TNF-α induces acyl-CoA synthetase 3 to promote lipid droplet formation in human endothelial cells

Coronary Microvascular Dysfunction is Associated with Augmented Lysosomal Signaling in Hypercholesterolemic Mice

Accumulating evidence indicates that coronary microvascular dysfunction (CMD) caused by hypercholesterolemia can lead to myocardial ischemia, with or without obstructive atherosclerotic coronary artery disease (CAD). However, the molecular pathways associated with compromised coronary microvascular function prior to the development of myocardial ischemic injury remain poorly defined. In this study, we investigated the effects of hypercholesterolemia on the function and integrity of the coronary microcirculation in mice and the underlying mechanisms. Mice were fed with a hypercholesterolemic Paigen's diet (PD) for 8 weeks. Echocardiography data showed that PD caused CMD, characterized by significant reductions in coronary blood flow and coronary flow reserve (CFR), but did not affect cardiac remodeling or dysfunction. Immunofluorescence studies revealed that PD-induced CMD was associated with activation of coronary arterioles inflammation and increased myocardial inflammatory cell infiltration. These pathological changes occurred in parallel with the upregulation of lysosomal signaling pathways in endothelial cells (ECs). Treating hypercholesterolemic mice with the cholesterol-lowering drug ezetimibe significantly ameliorated PD-induced adverse effects, including hypercholesterolemia, steatohepatitis, reduced CFR, coronary EC inflammation, and myocardial inflammatory cell infiltration. In cultured mouse cardiac endothelial cells (MCECs), 7-ketocholesterol (7K) increased mitochondrial reactive oxygen species (ROS) and inflammatory responses. Meanwhile, 7K induced the activation of TFEB and lysosomal signaling in MCECs, whereas the lysosome inhibitor bafilomycin A1 blocked 7K-induced TFEB activation and exacerbated 7K-induced inflammation and cell death. Interestingly, ezetimibe synergistically enhanced 7K-induced TFEB activation and attenuated 7K-induced mitochondrial ROS and inflammatory responses in MCECs. These results suggest that CMD can develop and precede detectable cardiac functional or structural changes in the setting of hypercholesterolemia, and that upregulation of TFEB-mediated lysosomal signaling in ECs plays a protective role against CMD.

Ferroptosis in ulcerative colitis: Potential mechanisms and promising therapeutic targets

Ulcerative colitis (UC) is a complex immune-mediated chronic inflammatory bowel disease. It is mainly characterized by diffuse inflammation of the colonic and rectal mucosa with barrier function impairment. Identifying new biomarkers for the development of more effective UC therapies remains a pressing task for current research. Ferroptosis is a newly identified form of regulated cell death characterized by iron-dependent lipid peroxidation. As research deepens, ferroptosis has been demonstrated to be involved in the pathological processes of numerous diseases. A growing body of evidence suggests that the pathogenesis of UC is associated with ferroptosis, and the regulation of ferroptosis provides new opportunities for UC treatment. However, the specific mechanisms by which ferroptosis participates in the development of UC remain to be more fully and thoroughly investigated. Therefore, in this review, we focus on the research advances in the mechanism of ferroptosis in recent years and describe the potential role of ferroptosis in the pathogenesis of UC. In addition, we explore the underlying role of the crosslinked pathway between ferroptosis and other mechanisms such as macrophages, neutrophils, autophagy, endoplasmic reticulum stress, and gut microbiota in UC. Finally, we also summarize the potential compounds that may act as ferroptosis inhibitors in UC in the future.

Lipid droplets in pathogen infection and host immunity

As the hub of cellular lipid metabolism, lipid droplets (LDs) have been linked to a variety of biological processes. During pathogen infection, the biogenesis, composition, and functions of LDs are tightly regulated. The accumulation of LDs has been described as a hallmark of pathogen infection and is thought to be driven by pathogens for their own benefit. Recent studies have revealed that LDs and their subsequent lipid mediators contribute to effective immunological responses to pathogen infection by promoting host stress tolerance and reducing toxicity. In this comprehensive review, we delve into the intricate roles of LDs in governing the replication and assembly of a wide spectrum of pathogens within host cells. We also discuss the regulatory function of LDs in host immunity and highlight the potential for targeting LDs for the diagnosis and treatment of infectious diseases.

Lipid peroxidation of immune cells in cancer

Growing evidence indicates that cellular metabolism is a critical determinant of immune cell viability and function in antitumor immunity and lipid metabolism is important for immune cell activation and adaptation to the tumor microenvironment (TME). Lipid peroxidation is a process in which oxidants attack lipid-containing carbon-carbon double bonds and is an important part of lipid metabolism. In the past decades, studies have shown that lipid peroxidation participates in signal transduction to control cell proliferation, differentiation, and cell death, which is essential for cell function execution and human health. More importantly, recent studies have shown that lipid peroxidation affects immune cell function to modulate tumor immunity and antitumor ability. In this review, we briefly overview the effect of lipid peroxidation on the adaptive and innate immune cell activation and function in TME and discuss the effectiveness and sensitivity of the antitumor ability of immune cells by regulating lipid peroxidation.

Global Transcriptome Analysis Reveals Distinct Phases of the Endothelial Response to TNF

The vascular endothelium acts as a dynamic interface between blood and tissue. TNF-α, a major regulator of inflammation, induces endothelial cell (EC) transcriptional changes, the overall response dynamics of which have not been fully elucidated. In the present study, we conducted an extended time-course analysis of the human EC response to TNF, from 30 min to 72 h. We identified regulated genes and used weighted gene network correlation analysis to decipher coexpression profiles, uncovering two distinct temporal phases: an acute response (between 1 and 4 h) and a later phase (between 12 and 24 h). Sex-based subset analysis revealed that the response was comparable between female and male cells. Several previously uncharacterized genes were strongly regulated during the acute phase, whereas the majority in the later phase were IFN-stimulated genes. A lack of IFN transcription indicated that this IFN-stimulated gene expression was independent of de novo IFN production. We also observed two groups of genes whose transcription was inhibited by TNF: those that resolved toward baseline levels and those that did not. Our study provides insights into the global dynamics of the EC transcriptional response to TNF, highlighting distinct gene expression patterns during the acute and later phases. Data for all coding and noncoding genes is provided on the Web site (http://www.endothelial-response.org/). These findings may be useful in understanding the role of ECs in inflammation and in developing TNF signaling-targeted therapies.

Metabolomics and mitochondrial dysfunction in cardiometabolic disease

Circulating metabolites are indicators of systemic metabolic dysfunction and can be detected through contemporary techniques in metabolomics. These metabolites are involved in numerous mitochondrial metabolic processes including glycolysis, fatty acid β-oxidation, and amino acid catabolism, and changes in the abundance of these metabolites is implicated in the pathogenesis of cardiometabolic diseases (CMDs). Epigenetic regulation and direct metabolite-protein interactions modulate metabolism, both within cells and in the circulation. Dysfunction of multiple mitochondrial components stemming from mitochondrial DNA mutations are implicated in disease pathogenesis. This review will summarize the current state of knowledge regarding: i) the interactions between metabolites found within the mitochondrial environment during CMDs, ii) various metabolites' effects on cellular and systemic function, iii) how harnessing the power of metabolomic analyses represents the next frontier of precision medicine, and iv) how these concepts integrate to expand the clinical potential for translational cardiometabolic medicine.

Aflatoxin B1-induced early developmental hepatotoxicity in larvae zebrafish

Aflatoxin B1 (AFB1) is a ubiquitous mycotoxin that causes oxidative damage in various organs. At present, the research studies on AFB1 are primarily focused on its effects on the terrestrial environment and animals. However, its toxicity mechanism in aquatic environments and aquatic animals has not been largely explored. Thus, in this study, zebrafish was used as a model to study the toxicity mechanism of AFB1 on the liver of developing larvae. The results showed that AFB1 exposure inhibited liver development and promoted fat accumulation in the liver. Transcriptome sequencing analysis showed that AFB1 affected liver redox metabolism and oxidoreductase activity. KEGG analysis showed that AFB1 inhibited the expression of gsto1, gpx4a, mgst3a, and idh1 in the glutathione metabolizing enzyme gene pathway, resulting in hepatic oxidative stress. At the same time, AFB1 also inhibited the expression of acox1, acsl1b, pparα, fabp2, and cpt1 genes in peroxidase and PPAR metabolic pathways, inducing hepatic steatosis and lipid droplet accumulation. Antioxidant N-Acetyl-l-cysteine (NAC) preconditioning up-regulated gsto1, gpx4a and idh1 genes, and improved the AFB1-induced lipid droplet accumulation in the liver. In summary, AFB1 induced hepatic oxidative stress and steatosis, resulting in abnormal liver fat metabolism and accumulation of cellular lipid droplets. NAC could be used as a potential preventative drug to improve AFB1-induced fat accumulation.

Ferroptosis as an emerging target in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology. Due to the rise in the incidence rate of RA and the limitations of existing therapies, the search for new treatment strategies for RA has become a global focus. Ferroptosis is a novel programmed cell death characterized by iron-dependent lipid peroxidation, with distinct differences from apoptosis, autophagy, and necrosis. Under the conditions of iron accumulation and the glutathione peroxidase 4 (GPX4) activity loss, the lethal accumulation of lipid peroxide is the direct cause of ferroptosis. Ferroptosis mediates inflammation, oxidative stress, and lipid oxidative damage processes, and also participates in the occurrence and pathological progression of inflammatory joint diseases including RA. This review provides insight into the role and mechanism of ferroptosis in RA and discusses the potential and challenges of ferroptosis as a new therapeutic strategy for RA, with an effort to provide new targets for RA prevention and treatment.

Uptake and anti-inflammatory effects of liposomal astaxanthin on endothelial cells tracked by Raman and fluorescence imaging

Astaxanthin (AXT) is a lipophilic antioxidant and anti-inflammatory natural pigment whose cellular uptake and bioavailability could be improved via liposomal encapsulation. Endothelial cells (EC) line the lumen of all blood vessels and are tasked with multiple roles toward maintaining cardiovascular homeostasis. Endothelial dysfunction is linked to the development of many diseases and is closely interconnected with oxidative stress and vascular inflammation. The uptake of free and liposomal AXT into EC was investigated using Raman and fluorescence microscopies. AXT was either encapsulated in neutral or cationic liposomes. Enhanced uptake and anti-inflammatory effects of liposomal AXT were observed. The anti-inflammatory effects of liposomal AXT were especially prominent in reducing EC lipid unsaturation, lowering numbers of lipid droplets (LDs), and decreasing intercellular adhesion molecule 1 (ICAM-1) overexpression, which is considered a well-known marker for endothelial inflammation. These findings highlight the benefits of AXT liposomal encapsulation on EC and the applicability of Raman imaging to investigate such effects.

The cause-effect relation of tuberculosis on incidence of diabetes mellitus

Tuberculosis (TB) is one of the oldest human diseases and is one of the major causes of mortality and morbidity across the Globe. Mycobacterium tuberculosis (Mtb), the causal agent of TB is one of the most successful pathogens known to mankind. Malnutrition, smoking, co-infection with other pathogens like human immunodeficiency virus (HIV), or conditions like diabetes further aggravate the tuberculosis pathogenesis. The association between type 2 diabetes mellitus (DM) and tuberculosis is well known and the immune-metabolic changes during diabetes are known to cause increased susceptibility to tuberculosis. Many epidemiological studies suggest the occurrence of hyperglycemia during active TB leading to impaired glucose tolerance and insulin resistance. However, the mechanisms underlying these effects is not well understood. In this review, we have described possible causal factors like inflammation, host metabolic changes triggered by tuberculosis that could contribute to the development of insulin resistance and type 2 diabetes. We have also discussed therapeutic management of type 2 diabetes during TB, which may help in designing future strategies to cope with TB-DM cases.

The Emerging Roles of Ferroptosis in Neonatal Diseases

Ferroptosis is a novel type of programmed cell death involved in many diseases' pathological processes. Ferroptosis is characterized by lipid peroxidation, reactive oxygen species accumulation, and iron metabolism disorder. Newborns are susceptible to ferroptosis due to their special physiological state, which is prone to abnormal iron metabolism and the accumulation of reactive oxygen species. Recent studies have linked ferroptosis to a variety of diseases in the neonatal period (including hypoxic-ischemic encephalopathy, bronchopulmonary dysplasia, and necrotizing enterocolitis). Ferroptosis may become an effective target for the treatment of neonatal-related diseases. In this review, the ferroptosis molecular mechanism, metabolism characteristics of iron and reactive oxygen species in infants, the relationship between ferroptosis and common infant disorders, and the treatment of infant diseases targeted for ferroptosis are systematically summarized.

Activation of Kupffer cells in NAFLD and NASH: mechanisms and therapeutic interventions

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are emerging as the leading causes of liver disease worldwide. These conditions can lead to cirrhosis, liver cancer, liver failure, and other related ailments. At present, liver transplantation remains the sole treatment option for end-stage NASH, leading to a rapidly growing socioeconomic burden. Kupffer cells (KCs) are a dominant population of macrophages that reside in the liver, playing a crucial role in innate immunity. Their primary function includes phagocytosing exogenous substances, presenting antigens, and triggering immune responses. Moreover, they interact with other liver cells during the pathogenesis of NAFLD, and this crosstalk may either delay or exacerbate disease progression. Stimulation by endogenous signals triggers the activation of KCs, resulting in the expression of various inflammatory factors and chemokines, such as NLRP3, TNF-α, IL-1B, and IL-6, and contributing to the inflammatory cascade. In the past 5 years, significant advances have been made in understanding the biological properties and immune functions of KCs in NAFLD, including their interactions with tissue molecules, underlying molecular mechanisms, signaling pathways, and relevant therapeutic interventions. Having a comprehensive understanding of these mechanisms and characteristics can have enormous potential in guiding future strategies for the prevention and treatment of NAFLD.

Ferroptosis as a therapeutic target for inflammation-related intestinal diseases

Ferroptosis is an iron-dependent programmed cell death characterized by reactive oxygen species-induced lipid peroxidation and resultant membrane damage. Recent research has elucidated the mechanism of ferroptosis and investigated the relationship between ferroptosis and various diseases, including degenerative diseases, cancer, and inflammation. Ferroptosis is associated with inflammation-related intestinal diseases such as colitis and colitis-associated cancer. New insights into the role of ferroptosis in the pathogenesis of inflammation-related gut diseases have suggested novel therapeutic targets. In this review, we summarize current information on the molecular mechanisms of ferroptosis and describe its emerging role and therapeutic potential in inflammation-related intestinal diseases.

Ferroptosis increases obesity: Crosstalk between adipocytes and the neuroimmune system

Ferroptosis requires not only the accumulation of iron ions, but also changes in many ferroptosis-related regulators, including a decrease in GPX4 and inhibition of SLC7A11 for classical ferroptosis, a deletion of FSP1 or GCH1. Surprisingly, adipose tissue (AT) in the obesity conditions is also accompanied by iron buildup, decreased GSH, and increased ROS. On the neurological side, the pro-inflammatory factor released by AT may have first caused ferroptosis in the vagus nerve by inhibiting of the NRF2-GPX4 pathway, resulting in disorders of the autonomic nervous system. On the immune side, obesity may cause M2 macrophages ferroptosis due to damage to iron-rich ATMs (MFe^hi) and antioxidant ATMs (Mox), and lead to Treg cells ferroptosis through reductions in NRF2, GPX4, and GCH1 levels. At the same time, the reduction in GPX4 may also trigger the ferroptosis of B1 cells. In addition, some studies have also found the role of GPX4 in neutrophil autophagy, which is also worth pondering whether there is a connection with ferroptosis. In conclusion, this review summarizes the associations between neuroimmune regulation associated with obesity and ferroptosis, and on the basis of this, highlights their potential molecular mechanisms, proposing that ferroptosis in one or more cells in a multicellular tissue changes the fate of that tissue.

The hypolipidemic mechanism of chrysanthemum flavonoids and its main components, luteolin and luteoloside, based on the gene expression profile

In this study, the following four groups of mice with hyperlipidemia were involved: the model control group (MC), the Chrysanthemum flavonoids group (CF), the luteolin group, and the luteoloside group. The whole gene expression profile was detected in the liver tissues of each group. Differential genes significantly enriched in the biological process of gene ontology (GO) items and Kyoto Encyclopedia of Genes and Genomes (KEGG) were selected, and 4 differential genes related to lipid metabolism were selected for further real-time quantitative PCR verification. Compared with the MC, 41 differential genes such as Sqle, Gck, and Idi1 were screened in the CF intervention group; 68 differential genes such as Acsl3, Cyp7a1, and Lpin1 were screened in the luteolin intervention group (CF); and 51 differential genes such as Acaca, Cyp7a1, and Lpin1 were screened in the luteoloside group. The mechanism of CF to improve hyperlipidemia is very complex, mainly involving biological processes such as cholesterol and fatty acid metabolism and glycolysis, luteolin mainly involves the synthesis and transport of cholesterol, and luteoloside mainly involves fatty acid metabolism. The functional pathways of CF may not be completely the same as luteolin and luteoloside, and further study is needed on the mechanism of action of other components.

Molecular Characterization, Tissue Distribution Profile, and Nutritional Regulation of acsl Gene Family in Golden Pompano (Trachinotus ovatus)

Long chain acyl-coA synthase (acsl) family genes activate the conversion of long chain fatty acids into acyl-coA to regulate fatty acid metabolism. However, the evolutionary characteristics, tissue expression and nutritional regulation of the acsl gene family are poorly understood in fish. The present study investigated the molecular characterization, tissue expression and nutritional regulation of the acsl gene family in golden pompano (Trachinotus ovatus). The results showed that the coding regions of acsl1, acsl3, acsl4, acsl5 and acsl6 cDNA were 2091 bp, 2142 bp, 2136 bp, 1977 bp and 2007 bp, encoding 697, 714, 712, 659 and 669 amino acids, respectively. Five acsl isoforms divided into two branches, namely, acsl1, acsl5 and acsl6, as well as acsl3 and acsl4. The tissue expression distribution of acsl genes showed that acsl1 and acsl3 are widely expressed in the detected tissues, while acsl4, acsl5 and acsl6 are mainly expressed in the brain. Compared to the fish fed with lard oil diets, the fish fed with soybean oil exhibited high muscular C₁₈ PUFA contents and acsl1 and acsl3 mRNA levels, as well as low muscular SFA contents and acsl4 mRNA levels. High muscular n-3 LC-PUFA contents, and acsl3, acsl4 and acsl6 mRNA levels were observed in the fish fed with fish oil diets compared with those of fish fed with lard oil or soybean oil diets. High n-3 LC-PUFA levels and DHA contents, as well as the acsl3, acsl4 and acsl6 mRNA levels were exhibited in the muscle of fish fed diets with high dietary n-3 LC-PUFA levels. Additionally, the muscular acsl3, acsl4 and acsl6 mRNA expression levels, n-3 LC-PUFA and DHA levels were significantly up-regulated by the increase of dietary DHA proportions. Collectively, the positive relationship among dietary fatty acids, muscular fatty acids and acsl mRNA, indicated that T. ovatus Acsl1 and Acsl3 are beneficial for the C₁₈ PUFA enrichment, and Acsl3, Acsl4 and Acsl6 are for n-3 LC-PUFA and DHA enrichment. The acquisition of fish Acsl potential function in the present study will play the foundation for ameliorating the fatty acids nutrition in farmed fish products.

Relationship of polycyclic aromatic hydrocarbons exposure with vascular damages among sanitation workers

Chronic exposure to polycyclic aromatic hydrocarbons (PAHs) leads to a high incidence of cardiovascular diseases. To assess the effects of PAHs exposure on vascular damages in occupationally exposed populations, 196 sanitation workers were recruited. According to the differences of occupation or operation, they were divided into exposure group (n = 115) and control group (n = 81). Sixteen serum PAHs were determined by gas chromatography-tandem mass spectrometery. Tumor necrosis factor ɑ (TNF-ɑ) and angiotensin II (ANG-II) in serum, blood lipids and blood pressure were also measured. Results showed that, except for indeno(1,2,3-cd)pyrene, dibenzo(a,h)anthracene and benzo(g,h,i)perylene, the detection frequencies of other PAHs were above 85%, showing that subjects are generally exposed to PAHs. The top three compounds in serum concentrations of PAHs were phenanthrene, acenaphthylene and anthracene. Moreover, the concentrations of total serum PAHs in the exposure group were significantly higher than those in the control (p < 0.05), suggesting a higher PAHs exposure in the former. Though there was no significant difference in blood lipids and blood pressure between groups (p > 0.05), TNF-ɑ and ANG-II levels in the exposure group were significantly higher than those in the control group (p < 0.05), suggesting that PAHs exposure may be related to pro-inflammatory effects and vascular endothelial damages.

Interaction between macrophages and ferroptosis

Abstract

Ferroptosis, a newly discovered iron-dependent cell death pathway, is characterized by lipid peroxidation and GSH depletion mediated by iron metabolism and is morphologically, biologically and genetically different from other programmed cell deaths. Besides, ferroptosis is usually found accompanied by inflammatory reactions. So far, it has been found participating in the development of many kinds of diseases. Macrophages are a group of immune cells that widely exist in our body for host defense and play an important role in tissue homeostasis by mediating inflammation and regulating iron, lipid and amino acid metabolisms through their unique functions like phagocytosis and efferocytosis, cytokines secretion and ROS production under different polarization. According to these common points in ferroptosis characteristics and macrophages functions, it’s obvious that there must be relationship between macrophages and ferroptosis. Therefore, our review aims at revealing the interaction between macrophages and ferroptosis concerning three metabolisms and integrating the application of certain relationship in curing diseases, mostly cancer. Finally, we also provide inspirations for further studies in therapy for some diseases by targeting certain resident macrophages in distinct tissues to regulate ferroptosis.

Facts

Ferroptosis is considered as a newly discovered form characterized by its nonapoptotic and iron-dependent lipid hydroperoxide, concerning iron, lipid and amino acid metabolisms.

Ferroptosis has been widely found playing a crucial part in various diseases, including hepatic diseases, neurological diseases, cancer, etc.

Macrophages are phagocytic immune cells, widely existing and owning various functions such as phagocytosis and efferocytosis, cytokines secretion and ROS production.

Macrophages are proved to participate in mediating metabolisms and initiating immune reactions to maintain balance in our body.

Recent studies try to treat cancer by altering macrophages’ polarization which damages tumor microenvironment and induces ferroptosis of cancer cells.

Open questions

How do macrophages regulate ferroptosis of other tissue cells specifically?

Can we use the interaction between macrophages and ferroptosis in treating diseases other than cancer?

What can we do to treat diseases related to ferroptosis by targeting macrophages?

Is the use of the relationship between macrophages and ferroptosis more effective than other therapies when treating diseases?

Triglyceride breakdown from lipid droplets regulates the inflammatory response in macrophages

Lipid droplets (LDs) are ubiquitous organelles that play important roles in cellular energy homeostasis, tightly regulating the accumulation and release of lipids. In macrophages, lipids accumulate in LDs during inflammation. However, it is unclear how inflammatory activation promotes the accumulation of lipids in LDs, and how the dynamic between lipid accumulation and breakdown could drive or inhibit inflammation. Elucidating the role of lipid accumulation during inflammation may provide important knowledge to influence inflammatory processes during health and disease. We identify the importance of the hypoxia-inducible lipid droplet–associated protein and the intracellular adipose triglyceride lipase in the regulation of lipid accumulation and breakdown in inflammatory macrophages. Furthermore, we determine the regulatory effect of lipid breakdown from LDs in supporting inflammation.

In response to inflammatory activation by pathogens, macrophages accumulate triglycerides in intracellular lipid droplets. The mechanisms underlying triglyceride accumulation and its exact role in the inflammatory response of macrophages are not fully understood. Here, we aim to further elucidate the mechanism and function of triglyceride accumulation in the inflammatory response of activated macrophages. Lipopolysaccharide (LPS)-mediated activation markedly increased triglyceride accumulation in macrophages. This increase could be attributed to up-regulation of the hypoxia-inducible lipid droplet–associated (HILPDA) protein, which down-regulated adipose triglyceride lipase (ATGL) protein levels, in turn leading to decreased ATGL-mediated triglyceride hydrolysis. The reduction in ATGL-mediated lipolysis attenuated the inflammatory response in macrophages after ex vivo and in vitro activation, and was accompanied by decreased production of prostaglandin-E2 (PGE2) and interleukin-6 (IL-6). Overall, we provide evidence that LPS-mediated activation of macrophages suppresses lipolysis via induction of HILPDA, thereby reducing the availability of proinflammatory lipid precursors and suppressing the production of PGE2 and IL-6.

Identification of Novel Key Molecular Signatures in the Pathogenesis of Experimental Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a long-term major microvascular complication of uncontrolled hyperglycemia and one of the leading causes of end-stage renal disease (ESDR). The pathogenesis of DKD has not been fully elucidated, and effective therapy to completely halt DKD progression to ESDR is lacking. This study aimed to identify critical molecular signatures and develop novel therapeutic targets for DKD. This study enrolled 10 datasets consisting of 93 renal samples from the National Center of Biotechnology Information (NCBI) Gene Expression Omnibus (GEO). Networkanalyst, Enrichr, STRING, and Cytoscape were used to conduct the differentially expressed genes (DEGs) analysis, pathway enrichment analysis, protein-protein interaction (PPI) network construction, and hub gene screening. The shared DEGs of type 1 diabetic kidney disease (T1DKD) and type 2 diabetic kidney disease (T2DKD) datasets were performed to identify the shared vital pathways and hub genes. Strepotozocin-induced Type 1 diabetes mellitus (T1DM) rat model was prepared, followed by hematoxylin & eosin (HE) staining, and Oil Red O staining to observe the lipid-related morphological changes. The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was conducted to validate the key DEGs of interest from a meta-analysis in the T1DKD rat. Using meta-analysis, 305 shared DEGs were obtained. Among the top 5 shared DEGs, Tmem43, Mpv17l, and Slco1a1, have not been reported relevant to DKD. Ketone body metabolism ranked in the top 1 in the KEGG enrichment analysis. Coasy, Idi1, Fads2, Acsl3, Oxct1, and Bdh1, as the top 10 down-regulated hub genes, were first identified to be involved in DKD. The qRT-PCR verification results of the novel hub genes were mostly consistent with the meta-analysis. The positive Oil Red O staining showed that the steatosis appeared in tubuloepithelial cells at 6 w after DM onset. Taken together, abnormal ketone body metabolism may be the key factor in the progression of DKD. Targeting metabolic abnormalities of ketone bodies may represent a novel therapeutic strategy for DKD. These identified novel molecular signatures in DKD merit further clinical investigation.

The effects of Gentiana dahurica Fisch on alcoholic liver disease revealed by RNA sequencing

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Gentiana dahurica Fisch (called Qin-Jiao in China), a traditional Chinese medicine, is used in China to treat alcoholic liver disease (ALD), but there has been no scientific report on the treatment of ALD.

AIM OF THE STUDY

To investigate the therapeutic effects of Gentiana dahurica Fisch ethanol extract (GDEE) on ALD and to reveal its possible mechanism of action using RNA sequencing.

MATERIALS AND METHODS

The model of ALD was established by continuous gavage with alcohol in mice, and GDEE was used to treat ALD. Pathological observation (HE staining, oil red O staining) and biochemical indicators were performed to evaluate liver tissue lesions and efficacy of GDEE. RNA sequencing analysis of liver tissues was carried out to elucidate the pathogenesis of ALD and the mechanism of hepatoprotective effect by GDEE. The RNA sequencing results were verified by detecting mRNA and protein expressions of acetyl coenzyme A carboxylase α (Acacα), fatty acid synthase (Fasn) and carnitine palmitoyltransferase 1A (Cpt1a) by quantitative real-time polymerase chain reaction (PCR) and Western blot.

RESULTS

Measurements of biochemical parameters showed that GDEE could inhibit the increased transaminase activities in the serum and lipid levels in the liver caused by alcohol. It was observed that GDEE could alleviate fatty degeneration, edema and cell necrosis caused by alcohol in the liver tissue. RNA sequencing analysis of liver tissues found that 719 genes and 1137 genes were significantly changed by alcohol and GDEE, respectively. GDEE reversed most of the changes in triglycerides synthesis-related genes up-regulated by alcohol. GDEE up-regulated most of the genes involved in the fatty acid degradation in ALD mice, while alcohol had little effect on them. In addition, GDEE suppressed most of the genes involved in cholesterol synthesis that were up-regulated by alcohol. GDEE up-regulated genes related to bile acid synthesis in ALD mice, and down-regulated genes related to bile acid reabsorption, while alcohol had no significant effect on genes related to bile acid metabolism. In the validation experiments, the Acacα, Fasn and Cpt1a expressions quantified by real-time PCR and Western blot were consistent with the RNA sequencing results.

CONCLUSIONS

GDEE can alleviate liver damage and steatosis in ALD mice, and its mechanism of action may be related to the process of regulating triglycerides and cholesterol.

Raman imaging-based phenotyping of murine primary endothelial cells to identify disease-associated biochemical alterations

Raman spectroscopy is successfully becoming an analytical tool used to characterize alterations in the biochemical composition of cells. In this work, we identify the features of Raman spectra of murine primary endothelial cells (EC) isolated from lungs, heart, liver, brain, kidney and aorta of normal mice, as well as from heart, lung and liver in a murine model of heart failure (HF) in Tgαq*44 mice. Primary cells were measured in suspension immediately after their isolation. Raman images showed that isolated primary EC were elliptical or circular, and did not show organ-specific spectral features for any of the studied organ, i.e. lungs, heart, liver, brain, kidney and aorta. Principal Component Analysis pairwise analysis of primary endothelial cells from FVB mice and Tgαq*44 mice revealed an increased protein content in EC isolated from the heart and increased lipid content in EC isolated from the lung in Tgαq*44 mice. No significant differences were found in the EC isolated from the liver using the same chemometric procedure. To our knowledge, this is the first report in which Raman spectroscopy has been used to characterize the biochemical phenotype of primary murine EC with developing HF. This pilot study shows that Raman-based analysis of freshly isolated primary EC did not revealed organ-specific features, however disease-associated changes were found in the coronary and pulmonary EC in the early stage of heart failure in Tgαq*44 mice.

Downregulating testosterone levels enhance immunotherapy efficiency

Low response rates to certain tumor types remain a major challenge for immune checkpoint blockade therapy. In this study, we first conducted an integrated biomarker evaluation of bladder cancer patients from confirmatory cohorts (IMvigor210) and found that no significant differences exist between sexes before acceptance of anti-PD-L1 treatment, whereas male patients showed a better response. Thus, we then focused on sex-related changes post anti-PD-L1 treatment and found no obvious impact on the gut microbiota in male mice but a significant decrease in the sex hormone levels. Further, castration dramatically enhanced the antitumor efficacy against murine colon adenocarcinoma in male mice. Moreover, a narrow-spectrum antibiotic, colistin was innovatively used for deregulation of testosterone levels to enhance the immunotherapy efficiency in male mice. These findings indicate that the impact on the sex hormone levels in males may contribute to the sexual dimorphism in response and provide a promising way to enhance immunotherapy efficiency.

Labeled vs. Label-Free Raman Imaging of Lipids in Endothelial Cells of Various Origins

Endothelial cells (EC) constitute a single layer of the lining of blood vessels and play an important role in maintaining cardiovascular homeostasis. Endothelial dysfunction has been recognized as a primary or secondary cause of many diseases and it manifests itself, among others, by increased lipid content or a change in the lipid composition in the EC. Therefore, the analysis of cellular lipids is crucial to understand the mechanisms of disease development. Tumor necrosis factor alpha (TNF-α)-induced inflammation of EC alters the lipid content of cells, which can be detected by Raman spectroscopy. By default, lipid detection is carried out in a label-free manner, and these compounds are recognized based on their spectral profile characteristics. We consider (3S,3'S)-astaxanthin (AXT), a natural dye with a characteristic resonance spectrum, as a new Raman probe for the detection of lipids in the EC of various vascular beds, i.e., the aorta, brain and heart. AXT colocalizes with lipids in cells, enabling imaging of lipid-rich cellular components in a time-dependent manner using laser power 10 times lower than that commonly used to measure biological samples. The results show that AXT can be used to study lipids distribution in EC at various locations, suggesting its use as a universal probe for studying cellular lipids using Raman spectroscopy. The use of labeled Raman imaging of lipids in the EC of various organs could contribute to their easier identification and to a better understanding of the development and progression of various vascular diseases, and it could also potentially improve their diagnosis and treatment.

Transcriptomic analysis suggested the involvement of impaired lipid droplet biogenesis in graphene oxide-induced cytotoxicity in human umbilical vein endothelial cells

Previous studies revealed that direct contact with graphene oxide (GO) induced cytotoxic effects, but the importance of involvement of metabolic pathways, in particular lipid metabolism pathways, might be overlooked. In this study, human umbilical vein endothelial cells (HUVECs) were exposed to GO with large size (denoted as GO-L) or small size (denoted as GO-S), and transcriptomics were used to understand the mechanisms of cytotoxicity of GO at systemic levels. It was shown that GO-L more significantly induced cytotoxicity compared with GO-S. Transcriptomic analysis revealed that compared with GO-S, GO-L had larger impact on gene ontology terms related with mitochondrial function as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related with cell death and growth. But GO-S showed greater influence on KEGG pathways related with lipid metabolism. Both types of GO showed minimal impact on oxidative stress but increased de novo lipogenesis protein fatty acid synthase (FASN). However, only GO-S significantly promoted acyl-CoA synthetase 3 (ACSL3), a key enzyme responsible for esterification of free fatty acids and lipid droplet biogenesis. Not surprisingly, GO-L but not GO-S impaired lipid droplet biogenesis, and increasing lipid levels by oleic acid or α-linolenic acid reduced the cytotoxicity of GO-L to HUVECs. Combined, the results from this study suggested that impaired lipid droplet biogenesis was involved in GO-induced cytotoxicity in HUVECs, and inducing lipid droplet biogenesis could prevent the cytotoxicity of GO.

A Vectorial, ER-Mitochondria Link to Energy Homeostasis in the Vascular Endothelium

The precise mechanisms of free fatty acid (FFA) uptake in the vascular endothelium are unclear. In this issue of Cell Metabolism, Ibrahim et al. (2020) discover that FFA uptake is partially mediated by a vectorial, ER-mitochondria link, in which mitochondrial ATP production is locally used for the acyl-CoA synthetase activity of the ER-located fatty acid transport protein 4.

The Role of Secretory Activity Molecules of Visceral Adipocytes in Abdominal Obesity in the Development of Cardiovascular Disease: A Review

Adipose tissue is considered one of the endocrine organs in the body because of its ability to synthesize and release a large number of hormones, cytokines, and growth and vasoactive factors that influence a variety of physiological and pathophysiological processes, such as vascular tone, inflammation, vascular smooth muscle cell migration, endothelial function, and vascular redox state. Moreover, genetic factors substantially contribute to the risk of obesity. Research into the biochemical effects of molecules secreted by visceral adipocytes as well as their molecular genetic characteristics is actively conducted around the world mostly in relation to pathologies of the cardiovascular system, metabolic syndrome, and diabetes mellitus. Adipokines could be developed into biomarkers for diagnosis, prognosis, and therapeutic targets in different diseases. This review describes the relevance of secretory activity molecules of visceral adipocytes in cardiovascular disease associated abdominal obesity.