The multigene family of fatty acid-binding proteins (FABPs): function, structure and polymorphism

miR-125b-5p regulates FFA-induced hepatic steatosis in L02 cells by targeting estrogen-related receptor alpha

BACKGROUND & AIMS

NAFLD is a global and complex liver disease caused by multiple factors. Intrahepatocellular steatosis is the primary prerequisite for the occurrence and development of NAFLD. It has been shown that miR-125b-5p is highly correlated with NAFLD, and ESRRA is a factor that regulates lipid metabolism. The purpose of our study is to investigate whether miR-125b-5p regulates FFA-induced steatosis in L02 cells by targeting ESRRA.

APPROACHES AND RESULTS

Estrogen-related receptor alpha (ESRRA) was identified as a direct target of miR-125b-5p through database prediction and a dual-luciferase reporter gene assay. L02 cells were induced with free fatty acids (OA:PA, 2:1) at concentrations of 0.3 mM, 0.6 mM, 0.9 mM, 1.2 mM and 1.5 mM for 24 h, 48 h and 72 h, respectively. The degree of hepatocyte steatosis and triglyceride content were separately manifested by oil red O staining and colorimetric method. Cell viability per group was detected by CCK-8 assay. Eventually, 0.9 mM and 24 h were screened out as the optimal concentration and time for establishing the in-vitro model of hepatic steatosis. Followingly, miR-125b-5p and ESRRA were knocked down by transient transfection. We monitored the expressions of lipid metabolism factors SREBP-1c, ACC1 and FAS and determine triglyceride content within the cells per group. The data showed that knockdown of ESRRA led to down-regulation of the expressions of SREBP-1, ACC1, FAS and triglyceride content. Meanwhile, knockdown of ESRRA and miR-125b-5p resulted that the expressions of ESRRA, SREBP-1, ACC1, FAS and triglyceride content rebounded.

CONCLUSIONS

MiR-125b-5p down-regulates the expressions of lipid metabolism-related factors by negatively regulating ESRRA, thereby improving hepatic steatosis.

Compositional versatility enables biologically inspired reverse micelles for study of protein-membrane interactions

The study of membranes and their associated proteins is critical for understanding cellular processes. In vitro investigations utilizing membrane models often have limitations in their biological relevance due to the dissimilarity of experimentally compatible membrane mimetics to biological membranes. Development of membrane models that better mimic cellular membranes enables more biologically accurate observations of membrane associated proteins. In this work, we present upper tolerance concentrations for a range of lipids incorporated into reverse micelles (RMs), confirmed with dynamic light scattering (DLS). A breadth of lipid incorporation enabled biologically inspired RMs to be formulated based on the molar ratios of lipids present in eukaryotic membrane leaflets. Three systems were formulated matching lipid compositions of the inner leaflet of the plasma membrane (PM-RM), the outer mitochondrial membrane leaflet (MI-RM), and the outer rough endoplasmic reticulum membrane leaflet (ER-RM). The biologically-inspired RM formulations were characterized using DLS and cryo-electron microscopy (cryo-EM) and were found to have favorable properties for protein encapsulation. All three biologically inspired RM formulations effectively encapsulated fatty acid binding protein 4 (FABP4), a protein which shuttles fatty acids between membranes, confirmed by NMR. Also presented in this work is the first known high-resolution observation of the membrane-bound state of sterol carrier protein 2 (SCP2), a protein responsible for transporting an array of lipids between membranes. SCP2 was successfully encapsulated within all three RM systems, enabling NMR observation of the membrane interface of SCP2. The tolerances and formulations reported here allow for tailoring of RMs to mimic specific cellular membranes and will enhance studies of protein interactions with lipids and membranes among other investigations.

Prognostic value of a combination of cardiac biomarkers and risk indices for major adverse cardiovascular events following non-cardiac surgery in geriatric patients: a prospective cohort study

Major adverse cardiovascular events (MACEs) in geriatric patients are an important cause of increased mortality and morbidity. The results of current studies regarding the predictive value of the NT-proBNP, H-FABP, and AUB-HAS2 scales for cardiovascular complications are inconsistent, and there is no relevant large sample study. Therefore, this study aimed to investigate whether preoperative NT-proBNP, H-FABP, and AUB-HAS2 alone or in combination can effectively predict postoperative cardiovascular complications in geriatric patients. A total of 1736 geriatric patients (aged ≥ 65 years) who were scheduled for elective non-cardiac surgery under general anesthesia were enrolled. AUB-HAS2 risk assessment is required for each patient, and blood was collected 1 h before surgery for the measurement of NT-proBNP and H-FABP. The primary outcomes were MACEs within 30 days after surgery. The secondary outcomes were other complications. Its predictive value was analyzed by receiver operating characteristic (ROC) curves. Of the 1736 patients, 71 (4.1%) had MACEs. NT-proBNP was a predictor of MACEs (AUC = 0.763; 95% CI 0.695-0.832; P < 0.001). When H-FABP was combined with AUB-HAS2, AUB-HAS2 increased the predictive value of H-FABP (AUC = 0.736; 95% CI 0.673-0.799; P < 0.001). Multiple logistic regression analysis revealed increased predictive value of the modified AUB-HAS2 scale for MACEs (AUC = 0.794, 95% CI = 0.737-0.851, P < 0.001). Our study revealed the predictive efficacy and prognostic value of NT-proBNP, H-FABP and the AUB-HAS2 score alone or in combination for postoperative MACE risk assessment in geriatric patients undergoing non-cardiac surgery.This trial was registered at the Chinese Clinical Trial Registry (2019/09/27 ChiCTR1900026223, https://www.chictr.org.cn ).

ART26.12, an FABP5 Inhibitor, Shows Efficacy in Preclinical Psoriasis Models

FABP5 is upregulated in psoriasis. This study assessed the efficacy of the potent, selective, and orally active FABP5 inhibitor ART26.12 in preclinical psoriasis models. In vitro, reconstructed human epidermis was stimulated with cytokines (IL-17 + IL-22 + TNF at 3 ng/ml each) and treated with ART26.12 (1, 3, or 10 μM) or Jak1 inhibitor (10 μM) for 24 hours; after which, 64 psoriasis-related genes were measured. ART26.12 (3 and 10 μM) treatment reduced cytokines, chemokines, and markers of keratinocyte proliferation/differentiation and increased certain antimicrobial peptides. In vivo, ART26.12 (25 or 100 mg/kg twice a day) or BMS-986165 (TYK2 inhibitor; 10 mg/kg once a day) was given orally for 10 days in the imiquimod mouse model. Imiquimod increased psoriasis-like symptoms. ART26.12 (25 mg/kg twice a day) and BMS-986165 comparably reduced psoriasis-like symptoms by day 6 of imiquimod treatment. Histopathology showed that ART26.12 reduced symptom severity, for example, hyperkeratosis, parakeratosis, epidermal acanthosis, and inflammatory infiltrates. Proteomic analysis indicated that ART26.12 rescued the expression of FLG-2; promoted epidermal differentiation complex-associated proteins; and modulated peroxisome proliferator-activated receptor, NF-kB, and protein kinase C pathways likely downstream of lipid modulation. Lipidomic analysis showed widespread modulation, including ceramides and linoleic acid derivatives. These data suggest that ART26.12 may be a potential psoriasis treatment.

Investigation of Fatty Acids in Biological Fluid Samples and Analysis by Capillary Electrophoresis: State of the Art and Applications

Fatty acids are vital to various physiological processes, making their analysis crucial for understanding metabolic, nutritional, and pathological conditions. Traditional methods for its analysis in biological samples, such as gas chromatography and high-performance liquid chromatography, often require complex sample preparation, including derivatization and extraction steps. Capillary electrophoresis has emerged as a promising alternative, offering simpler sample preparation, fast analysis times, and reduced consumption of solvents and reagents, which is in line with the principles of green chemistry. Despite its potential, capillary electrophoresis remains underutilized in fatty acid analysis in biological samples. In this regard, this review discusses the state of the art in capillary electrophoresis application for fatty acid analysis in biological samples, highlighting the simplified sample preparation protocols and the technique's advantages over others.

Tissue-Specific Ablation of Liver Fatty Acid-Binding Protein Induces a Metabolically Healthy Obese Phenotype in Female Mice

Background/Objectives: Obesity is associated with numerous metabolic complications including insulin resistance, dyslipidemia, and a reduced capacity for physical activity. Whole-body ablation of liver fatty acid-binding protein (LFABP) in mice was shown to alleviate several of these metabolic complications; high-fat (HF)-fed LFABP knockout (LFABP-/-) mice developed higher fat mass than their wild-type (WT) counterparts but displayed a metabolically healthy obese (MHO) phenotype with normoglycemia, normoinsulinemia, and reduced hepatic steatosis compared with WT. Since LFABP is expressed in both liver and intestine, in the present study, we generated LFABP conditional knockout (cKO) mice to determine the contributions of LFABP specifically within the liver or within the intestine, to the whole-body phenotype of the global knockout. Methods: Female liver-specific LFABP knockout (LFABPliv-/-), intestine-specific LFABP knockout (LFABPint-/-), and "floxed" LFABP (LFABPfl/fl) control mice were fed a 45% Kcal fat semipurified HF diet for 12 weeks. Results: While not as dramatic as found for whole-body LFABP-/- mice, both LFABPliv-/- and LFABPint-/- mice had significantly higher body weights and fat mass compared with LFABPfl/fl control mice. As with the global LFABP nulls, both LFABPliv-/- and LFABPint-/- mice remained normoglycemic and normoinsulinemic. Despite their greater fat mass, the LFABPliv-/- mice did not develop hepatic steatosis. Additionally, LFABPliv-/- and LFABPint-/- mice had higher endurance exercise capacity when compared with LFABPfl/fl control mice. Conclusions: The results suggest, therefore, that either liver-specific or intestine-specific ablation of LFABP in female mice is sufficient to induce, at least in part, the MHO phenotype observed following whole-body ablation of LFABP.

Expression of fatty acid binding proteins in mesenteric adipose tissue

Adipose is a complex tissue comprised of adipocytes, immune cells, endothelial and progenitor stem cells. In humans, there are at least nine defined adipose depots, each containing variable numbers of genetically identified adipocyte clusters suggesting remarkable heterogeneity and potential functionality in each depot with respect to lipid metabolism. Although subcutaneous and visceral depots are commonly analyzed for biochemical and molecular functions, the mesenteric depot has been overlooked yet strongly implicated in lipid mediated immune surveillance. Since fatty acid binding proteins (FABPs) are primary cellular conduits to lipid trafficking, we evaluated the expression patterns for four major fatty acid binding proteins (FABP1, FABP3, FABP4 and FABP5) using a combination of gene expression, immunoblotting, and immunofluorescence in mesenteric fat from both young and old, male and female C57Bl/6J mice. All four FABPs were expressed at the mRNA and protein level in murine mesenteric adipose tissue. While there was no statistical change in expression of mesenteric FABP isoforms with sex or age, the expression of mesenteric FABP1 was increased, and FABP4 decreased, in both males and females as compared to perigonadal and inguinal depots. Surprisingly, immunofluorescence staining revealed that compared to subcutaneous or perigonadal depots, mesenteric fat expresses FABP3, but little FABP5, in adipocytes. These results highlight the diversity in adipose tissue and the importance of evaluating the mesenteric depot in the context of lipid transport and metabolism.

Evaluation of Thrombomodulin, Heart-Type Fatty-Acid-Binding Protein, Pentraxin-3 and Galectin-3 Levels in Patients with Myocardial Infarction, with and Without ST Segment Elevation

Background: Medical history, ECG findings and cardiac markers are used in the diagnosis of myocardial infarction (MI). Biomarkers used especially for the diagnosis of MI include high-sensitivity troponins (hsTns), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), myoglobin, cardiac myosin-binding protein C and new cardiac biomarkers. This study evaluated the levels of serum thrombomodulin (TM), heart-type fatty-acid-binding protein (H-FABP), pentraxin-3 (PTX-3) and galectin-3 (Gal-3) to determine their utility in distinguishing between ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI). Methods: This study included a total of 180 patients (90 patients with acute STEMI and 90 patients with NSTEMI) who presented to the Gaziosmanpaşa Training and Research Hospital, Cardiovascular Surgery and Emergency Department, with ischemic chest pain lasting longer than 30 min. Ninety healthy volunteers were included as the control group. Results: Serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), TM, H-FABP, PTX-3 and Gal-3 were significantly different across the STEMI, NSTEMI and control groups (p < 0.001). Strong positive correlations were observed between NT-proBNP and TM, H-FABP, PTX-3 and Gal-3 in the STEMI group. ROC analysis demonstrated excellent diagnostic accuracy for these biomarkers in distinguishing STEMI from NSTEMI and control groups. Conclusions: Vascular inflammation plays an important role in the pathophysiology of STEMI and NSTEMI. A comprehensive cardiac biomarker panel enhances diagnostic accuracy and risk stratification, particularly when distinguishing between STEMI and NSTEMI. The biomarkers hs-TnI, CK-MB, NT-proBNP, TM, H-FABP, PTX-3 and Gal-3 offer complementary information when used together as a panel. Further research and validation are essential to establish standardized protocols for their widespread use.

Identification of differentially expressed genes and polymorphisms related to intramuscular oleic-to-stearic fatty acid ratio in pigs

The intramuscular oleic-to-stearic fatty acid ratio (C18:1n-9/C18:0) is an important indicator of the biosynthesis and desaturation of fatty acids in muscle. By using an RNA-Seq approach in muscle samples from 32 BC1_DU (25% Iberian and 75% Duroc) pigs with divergent values (high: H and low: L) of C18:1n-9/C18:0 fatty acids ratio, a total of 81 differentially expressed genes (DEGs) were identified. Functional analyses of DEGs indicate that mainly peroxisome proliferator-activated receptor signaling pathway (associated genes: PPARG, SCD, PLIN1, and FABP3) was overrepresented. Notably, SCD is directly involved in the conversion of C18:0 to C18:1n-9, and PPARG is a transcription factor regulating lipid metabolism genes, including SCD. However, other DEGs (e.g., ACADVL, FADS3, EPHB2, HGFAC, NGFR, NR0B2, MDH1, MMAA, PPP1R1B, SFRP5, RAB30, and TRARG1) are plausible candidate genes to explain the phenotypic differences of the C18:1n-9/C18:0 ratio. Interestingly, seven genetic variants within the SCD (including the well-known AY487830:g.2228T>C SNP and other novel genotyped polymorphisms) are associated with two haplotypes. Although the haplotypes are segregating at different frequencies in the H and L groups, they do not fully explain the desaturation ratios or the SCD expression levels. A more complex model, including polyunsaturated fatty acids such as C18:2n-6, C20:4n-6, and C18:3n-3, is suggested to explain the regulation of the C18:1n-9/C18:0 desaturation ratio in porcine muscle.

A synthetic review: natural history of amniote reproductive modes in light of comparative evolutionary genomics

There is a current lack of consensus on whether the ancestral parity mode was oviparity (egg-laying) or viviparity (live-birth) in amniotes and particularly in squamates (snakes, lizards, and amphisbaenids). How transitions between parity modes occur at the genomic level has primary importance for how science conceptualises the origin of amniotes, and highly variable parity modes in Squamata. Synthesising literature from medicine, poultry science, reproductive biology, and evolutionary biology, I review the genomics and physiology of five broad processes (here termed the 'Main Five') expected to change during transitions between parity modes: eggshell formation, embryonic retention, placentation, calcium transport, and maternal-fetal immune dynamics. Throughout, I offer alternative perspectives and testable hypotheses regarding proximate causes of parity mode evolution in amniotes and squamates. If viviparity did evolve early in the history of lepidosaurs, I offer the nucleation site hypothesis as a proximate explanation. The framework of this hypothesis can be extended to amniotes to infer their ancestral state. I also provide a mechanism and hypothesis on how squamates may transition from viviparity to oviparity and make predictions about the directionality of transitions in three species. After considering evidence for differing perspectives on amniote origins, I offer a framework that unifies (i) the extended embryonic retention model and (ii) the traditional model which describes the amniote egg as an adaptation to the terrestrial environment. Additionally, this review contextualises the origin of amniotes and parity mode evolution within Medawar's paradigm. Medawar posited that pregnancy could be supported by immunosuppression, inertness, evasion, or immunological barriers. I demonstrate that this does not support gestation or gravidity across most amniotes but may be an adequate paradigm to explain how the first amniote tolerated internal fertilization and delayed egg deposition. In this context, the eggshell can be thought of as an immunological barrier. If serving as a barrier underpins the origin of the amniote eggshell, there should be evidence that oviparous gravidity can be met with a lack of immunological responses in utero. Rare examples of two species that differentially express very few genes during gravidity, suggestive of an absent immunological reaction to oviparous gravidity, are two skinks Lampropholis guichenoti and Lerista bougainvillii. These species may serve as good models for the original amniote egg. Overall, this review grounds itself in the historical literature while offering a modern perspective on the origin of amniotes. I encourage the scientific community to utilise this review as a resource in evolutionary and comparative genomics studies, embrace the complexity of the system, and thoughtfully consider the frameworks proposed.

Fatty acid binding protein as a new age biomarker

Small lipid-binding proteins known as fatty acid-binding proteins (FABPs) are extensively expressed in cells having elevated levels of fatty acid (FA) metabolism. There are ten known FABPs in mammals that exhibit expression patterns specific to tissues and tertiary structures that are substantially preserved. FABPs were first investigated as FA transport proteins inside cells. Subsequent research has shown that they are involved in signalling within their expression cells and in metabolism of lipid, directly and through the control of expression of gene. Additionally, there is evidence that they might be released and influence circulatory function. It has been observed that some tissues and organs linked to inflammatory, metabolic illnesses and also infectious disease have markedly elevated expression levels of FABPs. Thus, in addition to previously identified markers, FABPs represent a promising new biomarker that require additional investigation to optimise illness detection and prognosis techniques.

Limited Diagnostic Value of miRNAs in Early Trauma-Induced Liver Injury: Only miRNA-122 Emerges as a Late-Phase Marker

Background/Objectives: Liver injury is common after abdominal trauma. However, the established biomarkers of liver injury, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), lack accuracy. This study investigates whether specific liver-related microRNAs (miRNAs) are released into the circulation in trauma patients with liver injury and whether they can indicate liver damage in the early phase after major trauma. Methods: A retrospective analysis of prospectively collected data and blood samples from 26 trauma patients was conducted. The levels of miRNA-21-5p, -122-5p, -191-5p, -192-3p, and -212-3p were measured in patients with computed tomography-confirmed liver trauma (LT group, n = 12) and polytrauma patients without liver trauma (PT group, n = 14) upon emergency room (ER) admission, and 24 and 48 h after trauma. Additionally, liver-type fatty acid binding protein (L-FABP) was measured, as it has recently been discussed in the context of abdominal trauma. Results: Only miRNA-122-5p showed a significant increase in the LT group compared to the PT group, but only at the 48 h time point (p = 0.032). Conversely, L-FABP (p = 0.018) and ALT (p = 0.05) were significantly elevated in the LT group compared to the PT group at the time of ER admission. There was a moderate correlation between miRNA-122-5p and AISAbdomen (p = 0.056) and transfused red blood cell concentrates (p = 0.055). L-FABP correlated strongly with the ALT levels (p = 0.0009) and the length of stay in the ICU (p = 0.0086). Conclusions: In this study, the liver-specific miRNA-122-5p did not effectively indicate liver injury in the early acute post-traumatic phase. Future research with a large sample size should investigate whether other miRNAs can more accurately predict liver injury and the extent of hepatocellular injury, particularly in the acute post-traumatic phase.

Tissue-Specific Ablation of Liver Fatty Acid-Binding Protein Induces a Metabolically Healthy Obese Phenotype in Female Mice

Background/Objectives

Obesity is associated with numerous metabolic complications including insulin resistance, dyslipidemia, and a reduced capacity for physical activity. Whole-body ablation of liver fatty acid-binding protein (LFABP) in mice was shown to alleviate several of these metabolic complications; high fat (HF) fed LFABP knockout (LFABP-/-) mice developed higher fat mass than their wild-type (WT) counterparts but displayed a metabolically healthy obese (MHO) phenotype with normoglycemia, normoinsulinemia, and reduced hepatic steatosis compared with WT. LFABP is expressed in both liver and intestine, thus in the present study, LFABP conditional knockout (cKO) mice were generated to determine the contributions of LFABP specifically within the liver or the intestine to the whole body phenotype of the global knockout.

Methods

Female liver-specific LFABP knockout (LFABPliv-/-), intestine-specific LFABP knockout (LFABPint-/-), and floxed LFABP (LFABPfl/fl) control mice were fed a 45% Kcal fat semipurified HF diet for 12 weeks.

Results

While not as dramatic as found for whole-body LFABP-/- mice, both LFABPliv-/- and LFABPint-/- mice had significantly higher body weights and fat mass compared with LFABPfl/fl control mice. As with the global LFABP nulls, both LFABPliv-/- and LFABPint-/- mice remained normoglycemic and normoinsulinemic. Despite their greater fat mass, the LFABPliv-/- mice did not develop hepatic steatosis. Additionally, LFABPliv-/- and LFABPint-/- mice had higher endurance exercise capacity when compared with LFABPfl/fl control mice.

Conclusions

The results suggest, therefore, that either liver-specific or intestine-specific ablation of LFABP in female mice is sufficient to induce, at least in part, the MHO phenotype observed following whole-body ablation of LFABP.

How lipid transfer proteins and the mitochondrial membrane shape the kinetics of β-oxidation the liver

The mitochondrial fatty acid β-oxidation (mFAO) is important for producing ATP under conditions of energetic stress, such as fasting and cold exposure. The regulation of this pathway is dependent on the kinetic properties of the enzymes involved. To better understand pathway behaviour, accurate enzyme kinetics is required. Setting up and interpreting such proper assays requires a good understanding of what influences the enzymes' kinetics. Often, knowing the buffer composition, pH, and temperature is considered to be sufficient. Many mFAO enzymes are membrane-bound, however, and their kinetic properties depend on the composition and curvature of the mitochondrial membranes. These properties are, in turn, affected by metabolite concentrations, but are rarely accounted for in kinetic assays. Especially for carnitine palmitoyltransferase 1 (CPT1), this has been shown to be of great consequence. Moreover, the enzymes of the mFAO metabolise water-insoluble acyl-CoA derivatives, which become toxic at high concentrations. In vivo, these are carried across the cytosol by intracellular lipid transfer proteins (iLTPs), such as the fatty-acid and acyl-CoA-binding proteins (FABP and ACBP, respectively). In vitro, this is often mimicked by using bovine serum albumin (BSA), which differs from the iLPTs in terms of its binding behaviour and subcellular localisation patterns. In this review, we argue that the iLTPs and membrane properties cannot be ignored when measuring or interpreting the kinetics of mFAO enzymes. They should be considered fundamental to the activity of mFAO enzymes just as pH, buffer composition, and temperature are.

Evaluation of AlphaFold3 for the fatty acids docking to human fatty acid-binding proteins

Human fatty acid-binding proteins (FABPs) are involved in many aspects of lipid metabolism, such as the uptake, transport, and storage of lipophilic molecules, as well as cellular functions. Understanding how FABPs recognize fatty acids (FAs) is crucial for identifying FABP function and applications, such as in inhibitor design or biomarker development. The recently developed AlphaFold3 (AF3) demonstrates significantly higher accuracy than other prediction tools, particularly in predicting protein-ligand interactions with state-of-the-art docking tools. Studies on whether AF3 can be used to identify the FAs of FABP are lacking. To assess the accuracy of FA docking to FABPs using AF3, models of FA docked into FABP generated using AF3 were compared with experimentally determined FA-bound FABP structures. FA ligands in AF3 structures docked reliably into the FA-binding pocket of FABPs; however, the detailed binding configuration of most FA ligands docked into FABPs and the interaction between FA and FABP determined using AF3 and experimentally differed. These results will aid in understanding FA docking to FABPs and other FA-binding proteins using AF3.

The neuroprotective effect of short-chain fatty acids against hypoxia-reperfusion injury

Gut microbe-derived short-chain fatty acids (SCFAs) are known to have a profound impact on various brain functions, including cognition, mood, and overall neurological health. However, their role, if any, in protecting against hypoxic injury and ischemic stroke has not been extensively studied. In this study, we investigated the effects of two major SCFAs abundant in the gut, propionate (P) and butyrate (B), on hypoxia-reperfusion injury using a neuronal cell line and a zebrafish model. Neuro 2a (N2a) cells treated with P and B exhibited reduced levels of mitochondrial and cytosolic reactive oxygen species (ROS), diminished loss of mitochondrial membrane potential, suppressed caspase activation, and lower rates of cell death when exposed to CoCl2, a chemical commonly used to simulate hypoxia. Furthermore, adult zebrafish fed SCFA-supplemented feeds showed less susceptibility to hypoxic conditions compared to the control group, as indicated by multiple behavioral measures. Histological analysis of 2,3,5-Triphenyltetrazolium chloride (TTC) stained brain sections revealed less damage in the SCFA-fed group. We also found that Fatty Acid Binding Protein 7 (FABP7), also known as Brain Lipid Binding Protein (BLBP), a neuroprotective fatty acid binding protein, was upregulated in the brains of the SCFA-fed group. Additionally, when FABP7 was overexpressed in N2a cells, it protected the cells from injury caused by CoCl2 treatment. Overall, our data provide evidence for a neuroprotective role of P and B against hypoxic brain injury and suggest the potential of dietary supplementation with SCFAs to mitigate stroke-induced brain damage.

The impact of genetic variants related to the fatty acid metabolic process pathway on milk production traits in Jersey cows

The synthesis of fatty acids plays a critical role in shaping milk production characteristics in dairy cattle. Thus, identifying effective haplotypes within the fatty acid metabolism pathway will provide novel and robust insights into the genetics of dairy cattle. This study aimed to comprehensively examine the individual and combined impacts of fundamental genes within the fatty acid metabolic process pathway in Jersey cows. A comprehensive phenotypic dataset was compiled, considering milk production traits, to summarize a cow's productivity across three lactations. Genotyping was conducted through PCR-RFLP and Sanger sequencing, while the association between genotype and phenotype was quantified using linear mixed models. Moderate biodiversity and abundant variation suitable for haplotype analysis were observed across all examined markers. The individual effects of the FABP3, LTF and ANXA9 genes significantly influenced both milk yield and milk fat production. Additionally, this study reveals novel two-way interactions between genes in the fatty acid metabolism pathway that directly affect milk fat properties. Notably, we identified that the GGAAGG haplotype in FABP3×LTF×ANXA9 interaction may be a robust genetic marker concerning both milk fat yield and percentage. Consequently, the genotype combinations highlighted in this study serve as novel and efficient markers for assessing the fat content in cow's milk.

Nucleotide sequence variants, gene expression and serum profile of immune and antioxidant markers associated with bacterial diarrhea susceptibility in Barki lambs

BACKGROUND

Despite the fact that diarrhea is more accurately described as a clinical symptom than a disease. Diarrhea is one of the most important issues in ovine medicine, particularly in lambs, and because of high morbidity and mortality rate, sluggish growth performance, and veterinary costs, it is believed to be a major source of economic loss. Salmonella and enterotoxigenic Escherichia coli are the most common and commercially significant agents responsible for diarrhea.

OBJECTIVE

The objective of this study was to monitor the nucleotide sequence variations, gene expression, serum inflammatory and oxidative stress biomarkers in diarrheic lambs. Another aim was to identify different pathotypes and virulence genes of Salmonella and E. coli causing diarrhea.

METHODOLOGY

Blood samples were taken from 50 Barki who were diarrheal and 50 who appeared to be healthy, and then divided in 3 portions, with EDTA added to the first part for CBC, DNA and RNA extraction. The second sample received 5000 I.U. of heparin calcium, and a clean plain tube was used for the third component. The second and third sections were centrifuged to extract serum and plasma until the biochemical and immunological analysis was completed. Fecal samples were collected for bacteriological examination, and the bacteria were identified by PCR analysis. PCR-DNA sequencing was conducted for immune (SELL, JAK2, SLC11A1, IL10, FEZF1, NCF4, LITAF, SBD2, NFKB, TNF-α, IL1B, IL6, LGALS, and CATH1), antioxidant (SOD1, CAT, GPX1, GST, Nrf2, Keap1, HMOX1, and NQO1), and GIT health (CALB1, GT, and MUC2) genes in healthy and diarrheic lambs.

RESULTS

Virulent genetic markers of pathogenic characteristics of E. coli (astA, Vt2e (Stx2e), CFA/I, groES and luxS) and Salmonella (invA, SopB, bcfC and avrA) were detected in all diarrheic lambs. PCR-DNA sequencing of immune, antioxidant and intestinal health genes found eleven single nucleotide polymorphisms (SNPs) linked to either diarrhea resistance or susceptibility in Barki lambs. Transcript levels of immune, antioxidant, and GIT health (CALB1, GT, and MUC2) genes varied between healthy and diarrheic lambs. Nucleotide sequence variation of the genes under inquiry between reference sequences in GenBank and those of the animals under investigation verified all identified SNPs. Significant (P = 0.001) erythrocytosis, neutrophilic leukocytosis, with lymphocytopenia were observed in diarrheic lambs. Significant (P = 0.001) increases in serum IL-1α, IL-1β, IL-6, TNF-α (90.5 ± 1.7, 101.8 ± 1.7, 72.3 ± 6.6, 71.26 ± 4.89 Pg/ml, respectively), serum Fb, Cp, Hp, SAA (230.7 ± 12.4 mg/dl, 6.5 ± 0.07 mg/dl, 2.5 ± 0.09 g/dl, 7.4 ± 0.4 mg/L, respectively), free radicals (MDA, NO), cortisol (6.91 ± 0.18 μg/dl) and growth hormone, with significant (P = 0.001) decreases in serum IL-10 (81.71 ± 1.05 Pg/ml), antioxidants (CAT, GPx), insulin, triiodothyronine (T3) and thyroxine (T4) in diarrheic lambs.

CONCLUSIONS

The study's findings provided credence to the theory that marker-assisted selection (MAS) could be used to predict and prevent diarrhea in Barki sheep by selecting lambs based on SNPs in genes linked to inflammation, antioxidants, and intestinal health. In order to establish an efficient management protocol and determine the most susceptible risk period for disease occurrence, gene expression profiles of the genes under investigation, pro-inflammatory cytokines and acute phase proteins may also be utilized as proxy biomarkers for lamb enteritis.

The association between circulating saturated fatty acids and thyroid function: results from the NHANES 2011-2012

Background

Excessive saturated fatty acids (SFAs) are known to be detrimental to human health. Although the majority of research and dietary guidelines have focused on the intake of SFAs, there has been limited attention to the relationship between circulating SFA levels and hormonal regulation, such as that of thyroid hormones.

Methods

To explore potential associations, we conducted an investigation with 579 participants from the National Health and Nutrition Examination Survey (NHANES) 2011-2012. Subgroup analyses and multivariable linear regression models were used to estimate the relationships between eleven distinct SFA concentrations and various thyroid parameters.

Results

For 579 adults, subgroup analysis of thyroid stimulating hormone (TSH) revealed significant differences in nine specific SFAs and the total SFA levels (all p < 0.05). Furthermore, multivariable linear regression analysis identified positive correlations between certain SFAs and various parameters, including TSH, total triiodothyronine (TT3), free triiodothyronine (FT3), thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TgAb), thyroglobulin (Tg), the ratio of FT3 to free thyroxine (FT4) (FT3/FT4), and the thyrotroph T4 resistance index (TT4RI). Conversely, negative correlations were observed between certain SFAs and total thyroxine (TT4), FT4, the ratio of FT3/TT3, and the thyroid feedback quantile-based index (TFQI) (all p < 0.05).

Conclusion

These findings collectively suggest associations between SFAs and thyroid parameters, highlighting the need for future studies to elucidate the underlying mechanisms of these interactions.

Potential safety implications of fatty acid-binding protein inhibition

Fatty acid-binding proteins (FABPs) are small intracellular proteins that regulate fatty acid metabolism, transport, and signalling. There are ten known human isoforms, many of which are upregulated and involved in clinical pathologies. As such, FABP inhibition may be beneficial in disease states such as cancer, and those involving the cardiovascular system, metabolism, immunity, and cognition. Recently, a potent, selective FABP5 inhibitor (ART26.12), with 90-fold selectivity to FABP3 and 20-fold selectivity to FABP7, was found to be remarkably benign, with a no-observed-adverse-effect level of 1000 mg/kg in rats and dogs, showing no genotoxicity, cardiovascular, central, or respiratory toxicity. To understand the potential implication of FABP inhibition more fully, this review systematically assessed literature investigating genetic knockout, knockdown, and pharmacological inhibition of FABP3, FABP4, FABP5, or FABP7. Analysis of the literature revealed that animals bred not to express FABPs showed the most biological effects, suggesting key roles of these proteins during development. FABP ablation sometimes exacerbated symptoms of disease models, particularly those linked to metabolism, inflammatory and immune responses, cardiac contractility, neurogenesis, and cognition. However, FABP inhibition (genetic silencing or pharmacological) had a positive effect in many more disease conditions. Several polymorphisms of each FABP gene have also been linked to pathological conditions, but it was unclear how several polymorphisms affected protein function. Overall, analysis of the literature to date suggests that pharmacological inhibition of FABPs in adults is of low risk.

Heart-type fatty acid binding protein (H-FABP) as an early biomarker in sepsis-induced cardiomyopathy: a prospective observational study

BACKGROUND

Sepsis-induced cardiomyopathy (SICM) is a common and life-threatening complication of sepsis, significantly contributing to elevated mortality. This study aimed to identify crucial indicators for the prompt and early assessment of SICM.

METHODS

Patients diagnosed with sepsis or SICM within 24 h of intensive care unit (ICU) admission were enrolled in this prospective observational study. Patients were assigned to the training set, validation set and external test set. The primary endpoint was 7-day ICU mortality, and the secondary endpoint was 28-day ICU mortality. Three machine learning algorithms were utilized to identify relevant indicators for diagnosing SICM, incorporating 64 indicators including serum biomarkers associated with cardiac, renal, and liver function, lipid metabolism, coagulation, and inflammation. Internal and external validations were performed on the screening results. Patients were then stratified based on the cut-off value of the most diagnostically effective biomarker identified, and their prognostic outcomes were observed and analyzed.

RESULTS

A total of 270 patients were included in the training and validation set, and 52 patients were included in the external test set. Age, sex, and comorbidities did not significantly differ between the sepsis and SICM groups (P > 0.05). The support vector machine (SVM) algorithm identified six indicators with an accuracy of 84.5%, the random forest (RF) algorithm identified six indicators with an accuracy of 81.9%, and the logistic regression (LR) algorithm screened out seven indicators. Following rigorous selection, a diagnostic model for sepsis-induced cardiomyopathy was established based on heart-type fatty acid binding protein (H-FABP) (OR 1.308, 95% CI 1.170-1.462, P < 0.001) and retinol-binding protein (RBP) (OR 1.020, 95% CI 1.006-1.034, P < 0.05). H-FABP alone exhibited the highest diagnostic performance in both the internal (AUROC 0.689, P < 0.05) and external sets (AUROC 0.845, P < 0.05). Patients with SICM were further stratified based on an H-FABP diagnostic cut-off value of 8.335 ng/mL. Kaplan-Meier curve analysis demonstrated that elevated H-FABP levels at admission were associated with higher 7-day ICU mortality in patients with SICM (P < 0.05).

CONCLUSIONS

This study revealed that H-FABP concentrations measured within 24 h of patient admission could serve as a crucial biomarker for the early and rapid diagnosis and short-term prognostic evaluation of SICM.

In-silico binding affinity of a phage display library screened novel peptide against various FABPs

In accordance to the American Heart Association (AHA), cardiovascular diseases (CVDs) are the leading cause of death around the globe, causing more than 19.1 million deaths in 2020. Heart-type fatty acid binding protein (H-FABP) is required for the metabolism of fatty acids (FA) inside cardiomyocytes is reported as a biomarker for myocardial damage. As early as one hour after an Acute myocardial infarction (AMI), H-FABP can be used to detect myocardial ischemia. Thus, H-FABP based detection can reduce the burden on the emergency department. A peptide-based detection system can provide point-of-care diagnostics for CVDs. There is a lot of research being done on peptide-based detection, and it has a lot of potential to help with unmet medical diagnostic needs. A twelve (12) amino acid peptide has been discovered using Phage Display Library Screening. The affinity of peptide with H-FABP and other FABPs has been done using molecular docking and ADMET profile has been done. Molecular docking of small peptides against the target protein can play a crucial role in recognizing peptide binding sites and poses. The docking study was done using the HDOCK server and the visualization of the docked complex was done using Pymol and UCSF chimera. The molecular simulation study of three protein-peptide complexes were done which also validated the binding affinity of peptide with the proteins. The RMSD, RMSF and radius of gyration are also analyzed. The results indicate that H-FABP shows higher level of binding interaction with the peptide having bond length ranging from 2.3 to 3.4 Å. The screened peptide is suitable for H-FABP binding and can be used for prognosis purposes in the heart ischemic conditions.

Multiplexed Native Mass Spectrometry Determination of Ligand Selectivity for Fatty Acid-Binding Proteins

Although multiple approaches for characterizing protein-ligand interactions are available in target-based drug discovery, their throughput for determining selectivity is quite limited. Herein, we describe the application of native mass spectrometry for rapid, multiplexed screening of the selectivity of eight small-molecule ligands for five fatty acid-binding protein isoforms. Using high-resolution mass spectrometry, we were able to identify and quantify up to 20 different protein species in a single spectrum. We show that selectivity profiles generated by native mass spectrometry are in good agreement with those of traditional solution-phase techniques such as isothermal titration calorimetry and fluorescence polarization. Furthermore, we propose strategies for effective investigation of selectivity by native mass spectrometry, thus highlighting the potential of this technique to be used as an orthogonal method to traditional biophysical approaches for rapid, multiplexed screening of protein-ligand complexes.

Postmortem Immunohistochemical Findings in Early Acute Myocardial Infarction: A Systematic Review

The diagnosis of early acute myocardial infarction is of particular importance in forensic practice considering the frequency of sudden cardiac death and the difficulty of positively identifying it through classical histological methods if survival is less than 6 h. This article aims to analyze potential immunohistochemical markers that could be useful in diagnosing acute myocardial infarction within the first 6 h of its onset. We conducted an extensive evaluation of the literature according to the PRISMA guidelines for reporting systematic literature reviews. We searched the Web of Science and PubMed databases from their inception to 2023 using the following keywords: "myocardial infarction" and "immunohistochemistry". Fifteen studies met the inclusion criteria. Immunohistochemical markers as complement factors and CD59, myoglobin, fibrinogen, desmin, tumor necrosis factor alpha (TNF-α), P-38, JNK (Jun N Terminal Kinase), transforming growth factor β1 (TGF-β1), cardiac troponins, fibronectin, H-FABP (heart fatty acid binding protein), dityrosine, fibronectin, CD15, IL-1β, IL-6, IL-15, IL-8, MCP-1, ICAM-1, CD18, and tryptase can be used to identify the first six hours of acute myocardial infarction. These markers are mostly studied in experimental animal models. It is necessary to conduct extensive studies on human myocardial tissue fragments, which will involve the analysis of several immunohistochemical markers and careful analysis of the available data on perimortem events, resuscitation, and postmortem intervals in the context of a uniform laboratory methodology.

Weighted single-step genome-wide association study for direct and maternal genetic effects associated with birth and weaning weights in sheep

Body weight is an important economic trait for sheep meat production, and its genetic improvement is considered one of the main goals in the sheep breeding program. Identifying genomic regions that are associated with growth-related traits accelerates the process of animal breeding through marker-assisted selection, which leads to increased response to selection. In this study, we conducted a weighted single-step genome-wide association study (WssGWAS) to identify potential candidate genes for direct and maternal genetic effects associated with birth weight (BW) and weaning weight (WW) in Baluchi sheep. The data used in this research included 13,408 birth and 13,170 weaning records collected at Abbas-Abad Baluchi Sheep Breeding Station, Mashhad-Iran. Genotypic data of 94 lambs genotyped by Illumina 50K SNP BeadChip for 54,241 markers were used. The proportion of variance explained by genomic windows was calculated by summing the variance of SNPs within 1 megabase (Mb). The top 10 window genomic regions explaining the highest percentages of additive and maternal genetic variances were selected as candidate window genomic regions associated with body weights. Our findings showed that for BW, the top-ranked genomic regions (1 Mb windows) explained 4.30 and 4.92% of the direct additive and maternal genetic variances, respectively. The direct additive genetic variance explained by the genomic window regions varied from 0.31 on chromosome 1 to 0.59 on chromosome 8. The highest (0.84%) and lowest (0.32%) maternal genetic variances were explained by genomic windows on chromosome 10 and 17, respectively. For WW, the top 10 genomic regions explained 6.38 and 5.76% of the direct additive and maternal genetic variances, respectively. The highest and lowest contribution of direct additive genetic variances were 1.37% and 0.42%, respectively, both explained by genomic regions on chromosome 2. For maternal effects on WW, the highest (1.38%) and lowest (0.41%) genetic variances were explained by genomic windows on chromosome 2. Further investigation of these regions identified several possible candidate genes associated with body weight. Gene ontology analysis using the DAVID database identified several functional terms, such as translation repressor activity, nucleic acid binding, dehydroascorbic acid transporter activity, growth factor activity and SH2 domain binding.

Atorvastatin causes developmental and behavioral toxicity in yellowstripe goby (Mugilogobius chulae) embryos/larvae via disrupting lipid metabolism and autophagy processes

Atorvastatin (ATV) is one of the most commonly prescribed lipid-lowering drugs detected frequently in the environment due to its high use and low degradation rate. However, the toxic effects of residual ATV in the aquatic environment on non-target organisms and its toxic mechanisms are still largely unknown. In the present study, embryos of a native estuarine benthic fish, Mugilogobius chulae, were employed to investigate the developmental and behavioral toxic effects of ATV including environmentally relevant concentrations. The aim of this study was to provide a scientific basis for ecological risk assessment of ATV in the aquatic environment by investigating the changes of biological endpoints at multiple levels in M. chulae embryos/larvae. The results showed that ATV had significantly lethal and teratogenic effects on M. chulae embryos/larvae and caused abnormal changes in developmental parameters including hatch rate, body length, heart rate, and spontaneous movement. ATV exposure caused oxidative stress in M. chulae embryos/larvae subsequently inhibited autophagy and activated apoptosis, leading to abnormal developmental processes and behavioral changes in M. chulae embryos/larvae. The disruptions of lipid metabolism, autophagy, and apoptosis in M. chulae embryos/larvae caused by ATV exposure may pose a potential ecological risk at the population level.

Fatty acid binding to the human transport proteins FABP3, FABP4, and FABP5 from a Ligand's perspective

Fatty acid binding proteins (FABPs) are a family of amphiphilic transport proteins with high diversity in terms of their amino acid sequences and binding preferences. Beyond their main biological role as cytosolic fatty acid transporters, many aspects regarding their binding mechanism and functional specializations in human cells remain unclear. In this work, the binding properties and thermodynamics of FABP3, FABP4, and FABP5 were analyzed under various physical conditions. For this purpose, the FABPs were loaded with fatty acids bearing fluorescence or spin probes as model ligands, comparing their binding affinities via microscale thermophoresis (MST) and continuous-wave electron paramagnetic resonance (CW EPR) spectroscopy. The CW EPR spectra of non-covalently bound 5- and 16-DOXYL stearic acid (5/16-DSA) deliver in-depth information about the dynamics and chemical environments of ligands inside the binding pockets of the FABPs. EPR spectral simulations allow the construction of binding curves, revealing two different binding states ('intermediately' and 'strongly' bound). The proportion of bound 5/16-DSA depends strongly on the FABP concentration and the temperature but with remarkable differences between the three isoforms. Additionally, the more dynamic state ('intermediately bound') seems to dominate at body temperature with thermodynamic preference. The ligand binding studies were supplemented by aggregation studies via dynamic light scattering and bioinformatic analyses. Beyond the remarkably fine-tuned binding properties exhibited by each FABP, which were discernible with our EPR-centered approach, the results of this work attest to the power of simple spectroscopic experiments to provide new insights into the ligand binding mechanisms of proteins in general on a molecular level.

Clinical implications of septic cardiomyopathy: A narrative review

Sepsis is caused by the body's dysregulated response to infection, which can lead to multiorgan injury and death. Patients with sepsis may develop acute cardiac dysfunction, termed septic cardiomyopathy, which is a global but reversible dysfunction of both sides of the heart. This narrative review discusses the mechanistic changes in the heart during septic cardiomyopathy, its diagnosis, existing treatment options regarding severity and course, and emerging treatment approaches. Although no standardized definition for septic cardiomyopathy exists, it is described as a reversible myocardial dysfunction that typically resolves within 7 to 10 days. Septic cardiomyopathy is often diagnosed based on electrocardiography, cardiac magnetic resonance imaging, biomarkers, and direct invasive and noninvasive measures of cardiac output. Presently, the treatment of septic cardiomyopathy is similar to that of sepsis, primarily focusing on acute interventions. Treatments for cardiomyopathy often include angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and diuretics. However, because of profound hypotension in sepsis, many cardiomyopathy treatments are contraindicated in patients with septic cardiomyopathy. Substantial efforts have been made to study the pathophysiological mechanisms and diagnostic options; however, the lack of a uniform definition for septic cardiomyopathy is challenging for physicians when considering treatments. Another challenge for physicians is that the treatment for septic cardiomyopathy has only focused on acute intervention, whereas the treatment for other cardiomyopathies has been provided on a long-term basis. A better understanding of the underlying mechanisms of septic cardiomyopathy may contribute to the development of a unified definition of the condition and novel treatment options.

Association of Blast Exposure in Military Breaching with Intestinal Permeability Blood Biomarkers Associated with Leaky Gut

Injuries and subclinical effects from exposure to blasts are of significant concern in military operational settings, including tactical training, and are associated with self-reported concussion-like symptomology and physiological changes such as increased intestinal permeability (IP), which was investigated in this study. Time-series gene expression and IP biomarker data were generated from "breachers" exposed to controlled, low-level explosive blast during training. Samples from 30 male participants at pre-, post-, and follow-up blast exposure the next day were assayed via RNA-seq and ELISA. A battery of symptom data was also collected at each of these time points that acutely showed elevated symptom reporting related to headache, concentration, dizziness, and taking longer to think, dissipating ~16 h following blast exposure. Evidence for bacterial translocation into circulation following blast exposure was detected by significant stepwise increase in microbial diversity (measured via alpha-diversity p = 0.049). Alterations in levels of IP protein biomarkers (i.e., Zonulin, LBP, Claudin-3, I-FABP) assessed in a subset of these participants (n = 23) further evidenced blast exposure associates with IP. The observed symptom profile was consistent with mild traumatic brain injury and was further associated with changes in bacterial translocation and intestinal permeability, suggesting that IP may be linked to a decrease in cognitive functioning. These preliminary findings show for the first time within real-world military operational settings that exposures to blast can contribute to IP.

Fatty Acids and their Proteins in Adipose Tissue Inflammation

Chronic low-grade adipose tissue inflammation is associated with metabolic disorders. Inflammation results from the intertwined cross-talks of pro-inflammatory and anti-inflammatory pathways in the immune response of adipose tissue. In addition, adipose FABP4 levels and lipid droplet proteins are involved in systemic and tissue inflammation. Dysregulated adipocytes help infiltrate immune cells derived from bone marrow responsible for producing cytokines and chemokines. When adipose tissue expands in excess, adipocyte exhibits increased secretion of adipokines and is implicated in metabolic disturbances due to the release of free fatty acids. This review presents an emerging concept in adipose tissue fat metabolism, fatty acid handling and binding proteins, and lipid droplet proteins and their involvement in inflammatory disorders.

A Mixture of Formic Acid, Benzoic Acid, and Essential Oils Enhanced Growth Performance via Modulating Nutrient Uptake, Mitochondrion Metabolism, and Immunomodulation in Weaned Piglets

This study aimed to evaluate the effects of a complex comprising formic acid, benzoic acid, and essential oils (AO3) on the growth performance of weaned piglets and explore the underlying mechanism. Dietary AO3 supplementation significantly enhanced the average daily gain (ADG) and average daily feed intake (ADFI), while decreasing the feed conversion rate (FCR) and diarrhea rate (p < 0.05). Additionally, AO3 addition altered the fecal microflora composition with increased abundance of f_Prevotellaceae. LPS challenges were further conducted to investigate the detailed mechanism underlying the benefits of AO3 supplementation. The piglets fed with AO3 exhibited a significant increase in villus height and decrease in crypt depth within the jejunum, along with upregulation of ZO-1, occludin, and claudin-1 (p < 0.05) compared with those piglets subjected to LPS. Furthermore, AO3 supplementation significantly ameliorated redox disturbances (T-AOC, SOD, and GSH) and inflammation (TNF-α, IL-1β, IL-6, and IL-12) in both the serum and jejunum of piglets induced by LPS, accompanied by suppressed activation of the MAPK signaling pathway (ERK, JNK, P38) and NF-κB. The LPS challenge downregulated the activation of the AMPK signaling pathway, mRNA levels of electron transport chain complexes, and key enzymes involved in ATP synthesis, which were significantly restored by the AO3 supplementation. Additionally, AO3 supplementation restored the reduced transport of amino acids, glucose, and fatty acids induced by LPS back to the levels observed in the control group. In conclusion, dietary AO3 supplementation positively affected growth performance and gut microbiota composition, also enhancing intestinal barrier integrity, nutrient uptake, and energy metabolism, as well as alleviating oxidative stress and inflammation under LPS stimulation.

The utility of heart-type free fatty-acid binding-protein (HFABP) levels for differentiating acute ischemic stroke from stroke mimics

BACKGROUND

Heart-type fatty acid-binding protein (HFABP) is found in the myocardium, brain, and some organs and is rapidly released from damaged cells into the circulation in case of ischemia.

AIMS

We aimed to determine the diagnostic utility of HFABP levels in patients suggesting acute ischemic stroke (AIS).

METHODS

This study was a prospective, single-center, observational diagnostic accuracy study with a nested cohort design. The estimated sample size was 126 patients, with a 1:1 case and control ratio. We included all consecutive patients with a lateralizing symptom (motor or sensory) or finding suggesting AIS (139 patients) who presented to ED within 24 h of their symptom onset and collected plasma at admission to the ED. After further evaluations, 111 patients (79.8%) were diagnosed with AIS and 28 with other neurological diseases (stroke-mimics).

FINDINGS

In our study, the median HFABP levels of the cases and controls were 2.6 μg/ml and 2.2 μg/ml, respectively, without any statistically significant difference (p = 0.120). The diagnostic accuracy of HFABP for AIS was also insignificant at 0.60 (95% CI 0.51-0.68; p = 0.119).

DISCUSSION

Plasma HFABP level is not a marker that can differentiate AIS from other neurological pathologies in patients presenting to the ED, with findings suggesting AIS.

Structure-based design of potent FABP4 inhibitors with high selectivity against FABP3

Fatty-acid binding protein 4 (FABP4) presents an attractive target for therapeutic intervention in metabolic and inflammatory diseases in recent years. However, highly similar three-dimensional structures and fatty acid binding ability of multiple FABP family members pose a significant challenge in design of FABP4-selective inhibitors. Particularly, inhibition of FABP3 raises safety concerns such as cardiac dysfunction and exercise intolerance. Here, we reported the discovery of new FABP4 inhibitors with high selectivity over FABP3 by exploiting the little structural difference in the ligand binding pockets of FABP4 and FABP3. On the basis of our previously reported FABP4 inhibitors with nanomolar potency, different substituents were further introduced to perfectly occupy two sub-pockets of FABP4 that are distinct from those of FABP3. Remarkably, a single methyl group introduction leads to the discovery of compound C3 that impressively exhibits a 601-fold selectivity over FABP3 when maintained nanomolar binding affinity for FABP4. Moreover, C3 also shows good metabolic stability and potent cellular anti-inflammatory activity, making it a promising inhibitor for further development. Therefore, the present study highlights the utility of the structure-based rational design strategy for seeking highly selective and potent inhibitors of FABP4 and the importance of identifying the appropriate subsite as well as substituent for gaining the desired selectivity.

Response of lipid metabolism, energy supply, and cell fate in yellowstripe goby (Mugilogobius chulae) exposed to environmentally relevant concentrations atorvastatin

The usage of typical pharmaceuticals and personal care products (PPCPs) such as cardiovascular and lipid-modulating drugs in clinical care accounts for the largest share of pharmaceutical consumption in most countries. Atorvastatin (ATV), one of the most commonly used lipid-lowering drugs, is frequently detected with lower concentrations in aquatic environments owing to its wide application, low removal, and degradation rates. However, the adverse effects of ATV on non-target aquatic organisms, especially the molecular mechanisms behind the toxic effects, still remain unclear. Therefore, this study investigated the potentially toxic effects of ATV exposure (including environmental concentrations) on yellowstripe goby (Mugilogobius chulae) and addressed the multi-dimensional responses. The results showed that ATV caused typical hepatotoxicity to M. chulae. ATV interfered with lipid metabolism by blocking fatty acid β-oxidation and led to the over-consumption of lipids. Thus, the exposed organism was obliged to alter the energy supply patterns and substrates utilization pathways to keep the normal energy supply. In addition, the higher concentration of ATV exposure caused oxidative stress to the organism. Subsequently, M. chulae triggered the autophagy and apoptosis processes with the help of key stress-related transcriptional regulators FOXOs and Sestrins to degrade the damaged organelles and proteins to maintain intracellular homeostasis.

Nonalcoholic Fatty Liver Disease and Staging of Hepatic Fibrosis

Nonalcoholic fatty liver disease (NAFLD) is in parallel with the obesity epidemic, and it is the most common cause of liver diseases. The patients with severe insulin-resistant diabetes having high body mass index (BMI), high-grade adipose tissue insulin resistance, and high hepatocellular triacylglycerols (triglycerides; TAG) content develop hepatic fibrosis within a 5-year follow-up. Insulin resistance with the deficiency of insulin receptor substrate-2 (IRS-2)-associated phosphatidylinositol 3-kinase (PI3K) activity causes an increase in intracellular fatty acid-derived metabolites such as diacylglycerol (DAG), fatty acyl CoA, or ceramides. Lipotoxicity-related mechanism of NAFLD could be explained still best by the "double-hit" hypothesis. Insulin resistance is the major mechanism in the development and progression of NAFLD/nonalcoholic steatohepatitis (NASH). Metabolic oxidative stress, autophagy, and inflammation induce NASH progression. In the "first hit" the hepatic concentrations of diacylglycerol increase with an increase in saturated liver fat content in human NAFLD. Activities of mitochondrial respiratory chain complexes are decreased in the liver tissue of patients with NASH. Hepatocyte lipoapoptosis is a critical feature of NASH. In the "second hit," reduced glutathione levels due to oxidative stress lead to the overactivation of c-Jun N-terminal kinase (JNK)/c-Jun signaling that induces cell death in the steatotic liver. Accumulation of toxic levels of reactive oxygen species (ROS) is caused at least by two ineffectual cyclical pathways. First is the endoplasmic reticulum (ER) oxidoreductin (Ero1)-protein disulfide isomerase oxidation cycle through the downstream of the inner membrane mitochondrial oxidative metabolism and the second is the Kelch like-ECH-associated protein 1 (Keap1)-nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathways. In clinical practice, on ultrasonographic examination, the elevation of transaminases, γ-glutamyltransferase, and the aspartate transaminase to platelet ratio index indicates NAFLD. Fibrosis-4 index, NAFLD fibrosis score, and cytokeratin18 are used for grading steatosis, staging fibrosis, and discriminating the NASH from simple steatosis, respectively. In addition to ultrasonography, "controlled attenuation parameter," "magnetic resonance imaging proton-density fat fraction," "ultrasound-based elastography," "magnetic resonance elastography," "acoustic radiation force impulse elastography imaging," "two-dimensional shear-wave elastography with supersonic imagine," and "vibration-controlled transient elastography" are recommended as combined tests with serum markers in the clinical evaluation of NAFLD. However, to confirm the diagnosis of NAFLD, a liver biopsy is the gold standard. Insulin resistance-associated hyperinsulinemia directly accelerates fibrogenesis during NAFLD development. Although hepatocyte lipoapoptosis is a key driving force of fibrosis progression, hepatic stellate cells and extracellular matrix cells are major fibrogenic effectors. Thereby, these are pharmacological targets of therapies in developing hepatic fibrosis. Nonpharmacological management of NAFLD mainly consists of two alternatives: lifestyle modification and metabolic surgery. Many pharmacological agents that are thought to be effective in the treatment of NAFLD have been tried, but due to lack of ability to attenuate NAFLD, or adverse effects during the phase trials, the vast majority could not be licensed.

The Checkpoints of Intestinal Fat Absorption in Obesity

In this chapter, intestinal lipid transport, which plays a central role in fat homeostasis and the development of obesity in addition to the mechanisms of fatty acids and monoacylglycerol absorption in the intestinal lumen and reassembly of these within the enterocyte was described. A part of the resynthesized triglycerides (triacylglycerols; TAG) is repackaged in the intestine to form the hydrophobic core of chylomicrons (CMs). These are delivered as metabolic fuels, essential fatty acids, and other lipid-soluble nutrients, from enterocytes to the peripheral tissues following detachment from the endoplasmic reticulum membrane. Moreover, the attitudes of multiple receptor functions in dietary lipid uptake, synthesis, and transport are highlighted. Additionally, intestinal fatty acid binding proteins (FABPs), which increase the cytosolic flux of fatty acids via intermembrane transfer in enterocytes, and the functions of checkpoints for receptor-mediated fatty acid signaling are debated. The importance of the balance between storage and secretion of dietary fat by enterocytes in determining the physiological fate of dietary fat, including regulation of blood lipid concentrations and energy balance, is mentioned. Consequently, promising checkpoints regarding how intestinal fat processing affects lipid homeostatic mechanisms and lipid stores in the body and the prevention of obesity-lipotoxicity due to excessive intestinal lipid absorption are evaluated. In this context, dietary TAG digestion, pharmacological inhibition of TAG hydrolysis, the regulation of long-chain fatty acid uptake traffic into adipocytes, intracellular TAG resynthesis, the enlargement of cytoplasmic lipid droplets in enterocytes and constitutional alteration of their proteome, CD36-mediated conversion of diet-derived fatty acid into cellular lipid messengers and their functions are discussed.

Fatty-Acid-Binding Proteins: From Lipid Transporters to Disease Biomarkers

Fatty-acid-binding proteins (FABPs) serve a crucial role in the metabolism and transport of fatty acids and other hydrophobic ligands as an intracellular protein family. They are also recognized as a critical mediator in the inflammatory and ischemic pathways. FABPs are found in a wide range of tissues and organs, allowing them to contribute to various disease/injury developments that have not been widely discussed. We have collected and analyzed research journals that have investigated the role of FABPs in various diseases. Through this review, we discuss the findings on the potential of FABPs as biomarkers for various diseases in different tissues and organs, looking at their expression levels and their roles in related diseases according to available literature data. FABPs have been reported to show significantly increased expression levels in various tissues and organs associated with metabolic and inflammatory diseases. Therefore, FABPs are a promising novel biomarker that needs further development to optimize disease diagnosis and prognosis methods along with previously discovered markers.

Bombyx mori nucleopolyhedrovirus induces BmFABP1 downregulation to promote viral proliferation

Fatty acid binding proteins (FABPs) play an important role as endogenous cytoprotectants. However, studies on FABPs in invertebrates are scarce. Previously, we discovered Bombyx mori fatty acid binding protein 1 (BmFABP1) through co-immunoprecipitation. Here, we cloned and identified BmFABP1 from BmN cells. The results of immunofluorescence indicated that BmFABP1 was localized in the cytoplasm. The tissue expression profile of silkworms showed that BmFABP1 was expressed in all tissues except hemocytes. The expression level of BmFABP1 gradually decreases in BmN cells and B. mori larvae after infection with B. mori nucleopolyhedrovirus (BmNPV). Upregulation of BmFABP1 expression through overexpression or WY14643 treatment significantly inhibited the replication of BmNPV, while downregulation of BmFABP1 expression by RNA interference promoted the replication of BmNPV. The same results were obtained in experiments on silkworm larvae. These results suggest that BmNPV induces BmFABP1 downregulation to promote its proliferation and that BmFABP1 has a potential anti-BmNPV role. This is the first report on the antiviral effect of BmFABP1 in silkworms and provides new insights into the study of the FABP protein family. Also, it is important to study BmNPV resistance in silkworms to breed transgenic silkworms with BmNPV resistance.

Pathogenic Impact of Fatty Acid-Binding Proteins in Parkinson's Disease-Potential Biomarkers and Therapeutic Targets

Parkinson's disease is a neurodegenerative condition characterized by motor dysfunction resulting from the degeneration of dopamine-producing neurons in the midbrain. This dopamine deficiency gives rise to a spectrum of movement-related symptoms, including tremors, rigidity, and bradykinesia. While the precise etiology of Parkinson's disease remains elusive, genetic mutations, protein aggregation, inflammatory processes, and oxidative stress are believed to contribute to its development. In this context, fatty acid-binding proteins (FABPs) in the central nervous system, FABP3, FABP5, and FABP7, impact α-synuclein aggregation, neurotoxicity, and neuroinflammation. These FABPs accumulate in mitochondria during neurodegeneration, disrupting their membrane potential and homeostasis. In particular, FABP3, abundant in nigrostriatal dopaminergic neurons, is responsible for α-synuclein propagation into neurons and intracellular accumulation, affecting the loss of mesencephalic tyrosine hydroxylase protein, a rate-limiting enzyme of dopamine biosynthesis. This review summarizes the characteristics of FABP family proteins and delves into the pathogenic significance of FABPs in the pathogenesis of Parkinson's disease. Furthermore, it examines potential novel therapeutic targets and early diagnostic biomarkers for Parkinson's disease and related neurodegenerative disorders.

Identification of novel polymorphism in mammary-derived growth inhibitor gene of water buffalo and its expression analysis in the mammary gland

Mammary-derived growth inhibitor (MDGI), a member of the lipophilic family of fatty acid-binding proteins, plays an important role in the development, regulation, and differentiation of the mammary gland. The aim of the study was to identify polymorphism in the MDGI gene and its expression analysis in the mammary gland at various stages of lactation, in Indian buffalo. Nucleotide sequence analysis of MDGI gene in different breeds of riverine and swamp buffaloes revealed a total of 16 polymorphic sites and one Indel. Different transcription factor binding sites were predicted for buffalo MDGI gene promoter sequence, using online tools and in-silico analysis indicating that the SNPs in this region can impact the gene expression regulation. Phylogenetic analysis exhibited the MDGI of buffalo being closer to other ruminants like cattle, yak, sheep, and goats. Further, the expression analysis revealed that buffalo MDGI being highly expressed in well-developed mammary glands of lactating buffalo as compared to involution/non-lactating and before functional development to start the milk production stage in heifers. Stage-specific variation in expression levels signifies the important functional role of the MDGI gene in mammary gland development and milk production in buffalo, an important dairy species in Southeast Asia.

Metformin potentiates immunosuppressant activity and adipogenic differentiation of human umbilical cord-mesenchymal stem cells

Metformin, a first-line drug for type-2 diabetes, displays pleiotropic effects on inflammation, aging, and cancer. Obesity triggers a low-grade chronic inflammation leading to insulin resistance, characterized by increased pro-inflammatory cytokines produced by adipocytes and infiltrated immune cells, which contributes to metabolic syndrome. We investigated metformin's differentiation and immunoregulatory properties of human umbilical cord-mesenchymal stem cells (UC-MSC), as cellular basis of its beneficial role in metabolic dysfunctions. Isolation, characterization and multilineage differentiation of UC-MSC were performed using standard protocols and flow-cytometry. Metformin effects on UC-MSC growth was assessed by colony formation and MTT assay, gene and protein expression by qRT-PCR, and western blot analysis. Proliferation of peripheral blood mononuclear cells (PBMCs) co-cultured with metformin-treated UC-MSC-conditioned media was evaluated by dye dilution assay. We show that metformin decreases proliferation and colony formation of UC-MSCs and enhances their adipogenic lineage commitment. Metformin (3 mM) increases PPARγ and downregulates FABP4 mRNA both in basal and in adipogenic culture conditions; however, the modulation of PPARγ expression is unrelated to the antiproliferative effects. Moreover, metformin inhibits UC-MSC inflammatory activity reducing the expression of IL-6, MCP-1, and COX-2. Conditioned media, collected from metformin-treated UC-MSCs, down-regulate CD3+ T lymphocyte growth in stimulated PBMCs and, in particular, reduce the CD8+ T cell population. These results indicate that metformin may favor new adipocyte formation and potentiate immune suppressive properties of UC-MSCs. Thus, adipose tissue regeneration and anti-inflammatory activity may represent possible mechanisms by which metformin exerts its positive effect on lipid metabolism.

Lipid exchange in crystal-confined fatty acid binding proteins: X-ray evidence and molecular dynamics explanation

Fatty acid binding proteins (FABPs) are responsible for the long-chain fatty acids (FAs) transport inside the cell. However, despite the years, since their structure is known and the many studies published, there is no definitive answer about the stages of the lipid entry-exit mechanism. Their structure forms a β -barrel of 10 anti-parallel strands with a cap in a helix-turn-helix motif, and there is some consensus on the role of the so-called portal region, involving the second α -helix from the cap ( α 2), β C- β D, and β E- β F turns in FAs exchange. To test the idea of a lid that opens, we performed a soaking experiment on an h-FABP crystal in which the cap is part of the packing contacts, and its movement is strongly restricted. Even in these conditions, we observed the replacement of palmitic acid by 2-Bromohexadecanoic acid (Br-palmitic acid). Our MD simulations reveal a two-step lipid entry process: (i) The travel of the lipid head through the cavity in the order of tens of nanoseconds, and (ii) The accommodation of its hydrophobic tail in hundreds to thousands of nanoseconds. We observed this even in the cases in which the FAs enter the cavity by their tail. During this process, the FAs do not follow a single trajectory, but multiple ones through which they get into the protein cavity. Thanks to the complementary views between experiment and simulation, we can give an approach to a mechanistic view of the exchange process.

Molecular Characteristics of the Fatty-Acid-Binding Protein (FABP) Family in Spirometra mansoni-A Neglected Medical Tapeworm

The plerocercoid larva of the tapeworm Spirometra mansoni can parasitize humans and animals, causing serious parasitic zoonosis. The molecular characteristics and adaptive parasitism mechanism of Spirometra tapeworms are still unknown. In this study, 11 new members of the fatty-acid-binding protein (FABP) family were characterized in S. mansoni. A clustering analysis showed 11 SmFABPs arranged into two groups, and motif patterns within each group had similar organizations. RT-qPCR showed that SmFABPs were highly expressed in the adult stage, especially in gravid proglottid. A high genetic diversity of SmFABPs and relative conservation of FABPs in medical platyhelminthes were observed in the phylogenetic analysis. Immunolocalization revealed that natural SmFABP is mainly located in the tegument and parenchymal tissue of the plerocercoid and the uterus, genital pores, and cortex of adult worms. rSmFABP can build a more stable holo form when binding with palmitic acid to protect the hydrolytic sites of the protein. A fatty acid starvation induction test suggested that SmFABP might be involved in fatty acid absorption, transport, and metabolism in S. mansoni. The findings in this study will lay the foundation to better explore the underlying mechanisms of FABPs involved in Spirometra tapeworms as well as related taxa.

Fatty acid binding protein 4 has prognostic value in peripheral artery disease

OBJECTIVE

Peripheral artery disease (PAD) remains undertreated, despite its association with major amputation and mortality. This is partly due to a lack of available disease biomarkers. The intracellular protein fatty acid binding protein 4 (FABP4) is implicated in diabetes, obesity, and metabolic syndrome. Given that these risk factors are strong contributors to vascular disease, we assessed the prognostic ability of FABP4 in predicting PAD-related adverse limb events.

METHODS

This was a prospective case-control study with 3 years of follow-up. Baseline serum FABP4 concentrations were measured in patients with PAD (n = 569) and without PAD (n = 279). The primary outcome was major adverse limb event (MALE; defined as a composite of vascular intervention or major amputation). The secondary outcome was worsening PAD status (drop in ankle-brachial index ≥0.15). Kaplan-Meier and Cox proportional hazards analyses adjusted for baseline characteristics were conducted to assess the ability of FABP4 to predict MALE and worsening PAD status.

RESULTS

Patients with PAD were older and more likely to have cardiovascular risk factors compared with those without PAD. Over the study period, MALE and worsening PAD status occurred in 162 (19%) and 92 (11%) patients, respectively. Higher FABP4 levels were significantly associated with 3-year MALE (unadjusted hazard ratio [HR], 1.19; 95% confidence interval [CI], 1.04-1.27; adjusted HR, 1.18; 95% CI, 1.03-1.27; P = .022) and worsening PAD status (unadjusted HR, 1.18; 95% CI, 1.13-1.31; adjusted HR, 1.17; 95% CI, 1.12-1.28; P < .001). Three-year Kaplan-Meier survival analysis demonstrated that patients with high FABP4 levels had a decreased freedom from MALE (75% vs 88%; log rank = 22.6; P < .001), vascular intervention (77% vs 89%; log rank = 20.8; P < .001), and worsening PAD status (87% vs 91%; log rank = 6.16; P = .013).

CONCLUSIONS

Individuals with higher serum concentrations of FABP4 are more likely to develop PAD-related adverse limb events. FABP4 has prognostic value in risk-stratifying patients for further vascular evaluation and management.

Echinocystic acid prevents obesity and fatty liver via interacting with FABP1

Long-term high-fat diet (HFD) will lead to obesity and their complications. Echinocystic acid (EA), a triterpene, shows anti-inflammatory and antioxidant effects. We predict that EA supplementation can prevent obesity, diabetes, and nonalcoholic steatohepatitis. To test our hypothesis, we investigated the effects of EA supplementation on mice with HFD-induced obesity in vivo and in vitro by adding EA to the diet of mice and the medium of HepG2 cells, the protein target of EA was analyzed by molecular docking. The results showed that EA ameliorated obesity and inhibited blood triglyceride and liver triglyceride concentrations than those in the HFD groups. The data on molecular docking indicated that FABP1 was a potential target of EA. Further experimental results confirmed that EA affected the triglyceride level by regulating the function of FABP1. This study may provide a new potential inhibitor for FABP1 and a new strategy for the treatment of obesity.

Oxaliplatin-induced cardiotoxicity in mice is connected to the changes in energy metabolism in the heart tissue

Oxaliplatin is a platinum-based alkylating chemotherapeutic agent used for cancer treatment. At high cumulative dosage, the negative effect of oxaliplatin on the heart becomes evident and is linked to a growing number of clinical reports. The aim of this study was to determine how chronic oxaliplatin treatment causes the changes in energy-related metabolic activity in the heart that leads to cardiotoxicity and heart damage in mice. C57BL/6 male mice were treated with a human equivalent dosage of intraperitoneal oxaliplatin (0 and 10 mg/kg) once a week for eight weeks. During the treatment, mice were followed for physiological parameters, ECG, histology and RNA sequencing of the heart. We identified that oxaliplatin induces strong changes in the heart and affects the heart's energy-related metabolic profile. Histological post-mortem evaluation identified focal myocardial necrosis infiltrated with a small number of associated neutrophils. Accumulated doses of oxaliplatin led to significant changes in gene expression related to energy related metabolic pathways including fatty acid (FA) oxidation, amino acid metabolism, glycolysis, electron transport chain, and NAD synthesis pathway. At high accumulative doses of oxaliplatin, the heart shifts its metabolism from FAs to glycolysis and increases lactate production. It also leads to strong overexpression of genes in NAD synthesis pathways such as Nmrk2. Changes in gene expression associated with energy metabolic pathways can be used to develop diagnostic methods to detect oxaliplatin-induced cardiotoxicity early on as well as therapy to compensate for the energy deficit in the heart to prevent heart damage.

Evaluation of circulating insulin-like growth factor-1, heart-type fatty acid-binding protein, and endotrophin levels as prognostic markers of COVID-19 infection severity

BACKGROUND

Coronavirus Disease 2019 (COVID-19) is a worldwide pandemic challenge spreading enormously within a few months. COVID-19 is characterized by the over-activation of the immune system causing cytokine storm. Insulin-like growth factor-1 (IGF-1) pathway can regulate the immune response via interaction with various implicated cytokines. Heart-type fatty acid-binding protein (H-FABP) has been shown to promote inflammation. Given the fact that coronavirus infections induce cytokines secretion leading to inflammatory lung injury, it has been suggested that H-FABP levels are affected by COVID-19 severity. Moreover, endotrophin (ETP), the cleavage product of collagen VI, may be an indicator of an overactive repair process and fibrosis, considering that viral infection may predispose or exacerbate existing respiratory conditions, including pulmonary fibrosis. This study aims to assess the prognostic capacity of circulating IGF-1, HFABP, and ETP, levels for COVID-19 severity progression in Egyptian patients.

METHODS

The study cohort included 107 viral RNA-positive patients and an equivalent number of control individuals with no clinical signs of infection. Clinical assessments included profiling of CBC; serum iron; liver and kidney functions; inflammatory markers. Circulating levels of IGF-1; H-FABP, and ETP were estimated using the corresponding ELISA kits.

RESULTS

No statistical difference in the body mass index was detected between the healthy and control groups, while the mean age of infected patients was significantly higher (P = 0.0162) than the control. Patients generally showed elevated levels of inflammatory markers including CRP and ESR concomitant with elevated serum ferritin; D dimer and procalcitonin levels, besides the COVID-19 characteristic lymphopenia and hypoxemia were also frequent. Logistic regression analysis revealed that oxygen saturation; serum IGF-1, and H-FABP can significantly predict the infection progression (P < 0.001 each). Both serum IGF-1 and H-FABP as well as O₂ saturation showed remarkable prognostic potentials in terms of large AUC values, high sensitivity/specificity values, and wide confidence interval. The calculated threshold for severity prognosis was 25.5 ng/mL; 19.5 ng/mL, 94.5, % and for IGF-1, H-FABP, and O₂ saturation; respectively. The calculated thresholds of serum IGF-1; H-FABP, and O₂ saturation showed positive and negative value ranges of 79-91% and 72-97%; respectively, with 66-95%, 83-94% sensitivity, and specificity; respectively.

CONCLUSION

The calculated cut-off values of serum IGF-1 and H-FABP represent a promising non-invasive prognostic tool that would facilitate the risk stratification in COVID-19 patients, and control the morbidity/mortality associated with progressive infection.

Transcriptomic analysis of lipid metabolism in zebrafish offspring of parental long-term exposure to bisphenol A

Bisphenol A (BPA) is one of the most common environmental endocrine disruptor chemicals (EDCs) and exhibits reproductive, cardiovascular, immune, and neurodevelopmental toxic effects. The development of the offspring was examined in the present investigation to determine the cross-generational effects of long-term exposure of parental zebrafish to environmental concentrations of BPA (15 and 225 µg/L). Parents were exposed to BPA for 120 days, and their offspring were evaluated at 7 days after fertilization in BPA-free water. The offspring exhibited higher mortality, deformity, and heart rates, and showed significant fat accumulation in abdominal region. RNA-Seq data showed that more lipid metabolism-related KEGG pathways, such as the PPAR signaling pathway, adipocytokine signaling pathway, and ether lipid metabolism pathway were enriched in the 225 µg/L BPA-treated offspring compared to 15 µg/L BPA-treated offspring, indicating greater effects of high dose BPA on offspring lipid metabolism. Lipid metabolism-related genes implied that BPA is responsible for disrupting lipid metabolic processes in the offspring through increased lipid production, abnormal transport, and disruption of lipid catabolism. The present study will be helpful for further evaluation of the reproductive toxicity of environmental BPA to organisms and the subsequent parent-mediated intergenerational toxicity.

Heart-Type Fatty Acid Binding Protein Binds Long-Chain Acylcarnitines and Protects against Lipotoxicity

Heart-type fatty-acid binding protein (FABP3) is an essential cytosolic lipid transport protein found in cardiomyocytes. FABP3 binds fatty acids (FAs) reversibly and with high affinity. Acylcarnitines (ACs) are an esterified form of FAs that play an important role in cellular energy metabolism. However, an increased concentration of ACs can exert detrimental effects on cardiac mitochondria and lead to severe cardiac damage. In the present study, we evaluated the ability of FABP3 to bind long-chain ACs (LCACs) and protect cells from their harmful effects. We characterized the novel binding mechanism between FABP3 and LCACs by a cytotoxicity assay, nuclear magnetic resonance, and isothermal titration calorimetry. Our data demonstrate that FABP3 is capable of binding both FAs and LCACs as well as decreasing the cytotoxicity of LCACs. Our findings reveal that LCACs and FAs compete for the binding site of FABP3. Thus, the protective mechanism of FABP3 is found to be concentration dependent.