Human adipose angiotensinogen gene expression and secretion are stimulated by cyclic AMP via increased DNA cyclic AMP responsive element binding activity.

Components of the adipose renin-angiotensin system (RAS) have been suggested as providing a potential path-way linking obesity to hypertension. In adipose cells, the biological responses to beta-adrenergic stimulation are mediated by an increase in intracellular cAMP. Because an association exists among body fat mass, hypertension, and increased sympathetic stimulation, we examined the influence of cAMP on angiotensinogen (ATG) expression and secretion in human adipose tissue and in parallel we studied the DNA binding activity of CRE transcriptional factors.

cAMP-positive regulation of angiotensinogen gene expression and protein secretion in rat adipose tissue.

The adipose renin-angiotensin system (RAS) has been assigned to participate in the control of adipose tissue development and in the pathogenesis of obesity-related hypertension. In adipose cells, the biological responses to beta-adrenergic stimulation are mediated by an increase in intracellular cAMP. Because cAMP is known to promote adipogenesis and because an association exists between body fat mass, hypertension, and increased sympathetic stimulation, we examined the influence of cAMP on angiotensinogen (ATG) expression and secretion in rat adipose tissue.

Differences in type II, IV, V and VI adenylyl cyclase isoform expression between rat preadipocytes and adipocytes.

Adenylyl cyclase catalytic activity is low in preadipocyte membranes when compared to adipocytes. Under conditions promoting inhibition of adipocyte adenylyl cyclase activity by Gpp(NH)p, a stable GTP analog, a paradoxical increase in preadipocyte adenylyl cyclase activity was obtained. In order to explain this contradiction, expression of types II, IV, V and VI adenylyl cyclase isoforms was compared in adipocytes and undifferentiated preadipocytes both by western blots and by a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) assay.

Androgen regulation and site specificity of angiotensinogen gene expression and secretion in rat adipocytes.

Adipose tissue is an important source of angiotensinogen (ATG), and hypertension is commonly associated with android obesity. Therefore, we tested the hypothesis that androgens may control ATG gene expression and secretion in rat fat cells. In intact male rats, ATG mRNA expression (Northern blot and co-reverse transcription-polymerase chain reaction analysis) and protein secretion were significantly higher in deep intra-abdominal (perirenal and epididymal) than in subcutaneous adipocytes.

Semi-quantitative RT-PCR for comparison of mRNAs in cells with different amounts of housekeeping gene transcripts.

A simple method is reported here for the semi-quantitative assay of mRNAs in the presence of an exogenous mRNA (pBR322 transcript) as a standard. This method uses the co-reverse transcription and co-amplification (co RT-PCR) of the target and standard mRNAs. This procedure enables transcripts to be compared when the differentiation process affects the transcription pattern of the beta-actin housekeeping gene, a commonly used internal standard.

Mutant alpha-subunit of the G protein G12 activates proliferation and inhibits differentiation of 3T3-F442A preadipocytes.

We studied the G protein alpha-subunit Galpha12 in various tissues and cell lines. Significant amounts of Galpha12 were detected by immunoblots in liver, chromaffin cells, RINm5F cells, 3T3-F442A cells, and preadipocytes, but not in adipocytes, sperm, kidney, NB2A cells, or brain. To study the role of Galpha12 in adipose tissue differentiation, the preadipocyte cell line 3T3-F442A was transfected with wild-type Galpha12 or a constitutively activated mutant of Galpha12.

Role of factor VIII on activated protein C resistance ratio in inflammatory diseases.

Activated protein C resistance ratio (APC-Rr), factor VIIIC (FVIIIC) and plasma fibrinogen levels were studied in patients with inflammatory disease. The patient mean APC-Rr was significantly lower than in the control group. This decreased ratio in inflammatory diseases appeared to be connected with increased FVIIIC.

Activated protein C sensitivity ratio in pregnant women at delivery.

We studied activated protein C sensitivity ratio (APC-SR), factors V and VIII activity and von Willebrand antigen in control women, women using oral contraceptives, and pregnant women at delivery. The mean APC-SR of 2.4 in pregnant women was significantly lower than the mean APC-SR value of 3.