Epigenetic modifications in the development of bronchopulmonary dysplasia: a review.

While perinatal medicine advancements have bolstered survival outcomes for premature infants, bronchopulmonary dysplasia (BPD) continues to threaten their long-term health. Gene-environment interactions, mediated by epigenetic modifications such as DNA methylation, histone modification, and non-coding RNA regulation, take center stage in BPD pathogenesis. Recent discoveries link methylation variations across biological pathways with BPD. Also, the potential reversibility of histone modifications fuels new treatment avenues. The review also highlights the promise of utilizing mesenchymal stem cells and their exosomes as BPD therapies, given their ability to modulate non-coding RNA, opening novel research and intervention possibilities. IMPACT: The complexity and universality of epigenetic modifications in the occurrence and development of bronchopulmonary dysplasia were thoroughly discussed. Both molecular and cellular mechanisms contribute to the diverse nature of epigenetic changes, suggesting the need for deeper biochemical techniques to explore these molecular alterations. The utilization of innovative cell-specific drug delivery methods like exosomes and extracellular vesicles holds promise in achieving precise epigenetic regulation.

A Case Report of IPEX Syndrome with Neonatal Diabetes Mellitus and Congenital Hypothyroidism as the Initial Presentation, and a Systematic Review of neonatal IPEX.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) is a serious disorder, which may comprise diabetes, thyroid disease, enteropathy, cytopenias, eczema, and other multi-system autoimmune dysfunction features. IPEX syndrome is caused by mutations in the forkhead box P3 (FOXP3) gene. Here, we report the clinical manifestations of a patient with IPEX syndrome onset in the neonatal period. A de novo mutation at exon 11 of the FOXP3 gene (c.1190G > A, p.R397Q) was found, and its main clinical manifestations included hyperglycemia and hypothyroidism. Subsequently, we comprehensively reviewed the clinical characteristics and FOXP3 mutations of 55 reported neonatal IPEX cases. The most frequent clinical presentation included symptoms of gastrointestinal involvement (n = 51, 92.7%), followed by skin-related symptoms (n = 37, 67.3%), diabetes mellitus (DM) (n = 33, 60.0%), elevated IgE (n = 28, 50.9%), hematological abnormality (n = 23, 41.8%), thyroid dysfunction (n = 18, 32.7%), and kidney-related symptoms (n = 13, 23.6%). In total, 38 variants were observed in the 55 neonatal patients. The most frequent mutation was c.1150G > A (n = 6; 10.9%), followed by c.1189C > T (n = 4; 7.3%), c.816 + 5G > A (n = 3; 5.5%), and C.1015C > G (n = 3; 5.5%), which were reported more than twice. The genotype-phenotype relationship showed that the repressor domain mutations were associated with DM (P = 0.020), and the leucine zipper mutations were associated with nephrotic syndrome (P = 0.020). The survival analysis suggested that treatment with glucocorticoids increased the survival of the neonatal patients. This literature review provides an informative reference for the diagnosis and treatment of IPEX syndrome in the neonatal period.

Vitamin D ameliorates neonatal necrotizing enterocolitis via suppressing TLR4 in a murine model.

BackgroundThe toll-like receptor 4 (TLR4) has been reported to play an important role in necrotizing enterocolitis (NEC). As an established regulator of TLR4, vitamin D has been demonstrated to be intestinal-protective. This study aims at finding out whether the vitamin D/vitamin D receptor (VDR) pathway ameliorates NEC by regulating TLR4.MethodsSerum 25-hydrovitamin D (25(OH)D) was tested and compared in 15 preterm infants with NEC, 12 preterm infants without known complications and 20 healthy term infants. Neonatal Wistar rats were grouped and NEC was induced through formula feeding and cold/asphyxia stress. Vitamin D and the vehicle were administered to compare the microscopic structure, apoptotic protein expression, intestinal barrier function, inflammatory response, and TLR4 expression.ResultsPreterm infants with NEC had significantly lower 25(OH)D levels than those without NEC and healthy subjects. VDR expression was suppressed, whereas TLR4 expression was elevated in the NEC intestine. Vitamin D may increase the survival rate, alleviate structure damage, and preserve intestinal barrier function. These were achieved partly through restoration of VDR and suppression of TLR4.ConclusionNEC infants have lower levels of vitamin D. The vitamin D/VDR pathway protects against intestinal injury of NEC partly through suppressing the expression of TLR4.

Hyperoxia-induced lung injury increases CDKN1A levels in a newborn rat model of bronchopulmonary dysplasia.

Bronchopulmonary dysplasia (BPD) is a common, chronic lung disease of infants. Presently, high oxygen exposure and mechanical ventilation considerably influence the development of BPD. To clarify the pathological mechanisms of this disease, we developed a hyperoxia-induced BPD rat model and investigated the role of CDKN1A in the pathogenesis of BPD. Newborn rats were randomly assigned to the hyperoxia (85% O2) and control (normoxia, 21% O2) groups. Lung tissues were collected on days 1, 3, 7, 14, or 21 after the start of hyperoxia or normoxia exposure. The expression of CDKN1A was detected by immunohistochemistry, western blot, and real-time PCR. Starting from day 3, CDKN1A mRNA expression was higher in the hyperoxia group. From day 7, the radial alveolar count was significantly different between the two groups, and on day 14, the hyperoxia group had high CDKN1A protein expression compared to the control group. These results suggest that increased CDKN1A expression may be involved in the pathogenesis of BPD through alveolarization and lung retardation.

Hyperoxia stimulates the transdifferentiation of type II alveolar epithelial cells in newborn rats.

Supplemental oxygen treatment in preterm infants may cause bronchopulmonary dysplasia (BPD), which is characterized by alveolar simplification and vascular disorganization. Despite type II alveolar epithelial cell (AEC II) damage being reported previously, we found no decrease in the AEC II-specific marker, surfactant protein C (SP-C), in the BPD model in our previous study. We thus speculated that AEC II injury is not a unique mechanism of BPD-related pulmonary epithelial repair dysfunction and that abnormal transdifferentiation can exist. Newborn rats were randomly assigned to model (85% oxygen inhalation) and control groups (room air inhalation). Expressions of AEC I (aquaporin 5, T1α) and AEC II markers (SP-C, SP-B) were detected at three levels: 1) in intact lung tissue, 2) in AEC II isolated from rats in the two groups, and 3) in AEC II isolated from newborn rats, which were further cultured under either hyperoxic or normoxic conditions. In the model group, increased AEC I was observed at both the tissue and cell level, and markedly increased transdifferentiation was observed by immunofluorescent double staining. Transmission electron microscopy revealed morphological changes in alveolar epithelium such as damaged AECs, a fused air-blood barrier structure, and opened tight junctions in the model group. These findings indicate that transdifferentiation of AECs is not suppressed but rather is increased under hyperoxic treatment by compensation; however, such repair during injury cannot offset pulmonary epithelial air exchange and barrier dysfunction caused by structural damage to AECs.

NFAT signaling dysregulation in cancer: Emerging roles in cancer stem cells.

The nuclear factor of activated T cells (NFAT) was first identified as a transcriptional regulator of activated T cells. The NFAT family is involved in the development of tumors. Furthermore, recent evidence reveals that NFAT proteins regulate the development of inflammatory and immune responses. New discoveries have also been made about the mechanisms by which NFAT regulates cancer progression through cancer stem cells (CSC). Here, we discuss the role of the NFAT family in the immune system and various cancer types.

PD-L1 and tumor-infiltrating CD8+ lymphocytes are correlated with clinical characteristics in pediatric and adolescent pituitary adenomas.

Objective: To investigate the levels of tumor-infiltrating CD8+ lymphocytes (CD8+ TILs) and the expression of programmed cell death receptor ligand 1 (PD-L1) in the tumor microenvironment (TME) of pediatric and adolescent pituitary adenomas (PAPAs) and analyze the correlation between their levels and the clinical characteristics. Methods: A series of 43 PAPAs cases were enrolled over a period of 5 years. To compare the TME of PAPAs and adult PAs, 43 PAPAs cases were matched with 60 adult PAs cases (30 cases were between 20 and 40 years old, and 30 cases were older than 40 years) for main clinical characteristics. The expression of immune markers in PAPAs was detected by immunohistochemistry, and their correlation with the clinical outcomes was analyzed using statistical methods. Results: In the PAPAs group, CD8+ TILs level was significantly lower (3.4 (5.7) vs. 6.1 (8.5), p = 0.001), and PD-L1 expression (0.040 (0.022) vs. 0.024 (0.024), p < 0.0001) was significantly higher as compared with the older group. The level of CD8+ TILs was negatively correlated with the expression of PD-L1 (r = -0.312, p = 0.042). Moreover, CD8+ TILs and PD-L1 levels were associated with Hardy (CD8, p = 0.014; PD-L1, p = 0.018) and Knosp (CD8, p = 0.02; PD-L1, p = 0.017) classification. CD8+ TILs level was associated with high-risk adenomas (p = 0.015), and it was associated with the recurrence of PAPAs (HR = 0.047, 95% CI 0.003-0.632, p = 0.021). Conclusion: Compared with the TME in adult PAs, the TME in PAPAs was found to express a significantly altered level of CD8+ TILs and PD-L1. In PAPAs, CD8+ TILs and PD-L1 levels were associated with clinical characteristics.

Pericardial Effusion/Cardiac Tamponade Induced by Peripherally Inserted Central Catheters in Very Low Birth Weight Infants: A Case Report and Literature Review.

Background: Although pericardial effusion/cardiac tamponade (PCE/CT) is a rare complication of peripherally inserted central catheters (PICCs), with an incidence of 0. 07-2%, it is associated with high mortality and is often life threatening. We sought to improve understanding of PICC-induced PCE/CT among pediatricians. Case presentation: The clinical data of PICC-associated PCE/CT in a very low birth weight (VLBW) infant were summarized, and the relevant literature was also reviewed. Conclusions: In VLBW infants with a PICC, if unstable respiratory circulatory system states are observed that cannot be explained, such as tachycardia, bradycardia, apnea, hypotension, and metabolic acidosis, PICC-induced PCE/CT should be considered. Early diagnosis and pericardial puncture are key to saving infants' lives.

Constipation is associated with spina bifida occulta in children.

BACKGROUND & AIMS: Spina bifida occulta (SBO) is a common developmental variant. The aim of this study was to re-examine the possible association between SBO and constipation in children. METHODS: A total of 113 children with constipation underwent plain abdominal radiography, anorectal manometry, neurophysiologic study, electromyography testing, and colonic transit study. Eighty-six were diagnosed with functional constipation (FC) and 27 were diagnosed with nonretentive fecal incontinence (NRFI). The incidence of SBO in these children was compared with 226 sex- and age-matched controls. Twenty-four SBO children with either FC or NRFI also underwent individualized biofeedback training and electric stimulation therapy based on the investigation results. RESULTS: The incidence of SBO in the FC and NRFI groups was 47.7% and 77.8%, respectively. Statistically, this is significantly higher than that of the control group (chi-square, 23.9%; P < .05). Compared with the FC or NRFI children without SBO, the FC and NRFI children with SBO had decreased vector volumes and electromyography amplitudes, increased rectal sensory thresholds, and prolonged latency of pudendo-anal reflex. All 24 children who underwent individualized biofeedback training and electrical stimulation treatment had sustained symptomatic improvement with less straining, fewer incomplete bowel movements, and less abdominal pain. The recovery rate was 79.2% (19 of 24). CONCLUSIONS: Constipation in children is associated with increased incidence of SBO. Individualized biofeedback combined with electrical stimulation improves both the symptoms and the objective anorectal function measurements.

Decreased ZONAB expression promotes excessive transdifferentiation of alveolar epithelial cells in hyperoxia-induced bronchopulmonary dysplasia.

Previous studies by our group have confirmed excessive transdifferentiation of alveolar epithelial cells (AECs) in a hyperoxia­induced bronchopulmonary dysplasia (BPD) model, but the underlying mechanism have remained elusive. The transcription factor zonula occludens 1­associated nucleic acid binding protein (ZONAB) has the biological functions of inhibition of epithelial cell differentiation and promotion of epithelial cell proliferation. The aim of the present study was to explore the regulatory effect of ZONAB on the transdifferentiation and proliferation of AECs in a model of hyperoxia­induced lung injury. Newborn Wistar rats were randomly allocated to a model group (inhalation of 85% O2) or a control group (inhalation of normal air), and ZONAB expression in lung tissues was detected at different time­points. Type II AECs (AEC II) isolated from normal newborn rats were primarily cultured under an atmosphere of 85 or 21% O2, and ZONAB expression in the cells was examined. The primary cells were further transfected with ZONAB plasmid or small interfering (si)RNA and then exposed to hyperoxia, and the indicators for transdifferentiation and proliferation were measured. The present study indicated that ZONAB expression in AEC II of the BPD rats was significantly decreased from 7 days of exposure to hyperoxia onwards. In the AEC II isolated from normal neonatal rats, ZONAB expression in the model group was also reduced compared with that in the control group. After transfection with the plasmid pCMV6­ZONAB, the expression of aquaporin 5 (type I alveolar epithelial cell marker) decreased and the expression of surfactant protein C (AEC II marker), proliferating­cell nuclear antigen and cyclin D1 increased, which was opposite to the effects of ZONAB siRNA. Transfection with pCMV6­ZONAB also alleviated excessive transdifferentiation and inhibited proliferation of AEC II induced by hyperoxia treatment. These results suggest that ZONAB expression in AEC II decreases under hyperoxia conditions, which promotes transdifferentiation and inhibits proliferation of AECs. This may, at least in part, be the underlying mechanism of lung epithelial injury in the hyperoxia-induced BPD model.

Runx3 is a key modulator during the epithelial-mesenchymal transition of alveolar type II cells in animal models of BPD.

Bronchopulmonary dysplasia (BPD) is a major challenge for premature infants; however, the underlying mechanisms remain unclear. We previously reported that epithelial-mesenchymal transition (EMT) in alveolar type II (AT2) epithelial cells influences the normal alveolar development process. In this study, we wished to examine whether Runx3 is an important factor for BPD by regulating EMT in AT2 cells. In vivo, animal models of BPD were established by placing newborn rats in hyperoxia tanks. Lung tissue and isolated AT2 cells were collected on different days following exposure to oxygen. The pathological changes in lung tissue, alveolar development and Runx3 expression were then investigated. In vitro, RLE-6TN cells were divided into 5 groups as follows: the cont-rol, Runx3, siRunx3, transforming growth factor-ß1 (TGF-ß1) and Runx3 + TGF-ß1 groups, and the biomarkers of EMT were investigated. In the newborn rat model of BPD, Runx3 protein and mRNA levels in both lung tissue and BPD-derived AT2 cells were significantly lower than those in the control group. The correlation between Runx3 protein expression and pulmonary development indicators was analyzed; Runx3 expression positively correlated with the radial alveolar count (RAC) and the percentage of smooth muscle actin-positive secondary septa, but negatively correlated with alveolar wall thickness. EMT was observed in the RLE-6TN cells in which the Runx3 gene was knocked down and follwoing TGF-ß1­induced EMT stimulation; however, TGF-ß1 failed to induce EMT in the RLE-6TN cells overexpressing Runx3. On the whole, our data indicte that low Runx3 levels may promote EMT, while high Runx3 levels inhibit TGF-ß1-induced EMT. Therefore, we predict that low levels of Runx3 in BPD lung tissue may promote EMT in AT2 cells, thus affecting alveolar development.

Vitamin D attenuates hyperoxia-induced lung injury through downregulation of Toll-like receptor 4.

With considerable morbidity and mortality, bronchopulmonary dysplasia (BPD) is a focus of attention in neonatology. Hyperoxia-induced lung injury has long been used as a model of BPD. Among all the signaling pathways involved, Toll-like receptor 4 (TLR4) has been demonstrated to play an important role, and is known to be regulated by vitamin D. This study aimed at elucidating the effect of vitamin D on hyperoxia-induced lung injury and the role of TLR4 in the process. Vitamin D was administered to hyperoxia-treated neonatal rats to investigate changes in the morphology of lungs and expression of pro-inflammatory cytokines, apoptotic proteins and TLR4. Vitamin D attenuated hyperoxia-induced lung injury by protecting the integrity of the lung structure, decreasing extracellular matrix deposition and inhibiting inflammation. The upregulation of TLR4 by hyperoxia was ameliorated by vitamin D and apoptosis was reduced. Vitamin D administration antagonized the activation of TLR4 and therefore alleviated inflammation, reduced apoptosis and preserved lung structure.

Vitamin D/VDR signaling attenuates lipopolysaccharide­induced acute lung injury by maintaining the integrity of the pulmonary epithelial barrier.

Vitamin D and its receptor have a protective effect on epithelial barriers in various tissues. Low levels of vitamin D are associated with numerous pulmonary diseases, including acute lung injury (ALI) and acute respiratory distress syndrome. The present study investigated whether the vitamin D/vitamin D receptor (VDR) pathway may ameliorate lipopolysaccharide (LPS)­induced ALI through maintaining the integrity of the alveolar epithelial barrier. This was investigated by exposing wild­type (WT) and VDR knockout C57BL/6J mice to LPS, then comparing the healthy and LPS­treated mice lungs and bronchoalveolar lavage fluid (BALF). More specifically, lung histology, mRNA levels of proinflammatory cytokines and chemokines, and protein expression levels of tight junction proteins were determined. In addition, a vitamin D analog (paricalcitol) was administered to WT mice in order to investigate the effect of vitamin D on the alveolar epithelial barrier following exposure to LPS. VDR knockout mice exhibited severe lung injuries (P<0.001), increased alveolar permeability [demonstrated by a higher wet­dry ratio of lung weight (P<0.05), greater expression levels of BALF protein (P<0.001) and fluorescein isothiocyanate­conjugated 4 kDa dextran (P<0.001) leakage into the alveolar space], elevated proinflammatory cytokine and chemokine mRNA levels, as demonstrated by reverse transcription­quantitative polymerase chain reaction (P<0.05), and decreased protein and mRNA expression levels of occludin (P<0.01) and zonula occludens­1 (ZO­1; P<0.01) compared with WT mice. Paricalcitol treatment partially inhibited these pathological changes in WT mice by maintaining the mRNA and protein expression levels of occludin (P<0.01) and ZO­1 (P<0.05). A lack of VDRs in the pulmonary epithelial barrier appeared to compromise its defense, leading to more severe LPS­induced lung injury. Furthermore, vitamin D treatment alleviated LPS­induced lung injury and preserved alveolar barrier function. Therefore vitamin D treatment may present as a potential therapeutic strategy in ALI and acute respiratory distress syndrome.

Epithelial-mesenchymal transitions in bronchopulmonary dysplasia of newborn rats.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a major threat to the health of premature infants yet its pathogenesis is not fully understood. Epithelial-mesenchymal transition (EMT) of lung epithelial cells may lead to BPD. OBJECTIVE: To investigate the potential occurrence of EMT in a newborn rat model of BPD. METHODS: Newborn rats were exposed to a hyperoxic environment within 12 hr of birth. Lung tissue and isolated alveolar epithelial type II cells (AT2 cells) were collected on Days 1, 3, 7, 14, and 21 after hyperoxic exposure. Pathological changes in lung tissue, alveolar development, ultrastructural changes in AT2 cells, co-expression of surfactant associated surfactant protein C (SPC), and α-smooth muscle actin (α-SMA) were investigated. The relative expression of SPC, α-SMA, E-cadherin, and N-cadherin were investigated in lung tissue and isolated AT2 cells. RESULTS: In lung tissue, alveolar development was attenuated from Day 7 onwards in the BPD model group; co-expression of SPC and α-SMA and ultrastructural changes typical of EMT were observed in AT2 cells from rats in the BPD group. SPC and α-SMA expression levels were higher in tissue samples from the BPD group than in control samples. Beginning on Day 7, evidence of a switch from E-cadherin to N-cadherin expression was observed in BPD lung tissue sample and in isolated AT2 cells. CONCLUSION: EMT of AT2 cells occurred in the hyperoxia-induced newborn rat BPD model and resulted in attenuated alveolar development as a portion of the myofibroblasts accumulated in the lung originated from AT2 cells via EMT.