Risk factors for severe bronchopulmonary dysplasia in a Chinese cohort of very preterm infants.

OBJECTIVES: To examine the risk factors for severe bronchopulmonary dysplasia (BPD) in a cohort of very preterm infants (VPIs) in China, as BPD is common among VPIs and associated with a high mortality rate. METHODS: In this multicenter retrospective study, medical records from infants with BPD born at gestation age (GA) of <32 weeks with birth weight (BW) of <1,500 grams (g) in 7 regions of China were included. The cohort was stratified into different BPD severity groups based on their fraction of inspired oxygen requirement at a modified GA of 36 weeks or post discharge. Risk factors were identified using logistic regression analysis. RESULTS: A significant inverse correlation was revealed between BPD severity and both GA and BW (p<0.001). Independent risk factors for severe BPD (sBPD) were identified as invasive mechanical ventilation (≥7d), multiple blood transfusion (≥3), nosocomial infection (NI), hemodynamically significant patent ductus arteriosus (hsPDA), delayed initiation of enteral nutrition, and longer time to achieve total caloric intake of 110 kcal/kg. Conversely, administration of antenatal steroids was associated with reduced risk of sBPD. CONCLUSION: Our study not only reaffirmed the established risk factors of low GA and BW for sBPD in VPIs, but also identified additional, potentially modifiable risk factors. Further research is warranted to explore whether intervention in these modifiable factors might reduce the risk of sBPD.Clinical Trial Reg. No.: ChiCTR1900023418.

Hyperglycemia in pregnancy did not worsen the short-term outcomes of very preterm infants: a propensity score matching study.

Background: Hyperglycemia in pregnancy (HGP) has generally been considered a risk factor associated with adverse outcomes in offspring, but its impact on the short-term outcomes of very preterm infants remains unclear. Methods: A secondary analysis was performed based on clinical data collected prospectively from 28 hospitals in seven regions of China from September 2019 to December 2020. According to maternal HGP, all infants were divided into the HGP group or the non-HGP group. A propensity score matching analysis was used to adjust for confounding factors, including gestational age, twin or multiple births, sex, antenatal steroid administration, delivery mode and hypertensive disorders of pregnancy. The main complications and the short-term growth status during hospitalization were evaluated in the HGP and non-HGP groups. Results: A total of 2,514 infants were eligible for analysis. After matching, there were 437 infants in the HGP group and 874 infants in the non-HGP group. There was no significant difference between the two groups in main complications including respiratory distress syndrome, bronchopulmonary dysplasia, necrotizing enterocolitis, retinopathy of prematurity, patent ductus arteriosus, culture positive sepsis, intraventricular hemorrhage, periventricular leukomalacia, anemia, feeding intolerance, metabolic bone disease of prematurity, or parenteral nutrition-associated cholestasis. The incidences of extrauterine growth retardation and increased growth retardation for weight and head circumference in the non-HGP group were all higher than those in the HGP group after matching (P < 0.05). Conclusions: HGP did not worsen the short-term outcomes of the surviving very preterm infants, as it did not lead to a higher risk of the main neonatal complications, and the infants' growth improved during hospitalization.

Oxysterol 25-hydroxycholesterol activation of ferritinophagy inhibits the development of squamous intraepithelial lesion of cervix in HPV-positive patients.

Squamous intraepithelial lesion of cervix (SIL) in human papillomavirus (HPV)-positive patient often undergoes a silent and long-course development, and most of them with high-grade transit to cervical squamous cell carcinoma (CSCC). The oxysterol 25-hydroxycholesterol (25-HC) is associated with HPV inhibition, autophagy and cholesterol synthesis, however, its function in this long process of SIL development remain unclear. In this study, we demonstrate that 25-HC generation is inhibited through HSIL-to-CSCC transition. The 25-HC activates ferritinophagy in the early stage of SIL, promoting the vulnerability of HSILs to ferroptosis. Therefore, maintaining 25-HC level is crucial for suppressing HSIL progression and holds promise for developing novel clinical therapies for CSCC.

Macrophage-induced integrin signaling promotes Schlemm's canal formation to prevent intraocular hypertension and glaucomatous optic neuropathy.

Schlemm's canal (SC) functions to maintain proper intraocular pressure (IOP) by draining aqueous humor and has emerged as a promising therapeutic target for glaucoma, the second-leading cause of irreversible blindness worldwide. However, our current understanding of the mechanisms governing SC development and functionality remains limited. Here, we show that vitronectin (VTN) produced by limbal macrophages promotes SC formation and prevents intraocular hypertension by activating integrin αvß3 signaling. Genetic inactivation of this signaling system inhibited the phosphorylation of AKT and FOXO1 and reduced ß-catenin activity and FOXC2 expression, thereby causing impaired Prox1 expression and deteriorated SC morphogenesis. This ultimately led to increased IOP and glaucomatous optic neuropathy. Intriguingly, we found that aged SC displayed downregulated integrin ß3 in association with dampened Prox1 expression. Conversely, FOXO1 inhibition rejuvenated the aged SC by inducing Prox1 expression and SC regrowth, highlighting a possible strategy by targeting VTN/integrin αvß3 signaling to improve SC functionality.

JAM-C Is Important for Lens Epithelial Cell Proliferation and Lens Fiber Maturation in Murine Lens Development.

Purpose: The underlying mechanism of congenital cataracts caused by deficiency or mutation of junctional adhesion molecule C (JAM-C) gene remains unclear. Our study aims to elucidate the abnormal developmental process in Jamc-/- lenses and reveal the genes related to lens development that JAM-C may regulate. Methods: Jamc knockout (Jamc-/-) mouse embryos and pups were generated for in vivo studies. Four key developmental stages from embryonic day (E) 12.5 to postnatal day (P) 0.5 were selected for the following experiments. Hematoxylin and eosin staining was used for histological analysis. The 5-bromo-2'-deoxyuridine (BrdU) incorporation assay and TUNEL staining were performed to label lens epithelial cell (LEC) proliferation and apoptosis, respectively. Immunofluorescence and Western blot were used to analyze the markers of lens epithelium, cell cycle exit, and lens fiber differentiation. Results: JAM-C was expressed throughout the process of lens development. Deletion of Jamc resulted in decreased lens size and disorganized lens fibers, which arose from E16.5 and aggravated gradually. The LECs of Jamc-/- lenses showed decreased quantity and proliferation, accompanied with reduction of key transcription factor, FOXE3. The fibers in Jamc-/- lenses were disorganized. Moreover, Jamc-deficient lens fibers showed significantly altered distribution patterns of Cx46 and Cx50. The marker of fiber homeostasis, γ-crystallin, was also decreased in the inner cortex and core fibers of Jamc-/- lenses. Conclusions: Deletion of JAM-C exhibits malfunction of LEC proliferation and fiber maturation during murine lens development, which may be related to the downregulation of FOXE3 expression and abnormal localization patterns of Cx46 and Cx50.

ERp29 Attenuates Nicotine-Induced Endoplasmic Reticulum Stress and Inhibits Choroidal Neovascularization.

Nicotine-induced endoplasmic reticulum (ER) stress in retinal pigment epithelium (RPE) cells is thought to be one pathological mechanism underlying age-related macular degeneration (AMD). ERp29 attenuates tobacco extract-induced ER stress and mitigates tight junction damage in RPE cells. Herein, we aimed to further investigate the role of ERp29 in nicotine-induced ER stress and choroidal neovascularization (CNV). We found that the expression of ERp29 and GRP78 in ARPE-19 cells was increased in response to nicotine exposure. Overexpression of ERp29 decreased the levels of GRP78 and the C/EBP homologous protein (CHOP). Knockdown of ERp29 increased the levels of GRP78 and CHOP while reducing the viability of ARPE-19 cells under nicotine exposure conditions. In the ARPE-19 cell/macrophage coculture system, overexpression of ERp29 decreased the levels of M2 markers and increased the levels of M1 markers. The viability, migration and tube formation of human umbilical vein endothelial cells (HUVECs) were inhibited by conditioned medium from the ERp29-overexpressing group. Moreover, overexpression of ERp29 inhibits the activity and growth of CNV in mice exposed to nicotine in vivo. Taken together, our results revealed that ERp29 attenuated nicotine-induced ER stress, regulated macrophage polarization and inhibited CNV.

An ultrasound-controllable ROS-responsive nanoplatform for O2 and NO generation to enhance sonodynamic therapy against multidrug-resistant bacterial infections.

Antimicrobial sonodynamic therapy (SDT) has broad application potential in the eradication of multidrug-resistant (MDR) bacterial infections due to its non-invasiveness, absence of resistance concern, and high cytotoxicity. However, the hypoxic infection microenvironment and the rapid depletion of O2 during SDT severely limit the therapeutic efficacy of SDT. Herein, an ultrasound-controllable ROS-responsive nanoplatform (FOT/Fe3O4@Lipo-ICG) was constructed and prepared by encapsulating FOT and Fe3O4 nanoparticles (Fe3O4 NPs) within sonosensitiser ICG-modified liposomes. Both in vitro and in vivo, we observed that ICG conjugation on the surface of liposomes could effectively maintain good dispersion and prevent ICG aggregates in complex biological matrices. In addition, liposomes could significantly block the catalytic activity of Fe3O4 NPs, as well as the release of FOT, whereas upon US irradiation, the catalytic activity of Fe3O4 NPs was recovered to catalyse the decomposition of endogenous H2O2 into O2 and ˙OH. Meanwhile, the FOT was successfully released to react with endogenous glutathione to sequentially produce NO. Based on the aforementioned advantages, the FOT/Fe3O4@Lipo-ICG demonstrated potent efficacy in eradicating methicillin-resistant Staphylococcus aureus-induced local infection and sepsis resulting from local infection. Thus, the developed US-controllable nanoplatform offers a promising strategy for enhancing SDT for eradicating MDR bacterial infections.

Chylomicrons Regulate Lacteal Permeability and Intestinal Lipid Absorption.

BACKGROUND: Lymphatic vessels are responsible for tissue drainage, and their malfunction is associated with chronic diseases. Lymph uptake occurs via specialized open cell-cell junctions between capillary lymphatic endothelial cells (LECs), whereas closed junctions in collecting LECs prevent lymph leakage. LEC junctions are known to dynamically remodel in development and disease, but how lymphatic permeability is regulated remains poorly understood. METHODS: We used various genetically engineered mouse models in combination with cellular, biochemical, and molecular biology approaches to elucidate the signaling pathways regulating junction morphology and function in lymphatic capillaries. RESULTS: By studying the permeability of intestinal lacteal capillaries to lipoprotein particles known as chylomicrons, we show that ROCK (Rho-associated kinase)-dependent cytoskeletal contractility is a fundamental mechanism of LEC permeability regulation. We show that chylomicron-derived lipids trigger neonatal lacteal junction opening via ROCK-dependent contraction of junction-anchored stress fibers. LEC-specific ROCK deletion abolished junction opening and plasma lipid uptake. Chylomicrons additionally inhibited VEGF (vascular endothelial growth factor)-A signaling. We show that VEGF-A antagonizes LEC junction opening via VEGFR (VEGF receptor) 2 and VEGFR3-dependent PI3K (phosphatidylinositol 3-kinase)/AKT (protein kinase B) activation of the small GTPase RAC1 (Rac family small GTPase 1), thereby restricting RhoA (Ras homolog family member A)/ROCK-mediated cytoskeleton contraction. CONCLUSIONS: Our results reveal that antagonistic inputs into ROCK-dependent cytoskeleton contractions regulate the interconversion of lymphatic junctions in the intestine and in other tissues, providing a tunable mechanism to control the lymphatic barrier.

The relationship between triglyceride, cholesterol and lipoprotein levels, and immune responses to hepatitis B vaccine.

Cholesterol homeostasis disorder and hypertriglyceridemia, as common metabolic conditions, have rarely been reported to affect the immune responses to the hepatitis B vaccine. Our study found that higher high-density lipoprotein (HDL) level showed a significant relationship with positive anti-HBs results (cOR = 1.479, 95% CI: 1.150, 1.901, p = 0.002; aOR = 1.304, 95% CI: 1.006, 1.691, p = 0.045), especially in individuals aged 18- to 40-year-old, female, smoking more than 100 cigarettes in life, and drinking more than 12 times every year. Lower low-density lipoprotein (LDL) level was associated with a negative anti-HBs result among participants aged 18- to 40-year-old, and participants who were obese. Higher level of HDL and lower level of LDL may be protective factors of better immune effect of hepatitis B vaccine. More research should be conducted to investigate the influence of the cholesterol level on the immune responses to the hepatitis B vaccine, and more in-depth research should be performed to uncover the mechanism.

BMP-4 and BMP-7 Inhibit EMT in a Model of Anterior Subcapsular Cataract in Part by Regulating the Notch Signaling Pathway.

Purpose: The proliferation, migration, and epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) are believed to be the pathological mechanisms underlying anterior subcapsular cataract (ASC). Bone morphogenetic proteins (BMPs) inhibit transforming growth factor-beta (TGF-ß)-induced fibrosis in the lens. Herein, we aimed to further clarify the roles of BMP-4/BMP-7 in the progression and the underlying mechanisms of fibrotic cataract. Methods: BMP-4/BMP-7, TGF-ß2, jagged-1 peptide, or DAPT were applied in a mouse injury-induced ASC model and in the human LEC cell line SRA01/04. The volume of opacity was examined by a slit lamp and determined by lens anterior capsule whole-mount immunofluorescence. Global gene expression changes were assessed by RNA sequencing, and the levels of individual mRNAs were validated by real-time PCR. Protein expression was determined by the Simple Western sample dilution buffer. Cell proliferation was examined by CCK8 and EdU assays, and cell migration was measured by Transwell and wound healing assays. Results: Anterior chamber injection of BMP-4/BMP-7 significantly suppressed subcapsular opacification formation. RNA sequencing of the mouse ASC model identified the Notch pathway as a potential mechanism involved in BMP-mediated inhibition of ASC. Consistently, BMP-4/BMP-7 selectively suppressed Notch1 and Notch3 and their downstream genes, including Hes and Hey. BMP-4/BMP-7 or DAPT suppressed cell proliferation by inducing G1 cell cycle arrest. BMP-4/BMP-7 also inhibited TGF-ß2-induced cell migration and EMT by modulating the Notch pathway. Conclusions: BMP-4/BMP-7 attenuated ASC by inhibiting proliferation, migration, and EMT of LECs via modulation of the Notch pathway, thereby providing a new avenue for ASC treatment.

Targeting VEGF-A/VEGFR2 Y949 Signaling-Mediated Vascular Permeability Alleviates Hypoxic Pulmonary Hypertension.

BACKGROUND: Pulmonary hypertension (PH) is associated with increased expression of VEGF-A (vascular endothelial growth factor A) and its receptor, VEGFR2 (vascular endothelial growth factor 2), but whether and how activation of VEGF-A signal participates in the pathogenesis of PH is unclear. METHODS: VEGF-A/VEGFR2 signal activation and VEGFR2 Y949-dependent vascular leak were investigated in lung samples from patients with PH and mice exposed to hypoxia. To study their mechanistic roles in hypoxic PH, we examined right ventricle systolic pressure, right ventricular hypertrophy, and pulmonary vasculopathy in mutant mice carrying knock-in of phenylalanine that replaced the tyrosine at residual 949 of VEGFR2 (Vefgr2Y949F) and mice with conditional endothelial deletion of Vegfr2 after chronic hypoxia exposure. RESULTS: We show that PH leads to excessive pulmonary vascular leak in both patients and hypoxic mice, and this is because of an overactivated VEGF-A/VEGFR2 Y949 signaling axis. In the context of hypoxic PH, activation of Yes1 and c-Src and subsequent VE-cadherin phosphorylation in endothelial cells are involved in VEGFR2 Y949-induced vascular permeability. Abolishing VEGFR2 Y949 signaling by Vefgr2Y949F point mutation was sufficient to prevent pulmonary vascular permeability and inhibit macrophage infiltration and Rac1 activation in smooth muscle cells under hypoxia exposure, thereby leading to alleviated PH manifestations, including muscularization of distal pulmonary arterioles, elevated right ventricle systolic pressure, and right ventricular hypertrophy. It is important that we found that VEGFR2 Y949 signaling in myeloid cells including macrophages was trivial and dispensable for hypoxia-induced vascular abnormalities and PH. In contrast with selective blockage of VEGFR2 Y949 signaling, disruption of the entire VEGFR2 signaling by conditional endothelial deletion of Vegfr2 promotes the development of PH. CONCLUSIONS: Our results support the notion that VEGF-A/VEGFR2 Y949-dependent vascular permeability is an important determinant in the pathogenesis of PH and might serve as an attractive therapeutic target pathway for this disease.

Analysis of "true extrauterine growth retardation" and related factors in very preterm infants-A multicenter prospective study in China.

Objective: To investigate the incidence and related factors of extrauterine growth retardation (EUGR) and "true EUGR" in very preterm infants (VPI) from different regions of China. Materials and methods: Clinical data of VPI were prospectively collected from 28 hospitals in seven different regions of China from September 2019 to December 2020. The infants were divided into a small for gestational age (SGA) group or non-SGA group at birth, with non-SGA infants at 36 weeks of gestation or at discharge being further divided into a EUGR group or a non-EUGR group. Infants in the EUGR and non-SGA group were defined as "true EUGR." The general information of VPI, such as maternal complications during pregnancy, use of enteral nutrition and parenteral nutrition, and complications during hospitalization were compared between the groups. Results: Among the 2,514 VPI included in this study, 47.3, 41.5, and 33.3% of VPI were below the 10th percentile, and 22.6, 22.4, and 16.0% of VPI were below the 3rd percentile for weight, height, and head circumference at 36 weeks of gestation or at discharge, respectively, by the percentile on the 2013 Fenton curve. The incidences of EUGR and "true EUGR" evaluated by weight were 47.3 and 44.5%, respectively. Univariate analysis showed that there were statistically significant differences in the aspects of perinatal and nutritional characteristics, treatment, and complications between the groups. Multivariate analysis showed that in non-SGA infants, the cumulative caloric intake during the first week was a protective factor for "true EUGR," while days to reach total enteral nutrition, late initiation of human milk fortifier, and moderate to severe bronchopulmonary dysplasia were independent risk factors for "true EUGR." Conclusion: More attention should be paid to the nutritional management of VPI to prevent "true EUGR." Cumulative caloric intake should be ensured and increased during the first week, total enteral nutrition should be achieved as early as possible, human milk fortifier should be added early, and moderate to severe bronchopulmonary dysplasia should be prevented. These strategies are very important for reducing the incidence of "true EUGR" in VPI.

Multicellular immune dynamics implicate PIM1 as a potential therapeutic target for uveitis.

Uveitis is a severe autoimmune disease, and a common cause of blindness; however, its individual cellular dynamics and pathogenic mechanism remain poorly understood. Herein, by performing single-cell RNA sequencing (scRNA-seq) on experimental autoimmune uveitis (EAU), we identify disease-associated alterations in cell composition and transcriptional regulation as the disease progressed, as well as a disease-related molecule, PIM1. Inhibiting PIM1 reduces the Th17 cell proportion and increases the Treg cell proportion, likely due to regulation of PIM1 to the protein kinase B (AKT)/Forkhead box O1 (FOXO1) pathway. Moreover, inhibiting PIM1 reduces Th17 cell pathogenicity and reduces plasma cell differentiation. Importantly, the upregulation of PIM1 in CD4+ T cells and plasma cells is conserved in a human uveitis, Vogt-Koyanagi-Harada disease (VKH), and inhibition of PIM1 reduces CD4+ T and B cell expansion. Collectively, a dynamic immune cellular atlas during uveitis is developed and implicate that PIM1 may be a potential therapeutic target for VKH.

Inflammatory factor tumor necrosis factor-α (TNF-α) activates P-glycoprotein (P-gp) by phosphorylating c-Jun and thus promotes transportation in placental cells.

Background: P-glycoprotein (P-gp), encoded by the ABCB1 gene, actively pumps drugs and other xenobiotics from trophoblast cells back into the maternal circulation and thus acts as one of the most critical protectors of the fetus. The effect of tumor necrosis factor-α (TNF-α) on P-gp and molecule-transporting activity remains unknown. The goal of this study was to investigate the role of TNF-α in placental molecule-transporting activity and the underlies mechanisms. Methods: Cultured human placental choriocarcinoma cell lines, Bewo, JEG-3 and JAR, were used in this study. Cultured cells were incubated with 5, 10 and 20 ng/mL of recombinant TNF-α (rTNF-α) for 24 h, respectively, for follow-up experiments. The dimer form and expression of activator protein-1 (AP-1) family members were detected using Western blot (WB) and chromatin immunoprecipitation (ChIP). mRNA and protein expression of ABCB1 were detected using reverse transcriptional quantitative polymerase chain reaction (RT-qPCR) and WB, respectively. Double luciferase labeling was used to verify the concentration of digoxin. Electromobility shift assay (EMSA) and ChIP were used to identify the binding ability of c-Jun to ABCB1 gene promoter. Proliferation and apoptosis of Bewo cells were determined using flow cytometry. Digoxin concentration were determined using dual luciferase labeling method. Results: Administration of rTNF-α upregulated the expression of c-Jun but not JunB or JunD in a dose-dependent manner and promoted the binding of c-Jun to the ABCB1 promoter region in Bewo cells. rTNF-α also increased the uptake of two P-gp-specific substrates, Rh123 and DiOC2(3), a function reversed by the addition of SP600125 and SR11302. We also found that rTNF-α increased the efflux ratio of digoxin, an outcome that was reversed, as expected, by inhibiting c-Jun and P-gp binding activities. Furthermore, we identified that rTNF-α tightly regulates the molecule-transporting activity of P-gp by promoting the phosphorylation of c-Jun. Conclusions: TNF-α activates P-gp to promote placental molecule-transporting activity by directly upregulating c-Jun expression and phosphorylation. These findings demonstrate the clinical significance of TNF-α in modulating the placental barrier, which plays an important role in protecting fetus against harmful drugs.

Protective role for C3aR in experimental chronic pyelonephritis.

Emerging evidence suggest that C3aR plays important roles in homeostasis, host defense and disease. Although it is known that C3aR is protective in several models of acute bacterial infections, the role for C3aR in chronic infection is largely unknown. Here we show that C3aR is protective in experimental chronic pyelonephritis. Global C3aR deficient (C3ar-/- ) mice had higher renal bacterial load, more pronounced renal histological lesions, increased renal apoptotic cell accumulation, tissue inflammation and extracellular matrix deposition following renal infection with uropathogenic E. coli (UPEC) strain IH11128, compared to WT control mice. Myeloid C3aR deficient (Lyz2-C3ar-/- ) mice exhibited a similar disease phenotype to global C3ar-/- mice. Pharmacological treatment with a C3aR agonist reduced disease severity in experimental chronic pyelonephritis. Furthermore, macrophages of C3ar-/- mice exhibited impaired ability to phagocytose UPEC. Our data clearly demonstrate a protective role for C3aR against experimental chronic pyelonephritis, macrophage C3aR plays a major role in the protection, and C3aR is necessary for phagocytosis of UPEC by macrophages. Our observation that C3aR agonist curtailed the pathology suggests a therapeutic potential for activation of C3aR in chronic infection.

A review on development of placental transfusion in term and preterm infants.

In recent years, it has been verified that placental transfusion can replenish blood volume of neonates, improve organ perfusion in the early postnatal stage, and facilitate the transition from fetal circulation to adult circulation. Meanwhile, placental transfusion can reduce the need for blood transfusion and the onset of intraventricular hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia, and other complications. Furthermore, it can improve the iron store and the long-term prognosis of central nervous system, and reduce infant mortality. Different methods have been used, including delayed cord clamping, intact umbilical cord milking, and cut umbilical cord milking. The World Health Organization (WHO) and other academic organizations recommend the routine use of delayed cord clamping at birth for the most vigorous term and preterm neonates. However, details of placental transfusion should be clarified, and the short/long-term impacts of this technology on some infants with special conditions still require further study.

Human umbilical cord blood mononuclear cells transplantation for perinatal brain injury.

Perinatal brain injury is a leading cause of death and disability in children. Hypoxic-ischemic encephalopathy in full term infants, and white matter injury in premature infants are most known brain injury in perinatal period. Human umbilical cord blood mononuclear cells contain hematopoietic stem cells, mesenchymal stem cells, endothelial progenitor cells, lymphocytes, monocytes, and so on. Human umbilical cord blood mononuclear cells have many biological functions, such as nerve and vascular regeneration, anti-apoptosis, anti-inflammation, and immune regulation. Human umbilical cord blood mononuclear cells transplantation has achieved significant efficacy and safety in animal and clinical trials for the treatment of perinatal brain injury. We will review human umbilical cord blood mononuclear cells transplantation for perinatal brain injury in this review.

Risk factors of extrauterine growth restriction in very preterm infants with bronchopulmonary dysplasia: a multi-center study in China.

OBJECTIVE: Nutritional deficiency soon after birth is a risk factor of chronic lung disease (bronchopulmonary dysplasia, BPD). Afflicted infants are further prone to inadequate growth during hospitalization (extrauterine growth restriction, EUGR). This multi-center retrospective study investigated risk factors of EUGR, specifically in very preterm infants with BPD. METHOD: Data of infants with BPD who were born less than 32 weeks gestation (n = 1010) were collected from 7 regions of China. All infants were non-small for gestational age at birth. Infants were characterized as EUGR or non-EUGR at 36 weeks gestation or discharge, or stratified by gestational age or birthweight. Logistic regression analysis was applied. RESULTS: In 65.5% of the population, the BPD was mild. Infants with severe BPD (8.3%) had the highest rate of EUGR (72.6%, P < 0.001). Groups stratified by gestational age did not differ in rates of EUGR, but the birthweight of the EUGR group was significantly lower than that of the non-EUGR (P < 0.001). Birthweights of < 1000, 1000-1499, and ≥ 1500 g showed EUGR rates of 65.9%, 43.4%, and 23.8%, respectively (P < 0.001). Overall, the independent risk factors of EUGR were: moderate-to-severe BPD, gestational hypertension, cesarean section, cumulative fasting time, time required to achieve 110 kcal/kg/d, and hemodynamically significant patent ductus arteriosus (hsPDA). CONCLUSION: In very preterm infants with BPD, the lower the birthweight or the more severe the BPD, the greater the risk of EUGR. In those with hsPDA, or moderate-to-severe BPD, it is especially important to prevent EUGR through perinatal management, enteral nutrition, and nutritional strategies.

The C5a/C5aR1 Axis Contributes to the Pathogenesis of Acute Cystitis Through Enhancement of Adhesion and Colonization of Uropathogenic E. coli.

Our previous work using a murine model of pyelonephritis demonstrated that the C5a/C5aR1 axis plays a pathogenic role in acute kidney infection. In this study, we report that the C5a/C5aR1 axis also plays a pathogenic role in acute bladder infection. C5aR1-deficient mice had reduced bladder bacterial load and attenuated bladder tissue injury, which is associated with reduced expression of terminal α-mannosyl residues (Man) (a potential ligand for type 1 fimbriae of E. coli) at the luminal surface of the bladder epithelium and reduced early bacterial colonization of the bladder. In vitro, C5a stimulation enhanced mannose expression in and facilitated bacterial adhesion/colonization to human bladder epithelial cells. C5a stimulation also upregulated the activation of ERK1/2 and NF-κB signaling and gene expression of proinflammatory cytokines (i.e., Il6, Il1b, Cxcl1, Ccl2) in the epithelial cells, which could drive pro-inflammatory responses leading to tissue injury. Administration of the C5aR1 antagonist effectively reduced bladder bacterial load and tissue injury. Thus, our findings demonstrate a previously unknown pathogenic role for the C5a/C5aR1 axis in bladder infection and suggest that the C5a/C5aR1 axis-mediated upregulation of Man expression, enhancement of bacterial adhesion/colonization, and excessive inflammatory responses contribute to acute bladder infection. These findings improve our understanding of the pathogenesis of bladder infection with therapeutic implications for UTI.

Mesenchymal Stem Cell-Derived Extracellular Vesicles for the Treatment of Bronchopulmonary Dysplasia.

Bronchopulmonary dysplasia (BPD) is the most common chronic respiratory disease in premature infants. However, there is a lack of effective treatment. Mesenchymal stromal cells derived extracellular vesicles (MSC-EVs), as nano- and micron-sized heterogeneous vesicles secreted by MSCs, are the main medium for information exchange between MSCs and injured tissue and organ, playing an important role in repairing tissue and organ injury. EVs include exosomes, microvesicles and so on. They are rich with various proteins, nucleic acids, and lipids. Now, EVs are considered as a new way of cell-to-cell communication. EVs mainly induce regeneration and therapeutic effects in different tissues and organs through the biomolecules they carry. The surface membrane protein or loaded protein and nucleic acid molecules carried by EVs, can activate the signal transduction of target cells and regulate the biological behavior of target cells after binding and cell internalization. MSC-EVs can promote the development of pulmonary vessels and alveoli and reduce pulmonary hypertension (PH) and inflammation and play an important role in the repair of lung injury in BPD. The regeneration potential of MSC-EVs is mainly due to the regulation of cell proliferation, survival, migration, differentiation, angiogenesis, immunoregulation, anti-inflammatory, mitochondrial activity and oxidative stress. As a new type of cell-free therapy, MSC-EVs have non-immunogenic, and are small in size and go deep into most tissues. What's more, it has good biological stability and can be modified and loaded with drugs of interest. Obviously, MSC-EVs have a good application prospect in the treatment of lung injury and BPD. However, there are still many challenges to make MSC-EVs really enter clinical application.