ATP5A1 Research Articles

Significance and expression of adenosine triphosphate synthase subunit alpha and human epidermal growth factor receptor in colorectal cancer

Objective To explore significance and expression of adenosine triphosphate synthase subunit alpha (ATP5A1), human epidermal growth factor receptor-2 (Her-2) and Her-3 in colorectal cancer. Methods The expression of ATP5A1, Her-2 and Her-3 in 100 cases of colorectal cancer and adjacent normal tissues was detected by immunohistochemical method. The relationship between ATP5A1, Her-2 and Her-3 and age, sex, tumor size and tumor location, Dukes stage, differentiation degree, lymph node metastasis was analyzed. Results The positive rate of ATP5A1 in colorectal cancer (46/100) was higher than that in adjacent normal tissues (0/100) (P<0.05). The positive rate of Her-2 in colorectal cancer (56/100) was higher than that in adjacent normal tissues (14/100) (P<0.05). The positive rate of Her-3 in colorectal cancer (56/100) was higher than that in adjacent normal tissues (6/100) (P<0.05). The positive rate of ATP5A1, Her-2 and Her-3 in poorly differentiated was higher than that in the high and moderately differentiated (P<0.05). The positive rate of ATP5A1, Her-2 and Her-3 in C+ D stage was higher than that in A+ B stage (P<0.05). The positive rate of ATP5A1, Her-2 and Her-3 in lymph node metastasis was higher than that in without lymph node metastasis (P<0.05). The positive expression rates of ATP5A1, Her-2 and Her-3 in colorectal cancer were independent of age, sex, tumor size and tumor location. The expression of ATP5A1 was positively correlated with the expression of Her-2 in colorectal cancer (r=0.659, P<0.05). The expression of ATP5A1 was negatively correlated with the expression of Her-3 in colorectal cancer (r=0.546, P<0.05). The expression of Her-2 was negatively correlated with the expression of Her-3 in colorectal cancer (r=0.878, P<0.05). Conclusion High expression of ATP5A1, Her-2 and Her-3 played an important role in the occurrence, invasion and metastasis of colorectal cancer. The combined detection of these three protein could play a guiding role in the diagnosis of colorectal cancer. Key words: Adenosine triphosphate synthase subunit alpha; Human epidermal growth factor receptor-2; Human epidermal growth factor receptor-3; Colorectal cancer; Expression

A novel correlation between ATP5A1 gene expression and progression of human clear cell renal cell carcinoma identified by co‑expression analysis.

Clear cell renal cell carcinoma (ccRCC) is the most common solid lesion within kidneys, and its prognostic is influenced by the progression covering a complex network of gene interactions. In our study, a weighted gene co-expression network was constructed to identify gene modules associated with the progression of ccRCC (n=35). In the significant module (R2 = −0.53), a total of 13 network hub genes were identified, and 2 of them were hub nodes in the protein-protein interaction network as well. In validation, ATP5A1 showed a higher correlation with the disease progression than any other hub gene in the hub module (P=0.001219). In the test set (n=202), ATP5A1 was also highly expressed in normal kidney than ccRCC tissues of each grade (P<0.001). Functional and pathway enrichment analysis demonstrated that ATP5A1 is overrepresented in pathway of oxidative phosphorylation, which associated with tumorigenesis and tumor progression. Gene set enrichment analysis (GSEA) also demonstrated that the gene set of ‘oxidative phosphorylation’ and metabolic pathways were enriched in ccRCC samples with ATP5A1 highly expressed (P<0.05). In conclusion, based on the co-expression analysis, ATP5A1 was validated to be associated with progression of ccRCC, probably by regulating tumor-related phosphorylation.

Serum and tumor tissue microRNA-23a expression level in glioblastoma patients and the regulation mechanism of ATP5A1 expression by microRNA-23a

Objective To test the serum and tumor tissue expression level of microRNA (miRNA, miR)-23a in glioblastoma (GBM) patients and the functional role of miR-23a in GBM. Methods Expression level of serum and tumor tissue miR-23a in GBM patients was detected by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR). U87MG, U251, T98G and A172 cells were transfected with miR-23a mimic and the cell proliferation assay was done by CellTiter-Glo® Luminescent Cell Viability Assay kit, at the same time, the tumor growth of U87MG and U251 cells transfected with miR-23a mimic was measured. The expression level of ATP5A1 in GBM tumor tissue was evaluated by RT-qPCR and immunostaining. U87MG, U251, T98G and A172 cells were transfected with miR-23a mimic and the ATP5A1 protein expression was measured by Western blotting. Results The miR-23a expression level in serum (0.40±0.18) and tumor tissue (1.00±0.12) of GBM patients was downregulated compared with health control and tumor adjacent tissue (2.60±0.45 and 1.50±0.56, P=0.005); the miR-23a mimic could suppress the cell growth of U87MG, U251, T98G and A172 cells in vitro (P=0.011), tumor growth of U87MG and U251 cells in vivo, tumor volume of pLKO.1 infected U87MG and U251 was (597.1±95.4) cm3 and (429.5±78.7) cm3, tumor volume of miR-23a mimic infected U87MG and U251 was (153.2±38.6) cm3 and (168.7±33.1) cm3(P=0.008); RT-qPCR and Western blotting results revealed that ATP5A1 (5.4±1.1) was upregulated in GBM tumor tissue, and miR-23a mimic could suppress the protein expression level of ATP5A1 in U87MG, U251, T98G and A172 cells. Conclusion miR-23a could suppress the proliferation and tumor growth of GMB cell lines. Besides it could regulate the protein expression of ATP5A1. Key words: Gioblastoma; MicroRNA-23a; ATP5A1

The importance of a large sample cohort for studies on modifier genes influencing disease severity in FAP patients

BackgroundFamilial adenomatous polyposis (FAP) is usually characterised by the appearance of hundreds-to-thousands of adenomas throughout the colon and rectum and if left untreated the condition will develop into CRC with close to 100% penetrance. Germline mutations in the APC gene, which plays an integral role in the Wnt-signalling pathway, have been found to be responsible for 70-90% of FAP cases. Several studies suggest that modifier genes may play an important role in the development of CRC and possible modifiers for FAP have been suggested. Interestingly, a study has found that SNPs within ATP5A1 is associated with raised levels of ATP5A1 expression and high expression levels may facilitate CRC development. We aimed to determine if SNPs in ATP5A1 modify the risk of developing CRC/adenomas in FAP patients.MethodsGenomic DNA from 139 Australian FAP patients with a germline APC mutation underwent genotyping at the Australian Genome Research Facility (AGRF) utilising iPLEX GOLD chemistry with Sequenom MassArray on an Autoflex Spectrometer for 16 SNPs in the ATP5A1 gene. Association between ages of diagnosis/risk of CRC/adenomas was tested with Kaplan-Meier estimator analysis, logistic regression and cox proportional hazard regression.ResultsAn association between age of diagnosis of CRC and genotypes was observed for SNP rs2578189 (p = 0.0014), with individuals harbouring the variant genotype developing CRC 29 years earlier than individuals harbouring the wildtype genotype. Individuals harbouring the variant genotype of SNP rs2578189 were also at increased risk of CRC (HR = 13.79, 95% CI = 2.36-80.64, p = 0.004). We used an independent Dutch FAP cohort (n = 427) to validate our results; no association between SNP rs2578189 and CRC was observed.ConclusionThese results highlight the difficulties in studying a disease that has a high degree of intervention and also emphasize the importance of large sample sizes when searching for modifier genes in patients with an inherited predisposition to disease. To fully determine if there are genetic modifiers of disease in FAP we would encourage people that are interested in collaborating in future studies into the role of modifier genes in disease expression in FAP to join forces.

A complex V ATP5A1 defect causes fatal neonatal mitochondrial encephalopathy

Whole exome sequencing is a powerful tool to detect novel pathogenic mutations in patients with suspected mitochondrial disease. However, the interpretation of novel genetic variants is not always straightforward. Here, we present two siblings with a severe neonatal encephalopathy caused by complex V deficiency. The aim of this study was to uncover the underlying genetic defect using the combination of enzymatic testing and whole exome sequence analysis, and to provide evidence for causality by functional follow-up. Measurement of the oxygen consumption rate and enzyme analysis in fibroblasts were performed. Immunoblotting techniques were applied to study complex V assembly. The coding regions of the genome were analysed. Three-dimensional modelling was applied. Exome sequencing of the two siblings with complex V deficiency revealed a heterozygous mutation in the ATP5A1 gene, coding for complex V subunit α. The father carried the variant heterozygously. At the messenger RNA level, only the mutated allele was expressed in the patients, whereas the father expressed both the wild-type and the mutant allele. Gene expression data indicate that the maternal allele is not expressed, which is supported by the observation that the ATP5A1 expression levels in the patients and their mother are reduced to ∼50%. Complementation with wild-type ATP5A1 restored complex V in the patient fibroblasts, confirming pathogenicity of the defect. At the protein level, the mutation results in a disturbed interaction of the α-subunit with the β-subunit of complex V, which interferes with the stability of the complex. This study demonstrates the important value of functional studies in the diagnostic work-up of mitochondrial patients, in order to guide genetic variant prioritization, and to validate gene defects.

A genetic polymorphism in the sex‐linked ATP5A1 gene is associated with individual fitness in Ovenbirds (Seiurus aurocapilla)

While testing genetic sexing techniques in Ovenbirds (Seiurus aurocapilla), we found a genetic polymorphism in the ATP5A1 gene in 38% of individuals. The Z′ allele included changes in both intronic and exonic portions of the sequenced region, but there was no evidence that this changed the resulting ATP synthase product. Males that had one or more copies of this allele had higher relative body mass (mass corrected for size) than other genotypes. This allele was unrelated to stable isotope signatures, and so was not a useful predictor of latitude within the eastern portion of the Ovenbird breeding range. Future studies are needed to determine whether this polymorphism may be a useful geographic marker. This study is the first to link polymorphisms in the sex-linked ATP5A1 gene with fitness effects.

Investigation of pseudoautosomal and bordering regions in avian Z and W chromosomes with the use of large insert genomic BAC clones

To study pseudoautosomal and bordering regions in the avian Z and W chromosomes, we used seven BAC clones from genomic libraries as DNA probes of fragments of different gametologs of the ATP5A1 gene located close to the proximal border of the pseudoautosomal region (PAR) of sex chromosomes of domestic chicken and Japanese quail. Localization of BAC clones TAM31-b100C09, TAM31-b99N01, TAM31-b27P16, and TAM31-b95L18 in the short arm of Z chromosomes of domestic chicken and Japanese quail (region Zp23-p22) and localization of the BAC clones CHORI-261-CH46G16, CHORI-261-CH33F10, and CHORI-261-CH64F22 on W chromosomes of these species and in the short arm of Z chromosomes (region Zp23-p22) were determined by fluorescence in situ hybridization with the use of W-specific probes. The difference in the localization of the BAC clones on the Z and W chromosomes is probably explained by divergence of the nucleotide sequences of different sex chromosomes located beyond the pseudoautosomal region.

Inhibition of mammalian ribonucleases by endogenous adenosine dinucleotides

The most potent low molecular weight inhibitors of pancreatic RNase superfamily enzymes reported to date are synthetic derivatives of adenosine 5 ′-pyrophosphate. Here we have investigated the effects of six natural nucleotides that also incorporate this moiety (NADP +, NADPH, ATP, Ap 3A, Ap 4A, and Ap 5A) on the activities of RNase A and two of its homologues, eosinophil-derived neurotoxin and angiogenin. With eosinophil-derived neurotoxin and angiogenin, Ap 5A is comparable to the tightest binding inhibitors identified previously ( K i values at pH 5.9 are 370 nM and 100 μM, respectively); it ranks among the strongest small antagonists of RNase A as well ( K i=230 nM). The K i for NADPH with angiogenin is similar to that of Ap 5A. These findings suggest that Ap 5A and NADPH may serve as useful new leads for inhibitor design. Examination of inhibition under physiological conditions indicates that NADPH, ATP, and Ap 5A may suppress intracellular RNase activity significantly in vivo.

Presynaptic signalling mediated by mono- and dinucleotides in the central nervous system

Synaptosomal preparations from rat midbrain exhibit specific responses to both ATP and Ap 5A, which elicit a Ca 2+ entrance to the presynaptic terminals. Studies of isolated single terminals showed that not all the terminals contain ionotropic receptors for nucleotides, in fact only 46% of them do. Of these, 12% responded only to the dinucleotide Ap 5A, and 20% to the mononucleotide ATP. At the presynaptic level, diinosine pentaphosphate, Ip 5I, is a good tool to specifically block dinucleotide responses, which are inhibited at low nM concentration, versus the high μM concentrations required to block ATP responses. There is evidence for a presynaptic control of mononucleotide and dinucleotide responses, mediated by metabotropic and ionotropic receptors. Stimulation of adenosine A1 receptors increases the affinity of dinucleotide receptors by five orders of magnitude, from 30 μM to 680 pM for control and in the presence of A1 agonist, respectively.