Sonodynamic-chemotherapy synergy with chlorin e6-based carrier-free nanoparticles for non-small cell lung cancer.

Sonodynamic therapy (SDT), an emerging cancer treatment with significant potential, offers the advantages of non-invasiveness and deep tissue penetrability. The method involves activating sonosensitizers with ultrasound to generate reactive oxygen species (ROS) capable of eradicating cancer cells, addressing the challenge faced by photodynamic therapy (PDT) where conventional light sources struggle to penetrate deep tissues, impacting treatment efficacy. This study addresses prevalent challenges in numerous nanodiagnostic and therapeutic agents, such as intricate synthesis, poor repeatability, low stability, and high cost, by introducing a streamlined one-step assembly method for nanoparticle preparation. Specifically, the sonosensitizer Chlorin e6 (Ce6) and the chemotherapy drug erlotinib are effortlessly combined and self-assembled under sonication, yielding carrier-free nanoparticles (EC-NPs) for non-small cell lung cancer (NSCLC) treatment. The resulting EC-NPs exhibit optimal drug loading capacity, a simplified preparation process, and robust stability both in vitro and in vivo, owing to their carrier-free characteristics. Under the synergistic treatment of sonodynamic therapy and chemotherapy, EC-NPs induce an excess of reactive oxygen in tumor tissue, prompting apoptosis of cancer cells and reducing their proliferative capacity. Both in vitro and in vivo experiments demonstrate superior therapeutic effects of EC-NPs under ultrasound conditions compared to free Ce6. In summary, our research findings highlight that the innovatively designed carrier-free sonosensitizer EC-NPs present a therapeutic option with commendable efficacy and minimal side effects.

Sialic Acid Conjugate-Modified Cationic Liposomal Paclitaxel for Targeted Therapy of Lung Metastasis in Breast Cancer: What a Difference the Cation Content Makes.

Cationic lipids play a pivotal role in developing novel drug delivery systems for diverse biomedical applications, owing to the success of mRNA vaccines against COVID-19 and the Phase III antitumor agent EndoTAG-1. However, the therapeutic potential of these positively charged liposomes is limited by dose-dependent toxicity. While an increased content of cationic lipids in the formulation can enhance the uptake and cytotoxicity toward tumor-associated cells, it is crucial to balance these advantages with the associated toxic side effects. In this work, we synthesized the cationic lipid HC-Y-2 and incorporated it into sialic acid (SA)-modified cationic liposomes loaded with paclitaxel to target tumor-associated immune cells efficiently. The SA-modified cationic liposomes exhibited enhanced binding affinity toward both RAW264.7 cells and 4T1 tumor cells in vitro due to the increased ratios of cationic HC-Y-2 content while effectively inhibiting 4T1 cell lung metastasis in vivo. By leveraging electrostatic forces and ligand-receptor interactions, the SA-modified cationic liposomes specifically target malignant tumor-associated immune cells such as tumor-associated macrophages (TAMs), reduce the proportion of cationic lipids in the formulation, and achieve dual objectives: high cellular uptake and potent antitumor efficacy. These findings highlight the potential advantages of this innovative approach utilizing cationic liposomes.

Learning curve of junior surgeons in robot-assisted pedicle screw placement: a comparative cohort study.

OBJECTIVE: Robot-assisted technology has been gradually applied to pedicle screw placement in spinal surgery. This study was designed to detailedly evaluate the learning curve of junior surgeons in robot-assisted spine surgery. METHODS: From December 2020 to February 2022, 199 patients requiring surgical treatment with posterior pedicle screw fixation were prospectively recruited into the study. The patients were randomized to the robot-assisted group (the RA group) or the conventional freehand group (the CF group). Under the senior specialist's supervision, pedicle screws were placed by two junior fellows without prior experience. Cumulative summation (CUSUM) analysis was performed on the learning curve of pedicle screw placement for performing quantitative assessment based on the time of screw insertion. RESULTS: In total, 769 and 788 pedicle screws were placed in the RA and CF groups. Compared with the CF group, the learning duration in the RA group was shorter in the upper thoracic region (57 vs. 70 screws), but longer in the lower thoracic (62 vs. 58 screws) and the lumbosacral region (56 vs. 48 screws). The slope of learning curve was lower in the RA group than in the CF group. The screw accuracy in the RA group was superior to that in the CF group, especially in upper thoracic region (89.4% vs. 76.7%, P < 0.001). This disparity of accuracy became wider in deformity cases. In the upper thoracic region, the mean placement time was 5.34 ± 1.96 min in the RA group and 5.52 ± 2.43 min in the CF groups, while in the lower thoracic and lumbosacral regions, the CF group's mean placement times were statistically shorter. Three screw-related neural complications occurred in the CF group. CONCLUSION: Robot-assisted technique has its advantages in the upper thoracic region and deformity cases, which is easier and safer to insert pedicle screws. The robot-assisted technique allowed a short learning curve for junior surgeons and exhibited consistently excellent results even in the early application period.

Mn-Doped Nano-Hydroxyapatites as Theranostic Agents with Tumor pH-Amplified MRI-Signal Capabilities for Guiding Photothermal Therapy.

Background: The integration of diagnostic and therapeutic functions into a biosafe nanoplatform with intelligent response functions at the tumor microenvironment (TME) is a promising strategy for cancer therapy. Methods: Mn-doped nano-hydroxyapatite (nHAPMn) nanoparticles were successfully prepared via a simple coprecipitation method for magnetic resonance imaging (MRI)-guided photothermal therapy. This study is the first to report on the use of Mn to render biodegradable hydroxyapatite suitable for MRI and effective photothermal therapy (PTT) simultaneously by regulating the pH of nHAPMn during the preparation process. Results: Combined with near-infrared (NIR) laser irradiation, a photothermal conversion efficiency of 26% and effective photothermal lethality in vitro were achieved. Moreover, the degradation of nHAPMn led to the release of Mn ions and amplified the MRI signals in an acidic TME, which confirmed that nHAPMn had a good pH-responsive MRI capacity in solid tumors. In animal experiments, tumors in the nHAPMn5+NIR group completely abated after 14 days of treatment, with no significant recurrence during the experiment. Conclusion: Therefore, nHAPMn is promising as a nanotheranostic agent and can be effective in clinical diagnosis and therapy for treating cancer.

A Novel NQO1 Enzyme-Responsive Polyurethane Nanocarrier for Redox-Triggered Intracellular Drug Release.

The design of nano-drug delivery vehicles responsive to tumor microenvironment stimuli has become a crucial aspect in developing cancer therapy in recent years. Among them, the enzyme-responsive nano-drug delivery system is particularly effective, as it utilizes tumor-specific and highly expressed enzymes as precise targets, leading to increased drug release at the target sites, reduced nonspecific release, and improved efficacy while minimizing toxic side effects on normal tissues. NAD(P)H:quinone oxidoreductase 1 (NQO1) is an important reductase associated with cancer and is overexpressed in some cancer cells, particularly in lung and breast cancer. Thus, the design of nanocarriers with high selectivity and responsiveness to NQO1 is of great significance for tumor diagnosis and treatment. It has been reported that under physiological conditions, NQO1 can specifically reduce the trimethyl-locked benzoquinone structure through a two-electron reduction, resulting in rapid lactonization via an enzymatic reaction. Based on this, a novel reduction-sensitive polyurethane (PEG-PTU-PEG) block copolymer was designed and synthesized by copolymerizing diisocyanate, a reduction-sensitive monomer (TMBQ), and poly(ethylene glycol). The successful synthesis of monomers and polymers was verified by nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). Then, the PEG-PTU-PEG micelles were successfully prepared by self-assembly, and their reductive dissociation behavior in the presence of Na2S2O4 was verified by dynamic light scattering (DLS), 1H NMR, and GPC. Next, the model drug doxorubicin (DOX) was encapsulated into the hydrophobic core of this polyurethane micelles by microemulsion method. It was observed that the drug-loaded micelles could also achieve a redox response and rapidly release the encapsulated substances. In vitro cell experiments demonstrated that PEG-PTU-PEG micelles had good biocompatibility and a low hemolysis rate (<5%). Furthermore, in the presence of an NQO1 enzyme inhibitor (dicoumarol), lower drug release from micelles was observed in A549 and 4T1 cells by both fluorescence microscopy and flow cytometry assays, but not in NIH-3T3 control cells. Predictably, DOX-loaded micelles also showed lower cytotoxicity in 4T1 cells in the presence of NQO1 enzyme inhibitors. These results indicate that drug-loaded polyurethane micelles could accomplish specific drug release in the reducing environment in the presence of NQO1 enzymes. Therefore, this study provides a new option for the construction of polyurethane nanocarriers for precise targeting and reductive release, which could benefit the intracellular drug-specific release and precision therapy of tumors.

Percutaneous Curved Vertebroplasty Versus Unipedicular Approach Vertebroplasty for Acute Osteoporotic Vertebral Compression Fractures : A Randomized Controlled Trial.

STUDY DESIGN: Prospective randomized controlled trial. OBJECTIVE: To clarify whether percutaneous curved vertebroplasty (PCVP) is superior to conventional unipedicular approach vertebroplasty (UVP) in patients with acute osteoporotic vertebral compression fractures (OVCFs). SUMMARY OF BACKGROUND DATA: Unilateral curved vertebroplasty devices were designed and applied to provide better control of cement placement, which may be superior to traditional UVP for the treatment of acute OVCFs. MATERIALS AND METHODS: Patients with single-level OVCFs of <6 weeks duration and visual analog scale (VAS) of back pain 5 or more were randomly allocated to undergo PCVP or UVP and were followed up for 1 year. The primary outcome was overall VAS scores for back pain during 12 months of follow-up. The secondary outcomes were scores on the Oswestry disability index at each postprocedure clinic visit. Radiographic (cement distribution) and surgical data (operation time, fluoroscopy frequency, and cement volume) were assessed. Complications and adverse events were recorded. RESULTS: No statistical difference was found between the PCVP and UVP groups with respect to VAS and Oswestry disability index scores at any follow-up time point. Operative time, fluoroscopy frequency, and cement leakage were similar in both groups, while the PCVP techniques had a larger injection of polymethylmethacrylate (5.5 ± 1.4 vs . 4.2 ± 1.0 mL) and a greater dispersion pattern of cement ( P < 0.001). Post hoc observations found that the analgesic effect was positively correlated with the symmetry of bone cement distribution, but not with the surgical method. Two serious adverse events occurred in the vertebroplasty group: one stress ulcer and one allergic reaction. CONCLUSIONS: Although PCVP achieved more symmetrical cement distribution, which seemed to be associated with a greater analgesic effect, PCVP did not result in significantly greater pain relief than a UVP in the 12 months after treatment.

The CRL4DCAF6 E3 ligase ubiquitinates CtBP1/2 to induce apoptotic signalling and promote intervertebral disc degeneration.

Inflammation and apoptosis are two important pathological causes of intervertebral disc degeneration (IDD). The crosstalk between these two biological processes during IDD pathogenesis remains elusive. Herein, we discovered that chronic inflammation induced apoptosis through a cullin-RING E3 ligase (CRL)-dependent mechanism. Two cullin proteins, CUL4A and 4B, recruited DNA damage-binding protein 1 (DDB1), RING-box protein 1 (RBX1) and DDB1- and CUL4-associated factor 6 (DCAF6) to assemble a CRL4DCAF6 E3 ligase in intervertebral discs (IVDs) derived from IDD patients. The CRL4DCAF6 E3 ligase ubiquitinated and degraded C-terminal-binding protein 1 and 2 (CtBP1/2), two homologues of transcriptional corepressors. The degradation of CtBP1/2 disassociated from the p300-forkhead box O3a (FOXO3a) complex, inducing the expression of B-cell lymphoma 2 (Bcl2)-binding component 3 (BBC3) and causing BBC3-dependent apoptosis. TSC01131, a small molecule that specifically targets CUL4-DDB1 interaction, could inhibit the ubiquitination of CtBP1/2 in vitro and in vivo, thereby decreasing the BBC3 expression level and preventing apoptosis signalling. Using a mouse chronic inflammation model, we found that chronic inflammation could accelerate the IDD process through a conserved CRL4DCAF6-mediated mechanism. The administration of TSC01131 to mice could significantly improve the outcome of IDD. Collectively, our results revealed that inflammation-dependent CRL4DCAF6 E3 ligase triggered apoptosis through the removal of CtBP-mediated transrepression. The blockage of the CRL4DCAF6 E3 ligase by TSC01131 may represent a new therapeutic strategy for IDD treatment. KEY MESSAGES: CUL4A and CUL4B recruited DDB1, RBX1 and DCAF6 to assemble a CRL4DCAF6 E3 ligase in human IDD biopsies. The CRL4DCAF6 E3 ligase ubiquitinated and degraded CtBP1/2, causing BBC3-dependent apoptosis. A small molecule TSC01131 that specifically targets CUL4-DDB1 interaction could inhibit the ubiquitination of CtBP1/2, improving the outcome of IDD in a mouse model.

Glucose-stimulated PGC-1α couples with CBP and Runx2 to mediate intervertebral disc degeneration through transactivation of ADAMTS4/5 in diet-induced obesity mice.

Emerging evidence suggests that type 2 diabetes mellitus (T2DM) is associated with the pathogenesis of intervertebral disc degeneration (IDD). However, it is still unclear how T2DM contributes to IDD. Herein, we observed the accumulation of blood glucose and degenerative lumbar discs in mice fed a high-fat diet. Detection of differentially expressed genes in degenerative lumbar discs revealed that ADAMTS4 (A Disintegrin and Metalloproteinase with Thrombospondin motifs) and ADAMTS5 genes were significantly increased. In vitro analyses demonstrated that Runt-Related Transcription Factor 2 (Runx2) recruited both PPARgamma Coactivator 1alpha (PGC-1α) and CREB-Binding Protein (CBP) to transactivate the expression of ADAMTS4/5. Glucose stimulation could dose-dependently induce the accumulation of PGC-1α and promoted the binding of the CBP-PGC-1α-Runx2 complex to the promoters of ADAMTS4/5. Depletion of CBP-PGC-1α-Runx2 complex members and treatment with either PGC-1α inhibitor SR-18292 or CBP inhibitor EML425 in vitro could dramatically inhibit the glucose-induced expression of ADAMTS4/5. Administration of SR-18292 and EML425 in diabetic mice could prevent the degeneration of lumbar discs. Collectively, our results revealed a molecular mechanism by which the hyperglycemia-dependent CBP-PGC-1α-Runx2 complex was required for the transactivation of ADAMTS4/5. The blockage of this complex in diabetic mice may help prevent IDD.

Hydrothermal Synthesis and In Vivo Fluorescent Bioimaging Application of Eu3+/Gd3+ Co-Doped Fluoroapatite Nanocrystals.

In this study, Eu3+/Gd3+ co-doped fluoroapatitååe (Eu/Gd:FAP) nanocrystals were synthesized by the hydrothermal method as a fluorescent bioimaging agent. The phase composition, morphology, fluorescence, and biosafety of the resulting samples were characterized. Moreover, the in vivo fluorescent bioimaging application of Eu/Gd:FAP nanocrystals was evaluated in mice with subcutaneously transplanted tumors. The results showed that the Eu/Gd:FAP nanocrystals were short rod-like particles with a size of 59.27 ± 13.34 nm × 18.69 ± 3.32 nm. With an increasing F substitution content, the Eu/Gd:FAP nanocrystals displayed a decreased size and enhanced fluorescence emission. Eu/Gd:FAP nanocrystals did not show hemolysis and cytotoxicity, indicating good biocompatibility. In vivo fluorescent bioimaging study demonstrated that Eu/Gd:FAP nanocrystals could be used as a bioimaging agent and displayed stable fluorescence emitting in tumors, indicating an accumulation in tumor tissue due to the passive targeting ability. In addition, any adverse effects of Eu/Gd:FAP nanocrystals on major organs were not observed. This study shows that biocompatible rare earth co-doped FAP nanocrystals have the potential to be used as a bioimaging agent in vivo.

Comparison of Accuracy and Clinical Outcomes of Robot-Assisted Versus Fluoroscopy-Guided Pedicle Screw Placement in Posterior Cervical Surgery.

STUDY DESIGN: This was a prospective controlled study. OBJECTIVE: To compare the accuracy and clinical outcomes of robot-assisted (RA) and fluoroscopy-guided (FG) pedicle screw placement in posterior cervical surgery. METHODS: This study included 58 patients. The primary outcome measures were the 1-time success rate and the accuracy of pedicle screw placement according to the Gertzbein-Robbins scales. The secondary outcome measures, including the operative time, intraoperative blood loss, hospital stay, cumulative radiation time, radiation dose, intraoperative advent events, and postoperative complications, were recorded and analyzed. The Japanese Orthopedics Association (JOA) scores and Neck Disability Index (NDI) were used to assess the neurological function of patients before and at 3 and 6 months after surgery. RESULTS: The rate of grade A was significantly higher in the RA group than in the FG group (90.6% and 71.1%; P < .001). The clinically acceptable accuracy was 97.2% in the RA group and 90.7% in the FG group (P = .009). Moreover, the 1-time success rate was significantly higher in the RA group than in the FG group. The RA group had less radiation time (P < .001) and less radiation dose (P = .002) but longer operative time (P = .001). There were no significant differences in terms of intraoperative blood loss, hospital stay, intraoperative adverse events, postoperative complications, JOA scores, and NDI scores at each follow-up time point between the 2 groups. CONCLUSIONS: The RA technique achieved higher accuracy and 1-time success rate of pedicle screw placement in posterior cervical surgery while achieving comparable clinical outcomes.

miR-29a and the PTEN-GSK3ß axis are involved in aluminum-induced damage to primary hippocampal neuronal networks.

We previously reported that aluminum (Al) can cause a range of neurotoxic injuries including progressive irreversible synaptic structural damage and synaptic dysfunction, and eventually neuronal deaths. Mechanism of Al-induced electrophysiological and neuronal connectivity changes in neurons may indicate damage to the neuronal network. Here, mouse primary hippocampal neurons were cultured on micro-electrode array (MEA)- and high-content analysis (HCA)-related plates, showing that Al exposure significantly inhibited hippocampal neuronal electrical spike activity and neurite outgrowth characterized by a reduction in neurite branching and a decrease in the average total neurite length in relation to both Al dose and time of incubation. In recent years, miR-29a/ phosphatase and tensin homolog (PTEN) have been found to play pivotal roles in the morphogenesis of neurons, it has been confirmed in vitro and in vivo that the PTEN-Glycogen synthase kinase-3ß (GSK-3ß) axis regulates neurite outgrowth. The present study demonstrated that increases in Al exposure and dose gradually reduce miR-29a expression. Up-regulation of miR-29a in the hippocampal neurons by lentivirus transfection reversed the decrease in electrical spike activity and the reduction in both neurite branching and length induced by Al. Moreover, miR-29a suppressed the expression of PTEN and increased the level of phosphorylated Protein Kinase B (p-AKT) and p-GSK-3ß which were inhibited by the Al treatment. This suggests that miR-29a is critically involved in the functional and structural neuronal damage induced by Al and is a potential target for Al neurotoxicity. Moreover, the reduction of neurite length and branching induced by Al exposure was regulated by miR-29a and its target neuronal PTEN-GSK3ß signaling pathway, which also represents a possible mechanism of Al-induced the inhibition of the electrical activity. Collectively, Al-induced damage to the neuronal network occurred through miR-29a-mediated alterations of the PTEN-GSK3ß signaling pathway.

Relationship between the expression of TNFR1-RIP1/RIP3 in peripheral blood and cognitive function in occupational Al-exposed workers: A mediation effect study.

Aluminium (Al), not essential for biological activities, accumulates in the tissues. It exerts toxic effects on the nervous system, inducing in humans' irreversible cognitive impairment. In this study, a cluster sampling method was used to observe the cognitive function of long-term occupational Al-exposed workers in a large Al factory, and determine the expression of peripheral blood tumour necrosis factor receptor 1 (TNFR1), receptor-interacting protein 1 (RIP1), and RIP3. TNF-alpha, expressed in blood macrophages and microglia, with its receptors TNFR1, TR1 and TR3, enhances the necroptosis of neurons. Additionally, the relationship between the expression of TNFR1, RIP1, and RIP3 in the peripheral blood of long-term occupational Al-exposed workers and changes in their cognitive function was explored. The differences in the distributions of clock drawing test (CDT) scores among the three groups were statistically significant (P < 0.05). The results of correlation analysis showed that RIP1 and RIP3 protein contents were negatively correlated with mini-mental state examination (MMSE) and CDT scores (P < 0.05). Plasma Al content was positively correlated with other biological indicators (P < 0.05), and negatively correlated with MMSE and CDT scores (P < 0.05). Results showed that RIP3 protein had an incomplete mediation effect between plasma Al content and cognitive function. This suggests that Al may affect cognitive function by influencing the expression of TNFR1, RIP1, and RIP3 in the nervous system.

Inclination of the small laminar slope angle leads to lumbar spinal stenosis due to hypertrophy of the ligamentum flavum.

OBJECTIVE: This study was designed to investigate the relationship between the laminar slope angle (LSA) and the lumbar disc degenerative grade, the cross-section area (CSA) of multifidus muscle, the muscle-fat index, and the thickness of the ligamentum flavum. METHODS: Retrospective analysis of 122 patients who were scheduled to undergo a lumbar operation for diagnoses associated with degenerative lumbar disease between January and December 2017. The L4-L5 disc grade was evaluated from preoperative sagittal T2-weighed magnetic resonance imaging of the lumber region; the CSA of the multifidus and muscle-fat index were measured at the L4 level, while the thickness of the ligamentum flavum was measured at the L4-L5 facet level from axis T2-weighed magnetic resonance imaging. The slope of the laminar was evaluated from preoperative three-dimensional computer tomography at the tip level of the facet joints and selected by the axis plane. Independent-sample T-tests were used to assess the association between age and measurement indices. RESULTS: Our results showed that age was positively connected with the LSA of L4 and L5 in different patients, although there was no significant difference between age and the difference of the two segment LSA. Partial correlation analysis, excluding the interference of age, revealed a strong negative relationship between the LSA of L4 and the thickness of the ligamentum flavum, irrespective of whether we considered the left or right. However, there was no correlation with lumbar disc degenerative grade, the CSA of the multifidus, and the muscle-fat index. CONCLUSION: The thickness of the ligamentum flavum showed changes with anatomical differences in the LSA, but not the lumbar disc degenerative grade, the CSA of the multifidus, and the muscle-fat index. A small change in LSA may cause large mechanical stress; this may be one of the causative factors responsible for lumbar spinal stenosis.

Robot-assisted minimally invasive transforaminal lumbar interbody fusion versus open transforaminal lumbar interbody fusion: a retrospective matched-control analysis for clinical and quality-of-life outcomes.

Aim: To compare the screw accuracy and clinical outcomes between robot-assisted minimally invasive transforaminal lumbar interbody fusion (RA MIS-TLIF) and open TLIF in the treatment of one-level lumbar degenerative disease. Materials & methods: From May 2018 to December 2019, a consecutive series of patients undergoing robot-assisted minimally invasive one-level lumbar fusion procedures were retrospectively compared with matched controls who underwent one-level open TLIF procedures for clinical and quality-of-life outcomes. Results: A total of 52 patients underwent RA MIS-TLIF procedures (robot-assisted [RA] group) and 52 matched controls received freehand open TLIF procedures (open [OP] group). The RA group had more grade A screws with 96.2% one-time success rate of screw placement (p < 0.05). Besides, the RA group experienced less intraoperative blood loss and shorter length of hospital stay, while the OP group had shorter operative duration and cumulative radiation time (p < 0.001). What is more, the average VAS score for low back pain and ODI score in the RA group were lower than that in the OP group 1 month after operation (p < 0.05). Conclusion: The use of real-time, image-guided robot system may further expand the advantages of MIS-TLIF technique in terms of accuracy and safety.

ISSLS prize in basic science 2021: a novel inducible system to regulate transgene expression of TIMP1.

PURPOSE: Inflammatory and oxidative stress upregulates matrix metalloproteinase (MMP) activity, leading to intervertebral disc degeneration (IDD). Gene therapy using human tissue inhibitor of metalloproteinase 1 (hTIMP1) has effectively treated IDD in animal models. However, persistent unregulated transgene expression may have negative side effects. We developed a recombinant adeno-associated viral (AAV) gene vector, AAV-NFκB-hTIMP1, that only expresses the hTIMP1 transgene under conditions of stress. METHODS: Rabbit disc cells were transfected or transduced with AAV-CMV-hTIMP1, which constitutively expresses hTIMP1, or AAV-NFκB-hTIMP1. Disc cells were selectively treated with IL-1ß. NFκB activation was verified by nuclear translocation. hTIMP1 mRNA and protein expression were measured by RT-PCR and ELISA, respectively. MMP activity was measured by following cleavage of a fluorogenic substrate. RESULTS: IL-1ß stimulation activated NFκB demonstrating that IL-1ß was a surrogate for inflammatory stress. Stimulating AAV-NFκB-hTIMP1 cells with IL-1ß increased hTIMP1 expression compared to unstimulated cells. AAV-CMV-hTIMP1 cells demonstrated high levels of hTIMP1 expression regardless of IL-1ß stimulation. hTIMP1 expression was comparable between IL-1ß stimulated AAV-NFκB-hTIMP1 cells and AAV-CMV-hTIMP1 cells. MMP activity was decreased in AAV-NFκB-hTIMP1 cells compared to baseline levels or cells exposed to IL-1ß. CONCLUSION: AAV-NFκB-hTIMP1 is a novel inducible transgene delivery system. NFκB regulatory elements ensure that hTIMP1 expression occurs only with inflammation, which is central to IDD development. Unlike previous inducible systems, the AAV-NFκB-hTIMP1 construct is dependent on endogenous factors, which minimizes potential side effects caused by constitutive transgene overexpression. It also prevents the unnecessary production of transgene products in cells that do not require therapy.

Regulation of mGluR1 on the Expression of PKC and NMDAR in Aluminum-Exposed PC12 Cells.

Aluminum demonstrates clear neurotoxicity and can cause Alzheimer's disease (AD)-like symptoms, including cognitive impairment. One toxic effect of aluminum is a decrease in synaptic plasticity, but the specific mechanism remains unclear. In this study, PC12 cells were treated with Al(mal)3 to construct a toxic cell model. (S)-3,5-Dihydroxyphenylglycine (DHPG), α-methyl-4-carboxyphenylglycine (MCPG), and mGluR1-siRNA were used to interfere with the expression of metabotropic glutamate receptor subtype 1 (mGluR1). Polymerase chain reaction and western blotting were used to investigate the expression of mGluR1, protein kinase C (PKC), and N-methyl-D-aspartate receptor (NMDAR) subunits. ELISA was used to detect PKC enzyme activity. In PC12 cells, mRNA and protein expressions of PKC and NMDAR subunits were inhibited by Al(mal)3. Aluminum may further regulate the expression of NMDAR1 and NMDAR2B through mGluR1 to regulate PKC enzyme activity, thereby affecting learning and memory functions. Furthermore, the results implied that the mGluR1-PKC-NMDAR signaling pathway may predominately involve positive regulation. These findings provide new targets for studying the neurotoxic mechanism of aluminum.

The GSK-3ß/ß-Catenin Signaling-Mediated Brain-Derived Neurotrophic Factor Pathway Is Involved in Aluminum-Induced Impairment of Hippocampal LTP In Vivo.

The neurotoxic effects of aluminum (Al) are associated with the impairment of synaptic plasticity, the biological basis of learning and memory, the major form of which is long-term potentiation (LTP). The canonical glycogen synthase kinase-3ß (GSK-3ß)/ß-catenin signaling-mediated brain-derived neurotrophic factor (BDNF) pathway has been suggested to play important roles in memory. Thus, Al may affect LTP through this pathway. In this study, a Sprague-Dawley rat model of neurotoxicity was established through intracerebroventricular (i.c.v.) injection of aluminum maltol (Al(mal)3), which was achieved by preimplantation of a cannula into the lateral ventricle. The rats in the control and Al-treated groups received a daily injection of SB216763, an inhibitor of GSK-3ß. Electrophysiology and western blot analysis were used to investigate the regulatory effect of the GSK-3ß/ß-catenin signaling-mediated BDNF pathway on LTP impairment induced by Al(mal)3. The results confirmed that i.c.v. injection of Al(mal)3 significantly suppressed the field excitatory postsynaptic potential (fEPSP) amplitude, as indicated by a decrease in BDNF protein expression, which was accompanied by dose-dependent decreases in ß-catenin protein expression and the phosphorylation of GSK-3ß at Ser9. Rats that received SB216763, a GSK-3ß inhibitor, exhibited higher fEPSP amplitudes than control rats. Furthermore, SB216763 treatment upregulated the hippocampal protein expression of BDNF and ß-catenin while increasing the ratio of p-GSK-3ß/GSK-3ß. From the perspective of the identified ß-catenin-BDNF axis, Al impairs hippocampal LTP, possibly through the GSK-3ß/ß-catenin signaling-mediated BDNF pathway.

Effect of aluminum combined with ApoEε4 on Tau phosphorylation and Aß deposition.

BACKGROUND: Aluminum is an environmental neurotoxin widely exposed to animals and humans. Studies have shown that Alzheimer's disease (AD) is characterized by abnormally phosphorylated tau and Aß deposition, aluminum exposure can lead to abnormal phosphorylated tau and Aß deposition. Numerous epidemiological data and studies have confirmed that ApoEε4 is a risk factor for AD. However, whether there is an interaction effect between aluminum and ApoEε4 has yet to be verified. METHODS: SH-SY5Y cells were exposed with AlCl3 and transfected with ApoEε4 respectively. The experimental groups included the blank control group, the low dose group (200 µM AlCl3), the medium dose group (400 µM AlCl3), the high dose group (800 µM AlCl3), empty plasmid group, ApoEε4 group and 400 µM AlCl3+ApoEε4 group. The cell viability was determined by CCK-8 kit after transfection for 48 h.The contents of total tau proteins, tau-181, tau-231, tau-262, tau-396 and Aß42, were determined by ELISA kit. The interaction between AlCl3 and ApoEε4 was analyzed by factorial design. RESULTS: With the increase of aluminum exposure, SH-SY5Y cell viability decreased, and the expression of the total tau, tau-181, tau-231, tau-262, tau-396 and Aß content increased. The viability of cells transfected with ApoEε4 is significantly lower than control group, and the expressions of total tau, tau-181, tau-231, tau-262, tau-396 and Aß in ApoEε4 transfected cells were significantly higher than control group. The viability of cells treated with AlCl3 plus ApoEε4 was lower than those treated with, either AlCl3, or ApoEε4. The expression of total tau, tau-181, tau-231, tau-262, tau-396 and Aß in the cells treated with AlCl3 plus ApoEε4 were significantly higher than those in other groups (p < 0.05). Moreover, analyzing data based on the factorial design, there was existed an interaction between AlCl3 and ApoEε4 (p < 0.05). CONCLUSION: Al and ApoEε4 gene can cause morphological changes of SH-SY5Y cells, reduce cell activity, and have obvious cytotoxic effects, and increase the phosphorylation levels of tau and the deposition of Aß increases. In the presence of both Al and ApoEε4 genes, the two factors interact with each other and show a synergistic effect.

Robot-assisted orthopedic surgery in the treatment of adult degenerative scoliosis: a preliminary clinical report.

STUDY DESIGN: A single-institution, retrospective cohort study. OBJECTIVE: To compare the accuracy and short-term clinical outcomes of pedicle screw placement between robot-assisted (RA) and freehand (FH) technique in the treatment of adult degenerative scoliosis (ADS). METHODS: From February 2018 to October 2019, 97 adult patients with degenerative scoliosis admitted to our department were retrospectively reviewed. Thirty-one patients received robot-assisted pedicle screw placement (RA group), and 66 patients underwent freehand pedicle screw placement (FH group). Patient demographics and short-term clinical outcomes were recorded and compared between two groups. Gertzbein-Robbins grading system was adopted to evaluate the accuracy of pedicle screw placement by means of postoperative CT scan. Short-term clinical outcomes consist of operative time, intraoperative blood loss, length of hospital stay (LOS), radiological parameters, Scoliosis Research Society-22 (SRS-22) scores before the operation, 6 months after operation, adverse events, and revisions. RESULTS: The accuracy of screw placement was higher than that of the FH group (clinically acceptable 98.7% vs. 92.2%; P< 0.001). Intraoperative blood loss of the RA group was less than those in the FH group (499 vs. 573 ml; P < 0.001). Operative time (283.1 vs. 291.9 min; P = 0.31) and length of stay (12.8 vs. 13.7 days; P = 0.36) were compared between RA and FH groups. In terms of radiological parameters, both of groups were improved postoperatively. The SRS-22 scores at 6 months after operation from both groups were better than those before operation. For surgery-related complication, one case had pressure sores in the RA group while two cases developed dural tears in the FH group. No revision was required in both groups. CONCLUSION: Combined with other surgical correction modalities, robot-assisted pedicle screw fixation is an effective and safe method of treating degenerative scoliosis. Due to its satisfactory surgical outcomes such as higher accuracy and less trauma, it provides a good alternative for clinical practice. LEVEL OF EVIDENCE: 3.

Antinociceptive effect of intrathecal injection of miR-9-5p modified mouse bone marrow mesenchymal stem cells on a mouse model of bone cancer pain.

BACKGROUND: A growing body of studies have indicated that bone marrow mesenchymal stem cells (BMSCs) have powerful analgesic effects in animal models of bone cancer pain. Here, we explored the molecular mechanisms underlying how BMSCs alleviate pain sensation in a mouse model of bone cancer pain. METHODS: C3H/HeN adult male mice were used to generate a bone cancer pain model. BMSCs were isolated from mouse bone marrow, modified by transfection with microRNA-9-5p (miR-9-5p), and infused into the spinal cord. Spontaneous flinches, paw withdrawal latency, limb-use score, and weight-bearing score were used to assess pain-related behaviors. ELISA, RT-PCR, western blot, and luciferase assay were used to assess gene expressions. RESULTS: Our results show that miR-9-5p regulated the expression of both repressor element silencing transcription factor (REST) and µ-opioid receptors (MOR) by targeting REST in primary mouse BMSCs. Overexpression of miR-9-5p reversed the activation of inflammatory pathway in TNF-α- and IL-6-treated BMSCs. In addition, miR-9-5p modified BMSCs alleviated cancer pain in the sarcoma-inoculated mouse model. MiR-9-5p modified BMSCs suppressed cytokine expression in the spinal cord of sarcoma-inoculated mice by suppressing REST gene expression. CONCLUSIONS: Our results indicate that miR-9-5p modified BMSCs can relieve bone cancer pain via modulating neuroinflammation in the central nervous system, suggesting genetically modified BMSCs could be a promising cell therapy in pain management.