Delivery of mRNA Using Biomimetic Vectors: Progress and Challenges.

Messenger RNA (mRNA) is an emerging class of therapeutic agents for treating a wide range of diseases. However, due to the instability and low cell transfection rate of naked mRNA, the expression of delivered mRNA in target cells or tissues in vivo requires delivery strategies. Biomimetic vectors hold advantages such as high biocompatibility, tissue specific targeting ability and efficient delivery mechanisms, potentially overcoming challenges faced by other delivery vectors. In this review, biomimetic vector-based mRNA delivery systems are summarized and discuss the possible challenges and prospects of such delivery systems, which may contribute to the progress and application of mRNA-based therapy in the biomedical field.

Transformation of A1/A2 Astrocytes Participates in Brain Ischemic Tolerance Induced by Cerebral Ischemic Preconditioning via Inhibiting NDRG2.

Cerebral ischemic preconditioning (CIP) has been shown to improve brain ischemic tolerance against subsequent lethal ischemia. Reactive astrocytes play important roles in cerebral ischemia-reperfusion. Recent studies have shown that reactive astrocytes can be polarized into neurotoxic A1 phenotype (C3d) and neuroprotective A2 phenotype (S100A10). However, their role in CIP remains unclear. Here, we focused on the role of N-myc downstream-regulated gene 2 (NDRG2) in regulating the transformation of A1/A2 astrocytes and promoting to brain ischemic tolerance induced by CIP. A Sprague Dawley rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) was used. Rats were divided into the following six groups: (1) sham group; (2) CIP group: left middle cerebral artery was blocked for 10 min; (3) MCAO/R group: left middle cerebral artery was blocked for 90 min; (4) CIP + MCAO/R group: CIP was performed 72 h before MCAO/R; (5) AAV-NDRG2 + CIP + MCAO/R group: adeno-associated virus (AAV) carrying NDRG2 was administered 14 days before CIP + MCAO/R; (6) AAV-Ctrl + CIP + MCAO/R group: empty control group. The rats were subjected to neurological evaluation 24 h after the above treatments, and then were sacrificed for 2, 3, 5-triphenyltetraolium chloride staining, thionin staining, immunofluorescence and western blot analysis. In CIP + MCAO/R group, the neurological deficit scores decreased, infarct volume reduced, and neuronal density increased compared with MCAO/R group. Notably, CIP significantly increased S100A10 expression and the number of S100A10+/GFAP+ cells, and also increased NDRG2 expression. MCAO/R significantly decreased S100A10 expression and the number of S100A10+/GFAP+ cells yet increased C3d expression and the number of C3d+/GFAP+ cells and NDRG2 expression, and these trends were reversed by CIP + MCAO/R. Furthermore, over-expression of NDRG2 before CIP + MCAO/R, the C3d expression and the number of C3d+/GFAP+ cells increased, while S100A10 expression and the number of S100A10+/GFAP+ cells decreased. Meanwhile, over-expression of NDRG2 blocked the CIP-induced brain ischemic tolerance. Taken together, these results suggest that CIP exerts neuroprotective effects against ischemic injury by suppressing A1 astrocyte polarization and promoting A2 astrocyte polarization via inhibiting NDRG2 expression.

STAT4-Mediated Klotho Up-Regulation Contributes to the Brain Ischemic Tolerance by Cerebral Ischemic Preconditioning via Inhibiting Neuronal Pyroptosis.

Our previous study has proved that the Klotho up-regulation participated in cerebral ischemic preconditioning (CIP)-induced brain ischemic tolerance. However, the exact neuroprotective mechanism of Klotho in CIP remains unclear. We explored the hypothesis that STAT4-mediated Klotho up-regulation contributes to the CIP-induced brain ischemic tolerance via inhibiting neuronal pyroptosis. Firstly, the expressions of pyroptosis-associated proteins (i.e., NLRP3, GSDMD, pro-caspase-1, and cleaved caspase-1) in hippocampal CA1 region were determined during the process of brain ischemic tolerance. We found the expression of pyroptosis-associated proteins was significantly up-regulated in the ischemic insult (II) group, and showed no significant changes in the CIP group. The expression level of each pyroptosis-associated proteins was lower in the CIP + II group than that in the II group. Inhibition of Klotho expression increased the expression of pyroptosis-associated proteins in the CIP + II group and blocked the CIP-induced brain ischemic tolerance. Injection of Klotho protein decreased the expression of pyroptosis-associated proteins in the II group, and protected neurons from ischemic injury. Secondly, the transcription factor STAT4 of Klotho was identified by bioinformatic analysis. Double luciferase reporter gene assay and chromatin immunoprecipitation assay showed STAT4 can bind to the site between nt - 881 and - 868 on the Klotho promoter region and positively regulates Klotho expression. Moreover, we found CIP significantly enhanced the expression of STAT4. Knockdown STAT4 suppressed Klotho up-regulation after CIP and blocked the CIP-induced brain ischemic tolerance. Collectively, it can be concluded that STAT4-mediated the up-regulation of Klotho contributed to the brain ischemic tolerance induced by CIP via inhibiting pyroptosis.

The Role of Astrocytic Mitochondria in the Pathogenesis of Brain Ischemia.

The morbidity rate of ischemic stroke is increasing annually with the growing aging population in China. Astrocytes are ubiquitous glial cells in the brain and play a crucial role in supporting neuronal function and metabolism. Increasing evidence shows that the impairment or loss of astrocytes contributes to neuronal dysfunction during cerebral ischemic injury. The mitochondrion is increasingly recognized as a key player in regulating astrocyte function. Changes in astrocytic mitochondrial function appear to be closely linked to the homeostasis imbalance defects in glutamate metabolism, Ca2+ regulation, fatty acid metabolism, reactive oxygen species, inflammation, and copper regulation. Here, we discuss the role of astrocytic mitochondria in the pathogenesis of brain ischemic injury and their potential as a therapeutic target.

"Spark" PtMnIr Nanozymes for Electrodynamic-Boosted Multienzymatic Tumor Immunotherapy.

Multienzyme-mimicking redox nanozymes capable of efficient reactive oxygen species (ROS) generation and cellular homeostasis disruption are highly pursued for cancer therapy. However, it still faces challenges from the complicate tumor microenvironment (TME) and high chance for tumor metastasis. Herein, well-dispersed PtMnIr nanozymes are designed with multiple enzymatic activities, including catalase (CAT), oxidase (OXD), superoxide dismutase (SOD), peroxidase (POD), and glutathione peroxidase (GPx), which continuously produce ROS and deplete glutathione (GSH) concurrently in an "inner catalytic loop" way. With the help of electrodynamic stimulus, highly active "spark" species (Ir3+ and Mn3+) are significantly increased, resulting in an effective cascade enzymatic and electrodynamic therapy. Moreover, the cyclic generation of ROS can also facilitate ferroptosis and apoptosis in tumor cells, boosting synergistic therapy. Importantly, lung metastasis inhibition is found, which confirms efficient immunotherapy by the combined effect of immunogenic cell death (ICD) and Mn2+-induced cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase (cGAS)-stimulator of interferon genes (cGAS-STING) pathway, contributing great potential in the treatment of malignant tumors.

Biomimetic Mineralized CRISPR/Cas RNA Nanoparticles for Efficient Tumor-Specific Multiplex Gene Editing.

CRISPR/Cas9 systems have great potential to achieve sophisticated gene therapy and cell engineering by editing multiple genomic loci. However, to achieve efficient multiplex gene editing, the delivery system needs adequate capacity to transfect all CRISPR/Cas9 RNA species at the required stoichiometry into the cytosol of each individual cell. Herein, inspired by biomineralization in nature, we develop an all-in-one biomimetic mineralized CRISPR/Cas9 RNA delivery system. This system allows for precise control over the coencapsulation ratio between Cas9 mRNA and multiple sgRNAs, while also exhibiting a high RNA loading capacity. In addition, it enhances the storage stability of RNA at 4 °C for up to one month, and the surface of the nanoparticles can be easily functionalized for precise targeting of RNA nanoparticles in vivo at nonliver sites. Based on the above characteristics, as a proof-of-concept, our system was able to achieve significant gene-editing at each target gene (Survivin: 31.9%, PLK1: 24.41%, HPV: 23.2%) and promote apoptosis of HeLa cells in the mouse model, inhibiting tumor growth without obvious off-target effects in liver tissue. This system addresses various challenges associated with multicomponent RNA delivery in vivo, providing an innovative strategy for the RNA-based CRISPR/Cas9 gene editing.

Dual enzyme-like Co-FeSe2 nanoflowers with GSH degradation capability for NIR II-enhanced catalytic tumor therapy.

Nanozymes mediated catalytic therapy can produce toxic reactive oxygen species (ROS) and destroy the metabolic balance of tumor cells, providing a new direction for cancer treatment. However, the catalytic efficiency of a single nanozyme is limited by the complexity of the tumor microenvironment (hypoxia, GSH overexpression, etc.). In order to overcome these problems, we designed flower-like Co-doped FeSe2 (Co-FeSe2) nanozymes by a simple wet chemistry method. Co-FeSe2 nanozymes not only exhibit high POD and OXD-mimicking activities for facile kinetics, but also effectively consume over-expressed glutathione (GSH), inhibiting the consumption of generated ROS and destroying the metabolic balance of the tumor microenvironment. These catalytic reactions trigger cell death through apoptosis and ferroptosis dual pathways. More importantly, under the NIR II laser irradiation, the catalytic activities of Co-FeSe2 nanozymes are boosted, confirming the photothermal and catalytic synergistic tumor therapy. This study takes advantage of self-cascading engineering that offers new ideas for designing efficient redox nanozymes and promoting their clinical translation.

Remodeling Collagen Microenvironment in Liver Using a Biomimetic Nano-Regulator for Reversal of Liver Fibrosis.

Liver fibrosis is a progressive histological manifestation that happens in almost all chronic liver diseases. An unabated liver fibrosis may eventually develop into liver cirrhosis or hepatocellular carcinoma. Yet, the strategy for reversal of liver fibrosis is still limited. Herein, a biomimetic nano-regulator (P-ZIF8-cirDNAzyme) is developed to affect both collagen synthesis and degradation in liver to remodel collagen microenvironment. It is found that Zn (II) interference can efficiently inhibit collagen synthesis in activated hepatic stellate cells (aHSC) by inactivating proline 4 hydroxylase and affecting many fibrosis-related signaling pathways. Meanwhile, Zn (II)-dependent circular DNAzymes (cirDNAzymes) are used to efficiently silence tissue inhibitors of metalloproteinase-1, accelerating the degradation of collagen. They act in concert to recover the balance between collagen deposition and degradation. Additionally, ZIF-8-cirDNAzyme is coated by platelet membrane (PM) for precisely targeting aHSC via PM's inflammatory tropism and CD62p-CD44 interaction. In carbon tetrachloride-induced fibrotic mice, P-ZIF-8-cirDNAzyme shows a potent anti-fibrotic effect, greatly reducing the expression of collagen by 73.12% and restoring liver function nearly to normal. This work proposes a prospective platform enabling ion interference and gene silencing, collectively acting in aHSC for reversal of liver fibrosis.

Klotho Upregulation via PPARγ Contributes to the Induction of Brain Ischemic Tolerance by Cerebral Ischemic Preconditioning in Rats.

Cerebral ischemic preconditioning (CIP)-induced brain ischemic tolerance protects neurons from subsequent lethal ischemic insult. However, the specific mechanisms underlying CIP remain unclear. In the present study, we explored the hypothesis that peroxisome proliferator-activated receptor gamma (PPARγ) participates in the upregulation of Klotho during the induction of brain ischemic tolerance by CIP. First we investigated the expression of Klotho during the brain ischemic tolerance induced by CIP. Lethal ischemia significantly decreased Klotho expression from 6 h to 7 days, while CIP significantly increased Klotho expression from 12 h to 7 days in the hippocampal CA1 region. Inhibition of Klotho expression by its shRNA blocked the neuroprotection induced by CIP. These results indicate that Klotho participates in brain ischemic tolerance by CIP. Furthermore, we tested the role of PPARγ in regulating Klotho expression after CIP. CIP caused PPARγ protein translocation to the nucleus in neurons in the CA1 region of the hippocampus. Pretreatment with GW9962, a PPARγ inhibitor, significantly attenuated the upregulation of Klotho protein and blocked the brain ischemic tolerance induced by CIP. Taken together, it can be concluded that Klotho upregulation via PPARγ contributes to the induction of brain ischemic tolerance by CIP.

A synergistic chemodynamic-photodynamic-photothermal therapy platform based on biodegradable Ce-doped MoOx nanoparticles.

Near-infrared light-induced catalysts are considered to be potential nanoagents for tumor therapy. Cerium (Ce) is a non-biotoxic lanthanide element and exhibits variable valence states for catalytic reactions. In this work, we report a one-step hydrothermal synthesis for Ce-doped MoOx (CMO) nanomaterials. The obtained CMO nanomaterials show high absorption in the NIR II regime and a high photothermal conversion efficiency of 67.7% (1064 nm). Moreover, due to the doping of Ce element, the consumption of hydrogen peroxide (H2O2) and glutathione (GSH) is boosted which enhances the chemodynamic and photodynamic therapy simultaneously. Under NIR II laser irradiation, the designed CMO nanocatalysts induce metabolism disruption and mitochondrial damage in the tumor cells. As-prepared CMO nanomaterials also show good biocompatibility and pH-responsive degradation behavior, which can be degraded rapidly under alkaline conditions (pH = 7.4) and remain stable in acidic solution (pH = 5.6). These properties make CMO nanomaterials ideal biodegradable nanotheranostic agents for synergistic chemodynamic-photodynamic-photothermal antitumor therapy.

The Regulation of Autophagy by p38 MAPK-PPARγ Signaling During the Brain Ischemic Tolerance Induced by Cerebral Ischemic Preconditioning.

Several studies indicated that autophagy activation participates in brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIP). However, the mechanism of autophagy activation during the process still remains unclear. The present study aimed to evaluate the role of p38 MAPK-peroxisome proliferator-activated receptor γ (PPARγ) signaling cascade in autophagy during the CIP-induced BIT. The results shown that, initially, autophagy activation was observed after CIP in the model of global cerebral ischemia in rats, as was indicated by the upregulation of Beclin 1 expression, an increase in LC3-II/LC3-I ratio, the enhanced LC3 immunofluorescence, and a rise in the number of autophagosomes in the neurons of the hippocampal CA1 area. Besides, the inhibitor of autophagy 3-methyladenine obliterated the neuroprotection induced by CIP. Furthermore, the upregulation of p-p38 MAPK and PPARγ expressions was earlier than autophagy activation after CIP. In addition, pretreatment with SB203580 (the inhibitor of p38 MAPK) reversed CIP-induced PPARγ upregulation, autophagy activation, and neuroprotection. Pretreatment with GW9662 (the inhibitor of PPARγ) reversed autophagy activation and neuroprotection, while it had no effect on p-p38 MAPK upregulation induced by CIP. These data suggested that the p38 MAPK-PPARγ signaling pathway participates in autophagy activation during the induction of BIT by CIP.

Ultrasmall AgBiSe2 nanodots for CT/thermal imaging-guided photothermal tumor therapy in the NIR-II biowindow.

Stimulus-responsive ternary chalcogenide nanomaterials are regarded as promising 'all-in-one' nanotheranostics agents on account of their tunable band structures and multi-metal intrinsic properties. Herein, ultrasmall AgBiSe2 nanodots are prepared by a simple thermal injection method. It shows a narrow band gap of 0.91 eV and high absorption coefficient in the NIR-II biowindow, resulting in excellent photothermal performance. Under the irradiation of a 1064 nm laser, AgBiSe2 can induce the overexpression of intracellular heat shock protein (Hsp70) and cell apoptosis to inhibit the growth of tumor cells. The strong signal from CT/thermal imaging also provides guidance for tumor diagnosis. Importantly, AgBiSe2 can be rapidly excreted from the body, thus avoiding long term toxicity. This study presents the first biomedical application of AgBiSe2 nanodots in cancer treatment and extends the development of ternary chalcogenide-based semiconductor nanomedicine.

LncRNA BIRF Promotes Brain Ischemic Tolerance Induced By Cerebral Ischemic Preconditioning Through Upregulating GLT-1 via Sponging miR-330-5p.

Long noncoding RNAs (lncRNAs) play an important regulatory role in various diseases. However, the role of lncRNAs in brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIPC) is still unknown. The lncRNA profile of rat cortical astrocytes pretreated with ischemic preconditioning was analyzed by high-throughput sequencing. The results of Cell-Counting Kit-8 (CCK-8) assay showed that a novel lncRNA, NONRATT009133.2, which we referred to as brain ischemia-related factor (BIRF), was highly correlated with BIT. Through bioinformatics analysis, we predicted that BIRF, miR-330-5p, and GLT-1 (also named Slc1a2) might constitute a ceRNA regulatory network in the induction of BIT. We found that BIRF was upregulated by CIPC, which promoted GLT-1 expression and BIT induction. BIRF could directly bind to miR-330-5p. Furthermore, miR-330-5p directly targeted GLT-1, and miR-330-5p inhibited both GLT-1 expression and BIT induction in vitro and in vivo. Moreover, BIRF acts as a molecular sponge to competitively bind to miR-330-5p with GLT-1 mRNA, while the miR-330-5p inhibitor reversed all the effects of BIRF siRNA on GLT-1 expression and neuronal vitality. Taken together, our results demonstrate the important roles of the BIRF/miR-330-5p/GLT-1 axis in the induction of BIT by CIPC. BIRF may be a potentially effective therapeutic strategy against stroke injury.

The Human Positive Cofactor 4 is a Promising Chemotherapeutic Target in Lung Adenocarcinoma.

Reduced sensitivity to chemotherapeutic drugs is almost inevitable in lung adenocarcinoma patients. Thus, understanding the relevant mechanisms is urgent. Positive cofactor 4 (PC4) was at first revealed to be a coactivator of basal transcription. Previous research has shown that PC4 participates in various cellular processes in normal and malignant cells. However, it is still unknown whether PC4 participates in altering the lung adenocarcinoma cell sensitivity to chemotherapy, and the relevant mechanisms remain to be explained. In this study, we discovered that PC4 was overexpressed in cisplatin-resistant lung adenocarcinoma cells. PC4 decreased cisplatin's cytotoxic effects on lung adenocarcinoma in vivo and in vitro. Furthermore, PC4 positively correlated with SOX9 in multiple cancers. PC4 was an upstream regulator of SOX9 in lung adenocarcinoma. Furthermore, PC4 mediated lung adenocarcinoma cell sensitivity to the HIF-PH inhibitor DMOG and the mTOR inhibitor rapamycin, and PC4 mediated the synergistic effect of DMOG and cisplatin. Finally, PC4 destabilized HIF-1α upon cisplatin treatment. Our research showed that PC4 participates in mediating lung adenocarcinoma cell sensitivity to multiple drugs. Mechanistically, PC4 governs multiple downstream pathways associated with chemotherapy resistance, including the SOX9 and HIF-1α pathways. Thus, PC4 is a promising chemotherapeutic target in lung adenocarcinoma.

Long-term carbon black inhalation induced the inflammation and autophagy of cerebellum in rats.

Carbon black (CB) has been demonstrated to have adverse effects on the lung tissue. Few studies explored the effects of CB on the cerebellum, widely recognized to contribute to gait and balance coordination and timing in the motor domain. Some studies have reported that inflammatory response and damaged autophagy are important mechanisms of CB toxicity and can be repaired after the recovery. The present study aimed to determine whether long-term CB exposure could induce the inflammation and damaged autophagy of the cerebellum. The rats were randomly divided into four groups. The control group received the filtered air for 90 days; the carbon black (CB) group received CB particles for 90 days; the recovery (R) group received CB for 90 days and recovered for another 14 days; the recovery control (RC) group received filtered air for 104 days. The purpose of the R group was to test whether neuroinflammation and autophagy could be repaired after short-term recovery. The western blot and immunohistochemistry revealed that long-term CB exposure induced augmented level of pro-inflammatory cytokines (Interleukin-1ß, IL-1ß; Interleukin-6, IL-6; and Tumor Necrosis Factor-α, TNF-α) and anti-inflammatory cytokine (Interleukin-10, IL-10). The autophagic markers (Beclin1 and LC3) were increased in both CB group and R group. These findings clearly demonstrated that long-term CB exposure induced inflammation and autophagy in the cerebellum, which were not obviously improved after short-term recovery.

The p38 MAPK/NF-κB pathway mediates GLT-1 up-regulation during cerebral ischemic preconditioning-induced brain ischemic tolerance in rats.

Our previous finding suggests that p38 MAPK contributes to the GLT-1 upregulation during induction of brain ischemic tolerance by cerebral ischemic preconditioning (CIP), however, the underlying mechanism is still unclear. Here, we investigated the molecular mechanisms underlying the CIP-induced GLT-1 upregulation by using Western blotting, Co-immunoprecipitation (Co-IP), electrophoretic mobility shift assay (EMSA) and thionin staining in rat hippocampus CA1 subset. We found that application of BAY11-7082 (an inhibitor of NF-κB), or dihydrokainate (an inhibitor of GLT-1), or SB203580 (an inhibitor of p38 MAPK) could attenuate the CIP-induced neuronal protection in hippocampus CA1 region of rats. Moreover, CIP caused rapid activation of NF-κB, as evidenced by nuclear translocation of NF-κB p50 protein, which led to active p50/p65 dimer formation and increased DNA binding activity. GLT-1 was also increased after CIP. Pretreatment with BAY11-7082 blocked the CIP-induced GLT-1 upregulation. The above results suggest that NF-κB participates in GLT-1 up-regulation during the induction of brain ischemic tolerance by CIP. We also found that pretreatment with SB203580 caused significant reduction of NF-κB p50 protein in nucleus, NF-κB p50/p65 dimer nuclear translocation and DNA binding activity of NF-κB. Together, we conclude that p38 MAPK/NF-κB pathway participates in the mediation of GLT-1 up-regulation during the induction of brain ischemic tolerance induced by CIP.

FOXO1 and FOXO3a sensitize non-small-cell lung cancer cells to cisplatin-induced apoptosis independent of Bim.

Low sensitivity to chemotherapy has been a major challenge in the treatment of non-small-cell lung cancer (NSCLC). It is of great clinical significance to discover its mechanisms to improve cell sensitivity to chemotherapeutic drugs. The forkhead box subfamily O (FOXO) transcriptional factors are downstream factors of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway and are reported to play pro-apoptotic roles in a variety of cells including NSCLC cells. But their roles and mechanisms in mediating cell response to chemotherapy remain to be discovered. We proposed that FOXO1 and FOXO3a may increase the sensitivity of NSCLC cells to cisplatin. Moreover, we presumed that LY294002, an inhibitor of the PI3K/AKT pathway, may enhance the cytotoxic effects of cisplatin through upregulating FOXO1 and FOXO3a. In the present study, we found that cisplatin initially increased the expressions and nuclear accumulation of FOXO1 and FOXO3a in NSCLC. Knockdown of FOXO1 and FOXO3a significantly decreased the cell sensitivity to cisplatin in vitro and in vivo. Moreover, inhibition of FOXO1 and FOXO3a attenuated cisplatin-induced cell apoptosis independent of Bim, a pro-apoptotic protein downstream of the FOXOs. Moreover, LY294002 synergistically increased the cytotoxic effects of cisplatin. Mechanistically, LY294002 increased the expressions and nuclear accumulation of FOXO1 and FOXO3a. Knockdown of FOXO1 and FOXO3a abrogated the enhancing effect of LY294002 on cisplatin. Taken together, our results suggested that FOXO1 and FOXO3a sensitize NSCLC cells to cisplatin and mediate the enhancing effects of LY294002 on cisplatin.

Overexpression of U three protein 14a (UTP14a) is associated with poor prognosis of esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive and lethal cancers lacking valid prognostic biomarkers. As an essential component of a large ribonucleoprotein complex, U Three Protein 14a (UTP14a) might play important roles in human tumorigenesis. However, the clinical significance and functions of UTP14a in ESCC still remain unclear. METHODS: From September 2009 to August 2015, 210 patients with ESCC of the thoracic esophagus underwent thoracoscopic esophagectomy in our institute. The corresponding 210 tissue samples and 30 cancer-distant mucosa (CDM) samples were tested for UTP14a expression by immunohistochemical staining. The long-term survival was analyzed by the Kaplan-Meier method and Cox proportional hazards regression analyses. CCK8, cell colony formation, cell cycle, apoptosis, cell invasion, and wound healing assays were carried out with ECA109 cells to evaluate the effects of UTP14a on ESCC in vitro. RESULTS: UTP14a was positively expressed in 88.1% (185/210) of the ESCC samples. UTP14a expression in ESCC was significantly higher than in CDM, as further confirmed by Western blot analysis. High expression of UTP14a in ESCC correlated significantly with tumor invasive depth (pT stage), which predicts poor disease-free survival and disease-specific survival, as indicated by the log-rank test and Cox proportional hazards regression analysis. Additionally, our in vitro experiments further demonstrated that knockdown of UTP14a inhibits cell proliferation and invasion in ECA109 cells. CONCLUSIONS: Our results suggest that UTP14a is aberrantly expressed in ESCC, plays a critical role in cancer progression and could be a potential prognosis predictor of ESCC.

Peroxisome proliferator-activated receptor gamma participates in the acquisition of brain ischemic tolerance induced by ischemic preconditioning via glial glutamate transporter 1 in vivo and in vitro.

Glial glutamate transporter 1 (GLT-1) plays a vital role in the induction of brain ischemic tolerance (BIT) by ischemic preconditioning (IPC). However, the mechanism still needs to be further explained. The aim of this study was to investigate whether peroxisome proliferator-activated receptor gamma (PPARγ) participates in regulating GLT-1 during the acquisition of BIT induced by IPC. Initially, cerebral IPC induced BIT and enhanced PPARγ and GLT-1 expression in the CA1 hippocampus in rats. The ratio of nuclear/cytoplasmic PPARγ was also increased. At the same time, the up-regulation of PPARγ expression in astrocytes in the CA1 hippocampus was revealed by double immunofluorescence for PPARγ and glial fibrillary acidic protein. Then, the mechanism by which PPARγ regulates GLT-1 was studied in rat cortical astrocyte-neuron cocultures. We found that IPC [45 min of oxygen glucose deprivation (OGD)] protected neuronal survival after lethal OGD (4 h of OGD), which usually leads to neuronal death. The activation of PPARγ occurred earlier than the up-regulation of GLT-1 in astrocytes after IPC, as determined by western blot and immunofluorescence. Moreover, the preadministration of the PPARγ antagonist T0070907 or PPARγ siRNA significantly attenuated GLT-1 up-regulation and the neuroprotective effects induced by IPC in vitro. Finally, the effect of the PPARγ antagonist on GLT-1 expression and BIT was verified in vivo. We observed that the preadministration of T0070907 by intracerebroventricular injection dose-dependently attenuated the up-regulation of GLT-1 and BIT induced by cerebral IPC in rats. In conclusion, PPARγ participates in regulating GLT-1 during the acquisition of BIT induced by IPC. Cover Image for this issue: doi: 10.1111/jnc.14532. Open Science: This manuscript was awarded with the Open Materials Badge For more information see: https://cos.io/our-services/open-science-badges/.

The mechanism of GLT-1 mediating cerebral ischemic injury depends on the activation of p38 MAPK.

The previous studies have shown that glial glutamate transporter-1 (GLT-1) participates in cerebral ischemic injury in rats. However, the mechanism involved remains to be elucidated. This study was undertaken to investigate whether p38 MAPK was involved in regulating GLT-1 in the process. At first, it was observed that global brain ischemia for 8 min led to obvious delayed neuronal death, GLT-1 down-regulation and p-p38 MAPK up-regulation in CA1 hippocampus in rats. Then, whether p-p38 MAPK was involved in regulating GLT-1 during cerebral ischemic injury was studied in vitro. Astrocyte-neuron co-cultures exposed to oxygen and glucose deprivation (OGD) were used to mimic brain ischemia. It was observed that lethal OGD (4-h OGD) decreased GLT-1 expression and increased p-p38 MAPK expression in astrocytes. The p-p38 MAPK protein rised from 0 min to 48 h that is the end time of the observation, and the peak value was at 12 h, which was 12.45 times of the control group. Moreover, pre-administration of p38 MAPK inhibitor SB203580 or its siRNA dose-dependently increased GLT-1 expression, and meanwhile alleviated the neuronal death induced by lethal OGD. The above results indicated that p38 MAPK signaling pathway participated in regulating GLT-1 during OGD injury in vitro. Finally, back to in vivo experiment, it was found that pre-administration of SB203580 by intracerebroventricular injection dose-dependently reversed the down-regulation of GLT-1 expression and attenuated the delayed neuronal death normally induced by global brain ischemia in CA1 hippocampus in rats. Taken together, it can be concluded that the mechanism of GLT-1 mediating cerebral ischemic injury depends on the activation of p38 MAPK.