Hsp72 (HSPA1A) Prevents Human Islet Amyloid Polypeptide Aggregation and Toxicity: A New Approach for Type 2 Diabetes Treatment

Type 2 diabetes is a growing public health concern and accounts for approximately 90% of all the cases of diabetes. Besides insulin resistance, type 2 diabetes is characterized by a deficit in β-cell mass as a result of misfolded human islet amyloid polypeptide (h-IAPP) which forms toxic aggregates that destroy pancreatic β-cells. Heat shock proteins (HSP) play an important role in combating the unwanted self-association of unfolded proteins. We hypothesized that Hsp72 (HSPA1A) prevents h-IAPP aggregation and toxicity. In this study, we demonstrated that thermal stress significantly up-regulates the intracellular expression of Hsp72, and prevents h-IAPP toxicity against pancreatic β-cells. Moreover, Hsp72 (HSPA1A) overexpression in pancreatic β-cells ameliorates h-IAPP toxicity. To test the hypothesis that Hsp72 (HSPA1A) prevents aggregation and fibril formation, we established a novel C. elegans model that expresses the highly amyloidogenic human pro-IAPP (h-proIAPP) that is implicated in amyloid formation and β-cell toxicity. We demonstrated that h-proIAPP expression in body-wall muscles, pharynx and neurons adversely affects C. elegans development. In addition, we demonstrated that h-proIAPP forms insoluble aggregates and that the co-expression of h-Hsp72 in our h-proIAPP C. elegans model, increases h-proIAPP solubility. Furthermore, treatment of transgenic h-proIAPP C. elegans with ADAPT-232, known to induce the expression and release of Hsp72 (HSPA1A), significantly improved the growth retardation phenotype of transgenic worms. Taken together, this study identifies Hsp72 (HSPA1A) as a potential treatment to prevent β-cell mass decline in type 2 diabetic patients and establishes for the first time a novel in vivo model that can be used to select compounds that attenuate h-proIAPP aggregation and toxicity

Deletion of Cdc42 in embryonic cardiomyocytes results in right ventricle hypoplasia

Abstract Background Cdc42 is a member of the Rho GTPase family and functions as a molecular switch in regulating cytoskeleton remodeling and cell polarity establishment. Inactivating Cdc42 in cardiomyocytes resulted in embryonic lethality with heart developmental defects, including ventricular septum defects and thin ventricle wall syndrome. Findings In this study, we have generated a Cdc42 cardiomyocyte knockout mouse line by crossing Cdc42/flox mice with myosin light chain 2a (MLC2a)-Cre mice. We found that the deletion of Cdc42 in embryonic cardiomyocytes resulted in an underdeveloped right ventricle. Microarray analysis and real-time PCR data analysis displayed that the deletion of Cdc42 decreased dHand expression level. In addition, we found evaginations in the ventricle walls of Cdc42 knockout hearts. Conclusion We concluded that Cdc42 plays an essential role in right ventricle growth

Synthesis of Neurosteroids: Modulators of NMDA Receptor

Charles University in Prague Faculty of Science Department of Organic and Nuclear Chemistry Karlova Universita v Praze Přírodovědecká fakulta Katedra organické chemie a jaderné chemie Mgr. Eva Šťastná Synthesis of Neurosteroids: Modulators of NMDA receptor Syntéza neurosteroidů: modulátorů NMDA receptoru PhD. Thesis Abstract Autoreferát disetační práce Praha 2009 Prague, 2009 Scientific Presentations and Posters Papers Šťastná E.: Diazomethane (CH2N2). Synlett, 2007,15,2454. Stastna E., Chodounska H., Pouzar V., Kapras V., Borovska J, Cais O., L Vyklicky L.: Synthesis of C3, C5, and C7 pregnane derivatives and their effect on NMDA receptor responses in cultured rat hippocampal neurons. Steroids 2009, 74, 256-263. Kapras V., Šťastná E., Chodounská H., Pouzar V., Krištofíková Z.: Preparation of steroid sulfamates and their interaction with GABAA receptor. Coll. Czech. Chem. Comm., submitted, manuscript number CCCC/2008/000187. Eignerová B., Slavíková B., Buděšínský M., Stastna E., Kotora M.: Synthesis of Fluorinated Brassinosteroids Based on Alkane Cross-Metathesis and Preliminary Biological Assessment. J. Org. Chem., under revision, manuscript number jo-2009- 002079. Patents Stastna E., Chodounska H., Cais O., Vyklicky L., Kapras V., Pouzar V., Kohout L.: Steroidní anionické sloučeniny, způsob..