Alpha-1 antitrypsin gene exon use in stimulated lymphocytes

Lipoproteins in Negative Feedback with Alpha-1 Antitrypsin

Alpha-1 antitrypsin deficiency patients (AATD) have lower risk of myocardial infarction, a cardiovascular disease that is related to increased remnant cholesterol levels, but not to low-density lipoprotein (LDL) levels. However, when AAT is knocked out in mice (AAT-KO), inflammatory-related, cholesterol metabolism-related, and lipid metabolism-related gene expression in mouse liver was increased, and these data support previous evidence from clinic patients and from a small clinical trial that AAT is in negative feedback regulation with LDL. Herein is a brief summary to examine the roles of AAT in these overlapping pathways.

Detection of tumour necrosis factor alpha in sarcoidosis and tuberculosis granulomas using in situ hybridisation

AIMS

To determine the site of tumour necrosis factor alpha (TNF alpha) product and mRNA in granulomas.

METHOD

In situ hybridisation with digoxigenin labelled or biotinylated oligonucleotide probes was used to demonstrate the presence of total mRNA, and then the presence of TNF alpha mRNA in the biopsy specimens of 37 granulomas (31 sarcoidosis, six tuberculosis).

RESULTS

TNF alpha mRNA was detected in epithelioid cells, giant cells, and lymphocytes in the granulomas. Some sarcoidosis specimens did not contain detectable mRNA for TNF, but did contain TNF peptide in the epithelioid or giant cells on immunostaining. This may have been due to stored TNF present in cells in which mRNA for TNF is no longer being produced.

CONCLUSION

The results suggest that giant cells should not be regarded as effete cells, as they contain large amounts of mRNA and seem to be actively producing TNF alpha.