Search Results (270)

Vibrio parahaemolyticus is a major foodborne pathogen worldwide, responsible for seafood-associated poisoning. Among its toxin genes, tdh2 is the most critical. To investigate the role of tdh2 in V. parahaemolyticus under gastrointestinal conditions, we constructed tdh2 deletion and complementation strains and compared their survival under acid (pH 3 and 4) and bile stress (2%). The results showed that tdh2 expression was significantly upregulated under cold (4 °C) and bile stress (0.9%). Survival assays and PI staining revealed that the tdh2 mutant strain (VP: △tdh2) was more sensitive to acid and bile stress than the wild-type (WT), and this sensitivity was rescued by tdh2 complementation. These findings suggest that tdh2 plays a protective role in enhancing V. parahaemolyticus tolerance to acid and bile stress. In the VP: △tdh2 strain, seven genes were significantly upregulated and six were downregulated as a result of tdh2 deletion. These genes included VPA1332 (vtrA), VPA1348 (vtrB), VP2467 (ompU), VP0301 and VP1995 (ABC transporters), VP0527 (nhaR), and VP2553 (rpoS), among others. Additionally, LC-MS/MS analysis identified 12 differential metabolites between the WT and VP: △tdh2 strains, including phosphatidylserine (PS) (17:2 (9Z,12Z) /0:0 and 20:1 (11Z) /0:0), phosphatidylglycerol (PG) (17:0/0:0), flavin mononucleotide (FMN), and various nucleotides. The protective mechanism of tdh2 may involve preserving cell membrane permeability through regulation of ompU and ABC transporters and enhancing electron transfer efficiency via regulation of nhaR. The resulting reduction in ATP, DNA, and RNA synthesis—along with changes in membrane permeability and electron transfer due to decreased FMN—likely contributed to the reduced survival of the VP: △tdh2 strain. Meanwhile, the cells actively synthesized phospholipids to repair membrane damage, leading to increased levels of PS and PG. This study provides important insights into strategies for preventing and controlling food poisoning caused by tdh⁺ V. parahaemolyticus. Full article

Nonspecific toxicity to normal and malignant cells restricts the clinical utility of many anticancer drugs. In particular, anemia in cancer patients develops due to drug-induced toxicity to red blood cells (RBCs). The anticancer alkaloid, cepharanthine (CEP), elicits distinct forms of cell death including apoptosis and autophagy, but its cytotoxicity to RBCs has not been investigated. Colorimetric and fluorometric techniques were used to assess eryptosis and hemolysis in control and CEP-treated RBCs. Cells were labeled with Fluo4/AM and annexin-V-FITC to measure Ca²⁺ and phosphatidylserine (PS) exposure, respectively. Forward scatter (FSC) was detected to estimate cell size, and extracellular hemoglobin along with lactate dehydrogenase and aspartate transaminase activities were assayed to quantify hemolysis. Physiological manipulation of the extracellular milieu and various signaling inhibitors were tested to dissect the underlying mechanisms of CEP-induced RBC death. CEP increased PS exposure and hemolysis indices and decreased FSC in a concentration-dependent manner with prominent membrane blebbing. Although no Ca²⁺ elevation was detected, chelation of intracellular Ca²⁺ by BAPTA-AM reduced hemolysis. Whereas SB203580, D4476, acetylsalicylic acid, necrosulfonamide, and melatonin inhibited both PS exposure and hemolysis, staurosporin, L-NAME, ascorbate, caffeine, adenine, and guanosine only prevented hemolysis. Interestingly, sucrose had a unique dual effect by exacerbating PS exposure and reversing hemolysis. Of note, blocking KCl efflux augmented PS exposure while aggravating hemolysis only under Ca²⁺-depleted conditions. CEP activates Ca²⁺-independent pathways to promote eryptosis and hemolysis. The complex cytotoxic profile of CEP can be mitigated by targeting the identified modulatory pathways to potentiate its anticancer efficacy. Full article

Procoagulant platelets are a specialized subset of activated platelets that externalize phosphatidylserine (PS) on their surface, facilitating the assembly of tenase and prothrombinase complexes and enhancing thrombin generation and clot formation. Although procoagulant platelet formation shares certain features with nucleated cell death pathways, such as mitochondrial dysfunction, calcium (Ca²⁺) overload, membrane blebbing, and microvesiculation, it differs in key molecular mechanisms, notably lacking nuclei and caspase-dependent deoxyribonucleic acid (DNA) fragmentation. Interestingly, molecular components of nucleated cell death pathways in platelets can promote thrombus formation without impacting platelet lifespan. Under pathological conditions, excessive platelet activation may result in platelet lysis, resembling the complete activation of nucleated cell death pathways and contribute to thrombocytopenia. This review compares procoagulant platelet formation with various nucleated cell death pathways, including necrosis, necroptosis, pyroptosis, and ferroptosis, and explores their role in pathological thrombosis and blood clotting. A deeper understanding of mechanisms may help in developing targeted therapies to prevent aberrant blood clotting, platelet death and thrombocytopenia. Full article

Gynecological malignancies (ovarian, endometrial, and cervical cancers), including disseminated intravascular coagulation (DIC), often provoke systemic coagulopathy. In recent years, tumor-derived, tissue factor–positive microparticles (TF⁺ MPs) have emerged as potent drivers of cancer-associated thrombosis and possibly DIC. These small (0.1–1 µm) membrane vesicles bud from cancer cell surfaces and carry procoagulant factors (phosphatidylserine and TF) on their surface. We review how TF⁺ MPs are generated by tumor cells and amplify the extrinsic coagulation cascade, potentially triggering DIC in patients with advanced gynecologic cancers. Clinical studies have linked el evated TF⁺ MP levels and activity to venous thromboembolism (VTE) in cancer, and small case series suggest dramatically high MP–TF activity in cancer-related DIC. We summarize evidence that TF⁺ MPs from ovarian tumors carry exceptionally high TF procoagulant activity (median ~80 pg/mL), and nearly all patients with cancer-associated VTE or DIC have MP–TF levels above normal. This review discusses diagnostic implications (e.g., measuring MP–TF activity as a biomarker) and treatment strategies (through the reduction in tumors, anticoagulation, and experimental TF inhibitors) in this setting. We also identify gaps in knowledge (standardized MP assays, prospective studies) and propose future directions (targeting MP formation or TF signaling). Two summary tables highlight recent studies of TF⁺ MPs in gynecologic cancer and their clinical outcomes. Illustrative figures depict the TF⁺ MP-triggered coagulation cascade and a conceptual framework for clinical management. Understanding TF⁺ MPs in gynecological cancer could improve the prediction and management of DIC and related thromboses. Full article

Nowadays, healthcare systems face two global challenges: the rise of multidrug-resistant pathogens and the growing incidence of cancer. Due to their broad spectrum of activities, antimicrobial peptides emerged as potential alternatives against both threats. Our group previously described the antifungal activity of the α-helical peptide Cm-p5, a derivative of the natural peptide Cm-p1, isolated from the coastal mollusk Cenchritis muricatus; however, its anti-cancer properties remained unexplored. Analyses through calorimetry and molecular dynamics simulations suggest the relevance of phosphatidylserine for the attachment of Cm-p5 to cancer cell membranes. Cm-p5 exhibited cytotoxic activity in a dose-dependent manner against A375 melanoma cells, without toxicity against non-malignant cells or hemolytic activity. DAPI/PI and DiSC3(5) staining confirmed permeabilization, disruption, and depolarization of A375 cytoplasmic membranes by Cm-p5. Furthermore, Annexin V-FITC/PI assay revealed the induction of cellular death in melanoma cells, which can result from the cumulative membrane damage and oxidative stress due to the overproduction of reactive oxygen species (ROS). Moreover, after the treatment, the proliferation of A375 cells was dampened for several days, suggesting that Cm-p5 might inhibit the recurrence of melanomas. These findings highlight the multifunctional nature of Cm-p5 and its potential for treating malignant melanoma. Full article

The resistance of breast cancer cells to therapeutic antibodies such as anti-HER2 trastuzumab can be overcome by engaging natural killer (NK) cells for killing antibody-binding tumor cells via antibody-dependent cellular cytotoxicity (ADCC). Here, we investigated how autophagy modulation affects trastuzumab-mediated ADCC in HER2-positive JIMT1 breast cancer cells and NK cells. Autophagy inducers (rapamycin and resveratrol) had no significant impact, but the inhibitor bafilomycin nearly abolished ADCC. Protection occurred when either cancer or NK cells were pretreated, indicating dual effects. Bafilomycin reduced phosphatidylserine externalization, the loss of plasma membrane integrity, caspase-3/7 activity, and DNA fragmentation. It downregulated pro-apoptotic BAK1 and BAX without altering BCL-2. Additionally, bafilomycin decreased HER2 surface expression, impairing trastuzumab binding, and modulated immune regulators (STAT1, CD95, and PD-L1) in NK and/or in the cancer cells. Bafilomycin disrupted HER2 trafficking and induced HER2 internalization, leading to its accumulation in cytoplasmic vesicles. These findings show that autophagy inhibition by bafilomycin confers ADCC resistance by altering apoptosis, immune signaling, and HER2 dynamics. The study underscores autophagy’s role in antibody-based cancer therapy efficacy. Full article

Eryptosis is a programmed cellular death involving red blood cells (RBCs). It is a physiological mechanism that leads to the removal of defective erythrocytes, similarly to apoptosis. Its typical features are cell shrinkage, cell membrane blebbing, and membrane scrambling with the consequent exposure of the aminophospholipid phosphatidylserine on the outer surface of RBCs. Different mechanisms play a role in the pathogenesis of eryptosis, such as the increase in cytosolic calcium concentration, oxidative stress, inflammation, and uremic toxins. If erythrocyte synthesis does not compensate for the accelerated eryptosis, anemia may develop. Moreover, enhanced eryptosis contributes to the pathogenesis of different clinical diseases, such as diabetes, sepsis, metabolic syndrome, and uremia. In particular, in patients with chronic kidney disease (CKD), deficiencies of erythropoietin and iron may further reduce the lifespan of RBCs. In this review, we focused on eryptosis in CKD and end-stage renal disease on peritoneal dialysis (PD) and hemodialysis (HD). Full article

Little is known about the regulation of B cell subpopulations in association with programmed cell death during dengue virus (DENV) infection. Therefore, blood samples from dengue-infected patients and healthy donors were obtained for B cell subset characterization and the analysis of pro-apoptotic CD95 expression in these cell subsets. The results showed that the activated memory (AM) subset in the patients remained unchanged compared to the healthy donors. In contrast, tissue memory (TM) and antibody-secreting cells (ASCs) were notably increased, whereas naïve cells and resting memory (RM) cells were considerably decreased. Although the ASCs maintained comparably high levels of CD95 expression in both groups, significantly increased percentages of CD95-expressing cells in the other B cell subsets were found in the patients. When B cells from the healthy donors were treated with DENV non-structural protein 1 (NS1), the results showed that the NS1 protein at 2 µg/mL could induce CD95 expression and the exposure of phosphatidylserine on the cell membrane in most B cell subsets, except for the RM. This study demonstrates that DENV infection could induce CD95 expression in both activated and resting B cell subsets in all patients. The results also suggest a potential mechanism of apoptotic regulation in B cell subsets through the increased CD95 expression caused by the interaction between the B cells and the NS1 protein. Full article

Background: Despite many efforts to effectively treat PDAC, PDAC carries one of the highest mortality rates of all major cancers. Thus, there is a critical unmet need to develop novel approaches to improve the clinical outcome of PDAC. It is well known that many cancers, including PDAC, generate a local TME that allows cancer to escape normal immune surveillance. Phosphatidylserine (PS), a negatively charged phospholipid that is abundant on the cancer cell membrane and with known actions to promote the secretion of immunomodulatory proteins, may provide a mechanism to regulate the TME. This study explored that possibility. Methods: MΦ differentiation and polarization were assessed by Western blotting and flow cytometric approaches. PS exposure and surface markers were analyzed by flow cytometry. Protein–protein and protein–lipid interactions were analyzed by immunofluorescence and enzyme-linked immunosorbent assay (ELISA). Phospholipid and SapC-DOPG treatment were employed to assess target protein functions in MΦ polarization, tumor growth, and survival in subcutaneous and orthotopic tumor models. The PK-PD and safety of SapC-DOPG were tested on orthotopic mouse models. Results: Our studies show that PDAC secretes Hsp70 that stimulates the MΦ polarization to the immunosuppressive M2 phenotype. We found that high surface PS on cancer cells correlates with increased secretion of Hsp70 and is associated with higher MΦ differentiation activity in vitro and in vivo. Furthermore, blocking cancer cell-secreted Hsp70 with SapC-DOPG reverses the immune suppression and reduces tumor growth. Conclusions: These preclinical results reveal a novel immunotherapeutic approach to potentially improve the outcome of PDAC treatment in humans. Full article

Growing neurochemical evidence highlights cerebral lipid dysregulation as a key factor in the pathophysiology of major depressive disorder (MDD). This review systematically explores the dual roles of lipid species in both normal behavioral regulation and MDD development. By critically examining the recent literature, we classify these lipid species into two functional categories based on their functional neuroactivity: (1) neuroprotective lipids (sphingomyelin, cholesterol, cardiolipin, sphingosine, phosphatidic acid, and phosphatidylserine), which exert neuroprotective effects by modulating membrane fluidity and supporting synaptic vesicle trafficking; and (2) neurotoxic lipids (ceramides, phosphatidylinositol, phosphocholine, and phosphatidylethanolamine), which promote apoptotic signaling cascades and disrupt mitochondrial bioenergetics. An unresolved but critical question pertains to the maintenance of homeostatic equilibrium between these opposing lipid classes. This balance is essential, given their significant impact on membrane protein localization and function, monoaminergic neurotransmitter metabolism, energy homeostasis, and redox balance in neural circuits involved in mood regulation. This emerging framework positions cerebral lipidomics as a promising avenue for identifying novel therapeutic targets and developing biomarker-based diagnostic approaches for MDD treatment. Full article

Infertility is increasingly recognized as being closely linked to obesity in humans. The successful production of fertile spermatozoa requires adequate spermatogenesis within the testis and proper spermatozoa maturation through the epididymis. This study aimed to evaluate the impact of body adiposity on male fertility, focusing on sperm parameters, epididymal sperm maturation, and sperm capacitation in Wistar rats. Male rats were randomized into three dietary groups over four weeks: a control group receiving less than 4% lard, regular chow, a 10% lard group, and a 60% lard group. Following dietary interventions, fertility tests were conducted across the groups. The epididymis was dissected into caput, corpus, and cauda regions to assess sperm concentration, vitality capacitation, carbohydrate distribution, tyrosine phosphorylation, and phosphatidylserine levels. Additionally, serum testosterone levels were measured to evaluate hormonal influences on fertility. The rats subjected to high-fat diets leading to overweight and obesity exhibited significant alterations in fertility. These changes were characterized by impaired epididymal sperm maturation, as evidenced by lower testosterone levels, decreased sperm viability, and capacitation. Furthermore, increased adiposity was associated with a lack of asymmetry in the plasma membrane, alteration in carbohydrate distribution, and changes in tyrosine phosphorylation. This study underscores the adverse effects of high-fat diets on male fertility, particularly through mechanisms affecting sperm maturation in the epididymis. The evidence suggests that obesity-induced alterations in sperm parameters and hormonal profiles may contribute to reduced fertility in male rats, which could have implications for understanding similar human processes. Full article

Morphological changes in erythrocytes during disease, aging, or reactions to external agents are significant as they can influence disease progression. However, the exact mechanisms behind these temporary alterations and their potential to cause dysfunction remain unclear. Using a saponin-induced erythrocyte shape transition (EST) model, we studied the gradual shift of erythrocytes towards echino-stomato-spherocytic forms and its link to hemolysis and thrombosis. We observed that different saponin concentrations elicited varying shape transformations. At low concentrations, erythrocytes transition from discocytic shapes to echinocytic, echino-stomatocytic, and ultimately stomatocytic forms. As the concentration moderately increases, the morphology evolves into stomato-spherocytic forms. At higher saponin concentrations, the erythrocytes completely transform into spherocytic forms. Regardless of the transformation degree, all forms showed increased phosphatidylserine exposure (PS) and microvesicle (MV) production, primarily due to increased scramblase and decreased flippase activity, which were influenced by elevated calcium levels and caspase 3 activity, effectively managing PS distribution and influencing cell membrane expansion and invagination. These alterations increased thrombin production, erythrocyte adhesion, and aggregation, promoting thrombosis in rats. Altogether, our findings indicate that the shift towards echino-stomato-spherocytic forms fosters a hypercoagulable state through PS externalization, heightening thrombotic risk. Full article

Kefir, a fermented milk product produced using kefir grains, is a symbiotic consortium of bacteria and yeasts responsible for driving the fermentation process. In this study, an in-depth analysis of kefir’s lipid profile was conducted, with a focus on its phospholipid (PL) content, employing liquid chromatography with high-resolution mass spectrometry (LC-HRMS). Nearly 300 distinct polar lipids were identified through hydrophilic interaction liquid chromatography (HILIC) coupled with electrospray ionization (ESI) and Fourier-transform orbital-trap MS and linear ion-trap tandem MS/MS. The identified lipids included phosphatidylcholines (PCs), lyso-phosphatidylcholines (LPCs), phosphatidylethanolamines (PEs) and lyso-phosphatidylethanolamines (LPEs), phosphatidylserines (PSs), phosphatidylglycerols (PGs), and phosphatidylinositols (PIs). The presence of lysyl-phosphatidylglycerols (LyPGs) was identified as a key finding, marking a lipid class characteristic of Gram-positive bacterial membranes. This discovery highlights the role of viable bacteria in kefir and underscores its probiotic potential. The structural details of minor glycolipids (GLs) and glycosphingolipids (GSLs) were further elucidated, enriching the understanding of kefir’s lipid complexity. Fatty acyl (FA) composition was characterized using reversed-phase LC coupled with tandem MS. A mild epoxidation reaction with meta-chloroperoxybenzoic acid (m-CPBA) was performed to pinpoint double-bond positions in FAs. The dominant fatty acids were identified as C18:3, C18:2, C18:1, C18:0 (stearic acid), C16:0 (palmitic acid), and significant levels of C14:0 (myristic acid). Additionally, two isomers of FA 18:1 were distinguished: ∆9-cis (oleic acid) and ∆11-trans (vaccenic acid). These isomers were identified using diagnostic ion pairs, retention times, and accurate m/z values. This study provides an unprecedented level of detail on the lipid profile of kefir, shedding light on its complex composition and potential nutritional benefits. Full article

Cryopreservation can adversely affect sperm motility, structural integrity, and fertilization ability. This study investigated the effects of MitoQ and antifreeze protein III (AFP III) on frozen–thawed semen from eight adult dogs using a Tris–fructose extender. Ejaculates were divided and diluted with a standard Tris–fructose–egg yolk extender containing MitoQ (200 nM/mL) and AFP III (0.75, 1.0, 2.0 µg/mL), individually or combined. Post-thaw, samples were evaluated for motility, viability, membrane and acrosome integrity, lipid peroxidation, apoptosis indicators, mitochondrial function, and reactive oxygen species (ROS-H₂O₂). The results showed significant (p < 0.05) improvements in motility rate, progressive motility, VAP, VSL, VCL, ALH, and BCF with MitoQ or AFP alone. AFP III (0.75, 1.0 µg/mL) showed higher values than controls (p > 0.05), while MitoQ alone showed no significant effect. Viability and acrosome integrity improved with AFP III. Membrane integrity and lipid peroxidation were better in 0.75 and 1.0 µg/mL AFP III groups. ROS-H₂O₂ levels and mitochondrial membrane potential were unaffected except at 1.0 µg/mL AFP III. The phosphatidylserine translocation assay showed no significant differences in dead sperm between controls and individual treatments, but significant differences occurred with combined MitoQ/AFP III. In conclusion, AFP III and MitoQ in diluents protect canine sperm cells from cryodamage. Full article

Although curcumin is a well-known natural polyphenol with many biological activities, its clinical application has been limited by low aqueous solubility and stability. Therefore, curcumin derivatives have been proposed to overcome these limitations and increase anticancer activity. This study tested curcumin derivatives with modified feruloyl moieties (2a and 2a-B) and the β-diketo moiety (2a-B) to better understand their anticancer mechanism against human bladder cancer cells. The anticancer activity of 2a and 2a-B was determined using MTT (hypoxic conditions) and LDH (normoxic conditions) assays. An ELISA-based protein panel was used to find the potential molecular targets, while flow cytometric, colorimetric, fluorescent, and luminescent assays were used to investigate the cell death mechanism. It was shown that compound 2a exerted a more potent cytotoxic effect under hypoxic conditions, while compound 2a-B demonstrated a comparable effect in normoxic and hypoxic conditions. The potential molecular targets modified by 2a and 2a-B depending on oxygen concentration were also proposed. Both compounds alter cell cycle progression by blocking the cell cycle in the G2/M phase and decreasing the percentage of cells in the G0/G1 phase. Compound 2a-B led to phosphatidylserine translocation, increased caspase 3/7 activity, and decreased mitochondrial membrane potential, suggesting a mitochondrial apoptosis pathway. We found that the Akt signaling pathway may modulate the activity of compound 2a-B, as evidenced by enhanced cytotoxic activity in combination with MK-2206, an Akt 1/2/3 inhibitor. Thus, our results provide new insights into the anticancer activity of compounds 2a and 2a-B; however, further studies are needed to better understand their therapeutic potential. Full article