Tomoya Nishino

Immunohistochemical Analysis of Histone H3 Modifications in Germ Cells during Mouse Spermatogenesis

Histone modification has been implicated in the regulation of mammalian spermatogenesis. However, the association of differently modified histone H3 with a specific stage of germ cells during spermatogenesis is not fully understood. In this study, we examined the localization of variously modified histone H3 in paraffin-embedded sections of adult mouse testis immunohistochemically, focusing on acetylation at lysine 9 (H3K9ac), lysine 18 (H3K18ac), and lysine 23 (H3K23ac); tri-methylation at lysine 4 (H3K4me3) and lysine 27 (H3K27me3); and phosphorylation at serine 10 (H3S10phos). As a result, we found that there was a significant fluctuation in the modifications; in spermatogonia, the stainings for H3K9ac, H3K18ac, and H3K23ac were strong while that for H3K4me3 was weak. In spermatocytes, the stainings for H3K9ac, H3K18ac, H3K23ac, and H3K4me3 were reduced in the preleptotene to pachytene stage, but in diplotene stage the stainings for H3K18ac, H3K23ac, and H3K4me3 seemed to become intense again. The staining for H3K27me3 was nearly constant throughout these stages. In the ensuing spermiogenesis, a dramatic acetylation and methylation of histone H3 was found in the early elongated spermatids and then almost all signals disappeared in the late elongated spermatids, in parallel with the replacement from histones to protamines. In addition, we confirmed that the staining of histone H3S10phos was exclusively associated with mitotic and meiotic cell division. Based upon the above results, we indicated that the modification pattern of histone H3 is subject to dynamic change and specific to a certain stage of germ cell differentiation during mouse spermatogenesis.

A multicenter cross-sectional study of circulating soluble urokinase receptor in Japanese patients with glomerular disease

Elevated serum-soluble urokinase receptor (suPAR) levels have been described in patients with focal segmental glomerulosclerosis (FSGS) in several different cohorts. However, it remains unclear whether this is the case for Japanese patients and whether circulating suPAR can be clinically useful as a diagnostic marker. To determine this, we measured serum suPAR levels in 69 Japanese patients with biopsy-proven glomerular diseases in a cross-sectional manner. The serum suPAR levels showed a significant inverse correlation with renal function by univariate (R(2) of 0.242) and multivariate (β=0.226) analyses. Even after excluding patients with renal dysfunction, no significant difference in the suPAR levels was detected among the groups. Receiver operating characteristic analysis and measures of the diagnostic test performance showed that suPAR was not a useful parameter for differentiating FSGS from the other glomerular diseases (AUC-ROC: 0.621), although a small subgroup analysis showed that patients with FSGS, treated with steroids and/or immunosuppressants, had significantly lower suPAR levels. Patients with ANCA-associated glomerulonephritis had significantly higher levels of suPAR compared with the other disease groups, which may be owing to their lower renal function and systemic inflammation. Thus, suPAR levels are significantly affected by renal function and have little diagnostic value even in patients with normal renal function.

Correlation between triazole treatment history and susceptibility in clinically isolated Aspergillus fumigatus

ABSTRACT This is the first report of a detailed relationship between triazole treatment history and triazole MICs for 154 Aspergillus fumigatus clinical isolates. The duration of itraconazole dosage increased as the itraconazole MIC increased, and a positive correlation was observed (r = 0.5700, P < 0.0001). The number of itraconazole-naïve isolates dramatically decreased as the itraconazole MIC increased, particularly for MICs exceeding 2 μg/ml (0.5 μg/ml versus 2 μg/ml, P = 0.03). We also examined the relationship between cumulative itraconazole usage and the MICs of other azoles. A positive correlation existed between itraconazole dosage period and posaconazole MIC (r = 0.5237, P < 0.0001). The number of itraconazole-naïve isolates also decreased as the posaconazole MIC increased, particularly for MICs exceeding 0.5 μg/ml (0.25 μg/ml versus 0.5 μg/ml, P = 0.004). Conversely, the correlation coefficient obtained from the scattergram of itraconazole usage and voriconazole MICs was small (r = −0.2627, P = 0.001). Susceptibility to three triazole agents did not change as the duration of voriconazole exposure changed. In addition, we carried out detailed analysis, including microsatellite genotyping, for isolates obtained from patients infected with azole-resistant A. fumigatus. We confirmed the presence of acquired resistance to itraconazole and posaconazole due to a G54 substitution in the cyp51A gene for a patient with chronic pulmonary aspergillosis after oral itraconazole therapy. We should consider the possible appearance of azole-resistant A. fumigatus if itraconazole is used for extended periods.

Antifungal Susceptibilities of Aspergillus fumigatus Clinical Isolates Obtained in Nagasaki, Japan

ABSTRACT We investigated the triazole, amphotericin B, and micafungin susceptibilities of 196 A. fumigatus clinical isolates in Nagasaki, Japan. The percentages of non-wild-type (non-WT) isolates for which MICs of itraconazole, posaconazole, and voriconazole were above the ECV were 7.1%, 2.6%, and 4.1%, respectively. A G54 mutation in cyp51A was detected in 64.2% (9/14 isolates) and 100% (5/5 isolates) of non-WT isolates for itraconazole and posaconazole, respectively. Amphotericin B MICs of ≥2 μg/ml and micafungin minimum effective concentrations (MECs) of ≥16 μg/ml were recorded for two and one isolates, respectively.

HSP47 siRNA conjugated with cationized gelatin microspheres suppresses peritoneal fibrosis in mice

Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, is essential for the biosynthesis and secretion of collagen and is expressed in the fibrotic peritoneum. In the present study, we evaluated the efficacy of HSP47 small interfering RNA (siRNA) to suppress the development of peritoneal fibrosis induced by chlorhexidine gluconate in mice. We initially confirmed that biodegradable cationized gelatin microspheres (CGMs) containing HSP47 siRNA could continuously release siRNA over 21 days as a result of microsphere degradation. We then determined that a single injection of CGMs incorporating HSP47 siRNA suppressed collagen expression and macrophage infiltration, thereby preventing peritoneal fibrosis. Therefore, we suggest that this controlled-release technology using HSP47 siRNA is a potential treatment for peritoneal fibrosis. Additionally, RNA interference combined with CGMs as a drug-delivery system may lead to new strategies for knocking down specific genes in vivo.

Bronchoalveolar lavage galactomannan for the diagnosis of chronic pulmonary aspergillosis

Diagnosing chronic pulmonary aspergillosis (CPA) is complicated, and there are limited data available regarding the identification of galactomannan (GM) in clinical specimens to assist the detection of this infection. The purpose of this study was to evaluate the detection of GM in bronchoalveolar lavage fluid (BALF) and serum and to assess its utility for diagnosing CPA. We retrospectively reviewed the diagnostic and clinical characteristics of 144 patients, with and without CPA, in Nagasaki University Hospital, Japan, whose BAL and serum specimens were examined for the presence of GM. The Platelia Aspergillus enzyme immunoassay (PA EIA) was performed according to the manufacturers instructions. The mean values of BALF GM antigen were 4.535 (range, 0.062-14.120) and 0.430 (range, 0.062-9.285) in CPA (18) and non-CPA (126) patients, respectively. The mean values of serum GM antigen were 1.557 (range, 0.232-5.397) and 0.864 (range, 0.028-8.956) in CPA and non-CPA patients, respectively. PA EIA of BALF is superior to the test with serum, with the optimal cut-off values for BALF and serum of 0.4 and 0.7, respectively. The sensitivity and specificity of PA EIA in BALF at a cut-off of 0.4 were 77.2% and 77.0%, respectively, whereas with serum at a cut-off of 0.7, they were 66.7% and 63.5%, respectively. GM testing using BALF showed reasonable sensitivity and specificity as compared to that using serum. Thus, assessing GM levels in BALF may enhance the accuracy of diagnosing CPA.

Imaging mass spectrometry analysis reveals an altered lipid distribution pattern in the tubular areas of hyper-IgA murine kidneys.

Immunoglobulin A (IgA) nephropathy is the most common glomerular disease worldwide. To investigate the pathogenesis of this renal disease, we used animal models that spontaneously develop mesangioproliferative lesions with IgA deposition, which closely resemble the disease in humans. We analyzed the molecular distribution of lipids in hyper-IgA (HIGA) murine kidneys using matrix-assisted laser desorption/ionization-quadrupole ion trap-time of flight (MALDI-QIT-TOF)-based imaging mass spectrometry (IMS), which supplies both spatial distribution of the detected molecules and allows identification of their structures by their molecular mass signature. For both HIGA and control (Balb/c) mice, we found two phosphatidylcholines, PC(16:0/22:6) and PC(18:2/22:6), primarily located in the cortex area and two triacylglycerols, TAG(16:0/18:2/18:1) and TAG(18:1/18:2/18:1), primarily located in the hilum area. However, several other molecules were specifically seen in the HIGA kidneys, particularly in the tubular areas. Two HIGA-specific molecules were O-phosphatidylcholines, PC(O-16:0/22:6) and PC(O-18:1/22:6). Interestingly, common phosphatidylcholines and these HIGA-specific ones possess 22:6 lipid side chains, suggesting that these molecules have a novel, unidentified renal function. Although the primary structure of the HIGA-specific molecules corresponding to m/z 854.6, 856.6, 880.6, and 882.6 remained undetermined, they shared similar fragmentation patterns, indicating their relatedness. We also showed that all the HIGA-specific molecules were derived from urine, and that artificial urinary stagnation-due to unilateral urethral obstruction-caused HIGA-specific distribution of lipids in the tubular area.

Epigallocatechin gallate suppresses peritoneal fibrosis in mice

Long-term peritoneal dialysis (PD) leads to histological changes in the peritoneal membrane. Angiogenesis and inflammation caused by glucose degradation products (GDPs) play crucial roles in peritoneal fibrosis. One such GDP is methylglyoxal (MGO), which enhances the formation of advanced glycation end products (AGEs). AGEs bind to their receptor (RAGE) and activate nuclear factor-κB (NF-κB), which is a key regulator of angiogenesis and inflammation. Recent studies have indicated that (-)-epigallocatechin gallate (EGCG), a tea polyphenol, inhibits angiogenesis and inflammation. Here, we examined whether EGCG suppresses peritoneal fibrosis in mice. Based on preliminary examination, 2mL of 40mM MGO or PD fluid was injected intraperitoneally and EGCG (50mg/kg) or saline was injected subcutaneously for 3weeks. In comparison to PD fluid+saline-treated mice, the peritoneal tissues of MGO+saline-treated mice showed marked thickening of the submesothelial compact zone. In the submesothelial compact zone of the MGO+saline-treated mice, CD31-positive vessels and vascular endothelial growth factor-positive cells were significantly increased, as were inflammation, F4/80-positive macrophages, and monocyte chemotactic protein-1. Moreover, 8-hydroxydeoxyguanosine, a marker of reactive oxygen species, and NF-κB, determined by Southwestern histochemistry, in the submesothelial compact zone were also increased in MGO+saline-treated mice. These changes were attenuated in MGO+EGCG-treated mice. We demonstrated that EGCG treatment suppresses peritoneal fibrosis via inhibition of NF-κB. Furthermore, EGCG inhibits reactive oxygen species production. The results of this study indicate that EGCG is a potentially novel candidate for the treatment of peritoneal fibrosis.

Identification of a Novel Mutation and Prevalence Study for Fabry Disease in Japanese Dialysis Patients

Fabry disease—a genetic disorder characterized by the accumulation of globotriaosylceramide in cell lysosomes resulting from an X-linked deficiency of α-galactosidase A activity—presents with multiorgan manifestations, including progressive renal disease. Recently, its prevalence has been reported to be higher in hemodialysis (HD) patients than in the general population. We, therefore, examined patients on maintenance dialysis living in the Nagasaki Prefecture, Japan, to clarify the prevalence of Fabry disease. We screened 933 patients on maintenance dialysis, who were residents of Nagasaki Prefecture in Japan, for α-galactosidase A activity using a dried blood spot on filter paper. Patients with low α-galactosidase A activity were clinically assessed; subsequently, genetic analysis of the α-Galactosidase A gene (MIM:30064) was performed in these patients. Of the 933 patients, 55 had low α-galactosidase A activity; of these, one male and two females had α-Galactosidase A mutations. The prevalence of Fabry disease was thus 0.32%, which was similar to that reported previously. However, one mutation was newly identified, while the E66Q mutation observed in two patients was as previously identified. These two patients with the E66Q mutation were excluded because of the possibility of polymorphism; the prevalence of Fabry disease in the HD population was finally calculated to be 0.11%. The prevalence of Fabry disease in patients on maintenance dialysis living in Nagasaki Prefecture was 0.32%. Dried blood spot screening was considered as a simple and effective method for screening patients on maintenance dialysis for Fabry disease.

Thalidomide Prevents the Progression of Peritoneal Fibrosis in Mice

Thalidomide is clinically recognized as a therapeutic agent for multiple myeloma and has been known to exert anti-angiogenic actions. Recent studies have suggested the involvement of angiogenesis in the progression of peritoneal fibrosis. The present study investigated the effects of thalidomide on the development of peritoneal fibrosis induced by injection of chlorhexidine gluconate (CG) into the mouse peritoneal cavity every other day for 3 weeks. Thalidomide was given orally every day. Peritoneal tissues were dissected out 21 days after CG injection. Expression of CD31 (as a marker of endothelial cells), proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), α-smooth muscle actin (as a marker of myofibroblasts), type III collagen and transforming growth factor (TGF)-β was examined using immunohistochemistry. CG group showed thickening of the submesothelial zone and increased numbers of vessels and myofibroblasts. Large numbers of VEGF-, PCNA-, and TGF-β-positive cells were observed in the submesothelial area. Thalidomide treatment significantly ameliorated submesothelial thickening and angiogenesis, and decreased numbers of PCNA- and VEGF-expressing cells, myofibroblasts, and TGF-β-positive cells. Moreover, thalidomide attenuated peritoneal permeability for creatinine, compared to the CG group. Our results indicate the potential utility of thalidomide for preventing peritoneal fibrosis.