Biology subjects

Banach, M.

Publications and source records attributed to Banach, M..

3 recordsLinked to original sources

bioRxiv2024

Endothelial MICU1 protects against vascular inflammation and atherosclerosis by inhibiting mitochondrial calcium uptake

Atherosclerosis is triggered by endothelial activation and vascular inflammation, which is closely related to mitochondrial dysfunction. Mitochondrial calcium uptake 1 (MICU1), as the gatekeeper of mitochondrial Ca2+ homeostasis, is a critical player in mitochondrial function and implicated in a plethora of pathophysiological conditions. However, the role of MICU1 in the pathogenesis of vascular inflammation and atherosclerosis is unknown. We ask whether endothelial MICU1 can prevent vascular inflammation and atherosclerosis by maintaining mitochondrial homeostasis. We observed that vascular inflammation in response to LPS was aggravated in EC-specific Micu1 knockout mice (Micu1ECKO) and reduced in EC-specific Micu1 transgenic mice (Micu1ECTg). Furthermore, hypercholesterolemic Micu1ECKO mice also showed accelerated formation of atherosclerotic plaques, while Micu1ECTg mice protected against atherosclerosis. Mechanistically, MICU1 regulated mitochondrial Ca2+ influx, thereby reducing the expression of the mitochondrial deacetylase SIRT3 and the ensuing deacetylation of SOD2, leading to the burst of mitochondrial reactive oxygen species (mROS). Of clinical relevance, we identified decreased MICU1 level in endothelial layer of human atherosclerotic plaques, as well as in primary human aortic endothelial cells (HAECs) exposed to serum from patients with coronary artery diseases. Two-sample Wald ratio Mendelian randomization further revealed that increased expression of MICU1 was associated with decreased risk of coronary artery bypass grafting (CABG). Our findings unravel a critical and unrecognized role of MICU1 in preventing vascular inflammation and atherosclerosis by maintaining mitochondrial Ca2+ homeostasis.

molecular biology↗

bioRxiv2020

TOP2A substitution enhances topoisomerase activity and causes transcriptional dysfunction in glioblastoma patients

BackgroundHigh grade gliomas (HGGs) are aggressive, primary brain tumors with poor clinical outcomes. We aim to better understand glioma pathobiology and find potential therapeutic susceptibilities. MethodsWe designed a custom panel of 664 cancer- and epigenetics-related genes, and employed targeted next generation sequencing to study the genomic landscape of somatic and germline variants in 182 gliomas of different malignancy grades. mRNA sequencing was performed to detect transcriptomic abnormalities. ResultsIn addition to known alterations in TP53, IDH1, ATRX, EGFR genes found in this cohort, we identified a novel, recurrent mutation in the TOP2A gene coding for Topoisomerase 2A occurring only in glioblastomas (GBM, WHO grade IV gliomas). Biochemical assays with recombinant proteins demonstrated stronger DNA binding and DNA supercoil relaxation activities of the variant proteins. GBM patients carrying the mutated TOP2A had shorter overall survival than those with the wild type TOP2A. Computational analyses of transcriptomic data showed that GBMs with the mutated TOP2A have different transcriptomic patterns suggesting higher transcriptomic activity. ConclusionWe identified a novel TOP2A E948Q variant that strongly binds to DNA and is more active than the wild type protein. Our findings suggest that the discovered TOP2A variant is gain-of-function mutation. Key pointsO_LIThe most frequent genetic alterations in high grade gliomas are reported. C_LIO_LIA new mutation in the TOP2A gene was found in 4 patients from Polish population. C_LIO_LIA E948Q substitution changes TOP2A activities towards DNA. C_LIO_LIThe recurrent TOP2A variant is a gain-of-function mutation. C_LI Importance of the studyGlioblastoma is a deadly disease. Despite recent advancements in genomics and innovative targeted therapies, glioblastoma therapy has not shown improvements. Insights into glioblastoma biology may improve diagnosis, prognosis, and treatment prediction, directing to a better outcome. We performed targeted sequencing of 664 cancer genes, and identified a new variant of the TOP2A gene encoding topoisomerase 2A in glioblastomas. The TOP2A protein variant shows a higher affinity towards DNA and causes transcriptional alterations, suggesting a higher de novo transcription rate.

cancer biology↗

bioRxiv2018

PCSK9 genetic variants, life-long lowering of LDL-cholesterol and cognition: a large-scale Mendelian randomization study

AimsPCSK9 inhibitors lower LDL cholesterol and are efficacious at reducing risk of vascular disease, however questions remain about potential adverse effects on cognitive function. We examined the association of LDL cholesterol-lowering genetic variants in PCSK9 with continuous measures of cognitive ability\n\nMethods and ResultsSix independent SNPs in PCSK9 were used in up to 337,348 individuals from the UK Biobank who underwent measures of cognitive ability (fluid reasoning, reaction time, trial making test and digit symbol coding. Scaled to a 50mg/dL lower LDL cholesterol, the PCSK9 allele score was associated with a lower risk of CHD (odds ratio 0.73; 95% CI: 0.60 to 0.90, P = 0.003). The scaled PCSK9 allele score nominally associated with worse log reaction time (0.04 standard deviations; 95%CI: 0.00, 0.08; P=0.038). Although no strong associations of the PCSK9 allele score were identified with any cognitive trait, the imprecision around the estimates meant that we could not exclude a similar magnitude of effect of genetic inhibition of PCSK9 to that seen with established risk factors, including APOEe4 or smoking status for any of the individual cognition traits. Point estimates for the PCSK9 allele score and cognition traits were all on the harmful side of unity.\n\nConclusionsUsing currently available data in UK Biobank, we are not able to rule out meaningful associations of PCSK9 genetic variants with cognition traits. These data highlight the need for further large-scale genetic analyses and, in parallel, continued pharmacovigilance for patients currently treated with PCSK9 inhibitors.

epidemiology↗