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Unlike mammals, adult zebrafish are capable of regenerating severed axons and regaining locomotor function after spinal cord injury. A key factor for this regenerative capacity is the innate ability of neurons to re-express growth-associated genes and regrow their axons after injury in a permissive environment. By microarray analysis, we have previously shown that the expression of legumain (also known as asparaginyl endopeptidase) is upregulated after complete transection of the spinal cord. In situ hybridization showed upregulation of legumain expression in neurons of regenerative nuclei during the phase of axon regrowth/sprouting after spinal cord injury. Upregulation of Legumain protein expression was confirmed by immunohistochemistry. Interestingly, upregulation of legumain expression was also observed in macrophages/microglia and neurons in the spinal cord caudal to the lesion site after injury. The role of legumain in locomotor function after spinal cord injury was tested by reducing Legumain expression by application of anti-sense morpholino oligonucleotides. Using two independent anti-sense morpholinos, locomotor recovery and axonal regrowth were impaired when compared with a standard control morpholino. We conclude that upregulation of legumain expression after spinal cord injury in the adult zebrafish is an essential component of the capacity of injured neurons to regrow their axons. Another feature contributing to functional recovery implicates upregulation of legumain expression in the spinal cord caudal to the injury site. In conclusion, we established for the first time a function for an unusual protease, the asparaginyl endopeptidase, in the nervous system. This study is also the first to demonstrate the importance of legumain for repair of an injured adult central nervous system of a spontaneously regenerating vertebrate and is expected to yield insights into its potential in nervous system regeneration in mammals.

BACKGROUND: Interleukin-4 (IL-4) is best known as an important mediator and modulator of immune and inflammatory responses. Hepatocellular carcinoma (HCC) is a typical inflammation-related cancer, and genetic variations in the IL-4 gene may be associated with the risk of hepatitis B virus (HBV)-related HCC. However, few studies have been conducted on their association. OBJECTIVES: To clarify the effects of IL-4 gene polymorphisms on the risk of HBV-related HCC, two common variants, -590C/T (rs2243250) and -33C/T (rs2070874), and their relationship with HBV-related disease risk were investigated in a Chinese population. METHODS: IL-4 -590C/T and -33C/T polymorphisms were examined in 154 patients with HBV-related HCC, 62 patients with HBV-induced liver cirrhosis (LC), 129 patients with chronic hepatitis B (CHB), and 94 healthy controls, using the polymerase chain reaction-restriction fragment length polymorphism method and DNA sequencing. RESULTS: Overall, no significant differences were observed regarding the IL-4 -590C/T and -33C/T polymorphism genotypes, alleles, or haplotypes between the patient groups and the healthy controls. However, the CC genotypes of IL-4 -590C/T and -33C/T polymorphisms were observed to be significantly associated with CHB in subgroup analysis in males [CC versus TT (OR: 4.193, 95% CI: 1.094-16.071, P = 0.037; and OR: 3.438, 95% CI: 1.032-11.458, P = 0.044) and CC versus TT+CT (OR: 4.09, 95% CI: 1.08-15.49, P = 0.038; and OR: 3.43, 95% CI: 1.04-11.28, P = 0.042)]. CONCLUSIONS: These findings suggest that genetic variants in IL-4 -590C/T and -33C/T polymorphisms may be a risk factor for CHB in Chinese males but not for HBV-related LC or HCC.

BACKGROUND: The diagnosis of pleural tuberculosis (TB) remains to be difficult. Interferon-gamma release assay (IGRA) is a promising method for diagnosing TB in low TB burden countries. The release of interferon-gamma (IFN-γ) by T lymphocytes increases at a localized site of infection with Mycobacterium tuberculosis antigen. This study aimed to examine the clinical accuracy of T-SPOT.TB on pleural fluid and peripheral blood for the diagnosis of pleural TB in high TB burden country. METHODS: 168 subjects with pleural effusion were enrolled prospectively and examined with T-SPOT.TB on pleural fluid and peripheral blood samples simultaneously. RESULTS: The receiver operating characteristic (ROC) curve and cut-off value of pleural fluid T-SPOT.TB was established according to spot forming cells (SFC) between culture/biopsy-confirmed pleural TB group and no pleural TB group. The sensitivity of pleural fluid T-SPOT.TB and peripheral blood T-SPOT.TB was similar (96.3% and 92.7%, respectively) (P= 0.691). In contrast, the specificity of pleural fluid T-SPOT.TB (94.5%) was significantly higher than that of peripheral blood T-SPOT.TB (76.1%) (P=0.002). 2% (2/98) of pleural fluid T-SPOT.TB results were indeterminate. CONCLUSION: The diagnostic accuracy of peripheral blood T-SPOT.TB is low in high TB burden countries due to latent tuberculosis infection. Pleural fluid T-SPOT.TB is a relatively useful and supplementary test to explore pleural TB in high TB burden countries, but its diagnostic accuracy needs to be validated in further large scale research.

Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is prevalent worldwide. Despite its limitations, serum alpha-fetoprotein (AFP) remains the most widely-used biomarker for the diagnosis of HCC. This study aimed to assess whether measurement of peripheral plasma Dickkopf-1 (DKK1) and Tie2-expressing monocytes (TEMs) could overcome the limitations of AFP and improve the diagnostic accuracy of HCC.Plasma DKK1 level and the percentage of TEMs in peripheral CD14+CD16+ monocytes from HCC patients (n = 82), HBV-related liver cirrhosis (LC) patients (n = 29), chronic hepatitis B (CHB) infected patients (n = 28) and healthy volunteers (n = 31) were analyzed by ELISA and flow cytometry. Receiver operating characteristic (ROC) curves were used to analyze a single biomarker, or a combination of two or three biomarkers. Univariate and multivariate analyses were performed to assess the significance of each marker in prediction of HCC and AFP-negative HCC from LC patients.The percentage of TEMs in peripheral CD14+CD16+ monocytes and plasma level of DKK1 in HCC group were significantly higher than those in LC, CHB and healthy control groups (all P-values 0.05). A combination of DKK1, TEMs and AFP measurements increased the AUC for HCC diagnosis as compared with either marker alone (0.833; 95%CI 0.768-0.886). The AUC for TEMs was 0.692 (95% CI 0.564-0.819) in differentiating AFP-negative HCC from LC, with a sensitivity of 80.0% and a specificity of 65.52%. Only TEMs prevailed as a significant predictor for AFP-negative HCC differentiating from LC patients in univariate and multivariate analyses (P = 0.016, P = 0.023).TEMs and DKK1 may prove to be potential complementary biomarkers for AFP in the diagnosis of HCC. TEMs rather than DKK1 could serve as a complementary biomarker for AFP in the differential diagnosis of AFP-negative HCC versus LC patients.