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Dive into the research topics where Merja R. Häkkinen is active.

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Featured researches published by Merja R. Häkkinen.


Journal of Controlled Release | 2011

Immobilization of protein-coated drug nanoparticles in nanofibrillar cellulose matrices-Enhanced stability and release

Hanna Valo; Miia Kovalainen; Päivi Laaksonen; Merja R. Häkkinen; Seppo Auriola; Leena Peltonen; Markus B. Linder; Kristiina Järvinen; Jouni Hirvonen; Timo Laaksonen

Nanosizing is an advanced approach to overcome poor aqueous solubility of active pharmaceutical ingredients. One main problem in pharmaceutical nanotechnology is maintaining of the morphology of the nanometer sized particles during processing and storage to make sure the formulation behaves as originally planned. Here, a genetically engineered hydrophobin fusion protein, where the hydrophobin (HFBI) was coupled with two cellulose binding domains (CBDs), was employed in order to facilitate drug nanoparticle binding to nanofibrillar cellulose (NFC). The nanofibrillar matrix provides protection for the nanoparticles during the formulation process and storage. It was demonstrated that by enclosing the functionalized protein coated itraconazole nanoparticles to the external nanofibrillar cellulose matrix notably increased their storage stability. In a suspension with cellulose nanofibrils, nanoparticles around 100 nm could be stored for more than ten months when the specific cellulose binding domain was fused to the hydrophobin. Also freeze-dried particles in the cellulose nanofibrils matrix were preserved without major changes in their morphology. In addition, as a consequence of formation of the immobilized nanodispersion, dissolution rate of itraconazole was increased significantly, which also enhanced the in vivo performance of the drug.


Journal of Controlled Release | 2014

Nanocrystal-based per-oral itraconazole delivery: superior in vitro dissolution enhancement versus Sporanox® is not realized in in vivo drug absorption.

Annika Sarnes; Miia Kovalainen; Merja R. Häkkinen; Timo Laaksonen; Johanna Laru; Juha Kiesvaara; Jukka Ilkka; Olli Oksala; Seppo Rönkkö; Kristiina Järvinen; Jouni Hirvonen; Leena Peltonen

Nanoscience holds true promise in enabling efficient formulation development and in vivo delivery of poorly water soluble drugs. The objective of this study was to formulate solid oral nanocrystal delivery systems of itraconazole, and thus enhance the oral bioavailability of the very poorly soluble drug. Nanocrystal suspensions were prepared by a rapid wet milling technique, after which the suspensions were transformed into solid dosage forms by both freeze drying and granulating. Finally, the obtained nanocrystalline powders were capsule-packed as well as compacted to tablets. After in vitro analysis, the formulations (nanocrystal suspension (NPs), freeze dried NPs, granulated NPs) were tested in vivo in a rat model, and compared with commercial itraconazole formulation (Sporanox). Importantly, the results indicated rapid dissolution of the nanocrystalline itraconazole with enhanced bioavailability compared to physical mixture. Drug dissolution in vitro was immediate from NPs and freeze dried powder, and differed significantly from the marketed product (P=0.004 and 0.002, correspondingly) until 30min. Freeze drying was detected to be especially advantageous for the solid dosage forms. It is possible to maintain the original character of the nanocrystals, e.g. rapid dissolution, even after tableting of the nanocrystalline powders. Interestingly, the marketed product out-performed the nanocrystalline formulations in vivo, even though the nanocrystals provided reasonable bioavailability of itraconazole absorption as well. The efficient in vitro dissolution enhancement of the nanocrystalline formulations compared to Sporanox® was not realized in in vivo drug absorption.


The Journal of Urology | 2014

Detection of prostate cancer by an electronic nose: a proof of principle study.

Antti Roine; Erik Veskimäe; Antti Tuokko; Pekka Kumpulainen; Juha Koskimäki; Tuomo A. Keinänen; Merja R. Häkkinen; Jouko Vepsäläinen; Timo Paavonen; Jukka Lekkala; Terho Lehtimäki; Teuvo L.J. Tammela; Niku Oksala

PURPOSE We evaluate the ability of an electronic nose to discriminate prostate cancer from benign prostatic hyperplasia using urine headspace, potentially offering a clinically applicable noninvasive and rapid diagnostic method. MATERIALS AND METHODS The ChemPro® 100-eNose was used to discriminate prostate cancer from benign prostatic hyperplasia using urine sample headspace. Its performance was tested with 50 patients with confirmed prostate cancer and 24 samples from 15 patients with benign prostatic hyperplasia (15 patients provided urine preoperatively and 9 patients provided samples 3 months postoperatively) scheduled to undergo robotic assisted laparoscopic radical prostatectomy or transurethral resection of prostate, respectively. The patients provided urine sample preoperatively and those with benign prostatic hyperplasia also provided samples 3 months postoperatively to be used as a pooled control sample population. A discrimination classifier was identified for eNose and subsequently, sensitivity and specificity values were determined. Leave-one-out cross-validation was performed. RESULTS Using leave-one-out cross-validation the eNose reached a sensitivity of 78%, a specificity of 67% and AUC 0.77. CONCLUSIONS The electronic nose is capable of rapidly and noninvasively discriminating prostate cancer and benign prostatic hyperplasia using urine headspace in patients undergoing surgery.


American Journal of Pathology | 2014

Castration Induces Up-Regulation of Intratumoral Androgen Biosynthesis and Androgen Receptor Expression in an Orthotopic VCaP Human Prostate Cancer Xenograft Model

Matias Knuuttila; Emrah Yatkin; Jenny Kallio; Saija Savolainen; Teemu D. Laajala; Tero Aittokallio; Riikka Oksala; Merja R. Häkkinen; Pekka Keski-Rahkonen; Seppo Auriola; Matti Poutanen; Sari Mäkelä

Androgens are key factors involved in the development and progression of prostate cancer (PCa), and PCa growth can be suppressed by androgen deprivation therapy. In a considerable proportion of men receiving androgen deprivation therapy, however, PCa progresses to castration-resistant PCa (CRPC), making the development of efficient therapies challenging. We used an orthotopic VCaP human PCa xenograft model to study cellular and molecular changes in tumors after androgen deprivation therapy (castration). Tumor growth was monitored through weekly serum prostate-specific antigen measurements, and mice with recurrent tumors after castration were randomized to treatment groups. Serum prostate-specific antigen concentrations showed significant correlation with tumor volume. Castration-resistant tumors retained concentrations of intratumoral androgen (androstenedione, testosterone, and 5α-dihydrotestosterone) at levels similar to tumors growing in intact hosts. Accordingly, castration induced up-regulation of enzymes involved in androgen synthesis (CYP17A1, AKR1C3, and HSD17B6), as well as expression of full-length androgen receptor (AR) and AR splice variants (AR-V1 and AR-V7). Furthermore, AR target gene expression was maintained in castration-resistant xenografts. The AR antagonists enzalutamide (MDV3100) and ARN-509 suppressed PSA production of castration-resistant tumors, confirming the androgen dependency of these tumors. Taken together, the findings demonstrate that our VCaP xenograft model exhibits the key characteristics of clinical CRPC and thus provides a valuable tool for identifying druggable targets and for testing therapeutic strategies targeting AR signaling in CRPC.


The Journal of Clinical Endocrinology and Metabolism | 2014

Intra-Tissue Steroid Profiling Indicates Differential Progesterone and Testosterone Metabolism in the Endometrium and Endometriosis Lesions

Kaisa Huhtinen; Taija Saloniemi-Heinonen; Pekka Keski-Rahkonen; Reena Desai; Daniel Laajala; Mia Ståhle; Merja R. Häkkinen; Michael Awosanya; Pia Suvitie; Harry Kujari; Tero Aittokallio; David J. Handelsman; Seppo Auriola; Antti Perheentupa; Matti Poutanen

CONTEXT Aberrant sex steroid signaling is suggested to promote endometriosis growth by several mechanisms, and the tissue concentrations of sex steroids are key determinants of the hormone action. However, their concentrations are only superficially known in the endometrium and endometriosis lesions. OBJECTIVE This study sought to evaluate whether the tissue steroid hormone concentrations in endometriosis differ from the endometrium or serum. MAIN OUTCOME MEASURES Steroid analysis of serum and tissue specimens of women with endometriosis (n = 60) and healthy controls (n=16) was measured, and supporting data from quantitative RT-PCR for steroidogenic enzymes and explant cultures of a subset of specimens is provided. RESULTS Endometrial tissue progesterone (P4) concentrations reflected the serum P4 levels during the menstrual cycle, whereas in endometriosis lesions, the cycle-dependent change was missing. Remarkably high tissue T concentrations were measured in endometriosis lesions independent of the cycle phase, being 5-19 times higher than the corresponding serum levels. Tissue/serum ratio of T was further increased in patients with contraceptive medication. The altered tissue steroid concentrations in endometriosis were in line with the expression of various steroidogenic enzymes in the lesions, of which HSD3B2 showed constantly high expression, whereas CYP11A1 expression was low. Furthermore, the high concentration of sex steroids detected in the ovarian lesions involves their production by the lesion and by the adjacent ovarian tissue. CONCLUSIONS Endometriosis lesions present with progestin and androgen metabolism, which are different from that of the endometrium, and the lesions are characterized by high tissue T and a loss of cyclical changes in tissue P4 concentration.


The Journal of Clinical Endocrinology and Metabolism | 2014

Human testicular peritubular cells host putative stem Leydig cells with steroidogenic capacity.

Luise Landreh; Katrin Spinnler; Kerstin Schubert; Merja R. Häkkinen; Seppo Auriola; Matti Poutanen; Olle Söder; Konstantin Svechnikov; Artur Mayerhofer

AIM We aim to examine the steroidogenic phenotype and the differentiation potential of human testicular peritubular cells (HTPCs) and to explore their possible relationship to the adult Leydig cell lineage. BACKGROUND The cells of the adult Leydig cell lineage may reside in the peritubular compartment of the testis. This suggestion is supported by the facts that the rodent peritubular cells can be differentiated toward this lineage and that cAMP enhances their steroidogenic potential. METHODS Human testicular biopsies, and derived HTPCs, were analyzed by immunohistochemistry, RT-PCR, and Western blotting. After stimulation by forskolin or platelet-derived growth factor-BB, quantitative RT-PCR was used to compare the levels of mRNAs encoding proteins involved in steroidogenesis and steroid production was analyzed by liquid chromatography and tandem mass spectrometry. RESULTS Immunohistochemical analysis revealed that the peritubular cells that form the outer part of the tubular wall express platelet derived growth factor receptor-α. Furthermore, the pluripotency markers (POU domain class 5 transcription factor 1, GATA-binding protein 4), stem Leydig cell markers (platelet derived growth factor receptor-A, leukemia inhibitory factor receptor), and mRNAs encoding proteins involved in steroidogenesis (nuclear receptor subfamily 5, group A, member 1; steroidogenic acute regulatory protein; CYP11A1; CYP17A1; 3β-hydroxysteroid dehydrogenase) were expressed by the HTPCs. Stimulation with forskolin increased the expression of the steroidogenic markers, which was accompanied by the production of pregnenolone and progesterone by HTPCs in vitro. Treatment with platelet-derived growth factor-BB induced expression of steroidogenic acute regulatory protein. CONCLUSIONS Our results indicate that the tubular wall of the human testis is a reservoir for cells of the adult Leydig cell lineage and that the steroidogenic potential of these cells can be activated in culture.


Alcohol and Alcoholism | 2008

5-HT1A receptors in the frontal cortical brain areas in Cloninger type 1 and 2 alcoholics measured by whole-hemisphere autoradiography

Markus Storvik; Merja R. Häkkinen; Erkki Tupala; Jari Tiihonen

AIMS The Cloninger type 1 alcoholics are prone to anxiety, and in many cases patients have begun to use alcohol in order to relieve their anxiety. We have previously reported a decrease of the serotonin transporter density in the perigenual anterior cingulate cortex (pACC) in type 1 alcoholics. The 5-HT(1A) receptors are the binding sites for anxiolytic drug buspirone. We aimed to investigate the alteration in the density of 5-HT(1A) receptors, that may also alter the effect of serotonin in the pACC in alcoholics. METHODS The density of the serotonin receptor 5-HT(1A) among Cloninger type 1 and 2 alcoholics (nine and eight subjects, respectively) and 10 control subjects were determined by postmortem whole-hemisphere autoradiography with WAY-100635. RESULTS Substantially sparser 5-HT(1A) (by -31%, P = 0.010) density was observed in the pACC of alcoholic subjects in relation to non-alcoholic comparison subjects. In a secondary analysis for the difference between the alcoholic subtypes and controls, the 5-HT(1A) density was decreased significantly by -32% (P = 0.015) in the upper level of pACC in type 1 alcoholics. CONCLUSIONS The detected decrease of 5-HT(1A) receptor density on the pACC suggests further that the serotoninergic system is defected in the so-called affect region, especially in the type 1 alcoholics.


Journal of Medicinal Chemistry | 2010

Synthesis and Biological Characterization of Novel Charge-Deficient Spermine Analogues

Janne Weisell; Mervi T. Hyvönen; Merja R. Häkkinen; Nikolay Grigorenko; Marko Pietilä; Anita Lampinen; S. N. Kochetkov; Leena Alhonen; Jouko Vepsäläinen; Tuomo A. Keinänen; Alex R. Khomutov

Biogenic polyamines, spermidine and spermine, are positively charged at physiological pH. They are present in all cells and essential for their growth and viability. Here we synthesized three novel derivatives of the isosteric charge-deficient spermine analogue 1,12-diamino-3,6,9-triazadodecane (SpmTrien, 5a) that are N(1)-Ac-SpmTrien (5c), N(12)-Ac-SpmTrien (5b), and N(1),N(12)-diethyl-1,12-diamino-3,6,9-triazadodecane (N(1),N(12)-Et(2)-SpmTrien, 5d). 5a and 5d readily accumulated in DU145 cells at the same concentration range as natural polyamines and moderately competed for the uptake with putrescine (1) but not with spermine (4a) or spermidine (2). 5a efficiently down-regulated ornithine decarboxylase and decreased polyamine levels, while 5d proved to be inefficient, compared with N(1),N(11)-diethylnorspermine (6). None of the tested analogues were substrates for human recombinant spermine oxidase, but those having free aminoterminus, including 1,8-diamino-3,6-diazaoctane (Trien, 3a), were acetylated by mouse recombinant spermidine/spermine N(1)-acetyltransferase. 5a was acetylated to 5c and 5b, and the latter was further metabolized by acetylpolyamine oxidase to 3a, a drug used to treat Wilsons disease. Thus, 5a is a bioactive precursor of 3a with enhanced bioavailability.


Journal of Pharmaceutical and Biomedical Analysis | 2008

Quantitative determination of underivatized polyamines by using isotope dilution RP-LC-ESI-MS/MS

Merja R. Häkkinen; Tuomo A. Keinänen; Jouko Vepsäläinen; Alex R. Khomutov; Leena Alhonen; Juhani Jänne; Seppo Auriola

A rapid, sensitive and selective method using LC-MS/MS was developed and validated for the simultaneous quantitative determination of five polyamines N1,N12-diethylspermine (DESpm), N-ethylspermine (EtSpm), N1-ethylspermidine (EtSpd), spermidine (Spd) and N1-ethyl-1,3-diaminopropane (EtDAP) without any derivatization steps. The LC-MS/MS system was operated using the positive electrospray ionization (ESI) mode. The chromatographic separation only took 10min and was performed on a reversed phase C18 column with 0.1% heptafluorobutyric acid as the ion-pairing agent and acetonitrile gradient. Stable, deuterium labelled internal reference compounds of the five analytes were included in the quantification. The lower limit of quantification for all of the five analytes was 0.03microM and the method was linear for DESpm, EtSpd, Spd and EtDAP over the range of 0.03-60microM and for EtSpm over the range of 0.03-30microM. Correlation coefficients (R2) were always >0.995 for all the analytes. The precision of the overall method ranged from 0.2 to 9.7% as intra-day variability and from 0.9 to 6.8% as inter-day variability. The intra-day and inter-day accuracy of the assay ranged between 87.6-109.8% and 89.6-106.6%, respectively. The method has been applied successfully to quantify metabolites of DESpm as a substrate for recombinant human polyamine oxidase.


Reproductive Toxicology | 2016

The human placental proteome is affected by maternal smoking

Pasi Huuskonen; Maria R. Amezaga; Michelle Bellingham; Lucy H. Jones; Markus Storvik; Merja R. Häkkinen; Leea Keski-Nisula; Seppo Heinonen; Peter J. O’Shaughnessy; Paul A. Fowler; Markku Pasanen

Highlights • The effects of maternal smoking on the term placental proteome was studied.• Maternal smoking significantly affected 18% of protein spots.• Maternal smoking affects systems controlling the development and function of placenta.• The observed placental changes may contribute to the lowered birth weights.

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Seppo Auriola

University of Eastern Finland

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Jouko Vepsäläinen

University of Eastern Finland

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Tuomo A. Keinänen

University of Eastern Finland

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Markus Storvik

University of Eastern Finland

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Markku Pasanen

University of Eastern Finland

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Leena Alhonen

University of Eastern Finland

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Risto O. Juvonen

University of Eastern Finland

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Alex R. Khomutov

Russian Academy of Sciences

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