Corticotropin-releasing hormone, its binding protein and receptors in human cervical tissue at preterm and term labor in comparison to non-pregnant state

BACKGROUND: Preterm birth is still the leading cause of neonatal morbidity and mortality. The level of corticotropin-releasing hormone (CRH) is known to be significantly elevated in the maternal plasma at preterm birth. Although, CRH, CRH-binding protein (CRH-BP), CRH-receptor 1 (CRH-R1) and CRH-R2 have been identified both at mRNA and protein level in human placenta, deciduas, fetal membranes, endometrium and myometrium, no corresponding information is yet available on cervix. Thus, the aim of this study was to compare the levels of the mRNA species coding for CRH, CRH-BP, CRH-R1 and CRH-R2 in human cervical tissue and myometrium at preterm and term labor and not in labor as well as in the non-pregnant state, and to localize the corresponding proteins employing immunohistochemical analysis. METHODS: Cervical, isthmic and fundal (from non-pregnant subjects only) biopsies were taken from 67 women. Subjects were divided in 5 groups: preterm labor (14), preterm not in labor (7), term labor (18), term not in labor (21) and non-pregnant (7). Real-time RT-PCR was employed for quantification of mRNA levels and the corresponding proteins were localized by immunohistochemical analysis. RESULTS: The levels of CRH-BP, CRH-R1 and CRH-R2 mRNA in the pregnant tissues were lower than those in non-pregnant subjects. No significant differences were observed between preterm and term groups. CRH-BP and CRH-R2 mRNA and the corresponding proteins were present at lower levels in the laboring cervix than in the non-laboring cervix, irrespective of gestational age. In most of the samples, with the exception of four myometrial biopsies the level of CRH mRNA was below the limit of detection. All of these proteins could be detected and localized in the cervix and the myometrium by immunohistochemical analysis. CONCLUSION: Expression of CRH-BP, CRH-R1 and CRH-R2 in uterine tissues is down-regulated during pregnancy. The most pronounced down-regulation of CRH-BP and CRH-R2 occurred in laboring cervix, irrespective the length of gestation. The detection of substantial expression of the CRH and its receptor proteins, as well as receptor mRNA in the cervix suggests that the cervix may be a target for CRH action. Further studies are required to elucidate the role of CRH in cervical ripening

Differentiation dependent expression of urocortin’s mRNA and peptide in human osteoprogenitor cells: influence of BMP-2, TGF-beta-1 and dexamethasone

Urocortin-1 (UCN) a corticotropin releasing-factor (CRF) related peptide, has been found to be expressed in many different tissues like the central nervous system, the cardiovascular system, adipose tissue, and skeletal muscle. The effects of UCN are mediated via stimulation of CRF-receptors 1 and 2 (CRFR1 and 2, CRFR’s) with a high affinity for CRFR2. It has been shown that the CRF-related peptides and CRFR’s are involved in the regulation of stress-related endocrine, autonomic and behavioural responses. Using immunocytochemistry, immunohistochemistry and RT–PCR, we now can show the differentiation dependent expression of UCN mRNA and peptide in human mesenchymal progenitor cells (MSCs) directed to the osteoblastic phenotype for the first time. UCN expression was down regulated by TGF-beta and BMP-2 in the early proliferation phase of osteoblast development, whereas dexamethasone (dex) minimally induced UCN gene expression during matrix maturation after 24 h stimulation. Stimulation of MSCs for 28 days with ascorbate/beta-glycerophosphate (asc/bGp) induced UCN gene expression at day 14. This effect was prevented when using 1,25-vitamin D3 or dex in addition. There was no obvious correlation to osteocalcin (OCN) gene expression in these experiments. In MSCs from patients with metabolic bone disease (n = 9) UCN gene expression was significantly higher compared to MSCs from normal controls (n = 6). Human MSCs did not express any of the CRFR’s during differentiation to osteoblasts. Our results indicate that UCN is produced during the development of MSCs to osteoblasts and differentially regulated during culture as well as by differentiation factors. The expression is maximal between proliferation and matrix maturation phase. However, UCN does not seem to act on the osteoblast itself as shown by the missing CRFR’s. Our results suggest new perspectives on the role of urocortin in human skeletal tissue in health and disease

A computational model of lipopolysaccharide-induced nuclear factor kappa B activation:a key signalling pathway in infection-induced preterm labour

Preterm birth is the single biggest cause of significant neonatal morbidity and mortality, and the incidence is rising. Development of new therapies to treat and prevent preterm labour is seriously hampered by incomplete understanding of the molecular mechanisms that initiate labour at term and preterm. Computational modelling provides a new opportunity to improve this understanding. It is a useful tool in (i) identifying gaps in knowledge and informing future research, and (ii) providing the basis for an in silico model of parturition in which novel drugs to prevent or treat preterm labour can be "tested". Despite their merits, computational models are rarely used to study the molecular events initiating labour. Here, we present the first attempt to generate a dynamic kinetic model that has relevance to the molecular mechanisms of preterm labour. Using published data, we model an important candidate signalling pathway in infection-induced preterm labour: that of lipopolysaccharide (LPS) -induced activation of Nuclear Factor kappa B. This is the first model of this pathway to explicitly include molecular interactions upstream of Nuclear Factor kappa B activation. We produced a formalised graphical depiction of the pathway and built a kinetic model based on ordinary differential equations. The kinetic model accurately reproduced published in vitro time course plots of Lipopolysaccharide-induced Nuclear Factor kappa B activation in mouse embryo fibroblasts. In this preliminary work we have provided proof of concept that it is possible to build computational models of signalling pathways that are relevant to the regulation of labour, and suggest that models that are validated with wet-lab experiments have the potential to greatly benefit the field

Causes of Adverse Pregnancy Outcomes and the Role of Maternal Periodontal Status – A Review of the Literature

Preterm (PT) and Low birth weight (LBW) are considered to be the most relevant biological determinants of newborn infants survival, both in developed and in developing countries. Numerous risk factors for PT and LBW have been defined in the literature. Infections of the genitourinary tract infections along with various biological and genetic factors are considered to be the most common etiological factors for PT/LBW deliveries. However, evidence suggests that sub-clinical infection sites that are also distant from the genitor-urinary tract may be an important cause for PT/LBW deliveries. Maternal periodontal status has also been reported by many authors as a possible risk factor for PT and LBW, though not all of the actual data support such hypothesis. The aim of this paper is to review the evidence from various published literature on the association between the maternal periodontal status and adverse pregnancy outcomes. Although this review found a consistent association between periodontitis and PT/LBW, this finding should be treated with great caution until the sources of heterogeneity can be explained