| 1. |
- Hobro, Sture, et al.
(author)
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Dialysis as a Novel Adjuvant Treatment for Malignant Cancers
- 2022
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In: Cancers. - : MDPI AG. - 2072-6694. ; 14:20
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Research review (peer-reviewed)abstract
- Cancer metabolism is characterized by an increased utilization of fermentable fuels, such as glucose and glutamine, which support cancer cell survival by increasing resistance to both oxidative stress and the inherent immune system in humans. Dialysis has the power to shift the patient from a state dependent on glucose and glutamine to a ketogenic condition (KC) combined with low glutamine levels—thereby forcing ATP production through the Krebs cycle. By the force of dialysis, the cancer cells will be deprived of their preferred fermentable fuels, disrupting major metabolic pathways important for the ability of the cancer cells to survive. Dialysis has the potential to reduce glucose levels below physiological levels, concurrently increase blood ketone body levels and reduce glutamine levels, which may further reinforce the impact of the KC. Importantly, ketones also induce epigenetic changes imposed by histone deacetylates (HDAC) activity (Class I and Class IIa) known to play an important role in cancer metabolism. Thus, dialysis could be an impactful and safe adjuvant treatment, sensitizing cancer cells to traditional cancer treatments (TCTs), potentially making these significantly more efficient.
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| 2. |
- Källquist, Linda, et al.
(author)
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Neutrophil elastase and proteinase 3 trafficking routes in myelomonocytic cells.
- 2010
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In: Experimental Cell Research. - : Elsevier BV. - 1090-2422 .- 0014-4827. ; Okt, s. 3182-3196
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Journal article (peer-reviewed)abstract
- Neutrophil elastase (NE) and proteinase 3 (PR3) differ in intracellular localization, which may reflect different trafficking mechanisms of the precursor forms when synthesized at immature stages of neutrophils. To shed further light on these mechanisms, we compared the trafficking of precursor NE (proNE) and precursor PR3 (proPR3). Like proNE [1], proPR3 interacted with CD63 upon heterologous co-expression in COS cells but endogenous interaction was not detected although cell surface proNE/proPR3/CD63 were co-endocytosed in myelomonocytic cells. Cell surface proNE/proPR3 turned over more rapidly than cell surface CD63 consistent with processing/degradation of the pro-proteases but recycling of CD63. Colocalization of proNE/proPR3/CD63 with clathrin and Rab 7 suggested trafficking through coated vesicles and late endosomes. Partial caveolar trafficking of proNE/CD63 but not proPR3 was suggested by colocalization with caveolin-1. Blocking the C-terminus of proNE/proPR3 by creating a fusion with FK506 binding protein inhibited endosomal re-uptake of proNE but not proPR3 indicating "pro(C)"-peptide-dependent structural/conformational requirements for proNE but not for proPR3 endocytosis. The NE aminoacid residue Y199 of a proposed NE sorting motif that interacts with AP-3 [2] was not required for proNE processing, sorting or endocytosis in rat basophilic leukemia (RBL) cells expressing heterologous Y199-deleted proNE; this suggests operation of another AP-3-link for proNE targeting. Our results show intracellular multi-step trafficking to be different between proNE and proPR3 consistent with their differential subcellular NE/PR3 localization in neutrophils.
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| 3. |
- Källquist, Linda
(author)
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Novel findings on cellular trafficking and targeting for granule storage of neutrophil elastase, a multifunctional effector molecule of innate immunity
- 2009
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Doctoral thesis (other academic/artistic)abstract
- Neutrophil elastase (NE) has important roles in innate immunity, killing pathogens and controlling the immune response; but how NE is targeted to developing granules is not understood. Therefore, the aim of this thesis was to investigate the sorting of NE. Transfection experiments in a leukemic cell line, which were confirmed in normal hematopoietic cells, showed that a population of proNE was targeted to the plasma membrane and endocytosed. This targeting required an intact carboxy-terminal propeptide. Furthermore, modified proNE was not endocytosed, indicating structural requirements for endocytosis. An association was demonstrated between the tetraspanin CD63 and proNE upon coexpression in COS cells. Furthermore, depletion of CD63 in a promyelocytic cell line (achieved by RNA interference or a CD63 mutant) caused reduced processing of proNE into mature NE and reduced constitutive secretion of proNE. We therefore propose that CD63 may be a transmembrane linker that facilitates granule targeting of proNE. Results from a monocytic cell line indicated that the sorting of proNE was a multistage process including trafficking to the cell surface, endocytosis through coated vesicles and possibly lipid rafts, and possible conversion to mature NE in late endosomes. The inhibition of proNE’s activation into mature NE was accompanied by the accumulation of proNE, suggesting a requirement for activation before granule targeting. This research provided new perspectives on the cellular trafficking of NE. The thesis proposes that granule sorting of proNE is facilitated by a tetraspanin protein serving as a transmembrane linker and transporter. The hypothesis needs further testing in primary cells to acquire additional evidence of the interactions involved.
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| 4. |
- Källquist, Linda, et al.
(author)
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The tetraspanin CD63 is involved in granule targeting of neutrophil elastase.
- 2008
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In: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 112, s. 3444-3454
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Journal article (peer-reviewed)abstract
- Targeting mechanisms of neutrophil elastase (NE) and other luminal proteins stored in myeloperoxidase (MPO)-positive secretory lysosomes/primary granules of neutrophils are unknown. These granules contain an integral membrane protein, CD63 with an adaptor protein-3-dependent granule delivery system. Therefore, we hypothesized that CD63 cooperates in granule delivery of the precursor of NE (proNE). Supporting this hypothesis, an association was demonstrated between CD63 and proNE upon coexpression in COS cells. This also involved augmented cellular retention of proNE requiring intact large extracellular loop of CD63. Furthermore, depletion of CD63 in promyelocytic HL-60 cells with RNA interference or a CD63 mutant caused reduction of cellular NE. However, the proNE steady state level was similar to wild type in CD63-depleted clones making it feasible to examine possible effects of CD63 on NE trafficking. Thus, depletion of CD63 led to reduced processing of proNE into mature NE and reduced constitutive secretion. Furthermore, CD63 -depleted cells showed a lack of morphologically normal granules, but contained MPO-positive cytoplasmic vacuoles with a lack of proNE and NE. Collectively, our data suggest that granule proteins may cooperate in targeting; CD63 can be involved in ER or Golgi export, cellular retention and granule targeting of proNE before storage as mature NE.
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| 5. |
- Tapper, Hans, et al.
(author)
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Neutrophil elastase sorting involves plasma membrane trafficking requiring the C-terminal propeptide.
- 2006
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In: Experimental Cell Research. - : Elsevier BV. - 1090-2422 .- 0014-4827. ; 312:18, s. 3471-3484
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Journal article (peer-reviewed)abstract
- The primary granules/secretory lysosomes of neutrophils store mature neutrophil elastase (NE) as a luminal protein after proteolytic removal of N-terminal and C-terminal pro-peptides from a proform of NE. The N-terminal pro-peptide prevents premature activation that might be toxic to the cell, but the C-terminal pro-peptide has no defined function. In this study, we investigated the role of the C-terminal pro-peptide in trafficking of NE by expressing, in rat basophilic leukemia (RBL) cells, both wild-type NE and the mutant NE/Delta 248-267, which lacks the C-terminal pro-peptide. Both transfected proteins were found to be targeted to secretory lysosomes. in addition, results from antibody ligation and cell-surface biotinylation indicated that proform of NE was targeted to the plasma membrane, and then subjected to endocytosis. The results were supported by the detection of targeting of the proform to the plasma membrane followed by internalization both in RBL cells and normal granulopoietic precursor cells. Targeting of NE to the plasma membrane required the C-terminal pro-peptide as NE/ Delta 248-267 expressed in RBL cells bypassed plasma membrane trafficking. our results indicate targeting of a population of NE to the plasma membrane and internalization dependent on the C-terminal NE pro-peptide. (c) 2006 Elsevier Inc. All rights reserved.
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