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1.
J Pediatr ; 268: 113957, 2024 May.
Article in English | MEDLINE | ID: mdl-38360261

ABSTRACT

OBJECTIVE: To assess among a cohort of neonates with hypoxic-ischemic encephalopathy (HIE) the association of pretreatment maximal hourly seizure burden and total seizure duration with successful response to initial antiseizure medication (ASM). STUDY DESIGN: This was a retrospective review of data collected from infants enrolled in the HEAL Trial (NCT02811263) between January 25, 2017, and October 9, 2019. We evaluated a cohort of neonates born at ≥36 weeks of gestation with moderate-to-severe HIE who underwent continuous electroencephalogram monitoring and had acute symptomatic seizures. Poisson regression analyzed associations between (1) pretreatment maximal hourly seizure burden, (2) pretreatment total seizure duration, (3) time from first seizure to initial ASM, and (4) successful response to initial ASM. RESULTS: Among 39 neonates meeting inclusion criteria, greater pretreatment maximal hourly seizure burden was associated with lower chance of successful response to initial ASM (adjusted relative risk for each 5-minute increase in seizure burden 0.83, 95% CI 0.69-0.99). There was no association between pretreatment total seizure duration and chance of successful response. Shorter time-to-treatment was paradoxically associated with lower chance of successful response to treatment, although this difference was small in magnitude (relative risk 1.007, 95% CI 1.003-1.010). CONCLUSIONS: Maximal seizure burden may be more important than other, more commonly used measures in predicting response to acute seizure treatments.


Subject(s)
Anticonvulsants , Electroencephalography , Hypoxia-Ischemia, Brain , Seizures , Humans , Seizures/drug therapy , Retrospective Studies , Hypoxia-Ischemia, Brain/drug therapy , Male , Anticonvulsants/therapeutic use , Infant, Newborn , Female , Treatment Outcome
2.
J Physiol ; 601(11): 2099-2120, 2023 06.
Article in English | MEDLINE | ID: mdl-35661362

ABSTRACT

Visceral adipose tissue (VAT) is a metabolic organ known to regulate fat mass, and glucose and nutrient homeostasis. VAT is an active endocrine gland that synthesizes and secretes numerous bioactive mediators called 'adipocytokines/adipokines' into systemic circulation. These adipocytokines act on organs of metabolic importance like the liver and skeletal muscle. Multiple preclinical and in vitro studies showed strong evidence of the roles of adipocytokines in the regulation of metabolic disorders like diabetes, obesity and insulin resistance. Adipocytokines, such as adiponectin and omentin, are anti-inflammatory and have been shown to prevent atherogenesis by increasing nitric oxide (NO) production by the endothelium, suppressing endothelium-derived inflammation and decreasing foam cell formation. By inhibiting differentiation of vascular smooth muscle cells (VSMC) into osteoblasts, adiponectin and omentin prevent vascular calcification. On the other hand, adipocytokines like leptin and resistin induce inflammation and endothelial dysfunction that leads to vasoconstriction. By promoting VSMC migration and proliferation, extracellular matrix degradation and inflammatory polarization of macrophages, leptin and resistin increase the risk of atherosclerotic plaque vulnerability and rupture. Additionally, the plasma concentrations of these adipocytokines alter in ageing, rendering older humans vulnerable to cardiovascular disease. The disturbances in the normal physiological concentrations of these adipocytokines secreted by VAT under pathological conditions impede the normal functions of various organs and affect cardiovascular health. These adipokines could be used for both diagnostic and therapeutic purposes in cardiovascular disease.


Subject(s)
Cardiovascular Diseases , Leptin , Humans , Resistin/metabolism , Adiponectin/metabolism , Cardiovascular Diseases/metabolism , Intra-Abdominal Fat/metabolism , Adipokines/metabolism , Inflammation/metabolism , Adipose Tissue/metabolism
3.
J Pediatr ; 260: 113533, 2023 09.
Article in English | MEDLINE | ID: mdl-37269901

ABSTRACT

OBJECTIVE: To characterize the presentation and evaluation of infants with neonatal encephalopathy (NE) not due to hypoxic-ischemic encephalopathy (non-HIE NE) and to describe the genetic abnormalities identified. STUDY DESIGN: Retrospective cohort study of 193 non-HIE NE neonates admitted to a level IV NICU from 2015 through 2019. For changes in testing over time, Cochrane-Armitage test for trend was used with a Bonferroni-corrected P-value, and comparison between groups was performed using Fisher exact test. RESULT: The most common symptom of non-HIE NE was abnormal tone in 47% (90/193). Ten percent (19/193) died prior to discharge, and 48% of survivors (83/174) required medical equipment at discharge. Forty percent (77/193) underwent genetic testing as an inpatient. Of 52 chromosomal studies, 54 targeted tests, and 16 exome sequences, 10%, 41%, and 69% were diagnostic, respectively, with no difference in diagnostic rates between infants with and without an associated congenital anomaly and/or dysmorphic feature. Twenty-eight genetic diagnoses were identified. CONCLUSIONS: Neonates with non-HIE NE have high rates of morbidity and mortality and may benefit from early genetic testing, even in the absence of other exam findings. This study broadens our knowledge of genetic conditions underlying non-HIE NE, which may enable families and care teams to anticipate the needs of the individual, allow early initiation of targeted therapies, and facilitate decisions surrounding goals of care.


Subject(s)
Hypothermia, Induced , Hypoxia-Ischemia, Brain , Infant, Newborn, Diseases , Infant, Newborn , Humans , Infant , Hypoxia-Ischemia, Brain/diagnosis , Hypoxia-Ischemia, Brain/genetics , Hypoxia-Ischemia, Brain/complications , Cohort Studies , Retrospective Studies , Infant, Newborn, Diseases/therapy , Genetic Testing
4.
Pediatr Res ; 94(4): 1408-1415, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37138026

ABSTRACT

BACKGROUND: Cerebral near-infrared spectroscopy is a non-invasive tool used to measure regional cerebral tissue oxygenation (rScO2) initially validated in adult and pediatric populations. Preterm neonates, vulnerable to neurologic injury, are attractive candidates for NIRS monitoring; however, normative data and the brain regions measured by the current technology have not yet been established for this population. METHODS: This study's aim was to analyze continuous rScO2 readings within the first 6-72 h after birth in 60 neonates without intracerebral hemorrhage born at ≤1250 g and/or ≤30 weeks' gestational age (GA) to better understand the role of head circumference (HC) and brain regions measured. RESULTS: Using a standardized brain MRI atlas, we determined that rScO2 in infants with smaller HCs likely measures the ventricular spaces. GA is linearly correlated, and HC is non-linearly correlated, with rScO2 readings. For HC, we infer that rScO2 is lower in infants with smaller HCs due to measuring the ventricular spaces, with values increasing in the smallest HCs as the deep cerebral structures are reached. CONCLUSION: Clinicians should be aware that in preterm infants with small HCs, rScO2 displayed may reflect readings from the ventricular spaces and deep cerebral tissue. IMPACT: Clinicians should be aware that in preterm infants with small head circumferences, cerebral near-infrared spectroscopy readings of rScO2 displayed may reflect readings from the ventricular spaces and deep cerebral tissue. This highlights the importance of rigorously re-validating technologies before extrapolating them to different populations. Standard rScO2 trajectories should only be established after determining whether the mathematical models used in NIRS equipment are appropriate in premature infants and the brain region(s) NIRS sensors captures in this population, including the influence of both gestational age and head circumference.


Subject(s)
Infant, Premature , Spectroscopy, Near-Infrared , Infant , Child , Humans , Infant, Newborn , Spectroscopy, Near-Infrared/methods , Oxygen , Gestational Age , Brain/diagnostic imaging , Cerebrovascular Circulation
5.
Pediatr Res ; 94(1): 252-259, 2023 07.
Article in English | MEDLINE | ID: mdl-36470964

ABSTRACT

BACKGROUND: An ancillary study of the High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) trial for neonates with hypoxic-ischemic encephalopathy (HIE) and treated with therapeutic hypothermia examined the hypothesis that neonates randomized to receive erythropoietin (Epo) would have a lower seizure risk and burden compared with neonates who received placebo. METHODS: Electroencephalograms (EEGs) from 7/17 HEAL trial centers were reviewed. Seizure presence was compared across treatment groups using a logistic regression model adjusting for treatment, HIE severity, center, and seizure burden prior to the first dose. Among neonates with seizures, differences across treatment groups in median maximal hourly seizure burden were assessed using adjusted quantile regression models. RESULTS: Forty-six of 150 (31%) neonates had EEG seizures (31% in Epo vs 30% in placebo, p = 0.96). Maximal hourly seizure burden after the study drug was not significantly different between groups (median 11.4 for Epo, IQR: 5.6, 18.1 vs median 9.7, IQR: 4.9, 21.0 min/h for placebo). CONCLUSION: In neonates with HIE treated with hypothermia who were randomized to Epo or placebo, we found no meaningful between-group difference in seizure risk or burden. These findings are consistent with overall trial results, which do not support Epo use for neonates with HIE undergoing therapeutic hypothermia. IMPACT: In the HEAL trial of erythropoietin (Epo) vs placebo for neonates with encephalopathy presumed due to hypoxic-ischemic encephalopathy (HIE) who were also treated with therapeutic hypothermia, electrographic seizures were detected in 31%, which is lower than most prior studies. Epo did not reduce the proportion of neonates with acute provoked seizures (31% in Epo vs 30% in placebo) or maximal hourly seizure burden after the study drug (median 11.4, IQR 5.6, 18.1 for Epo vs median 9.7, IQR 4.9, 21.0 min/h for placebo). There was no anti- or pro-convulsant effect of Epo when combined with therapeutic hypothermia for HIE.


Subject(s)
Erythropoietin , Hypothermia, Induced , Hypothermia , Hypoxia-Ischemia, Brain , Infant, Newborn , Humans , Hypoxia-Ischemia, Brain/therapy , Hypoxia-Ischemia, Brain/drug therapy , Hypothermia/therapy , Seizures/drug therapy , Erythropoietin/therapeutic use , Asphyxia , Hypothermia, Induced/methods
6.
Semin Cell Dev Biol ; 100: 20-28, 2020 04.
Article in English | MEDLINE | ID: mdl-31587963

ABSTRACT

The adult mammalian heart is incapable of clinically relevant regeneration. The regenerative deficit in adult mammalian heart contrasts with the fetal and neonatal heart, which demonstrate substantial regenerative capacity after injury. This deficiency in adult mammals is attributable to the lack of resident stem cells after birth, combined with an inability of pre-existing cardiomyocytes to complete cytokinesis. Studies of neonatal heart regeneration in mammals suggest that latent regenerative potential can be re-activated. Dissecting the cellular and molecular mechanisms that promote cardiomyocyte proliferation is key to stimulating true regeneration in adult humans. Here, we review recent advances in our understanding of cardiomyocyte proliferation that suggest molecular approaches to heart regeneration.


Subject(s)
Heart/physiology , Myocytes, Cardiac/cytology , Myocytes, Cardiac/metabolism , Regeneration , Animals , Cell Proliferation , Humans , Stem Cells/cytology , Stem Cells/metabolism
7.
Muscle Nerve ; 63(5): 668-677, 2021 05.
Article in English | MEDLINE | ID: mdl-33501671

ABSTRACT

INTRODUCTION: The EMBRACE study (Clinical Trials No. NCT02462759) evaluated nusinersen in infants/children with infantile- or later-onset spinal muscular atrophy (SMA) who were ineligible for the ENDEAR and CHERISH studies. METHODS: Participants were randomized to intrathecal nusinersen (12-mg scaled equivalent dose; n = 14) or sham procedure (n = 7) in part 1 (~14 months) and subsequently received open-label nusinersen for ~24 months in part 2 of the study. RESULTS: Part 1 was stopped early after the demonstration of motor function benefit with nusinersen in ENDEAR. There were no nusinersen-related adverse events (AEs) and no study discontinuations due to nusinersen-related AEs. The most common AEs included pyrexia, cough, pneumonia, and upper respiratory tract infections. Motor milestone responder rates were higher in those receiving nusinersen at last available assessment (93%) than in those receiving sham procedure in part 1 (29%) or transitioned from sham to nusinersen in part 2 (83%). This functional improvement was observed despite the small sample size and shortened part 1 trial duration that undermined the power of the study to demonstrate such treatment effects at a significant level. DISCUSSION: Nusinersen demonstrated a favorable long-term benefit-risk profile in this broad population of individuals with infantile- or later-onset SMA.


Subject(s)
Oligonucleotides/therapeutic use , Spinal Muscular Atrophies of Childhood/drug therapy , Child, Preschool , Double-Blind Method , Female , Humans , Infant , Injections, Spinal , Male , Oligonucleotides/adverse effects , Treatment Outcome
9.
J Physiol ; 597(2): 499-519, 2019 01.
Article in English | MEDLINE | ID: mdl-30242840

ABSTRACT

KEY POINTS: Significant and selective up-regulation of the Na+ /H+ exchanger NHA2 (SLC9B2) was observed in cysts of patients with autosomal dominant polycystic kidney disease. Using the MDCK cell model of cystogenesis, it was found that NHA2 increases cyst size. Silencing or pharmacological inhibition of NHA2 inhibits cyst formation in vitro. Polycystin-1 represses NHA2 expression via Ca2+ /NFAT signalling whereas the dominant negative membrane-anchored C-terminal fragment (PC1-MAT) increased NHA2 levels. Drugs (caffeine, theophylline) and hormones (vasopressin, aldosterone) known to exacerbate cysts elicit NHA2 expression. Taken together, the findings reveal NHA2 as a potential new player in salt and water homeostasis in the kidney and in the pathogenesis of polycystic kidney disease. ABSTRACT: Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 and PKD2 encoding polycystin-1 (PC1) and polycystin-2 (PC2), respectively. The molecular pathways linking polycystins to cyst development in ADPKD are still unclear. Intracystic fluid secretion via ion transporters and channels plays a crucial role in cyst expansion in ADPKD. Unexpectedly, we observed significant and selective up-regulation of NHA2, a member of the SLC9B family of Na+ /H+ exchangers, that correlated with cyst size and disease severity in ADPKD patients. Using three-dimensional cultures of MDCK cells to model cystogenesis in vitro, we showed that ectopic expression of NHA2 is causal to increased cyst size. Induction of PC1 in MDCK cells inhibited NHA2 expression with concordant inhibition of Ca2+ influx through store-dependent and -independent pathways, whereas reciprocal activation of Ca2+ influx by the dominant negative membrane-anchored C-terminal tail fragment of PC1 elevated NHA2. We showed that NHA2 is a target of Ca2+ /NFAT signalling and is transcriptionally induced by methylxanthine drugs such as caffeine and theophylline, which are contraindicated in ADPKD patients. Finally, we observed robust induction of NHA2 by vasopressin, which is physiologically consistent with increased levels of circulating vasopressin and up-regulation of vasopressin V2 receptors in ADPKD. Our findings have mechanistic implications on the emerging use of vasopressin V2 receptor antagonists such as tolvaptan as safe and effective therapy for polycystic kidney disease and reveal a potential new regulator of transepithelial salt and water transport in the kidney.


Subject(s)
Antiporters/genetics , Polycystic Kidney Diseases , Animals , Antiporters/metabolism , Cell Culture Techniques , Cysts , Dogs , HEK293 Cells , Homeostasis , Humans , Kidney/metabolism , Kidney/physiopathology , Madin Darby Canine Kidney Cells , Models, Biological , Polycystic Kidney Diseases/genetics , Polycystic Kidney Diseases/metabolism , Polycystic Kidney Diseases/physiopathology
10.
Circulation ; 137(20): 2152-2165, 2018 05 15.
Article in English | MEDLINE | ID: mdl-29348261

ABSTRACT

BACKGROUND: Defining conserved molecular pathways in animal models of successful cardiac regeneration could yield insight into why adult mammals have inadequate cardiac regeneration after injury. Insight into the transcriptomic landscape of early cardiac regeneration from model organisms will shed light on evolutionarily conserved pathways in successful cardiac regeneration. METHODS: Here we describe a cross-species transcriptomic screen in 3 model organisms for cardiac regeneration: axolotl, neonatal mice, and zebrafish. Apical resection to remove ≈10% to 20% of ventricular mass was carried out in these model organisms. RNA-sequencing analysis was performed on the hearts harvested at 3 time points: 12, 24, and 48 hours after resection. Sham surgery was used as internal control. RESULTS: Genes associated with inflammatory processes were found to be upregulated in a conserved manner. Complement receptors (activated by complement components, part of the innate immune system) were found to be highly upregulated in all 3 species. This approach revealed induction of gene expression for complement 5a receptor 1 in the regenerating hearts of zebrafish, axolotls, and mice. Inhibition of complement 5a receptor 1 significantly attenuated the cardiomyocyte proliferative response to heart injury in all 3 species. Furthermore, after left ventricular apical resection, the cardiomyocyte proliferative response was diminished in mice with genetic deletion of complement 5a receptor 1. CONCLUSIONS: These data reveal that activation of complement 5a receptor 1 mediates an evolutionarily conserved response that promotes cardiomyocyte proliferation after cardiac injury and identify complement pathway activation as a common pathway of successful heart regeneration.


Subject(s)
Evolution, Molecular , Heart/physiology , Receptor, Anaphylatoxin C5a/metabolism , Regeneration/physiology , Ambystoma mexicanum , Animals , Animals, Newborn , Cell Proliferation , Gene Expression Profiling , Gene Ontology , Mice , Myocardium/pathology , Myocytes, Cardiac/cytology , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Peptides, Cyclic/pharmacology , RNA/chemistry , RNA/isolation & purification , RNA/metabolism , Receptor, Anaphylatoxin C5a/antagonists & inhibitors , Receptor, Anaphylatoxin C5a/genetics , Sequence Analysis, RNA , Troponin T/analysis , Zebrafish
11.
Am J Med Genet A ; 176(1): 235-240, 2018 01.
Article in English | MEDLINE | ID: mdl-29090527

ABSTRACT

Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) syndrome (OMIM# 601338) is a rare autosomal dominant disorder characterized by episodic, fever-induced ataxic encephalopathy in childhood with residual symptoms. All identified patients have the same heterozygous missense variant c.2452G>A (p.Glu818Lys) in the ATP1A3 gene, encoding Na+ /K+ ATPase α3. We describe a large CAPOS pedigree with three generations of affected members, the first ascertained in the United States. Deafness, optic atrophy, and pes cavus were present in all three members of the family evaluated. In addition, one of the affected individuals experienced markedly worsening features during her three pregnancies and in the immediate postpartum period, a potential element of the natural history of CAPOS previously unreported. We conclude that the triggering factors and clinical spectrum of pathogenic ATP1A3 variants may be broader than previously described. Targeted sequencing of ATP1A3 should be considered in any patient presenting with cerebellar ataxia triggered by febrile illness, or pregnancy and delivery, especially in the presence of sensorineural hearing loss, optic atrophy, pes cavus, or early childhood history of acute encephalopathic ataxia. Prophylactic administration of acetazolamide or flunarizine may prevent acute episodes of ataxia or mitigate neurologic symptoms, although their efficacies have not been well studied.


Subject(s)
Cerebellar Ataxia/diagnosis , Cerebellar Ataxia/genetics , Foot Deformities, Congenital/diagnosis , Foot Deformities, Congenital/genetics , Hearing Loss, Sensorineural/diagnosis , Hearing Loss, Sensorineural/genetics , Optic Atrophy/diagnosis , Optic Atrophy/genetics , Phenotype , Pregnancy Complications , Reflex, Abnormal/genetics , Alleles , Child, Preschool , Female , Genetic Association Studies , Genotype , Humans , Infant , Male , Pedigree , Pregnancy , Sodium-Potassium-Exchanging ATPase/genetics
12.
Pediatr Radiol ; 48(3): 392-397, 2018 03.
Article in English | MEDLINE | ID: mdl-29130140

ABSTRACT

BACKGROUND: Nusinersen, the only treatment approved by the United States Food and Drug Administration for spinal muscular atrophy (SMA), is delivered intrathecally. Many children with SMA have extensive spinal instrumentation and deformities, often precluding the use of standard approaches for gaining intrathecal access. Furthermore the anatomical distortion that often occurs with rotoscoliosis can complicate the use of fluoroscopic guidance. Compared to fluoroscopy, CT affords superior guidance for complex needle placements. This opens up alternatives to the posterior (interlaminar) technique, including transforaminal and caudal approaches. OBJECTIVE: This study describes the early results of technical success, complications and radiation dose of intrathecal delivery of nusinersen using cone-beam CT guidance with two-axis fluoroscopic navigational overlay. MATERIALS AND METHODS: We conducted a retrospective review of 15 consecutive nusinersen injections performed in four children with SMA and extensive spinal hardware precluding standard posterior lumbar puncture techniques. These children were treated using transforaminal thecal access employing cone-beam CT with navigational overlay. We analyzed results including technical success, complications and total fluoroscopy time. RESULTS: All procedures were technically successful. No major complications and one minor complication were reported; the minor complication was a post-procedural neuropathic headache that was attributed to procedural positioning and was treated successfully with gabapentin. The average procedural fluoroscopy time and air kerma were 1.9 min and 55.8 mGy, respectively. CONCLUSION: Cone-beam CT guidance with two-axis navigational overlay is a safe, effective method for gaining transforaminal intrathecal access in children with spinal abnormalities and hardware precluding the use of standard techniques.


Subject(s)
Cone-Beam Computed Tomography , Muscular Atrophy, Spinal/drug therapy , Oligonucleotides/administration & dosage , Radiography, Interventional , Adolescent , Female , Humans , Injections, Spinal , Internal Fixators , Male , Muscular Atrophy, Spinal/diagnostic imaging , Muscular Atrophy, Spinal/surgery , Retrospective Studies
13.
Dev Neurosci ; 39(1-4): 124-140, 2017.
Article in English | MEDLINE | ID: mdl-28486224

ABSTRACT

BACKGROUND: Cerebral palsy (CP) is the most common motor disability in childhood, with a worldwide prevalence of 1.5-4/1,000 live births. Hypoxic-ischemic encephalopathy (HIE) contributes to the burden of CP, but the long-term neuropathological findings of this association remain limited. METHODOLOGY: Thirty-four term Macaca nemestrina macaques were included in this long-term neuropathological study: 9 control animals delivered by cesarean section and 25 animals with perinatal asphyxia delivered by cesarean section after 15-18 min of umbilical cord occlusion (UCO). UCO animals were randomized to saline (n = 11), therapeutic hypothermia (TH; n = 6), or TH + erythropoietin (Epo; n = 8). Epo was given on days 1, 2, 3, and 7. Animals had serial developmental assessments and underwent magnetic resonance imaging with diffusion tensor imaging at 9 months of age followed by necropsy. Histology and immunohistochemical (IHC) staining of brain and brainstem sections were performed. RESULTS: All UCO animals demonstrated and met the standard diagnostic criteria for human neonates with moderate-to-severe HIE. Four animals developed moderate-to-severe CP (3 UCO and 1 UCO + TH), 9 had mild CP (2 UCO, 3 UCO + TH, 3 UCO + TH + Epo, and 1 control), and 2 UCO animals died. None of the animals treated with TH + Epo died, had moderate-to-severe CP, or demonstrated signs of long-term neuropathological toxicity. Compared to animals grouped together as having no CP (no-CP; controls and mild CP only), animals with CP (moderate and severe) demonstrated decreased fractional anisotropy of multiple white-matter tracts including the corpus callosum and internal capsule, when using Tract-Based Spatial Statistics (TBSS). Animals with CP had decreased staining for cortical neurons and increased brainstem glial scarring compared to animals without CP. The cerebellar cell density of the internal granular layer and white matter was decreased in CP animals compared to that in control animals without CP. CONCLUSIONS/SIGNIFICANCE: In this nonhuman primate HIE model, animals treated with TH + Epo had less brain pathology noted on TBSS and IHC staining, which supports the long-term safety of TH + Epo in the setting of HIE. Animals that developed CP showed white-matter changes noted on TBSS, subtle histopathological changes in both the white and gray matter, and brainstem injury that correlated with CP severity. This HIE model may lend itself to further study of the relationship between brainstem injury and CP.


Subject(s)
Asphyxia Neonatorum/complications , Cerebral Palsy/pathology , Disease Models, Animal , Hypoxia-Ischemia, Brain/etiology , Animals , Animals, Newborn , Asphyxia Neonatorum/pathology , Cerebral Palsy/etiology , Erythropoietin/pharmacology , Hypothermia, Induced , Hypoxia-Ischemia, Brain/pathology , Macaca nemestrina , Random Allocation
14.
Physiol Genomics ; 48(11): 826-834, 2016 11 01.
Article in English | MEDLINE | ID: mdl-27664183

ABSTRACT

Short chain fatty acid (SCFA) metabolites are byproducts of gut microbial metabolism that are known to affect host physiology via host G protein-coupled receptor (GPCRs). We previously showed that an acute SCFA bolus decreases blood pressure (BP) in anesthetized mice, an effect mediated primarily via Gpr41. In this study, our aims were to identify the cellular localization of Gpr41 and to determine its role in BP regulation. We localized Gpr41 to the vascular endothelium using RT-PCR: Gpr41 is detected in intact vessels (with endothelium) but is absent from denuded vessels (without endothelium). Furthermore, using pressure myography we confirmed that SCFAs dilate resistance vessels in an endothelium-dependent manner. Since we previously found that Gpr41 mediates a hypotensive response to acute SCFA administration, we hypothesized that Gpr41 knockout (KO) mice would be hypertensive. Here, we report that Gpr41 KO mice have isolated systolic hypertension compared with wild-type (WT) mice; diastolic BP was not different between WT and KO. Older Gpr41 KO mice also exhibited elevated pulse wave velocity, consistent with a phenotype of systolic hypertension; however, there was no increase in ex vivo aorta stiffness (measured by mechanical tensile testing). Plasma renin concentrations were also similar in KO and WT mice. The systolic hypertension in Gpr41 KO is not salt sensitive, as it is not significantly altered on either a high- or low-salt diet. In sum, these studies suggest that endothelial Gpr41 lowers baseline BP, likely by decreasing active vascular tone without altering passive characteristics of the blood vessels, and that Gpr41 KO mice have hypertension of a vascular origin.


Subject(s)
Bacteria/metabolism , Blood Pressure/drug effects , Endothelium, Vascular/metabolism , Fatty Acids, Volatile/pharmacology , Receptors, G-Protein-Coupled/metabolism , Animals , Female , Hypertension/blood , Hypertension/physiopathology , Male , Metabolome/drug effects , Mice, Inbred C57BL , Mice, Knockout , Renin/blood , Sodium Chloride, Dietary/adverse effects , Sus scrofa , Systole/drug effects , Vasodilation/drug effects
15.
Exp Physiol ; 101(4): 478-81, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26238273

ABSTRACT

NEW FINDINGS: What is the topic of this review? This review covers recent findings highlighting roles for renal and vascular sensory receptors that modify blood pressure control in response to changes in gut microbial metabolites. What advances does it highlight? This review highlights the novel roles that G-protein-coupled receptor 41 and olfactory receptor 78 play in blood pressure regulation. The gut microbiota have recently been recognized as an important component of host physiology and pathophysiology. Our recent studies have shown that a subset of gut microbial metabolites, known as short-chain fatty acids, act as ligands for host G-protein-coupled receptors (G-protein-coupled receptor 41 and olfactory receptor 78). Short-chain fatty acid-mediated activation of G-protein-coupled receptor 41 and olfactory receptor 78 modulates blood pressure control, both by modulating renin secretion and by modulating vascular tone directly. Further studies are needed in order to gain a better understanding of the underlying mechanism by which microbiota and microbial metabolites modulate host physiology and their potential implications in health and disease.


Subject(s)
Gastrointestinal Microbiome/physiology , Gastrointestinal Tract/metabolism , Gastrointestinal Tract/microbiology , Kidney/metabolism , Receptors, Odorant/metabolism , Animals , Fatty Acids, Volatile/metabolism , Humans , Receptors, G-Protein-Coupled/metabolism
16.
Pediatr Radiol ; 46(9): 1354-7, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27026023

ABSTRACT

We present the case of a female infant referred for prenatal MR evaluation of ventriculomegaly, which had been attributed by the referring obstetrician to aqueductal stenosis. Fetal MR confirmed ventriculomegaly but also demonstrated cerebral volume loss and white matter abnormalities. After birth, the infant developed persistent lactic acidosis. A diagnosis of pyruvate dehydrogenase complex deficiency was made on the basis of metabolic and molecular genetic studies. Ventriculomegaly is a common referral reason for fetal MR, yet there are few published reports of the radiographic findings that accompany inborn errors of metabolism, one potentially under-recognized cause of enlarged ventricles. This case contributes to this small body of literature on the imaging features of pyruvate dehydrogenase complex deficiency by describing pre- and postnatal MR findings and key clinical details. Our report emphasizes the necessity of considering pyruvate dehydrogenase complex deficiency and other metabolic disorders as potential etiologies for fetal ventriculomegaly since prompt diagnosis may allow for early initiation of treatment and improve outcome.


Subject(s)
Magnetic Resonance Imaging/methods , Pyruvate Dehydrogenase Complex Deficiency Disease/diagnostic imaging , Ultrasonography, Prenatal/methods , Adult , Diagnosis, Differential , Female , Humans , Infant, Newborn , Pregnancy , Prenatal Diagnosis , Pyruvate Dehydrogenase Complex Deficiency Disease/therapy
17.
Am J Physiol Cell Physiol ; 307(11): C979-85, 2014 Dec 01.
Article in English | MEDLINE | ID: mdl-25273884

ABSTRACT

Recent studies have highlighted a myriad of ways in which the activity and composition of the gut microbiota can affect the host organism. A primary way in which the gut microbiota affect host physiology is by the production of metabolites, such as short-chain fatty acids (SCFAs), which are subsequently absorbed into the bloodstream of the host. Although recent studies have begun to unravel the ways in which gut microbial SCFAs affect host physiology, less is understood regarding the underlying cell biological mechanisms. In this review, we will outline the known receptors and transporters for SCFAs, and review what is known about the cell biological effects of microbial SCFAs.


Subject(s)
Bacteria/metabolism , Fatty Acids, Volatile/chemistry , Fatty Acids, Volatile/metabolism , Gastrointestinal Tract/microbiology , Humans
18.
J Biol Chem ; 288(15): 10214-29, 2013 Apr 12.
Article in English | MEDLINE | ID: mdl-23449976

ABSTRACT

C1q/TNF-related proteins (CTRPs) are a family of secreted regulators of glucose and lipid metabolism. Here, we describe CTRP11, a novel and phylogenetically conserved member of the C1q family. Our studies revealed that white and brown adipose are major tissues that express CTRP11, and its expression is acutely regulated by changes in metabolic state. Within white adipose tissue, CTRP11 is primarily expressed by stromal vascular cells. As a secreted multimeric protein, CTRP11 forms disulfide-linked oligomers. Although the conserved N-terminal Cys-28 and Cys-32 are dispensable for the assembly of higher-order oligomeric structures, they are unexpectedly involved in modulating protein secretion. When co-expressed, CTRP11 forms heteromeric complexes with closely related CTRP10, CTRP13, and CRF (CTRP14) via the C-terminal globular domains, combinatorial associations that potentially generate functionally distinct complexes. Functional studies revealed a role for CTRP11 in regulating adipogenesis. Ectopic expression of CTRP11 or exposure to recombinant protein inhibited differentiation of 3T3-L1 adipocytes. The expression of peroxisome proliferator-activated receptor-γ and CAAT/enhancer binding protein-α, which drive the adipogenic gene program, was markedly suppressed by CTRP11. Impaired adipogenesis was caused by a CTRP11-mediated decrease in p42/44-MAPK signaling and inhibition of mitotic clonal expansion, a process essential for adipocyte differentiation in culture. These results implicate CTRP11 as a novel secreted regulator of adipogenesis and highlight the potential paracrine cross-talk between adipocytes and cells of the stromal vascular compartment in maintaining adipose tissue homeostasis.


Subject(s)
Adipogenesis/physiology , Adipokines/biosynthesis , Cell Differentiation/physiology , Gene Expression Regulation/physiology , MAP Kinase Signaling System/physiology , Paracrine Communication/physiology , 3T3-L1 Cells , Adipogenesis/drug effects , Adipokines/genetics , Adipokines/pharmacology , Animals , Cell Differentiation/drug effects , Female , MAP Kinase Signaling System/drug effects , Male , Mice , Mice, Obese , Mitogen-Activated Protein Kinase 1/genetics , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/genetics , Mitogen-Activated Protein Kinase 3/metabolism , Paracrine Communication/drug effects , Protein Structure, Tertiary , Recombinant Proteins/biosynthesis , Recombinant Proteins/genetics , Recombinant Proteins/pharmacology
19.
Arch Dis Child Fetal Neonatal Ed ; 109(3): 308-316, 2024 Apr 18.
Article in English | MEDLINE | ID: mdl-38071538

ABSTRACT

OBJECTIVE: To study the association between the Sarnat exam (SE) performed before and after therapeutic hypothermia (TH) and outcomes at 2 years in infants with moderate or severe hypoxic-ischaemic encephalopathy (HIE). DESIGN: Secondary analysis of the High-dose Erythropoietin for Asphyxia and EncephaLopathy Trial. Adjusted ORs (aORs) for death or neurodevelopmental impairment (NDI) based on SE severity category and change in category were constructed, adjusting for sedation at time of exam. Absolute SE Score and its change were compared for association with risk for death or NDI using locally estimated scatterplot smoothing curves. SETTING: Randomised, double-blinded, placebo-controlled multicentre trial including 17 centres across the USA. PATIENTS: 479/500 enrolled neonates who had both a qualifying SE (qSE) before TH and a SE after rewarming (rSE). INTERVENTIONS: Standardised SE was used across sites before and after TH. All providers underwent standardised SE training. MAIN OUTCOME MEASURES: Primary outcome was defined as the composite outcome of death or any NDI at 22-36 months. RESULTS: Both qSE and rSE were associated with the primary outcome. Notably, an aOR for primary outcome of 6.2 (95% CI 3.1 to 12.6) and 50.3 (95% CI 13.3 to 190) was seen in those with moderate and severe encephalopathy on rSE, respectively. Persistent or worsened severity on rSE was associated with higher odds for primary outcome compared with those who improved, even when qSE was severe. CONCLUSION: Both rSE and change between qSE and rSE were strongly associated with the odds of death/NDI at 22-36 months in infants with moderate or severe HIE.

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