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1.
Mol Neurobiol ; 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38837103

ABSTRACT

Oxidative stress and the accumulation of misfolded proteins in the brain are the main causes of Parkinson's disease (PD). Several nanoparticles have been used as therapeutics for PD. Despite their therapeutic potential, these nanoparticles induce multiple stresses upon entry. Selenium (Se), an essential nutrient in the human body, helps in DNA formation, stress control, and cell protection from damage and infections. It can also regulate thyroid hormone metabolism, reduce brain damage, boost immunity, and promote reproductive health. Selenium nanoparticles (Se-NPs), a bioactive substance, have been employed as treatments in several disciplines, particularly as antioxidants. Se-NP, whether functionalized or not, can protect mitochondria by enhancing levels of reactive oxygen species (ROS) scavenging enzymes in the brain. They can also promote dopamine synthesis. By inhibiting the aggregation of tau, α-synuclein, and/or Aß, they can reduce the cellular toxicities. The ability of the blood-brain barrier to absorb Se-NPs which maintain a healthy microenvironment is essential for brain homeostasis. This review focuses on stress-induced neurodegeneration and its critical control using Se-NP. Due to its ability to inhibit cellular stress and the pathophysiologies of PD, Se-NP is a promising neuroprotector with its anti-inflammatory, non-toxic, and antimicrobial properties.

2.
Cureus ; 16(3): e56195, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38618468

ABSTRACT

Background Stress affects mental health significantly and is a ubiquitous feature of contemporary living. Among the possible antibiotics are omadacycline and vancomycin, whose anti-inflammatory properties have also been thoroughly documented in recent research. The goal of the current study was to examine their complex involvement in the brain's stress response circuits and how they modulate stress. An established model organism that provides a useful platform for examining stress-induced behaviors and possible therapeutic approaches is the zebrafish. To investigate how dopamine affects the stress response, we used a zebrafish model that was exposed to stress. Methodology For three minutes, zebrafish were continually subjected to chasing stress. They were then given antibiotic combinations of 50 µg/mL each of vancomycin and omadacycline at various ratios of 1:1, 3:1, and 3:1. Behavior alterations, including freezing bouts, top-bottom ratios, and latency periods, were analyzed and contrasted with control groups. ImageJ software was utilized to analyze the video footage of the fish. Results The study showed that the combination of omadacycline and vancomycin greatly reduced the behaviors in zebrafish caused by stress. They chose their concentration (50 µg/mL) according to the lethal concentration 50% result. By shortening the latency time and increasing the intensity of breezing sessions, these chemicals restored almost normal activity. There was statistical significance in the outcomes. The results show that the combination of vancomycin and omadacycline may have an anti-psychotic impact on zebrafish behaviors brought on by stress. Their control of stress reactions is consistent with their known roles in the reward and stress circuits of the brain. These results emphasize the complex interactions between neurotransmitter systems and the control of stress, highlighting the therapeutic potential of dopamine in the treatment of stress-related mental illnesses. Conclusions The combination of vancomycin and omadacycline has been shown to have anti-psychotic effects, which presents potential opportunities for the development of new treatment strategies for mental diseases associated with stress. To fully understand the specific processes underpinning their involvement in stress management and how they relate to mental illnesses in humans, more investigation is necessary.

3.
Cureus ; 16(2): e53949, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38468988

ABSTRACT

Tumor epithelial development and chemoresistance are highly promoted by the tumor microenvironment (TME), which is mostly made up of the cancer stroma. This is due to several causes. Cancer-associated fibroblasts (CAFs) stand out among them as being essential for the promotion of tumors. Understanding the fibroblastic population within a single tumor is made more challenging by the undeniable heterogeneity within it, even though particular stromal alterations are still up for debate. Numerous chemical signals released by tumors improve the connections between heterotypic fibroblasts and CAFs, promoting the spread of cancer. It becomes essential to have a thorough understanding of this complex microenvironment to effectively prevent solid tumor growth. Important new insights into the role of CAFs in the TME have been revealed by recent studies. The objective of this review is to carefully investigate the relationship between CAFs in tumors and plant secondary metabolites, with a focus on thymoquinone (TQ). The literature published between 2010 and 2023 was searched in PubMed and Google Scholar with keywords such as TQ, TME, cancer-associated fibroblasts, mechanism of action, and flavonoids. The results showed a wealth of data substantiating the activity of plant secondary metabolites, particularly TQ's involvement in blocking CAF operations. Scrutinized research also clarified the wider effect of flavonoids on pathways related to cancer. The present study highlights the complex dynamics of the TME and emphasizes the critical role of CAFs. It also examines the possible interventions provided by secondary metabolites found in plants, with TQ playing a vital role in regulating CAF function based on recent literature.

4.
Mol Biol Rep ; 51(1): 423, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38489102

ABSTRACT

BACKGROUND: Oral health remains a significant global concern with the prevalence of oral pathogens and the increasing incidence of oral cancer posing formidable challenges. Additionally, the emergence of antibiotic-resistant strains has complicated treatment strategies, emphasizing the urgent need for alternative therapeutic approaches. Recent research has explored the application of plant compounds mediated with nanotechnology in oral health, focusing on the antimicrobial and anticancer properties. METHODS: In this study, curcumin (Cu)-mediated zinc oxide nanoparticles (ZnO NPs) were synthesized and characterized using SEM, EDAX, UV spectroscopy, FTIR, and XRD to validate their composition and structural features. The antioxidant and antimicrobial activity of ZnO-CU NPs was investigated through DPPH, ABTS, and zone of inhibition assays. Apoptotic assays and gene expression analysis were performed in KB oral squamous carcinoma cells to identify their anticancer activity. RESULTS: ZnO-CU NPs showcased formidable antioxidant prowess in both DPPH and ABTS assays, signifying their potential as robust scavengers of free radicals. The determined minimal inhibitory concentration of 40 µg/mL against dental pathogens underscored the compelling antimicrobial attributes of ZnO-CU NPs. Furthermore, the interaction analysis revealed the superior binding affinity and intricate amino acid interactions of ZnO-CU NPs with receptors on dental pathogens. Moreover, in the realm of anticancer activity, ZnO-CU NPs exhibited a dose-dependent response against Human Oral Epidermal Carcinoma KB cells at concentrations of 10 µg/mL, 20 µg/mL, 40 µg/mL, and 80 µg/mL. Unraveling the intricate mechanism of apoptotic activity, ZnO-CU NPs orchestrated the upregulation of pivotal genes, including BCL2, BAX, and P53, within the KB cells. CONCLUSIONS: This multifaceted approach, addressing both antimicrobial and anticancer activity, positions ZnO-CU NPs as a compelling avenue for advancing oral health, offering a comprehensive strategy for tackling both oral infections and cancer.


Subject(s)
Anti-Infective Agents , Benzothiazoles , Carcinoma, Squamous Cell , Curcumin , Metal Nanoparticles , Mouth Neoplasms , Sulfonic Acids , Zinc Oxide , Humans , Zinc Oxide/pharmacology , Zinc Oxide/chemistry , Curcumin/pharmacology , Metal Nanoparticles/chemistry , Antioxidants/pharmacology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Carcinoma, Squamous Cell/drug therapy , Mouth Neoplasms/drug therapy , Biofilms , Plant Extracts/chemistry , Microbial Sensitivity Tests
5.
Mol Biol Rep ; 51(1): 352, 2024 Feb 24.
Article in English | MEDLINE | ID: mdl-38400866

ABSTRACT

BACKGROUND: Oral diseases are often attributed to dental pathogens such as S. aureus, S. mutans, E. faecalis, and C. albicans. In this research work, a novel approach was employed to combat these pathogens by preparing zinc oxide nanoparticles (ZnO NPs) capped with cinnamic acid (CA) plant compounds. METHODS: The synthesized ZnO-CA NPs were characterized using SEM, FTIR, and XRD to validate their composition and structural features. The antioxidant activity of ZnO-CA NPs was confirmed using DPPH and ABTS free radical scavenging assays. The antimicrobial effects of ZnO-CA NPs were validated using a zone of inhibition assay against dental pathogens. Autodock tool was used to identify the interaction of cinnamic acid with dental pathogen receptors. RESULTS: ZnO-CA NPs exhibited potent antioxidant activity in both DPPH and ABTS assays, suggesting their potential as powerful antioxidants. The minimal inhibitory concentration of ZnO-CA NPs against dental pathogens was found 25 µg/mL, indicating their effective antimicrobial properties. Further, ZnO-CA NPs showed better binding affinity and amino acid interaction with dental pathogen receptors. Also, the ZnO-CA NPs exhibited dose-dependent (5 µg/mL, 15 µg/mL, 25 µg/mL, and 50 µg/mL) anticancer activity against Human Oral Epidermal Carcinoma KB cells. The mechanism of action of apoptotic activity of ZnO-CA NPs on the KB cells was identified through the upregulation of BCL-2, BAX, and P53 genes. CONCLUSIONS: This research establishes the potential utility of ZnO-CA NPs as a promising candidate for dental applications. The potent antioxidant, anticancer, and effective antimicrobial properties of ZnO-CA NPs make them a valuable option for combating dental pathogens.


Subject(s)
Anti-Infective Agents , Benzothiazoles , Carcinoma , Cinnamates , Metal Nanoparticles , Sulfonic Acids , Zinc Oxide , Humans , Zinc Oxide/pharmacology , Zinc Oxide/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Metal Nanoparticles/chemistry , Antioxidants/pharmacology , Staphylococcus aureus , KB Cells , Anti-Infective Agents/pharmacology
6.
Mol Biol Rep ; 51(1): 89, 2024 Jan 07.
Article in English | MEDLINE | ID: mdl-38184807

ABSTRACT

BACKGROUND: Kappaphycus alvarezii, a marine red algae species, has gained significant attention in recent years due to its versatile bioactive compounds. Among these, κ-carrageenan (CR), a sulfated polysaccharide, exhibits remarkable antimicrobial properties. This study emphasizes the synergism attained by functionalizing zinc oxide nanoparticles (ZnO NPs) with CR, thereby enhancing its antimicrobial efficacy and target specificity against dental pathogens. METHODS: In this study, we synthesized ZnO-CR NPs and characterized them using SEM, FTIR, and XRD techniques to authenticate their composition and structural attributes. Moreover, our investigation revealed that ZnO-CR NPs possess better free radical scavenging capabilities, as evidenced by their effective activity in the DPPH and ABTS assay. RESULTS: The antimicrobial properties of ZnO-CR NPs were systematically assessed using a zone of inhibition assay against dental pathogens of S. aureus, S. mutans, E. faecalis, and C. albicans, demonstrating their substantial inhibitory effects at a minimal concentration of 50 µg/mL. We elucidated the interaction between CR and the receptors of dental pathogens to further understand their mechanism of action. The ZnO-CR NPs demonstrated a dose-dependent anticancer effect at concentrations of 5 µg/mL, 25 µg/mL, 50 µg/mL, and 100 µg/mL on KB cells, a type of Human Oral Epidermal Carcinoma. The mechanism by which ZnO-CA NPs induced apoptosis in KB cells was determined by observing an increase in the expression of the BCL-2, BAX, and P53 genes. CONCLUSION: Our findings unveil the promising potential of ZnO-CR NPs as a candidate with significant utility in dental applications. The demonstrated biocompatibility, potent antioxidant and antiapoptotic activity, along with impressive antimicrobial efficacy position these NPs as a valuable resource in the ongoing fight against dental pathogens and oral cancer.


Subject(s)
Anti-Infective Agents , Mouth Neoplasms , Zinc Oxide , Humans , Zinc Oxide/pharmacology , Carrageenan/pharmacology , Staphylococcus aureus , Mouth Neoplasms/drug therapy , Apoptosis , Candida albicans
7.
Cureus ; 15(10): e46624, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37937007

ABSTRACT

Introduction Dopamine is an important neuroregulatory hormone and is secreted during exercise. Its role in physiological regulation is not fully uncovered. Recent studies showed that it suppresses inflammation. Colon cancer is one of the most predominant cancers in the population and is influenced by prolonged inflammation. The anti-inflammatory effect of dopamine using the colon cancer model was analyzed in KB cells. Methods KB cells were cultured using Dulbecco's Modified Eagle Medium and Inhibitory Concentration- 50 (IC50) was determined by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay. BCl-2, tumour necrosis factor-α (TNF-α), nuclear factor kappa- B (​​​​​NF-kB), and interleukin (IL)-6 were assessed using reverse transcription polymerase chain reaction (RT-PCR)(at 50 and 100 µg/ ml < IC50). Schrödinger was used for docking analysis using nuclear factor Kappa B (NF-kB) (Protein Data Bank: 5T8O) and dopamine (CID 681). Results Results were represented as mean ± standard deviation and statistically evaluated. Dopamine showed severe growth inhibition in KB cells (IC50- 225±3.1µg/ ml). It downregulated the expression of BCl-2, NF-k, and IL-6, but increased TNF-α expression. Dopamine bonded with NF-kB by two hydrogen bonds with aspartic acid​​-53and alanine-54, respectively). Conclusion The present study revealed that dopamine has a significant anti-cancer potential by blocking NF-kB pathways in KB cells.

8.
Mol Biol Rep ; 50(12): 10485-10507, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37917415

ABSTRACT

Mucormycosis, an extremely fatal fungal infection, is a major hurdle in the treatment of diabetes consequences. The increasing prevalence and restricted treatment choices urge the investigation of novel therapeutic techniques. Because of their effective antimicrobial characteristics and varied modes of action, fish-derived peptides have lately emerged as viable options in the fight against mucormycosis. This review examines the potential further application of fish-derived peptides in diagnosing and managing mucormycosis in relation to diabetic complications. First, we examine the pathophysiology of mucormycosis and the difficulties in treating it in diabetics. We emphasize the critical need for alternative therapeutic methods for tackling the limitations of currently available antifungal medicines. The possibility of fish-derived peptides as an innovative approach to combat mucormycosis is then investigated. These peptides, derived from several fish species, provide wide antimicrobial properties against a variety of diseases. They also have distinct modes of action, such as rupture of cell membranes, suppression of development, and modification of the host immunological response. Furthermore, we investigate the problems and prospects connected with the clinical application of fish-derived peptides. Ultimately, future advances in fish-derived peptides, offer interesting avenues for the management of mucormycosis in the context of diabetic comorbidities. More research and clinical trials are needed to properly investigate these peptide's therapeutic potential and pave the way for their adoption into future antifungal therapies.


Subject(s)
Diabetes Complications , Diabetes Mellitus , Mucormycosis , Animals , Mucormycosis/drug therapy , Mucormycosis/microbiology , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Diabetes Mellitus/drug therapy , Diabetes Complications/drug therapy
9.
J Mol Biol ; 435(6): 167972, 2023 03 15.
Article in English | MEDLINE | ID: mdl-36690069

ABSTRACT

Deficient nucleocytoplasmic transport is emerging as a pathogenic feature of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), including in ALS caused by mutations in Fused in Sarcoma (FUS). Recently, both wild-type and ALS-linked mutant FUS were shown to directly interact with the phenylalanine-glycine (FG)-rich nucleoporin 62 (Nup62) protein, where FUS WT/ Nup62 interactions were enriched within the nucleus but ALS-linked mutant FUS/ Nup62 interactions were enriched within the cytoplasm of cells. Nup62 is a central channel Nup that has a prominent role in forming the selectivity filter within the nuclear pore complex and in regulating effective nucleocytoplasmic transport. Under conditions where FUS phase separates into liquid droplets in vitro, the addition of Nup62 caused the synergistic formation of amorphous assemblies containing both FUS and Nup62. Here, we examined the molecular determinants of this process using recombinant FUS and Nup62 proteins and biochemical approaches. We demonstrate that the structured C-terminal domain of Nup62 containing an alpha-helical coiled-coil region plays a dominant role in binding FUS and is sufficient for inducing the formation of FUS/Nup62 amorphous assemblies. In contrast, the natively unstructured, F/G repeat-rich N-terminal domain of Nup62 modestly contributed to FUS/Nup62 phase separation behavior. Expression of individual Nup62 domain constructs in human cells confirmed that the Nup62 C-terminal domain is essential for localization of the protein to the nuclear envelope. Our results raise the possibility that interactions between FUS and the C-terminal domain of Nup62 can influence the function of Nup62 under physiological and/or pathological conditions.


Subject(s)
Amyotrophic Lateral Sclerosis , Frontotemporal Dementia , Membrane Glycoproteins , Nuclear Pore Complex Proteins , Protein Interaction Domains and Motifs , RNA-Binding Protein FUS , Humans , Active Transport, Cell Nucleus/genetics , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/metabolism , Cytoplasm/metabolism , Frontotemporal Dementia/genetics , Frontotemporal Dementia/metabolism , Mutation , RNA-Binding Protein FUS/chemistry , RNA-Binding Protein FUS/metabolism , Membrane Glycoproteins/metabolism , Nuclear Pore Complex Proteins/metabolism
10.
Int J Mol Sci ; 23(24)2022 Dec 16.
Article in English | MEDLINE | ID: mdl-36555655

ABSTRACT

ALS-linked mutations induce aberrant conformations within the SOD1 protein that are thought to underlie the pathogenic mechanism of SOD1-mediated ALS. Although clinical trials are underway for gene silencing of SOD1, these approaches reduce both wild-type and mutated forms of SOD1. Here, we sought to develop anti-SOD1 nanobodies with selectivity for mutant and misfolded forms of human SOD1 over wild-type SOD1. Characterization of two anti-SOD1 nanobodies revealed that these biologics stabilize mutant SOD1 in vitro. Further, SOD1 expression levels were enhanced and the physiological subcellular localization of mutant SOD1 was restored upon co-expression of anti-SOD1 nanobodies in immortalized cells. In human motor neurons harboring the SOD1 A4V mutation, anti-SOD1 nanobody expression promoted neurite outgrowth, demonstrating a protective effect of anti-SOD1 nanobodies in otherwise unhealthy cells. In vitro assays revealed that an anti-SOD1 nanobody exhibited selectivity for human mutant SOD1 over endogenous murine SOD1, thus supporting the preclinical utility of anti-SOD1 nanobodies for testing in animal models of ALS. In sum, the anti-SOD1 nanobodies developed and presented herein represent viable biologics for further preclinical testing in human and mouse models of ALS.


Subject(s)
Amyotrophic Lateral Sclerosis , Single-Domain Antibodies , Humans , Mice , Animals , Superoxide Dismutase-1/genetics , Superoxide Dismutase-1/metabolism , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism , Single-Domain Antibodies/metabolism , Amyotrophic Lateral Sclerosis/metabolism , Protein Folding , Motor Neurons/metabolism , Neuronal Outgrowth , Mutation
11.
Neuron ; 110(10): 1656-1670.e12, 2022 05 18.
Article in English | MEDLINE | ID: mdl-35276083

ABSTRACT

Non-cell-autonomous mechanisms contribute to neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), in which astrocytes release unidentified factors that are toxic to motoneurons (MNs). We report here that mouse and patient iPSC-derived astrocytes with diverse ALS/FTD-linked mutations (SOD1, TARDBP, and C9ORF72) display elevated levels of intracellular inorganic polyphosphate (polyP), a ubiquitous, negatively charged biopolymer. PolyP levels are also increased in astrocyte-conditioned media (ACM) from ALS/FTD astrocytes. ACM-mediated MN death is prevented by degrading or neutralizing polyP in ALS/FTD astrocytes or ACM. Studies further reveal that postmortem familial and sporadic ALS spinal cord sections display enriched polyP staining signals and that ALS cerebrospinal fluid (CSF) exhibits increased polyP concentrations. Our in vitro results establish excessive astrocyte-derived polyP as a critical factor in non-cell-autonomous MN degeneration and a potential therapeutic target for ALS/FTD. The CSF data indicate that polyP might serve as a new biomarker for ALS/FTD.


Subject(s)
Amyotrophic Lateral Sclerosis , Frontotemporal Dementia , Amyotrophic Lateral Sclerosis/genetics , Animals , Astrocytes , C9orf72 Protein/genetics , Culture Media, Conditioned/pharmacology , Frontotemporal Dementia/genetics , Humans , Mice , Motor Neurons , Polyphosphates
12.
Nat Neurosci ; 24(8): 1077-1088, 2021 08.
Article in English | MEDLINE | ID: mdl-34059832

ABSTRACT

Nucleocytoplasmic transport (NCT) decline occurs with aging and neurodegeneration. Here, we investigated the NCT pathway in models of amyotrophic lateral sclerosis-fused in sarcoma (ALS-FUS). Expression of ALS-FUS led to a reduction in NCT and nucleoporin (Nup) density within the nuclear membrane of human neurons. FUS and Nups were found to interact independently of RNA in cells and to alter the phase-separation properties of each other in vitro. FUS-Nup interactions were not localized to nuclear pores, but were enriched in the nucleus of control neurons versus the cytoplasm of mutant neurons. Our data indicate that the effect of ALS-linked mutations on the cytoplasmic mislocalization of FUS, rather than on the physiochemical properties of the protein itself, underlie our reported NCT defects. An aberrant interaction between mutant FUS and Nups is underscored by studies in Drosophila, whereby reduced Nup expression rescued multiple toxic FUS-induced phenotypes, including abnormal nuclear membrane morphology in neurons.


Subject(s)
Active Transport, Cell Nucleus/physiology , Neurons/metabolism , Nuclear Pore Complex Proteins/metabolism , RNA-Binding Protein FUS/metabolism , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/metabolism , Animals , Animals, Genetically Modified , Drosophila , Humans , Mutation , RNA-Binding Protein FUS/genetics
13.
Free Radic Res ; 54(6): 419-430, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32623917

ABSTRACT

pLG72 is a primate-specific protein of enigmatic function that was proposed to modulate mitochondria fragmentation and the activity of the peroxisomal enzyme D-amino acid oxidase (DAAO). DAAO is deputed to degradation of the NMDA receptor co-agonist D-serine in human brain and the R199W substitution in DAAO was identified in a familial case of amyotrophic lateral sclerosis (ALS). A recent work reported that U87 glioblastoma cells ectopically expressing pLG72 showed a lower proliferation, produced superoxide radicals, induced SOD1 aggregation and decreased its activity. Because of the role of SOD1 in eliminating ROS species and its relevance in ALS we evaluated the link between pLG72 and SOD1 using both wild-type pLG72 and its R30K variant related to schizophrenia susceptibility. In vitro studies on recombinant proteins excluded the establishment of a stable complex and that pLG72 could affect SOD1 activity and stability. At cellular level, ectopic expression of pLG72 in glioblastoma U87 cells did not affect cell viability and ROS/superoxide production: only caspase activity (a marker of apoptosis) was slightly increased in cells expressing the R30K pLG72 variant. SOD1 and pLG72 did not colocalize in transfected U87 glioblastoma cells: pLG72 largely localised to mitochondria and SOD1 was largely cytosolic. Moreover, the ectopic expression of pLG72 appeared not to alter the expression of SOD1 and its aggregation. Altogether, the combination of biochemical and cellular studies allow to exclude that pLG72 modulates SOD1 function and aggregation, thus that it could play a role in ALS susceptibility.


Subject(s)
Intracellular Signaling Peptides and Proteins/metabolism , Superoxide Dismutase-1/genetics , Superoxides/metabolism , Humans , Transfection
14.
Hum Vaccin Immunother ; 12(1): 124-31, 2016.
Article in English | MEDLINE | ID: mdl-26379120

ABSTRACT

Abrin, obtained from the seeds of Abrus precatorius plant, is a potent toxin belonging to the family of type II ribosome-inactivating proteins. Recently, a recombinant vaccine consisting of the A subunits of abrin and its homolog Abrus precatorius agglutinin (APA) was demonstrated to protect mice from abrin lethality. Toward identifying neutralizing epitopes recognized during this response, we generated monoclonal antibodies against the proposed vaccine candidate. One antibody, namely A7C4, the corresponding epitope of which was found to be distal to the active site of the enzymatic A chain, prevented abrin-mediated toxicity on cells and abrin-induced lethality in mice but did not inhibit the catalytic activity of the A chain. The in vivo protection conferred by monoclonal antibody A7C4 highlights the potential use of this antibody as a promising immunotherapeutic.


Subject(s)
Abrin/immunology , Abrin/toxicity , Antibodies, Monoclonal/immunology , Antitoxins/immunology , Epitopes/immunology , Poisoning/prevention & control , Animals , Antibodies, Monoclonal/administration & dosage , Antitoxins/administration & dosage , Mice, Inbred BALB C , Survival Analysis
15.
Mol Cell Biochem ; 403(1-2): 255-65, 2015 May.
Article in English | MEDLINE | ID: mdl-25753921

ABSTRACT

Abrin obtained from the plant Abrus precatorius inhibits protein synthesis and also triggers apoptosis in cells. Previous studies from our laboratory suggested a link between these two events. Using an active site mutant of abrin A-chain which exhibits 225-fold lower protein synthesis inhibitory activity than the wild-type abrin A-chain, we demonstrate in this study that inhibition of protein synthesis induced by abrin is the major factor triggering unfolded protein response leading to apoptosis. Since abrin A-chain requires the B-chain for internalization into cells, the wild-type and mutant recombinant abrin A-chains were conjugated to native ricin B-chain to generate hybrid toxins, and the toxic effects of the two conjugates were compared. The rate of inhibition of protein synthesis mediated by the mutant ricin B-rABRA (R167L) conjugate was slower than that of the wild-type ricin B-rABRA conjugate as expected. The mutant conjugate activated p38MAPK and caspase-3 similar to its wild-type counterpart although at later time points. Overall, these results confirm that inhibition of protein synthesis is the major event contributing to abrin-mediated apoptosis.


Subject(s)
Abrin/pharmacology , Apoptosis/drug effects , Protein Biosynthesis/drug effects , Unfolded Protein Response/drug effects , Abrin/isolation & purification , Caspase 3/metabolism , Chromatography, Affinity , Endocytosis/drug effects , Escherichia coli/metabolism , Humans , Jurkat Cells , Kinetics , Mutant Proteins/toxicity , Protein Structure, Secondary , Ricin/chemistry , Ricin/isolation & purification , p38 Mitogen-Activated Protein Kinases/metabolism
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