Natural resistance-associated macrophage proteins (NRAMPs) have been shown to transport a wide range of divalent metal ions, such as manganese (Mn), cadmium (Cd), and Iron (Fe). Iron is an essential ...micronutrient for plants and Fe deficiency can lead to chlorosis or decreased biomass. AtNRAMP6 has demonstrated the capability to transport Cd, but its physiological function is currently unclear. This study demonstrates that AtNRAMP6 is localized to the Golgi/
trans
-Golgi network and plays an important role in intracellular Fe homeostasis in the flowering plant genus
Arabidopsis
. GUS tissue-specific expression revealed that
AtNRAMP6
is highly expressed in the lateral roots and young leaves (three to four top leaves) of
Arabidopsis
. Moreover, knocking out
AtNRAMP6
was shown to impair lateral root growth without having a differential effect on the main root under Fe-deficient conditions. Lastly, the expression of
AtNRAMP6
was found to exacerbate the sensitivity of the yeast mutant
Δccc1
to an excessive amount of Fe. These findings indicate that AtNRAMP6 plays an important role in the growth of
Arabidopsis
in Fe-deficient conditions.
Large-sized step shafts are important devices for supporting and transferring heavy parts, and online inspection equipment for runout errors is affected by the environment and is subject to ...coaxiality errors and center-position errors, leading to problems such as reduced measurement accuracy in imaging systems. In view of the above problems, this paper proposes an improved optical imaging system design for runout error detection based on the plane-mirror-group correction method. Zemax was used to optimize the structure and simulate the optical path of the optical imaging system. The total length of the structure was 50 mm, and the MTF function for each field of view was greater than 0.3 at the spatial level up to a frequency of 42 lp/mm. The system was applied to a test platform for runout error detection, achieving the detection of runout errors of a large size in the radial direction and at the end face with a diameter range of 500–700 mm. The measurement repeatability was less than 30 μm, and the system corrected the coaxiality error of the stepped-shaft online inspection equipment considered in this paper.
Ischemic stroke is one of the leading causes of death and permanent disability in adults. Recently, we found that light alcohol consumption (LAC) suppresses post-ischemic inflammatory response, which ...plays an important role in ischemic brain damage. Our goal was to determine the role of peroxisome proliferator-activated receptor-gamma (PPARγ) in the anti-inflammatory effect of LAC against transient focal cerebral ischemia. In in vivo study, male C57BL/6J wild type (WT) and endothelial-specific conditional PPARγ knockout mice were gavage fed with 0.7 g/kg/day ethanol or volume-matched water daily for 8 weeks. From the 7th week, 3 mg/kg/day GW9662 (a selective PPARγ antagonist) was intraperitoneally given for two weeks. Cerebral ischemia/reperfusion (I/R) injury and expression of manganese superoxide dismutase (MnSOD) and adhesion molecules, neutrophil infiltration, and microglial activation in the cerebral cortex before and following a 90 min unilateral middle cerebral artery occlusion (MCAO)/24 h reperfusion were evaluated. In in vitro study, the impact of chronic alcohol exposure on expression of PPARγ and MnSOD in C57BL/6J mouse brain microvascular endothelial cells (MBMVECs) was measured. PPARγ and MnSOD were significantly upregulated in the cerebral cortex of ethanol-fed WT mice and low-concentration ethanol-exposed C57BL/6J MBMVECs. GW9662 significantly inhibited alcohol-induced upregulation of MnSOD. Eight-week ethanol feeding significantly reduced cerebral I/R injury and alleviated the post-ischemic inflammatory response (upregulation of intercellular adhesion molecule-1 (ICAM-1) and E-selectin, microglial activation, and neutrophil infiltration). Treatment with GW9662 and endothelial-specific conditional knockout of PPARγ did not alter cerebral I/R injury and the inflammatory response in the control mice but abolish the neuroprotective effect in ethanol-fed mice. In addition, GW9662 and endothelial-specific conditional knockout of PPARγ diminished the inhibitory effect of LAC on the post-ischemic expression of adhesion molecules and neutrophil infiltration. Our findings suggest that LAC may protect against cerebral I/R injury by suppressing the post-ischemic inflammation via activation of PPARγ.
Ischemic stroke is one of the leading causes of permanent disability and death in adults worldwide. Apoptosis is a major element contributing to post-ischemic neuronal death. We previously found that ...low-dose alcohol consumption (LAC) protects against neuronal apoptosis in the peri-infarct cortex following transient focal cerebral ischemia. Lipocalin-type prostaglandin D2 synthase (L-PGDS), which is mainly localized in the central nervous system (CNS), was previously shown to inhibit neuronal apoptosis. Therefore, we determined whether L-PGDS is involved in the protective effect of LAC against post-ischemic neuronal apoptosis. Wild-type (WT), CaMKIIα
/L-PGDS
, and CaMKIIα
/L-PGDS
mice on a C57BL/6J background were gavage fed with ethanol or volume-matched water once a day for 8 weeks. Tamoxifen (2 mg/day) was given intraperitoneally to CaMKIIα
/L-PGDS
and CaMKIIα
/L-PGDS
mice for 5 days during the fourth week. AT-56 (30 mg/kg/day), a selective inhibitor of L-PGDS, was given orally to AT-56-treated WT mice from the fifth week for four weeks. Cerebral ischemia/reperfusion (I/R) injury, TUNEL-positive neurons, and cleaved caspase-3-positive neurons were measured at 24 h of reperfusion after a 90 min unilateral middle cerebral artery occlusion (MCAO). We found that 0.7 g/kg/day but not 2.8 g/kg/day ethanol significantly upregulated L-PGDS in the cerebral cortex. In addition, 0.7 g/kg/day ethanol diminished cerebral ischemia/reperfusion (I/R) injury and TUNEL-positive and cleaved caspase-3-positive neurons in the peri-infarct cortex in WT and CaMKIIα
/L-PGDS
mice. Furthermore, the neuroprotective effect of 0.7 g/kg/day ethanol was alleviated in AT-56-treated WT and CaMKIIα
/L-PGDS
mice. Our findings suggest that LAC may protect against cerebral I/R injury by suppressing post-ischemic neuronal apoptosis via an upregulated L-PGDS.
A disorder of cholesterol homeostasis is one of the main initiating factors in the progression of atherosclerosis (AS). Metabolism and removal of excess cholesterol facilitates the prevention of foam ...cell formation. However, the failure of treatment with drugs (e.g. methotrexate, MTX) to effectively regulate progression of disease may be related to the limited drug bioavailability and rapid clearance by immune system. Thus, based on the inflammatory lesion "recruitment" properties of macrophages, MTX nanoparticles (MTX NPs) camouflaged with macrophage membranes (MM@MTX NPs) were constructed for the target to AS plaques. MM@MTX NPs exhibited a uniform hydrodynamic size around ~ 360 nm and controlled drug release properties (~ 72% at 12 h). After the macrophage membranes (MM) functionalized "homing" target delivery to AS plaques, MM@MTX NPs improved the solubility of cholesterol by the functionalized beta-cyclodextrin (beta-CD) component and significantly elevate cholesterol efflux by the loaded MTX mediated the increased expression levels of ABCA1, SR-B1, CYP27A1, resulting in efficiently inhibiting the formation of foam cells. Furthermore, MM@MTX NPs could significantly reduce the area of plaque, aortic plaque and cholesterol crystals deposition in ApoE.sup.-/- mice and exhibited biocompatibility. It is suggested that MM@MTX NPs were a safe and efficient therapeutic platform for AS.
Chemotherapy is the main strategy for inhibiting the tumor growth. However, during the therapy, the side effect of anti-cancer drug will injure normal cells. For reducing the toxic of the free drug, ...stimuli responsive nanoparticles (NPs) have been prepared base on the pathological acidic environment around tumor for safe and efficient anti-tumor applications. In this study, we fabricated the phenylboronic acid (PBA) modified monomethoxy polyethylene glycol (MEPG) for encapsulating doxorubicin (DOX NPs). In the drug delivery system (DDS), the pH-responsive boric ester could be stable during drug delivery, and enhance DOX rapidly release in tumor lesion under the acidic stimuli. In vitro studies further demonstrated that DOX NPs could efficiently endocytose by tumor cells, and exhibit the similar anti-tumor activity as the free DOX resulting from the pH-responsive drug release profiles under tumor acidic stimuli. In summary, DOX NPs could be a feasible candidate to improve the safe and efficient DOX delivery for improving the potential anti-tumor applications.
Graphical abstract
Circular RNAs (circRNAs) are a class of non-coding RNAs broadly expressed in cells of various species. However, the molecular mechanisms that link circRNAs with progression of papillary thyroid ...carcinoma (PTC) are not well understood. In the present study, we attempted to provide novel basis for targeted therapy for PTC from the aspect of circRNA-miRNA-mRNA interaction. We investigated the expression of circRNAs in five paired PTC tissues and normal tissues by microarray analysis. The circRNA microarray assay followed by qRT-PCR was used to verify the differential expression of hsa_circ_0059354, which is located on chromosome 20 and derived from RASSF2, and thus we named it circRASSF2. The qRT-PCR analysis was to investigate the expression pattern of circRASSF2 in PTC tissues and cell lines. Then the effects of circRASSF2 on cell proliferation and apoptosis were assessed in PTC in vitro. Furthermore, bioinformatics online programs predicted and luciferase reporter assays were used to validate the association of circRASSF2 and miR-1178 in PTC cells. In this study, circRASSF2 was observed to be upregulated in PTC tissues and cell lines. Knockdown of circRASSF2 inhibited cell proliferation and promoted cell apoptosis in PTC cells. Bioinformatics analysis predicted that there is a circRASSF2/miR-1178/TLR4 axis in PTC. A dual-luciferase reporter system validated the direct interaction of circRASSF2, miR-1178, and TLR4. Furthermore, circRASSF2 facilitates PTC progression in vivo. Importantly, we demonstrated that circRASSF2 was upregulated in serum exosomes from PTC patients. In summary, our study demonstrates that circRASSF2 modulates PTC progression through the miR-1178/TLR4 pathway. Our findings indicate that circRASSF2 may serve as a promising therapeutic target for the treatment of PTC patients.
The role and regulators of extracellular vesicle (EV) secretion in hepatic ischemia/reperfusion (IR) injury have not been defined. Rab27a is a guanosine triphosphatase known to control EV release. ...Interferon regulatory factor 1 (IRF‐1) is a transcription factor that plays an important role in liver IR and regulates certain guanosine triphosphatases. However, the relationships among IRF‐1, Rab27a, and EV secretion are largely unknown. Here, we show induction of IRF‐1 and Rab27a both in vitro in hypoxic hepatocytes and in vivo in warm IR and orthotopic liver transplantation livers. Interferon γ stimulation, IRF‐1 transduction, or IR promoted Rab27a expression and EV secretion. Meanwhile, silencing of IRF‐1 decreased Rab27a expression and EV secretion. Rab27a silencing decreased EV secretion and liver IR injury. Ten putative IRF‐1 binding motifs in the 1,692‐bp Rab27a promoter region were identified. Chromatin immunoprecipitation and electrophoretic mobility shift assay verified five functional IRF‐1 binding motifs, which were confirmed by a Rab27a promoter luciferase assay. IR‐induced EVs contained higher oxidized phospholipids (OxPL). OxPLs on the EV surface activated neutrophils through the toll‐like receptor 4 pathway. OxPL‐neutralizing E06 antibody blocked the effect of EVs and decreased liver IR injury. Conclusion: These findings provide a novel mechanism by which IRF‐1 regulates Rab27a transcription and EV secretion, leading to OxPL activation of neutrophils and subsequent hepatic IR injury. (Hepatology 2018;67:1056–1070)
Background/Aims: Breast cancer (BC) is the most common cancer in women worldwide. Despite great advancements in cancer therapy in recent years, surgery and chemotherapy are still the mainstays of BC ...treatment. However, cancer cells usually develop mechanisms to evade cell death induced by chemotherapy. Thus, strategies are needed to reverse the chemoresistance of cancer cells. Methods: We established cisplatin-resistant BC models in MDA-MB-231 and MCF-7 BC cell lines through long-term exposure to cisplatin. Quantitative reverse transcription PCR was used to examine the expression of microRNA (miR)-100. MTT cell viability assays were performed to determine cell viability. Regulation of hematopoietic cell-specific protein 1-associated protein X-l (HAX-1) targeted by miR-100 was confirmed by western blotting and luciferase reporter assays. The mitochondrial membrane potential and apoptosis were measured by flow cytometry. Release of cytochrome c from the mitochondria into the cytoplasm, HAX-1 expression, and activation of caspase-9 and caspase-3 were detected by western blotting. Results: A clear decrease in miR-100 expression was observed in cisplatin-resistant MDA-MB-231 and MCF-7 cells (MDA-MB-231/R and MCF-7/R). Overexpression of miR-100 increased the sensitivity of MDA-MB-231/R and MCF-7/R cells to cisplatin treatment and promoted cisplatin-induced mitochondrial apoptosis by targeting HAX-1 gene. Conclusions: MiR-100 targeted HAX-1 to increase the chemosensitivity of BC by mediating the mitochondrial apoptosis pathway.
natural resistance-associated macrophage protein 3 (AtNRAMP3) is involved in the transport of cadmium (Cd), iron (Fe), and manganese (Mn). Here, we present a structure-function analysis of AtNRAMP3 ...based on site-directed mutagenesis and metal toxicity growth assays involving yeast mutants, combined with three-dimensional (3D) structure modeling based on the crystal structure of the
NRAMP family transporter, EcoDMT. We demonstrated that two conservative sites, D72 and N75, are essential for the transport activity. The M248A mutation resulted in a decrease in Cd sensitivity, while maintaining Mn transport. The mutation involving G61 caused a significant impairment of Fe and Mn transport, thereby indicating the importance of the conserved residue for proper protein function. The mutation involving G171 disrupted Fe transport activity but not that of Mn and Cd, suggesting that G171 is essential to metal binding and selectivity. Two residues, E194 and R262, may play an important role in stabilizing outward-facing conformation, which is essential for transport activity. Deletion assays indicated that the N-terminus is necessary for the function of AtNRAMP3. The findings of the present study revealed the structure-function relationship of AtNRAMP3 and metal transport activity and selectivity, which may possibly be applied to other plant NRAMP proteins.
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