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1.
Pediatr Surg Int ; 40(1): 35, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38216767

RESUMO

PURPOSE: Necrotizing enterocolitis (NEC) is a severe intestinal disease primarily affecting premature infants, marked by impaired epithelial regeneration. Breastfed infants are less susceptible to NEC than formula-fed ones, and human milk oligosaccharides (HMO) found in breast milk have prebiotic properties that can protect against NEC. However, it is unclear how HMOs influence intestinal epithelium regeneration in relation to the gut microbiota. METHODS: Broad-spectrum antibiotics were administered to pregnant dams to reduce the microbiota in offspring. NEC was induced through administration of hyperosmolar formula, lipopolysaccharide, and hypoxia from postnatal days (p) 5-9. Intestinal epithelial organoids were derived from p9 mice. HMOs were isolated from human donor breast milk and then solubilized in the formula for each feed or culture media for organoids. RESULTS: HMOs did not alter the microbiota profile in the presence of a normal or reduced microbiota. In the reduced microbiota, HMO treatment decreased NEC intestinal injury, and increased proliferation and stem cell activity. Additionally, in the complete absence of the microbiota, HMOs stimulated intestinal organoid growth. CONCLUSION: This study demonstrates that HMOs promoted intestinal epithelial regeneration independent of the gut microbiota. These findings provide further insight into the various benefits HMOs may have in the protection against NEC.


Assuntos
Enterocolite Necrosante , Doenças do Recém-Nascido , Microbiota , Lactente , Feminino , Gravidez , Recém-Nascido , Animais , Humanos , Camundongos , Leite Humano , Enterocolite Necrosante/prevenção & controle , Mucosa Intestinal , Oligossacarídeos/farmacologia , Regeneração
2.
Pediatr Surg Int ; 40(1): 21, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38108911

RESUMO

PURPOSE: Neonatal sepsis is a systemic inflammatory infection common in premature infants and a leading cause of mortality. Argon is an emerging interest in the field of noble gas therapy. Neonates with severe sepsis are frequently mechanically ventilated creating an opportunity for inhalation therapy. We aimed to investigate argon inhalation as a novel experimental therapy in neonatal sepsis. METHODS: Sepsis was established in C57BL/6 neonatal mice by a lipopolysaccharide intraperitoneal injection on postnatal day 9. Septic pup mice were exposed to room air as well as non-septic controls. In the argon group, septic pup mice were exposed to argon (70% Ar, 30% O2) for 6 h in a temperature-controlled environment. RESULTS: At 6 h, survival was significantly enhanced when septic mice received argon compared to septic controls. Serum profiles of cytokine release were significantly attenuated as well as lung architecture restored. CONCLUSIONS: Our findings suggest that argon inhalation as a novel treatment for neonatal sepsis, reducing mortality and counteracting the acute systemic inflammatory response in the blood and preserving the architecture of the lung. This research can contribute to a paradigm shift in the treatment and outcome of neonates with sepsis.


Assuntos
Sepse Neonatal , Sepse , Humanos , Lactente , Animais , Camundongos , Camundongos Endogâmicos C57BL , Argônio/uso terapêutico , Sepse/terapia , Inflamação
3.
Pediatr Surg Int ; 39(1): 298, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37982893

RESUMO

PURPOSE: Intestinal neuronal dysplasia (IND) is a congenital anomaly affecting gastrointestinal neural innervation, but the pathogenesis remains unclear. The homozygous Ncx/Hox11L.1 knockout (Ncx-/-) mice exhibit megacolon and enteric ganglia anomalies, resembling IND phenotypes. Sox10-Venus transgenic mouse were used to visualize enteric neural crest cells in real time. This study aims to establish a novel mouse model of Sox10-Venus+/Ncx-/- mouse to study the pathogenesis of IND. METHODS: Sox10-Venus+/Ncx-/- (Ncx-/-) (n = 8) mice and Sox10-Venus+/Ncx+/+ controls (control) (n = 8) were euthanized at 4-5 weeks old, and excised intestines were examined with fluorescence microscopy. Immunohistochemistry was performed on tissue sections with neural marker Tuj1. RESULTS: Ncx-/- mice exhibited dilated cecum and small intestine. Body weight of Ncx-/- mice was lower with higher ratio of small intestine length relative to body weight. The neural network (Sox10-Venus) was observed along the intestine wall in Ncx-/- and control mice without staining. Ectopic and increased expression of Tuj1 was observed in both small intestine and proximal colon of Ncx-/- mice. CONCLUSION: This study has established a reliable animal model that exhibits characteristics similar to patients with IND. This novel mouse model can allow the easy visualization of ENS in a time- and cost-effective way to study the pathogenesis of IND.


Assuntos
Sistema Nervoso Entérico , Doença de Hirschsprung , Humanos , Camundongos , Animais , Intestinos , Sistema Nervoso Entérico/patologia , Colo/patologia , Camundongos Transgênicos , Peso Corporal , Crista Neural , Doença de Hirschsprung/genética , Doença de Hirschsprung/patologia
5.
Biol Open ; 12(8)2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37470706

RESUMO

G9a, also known as EHMT2, is essential for embryogenesis and has specific functions in multiple developmental processes. G9a inactivation affects development of the nervous system, which is formed with contribution of descendants of progenitor cells expressing the transcription factor Isl1. However, the function of G9a in Isl1-expressing progenitors is unknown. Here, we show that G9a is required for proper development of multiple structures formed with contribution of Isl1-expressing progenitors. A Cre-dependent GFP reporter revealed that the recombinase activity of the Isl1-Cre used in this study to inactivate G9a was reduced to a subset of Isl1-expressing progenitor cells. G9a mutants reached endpoint by 7 weeks of age with cardiac hypertrophy, hydrocephalus, underdeveloped cerebellum and hind limb paralysis, modeling aspects of Dandy-Walker complex. Moreover, neuroepithelium of the lateral ventricle derived from Isl1-expressing progenitors was thinner and disorganized, potentially compromising cerebrospinal fluid dynamics in G9a mutants. Micro-computed tomography after iodine staining revealed increased volume of the heart, eye lens and brain structures in G9a mutant fetuses. Thus, altered development of descendants of the second heart field and the neural crest could contribute to multicomponent malformation like Dandy-Walker.


Assuntos
Síndrome de Dandy-Walker , Antígenos de Histocompatibilidade , Histona-Lisina N-Metiltransferase , Integrases/genética , Células-Tronco , Microtomografia por Raio-X , Animais
6.
Pediatr Surg Int ; 39(1): 211, 2023 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-37268798

RESUMO

PURPOSE: Necrotizing enterocolitis (NEC), an inflammatory intestinal disease common in premature infants, has been associated with the development of lung damage. Toll-like receptor 4 has been shown to regulate inflammation in the NEC lungs, however, other important inflammatory mechanisms have not been thoroughly investigated. In addition, we reported that milk-derived exosomes were able to attenuate intestinal injury and inflammation in experimental NEC. This study aims to (i) investigate the role of the NLRP3 inflammasome and NF-κB pathway in regulating lung damage during experimental NEC; and (ii) evaluate the therapeutic potential of bovine milk exosomes in reducing lung inflammation and injury during NEC. METHODS: NEC was induced by gavage feeding of hyperosmolar formula, hypoxia, and lipopolysaccharide administration in neonatal mice from postnatal days 5-9. Exosomes were obtained by ultracentrifugation of bovine milk and administered during each formula feed. RESULTS: The lung of NEC pups showed increased inflammation, tissue damage, NLRP3 inflammasome expression, and NF-κB pathway activation, which were attenuated upon exosome administration. CONCLUSION: Our findings suggest that the lung undergoes significant inflammation and injury following experimental NEC which are attenuated by bovine milk-derived exosomes. This emphasizes the therapeutic potential of exosomes not just on the intestine but also on the lung.


Assuntos
Enterocolite Necrosante , Exossomos , Doenças do Recém-Nascido , Recém-Nascido , Humanos , Animais , Camundongos , NF-kappa B/metabolismo , Leite/metabolismo , Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Enterocolite Necrosante/metabolismo , Exossomos/metabolismo , Inflamação/metabolismo , Pulmão/metabolismo , Animais Recém-Nascidos , Modelos Animais de Doenças , Mucosa Intestinal/metabolismo
7.
Cell Mol Life Sci ; 80(7): 183, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37338571

RESUMO

Peroxisomes are essential for mitochondrial health, as the absence of peroxisomes leads to altered mitochondria. However, it is unclear whether the changes in mitochondria are a function of preserving cellular function or a response to cellular damage caused by the absence of peroxisomes. To address this, we developed conditional hepatocyte-specific Pex16 deficient (Pex16 KO) mice that develop peroxisome loss and subjected them to a low-protein diet to induce metabolic stress. Loss of PEX16 in hepatocytes led to increased biogenesis of small mitochondria and reduced autophagy flux but with preserved capacity for respiration and ATP capacity. Metabolic stress induced by low protein feeding led to mitochondrial dysfunction in Pex16 KO mice and impaired biogenesis. Activation of PPARα partially corrected these mitochondrial disturbances, despite the absence of peroxisomes. The findings of this study demonstrate that the absence of peroxisomes in hepatocytes results in a concerted effort to preserve mitochondrial function, including increased mitochondrial biogenesis, altered morphology, and modified autophagy activity. Our study underscores the relationship between peroxisomes and mitochondria in regulating the hepatic metabolic responses to nutritional stressors.


Assuntos
Biogênese de Organelas , Peroxissomos , Camundongos , Animais , Peroxissomos/metabolismo , Mitocôndrias/metabolismo , Fígado/metabolismo , Autofagia
8.
Nat Cardiovasc Res ; 2(2): 174-191, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38665902

RESUMO

Cardiac metabolism is deranged in heart failure, but underlying mechanisms remain unclear. Here, we show that lysine demethylase 8 (Kdm8) maintains an active mitochondrial gene network by repressing Tbx15, thus preventing dilated cardiomyopathy leading to lethal heart failure. Deletion of Kdm8 in mouse cardiomyocytes increased H3K36me2 with activation of Tbx15 and repression of target genes in the NAD+ pathway before dilated cardiomyopathy initiated. NAD+ supplementation prevented dilated cardiomyopathy in Kdm8 mutant mice, and TBX15 overexpression blunted NAD+-activated cardiomyocyte respiration. Furthermore, KDM8 was downregulated in human hearts affected by dilated cardiomyopathy, and higher TBX15 expression defines a subgroup of affected hearts with the strongest downregulation of genes encoding mitochondrial proteins. Thus, KDM8 represses TBX15 to maintain cardiac metabolism. Our results suggest that epigenetic dysregulation of metabolic gene networks initiates myocardium deterioration toward heart failure and could underlie heterogeneity of dilated cardiomyopathy.

9.
Nat Commun ; 13(1): 7576, 2022 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-36481684

RESUMO

Mortality in children with severe malnutrition is strongly related to signs of metabolic dysfunction, such as hypoglycemia. Lower circulating tryptophan levels in children with severe malnutrition suggest a possible disturbance in the tryptophan-nicotinamide adenine dinucleotide (TRP-NAD+) pathway and subsequently in NAD+ dependent metabolism regulator sirtuin1 (SIRT1). Here we show that severe malnutrition in weanling mice, induced by 2-weeks of low protein diet feeding from weaning, leads to an impaired TRP-NAD+ pathway with decreased NAD+ levels and affects hepatic mitochondrial turnover and function. We demonstrate that stimulating the TRP-NAD+ pathway with NAD+ precursors improves hepatic mitochondrial and overall metabolic function through SIRT1 modulation. Activating SIRT1 is sufficient to induce improvement in metabolic functions. Our findings indicate that modulating the TRP-NAD+ pathway can improve liver metabolic function in a mouse model of severe malnutrition. These results could lead to the development of new interventions for children with severe malnutrition.


Assuntos
Hepatopatias , NAD , Camundongos , Animais , Triptofano
10.
Immunity ; 55(12): 2300-2317.e6, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36473468

RESUMO

Intestinal stem cell maturation and development coincide with gut microbiota exposure after birth. Here, we investigated how early life microbial exposure, and disruption of this process, impacts the intestinal stem cell niche and development. Single-cell transcriptional analysis revealed impaired stem cell differentiation into Paneth cells and macrophage specification upon antibiotic treatment in early life. Mouse genetic and organoid co-culture experiments demonstrated that a CD206+ subset of intestinal macrophages secreted Wnt ligands, which maintained the mesenchymal niche cells important for Paneth cell differentiation. Antibiotics and reduced numbers of Paneth cells are associated with the deadly infant disease, necrotizing enterocolitis (NEC). We showed that colonization with Lactobacillus or transfer of CD206+ macrophages promoted Paneth cell differentiation and reduced NEC severity. Together, our work defines the gut microbiota-mediated regulation of stem cell niches during early postnatal development.


Assuntos
Enterocolite Necrosante , Microbioma Gastrointestinal , Camundongos , Animais , Celulas de Paneth/fisiologia , Diferenciação Celular/fisiologia , Macrófagos
11.
Sci Adv ; 8(7): eabj6779, 2022 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-35171682

RESUMO

Children admitted to hospital with an acute illness and concurrent severe malnutrition [complicated severe malnutrition (CSM)] have a high risk of dying. The biological processes underlying their mortality are poorly understood. In this case-control study nested within a multicenter randomized controlled trial among children with CSM in Kenya and Malawi, we found that blood metabolomic and proteomic profiles robustly differentiated children who died (n = 92) from those who survived (n = 92). Fatalities were characterized by increased energetic substrates (tricarboxylic acid cycle metabolites), microbial metabolites (e.g., propionate and isobutyrate), acute phase proteins (e.g., calprotectin and C-reactive protein), and inflammatory markers (e.g., interleukin-8 and tumor necrosis factor-α). These perturbations indicated disruptions in mitochondria-related bioenergetic pathways and sepsis-like responses. This study identified specific biomolecular disturbances associated with CSM mortality, revealing that systemic inflammation and bioenergetic deficits are targetable pathophysiological processes for improving survival of this vulnerable population.


Assuntos
Pacientes Internados , Desnutrição , Estudos de Casos e Controles , Criança , Humanos , Inflamação , Desnutrição/complicações , Proteômica
12.
Mol Nutr Food Res ; 66(4): e2100893, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34921749

RESUMO

SCOPE: Necrotizing enterocolitis (NEC) is a devastating gastrointestinal emergency affecting preterm infants. Breastmilk protects against NEC, partly due to human milk oligosaccharides (HMOs). HMO compositions are highly diverse, and it is unclear if anti-NEC properties are specific to carbohydrate motifs. Here, this study compares intestinal epithelial transcriptomes of five synthetic HMOs (sHMOs) and examines structure-function relationships of HMOs on intestinal signaling. METHODS AND RESULTS: This study interrogates the transcriptome of Caco-2Bbe1 cells in response to five synthetic HMOs (sHMOs) using RNA sequencing: 2'-fucosyllactose (2'-FL), 3-fucosyllactose (3FL), 6'-siallyllactose (6'-SL), lacto-N-tetraose (LNT), lacto-N-neotetraose (LNnT). Protection against intestinal barrier dysfunction and inflammation occurred in an HMO-dependent manner. Each sHMO exerts a unique set of host transcriptome changes and modulated unique signaling pathways. There is clustering between HMOs bearing similar side chains, with little overlap in gene regulation which is shared by all sHMOs. Interestingly, most sHMOs protect pups against NEC, exerting divergent mechanisms on intestinal cell morphology and inflammation. CONCLUSIONS: These results demonstrate that while structurally distinct HMOs impact intestinal physiology, their mechanisms of action differ. This finding establishes the first structure-function relationship of HMOs in the context of intestinal cell signaling responses and offers a functional framework by which to screen and design HMO-like compounds.


Assuntos
Enterocolite Necrosante , Leite Humano , Animais , Células CACO-2 , Modelos Animais de Doenças , Enterocolite Necrosante/prevenção & controle , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Camundongos , Leite Humano/química , Oligossacarídeos/química , Relação Estrutura-Atividade , Transcriptoma
13.
Pediatr Res ; 91(1): 101-106, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34561550

RESUMO

BACKGROUND: Stem cell therapy has been proven to rescue intestinal injury and stimulate intestinal regeneration in necrotizing enterocolitis (NEC). Specifically, stem cells derived from amniotic fluid (AFSCs) and mesenchymal stem cells (MSCs) derived from bone marrow have shown promising results in the treatment of experimental NEC. This study aims to examine the effects of AFSCs and MSCs on the prevention of intestinal injury during experimental NEC. METHODS: Supernatants from AFSC and MSC cultures were collected to perform proteomic analysis. Prior to NEC induction, mice received intraperitoneal injections of phosphate-buffered saline (PBS), 2 × 106 AFSCs, or 2 × 106 MSCs. RESULTS: We found that AFSCs grew faster than MSCs. Proteomic analysis indicated that AFSCs are primarily involved in cell development and growth, while MSCs are involved in immune regulation. Administering AFSCs before NEC induction decreased NEC severity and mucosal inflammation. Intestinal proliferation and endogenous stem cell activation were increased after AFSC administration. However, administering MSCs before NEC induction had no beneficial effects. CONCLUSIONS: This study demonstrated that AFSCs and MSCs have different protein release profiles. AFSCs can potentially be used as a preventative strategy for neonates at risk of NEC, while MSCs cannot be used. IMPACT: AFSCs and MSCs have distinct protein secretory profiles, and AFSCs are primarily involved in cell development and growth, while MSCs are involved in immune regulation. AFSCs are unique in transiently enhancing healthy intestinal epithelial cell growth, which offers protection against the development of experimental NEC. The prevention of NEC via the administration of AFSCs should be evaluated in infants at great risk of developing NEC or in infants with early signs of NEC.


Assuntos
Líquido Amniótico/citologia , Transplante de Células-Tronco , Animais , Enterocolite Necrosante , Humanos , Recém-Nascido , Camundongos
14.
FASEB J ; 35(1): e21265, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33373067

RESUMO

Necrotizing enterocolitis (NEC) is one of the most severe gastrointestinal diseases affecting premature infants. It has been shown that NEC is associated with disrupted intestinal barrier and dysregulated endoplasmic reticulum (ER)-stress response. It has also been shown that stem cells derived from amniotic fluid (AFSC) rescued intestinal injury in experimental NEC. Herein, we hypothesized that the beneficial effects of AFSC in the injured intestine are due to the restoration of intestinal barrier function. We evaluated intestinal barrier function using an ex vivo intestinal organoid model of NEC. We found that AFSC restored the expression and localization of tight junction proteins in intestinal organoids, and subsequently decreased epithelial permeability. AFSC rescued tight junction expression by inducing a protective ER stress response that prevents epithelial cell apoptosis in injured intestinal organoids. Finally, we validated these results in our experimental mouse model of NEC and confirmed that AFSC induced sustained ER stress and prevented intestinal apoptosis. This response led to the restoration of tight junction expression and localization, which subsequently reduced intestinal permeability in NEC pups. These findings confirm that intestinal barrier function is disrupted during NEC intestinal injury, and further demonstrate the disruption can be reversed by the administration of AFSC through the activation of the ER stress pathway. This study provides insight into the pathogenesis of NEC and highlights potential therapeutic targets for the treatment of NEC.


Assuntos
Líquido Amniótico/metabolismo , Estresse do Retículo Endoplasmático , Enterocolite Necrosante/metabolismo , Mucosa Intestinal/metabolismo , Células-Tronco/metabolismo , Junções Íntimas/metabolismo , Animais , Apoptose , Enterocolite Necrosante/patologia , Mucosa Intestinal/patologia , Camundongos , Organoides/metabolismo , Organoides/patologia , Permeabilidade , Ratos , Células-Tronco/patologia , Junções Íntimas/patologia
15.
J Pediatr Surg ; 56(1): 11-16, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33129508

RESUMO

PURPOSE: Biliary atresia (BA) is a fibro-obliterative cholangiopathy that involves both extrahepatic and intrahepatic bile ducts in infants. Cholangiocyte apoptosis has an influence on the fibrogenesis process of bile ducts and the progression of liver fibrosis in BA. Human amniotic fluid stem cells (hAFSCs) are multipotent cells that have ability to inhibit cell apoptosis. We aimed to investigate whether hAFSCs have the potential to attenuate cholangiocyte apoptosis and injury induced fibrogenic response in our ex vivo bile duct injury model of liver ductal organoids. METHODS: The anti-apoptotic effect of hAFSCs was tested in the acetaminophen-induced injury model of neonatal mouse liver ductal organoids (AUP #42681) by using direct and indirect co-culture systems. Cell apoptosis and proliferation were evaluated by immunofluorescent staining. Expression of fibrogenic cytokines was analyzed by RT-qPCR. Data were compared using one-way ANOVA with post hoc test. RESULTS: In our injury model, liver ductal organoids that were treated with hAFSCs in both direct and indirect co-culture systems had a significantly smaller number of apoptotic cholangiocytes and decreased expression of fibrogenic cytokines, transforming growth factor beta-1 (TGF-ß1) and platelet-derived growth factor-BB (PDGF-BB). Moreover, hAFSCs increased cholangiocyte proliferation in injured organoids. CONCLUSION: hAFSCs have the ability to protect the organoids from injury by decreasing cholangiocyte apoptosis and promoting cholangiocyte proliferation. This protective ability of hAFSCs leads to inhibition of the fibrogenic response in the injured organoids. hAFSCs have high therapeutic potential to attenuate liver fibrogenesis in cholangiopathic diseases such as BA.


Assuntos
Líquido Amniótico , Organoides , Apoptose , Ductos Biliares/cirurgia , Humanos , Fígado , Células-Tronco
16.
Pediatr Surg Int ; 36(12): 1471-1479, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33084932

RESUMO

PURPOSE: The fibrogenic process in cholangiopathic diseases such as biliary atresia (BA) involves bile duct injury and apoptosis of cholangiocytes, which leads to the progression of liver fibrosis into liver cirrhosis and can result in end-staged liver disease. Recent advances in the development of organoids or mini-organ structures have allowed us to create an ex vivo injury model of the bile duct that mimics bile duct injury in BA. The aim of this experimental study was to develop a novel model of injured intrahepatic cholangiocytes as this can be relevant to BA. Our new model is important for studying the pathophysiological response of bile ducts to injury and the role of cholangiocytes in initiating the fibrogenic cascade. In addition, it has the potential to be used as a tool for developing new treatment strategies for BA. METHODS: Liver ductal organoids were generated from the liver of healthy neonatal mouse pups. Intrahepatic bile duct fragments were isolated and cultured in Matrigel dome. Injury was induced in the organoids by administration of acetaminophen in culture medium. The organoids were then evaluated for fibrogenic cytokines expression, cell apoptosis marker and cell proliferation marker. RESULTS: Organoids generated from intrahepatic bile duct fragments organized themselves into single-layer epithelial spheroids with lumen on the inside mimicking in vivo bile ducts. After 24-h exposure to acetaminophen, cholangiocytes in the organoids responded to the injury by increasing expression of fibrogenic cytokines, transforming growth factor beta-1 (TGF-ß1) and platelet-derived growth factor-BB (PDGF-BB). This fibrogenic response of injured organoids was associated with increased cholangiocyte apoptosis and decreased cholangiocyte proliferation. CONCLUSION: To our knowledge this is the first description of cholangiocyte injury in the organoids derived from intrahepatic bile ducts. Our injury model demonstrated that cholangiocyte apoptosis and its fibrogenic response may play a role in initiation of the fibrogenic process in cholangiopathic diseases such as BA. These findings are important for the development of novel therapy to reduce cholangiocyte apoptosis and to halt the early fibrogenic cascade in liver fibrogenesis. This novel injury model can prove very valuable for future research in biliary atresia.


Assuntos
Apoptose , Atresia Biliar/patologia , Organoides/patologia , Animais , Animais Recém-Nascidos , Ductos Biliares/patologia , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL
17.
Nat Commun ; 11(1): 4950, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009377

RESUMO

Necrotizing enterocolitis (NEC) is a devastating disease of premature infants with high mortality rate, indicating the need for precision treatment. NEC is characterized by intestinal inflammation and ischemia, as well derangements in intestinal microcirculation. Remote ischemic conditioning (RIC) has emerged as a promising tool in protecting distant organs against ischemia-induced damage. However, the effectiveness of RIC against NEC is unknown. To address this gap, we aimed to determine the efficacy and mechanism of action of RIC in experimental NEC. NEC was induced in mouse pups between postnatal day (P) 5 and 9. RIC was applied through intermittent occlusion of hind limb blood flow. RIC, when administered in the early stages of disease progression, decreases intestinal injury and prolongs survival. The mechanism of action of RIC involves increasing intestinal perfusion through vasodilation mediated by nitric oxide and hydrogen sulfide. RIC is a viable and non-invasive treatment strategy for NEC.


Assuntos
Enterocolite Necrosante/patologia , Intestinos/irrigação sanguínea , Intestinos/patologia , Isquemia/patologia , Microcirculação , Animais , Enterócitos/patologia , Humanos , Hipóxia , Mucosa Intestinal/patologia , Camundongos Endogâmicos C57BL , Microvilosidades/patologia , Microvilosidades/ultraestrutura
18.
Mol Nutr Food Res ; 64(21): e2000519, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32926533

RESUMO

SCOPE: Necrotizing enterocolitis (NEC) is a devastating gastrointestinal emergency and currently the leading cause of mortality in preterm infants. Recent studies show that human milk oligosaccharides (HMOs) reduce the frequency and incidence of NEC; however, the molecular mechanisms for their protection are largely unexplored. METHODS AND RESULTS: To address this gap, a genome-wide profiling of the intestinal epithelial transcriptome in response to HMOs using RNA-sequencing is performed. It is found that HMOs alter the host transcriptome in 225 unique target genes pertaining to cell proliferation and differentiation, including upregulation of stem cell differentiation marker HMGCS2. To validate these results, differentiation in Caco-2Bbe1 (Caco-2) intestinal cells is verified by Alcian Blue staining and transepithelial electrical resistance (TER) recordings. Furthermore, an in vivo model of NEC is also employed whereby neonatal pups are gavage fed HMOs. Interestingly, HMOs-fed pups show enhanced cell MUC2 differentiation and HMGCS2 expression. CONCLUSIONS: These findings demonstrate HMOs protect against NEC in part by altering the differentiation of the crypt-villus axis. In addition, this study suggests that pooled HMOs directly induce a series of biological processes, which provide mechanistic insights to how HMOs protect the host intestine.


Assuntos
Enterocolite Necrosante/patologia , Enterocolite Necrosante/prevenção & controle , Leite Humano/química , Oligossacarídeos/farmacologia , Animais , Células CACO-2 , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cães , Enterocolite Necrosante/genética , Feminino , Perfilação da Expressão Gênica , Humanos , Hidroximetilglutaril-CoA Sintase/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Células Madin Darby de Rim Canino , Masculino , Camundongos Endogâmicos C57BL , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/metabolismo
19.
Pediatr Surg Int ; 36(10): 1157-1165, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32740829

RESUMO

PURPOSE: Intestinal absorption in premature infants occurs via direct epithelial cellular endocytosis and degradation by intracellular lysosomes. Autophagy is a mechanism by which cytoplasmic organelles contribute to lysosomal degradation. However, excessive autophagy can lead to cell death. The purpose of this study was to investigate whether autophagy and endocytosis are present in the small intestinal mucosa during experimental necrotizing enterocolitis (NEC). METHODS: NEC was induced by gavage feeding of hyperosmolar formula, lipopolysaccharide and hypoxia between P5 and P9 (ethical approval 44032). Breastfed mice were used as control. Distal ileum was harvested on P5, P7 and P9 and analyzed for intestinal epithelial cellular morphology as well as autophagy/lysosomal activity, and cell death. Groups were compared using Student's t test. RESULTS: During NEC, giant lysosomes were present in the intestinal villi, with some exceeding their degradation ability leading to their rupture. The NEC group had significantly increased inflammation and autophagy activity, decreased lysosome activity, and increased apoptosis compared to control. CONCLUSIONS: NEC induction causes excessive autophagy and endocytosis leading to lysosomal overloading, lysosomal membrane permeabilization and rupture which results in cell death. These novel findings may help to clarify the pathogenesis of NEC. Reduction of lysosome overload and assisting in their degradation capability may reduce the burden of NEC.


Assuntos
Enterocolite Necrosante/patologia , Íleo/patologia , Mucosa Intestinal/patologia , Lisossomos/patologia , Animais , Animais Recém-Nascidos , Autofagia , Modelos Animais de Doenças , Enterocolite Necrosante/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Mucosa Intestinal/metabolismo , Lisossomos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL
20.
Jt Comm J Qual Patient Saf ; 46(12): 706-714, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32653365

RESUMO

BACKGROUND: The use of pro re nata (PRN) medication orders increases nursing flexibility and efficiency of bedside patient care. However, misuse and/or ambiguity of PRN medication orders may increase the propensity for medication errors. The Joint Commission has Medication Management (MM) standards to mitigate such risks. This quality improvement study with a pre-post design aimed to increase compliance of PRN sedative and analgesic orders with use of failure mode and effects analysis (FMEA) and human factors risk assessment methodologies in a pediatric ICU (PICU). METHODS: Staff education and a PICU analgesia, sedation, and paralysis order set, with predefined PRN orders, were implemented to enhance PRN medication compliance with Joint Commission MM standards. The primary goal was to achieve and maintain a weekly average compliance of ≥ 90%. Proportions of compliant PRN analgesic and sedative orders before and after interventions were compared. RESULTS: Weekly average PRN orders compliance increased from 62.0% ± 9.2% to 77.7% ± 10.1% after staff education was implemented (p = 0.013). After order set implementation, weekly average compliance further increased to 93.2% ± 3.6% (p < 0.0001) and remained > 90% until the end of the study period. CONCLUSION: Interdisciplinary synthesis using FMEA and human factors risk assessment is effective for identifying system failure modes associated with Joint Commission MM standard noncompliance. Implementation of an order set with forced functionality to include order information compliant with Joint Commission MM standards can enhance and maintain Joint Commission-compliant PRN medication orders.


Assuntos
Analgesia , Conduta do Tratamento Medicamentoso , Criança , Humanos , Unidades de Terapia Intensiva Pediátrica , Erros de Medicação/prevenção & controle , Paralisia
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