Browsing by Author "Moura, RS"
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- Ghrelin and obestatin: Different role in fetal lung development?Publication . Nunes, S; Nogueira-Silva, C; Dias, E; Moura, RS; Correia-Pinto, JGhrelin and obestatin are two proteins that originate from post-translational processing of the preproghrelin peptide. Various authors claim an opposed role of ghrelin and obestatin in several systems. Preproghrelin mRNA is significantly expressed in airway epithelium throughout lung development, predominantly during the earliest stages. The aim of this study was to evaluate the role of ghrelin and obestatin in fetal lung development in vitro. Immunohistochemistry studies were performed at different gestational ages in order to clarify the expression pattern of ghrelin, GHS-R1a, obestatin and GPR39 during fetal lung development. Fetal rat lung explants were harvested at 13.5 days post-conception (dpc) and cultured during 4 days with increasing doses of total ghrelin, acylated ghrelin, desacyl-ghrelin, ghrelin antagonist (D-Lys(3)-GHRP-6) or obestatin. Immunohistochemistry studies demonstrated that ghrelin, GHS-R1a, obestatin and GPR39 proteins were expressed in primitive rat lung epithelium throughout all studied gestational ages. Total and acylated ghrelin supplementation significantly increased the total number of peripheral airway buds, whereas desacyl-ghrelin induced no effect. Moreover, GHS-R1a antagonist significantly decreased lung branching. Finally, obestatin supplementation induced no significant effect in the measured parameters. The present study showed that ghrelin has a positive effect in fetal lung development through its GHS-R1a receptor, whereas obestatin has no effect on lung branching.
- Leukemia inhibitory factor in rat fetal lung development: expression and functional studiesPublication . Nogueira-Silva, C; Piairo, P; Carvalho-Dias, E; Peixoto, FO; Moura, RS; Correia-Pinto, JBACKGROUND: Leukemia inhibitory factor (LIF) and interleukin-6 (IL-6) are members of the family of the glycoprotein 130 (gp130)-type cytokines. These cytokines share gp130 as a common signal transducer, which explains why they show some functional redundancy. Recently, it was demonstrated that IL-6 promotes fetal lung branching. Additionally, LIF has been implicated in developmental processes of some branching organs. Thus, in this study LIF expression pattern and its effects on fetal rat lung morphogenesis were assessed. METHODOLOGY/PRINCIPAL FINDINGS: LIF and its subunit receptor LIFRα expression levels were evaluated by immunohistochemistry and western blot in fetal rat lungs of different gestational ages, ranging from 13.5 to 21.5 days post-conception. Throughout all gestational ages studied, LIF was constitutively expressed in pulmonary epithelium, whereas LIFRα was first mainly expressed in the mesenchyme, but after pseudoglandular stage it was also observed in epithelial cells. These results point to a LIF epithelium-mesenchyme cross-talk, which is known to be important for lung branching process. Regarding functional studies, fetal lung explants were cultured with increasing doses of LIF or LIF neutralizing antibodies during 4 days. MAPK, AKT, and STAT3 phosphorylation in the treated lung explants was analyzed. LIF supplementation significantly inhibited lung growth in spite of an increase in p44/42 phosphorylation. On the other hand, LIF inhibition significantly stimulated lung growth via p38 and Akt pathways. CONCLUSIONS/SIGNIFICANCE: The present study describes that LIF and its subunit receptor LIFRα are constitutively expressed during fetal lung development and that they have an inhibitory physiological role on fetal lung
- Local Fetal Lung Renin-Angiotensin System as a Target to Treat Congenital Diaphragmatic HerniaPublication . Nogueira-Silva, C; Carvalho-Dias, E; Piairo, P; Nunes, S; Baptista, MJ; Moura, RS; Correia-Pinto, JAntenatal stimulation of lung growth is a reasonable approach to treat congenital diaphragmatic hernia (CDH), a disease characterized by pulmonary hypoplasia and hypertension. Several evidences from the literature demonstrated a possible involvement of renin-angiotensin system (RAS) during fetal lung development. Thus, the expression pattern of renin, angiotensin-converting enzyme, angiotensinogen, type 1 (AT(1)) and type 2 (AT(2)) receptors of angiotensin II (ANGII) was assessed by immunohistochemistry throughout gestation, whereas the function of RAS in the fetal lung was evaluated using fetal rat lung explants. These were morphometrically analyzed and intracellular pathway alterations assessed by Western blot. In nitrofen-induced CDH model, pregnant rats were treated with saline or PD-123319. In pups, lung growth, protein/DNA ratio, radial saccular count, epithelial differentiation and lung maturation, vascular morphometry, right ventricular hypertrophy and overload molecular markers, gasometry and survival time were evaluated. Results demonstrated that all RAS components were constitutively expressed in the lung during gestation and that ANGII had a stimulatory effect on lung branching, mediated by AT(1) receptor, through p44/42 and Akt phosphorylation. This stimulatory effect on lung growth was mimicked by AT(2)-antagonist (PD-123319) treatment. In vivo antenatal PD-123319 treatment increased lung growth, ameliorated indirect parameters of pulmonary hypertension, improved lung function and survival time in non-ventilated CDH pups, without maternal or fetal deleterious effects. Therefore, this study demonstrated a local and physiologically active RAS during lung morphogenesis. Moreover, selective inhibition of AT(2) receptor is presented as a putative antenatal therapy for CDH.
- Neuroendocrine factors regulate retinoic acid receptors in normal and hypoplastic lung developmentPublication . Pereira-Terra, P; Moura, RS; Nogueira-Silva, C; Correia-Pinto, JRetinoic acid (RA) and ghrelin levels are altered in human hypoplastic lungs when compared to healthy lungs. Although considerable data have been obtained about RA, ghrelin and bombesin in the congenital diaphragmatic hernia (CDH) rat model, neuroendocrine factors have never been associated with the RA signalling pathway in this animal model. In this study, the interaction between neuroendocrine factors and RA was explored in the CDH rat model. The authors found that normal fetal lung explants treated with RA, bombesin and ghrelin showed an increase in lung growth. Hypoplastic lungs presented higher expression levels of the RA receptors α and γ. Moreover bombesin and ghrelin supplementation, in vitro, to normal lungs increased RA receptor α/γ expression whereas administration of bombesin and ghrelin antagonists to normal and hypoplastic lungs decreased it. These data reveal for the first time that there is a link between neuroendocrine factors and RA, and that neuroendocrine factors sensitise the lung to the RA action through RA receptor modulation.
- STATs in Lung Development: Distinct Early and Late Expression, Growth Modulation and Signaling Dysregulation in Congenital Diaphragmatic HerniaPublication . Piairo, P; Moura, RS; Baptista, MJ; Correia-Pinto, J; Nogueira-Silva, CCongenital diaphragmatic hernia (CDH) is a life-threatening developmental anomaly, intrinsically combining severe pulmonary hypoplasia and hypertension. During development, signal transducers and activators of transcription (STAT) are utilized to elicit cell growth, differentiation, and survival.
- The apelinergic system in the developing lung: expression and signalingPublication . Piairo, P; Moura, RS; Nogueira-Silva, C; Correia-Pinto, JApelin and its receptor APJ constitute a signaling pathway best recognized as an important regulator of cardiovascular homeostasis. This multifunctional peptidergic system is currently being described to be involved in embryonic events which extend into vascular, ocular and heart development. Additionally, it is highly expressed in pulmonary tissue. Therefore, the aim of this study was to investigate the role of apelinergic system during fetal lung development. Immunohistochemistry and Western blot analysis were used to characterize apelin and APJ expression levels and cellular localization in normal fetal rat lungs, at five different gestational ages as well as in the adult. Fetal rat lung explants were cultured in vitro with increasing doses of apelin. Treated lung explants were morphometrically analyzed and assessed for MAPK signaling modifications. Both components of the apelinergic system are constitutively expressed in the developing lung, with APJ exhibiting monomeric, dimeric and oligomeric forms in the pulmonary tissue. Pulmonary epithelium also displayed constitutive nuclear localization of the receptor. Fetal apelin expression is higher than adult expression. Apelin supplementation inhibitory effect on branching morphogenesis was associated with a dose dependent decrease in p38 and JNK phosphorylation. The results presented provide the first evidence of the presence of an apelinergic system operating in the developing lung. Our findings also suggest that apelin inhibits fetal lung growth by suppressing p38 and JNK signaling pathways.
- The role of glycoprotein 130 family of cytokines in fetal rat lung developmentPublication . Nogueira-Silva, C; Piairo, P; Carvalho-Dias, E; Veiga, C; Moura, RS; Correia-Pinto, JThe glycoprotein 130 (gp130) dependent family of cytokines comprises interleukin-6 (IL-6), IL-11, leukemia inhibitory factor (LIF), cardiotrophin-like cytokine (CLC), ciliary neurotrophic factor (CNTF), cardiotrophin-1 (CT-1) and oncostatin M (OSM). These cytokines share the membrane gp130 as a common signal transducer. Recently, it was demonstrated that IL-6 promotes, whereas LIF inhibits fetal lung branching. Thus, in this study, the effects on fetal lung morphogenesis of the other classical members of the gp130-type cytokines (IL-11, CLC, CNTF, CT-1 and OSM) were investigated. We also provide the first description of these cytokines and their common gp130 receptor protein expression patterns during rat lung development. Fetal rat lung explants were cultured in vitro with increasing concentrations of IL-11, CLC, CNTF, CT-1 and OSM. Treated lung explants were morphometrically analyzed and assessed for MAPK, PI3K/AKT and STAT3 signaling modifications. IL-11, which similarly to IL-6 acts through a gp130 homodimer receptor, significantly stimulated lung growth via p38 phosphorylation. On the other hand, CLC, CNTF, CT-1 and OSM, whose receptors are gp130 heterodimers, inhibited lung growth acting in different signal-transducing pathways. Thus, the present study demonstrated that although cytokines of the gp130 family share a common signal transducer, there are specific biological activities for each cytokine on lung development. Indeed, cytokine signaling through gp130 homodimers stimulate, whereas cytokine signaling through gp130 heterodimers inhibit lung branching.