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Nardini P, Zizi V, Molino M, Fazi C, Calvani M, Carrozzo F, Giuseppetti G, Calosi L, Guasti D, Biagini D, Di Francesco F, Filippi L, Pini A. Protective Effects of Beta-3 Adrenoceptor Agonism on Mucosal Integrity in Hyperoxia-Induced Ileal Alterations. Antioxidants (Basel) 2024; 13:863. [PMID: 39061931 DOI: 10.3390/antiox13070863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 07/15/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
Organogenesis occurs in the uterus under low oxygen levels (4%). Preterm birth exposes immature newborns to a hyperoxic environment, which can induce a massive production of reactive oxygen species and potentially affect organ development, leading to diseases such as necrotizing enterocolitis. The β3-adrenoreceptor (β3-AR) has an oxygen-dependent regulatory mechanism, and its activation exerts an antioxidant effect. To test the hypothesis that β3-AR could protect postnatal ileal development from the negative impact of high oxygen levels, Sprague-Dawley rat pups were raised under normoxia (21%) or hyperoxia (85%) for the first 2 weeks after birth and treated or not with BRL37344, a selective β3-AR agonist, at 1, 3, or 6 mg/kg. Hyperoxia alters ileal mucosal morphology, leading to increased cell lipid oxidation byproducts, reduced presence of β3-AR-positive resident cells, decreased junctional protein expression, disrupted brush border, mucin over-production, and impaired vascularization. Treatment with 3 mg/kg of BRL37344 prevented these alterations, although not completely, while the lower 1 mg/kg dose was ineffective, and the higher 6 mg/kg dose was toxic. Our findings indicate the potential of β3-AR agonism as a new therapeutic approach to counteract the hyperoxia-induced ileal alterations and, more generally, the disorders of prematurity related to supra-physiologic oxygen exposure.
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Affiliation(s)
- Patrizia Nardini
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy
- Imaging Platform, Department Experimental and Clinical Medicine & Joint Laboratory with Department Biology, University of Florence, 50139 Florence, Italy
| | - Virginia Zizi
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy
| | - Marta Molino
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy
| | - Camilla Fazi
- Department of Pediatric, Meyer Children's University Hospital, 50139 Florence, Italy
| | - Maura Calvani
- Azienda Ospedaliera Universitaria Meyer, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), 50139 Florence, Italy
| | - Francesco Carrozzo
- Department of Health Science, University of Florence, 50139 Florence, Italy
| | - Giorgia Giuseppetti
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy
| | - Laura Calosi
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy
- Imaging Platform, Department Experimental and Clinical Medicine & Joint Laboratory with Department Biology, University of Florence, 50139 Florence, Italy
| | - Daniele Guasti
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy
- Imaging Platform, Department Experimental and Clinical Medicine & Joint Laboratory with Department Biology, University of Florence, 50139 Florence, Italy
| | - Denise Biagini
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Fabio Di Francesco
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Luca Filippi
- Neonatology and Neonatal Intensive Care Unit, Department of Clinical and Experimental Medicine, University of Pisa, 56124 Pisa, Italy
| | - Alessandro Pini
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy
- Imaging Platform, Department Experimental and Clinical Medicine & Joint Laboratory with Department Biology, University of Florence, 50139 Florence, Italy
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Paradis H, Werdyani S, Zhai G, Gendron RL, Tabrizchi R, McGovern M, Jumper JM, Brinton D, Good WV. Genetic Variants of the Beta-Adrenergic Receptor Pathways as Both Risk and Protective Factors for Retinopathy of Prematurity. Am J Ophthalmol 2024; 263:179-187. [PMID: 38224928 DOI: 10.1016/j.ajo.2023.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 12/21/2023] [Accepted: 12/28/2023] [Indexed: 01/17/2024]
Abstract
PURPOSE There is strong evidence that genetic factors influence retinopathy of prematurity (ROP), a neovascular eye disease. It has been previously suggested that polymorphisms in the genes involved in β-adrenergic receptor (ADRβ) pathways could protect against ROP. Antagonists for the ADRβ are actively tested in clinical trials for ROP treatment, but not without controversy and safety concerns. This study was designed to assess whether genetic variations in components of the ADRβ signaling pathways associate with risk of developing ROP. DESIGN An observational case-control targeted genetic analysis. METHODS A study was carried out in premature participants with (n = 30) or without (n = 34) ROP and full-term controls (n = 20), who were divided into a discovery cohort and a validation cohort. ROP was defined using International Classification of Retinopathy of Prematurity criteria (ICROP). Targeted sequencing of 20 genes in the ADRβ pathways was performed in the discovery cohort. Polymerase chain reaction (PCR)/restriction enzyme analysis for some of the discovered ROP-associated variants was performed for validation of the results using the validation cohort. RESULTS The discovery cohort revealed 543 bi-allelic variants within 20 genes of the ADRβ pathways. Ten single-nucleotide variants (SNVs) in 5 genes including protein kinase A regulatory subunit 1α (PRKAR1A), rap guanine exchange factor 3 (RAPGEF3), adenylyl cyclase 4 (ADCY4), ADCY7, and ADCY9 were associated with ROP (P < .05). The most significant SNV was found in PRKAR1A (P = .001). Multiple variants located in the 3'-untranslated region (3'UTR) of RAPGEF3 were also associated with ROP (P < .05). PCR/restriction enzyme analysis of the 3'UTR of RAPGEF3 methodologically validated these findings. CONCLUSION SNVs in PRKAR1A may represent protective factors whereas SNVs in RAPGEF3 may represent risk factors for ROP. PRKAR1α has previously been implicated in retinal vascular development whereas the RAPGEF3 product has a role in the maintenance of vascular barrier function, 2 processes important in ROP. Multicenter validation of these newly discovered risk factors could lead to valuable tools for predicting and preventing the development of severe ROP.
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Affiliation(s)
- Hélène Paradis
- From the Division of BioMedical Sciences (H.P., S.W., G.Z., R.L.G., R.T.), Faculty of Medicine, Memorial University, St. John's, Newfoundland, Canada
| | - Salem Werdyani
- From the Division of BioMedical Sciences (H.P., S.W., G.Z., R.L.G., R.T.), Faculty of Medicine, Memorial University, St. John's, Newfoundland, Canada
| | - Guangju Zhai
- From the Division of BioMedical Sciences (H.P., S.W., G.Z., R.L.G., R.T.), Faculty of Medicine, Memorial University, St. John's, Newfoundland, Canada
| | - Robert L Gendron
- From the Division of BioMedical Sciences (H.P., S.W., G.Z., R.L.G., R.T.), Faculty of Medicine, Memorial University, St. John's, Newfoundland, Canada
| | - Reza Tabrizchi
- From the Division of BioMedical Sciences (H.P., S.W., G.Z., R.L.G., R.T.), Faculty of Medicine, Memorial University, St. John's, Newfoundland, Canada
| | - Margaret McGovern
- Smith Kettlewell Eye Research Institute (M.M., W.V.G.), San Francisco, California, USA
| | | | - Daniel Brinton
- East Bay Retina Consultants, Inc. (D.B.), Oakland, California, USA
| | - William V Good
- Smith Kettlewell Eye Research Institute (M.M., W.V.G.), San Francisco, California, USA.
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Scaramuzzo RT, Crucitta S, del Re M, Cammalleri M, Bagnoli P, Dal Monte M, Pini A, Filippi L. β3-adREnoceptor Analysis in CORD Blood of Neonates (β3 RECORD): Study Protocol of a Pilot Clinical Investigation. Life (Basel) 2024; 14:776. [PMID: 38929758 PMCID: PMC11204445 DOI: 10.3390/life14060776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/12/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024] Open
Abstract
Background and Objective: The embryo and the fetus develop in a physiologically hypoxic environment, where vascularization is sustained by HIF-1, VEGF, and the β-adrenergic system. In animals, β3-adrenoceptors (β3-ARs), up-regulated by hypoxia, favor global fetal wellness to such an extent that most diseases related to prematurity are hypothesized to be induced or aggravated by a precocious β3-AR down-regulation, due to premature exposure to a relatively hyperoxic environment. In animals, β3-AR pharmacological agonism is currently investigated as a possible new therapeutic opportunity to counteract oxygen-induced damages. Our goal is to translate the knowledge acquired in animals to humans. Recently, we have demonstrated that fetuses become progressively more hypoxemic from mid-gestation to near-term, but starting from the 33rd-34th week, oxygenation progressively increases until birth. The present paper aims to describe a clinical research protocol, evaluating whether the expression level of HIF-1, β3-ARs, and VEGF is modulated by oxygen during intrauterine and postnatal life, in a similar way to animals. Materials and Methods: In a prospective, non-profit, single-center observational study we will enroll 100 preterm (group A) and 100 full-term newborns (group B). We will collect cord blood samples (T0) and measure the RNA expression level of HIF-1, β3-ARs, and VEGF by digital PCR. In preterms, we will also measure gene expression at 48-72h (T1), 14 days (T2), and 30 days (T3) of life and at 40 ± 3 weeks of post-menstrual age (T4), regardless of the day of life. We will compare group A (T0) vs. group B (T0) and identify any correlations between the values obtained from serial samples in group A and the clinical data of the patients. Our protocol has been approved by the Pediatric Ethical Committee for Clinical Research of the Tuscany region (number 291/2022). Expected Results: The observation that in infants, the HIF-1/β3-ARs/VEGF axis shows similar modulation to that of animals could suggest that β3-ARs also promote fetal well-being in humans.
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Affiliation(s)
| | - Stefania Crucitta
- Clinical Pharmacology and Pharmacogenetics Unit, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy; (S.C.); (M.d.R.)
| | - Marzia del Re
- Clinical Pharmacology and Pharmacogenetics Unit, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy; (S.C.); (M.d.R.)
| | - Maurizio Cammalleri
- Unit of General Physiology, Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.C.); (P.B.); (M.D.M.)
| | - Paola Bagnoli
- Unit of General Physiology, Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.C.); (P.B.); (M.D.M.)
| | - Massimo Dal Monte
- Unit of General Physiology, Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.C.); (P.B.); (M.D.M.)
| | - Alessandro Pini
- Department of Experimental and Clinical Medicine, University of Florence, 50121 Florence, Italy;
| | - Luca Filippi
- Neonatology Unit, Azienda Ospedaliero Universitaria Pisana, 56126 Pisa, Italy
- Neonatology Unit, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
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Pascarella F, Scaramuzzo RT, Pini A, Cammalleri M, Bagnoli P, Ciantelli M, Filippi L. Propranolol: a new pharmacologic approach to counter retinopathy of prematurity progression. Front Pediatr 2024; 12:1322783. [PMID: 38292211 PMCID: PMC10824858 DOI: 10.3389/fped.2024.1322783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 01/04/2024] [Indexed: 02/01/2024] Open
Abstract
Despite the evident progress in neonatal medicine, retinopathy of prematurity (ROP) remains a serious threat to the vision of premature infants, due to a still partial understanding of the mechanisms underlying the development of this disease and the lack of drugs capable of arresting its progression. Although ROP is a multifactorial disease, retinal vascularization is strictly dependent on oxygen concentration. The exposition of the retina of a preterm newborn, still incompletely vascularized, to an atmosphere relatively hyperoxic, as the extrauterine environment, induces the downregulation of proangiogenic factors and therefore the interruption of vascularization (first ischemic phase of ROP). However, over the following weeks, the growing metabolic requirement of this ischemic retina produces a progressive hypoxia that specularly promotes the surge of proangiogenic factors, finally leading to proliferative retinopathy (second proliferative phase of ROP). The demonstration that the noradrenergic system is actively involved in the coupling between hypoxia and the induction of vasculogenesis paved the way for a pharmacologic intervention aimed at counteracting the interaction of noradrenaline with specific receptors and consequently the progression of ROP. A similar trend has been observed in infantile hemangiomas, the most common vascular lesion of childhood induced by pre-existing hypoxia, which shares similar characteristics with ROP. The fact that propranolol, an unselective antagonist of β1/2 adrenoceptors, counteracts the growth of infantile hemangiomas, suggested the idea of testing the efficacy of propranolol in infants with ROP. From preclinical studies, ongoing clinical trials demonstrated that topical administration of propranolol likely represents the optimal approach to reconcile its efficacy and maximum safety. Given the strict relationship between vessels and neurons, recovering retinal vascularization with propranolol may add further efficacy to prevent retinal dysfunction. In conclusion, the strategy of contrasting precociously the progression of the disease appears to be more advantageous than the current wait-and-see therapeutic approach, which instead is mainly focused on avoiding retinal detachment.
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Affiliation(s)
| | | | - Alessandro Pini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Maurizio Cammalleri
- Unit of General Physiology, Department of Biology, University of Pisa, Pisa, Italy
| | - Paola Bagnoli
- Unit of General Physiology, Department of Biology, University of Pisa, Pisa, Italy
| | | | - Luca Filippi
- Neonatology Unit, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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Fitriana I, Wu CH, Hsu TJ, Chan YJ, Li CH, Lee CC, Hsiao G, Cheng YW. Activation of aryl hydrocarbon receptor by azatyrosine-phenylbutyric hydroxamide inhibits progression of diabetic retinopathy mice. Biochem Pharmacol 2023; 215:115700. [PMID: 37482199 DOI: 10.1016/j.bcp.2023.115700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 07/25/2023]
Abstract
Diabetic retinopathy (DR) is a severe consequence of long-term diabetes mellitus and may lead to vision loss. Retinal pigment epithelial (RPE) cells are a diverse group of retinal cells with varied metabolic and functional roles. In hypoxic conditions, RPE cells have been shown to produce angiogenic factors, such as vascular endothelial growth factor (VEGF), which is regulated by hypoxia-inducible factor 1-alpha (HIF1A). VEGF plays a crucial role in angiogenesis in DR. In the present study, we investigated whether azatyrosine-phenylbutyric hydroxamide (AZP) has therapeutic effect on DR therapy. In this study, we treated high glucose-activated human retinal pigment epithelial cells (ARPE-19) with and without AZP. The effector proteins were evaluated using western blotting. In the in vivo study, AZP was administered to the db/db mice as a DR animal model. Moreover, invasive imaging techniques such as optical coherence tomography (OCT), fundus photography, and fundus fluorescein angiography (FFA) were performed on the mice to assess DR progression. We found that treatment of AZP for 12 weeks reversed increasing DR retinal alterations in db/db mice, decreasing vascular density, retinal blood perfusion, retinal thickness, decreasing DR lesion, lipofuscin accumulation, HIF1A, VEGF, and inflammation factor expression. In addition, AZP treatment could activate the aryl hydrocarbon receptor AHR and reverse the high-glucose-induced HIF1A and VEGF in ARPE-19 cells and db/db mice. In conclusion, AZP activated AHR while inhibiting HIF1A and VEGF. This study indicates that AZP may be a promising therapeutic agent for treating DR.
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Affiliation(s)
- Ida Fitriana
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan; Department of Pharmacology, Faculty of Veterinary Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Chia-Hua Wu
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan
| | - Tai-Ju Hsu
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan
| | - Yen-Ju Chan
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan
| | - Ching-Hao Li
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chen-Chen Lee
- Department of Microbiology and Immunology, School of Medicine, China Medical University, Taichung, Taiwan
| | - George Hsiao
- Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Yu-Wen Cheng
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan; Ph.D. Program in Drug Discovery and Development Industry, College of Pharmacy, Taipei Medical University, Taiwan.
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Filippi L, Pascarella F, Pini A, Cammalleri M, Bagnoli P, Morganti R, Innocenti F, Castagnini N, Melosi A, Scaramuzzo RT. Fetal Oxygenation from the 23rd to the 36th Week of Gestation Evaluated through the Umbilical Cord Blood Gas Analysis. Int J Mol Sci 2023; 24:12487. [PMID: 37569862 PMCID: PMC10419490 DOI: 10.3390/ijms241512487] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023] Open
Abstract
The embryo and fetus grow in a hypoxic environment. Intrauterine oxygen levels fluctuate throughout the pregnancy, allowing the oxygen to modulate apparently contradictory functions, such as the expansion of stemness but also differentiation. We have recently demonstrated that in the last weeks of pregnancy, oxygenation progressively increases, but the trend of oxygen levels during the previous weeks remains to be clarified. In the present retrospective study, umbilical venous and arterial oxygen levels, fetal oxygen extraction, oxygen content, CO2, and lactate were evaluated in a cohort of healthy newborns with gestational age < 37 weeks. A progressive decrease in pO2 levels associated with a concomitant increase in pCO2 and reduction in pH has been observed starting from the 23rd week until approximately the 33-34th week of gestation. Over this period, despite the increased hypoxemia, oxygen content remains stable thanks to increasing hemoglobin concentration, which allows the fetus to become more hypoxemic but not more hypoxic. Starting from the 33-34th week, fetal oxygenation increases and ideally continues following the trend recently described in term fetuses. The present study confirms that oxygenation during intrauterine life continues to vary even after placenta development, showing a clear biphasic trend. Fetuses, in fact, from mid-gestation to near-term, become progressively more hypoxemic. However, starting from the 33-34th week, oxygenation progressively increases until birth. In this regard, our data suggest that the placenta is the hub that ensures this variable oxygen availability to the fetus, and we speculate that this biphasic trend is functional for the promotion, in specific tissues and at specific times, of stemness and intrauterine differentiation.
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Affiliation(s)
- Luca Filippi
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
- Neonatology Unit, Azienda Ospedaliero-Universitaria Pisana, 56126 Pisa, Italy; (F.P.); (F.I.); (N.C.); (A.M.); (R.T.S.)
| | - Francesca Pascarella
- Neonatology Unit, Azienda Ospedaliero-Universitaria Pisana, 56126 Pisa, Italy; (F.P.); (F.I.); (N.C.); (A.M.); (R.T.S.)
| | - Alessandro Pini
- Department of Experimental and Clinical Medicine, University of Florence, 50121 Florence, Italy
| | - Maurizio Cammalleri
- Unit of General Physiology, Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.C.); (P.B.)
| | - Paola Bagnoli
- Unit of General Physiology, Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.C.); (P.B.)
| | - Riccardo Morganti
- Section of Statistics, Azienda Ospedaliero-Universitaria Pisana, 56126 Pisa, Italy;
| | - Francesca Innocenti
- Neonatology Unit, Azienda Ospedaliero-Universitaria Pisana, 56126 Pisa, Italy; (F.P.); (F.I.); (N.C.); (A.M.); (R.T.S.)
| | - Nicola Castagnini
- Neonatology Unit, Azienda Ospedaliero-Universitaria Pisana, 56126 Pisa, Italy; (F.P.); (F.I.); (N.C.); (A.M.); (R.T.S.)
| | - Alice Melosi
- Neonatology Unit, Azienda Ospedaliero-Universitaria Pisana, 56126 Pisa, Italy; (F.P.); (F.I.); (N.C.); (A.M.); (R.T.S.)
| | - Rosa Teresa Scaramuzzo
- Neonatology Unit, Azienda Ospedaliero-Universitaria Pisana, 56126 Pisa, Italy; (F.P.); (F.I.); (N.C.); (A.M.); (R.T.S.)
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Filippi L, Scaramuzzo RT, Pascarella F, Pini A, Morganti R, Cammalleri M, Bagnoli P, Ciantelli M. Fetal oxygenation in the last weeks of pregnancy evaluated through the umbilical cord blood gas analysis. Front Pediatr 2023; 11:1140021. [PMID: 37152310 PMCID: PMC10160648 DOI: 10.3389/fped.2023.1140021] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 04/04/2023] [Indexed: 05/09/2023] Open
Abstract
Introduction Embryo and fetus grow and mature over the first trimester of pregnancy in a dynamic hypoxic environment, where placenta development assures an increased oxygen availability. However, it is unclear whether and how oxygenation changes in the later trimesters and, more specifically, in the last weeks of pregnancy. Methods Observational study that evaluated the gas analysis of the umbilical cord blood collected from a cohort of healthy newborns with gestational age ≥37 weeks. Umbilical venous and arterial oxygen levels as well as fetal oxygen extraction were calculated to establish whether oxygenation level changes over the last weeks of pregnancy. In addition, fetal lactate, and carbon dioxide production were analyzed to establish whether oxygen oscillations may induce metabolic effects in utero. Results This study demonstrates a progressive increase in fetal oxygenation levels from the 37th to the 41st weeks of gestation (mean venous PaO2 approximately from 20 to 25 mmHg; p < 0.001). This increase is largely attributable to growing umbilical venous PaO2, regardless of delivery modalities. In neonates born by vaginal delivery, the increased oxygen availability is associated with a modest increase in oxygen extraction, while in neonates born by cesarean section, it is associated with reduced lactate production. Independently from the type of delivery, carbon dioxide production moderately increased. These findings suggest a progressive shift from a prevalent anaerobic metabolism (Warburg effect) towards a growing aerobic metabolism. Conclusion This study confirms that fetuses grow in a hypoxic environment that becomes progressively less hypoxic in the last weeks of gestation. The increased oxygen availability seems to favor aerobic metabolic shift during the last weeks of intrauterine life; we hypothesize that this environmental change may have implications for fetal maturation during intrauterine life.
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Affiliation(s)
- Luca Filippi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- Neonatology Unit, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
- Correspondence: Luca Filippi
| | | | | | - Alessandro Pini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Riccardo Morganti
- Section of Statistics, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Maurizio Cammalleri
- Unit of General Physiology, Department of Biology, University of Pisa, Pisa, Italy
| | - Paola Bagnoli
- Unit of General Physiology, Department of Biology, University of Pisa, Pisa, Italy
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