Endothelin messenger RNA and receptors are differentially expressed in cultured human breast epithelial and stromal cells.

Paracrine regulation is implicit in the biosynthesis and secretion of milk in the breast. An important determinant for this regulation in vivo is proximate cellular location as exemplified by stromal and epithelial cells in breast tissue. Cultured human breast epithelial cells exhibited low constitutive expression of mRNA for endothelin which was enhanced 20-fold after prolactin stimulation. Human breast stromal cells did not express measurable levels of endothelin mRNA under similar conditions. In a similar differential manner, the stimulated release of immunoreactive endothelin into medium overlay was observed only for breast epithelial and not stromal cells. Specific cell-surface receptors for endothelin and biochemical responsiveness to the peptide were observed only in the stromal cells.     

Transient elevation of messenger RNA encoding gastrin-releasing peptide, a putative pulmonary growth factor in human fetal lung.

Gastrin-releasing peptide (GRP), the mammalian homologue of the amphibian peptide bombesin, is present in pulmonary neuroendocrine cells and appears to be a growth factor for both normal and neoplastic pulmonary cells. Previously we have reported the cloning of the messenger RNAs (mRNAs) and gene that encode human GRP. We now report that GRP mRNAs are markedly elevated in human fetal lung during the canalicular phase of pulmonary development (from approximately 16 to 30 wk gestation). By RNA blot and in situ hybridization analyses, GRP mRNAs were first detectable in fetal lung at 9-10 wk, plateaued at levels 25-fold higher than in adult lungs from 16 to approximately 30 wk and then declined to near adult levels by 34 wk gestation. By contrast, GRP peptide levels remain elevated until several months after birth. Consistent with this, in situ hybridization and immunohistochemical studies showed that GRP mRNA and peptide consistently colocalized in early gestation lung but that in neonatal lung, many cells that contained GRP peptide no longer contained GRP mRNA. The transient expression of high levels of GRP mRNAs during an approximately 12-wk phase of fetal lung development suggests that the secretion of GRP or its COOH-terminal peptides from pulmonary neuroendocrine cells may play a role in normal lung development.     

Survivin和CD133在急性白血病中的表达及其意义

目的：探讨survivin和CD133在急性白血病（AL）患者骨髓液中的表达及其意义。方法：应用逆转录聚合酶链反应（RT-PCR）检测50例AL患者和10例正常对照者骨髓液中survivin、CD133mRNA表达，并将结果与AL临床特征、血液学特点及疗效相比较。结果：（1）AL患者骨髓液中survivin表达和CD133表达的阳性率分别为78％和42％，均高于正常对照组（P〈0．05），其表达及表达强度与年龄、性别、WBC计数、碱性磷酸酶、肝脾及淋巴结肿大均无明显关系（P〉0．05），survivin与化疗疗效有关（P〈0．05），CD133与分型有关（P〈0．05）。且表达强度越高，完全缓解率愈低（P〈0．05）。（2）Survivin和CD133在AL骨髓液中的表达呈正相关性（r=0．6429）。（3）Survivin、CD133mRNA均阳性的AL患者完全缓解率明显低于两者均阴性的患者（P〈0．05）。结论：（1）Survivin和CD133在AL患者骨髓液中表达上调，提示其可能在白血病的发生、发展中起重要作用。（2）Survivin表达与化疗疗效有关，CD133与AL分型有关。（3）Survivin、CD133mRNA可做为预后不良的因素之一。     

Activated peripheral blood mononuclear cells in IgA nephropathy express platelet-derived growth factor B-chain messenger RNA.

We investigated platelet-derived growth factor (PDGF) A- and B-chain messenger RNA expression in peripheral blood mononuclear cells or T cells obtained from 26 patients with IgA nephropathy and 15 healthy age-matched control subjects. Most patients with IgAN (88%) showed elevated PDGF B-chain expression in peripheral blood mononuclear cells; no PDGF B-chain expression was detected in peripheral blood mononuclear cells of normal control subjects. In T cells from both patients with IgAN and normal control subjects, however, PDGF B-chain messenger RNA expression was not detected. A positive correlation was noted between PDGF B-chain messenger RNA levels and urinary protein excretion. The PDGF B-chain messenger RNA expression in peripheral blood mononuclear cells also correlated with histopathologic changes in renal tissue obtained from patients with IgAN. Sixty-five percent of patients with grade III or IV histopathologic findings showed strong PDGF B-chain gene expression in their peripheral blood mononuclear cells. We could not detect PDGF A-chain messenger RNA expression in either peripheral blood mononuclear cells and T cells obtained from patients with IgAN and from healthy control subjects. These studies suggest that abnormally regulated PDGF B-chain expression in peripheral blood mononuclear cells may be associated with the progression of IgAN and may be useful as an indicator of disease activity.     

Identification of messenger RNA for nucleocapsid protein of Lassa virus in infected cells

Single-stranded RNAs from Lassa virus-infected cells were fractionated by affinity chromatography on an oligo(dT)-cellulose column as well as by sucrose gradient centrifugation. Fractionated RNAs were translated in rabbit reticulocyte lysates, and translation products were precipitated with monoclonal antibodies to the nucleocapsid protein of Lassa virus. It has been shown that mRNA for the nucleocapsid protein is 15-16S and the RNA does not contain long if any poly(A) sequences.     

大鼠脊髓损伤后诱导型一氧化氮合酶的表达及动态改变

目的:探讨大鼠急性脊髓损伤后不同时段髓内诱导型一氧化氮合酶(iNOS)mRNA动态表达。方法:36只SD大鼠抽签法随机分组,任选一组作为对照。采用Allen法制作急性脊髓损伤模型,在损伤后2,6,12,24,48h等时段,以反转录酶聚合酶链式反应(RT-PCR)分析iNOSmRNA表达。在脊髓损伤后24h,用免疫组化方法分析iNOS在脊髓不同类型神经细胞中的表达与分布,并以比色法测定脊髓损伤后血清NOS及一氧化氮的含量。结果:脊髓损伤后,神经元、星形细胞和小胶质中均可见iNOS表达,以神经元表达为主。脊髓损伤后2h可见iNOS表达0.56±0.02,24h达高峰1.20±0.05,48h开始降低0.70±0.06。血清中NOS及一氧化氮的动态改变与损伤组织iNOSmRNA变化趋势相一致。结论:研究资料提示脊髓损伤后脊髓内iNOS表达增高,过量产生的一氧化氮加重了继发性脊髓损伤。     

Developmental and hormonal regulation of glucocorticoid receptor messenger RNA in the rat.

HIV selectively inhibited the proliferative response of clonal CD4+ T lymphocytes to alloantigen while other alloantigen-dependent responses were unperturbed. Specifically, impaired blastogenesis could be dissociated from alloantigen-specific induction of the B cell activation molecule CD23, IL-4 release, and inositol lipid hydrolysis. In addition, membrane expression of pertinent T cell receptor molecules, including CD2, CD3, and T cell antigen receptor (Ti), remained intact. Using two MHC class II-specific human CD4+ helper T cell clones, the proliferative defect was shown to be an early consequence of HIV infection, occurring within 4 d of viral inoculation and preceding increases in mature virion production. It was generalizable to three distinct methods of T cell activation, all independent of antigen-presenting cells: anti-CD3 mediated cross-linking of the CD3/Ti complex; anti-CD2 and phorbol 12-myristic 13-acetate (PMA); and anti-CD28 plus PMA. These abnormalities were not mitigated by addition of exogenous IL-2, even though expression of the IL-2 receptor (CD25) was unaltered. These studies define a selective blockade in T cell function early after HIV exposure that could serve as a model for certain in vivo manifestations of AIDS.     

Defects in DNA and globin messenger RNA in homozygotes for hemoglobin Lepore.

Globin messenger RNA (mRNA) isolated from three patients homozygous for hemoglobin Lepore is shown to have a marked reduction of the amount of beta-like globin mRNA (Lepore-globin mRNA sequences) compared with alpha-globin mRNA by molecular hybridization. The relative amounts of alpha- and Lepore mRNA are similar to the amounts of alpha- and Lepore globin synthesized in intact cells and by isolated mRNA in a cell-free system. It is also demonstrated that Lepore-globin mRNA can completely hybridize to full-length or nearly full-length beta-globin specific complementary DNA and protect it from nuclease digestion, indicating close homology between the delta-mRNA sequences present in Lepore mRNA and the beta-complementary-DNA probe. We have also quantitated the numbers of beta-like globin gene sequences in genomic Lepore DNA by molecular hybridization and demonstrated a reduction in their number consistent with the Lepore gene being a delta beta-gene fusion product.     

Androgen regulation of rat renal angiotensinogen messenger RNA expression.

Renal angiotensinogen (ang-n) mRNA concentration in the male WKY rat increases significantly during puberty. Furthermore, renal angiotensinogen mRNA level in the adult female WKY rat is considerably lower than in the male. The present study investigates the role of androgen in differential renal ang-n mRNA expression. Northern and slot blot analyses with alpha-32P labeled ang-n cDNA (pRang 3) demonstrated that castration lowered ang-n mRNA levels in the male kidney by greater than or equal to 60% compared with control, suggesting that androgen may be involved with renal ang-n gene regulation. Moreover, male WKY rats castrated as weanlings and normal adult female WKY rats each implanted with testosterone displayed significant (P less than 0.05) increases in renal ang-n mRNA levels. Our observations, taken together with previous reports that androgen influences proximal tubule morphology and the tubular expression of transport proteins (e.g., Na+/H+ antiporter), may have important physiological implications for understanding the relationship between androgen and angiotensin in the regulation of tubular function.     

Delivery of functional DNA and messenger RNA to mammalian phagocytic cells by recombinant yeast

Among the different vaccination approaches, DNA/RNA vaccination represents a promising means in particular for the induction of effective cellular immune responses conferred by CD8-positive T lymphocytes. To achieve such immune responses, there is a need for novel delivery systems that allow the introduction of nucleic acids to the cytosol of immune cells. We show, for the first time, the delivery of functional DNA and messenger RNA (mRNA) to mammalian antigen-presenting cells, including murine macrophages and human dendritic cells, using the yeast Saccharomyces cerevisiae as the delivery vehicle. After transfer of the particular nucleic acid, subsequent antigen processing and presentation were demonstrated in a human system. Remarkably, release of DNA/mRNA does not require additional 'helper' proteins such as listeriolysin. In conclusion, the yeast-based system described here is superior to many bacterial and viral systems in terms of efficacy, safety and targeting suggesting 'mycofection' as a promising approach for the development of a novel type of live vaccines.     

Rabbit aortic smooth muscle cells express inducible macrophage scavenger receptor messenger RNA that is absent from endothelial cells.

Scavenger receptors mediate uptake of modified low density lipoproteins by macrophages. The accumulation of lipids via this process is thought to lead to foam cell formation in developing atherosclerotic plaques. Smooth muscle cells, which can also be converted to foam cells in vivo, have not been shown to express the same scavenger receptor previously cloned in macrophages. We report the cloning of two cDNAs that encode type I and type II scavenger receptors isolated from rabbit smooth muscle cells. The deduced protein sequences of these isolates are highly homologous to the scavenger receptors previously isolated from macrophages. Treatment of smooth muscle cells with phorbol esters induced a marked increase in scavenger receptor mRNA and a fivefold increase in receptor degradation activity. Rabbit venous endothelial cells in primary culture and a bovine aortic endothelial cell line had no detectable scavenger receptor mRNA, despite having scavenger receptor degradation activity. The latter finding suggests that endothelial cells may possess a scavenger receptor which is structurally distinct from that found in macrophages and smooth muscle cells. The isolation of cDNAs encoding the rabbit scavenger receptor should prove useful for in vitro and in vivo studies that employ the rabbit as a model of human atherosclerosis.     

Degradation of gastrin by gastric mucosal cells.

Specific binding of radiolabeled gastrin by gastric mucosal cells prepared from guinea pigs was detected and examined. Specific cell binding of gastrin was found to be both pH and temperature dependent. Maximum binding of radiolabeled gastrin by gastric mucosal cells was demonstrated at pH 7.4 and at 4 degrees C. Substantial degradation of 125I-gastrin occurred during incubation with gastric mucosal cells. Gastrin degradation was detected both by loss of immunological reactivity with antibodies to gastrin and by abolition of subsequent specific binding after prior incubation with gastric mucosal cells. Degradation of gastrin was most marked with incubations conducted at pH 7.4 and at low pH (pH 2.0), suggesting the activities of at least two gastrin-degrading enzyme systems in the gastric mucosal cell preparation.