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ACS Applied Bio Materials Dec 2023Delivering cargo to the cell membranes of specific cell types in the body is a major challenge for a range of treatments, including immunotherapy. This study...
Delivering cargo to the cell membranes of specific cell types in the body is a major challenge for a range of treatments, including immunotherapy. This study investigates employing protein-decorated microbubbles (MBs) and ultrasound (US) to "tag" cellular membranes of interest with a specific protein. Phospholipid-coated MBs were produced and functionalized with a model protein using a metallochelating complex through an NTA(Ni) and histidine residue interaction. Successful "tagging" of the cellular membrane was observed using microscopy in adherent cells and was promoted by US exposure. Further modification of the MB surface to enable selective binding to target cells was then achieved by functionalizing the MBs with a targeting protein (transferrin) that specifically binds to a receptor on the target cell membrane. Attachment and subsequent transfer of material from MBs functionalized with transferrin to the target cells significantly increased, even in the absence of US. This work demonstrates the potential of these MBs as a platform for the noninvasive delivery of proteins to the surface of specific cell types.
Topics: Microbubbles; Ultrasonography; Cell Membrane; Phospholipids; Transferrins
PubMed: 38048163
DOI: 10.1021/acsabm.3c00861 -
HGG Advances Oct 2023Ferritin, the iron-storage protein, is composed of light- and heavy-chain subunits, encoded by FTL and FTH1, respectively. Heterozygous variants in FTL cause hereditary...
Ferritin, the iron-storage protein, is composed of light- and heavy-chain subunits, encoded by FTL and FTH1, respectively. Heterozygous variants in FTL cause hereditary neuroferritinopathy, a type of neurodegeneration with brain iron accumulation (NBIA). Variants in FTH1 have not been previously associated with neurologic disease. We describe the clinical, neuroimaging, and neuropathology findings of five unrelated pediatric patients with de novo heterozygous FTH1 variants. Children presented with developmental delay, epilepsy, and progressive neurologic decline. Nonsense FTH1 variants were identified using whole-exome sequencing, with a recurrent variant (p.Phe171∗) identified in four unrelated individuals. Neuroimaging revealed diffuse volume loss, features of pontocerebellar hypoplasia, and iron accumulation in the basal ganglia. Neuropathology demonstrated widespread ferritin inclusions in the brain. Patient-derived fibroblasts were assayed for ferritin expression, susceptibility to iron accumulation, and oxidative stress. Variant FTH1 mRNA transcripts escape nonsense-mediated decay (NMD), and fibroblasts show elevated ferritin protein levels, markers of oxidative stress, and increased susceptibility to iron accumulation. C-terminal variants in FTH1 truncate ferritin's E helix, altering the 4-fold symmetric pores of the heteropolymer, and likely diminish iron-storage capacity. FTH1 pathogenic variants appear to act by a dominant, toxic gain-of-function mechanism. The data support the conclusion that truncating variants in the last exon of FTH1 cause a disorder in the spectrum of NBIA. Targeted knockdown of mutant FTH1 transcript with antisense oligonucleotides rescues cellular phenotypes and suggests a potential therapeutic strategy for this pediatric neurodegenerative disorder.
Topics: Humans; Child; Apoferritins; Iron Metabolism Disorders; Iron; Ferritins; Oxidoreductases; Neuroaxonal Dystrophies
PubMed: 37660254
DOI: 10.1016/j.xhgg.2023.100236 -
Journal of Trace Elements in Medicine... Jul 2023Evidence on the link between iron metabolism markers and endometriosis is limited. We aimed to investigate the associations of iron metabolism markers, including serum...
BACKGROUND
Evidence on the link between iron metabolism markers and endometriosis is limited. We aimed to investigate the associations of iron metabolism markers, including serum ferritin level and transferrin saturation, with endometriosis.
METHODS
This study involved 6551 participants from the National Health and Nutrition Examination Survey (NHANES). Univariable and multivariable logistic regression analyses were used to examine the linear relationships between iron metabolism markers and endometriosis. Furthermore, restricted cubic splines were used to identify the non-linear dose-response associations.
RESULTS
Univariable analysis showed that the factors associated with endometriosis included age, race, education level, and smoking status. In multivariable model, compared with lowest quartile, highest quartile of serum ferritin level was positively associated with endometriosis (OR: 2.11, 95% confidence intervals [CI]: 1.31, 3.40, P = 0.004), and third quartile of transferrin saturation positively associated with endometriosis (OR: 1.55, 95% CI: 1.05, 2.29, P = 0.033). The restricted cubic splines showed the non-linear (inverted U-shape) associations between serum ferritin level and transferrin saturation and endometriosis (all P for non-linear<0.01), indicating that the ORs of endometriosis increased with serum ferritin level and transferrin saturation up to the turning point and thereafter the ORs of endometriosis did not significantly increase with the increasing serum ferritin and transferrin saturation.
CONCLUSIONS
Our findings suggests that serum ferritin level and transferrin saturation were positively associated with endometriosis. Serum ferritin and transferrin saturation may be an important marker for endometriosis. Future prospective and longitudinal studies are necessary to better understand these findings.
Topics: Female; Humans; Ferritins; Transferrin; Cross-Sectional Studies; Nutrition Surveys; Endometriosis; Biomarkers; Iron; Life Style; Socioeconomic Factors
PubMed: 37075566
DOI: 10.1016/j.jtemb.2023.127175 -
Journal of Food Protection Oct 2023The iron-binding glycoprotein lactoferrin is well known for its wide range of antibacterial effects. However, the aim of this study was to show that its antibacterial...
The iron-binding glycoprotein lactoferrin is well known for its wide range of antibacterial effects. However, the aim of this study was to show that its antibacterial activity is not generally applicable to a bacterial species as a whole. In disk diffusion assays performed with 112 isolates from 13 bacterial species (including the foodborne pathogens Bacillus cereus and Staphylococcus aureus), a lactoferrin-based food supplement showed no inhibition of growth on 24%, moderate inhibition on 31%, and strong inhibition on 45% of all tested isolates. Minimal inhibitory concentrations against B. cereus and Bacillus thuringiensis strain-specifically ranged from 0.31 mg/mL to no impairment at all. Further 11 commercially available lactoferrin-based food supplements and purified bovine lactoferrin showed strain- as well as product-specific growth inhibition. In comparison to bovine lactoferrin, human lactoferrin showed no inhibitory effects. In summary, purified lactoferrin and lactoferrin-based food supplements inhibit bacterial growth in a dose-, strain-, and product-dependent manner. Thus, a general antimicrobial effect of lactoferrin against a specific bacterial species cannot be assumed.
Topics: Humans; Lactoferrin; Anti-Bacterial Agents; Bacteria; Microbial Sensitivity Tests; Dietary Supplements; Bacillus cereus
PubMed: 37640158
DOI: 10.1016/j.jfp.2023.100153 -
Molecular Cell Jan 2024Friedreich's ataxia (FA) is a debilitating, multisystemic disease caused by the depletion of frataxin (FXN), a mitochondrial iron-sulfur (Fe-S) cluster biogenesis...
Friedreich's ataxia (FA) is a debilitating, multisystemic disease caused by the depletion of frataxin (FXN), a mitochondrial iron-sulfur (Fe-S) cluster biogenesis factor. To understand the cellular pathogenesis of FA, we performed quantitative proteomics in FXN-deficient human cells. Nearly every annotated Fe-S cluster-containing protein was depleted, indicating that as a rule, cluster binding confers stability to Fe-S proteins. We also observed depletion of a small mitoribosomal assembly factor METTL17 and evidence of impaired mitochondrial translation. Using comparative sequence analysis, mutagenesis, biochemistry, and cryoelectron microscopy, we show that METTL17 binds to the mitoribosomal small subunit during late assembly and harbors a previously unrecognized [FeS] cluster required for its stability. METTL17 overexpression rescued the mitochondrial translation and bioenergetic defects, but not the cellular growth, of FXN-depleted cells. These findings suggest that METTL17 acts as an Fe-S cluster checkpoint, promoting translation of Fe-S cluster-rich oxidative phosphorylation (OXPHOS) proteins only when Fe-S cofactors are replete.
Topics: Humans; Iron-Sulfur Proteins; Cryoelectron Microscopy; Frataxin; Protein Biosynthesis; Mitochondria; Friedreich Ataxia; Methyltransferases
PubMed: 38199006
DOI: 10.1016/j.molcel.2023.12.016 -
ELife Jan 2024Mammalian ferredoxin 1 and 2 (FDX1/2) belong to an evolutionary conserved family of iron-sulfur cluster containing proteins and act as electron shutters between...
Mammalian ferredoxin 1 and 2 (FDX1/2) belong to an evolutionary conserved family of iron-sulfur cluster containing proteins and act as electron shutters between ferredoxin reductase (FDXR) and numerous proteins involved in critical biological pathways. FDX1 is involved in biogenesis of steroids and bile acids, Vitamin A/D metabolism, and lipoylation of tricarboxylic acid (TCA) cycle enzymes. FDX1 has been extensively characterized biochemically but its role in physiology and lipid metabolism has not been explored. In this study, we generated -deficient mice and showed that knockout of both alleles of the gene led to embryonic lethality. We also showed that like +/-, +/- had a shorter life span and were prone to steatohepatitis. However, unlike +/-, +/- were not prone to spontaneous tumors. Additionally, we showed that FDX1 deficiency led to lipid droplet accumulation possibly via the ABCA1-SREBP1/2 pathway. Specifically, untargeted lipidomic analysis showed that FDX1 deficiency led to alterations in several classes of lipids, including cholesterol, triacylglycerides, acylcarnitines, ceramides, phospholipids and lysophospholipids. Taken together, our data indicate that FDX1 is essential for mammalian embryonic development and lipid homeostasis at both cellular and organismal levels.
Topics: Animals; Mice; Embryonic Development; Ferredoxins; Homeostasis; Iron-Sulfur Proteins; Lipids; Mammals
PubMed: 38251655
DOI: 10.7554/eLife.91656 -
International Journal of Molecular... Apr 2024The persisting presence of opportunistic pathogens like poses a significant threat to many immunocompromised cancer patients with pulmonary infections. This review... (Review)
Review
The persisting presence of opportunistic pathogens like poses a significant threat to many immunocompromised cancer patients with pulmonary infections. This review highlights the complexity of interactions in the host's defensive eicosanoid signaling network and its hijacking by pathogenic bacteria to their own advantage. Human lipoxygenases (ALOXs) and their mouse counterparts are integral elements of the innate immune system, mostly operating in the pro-inflammatory mode. Taking into account the indispensable role of inflammation in carcinogenesis, lipoxygenases have counteracting roles in this process. In addition to describing the structure-function of lipoxygenases in this review, we discuss their roles in such critical processes as cancer cell signaling, metastases, death of cancer and immune cells through ferroptosis, as well as the roles of ALOXs in carcinogenesis promoted by pathogenic infections. Finally, we discuss perspectives of novel oncotherapeutic approaches to harness lipoxygenase signaling in tumors.
Topics: Humans; Animals; Mice; Lipoxygenases; Carcinogenesis; Ferroptosis; Immunocompromised Host; Inflammation
PubMed: 38612771
DOI: 10.3390/ijms25073961 -
Nature Reviews. Chemistry Feb 2024Lytic polysaccharide monooxygenases (LPMOs) have an essential role in global carbon cycle, industrial biomass processing and microbial pathogenicity by catalysing the... (Review)
Review
Lytic polysaccharide monooxygenases (LPMOs) have an essential role in global carbon cycle, industrial biomass processing and microbial pathogenicity by catalysing the oxidative cleavage of recalcitrant polysaccharides. Despite initially being considered monooxygenases, experimental and theoretical studies show that LPMOs are essentially peroxygenases, using a single copper ion and HO for C-H bond oxygenation. Here, we examine LPMO catalysis, emphasizing key studies that have shaped our comprehension of their function, and address side and competing reactions that have partially obscured our understanding. Then, we compare this novel copper-peroxygenase reaction with reactions catalysed by haem iron enzymes, highlighting the different chemistries at play. We conclude by addressing some open questions surrounding LPMO catalysis, including the importance of peroxygenase and monooxygenase reactions in biological contexts, how LPMOs modulate copper site reactivity and potential protective mechanisms against oxidative damage.
Topics: Hydrogen Peroxide; Copper; Polysaccharides; Mixed Function Oxygenases; Catalysis; Metalloproteins
PubMed: 38200220
DOI: 10.1038/s41570-023-00565-z -
Molecules (Basel, Switzerland) Oct 2023In prokaryotes, the role of Mo/W enzymes in physiology and bioenergetics is widely recognized. It is worth noting that the most diverse family of Mo/W enzymes is... (Review)
Review
In prokaryotes, the role of Mo/W enzymes in physiology and bioenergetics is widely recognized. It is worth noting that the most diverse family of Mo/W enzymes is exclusive to prokaryotes, with the probable existence of several of them from the earliest forms of life on Earth. The structural organization of these enzymes, which often include additional redox centers, is as diverse as ever, as is their cellular localization. The most notable observation is the involvement of dedicated chaperones assisting with the assembly and acquisition of the metal centers, including Mo/W-bisPGD, one of the largest organic cofactors in nature. This review seeks to provide a new understanding and a unified model of Mo/W enzyme maturation.
Topics: Metalloproteins; Prokaryotic Cells; Oxidation-Reduction; Energy Metabolism; Molecular Chaperones; Molybdenum
PubMed: 37894674
DOI: 10.3390/molecules28207195 -
Frontiers in Immunology 2024Multiple sclerosis (MS) is the most common chronic inflammatory disease of the central nervous system. Currently, the pathological mechanisms of MS are not fully...
BACKGROUND
Multiple sclerosis (MS) is the most common chronic inflammatory disease of the central nervous system. Currently, the pathological mechanisms of MS are not fully understood, but research has suggested that iron metabolism disorder may be associated with the onset and clinical manifestations of MS.
METHODS AND MATERIALS
The study utilized publicly available databases and bioinformatics techniques for gene expression data analysis, including differential expression analysis, weighted correlation network analysis, gene enrichment analysis, and construction of logistic regression models. Subsequently, Mendelian randomization was used to assess the causal relationship between different iron metabolism markers and MS.
RESULTS
This study identified IREB2, LAMP2, ISCU, ATP6V1G1, ATP13A2, and SKP1 as genes associated with multiple sclerosis (MS) and iron metabolism, establishing their multi-gene diagnostic value for MS with an AUC of 0.83. Additionally, Mendelian randomization analysis revealed a potential causal relationship between transferrin saturation and MS (p=2.22E-02; OR 95%CI=0.86 (0.75, 0.98)), as well as serum transferrin and MS (p=2.18E-04; OR 95%CI=1.22 (1.10, 1.36)).
CONCLUSION
This study comprehensively explored the relationship between iron metabolism and MS through integrated bioinformatics analysis and Mendelian randomization methods. The findings provide important insights for further research into the role of iron metabolism disorder in the pathogenesis of MS and offer crucial theoretical support for the treatment of MS.
Topics: Humans; Multiple Sclerosis; Genes, Regulator; Iron Metabolism Disorders; Transferrins; Iron
PubMed: 38590521
DOI: 10.3389/fimmu.2024.1376838