Accumulation Of Fatty Acids Research Articles

Spectral fingerprinting of cellular lipid droplets using stimulated Raman scattering microscopy and chemometric analysis.

Hyperspectral stimulated Raman scattering (SRS) microscopy is a powerful method for direct visualisation and compositional analysis of cellular lipid droplets. Here we report the application of spectral phasor analysis as a convenient method for the segmentation of lipid droplets using the hyperspectral SRS spectrum in the high wavenumber and fingerprint region of the spectrum. Spectral phasor analysis was shown to discriminate six fatty acids based on vibrational spectroscopic features in solution. The methodology was then applied to studying fatty acid metabolism and storage in a mammalian cancer cell model and during drug-induced steatosis in a hepatocellular carcinoma cell model. The accumulation of fatty acids into cellular lipid droplets was shown to vary as a function of the degree of unsaturation, whilst in a model of drug-induced steatosis, the detection of increased saturated fatty acid esters was observed. Taking advantage of the fingerprint and high wavenumber regions of the SRS spectrum has yielded a greater insight into lipid droplet composition in a cellular context. This approach will find application in the label-free profiling of intracellular lipids in complex disease models.

3D microscaffolds with triple-marker sensitive nanoprobes for studying fatty liver disease in vitro.

Non-alcoholic fatty liver disease (NAFLD) is a heterogeneous condition that encompasses a wide range of liver diseases that progresses from simple hepatic steatosis to the life-threatening state of cirrhosis. However, due to the heterogeneity of this disease, comprehensive analysis of several physicochemical and biological factors that drive its progression is necessary. Therefore, an in vitro platform is required that would enable real-time monitoring of these changes to better understand the progression of these diseases. The earliest stage of NAFLD, i.e. hepatic steatosis, is characterised by triglyceride accumulation in the form of lipid vacuoles in the cytosol of hepatocytes. This fatty acid accumulation is usually accompanied by hepatic inflammation, leading to tissue acidification and dysregulated expression of certain proteases such as matrix metalloproteinases (MMPs). Taking cues from the biological parameters of the disease, we report here a 3D in vitro GelMA/alginate microscaffold platform encapsulating a triple-marker (pH, MMP-3 and MMP-9) sensitive fluorescent nanoprobe for monitoring, and hence, distinguishing the fatty liver disease (hepatic steatosis) from healthy livers on the basis of pH change and MMP expression. The nanoprobe consists of a carbon nanoparticle (CNP) core, which exhibits intrinsic pH-dependent fluorescence properties, decorated either with an MMP-3 (NpMMP3) or MMP-9 (NpMMP9) sensitive peptide substrate. These peptide substrates are flanked with a fluorophore-quencher pair that separates on enzymatic cleavage, resulting in fluorescence emission. The cocktail of these nanoprobes generated multiple fluorescence signals corresponding to slightly acidic pH (blue) and overexpression of MMP-3 (green) and MMP-9 (red) enzymes in a 3D in vitro fatty liver model, whereas no/negligible fluorescence signals were observed in a healthy liver model. Moreover, this platform enabled us to mimic fatty liver disease in a more realistic manner. Therefore, this 3D in vitro platform encapsulating triple-marker sensitive fluorescent nanoprobes would facilitate the monitoring of the changes in pH and MMP expression, thereby enabling us to distinguish a healthy liver from a diseased liver and to study liver disease stages on the basis of these markers.

A case of primary adrenal insufficiency unfolding itself as a genetic syndrome

ABSTRACT Addison disease can occur at any age but most often presents during the second or third decades of life. An 11-year-old male child presented to us with complaints of pigmentation of the skin, decreased appetite, and weight loss from the last 1 year. He also had visual disturbances and learning disabilities from last 6 months. Investigations revealed the diagnosis of adrenal insufficiency and neuroimaging done was suggestive of diffuse demyelination. For further confirmation, a blood sample was sent for determination of very long chain fatty acids, which revealed accumulation of C26 fatty acids, thus confirming the diagnosis of adrenoleukodystrophy. He was treated with hydrocortisone, fludrocortisone, and anti-oxidants and was referred for bone marrow transplantation. X-linked adrenoleukodystrophy is a genetic disease, so a high index of suspicion is required to diagnose it in cases presenting primarily with non-neurological symptoms.

The identification and expression analysis of walnut Acyl-ACP thioesterases.

Walnuts (Juglans regia L.), renowned for their nutritional potency, are a rich source of unsaturated fatty acids. Their regular intake plays a pivotal role in health maintenance and recuperation from a myriad of ailments. Fatty acyl-acyl carrier protein thioesterases, which orchestrate the hydrolysis of acyl-ACP thioester bonds, thereby yielding fatty acids of varying chain lengths, are instrumental in augmenting plant fatty acid content and modulating the balance between saturated and unsaturated fatty acids. Despite some investigative efforts into the synthesis and metabolic pathways of fatty acids in walnuts, our comprehension of Fat in walnuts remains rudimentary. This research undertook a comprehensive characterization of the JrFat family, predicated on the complete genome sequence of walnuts, leading to the identification of 8 JrFat genes and an exploration of their protein physicochemical properties. Utilizing Arabidopsis and soybean Fat genes as outgroups, JrFat genes can be categorized into 5 distinct subgroups, three of which encompass a pair of homologous gene pairs. These genes have demonstrated remarkable conservation throughout the evolutionary process, with highly analogous conserved base sequences. The promoter region of JrFats genes predominantly harbors light response and plant hormone response regulatory elements, with no discernible disparity in promoter elements among different JrFats. Predictive analyses indicate that JrFats proteins engage extensively with walnut fatty acid synthesis and metabolism-associated proteins. qRT-PCR analysis reveals an initial surge in the expression of JrFats during the development of walnut kernels, which either stabilizes or diminishes following the hard core period. Homologous gene pairs exhibit analogous expression patterns, and the expression trajectory of JrFats aligns with the dynamic accumulation of fatty acids in kernels. The expression of JrFatA2 exhibits a strong correlation with the content of Alpha-linolenic acid, while the expression of JrFatB2 is inversely correlated with the content of two saturated fatty acids. Collectively, these findings enrich our understanding of fatty acid synthesis and metabolism in walnuts and furnish gene resources for enhancing the content and ratio of fatty acids in walnuts.

Effects of different dietary lipid levels on physiological metabolism and odor quality of hepatopancreas in adult female Chinese mitten crab (Eriocheir sinensis)

Abstract Objectives This study aimed to investigate the impact of different dietary lipid levels on the physiological metabolism and odor quality of adult female Eriocheir sinensis during the fattening phase. Materials and Methods Five dietary schemes, each containing different total lipid levels (4%, 7%, 10%, 13%, and 16%), were administered over a 60-d fattening period for adult female crab (approximately 50 g, n=60). Chromatography and spectroscopy techniques were used for the detection of aroma and key aroma precursors. Results Dietary lipids had no significant effect on growth performance and hepatopancreas index (P<0.05). The carotenoid content showed an increasing and then decreasing trend, with a significant increase to 1312.51 mg/kg (P<0.05) at 7% lipid content of the diet. In contrast, a diet with a 13% lipid level led to a significant increase in total unsaturated fatty acids (115.3 mg/g, P<0.05), which maximized the contents of major fatty acids (oleic, linoleic, and linolenic, among others), and presented a fluctuating trend. A diet with higher lipid levels (16%) inhibited fatty acid accumulation. Moreover, a 13% dietary lipid level enhanced characteristic aroma compounds (for example, nonanal, octanal, hexanal, 3-methylbutanal, and 2-heptanone) in E. sinensis cooked hepatopancreas. Through an orthogonal partial least squares discriminant analysis model, it becomes evident that lipids and carotenoids together promote aroma formation in hepatopancreas. Conclusions Based on the current findings, the optimal dietary lipid level for enhancing the odor quality of hepatopancreas in adult female E. sinensis during the fattening phase was 13%. This study provides more precise options for the high-quality cultivation of E. sinensis.

Use of thistle seeds of modified composition in chocolate mass technology

The object of the study is the analytical values of lipids of milk thistle seeds of a modified composition, namely acid and peroxide values, as well as the induction period of lipids of chocolate mass with the addition of milk thistle seeds. The paper substantiates rational parameters of thistle seed processing for the inactivation of lipases and lipoxygenases. Approximate dependences of the acid and peroxide values of thistle seed lipids on the pH of the wetting solution and the wetting degree of seeds were obtained. This makes it possible to substantiate such rational processing parameters of thistle seeds that inhibit the accumulation of free fatty acids and primary oxidation products in seeds during storage. An increase in the induction period of the oxidation of the lipid component of the chocolate mass with the use of thistle seeds of a modified composition was proven, which is 2.5 times higher than the induction period of the chocolate mass sample with thistle seeds with a native enzyme complex. The research results make it possible to develop a technology of healthy chocolate mass using thistle seeds of a modified composition, the lipid component of such mass is stable to oxidation and hydrolysis. The data obtained in the work are explained by an increase in the ability to inactivate lipolytic and lipoxygenase enzymes of milk thistle at high humidity in an acidic environment under the influence of microwave radiation. The advantage of the obtained results is the possibility of not violating the integrity of thistle seeds during the inactivation of the enzyme complex, which allows extending the shelf life of this raw material. An applied aspect of using the scientific result is the possibility of expanding the range of healthy chocolate masses with the use of thistle seeds

Enhancing anaerobic digestion performance of oxytetracycline-laden wastewater through micro-nano bubble ozonation pretreatment

This study investigated the potential of micro-nano bubble (MNB) ozonation pretreatment to eliminate oxytetracycline (OTC) from wastewater and improve subsequent anaerobic digestion (AD) performance. The findings revealed that MNB ozonation achieved efficient OTC oxidation (>99 % in 60 min), and significantly enhanced methane production by 51 % compared to conventional ozonation (under 30 min of pretreatment). Additionally, MNB ozonation resulted in a decrease in the soluble chemical oxygen demand and reduced volatile fatty acid accumulation compared to conventional ozonation. Furthermore, the study sheds light on the profound impact of OTC and its oxidation by-products on the sludge microbiome. Exposure to OTC and its oxidation by-products resulted in alterations in extracellular polymeric substances composition and led to significant shifts in microbial community structure. This study highlights the promise of MNB ozonation as an effective approach for pharmaceutical pollutant removal and the optimization of AD performance in wastewater treatment, with implications for improved environmental sustainability.

Immune response of BV-2 microglial cells is impacted by peroxisomal beta-oxidation.

Microglia are crucial for brain homeostasis, and dysfunction of these cells is a key driver in most neurodegenerative diseases, including peroxisomal leukodystrophies. In X-linked adrenoleukodystrophy (X-ALD), a neuroinflammatory disorder, very long-chain fatty acid (VLCFA) accumulation due to impaired degradation within peroxisomes results in microglial defects, but the underlying mechanisms remain unclear. Using CRISPR/Cas9 gene editing of key genes in peroxisomal VLCFA breakdown (Abcd1, Abcd2, and Acox1), we recently established easily accessible microglial BV-2 cell models to study the impact of dysfunctional peroxisomal β-oxidation and revealed a disease-associated microglial-like signature in these cell lines. Transcriptomic analysis suggested consequences on the immune response. To clarify how impaired lipid degradation impacts the immune function of microglia, we here used RNA-sequencing and functional assays related to the immune response to compare wild-type and mutant BV-2 cell lines under basal conditions and upon pro-inflammatory lipopolysaccharide (LPS) activation. A majority of genes encoding proinflammatory cytokines, as well as genes involved in phagocytosis, antigen presentation, and co-stimulation of T lymphocytes, were found differentially overexpressed. The transcriptomic alterations were reflected by altered phagocytic capacity, inflammasome activation, increased release of inflammatory cytokines, including TNF, and upregulated response of T lymphocytes primed by mutant BV-2 cells presenting peptides. Together, the present study shows that peroxisomal β-oxidation defects resulting in lipid alterations, including VLCFA accumulation, directly reprogram the main cellular functions of microglia. The elucidation of this link between lipid metabolism and the immune response of microglia will help to better understand the pathogenesis of peroxisomal leukodystrophies.

Restoring the Stability of Long-Term Operated Thermophilic Anaerobic Digestion of Maize Straw by Supplying Trace Elements

Maize straw has been widely used for the production of energy through anaerobic digestion, but biogas production can be hindered by a lack of trace elemental nutrients. To address this issue, a lab-scale anaerobic plug flow reactor was continuously operated at 55 °C for 300 days, with a hydraulic retention time of 42 days and an organic loading rate of 2.1 g total solids/(L·day). Results from this study showed that between days 101 and 194, the methane yield slightly decreased from 0.26 ± 0.04 to 0.24 ± 0.03 L/g volatile solids (VS), but significant volatile fatty acid accumulation was observed by reaching up to 2759 ± 261 mg/L. After trace elements were added to the reactor, the methane yield increased to 0.30 ± 0.03 L/g VS, with 53% methane content. Around 62% of the total chemical oxygen demand and volatile solids were broken down into methane. Volatile fatty acid levels dropped and stabilized at around 210 ± 50 mg/L, indicating restored process stability. The addition of trace elements increased the abundance of Firmicutes and decreased Synergistetes in bacteria while simultaneously increasing the abundance of Methanosarcina in archaea. In conclusion, trace element supplementation was experimentally found to be necessary for stable thermophilic anaerobic digestion of maize straw.

Tuning Fatty Acid Profile and Yield in Pichia pastoris.

Fatty acids have been supplied for diverse non-food, industrial applications from plant oils and animal fats for many decades. Due to the massively increasing world population demanding a nutritious diet and the thrive to provide feedstocks for industrial production lines in a sustainable way, i.e., independent from food supply chains, alternative fatty acid sources have massively gained in importance. Carbohydrate-rich side-streams of agricultural production, e.g., molasses, lignocellulosic waste, glycerol from biodiesel production, and even CO2, are considered and employed as carbon sources for the fermentative accumulation of fatty acids in selected microbial hosts. While certain fatty acid species are readily accumulated in native microbial metabolic routes, other fatty acid species are scarce, and host strains need to be metabolically engineered for their high-level production. We report the metabolic engineering of Pichia pastoris to produce palmitoleic acid from glucose and discuss the beneficial and detrimental engineering steps in detail. Fatty acid secretion was achieved through the deletion of fatty acyl-CoA synthetases and overexpression of the truncated E. coli thioesterase 'TesA. The best strains secreted >1 g/L free fatty acids into the culture medium. Additionally, the introduction of C16-specific ∆9-desaturases and fatty acid synthases, coupled with improved cultivation conditions, increased the palmitoleic acid content from 5.5% to 22%.

Adipsin inhibits Irak2 mitochondrial translocation and improves fatty acid β-oxidation to alleviate diabetic cardiomyopathy

BackgroundDiabetic cardiomyopathy (DCM) causes the myocardium to rely on fatty acid β-oxidation for energy. The accumulation of intracellular lipids and fatty acids in the myocardium usually results in lipotoxicity, which impairs myocardial function. Adipsin may play an important protective role in the pathogenesis of DCM. The aim of this study is to investigate the regulatory effect of Adipsin on DCM lipotoxicity and its molecular mechanism.MethodsA high-fat diet (HFD)-induced type 2 diabetes mellitus model was constructed in mice with adipose tissue-specific overexpression of Adipsin (Adipsin-Tg). Liquid chromatography-tandem mass spectrometry (LC–MS/MS), glutathione-S-transferase (GST) pull-down technique, Co-immunoprecipitation (Co-IP) and immunofluorescence colocalization analyses were used to investigate the molecules which can directly interact with Adipsin. The immunocolloidal gold method was also used to detect the interaction between Adipsin and its downstream modulator.ResultsThe expression of Adipsin was significantly downregulated in the HFD-induced DCM model (P < 0.05). Adipose tissue-specific overexpression of Adipsin significantly improved cardiac function and alleviated cardiac remodeling in DCM (P < 0.05). Adipsin overexpression also alleviated mitochondrial oxidative phosphorylation function in diabetic stress (P < 0.05). LC–MS/MS analysis, GST pull-down technique and Co-IP studies revealed that interleukin-1 receptor-associated kinase-like 2 (Irak2) was a downstream regulator of Adipsin. Immunofluorescence analysis also revealed that Adipsin was co-localized with Irak2 in cardiomyocytes. Immunocolloidal gold electron microscopy and Western blotting analysis indicated that Adipsin inhibited the mitochondrial translocation of Irak2 in DCM, thus dampening the interaction between Irak2 and prohibitin (Phb)-optic atrophy protein 1 (Opa1) on mitochondria and improving the structural integrity and function of mitochondria (P < 0.05). Interestingly, in the presence of Irak2 knockdown, Adipsin overexpression did not further alleviate myocardial mitochondrial destruction and cardiac dysfunction, suggesting a downstream role of Irak2 in Adipsin-induced responses (P < 0.05). Consistent with these findings, overexpression of Adipsin after Irak2 knockdown did not further reduce the accumulation of lipids and their metabolites in the cardiac myocardium, nor did it enhance the oxidation capacity of cardiomyocytes expose to palmitate (PA) (P < 0.05). These results indicated that Irak2 may be a downstream regulator of Adipsin.ConclusionsAdipsin improves fatty acid β-oxidation and alleviates mitochondrial injury in DCM. The mechanism is related to Irak2 interaction and inhibition of Irak2 mitochondrial translocation.

Sex hormone-binding globulin improves lipid metabolism and reduces inflammation in subcutaneous adipose tissue of metabolic syndrome-affected horses.

Equine metabolic syndrome (EMS) is a steadily growing endocrine disorder representing a real challenge in veterinary practice. As a multifactorial condition, EMS is characterized by three main metabolic abnormalities including insulin resistance, increased adiposity or obesity and hoof laminitis. Adipose tissue dysfunction is recognized as a core pathophysiological determinant of EMS, as it strongly participates to lipotoxicity and systemic metaflammation, both of which have been closely linked to the development of generalized insulin resistance. Besides, sex hormone binding globulin (SHBG) is an important sex steroids transporters that has been recently proposed as an important metabolic mediator. Therefore, the aim of this study was to verify whether SHBG treatment may ameliorate subcutaneous adipose tissue metabolic failure under EMS condition in terms of lipidome homeostasis, lipid metabolism programs, insulin signalling and local inflammation. Subcutaneous adipose tissue (SAT) biopsies were collected post-mortem from healthy (n = 3) and EMS (n = 3) slaughtered horses. SHBG protein has been applied to SAT samples from EMS horses for 24h at a final concentration of 50nM, while control groups (healthy and untreated EMS) were cultured in the presence of SHBG-vehicle only. Tissues from all groups were afterwards secured for downstream analysis of gene expression using RT-qPCR, protein levels by Western blot and ELISA assay and lipidomics through GC-MS technique. Obtained results showcased that SHBG intervention efficiently normalized the altered fatty acids (FAs) profiles by lowering the accumulation of saturated and trans FAs, as well as the pro-inflammatory arachidonic and linoleic acids. Moreover, SHBG showed promising value for the regulation of adipocyte lipolysis and engorgement by lowering the levels of perilipin-1. SHBG exerted moderated effect toward SCD1 and FASN enzymes expression, but increased the LPL abundance. Interestingly, SHBG exhibited a negative regulatory effect on pro-adipogenic stimulators and induced higher expression of KLF3, IRF3 and β-catenin, known as strong adipogenesis repressors. Finally, SHBG protein showed remarkable ability in restoring the insulin signal transduction, IR/IRS/Pi3K/AKT phosphorylation events and GLUT4 transporter abundance, and further attenuate pro-inflammatory response by lowering IL-6 tissue levels and targeting the PDIA3/ERK axis. Overall, the obtained data clearly demonstrate the benefice of SHBG treatment in the regulation of adipose tissue metabolism in the course of EMS and provide new insights for the development of molecular therapies with potential translational application to human metabolic disorders.

Using landfill leachate to indicate the chemical and biochemical activities in elevated temperature landfills

Landfill leachate properties contain important information and can be a unique indicator for the chemical and biochemical activities in landfills. In the recent decade, more landfills are experiencing elevated temperature, causing an imbalance in the decomposition of solid waste and affecting the properties of the landfill leachate. This study analyzes the properties of leachate from two landfills that were experiencing elevated temperature (ETLFs), samples were collected from both elevated temperature impacted and non-impacted areas in each landfill. The accumulation of volatile fatty acids (VFA) in leachates from elevated temperature impacted areas of both landfill sites revealed that methanogenesis was inhibited by the elevated temperature, which was further confirmed by the more acidic pH, higher H/C elemental ratio, and lower degree of aromaticity of the elevated temperature impacted leachates. Also, carbohydrates depletion indicated possible enhancement of hydrolysis and acidogenesis by elevated temperature, which was supported by compositional comparison of isolated acidic species by negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICRMS) at 21 T derived from both elevated temperature impacted and non-impacted areas in the same landfill site. Furthermore, leachate organics fractionation showed that leachates not impacted by elevated temperature contain less hydrophilic fraction and more humic fraction than elevated temperature-impacted leachates for both ETLFs.

Anaerobic co-digestion of cabbage waste and cattle manure: Effect of mixing ratio and hydraulic retention time

The aim of this study is to optimize the process parameters for the anaerobic co-digestion of cabbage waste and cattle manure, with the objective of maximizing methane production. Batch experiments were conducted using five different mixing ratios (1:0, 3:1, 1:1, 1:3, and 0:1), and continuous experiments were run at six different hydraulic retention times (HRTs) of 25, 20, 15, 10, 8, and 5 days. The results indicate that the co-digestion displayed a synergistic effect, as evidenced by a cooperative index greater than 1. Additionally, an appropriate cabbage waste to cattle manure ratio of 3:1 yielded a maximum methane production of 440 mL/g-VS. During the continuous study, the highest methane production rate of 1.55 L/(L·d) was achieved at 10-day HRT. Efficient methane yields in the range of 322–336 mL/g-VS were obtained at HRTs of 25, 20, and 15 days. Methane yield decreased when HRTs were shortened to 10 or 8 days due to the accumulation of volatile fatty acids and the loss of methanogens. At an HRT of 4 days, methane production nearly ceased. These results provide insights for the optimization of anaerobic co-digestion of cabbage waste and cattle manure, leading to higher methane production.

Fatty acid composition of quail blood erythrocyte membranes under condition of feeding sodium selenite and nanoselenium

Infectious diseases are a significant problem in poultry farming, because they significantly slow down the growth rate of the industry and lead to losses. For the productive development of the industry and the avoidance of danger to the health of consumers due to the uncontrolled use of these drugs, it is worth using alternative methods of protecting poultry and improving the quality of the obtained products, in particular drugs obtained by nanotechnological means. Nowadays, nanoparticles of various minerals are used in poultry farming, the mineral antagonism of which is reduced in the intestines, compared to preparations of the usual size, which contributes to the modulation of absorption mechanisms, optimization of the immune response, and increased efficiency of digestion. Oxidative stress is a harmful factor for cellular integrity due to the constant release of reactive forms of oxygen. Se is widely used as a supplement to reduce oxidative stress. The element is found in organic and inorganic compounds, replaces Sulfur in protein molecules and is an important part of selenoproteins. Se is known for its antioxidant activity, plays a major role in optimizing redox potential, reproductive processes, hormone metabolism, muscle development, and anticarcinogenesis. Nano-Se results in higher Se retention activity due to smaller size and greater bioavailability. Biogenic selenium nanoparticles (SeNPs), synthesized with the participation of bacteria, have unique physicochemical and biological properties compared to inorganic and organic compounds, and nanoselenium-enriched probiotic bacteria can be effectively used as an alternative to other forms of selenium as food and feed additives. The work compared the composition of fatty acids of lipids extracted from erythrocytes of quail blood, which were injected with sodium selenite and pro-oxidant nano-Se. With the introduction of nanoselenium, a decrease in the level of NFAs was noted, as well as a significant increase in the level of the main PUFAs. The lack of compensatory accumulation of docosapolyene fatty acids in the cell membranes of erythrocytes of birds of the 2nd group can be considered as a factor of the beneficial effect of the administered drug, as well as as a justification for the need to prescribe complex drugs to birds capable of modulating the fatty acid composition of cell membranes. The effectiveness of using a complex nanopreparation consists in normalizing the level of fatty acids and restoring their metabolism at the stage of eicosanoid formation. Key words: fatty acids, quails, peroxide oxidation, selenium, sodium selenite, nanoselenium, nanoparticles, lipids.

A new efficient paradigm of energy and resource recovery from sewage: AnMBR treating chemically pre-precipitated concentrate in sidestream

Urged by the requirement for sustainable development, the recovery of energy and resources from sewage is imperative. In this study, a lab-scale anaerobic membrane bioreactor (AnMBR) treating chemically pre-concentrated real sewage with a high content of carbon, phosphorus, and iron in sidestream was established, and its performance at organic loading rate (OLR) varied from 0.67 to 2 g-COD/(L⋅d) was assessed comprehensively. When OLR ≤ 1.33 g-COD/(L⋅d), it achieved high COD removal (∼99 %), and around 60 % of the total influent COD was converted to methane (0.21 L-CH4/g-CODinf). Gaseous methane accounted for up to 95 % of the biogas. Only 1.5 % of yield methane was lost in permeate, far less than the dissolved methane in AnMBR treating sewage in mainstream. Considerable phosphorus (85 %-98 %) was retained in AnMBR. When OLR reached 2 g-COD/(L⋅d), the treatment performance was exacerbated with volatile fatty acids accumulation. The sludge flocs disintegrated with smaller particle sizes. The microbial community of mixed liquor shifted towards that of the pre-concentrated sewage. A specific relative abundance of Epsilonbacteraeota (a biomarker in this research) can be set as a warning of overloading. Compared with AnMBRs treating sewage in the mainstream, this sidestream AnMBR provided a new perspective and paradigm for treating sewage in an energy-efficient, resource-recovered, and low-carbon way.

Effect of Uncaria tomentosa aqueous extract on the response to palmitate-induced lipotoxicity in cultured skeletal muscle cells

BackgroundType 2 diabetes mellitus (T2DM) is frequently associated with dyslipidemia, which corresponds to the increase in the triglycerides and fatty acid concentrations in tissues, such as the skeletal muscle. Also, T2DM molecular mechanism involves increasing in reactive oxygen species (ROS) production and oxidative stress. The use of herbal medicines such as Uncaria tomentosa (Ut) has been proposed as an auxiliary treatment for patients with T2DM. In this study, it was evaluated the effect of Ut aqueous extract on cell viability and ROS production, in skeletal myoblasts from C2C12 lineage exposed to the free fatty acid palmitate (PA).MethodsCells were incubated with PA in different concentrations ranging from 10 to 1000 μM, for 24 or 48 h, for cytotoxicity assay. Cell death, DNA fragmentation and ROS production assays were performed in cell cultures incubated with PA for 24 h, in the pre (preventive condition) or post treatment (therapeutic condition) with 250 μg/ml Ut aqueous extract, for 2 or 6 h. Cell death was evaluated by MTT method or flow cytometry. ROS generation was measured by fluorescence spectroscopy using the DCFDA probe.ResultsCell viability was reduced to approximately 44% after the incubation with PA for 24 h from the concentration of 500 µM. In the incubation of cells with 500 μM PA and Ut extract for 6 h, in both conditions (preventive or therapeutic), it was observed an increase of 27 and 70% in cell viability respectively, in comparison to the cultures incubated with only PA. Also, the incubation of cultures with 500 μM PA, for 24 h, increased 20-fold the ROS formation, while the treatment with Ut extract, for 6 h, both in the preventive or therapeutic conditions, promoted decrease of 21 and 55%, respectively.ConclusionThe Ut extract was efficient in promoting cell protection against PA lipotoxicity and ROS generation, potentially preventing oxidative stress in C2C12 skeletal muscle cells. Since T2DM molecular mechanism involves oxidative stress condition and it is often associated with dyslipidemia and fatty acid accumulation in muscle tissue, these results open perspectives for the use of Ut as an auxiliary strategy for T2DM management.

Exosomes drive ferroptosis by stimulating iron accumulation to inhibit bacterial infection in crustaceans

Ferroptosis, characterized by iron-dependent cell death, has recently emerged as a critical defense mechanism against microbial infections. The present study aims to investigate the involvement of exosomes in the induction of ferroptosis and the inhibition of bacterial infection in crustaceans. Our findings provide compelling evidence for the pivotal role of exosomes in the immune response of crustaceans, wherein they facilitate intracellular iron accumulation and activate the ferroptotic pathways. Using RNA-seq and bioinformatic analysis, we demonstrate that cytochrome P450 (CYP) can effectively trigger ferroptosis. Moreover, by conducting an analysis of exosome cargo proteins, we have identified the participation of six-transmembrane epithelial antigen of prostate 4 (STEAP4) in the regulation of hemocyte ferroptotic sensitivity. Subsequent functional investigations unveil that STEAP4 enhances cellular Fe2+ levels, thereby triggering Fenton reactions and accelerating CYP-mediated lipid peroxidation, ultimately culminating in ferroptotic cell death. Additionally, the Fe2+-dependent CYP catalyzes the conversion of arachidonic acid into 20-hydroxyeicosatetraenoic acid (20-HETE), which activates the peroxisome proliferator-activated receptor (PPAR). Consequently, the downstream target of PPAR, cluster of differentiation 36 (CD36), promotes intracellular fatty acid accumulation, lipid peroxidation, and ferroptosis. These significant findings shed light on the immune defense mechanisms employed by crustaceans and provide potential strategies for combating bacterial infections in this species.

Effect of seawater on the biomass composition of Spirulina produced at a pilot-scale

The microalga Arthrospira platensis BEA 005B was produced in 11.4 m3 raceway photobioreactors and a culture medium based on commercial fertilisers and either freshwater or seawater. The biomass productivity of the reactors operated at a fixed dilution rate of 0.3 day−1 decreased from 22.9 g·m−2·day−1 when operated using freshwater to 16.3 g·m−2·day−1 when the biomass was produced using seawater. The protein content of the biomass produced in seawater was lower; however, the content of essential amino acids including valine, leucine and isoleucine was higher. Seawater also triggered the production of carotenoids and altered the synthesis and accumulation of fatty acids. For example, the biomass produced using seawater showed a 319% and 210% higher content of oleic and eicosenoic acid, respectively. The results demonstrate that it is possible to produce the selected microalga using seawater after an adaptation period and that the composition of the produced biomass is suitable for food applications.

The Interconnection between Hepatic Insulin Resistance and Metabolic Dysfunction-Associated Steatotic Liver Disease-The Transition from an Adipocentric to Liver-Centric Approach.

The central mechanism involved in the pathogenesis of MAFLD is insulin resistance with hyperinsulinemia, which stimulates triglyceride synthesis and accumulation in the liver. On the other side, triglyceride and free fatty acid accumulation in hepatocytes promotes insulin resistance via oxidative stress, endoplasmic reticulum stress, lipotoxicity, and the increased secretion of hepatokines. Cytokines and adipokines cause insulin resistance, thus promoting lipolysis in adipose tissue and ectopic fat deposition in the muscles and liver. Free fatty acids along with cytokines and adipokines contribute to insulin resistance in the liver via the activation of numerous signaling pathways. The secretion of hepatokines, hormone-like proteins, primarily by hepatocytes is disturbed and impairs signaling pathways, causing metabolic dysregulation in the liver. ER stress and unfolded protein response play significant roles in insulin resistance aggravation through the activation of apoptosis, inflammatory response, and insulin signaling impairment mediated via IRE1/PERK/ATF6 signaling pathways and the upregulation of SREBP 1c. Circadian rhythm derangement and biological clock desynchronization are related to metabolic disorders, insulin resistance, and NAFLD, suggesting clock genes as a potential target for new therapeutic strategies. This review aims to summarize the mechanisms of hepatic insulin resistance involved in NAFLD development and progression.