Search Results (216)

Background/Objectives: Non–small cell lung cancer (NSCLC) is a leading cause of cancer-related mortality, driven by invasive behavior and frequent resistance to systemic therapies. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) benefit patients with EGFR-mutant NSCLC, but their efficacy is often limited by tumor-intrinsic and environmental resistance mechanisms. Benzo[a]pyrene (BaP), a ubiquitous polycyclic aromatic hydrocarbon from tobacco smoke, combustion, and dietary sources, is a known carcinogen; however, its role in modulating therapeutic responses is poorly understood. Studies, including ours, implicate the platelet-activating factor-receptor (PAFR) pathway in mediating environmental pollutant and therapy-induced effects on tumor growth and microvesicle particle (MVP) release. We hypothesized that PAFR activation mediates BaP-induced NSCLC progression and influences EGFR-TKI responses. Methods: We assessed the effects of BaP, PAFR agonist CPAF, EGFR-TKIs, and their combinations on cell viability, proliferation, migration, anchorage-independent growth, and MVP secretion. Results: BaP did not alter cell survival but significantly increased migration, growth, colony formation, and MVP release, similar to CPAF, and these effects were blocked by a PAFR antagonist or acid sphingomyelinase inhibitor. Notably, BaP did not significantly reduce EGFR-TKI efficacy at tested concentrations. Conclusions: These results show that environmental carcinogens modulate NSCLC behavior through PAFR signaling without compromising EGFR-TKI responsiveness, highlighting PAFR as a potential therapeutic target. Full article

Lysosomal diseases (LDs, or Lysosomal Storage Disorders) have become increasingly visible in the newborn screening community, with the addition of mucopolysaccharidosis type II (MPS-II) into the Recommended Uniform Screening Panel in August 2022 and Infantile Krabbe disease in June 2024. As more LDs are expected to be considered for screening adoption, the ability to multiplex conditions and expand proficiency testing (PT) using quality control materials is essential. This study examines the use of recombinant enzymes to produce first-tier PT materials for mucopolysaccharidosis type I, MPS-II, Gaucher, Fabry, Krabbe, Pompe, and Niemann–Pick A/B (acid sphingomyelinase deficiency)—adding four disorders to the CDC’s Newborn Screening Quality Assurance Program (NSQAP) LD PT panel. Through an iterative process that included two prototype phases, two pilot phases, and external testing by up to 31 external laboratories, a new manufacturing process was developed for producing high-performing dried blood spot-based LD PT specimens. Materials were evaluated using several methods commonly employed by newborn screening laboratories, including tandem mass spectrometry with flow injection and liquid chromatography, digital microfluidics, and fluorometric assays. This novel process for producing LD PT materials offers several advantages over previous manufacturing methods that relied on immortalized cell lines from affected patients. Improved scalability, for example, has enabled NSQAP to expand LD PT enrollment internationally. Furthermore, the new process makes it easier to support future expansions of the LD screening panel. The updated specimens and expanded program were launched in January 2025. Full article

Acid sphingomyelinase deficiency is a lysosomal storage disease that is characterized by the systemic accumulation of sphingomyelin in cells. This condition is frequently associated with hepatomegaly and hepatic dysfunction, with 91.4% of patients showing clinically relevant signs of liver involvement. Both clinical observations and experimental models show excessive sphingomyelin accumulation in hepatocytes. Studies using ASMD models have yielded conflicting results, showing hepatoprotective effects on one hand and detrimental effects on the other. Murine models demonstrated hepatoprotective effects of ASMD due to the modulation of endoplasmic reticulum stress. Patients with ASMD exhibit signs of impaired autophagy, which can lead to the accumulation of damaged cellular components and metabolic dysfunction. Furthermore, patients exhibit disrupted lipid metabolism, highlighting the dysfunction of hepatic lipid homeostasis. This review explores the involvement of ASMD in hepatocytes to better understand the disease mechanisms and possible therapeutic approaches. Full article

Eryptosis is a programmed cellular death that leads to the removal of defective red blood cells (RBCs). It is driven by convergent intracellular pathways centered on cytosolic Ca²⁺ overload, ceramide formation, caspase and calpain activation, disruption of membrane phospholipid asymmetry, and the externalization of phosphatidylserine on the cell surface, which marks the cell for clearance by macrophages. In hemodialysis (HD), intermittent extracorporeal circulation exposes erythrocytes to mechanical stress, bio-incompatible membrane surfaces, and rapid osmotic and ionic shifts. Experimental evidence indicates that osmotic shock induces eryptosis through synergistic Ca²⁺ influx and sphingomyelinase-dependent ceramide generation, providing a mechanistic framework for intradialytic erythrocyte injury. Clinical studies report heterogeneous eryptotic responses during HD, reflecting the balance between toxin removal and procedure-related stress. In contrast, peritoneal dialysis (PD) imposes sustained exposure to hyperosmolar, glucose-based solutions and is strongly influenced by inflammation and residual kidney function. Clinical and experimental data consistently demonstrate increased eryptosis in PD patients, with marked amplification during peritonitis and close associations with inflammatory mediators. This review integrates mechanistic and clinical evidence on eryptosis in HD and PD, highlights modality-specific triggers converging on shared downstream pathways and discusses translational implications and research priorities for improving dialysis biocompatibility and anemia management. Full article

Background: Accidents caused by the Loxosceles laeta spider constitute a health problem in South America. Envenomation can lead to severe systemic manifestations, eventually compromising the patient’s life. Most regional health authorities consider antivenom administration the basis of effective treatment in the most serious cases. The availability of spider venom is the primary bottleneck for antivenom production. Herein, we present a novel biotechnological approach, based on the expression of recombinant versions of the most relevant toxin in loxoscelism, sphingomyelinase D (SphD), in insect larvae (Spodoptera frugiperda). Methods: We produced two versions of SphD: one conserving its biological activities (wtSphD) and a second alternative that was designed to be genetically detoxified (dSphD). Two horses were subjected to three consecutive hyperimmunization cycles with dSphD. The horses’ plasma was extracted at the end of each cycle and used to produce Active Pharmaceutical Ingredients (APIs) of antivenoms at a pilot scale. Results: Dermonecrotic activity of wtSphD was completely neutralized with the sera obtained from one horse and partially with that of the other. In contrast, the APIs derived in both cases completely neutralized wtSphD dermonecrotic activity. Direct hemolysis of human red blood cells by wtSphD was also neutralized by sera and APIs. Conclusions: These results show venom replacement or complementation potential by recombinant dSphD produced in this novel platform. Full article

Acid sphingomyelinase deficiency (ASMD) is currently treatable with olipudase alfa, increasing the need for early newborn screening (NBS). We conducted a two-center pilot cohort study to characterize dried blood spot (DBS) acid sphingomyelinase (ASM) activity in Japanese neonates in the neonatal intensive care unit (NICU). ASM activity was measured by flow injection-tandem mass spectrometry in 244 NICU-admitted neonates (gestational age 25–41 weeks; birth weight 773–4201 g); longitudinal paired samples were available in 34 neonates with birth weight < 2000 g and concurrent hematology in 43 neonates. The mean ASM activity was 3.7 ± 1.2 μmol/h/L (95% confidence interval, 3.54–3.84; range, 1.7–11.6), with a right-skewed distribution. ASM activity correlated positively with birth weight (r = 0.184, p = 0.0039), gestational age (r = 0.219, p = 0.0006), and lymphocyte count (ρ = 0.394, p = 0.0089) and negatively with hematocrit (ρ = −0.372, p = 0.014). In neonates with a birth weight < 2000 g, ASM increased significantly on repeat sampling (mean difference, 1.60 μmol/h/L; p < 0.0001; Cohen’s d = 0.912). These findings support NICU-specific reference ranges, hematology-informed interpretations, repeat testing after maturation, and the use of second-tier biomarkers for ASMD NBS implementation in Japan. Full article

Sphingolipids (SL) are essential structural and bioactive components of cell membranes, remarkably involved in inflammatory signaling and membrane dynamics. Dysregulation of SL metabolism contributes to pathological inflammation and cellular stress. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine (FXT), are known inhibitors of acid sphingomyelinase (aSMase), although their impact on macrophage SL remodeling and inflammatory responses remains unclear. Here, we investigated the modulation of FXT on SL species composition and inflammatory activation in THP-1-derived macrophages stimulated with inactivated SARS-CoV-2 particles, which is a model of viral-induced inflammation. Sphingolipidomic profiling revealed that FXT pre-treatment markedly reduced ceramide (Cer) species while increasing sphingomyelin (SM) and sphingosine-1-phosphate (S1P) levels, consistent with inhibition of the aSMase-Cer axis. These changes were accompanied by attenuation of proinflammatory components, including interleucin (IL)-6, IL-1β, and matrix metalloproteinase (MMP)-9, indicating that SL remodeling correlates with reduced macrophage activation. Despite pronounced alterations in membrane lipid composition, the quantification of extracellular vesicles (EVs) released by FXT-treated macrophages remained unchanged, however the EVs size distribution was smaller compared to non-treated cells. Altogether, our findings demonstrate that FXT reshapes SL metabolism and lipid membrane composition, thereby diminishing macrophage activation without affecting EVs biogenesis. This study emphasizes the immunometabolic role of SL on membrane reprogramming as a mechanism by which pharmacological aSMase inhibition modulates viral inflammation responses. Full article

Background: Acid sphingomyelinase deficiency (ASMD) is a rare, progressive lysosomal storage disease with heterogeneous clinical manifestations. Evidence on the disease burden of ASMD is limited in Brazil. Methods: This observational, multicenter, retrospective study assessed the characteristics and clinical data of patients with ASMD type B and type A/B. Patients’ demographic data were retrieved from Hospital de Clínicas de Porto Alegre between January 1, 1986 and May 31, 2021, and available medical records were collected from eight centers in Brazil. Results: The study included 124 patients (full cohort: ASMD type B [75.8%] and type A/B [24.2%]; median [interquartile range {IQR}] age: 10.0 [3.6–19.9] years at diagnosis, n = 94), while medical records were available for 24 patients (subset cohort: ASMD type B [87.5%] and type A/B [12.5%]; median [IQR] age: 6.7 [1.9–11.3] years at diagnosis). Hepatobiliary and splenic manifestations were the most common clinical findings at symptom onset/diagnosis (75.0% and 70.8%, respectively) and at the last follow-up/death (83.3% each), with the majority of patients showing abnormal liver function parameters at both time points. At least 50.0% of patients had comorbidities at symptom onset or diagnosis. The incidence of hospitalization was reported in 33.3% patients at symptom onset/diagnosis and in 45.9% at the last follow-up/death. During the follow-up period, two patients with ASMD type A/B died in the subset cohort. Conclusions: The study provides insights into the high burden of illness in patients with ASMD, highlighting the need for disease awareness and early diagnosis in Brazil. Full article

Exosomes are important mediators of host–parasite communication and contain diverse molecules that may support the survival of Clonorchis sinensis in the biliary tract. To explore their biochemical properties, exosomes isolated from excretory–secretory products of Korean C. sinensis isolates were characterized through integrated morphological, proteomic, and gene ontology analyses. The vesicles exhibited typical exosomal size ranges and marker profiles, and their protein components were enriched for cytoskeletal, metabolic, and vesicle-trafficking components relevant to epithelial signaling and immune modulation. Among these proteins, sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) was examined in detail to obtain molecular evidence suggesting its role in sphingolipid metabolism in the parasite. The C. sinensis SMPDL3A (Cs_SMPDL3A) shared the overall structure and core catalytic residues with mammalian homologs, SMPDL3A and sphingomyelin phosphodiesterase 1 (SMPD1), a finding consistent with the possibility that Cs_SMPDL3A may retain authentic sphingomyelinase activity. Although lacking the saponin B domain of SMPD1, Cs_SMPDL3A carries a C-terminal transmembrane segment that may facilitate sphingomyelin access by positioning the enzyme on lipid bilayers. Collectively, these findings suggest that Cs_SMPDL3A participates in host sphingomyelin turnover, potentially generating ceramide for uptake by SMPD1-lacking C. sinensis or contributing to ceramide-associated immune responses in the biliary tract, offering new insight into lipid-centered host–parasite interactions during clonorchiasis. Full article

Ceramide kinase (CerK) catalyzes the phosphorylation of ceramide to ceramide-1-phosphate (C1P), a bioactive sphingolipid with diverse signaling roles. While CerK has been identified in several cellular compartments, its presence and functional significance in kidney proximal tubules remain unexplored. Herein, we report the first characterization of CerK activity in basolateral membranes (BLMs) from porcine proximal tubule cells. We demonstrate that BLM fractions contain neutral and acidic sphingomyelinases, providing local substrate for CerK, which efficiently generates C1P under physiological pH (6.5–7.2) and temperature (30–37 °C) conditions. Enzyme activity was stimulated by cAMP in a protein kinase A-dependent manner but was not affected by angiotensin II. Lipidomic analysis confirmed the presence of C1P in human proximal tubule (HK-2) cells under basal conditions and revealed changes during ischemic stress. Transcriptomic analysis of kidney biopsies from patients with chronic kidney disease (CKD) further uncovered coordinated remodeling of sphingolipid metabolism genes, with increased expression of ceramidases (ASAH1 and NAAA) and downregulation of ceramide synthases (CERS4, CERS5), consistent with adaptive regulation of the Cer/CerK/C1P axis. Together, these findings identify for the very first time CerK activity in renal BLM, establish its biochemical requirements, and highlight its potential role in modulating transporter function and sphingolipid signaling in physiology and kidney disease. Full article

Fermented dairy products such as yogurt, kefir, and traditional cheeses are increasingly consumed worldwide for their nutritional and probiotic properties. Lipidomic profiling provides valuable insights into microbial-driven biochemical changes during fermentation. In this study, we performed a comprehensive untargeted lipidomic analysis of sheep milk and Gioddu, a traditional Sardinian fermented dairy product. Using UHPLC-QTOF-MS platform, we observed that fermentation significantly reshaped the lipidome. Gioddu samples showed higher levels of phosphatidylethanolamines (PE) and lysophosphatidylethanolamines (LPE), together with a pronounced reduction in sphingolipids (glucosylceramides, ceramides, sphingomyelins) and glycerophospholipids (phosphatidylinositols, phosphatidylserines, phosphatidylcholines) compared to sheep milk. These findings align with known enzymatic activities of lactic acid bacteria (LAB), including phospholipases A1 and A2, phosphatidylinositol-specific phospholipase C (PI-PLC), and sphingomyelinase. Fermentation also affected triglycerides, with reduced levels of FA 18:1-containing species, suggesting the selective lipolysis of monounsaturated fatty acids by microbial lipases. Complementary metabolomic profiling revealed reduced levels of simple sugars such as galactose and inositol in Gioddu samples, consistent with their use as primary carbon sources during early fermentation. Conversely, a marked accumulation of carboxylic acids (succinic, malic, hydroxyisovaleric, hydroxyglutaric, glyceric) was revealed, reflecting enhanced microbial fermentative activity. Increased levels of amino acids, including alanine, serine, proline, and ethanolamine, further highlighted active proteolysis and membrane remodeling driven by LAB metabolism. These findings show that LAB enzymes play a key role in modifying the lipidome of fermented dairy products, highlighting their metabolic flexibility and potential impact on nutritional and health properties. This integrated approach sheds new light on the metabolic plasticity of fermentative processes and underscores the value of omics-based tools in understanding traditional food systems. Full article

Ceramide 1-phosphate (C1P) is a key regulator of cell proliferation and survival in both normal and transformed cells. Major pathways implicated in the mitogenic actions of C1P include activation of the mitogen-activated protein kinases (MAPKs) ERK1-2 and JNK, as well as stimulation of the phosphatidylinositol 3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway, the product of retinoblastoma, or the sphingomyelin synthase (SMS)/diacylglycerol (DAG)/protein kinase C-alpha (PKC-α) pathway. C1P-stimulated cell proliferation can also be mediated through enhanced secretion of vascular endothelial growth factor (VEGF) in macrophages or by releasing lysophosphatidic acid (LPA) in myoblasts. Also, the production of low levels of reactive oxygen species (ROS) can mediate the stimulation of cell growth by C1P, particularly in macrophages. Upregulation of the PI3K/Akt/mTOR pathway is also involved in the inhibition of cell death by C1P, which can also contribute to cell survival by blocking the activity of the ceramide-generating enzymes acid sphingomyelinase (ASMase) and serine palmitoyl transferase (SPT). Moreover, C1P-promoted cell survival involves upregulation of inducible nitric oxide synthase (iNOS) and the subsequent production of nitric oxide (NO). Using photosensitive C1P analogues, it could be concluded that promotion of cell growth and inhibition of cell death were elicited by intracellularly generated C1P in a receptor-independent manner. The aim of the present review is to evaluate in detail the implication of the CerK/C1P axis in controlling cell proliferation and survival in mammalian cells, as well as to discuss and update on the molecular mechanisms by which C1P can accomplish these actions. Full article

The sphingolipidoses Fabry disease, Gaucher disease and Acid sphingomyelinase deficiency (ASMD) are the three most common lysosomal storage diseases for which treatment is currently available. Timely diagnosis with estimation of the disease severity and possibilities of follow-up of patients, whether or not under therapy, is crucial for providing good care and for the prevention of possible lethal complications. With this research we provide an efficient and sensitive detection method; its implementation in clinical practice could optimize the diagnosis and follow-up of patients with Gaucher, Fabry and ASMD. This detection method on dried blood spots (DBS) was validated according to the international Clinical and Laboratory Standards Institute (CLSI) guidelines, looking at reproducibility, linearity, carry-over and lower limit of quantification. Analogously, validation and subsequent comparison of the method validation results using another matrix, the Capitainer blood sampling cards (Capitainers), was fulfilled. The results showed that this detection method is fully applicable clinically when using DBS as well as Capitainers. In addition, even additional improvements of some validation parameters were found when using the Capitainers. Twenty-six patient samples and fifteen healthy samples were analyzed for case finding control. All patient cases were detected without ambiguity. We present a high-resolution mass spectrometry method that provides an accurate analysis for targeted screening, aiming for improved/accelerated diagnosis when added in the diagnostic pathway and monitoring of Fabry, Gaucher and ASMD in DBS as well as in Capitainers, with the main advantages of a small volume of blood samples, guaranteeing stability and easy transportation from the collection site to the laboratory. Full article

GW4869, a cell-permeable, selective inhibitor of neutral sphingomyelinase is a pharmacological agent that blocks the production and release of extracellular vesicles (EVs). Our previous studies have shown that GW4869 inhibits flaviviral loads in tick, mosquito and mammalian cells, including murine cortical neurons. Yet the mechanism(s) of GW4869 inhibitor upon viral infections were not addressed. In the current study, we focused on how GW4869 interferes with Langat Virus (LGTV, a tick-borne flavivirus) replication in ISE6 tick cells. First, we found that GW4869 is neither cytotoxic at tested doses of 50, 100, and 150 µM in tick cells, nor does it directly bind to the free LGTV present in cell culture supernatants. When tick cells were treated with GW4869, followed by infection with viral stock at dilutions of 10⁻², 10⁻³, 10⁻⁴ (the infectious dose determination by viral dilution assay), it affected LGTV replication in tick cells. A reduction in viral burden was noted in GW4869-treated tick cells, which constituted more than half the amount of decrease when compared to the mock control. Next, GW4869 treatment not only resulted in decreased LGTV transcript levels in tick cells and EVs derived from these infected cells, but also revealed diminished EVs concentrations. Enhanced IsSMase transcripts in the LGTV-infected group was noted upon GW4869 treatment, thus suggesting a host response to perhaps inhibit virus replication. In addition, GW4869 treatment reduced LGTV loads in density gradient EVs fractions, which correlated with decreased EVs concentration in those fractions. These data not only indicate that GW4869 affects LGTV replication, but that it also interferes with EV secretion and release from tick cells. Lastly, we found that GW4869 inhibits LGTV replication in tick cells but does not directly affect the infectivity of LGTV viral particles. Overall, our study suggests that GW4869 is a potential therapeutic inhibitor in controlling tick-borne diseases. Full article