Deficiency in the mRNA export mediator Gle1 impairs Schwann cell development in the zebrafish embryo

GLE1 mutations cause lethal congenital contracture syndrome 1 (LCCS1), a severe autosomal recessive fetal motor neuron disease, and more recently have been associated with amyotrophic lateral sclerosis (ALS). The gene encodes a highly conserved protein with an essential role in mRNA export. The mechanism linking Gle1 function to motor neuron degeneration in humans has not been elucidated, but increasing evidence implicates abnormal RNA processing as a key event in the pathogenesis of several motor neuron diseases. Homozygous gle1(-/-) mutant zebrafish display various aspects of LCCS, showing severe developmental abnormalities including motor neuron arborization defects and embryonic lethality. A previous gene expression study on spinal cord from LCCS fetuses indicated that oligodendrocyte dysfunction may be an important factor in LCCS. We therefore set out to investigate the development of myelinating glia in gle1(-/-) mutant zebrafish embryos. While expression of myelin basic protein (mbp) in hindbrain oligodendrocytes appeared relatively normal, our studies revealed a prominent defect in Schwann cell precursor proliferation and differentiation in the posterior lateral line nerve. Other genes mutated in LCCS have important roles in Schwann cell development, thereby suggesting that Schwann cell deficits may be a common factor in LCCS pathogenesis. These findings illustrate the potential importance of glial cells such as myelinating Schwann cells in motor neuron diseases linked to RNA processing defects.

Th17 cytokines regulate osteoclastogenesis in rheumatoid arthritis

This study determined the effect of type 17 helper T-cell (Th17) cytokines on osteoclastogenesis in rheumatoid arthritis (RA). The expression of IL-17 and receptor activator of NF-κB ligand (RANKL) was determined in synovial tissue, fibroblast-like synoviocytes (FLSs), and synovial fluids of RA patients using immunostaining and enzyme-linked immunosorbent assay. Th17 cytokine-induced RANKL expression was studied in RA FLS by using real-time PCR, luciferase activity assays, and Western blot analysis. Human peripheral blood monocytes were cultured with macrophage colony-stimulating factor and Th17 cytokines, after which osteoclastogenesis was evaluated by counting the number of tartrate-resistant acid phosphatase-positive multinucleated cells. Osteoclastogenesis was also evaluated after monocytes were co-cultured with IL-17-prestimulated FLS. There was significant correlation between RANKL and IL-17 levels in RA synovial fluid. IL-17, IL-21, and IL-22 increased the expression of Rankl mRNA in RA FLS, and the IL-17-induced RANKL expression decreased by the inhibition of Act1, tumor necrosis factor receptor-associated factor 6, NF-κB, and activator protein-1. Th17 cytokines and IL-17-prestimulated FLS induced osteoclastogenesis from monocytes in the absence of exogenous RANKL. The osteoclastic effect was reduced by inhibition of tumor necrosis factor-α. Th17 cytokines have a dual effect on osteoclastogenesis in RA: direct induction of osteoclastogenesis from monocytes and up-regulation of RANKL production in RA FLS. This Th17 cytokine/RANKL axis could be a potential therapeutic target for bone destruction in RA.

The effect of vascular endothelial growth factor on osteoclastogenesis in rheumatoid arthritis

Vascular endothelial growth factor (VEGF) has angiogenic, inflammatory, and bone-destructive roles in rheumatoid arthritis (RA). We aimed to determine the unique role of VEGF in osteoclastogenesis in RA. VEGF-induced receptor activator of nuclear factor ҡB ligand (RANKL) expression was determined in RA synovial fibroblasts by real-time PCR, luciferase assays, and ELISA. Osteoclastogenesis in peripheral blood monocytes cultured with VEGF was assessed by determining the numbers of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells. Synovial fluid RANKL was correlated with VEGF concentration in the RA patients. VEGF stimulated the expression of RANKL in RA synovial fibroblasts. The RANKL promoter activity was upregulated by VEGF in the synovial fibroblasts transfected with RANKL-reporter plasmids. The VEGF-induced RANKL expression was decreased by the inhibition of both VEGF receptors (VEGFR) 1 and 2, Src, protein kinase C (PKC) and p38 MAPK. VEGF induced osteoclast differentiation from monocytes in the absence of RANKL and this was decreased by the inhibition of VEGFR1 and 2, Src, PKC and p38 MAPK. On coculturing with VEGF-prestimulated RA synovial fibroblasts, the monocytes differentiated into osteoclasts, and the osteoclastogenesis decreased by inhibition of Src and PKC pathways. VEGF plays dual roles on osteoclastogenesis in RA: direct induction of osteoclastogenesis from the precursors and stimulation of RANKL production in synovial fibroblasts, which is mediated by Src and PKC pathways. The axis of VEGF and RANKL could be a potential therapeutic target for RA-associated bone destruction.

Role of C-reactive protein in osteoclastogenesis in rheumatoid arthritis

Introduction

C-reactive protein (CRP) is one of the biomarkers for the diagnosis and assessment of disease activity in rheumatoid arthritis (RA). CRP is not only the by-product of inflammatory response, but also plays proinflammatory and prothrombotic roles. The aim of this study was to determine the role of CRP on bone destruction in RA.

Methods

CRP levels in RA synovial fluid (SF) and serum were measured using the immunoturbidimetric method. The expression of CRP in RA synovium was assessed using immunohistochemical staining. CD14+ monocytes from peripheral blood were cultured with CRP, and receptor activator of nuclear factor-κB ligand (RANKL) expression and osteoclast differentiation were evaluated using real-time PCR, counting tartrate resistant acid phosphatase (TRAP)-positive multinucleated cells and assessing bone resorbing function. CRP-induced osteoclast differentiation was also examined after inhibition of Fcγ receptors.

Results

There was a significant correlation between CRP levels in serum and SF in RA patients. The SF CRP level was correlated with interleukin (IL)-6 levels, but not with RANKL levels. Immunohistochemical staining revealed that compared with the osteoarthritis synovium, CRP was more abundantly expressed in the lining and sublining areas of the RA synovium. CRP stimulated RANKL production in monocytes and it induced osteoclast differentiation from monocytes and bone resorption in the absence of RANKL.

Conclusions

CRP could play an important role in the bony destructive process in RA through the induction of RANKL expression and direct differentiation of osteoclast precursors into mature osteoclasts. In the treatment of RA, lowering CRP levels is a significant parameter not only for improving disease activity but also for preventing bone destruction.

The relationship between synovial fluid VEGF and serum leptin with ultrasonographic findings in knee osteoarthritis

AIM

This study aimed to determine synovial fluid and serum biomarkers which could accord with radiological and ultrasonographic findings in knee osteoarthritis.

METHODS

Thirty-four patients with knee osteoarthritis were detected with joint effusion by clinical examination. Both knee joints were examined using plain radiographs and ultrasonography. Questions were obtained for visual analog scale (VAS), Western Ontario McMaster Universities Osteoarthritis Index and Health Assessment Questionnaire (HAQ). Synovial fluid (SF) and serum levels of vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-13, leptin, resistin and cartilage oligomeric matrix protein (COMP) were measured using enzyme-linked immunosorbent assay.

RESULTS

Synovial fluid VEGF level was positively correlated with Kellgren-Lawrence (KL) grades and it was higher in patients with KL grade 4 than those with KL grade 2. SF VEGF correlated with ultrasonographic findings, such as the length of medial osteophytes. The amount of effusion was positively correlated with SF resistin. Serum leptin level had positive correlation with HAQ and the length of medial osteophytes. MMP-13 or COMP levels were not correlated with radiographic or ultrasonographic findings.

CONCLUSION

Synovial fluid VEGF level was correlated with radiographic grading, ultrasonographic findings and functional statues in knee osteoarthritis, and serum leptin level also correlated with the ultrasonographic findings and functional status of knee osteoarthritis.

Development and characterization of mouse monoclonal antibodies reactive with chicken IL-1β

Interleukin-1β proteins from chicken, duck, goose, turkey, and pigeon share 77 to 99% amino acid sequence similarity among themselves, and only 31 to 35% sequence similarity is shared between avian and mammalian IL-1β. There have been no antibodies that specifically detect avian IL-1β, and the current study was conducted to develop mouse monoclonal antibodies (mAb) against chicken IL-1β (chIL-1β) to further define its biochemical and immunological properties. In this study, 2 mouse mAb that are specific for chIL-1β were produced and characterized. Both mAb identified a 66.0 kDa recombinant chIL-1β protein expressed in Escherichia coli by Western blot analysis that corresponded to the expected molecular weight of a recombinant fusion protein containing the full-length 23.0 kDa chIL-1β protein and a 43.0 kDa maltose binding protein tag. Immunohistochemical analysis identified cells producing endogenous chIL-1β in the cecal tonsils, bursa of Fabricius, and spleen. Purified recombinant chIL-1β dose-dependently stimulated the proliferation and nitric oxide production by thymocytes, and both activities were inhibited by co-incubation with the 2 chIL-1β mAb described in this paper. These mAb will be important immune reagents for basic and applied poultry research of IL-1β in poultry.

Effects of in ovo injection with selenium on immune and antioxidant responses during experimental necrotic enteritis in broiler chickens

This study was conducted to investigate the effects of in ovo injection of Se on modulating the immune system and antioxidant responses in broiler chickens with experimental necrotic enteritis. Broiler eggs were injected at 18 d of embryo age with either 100 μL of PBS alone or sodium selenite (Na2SeO3) in PBS, providing 0 (SS0), 10 (SS10), or 20 (SS20) μg of Se/egg. At 14 d posthatch, PBS-treated and uninfected chickens were kept as the control group, whereas the remaining chickens were orally infected with 1.0 × 10(4) sporulated oocysts of Eimeria maxima (SS0, SS10, SS20). At 18 d posthatch, E. maxima-infected chickens were orally infected with 1.0 × 10(9) cfu of Clostridium perfringens. Infected control SS0 group showed significantly decreased BW compared with the uninfected control. However, SS20 group showed significantly increased BW compared with the infected control SS0 group, whereas the BW were similar among uninfected control and infected SS10 and SS20 groups. The SS10 group showed significantly lower intestinal lesions compared with the SS0 group, and oocyst production was decreased in both SS10 and SS20 groups. Serum malondialdehyde level and catalase activity were also decreased in both SS10 and SS20 groups, whereas the superoxide dismutase level was significantly lower in the SS10 group compared with the SS0 group. The SS20 group showed significantly higher levels of transcripts for IL-1β and IL-6 in intestine, and SS10 and SS20 groups had higher levels of transcripts for IL-8 and inducible nitric oxide synthase expression and decreased glutathione peroxidase 7 mRNA levels compared with the SS0 group. The SS10 and SS20 groups also showed increased serum antibody levels to C. perfringens α-toxin and NetB toxin compared with the SS0 group. These collective results suggest that the injection of Se into the amniotic cavity of developing eggs may be beneficial for enhancing immune and antioxidant responses in the hatched chickens exposed to the necrotic enteritis-causing pathogens.

Reciprocal activation of CD4+ T cells and synovial fibroblasts by stromal cell-derived factor 1 promotes RANKL expression and osteoclastogenesis in rheumatoid arthritis

OBJECTIVE

Stromal cell-derived factor 1 (SDF-1) is a chemokine that is involved in the bone-destructive process in rheumatoid arthritis (RA) and bony metastasis in malignancy. This study was undertaken to determine the role and mechanism of SDF-1 in RA-associated osteoclastogenesis.

METHODS

The expression of SDF-1, tumor necrosis factor α (TNFα), and RANKL in RA synovial tissue was analyzed using confocal microscopy. After synovial fibroblasts and CD4+ T cells were treated with SDF-1, RANKL messenger RNA expression was determined by real-time and reverse transcription polymerase chain reaction. Osteoclastogenesis was assessed by counting tartrate-resistant acid phosphatase-positive multinucleated cells in CD14+ monocytes cultured with SDF-1 in the presence of anticytokine antibodies or signal inhibitors and in monocytes cocultured with SDF-1-pretreated synovial fibroblasts and CD4+ T cells.

RESULTS

RANKL, TNFα, and SDF-1 were coexpressed in the lining and sublining of RA synovium. SDF-1 stimulated RANKL expression in RA synovial fibroblasts and CD4+ T cells, and TNFα inhibition reduced this stimulation. When monocytes isolated from human peripheral blood were cultured with SDF-1, they were differentiated into osteoclasts in the absence of RANKL. Monocytes were also differentiated into osteoclasts when they were cocultured with SDF-1-pretreated synovial fibroblasts or CD4+T cells; however, this osteoclastogenesis was reduced by TNFα inhibition.

CONCLUSION

Our findings indicate that SDF-1 induces osteoclastogenesis directly and indirectly via up-regulating RANKL expression in RA synovial fibroblasts and CD4+ T cells, and that this is mediated by TNFα. The axis of SDF-1 and RANKL is a potential therapeutic target for RA-associated bone destruction.

Advances in systems biology approaches for autoimmune diseases

Because autoimmune diseases (AIDs) result from a complex combination of genetic and epigenetic factors, as well as an altered immune response to endogenous or exogenous antigens, systems biology approaches have been widely applied. The use of multi-omics approaches, including blood transcriptomics, genomics, epigenetics, proteomics, and metabolomics, not only allow for the discovery of a number of biomarkers but also will provide new directions for further translational AIDs applications. Systems biology approaches rely on high-throughput techniques with data analysis platforms that leverage the assessment of genes, proteins, metabolites, and network analysis of complex biologic or pathways implicated in specific AID conditions. To facilitate the discovery of validated and qualified biomarkers, better-coordinated multi-omics approaches and standardized translational research, in combination with the skills of biologists, clinicians, engineers, and bioinformaticians, are required.

Novel phosphoinositide 3-kinase δ,γ inhibitor: potent anti-inflammatory effects and joint protection in models of rheumatoid arthritis

Phosphoinositide 3-kinases γ and δ (PI3Kγ and PI3Kδ) are expressed in rheumatoid arthritis (RA) synovium and regulate innate and adaptive immune responses. We determined the effect of a potent PI3Kδ,γ inhibitor, IPI-145, in two preclinical models of RA. IPI-145 was administered orally in rat adjuvant-induced arthritis (AA) and intraperitoneally in mouse collagen-induced arthritis (CIA). Efficacy was assessed by paw swelling, clinical scores, histopathology and radiography, and microcomputed tomography scanning. Gene expression and Akt phosphorylation in joint tissues were determined by quantitative real-time polymerase chain reaction and Western blot analysis. Serum concentrations of anti-type II collagen (CII) IgG and IgE were measured by immunoassay. T-cell responses to CII were assayed using thymidine incorporation and immunoassay. IPI-145 significantly reduced arthritis severity in both RA models using dosing regimens initiated before onset of clinical disease. Treatment of established arthritis with IPI-145 in AA, but not CIA, significantly decreased arthritis progression. In AA, histology scores, radiographic joint damage, and matrix metalloproteinase (MMP)-13 expression were reduced in IPI-145-treated rats. In CIA, joint histology scores and expression of MMP-3 and MMP-13 mRNA were lower in the IPI-145 early treatment group than in the vehicle group. The ratio of anti-CII IgG2a to total IgG in CIA was modestly reduced. Interleukin-17 production in response to CII was decreased in the IPI-145-treated group, suggesting an inhibitory effect on T-helper cell 17 differentiation. These data show that PI3Kδ,γ inhibition suppresses inflammatory arthritis, as well as bone and cartilage damage, through effects on innate and adaptive immunity and that IPI-145 is a potential therapy for RA.

Identification of a novel HLA-B allele, B*46:39, by sequence-based typing

The new allele B*46:39 showed a single-nucleotide substitution compared with B*46:01 at codon 185 (CCA/ACA).

Comparison of clinical outcomes after conservative and surgical treatment of isolated anastomotic leaks after esophagectomy for esophageal cancer

The clinical course and outcome of isolated anastomotic leaks (IALs) after esophagectomy are significantly different from those of necrotic leaks. The purpose of this study was to investigate the clinical features, diagnosis, treatment, and long-term outcome in patients with IALs after esophagectomy with reconstruction for esophageal cancer. A total of 663 patients underwent esophagectomy with esophageal reconstruction because of esophageal cancer between 2000 and 2010 at the Seoul Asan Medical Center. IALs occurred in 23 patients (3.5%). All patients with IAL were male, with a median age of 61 years. Patients with IAL were divided into three groups based on their clinical course. group A comprised patients who had definite clinical symptoms and/or signs indicating mediastinal contamination or leak before routine contrast esophagography was performed. Groups B and C comprised patients who had no definite clinical symptoms and/or signs of leaks before the routine contrast examination. Furthermore, group B contained those patients who resumed oral intake because no leak was found in the routine contrast examination and was diagnosed some days after resuming oral intake. Group C contained those patients who kept fasting because the leak was found in the routine contrast examination. The median follow-up period was 30 months. The mean time to closure of the IAL was 70.1 ± 96.0 days (range 4-364). There was a 72.7% overall closure rate within 60 days. By univariate analysis, the mean time to closure of the IAL was found to be significantly longer for group A patients or in cases where the patients had an uncontained leak, leukocytosis, or empyema. However, there was no statistically significant differences in age, neoadjuvant treatment, site of anastomosis (cervical vs. thoracic), fever, or treatment of the leak. By multivariate analysis, group A was found to be an independent predictive factor for the time to closure of the IAL. Repeat contrast studies revealed no anastomotic leaks in 18 patients and the formation of contained fistula in four cases (excluding one patient who died in hospital). The four patients with a contained fistula showed no clinical symptoms or signs, and tolerated resumed oral intake. IALs were resolved in most cases with low leak-related mortality, and resolution of the leaks occurred within 2 months in the majority of patients.

Long-term results of thoracoscopic thymectomy for thymoma without myasthenia gravis

OBJECTIVE

To compare the feasibility and safety of thoracoscopic thymectomy with conventional sternotomy thymectomy for thymoma without myasthenia gravis.

METHODS

Data from 70 patients diagnosed with thymoma, who underwent thoracoscopic thymectomy (n = 25, Group T) or sternotomy thymectomy (n = 45, Group S) between March 2002 and March 2008, were retrospectively evaluated.

RESULTS

Mean follow-up durations were 78.0 ± 21.9 months and 70.0 ± 23.6 months in Groups T and S, respectively. No deaths occurred in Group T; seven deaths occurred in Group S, all > 1 month post follow-up. Durations of chest intubation and hospitalization were significantly shorter in Group T than in Group S. No significant between-group difference in the incidence of operative complications was observed. Tumour recurrence-free rates at 5 and 7 years postsurgery were 96% (both years) in Group T and 95% (both years) in Group S.

CONCLUSIONS

Long-term follow-up indicates that thoracoscopic thymectomy for thymoma without myasthenia gravis is effective and is well tolerated, and associated with low rates of operative complications and recurrence.

The frequency and impact of ROS1 rearrangement on clinical outcomes in never smokers with lung adenocarcinoma

BACKGROUND

To determine the frequency and predictive impact of ROS1 rearrangements on treatment outcomes in never-smoking patients with lung adenocarcinoma.

PATIENTS AND METHODS

We concurrently analyzed ROS1 and ALK rearrangements and mutations in the epidermal growth factor receptor (EGFR), and KRAS in 208 never smokers with lung adenocarcinoma. ROS1 and ALK rearrangements were identified by fluorescent in situ hybridization.

RESULTS

Of 208 tumors screened, 7 (3.4%) were ROS1 rearranged, and 15 (7.2%) were ALK-rearranged. CD74-ROS1 fusions were identified in two patients using reverse transcriptase-polymerase chain reaction. The frequency of ROS1 rearrangement was 5.7% (6 of 105) among EGFR/KRAS/ALK-negative patients. Patients with ROS1 rearrangement had a higher objective response rate (ORR; 60.0% versus 8.5%; P = 0.01) and a longer median progression-free survival (PFS; not reached versus 3.3 months; P = 0.008) to pemetrexed than those without ROS1/ALK rearrangement. The PFS to EGFR-tyrosine kinase inhibitors in patients harboring ROS1 rearrangement was shorter than those without ROS1/ALK rearrangement (2.5 versus 7.8 months; P = 0.01).

CONCLUSIONS

The frequency of ROS1 rearrangements in clinically selected patients is higher than that reported for unselected patients, suggesting that ROS1 rearrangement is a druggable target in East-Asian never smokers with lung adenocarcinoma. Given the different treatment outcomes to conventional therapies and availability of ROS1 inhibitors, identification of ROS1 rearrangement can lead to successful treatment in ROS1-rearranged lung adenocarcinomas.

Clinicopathological characteristics of T1 colorectal cancer without background adenoma

AIM

Background adenoma (BGA) is defined as benign adenomatous tissue contiguous to resected carcinomas, and the absence of BGA in a tumour is considered a histological criterion of de novo cancers. The present study aimed to identify the clinicopathological characteristics of T1 colorectal cancer (CRC) without BGA.

METHOD

A retrospective review was carried out of prospectively collected data from two centres: the National Cancer Center, Korea; and Chonnam National University Hwasun Hospital, Korea. A total of 590 patients with T1 CRC, treated by endoscopic or surgical resection between January 2001 and August 2011, were enrolled. Details regarding gender, age, tumour location, endoscopic gross type, tumour size, depth of submucosal (SM) invasion, angiolymphatic invasion, tumour grade, budding and lymph node (LN) metastasis were evaluated with regard to the presence or absence of BGA.

RESULTS

BGA was absent in 197 (33.4%) patients. Tumour size <20 mm, flat or depressed type, deep SM depth and tumour budding were associated with the absence of BGA in univariate and multivariate analyses (P < 0.05). In surgically resected patients, LN metastases were significantly associated with the absence of BGA (P = 0.022).

CONCLUSION

T1 CRC without BGA presented several characteristics of small size (<20 mm), flat or depressed type, deep SM depth (SM 2/3), LN metastasis and tumour budding. These results indicate that de novo cancers may have a more invasive potential.