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Toxicon : Official Journal of the... May 2024Crotalus neutralizing factor (CNF) is an endogenous glycoprotein from Crotalus durissus terrificus snake blood that inhibits secretory phospholipases A (sPLA) from the...
Crotalus neutralizing factor (CNF) is an endogenous glycoprotein from Crotalus durissus terrificus snake blood that inhibits secretory phospholipases A (sPLA) from the Viperid but not from Elapid venoms (subgroups IA and IIA, respectively). In the present study, we demonstrated that CNF can inhibit group III-PLA from bee venom by forming a stable enzyme-inhibitor complex. This finding opens up new possibilities for the potential use of CNF and/or CNF-based derivatives in the therapeutics of bee stings.
Topics: Animals; Bee Venoms; Crotalus; Phospholipase A2 Inhibitors; Crotalid Venoms; Bees; Phospholipases A2; Glycoproteins; Phospholipases A2, Secretory; Venomous Snakes
PubMed: 38583578
DOI: 10.1016/j.toxicon.2024.107711 -
Biomedicine & Pharmacotherapy =... May 2024Neuronal ferroptosis and autophagy are crucial in the pathogenesis of cerebral ischemia-reperfusion injury (CIRI). Mastoparan M (Mast-M), extracted from the crude venom...
Neuronal ferroptosis and autophagy are crucial in the pathogenesis of cerebral ischemia-reperfusion injury (CIRI). Mastoparan M (Mast-M), extracted from the crude venom of Vespa magnifica (Smith), comprises 14 amino acid residues. Previous studies suggested that Mast-M reduces neuronal damage following global CIRI, but its protective mechanisms remain unclear. The present study examined the effect of Mast-M on middle cerebral artery occlusion/reperfusion (MCAO/R) induced neurological deficits using Grip, Rotarod, Longa test, and TTC staining, followed by treating the mice for three days with Mast-M (20, 40, and 80 μg/kg, subcutaneously). The results demonstrate that Mast-M promotes functional recovery in mice post-ischemic stroke, evidenced by improved neurological impairment, reduced infarct volume and neuronal damage. Meanwhile, the level of iron (Fe) and malonyldialdehyde was decreased in the ischemic hemisphere of MCAO/R mice at 24 hours or 48 hours by Mast-M (80 μg/kg) treatment, while the expression of NRF2, x-CT, GPX4, and LC3B protein was increased. Furthermore, these findings were validated in three models-oxygen-glucose deprivation/ reoxygenation, HO-induced peroxidation, and erastin-induced ferroptosis-in hippocampal neuron HT22 cells or primary neurons. These data suggested that Mast-M activates autophagy as well as inhibits ferroptosis. Finally, autophagy inhibitors were introduced to determine the relationship between the autophagy and ferroptosis, indicating that Mast-M alleviates ferroptosis by activating autophagy. Taken together, this study described that Mast-M alleviates cerebral infarction, neurologic impairment, and neuronal damage by activating autophagy and inhibiting ferroptosis, presenting a potential therapeutic approach for CIRI.
Topics: Animals; Autophagy; Ferroptosis; Male; Mice; Recovery of Function; Infarction, Middle Cerebral Artery; Mice, Inbred C57BL; Wasp Venoms; Neuroprotective Agents; Reperfusion Injury; Neurons; Disease Models, Animal; Stroke
PubMed: 38583338
DOI: 10.1016/j.biopha.2024.116560 -
FEBS Letters Apr 2024BeKm-1 is a peptide toxin from scorpion venom that blocks the pore of the potassium channel hERG (K11.1) in the human heart. Although individual protein structures have...
BeKm-1 is a peptide toxin from scorpion venom that blocks the pore of the potassium channel hERG (K11.1) in the human heart. Although individual protein structures have been resolved, the structure of the complex between hERG and BeKm-1 is unknown. Here, we used molecular dynamics and ensemble docking, guided by previous double-mutant cycle analysis data, to obtain an in silico model of the hERG-BeKm-1 complex. Adding to the previous mutagenesis study of BeKm-1, our model uncovers the key role of residue Arg20, which forms three interactions (a salt bridge and hydrogen bonds) with the channel vestibule simultaneously. Replacement of this residue even by lysine weakens the interactions significantly. In accordance, the recombinantly produced BeKm-1 mutant exhibited dramatically decreased activity on hERG. Our model may be useful for future drug design attempts.
Topics: Animals; Humans; Arginine; ERG1 Potassium Channel; HEK293 Cells; Molecular Docking Simulation; Molecular Dynamics Simulation; Mutation; Potassium Channel Blockers; Scorpion Venoms
PubMed: 38563123
DOI: 10.1002/1873-3468.14850 -
Nuclear Medicine and Biology 2024DOTATATE is a somatostatin peptide analog used in the clinic to detect somatostatin receptors which are highly expressed on neuroendocrine tumors. Somatostatin receptors...
Investigation of imaging the somatostatin receptor by opening the blood-brain barrier with melittin - A feasibility study using positron emission tomography and [Cu]Cu-DOTATATE.
DOTATATE is a somatostatin peptide analog used in the clinic to detect somatostatin receptors which are highly expressed on neuroendocrine tumors. Somatostatin receptors are found naturally in the intestines, pancreas, lungs, and brain (mainly cortex). In vivo measurement of the somatostatin receptors in the cortex has been challenging because available tracers cannot cross the blood-brain barrier (BBB) due to their intrinsic polarity. A peptide called melittin, a main component of honeybee venom, has been shown to disrupt plasma membranes and increase the permeability of biological membranes. In this study, we assessed the feasibility of using melittin to facilitate the passage of [Cu]Cu-DOTATATE through the BBB and its binding to somatostatin receptors in the cortex. Evaluation included in vitro autoradiography on Long Evans rat brains to estimate the binding affinity of [Cu]Cu-DOTATATE to the somatostatin receptors in the cortex and an in vivo evaluation of [Cu]Cu-DOTATATE binding in NMRI mice after injection of melittin. This study found an in vitro B = 89 ± 4 nM and K = 4.5 ± 0.6 nM in the cortex, resulting in a theoretical binding potential (BP) calculated as B/K ≈ 20, which is believed suitable for in vivo brain PET imaging. However, the in vivo results showed no significant difference between the control and melittin injected mice, indicating that the honeybee venom failed to open the BBB. Additional experiments, potentially involving faster injection rates are required to verify that melittin can increase brain uptake of non-BBB permeable PET tracers. Furthermore, an evaluation of whether a venom with a narrow therapeutic range can be used for clinical purposes needs to be considered.
Topics: Animals; Receptors, Somatostatin; Melitten; Rats; Feasibility Studies; Positron-Emission Tomography; Organometallic Compounds; Blood-Brain Barrier; Male; Mice; Copper Radioisotopes; Octreotide
PubMed: 38555651
DOI: 10.1016/j.nucmedbio.2024.108905 -
International Immunopharmacology May 2024Scorpion venoms identified as agents with anti-tumor and anti-angiogenic features. Tumor microenvironment (TME) plays a pivotal role in the process of tumorigenesis,...
F1 fraction isolated from Mesobuthus eupeus scorpion venom induces macrophage polarization toward M1 phenotype and exerts anti-tumoral effects on the CT26 tumor cell line.
Scorpion venoms identified as agents with anti-tumor and anti-angiogenic features. Tumor microenvironment (TME) plays a pivotal role in the process of tumorigenesis, tumor development, and polarization of M2 phenotype tumor associated macrophages (TAMs). M2 polarized cells are associated with tumor growth, invasion, and metastasis. The fractionation process was performed by gel filtration chromatography on a Sephadex G50 column. To elucidate whether scorpion venom can alter macrophage polarization, we treated interleukin (IL)-4-polarized M2 cells with isolated fractions from Mesobuthus eupeus. Next, we evaluated the cytokine production and specific markers expression for M2 and M1 phenotype using enzyme linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR), respectively. The phagocytic capacity of macrophages was also assessed. In addition, the migration assay and MTT analysis were performed to investigate the effects of reprogrammed macrophages on the CT-26 colon cancer cells. The results indicated that F1 fraction of venom significantly upregulated the levels and expression of M1-associated cytokines and markers, including tumor necrosis factor-alpha (TNF-α) (p < 0.001), IL-1 (p < 0.01), interferon regulatory factor 5 (IRF5) (p < 0.0001), induced nitric oxide synthase (iNOS) (p < 0.0001), and CD86 (p < 0.0001), and downregulated M2-related markers, including transforming growth factor-beta (TGF-β) (p < 0.05), IL-10 (p < 0.05), Fizz1 (p < 0.0001), arginase-1 (Arg-1) (p < 0.0001), and CD206 (p < 0.001). The macrophage phagocytic capacity was enhanced after treatment with F1 fraction (p < 0.01). Moreover, incubation of CT-26 cell line with conditioned media of F1-treated macrophages suppressed migration (p < 0.0001) and proliferation (p < 0.01) of tumor cells. In conclusion, our findings demonstrated the potential of Mesobuthus eupeus venom in M2-to-M1 macrophage polarization as a promising therapeutic approach against proliferation and metastasis of colon cancer cells.
Topics: Animals; Scorpion Venoms; Mice; Cell Line, Tumor; Cytokines; Colonic Neoplasms; Antineoplastic Agents; Scorpions; Macrophages; Cell Movement; Phagocytosis; Tumor Microenvironment; Macrophage Activation; Tumor-Associated Macrophages; Mice, Inbred BALB C; RAW 264.7 Cells; Humans; Phenotype; Animals, Poisonous
PubMed: 38554440
DOI: 10.1016/j.intimp.2024.111960 -
Methods in Molecular Biology (Clifton,... 2024Spider venoms are composed of hundreds of proteins and peptides. Several of these venom toxins are cysteine-rich peptides in the mass range of 3-9 kDa. Small peptides...
Spider venoms are composed of hundreds of proteins and peptides. Several of these venom toxins are cysteine-rich peptides in the mass range of 3-9 kDa. Small peptides (<3 kDa) can be fully characterized by mass spectrometry analysis, while proteins are generally identified by the bottom-up approach in which proteins are first digested with trypsin to generate shorter peptides for MS/MS characterization. In general, it is sufficient for protein identification to sequence two or more peptides, but for venom peptidomics it is desirable to completely elucidate peptide sequences and the number of disulfide bonds in the molecules. In this chapter, we describe a methodology to completely sequence and determine the number of disulfide bonds of spider venom peptides in the mass range of 3-9 kDa by multiple enzyme digestion, mass spectrometry of native and digested peptides, de novo analysis, and sequence overlap alignment.
Topics: Animals; Tandem Mass Spectrometry; Spider Venoms; Peptides; Amino Acid Sequence; Disulfides; Spiders
PubMed: 38549023
DOI: 10.1007/978-1-0716-3646-6_18 -
Langmuir : the ACS Journal of Surfaces... Apr 2024The primary constituents of honeybee venom, melittin and phospholipase A (PLA), display toxin synergism in which the PLA activity is significantly enhanced by the...
The primary constituents of honeybee venom, melittin and phospholipase A (PLA), display toxin synergism in which the PLA activity is significantly enhanced by the presence of melittin. It has been shown previously that this is accomplished by the disruption in lipid packing, which allows PLA to become processive on the membrane surface. In this work, we show that melittin is capable of driving miscibility phase transition in giant unilamellar vesicles (GUVs) and that it raises the miscibility transition temperature () in a concentration-dependent manner. The induced phase separation enhances the processivity of PLA, particularly at its boundaries, where a substantial difference in domain thickness creates a membrane discontinuity. The catalytic action of PLA, in response, induces changes in the membrane, rendering it more conducive to melittin binding. This, in turn, facilitates further lipid phase separation and eventual vesicle lysis. Overall, our results show that melittin has powerful membrane-altering capabilities that activate PLA in various membrane contexts. More broadly, they exemplify how this biochemical system actively modulates and capitalizes on the spatial distribution of membrane lipids to efficiently achieve its objectives.
Topics: Melitten; Unilamellar Liposomes; Phospholipases A2; Bee Venoms; Membrane Lipids
PubMed: 38546877
DOI: 10.1021/acs.langmuir.3c03920 -
International Journal of Molecular... Mar 2024Allergen-specific venom immunotherapy (VIT) is a well-established therapy for venom allergy (HVA). However, the precise mechanism underlying its clinical effect remains...
Allergen-specific venom immunotherapy (VIT) is a well-established therapy for venom allergy (HVA). However, the precise mechanism underlying its clinical effect remains uncertain. Our study aimed to identify the molecular mechanisms associated with VIT efficiency. We prospectively included 19 patients with HVA undergoing VIT (sampled before the beginning of VIT, after reaching the maintenance dose, one year after finishing VIT, and after a sting challenge) and 9 healthy controls. RNA sequencing of whole blood was performed on an Illumina sequencing platform. Longitudinal transcriptomic profiling revealed the importance of the inhibition of the NFκB pathway and the downregulation of transcripts for the early protection and induction of tolerance after finishing VIT. Furthermore, successful treatment was associated with inhibiting Th2, Th17, and macrophage alternative signalling pathways in synergy with the inhibition of the PPAR pathway and further silencing of the Th2 response. The immune system became activated when reaching the maintenance dose and was suppressed after finishing VIT. Finally, successful VIT restores the immune system's balance to a state similar to that of healthy individuals. Our results underline the important role of the inhibition of four pathways in the clinical effect of VIT: Th2, Th17, NFκB, and macrophage signalling. Two biomarkers specific for successful VIT, regardless of the time of sampling, were and and should be further tested as potential biomarkers.
Topics: Animals; Humans; Arthropod Venoms; Hymenoptera; Desensitization, Immunologic; Hypersensitivity; Treatment Outcome; Immunotherapy; Biomarkers; Gene Expression Profiling; Gene Expression
PubMed: 38542470
DOI: 10.3390/ijms25063499 -
Molecular Pharmaceutics May 2024Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer for which effective therapies are lacking. Targeted remodeling of the immunosuppressive tumor...
Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer for which effective therapies are lacking. Targeted remodeling of the immunosuppressive tumor microenvironment (TME) and activation of the body's immune system to fight tumors with well-designed nanoparticles have emerged as pivotal breakthroughs in tumor treatment. To simultaneously remodel the immunosuppressive TME and trigger immune responses, we designed two potential therapeutic nanodelivery systems to inhibit TNBC. First, the bromodomain-containing protein 4 (BRD4) inhibitor JQ1 and the cyclooxygenase-2 (COX-2) inhibitor celecoxib (CXB) were coloaded into chondroitin sulfate (CS) to obtain CS@JQ1/CXB nanoparticles (NPs). Then, the biomimetic nanosystem MM@P3 was prepared by coating branched polymer poly(β-amino ester) self-assembled NPs with melittin embedded macrophage membranes (MM). Both and , the CS@JQ1/CXB and MM@P3 NPs showed excellent immune activation efficiencies. Combination treatment exhibited synergistic cytotoxicity, antimigration ability, and apoptosis-inducing and immune activation effects on TNBC cells and effectively suppressed tumor growth and metastasis in TNBC tumor-bearing mice by activating the tumor immune response and inhibiting angiogenesis. In summary, this study offers a novel combinatorial immunotherapeutic strategy for the clinical TNBC treatment.
Topics: Triple Negative Breast Neoplasms; Tumor Microenvironment; Animals; Female; Mice; Humans; Celecoxib; Cell Line, Tumor; Chondroitin Sulfates; Nanoparticles; Melitten; Apoptosis; Nanoparticle Drug Delivery System; Xenograft Model Antitumor Assays; Mice, Inbred BALB C; Cyclooxygenase 2 Inhibitors; Polymers; Mice, Nude; Drug Delivery Systems; Azepines; Triazoles
PubMed: 38536949
DOI: 10.1021/acs.molpharmaceut.3c00242 -
Toxins Mar 2024More recently, short peptides in scorpion venom have received much attention because of their potential for drug discovery. Although various biological effects of these...
More recently, short peptides in scorpion venom have received much attention because of their potential for drug discovery. Although various biological effects of these short peptides have been found, their studies have been hindered by the lack of structural information especially in modifications. In this study, small peptides from scorpion venom were investigated using high-performance liquid chromatography high-resolution mass spectrometry followed by de novo sequencing. A total of 156 sequences consisting of 2~12 amino acids were temporarily identified from scorpion venom. The identified peptides exhibited various post-translational modifications including N-terminal and C-terminal modifications, in which the N-benzoyl modification was first found in scorpion venom. Moreover, a short peptide Bz-ARF-NH demonstrated both N-terminal and C-terminal modifications simultaneously, which is extremely rare in natural peptides. In conclusion, this study provides a comprehensive insight into the diversity, modifications, and potential bioactivities of short peptides in scorpion venom.
Topics: Amino Acids; Liquid Chromatography-Mass Spectrometry; Peptides; Scorpion Venoms; Animals, Poisonous; Scorpions
PubMed: 38535821
DOI: 10.3390/toxins16030155