Effects of polyphenols and omega-3 pufas on hepatic oxidative stress

Over the past years it has been described the important role of oxidative stress in the Metabolic Stress related manifestations, specifically in the obesity. It is well known that agents that reduce oxidative stress represent an important tool to reduce the obesity-induced complications such as hepatic steatosis. In this sense, flavonoids are described as antioxidant molecules, due to their scavenging properties. Moreover, omega-3 PUFAs are considered effective in the treatment and prevention of several chronic diseases. Therefore, the principal aim of this thesis was to study the antioxidant effects of flavonoids and n-3 PUFAs, as well as the possible additive effects of two compounds together. These studies were developed under several oxidative stress conditions (metabolic, chemical) both in vitro and in vivo. It has been demonstrated the importance of using nutritional supplements in different oxidative stress conditions.Durant els últims anys s’ha descrit la importància que té l’estrès oxidatiu en les diferents patologies associades al Síndrome Metabòlic, especialment en l’obesitat. Així, agents que redueixen l’estrès oxidatiu son una important eina per reduir les complicacions relacionades amb l’obesitat, incloent la esteatosis hepàtica, definida com l’acumulació de greix al fetge. En aquest sentit, els polifenols, que presenten activitat antioxidant, i els àcids grassos poliinsaturats omega-3 que són considerats efectius en el tractament d’esteatosis hepàtica i en el desenvolupament de malalties cardiovasculars, són una bona eina per combatre aquest estrès oxidatiu. En aquesta tesi, s’ha estudiat en condicions d’estrès oxidatiu tant in vitro (hepatòcits) com in vivo (estat postprandial, estat d’obesitat induïda per la dieta o d’obesitat genètica) els efectes antioxidants dels flavonoides i/o omega-3 tant de manera individual com conjunta. S’ha demostrat la importància d’utilitzar suplements alimentaris en condicions metabòliques d’estrès oxidatiu

Comprehensive Analysis of Nivolumab, A Therapeutic Anti-Pd-1 Monoclonal Antibody: Impact of Handling and Stress

This study was partially funded by Project P20-01029 (I+D+i-Junta de Andalucia, Spain) and by Project B-FQM-308-UGR20 (Universidad de Granada, Proyectos I+D+i del Programa Operativo FEDER Andalucia 2020) which means that it was also partially supported by European Regional Development Funds.Nivolumab, formulated in the medicine Opdivo (R) (10 mg/mL), is a therapeutic monoclonal antibody (mAb) used in the treatment of different types of cancer. Currently, there is insufficient knowledge about the behaviour of this protein with regards to the risk associated with its routine handling or unintentional mishandling, or when subjected to stress conditions in hospitals. These conditions can be simulated in forced degradation studies, which provide an in-depth understanding of the biophysical and biochemical properties of mAbs. In this study, we carried out a physicochemical and functional characterisation of nivolumab, which was subjected to various stress conditions: heat, freeze/thaw cycles, agitation, light exposure and high hypertonic solution. We used a wide range of analytical techniques: Far-UV CD, IT-FS, DLS, SE/UHPLC(UV)-[Native]MS, and ELISA. The results show that exposure to light was the stress test with the greatest impact on the samples, revelling the formation of non-natural dimers and a different isoform profile. In addition, nivolumab (Opdivo (R)) demonstrated stability up to 60 degrees C (1 h). As regards functionality all the nivolumab (Opdivo (R)) stressed samples were found to be stable except for those subjected to light and agitation, and to a lesser extent, those subjected to FTC 5 and NaCl stresses.I+D+i-Junta de Andalucia, Spain P20-01029European Commission B-FQM-308-UGR2

Combined use of UV and MS data for ICH Stability-Indication Method: Quantification and isoforms identification of intact nivolumab

Nivolumab (Opdivo®) is a fully human immunoglobulin G4 isotype approved for the treatment of many cancers. It acts as an immune checkpoint inhibitor by blocking the interaction between PD-1 (Programmed Cell Death Protein 1) – an inhibitory receptor expressed on activated T cells- and its ligands, PD-L1 and PD-L2. The quantification of therapeutic proteins in their medicines and pharmaceutical preparations remains challenging because the protein content, a critical quality attribute, must be rigorously calculated using a validated stabilityindicating method, such as that indicated by the International Conference on Harmonization (ICH) quality guidelines, and this requires the analysis of the drug in the presence of its degraded products. In this work, we present an strategy based on the combined use of the UV and MS data to full file the requirement of the ICH-Q2 (R1) to develop and validated as stability indicated a (RP)UHPLC/UV-(HESI/Orbitrap™)MS method for the quantification of nivolumab in medicinal products. A comparative study of all figures of merit of the method using UV or MS data are shown and discussed. The results show that linearity was similar for the two detectors and was established over a range of 4–45 μg/mL and 1–45 μg/mL for the UV and (HESI/Orbitrap™)MS signals, respectively. The sensitivity of the method was higher when using the (HESI/Orbitrap™)MS signal (0.2 μg/mL) than with the UV(2.0 μg/mL). However, the UV signal provided better accuracy and precision than the (HESI/ Orbitrap™)MS signal, which did not meet the criteria for method robustness and system suitability. In spite of this, the MS signal plays a crucial role in this methodology by obtaining the molecular weight profile of the nivolumab isoforms, so enabling us to propose the glycans profile and detect structural modification due to degradation. The specificity of the method was evaluated by conducting forced degradation tests on samples of nivolumab in medicine form. The aim was to find out whether nivolumab suffers structural modifications when subject to stress. Structural modifications were detected by analysing the MS isoform profile, as changes of this kind promote new isoforms that are not chromatographically separated or detected by the UV signal. In this way, we demonstrated that the (RP)UHPLC/UV-(HESI/Orbitrap™)MS method was capable of detecting nivolumab degradation, and was suitable for use in nivolumab stability studies. Thus, the protein content in the daily surplus of the Opdivo® medicine, stored either at room temperature (20 ◦C) or refrigerated at 4 ◦C, could be tracked for 15 days.FPU18/03131 Ministry of Universities, Spain(P20_01029) Junta de Andalucía (Spain) and European Regional Development Fundspostdoctoral position from the Junta de Andalucía, SpainProject P20-01029 (I + D + i - Junta de Andalucía, Spain) Project B-FQM-308-UGR20 (Universidad de Granada, Proyectos I + D + i del Programa Operativo FEDER Andalucía 2020)CBUA/ Universidad de Granad

Improved hemodynamic and liver function in portal hypertensive cirrhotic rats after administration of B. pseudocatenulatum CECT 7765

Purpose: Evaluating whether changes in gut microbiota induced by a bifidobacterial strain may have an effect on the hepatic vascular function in portal hypertensive cirrhotic rats.Methods: Bile duct ligation (BDL) was performed in rats. A subgroup of animals received B. pseudocatenulatum CECT7765 (109 cfu/daily ig.) for 1 week prior to laparotomy. Hemodynamic, biochemical and inflammatory markers were evaluated. Ileal microbiota composition was identified. Statistical analysis was performed.Results: Sham-operated (n = 6), BDL (n = 6) and BDL treated with bifidobacteria (n = 8) rats were included. B. pseudocatenulatum CECT7765 significantly decreased proteobacteria (p = 0.001) and increased Bacteroidetes (p = 0.001) relative abundance. The bifidobacteria decreased the Firmicutes/Bacteroidetes ratio in the BDL model (p = 0.03). BDL with bifidobacteria vs BDL rats showed: significantly reduced portal vein area, portal flow, congestion index, alkaline phosphatase and total bilirubin, significantly increased serum cytokines and nitric oxide levels, gene expression levels of bile acids receptor FXR and endothelial nitric oxide synthase. Quantitative changes in the Clostridiales and Bacteroidales orders were independently associated with variations in portal vein area and portal flow, while changes in the Proteobacteria phylum were independently associated with congestion. Variations in all liver function markers significantly correlated with total OTUs mainly in the Firmicutes, but only changes in the Clostridiales were independently associated with alkaline phosphatase in the ANCOVA analysis.Conclusion: Hemodynamic alterations and liver dysfunction induced by BDL in rats are partially restored after oral administration of B. pseudocatenulatum CECT7765. Results provide a proof-of-concept for the beneficial effect of this bifidobacterial strain in reducing complications derived from portal hypertension in cirrhosis

Ischemia/reperfusion injury in the aged liver: The importance of the sinusoidal endothelium in developing therapeutic strategies for the elderly.

The liver endothelium plays a key role in the progression and resolution of liver diseases in young and adult individuals. However, its role in older people remains unknown. We have herein evaluated the importance of the sinusoidal endothelium in the pathophysiology of acute liver injury, and investigated the applicability of simvastatin, in aged animals.18 months old male Wistar rats underwent 60 min of partial warm ischemia followed by 2h of reperfusion (WIR). A group of aged rats received simvastatin for 3 days before WIR. Endothelial phenotype, parenchymal injury, oxidative and nitrosative stress, and fenestrae dynamics were analysed. The effects of WIR and simvastatin were investigated in primary LSEC from aged animals.The results of this study demonstrated that WIR significantly damages the liver endothelium and its effects are markedly worse in old animals. WIR-aged livers exhibited reduced vasodilation and sinusoidal capillarization, associated with liver damage and cellular stress. Simvastatin prevented the detrimental effects of WIR in aged livers.In conclusion, the liver sinusoidal endothelium of old animals is highly vulnerable to acute insult, thus targeted protection is especially relevant in preventing liver damage. Simvastatin represents a useful therapeutic strategy in aging

Resemblance of the human liver sinusoid in a fluidic device with biomedical and pharmaceutical applications

Maintenance of the complex phenotype of primary hepatocytes in vitro represents a limitation for developing liver support systems and reliable tools for biomedical research and drug screening. We herein aimed at developing a biosystem able to preserve human and rodent hepatocytes phenotype in vitro based on the main characteristics of the liver sinusoid: unique cellular architecture, endothelial biodynamic stimulation, and parenchymal zonation. Primary hepatocytes and liver sinusoidal endothelial cells (LSEC) were isolated from control and cirrhotic human or control rat livers and cultured in conventional in vitro platforms or within our liver-resembling device. Hepatocytes phenotype, function, and response to hepatotoxic drugs were analyzed. Results evidenced that mimicking the in vivo sinusoidal environment within our biosystem, primary human and rat hepatocytes cocultured with functional LSEC maintained morphology and showed high albumin and urea production, enhanced cytochrome P450 family 3 subfamily A member 4 (CYP3A4) activity, and maintained expression of hepatocyte nuclear factor 4 alpha (hnf4α) and transporters, showing delayed hepatocyte dedifferentiation. In addition, differentiated hepatocytes cultured within this liver-resembling device responded to acute treatment with known hepatotoxic drugs significantly different from those seen in conventional culture platforms. In conclusion, this study describes a new bioengineered device that mimics the human sinusoid in vitro, representing a novel method to study liver diseases and toxicology

A Nutraceutical Rich in Docosahexaenoic Acid Improves Portal Hypertension in a Preclinical Model of Advanced Chronic Liver Disease

Inflammation and oxidative stress play a key role in the pathophysiology of advanced chronic liver disease (ACLD) and portal hypertension (PH). Considering the current lack of effective treatments, we evaluated an anti-inflammatory and antioxidant nutraceutical rich in docosahexaenoic acid (DHA) as a possible therapy for ACLD. We investigated the effects of two-week DHA supplementation (500 mg/kg) on hepatic fatty acids, PH, oxidative stress, inflammation, and hepatic stellate cell (HSC) phenotype in rats with ACLD. Additionally, the effects of DHA were evaluated in murine macrophages and human HSC. In contrast to vehicle-treated animals, cirrhotic rats receiving DHA reestablished a healthy hepatic fatty acid profile, which was associated with an improvement in PH. The mechanisms underlying this hemodynamic improvement included a reduction in oxidative stress and inflammation, as well as a marked HSC deactivation, confirmed in human HSC. Experiments with cultured macrophages showed that treatment with DHA protects against pro-inflammatory insults. The present preclinical study demonstrates that a nutraceutical rich in DHA significantly improves PH in chronic liver disease mainly by suppressing inflammation and oxidative stress-driven HSC activation, encouraging its evaluation as a new treatment for PH and cirrhosis

Cirrhosis-downregulated LSECtin can be retrieved by cytokines, shifts the TLR-induced LSECs secretome and correlates with the hepatic Th response

[Background and aims]: We evaluated tolerogenic C-type lectin LSECtin loss in cirrhosis and its potential regulation by cytokines.[Methods]: Liver tissue from patients with cirrhosis and healthy controls, immortalised and generated LSECtin-CRISPR immortalised LSECs, and murine primary LSECs from the CCl4 model were handled.[Results]: LSECtin expression was reduced in liver tissue from cirrhotic patients, and it decreased from compensated to decompensated disease. Increased phosphorylation of MAPK, Akt and NFkB was observed upon LSECtin stimulation in LSEC murine cell line, showing a pattern of inflammatory and chemotactic cytokines either restrained (IL-10, CCL4) or unrestrained (TNF-α, IL-1β, IL-6, CCL2). CD44 attenuated whereas LAG-3 increased all substrates phosphorylation in combination with TLR4 and TLR2 ligands except for NFkB. TNF-α, IL-1 β, IL-6 and CCL2 were restrained by LSECtin crosslinking on TLRs studied. Conversely, IL-10 and CCL4 were upregulated, suggesting a LSECtin-TLRs synergistic effect. Also, LSECtin was significantly induced after IL-13 stimulation or combined with anti-inflammatory cytokines in cirrhotic and immortalised LSECs. Th17 and regulatory T cells were progressively increased in the hepatic tissue from compensated to decompensated patients. A significant inverse correlation was present between gene expression levels of CLEC4G/LSECtin and RORγT and FOXP3 in liver tissues.[Conclusion]: LSECtin restrains TLR proinflammatory secretome induced on LSECs by interfering immune response control, survival and MAPKs signalling pathways. The cytokine-dependent induction of LSECtin and the association between LSECtin loss and Th17 cell subset expansion in the liver, provides a solid background for exploring LSECtin retrieval as a mechanism to reprogram LSEC homeostatic function hampered during cirrhosis.This work was supported by grants from the Ministerio de Ciencia e Innovación PID2019-107036RB-I00 and PID2020-117941RB-I00, Instituto de Salud Carlos III PMP21/0082, PI20/00220 and DTS22/00010, EU Horizon-HLTH-2022-STAYHLTH-02 under agreement No. 101095679, Generalitat Valenciana Prometeo 2021/033, Comunidad de Madrid ExoHep2 S2022/BMD-7409 and AGAUR-Generalitat Catalunya (2021 SGR 01322 and 2021 PROD 00036). CIBEREHD is funded by the Instituto de Salud Carlos III using grants cofinanced by the European Development Regional Fund “A way to achieve Europe” (EDRF).Peer reviewe