Newspaper space for science

In recent years, courses, events and incentive programs for scientific journalism and the divulgation of science have proliferated in Brazil. Part of this context is “Sunday is science day, history of a supplement from the post-war years”, a book published this year that is based on the Master’s degree research of Bernardo Esteves, a journalist specialized in science

New therapeutic approach to heart failure due to myocardial infarction based on targeting growth hormone-releasing hormone receptor

Background We previously showed that growth hormone-releasing hormone (GHRH) agonists are cardioprotective following myocardial infarction (MI). Here, our aim was to evaluate the in vitro and in vivo activities of highly potent new GHRH agonists, and elucidate their mechanisms of action in promoting cardiac repair. Methods and Results H9c2 cells were cultured in serum-free medium, mimicking nutritional deprivation. GHRH agonists decreased calcium influx and significantly improved cell survival. Rats with cardiac infarction were treated with GHRH agonists or placebo for four weeks. MI size was reduced by selected GHRH agonists (JI-38, MR-356, MR-409); this accompanied an increased number of cardiac c-kit+ cells, cellular mitotic divisions, and vascular density. One week post-MI, MR-409 significantly reduced plasma levels of IL-2, IL-6, IL-10 and TNF-? compared to placebo. Gene expression studies revealed favorable outcomes of MR-409 treatment partially result from inhibitory activity on pro-apoptotic molecules and pro-fibrotic systems, and by elevation of bone morphogenetic proteins. Conclusions Treatment with GHRH agonists appears to reduce the inflammatory responses post-MI and may consequently improve mechanisms of healing and cardiac remod eling by regulating pathways involved in fibrosis, apoptosis and cardiac repair. Patients with cardiac dysfunction could benefit from treatment with novel GHRH agonists

Newspaper space for science (Portuguese original version)

In recent years, courses, events and incentive programs for scientific journalism and the divulgation of science have proliferated in Brazil. Part of this context is “Sunday is science day, history of a supplement from the post-war years”, a book published this year that is based on the Master’s degree research of Bernardo Esteves, a journalist specialized in science

Synthesis of new potent agonistic analogs of growth hormone-releasing hormone (GHRH) and evaluation of their endocrine and cardiac activities

•Analogs of GHRH modified at the N- and/or C-terminus were designed and synthesized.•Endocrine activities and binding affinities were determined.•Two analogs highly activated myocardial repair after induced myocardial infarction.•The relationship between GH-releasing potency and structure is discussed.•Substitutions with N-Me-Tyr1, Arg30-NHCH3, or Apa30-NH2 increased GHRH activities. In view of the recent findings of stimulatory effects of GHRH analogs, JI-34, JI-36 and JI-38, on cardiomyocytes, pancreatic islets and wound healing, three series of new analogs of GHRH(1–29) have been synthesized and evaluated biologically in an endeavor to produce more potent compounds. “Agmatine analogs”, MR-356 (N-Me-Tyr1-JI-38), MR-361(N-Me-Tyr1, D-Ala2-JI-38) and MR-367(N-Me-Tyr1, D-Ala2, Asn8-JI-38), in which Dat in JI-38 is replaced by N-Me-Tyr1, showed improved relative potencies on GH release upon subcutaneous administration in vivo and binding in vitro. Modification with N-Me-Tyr1 and Arg29-NHCH3 as in MR-403 (N-Me-Tyr1, D-Ala2, Arg29-NHCH3-JI-38), MR-406 (N-Me-Tyr1, Arg29-NHCH3-JI-38) and MR-409 (N-Me-Tyr1, D-Ala2, Asn8, Arg29-NHCH3-JI-38), and MR-410 (N-Me-Tyr1, D-Ala2, Thr8, Arg29-NHCH3-JI-38) resulted in dramatically increased endocrine activities. These appear to be the most potent GHRH agonistic analogs so far developed. Analogs with Apa30-NH2 such as MR-326 (N-Me-Tyr1, D-Ala2, Arg29, Apa30-NH2-JI-38), and with Gab30-NH2, as MR-502 (D-Ala2, 5F-Phe6, Ser28, Arg29,Gab30-NH2-JI-38) also exhibited much higher potency than JI-38 upon i.v. administration. The relationship between the GH-releasing potency and the analog structure is discussed. Fourteen GHRH agonists with the highest endocrine potencies were subjected to cardiologic tests. MR-409 and MR-356 exhibited higher potency than JI-38 in activating myocardial repair in rats with induced myocardial infarction. As the previous class of analogs, exemplified by JI-38, had shown promising results in multiple fields including cardiology, diabetes and wound healing, our new, more potent, GHRH agonists should manifest additional efficacy for possible medical applications