Trimethylamine oxide induces pyroptosis of vascular endothelial cells through ALDH2/ROS/NLRP3/GSDMD pathway / 中南大学学报(医学版)

Objective: Trimethylamine oxide (TMAO) is a metabolite of intestinal flora and is known to promote the progression of atherosclerotic plaques. However, how TMAO works, including its effect on vascular endothelial cells, is not fully understood. This study aims to explore the biological role of TMAO in human umbilical vein endothelial cells (HUVECs) and the underlying mechanism. Methods: Cell pyroptosis and the loss of plasma membrane integrity were induced under TMAO stimulation in HUVECs. The plasma membrane integrity of the cells was measured by Hoechst 33342/propidium iodide (PI) staining and lactate dehydrogenase leakage assay, and the changes in cell morphology were observed by atomic force microscope. The expression of proteins related to pyroptosis was determined by Western blotting or immunofluorescence. Mitochondrial acetaldehyde dehydrogenase 2 (ALDH2) activity in HUVECs was measured by the ALDH2 activity assay kit, and the level of reactive oxygen species (ROS) was detected by fluorescent probe DCFH-DA. Results: TMAO induced pyroptotic cell death, manifesting by the presence of propidium iodide-positive cells, the leakage of lactate dehydrogenase, the production of N-terminal gasdermin D (GSDMD-N), and the formation of plasma membrane pores. Moreover, TMAO induced elevated expression of inflammasome components, nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3),apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), and caspase-1 in cells. TMAO significantly inhibited ALDH2 activity and increased intracellular ROS production. However, the activation of ALDH2 by pharmacological manipulation attenuated TMAO-induced inflammasome activation and GSDMD-N production.Conclusion: TMAO induces pyroptosis of vascular endothelial cells through the ALDH2/ROS/NLRP3/GSDMD signaling pathway, which may be a potential therapeutic target for improving the treatment of atherosclerosis.

Study on genetic etiology of two patients with mucopolysaccharidosis using whole-exome sequencing / 中华内分泌代谢杂志

Objective:To explore the underlying genetic cause in two patients with mucopolysaccharidosis(MPS)using the whole-exome sequencing.Methods:Genomic DNA was extracted from the peripheral blood of two patients with MPS and their family members. Sanger sequencing and pedigree verification were performed on the pathogenic variants filtered by whole-exome sequencing. The function of the mutation sites was analyzed by bioinformatics software. The effect of the splice mutation on mRNA was further determined by reverse transcription-PCR(RT-PCR).Results:The proband 1 was a 25-year-old male, who carried compound heterozygous mutations of α-L-iduronidas(IDUA) gene: p. T179R and p. S633L, and was diagnosed as MPSⅠ. His mother and sister carried heterozygous p. T179R, while his father carried heterozygous p. S633L, consistent with the autosomal recessive inheritance pattern. The proband 2 was a 3-year-old male, who was hemizygous for IVS 6-8A>G of iduronate-2-sulfatase(IDS) gene. His mother and grandmother were heterozygous for this mutation, consistent with the X-linked recessive inheritance. The proband 2 was diagnosed as MPSⅡ. Sequencing of RT-PCR products showed that the IVS 6-8A>G mutation activated an upstream cryptic splice-site in intron 6, leading to 7 nucleotide insertion in exon 7, frameshift, and shorter peptide chain.Conclusion:In this study, IDUA p. T179R and p. S633L, and IDS IVS 6-8A>G mutations were found in two patients with MPS by whole exome sequencing, which further expanded the genotypic and phenotype spectrum of MPS.

Human leukocyte antigen analysis in a case of autoimmune polyendocrine syndrome type Ⅲ and complicated with myasthenia gravis / 中华内分泌代谢杂志

Type 1 diabetes mellitus and autoimmune thyroid disorders are the most common combination of autoimmune polyendocrine syndrome type Ⅲ(APS Ⅲ). However, APS Ⅲ combined with myasthenia gravis is rare. We described a male patient with myasthenia gravis, type 1 diabetes mellitus, and Hashimoto thyroiditis, who was diagnosed as APS Ⅲ. The human leukocyte antigen (HLA)type was analyzed in this patient. We subsequently reviewed 11 cases of APS Ⅲ combined with myasthenia gravis. This review revealed that HLA-DR9/DQ9 might be a specific HLA subtype associated with APS Ⅲ and complicated with myasthenia gravis .

Clinical and genetic analysis of a child with 2q37 deletion syndrome resulting from a translocation involving chromosome satellite / 中华医学遗传学杂志

OBJECTIVE@#To carry out cyto- and molecular genetic testing for a child featuring facial dysmorphism and attention deficit and hyperactive disorder.@*METHODS@#The child was subjected to routine peripheral blood lymphocyte chromosomal karyotyping, fluorescence in situ hybridization (FISH) and single nucleotide polymorphism array (SNP-array) analyses.@*RESULTS@#The child's facial dysmorphism included low-set ears, curly ear auricle, protuberance of eyebrow arch, nostril notch, short and flat philtrum and thin upper lip. SNP-array revealed that he has carried a 4.883 Mb deletion at 2q37. His chromosomal karyotype was ultimately determined as 45, XY, der(2;21) (2pter→ 2q37.3::21p13→ 21p10::20p10→ 20pter), der(20) (21qter→ 21q10::20q10→ 20qter).@*CONCLUSION@#A rare case of 2q37 deletion syndrome involving three chromosomes was discovered. Combined use of various cyto- and molecular genetic techniques is crucial for the diagnosis of chromosomal abnormalities with complex structures.