Accurate and highly sensitive detection of Alzheimer's disease-related extracellular vesicles via förster resonance energy transfer.

Alzheimer's disease (AD) is the most common neurodegenerative disease in the world and poses a huge challenge to global healthcare. Early and accurate detection of amyloid-ß (1-42) (Aß42), a key biomarker of AD, is crucial for effective diagnosis and intervention of AD. Specific or overexpressed proteins on extracellular vesicles (EVs) describe a close correlation with the occurrence and development of diseases. EVs are a very promising non-invasive biomarker for the diagnosis of AD and other diseases. As a sensitive, simple and rapid analytical method, fluorescence resonance energy transfer (FRET) has been widely applied in the detection of EVs. Herein, we developed a dual labelling strategy for simultaneously detecting EV membrane proteins of Aß42 and CD63 based on FRET pair consisting of Au nanoclusters (AuNCs) and polydopamine nanospheres (PDANSs). The constructed nanoprobe, termed EVMPFAP assay, could specifically measure the Aß42 and CD63 on EVs with excellent sensitivity, high specificity and satisfactory accuracy. The limit of detection of EVMPFAP assay was 1.4 × 103 particles mL-1 and the linear range was from 104 to 108 particles mL-1. EVMPFAP assay was successfully used to analyze plasma EVs to distinguish AD and healthy mice. We expect that EVMPFAP assay can be routinely applied for early diagnosis and development-monitoring of AD, thus facilitating the fight against AD.

MicroRNA Let-7i Regulates Innate TLR4 Pathways in Peripheral Blood Mononuclear Cells of Patients with Ankylosing Spondylitis.

Purpose: This study aimed to compare the changes in the expression of microRNA Let-7i in peripheral blood mononuclear cells (PBMCs) of patients with ankylosing spondylitis (AS) and the correlation between Let-7i and innate pro-inflammatory factors. It is necessary to search for a new biomarker to guide the prognosis of AS. Methods: A total of 10 patients with AS and 10 healthy volunteers were selected as AS and control groups, respectively. The expression levels of Let-7i, Toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB), and interferon-gamma (IFN-γ) in PBMCs were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting (WB) to explore the relationship between Let-7i and pro-inflammatory factors. Furthermore, the relationship between Let-7i and TLR4 was determined by the luciferase reporter technology. Results: The expression level of Let-7i in PBMCs of patients with AS was significantly lower than that of healthy control. The expression levels of TLR4, NF-κB, and IFN-γ in PBMCs derived from patients with AS were significantly higher than those of healthy control. The results show that Let-7i manipulation can regulate lipopolysaccharide (LPS)-induced TLR4 and IFN-γ expression in CD4+ T cells of patients with AS. The overexpression of Let-7i in T cells of patients with AS can suppress TLR4 and IFN-γ LPS-induced expression levels of cellular mRNA and protein. Let-7i can directly interfere TLR4-3'untranslated region (UTR) sequence and regulate the expression of the TLR4 gene in Jurkat T cells. Conclusion: Let-7i may be involved in the pathogenesis of AS, and Let-7i expression in PBMCs may be helpful for the diagnosis and treatment of AS in the future.

Safe engineering of cancer-associated fibroblasts enhances checkpoint blockade immunotherapy.

Abundant cancer-associated fibroblasts (CAFs) in highly fibrotic breast cancer constitute an immunosuppressive barrier for T cell activity and are closely related to the failure of immune checkpoint blockade therapy (ICB). Inspired by the similar antigen-processing capacity of CAFs to professional antigen-presenting cells (APCs), a "turning foes to friends" strategy is proposed by in situ engineering immune-suppressed CAFs into immune-activated APCs for improving response rates of ICB. To achieve safe and specific CAFs engineering in vivo, a thermochromic spatiotemporal photo-controlled gene expression nanosystem was developed by self-assembly of molten eutectic mixture, chitosan andfusion plasmid. After photoactivatable gene expression, CAFs could be engineered as APCs via co-stimulatory molecule (CD86) expression, which effectively induced activation and proliferation of antigen-specific CD8 + T cells. Meanwhile, engineered CAFs could also secrete PD-L1 trap protein in situ for ICB, avoiding potential autoimmune-like disorders caused by "off-target" effects of clinically applied PD-L1 antibody. The study demonstrated that the designed nanosystem could efficiently engineer CAFs, significantly enhance the percentages of CD8+ T cells (4-folds), result in about 85% tumor inhibition rate and 83.3% survival rate at 60 days in highly fibrotic breast cancer, further inducing long-term immune memory effects and effectively inhibiting lung metastasis.

[CT assisted morphological study of lumbar endplate].

OBJECTIVE: To study and measure the anatomic structure of lumbar vertebral endplate structure in healthy adults by computed tomography(CT) technique in order to provide a useful guidance for the optimal design and clinical application of lumbar prostheses. METHODS: Sixty healthy adults (male and female equals) were recruited for full-waist CT scan after signing the informed consent form in the imaging department of the Second Affiliated Hospital of Xi'an Jiaotong University. The scanning data was imported into the computer aided software Mimics 16.0 for 3D reconstruction and measurement. The acquisition indexes included median sagittal diameter, maximum coronal diameter, concavity depth, median sagittal depression angle, coronal depression angle and so on. Finally, the collected data were statistically analyzed by the statistical software. RESULTS: The median sagittal diameter and the maximum coronal diameter of the upper and lower endplates were not only different between the different sexes(P<0.05), but also were increased with the increase of the lumbar spine sequence. The concavity depth of upper and lower endplates had no gender differences(P>0.05), but had a little change from L1 to L5, fluctuating from 1.5 to 2.0 mm and from 2.2 to 3.9 mm, respectively. In the same sequence, the concavity depth of lower endplate in males was greater than that of upper endplate, and the difference was statistically significant(P<0.05), but there was no significant difference in the concavity depth of upper and lower endplate in females(P>0.05). Sagittal concavity angle and coronal concavity angle of upper and lower endplates changed slightly with the increase of vertebral order, and there was no gender difference in sagittal and coronal concavity angle of most vertebral sequences (P>0.05). Statistics showed that the largest concavity near the caudal lumbar endplate was located on the dorsal side of the endplate plane. CONCLUSIONS: The anatomical structure of the lumbar endplate is very complicated. It is important to master the anatomical parameters of the endplate and make full use of CT before operation for the development and clinical application of the lumbar prosthesis.

[CT assisted goat lumbar vertebrae anatomical measurement and comparison with human lumbar vertebrae].

OBJECTIVE: To study the anatomical measurement of goat lumbar vertebrae and to compare with human lumbar vertebrae, so as to build the foundation for establishing animal models of lumbar prosthesis. METHODS: The anatomical parameters of the vertebral body, pedicle and intervertebral disc in the fresh lumbar vertebrae of Boer goat and the lumbar vertebrae of healthy adults were collected by computer aided software Mimics16.0, and the anatomical characteristics of the two lumbar vertebrae were compared with the statistical software. RESULTS: The anterior vertebral body height(VBHa) of goat lumbar was less than the middle vertebral body height(VBHm), which was less than the posterior vertebral body height(VBHp), and the maximum values were (38.7±2.9), (40.1±2.6) and (40.7±2.7) mm respectively. Its endplate width was greater than its depth, with the whole shaped like a heart or a kidney. The cranial endplate of goats was convex while the caudal endplate was depressed and the depression was small, with a maximum value of (1.6±0.6) mm. The pedicle height of goats increased from L11 to L̀ with the maximum of (30.5±1.9) mm; its pedicle width and angle increased firstly and then decreased with the increase of vertebra level and the minimum values were (6.7±0.4) mm and(45.9±2.6)° respectively. The anterior intervertebral disc height was larger than the middle which was larger than the posterior and all varied slightly with the changes of intervertebral spaces; the height and width of intervertebral foramen separately waved at (12.9±0.3) to (14.3±1.0) mm and (5.7±1.0) to (6.7±0.9) mm. The comparative results showed that the vertebral body height, pedicle height and angle of goats were greater than those of humans (P<0.05) while the width and depth of the endplate, the intervertebral disc height, and etc. were significantly smaller than those of humans (P<0.05). In addition, some structures, such as the height of pedicle and intervertebral disc, also showed different changing laws with the increase of vertebra level. CONCLUSIONS: Although there are similarities in goat lumbar spine in some aspects, such as endplate and foramen foramen, there are still many differences in many aspects. Understanding the anatomical characteristics of goat lumbar vertebrae and the difference between goat and human is of great guiding significance for the research of goat prosthesis and related technology.

[Clinical effects of high frequency repeated transcranial magnetic stimulation therapy on dyskinesia in patients with incomplete spinal cord injury:a Meta-analysis].

OBJECTIVE: To systematically evaluate the clinical effect of high frequency repeated transcranial magnetic stimulation(HF rTMS)therapy on dyskinesia in patients with incomplete spinal cord injury. METHODS: Randomized controlled trials(RCTs) about HF rTMS therapy on patients with motor incomplete spinal cord injury were searched electronically in PubMed, Google scholar, Cochrane library, Clinical trial, Medline, Web of science, CNKI, VIP, and Wanfang database before October 2016. Two reviewers independently screened the literatures according to the inclusion and exclusion criteria, as well as extracted the data and assessed the methodological quality. The observed outcomes included ASIA motor score, ASIA lower extremities motor score(LEMS), Modified Ashworth score (MAS), Ten-meter walking test (10MWT) and Walking index for SCI II(WISCI II), and the outcomes were analyzed using RevMan5.2 software provided by the Cochrane information management system. RESULTS: Five RCTs involved 103 patients were included, and 61 patients(experimental group) accepted real rTMS and physical rehabilitation care for SCI, 51 patients(control group) accepted only physical rehabilitation care. There were significant differences in ASIA motor score, LEMS and 10MWT between two groups after HF rTMS therapy (statistics were Z=2.96, P=0.003; Z=3.04, P=0.002; Z=2.16, P=0.03; respectively). When stimulating the leg motor cortex, there was significant difference in MAS between two groups(Z=2.79, P=0.005), and when stimulating the vertex, there was no significant difference(Z=0.09, P=0.93). There was no significant difference in WISCI IIscore after HF rTMS therapy between two groups(Z=0.90, P=0.37). CONCLUSIONS: HF rTMS can raise motor score in patients with incomplete spinal cord injury, improve the spasticity of the lower extremities, and increase the motor ability.

Feasibility of Diffusion Tensor Imaging for Assessing Functional Recovery in Rats with Olfactory Ensheathing Cell Transplantation After Contusive Spinal Cord Injury (SCI).

BACKGROUND Olfactory ensheathing cell transplantation is a promising treatment for spinal cord injury. Diffusion tensor imaging has been applied to assess various kinds of spinal cord injury. However, it has rarely been used to evaluate the beneficial effects of olfactory ensheathing cell transplantation. This study aimed to explore the feasibility of diffusion tensor imaging in the evaluation of functional recovery in rats with olfactory ensheathing cell transplantation after contusive spinal cord injury. MATERIAL AND METHODS Immunofluorescence staining was performed to determine the purity of olfactory ensheathing cells. Rats received cell transplantation at week 1 after injury. Basso, Beattie, and Bresnahan score was used to assess the functional recovery. Magnetic resonance imaging was applied weekly, including diffusion tensor imaging. Diffusion tensor tractography was reconstructed to visualize the repair process. RESULTS The results showed that olfactory ensheathing cell transplantation increased the functional and histological recovery and restrained the secondary injury process after the initial spinal cord injury. The fractional anisotropy values in rats with cell transplantation were significantly higher than those in the control group, while the apparent diffusion coefficient values were significantly lower. Basso, Beattie, and Bresnahan score was positively and linearly correlated with fractional anisotropy value, and it was negatively and linearly correlated with apparent diffusion coefficient value. CONCLUSIONS These findings suggest that diffusion tensor imaging parameters are sensitive biomarker indices for olfactory ensheathing cell transplantation interventions, and diffusion tensor imaging scan can reflect the functional recovery promoted by the olfactory ensheathing cell transplantation after contusive spinal cord injury.

Conditioned medium of olfactory ensheathing cells promotes the functional recovery and axonal regeneration after contusive spinal cord injury.

OBJECTIVE: To investigate the effectiveness and the potential role of olfactory ensheathing cell conditioned medium (OEC-M) to treat contusive spinal cord injury (SCI). METHODS: The contusive SCI model was established by NYU weight-drop impactor at T10 segment. Male Sprague-Dawley rats received intraperitoneal injection of control medium (Con-M, n=18), low dose OEC-M (n=18) and high dose OEC-M (n=18). Immunofluorescence was performed to identify the purity of cultured OECs. BBB score was used to assess the functional recovery. BDNF concentrations of OEC-M, Con-M and rats plasma samples were determined by ELISA. Conventional MRI and diffusion tensor tractography (DTT) were applied to visualize the repair process of SCI. Diffusion tensor imaging (DTI) and immunohistochemistry of NF200 were carried out to evaluate the axonal regeneration. RESULTS: After the systemic delivery of treatment, BBB scores and BDNF levels in peripheral blood were significantly higher in OEC-M treated groups than in Con-M group. MRI and DTT demonstrated a better radiological recovery after SCI in OEC-M treated groups and higher dose of OEC-M were accompanied with better outcomes. DTI and NF200 staining revealed the OEC-M treatment promoted axonal regeneration around the injury epicenter but no axonal regeneration was observed at the lesion site. CONCLUSION: The results indicate that the OEC-M treatment improves the functional recovery and promotes the axonal regeneration around the injury epicenter after contusive SCI. This strategy represents a novel cell-free OEC based therapy to effectively treat SCI.