- Signal Transductions of BEAS-2B Cells in Response to Carcinogenic PM2.5 Exposure Based on Microfluidic System. [Journal Article]
- ACAnal Chem 2017 Apr 27
- PM2.5 (particulate matter less than 2.5 micrometers in diameter) is considered as a harmful carcinogen. Determining the precise relationship between the chemical constituents of PM2.5 in the air and ...
PM2.5 (particulate matter less than 2.5 micrometers in diameter) is considered as a harmful carcinogen. Determining the precise relationship between the chemical constituents of PM2.5 in the air and cancer progression could aid the treatment of environment related disease and establishing risk reduction strategies. Herein, we used transcriptomics (RNA-seq) and integrated microfluidic system to identify the global gene expression and differential target proteins expression induced by ambient fine particles collected from the heavy haze in China. The results clearly indicated that cancer related pathways exhibited the strongest dysregulation. The ambient fine particles could uptake into the cells by pinocytosis, mainly promoting the PI3K-Akt pathway, FGF/FGFR/MAPK/VEGF signaling, and JAK-STAT pathway, leading to evading apoptosis, sustained angiogenesis, and cell proliferation, which are the most important hallmarks of cancer. And fine particles also have been demonstrated to create intracellular reactive oxygen species (ROS) and mitochondrial ROS, change intracellular free Ca2+, and induce apoptosis, which are all key players in mediating cancer progression. It was observed by Transmission Electron Microscopy (TEM) that the particles from the haze could enter the mitochondria, resulting in the disturbance of the mitochondrial membrane and disruption of the mitochondria, and these particles can even enter inside the nucleus. It was also found in our study Organic (OC, PAHs) and metals (Zn, As, V) compounds of fine particles were more closely associated with the exacerbation of cancer and secondary aerosols generated by traffic had the largest impact on cancer related signal transductions.
- Emerging roles of calpain proteolytic systems in macrophage cholesterol handling. [Review]
- CMCell Mol Life Sci 2017 Apr 21
- Calpains are Ca(2+)-dependent intracellular proteases that play central roles in the post-translational processing of functional proteins. In mammals, calpain proteolytic systems comprise the endogen...
Calpains are Ca(2+)-dependent intracellular proteases that play central roles in the post-translational processing of functional proteins. In mammals, calpain proteolytic systems comprise the endogenous inhibitor calpastatin as well as 15 homologues of the catalytic subunits and two homologues of the regulatory subunits. Recent pharmacological and gene targeting studies in experimental animal models have revealed the contribution of conventional calpains, which consist of the calpain-1 and -2 isozymes, to atherosclerotic diseases. During atherogenesis, conventional calpains facilitate the CD36-dependent uptake of oxidized low-density lipoprotein (LDL), and block cholesterol efflux through ATP-binding cassette transporters in lesional macrophages, allowing the expansion of lipid-enriched atherosclerotic plaques. In addition, calpain-6, an unconventional non-proteolytic calpain, in macrophages reportedly potentiates pinocytotic uptake of native LDL, and attenuates the efferocytic clearance of apoptotic and necrotic cell corpses from the lesions. Herein, we discuss the recent progress that has been made in our understanding of how calpain contributes to atherosclerosis, in particular focusing on macrophage cholesterol handling.
- Akt3 Kinase Suppresses Pinocytosis of Low-Density-Lipoprotein By Macrophages via Novel WNK/SGK1/Cdc42 Pathway. [Journal Article]
- JBJ Biol Chem 2017 Apr 07
- Fluid-phase pinocytosis of Low-density lipoprotein (LDL) by macrophages is regarded as a novel promising target to reduce macrophage cholesterol accumulation in atherosclerotic lesions. The mechanism...
Fluid-phase pinocytosis of Low-density lipoprotein (LDL) by macrophages is regarded as a novel promising target to reduce macrophage cholesterol accumulation in atherosclerotic lesions. The mechanisms of regulation of fluid-phase pinocytosis in macrophages and specifically the role of Akt kinases are poorly understood. We have previously found that increased lipoprotein uptake via the receptor independent process in Akt3 kinase deficient macrophages contributes to increased atherosclerosis in Akt3-/- mice. The mechanism by which Akt3 deficiency promotes lipoprotein uptake in macrophages is unknown. We now report that Akt3 constitutively suppresses macropinocytosis in macrophages through a novel WNK1/SGK1/Cdc42 pathway. Mechanistic studies demonstrated that lack of Akt3 expression in murine and human macrophages results in increased expression of with-no-lysine kinase-1 (WNK1), which in turn, leads to increased activity of serum and glucocorticoid-inducible kinase 1 (SGK1). SGK1 promotes expression of Rho family GTPase Cdc42, a positive regulator of actin assembly, cell polarization and pinocytosis. Individual suppression of WNK1 expression, SGK1 or Cdc42 activity in Akt3 deficient macrophages rescued the phenotype. These results demonstrate that Akt3 is a specific negative regulator of macropinocytosis in macrophages.
- Two-dimensional gas chromatography time-of-flight mass spectrometry-based serum metabolic fingerprints of neonatal calves before and after first colostrum ingestion. [Journal Article]
- JDJ Dairy Sci 2017 Mar 29
- Neonatal calves show a remarkable increase in serum IgG levels after first ingestion of colostrum. They can absorb high-molecular IgG from colostrum in the small intestine by nonspecific receptor-ind...
Neonatal calves show a remarkable increase in serum IgG levels after first ingestion of colostrum. They can absorb high-molecular IgG from colostrum in the small intestine by nonspecific receptor-independent fluid pinocytosis within 24 h after birth. However, little is known about the temporal changes in serum small-molecule metabolites, such as carbohydrates and AA, in neonatal calves after first colostrum ingestion. In this study, we examined temporal changes in serum metabolites of neonatal calves after first ingestion of colostrum by comprehensive 2-dimensional gas chromatography mass spectrometry (GCxGC-MS). Forty serum samples obtained from 5 calves at 8 time points between 0 and 12 h after first colostrum ingestion were analyzed in triplicate by GCxGC-MS. Multivariate analyses of 120 GCxGC-MS results revealed significant variations in the serum metabolites, primary individual differences among the calves, and secondary temporal changes within each individual calf. Several serum metabolites increased temporally after ingestion in each calf, but only a limited number of compounds were increased universally in all 5 calves. Eight compounds, including oligosaccharides such as lactose, were associated with temporal changes in IgG. Some essential AA that must be supplied from the diet increased temporally after ingestion, but differed from the temporal pattern of the oligosaccharides and IgG. These results suggest that the colostral contents may be absorbed by complex mechanisms that include intestinal pinocytosis for IgG and oligosaccharides, along with others such as specific transporters in the intestinal epithelial cells for AA in calves.
- Amphotericin B Increases Transglutaminase 2 Expression Associated with Upregulation of Endocytotic Activity in Mouse Microglial Cell Line BV-2. [Journal Article]
- NRNeurochem Res 2017; 42(5):1488-1495
- Amphotericin B (AmB), a polyene antibiotic, is reported to cause the microglial activation to induce nitric oxide (NO) production and proinflammatory cytokines expression, and change neurotrophic fac...
Amphotericin B (AmB), a polyene antibiotic, is reported to cause the microglial activation to induce nitric oxide (NO) production and proinflammatory cytokines expression, and change neurotrophic factors expression in cultured microglia (Motoyoshi et al. in Neurochem Int 52:1290-1296, 2008). On the other hand, tissue-type transglutaminase (TG2) is involved in connection to phagocytes with apoptotic cells. Engulfment of neurons by activated microglia is thought to cause neurodegenerative diseases but detail is unclear, and involvement of TG2 in phagocytosis has been reported in our previous study using lipopolysaccharide-stimulated BV-2 cells (Kawabe et al. in Neuroimmunomodulation 22(4):243-249, 2015). In the present study, we examined the changes of TG2 expression, phagocytosis and pinocytosis in BV-2 cells stimulated by AmB. AmB stimulation increased TG2 expression and TG activity. Phagocytosis of dead cells and pinocytosis of fluorescent microbeads were also up-regulated by AmB stimulation in BV-2 cells. Blockade of TG activity by cystamine, an inhibitor of TGs, suppressed AmB-enhanced TG2 expression, TG activity, NO production, phagocytosis and pinocytosis. Excessive NO production from microglia and/or facilitation of phagocytosis might be involved in neuronal death. To control TG activity might make possible to protect neurons and care for CNS diseases.
- Highlights in endocytosis of nanostructured systems. [Journal Article]
- CMCurr Med Chem 2017 Feb 14
- The focus of this review is the cellular internalisation mechanism of nanostructured systems (NSs) and their endosomal escape for targeted drug delivery. Endocytosis is a cellular process of internal...
The focus of this review is the cellular internalisation mechanism of nanostructured systems (NSs) and their endosomal escape for targeted drug delivery. Endocytosis is a cellular process of internalisation of different molecules and foreign microorganisms. It is currently being studied for drug delivery through nanostructured systems. The most commonly studied routes of cellular uptake are phagocytosis, macro-pinocytosis, clathrin-mediated endocytosis, caveolin-mediated endocytosis, and clathrin and caveolin-independent endocytosis. The mechanism utilised by NSs for cellular entry depends on factors such as cell type and its physicochemical properties. Currently, with the development of drugs-loaded onto NSs, it has been possible to increase the therapeutic index against few diseases. The NSs can deliver the active drug at locations that conventional drugs cannot, thereby minimising unwanted side effects. On cellular entry of NSs, there is a possibility of an endosomal escape of the contents into the cytoplasm, a mechanism that can be exploited so that NSs can migrate intra-cellularly and deliver the drug to the target of interest. Designing endolysosomal escape strategy is not an easy task, but it is critical for the optimal pharmacological action on the target tissue. The cellular uptake of drugs is a very important factor in therapy. Although NSs have emerged as effective drug delivery vehicle for treatment of diseases, it is crucial to understand the mechanism of NSs endocytosis.
- Mouse Liver Sinusoidal Endothelium Eliminates HIV-Like Particles from Blood at a Rate of 100 Million per Minute by a Second-Order Kinetic Process. [Journal Article]
- FIFront Immunol 2017; 8:35
- We crafted human immunodeficiency virus (HIV)-like particles of diameter about 140 nm, which expressed two major HIV-1 proteins, namely, env and gag gene products, and used this reagent to simulate t...
We crafted human immunodeficiency virus (HIV)-like particles of diameter about 140 nm, which expressed two major HIV-1 proteins, namely, env and gag gene products, and used this reagent to simulate the rate of decay of HIV from the blood stream of BALB/c male mice. We found that most (~90%) of the particles were eliminated (cleared) from the blood by the liver sinusoidal endothelial cells (LSECs), the remainder from Kupffer cells; suggesting that LSECs are the major liver scavengers for HIV clearance from blood. Decay was rapid with kinetics suggesting second order with respect to particles, which infers dimerization of a putative receptor on LSEC. The number of HIV-like particles required for saturating the clearance mechanism was approximated. The capacity for elimination of blood-borne HIV-like particles by the sinusoid was 112 million particles per minute. Assuming that the sinusoid endothelial cells were about the size of glass-adherent macrophages, then elimination capacity was more than 540 particles per hour per endothelial cell.
- Intravenously Transplanted Human Bone Marrow Endothelial Progenitor Cells Engraft Within Brain Capillaries, Preserve Mitochondrial Morphology, and Display Pinocytotic Activity Toward Blood-Brain Barrier Repair in Ischemic Stroke Rats. [Journal Article]
- SCStem Cells 2017 Jan 31
- Stroke is a life-threatening disease with limited therapeutic options. Cell therapy has emerged as an experimental stroke treatment. Blood-brain barrier (BBB) impairment is a key pathological manifes...
Stroke is a life-threatening disease with limited therapeutic options. Cell therapy has emerged as an experimental stroke treatment. Blood-brain barrier (BBB) impairment is a key pathological manifestation of ischemic stroke, and barrier repair is an innovative target for neurorestoration in stroke. Here, we evaluated via electron microscopy the ability of transplanted human bone marrow endothelial progenitor cells (hBMEPCs) to repair the BBB in adult Sprague-Dawley rats subjected to transient middle cerebral artery occlusion (tMCAO). β-galactosidase prelabeled hBMEPCs were intravenously transplanted 48 hours post-tMCAO. Ultrastructural analysis of microvessels in nontransplant stroke rats revealed typical BBB pathology. At 5 days post-transplantation with hBMEPCs, stroke rats displayed widespread vascular repair in bilateral striatum and motor cortex, characterized by robust cell engraftment within capillaries. hBMEPC transplanted stroke rats exhibited near normal morphology of endothelial cells (ECs), pericytes, and astrocytes, without detectable perivascular edema. Near normal morphology of mitochondria was also detected in ECs and perivascular astrocytes from transplanted stroke rats. Equally notable, we observed numerous pinocytic vesicles within engrafted cells. Robust engraftment and intricate functionality of transplanted hBMEPCs likely abrogated stroke-altered vasculature. Preserving mitochondria and augmenting pinocytosis in cell-based therapeutics represent a new neurorestorative mechanism in BBB repair for stroke. Stem Cells 2017.
- 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.
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- 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.