Occupational Diseases ; prevention & control ; Occupational Health Services ; Public Health

AIMTo determine whether adenoviral gene transfer of insulin like growth factor-1 (IGF-1) to the penis of streptozotocin (STZ)-induced diabetic rats could improve erectile capacity.

METHODSTHE STZ diabetic rats were transfected with AdCMV-betagal or AdCMV-IGF-1. These rats underwent cavernous nerve stimulation to assess erectile function and their responses were compared with those of age-matched control rats 1 to 2 days after transfection. In control and transfected STZ diabetic rats, IGF-1 expression were examined by reverse transcription polymerase chain reaction (RT-PCR), Western blot and histology. The penis beta-galactosidase activity and localization of the STZ diabetic rats were also determined.

RESULTSOne to two days after transfection, the beta-galactosidase was found in the smooth muscle cells of the diabetic rat penis transfected with AdCMV-betagal. One to 2 days after administration of AdCMV-IGF-1, the cavernosal pressure, as determined by the ratio of maximal intracavernous pressure-to-mean arterial pressure (ICP/MAP) and total intracavernous pressure (ICP), was increased in response to cavernous nerve stimulation. Transgene expression was confirmed by RT-PCR, Western blot and histology.

CONCLUSIONGene transfer of IGF-1 significantly increased erectile function in the STZ diabetic rats. These results suggest that in vivo gene transfer of IGF-1 might be a new therapeutic intervention for the treatment of erectile dysfunction (ED) in the STZ diabetic rats.

Animals ; Blood Glucose ; metabolism ; Body Weight ; Diabetes Mellitus, Experimental ; physiopathology ; Erectile Dysfunction ; prevention & control ; Genetic Therapy ; Insulin-Like Growth Factor I ; genetics ; Male ; Penile Erection ; physiology ; Penis ; enzymology ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Reference Values ; beta-Galactosidase ; metabolism

BACKGROUNDThe genome of the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) includes sequences encoding the putative protein X4 (ORF8, ORF7a), consisting of 122 amino acids. The deduced sequence contains a probable cleaved signal peptide sequence and a C-terminal transmembrane helix, indicating that protein X4 is likely to be a type I membrane protein. This study was conducted to demonstrate whether the protein X4 was expressed and its essential function in the process of SARS-CoV infection.

METHODSThe prokaryotic and eukaryotic protein X4-expressing plasmids were constructed. Recombinant soluble protein X4 was purified from E. coli using ion exchange chromatography, and the preparation was injected into chicken for rising specific polyclonal antibodies. The expression of protein X4 in SARS-CoV-infected Vero E6 cells and lung tissues from patients with SARS was performed using immunofluorescence assay and immunohistochemistry technique. The preliminary function of protein X4 was evaluated by treatment with and over-expression of protein X4 in cell lines. Western blot was employed to evaluate the expression of protein X4 in SARS-CoV particles.

RESULTSWe expressed and purified soluble recombinant protein X4 from E.coli, and generated specific antibodies against protein X4. Western blot proved that the protein X4 was not assembled in the SARS-CoV particles. Indirect immunofluorescence assays revealed that the expression of protein X4 was detected at 8 hours after infection in SARS-CoV-infected Vero E6 cells. It was also detected in the lung tissues from patients with SARS. Treatment with and overexpression of protein X4 inhibited the growth of Balb/c 3T3 cells as determined by cell counting and MTT assays.

CONCLUSIONThe results provide the evidence of protein X4 expression following SARS-CoV infection, and may facilitate further investigation of the immunopathological mechanism of SARS.

Amino Acid Sequence ; Animals ; BALB 3T3 Cells ; Cercopithecus aethiops ; Growth Inhibitors ; analysis ; physiology ; HeLa Cells ; Humans ; Immunohistochemistry ; Lung ; chemistry ; Mice ; Molecular Sequence Data ; SARS Virus ; chemistry ; Severe Acute Respiratory Syndrome ; metabolism ; Vero Cells ; Viral Structural Proteins ; analysis ; physiology