Zinc Promotes Microglial Autophagy Through NLRP3 Inflammasome Inactivation via XIST/miR-374a-5p Axis in Spinal Cord Injury.

Zinc has reported to play a neuroprotective role in the development of spinal cord injury (SCI). The protective mechanism of zinc remains to be uncovered. The aim of the current study was to investigate the neuroprotective mechanism of zinc in the progression of SCI. The C57BL/6J mouse SCI model was established to confirm the protective role of zinc in vivo, while the cellular model was induced in mouse microglial BV2 cells by using lipopolysaccharide (LPS). The expression levels of XIST, miR-374a-5p and NLRP3 inflammasome as well as the autophagy-related proteins were detected using real-time PCR and immunoblotting. Cell viability was assessed by CCK-8 assay. Apoptosis was evaluated by TUNEL staining, flow cytometry, the determination of apoptosis-related proteins. The target relationship was confirmed by luciferase reporter assays. Zinc improved locomotor function in SCI mice and alleviated LPS-induced BV2 cell injuries by inhibiting apoptosis and initiating autophagy processes. XIST and NLRP3 inflammasome was upregulated while miR-374a-5p was downregulated in spinal cords of SCI mice and LPS-treated BV2 cells. All these effects were inhibited by Zinc treatment. XIST knockdown triggered microglial autophagy-mediated NLRP3 inactivation in LPS-induced BV2 cells by regulating miR-374a-5p. Zinc treatment protected BV2 cells from LPS-induced cell injury by the downregulation of XIST. This process might be through autophagy­mediated NLRP3 inflammasome inactivation by targeting miR-374a-5p. Zinc downregulates XIST and induces neuroprotective effects against SCI by promoting microglial autophagy-induced NLRP3 inflammasome inactivation through regulating miR-374a-5p. Our finding provides novel opportunities for the understanding of zinc-related therapy of SCI.

Receptor for Advanced Glycation End-Products (RAGE) Blockade Do Damage to Neuronal Survival via Disrupting Wnt/ß-Catenin Signaling in Spinal Cord Injury.

Wnt signaling are recognized key factors in neuronal development, cell proliferation and axonal guidance. However, RAGE effect on wnt signaling after spinal cord injury (SCI) are poorly understood. Our study aims to explore RAGE blockade effect on wnt signaling after SCI. We constructed Allen SCI model and micro-injected with RAGE neutralizing antibody or IgG after injury. We determined ß-catenin, wnt3a and its receptor frizzled-5 via Western blot. We determined ß-catenin/NeuN expression at 2 weeks after SCI via immunofluorescence (IF). We found that ß-catenin, wnt3a and wnt receptor frizzled5 expression were activated after SCI at 3 days after injury. However, RAGE blockade inhibit ß-catenin, wnt3a and frizzled5 expression. We found that ß-catenin accumulation in NeuN cells were activated after SCI via IF, however, RAGE blockade reduced ß-catenin and NeuN positive cells. RAGE blockade attenuated number of survived neurons and decreased area of spared white matter around the epicenter. RAGE signaling may involved in disrupting wnt signaling to aids neuronal recovery after SCI.

MiR-429 improved the hypoxia tolerance of human amniotic cells by targeting HIF-1α.

MicroRNA-429(miR-429) plays an important role in mesenchymal stem cells. Hypoxia-inducible factor 1α (HIF-1α) is a nuclear transcription factor that regulates the proliferation, apoptosis and tolerance to hypoxia of mesenchymal stem cells. HIF-1α is also a target gene of miR-429. We investigated whether miR-429 plays a role in hypoxia tolerance with HIF-1α in human amniotic mesenchymal stem cells (hAMSCs). The expression of miR-429 was increased by hypoxia in hAMSCs. miR-429 expression resulted in decreased HIF-1α protein level, but little effect on HIF-1α mRNA. While overexpression of HIF-1α increased the survival rate and exhibited anti-apoptosis effects in hAMSCs under hypoxia, co-expression of miR-429 reduced survival and increased apoptosis. However, miR-429 silencing with HIF-1α overexpression stimulated cell survival and reduced apoptosis. Co-expression of HIF-1α and miR-429 reduced VEGF and Bcl-2 proteins and increased Bax and C-Caspase-3 levels in hAMSCs under hypoxia compared with cells expressing only HIF-1α; cells with HIF-1α overexpression and miR-429 silencing showed the opposite effects. These results indicate that HIF-1α and angomiR-429 reciprocally antagonized each other, while HIF-1α and antagomiR-429 interacted with each other to regulate survival and apoptosis in hAMSCs under hypoxia. miR-429 increased VEGF and Bcl-2 protein levels and decreased Bax and cleaved Caspase-3 protein levels by promoting the synthesis of HIF-1α. These results indicate that miR-429 negatively regulates the survival and anti-apoptosis ability of hAMSCs by mediating HIF-1α expression and improves the ability of hAMSCs to tolerate hypoxia.

Simvastatin inhibits neural cell apoptosis and promotes locomotor recovery via activation of Wnt/ß-catenin signaling pathway after spinal cord injury.

Statins exhibit neuroprotective effects after spinal cord injury (SCI). However, the molecular mechanism underlying these effects remains unknown. This study demonstrates that the hydroxymethylglutaryl coenzyme A reductase inhibitor simvastatin (Simv) exhibits neuroprotective effects on neuronal apoptosis and supports functional recovery in a rat SCI model by activating the Wnt/ß-catenin signaling pathway. In specific, Simv administration after SCI significantly up-regulated the expression of low density lipoprotein receptor-related protein 6 phosphorylation and ß-catenin protein, increased the mRNA expression of lymphoid enhancer factor-1 and T-cell factor-1, and suppressed the expression of ß-catenin phosphorylation in the spinal cord neurons. Simv enhanced motor neuronal survival in the spinal cord anterior horn and decreased the lesion of spinal cord tissues after SCI. Simv administration after SCI also evidently reduced the expression levels of Bax, active caspase-3, and active caspase-9 in the spinal cord neurons and the proportion of transferase UTP nick end labeling (TUNEL)-positive neuron cells, but increased the expression level of Bcl-2 in the spinal cord neurons. However, the anti-apoptotic effects of Simv were reduced in cultured spinal cord nerve cells when the Wnt/ß-catenin signaling pathway was suppressed in the lipopolysaccharide-induced model. Furthermore, the Basso, Beattie, and Bresnahan scores indicated that Simv treatment significantly improved the locomotor functions of rats after SCI. This study is the first to report that Simv exerts neuroprotective effects by reducing neuronal apoptosis, and promoting functional and pathological recovery after SCI by activating the Wnt/ß-catenin signaling pathway. We verified the neuroprotective properties associated with simvastatin following spinal cord injury (SCI). Simvastatin reduced neuronal apoptosis, improved the functional and pathological recovery via activating Wnt/ß-catenin signal pathway, however, the anti-apoptosis effects of simvastatin were reversed following suppressing Wnt/ß-catenin signaling pathway in primary spinal cord neurons. The significant findings may provide clinical therapeutic value of simvastatin for treating SCI.

VEGF inhibits the inflammation in spinal cord injury through activation of autophagy.

Vascular endothelial growth factor (VEGF) is a secreted mitogen associated with angiogenesis and re-vascularization of spinal cord injury (SCI). VEGF has long been thought to be a potent neurotrophic factor for the survival of spinal cord neuron. However, the neuroprotective mechanism of VEGF is still unclear. The aim of this study was to investigate the effect of VEGF on spinal cord injury and its mechanisms. Young male Wistar rats were subjected to SCI and then VEGF165 were injected directly into the lesion epicenter 24 h post injury. We detected Basso, Beattie and Bresnahan (BBB) scores and numbers of motor neuron via Nissl staining. The expressions of autophagy related protein Beclin1 and LC3B were determined by Western blot and RT-PCR. We also detected the contents of inflammation factors interleukin-1ß (IL-1ß), tumor necrosis factor alpha (TNF-α) and interleukin-10(IL-10) in LPS (Lipopolysaccharide) treated spinal neuron-glia co-culture by ELISA. We found that VEGF165 administration increased the BBB score and reduced the loss of motor neuron of rats induced by SCI. VEGF decreased the protein expressions of IL-1ß, TNF-α and IL-10 and up-regulated the expressions of Beclin1 and LC3B of rats. In the in vitro study, VEGF165 decreased the levels of IL-1ß, IL-10 and TNF-a in the medium of LPS treated spinal neuron-glia co-culture, which was partially blocked by 3-MA, the inhibitor of autophagy. In addition, VEGF165 up-regulate the expressions of Beclin1 and LC3B in co-culture cells. The results suggested that VEGF165 attenuated the spinal cord injury by inhibiting the inflammation and increasing the autophagy function.

ShRNA-mediated knock-down of CXCR7 increases TRAIL-sensitivity in MCF-7 breast cancer cells.

This study aims to investigate the effects of CXCR7-shRNA on TRAIL-mediated apoptosis and suppression of invasive migration and the underlying mechanisms. (1) We constructed CXCR-7-shRNA lentiviral vectors and confirmed their silencing efficiency in MCF-7 cells by RT-PCR analysis. (2) The effects of CXCR7 and/or TRAIL on cell proliferation were examined by MTT assay. (3) Trans well invasion assay was used to examine the effects of CXCR7 silencing and/or TRAIL on MCF-7 cell invasive migration. (4) Expression of Caspase-3, and Caspase-8, and MMP-2 and MMP-9 proteins was examined by Western blot analysis. (1) Viral titers were 2.95 × 10(8) TU/ml, 3.01 × 10(8) TU/ml, 3.26 × 10(8) TU/ml, and 3.08 × 10(8) TU/ml, respectively. (2) CHXR7 shRNAs markedly decreased CXCR7 mRNA expression in MCF-7 cells, among which CXCR7-shRNA-1 showed significantly higher rate of inhibition (P < 0.05). (3) Combination of TRAIL and CXCR7-shRNA-1 resulted in marked suppression of cell proliferation in time-dependent manner (P < 0.05). (4) Cell invasion capacity was inhibited in each experimental group as compared to blank control group at 48 h post treatments (P < 0.05). Among them, combination of TRAIL and CXCR7-shRNA had the highest inhibitory effect (P < 0.05). (5) Western blot analysis indicated that TRAIL alone does not affect CXCR7 expression, but either TRAIL + CXCR7 shRNA or CXCR7 shRNA alone markedly suppressed CXCR7 protein expression. Furthermore, combination of TRAIL and CXCR-7-shRNA significantly increased Caspase-3 and Caspase-8 expression and decreased MMP-2 and MMP-9 expression (P < 0.05). Knock-down of CXCR-7 expression leads to augmented TRAIL-mediated suppression of MCF-7 cell proliferation and invasion.

Alloy nanozyme-reinforced hyaluronic acid-based hydrogel with wound environment-responsive properties for synergistically accelerating infectious wound healing.

The recovery of infectious wound tissues presents a significant global health challenge due to the impediments posed by the harsh healing microenvironment, which includes ongoing bacterial invasion, high oxidative stress, inflammatory response, and impaired angiogenesis. To overcome the above issues, we propose a composite hydrogel based on the multiple-crosslinked mechanism involving the covalent network of CC bonds within catechol and maleic-modified HA (CMHA), the self-assembly network of glycyrrhizic acid (GA), and the metal-polyphenol coordination induced by ZHMCe for accelerating infectious wound healing. The resulting CMHA/GA/ZHMCe hydrogels demonstrate enhanced mechanical, adhesive, antioxidative, and antibacterial properties. Importantly, the hydrogel system possesses wound environment-responsive properties that allow it to adapt to the specific therapeutic requirements of different stages by regulating various enzyme activities in the healing of infected wounds. Furthermore, the biocompatible CMHA/GA/ZHMCe shows the ability to promote cell migration and angiogenesis in vitro while reprogramming macrophages toward an anti-inflammatory phenotype due to the effective release of active ingredients. In vivo experiments confirm that the CMHA/GA/ZHMCe hydrogel significantly enhances infectious wound healing by accelerating re-epithelialization, promoting collagen deposition, regulating inflammation, and contributing to vascularization. These findings underscore the therapeutic potential of our hydrogel dressings for the treatment of bacterially infected cutaneous wound healing.

Short-term effect of magnesium implantation on the osteomyelitis modeled animals induced by Staphylococcus aureus.

Pure magnesium (Mg) granules were implanted into the tibial medullary cavity of osteomyelitis modeled animals after debridement, and the animals without implant were taken as the control group. The antibacterial and osteogenic effects on bone tissue during Mg degradation were evaluated through detecting Mg ions, counting bacteria culture in peripheral blood, histology and iconography. The results showed that there was no significant difference for the concentration of serum Mg between the preoperative and postoperative animals within 5 weeks, maintaining in the normal range, and the number of bacteria in bone tissue of the Mg implant group was significantly lower than that of the control group. Mg implantation showed good biocompatibility no harmful to the liver, spleen, kidney and other organs in the modeled animals. In addition, the formation rate of new bone tissues around the implanted Mg was faster, indicating that the degradation of Mg could also promote the osteogenic process with good biocompatibility.

Corrigendum: Therapy of spinal cord injury by folic acid polyethylene glycol amine-modified zeolitic imidazole framework-8 nanoparticles targeted activated M/Ms.

[This corrects the article DOI: 10.3389/fbioe.2022.959324.].

Preparation of NIR-Responsive Gold Nanocages as Efficient Carrier for Controlling Release of EGCG in Anticancer Application.

Hepatocellular carcinoma (HCC) is a type of cancer that has a restricted therapy option. Epigallocatechin gallate (EGCG) is one of the main biologically active ingredients in tea. A large number of studies have shown that EGCG has preventive and therapeutic effects on various tumors. In addition, the development of near-infrared (NIR)-responsive nano-platforms has been attracting cancer treatment. In this work, we designed and synthesized a strategy of gold nanocages (AuNCs) as an efficient carrier for controlling release of EGCG for anti-tumor to achieve the synergistic functions of NIR-response and inhibited tumor cell proliferation. The diameter of AuNCs is about 50 nm and has a hollow porous (8 nm) structure. Thermal imaging-graphic studies proved that the AuNCs-EGCG obtained have photothermal response to laser irradiation under near-infrared light and still maintain light stability after multiple cycles of laser irradiation. The resulted AuNCs-EGCG reduced the proliferation rate of HepG2 cells to 50% at 48 h. Western blot analysis showed that NIR-responsive AuNCs-EGCG can promote the expression of HepG2 cell apoptosis-related proteins HSP70, Cytochrome C, Caspase-9, Caspase-3, and Bax, while the expression of Bcl-2 is inhibited. Cell confocal microscopy analysis proved that AuNCs-EGCG irradiated by NIR significantly upregulates Caspase-3 by nearly 2-fold and downregulates Bcl-2 by nearly 0.33-fold, which is beneficial to promote HepG2 cell apoptosis. This study provides useful information for the NIR-responsive AuNCs-EGCG as a new type of nanomedicine for HCC.

Metformin Protects against Spinal Cord Injury and Cell Pyroptosis via AMPK/NLRP3 Inflammasome Pathway.

Spinal cord injury (SCI) is an extreme neurological impairment with few effective drug treatments. Pyroptosis is a recently found and proven type of programmed cell death that is characterized by a reliance on inflammatory caspases and the release of a large number of proinflammatory chemicals. Pyroptosis differs from other cell death mechanisms such as apoptosis and necrosis in terms of morphological traits, incidence, and regulatory mechanism. Pyroptosis is widely involved in the occurrence and development of SCI. In-depth research on pyroptosis will help researchers better understand its involvement in the onset, progression, and prognosis of SCI, as well as provide new therapeutic prevention and treatment options. Herein, we investigated the role of AMPK-mediated activation of the NLRP3 inflammasome in the neuroprotection of MET-regulated pyroptosis. We found that MET treatment reduced NLRP3 inflammasome activation by activating phosphorylated AMPK and reduced proinflammatory cytokine (IL-1ß, IL-6, and TNF-α) release. At the same time, MET improved motor function recovery in rats after SCI by reducing motor neuron loss in the anterior horn of the spinal cord. Taken together, our study confirmed that MET inhibits neuronal pyroptosis after SCI via the AMPK/NLRP3 signaling pathway, which is mostly dependent on the AMPK pathway increase, hence decreasing NLRP3 inflammasome activation.

Gold nanoclusters conjugated berberine reduce inflammation and alleviate neuronal apoptosis by mediating M2 polarization for spinal cord injury repair.

Spinal cord injury (SCI) leads to nerve cell apoptosis and loss of motor function. Herein, excessive activation of the M1 phenotype macrophages/microglia is found to be the main reason for the poor prognosis of SCI, but the selective activation phenotype (M2) macrophages/microglia facilitates the recovery of SCI. Thereafter, we used gold nanoclusters loaded berberine (BRB-AuNCs) to reduce inflammation by inhibiting the activation of M1 phenotype macrophages/microglia, which simultaneously inhibited neuronal apoptosis after SCI. In vitro and in vivo experiments showed that BRB-AuNCs reduced M1 protein marker CD86, increased M2 protein marker CD206, reduced inflammation and apoptotic cytokines (IL-1ß, IL-6, TNF-α, Cleaved Caspase-3 and Bax). These results indicate that BRB-AuNCs have excellent anti-inflammatory and anti-apoptotic effects by inducing the polarization of macrophages/microglia from M1 phenotype to M2 phenotype. Thereafter, the motor functions of SCI rats were significantly improved after treatment with BRB-AuNCs. This work not only provides a new way for the treatment of SCI but also broadens BRB utilization strategies.

Therapy of spinal cord injury by folic acid polyethylene glycol amine-modified zeolitic imidazole framework-8 nanoparticles targeted activated M/Ms.

Excessively activated microglia/macrophages (M/Ms) re-establish the proinflammatory microenvironment that exacerbates motor and/or sensory dysfunction after spinal cord injury (SCI). Thus, proinflammatory M/Ms-suppressed treatments may be effective strategies for SCI. However, the utilization of anti-inflammatory drugs for clinical approaches and biomedical research has side effects, such as nephrotoxicity and hepatotoxicity. In this study, we fabricated folic acid-polyethylene glycol (FA-PEG) amine-modified zeolitic imidazole framework-8 (ZIF-8) nanoparticles (FA-PEG/ZIF-8) and found that it effectively restored function in vivo. FA-PEG/ZIF-8 treatment significantly eliminated proinflammatory M/Ms without targeting other nerve cells and downregulated inflammation in the injured lesion. Furthermore, FA-PEG/ZIF-8 caused little toxicity in SCI mice compared to normal mice. These results suggest that FA-PEG/ZIF-8 has the potential to help recover from early-stage SCI by suppressing proinflammatory M/Ms.

Outcome of Humeral Shaft Fracture Treated with Intramedullary Nail and Plate Fixation.

OBJECTIVE: To compare the results of the intramedullary nail (IMN) and compression plate fixation performed for humeral shaft fracture as to determine a better option out of the two. STUDY DESIGN: Comparative study. PLACE AND DURATION OF STUDY: First Affiliated Hospital of Jinzhou Medical University, Liaoning, PR China, from October 2016 to January 2019. METHODOLOGY: Patients treated with IMN (n=26) or plate fixation (n=30) for humeral shaft fracture were included in this study. Assessment was done in terms of perioperative parameters, complications, union time, and functional outcomes. Functional outcome were compared between the two groups at each follow-up (6 weeks, 3, 6, and 12 months) and between the subsequent follow-ups in both groups using the repeated measures ANOVA. RESULTS: Intraoperative blood loss, operative time, hospital stay, and union time were significantly lower in the IMN group. There was no significant difference in the functional outcomes when it was compared between the two groups at each follow-up. However, when it was compared between subsequent follow-ups, a significant improvement was observed in both groups. Increase incidence of individual complication and reoperation were established in the plating group, but without a significant difference. Yet, the overall complications rate was significantly higher in the plating group. CONCLUSION: IMN fixation led to a significant decrease in intraoperative blood loss, shorter operating time, hospital stay, union time, and a lower rate of overall complications. Thus, IMN may be a better choice of internal fixation as it also accelerates the patients' recovery, and increases their satisfaction.

Nischarin downregulation attenuates cell injury induced by oxidative stress via Wnt signaling.

Nischarin (NISCH) is a key protein functioning as a molecular scaffold and thereby hosting interactions with several protein partners. Here, we aimed to investigate whether NISCH downregulation could protect rat pheochromocytoma (PC12) cells against oxidative stress-induced injury using a model of cell injury induced by hydrogen peroxide (H2O2). Cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis rate was evaluated using flow cytometry. The expressions of apoptosis-related proteins Bax, Bcl-2, caspase-3 and NISCH were examined via Western blot analysis and immunofluorescence staining analyses. The expressions of NISCH, glycogen synthase kinase-3ß (GSK-3ß) and T-cell factor-1 (TCF-1) were examined using Western blot analysis. The results showed that incubation of H2O2 for 48 h significantly decreased the cell viability, increased the cell apoptosis rate and the NISCH expression in PC12 cells, whereas NISCH downregulation blocked the effects of H2O2 on cells. In addition, the expression of Bcl-2 was significantly reduced, and the expression of Bax and caspase-3 were significantly increased by H2O2 treatment. However, these effects were partially inhibited by the downregulation of NISCH. Furthermore, H2O2 significantly weakened the transduction of Wnt signaling, including the increases of GSK-3ß and TCF-1 expressions and the decrease of ß-catenin expression, while NISCH downregulation attenuated the effect of H2O2 on Wnt signaling. Moreover, inhibition of the Wnt pathway further decreased the cell viability and promoted the cell apoptosis induced by H2O2 in PC12 cells. Our results suggest that NISCH downregulation may protect cells against oxidative stress-induced injury through regulating the transduction of Wnt signaling.

Zinc promotes autophagy and inhibits apoptosis through AMPK/mTOR signaling pathway after spinal cord injury.

Autophagy is a intracellular biological process that controls the homeostasis of nutrition deprivation and starvation and has been associated with the development of traumatic diseases. Zinc, an important chemical element involved in life activities, has improved nerve recovery effects through intraperitoneal injection. The purpose of this study was to probe the possible modulation of autophagy and apoptosis from the injured spinal cord and neurons by zinc administration. It was shown that zinc significantly induced the level of Beclin1 and LC3B by activating adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway. In addition, zinc suppressed apoptosis in the injured spinal cord. Taken together, these findings suggested that zinc through promoting neurons autophagy and inhibiting apoptosis.

Nischarin attenuates apoptosis induced by oxidative stress in PC12 cells.

Nischarin (NISCH) is a cytoplasmic protein known to serve an inhibitory role in breast cancer cell apoptosis, migration and invasion. Recently, NISCH has been reported to be involved in the regulation of spinal cord injury (SCI). However, the molecular mechanism is still unclear. Oxidative stress contributes to tissue injury and cell apoptosis during the development of various diseases, including SCI. The aim of the present study was to investigate the role of NISCH in the regulation of apoptosis induced by oxidative stress in PC12 cells. H2O2 was used to establish an oxidative stress model in PC12 cells. Apoptosis levels were examined using flow cytometry analysis, and the expression of NISCH, Bcl-2, Bcl-2-associated X (Bax) and caspase-3 were examined using western blot and immunofluorescence staining analyses. The results demonstrated that treatment with 100 µM H2O2 significantly increased the apoptotic rate and expression of NISCH in PC12 cells. At 48 h following incubation with 100 µM H2O2, NISCH downregulation partially inhibited apoptosis of PC12 cells. In addition, the expression of Bcl-2 was significantly reduced and the expression of Bax and caspase-3 were significantly increased by H2O2 treatment. These effects were also partially inhibited by the downregulation of NISCH. The authors of the present study therefore hypothesize that NISCH may function as a pro-apoptotic protein that participates in the regulation of oxidative stress, and NISCH downregulation may protect cells from oxidative stress-induced apoptosis.

Blockade of receptor for advanced glycation end products promotes oligodendrocyte autophagy in spinal cord injury.

Receptor for advanced glycation end product (RAGE) is involved in neuronal inflammation, cell cycle and differentiation. However, the role of RAGE in autophagy in the process of spinal cord injury (SCI) is yet unknown. The present study investigated the effect of RAGE blockade on autophagy in SCI. A rat Allen SCI model was established and the animals were micro-injected with rabbit RAGE neutralizing antibody or rabbit polyclonal Ig G immediately after the injury. The oligodendrocytes(OLs) marker, 2', 3'-cyclic nucleotide 3'-phosphodiesterase(CNPase) and autophagy-related marker microtubule associated protein light chain 3B(LC3B) were evaluated by Western blot. Furthermore, myelin basic protein (MBP) and LC3B double staining were observed in the SCI via immunofluorescence. The results showed that RAGE blockade reduced the expression of CNPase, promoted LC3B-II/I and p62 expression after SCI. In addition, the MBP/LC3B double positive oligodendrocytes-expressing LC3B was up-regulated by RAGE blockade. Moreover, RAGE blockade attenuated the neuronal survival at ventral horn after SCI. The present study revealed the role of RAGE in maintaining oligodendrocyte autophagy to promote neuronal regeneration post-SCI.

Novel Biocompatible Au Nanostars@PEG Nanoparticles for In Vivo CT Imaging and Renal Clearance Properties.

Nanoprobes are rapidly becoming potentially transformative tools on disease diagnostics for a wide range of in vivo computed tomography (CT) imaging. Compared with conventional molecular-scale contrast agents, nanoparticles (NPs) promise improved abilities for in vivo detection. In this study, novel polyethylene glycol (PEG)-functionalized Au nanoparticles with star shape (AuNS@PEG) with strong X-ray mass absorption coefficient were synthesized as CT imaging contrast agents. Experimental results revealed that AuNS@PEG nanoparticles are well constructed with ultrasmall sizes, effective metabolisability, high computed tomography value, and outstanding biocompatibility. In vivo imaging also showed that the obtained AuNS@PEG nanoparticles can be efficiently used in CT-enhanced imaging. Therefore, the synthesized contrast agent AuNS@PEG nanoparticles as a great potential candidate can be widely used for CT imaging.

The Role of Netrin-1 in Improving Functional Recovery through Autophagy Stimulation Following Spinal Cord Injury in Rats.

Our previous findings indicated that treatment with Netrin-1 could improve functional recovery through the stimulation of autophagy, by activating the AMP-activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) signaling pathway in rats following spinal cord injury (SCI). However, the underlying mechanisms were not elucidated. The purpose of this study was to investigate the underlying mechanisms by which Netrin-1 promotes autophagy and improves functional recovery after SCI. Following controlled SCI in Sprague-Dawley rats, we observed that the autophagic flux in neurons was impaired, as reflected by the accumulation of light chain 3-II (LC3-II)-positive and LC3-positive autophagosomes (APs), accompanied by the accumulation of the autophagic substrate, Sequestosome 1 (SQSTM1; also known as p62). Our results showed that treatment with Netrin-1 increases the levels of the lysosomal protease cathepsin D (CTSD) and lysosomal-associated membrane protein 1 (LAMP1), through the regulation of the nuclear localization of Transcription factor EB (TFEB) via the AMPK/mTOR signaling pathway. In addition, this enhancement of lysosomal biogenesis correlated strongly with the restoration of autophagic flux, inhibition of neural apoptosis and improved functional recovery. Suppression of lysosomal biogenesis via the inhibition of the nuclear translocation of TFEB by Compound C abolished this restoration of autophagic flux and the functional recovery effects of Netrin-1 following SCI. Taken together, these results indicate that Netrin-1 enhances lysosomal biogenesis by regulating the nuclear translocation of TFEB via the AMPK/mTOR signaling pathway. Furthermore, the enhancement of lysosomal biogenesis by Netrin-1 following SCI promotes autophagic flux and improves functional recovery in rats. Thus, the regulation of lysosomal biogenesis by modulating the nuclear localization of TFEB might be a novel approach for the treatment of SCI.