Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pituitary adenylate cyclase activating polypeptide (PACAP) is a new member of the secretin/glucagon/vasoactive intestinal peptide (VIP) family. It stimulates adenylate cyclase in cultured rat pituitary cells, which have PACAP-specific receptors and expression of pituitary hormones. Therefore, PACAP is considered as a hypophysiotropic hormone. If so, there might be a feedback regulatory mechanism between pituitary hormones and hypothalamic PACAP. In the present study, we used nuclear run-on and RNase protection assays to examine whether transcription of the PACAP gene in the rat hypothalamus would change after hypophysectomy. PACAP levels in the hypothalamus were also determined by radioimmunoassay. The transcriptional rate of the PACAP gene and PACAP mRNA content decreased 1 and 2 weeks after hypophysectomy. Radioimmunoassayable PACAP levels in the hypothalamus also decreased after hypophysectomy. These findings suggest that the reduced rate of PACAP gene transcription after hypophysectomy causes the decreased mRNA and peptide levels in the hypothalamus. Replacement with GH, PRL, T4, corticosterone, and testosterone significantly restored PACAP mRNA levels in hypophysectomized rats to those in control animals. The results suggest that feedback regulation takes place between pituitary hormones or pituitary-dependent factors and hypothalamic PACAP.
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PMID:Effect of hypophysectomy on pituitary adenylate cyclase activating polypeptide gene expression in the rat hypothalamus. 765 92

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a member of the secretin/glucagon/vasoactive intestinal peptide (VIP) family. Our immunohistochemical and in situ hybridization histochemical studies indicated that PACAP-like immunoreactivity (PACAP-LI) and its mRNA were present in the germ cells in the rat testis. Because the testicular function is regulated by the pituitary gonadotropins, effect of hypophysectomy on the PACAP gene expression was investigated in the rat testis as an attempt to reveal the regulation of the testicular PACAP by the pituitary. The levels of testicular PACAP mRNA, which were determined by RNase protection assay, increased 2 weeks after hypophysectomy. In contrast, the levels of radioimmunoassayable PACAP decreased 2 weeks after the surgery. Immunohistochemistry showed that hypophysectomy did not change the distribution of PACAP-LI, although the number of immunopositive cells was markedly reduced after hypophysectomy. The replacement treatments of hypophysectomized animals with FSH or LH+FSH restored testicular PACAP mRNA to the levels in the control animals. On the other hand, all of these treatments (testosterone, LH, FSH, or LH+FSH) significantly increased radioimmunoassayable PACAP in the hypophysectomized rat testis. The results suggest that both testicular PACAP and its mRNA expression are regulated by the hypothalamic-pituitary-gonadal activity, and that FSH may play a major role in this regulation.
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PMID:Effect of hypophysectomy on pituitary adenylate cyclase-activating polypeptide gene expression in the rat testis. 853 85

Pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) are two structurally related peptides with pleiotropic physiological effects. Biochemical and cloning experiments have demonstrated that there are two structurally distinct receptors which recognize PACAP and VIP peptides with similar affinities (PACAP/VIP R-1, PACAP/VIP R-2), as well as a receptor that is specific for the PACAP peptide (PACAP-Type 1 receptor). Using a homology-based cloning strategy we have identified PACAP/VIP R-2 receptor in human adipocytes, a tissue which was not previously identified as a target for PACAP and VIP action. This receptor type recognizes PACAP-38 and VIP similar affinity with inhibition concentrations of IC50 = 6.2 +/- 4.8 nM for PACAP-38 and IC50 = 9.4 +/- 4.6 nM for VIP. Like the other two PACAP receptors types, PACAP/VIP R-2 is coupled to cAMP-mediated signal transduction pathway with effective doses ED50 = 3.2 +/- 1.6 nM and ED50 = 2.2 +/- 0.9 nM for PACAP-38 and VIP respectively. Transcripts of the common PACAP/VIP R-2 are also found in human brain and a number of peripheral tissues, such as pancreas, muscle, heart, lund, kidney, stomach and low levels in the liver. Comparison of the tissue distribution of the human PACAP/VIP R-2 to that of the other two types of human PACAP receptors (PACAP-Type 1 and the other common PACAP/VIP R-1) by RNase protection showed that each of the three PACAP receptors is expressed in a unique set of human peripheral tissues. RNA transcripts for all three PACAP receptor types are found in human heart, brain and adipose tissue, while PACAP/VIP R-2 is the only one of these three receptor types that is expressed in the pancreas and skeletal muscle. These results suggest a novel and not yet characterized role for PACAP and VIP peptides in the neuroendocrine regulation of insulin-glucose homeostasis.
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PMID:Tissue specific expression of different human receptor types for pituitary adenylate cyclase activating polypeptide and vasoactive intestinal polypeptide: implications for their role in human physiology. 893 57

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide which was first isolated from ovine hypothalamic tissue by screening for pituitary adenylate cyclase stimulating activity. Our previous data showed that radioimmunoassayable PACAP and PACAP-binding sites were detected in the whole rat brain as early as embryonic day 14(E14). In order to understand more precisely the developmental pattern of the synthesis of PACAP and its receptors in the brain, we studied the expression of PACAP and its receptor genes in the prenatal and postnatal mouse brain using RNase protection assay. The mRNAs for both PACAP and its receptor were detected as early as 9.5 days of gestation (E9.5) in the whole head of mouse embryos. The levels of PACAP mRNA in the brain increased during the prenatal period peaking at postnatal day 0 (P0). On the other hand, the levels of PACAP receptor mRNA gradually increased after E9.5. The levels sharply increased at P6 (479.0 +/- 82.5% of P0 levels), and then fell to the P3 levels at P10. These data together with our previous study on the ontogeny of PACAP immunoreactivity and its binding sites in the rat brain support the view that PACAP plays an important regulatory role in the development of brain.
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PMID:Ontogeny of pituitary adenylate cyclase activating polypeptide and its receptor mRNA in the mouse brain. 895 77

Expression of pituitary adenylate cyclase-activating polypeptide (PACAP), a neuropeptide with considerable homology to vasoactive intestinal peptide, has been shown to be stimulated by gonadotropins in the ovary. The present studies further evaluated the cell-type specific expression and gonadotropin regulation of PACAP type I receptor (PACAPR) messenger RNA in immature rat ovaries and in cultured preovulatory follicles. Northern blot analysis of ovaries obtained from prepubertal rats revealed the increased expression of PACAPR during prepubertal development. The major cell types expressing PACAPR messenger RNA were granulosa cells of large preantral follicles. Treatment of immature rats with PMSG caused a decrease in ovarian PACAPR expression. In contrast, treatment with human (h) CG at 2 days after PMSG treatment stimulated ovarian PACAPR messenger RNA within 3-6 h in granulosa cells of preovulatory follicles. Treatment of cultured preovulatory follicles in vitro with LH further confirmed the time- and dose-dependent stimulation of PACAPR by gonadotropins in granulosa cells of preovulatory follicles. Moreover, RNase protection assay revealed that the short variant of ovarian PACAPR was the predominant form stimulated during prepubertal development and by gonadotropins. These results demonstrate the expression of PACAPR messenger RNA in granulosa cells of growing follicles and of preovulatory follicles stimulated by gonadotropins, and suggest that PACAP may play a role in the growth of developing follicles and in ovulation as an autocrine/paracrine factor.
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PMID:Stage-specific expression of pituitary adenylate cyclase-activating polypeptide type I receptor messenger ribonucleic acid during ovarian follicle development in the rat. 1065 Sep 52

Pituitary adenylate cyclase-activating polypeptide (PACAP) regulates pituitary hormone biosynthesis and secretion through its cognate receptors. PACAP also plays an important role in the regulation of ovarian steroid biosynthesis. If so, there might be a feedback regulation of hypothalamic PACAP synthesis by the pituitary and by ovarian steroids. In the present study, we used RNase protection assays to determine changes in mRNA levels of PACAP and type I PACAP receptor (PAC(1)) under the conditions of ovariectomy and replacement with ovarian steroids. Progesterone (P) alone or in combination with estradiol (E) induced significant increases in PACAP mRNA level in the medial basal hypothalamus (MBH) and PAC(1) mRNA levels in MBH and the preoptic area (POA). This finding suggests that feedback regulation takes place between the ovary and hypothalamic PACAP neurons. P is known to be a major regulatory feedback factor for hypothalamic luteinizing hormone-releasing hormone (LHRH) neurons, but P receptor is not present in these neurons. Therefore, we examined a possible involvement of PACAP in the feedback regulatory pathway of P to LHRH neurons. After an antisense PAC(1) oligodeoxynucleotide (ODN) was i.c.v.-injected into the third ventricle of E and P-treated rats, LHRH mRNA levels were determined. The ODN markedly decreased the P-induced increase in the LHRH mRNA level. Taken together, the present data suggest that PACAP may play a role as a mediator in the regulation of LHRH synthetic machinery by stimulatory feedback of P.
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PMID:Progesterone increases mRNA levels of pituitary adenylate cyclase-activating polypeptide (PACAP) and type I PACAP receptor (PAC(1)) in the rat hypothalamus. 1089 85

Pituitary adenylate cyclase-activating polypeptide (PACAP) is abundant not only in the brain, but also in the testis. Immunohistochemical studies have shown that PACAP-LI in rat testis is expressed stage specifically in spermatids. This suggests that testicular PACAP participates in the regulatory mechanism of spermatogenesis. Additionally, the ovary contains a relatively small amount of PACAP, conceivably involved in the regulation of folliculogenesis. PACAP is synthesized as a preprohormone and is processed by prohormone convertases, such as PC1, PC2, and PC4. PC4 is expressed only in the testis and ovary, where neither PC1 nor PC2 is expressed. However, whether PC4 is the sole endoprotease for the PACAP precursor in the gonads remains unknown. Recent studies using PC4-transgenic mice revealed that male PC4-null mice exhibited severely impaired fertility, although spermatogenesis appeared to be normal. The female PC4-null mice exhibited delayed folliculogenesis in the ovaries. To examine whether PC4 is the sole processing enzyme for the PACAP precursor in the gonads, we analyzed testicular and ovarian extracts from the PC4-null and wild-type mice for PACAP (PACAP38 and PACAP27) and its messenger RNA using reverse phase HPLC combined with specific RIAs and ribonuclease protection assay, respectively. For RIAs, three different polyclonal antisera with different recognition sites were used to identify PACAP38, PACAP27, and its precursor. Neither the testis nor the ovary from the PC4-null mice expressed PACAP38 or PACAP27, but the levels of PACAP transcripts in the testis and ovary of homozygous PC4-deficient mice were considerably elevated compared with those of the wild-type and heterozygous animals. The findings indicate that PC4 is the sole processing enzyme for the precursor of PACAP in the testis and ovary of mice. The possibility that the absence of bioactive PACAP in the testis and ovary of PC4-null mice caused severely impaired fertility in the males and delayed folliculogenesis in females warrants investigation.
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PMID:Pituitary adenylate cyclase-activating polypeptide precursor is processed solely by prohormone convertase 4 in the gonads. 1101 28

The ribonuclease (RNase) protection assay (RPA) is an extremely sensitive technique used to determine specific mRNAs from cell and tissue extracts. The present protocol presents detailed procedures for a conventional RPA using antisense RNA probes purified with a Fullengther apparatus. The Fullengther has the advantage of being a relatively quick and safe procedure compared to more conventional methods for purification of full-length RNA probes. Using this protocol, we sought to simultaneously determine multiple mRNA species, including splice variants of the type I receptor (PAC(1)) of pituitary adenylate cyclase-activating polypeptide (PACAP), an important mediator in the regulation of luteinizing hormone-releasing hormone (LHRH) synthesis by ovarian steroids such as progesterone [7]. PAC(1) has more than eight splice variants. We have been able to discriminate the hop1 variant from other splice variants. To improve our understanding of the regulation mechanism of genes that are related to each other, such as LHRH and PACAP, it is most important to simultaneously determine genes that are involved in the same physiological areas of regulation. Using only 5 microg of total RNA sample from a single rat preoptic area, we simultaneously determined five different transcripts, including four rare mRNA species such as LHRH, PACAP, and hop1 variant and other splice variants of PAC(1), as well as the internal control of cyclophilin mRNA. This protocol provides a method for the simultaneous determination of multiple transcripts using the RPA.
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PMID:Simultaneous determination of multiple transcripts and splice variants of a primary transcript using ribonuclease protection assays. 1143 Nov 30

Pituitary adenylate cyclase-activating polypeptide (PACAP) is an important hypophysiotrophic factor as well as a regulator for immune, reproductive, and neural tissues. We recently found that TTF-1, a homeodomain-containing transcription factor essential for the development of the fetal diencephalon, is postnatally expressed in the hypothalamic area and plays a transcription regulatory role for certain neurohormones. Based on the similarity of synthesis sites between PACAP and TTF-1 and, moreover, on the presence of conserved core TTF-1 binding motifs in the 5'-flanking region of the PACAP gene, we sought to uncover a regulatory role of TTF-1 in PACAP gene transcription. The TTF-1 homeodomain binds to six of the seven putative binding domains observed in the 5'-flanking region of the PACAP gene. In the C6 glioma cell-line, TTF-1 activates the PACAP promoter in a dose-dependent manner. This transactivation of PACAP by TTF-1 was totally removed when the core TTF-1 binding motif at -369 was deleted. RNase protection assays showed that TTF-1 and PACAP mRNAs have daily fluctuations in the rat hypothalamus. They both were at low levels during the day and high levels during the night. Intracerebroventricular administration of an antisense TTF-1 oligodeoxynucleotide significantly decreased the PACAP mRNA level as well as TTF-1 protein content in the rat hypothalamus, suggesting that TTF-1 also regulates PACAP transcription in vivo. Moreover, the TTF-1 promoter was inhibited by molecular oscillators of CLOCK and BMAL-1. Taken together, these data suggest that TTF-1 plays an important regulatory role in the gene transcription for PACAP, which may be important for the generation of a daily rhythm of hypothalamic PACAP gene expression.
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PMID:Regulation of pituitary adenylate cyclase-activating polypeptide gene transcription by TTF-1, a homeodomain-containing transcription factor. 1212 16