Decrease of MtDNA copy number affects mitochondrial function and involves in the pathological consequences of ischaemic stroke.

The mtDNA copy number can affect the function of mitochondria and play an important role in the development of diseases. However, there are few studies on the mechanism of mtDNA copy number variation and its effects in IS. The specific mechanism of mtDNA copy number variation is still unclear. In this study, mtDNA copy number of 101 IS patients and 101 normal controls were detected by qRT-PCR, the effect of D-loop variation on mtDNA copy number of IS patients was explored. Then, a TFAM gene KD-OE PC12 cell model was constructed to explore the effect of mtDNA copy number variation on mitochondrial function. The results showed that the mtDNA copy number level of the IS group was significantly lower than that of the normal control group (p < 0.05). The relative expression of TFAM gene mRNA in the cells of the OGD/R treatment group was significantly lower than that of the control group (p < 0.05). In addition, after TFAM gene knockdown and over-expression plasmids were transfected into HEK 293T cells, mtDNA copy number and ATP production level of Sh-TFAM transfection group was significantly decreased (p < 0.05), while mtDNA copy number and ATP production level of OE-TFAM transfected group were significantly higher than that of blank control group and OE-ctrl negative control group (p < 0.01). Our study demonstrated that mitochondrial D-loop mutation and TFAM gene dysfunction can cause the decrease of mtDNA copy number, thus affecting the mitochondrial metabolism and function of nerve cells, participating in the pathological damage mechanism of IS.

A Promoter Polymorphism (Rs57137919) of ABCG1 Gene Influence on Blood Lipoprotein in Chinese Han Population.

BACKGROUND: Adenosine triphosphate-binding cassette subfamily G member 1 (ABCG1) has the function of transporting free intracellular cholesterol to extracellular high-density lipoprotein (HDL) particles, which play a crucial role in atherosclerosis. The goal of this study is to examine the relationship between the polymorphisms of the ABCG1 gene promoter region and ischemic stroke. METHODS: In the present study, a case-control association study was designed to identify 3 single-nucleotide polymorphisms (SNPs; rs5713919, rs1378577, and rs1893590), which were located in the promoter region of ABCG1 gene by kompetitive allele-specific polymerase chain reaction genotyping approach. The in vitro luciferase assay was done to estimate the effect of rs5713919 on gene expression. Finally, the relationships of 3 SNPs of ABCG1 gene with plasma lipids and lipoproteins were investigated in this Chinese cohort. RESULTS: The correlation analysis between lipids and genotypes showed that the rs57137919 locus genotype was significantly associated with HDL cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels (P = 0.021 and P = 0.017, respectively), and the GA and AA genotypes had higher HDL-C levels than the GG genotype. CONCLUSIONS: Our study provides evidence that ABCG1 promoter region polymorphism rs57137919 has an influence on plasma HDL-C and LDL-C levels in Chinese Han population.

A c.544_618del75bp mutation in the splicing factor gene PRPF31 is involved in non-syndromic retinitis pigmentosa by reducing the level of mRNA expression.

PURPOSE: A previous study reported a novel c.544_618del75bp mutation in exon 7 of the PRPF31 gene in a Chinese family with autosomal dominant retinal pigmentosa (ADRP). However, the selected pedigree was a small part of the whole family and the function of the c.544_618del75bp mutation was not explored deeply. The aim of the present study was to validate the previous results and explore the functional significance of the c.544_618del75bp mutation. METHODS: We extended the size of the ADRP pedigree and sequenced DNA and cDNA of the PRPF31 gene for all members of the family and 100 healthy controls. Real-time quantitative polymerase chain reaction (PCR) analysis was performed on the cDNA of patients in the family and cell culture, plasmids transfection and western blot analysis were done to evaluate the functional effect of the mutation in vitro. RESULTS: Sanger sequencing showed that the mutation was present in all patients and absent in all normal individuals, except for participant III-9. Bioinformatics analysis revealed that the c.544_618del75bp mutation caused a 25 amino acid deletion in the PRPF31 protein. In addition, the mRNA expression assay revealed that the mRNA expression level of the PRPF31 and RP9 genes were significantly lower in RP patients than controls (p < 0.05). Finally, the in vitro transfection assay demonstrated that the mRNA expression level of the mutant transfection group was significantly lower than the wild-type transfection group (p < 0.05). CONCLUSIONS: Our study suggested that the c.544_618del75bp mutation in the PRPF31 gene was a causative mutation in this ADRP family and affected the expression of RP9 gene by influencing the formation of U4/U6-U5 tri-snRNP, eventually leading to the occurrence of RP.

Identification of microRNAs for the early diagnosis of Parkinson's disease and multiple system atrophy.

MicroRNAs are reportedly involved in the pathogenesis of neurodegenerative diseases, including Parkinson's disease and multiple system atrophy. We previously identified 7 differentially expressed microRNAs in Parkinson's disease patients and control sera (miR-30c, miR-31, miR-141, miR-146b-5p, miR-181c, miR-214, and miR-193a-3p). To investigate the expression levels of the 7 serum microRNAs in Parkinson's disease and multiple system atrophy, 23 early Parkinson's disease patients (who did not take any anti- Parkinson's disease drugs), 23 multiple system atrophy patients, and 24 normal controls were recruited at outpatient visits in this study. The expression levels of the 7 microRNAs in serum were detected using quantitative real-time polymerase chain reaction. A receiver operating characteristic curve was used to evaluate whether microRNAs can differentially diagnose Parkinson's disease and multiple system atrophy. Clinical scales were used to analyze the correlations between serum microRNAs and clinical features. The results indicated that miR-214 could distinguish Parkinson's disease from the controls, and another 3 microRNAs could differentiate multiple system atrophy from the controls (miR-141, miR-193a-3p, and miR-30c). The expression of miR-31, miR-141, miR-181c, miR-193a-3p, and miR-214 were lower in multiple system atrophy than in Parkinson's disease (all P < 0.05). Combinations of microRNAs accurately discriminated Parkinson's disease from multiple system atrophy (area under the receiver operating characteristic curve = 0.951). For the correlation analysis, negative correlations were discovered between the expression of miR-214 and the Hamilton Anxiety Scale and Parkinson's Disease Non-Motor Symptom scores (all P < 0.05). Our results demonstrate that the distinctive characteristics of microRNAs differentiate Parkinson's disease and multiple system atrophy patients from healthy controls and may be used for the early diagnosis of Parkinson's disease and multiple system atrophy.

Case Report: A Case Report of a Histological Transformation of ALK-Rearranged Adenocarcinoma With High Expression of PD-L1 to Squamous Cell Carcinoma After Treatment With Alectinib.

We report an anaplastic lymphoma kinase (ALK)-positive patient shows a poor response to the ALK inhibitor alectinib due to the high expression of programmed death-ligand 1 (PD-L1). After treatment with alectinib, the pathological form changed from adenocarcinoma into squamous cell carcinoma without novel genetic changes. This case may reveal a direct relationship between ALK mutation and a high level of PD-L1 expression.