Effects of Fluid Shear Stress on Human Intervertebral Disc Nucleus Pulposus Cells Based on Label-Free Quantitative Proteomics.

Objective: To explore the possible mechanism of fluid shear stress on human nucleus pulposus cells based on label-free proteomics technology. Methods: The human nucleus pulposus cell line was purchased and subcultured in vitro. The Flexcell STR-4000 multiflow field cell fluid shear stress loading culture system was used to apply continuous laminar fluid shear stress (12 dyne/cm2, 45 mins) to the monolayer adherent cells. Those without mechanical loading were used as the control group, and those subjected to fluid shear loading were used as the experimental group. Differential protein expression was identified using mass spectrometry identification technology, and bioinformatics analysis was performed using Gene Ontology GO (Gene Ontology) and Kyoto Encyclopedia of Genes and Genomes KEGG (Kyoto Encyclopedia of Genes and Genomes). Results: The proteomics results of the experimental group and the control group showed that the total number of mass spectra was 638653, the number of matched mass spectra was 170110, the total number of identified peptides was 32050, the specific peptide was 30564, and the total number of identified proteins was 4745. Comparing the two groups, 47 proteins were significantly differentially expressed, namely, 25 upregulated proteins and 22 downregulated proteins. Bioinformatics analysis showed that significantly different proteins were mainly manifested in cellular process, biological regulation, metabolic process, binding, catalytic activity, cellular components (cell part), organelle part (organelle part), and other molecular biological functions. Conclusion: Using proteomics technology to screen human nucleus pulposus cells after fluid shear stress loading, the differential protein expression provides a basis for further exploration of the mechanism of mechanical factors on nucleus pulposus.

Decreased Adiponectin Levels Are a Risk Factor for Cognitive Decline in Spinal Cord Injury.

OBJECTIVE: Spinal cord injury (SCI) has become popular in recent years, and cognitive decline is a common complication. Adiponectin is a common protein hormone involved in the course of many diseases, but its relationship with SCI has not yet been elucidated. The purpose of our prospective study is to explore whether adiponectin can be used as a biomarker of cognitive decline in SCI. METHODS: A total of 64 healthy volunteers and 92 patients with acute SCI were recruited by us. Serum adiponectin levels, demographic data (age and gender), lifestyle (smoking and drinking), medical history (diabetes and hypertension), and clinical baseline data (low-density lipoprotein, high-density lipoprotein, and fasting blood glucose) were recorded. Three months after enrollment, we used the Montreal Cognitive Assessment (MoCA) to evaluate cognitive function. Based on a quarter of the serum adiponectin levels, SCI patients were divided into 4 groups, and the differences in their MoCA scores were compared. In addition, we used multivariate linear regression to predict the risk factors of the MoCA score. RESULTS: The serum adiponectin level (6.1 ± 1.1 µg/ml) of SCI patients was significantly lower than that of the healthy control group (6.7 ± 0.9 µg/ml), and there was a significant difference between the two (p < 0.001). The group with higher serum adiponectin levels after 3 months of spinal cord injury had higher MoCA scores. Multivariate regression analysis showed that serum adiponectin level is a protective factor for cognitive function after SCI (ß = 0.210, p = 0.043). CONCLUSIONS: Serum adiponectin levels can be used as an independent predictor of cognitive function in patients with acute SCI.

Expression of ANGPTL4 in Nucleus Pulposus Tissues Is Associated with Intervertebral Disc Degeneration.

OBJECTIVE: Angiopoietin-like protein 4 (ANGPTL4), encoding a glycosylated secreted protein, has been reported to be closely related to many kinds of diseases, including diabetes, tumor, and some musculoskeletal pathologies, such as rheumatoid arthritis, osteoarthritis, and osteoporosis. The aim of the current study is to investigate the role of ANGPTL4 in intervertebral disc degeneration and analyze the association of ANGPTL4 expression with Pfirrmann grades. METHODS: A total of 162 nucleus pulposus tissues were collected from lumbar intervertebral disc herniation patients undergoing interforaminal endoscopic surgery. Real-time quantitative PCR and western blot were performed to determine the mRNA and protein expression of ANGPTL4 in nucleus pulposus samples. Statistical analysis was performed to analyze the association of ANGPTL4 expression with Pfirrmann grades. RESULTS: Based on the clinical data of 162 patients, results showed that Pfirrmann grades were significantly associated with patients' age (r = 0.162, P = 0.047) and were not significantly associated with patients' gender (P > 0.05). RT-qPCR and western blot results showed that the mRNA (r = 0.287, P < 0.05) and protein (r = 0.356, P < 0.05) expressions of ANGPTL4 were both closely associated with Pfirrmann grades. The expression of ANGPTL4 was remarkably increased in the groups of high IVDD Pfirrmann grades. CONCLUSION: The results demonstrated that ANGPTL4 expression was positively associated with the Pfirrmann grades and the severity of intervertebral disc degeneration. ANGPTL4 may be served as a candidate biomarker for intervertebral disc degeneration.

Therapeutic potential of enhancer of zeste homolog 2 in autoimmune diseases.

Introduction: Autoimmune diseases (ADs) are idiopathic and heterogeneous disorders with contentious pathophysiology. Great strides have been made in epigenetics and its involvement in ADs. Zeste homolog 2 (EZH2) has sparked extensive interest because of its pleiotropic roles in distinct pathologic contexts.Areas covered: This review summarizes the epigenetic functions and the biological significance of EZH2 in the etiology of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), inflammatory bowel disease (IBD), multiple sclerosis (MS), and systemic sclerosis (SSc). A brief recapitulation of the therapeutic potential of EZH2 targeting is provided.Expert opinion: There are questions marks and controversies surrounding the feasibility and safety of EZH2 targeting; it is recommended in RA and SLE, but queried in T1D, IBD, MS, and SSc. Future work should focus on contrast studies, systematic analyses and preclinical studies with optimizing methodologies. Selective research studies conducted in a stage-dependent manner are necessary because of the relapsing-remitting clinical paradigms.

[Isolation and biological characterization of human amniotic fluid-derived stem cells].

OBJECTIVE: To establish in vitro culture procedure for human amniotic fluid-derived CD117 positive stem cells, and to identify the characteristics of CD117 positive stem cells. METHODS: 86 amniotic fluid samples (10 mL of each) were obtained by second-trimester amniocentesis. Isolation of amniotic fluid-derived stem cells expressing CD117 antigen was performed via magnetic cell sorting using the CD117 MicroBead Kit. The karyotype of CD117 positive stem cells was analysed through repeated freezing. Adipogenic differentiation of these CD117 positive stem cells was displayed by Oil Red O staining. Osteogeneic differentiation of these CD117 positive stem cells was confirmed by Alizarin Red staining. RESULTS: The CD117 positive stem cells were successfully isolated and cultured from 61 samples, with all showing normal karyotype. Product analysis of specific staining confirmed that under specific culture mediums, these cells could be successfully induced to differentiate into adipocytes and osteocytes. CONCLUSION: Based on this study, we estimate that isolating CD117 positive stem cells from second-trimester amniotic fluid obtained by amniocentesis has a success rate of 70.93%. These cells maintain morphological and genetic stability in vitro. Human amniotic fluid-derived CD117 positive stem cells have the ability to differentiate in vitro into adipocytes and osteocytes under specific culture mediums and may be applied in cell transplantation and regenerative medicine.