- Histopathological Evaluation of Contrast-Induced Acute Kidney Injury Rodent Models. [Review]
- BRBiomed Res Int 2016; 2016:3763250
- Contrast-induced acute kidney injury (CI-AKI) can occur in 3-25% of patients receiving radiocontrast material (RCM) despite appropriate preventive measures. Often patients with an atherosclerotic vas...
Contrast-induced acute kidney injury (CI-AKI) can occur in 3-25% of patients receiving radiocontrast material (RCM) despite appropriate preventive measures. Often patients with an atherosclerotic vasculature have to receive large doses of RCM. Thus, animal studies to uncover the exact pathomechanism of CI-AKI are needed. Sensitive and specific histologic end-points are lacking; thus in the present review we summarize the histologic appearance of different rodent models of CI-AKI. Single injection of RCM causes overt renal damage only in rabbits. Rats and mice need an additional insult to the kidney to establish a clinically manifest CI-AKI. In this review we demonstrate that the concentrating ability of the kidney may be responsible for species differences in sensitivity to CI-AKI. The most commonly held theory about the pathomechanism of CI-AKI is tubular cell injury due to medullary hypoxia. Thus, the most common additional insult in rats and mice is some kind of ischemia. The histologic appearance is tubular epithelial cell (TEC) damage; however severe TEC damage is only seen if RCM is combined by additional ischemia. TEC vacuolization is the first sign of CI-AKI, as it is a consequence of RCM pinocytosis and lysosomal fusion; however it is not sensitive as it does not correlate with renal function and is not specific as other forms of TEC damage also cause vacuolization. In conclusion, histopathology alone is insufficient and functional parameters and molecular biomarkers are needed to closely monitor CI-AKI in rodent experiments.
- Chicken IgY Fc Linked to Bordetella avium ompA and Taishan Pinus massoniana Pollen Polysaccharide Adjuvant Enhances Macrophage Function and Specific Immune Responses. [Journal Article]
- FMFront Microbiol 2016; 7:1708
- Fc-fusion technologies, in which immunoglobulin Fc is genetically fused to an antigenic protein, have been developed to confer antibody-like properties to proteins and peptides. Mammalian IgG Fc fusi...
Fc-fusion technologies, in which immunoglobulin Fc is genetically fused to an antigenic protein, have been developed to confer antibody-like properties to proteins and peptides. Mammalian IgG Fc fusion exhibits improved antigen-induced immune responses by providing aggregates with high avidity for the IgG Fc receptor and salvaging the antigenic portion from endosomal degradation. However, whether the linked chicken IgY Fc fragment shares similar characteristics to mammalian IgG Fc remains unclear. In this study, we linked the chicken IgY Fc gene to the outer membrane protein A (ompA) of Bordetella avium through overlapping PCR. The fusion gene was cloned into the pPIC9 plasmid to construct the recombinant Pichia pastoris transformant expressing the ompA-Fc fusion protein. The effects of the linked Fc on macrophage vitality, activity, efficiency of antigen processing, and immune responses induced by the fused ompA were investigated. Furthermore, the effect of Taishan Pinus massoniana pollen polysaccharide (TPPPS), an immunomodulator, on chicken macrophage activation was evaluated. TPPPS was also used as an adjuvant to investigate its immunomodulatory effect on immunoresponses induced by the fused ompA-Fc in chickens. The pinocytosis, phagocytosis, secretion of nitric oxide and TNF-α, and MHC-II molecular expression of the macrophages treated with the fused ompA-Fc were significantly higher than those of the macrophages treated with ompA alone. The addition of TPPPS to the fused ompA-Fc further enhanced macrophage functions. The fused ompA-Fc elicited higher antigen-specific immune responses and protective efficacy compared with ompA alone. Moreover, the fused ompA-Fc conferred higher serum antibody titers, serum IL-2 and IL-4 concentrations, CD4+ and CD8+ T-lymphocyte counts, lymphocyte transformation rate, and protection rate compared with ompA alone. Notably, the prepared TPPPS adjuvant ompA-Fc vaccines induced high immune responses and protection rate. The linked Fc and TPPPS adjuvant can remarkably enhance macrophage functions and specific immune responses. This study provides new perspectives to improve the immune effects of subunit vaccines for prevention of poultry diseases.
- The microvascular alterations in frontal cortex during treatment with antipsychotics: a post-mortem study. [Journal Article]
- RJRom J Morphol Embryol 2016; 57(2):501-6
- CONCLUSIONS: The evidences shown in our study highlight the fact that antipsychotics with potent antagonist action on D2 receptors may affect the neurovascular unit and small vessels in frontal cortex by altering the balance vasoconstriction-vasodilatation, thus reducing the blood flow and metabolism and generating structural microvascular changes proportional with the level of apoptosis at this level. The functional integrity of the dopaminergic system in frontal cortex depends on the vascular support and the capabilities of the neurovascular unit and any dysfunction increases the neuronal loss with clinically significant changes.The pathological data of our study raises the hypothesis for the pathogenic stages at the level of microvessels in the frontal cortex of the patients with schizophrenia or schizophrenia-spectrum disorders treated with D2-blocking antipsychotics: a stage with functional, reversible alterations that may be correlated with the impairments of working memory and presence of extrapyramidal symptoms and a lesional, irreversible stage with significant deterioration of cognition and global functioning. Further studies are needed to verify this hypothesis.
- Nox2-Mediated PI3K and Cofilin Activation Confers Alternate Redox Control of Macrophage Pinocytosis. [Journal Article]
- ARAntioxid Redox Signal 2016 Sep 13
- CONCLUSIONS: In summary, these findings demonstrate a novel Nox2-mediated mechanism of solute uptake via macropinocytosis, with broad implications for both general cellular physiology and pathological processes. The redox mechanism described here may also identify new targets in atherosclerosis and other disease conditions involving macropinocytosis. Antioxid. Redox Signal. 00, 000-000.
- Poly (l-γ-glutamylglutamine) Polymer Enhances Doxorubicin Accumulation in Multidrug Resistant Breast Cancer Cells. [Journal Article]
- MMolecules 2016 Jun 02; 21(6)
- CONCLUSIONS: This study indicated that both polymer-drug conjugate and unconjugated complex are promising strategies of overcoming resistance of anti-tumor drugs.
- Distinct Cellular Pathways for Induction of CD4+ T Cell-Dependent Antibody Responses to Antigen Expressed by Intact Bacteria Versus Isolated Soluble Antigen. [Journal Article]
- JIJ Immunol 2016 May 15; 196(10):4204-13
- Uptake of intact bacteria and soluble Ags by APCs is mediated by phagocytosis and endocytosis or pinocytosis, respectively. Thus, we predicted that injection of clodronate-containing liposomes (CLs),...
Uptake of intact bacteria and soluble Ags by APCs is mediated by phagocytosis and endocytosis or pinocytosis, respectively. Thus, we predicted that injection of clodronate-containing liposomes (CLs), which selectively deplete cells efficient in phagocytosis, would inhibit murine CD4(+) T cell-dependent IgG responses to Ags expressed by intact bacteria but not isolated soluble Ags. Surprisingly, injection of CLs markedly inhibited protein-specific IgG responses to intact, heat-killed Streptococcus pneumoniae, as well as a soluble OVA-polysaccharide conjugate or OVA alone. IgG anti-polysaccharide responses to bacteria and conjugate were also reduced, but more modestly. In both instances, CL-mediated inhibition was associated with a significant reduction in induced germinal centers and CD4(+) germinal center T follicular helper cells. However, CL injection, which largely abrogated the proliferative response of adoptively transferred OVA peptide-specific-transgenic CD4(+) T cells in response to immunization with S. pneumoniae expressing OVA peptide, did not inhibit T cell proliferation in response to OVA-polysaccharide conjugate or OVA. In this regard, monocyte-derived cells, depleted by CLs, internalized S. pneumoniae in vivo, whereas CD11c(low) dendritic cells, unaffected by CL injection, internalized soluble OVA. Ex vivo isolation and coculture of these respective APCs from S. pneumoniae- or OVA-immunized mice with OVA-specific T cells, in the absence of exogenous Ag, demonstrated their selective ability to induce T cell activation. These data suggest that, although distinct APCs initiate CD4(+) T cell activation in response to Ag expressed by intact bacteria versus Ag in soluble form, CL-sensitive cells appear to be necessary for the subsequent IgG responses to both forms of Ag.
- Calcium-sensing receptors signal constitutive macropinocytosis and facilitate the uptake of NOD2 ligands in macrophages. [Journal Article]
- NCNat Commun 2016; 7:11284
- Macropinocytosis can be induced in several cell types by stimulation with growth factors. In selected cell types, notably macrophages and dendritic cells, macropinocytosis occurs constitutively, supp...
Macropinocytosis can be induced in several cell types by stimulation with growth factors. In selected cell types, notably macrophages and dendritic cells, macropinocytosis occurs constitutively, supporting the uptake of antigens for subsequent presentation. Despite their different mode of initiation and contrasting physiological roles, it is tacitly assumed that both types of macropinocytosis are mechanistically identical. We report that constitutive macropinocytosis is stringently calcium dependent, while stimulus-induced macropinocytosis is not. Extracellular calcium is sensed by G-protein-coupled calcium-sensing receptors (CaSR) that signal macropinocytosis through Gα-, phosphatidylinositol 3-kinase and phospholipase C. These pathways promote the recruitment of exchange factors that stimulate Rac and/or Cdc42, driving actin-dependent formation of ruffles and macropinosomes. In addition, the heterologous expression of CaSR in HEK293 cells confers on them the ability to perform constitutive macropinocytosis. Finally, we show that CaSR-induced constitutive macropinocytosis facilitates the sentinel function of macrophages, promoting the efficient delivery of ligands to cytosolic pattern-recognition receptors.
- Mitochondria-specific conjugated polymer nanoparticles. [Journal Article]
- CCChem Commun (Camb) 2016 Apr 07; 52(27):4910-3
- Biodegradable conjugated polymer nanoparticles (CPNs) were prepared for high mitochondrial targeting in live cancer cells. The degradable CPNs are nontoxic and specifically localized to the mitochond...
Biodegradable conjugated polymer nanoparticles (CPNs) were prepared for high mitochondrial targeting in live cancer cells. The degradable CPNs are nontoxic and specifically localized to the mitochondria of live tumor cells through macropinocytosis followed by intracellular degradation and trafficking.
- Cellular uptake and intracellular fate of protein releasing bacterial amyloids in mammalian cells. [Journal Article]
- SMSoft Matter 2016 Apr 14; 12(14):3451-60
- Bacterial Inclusion Bodies (IBs) are amyloidal protein deposits that functionally mimic secretory granules from the endocrine system. When formed by therapeutically relevant proteins, they complement...
Bacterial Inclusion Bodies (IBs) are amyloidal protein deposits that functionally mimic secretory granules from the endocrine system. When formed by therapeutically relevant proteins, they complement missing intracellular activities in jeopardized cell cultures, offering an intriguing platform for protein drug delivery in substitutive therapies. Despite the therapeutic potential of IBs, their capability to interact with eukaryotic cells, cross the cell membrane and release their functional building blocks into the cytosolic space remains essentially unexplored. We have systematically dissected the process by which bacterial amyloids interact with mammalian cells. An early and tight cell membrane anchorage of IBs is followed by cellular uptake of single or grouped IBs of variable sizes by macropinocytosis. Although an important fraction of the penetrating particles is led to lysosomal degradation, biologically significant amounts of protein are released into the cytosol. In addition, our data suggest the involvement of the bacterial cell folding modulator DnaK in the release of functional proteins from these amyloidal reservoirs. The mechanisms supporting the internalization of disintegrable protein nanoparticles revealed here offer clues to implement novel approaches for protein drug delivery based on controlled protein packaging as bacterial IBs.
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- Attacking the supply wagons to starve cancer cells to death. [Review]
- FLFEBS Lett 2016; 590(7):885-907
- The constitutive anabolism of cancer cells not only supports proliferation but also addicts tumor cells to a steady influx of exogenous nutrients. Limiting access to metabolic substrates could be an ...
The constitutive anabolism of cancer cells not only supports proliferation but also addicts tumor cells to a steady influx of exogenous nutrients. Limiting access to metabolic substrates could be an effective and selective means to block cancer growth. In this review, we define the pathways by which cancer cells acquire the raw materials for anabolism, highlight the actionable proteins in each pathway, and discuss the status of therapeutic interventions that disrupt nutrient acquisition. Critical open questions to be answered before apical metabolic inhibitors can be successfully and safely deployed in the clinic are also outlined. In summary, recent studies provide strong support that substrate limitation is a powerful therapeutic strategy to effectively, and safely, starve cancer cells to death.