Changes in liver regenerative factors in a case of living-related liver transplantation

Liver regeneration in a patient with fulminant hepatic failure (FHF) who underwent living-related partial liver transplantation (LRLT) was investigated regarding hepatic growth factors. The patient was a 16-yr-old Japanese male who developed severe subacute FHF. LRLT was performed using an extended left lobe of the ABO matched patient's mother. In the recipient, the pre-transplant levels of both plasma hepatocyte growth factor (HGF) and transforming growth factor (TGF)-beta were extremely high and rapidly decreased following the liver replacement. The liver volume evaluated using a CAT scan increased 195% after 2 wk in graft liver and 110% after 2 wk in the hepatectomized donor. The explanted liver (FHF liver), the liver from donor (normal liver), and the graft liver [the 3rd post-transplant day (POD 3)] were all investigated immunohistochemically. FHF liver: No liver regeneration was observed [proliferative cell nuclear antigen (PCNA) labeling index (L.I.): 0%]. In the liver, both HGF in the hepatocytes and c-met on the membrane of the hepatocytes were positive. TGF-beta was positive in the hepatocytes and no apoptosis was detected by the TUNEL method. Donor liver (POD 0): Few PCNA stained hepatocytes were detected. No HGF was detected but c-met was clearly detected on the cell membrane of the hepatocytes. Neither TGF-beta nor apoptosis was detected. Graft liver (POD 3): The PCNA L.I. was conspicuous at 40%. HGF was positive in non-parenchymal cells and c-met was positive in the cytoplasm of the hepatocytes. TGF-beta was negative while apoptosis was positive in the zone 3 hepatocytes. In conclusion, these findings suggested that the liver of the patient with FHF did not respond to liver regenerative stimulus, in part, through involvement of inhibitor TGF-beta. On POD 3, the transplanted graft was in a vigorous regenerative status in comparison to that in the hepatectomized donor. The HGF/c-met system is thought to be involved in the mechanism of regeneration. Intrahepatic apoptosis was detected in the graft on the 3rd post-transplant day probably due to transient ischemia in the liver, which was not related to the Fas/Fas-ligand system.     

Evidence for regulation of myelin protein synthesis by contact between adjacent Schwann cell plasma membranes

The spontaneously immortalized S16 Schwann cell line expresses higher levels of myelin-associated glycoprotein (MAG) and PO glycoprotein and their messenger RNAs when grown at high density than at low density [Sasagasako et al: J Neurochem 1996;66:1432-1439]. This up-regulation of myelin protein expression at high density is not associated with decreased cellular proliferation and may be caused by direct cell-to-cell contact. To investigate the hypothesis that increased mRNA levels for myelin proteins are caused by contact between Schwann cells, sparse S16 cell cultures were treated for 48 h with plasma-membrane-enriched fractions isolated from dense S16 cells. The treatment had no effect on the proliferation of the cells, but MAG and PO mRNAs were elevated 2- and 1.3-fold, respectively, in comparison to untreated cells. These effects on levels of myelin protein mRNAs were eliminated by pretreatment of the membrane fraction with heat or trypsin and were not caused by plasma membrane fractions from NIH 3T3 cells. These data support the hypothesis that homotypic contact between Schwann cells up-regulates expression of myelin proteins and suggest the possibility of autotypic contact-mediated regulation of myelinogenesis by adjacent spiraled membranes of individual Schwann cells.     

Blocking angiotensin II ameliorates proteinuria and glomerular lesions in progressive mesangioproliferative glomerulonephritis

BACKGROUND: The renin-angiotensin system is thought to be involved in the progression of glomerulonephritis (GN) into end-stage renal failure (ESRF) because of the observed renoprotective effects of angiotensin-converting enzyme inhibitors (ACEIs). However, ACEIs have pharmacological effects other than ACE inhibition that may help lower blood pressure and preserve glomerular structure. We previously reported a new animal model of progressive glomerulosclerosis induced by a single intravenous injection of an anti-Thy-1 monoclonal antibody, MoAb 1-22-3, in uninephrectomized rats. Using this new model of progressive GN, we examined the hypothesis that ACEIs prevent the progression to ESRF by modulating the effects of angiotensin II (Ang II) on the production of transforming growth factor-beta (TGF-beta) and extracellular matrix components. METHODS: We studied the effect of an ACEI (cilazapril) and an Ang II type 1 receptor antagonist (candesartan) on the clinical features and morphological lesions in the rat model previously reported. After 10 weeks of treatment with equihypotensive doses of cilazapril, cilazapril plus Hoe 140 (a bradykinin receptor B2 antagonist), candesartan, and hydralazine, we examined systolic blood pressure, urinary protein excretion, creatinine clearance, the glomerulosclerosis index, and the tubulointerstitial lesion index. We performed a semiquantitative evaluation of glomerular immunostaining for TGF-beta and collagen types I and III by immunofluorescence study and of these cortical mRNA levels by Northern blot analysis. RESULTS: Untreated rats developed massive proteinuria, renal dysfunction, and severe glomerular and tubulointerstitial injury, whereas uninephrectomized control rats did not. There was a significant increase in the levels of glomerular protein and cortical mRNA for TGF-beta and collagen types I and III in untreated rats. Cilazapril and candesartan prevented massive proteinuria, increased creatinine clearance, and ameliorated glomerular and tubulointerstitial injury. These drugs also reduced levels of glomerular protein and cortical mRNA for TGF-beta and collagen types I and III. Hoe 140 failed to blunt the renoprotective effect of cilazapril. Hydralazine did not exhibit a renoprotective effect. CONCLUSION: These results indicate that ACEIs prevent the progression to ESRF by modulating the effects of Ang II via Ang II type 1 receptor on the production of TGF-beta and collagen types I and III, as well as on intrarenal hemodynamics, but not by either increasing bradykinin activity or reducing blood pressure in this rat model of mesangial proliferative GN.     

Bone marrow transplantation attenuates murine IgA nephropathy: role of a stem cell disorder

BACKGROUND: The pathogenesis of IgA nephropathy is still obscure. The aim of this study was to investigate whether the fundamental pathogenesis of IgA nephropathy lies in bone marrow stem cells (BMCs). METHODS: We used donors of two different strains for bone marrow transplantation (BMT) into mice with a high content of serum IgA (ddY strain, HIGA mice), a murine model of IgA nephropathy. One group (B6-->HIGA, N = 5) received BMCs of C57BL/6j (B6) mice, and the other (HIGA-->HIGA, N = 8) were reconstituted with BMCs of HIGA mice. RESULTS: Twenty-six weeks after BMT, in B6-->HIGA mice, mesangial deposits of IgA and C3 were statistically milder than those in HIGA-->HIGA mice. Light microscopic observations disclosed that glomerular sclerosis and mesangial matrix expansion in B6-->HIGA mice were decreased compared with those in HIGA-->HIGA mice. These B6-->HIGA mice also excreted less urinary albumin than HIGA-->HIGA mice. Furthermore, serum levels of IgA in B6-->HIGA mice were markedly lower than those in HIGA-->HIGA mice. Size analysis of serum IgA revealed that macromolecular IgA were notably lower in B6-->HIGA mice than in HIGA-->HIGA mice. CONCLUSIONS: Our results suggest that qualitative and quantitative changes of serum IgA are determined at the level of stem cells, and that BMT from normal donors can attenuate glomerular lesions in HIGA mice. This approach may offer a new avenue to study the pathogenesis of IgA nephropathy.     

Perifoveal microcirculation in eyes with epiretinal membranes

BACKGROUND/AIMS: Eyes with epiretinal membranes (ERMs) often have alterations of retinal vessels. The authors studied perifoveal microcirculation in eyes with epiretinal membranes (ERMs) using scanning laser ophthalmoscope (SLO) fluorescein angiography. METHODS: Mean capillary blood flow velocity (CFV) was measured as an index of perifoveal microcirculation by SLO fluorescein angiography in 26 eyes with ERMs (19 eyes with idiopathic epiretinal membranes, seven eyes with epiretinal membranes after retinal detachment surgery) before and 6 months after vitreous surgery, and in 23 healthy control subjects. RESULTS: The mean CFV was significantly reduced in eyes with ERMs compared with healthy controls (p=0.012), and the postoperative mean CFV was significantly increased compared with the preoperative mean CFV (p=0.041). CONCLUSION: Significant changes of capillary blood flow velocity in the perifoveal areas were observed between normal subjects and eyes with epiretinal membranes. This indicates that eyes with ERMs show abnormal haemodynamics in the perifoveal capillaries.     

Ocular manifestations of systemic infections

Ocular involvement, mainly uveitis or retinochoroiditis, is common in various systemic diseases, such as endogenous endophthalmitis, Lyme disease, human T-cell lymphotropic virus type I infection, toxoplasmosis, and toxocariasis. Recent progress, especially in laboratory microbiologic testing, has enabled us to reliably diagnose many formerly idiopathic intraocular inflammatory diseases. A group of systemic infectious diseases, including those discussed here, are implicated as a body of emerging or re-emerging diseases that have appeared in the past two decades and are thought to have a close relation with global socioenvironmental changes. This paper discusses recent clinical and experimental studies of the most important systemic infectious diseases that affect the eye.     

Involvement of cysteinyl leukotrienes in biphasic increase of nasal airway resistance of antigen-induced rhinitis in guinea pigs

We examined the effect of a specific cysteinyl leukotriene (LT) receptor antagonist, 4-oxo-8-[4-(4-phenylbutoxy)benzoylamino]-2-(tetrazol-5-yl)-4 H-1-benzopyran hemihydrate (pranlukast), on a novel model of allergic rhinitis induced by repeated intranasal ovalbumin challenge in actively sensitized guinea pigs. Repeated intranasal ovalbumin challenge caused a biphasic increase of nasal airway resistance, peaking 0.5 and 4 h after the final challenge. The early-phase response was accompanied by an increase in sneezing and nasal secretion, while that in the late phase was associated with edema and eosinophil infiltration of the nasal mucosa. Analysis of nasal lavage fluid showed that cysteinyl LTs increased in both phases. Pranlukast, when administered 1 h before every ovalbumin challenge, dose-dependently suppressed the increase of nasal airway resistance in the early- and late phase with evidence of histopathological improvements in the late phase. Pranlukast, however, failed to suppress sneezing and nasal secretion. We suggest that cysteinyl LTs play an important role in allergic rhinitis especially in the nasal obstruction due to edema of the nasal mucosa membrane.     

Effects of NTE-122, a novel acyl-CoA:cholesterol acyltransferase inhibitor, on cholesterol esterification and secretions of apolipoprotein B-containing lipoprotein and bile acids in HepG2

We studied the effect of NTE-122 (trans-1,4-bis[[1-cyclohexyl-3-(4-dimethylamino phenyl) ureido]methyl]cyclohexane), a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, on intracellular cholesterol esterification and the secretion of apolipoprotein B100 (apoB)-containing lipoprotein and bile acids in the human hepatoma cell line HepG2. NTE-122 markably inhibited [3H]oleate incorporation into cholesteryl esters in HepG2 cells incubated with 5 microg/ml 25-hydroxycholesterol as a stimulus for ACAT (IC50=6.0 nM). On the other hand, NTE-122 did not affect [3H]oleate incorporation into triglycerides and phospholipids and [14C]acetate incorporation into cholesterol. The stimulation of ACAT by 25-hydroxycholesterol caused significant increases in the secretion of radiolabeled cholesteryl esters, radiolabeled triglycerides and apoB mass. NTE-122 pronouncedly inhibited the secretion of radiolabeled cholesteryl esters in proportion to the inhibition of cellular cholesterol esterification, and it significantly reduced the secretion of radiolabeled triglycerides and apoB mass in HepG2 cells incubated with 25-hydroxycholesterol. Furthermore, NTE-122 increased the secretion of bile acids synthesized from [14C]-cholesterol. These results suggest that NTE-122 is capable of exhibiting anti-hyperlipidemic effects by reducing both the cholesterol content and the amount of secreted very low-density lipoprotein and enhancing the excretion of bile acid from the liver.     

Effects of NTE-122, a novel acyl-CoA:cholesterol acyltransferase inhibitor, on cholesterol esterification and high-density lipoprotein-induced cholesterol efflux in macrophages

We investigated the effects of a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, NTE-122 (trans-1,4-bis[[1-cyclohexyl-3-(4-dimethylamino phenyl)ureido]methyl]cyclohexane), on ACAT activities in macrophages originating from several species and high-density lipoprotein (HDL)-induced cholesterol efflux in phorbol 12-myristate 13-acetate (PMA)-treated THP-1 cells. NTE-122 inhibited cell-free ACAT activities in human PMA-treated THP-1 cells and mouse J774.1 cells with IC50 values of 0.88 and 360 nM, respectively. NTE-122 competively inhibited the ACAT activity in PMA-treated THP-1 cells. NTE-122 also inhibited cellular ACAT activities in PMA-treated THP-1 cells, rat peritoneal macrophages and J774.1 cells with IC50 values of 3.5, 84 and 6800 nM, respectively. Furthermore, NTE-122 prevented cholesterol accumulation in PMA-treated THP-1 cells incubated with acetylated low density lipoprotein, simultaneously with HDL, while it caused accumulation of a significant amount of free cholesterol in the absence and even in the presence of HDL. NTE-122 also enhanced HDL-induced cholesterol efflux from established foam cells converted from PMA-treated THP-1 cells. These results suggest that NTE-122, capable of inhibiting macrophage ACAT activity in humans more strongly than those in the other species, exhibits anti-atherogenic effects by preventing the foam cell formation and enhancing the foam cell regression in humans.     

New method for quantitative measurement of N-nitrosodimethylamine formation in the whole mouse

A simple method for the quantitative estimation of the formation of N-nitrosodimethylamine (NDMA) in mice has been developed. Mice were frozen in liquid nitrogen and homogenized. NDMA was then extracted and analyzed by a gas chromatograph equipped with a thermal energy analyzer. In normal mice NDMA (100 nmole) administered orally was rapidly metabolized and recovery of NDMA was about 10% after 60 min. However, when pyrazole (300 mg/kg) was injected i.p. to mice 60 min before the administration of NDMA, more than 80% of the administered NDMA could be recovered within 60 min. This result suggested that in pyrazole pretreated mice the accurate amount of NDMA formed could be estimated. Therefore the NDMA formation was measured in the pyrazole pretreated mice. When 0.25 mole of aminopyrine and from 0.25 to 2.0 umole of sodium nitrite were simultaneously administered orally, the amount of the NDMA formation in 20 min was found to be from 8.2 to 60.3 nmole. These values are equal to about from 30 to 200 g/kg of body weight which are nearly daily doses expected to cause the carcinogenic effect on mice or rats. This method of measuring NDMA in pyrazole pretreated mice appears to be useful for investigating the in vivo formation of NDMA quantitatively.