Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A model of gastric ulceration in the rat has been used to determine the expression of four messenger RNAs (mRNAs) encoding peptides considered to play active parts in the healing response. The trefoil peptides, rat spasmolytic polypeptide (rSP) and rat intestinal trefoil factor (rITF), along with epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) were the molecules studied. Ulceration was caused under anaesthesia by brief application of a liquid nitrogen-filled cryoprobe to the gastric serosal surface and RNA expression was monitored over the next 10 days. Each mRNA was quantified by ribonuclease protection assay, and mRNAs encoding rSP and rITF were localized within tissue sections by hybridization in situ with 35S antisense riboprobes. Ulceration induced the very rapid expression of first rSP and then rITF mRNA, whereas the mRNAs encoding EGF and TGF alpha increased at later times, with maxima recorded at 3 and 6 days, respectively. Hybridization in situ detected extensive rSP mRNA expression in the regenerative epithelia. The pronounced, but temporally different patterns of mRNA induction after ulceration suggest that the trefoil peptides may fulfil different and more immediate roles than the more 'traditional' healing proteins EGF and TGF alpha.
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PMID:Experimental ulceration leads to sequential expression of spasmolytic polypeptide, intestinal trefoil factor, epidermal growth factor and transforming growth factor alpha mRNAs in rat stomach. 779 Sep 95

Autocrine expression of polypeptide growth factors may be important in the growth regulation of cancer cells. Different growth factor activities have been identified in a variety of tumors. This article describes a case of malignant ascites in a patient recently treated for breast cancer. The use of growth factor mRNA expression as a factor to differentiate between breast and ovarian origins of cancer cells contained in malignant ascites was examined. Expression of insulin-like growth factor-I (IGF-I), IGF-II, and transforming growth factor alpha mRNA was examined by ribonuclease protection assay. The tumor cells expressed IGF-II and transforming growth factor alpha, but not IGF-I mRNA. This pattern of growth factor expression is compatible with a breast cancer primary of the malignant cells contained in the ascites fluid. Therefore, IGF-I mRNA expression may be useful in distinguishing between adenocarcinomas of breast or ovarian origins.
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PMID:Case report: use of insulin-like growth factor-I gene expression to distinguish between breast and ovarian cancer. 814 Nov 35

In order to study whether hypothalamic transforming growth factor alpha (TGFalpha) gene expression in the monkey is estrogen-sensitive, long-term ovariectomized rhesus macaques were implanted subcutaneously with either estradiol-containing (n = 3) or blank (n = 3) Silastic capsules. Blood samples were collected every other day while the animals were lightly sedated with ketamine hydrochloride to monitor circulating LH and estradiol concentrations. Animals were killed with a lethal dose of pentobarbital sodium after a marked suppression of LH secretion was confirmed (81 days of estradiol treatment); the preoptic area (POA), mediobasal hypothalamus (MBH) and samples of cerebral cortex were dissected out, snap-frozen in liquid nitrogen and processed for the determination of TGFalpha messenger RNA (mRNA) by ribonuclease protection assay using a cRNA probe. The opportunity was also taken to study the action of estrogen on hypothalamic GnRH mRNA levels. Although circulating estradiol concentrations of 50-150 pg/ml achieved in the steroid-treated group produced a decrease in hypothalamic GnRH mRNA levels, which was significant in the MBH, TGFalpha mRNA levels in this hypothalamic region and in the POA were not influenced by estrogen treatment. These findings indicate that TGFalpha is probably not involved in mediating the inhibitory action of estradiol on GnRH neurons. Additionally, the relevance of our results to the understanding of the neurobiological mechanisms underlying the initiation of puberty in primates is discussed.
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PMID:Effect of estrogen on hypothalamic transforming growth factor alpha and gonadotropin-releasing hormone gene expression in the female rhesus monkey. 958 92

Growth and differentiation of the mammary gland during development and lactation are controlled by complex hormonal mechanisms. Additionally growth factors are supposed to act as local mediators of the hormonally controlled developmental processes. Mammary tissue for this study was obtained from non pregnant control heifers, primigravid heifers (second part of pregnancy), around parturition, during lactation (early and late) and from dry cows. Using RT-PCR and ribonuclease protections assay (RPA) the expression of the following growth factors was studied in the different phases bovine mammary gland development: Insulin-like growth factor I (IGF-I), insulin-like growth factor II (IGF-II), fibroblast growth factor 1 (FGF-I), fibroblast growth factor 2 (FGF-2), transforming growth factor alpha (TGF-alpha). Additionally the expression of fibroblast growth factor receptor (FGFR) and growth hormone receptor (GHR) was investigated. The cellular distribution pattern of several of these growth factors and GHR was obtained using Immunocytochemical techniques. The detailed expression and localization pattern of these growth factors are presented and their role in the local regulation of the bovine mammary gland is briefly discussed.
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PMID:Expression and localization of growth factors during mammary gland development. 1095 6

Expression of transforming growth factor alpha (TGFalpha), a member of the epidermal growth factor (EGF) family, is a general response of adult murine motoneurons to genetic and experimental lesions, TGFalpha appearing as an inducer of astrogliosis in these situations. Here we address the possibility that TGFalpha expression is not specific to pathological situations but may participate to the embryonic development of motoneurons. mRNA of TGFalpha and its receptor, the EGF receptor (EGFR), were detected by ribonuclease protection assay in the ventral part of the cervical spinal cord from embryonic day 12 (E12) until adult ages. Reverse transcription-PCR amplification of their transcripts from immunopurified E15 motoneurons, associated with in situ double-immunohistological assays, identified embryonic motoneurons as cellular sources of the TGFalpha-EGFR couple. In vitro, TGFalpha promoted the survival of immunopurified E15 motoneurons in a dose-dependent manner, with a magnitude similar to BDNF neuroprotective effects at equivalent concentrations. In a transgenic mouse expressing a human TGFalpha transgene under the control of the metallothionein 1 promoter, axotomy of the facial nerve provoked significantly less degeneration in the relevant motor pool of 1-week-old mice than in wild-type animals. No protection was observed in neonates, when the transgene exhibits only weak expression levels in the brainstem. In conclusion, our results point to TGFalpha as a physiologically relevant candidate for a neurotrophic role on developing motoneurons. Its expression by the embryonic motoneurons, which also synthesize its receptor, suggests that this chemokine is endowed with the capability to promote motoneuron survival in an autocrine-paracrine manner.
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PMID:Transforming growth factor alpha: a promoter of motoneuron survival of potential biological relevance. 1154 18