Retrospective analysis of infliximab in the treatment of Kawasaki disease / 中华儿科杂志

Objective: To investigate the efficacy and safety of infliximab (IFX) therapy for children with Kawasaki disease. Methods: Sixty-eight children with Kawasaki disease who received IFX therapy in Children's Hospital of Fudan University from January 2014 to April 2021 were enrolled. The indications for IFX administration, changes in laboratory parameters before and after IFX administration, response rate, drug adverse events and complications and outcomes of coronary artery aneurysms (CAA) were retrospectively analyzed. Comparisons between groups were performed with unpaired Student t test or Mann-Whitney U test or chi-square test. Results: Among 68 children with Kawasaki disease, 52 (76%) were males and 16 (24%) were females. The age of onset was 2.1 (0.5, 3.8) years. IFX was administered to: (1) 35 children (51%) with persistent fever who did not respond to intravenous immunoglobulin (IVIG) or steroids, 28 of the 35 children (80%) developed CAA before IFX therapy; (2) 32 children (47%) with continuous progression of CAA; (3) 1 child with persistent arthritis. In all cases, IFX was administered as an additional treatment (the time from the onset of illness to IFX therapy was 21 (15, 30) days) which consisted of second line therapy in 20 (29%), third line therapy in 20 (29%), and fourth (or more) line therapy in 28 (41%). C-reactive protein (8 (4, 15) vs. 16 (8, 43) mg/L, Z=-3.38, P=0.001), serum amyloid protein A (17 (10, 42) vs. 88 (11, 327) mg/L, Z=-2.36, P=0.018) and the percentage of neutrophils (0.39±0.20 vs. 0.49±0.21, t=2.63, P=0.010) decreased significantly after IFX administration. Fourteen children (21%) did not respond to IFX and received additional therapies mainly including steroids and cyclophosphamide. There was no significant difference in gender, age at IFX administration, time from the onset of illness to IFX administration, the maximum coronary Z value before IFX administration, and the incidence of systemic aneurysms between IFX-sensitive group and IFX-resistant group (all P>0.05). Infections occurred in 11 cases (16%) after IFX administration, including respiratory tract, digestive tract, urinary tract, skin and oral infections. One case had Calmette-Guérin bacillus-related adverse reactions 2 months after IFX administration. All of these adverse events were cured successfully. One child died of CAA rupture, 6 children were lost to follow up, the remaining 61 children were followed up for 6 (4, 15) months. No CAA occurred in 7 children before and after IFX treatment, while CAA occurred in 54 children before IFX treatment. CAA regressed in 23 (43%) children at the last follow-up, and the diameter of coronary artery recovered to normal in 10 children. Conclusion: IFX is an effective and safe therapeutic choice for children with Kawasaki disease who are refractory to IVIG or steroids therapy or with continuous progression of CAA.

Effect of dhfr gene overexpression on ethanol-induced abnormal cardiovascular development in zebrafish embryos / 中国当代儿科杂志

OBJECTIVE@#To study the effect of dhfr gene overexpression on ethanol-induced abnormal cardiac and vascular development in zebrafish embryos and underlying mechanisms.@*METHODS@#dhfr mRNA was transcribed in vitro and microinjected into zebrafish fertilized eggs to induce the overexpression of dhfr gene, and the efficiency of overexpression was verified. Wild-type zebrafish were divided into a control group, an ethanol group, and an ethanol+dhfr overexpression group (microinjection of 6 nL dhfr mRNA). The embryonic development was observed for each group. The transgenic zebrafish Tg (cmlc2:mcherry) with heart-specific red fluorescence was used to observe atrial and ventricular development. Fluorescence microscopy was performed to observe the development of cardiac outflow tract and blood vessels. Heart rate and ventricular shortening fraction were used to assess cardiac function. Gene probes were constructed, and embryo in situ hybridization and real-time PCR were used to measure the expression of nkx2.5, tbx1, and flk-1 in the embryo.@*RESULTS@#Compared with the ethanol group, the ethanol+dhfr overexpression group had a significant reduction in the percentage of abnormal embryonic development and a significant increase in the percentage of embryonic survival (P<0.05), with significant improvements in the abnormalities of the atrium, ventricle, outflow tract, and blood vessels and cardiac function. Compared with the control group, the ethanol group had significant reductions in the expression of nkx2.5, tbx1, and flk-1 (P<0.05), and compared with the ethanol group, the ethanol+dhfr overexpression group had significant increases in the expression of nkx2.5, tbx1, and flk-1 (P<0.05), which were still lower than their expression in the control group.@*CONCLUSIONS@#The overexpression of the dhfr gene can partially improve the abnormal development of embryonic heart and blood vessels induced by ethanol, possibly by upregulating the decreased expression of nkx2.5, tbx1, and flk-1 caused by ethanol.

Effects of folic acid on the development of heart of zebrafish / 中华儿科杂志

<p><b>OBJECTIVE</b>To construct the folic acid deficient model in zebrafish and observe the abnormal cardiac phenotypes, to find the optimal period for supplementing folic acid that can most effectively prevent the heart malformation induced by folic acid deficiency, and to investigate the possible mechanisms by which folic acid deficiency induces malformations of heart.</p><p><b>METHOD</b>The folic acid deficient zebrafish model was constructed by using both the folic acid antagonist methotrexate (MTX) and knocking-down dhfr (dihydrofolate reductase gene). Exogenous tetrahydrofolic acid rescue experiment was performed. Folic acid was given to folic acid deficient groups in different periods. The percent of cardiac malformation, the cardiac phenotypes, the heart rate and the ventricular shortening fraction (VSF) were recorded. The out flow tract (OFT) was observed by using fluorescein micro-angiography. Whole-mount in situ hybridization and real-time PCR were performed to detect vmhc, amhc, tbx5 and nppa expressions.</p><p><b>RESULT</b>About (78.00 ± 3.74)% embryos in MTX treated group and (68.00 ± 6.32)% embryos in dhfr knocking-down group had heart malformations, including the abnormal cardiac shapes, the hypogenesis of OFT and the reduced heart rate and VSF. Giving exogenous tetrahydrofolic acid rescued the above abnormalities. Given the folic acid on 8 - 12 hours post-fertilization (hpf), both the MTX treated group (20.20% ± 3.77%) and dhfr knocking-down group (43.40% ± 4.51%) showed the most significantly reduced percent of cardiac malformation and the most obviously improved cardiac development. In folic acid deficient group, the expressions of tbx5 and nppa were reduced while the expressions of vmhc and amhc appeared normal. After being given folic acid to MTX treated group and dhfr knocking-down group, the expressions of tbx5 and nppa were increased.</p><p><b>CONCLUSIONS</b>The synthesis of tetrahydrofolic acid was decreased in our folic acid deficient model. Giving folic acid in the middle period, which is the early developmental stage, can best prevent the abnormal developments of hearts induced by folic acid deficiency. Folic acid deficiency did not disrupt the differentiations of myosins in ventricle and atrium. The cardiac malformations caused by folic acid deficiency were related with the reduced expressions of tbx5 and nppa.</p>

Effect of external retinoic acid on Tbx1 gene during zebrafish embryogenesis / 中华儿科杂志

<p><b>OBJECTIVE</b>DiGeorge/del22q11 syndrome is one of the most common genetic causes of outflow tract and aortic arch defects in human. DiGeorge/del22q11 is thought to involve an embryonic defect restricted to the pharyngeal arches and the corresponding pharyngeal pouches. Previous studies have evidenced that retinoic acid (RA) signaling is definitely indispensable for the development of the pharyngeal arches. Tbx1, one of the T-box containing genes, is proved to be the most attractive candidate gene for DiGeorge/del22q11 syndrome. However, the interaction between RA and Tbx1 has not been fully investigated. Exploring the interaction will contribute to discover the molecular pathways disrupted in DiGeorge/del22q11 syndrome, and will also be essential for understanding genetic basis for congenital heart disease. It now seems possible that genes and molecular pathways disrupted in DiGeorge syndrome will also account for some isolated cases of congenital heart disease. Accordingly, the present study aimed to extensively study the effects of external RA on the cardiac development and Tbx1 expression during zebrafish embryogenesis.</p><p><b>METHODS</b>The chemical genetics approach was applied by treating zebrafish embryos with 5 x 10(-8) mol/L RA and 10(-7) mol/L RA at 12.5 hour post fertilization (hpf). The expression patterns of Tbx1 were monitored by whole-mount in situ hybridization and quantitative real-time RT-PCR, respectively.</p><p><b>RESULTS</b>The zebrafish embryos treated with 5 x 10(-8) mol/L RA and 10(-7) mol/L RA for 1.5 h at 12.5 hpf exhibited selective defects of abnormal heart tube. The results of whole-mount in situ hybridization with Tbx1 RNA probe showed that Tbx1 was expressed in cardiac region, pharyngeal arches and otic vesicle during zebrafish embryogenesis. RA treatment led to a distinct spatio-temporal expression pattern for Tbx1 from that in wild type embryo. The real-time PCR analysis showed that Tbx1 expression levels were markedly reduced by RA treatment. Tbx1 expression in the pharyngeal arches and heart were obviously down regulated compared to the wild type embryos. In contrast to 5 x 10(-8) mol/L RA-treated groups, 10(-7) mol/L RA caused a more severe effect on the Tbx1 expression level.</p><p><b>CONCLUSION</b>These results suggested that there was a genetic link between RA and Tbx1 during development of zebrafish embryo. RA could produce an altered Tbx1 expression pattern in zebrafish. RA may regulate the Tbx1 expression in a dose-dependant manner. RA could represent a major epigenetic factor to cause abnormal expression of Tbx1, secondarily, disrupt the pharyngeal arch and heart development.</p>

Folic acid antagonist methotrexate causes the development malformation of heart and down-regulates the BMP2b and HAS2 expressions in zebrafish / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effect of methotrexate (MTX), a folic acid antagonist which can lead to folic acid deficient, on the cardiac development and on the expressions of BMP2b and HAS2 in zebrafish.</p><p><b>METHODS</b>The zebrafish embryos at 6-48 hrs post fertilization (hpf) were treated with various concentrations of MTX (0.5 x 10(-3), 1.0 x 10(-3) and 2.0 x 10(-3) M). At 48 hpf, the percentage of cardiac malformation and heart rate were recorded. The zebrafish embryos at 6-10 hpf treated with 1.5 x 10(-3) M MTX were used as the MTX treatment group. At 24 and 48 hpf the cardiac morphology was observed under a microscope. The expressions of BMP2b and HAS2 in zebrafish were detected by in situ antisense RNA hybridization and real-time PCR.</p><p><b>RESULTS</b>6-12 hpf, the early embryonic developmental stage, was a sensitive period that MTX affected cardiac formation of zebrafish. The retardant cardiac development and the evidently abnormal cardiac morphology was found in the MTX treatment group. The results of in situ antisense RNA hybridization showed that the expressions of BMP2b and HAS2 in the zebrafish heart were reduced in the MTX treatment group at 36 and 48 hpf. The real-time PCR results demonstrated that the BMP2b expression decreased at 12, 24, 36 and 48 hpf, and that the HAS2 expression decreased at 24, 36 and 48 hpf in the treatment group compared with the control group without MTX treatment.</p><p><b>CONCLUSIONS</b>The inhibition of folic acid function may affect cardiac development of early embryos, resulting in a retardant development and a morphological abnormality of the heart in zebrafish, possibly by down-regulating the expressions of BMP2b and HAS2.</p>

Effect of dihydrofolate reductase gene knock-down on the expression of heart and neural crest derivatives expressed transcript 2 in zebrafish cardiac development / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Folic acid is very important for embryonic development and dihydrofolate reductase is one of the key enzymes in the process of folic acid performing its biological function. Therefore, the dysfunction of dihydrofolate reductase can inhibit the function of folic acid and finally cause the developmental malformations. In this study, we observed the abnormal cardiac phenotypes in dihydrofolate reductase (DHFR) gene knock-down zebrafish embryos, investigated the effect of DHFR on the expression of heart and neural crest derivatives expressed transcript 2 (HAND2) and explored the possible mechanism of DHFR knock-down inducing zebrafish cardiac malformations.</p><p><b>METHODS</b>Morpholino oligonucleotides were microinjected into fertilized eggs to knock down the functions of DHFR or HAND2. Full length of HAND2 mRNA which was transcribed in vitro was microinjected into fertilized eggs to overexpress HAND2. The cardiac morphologies, the heart rates and the ventricular shortening fraction were observed and recorded under the microscope at 48 hours post fertilization. Whole-mount in situ hybridization and real-time PCR were performed to detect HAND2 expression.</p><p><b>RESULTS</b>DHFR or HAND2 knock-down caused the cardiac malformation in zebrafish. The expression of HAND2 was obviously reduced in DHFR knock-down embryos (P < 0.05). Microinjecting HAND2 mRNA into fertilized eggs can induce HAND2 overexpression. HAND2 overexpression rescued the cardiac malformation phenotypes of DHFR knock-down embryos.</p><p><b>CONCLUSIONS</b>DHFR plays a crucial role in cardiac development. The down-regulation of HAND2 caused by DHFR knock-down is the possible mechanism of DHFR knock-down inducing the cardiac malformation.</p>