Common variants at the GCK, GCKR, G6PC2-ABCB11 and MTNR1B loci are associated with fasting glucose in two Asian populations

AIMS/HYPOTHESIS

To test fasting glucose association at four loci recently identified or verified by genome-wide association (GWA) studies of European populations, we performed a replication study in two Asian populations.

METHODS

We genotyped five common variants previously reported in Europeans: rs1799884 (GCK), rs780094 (GCKR), rs560887 (G6PC2-ABCB11) and both rs1387153 and rs10830963 (MTNR1B) in the general Japanese (n = 4,813) and Sri Lankan (n = 2,319) populations. To identify novel variants, we further examined genetic associations near each locus by using GWA scan data on 776 non-diabetic Japanese samples.

RESULTS

Fasting glucose association was replicated for the five single nucleotide polymorphisms (SNPs) at p < 0.05 (one-tailed test) in South Asians (Sri Lankan) as well as in East Asians (Japanese). In fine-mapping by GWA scan data, we identified in the G6PC2-ABCB11 region a novel SNP, rs3755157, with significant association in Japanese (p = 2.6 x 10(-8)) and Sri Lankan (p = 0.001) populations. The strength of association was more prominent at rs3755157 than that of the original SNP rs560887, with allelic heterogeneity detected between the SNPs. On analysing the cumulative effect of associated SNPs, we found the per-allele gradients (beta = 0.055 and 0.069 mmol/l in Japanese and Sri Lankans, respectively) to be almost equivalent to those reported in Europeans.

CONCLUSIONS/INTERPRETATION

Fasting glucose association at four tested loci was proven to be replicable across ethnic groups. Despite this overall consistency, ethnic diversity in the pattern and strength of linkage disequilibrium certainly exists and can help to appreciably reduce potential causal variants after GWA studies.

Influence of anti-HBc seropositivity on the risk of hepatocellular carcinoma in HCV-infected patients after adjusting for confounding factors

It is controversial whether past hepatitis B virus infection constitutes an additional risk of hepatocellular carcinoma (HCC) among patients with hepatitis C virus (HCV). The incidence of HCC between 1994 and 2004 was analysed among 1262 patients who were only positive for HCV. The cumulative incidence of HCC was assessed by Kaplan-Meier analysis and the difference between two groups was assessed by the log-rank test. The effect of anti-HBc positivity on the risk of HCC was assessed with multivariate Cox proportional analysis. Anti-HBc was positive in 522 (41.4%) patients. The proportion of male patients (56.7 vs 46.8%, P < 0.001) and mean age (60.8 vs 56.9 years, P < 0.001) were significantly higher in the anti-HBc positive group. HCC developed in 339 patients (mean follow-up 7.0 years), with cumulative incidence rates at 3, 5 and 10 years of 12.7, 24.5 and 41.9% in the anti-HBc positive group and 10.6, 17.7 and 33.4% in the negative group, respectively (P = 0.005). However, anti-HBc seropositivity did not reach statistical significance in multivariate analysis including age and gender (hazard ratio, 1.06; 95% CI, 0.85-1.31; P = 0.63). Anti-HBc positivity and HCC incidence were confounded by male gender and older age.

Human leukocyte histocompatibility antigen class II-induced cytokines from human gingival fibroblasts promote proliferation of human umbilical vein endothelial cells: potential association with enhanced angiogenesis in chronic periodontal inflammation

BACKGROUND AND OBJECTIVE

The role of human leukocyte histocompatibility antigen (HLA) class II molecules on non-antigen-presenting cells has been a matter of controversy. We previously reported that HLA-II molecules on human gingival fibroblasts (GF) do not present antigens, but transduce signals into the cells, resulting in the expression of several cytokines, such as interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), regulated upon activation, normal T-cell expressed and secreted (RANTES) and IL-8. However, the exact role of these cytokines, as well as other cytokines which are potentially secreted from GF, in the pathogenesis of chronic periodontal inflammation is not fully understood. The aim of this study was to observe the effects of HLA-II-induced cytokines on the proliferation of human umbilical vein endothelial cells (HUVEC).

MATERIAL AND METHODS

Antibody-based cytokine-microarray analyses were performed to detect potential cytokines associated with angiogenesis. Next, cytokine productivity was confirmed by quantitative methods. Then, cell proliferation assay was performed to see whether these cytokines promoted the proliferation of HUVEC.

RESULTS

Besides IL-6, MCP-1, RANTES and IL-8, growth-related gene product (GRO) was newly identified as an HLA-II-induced cytokine released from GF. This was confirmed by a quantitative method. Cell culture supernatant from HLA-II-stimulated GF cultures promoted the growth of HUVEC. Addition of anti-IL-8 neutralizing antibody, anti-CXC receptor (CXCR)1 antibody and anti-MCP-1 antibody inhibited the growth of HUVEC in a dose-dependent manner, while addition of anti-GROalpha antibody did not.

CONCLUSION

The HLA-II-induced IL-8, via CXCR1, as well as MCP-1 from GF, promotes endothelial cell proliferation, which is possibly associated with enhanced angiogenesis in chronic periodontal lesions.

Primary cutaneous CD30+ anaplastic large-cell lymphoma with generalized skin involvement and involvement of one peripheral lymph node, successfully treated with low-dose oral etoposide

Primary cutaneous CD30+ anaplastic large-cell lymphoma (PCALCL) in adults is rare, and the prognosis is generally excellent. Multifocal PCALCL tends to relapse after multiagent chemotherapy and is generally considered more prone to progress to extracutaneous involvement than is the localized disease. We report a 43-year-old woman with PCALCL who had generalized skin involvement accompanied by involvement of one peripheral draining lymph-node region. Although the disease relapsed after multiagent chemotherapy regimens, the disease was successfully treated with low-dose etoposide. We reviewed the previously reported cases of PCALCL treated with low-dose etoposide. We suggest that oral etoposide might be a useful effective treatment for treatment of relapsed multifocal PCALCL.

Overexpression of osteopontin in clear cell carcinoma of the ovary: close association with HNF-1beta expression

AIMS

Transcription factor hepatocyte nuclear factor (HNF)-1beta is selectively expressed in clear cell carcinoma (CCC) of the ovary. One of the potential HNF-1beta target genes is osteopontin (OPN). Although elevation of OPN mRNA has been reported in CCC, it remains unclear whether CCC cells overexpress OPN protein. The aim was to investigate the expression of OPN protein and its correlation with HNF-1beta status in CCC.

METHODS AND RESULTS

Three CCC and two serous adenocarcinoma (SA) cell lines were evaluated for expression of OPN by reverse transcriptase-polymerase chain reaction and immunocytochemistry. OPN expression, at both the mRNA and protein levels, was higher in the three CCCs than in the two SAs. HNF-1beta expression was detected in the CCCs but not in the SAs. Subsequently, 60 surgical specimens (30 CCCs and 30 SAs) were examined immunohistochemically for expression of OPN and HNF-1beta. All 30 CCCs showed immunopositivity for both OPN and HNF-1beta. The 12 (40%) CCCs with a high OPN score all had a high HNF-1beta score. In contrast, SAs rarely showed immunoreactivity for OPN or HNF-1beta.

CONCLUSIONS

OPN expression is elevated in ovarian CCC and is closely associated with HNF-1beta overexpression. HNF-1beta is likely to participate in OPN up-regulation in CCC.

Aberrant DNA methylation associated with bipolar disorder identified from discordant monozygotic twins

To search DNA methylation difference between monozygotic twins discordant for bipolar disorder, we applied a comprehensive genome scan method, methylation-sensitive representational difference analysis (MS-RDA) to lymphoblastoid cells derived from the twins. MS-RDA isolated 10 DNA fragments derived from 5' region of known genes/ESTs. Among these 10 regions, four regions showed DNA methylation differences between bipolar twin and control co-twin confirmed by bisulfite sequencing. We performed a case-control study of DNA methylation status of these four regions by pyrosequencing. Two regions, upstream regions of spermine synthase (SMS) and peptidylprolyl isomerase E-like (PPIEL) (CN265253), showed aberrant DNA methylation status in bipolar disorder. SMS, a gene on X chromosome, showed significantly higher DNA methylation level in female patients with bipolar disorder compared with control females. However, there was no difference of mRNA expression. In PPIEL, DNA methylation level was significantly lower in patients with bipolar II disorder than in controls. The expression level of PPIEL was significantly higher in bipolar II disorder than in controls. We found strong inverse correlation between gene expression and DNA methylation levels of PPIEL. These results suggest that altered DNA methylation statuses of PPIEL might have some significance in pathophysiology of bipolar disorder..

Chimerism and T-cell receptor repertoire analysis after unrelated cord blood transplantation with a reduced-intensity conditioning regimen following autologous stem cell transplantation for multiple myeloma

A 65-year-old Japanese male was diagnosed as multiple myeloma with Bence Jones kappa type, clinical stage IIIA. His disease status reached partial remission after chemotherapy. Thereafter, he received tandem transplantation, consisting of high-dose chemotherapy with autologous stem cell transplantation (ASCT), followed by unrelated cord blood transplantation (U-CBT). U-CBT with a reduced-intensity conditioning regimen (RI-CBT) was performed in August 2003. HLA mismatch between the patient and the CBT donor was present at two serological loci (B and DR). A total nucleated CBT cell dose of 2.45 x 10(7)/kg body weight was infused on day 0. Graft-vs.-host disease (GVHD) prophylaxis consisted of cyclosporine A and short-term methotrexate. Neutrophil engraftment (>0.5 x 10(9)/l) was obtained on day 46. He developed positive cytomegalovirus antigenemia, grade II acute GVHD involving skin and liver, varicella-zoster virus infection, septic shock, hemorrhagic cystitis caused by adenovirus and acute hepatitis B virus infection after U-CBT. We retrospectively analyzed T-cell receptor (TCR) repertoire diversity and found that TCR repertoire diversity decreased continuously after U-CBT. Therefore, low-TCR repertoire diversity in this patient appears to be associated with various infections caused by immunodeficiency.

Mapping quantitative trait loci for proteinuria-induced renal collagen deposition

The progression of chronic kidney disease is a complex process influenced by genetic factors. Proteinuria is a predictor of functional deterioration and an accelerator of disease progression through renal parenchymal damage and interstitial fibrosis. To determine genetic components that might mediate renal fibrosis due to proteinuria, we mapped loci influencing the phenotype of two mouse strains differing in proteinuria-induced renal type I collagen (COLI) deposition. Collagen I deposition in 129S1/svImJ and C57BL/6J mice differs significantly among tested strains. We backcrossed 120 hemi-nephrectomized (129S1/svImJ x C57BL/6J) F1 x 129S1/svImJ backcrossed mice loaded with bovine serum albumin giving rise to proteinuria and renal COLI deposition. Quantitative trait loci (QTL) mapping was performed and our analysis identified one suggestive linkage for renal COLI deposition peaking at 87 cM near D2Mit224 (logarithm of odds: 2.41) on Chr 2. In silico analysis uncovered nine candidate genes. Hence, although more studies are needed, these QTL provide an initial cue to subsequent gene discovery, which might help unravel the genetics of renal fibrosis.

FK506-protective effects against trimethyltin neurotoxicity in rats: hippocampal expression analyses reveal the involvement of periarterial osteopontin

There is little information on the molecular mechanisms in FK506-mediated neuroprotection. In the present study, we investigated the protective effect of FK506, an immunosuppressant and neuroprotectant, on trimethyltin (TMT)-induced neurotoxicity in the rat hippocampus. Histologically, TMT-induced neuronal damage was partially prevented by FK506 in the hippocampal CA1 region, but not in CA3. FK506 treatment significantly reduced the number of apoptotic cells in CA1, but not in CA3, and also prevented induction of cognitive deficits by TMT. Microarray analysis of the rat hippocampus detected 14 genes with TMT-induced alteration of mRNA expression that was rescued by FK506 treatment. Subsequent quantitative RT-PCR analysis confirmed elevated mRNA levels for four inflammatory genes, glutathione S-transferase, lysozyme, matrix Gla protein, and osteopontin after TMT treatment. Upregulation of these genes was reversed by FK506 treatment at 5 days postgavage. Immunohistochemistry revealed that FK506 reduced osteopontin (OPN) induction by TMT in the periarterial area at 5 days postgavage. Our data suggest that inflammatory gene expression is involved in TMT-induced damage to the hippocampal CA1 region, resulting in apoptosis, and that this process is initiated by periarterial OPN activation, and can be alleviated by FK506.

Association between PRKCH gene polymorphisms and subcortical silent brain infarction

Recently, a large-scale genetic epidemiological study has shown significant association of single nucleotide polymorphisms (SNPs) in the protein kinase C eta (PRKCH) gene with cerebral infarction, particularly, with lacunar infarction. To extend the findings, we tested association of two SNPs previously reported--rs3783799 and rs2230500--in PRKCH with silent lacunar infarction (SLI), which has drawn substantial attention in the aging societies. Disease association was tested in the case-control study design. Subjects with and without SLI were recruited from people who underwent a health-screening examination including brain MRI. Two SNPs were genotyped and proven to be in complete linkage disequilibrium (D'=1.00, r(2)=1.00) and thus showed comparable results of disease association, which were reproduced in two panels collected independently. In the entire population involving 295 cases and 497 controls, two SNPs remained to be significantly associated with SLI under a dominant model even after adjustment for confounding factors such as hypertension (e.g., genetic effects of rs2230500, P=0.0026 for AA+AG vs. GG, adjusted odds ratio=1.27; 95% CI, 1.09-1.48). As the two SNPs appear to be common only in Asian people, further replication study is warranted in the other Asian populations as well as the Japanese.

Leukaemic dissemination of Merkel cell carcinoma in a patient with systemic lupus erythematosus

We describe an unusual bone-marrow metastasis of Merkel cell carcinoma (MCC) arising in the right cheek of a 73-year-old woman with systemic lupus erythematosus (SLE) and Sjögren's syndrome, who had been treated with oral prednisolone and methotrexate for 10 years. Seven months after wide local excision followed by local irradiation, the patient presented with thrombocytopaenia. Her bone marrow had been completely replaced by metastatic MCC cells, and metastatic cytokeratin 20-positive cells were also identified in the peripheral blood. To our knowledge, in the English literature, only six cases have been described previously of MCC bone-marrow involvement. Of these six cases, four were immunosuppressed, similar to our case. The high incidence of MCC in immunosuppressed patients such as those with SLE has been discussed previously. We consider that immunosuppression might be associated with bone-marrow metastasis, which is a rare form of MCC.

Serum macrophage migration inhibitory factor (MIF) levels after allogeneic hematopoietic stem cell transplantation

Macrophage migration inhibitory factor (MIF) may play an important role in the pathogenesis of acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT), as MIF plays an important role to regulate the production of tumor necrosis factor-alpha (TNF-alpha), one of the inflammatory cytokines which induces and exacerbates aGVHD. We examined the association between serum MIF levels and aGVHD vs. chronic GVHD (cGVHD) in allo-SCT patients in this study. We found a significant increase in the peak serum MIF (14.46 ng +/- 1.47 ng/ml) at onset in patients that developed aGVHD (n = 23, P = 0.009). We also found that mean serum MIF levels in patients who developed extensive type cGVHD within 6 months (12.58 +/- 2.18 ng/ml, n = 13) were significantly higher than MIF levels before allo-HSCT (7.86 +/- 1.17 ng/ml, n = 19, P = 0.04). Therefore, we speculated that serum MIF levels increase during the active phase of both aGVHD and cGVHD.