Recent insights into the biological functions of liver fatty acid binding protein 1

Bletilla striata polysaccharides alleviate metabolic dysfunction-associated steatotic liver disease through enhancing hepatocyte RelA/ HNF1α signaling

BACKGROUND

Bletilla striata polysaccharides (BSP) have antioxidant, immune regulation, and anti-fibrotic activities. However, the therapeutic effect and mechanisms underlying the action of BSP in metabolic dysfunction-associated steatotic liver disease (MASLD) have not been fully understood.

AIM

To investigate the therapeutic effects and mechanisms of BSP on MASLD by centering on the hepatocyte nuclear factor kappa B p65 (RelA)/hepatocyte nuclear factor-1 alpha (HNF1α) signaling.

METHODS

A mouse model of MASLD was induced by feeding with a high-fat-diet (HFD) and a hepatocyte model of steatosis was induced by treatment with sodium oleate (SO) and sodium palmitate (SP). The therapeutic effects of BSP on MASLD were examined in vivo and in vitro. The mechanisms underlying the action of BSP were analyzed for their effect on lipid metabolism disorder, endoplasmic reticulum (ER) stress, and the RelA/HNF1α signaling.

RESULTS

HFD feeding reduced hepatocyte RelA and HNF1α expression, induced ER stress, lipid metabolism disorder, and necroptosis in mice, which were significantly mitigated by treatment with BSP. Furthermore, treatment with BSP or BSP-containing conditional rat serum significantly attenuated the sodium oleate/sodium palmitate (SO/SP)-induced hepatocyte steatosis by decreasing lipid accumulation, and lipid peroxidation, and enhancing the expression of RelA, and HNF1α. The therapeutic effects of BSP on MASLD were partially abrogated by RELA silencing in mice and RELA knockout in hepatocytes. RELA silencing or knockout significantly down-regulated HNF1α expression, and remodeled ER stress and oxidative stress responses during hepatic steatosis.

CONCLUSION

Treatment with BSP ameliorates MASLD, associated with enhancing the RelA/HNF1α signaling, remodeling ER stress and oxidative stress responses in hepatocytes.

From Adipose to Ailing Kidneys: The Role of Lipid Metabolism in Obesity-Related Chronic Kidney Disease

Obesity has emerged as a significant public health crisis, closely linked to the pathogenesis and progression of chronic kidney disease (CKD). This review explores the intricate relationship between obesity-induced lipid metabolism disorders and renal health. We discuss how excessive free fatty acids (FFAs) lead to lipid accumulation in renal tissues, resulting in cellular lipotoxicity, oxidative stress, and inflammation, ultimately contributing to renal injury. Key molecular mechanisms, including the roles of transcriptional regulators like PPARs and SREBP-1, are examined for their implications in lipid metabolism dysregulation. The review also highlights the impact of glomerular and tubular lipid overload on kidney pathology, emphasizing the roles of podocytes and tubular cells in maintaining kidney function. Various therapeutic strategies targeting lipid metabolism, including pharmacological agents such as statins and SGLT2 inhibitors, as well as lifestyle modifications, are discussed for their potential to mitigate CKD progression in obese individuals. Future research directions are suggested to better understand the mechanisms linking lipid metabolism to kidney disease and to develop personalized therapeutic approaches. Ultimately, addressing obesity-related lipid metabolism disorders may enhance kidney health and improve outcomes for individuals suffering from CKD.

Metallomic Approach to Mercury and Selenium in the Liver Tissue of Psectrogaster amazonica and Raphiodon vulpinus from the Brazilian Amazon

This paper reports the results of a mercury (Hg) and selenium (Se) metallomic study in the liver tissues of Psectrogaster amazonica and Raphiodon vulpinus from the Brazilian Amazon. Two-dimensional electrophoresis, graphite furnace atomic absorption spectrometry, and liquid chromatography-tandem mass spectrometry were performed. Hg and Se determinations allowed the calculation of Hg:Se and Se:Hg molar ratio and Se values for health benefits (Se HBVs). The Se:Hg values were >1 for both fish species, whereas the Se HBVs were >5 for P. amazonica and >10 for R. vulpinus, indicating that both possess Se reserves to control Hg toxicity. The metallomic data allowed the identification of 11 Hg/Se-associated protein spots in the two fish species, with concentrations in the range of 9.70 ± 0.14 and 28.44 ± 0.31 mg kg-1 of Hg and 16.15 ± 0.21 and 43.12 ± 0.51 mg kg-1 of Se. Five metal binding proteins (MBP) in the Hg/Se-associated protein spots in the liver proteome of P. amazonica and eight in R. vulpinus were identified, indicating the possible formation of Hg/Se complexes on the MBP structures. The activities analysis of catalase, superoxide dismutase, GPx enzymes, and lipoperoxide concentrations demonstrated that Hg-induced oxidative stress did not occur, possibly because both fish species possess Se reserves necessary to inhibit the Hg's deleterious effects.

T-2 toxin triggers lipid metabolism disorder and oxidative stress in liver of ducks

T-2 toxin (T-2) is a highly toxic mycotoxin that threatens organism health, yet its hepatoxicity on ducks remains unknown. The present study aimed to assess the hepatoxicity and redox reactions induced by T-2 in ducks. Sixty 7-day-old ducklings were divided into 4 groups and exposed to 0, 200, 400 and 800 μg/kg bodyweight of T-2 through oral gavage for 2 weeks. The growth performance, liver histopathology, biochemical indicators, antioxidant capacity and hepatic damage-related genes of ducks were analyzed. The results revealed that 800 µg/kg T-2 inhibited the growth and feed intake of ducks, whereas liver index increased with the elevation of T-2 concentration. Histological examinations exhibited that T-2 caused hepatic cord disappeared and severe steatosis. Moreover, serum AST, ALT and TG were substantially higher in 400 μg/kg group, while γ-GT and ALB were reduced under 800 μg/kg T-2 exposure. In addition, significant increase of malondialdehyde (MDA) in liver, decrease of hepatic total antioxidant capacity (T-AOC) and serum glutathione peroxidase (GPx) were observed in all T-2 groups. Furthermore, T-2 disrupted lipid metabolism and oxidative stress-related genes expression in liver. The transcript level of fatty acid binding protein 1 (FABP1) was markedly raised in all T-2 groups, and hepatic acyl-CoA oxidase 1 (ACOX1) was significantly raised in 200 and 400 μg/kg T-2 groups. Under 800 μg/kg T-2, significant induction of hypoxia inducible factor-1 alpha (HIF-1α), and downregulated peroxisome proliferator-activated receptor (PPAR)-alpha, carnitine palmitoyl transferase 1A (CPT1A), peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1α), GPx1, catalase (CAT) mRNA levels were observed. Therefore, we conclude that T-2 caused liver injury through lipid metabolism disruption and oxidative stress in ducks, which reinforces understanding about the hepatoxicity mechanisms of T-2 and provides new targets for detoxication and prevention.

FABP1 induces lipogenesis by regulating the processing of SREBP1 in hepatocytes of large yellow croaker (Larimichthys crocea)

Fatty acid-binding protein 1 (FABP1) plays an important role in regulating fatty acid metabolism in liver, which is a potential therapeutic target for diseases such as non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanisms are not well defined. Using complementary experimental models, we discovered FABP1 induction in hepatocytes as a primary mediator of lipogenesis when exposed to fatty acids, especially saturated fatty acids (SFAs). In the feeding trial, palm oil led to excess lipid accumulation in the liver of large yellow croaker (Larimichthys crocea), accompanied by significant induction of FABP1. In cultured cells, palmitic acid (PA), a kind of SFA, triggered the fabp1 expression and increased triglyceride (TG) contents. Knockdown of FABP1 dampened PA-induced TG accumulation through mitigated lipogenesis. The overexpression of FABP1 showed the opposite result. Furthermore, the inactivation of FABP1 led to induction in insulin-induced gene 1 (INSIG1) expression, which attenuated the processing of sterol regulatory element-binding protein 1 (SREBP1) by down-regulating the nuclear-localized SREBP1. These results revealed a previously unrecognized function of FABP1 in response to PA, providing additional evidence for targeting FABP1 in the treatment of NAFLD caused by SFA.

Lactylome analysis reveals potential target modified proteins in the retina of form-deprivation myopia

The biological mechanisms underlying the development of myopia have not yet been completely elucidated. The retina is critical for visual signal processing, which primarily utilizes aerobic glycolysis to produce lactate as a metabolic end product. Lactate facilitates lysine lactylation (Kla), a posttranslational modification essential for transcriptional regulation. This study found increased glycolytic flux and lactate accumulation in the retinas of form-deprived myopic guinea pigs. Subsequently, a comprehensive analysis of Kla levels in retinal proteins revealed that Kla was upregulated at 124 sites in 92 proteins and downregulated at three sites in three proteins. Functional enrichment and protein interaction analyses showed significant enrichment in pathways related to energy metabolism, including glutathione metabolism, glycolysis, and the hypoxia-inducible factor-1 signaling pathway. Parallel-reaction monitoring confirmed data reliability. These findings suggest a connection between myopia and retinal energy metabolism imbalance, providing new insights into the pathogenesis of myopia.

Traditional Chinese medicine and plant-derived natural products in regulating triglyceride metabolism: Mechanisms and therapeutic potential

The incidence of cardiometabolic disease is increasing globally, with a trend toward younger age of onset. Among these, atherosclerotic cardiovascular disease is a leading cause of mortality worldwide. Despite the efficacy of traditional lipid-lowering drugs, such as statins, in reducing low-density lipoprotein cholesterol levels, a significant residual risk of cardiovascular events remains, which is closely related to unmet triglyceride (TG) targets. The clinical application of current TG-lowering Western medicines has certain limitations, necessitating alternative or complementary therapeutic strategies. Traditional Chinese medicine (TCM) and plant-derived natural products, known for their safety owing to their natural origins and diverse biological activities, offer promising avenues for TG regulation with potentially fewer side effects. This review systematically summarises the mechanisms of TG metabolism and subsequently reviews the regulatory effects of TCM and plant-derived natural products on TG metabolism, including the inhibition of TG synthesis (via endogenous and exogenous pathways), promotion of TG catabolism, regulation of fatty acid absorption and transport, enhancement of lipophagy, modulation of the gut microbiota, and other mechanisms. In conclusion, through a comprehensive analysis of recent studies, this review consolidates the multifaceted regulatory roles of TCM and plant-derived natural products in TG metabolism and elucidates their potential as safer, multi-target therapeutic agents in managing hypertriglyceridemia and mitigating cardiovascular risk, thereby providing a basis for new drug development.

Low molecular weight heparin promotes the PPAR pathway by protecting the glycocalyx of cells to delay the progression of diabetic nephropathy

Diabetic nephropathy (DN) is one of the most important comorbidities for diabetic patients, which is the main factor leading to end-stage renal disease. Heparin analogs can delay the progression of DN, but the mechanism is not fully understood. In this study, we found that low molecular weight heparin therapy significantly upregulated some downstream proteins of the peroxisome proliferator-activated receptor (PPAR) signaling pathway by label-free quantification of the mouse kidney proteome. Through cell model verification, low molecular weight heparin can protect the heparan sulfate of renal tubular epithelial cells from being degraded by heparanase that is highly expressed in a high-glucose environment, enhance the endocytic recruitment of fatty acid-binding protein 1, a coactivator of the PPAR pathway, and then regulate the activation level of intracellular PPAR. In addition, we have elucidated for the first time the molecular mechanism of heparan sulfate and fatty acid-binding protein 1 interaction. These findings provide new insights into understanding the role of heparin in the pathogenesis of DN and developing corresponding treatments.

A pre-vaccination immune metabolic interplay determines the protective antibody response to a dengue virus vaccine

Protective immunity to dengue virus (DENV) requires antibody response to all four serotypes. Systems vaccinology identifies a multi-OMICs pre-vaccination signature and mechanisms predictive of broad antibody responses after immunization with a tetravalent live attenuated DENV vaccine candidate (Butantan-DV/TV003). Anti-inflammatory pathways, including TGF-β signaling expressed by CD68low monocytes, and the metabolites phosphatidylcholine (PC) and phosphatidylethanolamine (PE) positively correlate with broadly neutralizing antibody responses against DENV. In contrast, expression of pro-inflammatory pathways and cytokines (IFN and IL-1) in CD68hi monocytes and primary and secondary bile acids negatively correlates with broad DENV-specific antibody responses. Induction of TGF-β and IFNs is done respectively by PC/PE and bile acids in CD68low and CD68hi monocytes. The inhibition of viral sensing by PC/PE-induced TGF-β is confirmed in vitro. Our studies show that the balance between metabolites and the pro- or anti-inflammatory state of innate immune cells drives broad and protective B cell response to a live attenuated dengue vaccine.

Dysfunctional VLDL metabolism in MASLD

Lipidomics has unveiled the intricate human lipidome, emphasizing the extensive diversity within lipid classes in mammalian tissues critical for cellular functions. This diversity poses a challenge in maintaining a delicate balance between adaptability to recurring physiological changes and overall stability. Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), linked to factors such as obesity and diabetes, stems from a compromise in the structural and functional stability of the liver within the complexities of lipid metabolism. This compromise inaccurately senses an increase in energy status, such as during fasting-feeding cycles or an upsurge in lipogenesis. Serum lipidomic studies have delineated three distinct metabolic phenotypes, or "metabotypes" in MASLD. MASLD-A is characterized by lower very low-density lipoprotein (VLDL) secretion and triglyceride (TG) levels, associated with a reduced risk of cardiovascular disease (CVD). In contrast, MASLD-C exhibits increased VLDL secretion and TG levels, correlating with elevated CVD risk. An intermediate subtype, with a blend of features, is designated as the MASLD-B metabotype. In this perspective, we examine into recent findings that show the multifaceted regulation of VLDL secretion by S-adenosylmethionine, the primary cellular methyl donor. Furthermore, we explore the differential CVD and hepatic cancer risk across MASLD metabotypes and discuss the context and potential paths forward to gear the findings from genetic studies towards a better understanding of the observed heterogeneity in MASLD.

Liver Fatty Acid-binding Protein Is a More Reliable Biomarker for Liver Injury in Nonalcoholic Steatohepatitis than Other Etiologies of Hepatitis

BACKGROUND/AIMS

 Liver fatty acid-binding protein (LFABP) controls hepatocyte lipid metabolism and can be a biomarker in liver diseases. We compared the correlation of LFABP levels with liver histology in viral hepatitis and nonalcoholic fatty liver disease (NAFLD) and investigated the utility of serum LFABP as a biomarker for liver damage.

MATERIALS AND METHODS

 We included 142 patients (60 chronic viral hepatitis B [CHB], 35 chronic viral hepatitis C [CHC], 47 NAFLD) and 40 healthy controls. LFABP levels were determined in all participants, and a liver biopsy was performed on patients. The nonalcoholic steatohepatitis (NASH) activity score (NAS), hepatosteatosis, liver inflammation, and fibrosis were evaluated for NAFLD patients. Ishak's histological scores were used for viral hepatitis. The correlation between LFABP levels and histologic scores was assessed in each group.

RESULTS

 Serum LFABP levels in CHB, CHC, NAFLD, and control groups were 2.2, 3.5, 7.6, and 2.1 ng/mL, respectively. LFABP levels were significantly higher in the NAFLD group compared to the control, CHC, and CHB groups. LFABP was significantly higher in the NASH group than in nonalcoholic steatohepatitis, 8 ng/mL and 5.4 ng/mL, respectively (P = .001). In the NAFLD group, LFABP levels showed a moderate positive correlation with NAS score (r = 0.58, P <.001), ballooning degeneration (r = 0.67, P <.001), and lobular inflammation (r = 0.62, P <.001). A logistic regression study showed that the level of LFABP was predictive of NASH independent of age, gender, homeostasis model of IR, body mass index, aspartate aminotransferase, and alanine aminotransferase (OR = 1.869, P = .01).

CONCLUSION

 LFABP specifically correlates with liver histology in NAFLD compared to viral hepatitis. Additionally, it can distinguish NASH from simple steatosis. LFABP may be a valuable biomarker for hepatocyte injury in NASH.

Integrated transcriptomic and metabolomic analysis of the hepatotoxicity of dichloroacetonitrile

Dichloroacetonitrile (DCAN), an emerged nitrogenous disinfection by-product (N-DBP) in drinking water, has garnered attention owing to its strong cytotoxicity, genotoxicity, and carcinogenicity. However, there are limited studies on its potential hepatotoxicity mechanisms. Understanding hepatotoxicity is essential in order to identify and assess the potential risks posed by environmental pollutants on liver health and to safeguard public health. Here, we investigated the viability, reactive oxygen species (ROS) levels, and cell cycle profile of DCAN-exposed HepG2 cells and analyzed the mechanism of DCAN-induced hepatotoxicity using both transcriptomic and metabolomic techniques. The study revealed that there was a decrease in cell viability, increase in ROS production, and increase in the number of cells in the G2/M phase with an increase in the concentration of DCAN. Omics analyses showed that DCAN exposure increased cellular ROS levels, leading to oxidative damage in hepatocytes, which further induced DNA damage, cell cycle arrest, and cell growth impairment. Thus, DCAN has significant toxic effects on hepatocytes. Integrated analysis of transcriptomics and metabolomics offers new insights into the mechanisms of DCAN-induced hepatoxicity.

Silencing the fatty acid elongase gene elovl6 induces reprogramming of nutrient metabolism in male Oreochromis niloticus

Elongation of very long-chain fatty acids protein 6 (ELOVL6) plays a pivotal role in the synthesis of endogenous fatty acids, influencing energy balance and metabolic diseases. The primary objective of this study was to discover the molecular attributes and regulatory roles of ELOVL6 in male Nile tilapia, Oreochromis niloticus. The full-length cDNA of elovl6 was cloned from male Nile tilapia, and was determined to be 2255-bp long, including a 5'-untranslated region of 193 bp, a 3'-untranslated region of 1252 bp, and an open reading frame of 810 bp encoding 269 amino acids. The putative protein had typical features of ELOVL proteins. The transcript levels of elovl6 differed among various tissues and among fish fed with different dietary lipid sources. Knockdown of elovl6 in Nile tilapia using antisense RNA technology resulted in significant alterations in hepatic morphology, long-chain fatty acid synthesis, and fatty acid oxidation, and led to increased fat deposition in the liver and disrupted glucose/lipid metabolism. A comparative transcriptomic analysis (elovl6 knockdown vs. the negative control) identified 5877 differentially expressed genes with significant involvement in key signaling pathways including the peroxisome proliferator-activated receptor signaling pathway, fatty acid degradation, glycolysis/gluconeogenesis, and the insulin signaling pathway, all of which are crucial for lipid and glucose metabolism. qRT-PCR analyses verified the transcript levels of 13 differentially expressed genes within these pathways. Our findings indicate that elovl6 knockdown in male tilapia impedes oleic acid synthesis, culminating in aberrant nutrient metabolism.

Hepatocellular Carcinoma LINC01116 Outcompetes T Cells for Linoleic Acid and Accelerates Tumor Progression

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer with a highly immunosuppressive tumor microenvironment and a typical pattern of disturbances in hepatic lipid metabolism. Long non-coding RNAs are shown to play an important role in the regulation of gene expression, but much remains unknown between tumor microenvironment and lipid metabolism as a bridging molecule. Here, long intergenic nonprotein coding RNA 01116 (LINC01116) acts as this molecular which is frequently upregulated in HCC patients and associated with HCC progression in vitro and in vivo is identified. Mechanistically, LINC01116 stabilizes EWS RNA-binding protein 1 (EWSR1) by preventing RAD18 E3 Ubiquitin Protein Ligase (RAD18) -mediated ubiquitination. The enhanced EWSR1 protein upregulates peroxisome proliferator activated receptor alpha (PPARA) and fatty acid binding protein1 (FABP1) expression, a long-chain fatty acid (LCFA) transporter, and thus cancer cells outcompete T cells for LCFAs, especially linoleic acid, for seeding their own growth, leading to T cell malfunction and HCC malignant progression. In a preclinical animal model, the blockade of LINC01116 leads to enhanced efficacy of anti-PD1 treatment accompanied by increased cytotoxic T cell and decreased exhausted T cell infiltration. Collectively, LINC01116 is an immunometabolic lncRNA and the LINC01116-EWSR1-PPARA-FABP1 axis may be targetable for cancer immunotherapy.

Drugs Form Ternary Complexes with Human Liver Fatty Acid Binding Protein 1 (FABP1) and FABP1 Binding Alters Drug Metabolism

Liver fatty acid binding protein 1 (FABP1) binds diverse endogenous lipids and is highly expressed in the human liver. Binding to FABP1 alters the metabolism and homeostasis of endogenous lipids in the liver. Drugs have also been shown to bind to rat FABP1, but limited data are available for human FABP1 (hFABP1). FABP1 has a large binding pocket, and up to two fatty acids can bind to FABP1 simultaneously. We hypothesized that drug binding to hFABP1 results in formation of ternary complexes and that FABP1 binding alters drug metabolism. To test these hypotheses, native protein mass spectrometry (MS) and fluorescent 11-(dansylamino)undecanoic acid (DAUDA) displacement assays were used to characterize drug binding to hFABP1, and diclofenac oxidation by cytochrome P450 2C9 (CYP2C9) was studied in the presence and absence of hFABP1. DAUDA binding to hFABP1 involved high (Kd,1 = 0.2 μM) and low (Kd,2 > 10 μM) affinity binding sites. Nine drugs bound to hFABP1 with equilibrium dissociation constant (Kd) values ranging from 1 to 20 μM. None of the tested drugs completely displaced DAUDA from hFABP1, and fluorescence spectra showed evidence of ternary complex formation. Formation of DAUDA-hFABP1-diclofenac ternary complex was verified with native MS. Docking predicted diclofenac binding in the portal region of FABP1 with DAUDA in the binding cavity. The catalytic rate constant of diclofenac hydroxylation by CYP2C9 was decreased by ∼50% (P < 0.01) in the presence of FABP1. Together, these results suggest that drugs form ternary complexes with hFABP1 and that hFABP1 binding in the liver will alter drug metabolism and clearance. SIGNIFICANCE STATEMENT: Many commonly prescribed drugs bind fatty acid binding protein 1 (FABP1), forming ternary complexes with FABP1 and the fluorescent fatty acid 11-(dansylamino)undecanoic acid. These findings suggest that drugs will bind to apo-FABP1 and fatty acid-bound FABP1 in the human liver. The high expression of FABP1 in the liver, together with drug binding to FABP1, may alter drug disposition processes in vivo.

Upregulation of Hepatic Glutathione S-Transferase Alpha 1 Ameliorates Metabolic Dysfunction-Associated Steatosis by Degrading Fatty Acid Binding Protein 1

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common metabolic disease of the liver, characterized by hepatic steatosis in more than 5% of hepatocytes. However, despite the recent approval of the first drug, resmetirom, for the management of metabolic dysfunction-associated steatohepatitis, decades of target exploration and hundreds of clinical trials have failed, highlighting the urgent need to find new druggable targets for the discovery of innovative drug candidates against MASLD. Here, we found that glutathione S-transferase alpha 1 (GSTA1) expression was negatively associated with lipid droplet accumulation in vitro and in vivo. Overexpression of GSTA1 significantly attenuated oleic acid-induced steatosis in hepatocytes or high-fat diet-induced steatosis in the mouse liver. The hepatoprotective and anti-inflammatory drug bicyclol also attenuated steatosis by upregulating GSTA1 expression. A detailed mechanism showed that GSTA1 directly interacts with fatty acid binding protein 1 (FABP1) and facilitates the degradation of FABP1, thereby inhibiting intracellular triglyceride synthesis by impeding the uptake and transportation of free fatty acids. Conclusion: GSTA1 may be a good target for the discovery of innovative drug candidates as GSTA1 stabilizers or enhancers against MASLD.

Proteomics-Derived Biomarker Panel Facilitates Distinguishing Primary Lung Adenocarcinomas With Intestinal or Mucinous Differentiation From Lung Metastatic Colorectal Cancer

The diagnosis of primary lung adenocarcinomas with intestinal or mucinous differentiation (PAIM) remains challenging due to the overlapping histomorphological, immunohistochemical (IHC), and genetic characteristics with lung metastatic colorectal cancer (lmCRC). This study aimed to explore the protein biomarkers that could distinguish between PAIM and lmCRC. To uncover differences between the two diseases, we used tandem mass tagging-based shotgun proteomics to characterize proteomes of formalin-fixed, paraffin-embedded tumor samples of PAIM (n = 22) and lmCRC (n = 17).Then three machine learning algorithms, namely support vector machine (SVM), random forest, and the Least Absolute Shrinkage and Selection Operator, were utilized to select protein features with diagnostic significance. These candidate proteins were further validated in an independent cohort (PAIM, n = 11; lmCRC, n = 19) by IHC to confirm their diagnostic performance. In total, 105 proteins out of 7871 proteins were significantly dysregulated between PAIM and lmCRC samples and well-separated two groups by Uniform Manifold Approximation and Projection. The upregulated proteins in PAIM were involved in actin cytoskeleton organization, platelet degranulation, and regulation of leukocyte chemotaxis, while downregulated ones were involved in mitochondrial transmembrane transport, vasculature development, and stem cell proliferation. A set of ten candidate proteins (high-level expression in lmCRC: CDH17, ATP1B3, GLB1, OXNAD1, LYST, FABP1; high-level expression in PAIM: CK7 (an established marker), NARR, MLPH, S100A14) was ultimately selected to distinguish PAIM from lmCRC by machine learning algorithms. We further confirmed using IHC that the five protein biomarkers including CDH17, CK7, MLPH, FABP1 and NARR were effective biomarkers for distinguishing PAIM from lmCRC. Our study depicts PAIM-specific proteomic characteristics and demonstrates the potential utility of new protein biomarkers for the differential diagnosis of PAIM and lmCRC. These findings may contribute to improving the diagnostic accuracy and guide appropriate treatments for these patients.

Design, synthesis, and biological evaluation of first-in-class FABP1 inhibitors for the treatment of NASH

The fatty acid-binding protein 1 (FABP1) is a fatty acid transporter protein that is considered as an emerging target for metabolic diseases. Despite forceful evidence that the inhibition of FABP1 is essential for ameliorating NASH, pharmacological control and validation of FABP1 are hindered by a lack of relevant inhibitors as pharmacological tool. Therefore, the development of effective FABP1 inhibitors is a current focus of research. Herein, we firstly reported the comprehensive structure-activity relationship (SAR) study of novel FABP1 inhibitors derived from high throughput screening of our in-house library, which resulting in the identification of the optimal compound 44 (IC50 = 4.46 ± 0.54 μM). Molecular docking studies revealed that 44 forms stable hydrogen bonds with amino acids around the active pocket of FABP1. Moreover, 44 alleviated the typical histological features of fatty liver in NASH mice, including steatosis, lobular inflammation, ballooning and fibrosis. Additionally, 44 has been demonstrated to have lipid metabolism regulating, anti-oxidative stress and hepatoprotective properties. This study might be provided a promising insight into the field of NASH and inspiration for the development of FABP1 inhibitors.

Integrated single-cell transcriptomics reveals the hypoxia-induced inflammation-cancer transformation in NASH-derived hepatocellular carcinoma

Non-alcoholic fatty liver disease (NAFLD) has emerged as the primary risk factor for hepatocellular carcinoma (HCC), owing to improved vaccination rates of Hepatitis B and the increasing prevalence of metabolic syndrome related to obesity. Although the importance of innate and adaptive immune cells has been emphasized, the malignant transformation of hepatocytes and their intricate cellular network with the immune system remain unclear. The study incorporated four single-cell transcriptomic datasets of liver tissues covering healthy and NAFLD-related disease status. To identify the subsets and functions of hepatocytes and macrophages, we employed differential composition analysis, functional enrichment analysis, pseudotime analysis, and scenic analysis. Furthermore, an experimental mouse model for the transformation of nonalcoholic steatohepatitis into hepatocellular carcinoma was established for validation purposes. We defined CYP7A1+ hepatocytes enriched in precancerous lesions as 'Transitional Cells' in the progression from NAFLD to HCC. CYP7A1+ hepatocytes upregulated genes associated with stress response, inflammation and cancer-associated pathways and downregulated the normal hepatocyte signature. We observed that hypoxia activation accompanied the entire process of inflammation-cancer transformation. Hepatocyte-derived HIF1A was gradually activated during the progression of NAFLD disease to adapt to the hypoxic microenvironment and hepatocytes under hypoxic environment led to changes in the metabolism, proliferation and angiogenesis, promoting the occurrence of tumours. Meanwhile, hypoxia induced the polarization of RACK1+ macrophages that enriched in the liver tissues of NASH towards immunosuppressed TREM2+ macrophages. Moreover, immunosuppressive TREM2+ macrophages were recruited by tumour cells through the CCL15-CCR1 axis to enhance immunosuppressive microenvironment and promote NAFLD-related HCC progression. The study provides a deep understanding of the development mechanism of NAFLD-related HCC and offers theoretical support and experimental basis for biological targets, drug research, and clinical application.

An evaluation of a hepatotoxicity risk induced by the microplastic polymethyl methacrylate (PMMA) using HepG2/THP-1 co-culture model

Inappropriate disposal of plastic wastes and their durability in nature cause uncontrolled accumulation of plastic in land/marine ecosystems, also causing destructive effects by bioaccumulating along the food chain. Microplastics may cause chronic inflammation in relation to their permanent structures, especially through oxidative stress and cytotoxic cellular damage, which could increase the risk of cancer development. The accumulation of microplastics in the liver is a major concern, and therefore, the identification of the mechanisms of their hepatotoxic effects is of great importance. Polymethyl methacrylate (PMMA) is a widely used thermoplastic. It has been determined that PMMA disrupts lipid metabolism in the liver in various aquatic organisms and causes reproductive and developmental toxicity. PMMA-induced hepatotoxic effects in humans have not yet been clarified. In our study, the toxic effects of PMMA (in the range of 3-10 μm) on the human liver were investigated using the HepG2/THP-1 macrophage co-culture model, which is a sensitive immune-mediated liver injury model. Cellular uptake of micro-sized PMMA in the cells was done by transmission electron microscopy. Determination of its effects on cell viability and inflammatory response, oxidative stress, along with gene and protein expression levels that play a role in the mechanism pathways underlying the effects were investigated. The results concluded that inflammation, oxidative stress, and disruptions in lipid metabolism should be the focus of attention as important underlying causes of PMMA-induced hepatotoxicity. Our study, which points out the potential adverse effects of microplastics on human health, supports the literature information on the subject.

Dietary Supplementation of Astragalus membranaceus Extract Affects Growth Performance, Antioxidant Capacity, Immune Response, and Energy Metabolism of Largemouth Bass (Micropterus salmoides)

The present study investigated the effects of Astragalus membranaceus extract (AME) on growth performance, immune response, and energy metabolism of juvenile largemouth bass (Micropterus salmoides). Seven diets containing 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, and 0.6% AME (Con, AME0.1, AME0.2, AME0.3, AME0.4, AME0.5, and AME0.6 groups) were formulated and fed to M. salmoides for 8 weeks. Final body weight (FBW), feed intake (FI), weight gain (WG), and specific growth rate (SGR) were all significantly higher in AME0.4 group than in Con group (P < 0.05). Feed conversion rate (FCR) was significantly improved in AME0.5 group compared with Con group (P < 0.05). Whole-body crude protein contents were significantly increased in AME0.2 group (P < 0.05). Whole-body crude lipid contents were significantly lower in AME0.2 and AME0.3 groups, while muscle lipid was upregulated by dietary AME (P < 0.05). Hepatic malondialdehyde (MDA) contents were significantly lowered in AME0.3 and AME0.4 groups, and catalase (CAT) activities were significantly increased in AME0.1 and AME0.2 groups (P < 0.05). Plasma aspartate aminotransferase (AST) level was significantly lowered in AME0.5, and AME0.6 groups, and alanine aminotransferase (ALT) level was lowered in AME0.5 groups (P < 0.05). Plasma triglyceride was declined in AME0.6 group, and glucose was decreased by 0.3%-0.5% AME (P < 0.05). Significantly higher hepatocyte diameter, lamina propria width, and submucosal layer thickness were recorded in AME0.6 groups, while the longest villi height was obtained in AME0.2 and AME0.3 groups (P < 0.05). The mRNA expression levels of insulin-like growth factor 1 (igf1) revealed the growth-promoting effect of AME. The anti-inflammatory and antiapoptotic effects of AME were demonstrated by transcription levels of interleukin 8 (il-8), tumor necrosis factor-alpha (tnf-a), caspase, B-cell lymphoma-xl (Bcl-xl), bcl-2 associated x (Bax), and bcl-2-associated death protein (Bad). The transcription levels of lipid metabolism and gluconeogenesis related genes, including acetyl-CoA carboxylase alpha (acc1), fatty acid synthase (fasn), fatty acid binding protein 1 (fabp1), phosphoenolpyruvate carboxykinase 2 (pepck2), and glucose-6-phosphatase catalytic subunit 1a (g6pc), were reduced by AME treatment, while the levels of glycolysis-related genes, including glucokinase (gck) and pyruvate kinase (pk), were the highest in AME0.2 and AME0.3 groups (P < 0.05). According to polynomial regression analysis of SGR, WG, FCR, whole-body crude lipid, MDA, and ALT, the optimal AME supplementation level was estimated to be 0.320%-0.429% of the diet. These results provided insights into the roles of AME in regulating immunity and metabolism, which highly indicated its potential as immunostimulants and metabolic regulators in diverse aquatic animals.

Single-cell transcriptome landscape of zebrafish liver reveals hepatocytes and immune cell interactions in understanding nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease in the world. Immunity is the major contributing factor in NAFLD; however, the interaction of immune cells and hepatocytes in disease progression has not been fully elucidated. As a popular species for studying NAFLD, zebrafish, whose liver is a complex immune system mediated by immune cells and non-immune cells in maintaining immune tolerance and homeostasis. Understanding the cellular composition and immune environment of zebrafish liver is of great significance for its application in NAFLD. Here, we established a liver atlas that consists of 10 cell types using single-cell RNA sequencing (scRNA-seq). By examining the heterogeneity of hepatocytes and analyzing the expression of NAFLD-associated genes in the specific cluster, we provide a potential target cell model to study NAFLD. Additionally, our analysis identified two subtypes of distinct resident macrophages with inflammatory and non-inflammatory functions and characterized the successive stepwise development of T cell subclusters in the liver. Importantly, we uncovered the possible regulation of macrophages and T cells on target cells of fatty liver by analyzing the cellular interaction between hepatocytes and immune cells. Our data provide valuable information for an in-depth study of immune cells targeting hepatocytes to regulate the immune balance in NAFLD.

The impact of dietary Laminaria digitata and alginate lyase supplementation on the weaned piglet liver: A comprehensive proteomics and metabolomics approach

The brown seaweed Laminaria digitata, a novel feedstuff for weaned piglets, has potentially beneficial prebiotic properties. However, its recalcitrant cell wall challenges digestion in monogastrics. Alginate lyase is a promising supplement to mitigate this issue. This study's aim was to investigate the impact of incorporating 10% dietary Laminaria digitata, supplemented with alginate lyase, on the hepatic proteome and metabolome of weaned piglets. These diets introduced minor variations to the metabolome and caused significant shifts in the proteome. Dietary seaweed provided a rich source of n-3 PUFAs that could signal hepatic fatty acid oxidation (FABP, ACADSB and ALDH1B1). This may have affected the oxidative stability of the tissue, requiring an elevated abundance of GST for regulation. The presence of reactive oxygen species likely inflicted protein damage, triggering increased proteolytic activity (LAPTM4B and PSMD4). Alginate lyase supplementation augmented the number of differentially abundant proteins, which included GBE1 and LDHC, contributing to maintain circulating glucose levels by mobilizing glycogen stores and branched-chain amino acids. The enzymatic supplementation with alginate lyase amplified the effects of the seaweed-only diet. An additional filter was employed to test the effect of missing values on the proteomics analysis, which is discussed from a technical perspective. SIGNIFICANCE: Brown seaweeds such as Laminaria digitata have prebiotic and immune-modulatory components, such as laminarin, that can improve weaned piglet health. However, they have recalcitrant cell wall polysaccharides, such as alginate, that can elicit antinutritional effects on the monogastric digestive system. The aim of this study was to evaluate the effect of a high level of dietary L. digitata and alginate lyase supplementation on the hepatic metabolism of weaned piglets, using high throughput Omics approaches.

Comparison of Lysophospholipids and Bile Acids on the Growth Performance, Lipid Deposition, and Intestinal Health of Largemouth Bass (Micropterus salmoides)

Lysophospholipids (LPLs) and bile acids (BA) are commonly used as emulsifiers in aquaculture. This study investigated the effects of dietary supplementation of LPLs or BA on the growth performance, lipid deposition, and intestinal health of largemouth juveniles. Fish were randomly allotted into three groups in quadruplicate and fed with a basal diet (CON) or diets containing 300 mg/kg LPLs (LPLs), or 300 mg/kg commercially available BA product (BA) for 8 weeks. The results showed that compared with the control group, LPLs and BA supplemented groups showed a higher weight gain trend, and LPLs supplementation promoted the protein deposition in fish body. Both BA and LPLs supplementations helped to maintain liver health by decreasing the activities of aspartate aminotransferase and alanine aminotransferase in serum. Besides, LPLs supplementation decreased overall lipid deposition in terms of mesenteric fat index and liver lipid content. Furthermore, LPLs supplementation showed unique advantage in improving intestinal barrier, as characterized by the increased villus length and higher expression of the tight junction protein zo-1 expression. LPLs supplementation also increased the alpha diversity index and the abundances of Proteobacteria in the intestinal microbiota which is positively correlated with the abundance of SCFA in the gut. These findings will promote the application of novel feed additives and especially provide a basis for the rational selection of emulsifiers in the aquaculture industry.

Significant association of elevated serum galectin-9 levels with the development of non-alcoholic fatty liver disease in patients with rheumatoid arthritis

Background

Non-alcoholic fatty liver disease (NAFLD) is prevalent among rheumatoid arthritis (RA) patients, but its pathogenesis has rarely been explored. Galectin-9 (Gal-9) interacts with T cell immunoglobulin and mucin-containing-molecule-3 (TIM-3) expressed on hepatocytes and thus regulates T cell proliferation in a murine model of NAFLD. We aimed to examine the pathogenic role of the Gal-9/TIM-3 pathway in RA-NAFLD.

Methods

Serum levels of Gal-9, soluble TIM-3 (sTIM-3), fatty acid-binding proteins (FABP)1, and FABP4 were determined by ELISA in forty-five RA patients and eleven healthy participants. Using Oil-red O staining and immunoblotting, we examined the effects of Gal-9 and free fatty acid (FFA) on lipid accumulation in human hepatocytes and FABP1 expression.

Results

Serum Gal-9, sTIM-3 and FABP1 level were significantly higher in RA patients (median 5.02 ng/mL, 3.42 ng/mL, and 5.76 ng/mL, respectively) than in healthy participants (1.86 ng/mL, 0.99 ng/mL, and 0.129 ng/mL, all p < 0.001). They were also significantly higher in patients with moderate-to-severe NAFLD compared with none-to-mild NAFLD (p < 0.01; p < 0.05; and p < 0.01, respectively). Serum Gal-9 levels were positively correlated with sTIM-3, FABP1, FABP4 levels, and ultrasound-fatty liver score, respectively, in RA patients. Multivariate regression analysis revealed that Gal-9 (cut-off>3.30) was a significant predictor of NAFLD development, and Gal-9 and sTIM-3 were predictors of NAFLD severity (both p < 0.05). The cell-based assay showed that Gal-9 and FFA could upregulate FABP1 expression and enhance lipid droplet accumulation in hepatocytes.

Conclusion

Elevated levels of Gal-9 and sTIM3 in RA patients with NAFLD and their positive correlation with NAFLD severity suggest the pathogenic role of Gal-9 signaling in RA-related NAFLD.

Comparative quantitation of liver-type fatty acid-binding protein localizations in liver injury and non-pathological liver tissue in dogs

Background and Aim

Liver injury results in the production of free radicals that can lead to hepatocytic degeneration, cirrhosis, and hepatocellular carcinoma (HCC). Liver-fatty acid-binding protein (L-FABP) is highly expressed in hepatocytes and is a key regulator of hepatic lipid metabolism and antioxidant characteristics. Interestingly, the increase in L-FABP expression could be used as a novel marker of liver injury. Therefore, this study aimed to use immunohistochemical techniques to investigate the expression of L-FABP in dogs with liver injury compared with dogs with non-pathological liver.

Materials and Methods

Liver tissue samples were collected from dog biopsy specimens at the Veterinary Diagnostic Laboratory at the Faculty of Veterinary Medicine, Chiang Mai University. The tissues were prepared for immunohistochemistry and the expression and localization of L-FABP were investigated using one-way analysis of variance.

Results

Immunohistochemical analysis showed that L-FABP was strongly expressed in the hepatocytes of dogs with lipidosis and HCC when compared with that in normal liver. Semi-quantitative immunohistochemistry evaluation showed the percentage of protein expression of L-FABP 0.023 ± 0.027 in the non-pathological liver. The percentage of L-FABP protein expression in lipidosis and HCC was found to be 8.517 ± 1.059 and 17.371 ± 4.026, respectively.

Conclusion

L-FABP expression in dogs with liver injuries was significantly higher than that in dogs with non-pathological liver injury (p = 0.05). These results suggest that L-FABP has the potential as a novel marker for specific diagnosis and prognosis of dogs with liver injury.

Drugs Form Ternary Complexes with Human Liver Fatty Acid Binding Protein (FABP1) and FABP1 Binding Alters Drug Metabolism

Liver fatty acid binding protein (FABP1) binds diverse endogenous lipids and is highly expressed in the human liver. Binding to FABP1 alters the metabolism and homeostasis of endogenous lipids in the liver. Drugs have also been shown to bind to rat FABP1, but limited data is available for human FABP1 (hFABP1). FABP1 has a large binding pocket and multiple fatty acids can bind to FABP1 simultaneously. We hypothesized that drug binding to hFABP1 results in formation of ternary complexes and that FABP1 binding alters drug metabolism. To test these hypotheses native protein mass spectrometry (MS) and fluorescent 11-(dansylamino)undecanoic acid (DAUDA) displacement assays were used to characterize drug binding to hFABP1 and diclofenac oxidation by cytochrome P450 2C9 (CYP2C9) was studied in the presence and absence of hFABP1. DAUDA binding to hFABP1 involved high (Kd,1=0.2 µM) and low affinity (Kd,2 >10 µM) binding sites. Nine drugs bound to hFABP1 with Kd values ranging from 1 to 20 µM. None of the tested drugs completely displaced DAUDA from hFABP1 and fluorescence spectra showed evidence of ternary complex formation. Formation of DAUDA-diclofenac-hFABP1 ternary complex was verified with native MS. Docking placed diclofenac in the portal region of FABP1 with DAUDA in the binding cavity. Presence of hFABP1 decreased the kcat and Km,u of diclofenac with CYP2C9 by ~50% suggesting that hFABP1 binding in the liver will alter drug metabolism and clearance. Together, these results suggest that drugs form ternary complexes with hFABP1 and that hFABP1 interacts with CYP2C9.

Association between nonalcoholic fatty liver disease and increased glucose-to-albumin ratio in adults without diabetes

Background

Nonalcoholic fatty liver disease (NAFLD) affects approximately 30% of individuals globally. Both serum glucose and albumin were demonstrated to be potential markers for the development of NAFLD. We hypothesized that the risk of NAFLD may be proportional to the glucose-to-albumin ratio (GAR).

Methods

Based on information from the National Health and Nutrition Examination Survey (NHANES) 1999-2018, it was determined that GAR was associated with an increased risk of NAFLD and liver fibrosis utilizing weighted multivariable logistic regression. Participants with a fatty liver index (FLI) over 60 were identified with NAFLD, and those with an NAFLD fibrosis score (NFS) >0.676 with evidence of NAFLD were labeled with advanced hepatic fibrosis (AHF). The liver biopsy was utilized to verify the relationship between GAR and FLD in our center cohort. Mendelian randomization analysis investigated the genetic relationship between GAR and NAFLD.

Results

Of 15,534 eligible participants, 36.4% of participants were identified as NAFLD without AHF. GAR was positively correlated with the probability of NAFLD following full adjustment for possible variables (OR = 1.53, 95% CI: 1.39-1.67). It was confirmed that patients with NAFLD and AHF had an inferior prognosis. The relationship between GAR and NFS was favorable (R = 0.46, P< 0.0001), and NAFLD patients with a higher GAR tended to develop poor survival. In our center cohort, the association between GAR and NAFLD was verified.

Conclusion

Among participants without diabetes, greater GAR was linked to higher risks of NAFLD. In addition, NAFLD patients with higher GAR tended to develop liver fibrosis and adverse outcomes.

Liver proteomics analysis reveals the differentiation of lipid mechanism and antioxidant enzyme activity during chicken embryonic development

Chicken embryo development is a dynamic process. However, no detailed information is available about the protein abundance changes associated with the lipid mechanism and antioxidant enzyme activity during the egg embryo development. Thus, in the present study, an TMT-based proteomic approach was used to quantify protein abundance changes at different stages of chicken embryonic development. A total of 289 significantly differentially abundant hepatic proteins were quantified, of which 180 were upregulated and 109 were downregulated in the comparison of Day 20 with Day 12 in chicken embryos. Pathway analysis showed that metabolic pathways were the most highly enriched pathways, followed by arachidonic acid metabolism and steroid biosynthesis. Integration of proteomic-based studies profiling of three incubation stages revealed that the two compare groups (Day 12 vs Day 20 and Day 16 vs Day 20) shared some key differentially abundant proteins (DAPs), including LBFABP, FABP5, CYP4V2, PDCD4, LAL, APOA1, APOA4, SAA, FABP2, ACBSG2, FABP2, CYP51A1, and FBXO9. The STRING database and GO analysis results showed that there was close connectivity between APOA4, LBFABP, SERPINC1, APOA1, FGB, FGA, ANGPTL3 and these proteins were involved in the oxidation-reduction process, lipid transport, iron ion, heme, and lipid binding. Importantly, APOA4, FABP2, and CYP51A1 might be key factors to control fat deposition and antioxidant enzyme activity during chicken embryonic development. These findings will facilitate a better understanding of antioxidant and lipid mechanisms in chicken embryo and these DAPs can be further investigated as candidate markers to predict lipid deposition and the activity of antioxidant enzymes.

Potential Biomarkers for the Earlier Diagnosis of Kidney and Liver Damage in Acute Intermittent Porphyria

Acute intermittent porphyria (AIP) is an inherited metabolic disorder associated with complications including kidney failure and hepatocellular carcinoma, probably caused by elevations in the porphyrin precursors porphobilinogen (PBG) and delta-aminolevulinic acid (ALA). This study explored differences in modern biomarkers for renal and hepatic damage between AIP patients and controls. Urine PBG testing, kidney injury panels, and liver injury panels, including both routine and modern biomarkers, were performed on plasma and urine samples from AIP cases and matched controls (50 and 48 matched pairs, respectively). Regarding the participants' plasma, the AIP cases had elevated kidney injury marker-1 (KIM-1, p = 0.0002), fatty acid-binding protein-1 (FABP-1, p = 0.04), and α-glutathione S-transferase (α-GST, p = 0.001) compared to the matched controls. The AIP cases with high PBG had increased FABP-1 levels in their plasma and urine compared to those with low PBG. In the AIP cases, KIM-1 correlated positively with PBG, CXCL10, CCL2, and TCC, and the liver marker α-GST correlated positively with IL-13, CCL2, and CCL4 (all p < 0.05). In conclusion, KIM-1, FABP-1, and α-GST could represent potential early indicators of renal and hepatic damage in AIP, demonstrating associations with porphyrin precursors and inflammatory markers.

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.

Chronic metabolic stress drives developmental programs and loss of tissue functions in non-transformed liver that mirror tumor states and stratify survival

Under chronic stress, cells must balance competing demands between cellular survival and tissue function. In metabolic dysfunction-associated steatotic liver disease (MASLD, formerly NAFLD/NASH), hepatocytes cooperate with structural and immune cells to perform crucial metabolic, synthetic, and detoxification functions despite nutrient imbalances. While prior work has emphasized stress-induced drivers of cell death, the dynamic adaptations of surviving cells and their functional repercussions remain unclear. Namely, we do not know which pathways and programs define cellular responses, what regulatory factors mediate (mal)adaptations, and how this aberrant activity connects to tissue-scale dysfunction and long-term disease outcomes. Here, by applying longitudinal single-cell multi -omics to a mouse model of chronic metabolic stress and extending to human cohorts, we show that stress drives survival-linked tradeoffs and metabolic rewiring, manifesting as shifts towards development-associated states in non-transformed hepatocytes with accompanying decreases in their professional functionality. Diet-induced adaptations occur significantly prior to tumorigenesis but parallel tumorigenesis-induced phenotypes and predict worsened human cancer survival. Through the development of a multi -omic computational gene regulatory inference framework and human in vitro and mouse in vivo genetic perturbations, we validate transcriptional (RELB, SOX4) and metabolic (HMGCS2) mediators that co-regulate and couple the balance between developmental state and hepatocyte functional identity programming. Our work defines cellular features of liver adaptation to chronic stress as well as their links to long-term disease outcomes and cancer hallmarks, unifying diverse axes of cellular dysfunction around core causal mechanisms.

Gowda SG, Chen Y, Hui SP. Crosstalk between Lipids and Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), a complex liver disorder that can result in non-alcoholic steatohepatitis, cirrhosis, and liver cancer, is the accumulation of fat in the liver seen in people due to metabolic dysfunction. The pathophysiology of NAFLD is influenced by several variables, such as metabolic dysregulation, oxidative stress, inflammation, and genetic susceptibility. This illness seriously threatens global health because of its link to obesity, insulin resistance, type 2 diabetes, and other metabolic disorders. In recent years, lipid–NAFLD crosstalk has drawn a lot of interest. Through numerous methods, lipids have been connected to the onset and advancement of the illness. The connection between lipids and NAFLD is the main topic of the current review, along with the various therapeutic targets and currently available drugs. The importance of hepatic lipid metabolism in the progression of NAFLD is summarized with the latest results in the field.

Crowdsourcing temporal transcriptomic coronavirus host infection data: Resources, guide, and novel insights

The emergence of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) reawakened the need to rapidly understand the molecular etiologies, pandemic potential, and prospective treatments of infectious agents. The lack of existing data on SARS-CoV-2 hampered early attempts to treat severe forms of coronavirus disease-2019 (COVID-19) during the pandemic. This study coupled existing transcriptomic data from severe acute respiratory syndrome-related coronavirus 1 (SARS-CoV-1) lung infection animal studies with crowdsourcing statistical approaches to derive temporal meta-signatures of host responses during early viral accumulation and subsequent clearance stages. Unsupervised and supervised machine learning approaches identified top dysregulated genes and potential biomarkers (e.g. CXCL10, BEX2, and ADM). Temporal meta-signatures revealed distinct gene expression programs with biological implications to a series of host responses underlying sustained Cxcl10 expression and Stat signaling. Cell cycle switched from G1/G0 phase genes, early in infection, to a G2/M gene signature during late infection that correlated with the enrichment of DNA damage response and repair genes. The SARS-CoV-1 meta-signatures were shown to closely emulate human SARS-CoV-2 host responses from emerging RNAseq, single cell, and proteomics data with early monocyte-macrophage activation followed by lymphocyte proliferation. The circulatory hormone adrenomedullin was observed as maximally elevated in elderly patients who died from COVID-19. Stage-specific correlations to compounds with potential to treat COVID-19 and future coronavirus infections were in part validated by a subset of twenty-four that are in clinical trials to treat COVID-19. This study represents a roadmap to leverage existing data in the public domain to derive novel molecular and biological insights and potential treatments to emerging human pathogens.

Direct androgen receptor control of sexually dimorphic gene expression in the mammalian kidney

Mammalian organs exhibit distinct physiology, disease susceptibility, and injury responses between the sexes. In the mouse kidney, sexually dimorphic gene activity maps predominantly to proximal tubule (PT) segments. Bulk RNA sequencing (RNA-seq) data demonstrated that sex differences were established from 4 and 8 weeks after birth under gonadal control. Hormone injection studies and genetic removal of androgen and estrogen receptors demonstrated androgen receptor (AR)-mediated regulation of gene activity in PT cells as the regulatory mechanism. Interestingly, caloric restriction feminizes the male kidney. Single-nuclear multiomic analysis identified putative cis-regulatory regions and cooperating factors mediating PT responses to AR activity in the mouse kidney. In the human kidney, a limited set of genes showed conserved sex-linked regulation, whereas analysis of the mouse liver underscored organ-specific differences in the regulation of sexually dimorphic gene expression. These findings raise interesting questions on the evolution, physiological significance, disease, and metabolic linkage of sexually dimorphic gene activity.

Investigation of gastrointestinal injury-related biomarkers in dairy cattle with displaced abomasum

BACKGROUND

Displaced abomasum (DA) is one of the most important metabolic disorders of dairy cattle. In DA, ischaemic damage may occur as a result of impaired perfusion due to abomasal displacement, which may result in gastrointestinal mucosal damage.

OBJECTIVE

Investigation of gastrointestinal tissue damage in cattle with right displacement of the abomasum (RDA) and left displacement of the abomasum (LDA) using intestinal-related biomarkers.

METHODS

Forty-eight DA (24 LDA, 24 RDA) and 15 healthy Holstein dairy cows were enrolled between March 2021 and July 2022. Serum biomarkers including gamma-enteric smooth muscle actin (ACTG-2), liver-fatty acid binding proteins (L-FABP), platelet activating factor (PAF), trefoil factor-3 (TFF-3), leptin, claudin-3 and interleukin-8 (IL-8) concentrations were measured from venous blood samples.

RESULTS

L-FABP concentrations in the LDA group and TFF-3 concentrations in the RDA group were lower than in the control group. The leptin concentration of the RDA group was higher than that of the other groups. There was a negative correlation between lactate, leptin and IL-8 concentrations. There was a negative correlation between lactate and TFF-3, whereas leptin and lactate were positively correlated. Leptin was the more reliable biomarker for discriminating between RDA and LDA cases.

CONCLUSION

Changes in serum L-FABP, TFF-3 and leptin concentrations in cattle with DA may reflect acute intestinal injury and the subsequent repair phase. However, these biomarkers had poor diagnostic performance in discriminating between healthy and cattle with DA, while leptin emerged as the most useful marker in differentiating LDA from RDA cases.

Therapeutic effects of fatty acid binding protein 1 in mice with pulmonary fibrosis by regulating alveolar epithelial regeneration

INTRODUCTION

Idiopathic pulmonary fibrosis is a progressive fibrotic lung disease with limited therapeutic options and high lethality, related to alveolar type II epithelial (ATII) cell dysregulation, the abnormal repair of alveolar epithelial cells and activation of fibroblasts promote the development of pulmonary fibrosis. Fatty acid binding protein 1 (FABP1) was significantly downregulated in the fibrotic state by proteomics screening in our previous date, and the ATII cell dysregulation can be mediated by FABP1 via regulating fatty acid metabolism and intracellular transport. The aim of this study was to evaluate the role and potential mechanism of FABP1 in the development of pulmonary fibrosis.

METHODS

Proteomics screening was used to detect changes of the protein profiles in two different types (induced by bleomycin and silica, respectively) of pulmonary fibrosis models. The localisation of FABP1 in mouse lung was detected by Immunofluorescence and immunohistochemistry. Experimental methods such as lung pathology, micro-CT, western blotting, small animal imaging in vivo, EdU, etc were used to verify the role of FABP1 in pulmonary fibrosis.

RESULTS

The expression of FABP1 in the mouse lung was significantly reduced in the model of pulmonary fibrosis from our proteomic analysis and immunological methods, the double immunofluorescence staining showed that FABP1 was mainly localised in type II alveolar epithelial cells. Additionally, the expression of FABP1 was negatively correlated with the progression of pulmonary fibrosis. Further in vivo and in vitro experiments showed that overexpression of FABP1 alleviated pulmonary fibrosis by protecting alveolar epithelium from injury and promoting cell survival.

CONCLUSION

Our findings provide a proof-of-principle that FABP1 may represent an effective treatment for pulmonary fibrosis by regulating alveolar epithelial regeneration, which may be associated with the fatty acid metabolism in ATII cells.

Glucocorticoid receptor modulator CORT125385 alleviates diet-induced hepatosteatosis in male and female mice

Non-alcoholic fatty liver disease (NAFLD) is a common condition that can progress to the more severe conditions like non-alcoholic steatohepatitis (NASH) for which limited effective therapeutic options are available. In this study, we set out to evaluate the novel glucocorticoid receptor modulator CORT125385, an analogue of the previously studied miricorilant but without mineralocorticoid receptor binding activity. Male and female mice that received high-fat diet and fructose water were treated with either vehicle, CORT125385 or mifepristone. We found that CORT125385 significantly lowered hepatic triglyceride levels in male mice, and hepatic triglyceride and cholesterol levels in female mice. Mifepristone treatment had no effect in male mice, but significantly lowered hepatic triglyceride and cholesterol levels in female mice. In reporter assays in vitro, CORT125385 showed weak partial agonism on the progesterone receptor (PR) at high doses, as well as PR antagonism at a potency 1000-fold lower than mifepristone. In vivo, CORT125385 treatment did not influence PR-responsive gene expression in the oviduct, while mifepristone treatment strongly influenced these genes in the oviduct, thus excluding in vivo PR cross-reactivity of CORT125385 at a therapeutically active dose. We conclude that CORT125385 is a promising glucocorticoid receptor modulator that effectively reduces liver steatosis in male and female mice without affecting other steroid receptors at doses that lower hepatic lipid content.

Trophic transfer of nanoplastics and di(2-ethylhexyl) phthalate in a freshwater food chain (Chlorella Pyrenoidosa-Daphnia magna-Micropterus salmoides) induced disturbance of lipid metabolism in fish

Nanoplastics and di(2-ethylhexyl) phthalate (DEHP) are ubiquitous emerging contaminants that are transferred among organisms through food chain in the ecosystem. This study evaluated the trophic transfer of polystyrene nanoplastics (PSNPs) and DEHP in a food chain including Chlorella pyrenoidosa, Daphnia magna and Micropterus salmoides (algae-crustacean-fish) and lipid metabolism at a higher trophic level in fish. Our results showed that the PSNPs and DEHP accumulated in C. pyrenoidosa or D. magna were transferred to the M. salmoides, of which the DEHP were not biomagnified, while the PSNPs were trophically amplified by the food chain. It is suggested that more PSNPs might be accumulated by higher level consumers in a longer food chain. Additionally, the trophic transfer of PSNPs and DEHP resulted in antioxidant response and histopathological damage in M. salmoides. Moreover, the lipid biochemical parameters and lipid metabolism related genes (fasn, hsl, cpt1a, atgl, apob, fabp1, lpl, cetp) of M. salmoides were significantly affected, which indicated disturbance of lipid metabolism. This study offers great insight into the transfer of contaminants by trophic transfer and their negative effects on organisms at higher trophic levels, which cause human exposure to MNPs and organic contaminants in the ecosystem.

Derlin-1 ameliorates nonalcoholic hepatic steatosis by promoting ubiquitylation and degradation of FABP1

BACKGROUND AND AIMS

The functions of liver fatty acid binding protein 1 (FABP1) in the regulation of nonalcoholic fatty liver disease (NAFLD) have been previously established. However, how FABP1 expression is dynamically regulated in metabolic disorders is unclear. Previous studies have reported that ubiquitin proteasome-mediated degradation of FABP1 is involved, but the mechanism remains unknown.

METHODS

Dysregulated expression of hepatic FABP1 and Derlin-1 was observed in NAFLD patients. We performed mice hepatic tissue coimmunoprecipitation based mass spectrum assays. Interaction between Derlin-1 and FABP1, and its impact on FABP1 ubiquitination status was evaluated by coimmunoprecipitation. The role of Derlin-1 in lipid deposition was tested using adenovirus-mediated overexpression in C57BL/6 mice, as well as by Derlin-1 overexpression or knockdown in HepG2 cells.

RESULTS

As a subunit of the endoplasmic reticulum-associated degradation complex, Derlin-1 was negatively associated with NAFLD patients, interacted with and ubiquitinated FABP1. Derlin-1 suppressed FABP1 levels and inhibited lipid deposition through a FABP1-dependent pathway. Additionally, Trim25, an E3 ubiquitin ligase present in the endoplasmic reticulum, was recruited to promote Derlin-1-related polyubiquitylation of FABP1, thereby creating a ubiquitin-associated network for FABP1 regulation. Derlin-1 overexpression ameliorated hepatic steatosis in both C57BL/6 mice and HepG2 cells, and contributed to attenuated weight gain, lower liver weight, and visceral fat mass.

CONCLUSIONS

FABP1 was degraded by Derlin-1 through ubiquitin modification. Negative regulation of FABP1 by Derlin-1 overexpression, suppressed lipid metabolism and alleviated lipid deposition in vivo and in vitro. Hence, Derlin-1 activation in hepatocytes may represent a potential therapeutic strategy for NAFLD.

Hop-derived Humulinones Reveal Protective Effects in in vitro Models of Hepatic Steatosis, Inflammation and Fibrosis

Nonalcoholic fatty liver disease (NAFLD) is emerging as leading cause of liver disease worldwide. Specific pharmacologic therapy for NAFLD is a major unmet medical need. Recently, iso-alpha acids, hop-derived bitter compounds in beer, have been shown to beneficially affect NAFLD pathology. Humulinones are further hop derived bitter acids particularly found in modern styles of beer. So far, biological effects of humulinones have been unknown. Here, we investigated the effect of humulinones in in vitro models for hepatic steatosis, inflammation and fibrosis. Humulinones dose-dependently inhibited fatty acid induced lipid accumulation in primary human hepatocytes. Humulinones reduced the expression of fatty acid uptake transporter CD36 and key enzymes of (de novo) lipid synthesis. Conversely, humulinones increased the expression of FABP1, CPT1 and ACOX1, indicative for increased lipid combustion. Furthermore, humulinones ameliorated steatosis induced pro-inflammatory gene expression. Furthermore, humulinones significantly reduced the expression of pro-inflammatory and pro-fibrogenic factors in control as well as lipopolysaccharide treated activated hepatic stellate cells, which play a key role in hepatic fibrosis. In conclusion, humulinones beneficially affect different pathophysiological steps of NAFLD. Our data suggest humulinones as promising therapeutic agents for the prevention and treatment of NAFLD.

Deletion of PGAM5 Downregulates FABP1 and Attenuates Long-Chain Fatty Acid Uptake in Hepatocellular Carcinoma

Phosphoglycerate mutase 5 (PGAM5) is a Ser/His/Thr phosphatase responsible for regulating mitochondrial homeostasis. Overexpression of PGAM5 is correlated with a poor prognosis in hepatocellular carcinoma, colon cancer, and melanoma. In hepatocellular carcinoma, silencing of PGAM5 reduces growth, which has been attributed to decreased mitophagy and enhanced apoptosis. Yet in colon cancer, PGAM5's pro-tumor survival effect is correlated to lipid metabolism. We sought to identify whether deletion of PGAM5 modulated lipid droplet accrual in hepatocellular carcinoma. HepG2 and Huh7 PGAM5 knockout cell lines generated using CRISPR/Cas9 technology were used to measure cell growth, cellular ATP, and long-chain fatty acid uptake. Expression of hepatocellular fatty acid transporters, cluster of differentiation 36 (CD36), solute carrier family 27 member 2 (SLC27A2), solute carrier family 27 member 5 (SLC27A5), and fatty acid binding protein 1 (FABP1) was measured by quantitative PCR and Western blot. We found that deletion of PGAM5 attenuates hepatocellular carcinoma cell growth and ATP production. Further, PGAM5 knockout ameliorates palmitate-induced steatosis and reduces expression of FABP1 in HepG2 and Huh7 cell lines. PGAM5's role in hepatocellular carcinoma includes regulation of fatty acid metabolism, which may be related to expression of the fatty acid transporter, FABP1.

PFAS Exposures and the Human Metabolome: A Systematic Review of Epidemiological Studies

Purpose of Review

There is a growing interest in understanding the health effects of exposure to per- and polyfluoroalkyl substances (PFAS) through the study of the human metabolome. In this systematic review, we aimed to identify consistent findings between PFAS and metabolomic signatures. We conducted a search matching specific keywords that was independently reviewed by two authors on two databases (EMBASE and PubMed) from their inception through July 19, 2022 following PRISMA guidelines.

Recent Findings

We identified a total of 28 eligible observational studies that evaluated the associations between 31 different PFAS exposures and metabolomics in humans. The most common exposure evaluated was legacy long-chain PFAS. Population sample sizes ranged from 40 to 1,105 participants at different stages across the lifespan. A total of 19 studies used a non-targeted metabolomics approach, 7 used targeted approaches, and 2 included both. The majority of studies were cross-sectional (n = 25), including four with prospective analyses of PFAS measured prior to metabolomics.

Summary

Most frequently reported associations across studies were observed between PFAS and amino acids, fatty acids, glycerophospholipids, glycerolipids, phosphosphingolipids, bile acids, ceramides, purines, and acylcarnitines. Corresponding metabolic pathways were also altered, including lipid, amino acid, carbohydrate, nucleotide, energy metabolism, glycan biosynthesis and metabolism, and metabolism of cofactors and vitamins. We found consistent evidence across studies indicating PFAS-induced alterations in lipid and amino acid metabolites, which may be involved in energy and cell membrane disruption.

Quantitative Lipid Profiling Reveals Major Differences between Liver Organoids with Normal Pi*M and Deficient Pi*Z Variants of Alpha-1-antitrypsin

Different mutations in the SERPINA1 gene result in alpha-1 antitrypsin (AAT) deficiency and in an increased risk for the development of liver diseases. More than 90% of severe deficiency patients are homozygous for Z (Glu342Lys) mutation. This mutation causes Z-AAT polymerization and intrahepatic accumulation which can result in hepatic alterations leading to steatosis, fibrosis, cirrhosis, and/or hepatocarcinoma. We aimed to investigate lipid status in hepatocytes carrying Z and normal M alleles of the SERPINA1 gene. Hepatic organoids were developed to investigate lipid alterations. Lipid accumulation in HepG2 cells overexpressing Z-AAT, as well as in patient-derived hepatic organoids from Pi*MZ and Pi*ZZ individuals, was evaluated by Oil-Red staining in comparison to HepG2 cells expressing M-AAT and liver organoids from Pi*MM controls. Furthermore, mass spectrometry-based lipidomics analysis and transcriptomic profiling were assessed in Pi*MZ and Pi*ZZ organoids. HepG2 cells expressing Z-AAT and liver organoids from Pi*MZ and Pi*ZZ patients showed intracellular accumulation of AAT and high numbers of lipid droplets. These latter paralleled with augmented intrahepatic lipids, and in particular altered proportion of triglycerides, cholesterol esters, and cardiolipins. According to transcriptomic analysis, Pi*ZZ organoids possess many alterations in genes and cellular processes of lipid metabolism with a specific impact on the endoplasmic reticulum, mitochondria, and peroxisome dysfunction. Our data reveal a relationship between intrahepatic accumulation of Z-AAT and alterations in lipid homeostasis, which implies that liver organoids provide an excellent model to study liver diseases related to the mutation of the SERPINA1 gene.

Desynchronization between Food Intake and Light Stimulations Induces Uterine Clock Quiescence in Female Mice

BACKGROUND

Dysmenorrhea is associated with breakfast skipping in young women, suggesting that fasting in the early active phase disrupts uterine functions.

OBJECTIVES

To investigate the possible involvement of the uterine clock system in fasting-induced uterine dysfunction, we examined core clock gene expressions in the uterus using a 28-h interval-fed mouse model.

METHODS

Young female mice (8 wk of age) were divided into 3 groups: group I (ad libitum feeding), group II (time-restricted feeding, initial 4 h of the active period every day), and group III (time-restricted feeding for 8 h with a 28-h cycle). Groups II and III have the same fasting interval of 20 h. After analyzing feeding and wheel running behaviors during 2 wk of dietary restriction, mice were sacrificed at 4-h intervals, and the expression profiles of clock genes in the uterus and liver were examined by qPCR.

RESULTS

The mice in group I took food mainly during the dark phase and those in group II during the initial 4 h of the dark phase, whereas those in group III delayed feeding time by 4 h per cycle. In all groups, spontaneous wheel running was observed during the dark phase. There was no difference in the quantity of feeding and the amount of running exercise among the 3 groups during the second week. The mRNA expressions of peripheral clock genes, Bmal1, Clock, Per1, Per2, Cry1, Nr1d1, and Dbp and a clock-controlled gene, Fabp1, in the uterus showed rhythmic oscillations with normal sequential expression cascade in groups I and II, whereas their expressions decreased and circadian cycles disappeared in group III. In contrast, liver core clock genes in group III showed clear circadian cycles.

CONCLUSIONS

Fluctuations in the timing of the first food intake impair the uterine clock oscillator system to reduce clock gene expressions and abolish their circadian rhythms.

Proteomics analysis of human breast milk by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) coupled with mass spectrometry to assess breast cancer risk

Breast cancer (BC) is one of the most common cancers and one of the most common causes for cancer-related mortality. Discovery of protein biomarkers associated with cancer is considered important for early diagnosis and prediction of the cancer risk. Protein biomarkers could be investigated by large-scale protein investigation or proteomics, using mass spectrometry (MS)-based techniques. Our group applies MS-based proteomics to study the protein pattern in human breast milk from women with BC and controls and investigates the alterations and dysregulations of breast milk proteins in comparison pairs of BC versus control. These dysregulated proteins might be considered potential future biomarkers of BC. Identification of potential biomarkers in breast milk may benefit young women without BC, but who could collect the milk for future assessment of BC risk. Previously we identified several dysregulated proteins in different sets of human breast milk samples from BC patients and controls using gel-based protein separation coupled with MS. Here, we performed 2D-PAGE coupled with nano-liquid chromatography-tandem MS (nanoLC-MS/MS) in a small-scale study on a set of six human breast milk pairs (three BC samples vs. three controls) and we identified several dysregulated proteins that have potential roles in cancer progression and might be considered potential BC biomarkers in the future.

Impact of Intracellular Lipid Binding Proteins on Endogenous and Xenobiotic Ligand Metabolism and Disposition

The family of intracellular lipid binding proteins (iLBPs) is comprised of 16 members of structurally related binding proteins that have ubiquitous tissue expression in humans. iLBPs collectively bind diverse essential endogenous lipids and xenobiotics. iLBPs solubilize and traffic lipophilic ligands through the aqueous milieu of the cell. Their expression is correlated with increased rates of ligand uptake into tissues and altered ligand metabolism. The importance of iLBPs in maintaining lipid homeostasis is well established. Fatty acid binding proteins (FABPs) make up the majority of iLBPs and are expressed in major organs relevant to xenobiotic absorption, distribution, and metabolism. FABPs bind a variety of xenobiotics including nonsteroidal anti-inflammatory drugs, psychoactive cannabinoids, benzodiazepines, antinociceptives, and peroxisome proliferators. FABP function is also associated with metabolic disease, making FABPs currently a target for drug development. Yet the potential contribution of FABP binding to distribution of xenobiotics into tissues and the mechanistic impact iLBPs may have on xenobiotic metabolism are largely undefined. This review examines the tissue-specific expression and functions of iLBPs, the ligand binding characteristics of iLBPs, their known endogenous and xenobiotic ligands, methods for measuring ligand binding, and mechanisms of ligand delivery from iLBPs to membranes and enzymes. Current knowledge of the importance of iLBPs in affecting disposition of xenobiotics is collectively described. SIGNIFICANCE STATEMENT: The data reviewed here show that FABPs bind many drugs and suggest that binding of drugs to FABPs in various tissues will affect drug distribution into tissues. The extensive work and findings with endogenous ligands suggest that FABPs may also alter the metabolism and transport of drugs. This review illustrates the potential significance of this understudied area.

Direct androgen receptor regulation of sexually dimorphic gene expression in the mammalian kidney

Mammalian organs exhibit distinct physiology, disease susceptibility and injury responses between the sexes. In the mouse kidney, sexually dimorphic gene activity maps predominantly to proximal tubule (PT) segments. Bulk RNA-seq data demonstrated sex differences were established from 4 and 8 weeks after birth under gonadal control. Hormone injection studies and genetic removal of androgen and estrogen receptors demonstrated androgen receptor (AR) mediated regulation of gene activity in PT cells as the regulatory mechanism. Interestingly, caloric restriction feminizes the male kidney. Single-nuclear multiomic analysis identified putative cis-regulatory regions and cooperating factors mediating PT responses to AR activity in the mouse kidney. In the human kidney, a limited set of genes showed conserved sex-linked regulation while analysis of the mouse liver underscored organ-specific differences in the regulation of sexually dimorphic gene expression. These findings raise interesting questions on the evolution, physiological significance, and disease and metabolic linkage, of sexually dimorphic gene activity.

Effects of bisphenols on lipid metabolism and neuro-cardiovascular toxicity in marine medaka larvae

Bisphenols are environmental endocrine disruptors that have detrimental effects on aquatic organisms. Using marine medaka larvae, this study explored the effects of bisphenol compounds [bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF)] on the early growth and development of aquatic organisms. Marine medaka larvae were exposed to bisphenol compounds at concentrations of 0.05, 0.5, and 5 μM for 72 h, and changes in heartbeat rate, behavior, hormone levels, and gene expression were determined. Bisphenols were shown to have a toxic effect on the cardiovascular system of larvae and can cause neurotoxicity and endocrine disruption, such as changes to thyroid-related hormones. Functional enrichment showed that bisphenols mainly affect lipid metabolism and cardiac muscle contraction of larvae, which implied that the main toxic effects of bisphenols on marine medaka larvae targeted the liver and heart. This study provides a theoretical foundation for evaluating the toxicological effects of bisphenols on the early development of aquatic organisms.