LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 28

Search options

  1. Article ; Online: Lipid Droplets in Disease.

    Dalhaimer, Paul

    Cells

    2019  Volume 8, Issue 9

    Abstract: Lipid droplets (LDs) are a crucial part of lipid storage; thus, they are important players in a variety of diseases that are affected by lipid imbalances such as obesity, fatty liver disease, type 2 diabetes, Alzheimer's disease, cardiovascular disease, ... ...

    Abstract Lipid droplets (LDs) are a crucial part of lipid storage; thus, they are important players in a variety of diseases that are affected by lipid imbalances such as obesity, fatty liver disease, type 2 diabetes, Alzheimer's disease, cardiovascular disease, and cancer [...].
    MeSH term(s) Cardiovascular Diseases ; Diabetes Mellitus, Type 2/metabolism ; Fatty Liver/metabolism ; Humans ; Lipid Droplets/metabolism ; Lipid Metabolism ; Mitochondria/metabolism ; Neoplasms/metabolism ; Obesity/metabolism
    Language English
    Publishing date 2019-08-26
    Publishing country Switzerland
    Document type Editorial ; Introductory Journal Article
    ZDB-ID 2661518-6
    ISSN 2073-4409 ; 2073-4409
    ISSN (online) 2073-4409
    ISSN 2073-4409
    DOI 10.3390/cells8090974
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: All-Atom Molecular Dynamics Simulations of Polyethylene Glycol (PEG) and LIMP-2 Reveal That PEG Penetrates Deep into the Proposed CD36 Cholesterol-Transport Tunnel.

    Dalhaimer, Paul / Blankenship, Kate R

    ACS omega

    2022  Volume 7, Issue 18, Page(s) 15728–15738

    Abstract: Polyethylene glycol (PEG) is the most prominent clinically administered synthetic polymer. For example, over 300 million people have been administered PEGylated liposome vaccines for SARS-CoV-2. PEG is used in mammals because it has low affinity for most ...

    Abstract Polyethylene glycol (PEG) is the most prominent clinically administered synthetic polymer. For example, over 300 million people have been administered PEGylated liposome vaccines for SARS-CoV-2. PEG is used in mammals because it has low affinity for most proteins and vice versa. However, this makes it difficult to study the few interactions with proteins that PEG has. On the atomistic level, there are two PEG-protein structures: (1) PEG-LIMP-2 and (2) PEG-αPEG. In the first structure, two monomers of a 1.5 kDa PEG polymer (PEG2) had electron density deep in the postulated cholesterol transport tunnel of LIMP-2, a lysosomal cholesterol transport protein and member of the CD36 super family of proteins. It is unclear how PEG entered this tunnel. In the second structure, PEG wrapped around a surface-exposed tryptophan on its antibody. Since tryptophan is a rare residue, it is unclear if this PEG-Trp interaction is ubiquitous. To gain deeper mechanistic insight into PEG-protein interactions, we surrounded the LIMP-2 apo structure with 13 PEG chains of 10 monomers each (PEG10), water, and KCl and simulated the system using NAMD. One of the 13 chains penetrated LIMP-2 and came within 3 Å of PEG2. This was possible because of the strong hydrogen bonding between multiple oxygens along PEG10 and Arg192 but, most importantly, the clamping of the tertiary structure on PEG10. Clamping stabilized the movements of PEG10, and the leading oxygen of PEG10 was able to penetrate LIMP-2 and head toward to the position occupied by PEG2. Phe383 appears to act as a gate for objects to move through this cavity, which continues to the basal/membrane side of LIMP-2. Of all residues, PEG10 molecules had the most sustained interactions with lysine and arginine because of their strong hydrogen-bonding capabilities. These results show that the oxygens of PEG bind residues with high hydrogen bonding capabilities. However, the PEG-protein interaction is likely to be transient unless groups of resides can clamp down on PEG or a cavity that at least part of the PEG chain can enter is in close proximity to lower PEG's entropy.
    Language English
    Publishing date 2022-04-27
    Publishing country United States
    Document type Journal Article
    ISSN 2470-1343
    ISSN (online) 2470-1343
    DOI 10.1021/acsomega.2c00667
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Interactions of Apolipoproteins with Lipid-Based Nanoparticles.

    Dalhaimer, Paul / Florey, Brice / Isaac, Sami

    ACS nano

    2023  

    Abstract: Serum proteins bind and form a dynamic protein corona around nanoparticles (NPs) that have been injected into the mammalian vasculature. Several fundamental studies have shown that apolipoproteins are prominent components of the NP corona. Since ... ...

    Abstract Serum proteins bind and form a dynamic protein corona around nanoparticles (NPs) that have been injected into the mammalian vasculature. Several fundamental studies have shown that apolipoproteins are prominent components of the NP corona. Since apolipoproteins control the distribution of lipoproteins, they may also control the distribution of NPs. Indeed, apolipoprotein affinity for NPs has been recently taken advantage of to deliver CRISPR reagents encapsulated in NPs to cells that express particular lipoprotein receptors. In this scenario, an apolipoprotein binds an NP and the resulting apolipoprotein-NP complex binds a cell that expresses the (apo)lipoprotein receptor. But the NP will be diverted from the target cell if it does not express the (apo)lipoprotein receptor. This may hamper NP treatment of diseases. Therefore, we must understand the kinetics of apolipoprotein-NP affinity and how apolipoprotein-NP interactions affect NP biodistribution. In this Perspective, we discuss the evolving topic of apolipoprotein-NP interactions, which is of great interest for all NP-based disease treatments. Many properties of apolipoprotein-NP complexes are yet to be determined and will have a significant impact on NP efficacy for many NP-based treatments in animal models and in the clinic.
    Language English
    Publishing date 2023-01-09
    Publishing country United States
    Document type Journal Article ; Review
    ISSN 1936-086X
    ISSN (online) 1936-086X
    DOI 10.1021/acsnano.2c10790
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article: Tetra-Primer Amplification-Refractory Mutation System (ARMS)-PCR for Genotyping Mouse Leptin Gene Mutation.

    Chen, Jiangang / Xu, Xinyun / Dalhaimer, Paul / Zhao, Ling

    Animals : an open access journal from MDPI

    2022  Volume 12, Issue 19

    Abstract: Due to spontaneous deficiency in leptin, ...

    Abstract Due to spontaneous deficiency in leptin,
    Language English
    Publishing date 2022-10-05
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2606558-7
    ISSN 2076-2615
    ISSN 2076-2615
    DOI 10.3390/ani12192680
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Obesity and inflammation influence pharmacokinetic profiles of PEG-based nanoparticles

    Raith, Mitch / Nguyen, Nicole / Kauffman, Sarah J. / Kang, Namgoo / Mays, Jimmy / Dalhaimer, Paul

    Journal of Controlled Release.

    2023  

    Abstract: Most patients that will be treated with soft nanoparticles (NPs) will be obese. Yet, NP testing, which begins with pharmacokinetic (PK) and toxicity studies, is carried out almost exclusively in lean rodents having healthy livers and low inflammation. To ...

    Abstract Most patients that will be treated with soft nanoparticles (NPs) will be obese. Yet, NP testing, which begins with pharmacokinetic (PK) and toxicity studies, is carried out almost exclusively in lean rodents having healthy livers and low inflammation. To address this knowledge gap, we determined the PK and toxicity of tail-vein-injected, PEG-based cylindrical nanoparticles (CNPs) and PEGylated liposomes (PLs) as a function of obesity, liver health, and inflammation in leptin-deficient ob/ob and wild-type C57BL/6 J mice. CNPs localized faster to obese livers than to healthy livers within 24 h of injection. PLs localized faster to obese livers than to healthy livers but only 30 min post-injection. Afterwards PL localization to lean livers was higher than localization to obese livers. Overall, PL liver signal peaked ~6 h post-injection in lean mice, ~24 h post-injection in heavy mice, and ~ 48 h post-injection in obese mice. CNPs and PLs were non-toxic to mouse livers as assessed by histology; they reduced many cytokine and chemokine levels that were elevated by obesity. Liver macrophage depletion reduced CNP and PL liver localization as expected; liver sinusoidal endothelial cell (LSEC) depletion reduced PL liver localization but surprisingly increased CNP liver localization. The intensity of RAW264.7 macrophages was higher after CNP incubations than with PL incubations; conversely, the intensity of LSECs was higher after PL incubations than with CNP incubations. This shows the potential for key differences in NP-liver interactions. Triggering inflammation by administering lipopolysaccharide (LPS) to mice increased CNP liver localization but decreased PL liver localization. The results show that obesity and inflammation in a mouse model and in vitro affect soft PEG-based NP interaction with macrophages and LSECs, but also that these NPs can reduce pro-inflammatory pathways increased by obesity.
    Keywords chemokines ; endothelial cells ; histology ; inflammation ; lipopolysaccharides ; liver ; macrophages ; mice ; models ; nanoparticles ; obesity ; pharmacokinetics ; toxicity ; Nanoparticle ; Macrophage ; Liver sinusoidal endothelial cell (LSEC) ; DAB ; HFD ; KCs ; LFD ; MCT ; PEG ; PEO ; PBD ; NAFLD ; NIR ; PBS ; ob/ob ; HPLM ; WAT
    Language English
    Publishing place Elsevier B.V.
    Document type Article ; Online
    Note Pre-press version
    ZDB-ID 632533-6
    ISSN 1873-4995 ; 0168-3659
    ISSN (online) 1873-4995
    ISSN 0168-3659
    DOI 10.1016/j.jconrel.2023.02.007
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  6. Article ; Online: Obesity and inflammation influence pharmacokinetic profiles of PEG-based nanoparticles.

    Raith, Mitch / Nguyen, Nicole / Kauffman, Sarah J / Kang, Namgoo / Mays, Jimmy / Dalhaimer, Paul

    Journal of controlled release : official journal of the Controlled Release Society

    2023  Volume 355, Page(s) 434–445

    Abstract: Most patients that will be treated with soft nanoparticles (NPs) will be obese. Yet, NP testing, which begins with pharmacokinetic (PK) and toxicity studies, is carried out almost exclusively in lean rodents having healthy livers and low inflammation. To ...

    Abstract Most patients that will be treated with soft nanoparticles (NPs) will be obese. Yet, NP testing, which begins with pharmacokinetic (PK) and toxicity studies, is carried out almost exclusively in lean rodents having healthy livers and low inflammation. To address this knowledge gap, we determined the PK and toxicity of tail-vein-injected, PEG-based cylindrical nanoparticles (CNPs) and PEGylated liposomes (PLs) as a function of obesity, liver health, and inflammation in leptin-deficient ob/ob and wild-type C57BL/6 J mice. CNPs localized faster to obese livers than to healthy livers within 24 h of injection. PLs localized faster to obese livers than to healthy livers but only 30 min post-injection. Afterwards PL localization to lean livers was higher than localization to obese livers. Overall, PL liver signal peaked ∼6 h post-injection in lean mice, ∼24 h post-injection in heavy mice, and ∼ 48 h post-injection in obese mice. CNPs and PLs were non-toxic to mouse livers as assessed by histology; they reduced many cytokine and chemokine levels that were elevated by obesity. Liver macrophage depletion reduced CNP and PL liver localization as expected; liver sinusoidal endothelial cell (LSEC) depletion reduced PL liver localization but surprisingly increased CNP liver localization. The intensity of RAW264.7 macrophages was higher after CNP incubations than with PL incubations; conversely, the intensity of LSECs was higher after PL incubations than with CNP incubations. This shows the potential for key differences in NP-liver interactions. Triggering inflammation by administering lipopolysaccharide (LPS) to mice increased CNP liver localization but decreased PL liver localization. The results show that obesity and inflammation in a mouse model and in vitro affect soft PEG-based NP interaction with macrophages and LSECs, but also that these NPs can reduce pro-inflammatory pathways increased by obesity.
    MeSH term(s) Mice ; Animals ; Mice, Inbred C57BL ; Liver/metabolism ; Obesity/metabolism ; Inflammation/pathology ; Liposomes/metabolism ; Nanoparticles ; Mice, Obese
    Chemical Substances Liposomes
    Language English
    Publishing date 2023-02-11
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 632533-6
    ISSN 1873-4995 ; 0168-3659
    ISSN (online) 1873-4995
    ISSN 0168-3659
    DOI 10.1016/j.jconrel.2023.02.007
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Lipid droplet organelle distribution in populations of dividing cells studied by simulation.

    Dalhaimer, Paul

    Physical biology

    2013  Volume 10, Issue 3, Page(s) 36007

    Abstract: One of the key questions in cell biology is how organelles are passed from parent to daughter cells. To help address this question, I used Brownian dynamics to simulate lipid droplets as model organelles in populations of dividing cells. Lipid droplets ... ...

    Abstract One of the key questions in cell biology is how organelles are passed from parent to daughter cells. To help address this question, I used Brownian dynamics to simulate lipid droplets as model organelles in populations of dividing cells. Lipid droplets are dynamic bodies that can form both de novo and by fission, they can also be depleted. The quantitative interplay among these three events is unknown but would seem crucial for controlling droplet distribution in populations of dividing cells. Surprisingly, of the three main events studied: biogenesis, fission, and depletion, the third played the key role in maintaining droplet organelle number-and to a lesser extent volume-in populations of dividing cells where formation events would have seemed paramount. In the case of lipid droplets, this provides computational evidence that they must be sustained, most likely through contacts with the endoplasmic reticulum. The findings also agree with video microscopy experiments over much shorter timescales where droplet depletion in fission yeast cells was not observed. In general, this work shows that organelle maintenance is invaluable and lack thereof cannot necessarily be compensated for by organelle formation. This study provides a time-accurate, physical-based template for long-term cell division studies.
    MeSH term(s) Computer Simulation ; Lipid Metabolism ; Lipids/analysis ; Models, Biological ; Schizosaccharomyces/cytology ; Schizosaccharomyces/metabolism
    Chemical Substances Lipids
    Language English
    Publishing date 2013-06
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2133216-2
    ISSN 1478-3975 ; 1478-3967
    ISSN (online) 1478-3975
    ISSN 1478-3967
    DOI 10.1088/1478-3975/10/3/036007
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Molecular links among non-biodegradable nanoparticles, reactive oxygen species, and autophagy.

    Anozie, Uche C / Dalhaimer, Paul

    Advanced drug delivery reviews

    2017  Volume 122, Page(s) 65–73

    Abstract: For nanoparticles to be successful in combating diseases in the clinic in the 21st century and beyond, they must localize to target areas of the body and avoid damaging non-target, healthy tissues. Both soft and stiff, bio-degradable and non- ... ...

    Abstract For nanoparticles to be successful in combating diseases in the clinic in the 21st century and beyond, they must localize to target areas of the body and avoid damaging non-target, healthy tissues. Both soft and stiff, bio-degradable and non-biodegradable nanoparticles are anticipated to be used to this end. It has been shown that stiff, non-biodegradable nanoparticles cause reactive oxygen species (ROS) generation and autophagy in a variety of cell lines in vitro. Both responses can lead to significant remodeling of the cytosol and even apoptosis. Thus these are crucial cellular functions to understand. Improved assays have uncovered crucial roles of the Akt/mTOR signaling pathway in both ROS generation and autophagy initiation after cells have internalized stiff, non-biodegradable nanoparticles over varying geometries in culture. Of particular - yet unresolved - interest is how these nanoparticles cause the activation of these pathways. This article reviews the most recent advances in nanoparticle generation of ROS and autophagy initiation with a focus on stiff, non-biodegradable technologies. We provide experimental guidelines to the reader for fleshing out the effects of their nanoparticles on the above pathways with the goal of tuning nanoparticle design.
    MeSH term(s) Animals ; Autophagy ; Humans ; Nanoparticles/chemistry ; Nanoparticles/metabolism ; Reactive Oxygen Species/metabolism
    Chemical Substances Reactive Oxygen Species
    Language English
    Publishing date 2017-01-06
    Publishing country Netherlands
    Document type Journal Article ; Review ; Research Support, N.I.H., Extramural
    ZDB-ID 639113-8
    ISSN 1872-8294 ; 0169-409X
    ISSN (online) 1872-8294
    ISSN 0169-409X
    DOI 10.1016/j.addr.2017.01.001
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: PEGylated nanoparticles interact with macrophages independently of immune response factors and trigger a non-phagocytic, low-inflammatory response.

    Asoudeh, Monireh / Nguyen, Nicole / Raith, Mitch / Denman, Desiree S / Anozie, Uche C / Mokhtarnejad, Mahshid / Khomami, Bamin / Skotty, Kaitlyn M / Isaac, Sami / Gebhart, Taylor / Vaigneur, Lauren / Gelgie, Aga / Dego, Oudessa Kerro / Freeman, Trevor / Beever, Jon / Dalhaimer, Paul

    Journal of controlled release : official journal of the Controlled Release Society

    2024  Volume 366, Page(s) 282–296

    Abstract: Poly-ethylene-glycol (PEG)-based nanoparticles (NPs) - including cylindrical micelles (CNPs), spherical micelles (SNPs), and PEGylated liposomes (PLs) - are hypothesized to be cleared in vivo by opsonization followed by liver macrophage phagocytosis. ... ...

    Abstract Poly-ethylene-glycol (PEG)-based nanoparticles (NPs) - including cylindrical micelles (CNPs), spherical micelles (SNPs), and PEGylated liposomes (PLs) - are hypothesized to be cleared in vivo by opsonization followed by liver macrophage phagocytosis. This hypothesis has been used to explain the rapid and significant localization of NPs to the liver after administration into the mammalian vasculature. Here, we show that the opsonization-phagocytosis nexus is not the major factor driving PEG-NP - macrophage interactions. First, mouse and human blood proteins had insignificant affinity for PEG-NPs. Second, PEG-NPs bound macrophages in the absence of serum proteins. Third, lipoproteins blocked PEG-NP binding to macrophages. Because of these findings, we tested the postulate that PEG-NPs bind (apo)lipoprotein receptors. Indeed, PEG-NPs triggered an in vitro macrophage transcription program that was similar to that triggered by lipoproteins and different from that triggered by lipopolysaccharide (LPS) and group A Streptococcus. Unlike LPS and pathogens, PLs did not increase transcripts involved in phagocytosis or inflammation. High-density lipoprotein (HDL) and SNPs triggered remarkably similar mouse bone-marrow-derived macrophage transcription programs. Unlike opsonized pathogens, CNPs, SNPs, and PLs lowered macrophage autophagosome levels and either reduced or did not increase the secretion of key macrophage pro-inflammatory cytokines and chemokines. Thus, the sequential opsonization and phagocytosis process is likely a minor aspect of PEG-NP - macrophage interactions. Instead, PEG-NP interactions with (apo)lipoprotein and scavenger receptors appear to be a strong driving force for PEG-NP - macrophage binding, entry, and downstream effects. We hypothesize that the high presence of these receptors on liver macrophages and on liver sinusoidal endothelial cells is the reason PEG-NPs localize rapidly and strongly to the liver.
    MeSH term(s) Humans ; Animals ; Mice ; Endothelial Cells ; Lipopolysaccharides ; Micelles ; Macrophages ; Immunologic Factors ; Phagocytosis ; Lipoproteins ; Mammals
    Chemical Substances Lipopolysaccharides ; Micelles ; Immunologic Factors ; Lipoproteins
    Language English
    Publishing date 2024-01-05
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 632533-6
    ISSN 1873-4995 ; 0168-3659
    ISSN (online) 1873-4995
    ISSN 0168-3659
    DOI 10.1016/j.jconrel.2023.12.019
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article: Elongated PEO-based nanoparticles bind the high-density lipoprotein (HDL) receptor scavenger receptor class B I (SR-BI)

    Raith, Mitch / Kauffman, Sarah J. / Asoudeh, Monireh / Buczek, Jennifer A. / Kang, Nam-Goo / Mays, Jimmy W. / Dalhaimer, Paul

    Journal of controlled release. 2021 Sept. 10, v. 337

    2021  

    Abstract: Targeting cell-surface receptors with nanoparticles (NPs) is a crucial aspect of nanomedicine. Here, we show that soft, flexible, elongated NPs with poly-ethylene-oxide (PEO) exteriors and poly-butadiene (PBD) interiors – PEO-PBD filomicelles - interact ... ...

    Abstract Targeting cell-surface receptors with nanoparticles (NPs) is a crucial aspect of nanomedicine. Here, we show that soft, flexible, elongated NPs with poly-ethylene-oxide (PEO) exteriors and poly-butadiene (PBD) interiors – PEO-PBD filomicelles - interact directly with the major high-density lipoprotein (HDL) receptor and SARS-CoV-2 uptake factor, SR-BI. Filomicelles have a ~ 6-fold stronger interaction with reconstituted SR-BI than PEO-PBD spheres. HDL, and the lipid transport inhibitor, BLT-1, both block the uptake of filomicelles by macrophages and Idla7 cells, the latter are constitutively expressing SR-BI (Idla7-SR-BI). Co-injections of HDL and filomicelles into wild-type mice reduced filomicelle signal in the liver and increased filomicelle plasma levels. The same was true with SCARB1⁻/⁻ mice. SR-BI binding is followed by phagocytosis for filomicelle macrophage entry, but only SR-BI is needed for entry into Idla7-SR-BI cells. PEO-PBD spheres did not interact strongly with SR-BI in the above experiments. The results show elongated PEO-based NPs can bind cells via cooperativity among SR-BI receptors on cell surfaces.
    Keywords Severe acute respiratory syndrome coronavirus 2 ; lipids ; liver ; macrophages ; nanomedicine ; phagocytosis
    Language English
    Dates of publication 2021-0910
    Size p. 448-457.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 632533-6
    ISSN 1873-4995 ; 0168-3659
    ISSN (online) 1873-4995
    ISSN 0168-3659
    DOI 10.1016/j.jconrel.2021.07.045
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

To top