Sphingolipids: regulators of crosstalk between apoptosis and autophagy

Extracellular Vesicles in the Crosstalk of Autophagy and Apoptosis: A Role for Lipid Rafts

Autophagy and apoptosis are two essential mechanisms regulating cell fate. Although distinct, their signaling pathways are closely interconnected through various crosstalk mechanisms. Lipid rafts are described to act as both physical and functional platforms during the early stages of autophagic and apoptotic processes. Only recently has a role for lipid raft-associated molecules in regulating EV biogenesis and release begun to emerge. In particular, lipids of EV membranes are essential components in conferring stability to these vesicles in different extracellular environments and/or to facilitate binding or uptake into recipient cells. In this review we highlight these aspects, focusing on the role of lipid molecules during apoptosis and secretory autophagy pathways. We describe the molecular machinery that connects autophagy and apoptosis with vesicular trafficking and lipid metabolism during the release of EVs, and how their alterations contribute to the development of various diseases, including autoimmune disorders and cancer. Overall, these findings emphasize the complexity of autophagy/apoptosis crosstalk and its key role in cellular dynamics, supporting the role of lipid rafts as new therapeutic targets.

Region-specific quantitation of glycosphingolipids in the elderly human brain with Nanoflow MEA Chip Q/ToF mass spectrometry

Glycosphingolipids are a unique class of bioactive lipids responsible for lateral membrane organization and signaling found in high abundance in the central nervous system. Using nanoflow MEA Chip Q/ToF mass spectrometry, we profiled the intact glycosphingolipids of the elderly human brain in a region-specific manner. By chromatographic separation of glycan and ceramide isomers, we determined gangliosides to be the highest source of heterogeneity between regions with the expression of a- and b-series glycan structures. Investigation of these trends showed that specific glycan structures were, in part, determined by the structure of their lipid backbone. This study provides insight into the dynamic process of membrane remodeling in the brain during aging.

hsa-miR-330-5p regulates serine palmitoyltransferase long chain base subunit 1 and augments host protective immune response against Leishmania donovani infection

Leishmaniasis, caused by the protozoan parasites of the genus Leishmania, poses a significant global health challenge, particularly in the resource-limited regions where it causes high mortality. Regardless in the progress of treatment strategies, the emergence of drug resistance and limited efficacy requires the search of novel therapy and therapeutic targets. MicroRNAs, the crucial post-transcriptional regulators of gene expression, play critical roles in host-pathogen interactions. Here, we screened the miRNAs dysregulated during Leishmania donovani infection through literature search. hsa-miR-330-5p, one of the miRNAs which through human KEGG 2021 and Human Cyc 2016 analysis was found to be involved in multiple pathways including sphingolipid signaling pathway. Sphingolipids are important class of lipids involved in different cellular processes and therefore are the targets of many pathogens including Leishmania. hsa-miR-330-5p was found downregulated after 24 h of Leishmania donovani infection in THP-1 derived human macrophages. Target prediction of sphingolipid biosynthetic genes through in silico prediction tools showed 3/ UTR of serine palmitoyltransferase long chain base subunit 1 to be a target of hsa-miR-330-5p. The in silico target prediction of hsa-miR-330-5p was validated by cloning the 3/ UTR target sequence of gene, transfecting and performing luciferase assay in HEK 293 T cell line. Transfection of mimic of hsa-miR-330-5p reduced the luciferase activity which validated the in silico target prediction. Further, mimic of hsa-miR-330-5p inhibited the expression of the target gene, serine palmitoyltransferase long chain base subunit 1 and augmented the expression of pro-inflammatory cytokines in L. donovani infected THP-1 derived macrophages. Mimic of hsa-miR-330-5p also led to a significant reduction in the intracellular parasite burden in both THP-1 derived as well as primary human macrophages. This study has not only identified the sphingolipid biosynthesis regulatory miRNA but will also help in the development of novel and effective treatment strategy against leishmaniasis in future.

Decoding ceramide function: how localization shapes cellular fate and how to study it

Recent studies emphasize that lipid synthesis, metabolism, and transport are crucial in modulating lipid function, underscoring the significance of lipid localization within the cell, in addition to their chemical structure. Ceramides stand out in this context because of their multifaceted roles in cellular processes. Here, we focus on the role of ceramides in apoptosis, senescence, and autophagy as these processes offer unique and contrasting perspectives on how ceramides function and can be intricately linked to their subcellular localization, providing critical insights into their complex biological interactions. Additionally, we highlight recent advancements in tools and techniques that have boosted our understanding of ceramide dynamics and different mechanisms of lipid functioning.

Antitumor activity of gamma-irradiated Rosa canina L. against lung carcinoma in rat model: a proposed mechanism

BACKGROUND

Lung cancer is one of the most prevalent malignancies globally and is the leading cause of cancer-related mortality. Although cisplatin is a widely utilized chemotherapeutic agent, its clinical efficacy is often hampered by significant toxicity and undesirable side effects. Rosa canina, a medicinal plant, has demonstrated a range of beneficial biological activities, including anti-inflammatory, anticancer, immunomodulatory, antioxidant, and genoprotective effects.

METHODS

This study aimed to investigate the potential of Rosa canina to enhance the anticancer efficacy of cisplatin in a dimethyl benz(a)anthracene-induced lung cancer model using female rats. The animals were administered Rosa canina, cisplatin, or a combination of both treatments. The expression levels of critical signaling molecules were evaluated, including phosphoinositide-3-kinase (PI3K), Akt, mammalian target of rapamycin (mTOR), cleaved poly (ADP-ribose) polymerase (PARP-1), myeloid differentiation factor 88 (MyD88), and tumor necrosis factor receptor-associated factor (TRAF), in addition to various autophagic markers. Furthermore, we assessed the levels of toll-like receptor 2 (TLR2), nuclear factor kappa B (NF-κB), and apoptotic markers in lung tissue, complemented by histopathological examinations.

RESULTS

The combined treatment of Rosa canina extract and cisplatin significantly inhibited lung cancer cell proliferation by downregulating PARP-1 and the TLR2/MyD88/TRAF6/NF-κB signaling pathway, as well as the PI3K/Akt/mTOR pathway. Moreover, this combination therapy promoted autophagy and apoptosis, evidenced by elevated levels of autophagic and apoptotic markers.

CONCLUSION

Overall, the findings of this study suggest that Rosa canina enhances the anticancer effects of cisplatin by inhibiting cancer cell proliferation while simultaneously inducing autophagy and apoptosis. Thus, Rosa can be used as adjuvant to cisplatin chemotherapy to overcome its limitations which may be considered a new approach during lung cancer treatment strategy.

Triptolide's impact on ACER1 signaling: Inducing autophagy for triple-negative breast cancer suppression

Given the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (Her-2) in triple-negative breast cancer (TNBC) cells, the efficacy of targeted therapies is limited. In this study, we uncovered that triptolide (TP) effectively suppresses the migration and invasiveness of MDA-MB-231 cells by activating autophagic pathways. Western blotting analysis revealed that TP significantly reduced the expression levels of p62 protein, while simultaneously markedly increasing the expression levels of LC3B-II, BNIP3, BNIP3L, ATG5, and ULK1 proteins, strongly suggesting an enhancement of autophagic activity in the cells. Based on PCR array screening, we identified the ACER1 gene as exhibiting notable expression alterations post-TP treatment. Overexpression of ACER1 gene enhanced the TP-induced apoptosis in MDA-MB-231 cells and augmented the regulation of autophagy-related proteins p62 and LC3B-II, leading to an increase in autophagosome numbers and a marked reduction in cellular migration and invasiveness. Conversely, ACER1 gene knockdown reversed these effects. In vivo experiments demonstrated that TP effectively inhibits the growth of MDA-MB-231 xenograft tumors, concurrently upregulating ACER1 and LC3B-II expression in tumor tissues, while p62 protein levels were notably decreased. Hematoxylin and eosin (H&E) staining results indicated no evident toxicity in liver and kidney tissues of BALB/c mice at a TP dose of 0.4 mg/kg. This study, for the first time, elucidates a novel mechanism by which TP inhibits TNBC through an autophagic process mediated by ACER1.

Syntheses of differentially fluorinated triazole-based 1-deoxysphingosine analogues en route to SphK inhibitors

This study focuses on the stereoselective syntheses of 1-deoxysphingosine analogues as potential inhibitors of sphingosine kinase (SphK), particularly targeting its isoforms SphK1 and SphK2, which are implicated in cancer progression and therapy resistance. The research builds on previous work by designing a series of analogues featuring systematic structural modifications like the incorporation of a triazole ring, varying degrees of fluorination, and different head groups (e.g., guanidino, N-methylamino, and N,N-dimethylamino). These modifications aimed to enhance polar and hydrophobic interactions especially with SphK2. The synthesized compounds were evaluated for their inhibitory activity, revealing that certain derivatives, particularly those with guanidino groups and heptafluoropropyl fragments at the lipidic tail, exhibited significant potency and selectivity towards SphK2. Docking studies supported these findings by showing favorable binding interactions within the SphK2 active site, which were less pronounced in SphK1, correlating with the observed selectivity. This work contributes to the development of novel 1-deoxysphingosine analogues targeting SphK inhibition, as well as to the knowledge of the differential topology of the active sites in SphK1 and SphK2.

Sphingosine-1-Phosphate Metabolic Pathway in Cancer: Implications for Therapeutic Targets

Cancer biology revolves around understanding how cells undergo uncontrolled proliferation leading to the formation of malignant tumors. Key aspects include self-sufficiency in growth signals, the lack of response to signals of growth inhibition, the evasion of apoptosis, sustained angiogenesis, the evasion of immune response, the capacity to invade and metastasize, and alterations in cellular metabolism. A vast amount of research, which is exponentially growing, over the past few decades highlights the role of sphingolipids in cancer. They act not only as structural membrane components but also as bioactive molecules that regulate cell fate in different physio-pathological conditions. In cancer, sphingolipid metabolism is dysregulated, contributing to tumor progression, metastasis, and drug resistance. In this review, we outline the impact of sphingosine-1-phosphate (S1P) as a key bioactive sphingolipid in cancer. We give an overview of its metabolism summarizing the role of S1P as an intracellular and extracellular mediator through specific plasma membrane receptors in different cancers. We also describe previous findings on how the disruption in the balance between S1P and ceramide (Cer) is common in cancer cells and can contribute to tumorigenesis and resistance to chemotherapy. We finally consider the potential of targeting the metabolic pathways of S1P as well as its receptors and transporters as a promising therapeutic approach in cancer treatments.

Lc-ms-based untargeted metabolomics reveals potential mechanisms of histologic chronic inflammation promoting prostate hyperplasia

BACKGROUND

Chronic prostatitis may be a risk factor for developing proliferative changes in the prostate, although the underlying mechanisms are not entirely comprehended.

MATERIALS AND METHODS

Fifty individual prostate tissues were examined in this study, consisting of 25 patients diagnosed with prostatic hyperplasia combined with histologic chronic inflammation and 25 patients diagnosed with prostatic hyperplasia alone. We employed UPLC-Q-TOF-MS-based untargeted metabolomics using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry to identify differential metabolites that can reveal the mechanisms that underlie the promotion of prostate hyperplasia by histologic chronic inflammation. Selected differential endogenous metabolites were analyzed using bioinformatics and subjected to metabolic pathway studies.

RESULTS

Nineteen differential metabolites, consisting of nine up-regulated and ten down-regulated, were identified between the two groups of patients. These groups included individuals with combined histologic chronic inflammation and those with prostatic hyperplasia alone. Glycerolipids, glycerophospholipids, and sphingolipids were primarily the components present. Metabolic pathway enrichment was conducted on the identified differentially expressed metabolites. Topological pathway analysis revealed the differential metabolites' predominant involvement in sphingolipid, ether lipid, and glycerophospholipid metabolism. The metabolites involved in sphingolipid metabolism were Sphingosine, Cer (d18:1/24:1), and Phytosphingosine. The metabolites involved in ether lipid metabolism were Glycerophosphocholine and LysoPC (O-18:0/0:0). The metabolites involved in glycerophospholipid metabolism were LysoPC (P-18:0/0:0) and Glycerophosphocholine. with Impact > 0. 1 and FDR < 0. 05, the most important metabolic pathway was sphingolipid metabolism.

CONCLUSIONS

In conclusion, our findings suggest that patients with prostate hyperplasia and combined histologic chronic inflammation possess distinctive metabolic profiles. These differential metabolites appear to play a significant role in the pathogenesis of histologic chronic inflammation-induced prostate hyperplasia, primarily through the regulation of sphingolipids and glycerophospholipids metabolic pathways. The mechanism by which histologic chronic inflammation promotes prostate hyperplasia was elucidated through the analysis of small molecule metabolites. These findings support the notion that chronic prostatitis may contribute to an increased risk of prostate hyperplasia.

Osteoblast-derived exosomal miR-140-3p targets ACER2 and increases the progression of prostate cancer via the AKT/mTOR pathway-mediated inhibition of autophagy

Advanced prostate cancer (aPCa) often results in bone metastases (BM). However, the mechanism underlying its progression and metastasis to bones remains unclear. Therefore, we examined whether exosomal miR-140-3p affects prostate cancer (PCa) progression. We obtained from cell lines, clinical data analyses, and animal models consistently provide important evidence. Patients with PCa having BM had higher miR-140-3p expression in their serum exosomes than those without BM. Clinical investigations have manifested that the exosomal miR-140-3p overexpression connects with serum prostate-specific antigen (PSA) levels and Gleason grade in patients with PCa. Osteoblast-derived exosomal miR-140-3p targeting ACER2 activates the AKT/mTOR pathway in vitro, inhibits autophagy, and promotes PCa cell proliferation, invasion, and migration. miR-140-3p significantly increased tumorigenesis and metastasis of LNCaP in vitro. Bone metastatic PCa tissues exhibited elevated levels of miR-140-3p, p-GSK3, p-mTOR, p62, p-AKT (S473), and p-AKT (T308) contrasted with non-BM tissues. Moreover, their expression was intensified in the metastatic bone tissues. However, ACER2 and LC3 II showed opposite expression patterns. Based on our study outcomes, the evidence suggests that osteoblast-derived miR-140-3p inhibition of autophagy through the AKT/mTOR pathway is involved in PCa progression. Osteoblast-secreted exosomal miR-140-3p activates the AKT/mTOR pathway by targeting ACER2, inhibiting autophagy, and promoting the progression of PCa cells in vitro. Moreover, miR-140-3p induces the progression and metastasis of PCa in vivo.

Modulation of physiological functions and metabolome of Vibrio alginolyticus by quorum-regulatory sRNA, Qrr1

Vibrio alginolyticus, the causative agent of aquatic vertebrates and invertebrates, can cause severe infections (e.g. septicemia, gill necrosis, and surface ulcers) and high mortality in aquatic organisms, leading to serious economic losses in global aquaculture. Small non-coding RNAs (sRNAs), emerging modulators of gene expression, played vital regulatory roles in virulence, pathogenicity, and physiological metabolism of bacteria. In this work, the modulation of physiological functions and metabolome of V. alginolyticus by the quorum-regulatory sRNA, Qrr1, was figured out. We found that the deletion of qrr1 induced significant cell shape elongation. Meanwhile, Qrr1 could inhibit the production of alkaline serine protease by weakening the expression of main regulator LuxR in the quorum sensing (QS) system. Moreover, the untargeted metabolomics and lipidomics approaches showed that most of nucleotides, organic acids, carbohydrates, and lipidome (both lipid content and category) were significantly altered in response to the qrr1 deletion. Spearman correlation analysis demonstrated that most of the intermediates involved in glutamate metabolism, sphingolipid metabolism, and glycerolipid metabolism displayed high correlations with cell virulence factors. These findings illuminate the mechanism of bacterial virulence regulation and further exploit potential therapeutic targets for virulence prevention in V. alginolyticus.

Imipridones inhibit tumor growth and improve survival in an orthotopic liver metastasis mouse model of human uveal melanoma

BACKGROUND

Uveal melanoma (UM) is a highly aggressive disease with very few treatment options. We previously demonstrated that mUM is characterized by high oxidative phosphorylation (OXPHOS). Here we tested the anti-tumor, signaling and metabolic effects of imipridones, which are CLPP activators, which inhibit OXPHOS indirectly and have demonstrated safety in patients.

METHODS

We assessed CLPP expression in UM patient samples. We tested the effects of imipridones (ONC201 and ONC212) on the growth, survival, signaling and metabolism of UM cell lines in vitro, and for therapeutic efficacy in vivo in UM liver metastasis models.

RESULTS

CLPP expression was detected in primary and mUM patient samples. ONC201 and 212 decreased OXPHOS effectors, inhibited cell growth and migration, and induced apoptosis in human UM cell lines in vitro. ONC212 inhibited OXPHOS, increased metabolic stress and apoptotic pathways, inhibited amino acid metabolism, and induced cell death-related lipids. ONC212 also decreased tumor burden and increased survival in vivo in two UM liver metastasis models.

CONCLUSIONS

Imipridones are a promising strategy for further testing and development in mUM.

Comprehensive profiling of serum glycosphingolipids to discover the diagnostic biomarkers of lung cancer and uncover the variation of glycosphingolipid networks in different lung cancer subtypes

Glycosphingolipids are glycolipid complexes formed by an oligosaccharide chain covalently linked to a ceramide backbone and play important roles in the occurrence and metastasis of lung cancer. In this study, an UHPLC-HRMS method was developed for the comprehensive profiling of glycosphingolipids, with an in-house library constructed for data interpretation. Serum glycosphingolipids were profiled in 31 healthy controls (HCs) and 92 lung cancer patients with different pathologic subtypes. Over 1700 glycosphingolipids were detected in human serum based on the novel method. A total of 567 differential glycosphingolipids (adjusted P < 0.05, and fold change > 2) were found between lung cancer patients and HCs. Glycosphingolipids can be used as potential biomarkers for lung cancer diagnosis, with sensitivity much higher than that of traditional serum tumor markers. The levels of most glycosphingolipids in squamous cell carcinoma (Squa) were significantly lower than those in small cell lung cancer (SCLC) and adenocarcinoma (Aden). The highest Cer1P abundance in SCLC patients among the three different subtypes of lung cancer was thought to be related to the high malignancy and metastasis of SCLC. An artificial neural network (ANN) model was constructed for the discrimination of the three different subtypes of lung cancer, with accuracy higher than 93%. Beyond providing biomarkers and statistical models for the diagnosis of lung cancer and discrimination of lung cancer subtypes, this study uncovered the variation of glycosphingolipid networks in different subtypes of lung cancer and thereby provided a novel insight to study the pathogenesis of lung cancer and explore therapeutic targets.

Biallelic variants in ERLIN1: a series of 13 individuals with spastic paraparesis

Biallelic variants in the ERLIN1 gene were recently reported as the cause of two motor neuron degeneration diseases, SPG62 and a recessive form of amyotrophic lateral sclerosis. However, only 12 individuals from five pedigrees have been identified so far. Thus, the description of the disease remains limited. Following the discovery of a homozygous pathogenic variant in a girl with SPG62, presenting with intellectual disability, and epilepsy, we gathered the largest series of SPG62 cases reported so far (13 individuals) to better understand the phenotype associated with ERLIN1. We collected molecular and clinical data for 13 individuals from six families with ERLIN1 biallelic variants. We performed RNA-seq analyses to characterize intronic variants and used Alphafold and a transcripts database to characterize the molecular consequences of the variants. We identified three new variants suspected to alter the bell-shaped ring formed by the ERLIN1/ERLIN2 complex. Affected individuals had childhood-onset paraparesis with slow progression. Six individuals presented with gait ataxia and three had superficial sensory loss. Aside from our proband, none had intellectual disability or epilepsy. Biallelic pathogenic ERLIN1 variants induce a rare, predominantly pure, spastic paraparesis, with possible cerebellar and peripheral nerve involvement.

Lipids associated with autophagy: mechanisms and therapeutic targets

Autophagy is a molecular process essential for maintaining cellular homeostasis, with its impairment or dysregulation linked to the progression of various diseases in mammals. Specific lipids, including phosphoinositides, sphingolipids, and oxysterols, play pivotal roles in inducing and regulating autophagy, highlighting their significance in this intricate process. This review focuses on the critical involvement of these lipids in autophagy and lipophagy, providing a comprehensive overview of the current understanding of their functions. Moreover, we delve into how abnormalities in autophagy, influenced by these lipids, contribute to the pathogenesis of various diseases. These include age-related conditions such as cardiovascular diseases, neurodegenerative disorders, type 2 diabetes, and certain cancers, as well as inflammatory and liver diseases, skeletal muscle pathologies and age-related macular degeneration (AMD). This review aims to highlight function of lipids and their potential as therapeutic targets in treating diverse human pathologies by elucidating the specific roles of phosphoinositides, sphingolipids, and oxysterols in autophagy.

Evaluating alternative compounds for strongyloidiasis therapy: Novel insights from larval migration inhibition test

Strongyloidiasis is a neglected tropical disease estimated to affect more than 600 million people worldwide. Recently, the World Health Organization road map on neglected tropical diseases 2021-2030 has put the focus on strongyloidiasis, including this disease within its mass drug administration campaigns. With the use of ivermectin in extensive treatment of all populations at-risk, identifying effective therapeutic alternatives is crucial in case ivermectin resistance arises. The objective of the present study was the development of a larval migration inhibition assay to evaluate the anthelmintic efficacy of commercial drugs and diamine and aminoalcohol derivatives against infective Strongyloides ratti third stage larvae. Through this technique, we successfully screened and estimated the in vitro anthelmintic efficacy of six commercial drugs, seven diamine derivatives and eight aminoalcohol derivatives. Unexpectedly, the half-maximal effective concentration of ivermectin and moxidectin (2.21 and 2.34 μM, respectively) were observed as the highest value obtained among all commercial drugs tested by this in vitro technique. Moreover, some diamine and aminoalcohol derivatives showed superior efficacy inhibiting S. ratti motility compared to ivermectin, with five compounds (AA23, AA34, AO2 AO7 and AO14b) also displaying selectivity indexes on HepG2 and Caco2 higher than 1. These findings underscore the potential of these derivatives as promising alternatives for strongyloidiasis treatment, warranting further investigation and in vivo efficacy assessment.

Emerging Roles for Sphingolipids in Cardiometabolic Disease: A Rational Therapeutic Target?

Cardiovascular disease is a leading cause of morbidity and mortality. New research elucidates increasingly complex relationships between cardiac and metabolic health, giving rise to new possible therapeutic targets. Sphingolipids are a heterogeneous class of bioactive lipids with critical roles in normal human physiology. They have also been shown to play both protective and deleterious roles in the pathogenesis of cardiovascular disease. Ceramides are implicated in dysregulating insulin signalling, vascular endothelial function, inflammation, oxidative stress, and lipoprotein aggregation, thereby promoting atherosclerosis and vascular disease. Ceramides also advance myocardial disease by enhancing pathological cardiac remodelling and cardiomyocyte death. Glucosylceramides similarly contribute to insulin resistance and vascular inflammation, thus playing a role in atherogenesis and cardiometabolic dysfunction. Sphingosing-1-phosphate, on the other hand, may ameliorate some of the pathological functions of ceramide by protecting endothelial barrier integrity and promoting cell survival. Sphingosine-1-phosphate is, however, implicated in the development of cardiac fibrosis. This review will explore the roles of sphingolipids in vascular, cardiac, and metabolic pathologies and will evaluate the therapeutic potential in targeting sphingolipids with the aim of prevention and reversal of cardiovascular disease in order to improve long-term cardiovascular outcomes.

Unveiling enigmatic essence of Sphingolipids: A promising avenue for glaucoma treatment

Treatment of glaucoma, the leading cause of irreversible blindness, remains challenging. The apoptotic loss of retinal ganglion cells (RGCs) in glaucoma is the pathological hallmark. Current treatments often remain suboptimal as they aim to halt RGC loss secondary to reduction of intraocular pressure. The pathophysiological targets for exploring direct neuroprotective approaches, therefore are highly relevant. Sphingolipids have emerged as significant target molecules as they are not only the structural components of various cell constituents, but they also serve as signaling molecules that regulate molecular pathways involved in cell survival and death. Investigations have shown that a critical balance among various sphingolipid species, particularly the ceramide and sphingosine-1-phosphate play a role in deciding the fate of the cell. In this review we briefly discuss the metabolic interconversion of sphingolipid species to get an insight into "sphingolipid rheostat", the dynamic balance among metabolites. Further we highlight the role of sphingolipids in the key pathophysiological mechanisms that lead to glaucomatous loss of RGCs. Lastly, we summarize the potential drug candidates that have been investigated for their neuroprotective effects in glaucoma via their effects on sphingolipid axis.

Multiple-matrices metabolomics combined with serum pharmacochemistry for discovering the potential targets and active constituents of Qifu decoction against heart failure

Qifu decoction (QFD) is an ancient traditional Chinese medicine (TCM) prescription for the treatment of heart failure. However, the mechanisms and active constituents of QFD are poorly understood. In this study, multi-matrices metabolomics (serum, urine, and myocardial mitochondria) based on ultra-high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOFMS), were employed for exploring the mechanisms of QFD against heart failure in rat model. Twenty-one, seventeen, and fifteen endogenous metabolite biomarkers associated with heart failure were identified from serum, urine, and myocardial mitochondria datasets, respectively. Fourteen, twelve, and ten of the identified serum, urine, and mitochondria biomarkers were significantly reversed by QFD, respectively. QFD-targeted pathways were involved in TCA cycle, branched chain amino acids metabolism, fatty acid β-oxidation, sphingolipid metabolism, glycerophospholipid metabolism, arachidonic acid metabolism, tryptophan metabolism, purine metabolism. In addition, QFD-derived constituents in serum were fully analyzed by UHPLC-Q-TOFMS and SUS-plot, and 24 QFD-derived components were identified in serum. Then, the correlation analysis between the QFD-reversed serum biomarkers and QFD-derived constituents in serum was employed to dissect the active constituents of QFD. It was found that eight prototypical components and three metabolites were highly correlated with efficacy and could serve as the active constituents of QFD against heart failure. Finally, neoline and calycosin, which highly correlated with branched-chain amino acid metabolism and fatty acid β-oxidation, were selected to validate in Na2S2O4-induced cell model. It was found that neoline and calycosin provided a significant protective effect against Na2S2O4-induced cell death in a low dose-dependent manner and increased the expressions of the pathway-related protein CPT1B and BCAT2 in the cell model. In conclusions, these findings provided light on the mechanisms and active constituents of QFD against heart failure. Neoline and calycosin could be selected as potential quality-markers of QFD against heart failure.

Biliary atresia and cholestasis plasma non-targeted metabolomics unravels perturbed metabolic pathways and unveils a diagnostic model for biliary atresia

The clinical diagnosis of biliary atresia (BA) poses challenges, particularly in distinguishing it from cholestasis (CS). Moreover, the prognosis for BA is unfavorable and there is a dearth of effective non-invasive diagnostic models for detection. Therefore, the aim of this study is to elucidate the metabolic disparities among children with BA, CS, and normal controls (NC) without any hepatic abnormalities through comprehensive metabolomics analysis. Additionally, our objective is to develop an advanced diagnostic model that enables identification of BA. The plasma samples from 90 children with BA, 48 children with CS, and 47 NC without any liver abnormalities children were subjected to metabolomics analysis, revealing significant differences in metabolite profiles among the 3 groups, particularly between BA and CS. A total of 238 differential metabolites were identified in the positive mode, while 89 differential metabolites were detected in the negative mode. Enrichment analysis revealed 10 distinct metabolic pathways that differed, such as lysine degradation, bile acid biosynthesis. A total of 18 biomarkers were identified through biomarker analysis, and in combination with the exploration of 3 additional biomarkers (LysoPC(18:2(9Z,12Z)), PC (22:5(7Z,10Z,13Z,16Z,19Z)/14:0), and Biliverdin-IX-α), a diagnostic model for BA was constructed using logistic regression analysis. The resulting ROC area under the curve was determined to be 0.968. This study presents an innovative and pioneering approach that utilizes metabolomics analysis to develop a diagnostic model for BA, thereby reducing the need for unnecessary invasive examinations and contributing to advancements in diagnosis and prognosis for patients with BA.

Proteomics and lipidomic analysis reveal dysregulated pathways associated with loss of sacsin

Introduction

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare incurable neurodegenerative disease caused by mutations in the SACS gene, which codes for sacsin, a large protein involved in protein homeostasis, mitochondrial function, cytoskeletal dynamics, autophagy, cell adhesion and vesicle trafficking. However, the pathogenic mechanisms underlying sacsin dysfunction are still largely uncharacterized, and so attempts to develop therapies are still in the early stages.

Methods

To achieve further understanding of how processes are altered by loss of sacsin, we used untargeted proteomics to compare protein profiles in ARSACS fibroblasts versus controls.

Results

Our analyses confirmed the involvement of known biological pathways and also implicated calcium and lipid homeostasis in ARSACS skin fibroblasts, a finding further verified in SH-SY5Y SACS -/- cells. Validation through mass spectrometry-based analysis and comparative quantification of lipids by LC-MS in fibroblasts revealed increased levels of ceramides coupled with a reduction of diacylglycerols.

Discussion

In addition to confirming aberrant Ca2+ homeostasis in ARSACS, this study described abnormal lipid levels associated with loss of sacsin.

Targeting IDH1-Mutated Oligodendroglioma with Acid Ceramidase Inhibitors

Oligodendroglioma is genetically defined as a tumor harboring isocitrate dehydrogenase 1 or 2 mutations (IDH1 mut /IDH2 mut ) and 1p/19q co-deletions. Previously, we reported that in IDH1 mut gliomas, D-2HG, the product of IDH1 mutant enzyme produces an increase in monounsaturated fatty acid levels that are incorporated into ceramides, tilting the S1P-to-ceramide rheostat toward apoptosis. Herein, we exploited this imbalance to further induce and IDH mut -specific glioma cell death. We report for the first time that the inhibition of acid ceramidase (AC) induces apoptosis and provides a benefit in mice survival in IDH1 mut oligodendroglioma. We demonstrated an IDH1 mut -specific cytotoxicity of SABRAC, an irreversible inhibitor of AC, in patient-derived oligodendroglioma cells. Exploring the mechanism of action of this drug, we found that SABRAC activates both extrinsic and intrinsic apoptosis in an ER stress-independent manner, pointing to a direct action of AC-related ceramides in mitochondria permeability. The activation of apoptosis detected under SABRAC treatment was associated with up to 30-fold increase in some ceramide levels and its derivatives from the salvage pathway. We propose that this novel enzyme, AC, has the potential to increase survival in oligodendroglioma with IDH1 mut and should be considered in the future.

Lipidomics reveals the significance and mechanism of the cellular ceramide metabolism for rotavirus replication

As one of the most important causative agents of severe gastroenteritis in children, piglets, and other young animals, species A rotaviruses have adversely impacted both human health and the global swine industry. Vaccines against rotaviruses (RVs) are insufficiently effective, and no specific treatment is available. To understand the relationships between porcine RV (PoRV) infection and enterocytes in terms of the cellular lipid metabolism, we performed an untargeted liquid chromatography mass spectrometry (LC-MS) lipidomics analysis of PoRV-infected IPEC-J2 cells. Herein, a total of 451 lipids (263 upregulated lipids and 188 downregulated lipids), spanning sphingolipid, glycerolipid, and glycerophospholipids, were significantly altered compared with the mock-infected group. Interestingly, almost all the ceramides among these lipids were upregulated during PoRV infection. LC-MS analysis was used to validated the lipidomics data and demonstrated that PoRV replication increased the levels of long-chain ceramides (C16-ceramide, C18-ceramide, and C24-ceramide) in cells. Furthermore, we found that these long-chain ceramides markedly inhibited PoRV infection and that their antiviral actions were exerted in the replication stage of PoRV infection. Moreover, downregulation of endogenous ceramides with the ceramide metabolic inhibitors enhanced PoRV propagation. Increasing the levels of ceramides by the addition of C6-ceramide strikingly suppressed the replication of diverse RV strains. We further found that the treatment with an apoptotic inhibitor could reverse the antiviral activity of ceramide against PoRV replication, demonstrating that ceramide restricted RV infection by inducing apoptosis. Altogether, this study revealed that ceramides played an antiviral role against RV infection, providing potential approaches for the development of antiviral therapies.IMPORTANCERotaviruses (RVs) are among the most important zoonosis viruses, which mainly infected enterocytes of the intestinal epithelium causing diarrhea in children and the young of many mammalian and avian species. Lipids play an essential role in viral infection. A comprehensive understanding of the interaction between RV and lipid metabolism in the enterocytes will be helpful to control RV infection. Here, we mapped changes in enterocyte lipids following porcine RV (PoRV) infection using an untargeted lipidomics approach. We found that PoRV infection altered the metabolism of various lipid species, especially ceramides (derivatives of the sphingosine). We further demonstrated that PoRV infection increased the accumulation of ceramides and that ceramides exerted antiviral effects on RV replication by inducing apoptosis. Our findings fill a gap in understanding the alterations of lipid metabolism in RV-infected enterocytes and highlight the antiviral effects of ceramides on RV infection, suggesting potential approaches to control RV infection.

Profiling Intact Glycosphingolipids with Automated Structural Annotation and Quantitation from Human Samples with Nanoflow Liquid Chromatography Mass Spectrometry

Sphingolipids are an essential subset of bioactive lipids found in most eukaryotic cells that contribute to membrane biophysical properties and are involved in cellular differentiation, recognition, and mediating interactions. The described nanoHPLC-ESI-Q/ToF methodology utilizes known biosynthetic pathways, accurate mass detection, optimized collision-induced disassociation, and a robust nanoflow chromatographic separation for the analysis of intact sphingolipids found in human tissue, cells, and serum. The methodology was developed and validated with an emphasis on addressing the common issues experienced in profiling these amphipathic lipids, which are part of the glycocalyx and lipidome. The high sensitivity obtained using nanorange flow rates with robust chromatographic reproducibility over a wide range of concentrations and injection volumes results in confident identifications for profiling these low-abundant biomolecules.

Natural products targeting autophagy and apoptosis in NSCLC: a novel therapeutic strategy

Lung cancer is the leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) being the predominant type. The roles of autophagy and apoptosis in NSCLC present a dual and intricate nature. Additionally, autophagy and apoptosis interconnect through diverse crosstalk molecules. Owing to their multitargeting nature, safety, and efficacy, natural products have emerged as principal sources for NSCLC therapeutic candidates. This review begins with an exploration of the mechanisms of autophagy and apoptosis, proceeds to examine the crosstalk molecules between these processes, and outlines their implications and interactions in NSCLC. Finally, the paper reviews natural products that have been intensively studied against NSCLC targeting autophagy and apoptosis, and summarizes in detail the four most retrieved representative drugs. This paper clarifies good therapeutic effects of natural products in NSCLC by targeting autophagy and apoptosis and aims to promote greater consideration by researchers of natural products as candidates for anti-NSCLC drug discovery.

The obesity-autophagy-cancer axis: Mechanistic insights and therapeutic perspectives

Autophagy, a self-degradative process vital for cellular homeostasis, plays a significant role in adipose tissue metabolism and tumorigenesis. This review aims to elucidate the complex interplay between autophagy, obesity, and cancer development, with a specific emphasis on how obesity-driven changes affect the regulation of autophagy and subsequent implications for cancer risk. The burgeoning epidemic of obesity underscores the relevance of this research, particularly given the established links between obesity, autophagy, and various cancers. Our exploration delves into hormonal influence, notably INS (insulin) and LEP (leptin), on obesity and autophagy interactions. Further, we draw attention to the latest findings on molecular factors linking obesity to cancer, including hormonal changes, altered metabolism, and secretory autophagy. We posit that targeting autophagy modulation may offer a potent therapeutic approach for obesity-associated cancer, pointing to promising advancements in nanocarrier-based targeted therapies for autophagy modulation. However, we also recognize the challenges inherent to these approaches, particularly concerning their precision, control, and the dual roles autophagy can play in cancer. Future research directions include identifying novel biomarkers, refining targeted therapies, and harmonizing these approaches with precision medicine principles, thereby contributing to a more personalized, effective treatment paradigm for obesity-mediated cancer.

Sphingolipids: drivers of cardiac fibrosis and atrial fibrillation

Sphingolipids (SLs) are vital constituents of the plasma membrane of animal cells and concurrently regulate numerous cellular processes. An escalating number of research have evinced that SLs assume a crucial part in the progression of tissue fibrosis, a condition for which no efficacious cure exists as of now. Cardiac fibrosis, and in particular, atrial fibrosis, is a key factor in the emergence of atrial fibrillation (AF). AF has become one of the most widespread cardiac arrhythmias globally, with its incidence continuing to mount, thereby propelling it to the status of a major public health concern. This review expounds on the structure and biosynthesis pathways of several pivotal SLs, the pathophysiological mechanisms of AF, and the function of SLs in cardiac fibrosis. Delving into the influence of sphingolipid levels in the alleviation of cardiac fibrosis offers innovative therapeutic strategies to address cardiac fibrosis and AF.

Imipridones inhibit tumor growth and improve survival in an orthotopic liver metastasis mouse model of human uveal melanoma

Purpose

Uveal melanoma (UM) is a highly aggressive disease with very few treatment options. We previously demonstrated that mUM is characterized by high oxidative phosphorylation (OXPHOS). Here we tested the anti-tumor, signaling and metabolic effects of imipridones, CLPP activators which reduce OXPHOS indirectly and have demonstrated safety in patients.

Experimental Design

We assessed CLPP expression in UM patient samples. We tested the effects of imipridones (ONC201, ONC212) on the growth, survival, signaling and metabolism of UM cell lines in vitro, and for therapeutic effects in vivo in UM liver metastasis models.

Results

CLPP expression was confirmed in primary and mUM patient samples. ONC201/212 treatment of UM cell lines in vitro decreased OXPHOS effectors, inhibited cell growth and migration, and induced apoptosis. ONC212 increased metabolic stress and apoptotic pathways, inhibited amino acid metabolism, and induced cell death-related lipids. ONC212 also decreased tumor burden and increased survival in vivo in two UM liver metastasis models.

Conclusion

Imipridones are a promising strategy for further testing and development in mUM.

Changes in lipid composition of host-derived extracellular vesicles following Salmonella infection

IMPORTANCE

This study delves into the previously unexplored territory of extracellular vesicle (EV) cargo and composition, specifically focusing on lipid composition changes in EVs following Salmonella infection. EVs play crucial roles in intercellular communication, carrying a variety of biomolecules. Investigating how these EV cargo lipids change post-infection with Salmonella is significant for understanding the molecular mechanisms underlying lipid trafficking during infection. Given the impact of lipid composition on EV function, this research uncovers distinct differences in the lipid profiles of EVs at different time points post-infection and between infected and uninfected macrophages. This study identified lipids that are differentially abundant in EVs produced by the host during infection, offering novel insights into the dynamics of lipid profiles in EVs during cellular processes and infections. This work advances our understanding of host-pathogen interactions, specifically lipid-mediated EV functions during infection.

AFB1 Triggers Lipid Metabolism Disorders through the PI3K/Akt Pathway and Mediates Apoptosis Leading to Hepatotoxicity

As the most prevalent mycotoxin in agricultural products, aflatoxin B1 not only causes significant economic losses but also poses a substantial threat to human and animal health. AFB1 has been shown to increase the risk of hepatocellular carcinoma (HCC) but the underlying mechanism is not thoroughly researched. Here, we explored the toxicity mechanism of AFB1 on human hepatocytes following low-dose exposure based on transcriptomics and lipidomics. Apoptosis-related pathways were significantly upregulated after AFB1 exposure in all three hES-Hep, HepaRG, and HepG2 hepatogenic cell lines. By conducting a comparative analysis with the TCGA-LIHC database, four biomarkers (MTCH1, PPM1D, TP53I3, and UBC) shared by AFB1 and HCC were identified (hazard ratio > 1), which can be used to monitor the degree of AFB1-induced hepatotoxicity. Simultaneously, AFB1 induced abnormal metabolism of glycerolipids, sphingolipids, and glycerophospholipids in HepG2 cells (FDR < 0.05, impact > 0.1). Furthermore, combined analysis revealed strong regulatory effects between PIK3R1 and sphingolipids (correlation coefficient > 0.9), suggesting potential mediation by the phosphatidylinositol 3 kinase (PI3K) /protein kinase B (AKT) signaling pathway within mitochondria. This study revealed the dysregulation of lipid metabolism induced by AFB1 and found novel target genes associated with AFB-induced HCC development, providing reliable evidence for elucidating the hepatotoxicity of AFB as well as assessing food safety risks.

Accumulation of sphingosine kinase 2 protein induces malignant transformation in oral keratinocytes associated with stemness, autophagy, senescence, and proliferation

Sphingosine-1-phosphate (S1P) signaling has been widely explored as a therapeutic target in cancer. Sphingosine kinase 2 (SK2), one of the kinases that phosphorylate sphingosine, has a cell type and cell location-dependent mechanism of action, so the ability of SK2 to induce cell cycle arrest, apoptosis, proliferation, and survival is strongly influenced by the cell-context. In contrast to SK1, which is widely studied in different types of cancer, including head and neck cancer, the role of SK2 in the development and progression of oral cancer is still poorly understood. In order to elucidate SK2 role in oral cancer, we performed the overexpression of SK2 in non-tumor oral keratinocyte cell (NOK SK2) and in oral squamous cell carcinoma (HN12 SK2), and RNA interference for SK2 in another oral squamous cell carcinoma (HN13 shSK2). In our study we demonstrate for the first time that accumulation of SK2 can be a starting point for oncogenesis and transforms a non-tumor oral keratinocyte (NOK-SI) into highly aggressive tumor cells, even acting on cell plasticity. Furthermore, in oral metastatic cell line (HN12), SK2 contributed even more to the tumorigenesis, inducing proliferation and tumor growth. Our work reveals the intriguing role of SK2 as an oral tumor promoter and regulator of different pathways and cellular processes.

Effect of Salvia miltiorrhiza Bunge extracts on improving the efficacy and reducing the toxicity of Tripterygium wilfordii polyglycosides in the treatment of rheumatoid arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium wilfordii polyglycosides (TWP), extracted from the traditional Chinese herb Tripterygium wilfordii, has been widely used in the treatment of rheumatoid arthritis (RA). However, the toxicity of TWP to a variety of organs such as liver, kidney and testis greatly limits its clinical application. Salvia miltiorrhiza Bunge is often used in the treatment of RA due to its blood circulation promoting, stasis resolving, and anti-inflammatory effects. Salvia miltiorrhiza Bunge has also been reported to possess multiple organ protective effects.

AIM OF THE STUDY

To investigate the influences of two main components of Salviorrhiza miltiorrhiza Bunge, hydrophilic salvianolic acids (SA) and lipophilic tanshinones (Tan), on the efficacy and toxicity of TWP in treating RA and to explore the underlying mechanisms.

MATERIALS AND METHODS

SA and Tan were extracted from Salvia miltiorrhiza Bunge and the extracts were quantitated by HPLC and identified by UPLC-Q/TOF-MS. Then, a collagen-induced arthritis (CIA) rat model was established using bovine type II collagen (CII) and incomplete Freund's adjuvant (IFA). CIA rats were treated with TWP and/or SA/Tan. After 21 days of continuous treatment, arthritis symptoms and organs toxicity were evaluated. Meanwhile, serum metabolomics were investigated by the UPLC-Q/TOF-MS to understand the underlying mechanism.

RESULTS

SA and Tan extracts could significantly alleviate arthritis symptoms in CIA rats and decrease the serum levels of inflammatory factors TNF-α, IL-1β and IL-6 when combined with TWP. Meanwhile, both extracts alleviated injury of liver, kidney and testis caused by TWP, and the hydrophilic extract SA was superior. Moreover, a total of 38 endogenous differential metabolites were identified between the CIA model group and the TWP group, among which 33 metabolites were significantly recovered after the combination of SA or Tan. Metabolic pathway analysis showed that SA and Tan can affect metabolic pathways including linoleic acid metabolism, glycerophospholipid metabolism, sphingolipid metabolism and steroid biosynthesis metabolism pathway.

CONCLUSIONS

Our findings indicated for the first time that two Salviorrhiza miltiorrhiza Bunge extracts could improve the efficacy and reduce the toxicity of TWP in the treatment of RA by adjusting metabolic pathways, and the hydrophilic extract SA was superior.

Anti-heart failure mechanism of saponin extract of black ginseng based on metabolomics

OBJECTIVE

This study aimed to explore the mechanism of total saponin of black ginseng (TSBG) in treating heart failure (HF) in DOX-induced HF model rats.

METHODS

Rats with HF induced by the intraperitoneal injection of DOX were treated with TSBG (low dose, 30 mg/kg/day; medium dose, 60 mg/kg/day; high dose, 120 mg/kg/day) and shakubar trivalsartan (80 mg/kg/day, positive control) for four weeks. Serum BNP and ANP levels were tested by ELISA, and pathological tissue sections were examined. Serum metabolites were measured using nontargeted metabolomic techniques. The expression of Akt/mTOR autophagy-associated proteins in heart tissue was detected using Western blot, including Beclin1, p62, LCII and LC3I.

RESULTS

Compared with the model group, rats in the TSBG-H group had a significantly lower heart index (p < 0.05), significantly lower serum levels of BNP (p < 0.01) and ANP (p < 0.01) and significantly fewer cardiac histopathological changes. Metabolomic results showed that TSBG significantly back-regulated 12 metabolites (p < 0.05), including cholesterol, histamine, sphinganine, putrescine, arachidonic acid, 3-sulfinoalanine, hypotaurine, gluconic acid and lysoPC (18:0:0). These metabolite changes were involved in taurine and hypotaurine metabolism, arachidonic acid metabolism, sphingolipid metabolism, etc. The protein expression level of p-Akt/Akt and p-mTOR/mTOR was significantly up-regulated (p < 0.001), whereas that of Beclin1, p62 (p < 0.001) and LCII/LC3I was down-regulated (p < 0.05).

CONCLUSION

TSBG has an excellent therapeutic effect on DOX-induced HF in rats, probably by regulating the Akt/mTOR autophagy signalling pathway, resulting in the improvement of taurine and hypotaurine metabolism, arachidonic acid metabolism and sphingolipid metabolism, which may provide a reference for elucidating the potential mechanism of action of TSBG against HF.

Single-cell sequencing analysis related to sphingolipid metabolism guides immunotherapy and prognosis of skin cutaneous melanoma

Background

We explore sphingolipid-related genes (SRGs) in skin melanoma (SKCM) to develop a prognostic indicator for patient outcomes. Dysregulated lipid metabolism is linked to aggressive behavior in various cancers, including SKCM. However, the exact role and mechanism of sphingolipid metabolism in melanoma remain partially understood.

Methods

We integrated scRNA-seq data from melanoma patients sourced from the GEO database. Through the utilization of the Seurat R package, we successfully identified distinct gene clusters associated with patient survival in the scRNA-seq data. Key prognostic genes were identified through single-factor Cox analysis and used to develop a prognostic model using LASSO and stepwise regression algorithms. Additionally, we evaluated the predictive potential of these genes within the immune microenvironment and their relevance to immunotherapy. Finally, we validated the functional significance of the high-risk gene IRX3 through in vitro experiments.

Results

Analysis of scRNA-seq data identified distinct expression patterns of 4 specific genes (SRGs) in diverse cell subpopulations. Re-clustering cells based on increased SRG expression revealed 7 subgroups with significant prognostic implications. Using marker genes, lasso, and Cox regression, we selected 11 genes to construct a risk signature. This signature demonstrated a strong correlation with immune cell infiltration and stromal scores, highlighting its relevance in the tumor microenvironment. Functional studies involving IRX3 knockdown in A375 and WM-115 cells showed significant reductions in cell viability, proliferation, and invasiveness.

Conclusion

SRG-based risk signature holds promise for precise melanoma prognosis. An in-depth exploration of SRG characteristics offers insights into immunotherapy response. Therapeutic targeting of the IRX3 gene may benefit melanoma patients.

Sphingolipids in mitochondria-from function to disease

Sphingolipids are not only structural components of cellular membranes but also play vital roles in cell signaling and modulation of cellular processes. Within mitochondria, sphingolipids exert diverse effects on mitochondrial dynamics, energy metabolism, oxidative stress, and cell death pathways. In this review, we summarize literature addressing the crucial role of sphingolipids in mitochondria, highlighting their impact on mitochondrial dynamics, cellular bioenergetics, and important cell processes including apoptosis and mitophagy.

NXC736 Attenuates Radiation-Induced Lung Fibrosis via Regulating NLRP3/IL-1β Signaling Pathway

Radiation-induced lung fibrosis (RILF) is a common complication of radiotherapy in lung cancer. However, to date no effective treatment has been developed for this condition. NXC736 is a novel small-molecule compound that inhibits NLRP3, but its effect on RILF is unknown. NLRP3 activation is an important trigger for the development of RILF. Thus, we aimed to evaluate the therapeutic effect of NXC736 on lung fibrosis inhibition using a RILF animal model and to elucidate its molecular signaling pathway. The left lungs of mice were irradiated with a single dose of 75 Gy. We observed that NXC736 treatment inhibited collagen deposition and inflammatory cell infiltration in irradiated mouse lung tissues. The damaged lung volume, evaluated by magnetic resonance imaging, was lower in NXC736-treated mice than in irradiated mice. NXC736-treated mice exhibited significant changes in lung function parameters. NXC736 inhibited inflammasome activation by interfering with the NLRP3-ASC-cleaved caspase-1 interaction, thereby reducing the expression of IL-1β and blocking the fibrotic pathway. In addition, NXC736 treatment reduced the expression of epithelial-mesenchymal transition markers such as α-SMA, vimentin, and twist by blocking the Smad 2,3,4 signaling pathway. These data suggested that NXC736 is a potent therapeutic agent against RILF.

Sphingolipid-Based Synergistic Interactions to Enhance Chemosensitivity in Lung Cancer Cells

Tumor heterogeneity leads to drug resistance in cancer treatment with the crucial role of sphingolipids in cell fate and stress signaling. We analyzed sphingolipid metabolism and autophagic flux to study chemotherapeutic interactions on the A549 lung cancer model. Loaded cells with fluorescent sphingomyelin analog (BODIPY) and mCherry-EGFP-LC3B were used to track autophagic flux and assess cytotoxicity when cells are exposed to chemotherapy (epirubicin, cisplatin, and paclitaxel) together with sphingolipid pathway inhibitors and autophagy modulators. Our cell model approach employed fluorescent sphingolipid biosensors and a Gaussian Mixture Model of cell heterogeneity profiles to map the influence of chemotherapy on the sphingolipid pathway and infer potential synergistic interactions. Results showed significant synergy, especially when combining epirubicin with autophagy inducers (rapamycin and Torin), reducing cell viability. Cisplatin also synergized with a ceramidase inhibitor. However, paclitaxel often led to antagonistic effects. Our mapping model suggests that combining chemotherapies with autophagy inducers increases vesicle formation, possibly linked to ceramide accumulation, triggering cell death. However, the in silico model proposed ceramide accumulation in autophagosomes, and kinetic analysis provided evidence of sphingolipid colocalization in autophagosomes. Further research is needed to identify specific sphingolipids accumulating in autophagosomes. These findings offer insights into potential strategies for overcoming chemotherapy resistance by targeting the sphingolipid pathway.

Serum, spleen metabolomics and gut microbiota reveals effect of catalpol on blood deficiency syndrome caused by cyclophosphamide and acetylphenylhydrazine

Catalpol (CA), extracted from Rehmannia Radix, holds extensive promise as a natural medicinal compound. This study employed 16S rRNA gene sequencing and combined serum and spleen metabolomics to profoundly investigate the therapeutic effects of CA on blood deficiency syndrome (BDS) and the underlying mechanisms. Notably, CA exhibited effectiveness against BDS induced by cyclophosphamide (CP) and acetylphenylhydrazine (APH) in rats-CA substantially elevated levels of crucial indicators such as erythropoietin (EPO), granulocyte colony-stimulating factor (G-CSF), tumor necrosis factor-alpha (TNF-a), and interleukin-6 (IL-6). Additionally, CA could alleviate peripheral blood cytopenia. Furthermore, the analysis of 16S rRNA revealed that CA had the potential to reverse the Firmicutes/Bacteroidetes (F/B) ratio associated with BDS. Through comprehensive serum and spleen metabolomic profiling, we successfully identified 22 significant biomarkers in the serum and 23 in the spleen, respectively. Enrichment analysis underscored Glycerophospholipid metabolism and Sphingolipid metabolism as potential pathways through which CA exerts its therapeutic effects on BDS.

Niclosamide as a chemical probe for analyzing SARS-CoV-2 modulation of host cell lipid metabolism

Introduction

SARS-CoV-2 subverts host cell processes to facilitate rapid replication and dissemination, and this leads to pathological inflammation.

Methods

We used niclosamide (NIC), a poorly soluble anti-helminth drug identified initially for repurposed treatment of COVID-19, which activates the cells' autophagic and lipophagic processes as a chemical probe to determine if it can modulate the host cell's total lipid profile that would otherwise be either amplified or reduced during SARS-CoV-2 infection.

Results

Through parallel lipidomic and transcriptomic analyses we observed massive reorganization of lipid profiles of SARS-CoV-2 infected Vero E6 cells, especially with triglycerides, which were elevated early during virus replication, but decreased thereafter, as well as plasmalogens, which were elevated at later timepoints during virus replication, but were also elevated under normal cell growth. These findings suggested a complex interplay of lipid profile reorganization involving plasmalogen metabolism. We also observed that NIC treatment of both low and high viral loads does not affect virus entry. Instead, NIC treatment reduced the abundance of plasmalogens, diacylglycerides, and ceramides, which we found elevated during virus infection in the absence of NIC, resulting in a significant reduction in the production of infectious virions. Unexpectedly, at higher viral loads, NIC treatment also resulted in elevated triglyceride levels, and induced significant changes in phospholipid metabolism.

Discussion

We posit that future screens of approved or new partner drugs should prioritize compounds that effectively counter SARS-CoV-2 subversion of lipid metabolism, thereby reducing virus replication, egress, and the subsequent regulation of key lipid mediators of pathological inflammation.

Profiling lipidomic changes in dengue-resistant and dengue-susceptible strains of Colombian Aedes aegypti after dengue virus challenge

The mosquito Aedes aegypti is the primary vector for all four serotypes of dengue viruses (DENV1-4), which infect millions across the globe each year. Traditional insecticide programs have been transiently effective at minimizing cases; however, insecticide resistance and habitat expansion have caused cases of DENV to surge over the last decade. There is an urgent need to develop novel vector control measures, but these are contingent on a detailed understanding of host-parasite interactions. Here, we have utilized lipidomics to survey the profiles of naturally DENV-resistant (Cali-MIB) or susceptible (Cali-S) populations of Ae. aegypti, isolated from Cali, Colombia, when fed on blood meals containing DENV. Control insects were fed on a DENV-free blood meal. Midguts were dissected from Cali-MIB and Cali-S females at three time points post-infectious blood meal, 18, 24 and 36h, to identify changes in the lipidome at key times associated with the entry, replication and exit of DENV from midgut cells. We used principal component analysis to visualize broad patterns in lipidomic profiles between the treatment groups, and significance analysis of microarray to determine lipids that were altered in response to viral challenge. These data can be used to identify molecules or metabolic pathways particular to the susceptible or refractory phenotypes, and possibly lead to the generation of stable, DENV-resistant strains of Ae. aegypti.

Oral Administration of Glucosylceramide Suppresses Tumor Growth by Affecting the Ceramide/Sphingosine-1-Phosphate Balance in Breast Cancer Tissue

Background

Ceramide and sphingosine-1-phosphate (S1P) play opposing roles in cell death and survival, and maintain a dynamic balance called the sphingolipid rheostat. Glucosylceramide is a substrate to generate ceramide but its effect on breast cancer by oral administration was never tested. The purpose of this study was to reveal the anticancer activity of glucosylceramide and its potential as a new therapeutic agent in breast cancer.

Methods

E0771 cells were inoculated into the breast tissue of female C57BL/6NJcl mice. Glucosylceramide was administered orally to the mice for nine consecutive days. The concentrations of sphingolipid mediators including ceramide, glucosylceramide, and S1P in tumor tissues and serum were determined by mass spectrometry.

Results

Oral administration of glucosylceramide significantly suppressed E0771 tumor growth compared with the control group (P = 0.006). There were no significant differences in the serum concentrations of sphingolipid mediators including ceramide and S1P between the mice treated with glucosylceramide and control-treated mice. The ceramide concentration was significantly lower in tumor tissues (P = 0.026), and the S1P concentration was significantly higher than that in paired non-tumor tissues (P = 0.009). The S1P concentration in tumor tissues was significantly lower in mice treated with glucosylceramide than in control-treated mice (P = 0.001). The ceramide-to-S1P concentration ratio in tumor tissues was significantly higher in mice treated with glucosylceramide than in control-treated mice (P = 0.034).

Conclusions

Breast tumors could enhance their survival by increasing S1P conversion from ceramide. Oral administration of glucosylceramide suppressed tumor growth by affecting the ceramide/S1P balance. Oral administration of glucosylceramide is a promising basis for a new therapeutic approach.

Ceramides and ceramide synthases in cancer: Focus on apoptosis and autophagy

Different studies corroborate a role for ceramide synthases and their downstream products, ceramides, in modulation of apoptosis and autophagy in the context of cancer. These mechanisms of regulation, however, appear to be context dependent in terms of ceramides' fatty acid chain length, subcellular localization, and the presence or absence of their downstream targets. Our current understanding of the role of ceramide synthases and ceramides in regulation of apoptosis and autophagy could be harnessed to pioneer the development of new treatments to activate or inhibit a single type of ceramide synthase, thereby regulating the apoptosis induction or cross talk of apoptosis and autophagy in cancer cells. Moreover, the apoptotic function of ceramide suggests that ceramide analogues can pave the way for the development of novel cancer treatments. Therefore, in the current review paper we discuss the impact of ceramide synthases and ceramides in regulation of apoptosis and autophagy in context of different types of cancers. We also briefly introduce the latest information on ceramide synthase inhibitors, their application in diseases including cancer therapy, and discuss approaches for drug discovery in the field of ceramide synthase inhibitors. We finally discussed strategies for developing strategies to use lipids and ceramides analysis in biological fluids for developing early biomarkers for cancer.

Ceramides and their roles in programmed cell death

Programmed cell death plays a crucial role in maintaining the homeostasis and integrity of multicellular organisms, and its dysregulation contributes to the pathogenesis of many diseases. Programmed cell death is regulated by a range of macromolecules and low-molecular messengers, including ceramides. Endogenous ceramides have different functions, that are influenced by their localization and the presence of their target molecules. This article provides an overview of the current understanding of ceramides and their impact on various types of programmed cell death, including apoptosis, anoikis, macroautophagy and mitophagy, and necroptosis. Moreover, it highlights the emergence of dihydroceramides as a new class of bioactive sphingolipids and their downstream targets as well as their future roles in cancer cell growth, drug resistance and tumor metastasis.

Phase I trial of intravenous fenretinide (4-HPR) plus safingol in advanced malignancies

PURPOSE

Fenretinide (4-HPR) is a synthetic retinoid that induces cytotoxicity through dihydroceramide production. Safingol, a stereochemical-variant dihydroceramide precursor, exhibits synergistic effects when administered with fenretinide in preclinical studies. We conducted a phase 1 dose-escalation clinical trial of this combination.

METHODS

Fenretinide was administered as a 600 mg/m2 24-h infusion on Day 1 of a 21-day cycle followed by 900 mg/m2/day on Days 2 and 3. Safingol was concurrently administered as a 48-h infusion on Day 1 and 2 using 3 + 3 dose escalation. Primary endpoints were safety and maximum tolerated dose (MTD). Secondary endpoints included pharmacokinetics and efficacy.

RESULTS

A total of 16 patients were enrolled (mean age 63 years, 50% female, median three prior lines of therapy), including 15 patients with refractory solid tumors and one with non-Hodgkin lymphoma. The median number of treatment cycles received was 2 (range 2-6). The most common adverse event (AE) was hypertriglyceridemia (88%; 38% ≥ Grade 3), attributed to the fenretinide intralipid infusion vehicle. Other treatment-related AEs occurring in ≥ 20% of patients included anemia, hypocalcemia, hypoalbuminemia, and hyponatremia. At safingol dose 420 mg/m2, one patient had a dose-limiting toxicity of grade 3 troponinemia and grade 4 myocarditis. Due to limited safingol supply, enrollment was halted at this dose level. Fenretinide and safingol pharmacokinetic profiles resembled those observed in monotherapy trials. Best radiographic response was stable disease (n = 2).

CONCLUSION

Combination fenretinide plus safingol commonly causes hypertriglyceridemia and may be associated with cardiac events at higher safingol levels. Minimal activity in refractory solid tumors was observed.

TRIAL REGISTRATION NUMBER

NCT01553071 (3.13.2012).

HIV and SIV Envelope Glycoproteins Interact with Glycolipids and Lipids

The present study demonstrates that, in addition to interacting with galactosylceramide (GalCer), HIV-1, HIV-2, and SIV envelope glycoproteins are able to interact with glucosylceramide (GlcCer), lactosylceramide (LacCer), and ceramide. These interactions were characterized by using three complementary approaches based on molecular binding and physicochemical assays. The binding assays showed that iodinated radiolabeled HIV-1 and HIV-2 glycoproteins (¹²⁵I-gp) interact physically with GalCer, GlcCer, LacCer, and ceramide previously separated by thin layer chromatography (TLC) or directly coated on a flexible 96-well plate. These interactions are specific as demonstrated, on the one hand, by the dose-dependent inhibition in the presence of various dilutions of immune, but not non-immune, sera, and, on the other hand, by the absence of interaction of these glycolipids/lipids with ¹²⁵I-IgG used as an unrelated control protein. These interactions were further confirmed in a physicochemical assay, based on the capacity of these glycolipids for insertion in a pre-established monomolecular film, as a model of the cell membrane, with each glycolipid/lipid. The addition of HIV envelope glycoproteins, but not ovomucoid protein used as a negative control, resulted in a rapid increase in surface pressure of the glycolipid/lipid films, thus indirectly confirming their interactions with GalCer, GlcCer, LacCer, and ceramide. In summary, we show that HIV and SIV envelope glycoproteins bind to GalCer, GlcCer, LacCer, and ceramide in a dose-dependent, saturable, and specific manner. These interactions may function as receptors of attachment in order to facilitate infection of CD4 low or negative cells or promote interactions with other receptors leading to the activation of signaling pathways or pathogenesis.

Lipid signatures of West Nile virus infection unveil alterations of sphingolipid metabolism providing novel biomarkers

West Nile virus (WNV) is a neurotropic flavivirus transmitted by the bites of infected mosquitoes. Severe forms of West Nile disease (WND) can curse with meningitis, encephalitis or acute flaccid paralysis. A better understanding of the physiopathology associated with disease progression is mandatory to find biomarkers and effective therapies. In this scenario, blood derivatives (plasma and serum) constitute the more commonly used biofluids due to its ease of collection and high value for diagnostic purposes. Therefore, the potential impact of this virus in the circulating lipidome was addressed combining the analysis of samples from experimentally infected mice and naturally WND patients. Our results unveil dynamic alterations in the lipidome that define specific metabolic fingerprints of different infection stages. Concomitant with neuroinvasion in mice, the lipid landscape was dominated by a metabolic reprograming that resulted in significant elevations of circulating sphingolipids (ceramides, dihydroceramides and dihydrosphingomyelins), phosphatidylethanolamines and triacylglycerols. Remarkably, patients suffering from WND also displayed an elevation of ceramides, dihydroceramides, lactosylceramides and monoacylglycerols in their sera. The dysregulation of sphingolipid metabolism by WNV may provide new therapeutic opportunities and supports the potential of certain lipids as novel peripheral biomarkers of WND progression.

Integrating Metabolomics and Network Pharmacology to Explore the Mechanism of Tongmai Yangxin Pills in Ameliorating Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX) is a broad-spectrum chemotherapeutic drug used in clinical treatment of malignant tumors. It has a high anticancer activity but also high cardiotoxicity. The aim of this study was to explore the mechanism of Tongmai Yangxin pills (TMYXPs) in ameliorating DOX-induced cardiotoxicity through integrated metabolomics and network pharmacology. In this study, first, an ultrahigh-performance liquid chromatography-quadrupole-time-of-flight/mass spectrometry (UPLC-Q-TOF/MS) metabonomics strategy was established to obtain metabolite information and potential biomarkers were determined after data processing. Second, network pharmacological analysis was used to evaluate the active components, drug-disease targets, and key pathways of TMYXPs to alleviate DOX-induced cardiotoxicity. Targets from the network pharmacology analysis and metabolites from plasma metabolomics were jointly analyzed to select crucial metabolic pathways. Finally, the related proteins were verified by integrating the above results and the possible mechanism of TMYXPs to alleviate DOX-induced cardiotoxicity was studied. After metabolomics data processing, 17 different metabolites were screened, and it was found that TMYXPs played a role in myocardial protection mainly by affecting the tricarboxylic acid (TCA) cycle of myocardial cells. A total of 71 targets and 20 related pathways were screened out with network pharmacological analysis. Based on the combined analysis of 71 targets and different metabolites, TMYXPs probably played a role in myocardial protection through regulating upstream proteins of the insulin signaling pathway, MAPK signaling pathway, and p53 signaling pathway, as well as the regulation of metabolites related to energy metabolism. They then further affected the downstream Bax/Bcl-2-Cyt c-caspase-9 axis, inhibiting the myocardial cell apoptosis signaling pathway. The results of this study may contribute to the clinical application of TMYXPs in DOX-induced cardiotoxicity.

Alkaline ceramidase (ClAC) inhibition enhances heat stress response in Cyrtorhinus lividipennis (Reuter)

Ceramidases (CDases) are vital sphingolipid enzymes involved in organismal growth and development. They have been reported as key mediators of thermal stress response. However, whether and how CDase responds to heat stress in insects remain unclear. Herein, we identified two CDase genes, C. lividipennis alkaline ceramidase (ClAC) and neutral ceramidase (ClNC), by searching the transcriptome and genome databases of the mirid bug, Cyrtorhinus lividipennis, an important natural predator of planthoppers. Quantitative PCR (qPCR) analysis showed that both ClNC and ClAC were highly expressed in nymphs than in adults. ClAC was especially highly expressed in the head, thorax, and legs, while ClNC was widely expressed in the tested organs. Only the ClAC transcription was significantly affected by heat stress. Knocking down ClAC increased the C. lividipennis nymph survival rate under heat stress. The transcriptome and lipidomics data showed that the RNA interference-mediated suppression of ClAC significantly upregulated the transcription level of catalase (CAT) and the content of long-chain base ceramides, including C16-, C18-, C24-, and C31- ceramides. In C. lividipennis nymphs, ClAC played an important role in heat stress response, and the upregulation of nymph survival rate might be caused by variation in the ceramide levels and transcriptional changes in CDase downstream genes. This study improves our understanding of the physiological functions of insect CDase under heat stress and provides valuable insights into the nature enemy application.

Calcium signaling in lysosome-dependent cell death

Calcium is a crucial messenger of intracellular and extracellular signals, regulating a great variety of cellular processes such as cell death, proliferation, and metabolism. Inside the cell, calcium signaling is one of the main interorganelle communication mediators, with central functional roles at the endoplasmic reticulum (ER), mitochondria, Golgi complex, and lysosomes. Lysosomal function is highly dependent on lumenal calcium and most of the lysosomal membrane-localised ion channels regulate several lysosomal functions and properties such as lumenal pH. One of these functions configures a specific type of cell death involving lysosomes, named lysosome-dependent cell death (LDCD), which contributes to maintenance of tissue homeostasis, development and pathology when deregulated. Here, we cover the fundamental aspects of LDCD with a special focus on recent advances in calcium signaling in LDCD.