Inherited copper toxicity in Long-Evans cinnamon rats exhibiting spontaneous hepatitis: a model of Wilson's disease.

The copper concentrations in organs of developing Long-Evans Cinnamon (LEC) rats (2 d to 13 mo) were measured to elucidate the pathogenesis of their hereditary hepatitis. Hepatic copper contents of LEC rats were significantly higher than those of control rats (26 to 92 times higher). The subcellular distribution of hepatic copper indicated that the nuclear and large granular fractions had been saturated and the cytosol fraction contained about 70% of all the hepatic copper in LEC rats. The serum concentrations of copper and ceruloplasmin were significantly lower than those of control rats from the 4th wk (10-12% and 5-19%, respectively). Copper contents in kidney of LEC rats did not exhibit an increase over those of control rats until 12 wk, but then increased to nearly 40 times higher during fulminant hepatic failure. Accumulation of copper was not detected in the brain or small intestines of LEC rats until 13 mo. The hepatic copper concentration, its subcellular distribution, and serum copper concentration of F1 rats (LEC x Long-Evans Agouti) exhibited the same levels as those of Long-Evans Agouti rats. In addition to their similarity concerning inheritance of autosomal recessive means and clinical course, we found causality relating copper accumulation to the pathogenesis of the disease. We propose that LEC rats will be the most promising animal model for the study of Wilson's disease.     

Activins A,AB, and B inhibit hepatocyte growth factor synthesis by MRC-5 human lung fibroblasts

The effect of activins A, AB, and B on hepatocyte growth factor (HGF) synthesis stimulated by 12-O-tetradecanoylphorbol beta-acetate (TPA) was studied in MRC-5 human lung fibroblasts. Activins A, AB, and B inhibited the increase in HGF secretion induced by TPA in different dose-dependent manners and potencies. At 5 ng/ml, activins A and AB inhibited the increase approximately 30% and 10%, respectively, and at 25 ng/ml both activins produced almost maximal inhibition, i.e., approximately 40%. Activin B caused 10% inhibition at 12 ng/ml, and at 25 ng/ml produced almost maximal inhibition, approximately 30%. Further analysis with activin A indicated that the inhibition was caused by decreased HGF mRNA levels, followed by decreased cellular HGF levels. At 25 ng/ml, activin A inhibited the increase in HGF in the cellular lysate and the increase in HGF mRNA level approximately 80% and 40%, respectively.     

Enhancement of hepatocyte growth factor-induced cell scattering in N-acetylglucosaminyltransferase III-transfected HepG2 cells

N-Acetylglucosaminyltransferase III (GnT-III), which catalyzes the synthesis of a bisecting GlcNAc residue of N-glycans, is thought to be involved in the function of glycoproteins such as growth factor receptors. We investigated the effects of the overexpression of GnT-III on the hepatocyte growth factor (HGF) receptor c-Met, a glycoprotein, in human hepatocarcinoma HepG2 cells. GnT-III activity was elevated about 250-fold in HepG2 cells stably transfected with the GnT-III gene, whereas no significant change in GnT-III activity was observed in mock transfectants. Cell scattering assay revealed that HGF-induced cell scattering was enhanced depending on the GnT-III activities in the GnT-III transfectants. Western blot analysis and E-PHA lectin blot analysis showed that the level of c-Met protein was the same in both transfectants; however, the bisecting GlcNAc residue on c-Met was detected only in the GnT-III transfectants. Although the peak level of c-Met phosphorylation was not different in both transfectants, the level of tyrosine phosphorylation of c-Met decreased more rapidly in the GnT-III transfectants than in the mock transfectants. Furthermore, HGF-induced extracellular-regulated kinase (ERK) phosphorylation was slightly higher in the GnT-III transfectants than in the mock transfectants. These results show that overexpression of GnT-III in HepG2 cells enhances HGF-induced cell scattering, which may result from, at least in part, enhancement of HGF-induced ERK phosphorylation.     

3D reconstruction and histopathological analyses on murine corporal body

PurposeErectile dysfunction (ED) is one of the increasing diseases with aging society. The basis of ED derived from local penile abnormality is poorly understood because of the complex three‐dimensional (3D) distribution of sinusoids in corpus cavernosum (CC). Understanding the 3D histological structure of penis is thus necessary. Analyses on the status of regulatory signals for such abnormality are also performed.MethodsTo analyze the 3D structure of sinusoid, 3D reconstruction from serial sections of murine CC were performed. Histological analyses between young (2 months old) and aged (14 months old) CC were performed. As for chondrogenic signaling status of aged CC, SOX9 and RBPJK staining was examined.ResultsSinusoids prominently developed in the outer regions of CC adjacent to tunica albuginea. Aged CC samples contained ectopic chondrocytes in such regions. Associating with the appearance of chondrocytes, the expression of SOX9, chondrogenic regulator, was upregulated. The expression of RBPJK, one of the Notch signal regulators, was downregulated in the aged CC.ConclusionsProminent sinusoids distribute in the outer region of CC which may possess important roles for erection. A possibility of ectopic chondrogenesis induced by alteration of SOX9/Notch signaling with aging is indicated.     

Developmental mutant mouse models for external genitalia formation

Development of external genitalia and perineum is the subject of developmental biology as well as toxicology and teratology researches. Cloaca forms in the lower (caudal) end of endoderm. Such endodermal epithelia and surrounding mesenchyme interact with various signals to form the external genitalia. External genitalia (the anlage termed as genital tubercle: GT) formation shows prominent sexually dimorphic morphogenesis in late embryonic stages, which is an unexplored developmental research field because of many reasons. External genitalia develop adjacent to the cloaca which develops urethra and corporal bodies. Developmental regulators including growth factor signals are necessary for epithelia‐mesenchyme interaction (EMI) in posterior embryos including the cloaca and urethra in the genitalia. In the case of male type urethra, formation of tubular urethra proceeds from the lower (ventral) side of external genitalia as a masculinization process in contrast to the case of female urethra. Mechanisms for its development are not elucidated yet due to the lack of suitable mutant mouse models. Because of the recent progresses of Cre (recombinase)‐mediated conditional target gene modification analyses, many developmental regulatory genes become increasingly analyzed. Conditional gene knockout mouse approaches and tissue lineage approaches are expected to offer vital information for such sexually dimorphic developmental processes. This review aims to offer recent updates on the progresses of these emerging developmental processes for the research field of congenital anomalies.     

Use of a butterfly ventilation tube in the treatment of otitis media with effusion

Sixty-three ears of 49 patients with serous otitis media were treated making use of butterfly ventilation tube in our 4 hospitals and 1 private office. The average time from intubation to extubation was 9 months and the longest case was 33 months. Main complications were infection and spontaneous extubation. The rate of hearing improvement after tympanostomy was more than 80% in all cases. The frequency of the most improvement was observed in 1kHz on the average. It was cleared that the butterfly ventilation tube was easy to use for the wide age patients and at any clinics. It was concluded that the butterfly ventilation tube was useful as a long-term ventilation tube.