Human beta defensin 3 knockdown inhibits the proliferation and migration of airway smooth muscle cells through regulating the PI3K/AKT signaling pathway.

Asthma, a common pediatric pulmonary disease, significantly affects children's healthy development. This study aimed to investigate the functions of human ß defensin-3 (HBD-3) in asthma progression. For this purpose, blood samples from asthmatic and healthy children were collected. Moreover, the airway smooth muscle cells (ASMCs) were treated with platelet-derived growth factor BB (PDGF-BB) to develop an in vitro asthma model, then evaluated cell viability and migration via CCK-8 and transwell assays. The mRNA levels of interferon γ (INF-γ), interleukin 4 (IL-4), interleukin 10 (IL-10), alpha-smooth muscle actin (α-SMA), HBD-3, and the protein levels of phosphatidylinositol 3-kinase (PI3K) along with protein kinase B (AKT) were detected. Similarly, the N6-methyladenosine (m6A) content in the ASMCs and m6A levels of HBD-3 were also measured. Results indicated an upregulated HBD-3 in the asthmatic children. The ASMCs were found to be stimulated by PDGF-BB, in addition to the promotion of cell viability and migration. The INF-γ, IL-4, and α-SMA levels were reduced, while IL-10 was elevated in PDGF-BB-stimulated ASMCs. Silencing HBD-3 in PDGF-BB stimulated ASMCs was found to exert the opposite effect by inhibiting cell viability and migration, enhancing the levels of INF-γ, IL-4, and α-SMA, while the IL-10 levels were found to decline. PDGF-BB stimulation of ASMCs resulted in activation of the PI3K/AKT signaling pathway, which was blocked post HBD-3 silencing, while the role of si-hBD in PDGF-BB stimulated ASMCs was neutralized post-treatment with IGF-1. Finally, it was found that METTL3 overexpression prominently upregulated the m6A levels of HBD-3 and decreased the mRNA expression and stability of HBD-3 in the PDGF-BB-stimulated ASMCs. The study concluded that METTL3-mediated HBD-3 participates in the progression of asthma through the PI3K/AKT signaling pathway.

DNA methylation dynamics of long noncoding RNA during human fetal development.

Aim: To determine whether the promoters of long noncoding RNAs (lncRNAs) undergo dynamic changes in DNA methylation during fetal development. Methods: ANOVA and the tissue specificity index were used to identify and validate tissue-specific methylation sites. Age-associated DNA methylation signatures were identified by applying the elastic net method. Results: The lncRNA methylome landscape was characterized in four types of fetal tissue and at three gestational time points, and specific characteristics relative to the tissue of origin and developmental age were identified. Higher levels of lncRNA methylation might be involved in tissue differentiation. LncRNAs harboring age-associated methylation signatures may participate in the fetal developmental process. Conclusion: This study provides novel insights into the role of lncRNA methylomes in fetal tissue specification and development.

Lay abstract The addition of a methyl group to DNA is known as DNA methylation and has a large impact on early embryonic development. The role of specific DNA methylation sites located in the promoter region of long noncoding RNA (lncRNA) during human fetal development is not fully understood. The DNA methylation of lncRNA promoters was investigated in four types of tissue and at three gestational time points. They display tissue-specific characteristics that change over time. Tissue-specific methylation sites have higher levels of methylation, suggesting they might play a role in tissue differentiation. The lncRNAs that show loss or gain of methylation over time may participate in the fetal developmental process. This study describes the DNA methylation status of lncRNA promoters and elucidates their potential role in fetal development.

Effects of Bifidobacterium infantis on cytokine-induced neutrophil chemoattractant and insulin-like growth factor-1 in the ileum of rats with endotoxin injury.

BACKGROUND: The digestive tract is the maximal immunizing tissue in the body, and mucosal integrity and functional status of the gut is very important to maintain a healthy organism. Severe infection is one of the most common causes of gastrointestinal dysfunction, and the pathogenesis is closely related to endotoxemia and intestinal barrier injury. Bifidobacterium is one of the main probiotics in the human body that is involved in digestion, absorption, metabolism, nutrition, and immunity. Bifidobacterium plays an important role in maintaining the intestinal mucosal barrier integrity. This study investigated the protective mechanism of Bifidobacterium during ileal injury in rats. AIM: To investigate the effects of Bifidobacterium on cytokine-induced neutrophil chemoattractant (CINC) and insulin-like growth factor 1 (IGF-1) in the ileum of rats with endotoxin injury. METHODS: Preweaning rats were randomly divided into three groups: Control (group C), model (group E) and treatment (group T). Group E was intraperitoneally injected with lipopolysaccharide (LPS) to create an animal model of intestinal injury. Group T was intragastrically administered Bifidobacterium suspension 7 d before LPS. Group C was intraperitoneally injected with normal saline. The rats were killed at 2, 6 or 12 h after LPS or physiological saline injection to collect ileal tissue samples. The expression of ileal CINC mRNA was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), and expression of ileal IGF-1 protein and mRNA was detected by immunohistochemistry and RT-PCR, respectively. RESULTS: The ileum of rats in Group C did not express CINC mRNA, ileums from Group E expressed high levels, which was then significantly decreased in Group T (F = 23.947, P < 0.05). There was no significant difference in CINC mRNA expression at different times (F = 0.665, P > 0.05). There was a high level of IGF-1 brown granules in ileal crypts and epithelial cells in Group C, sparse staining in Group E, and dark, dense brown staining in Group T. There was a significant difference between Groups C and E and Groups E and T (P < 0.05). There was no significant difference in IGF-1 protein expression at different times (F = 1.269, P > 0.05). IGF-1 mRNA expression was significantly different among the three groups (P < 0.05), though not at different times (F = 0.086, P > 0.05). CONCLUSION: Expression of CINC mRNA increased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium reduced CINC mRNA expression. IGF-1 protein and mRNA expression decreased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium prevented the decrease in IGF-1 expression. Bifidobacterium may increase IGF-1 expression and enhance intestinal immune barrier function in rats with endotoxin injury.

Lacidipine attenuates apoptosis via a caspase-3 dependent pathway in human kidney cells.

BACKGROUND: Acute kidney injury (AKI) is common in hospitalised patients and has a poor prognosis. Therefore, new therapeutic strategies are anticipated. Lacidipine, a novel third-generation dihydropyridine calcium channel blocker, has been demonstrated effective for hypertension. However, its potential effect on renal injury remains unknown. In the present study, an in vitro model of renal ischemia reperfusion (I/R) injury was used to investigate the protective effect and underlying mechanisms of lacidipine on human kidney cell (HKC) apoptosis. METHODS: HKCs were subjected to adenosine triphosphate (ATP) depletion and recovery (0.01 µM AA, depletion for 2 h and recovery for 30 min), with or without lacidipine (1 µM and 10 µM, 24 h), then cell viability and apoptosis were determined using the cell counting kit-8 (CCK-8) assay and Annexin V flow cytometry. The expression of Bcl-2, Bax, and cytochrome c (cyt c) was examined by western blot. RESULTS: Antimycin A (AA) was found to induce apoptosis of HKCs. The proportion of early apoptosis and activity of caspase-3 peaked at 30 min after ATP depletion and recovery and were attenuated by lacidipine. The expression of cyt c and Bax was decreased, while that of Bcl-2 was increased significantly in lacidipine treated group. CONCLUSION: We conclude that lacidipine protects HKCs against apoptosis induced by ATP depletion and recovery by regulating the caspase-3 pathway.

The GC, CYP2R1 and DHCR7 genes are associated with vitamin D levels in northeastern Han Chinese children.

Vitamin D deficiency is associated with risk in several diseases. Vitamin D status has high heritability, yet the genetic epidemiology of vitamin D or its metabolites has not been well studied. Our objective was to identify the relationship among three vitamin D-related genes (GC, CYP2R1 and DHCR7/NADSYN1) and the levels of 25(OH)D in northeastern Han Chinese children. A total of 506 northeastern Han Chinese children were enrolled in this study. Linear regression was used to examine the impact of 12 SNPs on 25(OH)D concentrations after adjustment for age, gender, BMI and regular usage of vitamin D, and Bonferroni's method was adopted for multiple corrections. The two SNPs in GC (rs222020, rs2298849), four SNPs in CYP2R1 (rs10741657, rs10766197, rs12794714 and rs1562902) and two SNPs in DHCR7/NADSYN1 (rs3829251, rs12785878) were significantly associated with plasma 25(OH)D concentrations under both additive and recessive models (P <0.05). The genotypes of the CYP2R1 rs2060793 polymorphism showed positive association with serum 25(OH)D status under all of the three genetic models even after correction for multiple comparison. This population-based study was the first to confirm the strong effects of the GC, CYP2R1 and DHCR7/NADSYN1 loci on circulating 25(OH)D concentrations in northeastern Han Chinese children.

Association of ADAM33 polymorphisms with childhood asthma in a northern Chinese population.

BACKGROUND: Genetic factors contribute to the increasing incidence of childhood asthma. The ADAM33 (a disintegrin and metalloprotease domain-containing protein 33) gene, discovered through positional cloning, is the first to be associated with asthma and bronchial hyperresponsiveness. This case-control study conducted in a Han Chinese population in northern China compared the genotypes of child asthmatic patients to healthy controls for the presence of 6 single nucleotide polymorphisms (SNPs) in the ADAM33 gene. METHODS: The study population was composed of 412 children with asthma and 397 healthy controls. We genotyped 6 SNPs (F+1, T+1, T2, T1, V4, and Q-1) of ADAM33 with the PCR-restriction fragment length polymorphism (PCR-RFLP) method. Data were statistically analyzed to determine if an association existed between these genotypes and childhood asthma morbidity. RESULTS: Three SNPs (T+1, T1, and V4) and 4 haplotypes (H1, H3, H5, and H8) were strongly associated with childhood asthma in children of northern China compared to healthy controls (P<0.05), whereas the other tested SNPs and haplotypes demonstrated no significant relationship. CONCLUSION: The ADAM33 gene plays an important role in facilitating susceptibility to childhood asthma in this Han Chinese population.