Cardiovascular Outcomes in Autonomous Cortisol Secretion and Nonfunctioning Adrenal Adenoma: A Systematic Review

There is growing evidence that autonomous cortisol secretion (ACS), previously known as subclinical Cushing syndrome, is associated with greater prevalence of cardiovascular (CV) risk factors. However, it is unclear whether ACS is associated with greater prevalence of CV outcomes compared with nonfunctioning adrenal adenomas (NFAAs). The objective of this study is to evaluate CV outcomes and CV risk factors in patients with adrenal adenoma with ACS compared with NFAA. A literature review was performed in Embase, Medline, Cochrane Library, and reference lists within selected articles. The study protocol was registered with PROSPERO. A literature search yielded six studies that met the inclusion criteria. Studies varied in their definitions of ACS and CV outcomes. Two retrospective longitudinal studies further demonstrated higher incidence of new CV events (ACS 16.7% vs NFAA 6.7%, P = 0.04) and higher CV mortality in patients with ACS (ACS 22.6% vs 2.5%, P = 0.02). The prevalence of CV outcomes in ACS was more than three times greater than in patients with NFAA. Three of five studies found that ACS was associated with higher prevalence of diabetes and hypertension. There was no difference in dyslipidemia or body mass index demonstrated in any study. There is heterogeneity among the few studies evaluating the association between ACS and CV outcomes. Although these studies suggest a higher risk of CV outcomes in patients with ACS, many did not adjust for known confounders. Larger, high quality, prospective studies are needed to evaluate this association and to identify modifiable risk factors.

A serine 37 mutation associated with two missense mutations at highly conserved regions of p53 affect pro-apoptotic genes expression in a T-lymphoblastoid drug resistant cell line

The p53 protein accumulates rapidly through post-transcriptional mechanisms following cellular exposure to DNA damaging agents and is also activated as a transcription factor leading to growth arrest or apoptosis. Phosphorylation of p53 occurs after DNA damage thereby modulating its activity and impeding the interaction of p53 with its negative regulator oncogene Mdm2. The serines 15 and 37 present in the amino terminal region of p53 are phosphorylated by the DNA-dependent protein kinase (DNA-PK) in response to DNA damage. In order to verify if specific p53 mutations occur in the multi-drug resistance phenotype, we analysed the p53 gene in two T-lymphoblastoid cell lines, CCRF-CEM and its multi-drug-resistant clone CCRF-CEM VLB100, selected for resistance to vinblastine sulfate and cross-resistant to other cytotoxic drugs. Both cell lines showed two heterozygous mutations in the DNA binding domain at codons 175 and 248. The multi-drug resistant cell line, CCRF-CEM VLB100, showed an additional mutation that involves the serine 37 whose phosphorylation is important to modulate the protein activity in response to DNA damage. The effects of these mutations on p53 transactivation capacity were evaluated. The activity of p53 on pro-apoptotic genes expression in response to DNA damage induced by (-irradiation, was affected in the vinblastine (VLB) resistant cell line but not in CCRF-CEM sensitive cell line resulting in a much reduced apoptotic cell death of the multi-drug resistant cells.

Molecular cloning, expression and site-directed mutagenesis of glutathione S-transferase from Ochrobactrum anthropi

The gene coding for a novel glutathione S-transferase (GST) has been isolated from the bacterium Ochrobactrum anthropi. A PCR fragment of 230 bp was obtained using oligonucleotide primers deduced from N-terminal and 'internal' sequences of the purified enzyme. The gene was obtained by screening of a genomic DNA partial library from O. anthropi constructed in pBluescript with a PCR fragment probe. The gene encodes a protein (OaGST) of 201 amino acids with a calculated molecular mass of 21738 Da. The product of the gene was expressed and characterized; it showed GST activity with substrates 1-chloro-2, 4-dinitrobenzene (CDNB), p-nitrobenzyl chloride and 4-nitroquinoline 1-oxide, and glutathione-dependent peroxidase activity towards cumene hydroperoxide. The overexpressed product of the gene was also confirmed to have in vivo GST activity towards CDNB. The interaction of the recombinant GST with several antibiotics indicated that the enzyme is involved in the binding of rifamycin and tetracycline. The OaGST amino acid sequence showed the greatest identity (45%) with a GST from Pseudomonas sp. strain LB400. A serine residue in the N-terminal region is conserved in almost all known bacterial GSTs, and it appears to be the counterpart of the catalytic serine residue present in Theta-class GSTs. Substitution of the Ser-11 residue resulted in a mutant OaGST protein lacking CDNB-conjugating activity; moreover the mutant enzyme was not able to bind Sepharose-GSH affinity matrices.