Mechanical stretch induced transcriptomic profiles in cardiac myocytes

Mechanical forces are able to activate hypertrophic growth of cardiomyocytes in the overloaded myocardium. However, the transcriptional profiles triggered by mechanical stretch in cardiac myocytes are not fully understood. Here, we performed the first genome-wide time series study of gene expression changes in stretched cultured neonatal rat ventricular myocytes (NRVM)s, resulting in 205, 579, 737, 621, and 1542 differentially expressed (> 2-fold, P < 0.05) genes in response to 1, 4, 12, 24, and 48 hours of cyclic mechanical stretch. We used Ingenuity Pathway Analysis to predict functional pathways and upstream regulators of differentially expressed genes in order to identify regulatory networks that may lead to mechanical stretch induced hypertrophic growth of cardiomyocytes. We also performed micro (miRNA) expression profiling of stretched NRVMs, and identified that a total of 8 and 87 miRNAs were significantly (P < 0.05) altered by 1-12 and 24-48 hours of mechanical stretch, respectively. Finally, through integration of miRNA and mRNA data, we predicted the miRNAs that regulate mRNAs potentially leading to the hypertrophic growth induced by mechanical stretch. These analyses predicted nuclear factor-like 2 (Nrf2) and interferon regulatory transcription factors as well as the let-7 family of miRNAs as playing roles in the regulation of stretch-regulated genes in cardiomyocytes.Peer reviewe

Lääkekorvausjärjestelmän kehittäminen : Selvityshenkilön loppuraportti

Lääkehuollon keskeinen tavoite on mahdollistaa tehokas, turvallinen ja kustannusvaikuttava lääkehoito. Lääkekorvausjärjestelmän tehtävänä on turvata sairauden hoidossa tarpeelliset avohoidon lääkkeet kohtuullisin kustannuksin. Selvitystyöni perusteella ehdotan, että yhtenäinen kansallinen lääkkeiden hoidollisen arvon arviointi ja kustannusvaikuttavuusarviointi tulisi tehdä kattavasti kansallisella tasolla kaikille lääkkeille lääkemuodosta riippumatta. Avohuollon reseptilääkkeiden ja sairaalalääkkeiden hoidollisen arvon arviointitoiminta ja päätöksenteko olisi tarkoituksenmukaista yhdistää yhteen yksikköön, jonka luonteva sijoituspaikka olisi lääkevirastoksi muutettava Fimea. Lääkekorvausjärjestelmää ja Kelan toimeenpanojärjestelmää olisi kehitettävä huomioimaan erityiset hoidolliset perusteet ja yksilöllisen lääkehoidon tarpeet potilaiden ja alueiden eriarvoisuuden vähentämiseksi. Ehdotan että korvattavuuden edellytyksiä tulisi ajantasaistaa muuttuvan lääkehoidon ja hyvän hoitokäytännön mukaisiksi ja esitän myös harkittavaksi eräiden sairauksien siirtoa alemmasta erityiskorvausluokasta ylempään erityiskorvausluokkaan. Rahoituksen osalta valtion osuus lääkekorvauksien rahoituksesta Sosiaali- ja terveyspalvelujärjestelmän uudistuksen yhteydessä tulisi siirtää maksuvastuulliselle maakunnalle yleiskatteellisena. Tällöin maakunnille muodostuisi kannuste ohjata lääkkeen määräämistä alueillaan kustannusvaikuttavasti, ja samalla myös lääkkeen määrääjien kustannustietoisuus lisääntyisi

Transcriptomics reveal stretched human pluripotent stem cell-derived cardiomyocytes as an advantageous hypertrophy model

Peer reviewe

Distinct Regulation of Cardiac Fibroblast Proliferation and Transdifferentiation by Classical and Novel Protein Kinase C Isoforms : Possible Implications for New Antifibrotic Therapies

Cardiac fibrosis is characterized by accumulation and activation of fibroblasts and excessive production of extracellular matrix, which results in myocardial stiffening and eventually leads to heart failure. Although previous work suggests that protein kinase C (PKC) isoforms play a role in cardiac fibrosis and remodeling, the results are conflicting. Moreover, the potential of targeting PKC with pharmacological tools to inhibit pathologic fibrosis has not been fully evaluated. Here we investigated the effects of selected PKC agonists and inhibitors on cardiac fibroblast (CF) phenotype, proliferation, and gene expression using primary adult mouse CFs, which spontaneously transdifferentiate into myofibroblasts in culture. A 48-hour exposure to the potent PKC activator phorbol 12-myristate 13-acetate (PMA) at 10 nM concentration reduced the intensity of a-smooth muscle actin staining by 56% and periostin mRNA levels by 60% compared with control. The decreases were inhibited with the pan-PKC inhibitor Gö6983 and the inhibitor of classical PKC isoforms Gö6976, suggesting that classical PKCs regulate CF transdifferentiation. PMA also induced a 33% decrease in 5-bromo-2’-deoxyuridine–positive CFs, which was inhibited with Gö6983 but not with Gö6976, indicating that novel PKC isoforms (nPKCs) regulate CF proliferation. Moreover, PMA downregulated the expression of collagen-encoding genes Col1a1 and Col3a1 nPKC-dependently, showing that PKC activation attenuates matrix synthesis in CFs. The partial PKC agonist isophthalate derivative bis(1-ethylpentyl) 5-(hydroxymethyl)isophthalate induced parallel changes in phenotype, cell cycle activity, and gene expression. In conclusion, our results reveal distinct PKC-dependent regulation of CF transdifferentiation and proliferation and suggest that PKC agonists exhibit potential as an antifibrotic treatment.Peer reviewe

Targeting vasoactive peptides for managing calcific aortic valve disease

Calcific aortic valve disease (CAVD) represents a spectrum of disease spanning from milder degrees of calcification of valve leaflets, i.e., aortic sclerosis, to severe calcification i.e., aortic stenosis (AS) with hemodynamic instability. The prevalence of CAVD is increasing rapidly due to the aging of the population, being up to 2.8% among patients over 75 years of age. Even without significant aortic valve stenosis, aortic sclerosis is associated with a 50% increased risk of myocardial infarction and death from cardiovascular causes. To date, there is no pharmacological treatment available to reverse or hinder the progression of CAVD. So far, the cholesterol-lowering therapies (statins) and renin-angiotensin system (RAS) blocking drugs have been the major pharmacological agents investigated for treatment of CAVD. Especially angiotensin receptor blockers (ARB)s and angiotensin convertase enzyme inhibitors (ACEI)s, have been under active investigation in clinical trials, but have proven to be unsuccessful in slowing the progression of CAVD. Several studies have suggested that other vasoactive hormones, including endothelin and apelin systems are also associated with development of AS. In the present review, we discuss the role of vasoactive factors in the pathogenesis of CAVD as novel pharmacological targets for the treatment of aortic valve calcification.Peer reviewe

A novel dual reporter embryonic stem cell line for toxicological assessment of teratogen-induced perturbation of anterior-posterior patterning of the heart

Reliable in vitro models to assess developmental toxicity of drugs and chemicals would lead to improvement in fetal safety and a reduced cost of drug development. The validated embryonic stem cell test (EST) uses cardiac differentiation of mouse embryonic stem cells (mESCs) to predict in vivo developmental toxicity, but does not take into account the stage-specific patterning of progenitor populations into anterior (ventricular) and posterior (atrial) compartments. In this study, we generated a novel dual reporter mESC line with fluorescent reporters under the control of anterior and posterior cardiac promoters. Reporter expression was observed in nascent compartments in transgenic mouse embryos, and mESCs were used to develop differentiation assays in which chemical modulators of Wnt (XAV939: 3, 10 mu M), retinoic acid (all-trans retinoic acid: 0.1, 1, 10 mu M; 9-cis retinoic acid: 0.1, 1, 10 mu M; bexarotene 0.1, 1, 10 mu M), and Tgf-beta (SB431542: 3, 10 mu M) pathways were tested for stage- and dose-dependent effects on in vitro anterior-posterior patterning. Our results suggest that with further development, the inclusion of anterior-posterior reporter expression could be part of a battery of high-throughput tests used to identify and characterize teratogens.Peer reviewe