Modifications in integrin expression and extracellular matrix composition in children with biliary atresia

BACKGROUND

The aetiology of biliary atresia (BA) is still unresolved. The study's aim was to investigate the distribution of extracellular matrix proteins and cellular adhesion molecules in children with BA compared to other cholestatic liver disease (CLD) and normal liver architecture (NLA).

PATIENTS

Liver biopsies were obtained from children with BA (n=13), CLD (n=6) and NLA (n=8).

METHOD

We systematically analysed ultra thin frozen sections from the liver hilum stained with 25 monoclonal antibodies for cellular characterisation, extracellular matrix proteins and adhesion molecules.

RESULTS

2 changes were specifically found in BA: laminin beta1 was reduced in children with BA vs. NLA and CLD. Conversely, integrin alpha 3 was increased in BA vs. NLA and CLD (p<0.05). Furthermore, we detected changes in a similar pattern for both BA and CLD vs. NLA: in BA and CLD perlecan was increased. On the contrary, integrin beta1 and entactin were decreased vs. NLA (p<0.05).

DISCUSSION

Extracellular matrix proteins and adhesion molecules mediate cellular polarity and integrity, development of tubular structures, and proliferation. Therefore, our findings can be important for the understanding of the genesis of BA.

CONCLUSION

The composition of extracellular matrix proteins and adhesion molecules in children with BA differs from NLA and other CLD in distribution of laminin beta1 and integrin alpha 3, which may have implications for genetic, immunologic and environmental associations in BA.

Assessment of biochemical liver markers, physical activity, fitness and body mass index for a cardiometabolic risk model in childhood

AIM

The aim of this study was to investigate clustered cardiometabolic risk scores in healthy 10- to 12-year-olds using anthropometric characteristics, measurements of cardiorespiratory fitness (CRF) and physical activity and blood markers of metabolic disease. We also evaluated how including markers of liver cell injury would affect the clustered cardiometabolic risk assessment model.

METHODS

This cross-sectional study focused on 99 children aged 10-12 years. The main outcome included assessing participants with increased and low cardiometabolic risk factors using a clustered risk score model that incorporated markers implicated in metabolic syndrome pathogenesis. Two clustered risk scores were calculated, one incorporating markers of liver cell injury.

RESULTS

Children classified as 'increased risk' exhibited significantly lower CRF and higher body mass index Z-scores than their 'low-risk' peers. No significant differences in physical activity were observed. This trend remained unchanged when markers of liver injury were included in the clustered risk assessment model.

CONCLUSION

The clustered risk score model is a scientifically robust method of cardiometabolic risk assessment, which reiterates the importance of weight reduction and CRF promotion in childhood. Our study did not show a significant contribution of liver injury markers, and further research is needed to evaluate their effect on cardiometabolic risk stratification in childhood.

The immunosuppressive drug mycophenolate mofetil impairs the adhesion capacity of gastrointestinal tumour cells

Immunosuppression correlates with the development and recurrence of cancer. Mycophenolate mofetil (MMF) has been shown to reduce adhesion molecule expression and leucocyte recruitment into the donor organ. We have hypothesized that MMF might also prevent receptor-dependent tumour dissemination. Therefore, we have investigated the effects of MMF on tumour cell adhesion to human umbilical vein endothelial cells (HUVEC) and compared them with the effects on T cell-endothelial cell interactions. Influence of MMF on cellular adhesion to HUVEC was analysed using isolated CD4+ and CD8+ T cells, or WiDr colon adenocarcinoma cells as the model tumour. HUVEC receptors ICAM-1, VCAM-1, E-selectin and P-selectin were detected by flow cytometry, Western blot or Northern blot analysis. Binding activity of T cells or WiDr cells in the presence of MMF were measured using immobilized receptor globulin chimeras. MMF potently blocked both T cell and WiDr cell binding to endothelium by 80%. Surface expression of the endothelial cell receptors was reduced by MMF in a dose-dependent manner. E-selectin mRNA was concurrently reduced with a maximum effect at 1 microm. Interestingly, MMF acted differently on T cells and WiDr cells. Maximum efficacy of MMF was reached at 10 and 1 microm, respectively. Furthermore, MMF specifically suppressed T cell attachment to ICAM-1, VCAM-1 and P-selectin. In contrast, MMF prevented WiDr cell attachment to E-selectin. In conclusion, our data reveal distinct effects of MMF on both T cell adhesion and tumour cell adhesion to endothelial cells. This suggests that MMF not only interferes with the invasion of alloactivated T cells, but might also be of value in managing post-transplantation malignancy.