Cutting edge: amelioration of kidney disease in a transgenic mouse model of lupus nephritis by administration of the caspase inhibitor carbobenzoxy-valyl-alanyl-aspartyl-(beta-o-methyl)-fluoromethylketone.

Systemic lupus erythematosus (SLE) is a common, potentially fatal, non-organ-specific autoimmune disorder. Immune complex-mediated kidney disease is the major cause of mortality. Apoptotic cells in the epidermis are a possible source of self Ags, and apoptosis of endothelial cells and lymphocytes is thought to contribute to end-organ damage. We have previously shown that female transgenic mice expressing IFN-gamma in the epidermis develop inflammatory skin disease and features of SLE that have striking parallels with the human condition. We have now tested the effects of a pan-caspase inhibitor, carbobenzoxy-valyl-alanyl-aspartyl-(beta-o-methyl)-fluoromethylketone, on disease progression. Daily s.c. administration of carbobenzoxy-valyl-alanyl-aspartyl-(beta-o-methyl)-fluoromethylketone to female transgenic mice over a 3-wk period resulted in significant amelioration of both glomerular and interstitial renal damage, independent of the effects on autoantibody levels or skin inflammation. We propose that apoptosis inhibitors could be beneficial in the treatment of human SLE.

Asymmetric stem-cell divisions define the architecture of human oesophageal epithelium.

In spite of its clinical importance, little is known about the stem-cell compartment of the human oesophageal epithelium [1,2]. The epithelial basal layer consists of two distinct zones, one overlying the papillae of the supporting connective tissue (PBL) and the other covering the interpapillary zone (IBL) [3]. In examining the oesophageal basal layer, we found that proliferating cells were rare in the IBL and a high proportion of mitoses were asymmetrical, giving rise to one basal daughter and one suprabasal, differentiating daughter. In the PBL, mitoses were more frequent and predominantly symmetrical. The IBL was characterised by low expression of ?1 integrins and high expression of the beta2 laminin chain. By combining fluorescence-activated cell sorting (FACS) with in vitro clonal analysis, we obtained evidence that the IBL is enriched for stem cells. A normal oesophageal epithelium with asymmetric divisions was reconstituted on denuded oesophageal connective tissue. In contrast, asymmetric divisions were not sustained on skin connective tissue, and the epithelium formed resembled epidermis. We propose that stem cells located in the IBL give rise to differentiating daughters through asymmetric divisions in response to cues from the underlying basement membrane. Until now, stem-cell fate in stratified squamous epithelia was believed to be achieved largely through populational asymmetry [4-6].

PA-FABP, a novel marker of human epidermal transit amplifying cells revealed by 2D protein gel electrophoresis and cDNA array hybridisation.

Human epidermal stem cells express higher levels of beta1 integrins than their more differentiated daughters, transit amplifying cells. In a search for additional stem and transit cell markers we used proteomics and differential cDNA hybridisation to compare keratinocytes fractionated on the basis of beta1 integrin expression. There were remarkably few differences between the two populations and none of the RNAs differed in abundance by more than 2-fold. Nevertheless, proteomics revealed upregulated expression of epidermal fatty acid binding protein (PA-FABP, also known as E-FABP), Annexin II and two keratin related proteins in the transit population. An unknown high molecular mass protein was upregulated in the stem cell population. The upregulation of PA-FABP was confirmed by Northern blotting and conventional and whole mount labelling of human epidermis. We conclude that PA-FABP is a novel marker of epidermal transit amplifying cells.

IFN-gamma transgenic mice: clues to the pathogenesis of systemic lupus erythematosus?

Transgenic mice overexpressing IFN-gamma in the epidermis develop an inflammatory skin disease resembling cutaneous lupus erythematosus shortly after birth. By 3 months of age, most female transgenics develop a lupus-like syndrome characterised by production of IgG anti-dsDNA, antihistone and antinucleosome autoantibodies. The autoantibodies are nephritogenic, with one-third of females developing a severe immune complex mediated glomerulonephritis. Analysis of these transgenics suggests that pathogenic autoantibodies arise via an antigen-driven T-cell-dependent mechanism with apoptotic keratinocytes acting as a potential source of autoantigen. The mechanism of autoantibody production in IFN-gamma transgenics may be relevant to human lupus and is consistent with a central role for cutaneous T cells in the pathogenesis of systemic lupus erythematosus in man.

Abnormal expression of the E-cadherin-catenin complex in dysplastic Barrett's oesophagus.

It is now accepted that altered E-cadherin-catenin complex expression in oesophageal cancer correlates with clinical and pathological parameters, while abnormal E-cadherin expression occurs early in Barrett's oesophagus. We evaluated immunohistochemically the expression and cellular localization of alpha-, beta-, and gamma-catenin, and E-cadherin in 5 dysplastic and 26 non-dysplastic cases of Barrett's oesophagus. Usually all three catenins were localized at the cell membrane, as was E-cadherin. A similar staining pattern for E-cadherin and the catenins was observed in all cases of non-dysplastic Barrett's syndrome. However, 60% (3/5) of cases with dysplasia showed loss of membranous beta-catenin staining and diffuse cytoplasmic distribution, with predominantly nuclear localization in two cases. Membranous staining and concomitant cytoplasmic localization of E-cadherin, alpha-catenin and gamma-catenin were seen in one case with abnormal beta-catenin immunoreactivity. Our results indicate that altered subcellular distribution of beta-catenin occurs frequently in dysplastic Barrett's oesophagus and possibly reflects the signalling function of this molecule.

A central role for alpha beta T cells in the pathogenesis of murine lupus.

We have previously shown that female transgenic mice expressing IFN-gamma in the epidermis, under the control of the involucrin promoter, develop inflammatory skin disease and a form of murine lupus. To investigate the pathogenesis of this syndrome, we generated female IFN-gamma transgenic mice congenitally deficient in either alpha beta or gamma delta T cells. TCR delta-/- transgenics continued to produce antinuclear autoantibodies and to develop severe kidney lesions. In contrast, TCR beta-/- IFN-gamma transgenic mice failed to produce antinucleosome, anti-dsDNA, or antihistone autoantibodies, and kidney disease was abolished. Both alpha beta- and gamma delta-deficient transgenics continued to develop IFN-gamma-associated skin disease, lymphadenopathy, and splenomegaly. The data show that the autoantibody-mediated pathology of murine lupus in IFN-gamma transgenic mice is completely alpha beta T cell dependent and that gamma delta T cells cannot drive autoantibody production. These results imply that production of antinuclear autoantibodies in IFN-gamma transgenic animals is Ag driven, and we identified clusters of apoptotic cells in the epidermis of the mice as a possible source of self Ags. Our findings emphasize the relevance of this murine lupus model to the human disease.

A proton magnetic resonance spectroscopy study of the striatum and cerebral cortex in Parkinson's disease.

Animal studies have suggested an increased striatal glutamate activity in Parkinson's disease models, although this has not been substantiated in magnetic resonance spectroscopy studies in patients. Our initial aim was to assess glutamate and glutamine levels in the striatum of patients with idiopathic Parkinson's disease, using multivoxel proton magnetic resonance spectroscopy techniques. Since data were collected from other areas of the brain without a priori selection, information on the cortex was also obtained. Twelve healthy volunteers, seven dyskinetic and five non-dyskinetic patients were studied. Peak area ratios of choline-containing compounds (Cho), glutamine and glutamate (Glx) and N-acetyl moieties including N-acetylaspartate (NAx), relative to creatine (Cr) were calculated. Spectra were analysed from the corpus striatum, the occipital cortex and the temporo-parietal cortex. The median Glx/Cr ratio was unaltered in the striatal spectra of Parkinson's disease patients compared to healthy controls. However, the more severely affected patients had significantly reduced NAx/Cr ratios in spectra localised to the temporo-parietal cortex, compared to healthy controls. Furthermore, the entire patient population had significantly reduced Cho/Cr ratios in spectra from the temporo-parietal cortex, compared to the reference population. We found no evidence of increased striatal glutamate in either dyskinetic or non-dyskinetic Parkinson's disease. However, the low NAx/Cr and Cho/Cr ratios in the temporo-parietal cortex may indicate the presence of subclinical cortical dysfunction.

Diagnosis and treatment of chronic hepatic encephalopathy.

Neuropsychiatric abnormalities affecting patients with chronic liver disease are termed chronic hepatic encephalopathy. They involve neurotransmitter changes, rather than a structural disorder of the brain. Diagnosis is based on clinical findings, and electroencephalographic and psychometric testing. There is no 'specific' treatment, but there are a number of non-specific measures that can be used.

Circadian rhythm of cutaneous hypersensitivity reactions in nocturnal asthma.

BACKGROUND: Diurnal variation in mast cell discharge may play a central role in the early morning fall in peak expiratory flow rate (PEFR) in nocturnal asthmatic patients. METHODS: We tested the hypothesis that there is a circadian rhythm in mast cell response to allergen in 15 patients with nocturnal asthma by measuring the magnitude of cutaneous hypersensitivity reactions at 0600, 1200, 1800, and 2400 hours. Pre-admission, prick skin testing on the ventral aspect of the forearm to various allergens was performed. The allergen producing the largest wheal was tested at six sites on one forearm. Response was quantified after 20 minutes by measuring the area of the wheal produced using planimetry. Every six hours the skin testing was repeated at six new sites on alternating forearms. The average area of the six wheals was calculated and recorded at each time. The prick skin technique was used at all times. RESULTS: Maximal reactions occurred in 10 of the 15 patients at noon (P = .031, Friedman's two way analysis of variance). In these 10 patients wheal area at the time of maximum reactivity was on average 3.3-fold higher than at the time of minimum reactivity. The mean wheal areas for all 15 patients at 0600, 1200, 1800, and 2400 hours were 34 mm2, 42 mm2, 34 mm2, and 35 mm2 respectively. CONCLUSIONS: These observations support the concept of a circadian rhythm in mast cell activity in patients with severe nocturnal asthma.

Antinuclear autoantibodies and lupus nephritis in transgenic mice expressing interferon gamma in the epidermis.

Systemic lupus erythematosus (SLE) is a potentially fatal non-organ-specific autoimmune disease that predominantly affects women. Features of the disease include inflammatory skin lesions and widespread organ damage caused by deposition of anti-dsDNA autoantibodies. The mechanism and site of production of these autoantibodies is unknown, but there is evidence that interferon (IFN) gamma plays a key role. We have used the involucrin promoter to overexpress IFN-gamma in the suprabasal layers of transgenic mouse epidermis. There was no evidence of organ-specific autoimmunity, but transgenic animals produced autoantibodies against dsDNA and histones. Autoantibody levels in female mice were significantly higher than in male transgenic mice. Furthermore, there was IgG deposition in the glomeruli of all female mice and histological evidence of severe proliferative glomerulonephritis in a proportion of these animals. Our findings are consistent with a central role for the skin immune system, acting under the influence of IFN-gamma, in the pathogenesis of SLE.

Transgenic mice expressing IFN-gamma in the epidermis have eczema, hair hypopigmentation, and hair loss.

To study the role of IFN-gamma in the pathogenesis of inflammatory skin diseases, we used the involucrin promoter to overexpress IFN-gamma in the suprabasal layers of transgenic mouse epidermis. IFN-gamma mRNA and protein were readily detectable in the skin but not in the blood. Mice exhibited striking hypopigmentation of the hair due to a reduced abundance of DOPA-positive melanocytes. Severely affected mice had reddened skin, growth retardation, hair loss, and flaky skin lesions. Keratinocyte proliferation was increased, and there was epidermal thickening with spongiosis and parakeratosis. Suprabasal beta1 integrin expression and induction of keratin 17 in interfollicular epidermis provided evidence of perturbed differentiation. IFN-gamma receptor expression was reduced, and there was induction of ICAM-1 and MHC class II molecules on the surface of transgenic keratinocytes. The skin of severely affected mice was characterized by a dermal infiltrate of T lymphocytes and macrophages/monocytes, but the epidermis was almost devoid of Langerhans cells and T lymphocytes. The number of Langerhans cells in the lymph nodes was increased in the transgenics, and autoantibodies to keratinocytes were produced. Transgenic mice showed an increased contact hypersensitivity reaction to topical application of DNFB. We conclude that constitutive IFN-gamma expression in the epidermis results in a form of eczema resembling contact dermatitis and in a profound contact hypersensitivity reaction.

Helicobacter pylori infection and upper gastrointestinal patholgy in a British immigrant Indian community.

OBJECTIVES: To assess the pattern of upper gastrointestinal pathology and the prevalence of Helicobacter pylori infection in the Southall Indian community. DESIGN: A prospective study of endoscopic findings in 124 Indian and 107 whites from the Southall area. In a separate study blood samples were taken from 100 Indian subjects presenting to a single general practitioner in Southall. METHODS: The presence of gastritis and H. pylori infection was assessed histologically in Indian and white patients undergoing endoscopy. Serum samples were analysed using a specific enzyme-linked immunosorbent assay (ELISA) for anti-H. pylori immunoglobulin G. RESULTS: In the endoscopic study, Indian and white patients had the same rate of H. pylori infection (52% vs. 43%, respectively) (P= NS). The pattern of upper gastrointestinal pathology was similar in whites and Indians. In the general practice based study 41 subjects were H. pylori seropositive. Seropositivity increased with age (P<0.05). CONCLUSION: There is no excess of H. pylori-related pathology in Southall immigrant Indians. The similarity of upper gastrointestinal pathology in UK Indian and white patients presenting for endoscopy suggests that the high rates of duodenal ulceration, gastritis and H. pylori infection in India are environmentally rather than racially determined.

Review article: pathogenesis and treatment of chronic hepatic encephalopathy.

The various treatment strategies for hepatic encephalopathy are compared in the light of the available body of scientific work on the pathogenesis of the syndrome. Data on animal models of hepatic encephalopathy and in vitro studies on brain slices are discussed. Difficulties in extrapolating the results obtained to the human situation are highlighted, while results of human positron emission tomography and magnetic resonance spectroscopy studies are outlined on the background of the potential weaknesses of these non-invasive techniques.

Resolution of panniculitis after placement of pancreatic duct stent in chronic pancreatitis.

The association of panniculitis and pancreatitis is well described. However, panniculitis remains a relatively uncommon manifestation of pancreatic inflammation. We report a case in which treatment of pancreatitis by the placement of a pancreatic stent led to simultaneous resolution of both the pancreatitis and the associated panniculitis. There are no other reports in the literature demonstrating resolution of panniculitis subsequent to stent placement or definitive surgery.

MR imaging and spectroscopy of the basal ganglia in chronic liver disease: correlation of T1-weighted contrast measurements with abnormalities in proton and phosphorus-31 MR spectra.

The purpose of this study was to correlate the hyperintensity in the globus pallidus seen on T1-weighted magnetic resonance imaging (MRI) of the brain in chronic liver disease with changes in metabolite ratios measured from both proton and phosphorus-31 magnetic resonance spectroscopy (MRS) localised to the basal ganglia. T1-weighted spin echo (T1WSE) images were obtained in 21 patients with biopsy-proven cirrhosis (nine Child's grade A, eight Child's grade B and four Child's grade C). Four subjects showed no evidence of neuropsychiatric impairment on clinical, psychometric and electrophysiological testing, four showed evidence of subclinical hepatic encephalopathy and 13 had overt hepatic encephalopathy. Signal intensities of the globus pallidus and adjacent brain parenchyma were measured and contrast calculated, which correlated with the severity of the underlying liver disease, when graded according to the Pugh's score (p < 0.05). Proton MRS of the basal ganglia was performed in 12 patients and 14 healthy volunteers. Peak area ratios of choline (Cho), glutamine and glutamate (Glx) and N-acetylaspartate relative to creatine (Cr) were measured. Significant reductions in mean Cho/Cr and elevations in mean Glx/Cr ratios were observed in the patient population. Phosphorus-31 MRS of the basal ganglia was performed in the remaining nine patients and in 15 healthy volunteers. Peak area ratios of phosphomonoesters (PME), inorganic phosphate, phosphodiesters (PDE) and phosphocreatine relative to beta ATP (ATP) were then measured. Mean values of PME/ATP and PDE/ATP were significantly lower in the patient population. No correlation was found between the T1WSE MRI contrast measurements of the globus pallidus and the abnormalities in the metabolite ratios measured from either proton or phosphorus-31 MR spectra. Our results suggest that pallidal hyperintensity seen on T1WSE MR imaging of patients with chronic liver disease is not related to the functional abnormalities of the brain observed in hepatic encephalopathy.