Ulla Aapola

Dr. Ulla Aapola

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Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 March 2005 in Proceedings of the National Academy of Sciences
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KWKylie E. Webster
Kylie E. Webster
MOMoira O'Bryan
Moira O'Bryan
SFStephen Fletcher
Stephen Fletcher
PCPauline E. Crewther
Pauline E. Crewther
UAUlla Aapola
Ulla Aapola
HSHamish S Scott
Hamish S Scott
The production of mature germ cells capable of generating totipotent zygotes is a highly specialized and sexually dimorphic process. The transition from diploid primordial germ cell to haploid spermatozoa requires genome-wide reprogramming of DNA methylation, stage- and testis-specific gene expression, mitotic and meiotic division, and the histone–protamine transition, all requiring unique epigenetic control. Dnmt3L, a DNA methyltransferase regulator, is expressed during gametogenesis, and its deletion results in sterility. We found that during spermatogenesis, Dnmt3L contributes to the acquisition of DNA methylation at paternally imprinted regions, unique nonpericentric heterochromatic sequences, and interspersed repeats, including autonomous transposable elements. We observed retrotransposition of an LTR-ERV1 element in the DNA from Dnmt3L –/ – germ cells, presumably as a result of hypomethylation. Later in development, in Dnmt3L –/– meiotic spermatocytes, we detected abnormalities in the status of biochemical markers of heterochromatin, implying aberrant chromatin packaging. Coincidentally, homologous chromosomes fail to align and form synaptonemal complexes, spermatogenesis arrests, and spermatocytes are lost by apoptosis and sloughing. Because Dnmt3L expression is restricted to gonocytes, the presence of defects in later stages reveals a mechanism whereby early genome reprogramming is linked inextricably to changes in chromatin structure required for completion of spermatogenesis.

30 March 2019 in Clinical Proteomics
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JNJanika Nättinen
Janika Nättinen
AJAntti Jylhä
Antti Jylhä
UAUlla Aapola
Ulla Aapola
PMPetri Mäkinen
Petri Mäkinen
RBRoger Beuerman
Roger Beuerman
HUHannu Uusitalo
Hannu Uusitalo
Prevalence of many eye and ocular surface diseases increases with age. While the clinical characteristics and pathophysiologic mechanisms of these conditions are often either known or extensively studied, the effects of normal aging on tear film and ocular surface have not been as widely researched. In order to examine the effects of aging on tear fluid proteomics, tear fluid samples were collected preoperatively from 115 subjects undergoing strabismus or refractive surgery using glass microcapillary tubes. In addition to their refractive error or strabismus, the subjects did not have any other current, known eye diseases. The non-pooled samples were analysed using NanoLC-TripleTOF implementing a sequential window acquisition of all theoretical fragment ion spectra mass spectrometry, resulting in quantified data of 849 proteins. According to correlation results, 17 tear proteins correlated significantly with increased age and many of these proteins were connected to inflammation, immune response and cell death. According to enrichment analysis, growth and survival of cells decreased while immune response and inflammation increased with aging. We also discovered several well-known, activated and inhibited upstream regulators, e.g. NF-κB, which has been previously connected to aging in numerous previous studies. Overall, the results show the common age-dependent alterations in tear fluid protein profile, which demonstrate similar age-associated alterations of biological functions previously shown in other tissue and sample types.

17 June 2022 in Molecules
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RMRiina Muilu-Mäkelä
Riina Muilu-Mäkelä
UAUlla Aapola
Ulla Aapola
JTJenni Tienaho
Jenni Tienaho
HUHannu Uusitalo
Hannu Uusitalo
TSTytti Sarjala
Tytti Sarjala
Volatile organic compounds (VOC) affect the quality of indoor air. Terpenes and especially monoterpenes are the main molecules emitted from softwood material (coniferous species), which is widely used in construction. The corneal epithelium is one of the first human membranes to encounter VOCs in the air. Moreover, the industrial use of pleasant-scented monoterpenes in cosmetics, food, and detergents exposes people to monoterpenes in their daily lives. In the present study, the health effective properties of five monoterpenes from softwood were tested; cytotoxicity and oxidative stress-protective effects of α- and β-pinenes, R- and S-limonene, and 3-carene were tested in a human corneal epithelial (HCE) cell model system and with two additional in vitro antioxidant tests: oxygen radical absorbance capacity (ORAC) and hydrogen peroxide (H2O2) scavenging. Antibacterial efficacies were tested with two bioluminescent bacterial biosensor strains (Escherichia coli K12+pcGLS11 and Staphylococcus aureus RN4220+pAT19) and with minimum inhibitory concentration (MIC) test against Escherichia coli. Only very high concentrations of monoterpenes (0.3–0.5 mg/mL) demonstrated cytotoxicity against HCE cells. Contrary to the original hypothesis, monoterpenes did not exhibit strong antioxidant properties in tested concentrations. However, biosensors and MIC tests indicated clear antibacterial activities for all tested monoterpenes.

Verified
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JNJanika Nättinen
Janika Nättinen
UAUlla Aapola
Ulla Aapola
PNPraveena Nukareddy
Praveena Nukareddy
HUHannu Uusitalo
Hannu Uusitalo
Tear fluid forms the outermost layer of the ocular surface and its characteristics and composition have been connected to various ocular surface diseases. As tear proteomics enables the non-invasive investigation of protein levels in the tear fluid, it has become an increasingly popular approach in ocular surface and systemic disease studies. Glaucoma, which is a set of multifactorial diseases affecting mainly the optic nerve and retinal ganglion cells, has also been studied using tear proteomics. In this condition, the complete set of pathophysiological changes occurring in the eye is not yet fully understood, and biomarkers for early diagnosis and accurate treatment selection are needed. More in-depth analyses of glaucoma tear proteomics have started to emerge only more recently with the implementation of LC-MS/MS and other modern technologies. The aim of this review was to examine the published data of the tear protein changes occurring during glaucoma, its topical treatment, and surgical interventions.


15 August 2024 in Cancer Gene Therapy
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AKAnnika Kohvakka
Annika Kohvakka
MSMina Sattari
Mina Sattari
JNJanika Nättinen
Janika Nättinen
UAUlla Aapola
Ulla Aapola
PGPavlina Gregorova
Pavlina Gregorova
Leena LatonenLeena Latonen
Leena Latonen
While hundreds of cancer-associated long noncoding RNAs (lncRNAs) have been discovered, their functional role in cancer cells is still largely a mystery. An increasing number of lncRNAs are recognized to function in the cytoplasm, e.g., as modulators of translation. Here, we investigated the detailed molecular identity and functional role of EPCART, a lncRNA we previously discovered to be a potential oncogene in prostate cancer (PCa). First, we interrogated the transcript structure of EPCART and then confirmed EPCART to be a non-peptide-coding lncRNA using in silico methods. Pathway analysis of differentially expressed protein-coding genes in EPCART knockout cells implied that EPCART modulates the translational machinery of PCa cells. EPCART was also largely located in the cytoplasm and at the sites of translation. With quantitative proteome analysis on EPCART knockout cells we discovered PDCD4, an inhibitor of protein translation, to be increased by EPCART reduction. Further studies indicated that the inhibitory effect of EPCART silencing on translation was mediated by reduced activation of AKT and inhibition of the mTORC1 pathway. Together, our findings identify EPCART as a translation-associated lncRNA that functions via modulation of the PI3K/AKT/mTORC1 pathway in PCa cells. Furthermore, we provide evidence for the prognostic potential of PDCD4 in PCa tumors in connection with EPCART.