Ventilation and oxygenation induce endothelial nitric oxide synthase gene expression in the lungs of fetal lambs.

At birth, ventilation and oxygenation immediately decrease pulmonary vascular resistance (PVR) and increase pulmonary blood flow (PBF); more gradual changes occur over the next several hours. Nitric oxide, produced by endothelial nitric oxide synthase (eNOS), mediates these gradual changes. To determine how ventilation and oxygenation affect eNOS gene expression, 12 fetal lambs were ventilated for 8 h without changing fetal descending aortic blood gases or pH (rhythmic distension) or with 100% oxygen (O2 ventilation). Vascular pressures and PBF were measured. Total RNA, protein, and tissue sections were prepared from lung tissue for RNase protection assays, Western blotting, and in situ hybridization. O2 ventilation increased PBF and decreased PVR more than rhythmic distension (P < 0.05). Rhythmic distension increased eNOS mRNA expression; O2 ventilation increased eNOS mRNA expression more and increased eNOS protein expression (P < 0.05). To define the mechanisms responsible for these changes, ovine fetal pulmonary arterial endothelial cells were exposed to 1, 21, or 95% O2 or to shear stress. 95% O2 increased eNOS mRNA and protein expression (P < 0.05). Shear stress increased eNOS mRNA and protein expression (P < 0.05). Increased oxygenation but more importantly increased PBF with increased shear stress induce eNOS gene expression and contribute to pulmonary vasodilation after birth.

Single nucleotide polymorphisms in the promoter region of mir-133a-1 and in pre-mir-152 rs1707 may contribute to the risk of asthma in a Chinese Han population.

OBJECTIVE: microRNAs (miRNAs) play important roles in the pathogenesis of asthma. Single-nucleotide polymorphisms (SNPs) in the promotor regions of miRNAs or pre-miRNAs are involved in the alteration of miRNA expression levels or their maturation process and can contribute to asthma pathogenesis. PATIENTS AND METHODS: A total of 591 asthma cases and 621 controls were recruited for this study to evaluate the genetic effects of the following five single nucleotide polymorphisms (SNPs) on the development of asthma: rs8089787 and rs9948906 in the promoter region of mir-133a-1, pre-mir-499 rs37464444, pre-mir-152 rs1707, pre-mir-155 rs5186. The genotypes were determined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). RESULTS: Logistic regression analysis revealed that the CT and CT+TT genotypes in the mir-133a-1 rs8089787 (CT vs. CC, OR = 0.413, 95% CI: 0.315-0.541; CT+TT vs. CC, OR = 0.443, 95% CI: 0.342-0.574, respectively) were significantly associated with a decreased risk for asthma in sample of the Chinese Han population, compared with CC genotype. Similarly, the CT and CT+TT genotypes in the mir-133a-1 rs9948906 (CT vs. CC, OR = 0.398, 95% CI: 0.300-0.528; CT+TT vs. CC, OR = 0.403, 95% CI: 0.306-0.532, respectively) were associated with a decreased risk of asthma. However, the C alleles of both mir-133a-1 rs8089787 (C vs. T, OR = 1.867, 95% CI: 1.486-2.345) and rs9948906 (C vs. T, OR = 2.177, 95% CI: 1.690-2.804) were significantly associated with an increased risk for asthma. The CT genotype frequencies of pre-mir-152 rs1707 (CT vs. TT, OR = 4.730, 95% CI: 2.425-9.223) were significantly associated with an increased risk for asthma in a Chinese Han population (p < 0.001). The C allele frequencies of pre-mir-152 rs1707 (C vs. T, OR = 6.671, 95% CI: 3.146-14.147) was also significantly associated with an increased risk of asthma in a Chinese Han population (p < 0.001). However, the genotype and allele frequencies of rs5186, located in pre-miR-155, did not significantly differ between the cases and the controls; as well as those of rs3746444 in pre-miR-499. CONCLUSIONS: Our study provided evidence that polymorphisms of rs8089787 and rs9948906 in the promotor region of mir-133a-1 and pre-mir-152 rs1707 may contribute to the risk of asthma in a Chinese Han population.

Increased proliferation of skin cells by sublethal doses of sodium lauryl sulfate.

Most quantitative in vitro approaches to determine irritancy have examined the potential of compounds to decrease biological functions or inhibit growth of cells. Irritants, however, are known to generally have the opposite effect in vivo, i.e. to stimulate cell division. This property has not been directly studied in vitro. We examined the ability of sublethal concentrations of sodium lauryl sulfate (SLS) to stimulate cultured keratinocyte and fibroblast proliferation in vitro. The growth of keratinocytes, without added growth factors, continuously exposed to SLS for 4 days was stimulated approximately 89% compared to control. Keratinocytes exposed to SLS for 1 or 18 h were stimulated 36 and 12%, respectively, over the next 4 days of growth. Subconfluent fibroblasts were also stimulated approximately 38%. Confluent fibroblasts were stimulated 40%. All stimulations were maximal between 10(-8) and 10(-5) M added SLS. Media conditioned by keratinocytes exposed to 10(-8) M SLS were able to increase the growth of naive keratinocytes by 117%. In all experiments doses of SLS > 10(-5) M inhibited cell growth. We conclude that sublethal doses of SLS can stimulate the growth of cultured keratinocytes and fibroblasts. The stimulation of growth seen may be related to the stimulation observed in in vivo irritation.

[Renal function in chronic cor pulmonale monitored with beta 2-microglobulin].

Serum and urine levels of beta 2-microglobulin (beta 2-MG) were measured with radioimmune assay in 40 chronic cor pulmonale patients (52 episodes) and 26 normal controls. The results showed that the serum and urine levels of beta 2-MG were 2.01 +/- 0.47 mg/L and 0.10 +/- 0.08 mg/L respectively, in the normal controls, while in the cor pulmonale group 3.86 +/- 1.58 mg/L and 0.66 +/- 0.34 mg/L respectively, with statistical significance (P less than 0.001, less than 0.005). It was shown that there was a positive correlation between the levels of serum and urine beta 2-MG and PaCO2 and a negative correlation between the levels of serum and urine beta 2-MG and PaO2. The results indicated that determination of serum and urine beta 2-MG could be used in the early detection of the renal impairment in chronic cor pulmonale. The predisposing factors of renal dysfunction in cor pulmonale were also discussed.

Cellular pharmacology and molecular biology of the trabecular meshwork inducible glucocorticoid response gene product.

Studies of the effects of glucocorticoid (GC) and oxidative stress stimuli in differentiated cultures of human trabecular meshwork (HTM) cells have provided the rationale for our studies of a major new gene termed TIGR (trabecular meshwork inducible GC response). The TIGR clone was isolated by differential library screening using selection criteria based on the induction pattern of a new protein/glycoprotein found in HTM cultures after prolonged but not brief exposure to GCs. This GC induction pattern matched the time course and dose response required for intraocular pressure elevation in patients receiving corticosteroids. The very large, progressive induction of TIGR combined with specific structural features of its cDNA suggested that TIGR should be considered a candidate gene for outflow obstruction in glaucoma. Among the properties of TIGR cDNA were a signal sequence for secretion, several structural features for interactions with glycosaminoglycans and other glycoproteins and putative sites for cell surface interactions. In addition, the leucine zippers in the structure were related to TIGR-TIGR oligomerization that was shown to occur with native and recombinant TIGR protein. The verification that TIGR was a major stress response protein in HTM cells following hydrogen peroxide (or phorbol esters) exposure provided a potential link between GC and oxidative mechanisms thought to be involved in glaucoma pathogenesis. Pharmacological evaluation showed that basic fibroblast growth factory and transforming growth factor beta decreased the GC induction of TIGR, and certain nonsteroidal anti-inflammatory drugs protected against both GC- and oxidation-induced stress responses in HTM cells. Our recent studies of TIGR's genomic structure have shown motifs in the promoter region that suggest a basis by which multiple hormonal/environmental stimuli can regulate TIGR production and by which putative genetic alterations could lead to an overexpression of the protein. Further application of cell biology/biochemistry, molecular biology, genetic and histological approaches will be helpful in understanding the role of TIGR in different glaucoma syndromes.