Dietary docosahexaenoic acid (DHA) downregulates liver DHA synthesis by inhibiting eicosapentaenoic acid elongation.

DHA is abundant in the brain where it regulates cell survival, neurogenesis, and neuroinflammation. DHA can be obtained from the diet or synthesized from alpha-linolenic acid (ALA; 18:3n-3) via a series of desaturation and elongation reactions occurring in the liver. Tracer studies suggest that dietary DHA can downregulate its own synthesis, but the mechanism remains undetermined and is the primary objective of this manuscript. First, we show by tracing 13C content (δ13C) of DHA via compound-specific isotope analysis, that following low dietary DHA, the brain receives DHA synthesized from ALA. We then show that dietary DHA increases mouse liver and serum EPA, which is dependant on ALA. Furthermore, by compound-specific isotope analysis we demonstrate that the source of increased EPA is slowed EPA metabolism, not increased DHA retroconversion as previously assumed. DHA feeding alone or with ALA lowered liver elongation of very long chain (ELOVL2, EPA elongation) enzyme activity despite no change in protein content. To further evaluate the role of ELOVL2, a liver-specific Elovl2 KO was generated showing that DHA feeding in the presence or absence of a functional liver ELOVL2 yields similar results. An enzyme competition assay for EPA elongation suggests both uncompetitive and noncompetitive inhibition by DHA depending on DHA levels. To translate our findings, we show that DHA supplementation in men and women increases EPA levels in a manner dependent on a SNP (rs953413) in the ELOVL2 gene. In conclusion, we identify a novel feedback inhibition pathway where dietary DHA downregulates its liver synthesis by inhibiting EPA elongation.

Growth patterns in infants born to women with pregestational overweight/obesity supplemented with docosahexaenoic acid during pregnancy.

BACKGROUND: Previous studies of maternal docosahexaenoic acid (DHA) supplementation during pregnancy have controversial and contrasting results on the short and long-term effects on early child growth. The impact of this nutritional intervention on the postnatal growth patterns in the offspring of women with pregestational overweight/obesity (PGO) also remains controversial. OBJECTIVE: To analyze the postnatal growth patterns during the first 4 months of life in the offspring of women with PGO randomly supplemented with 800 mg/day (PGO-800) compared with normative doses of 200 mg/day (PGO-200) of DHA during pregnancy (<15 weeks of gestation until delivery). METHODS: This study evaluated the growth patterns during the first 4 months of life of 169 infants of the women that participated in the MIGHT study (NCT02574767). We included the infants of women from the PGO-200 (n = 81) and PGO-800 group (n = 88). The growth patterns (weight, length, and head circumference) and change in z-score (WHO charts) were evaluated. RESULTS: Throughout the first 4 months of life, the infants of the PGO-800 group had lower weight-for-length z-score (coef. -0.65, 95% confidence interval [CI] -1.07, -0.22, p = 0.003) and lower body mass index-for-age z-score (coef. -0.56, 95% CI -0.99, -0.12, p = 0.012) compared with the PGO-200 group adjusted by maternal body mass index, gestational weight gain, gestational age, insulin in cord blood and infant feeding (exclusive breastfed, not breastfed, and partially breastfed). CONCLUSIONS: Maternal supplementation with DHA during pregnancy could beneficially limit the offspring's postnatal weight gain during the first 4 months of life.

Novel 13C enrichment technique reveals early turnover of DHA in peripheral tissues.

The brain is rich in DHA, which plays important roles in regulating neuronal function. Recently, using compound-specific isotope analysis that takes advantage of natural differences in carbon-13 content (13C/12C ratio or δ13C) of the food supply, we determined the brain DHA half-life. However, because of methodological limitations, we were unable to capture DHA turnover rates in peripheral tissues. In the current study, we applied compound-specific isotope analysis via high-precision GC combustion isotope ratio mass spectrometry to determine half-lives of brain, liver, and plasma DHA in mice following a dietary switch experiment. To model DHA tissue turnover rates in peripheral tissues, we added earlier time points within the diet switch study and took advantage of natural variations in the δ13C-DHA of algal and fish DHA sources to maintain DHA pool sizes and used an enriched (uniformly labeled 13C) DHA treatment. Mice were fed a fish-DHA diet (control) for 3 months, then switched to an algal-DHA treatment diet, the 13C enriched-DHA treatment diet, or they stayed on the control diet for the remainder of the study time course. In mice fed the algal and 13C enriched-DHA diets, the brain DHA half-life was 47 and 46 days, the liver half-life was 5.6 and 7.2 days, and the plasma half-life was 4.7 and 6.4 days, respectively. By using improved methodologies, we calculated DHA turnover rates in the liver and plasma, and our study for the first time, by using an enriched DHA source (very high δ13C), validated its utility in diet switch studies.

Omega-3 Lipid Mediators: Modulation of the M1/M2 Macrophage Phenotype and Its Protective Role in Chronic Liver Diseases.

The complex interplay between dietary factors, inflammation, and macrophage polarization is pivotal in the pathogenesis and progression of chronic liver diseases (CLDs). Omega-3 fatty acids (FAs) have brought in attention due to their potential to modulate inflammation and exert protective effects in various pathological conditions. Omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have shown promise in mitigating inflammation and enhancing the resolution of inflammatory responses. They influence the M1/M2 macrophage phenotype balance, promoting a shift towards the M2 anti-inflammatory phenotype. Specialized pro-resolving mediators (SPMs), such as resolvins (Rvs), protectins (PDs), and maresins (MaRs), have emerged as potent regulators of inflammation and macrophage polarization. They show anti-inflammatory and pro-resolving properties, by modulating the expression of cytokines, facilitate the phagocytosis of apoptotic cells, and promote tissue repair. MaR1, in particular, has demonstrated significant hepatoprotective effects by promoting M2 macrophage polarization, reducing oxidative stress, and inhibiting key inflammatory pathways such as NF-κB. In the context of CLDs, such as nonalcoholic fatty liver disease (NAFLD) and cirrhosis, omega-3s and their SPMs have shown promise in attenuating liver injury, promoting tissue regeneration, and modulating macrophage phenotypes. The aim of this article was to analyze the emerging role of omega-3 FAs and their SPMs in the context of macrophage polarization, with special interest in the mechanisms underlying their effects and their interactions with other cell types within the liver microenvironment, focused on CLDs and the development of novel therapeutic strategies.

Microencapsulated pomegranate peel extract induces mitochondrial complex IV activity and prevents mitochondrial cristae alteration in brown adipose tissue in mice fed on a high-fat diet.

Pomegranate peel is an agro-industrial residue obtained after fruit processing with high total polyphenol (TP) content, making it an attractive by-product for its reuse. Pomegranate peel extract (PPE) and its bioactive compounds have shown positive effects on obesity models. Effects on favouring mitochondrial biogenesis and function have also been described. However, once phenolic compounds are extracted, their stability can be affected by diverse factors. Microencapsulation could improve PPE stability, allowing its incorporation into functional foods. Nevertheless, studies on the potential biological effects of PPE microparticles (MPPE) in obesity models are lacking. This study aims to evaluate the effect of MPPE on brown adipose tissue (BAT) mitochondrial structure and function and metabolic alterations related to obesity in mice fed a high-fat diet (HFD). PPE was microencapsulated by spray drying using inulin (IN) as a wall material and physically-chemically characterised. Eight-week-old male C57BL/6J mice (n 40) were randomly distributed into five groups: control diet (CD), HFD, HFD + IN, HFD + PPE (50 mg/kg per d TP) and HFD + MPPE (50 mg/kg per d TP), for 14 weeks. A glucose tolerance test and indirect calorimetry were conducted. Blood and adipose tissue samples were obtained. MPPE supplementation prevented HFD-induced body weight gain (P < 0·001), fasting glycaemia (P = 0·007) and total cholesterol rise (P = 0·001). MPPE resulted in higher BAT mitochondrial complex IV activity (P = 0·03) and prevented HFD-induced mitochondrial cristae alteration (P = 0·02). In conclusion, MPPE prevented HFD-induced excessive body weight gain and associated metabolic disturbances, potentially by activating complex IV activity and preserving mitochondrial cristae structure in BAT in mice fed with a HFD.

[Clinical and epidemiological characteristics of the Philadelphia negative myeloproliferative neoplasms in Chile]. / Características clínicas y epidemiológicas de las neoplasias mieloproliferativas Philadelphia negativas en el sistema público de salud de Chile.

BACKGROUND: Philadelphia-negative myeloproliferative neoplasms (Ph-MPN) are chronic hematological disorders characterized by the overproduction of one or more mature myeloid blood cell lineages. Classical Ph-MPN are polycythemia vera (PV), essential thrombocytopenia (ET) and primary myelofibrosis (PMF). AIM: To assess the epidemiological, clinical and diagnostic characteristics of Ph-MPN in Chile. MATERIAL AND METHODS: Retrospective review of medical records of all patients referred as MPN from 2012 to 2017. Patients with (9;21) translocation were excluded. RESULTS: Data of 462 cases with a median age of 69 years from 10 public hospitals was reviewed. ET was the most frequently Ph-MNP found. The incidence of Ph-MPN was 1.5 x 100.000 cases. The JAK2 V617F mutation study was performed in 96% of patients and only 30% had a bone marrow biopsy. Thrombotic events were observed in 29% of patients. Bleeding events were observed in 7%. Five-year overall survival was 87%. CONCLUSIONS: ET is the most frequent Ph-MPN. The mean incidence was lower than reported in the literature, in part because of a sub diagnosis.

[Clinical and epidemiological characteristics of the Philadelphia negative myeloproliferative neoplasms in Chile]. / Características clínicas y epidemiológicas de las neoplasias mieloproliferativas Philadelphia negativas en el sistema público de salud de Chile.

BACKGROUND: Philadelphia-negative myeloproliferative neoplasms (Ph-MPN) are chronic hematological disorders characterized by the overproduction of one or more mature myeloid blood cell lineages. Classical Ph-MPN are polycythemia vera (PV), essential thrombocytopenia (ET) and primary myelofibrosis (PMF). AIM: To assess the epidemiological, clinical and diagnostic characteristics of Ph-MPN in Chile. MATERIAL AND METHODS: Retrospective review of medical records of all patients referred as MPN from 2012 to 2017. Patients with (9;21) translocation were excluded. RESULTS: Data of 462 cases with a median age of 69 years from 10 public hospitals was reviewed. ET was the most frequently Ph-MNP found. The incidence of Ph-MPN was 1.5 x 100.000 cases. The JAK2 V617F mutation study was performed in 96% of patients and only 30% had a bone marrow biopsy. Thrombotic events were observed in 29% of patients. Bleeding events were observed in 7%. Five-year overall survival was 87%. CONCLUSIONS: ET is the most frequent Ph-MPN. The mean incidence was lower than reported in the literature, in part because of a sub diagnosis.

Protective Effects of Eicosapentaenoic Acid Plus Hydroxytyrosol Supplementation Against White Adipose Tissue Abnormalities in Mice Fed a High-Fat Diet.

OBJECTIVE: Obesity induced by high-fat diet (HFD) elicits white adipose tissue dysfunction. In this study, we have hypothesized that the metabolic modulator eicosapentaenoic acid (EPA) combined with the antioxidant hydroxytyrosol (HT) attenuates HFD-induced white adipose tissue (WAT) alterations. METHODS: C57BL/6J mice were administered with a HFD (60% fat, 20% protein, 20% carbohydrates) or control diet (CD; 10% fat, 20% protein, 70% carbohydrates), with or without EPA (50 mg/kg/day), HT (5 mg/kg/day), or both for 12 weeks. Determinations in WAT include morphological parameters, EPA and docosahexaenoic acid content in phospholipids (gas chromatography), lipogenesis, oxidative stress (OS) and inflammation markers, and gene expression and activities of transcription factors, such as sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor-gamma (PPAR-γ), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) (p65 subunit) and nuclear factor erythroid 2-related factor 2 (Nrf2) (quantitative polymerase chain reaction and enzyme linked immunosorbent assay). RESULTS: HFD led to WAT hypertrophy in relation to PPAR-γ downregulation. WAT metabolic dysfunction was characterized by upregulation of lipogenic SREBP-1c system, mitochondrial energy metabolism depression, loss of the antioxidant Nrf2 signaling with OS enhancement, n-3 long-chain polyunsaturated fatty acids depletion and activation of the pro-inflammatory NF-κB system. EPA and HT co-supplementation diminished HFD-dependent effects additively, reaching values close or similar to controls. CONCLUSION: Data presented strengthen the importance of combined protocols such as EPA plus HT to attenuate metabolic-inflammatory states triggered by obesity.

EPA/DHA Concentrate by Urea Complexation Decreases Hyperinsulinemia and Increases Plin5 in the Liver of Mice Fed a High-Fat Diet.

Dietary intake of eicosapentaenoic/docosahexaenoic acid (EPA/DHA) reduces insulin resistance and hepatic manifestations through the regulation of metabolism in the liver. Obese mice present insulin resistance and lipid accumulation in intracellular lipid droplets (LDs). LD-associated proteins perilipin (Plin) have an essential role in both adipogenesis and lipolysis; Plin5 regulates lipolysis and thus contributes to fat oxidation. The purpose of this study was to compare the effects of deodorized refined salmon oil (DSO) and its polyunsaturated fatty acids concentrate (CPUFA) containing EPA and DHA, obtained by complexing with urea, on obesity-induced metabolic alteration. CPUFA maximum content was determined using the Box-Behnken experimental design based on Surface Response Methodology. The optimized CPUFA was administered to high-fat diet (HFD)-fed mice (200 mg/kg/day of EPA + DHA) for 8 weeks. No significant differences (p > 0.05) in cholesterol, glycemia, LDs or transaminase content were found. Fasting insulin and hepatic Plin5 protein level increased in the group supplemented with the EPA + DHA optimized product (38.35 g/100 g total fatty acids) compared to obese mice without fish oil supplementation. The results suggest that processing salmon oil by urea concentration can generate an EPA+DHA dose useful to prevent the increase of fasting insulin and the decrease of Plin5 in the liver of insulin-resistant mice.

Crosstalk mechanisms in hepatoprotection: Thyroid hormone-docosahexaenoic acid (DHA) and DHA-extra virgin olive oil combined protocols.

Normal liver function includes a number of metabolic processes, secretion of cellular mediators and its role in immunobiology; these require a high energy supply, which is further enhanced under adverse conditions triggering hepatic disorders or injury due to the operation of counteracting mechanisms. Alterations in oxygen availability, such as ischemia-reperfusion (IR) leading to liver inflammation and high-fat diet (HFD)-induced hepatic steatosis, are noxious responses encountered in hepatic surgery and obesity, respectively. Several strategies have been developed to attenuate or prevent these disorders, including thyroid hormone (T3), docosahexaenoic acid (DHA) and extra virgin olive oil (EVOO). These hormetic agents that exert beneficial effects in the low dose range were shown to abrogate IR-induced liver injury effectively in the case of T3, DHA, or their combined administration, whereas DHA plus EVOO attenuate HFD-induced hepatic steatosis, although they can induce adverse effects in other experimental settings. The use of combined hepatoprotective protocols (DHA + T3 or DHA + EVOO) using low doses or reduced supplementation periods is characterized by the stimulation of different types of molecular defensive mechanisms and similar signaling processes that exhibit synergism, thus constituting suitable experimental liver pharmacological preconditioning strategies with possible future clinical applications.

Hydroxytyrosol prevents reduction in liver activity of Δ-5 and Δ-6 desaturases, oxidative stress, and depletion in long chain polyunsaturated fatty acid content in different tissues of high-fat diet fed mice.

BACKGROUND: Eicosapentaenoic acid (EPA, C20:5n-3), docosahexaenoic acid (DHA, C22:6n-3) and arachidonic acid (AA, C20:4n-6) are long-chain polyunsaturated fatty acids (LCPUFAs) with relevant roles in the organism. EPA and DHA are synthesized from the precursor alpha-linolenic acid (ALA, C18:3n-3), whereas AA is produced from linoleic acid (LA, C18:2n-6) through the action of Δ5 and Δ6-desaturases. High-fat diet (HFD) decreases the activity of both desaturases and LCPUFA accretion in liver and other tissues. Hydroxytyrosol (HT), a natural antioxidant, has an important cytoprotective effects in different cells and tissues. METHODS: Male mice C57BL/6 J were fed a control diet (CD) (10% fat, 20% protein, 70% carbohydrates) or a HFD (60% fat, 20% protein, 20% carbohydrates) for 12 weeks. Animals were daily supplemented with saline (CD) or 5 mg HT (HFD), and blood and the studied tissues were analyzed after the HT intervention. Parameters studied included liver histology (optical microscopy), activity of hepatic desaturases 5 and 6 (gas-liquid chromatography of methyl esters derivatives) and antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase by spectrophotometry), oxidative stress indicators (glutathione, thiobarbituric acid reactants, and the antioxidant capacity of plasma), gene expression assays for sterol regulatory element-binding protein 1c (SREBP-1c) (qPCR and ELISA), and LCPUFA profiles in liver, erythrocyte, brain, heart, and testicle (gas-liquid chromatography). RESULTS: HFD led to insulin resistance and liver steatosis associated with SREBP-1c upregulation, with enhancement in plasma and liver oxidative stress status and diminution in the synthesis and storage of n-6 and n-3 LCPUFAs in the studied tissues, compared to animals given control diet. HT supplementation significantly reduced fat accumulation in liver and plasma as well as tissue metabolic alterations induced by HFD. Furthermore, a normalization of desaturase activities, oxidative stress-related parameters, and tissue n-3 LCPUFA content was observed in HT-treated rats over control animals. CONCLUSIONS: HT supplementation prevents metabolic alterations in desaturase activities, oxidative stress status, and n-3 LCPUFA content in the liver and extrahepatic tissues of mice fed HFD.

Hydroxytyrosol and Cytoprotection: A Projection for Clinical Interventions.

Hydroxytyrosol (HT) ((3,4-Dihydroxyphenyl)ethanol) is a polyphenol mainly present in extra virgin olive oil (EVOO) but also in red wine. It has a potent antioxidant effect related to hydrogen donation, and the ability to improve radical stability. The phenolic content of olive oil varies between 100 and 600 mg/kg, due to multiple factors (place of cultivation, climate, variety of the olive and level of ripening at the time of harvest), with HT and its derivatives providing half of that content. When consumed, EVOO's phenolic compounds are hydrolyzed in the stomach and intestine, increasing levels of free HT which is then absorbed in the small intestine, forming phase II metabolites. It has been demonstrated that HT consumption is safe even at high doses, and that is not genotoxic or mutagenic in vitro. The beneficial effects of HT have been studied in humans, as well as cellular and animal models, mostly in relation to consumption of EVOO. Many properties, besides its antioxidant capacity, have been attributed to this polyphenol. The aim of this review was to assess the main properties of HT for human health with emphasis on those related to the possible prevention and/or treatment of non-communicable diseases.

Relevant Aspects of Nutritional and Dietary Interventions in Non-Alcoholic Fatty Liver Disease.

Non-alcoholic fatty liver disease (NAFLD) is the main cause of liver disease worldwide. NAFLD is linked to circumstances such as type 2 diabetes, insulin resistance, obesity, hyperlipidemia, and hypertension. Since the obesity figures and related comorbidities are increasing, NAFLD has turned into a liver problem that has become progressively more common. Currently, there is no effective drug therapy for NAFLD; therefore, interventions in lifestyles remain the first line of treatment. Bearing in mind that adherence rates to this type of treatment are poor, great efforts are currently focused on finding novel therapeutic agents for the prevention in the development of hepatic steatosis and its progression to nonalcoholic steatohepatitis and cirrhosis. This review presents a compilation of the scientific evidence found in the last years showing the results of interventions in lifestyle, diet, and behavioral therapies and research results in human, animal and cell models. Possible therapeutic agents ranging from supplementation with vitamins, amino acids, prebiotics, probiotics, symbiotics, polyunsaturated fatty acids and polyphenols to interventions with medicinal plants are analyzed.

Independent anti-angiogenic capacities of coagulation factors X and Xa.

Knockout models have shown that the coagulation system has a role in vascular development and angiogenesis. Herein, we report for the first time that zymogen FX and its active form (FXa) possess anti-angiogenic properties. Both the recombinant FX and FXa inhibit angiogenesis in vitro using endothelial EA.hy926 and human umbilical cord vascular endothelial cells (HUVEC). This effect is dependent on the Gla domain of FX. We demonstrate that FX and FXa use different mechanisms: the use of Rivaroxaban (RX) a specific inhibitor of FXa attenuated its anti-angiogenic properties but did not modify the anti-angiogenic effect of FX. Furthermore, only the anti-angiogenic activity of FXa is PAR-1dependent. Using in vivo models, we show that FX and FXa are anti-angiogenic in the zebrafish intersegmental vasculature (ISV) formation and in the chick embryo chorioallantoic membrane (CAM) assays. Our results provide further evidence for the non-hemostatic functions of FX and FXa and demonstrate for the first time a biological role for the zymogen FX.

Relevant Aspects of Combined Protocols for Prevention of N(M)AFLD and Other Non-Communicable Diseases.

Obesity is a global health issue characterized by the excessive fat accumulation, leading to an increased risk of chronic noncommunicable diseases (NCDs), including metabolic dysfunction-associated fatty liver disease (MAFLD), which can progress from simple steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, there are no approved pharmacological protocols for prevention/treatment of MAFLD, and due the complexity lying beneath these mechanisms, monotherapies are unlikely to be efficacious. This review article analyzes the possibility that NCDs can be prevented or attenuated by the combination of bioactive substances, as they could promote higher response rates, maximum reaction results, additive or synergistic effects due to compounds having similar or different mechanisms of action and/or refraining possible side effects, related to the use of lower doses and exposures times than monotherapies. Accordingly, prevention of mouse MAFLD is observed with the combination of the omega-3 docosahexaenoic acid with the antioxidant hydroxytyrosol, whereas attenuation of mild cognitive impairment is attained by folic acid plus cobalamin in elderly patients. The existence of several drawbacks underlying published monotherapies or combined trials, opens space for adequate and stricter experimental and clinical tryouts to achieve meaningful outcomes with human applicability.

Protein concentrations and activities of fatty acid desaturase and elongase enzymes in liver, brain, testicle, and kidney from mice: Substrate dependency.

The synthesis rates of n-3 and n-6 polyunsaturated fatty acids (PUFAs) in rodents and humans are not agreed upon and depend on substrate availability independently of the capacity for synthesis. Therefore, we aimed to assess the activities of the enzymes for n-3 and n-6 PUFA synthesis pathways in liver, brain, testicle, kidney, heart, and lung, in relation to their protein concentration levels. Eight-week-old Balb/c mice (n = 8) were fed a standard chow diet (6.2% fat, 18.6% protein, and 44.2% carbohydrates) until 14 weeks of age, anesthetized with isoflurane and tissue samples were collected (previously perfused) and stored at -80°C. The protein concentration of the enzymes (Δ-6D, Δ-5D, Elovl2, and Elovl5) were assessed by ELISA kits; their activities were assayed using specific PUFA precursors and measuring the respective PUFA products as fatty acid methyl esters by gas chromatographic analysis. The liver had the highest capacity for PUFA biosynthesis, with limited activity in the brain, testicles, and kidney, while we failed to detect activity in the heart and lung. The protein concentration and activity of the enzymes were significantly correlated. Furthermore, Δ-6D, Δ-5D, and Elovl2 have a higher affinity for n-3 PUFA precursors compared to n-6 PUFA. The capacity for PUFA synthesis in mice mainly resides in the liver, with enzymes having preference for n-3 PUFAs.

Non-Infectious Uveitis and Pregnancy, is There an Optimal Treatment? Uveitis Course and Safety of Uveitis Treatment in Pregnancy.

In pregnancy, a plethora of factors causes changes in maternal immunity. Uveitis flare-ups are more frequent in the first trimester and in undertreated patients. Management of non-infectious uveitis during pregnancy remains understudied. A bibliographic review to consolidate existing evidence was performed by a multidisciplinary group of Ophthalmologists, Gynaecologists and Rheumatologists. Our group recommends initial management with minimum-required doses of corticosteroids, preferably locally, to treat intraocular inflammation whilst ensuring good neonatal outcomes. If ineffective, clinicians should consider addition of Cyclosporine, Azathioprine or Certolizumab pegol, which are seemingly safe in pregnancy. Other therapies (such as Methotrexate, Mycophenolate Mofetil and alkylating agents) are teratogenic or have a detrimental effect on the foetus. Furthermore, careful multidisciplinary preconception discussions and close follow-up are recommended, monitoring for flare-ups and actively tapering medication doses, with a primary endpoint focused on protecting ocular tissues from inflammation, whilst giving minimal risk of poor pregnancy and foetal outcomes.

High linoleic acid levels in red blood cells predict a poor response to neoadjuvant chemotherapy in human epidermal growth factor receptor type 2-positive breast cancer patients.

OBJECTIVE: Polyunsaturated fatty acids are categorized as ω-3 or ⍵-6. Previous studies demonstrate that breast cancers display a high expression of fatty acid synthase and high fatty acid levels. Our study sought to determine if changes in plasma or red blood cell membrane fatty acid levels were associated with the response to preoperative (neoadjuvant) chemotherapy in non-metastatic breast cancer patients. METHODS: Our prospective study assessed fatty acid levels in plasma and red blood cell membrane. Response to neoadjuvant chemotherapy was evaluated by the presence or absence of pathologic complete response and/or residual cancer burden. RESULTS: A total of 28 patients were included. First, patients who achieved pathologic complete response had significantly higher neutrophil-to-lymphocyte ratio versus no pathologic complete response (P = 0.003). Second, total red blood cell membrane polyunsaturated fatty acids were higher in the absence of pathologic complete response (P = 0.0028). Third, total red blood cell membrane ⍵-6 polyunsaturated fatty acids were also higher in no pathologic complete response (P < 0.01). Among ⍵-6 polyunsaturated fatty acids, red blood cell membrane linoleic acid was higher in the absence of pathologic complete response (P < 0.01). Notably, plasma polyunsaturated fatty acid, ⍵-6, and linoleic acid levels did not have significant differences. A multivariate analysis confirmed red blood cell membrane linoleic acid was associated with no pathologic complete response; this was further confirmed by receiver operating characteristic analysis (specificity = 92.3%, sensitivity = 76.9%, and area under the curve = 0.855). CONCLUSIONS: Pending further validation, red blood cell membrane linoleic acid might serve as a predictor biomarker of poorer response to neoadjuvant chemotherapy in non-metastatic human epidermal growth factor receptor type 2-positive breast cancer. Measuring fatty acids in red blood cell membrane could offer a convenient, minimally invasive strategy to identifying patients more likely to respond or those with chemoresistance.

Insulin-dependent H2O2 production is higher in muscle fibers of mice fed with a high-fat diet.

Insulin resistance is defined as a reduced ability of insulin to stimulate glucose utilization. C57BL/6 mice fed with a high-fat diet (HFD) are a model of insulin resistance. In skeletal muscle, hydrogen peroxide (H2O2) produced by NADPH oxidase 2 (NOX2) is involved in signaling pathways triggered by insulin. We evaluated oxidative status in skeletal muscle fibers from insulin-resistant and control mice by determining H2O2 generation (HyPer probe), reduced-to-oxidized glutathione ratio and NOX2 expression. After eight weeks of HFD, insulin-dependent glucose uptake was impaired in skeletal muscle fibers when compared with control muscle fibers. Insulin-resistant mice showed increased insulin-stimulated H2O2 release and decreased reduced-to-oxidized glutathione ratio (GSH/GSSG). In addition, p47phox and gp91phox (NOX2 subunits) mRNA levels were also high (~3-fold in HFD mice compared to controls), while protein levels were 6.8- and 1.6-fold higher, respectively. Using apocynin (NOX2 inhibitor) during the HFD feeding period, the oxidative intracellular environment was diminished and skeletal muscle insulin-dependent glucose uptake restored. Our results indicate that insulin-resistant mice have increased H2O2 release upon insulin stimulation when compared with control animals, which appears to be mediated by an increase in NOX2 expression.

Prevention of liver steatosis through fish oil supplementation: correlation of oxidative stress with insulin resistance and liver fatty acid content.

Non-alcoholic fatty liver disease (NAFLD) is triggered by a nutritional-metabolic alteration characterized by triacylglicerides acumulation, insulin resistance (IR), oxidative stress and depletion of polyunsaturated fatty acid (PUFA). The n-3 PUFA, such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, would be hepatoprotective against the development of NAFLD by stimulating lipolysis and inhibit lipogenesis. So, fish oil supplementation (EPA + DHA) prevents HFD-induced NAFLD. In this context, the aim of this study is to evaluate the correlation between liver oxidative stress with IR and levels of PUFA in supplemented mice. Male mice C57BL/6J (n = 9) were fed for 12th week: a) control diet (20% protein, 70% carbohydrate, 10% lipids), b) control diet and fish oil supplementation (200 mg EPA+DHA/kg/day), c) high fat diet (20% protein, 20% carbohydrate, 60% lipids), and d) high fat diet and fish oil supplementation. Liver steatosis (histology), insulin resistance (HOMA), liver oxidative stress (GSH/GSSG, carbonyl protein and 8-isoprostanes) and liver fatty acid content were evaluated. The significant decrease in liver oxidative stress parameters (p < 0.05, ANOVA followed by Newman Keuls test) were correlated (Pearson test) with HOMA and levels of PUFA, along with the hepatoprotection observed. It concludes that prevention of NAFLD by supplementation with fish oil (EPA+DHA) is dependent of the prevention of liver oxidative stress, IR and PUFA depletion.