Inverse correlation between insulin-like growth factor (IGF)-binding protein-5 and IGF-I and II during postnatal development of the anterior pituitary gland

The expression of IGFBP-5 in the reproductive axis and effect on the onset of puberty in female rats

Insulin-like growth factor-binding protein-5 (IGFBP-5) has recently been shown to alter the reproductive capacity by regulating insulin-like growth factor (IGF) bioavailability or IGF-independent effects. The present study aimed to investigate the effect and mechanism of IGFBP-5 on the onset of puberty in female rats. Immunofluorescence and real-time quantitative PCR were used to determine the expression and location of IGFBP-5 mRNA and protein distribution in the infant's hypothalamus-pituitary-ovary (HPO) axis prepuberty, peripuberty, puberty and adult female rats. Prepubertal rats with IGFBP-5 intracerebroventricular (ICV) were injected to determine the puberty-related genes expression and the concentrations of reproductive hormones. Primary hypothalamic cells were treated with IGFBP-5 to determine the expression of puberty-related genes and the Akt and mTOR proteins. Results showed that Igfbp-5 mRNA and protein were present on the HPO axis. The addition of IGFBP-5 to primary hypothalamic cells inhibited the expression of Gnrh and Igf-1 mRNAs (P < 0.05) and increased the expression of AKT and mTOR protein (P < 0.01). IGFBP-5 ICV-injection delayed the onset of puberty, reduced Gnrh, Igf-1, and Fshβ mRNAs, and decreased the concentrations of E2, P4, FSH,serum LH levels and the ovaries weight (P < 0.05). More corpus luteum and fewer primary follicles were found after IGFBP-5 injection (P < 0.05).

RNA-seq analysis of lncRNA-controlled developmental gene expression during puberty in goat & rat

Background

Puberty is a pivotal stage in female animal development, and marks the onset of reproductive capability. However, little is known about the function of lncRNAs (long noncoding RNAs) in puberty. Therefore, RNA-seq analysis were performed between goats and rats to clarify the roles of lncRNAs and mRNAs in the onset of puberty.

Results

In the present study, the length of lncRNAs, the length of the open reading frame and the exon count were compared between the two species. Furthermore, functional annotation analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis of lncRNAs target genes and differentially expressed mRNA demonstrated the significantly enriched terms, such as AMPK signaling pathway, oxytocin signaling pathway, insulin secretion as well as pheromone receptor activity, and some other signaling pathways which were involved in the regulation of female puberty. Moreover, our results of siRNA interference in vitro showed the candidate lncRNA XLOC_446331 may play a crucial role in regulating female puberty.

Conclusion

In conclusion, the RNA-seq analysis between goat and rat provide novel candidate regulators for genetic and molecular studies on female puberty.

Electronic supplementary material

The online version of this article (10.1186/s12863-018-0608-9) contains supplementary material, which is available to authorized users.

Effect of Furosemide Infusion on Renal Hemodynamics and Angiogenesis Gene Expression in Acute Renal Ischemia/Reperfusion

Loop diuretics are known to affect renal hemodynamics and possibly gene transcription, but the specific effect of furosemide on renal angiogenesis gene expression after acute ischemia is not known. We utilized an acute renal failure model in rats to test the hypothesis that furosemide improves renal hemodynamics and alters the transcriptional signature of acute ischemic nephropathy. Twenty-four male Sprague-Dawley rats were anesthetized by the intraperitoneal administration of 50 mg/kg urethane. Animals were divided into four groups (n = 6 each): (1) sham-operated group infused with saline; (2) sham-operated group infused with 30 microg/kg/hr furosemide (equivalent to a human dosage of 2 mg/hr); (3) unilateral renal ischemia (1 hr, left renal artery cross-clamping) followed by 6 hr of reperfusion; and (4) renal ischemia/ reperfusion (I/R) with furosemide. Renal artery blood flow (RBF), renal cortical perfusion (RCP), and renal corticomedullary tissue oxygen tension (PO2) were recorded throughout. Following 6 hr of reperfusion, left kidney RNA was used to probe microarrays. Gene expression was measured as percent positive control and confirmed using reverse transcriptase polymerase chain reaction. Physiologic data were analyzed by calculating area under the curve, and gene expression data were compared by using multiple analysis of variance with Tukey's post-hoc tests. Furosemide significantly increased RBF (P < 0.05) and PO2 (P < 0.05) in postischemic kidneys. Furosemide attenuated nine of the 13 ischemia-induced and 41 of 78 ischemia-suppressed angiogenesis-related genes. This attenuation was statistically significant (P < 0.05) for 17 I/R injury-suppressed genes. Data from this rat model of ischemic nephropathy suggest that furosemide improves renal hemodynamics and attenuates ischemia-related changes in gene expression.

Prenatal choline availability modulates hippocampal and cerebral cortical gene expression

An increased supply of the essential nutrient choline during fetal development [embryonic day (E) 11-17] in rats causes life-long improvements in memory performance, whereas choline deficiency during this time impairs certain aspects of memory. We analyzed mRNA expression in brains of prenatally choline-deficient, choline-supplemented, or control rats of various ages [postnatal days (P) 1 to 34 for hippocampus and E16 to P34 for cortex] using oligonucleotide microarrays and found alterations in gene expression levels evoked by prenatal choline intake that were, in most cases, transient occurring during the P15-P34 period. We selected a subset of genes, encoding signaling proteins, and verified the microarray data by reverse transcriptase-polymerase chain reaction analyses. Prenatally choline-supplemented rats had the highest expression of calcium/calmodulin (CaM)-dependent protein kinase (CaMK) I and insulin-like growth factor (IGF) II (Igf2) in the cortex and of the transcription factor Zif268/EGR1 in the cortex and hippocampus. Prenatally choline deficient rats had the highest expression of CaMKIIbeta, protein kinase Cbeta2, and GABA(B) receptor 1 isoforms c and d in the hippocampus. Similar changes in the expression of the proteins encoded by these genes were observed using immunoblot analyses. These data show that the prenatal supply of choline causes multiple modifications in the developmental patterns of expression of genes known to influence learning and memory and provide molecular correlates for the cognitive changes evoked by altered availability of choline in utero.

Fenoldopam Inhibits Nuclear Translocation of Nuclear Factor Kappa B in a Rat Model of Surgical Ischemic Acute Renal Failure

OBJECTIVE

Vasoactive compounds are known to modulate gene transcription, including nuclear factor kappa B (NF-kappaB), in renal tissues, but the molecular effects of fenoldopam in this setting are not known. The authors used a rat model of surgical acute ischemic nephropathy to test the hypothesis that fenoldopam attenuates ischemia/reperfusion (I/R)-induced NF-kappaB-mediated inflammation.

DESIGN

Prospective, single-blind, randomized, controlled animal study.

SETTING

Academic Department of Anesthesiology laboratory.

SUBJECTS

Twenty-four male Sprague-Dawley rats.

INTERVENTIONS

Rats were anesthetized by intraperitoneal administration of 50 mg/kg of urethane and randomly allocated into 4 groups (n = 6 each): sham operation, sham operation with infusion of 0.1 microg/kg/min of fenoldopam, unilateral renal ischemia (1 hour, left renal artery cross-clamping) followed by 4 hours of reperfusion, and unilateral renal I/R with fenoldopam infusion.

MEASUREMENTS AND MAIN RESULTS

Kidney samples were used to measure NF-kappaB DNA-binding activity with an electrophoretic mobility shift assay. NF-kappaB signaling-dependent gene transcription was assessed with microarray analysis, and validated with reverse transcriptase polymerase chain reaction (RT-PCR). Expression of insulin-like growth factor-1 and nitric oxide synthetase-3 messenger RNA (not included in the array) was studied with RT-PCR. NF-kappaB DNA binding activity was significantly higher (p < 0.001) after I/R injury. Of the 96 genes analyzed, 75 were induced and another 8 were suppressed completely (2-fold or greater change v control) after I/R. Treatment with fenoldopam prevented activation of NF-kappaB DNA binding activity (p < 0.001) and attenuated 72 of 75 I/R-induced genes and 3 of 8 I/R-suppressed genes.

CONCLUSION

Data from this rat model of renal I/R suggest that the mechanism by which fenoldopam attenuates I/R-induced inflammation appears to involve inhibition of NF-kappaB translocation and signal transduction.