are ß2-agonists-responsive, and supporting enhanced cell proliferation. The expression of the myogenic factor myf5 was significantly down-regulated, suggesting that the cells were already destined to the muscular linage; while insulin-like growth factors (igf-1 and igf-2) transcript levels were up-regulated, proposing an additional anabolic effect through their local production. Furthermore, SALM treatment up-regulated expression of the lipases (hsl and lipa) and the ß-oxidation marker cpt1a, and all three agonists increased mitochondrial dehydrogenase hadh mRNA levels. These data correspond with a situation of enhanced lipolytic and ß-oxidation capacity, a fact supported by the higher glycerol released into the media induced by the agonists. Overall, these results suggest a hyperplastic growth condition and a favorable protein/fat ratio profile upon these treatments; consequently, ß2-agonists (especially SALM) may be considered good candidates to optimize the growth in this aquaculture species.

A long-term growth hormone treatment stimulates growth and lipolysis in gilthead sea bream juveniles.

The enhancement of the endocrine growth hormone (GH)/insulin-like growth factor I (IGF-I) system by the treatment with a sustained release formulation of a recombinant bovine GH (rBGH), is a good strategy to investigate growth optimization in aquaculture fish species. To further deepen into the knowledge of rBGH effects in fish and to estimate the growth potential of juveniles of gilthead sea bream, the present work evaluated rBGH injection on growth, GH/IGF-I axis and lipid metabolism modulation, and explored the conservation of GH effects provoked by the in vivo treatment using in vitro models of different tissues. The rBGH treatment increased body weight and specific growth rate (SGR) in juveniles and potentiated hyperplastic muscle growth while reducing circulating triglyceride levels. Moreover, the results demonstrated that the in vivo treatment enhanced also lipolysis in both isolated hepatocytes and adipocytes, as well as in day 4 cultured myocytes. Furthermore, these cultured myocytes extracted from rBGH-injected fish presented higher gene expression of GH/IGF-I axis-related molecules and myogenic regulatory factors, as well as stimulated myogenesis (i.e. increased protein expression of a proliferation and a differentiation marker) compared to Control fish-derived cells. These data, suggested that cells in vitro can retain some of the pathways activated by in vivo treatments in fish, what can be considered an interesting line of applied research. Overall, the results showed that rBGH stimulates somatic growth, including specifically muscle hyperplasia, as well as lipolytic activity in gilthead sea bream juveniles.

Recombinant bovine growth hormone (rBGH) enhances somatic growth by regulating the GH-IGF axis in fingerlings of gilthead sea bream (Sparus aurata).

The growth hormone (GH)/insulin-like growth factors (IGFs) endocrine axis is the main growth-regulator system in vertebrates. Some authors have demonstrated the positive effects on growth of a sustained-release formulation of a recombinant bovine GH (rBGH) in different fish species. The aim of this work was to characterize the effects of a single injection of rBGH in fingerlings of gilthead sea bream on growth, GH-IGF axis, and both myogenic and osteogenic processes. Thus, body weight and specific growth rate were significantly increased in rBGH-treated fish respect to control fish at 6weeks post-injection, whereas the hepatosomatic index was decreased and the condition factor and mesenteric fat index were unchanged, altogether indicating enhanced somatic growth. Moreover, rBGH injection increased the plasma IGF-I levels in parallel with a rise of hepatic mRNA from total IGF-I, IGF-Ic and IGF-II, the binding proteins IGFBP-1a and IGFBP-2b, and also the receptors IGF-IRb, GHR-I and GHR-II. In skeletal muscle, the expression of IGF-Ib and GHR-I was significantly increased but that of IGF-IRb was reduced; the mRNA levels of myogenic regulatory factors, proliferation and differentiation markers (PCNA and MHC, respectively), or that of different molecules of the signaling pathway (TOR/AKT) were unaltered. Besides, the growth inhibitor myostatin (MSTN1 and MSTN2) and the hypertrophic marker (MLC2B) expression resulted significantly enhanced, suggesting altogether that the muscle is in a non-proliferative stage of development. Contrarily in bone, although the expression of most molecules of the GH/IGF axis was decreased, the mRNA levels of several osteogenic genes were increased. The histology analysis showed a GH induced lipolytic effect with a clear decrease in the subcutaneous fat layer. Overall, these results reveal that a better growth potential can be achieved on this species and supports the possibility to improve growth and quality through the optimization of its culture conditions.

Identification of non-coding genetic variants in samples from hypoxemic respiratory disease patients that affect the transcriptional response to hypoxia.

A wide range of diseases course with an unbalance between the consumption of oxygen by tissues and its supply. This situation triggers a transcriptional response, mediated by the hypoxia inducible factors (HIFs), that aims to restore oxygen homeostasis. Little is known about the inter-individual variation in this response and its role in the progression of disease. Herein, we sought to identify common genetic variants mapping to hypoxia response elements (HREs) and characterize their effect on transcription. To this end, we constructed a list of genome-wide HIF-binding regions from publicly available experimental datasets and studied the genetic variability in these regions by targeted re-sequencing of genomic samples from 96 chronic obstructive pulmonary disease and 144 obstructive sleep apnea patients. This study identified 14 frequent variants disrupting potential HREs. The analysis of the genomic regions containing these variants by means of reporter assays revealed that variants rs1009329, rs6593210 and rs150921338 impaired the transcriptional response to hypoxia. Finally, using genome editing we confirmed the functional role of rs6593210 in the transcriptional regulation of EGFR. In summary, we found that inter-individual variability in non-coding regions affect the response to hypoxia and could potentially impact on the progression of pulmonary diseases.

Obstructive Sleep Apnea Monocytes Exhibit High Levels of Vascular Endothelial Growth Factor Secretion, Augmenting Tumor Progression.

Obstructive sleep apnea (OSA) is a syndrome characterized by repeated pauses in breathing induced by a partial or complete collapse of the upper airways during sleep. Intermittent hypoxia (IH), a hallmark characteristic of OSA, has been proposed to be a major determinant of cancer development, and patients with OSA are at a higher risk of tumors. Both OSA and healthy monocytes have been found to show enhanced HIF1α expression under IH. Moreover, these cells under IH polarize toward a tumor-promoting phenotype in a HIF1α-dependent manner and influence tumor growth via vascular endothelial growth factor (VEGF). Monocytes from patients with OSA increased the tumor-induced microenvironment and exhibited an impaired cytotoxicity in a 3D tumor in vitro model as a result of the increased HIF1α secretion. Adequate oxygen restoration both in vivo (under continuous positive airway pressure treatment, CPAP) and in vitro leads the monocytes to revert the tumor-promoting phenotype, demonstrating the plasticity of the innate immune system and the oxygen recovery relevance in this context.

De novo lipogenesis in Atlantic salmon adipocytes.

BACKGROUND: Carnivorous teleost fish utilize glucose poorly, and the reason for this is not known. It is possible that the capacity of adipocytes to synthesize lipids from carbohydrate precursors through a process known as "de novo lipogenesis" (DNL) is one of the factors that contributes to glucose intolerance in Atlantic salmon. METHODS: Primary adipocytes from Atlantic salmon differentiated in vitro were incubated with radiolabelled glucose in order to explore the capacity of salmon adipocytes to synthesize and deposit lipids from glucose through DNL. The lipid-storage capacity of adipocytes incubated with glucose was compared with that of cells incubated with the fatty acid palmitic acid. Quantitative PCR and immunohistochemistry were used to assess changes of genes and proteins involved in glucose and lipid transport and metabolism. RESULTS: Less than 0.1% of the radiolabelled glucose was metabolized to the fatty acids 16:0 and the stearoyl-CoA desaturase products 16:1 and 18:1 by DNL, whereas approximately 40% was converted to glycerol to form the triacylglycerol backbone of lipids. Transcriptional analysis indicated that adipocytes ensure the availability of necessary cofactors and other substrates for lipid synthesis and storage from glycolysis, the pentose phosphate pathway and glyceroneogenesis. CONCLUSIONS: We have shown for the first time that the DNL pathway is active in fish adipocytes. The capacity of the pathway to convert glucose into cellular lipids for storage is relatively low. GENERAL SIGNIFICANCE: The limited capacity of adipocytes to utilize glucose as a substrate for lipid deposition may contribute to glucose intolerance in salmonids.

Gene expression profile during proliferation and differentiation of rainbow trout adipocyte precursor cells.

BACKGROUND: Excessive accumulation of adipose tissue in cultured fish is an outstanding problem in aquaculture. To understand the development of adiposity, it is crucial to identify the genes which expression is associated with adipogenic differentiation. Therefore, the transcriptomic profile at different time points (days 3, 8, 15 and 21) along primary culture development of rainbow trout preadipocytes has been investigated using an Agilent trout oligo microarray. RESULTS: Our analysis identified 4026 genes differentially expressed (fold-change >3) that were divided into two major clusters corresponding to the main phases observed during the preadipocyte culture: proliferation and differentiation. Proliferation cluster comprised 1028 genes up-regulated from days 3 to 8 of culture meanwhile the differentiation cluster was characterized by 2140 induced genes from days 15 to 21. Proliferation was characterized by enrichment in genes involved in basic cellular and metabolic processes (transcription, ribosome biogenesis, translation and protein folding), cellular remodelling and autophagy. In addition, the implication of the eicosanoid signalling pathway was highlighted during this phase. On the other hand, the terminal differentiation phase was enriched with genes involved in energy production, lipid and carbohydrate metabolism. Moreover, during this phase an enrichment in genes involved in the formation of the lipid droplets was evidenced as well as the activation of the thyroid-receptor/retinoic X receptor (TR/RXR) and the peroxisome proliferator activated receptors (PPARs) signalling pathways. The whole adipogenic process was driven by a coordinated activation of transcription factors and epigenetic modulators. CONCLUSIONS: Overall, our study demonstrates the coordinated expression of functionally related genes during proliferation and differentiation of rainbow trout adipocyte cells. Furthermore, the information generated will allow future investigations of specific genes involved in particular stages of fish adipogenesis.

The effect of treatment for sleep apnoea on determinants of blood pressure control.

Our aim was to assess the effect of continuous positive airway pressure (CPAP) on the nocturnal evolution of peripheral chemosensitivity, renin-angiotensin-aldosterone system activity, sympathetic tone and endothelial biomarkers in obstructive sleep apnoea (OSA) patients with isolated nocturnal hypertension (INH) or day-night sustained hypertension (D-NSH).In a crossover randomised trial, 32 OSA patients newly diagnosed with hypertension and without antihypertensive treatment were randomly assigned to 12 weeks of CPAP or sham CPAP. Peripheral chemosensitivity was evaluated before and after sleep using the hypoxic withdrawal test (%ΔVI).At baseline, D-NSH patients showed higher %ΔVI before sleep and higher levels of aldosterone and diurnal catecholamines. CPAP only reduced the nocturnal increase of %ΔVI in INH patients (6.9%, 95% CI 1.0-12.8%; p=0.026). CPAP-induced change from baseline in %ΔVI after sleep was 7.5% (95% CI 2.6-12.2%, p=0.005) in the INH group and 5.7% (95% CI 2.2-9.3%, p=0.004) in the D-NSH group. In contrast, %ΔVI before sleep only decreased with CPAP in the D-NSH patients (3.0%, 95% CI 0.5-5.6%; p=0.023).In conclusion, CPAP reduces the nocturnal increase of peripheral chemosensitivity experienced by INH patients and corrects the high daytime sensitivity of patients with D-NSH. Differences in response to CPAP between these patients can help better understand the mechanisms of perpetuation of hypertension in sleep apnoea.

Hypoxia-induced PD-L1/PD-1 crosstalk impairs T-cell function in sleep apnoea.

Obstructive sleep apnoea (OSA) is associated with higher cancer incidence, tumour aggressiveness and cancer mortality, as well as greater severity of infections, which have been attributed to an immune deregulation. We studied the expression of programmed cell death (PD)-1 receptor and its ligand (PD-L1) on immune cells from patients with OSA, and its consequences on immune-suppressing activity. We report that PD-L1 was overexpressed on monocytes and PD-1 was overexpressed on CD8+ T-cells in a severity-dependent manner. PD-L1 and PD-1 overexpression were induced in both the human in vitro and murine models of intermittent hypoxia, as well as by hypoxia-inducible factor-1α transfection. PD-L1/PD-1 crosstalk suppressed T-cell proliferation and activation of autologous T-lymphocytes and impaired the cytotoxic activity of CD8+ T-cells. In addition, monocytes from patients with OSA exhibited high levels of retinoic acid related orphan receptor, which might explain the differentiation of myeloid-derived suppressor cells. Intermittent hypoxia upregulated the PD-L1/PD-1 crosstalk in patients with OSA, resulting in a reduction in CD8+ T-cell activation and cytotoxicity, providing biological plausibility to the increased incidence and aggressiveness of cancer and the higher risk of infections described in these patients.