O receptor do peptídeo liberador de gastrina como novo alvo terapêutico para o tratamento da disfunção cognitiva associada à Doença de Alzheimer

Increasing evidence indicates that bombesin (BB)-like peptides (BLPs), such as the gastrin-releasing peptide (GRP) and its receptor (GRPR), might play a role in neurological and psychiatric disorders. The present study reviews fi ndings from animal and human studies suggesting that the GRPR should be considered a target for the treatment of cognitive dysfunction in patients with Alzheimer’s disease (AD). Abnormalities in GRPR-triggered signaling have been described in both fi broblasts from patients with AD, and in transgenic mouse models of AD. Pharmacological and genetic preclinical studies have indicated that BLPs and the GRPR are importantly involved in regulating cognitive function. Moreover, drugs acting at the GRPR have been shown to enhance memory and ameliorate cognitive dysfunction in experimental models of amnesia associated with AD. Taken together, these fi ndings support the view that the GRPR is a novel therapeutic target for the treatment of memory defi cits associated with AD.Estudos recentes indicam que os peptídeos da família da bombesina (BB), como o peptídeo liberador de gastrina (GRP) e seu receptor (GRPR), podem estar envolvidos em doenças neurológicas e psiquiátricas. Este artigo apresenta uma revisão de estudos tanto em humanos como em modelos animais que sugerem que o GRPR deve ser considerado um alvo molecular para o desenvolvimento de novas terapias para o tratamento de défi cits cognitivos em pacientes com doença de Alzheimer (DA). Anormalidades na sinalização celular dependente do GRPR têm sido descritas tanto em fi broblastos de pacientes com DA como em modelos de DA em camundongos transgênicos. Além disso, estudos pré-clínicos utilizando estratégias farmacológicas e genéticas indicam que os peptídeos da família da BB e o GRPR estão envolvidos de forma importante na regulação da função cognitiva. Finalmente, resultados recentes mostram que drogas que agem como ligantes do GRPR podem melhorar a memória e prevenir disfunções cognitivas em modelos experimentais de amnésia asssociada à DA. Em conjunto, os dados indicam que o GRPR é um novo alvo terapêutico para o tratamento de défi cits de memória associadas à DA. Palavras-chave: bombesina, peptídeo liberador de gastrina, receptor do peptídeo liberador de gastrina, facilitadores cognitivos, disfunções de memória, doença de Alzheimer

Recursos para a geração de conhecimento

Opiniã

A formação do oficial do Exército Brasileiro no início do século XX: a Missão Indígena na Escola Militar do Realengo (1919-1923)

The purpose of this study is to perform an analysis of the action of a group of instructors in the Military School of Realengo in the period between the years of 1919 and 1923, taking as its object the representations made by these actors, of what they allocated as Indigenous Mission. The effects of their actions were remarkable and they were felt by a whole generation of officers of the Brazilian Army, which became known as the “generation of Realengo”. Although constantly remembered by the military historiography, the Indigenous Mission was still very little exploited in the academic work, in terms of its appearance, its performance in Military School and the involvement of some of its members in the lieutenants’ movement

Receptor tyrosine kinases as candidate prognostic biomarkers and therapeutic targets in meningioma

Meningioma (MGM) is the most common type of intracranial tumor in adults. The validation of novel prognostic biomarkers to better inform tumor stratification and clinical prognosis is urgently needed. Many molecular and cellular alterations have been described in MGM tumors over the past few years, providing a rational basis for the identification of biomarkers and therapeutic targets. The role of receptor tyrosine kinases (RTKs) as oncogenes, including those of the ErbB family of receptors, has been well established in several cancer types. Here, we review histological, molecular, and clinical evidence suggesting that RTKs, including the epidermal growth factor receptor (EGFR, ErbB1), as well as other members of the ErbB family, may be useful as biomarkers and therapeutic targets in MGM

Inovação em saúde: conquistas e desafios

Desde que a palavra inovação foi introduzida por Joseph Schumpeter na teoria do desenvolvimento econômico, ampliou-se muito nossa compreensão sobre sua importância para estruturas produtivas. No Brasil, o crescente interesse em inovação é fruto não apenas da necessidade de produzir tecnologia de alto valor agregado e impacto social, mas também da capacidade dos pesquisadores brasileiros de gerar inovação. O Brasil e o HCPA já possuem comprovada competência num amplo espectro de atividades em inovação em saúde e têm potencial de ampliar ainda mais sua atuaçã

De-mystifying the epigenetic free for all : pharmacophore modeling for epigenetic cancer therapy

Epigenetic regulators have quickly become one of the most widely studied therapeutic agents for a vast array of diseases, making histone deacetylase inhibitors (HDIs) and DNA methyl-transferase (DNMT) inhibitors commonly used molecules in pre-clinical and clinical anti-cancer studies. Their ability to regulate gene expression and to potentiate the effects of other chemotherapeutic drugs has put HDIs and DNMT inhibitors in the spotlight not only as single agents, but also as combined therapy. The plethora of HDIs and DNMT inhibitors available nowadays has led to promising results in Phase I, II and III clinical oncology studies. While it was first believed that these molecules would all have an additive or synergistic effect when combined with the classical chemotherapeutic drugs available, our group and others have shown that epigenetic regulators potentiate the effects of some, but not all, anti-cancer molecules. Pharmacophore modeling may therefore serve the purpose to optimize pre-clinical research and to develop more efficient and targeted therapies incorporating epigenetic regulators

A Valepotriate Fraction of Valeriana glechomifolia Shows Sedative and Anxiolytic Properties and Impairs Recognition But Not Aversive Memory in Mice

Plants of the genus Valeriana (Valerianaceae) are used in traditional medicine as a mild sedative, antispasmodic and tranquilizer in many countries. This study was undertaken to explore the neurobehavioral effects of systemic administration of a valepotriate extract fraction of known quantitative composition of Valeriana glechomifolia (endemic of southern Brazil) in mice. Adult animals were treated with a single intraperitoneal injection of valepotriate fraction (VF) in the concentrations of 1, 3 or 10 mg kg−1, or with vehicle in the pre-training period before each behavioral test. During the exploration of an open field, mice treated with 10 mg kg−1 of VF showed reduced locomotion and exploratory behavior. Although overall habituation sessions for locomotion and exploratory behavior among vehicle control and doses of VF were not affected, comparison between open-field and habituation sessions within each treatment showed that VF administration at 1 and 10 mg kg−1 impaired habituation. In the elevated plus-maze test, mice treated with VF (10 mg kg−1) showed a significant increase in the percentage of time spent in the open arms without significant effects in the number of total arm entries. VF at 3 mg kg−1 produced an impairment of novel-object recognition memory. In contrast, VF did not affect fear-related memory assessed in an inhibitory avoidance task. The results indicate that VF can have sedative effects and affect behavioral parameters related to recognition memory

In vitro antitumor effect of sodium butyrate and zoledronic acid combined with traditional chemotherapeutic drugs : a paradigm of synergistic molecular targeting in the treatment of Ewing sarcoma

Histone deacetylase inhibitors and bisphosphonates have a promising future in the treatment of cancer as targeted anticancer drugs, particularly when used together or in combination with other cytotoxic agents. However, the effects of these combined treatments have not yet been systematically evaluated in Ewing sarcoma. The in vitro effects on cellular proliferation, viability and survival were investigated in two Ewing sarcoma cell lines, SK-ES-1 and RD-ES. The cell lines were treated with sodium butyrate, a histone deacetylase inhibitor and zoledronic acid, a bisphosphonate, alone, together or in combination with chemotherapeutic drugs recommended for clinical treatment of Ewing sarcoma. The data demonstrated that the combination of sodium butyrate and zoledronic acid had a synergistic cytotoxic effect at 72 h following treatment, persisting for 10-14 days post-treatment, in both cell lines tested. All combinations between sodium butyrate or zoledronic acid and the traditional antineoplastic drugs (doxorubicin, etoposide and vincristine) demonstrated a synergistic cytotoxic effect at 72 h in SK-ES-1 and RD-ES cells, except for the combinations of sodium butyrate with vincristine and of zoledronic acid with doxorubicin, which showed only an additive effect in RD-ES cell lines as compared to each agent alone. These acute effects observed in both Ewing sarcoma cell lines were confirmed by the clonogenic assay. The present data suggest that combining histone deacetylase inhibitors and bisphosphonates with traditional chemotherapeutic drugs is a promising therapeutic strategy for the treatment of Ewing sarcoma, and provides a basis for further studies in this field

Influence of GRPR and BDNF/TrkB signaling on the viability of breast and gynecologic cancer cells

Neuropeptide and neurotrophin receptors are increasingly important molecular targets in cancer. Scientific findings indicate that compounds blocking gastrin-releasing peptide receptors (GRPR) or tropomyosin receptor kinase (Trk) receptors are likely to have antiproliferative activities against cancer cells. The present study aimed to demonstrate that, in contrast to previous findings, GRPR activation reduces, whereas its blockade increases the viability of breast, ovarian and cervical cancer cell lines. However, consistent with previous studies, Trk inhibition was demonstrated to reduce the viability of these cells. MCF-7 (breast), OVCAR-3 (ovarian) and HeLa (cervical) human cancer cell lines were treated with GRP, the GRPR antagonists RC-3095 and RC-3940-II, brain-derived neurotrophic factor (BDNF) and the Trk antagonist K252α. Cell viability was measured by the MTT assay. Expression of GRPR and BDNF was confirmed with reverse transcription‑polymerase chain reaction (RT-PCR). GRP reduced, whereas RC-3940-II enhanced the viability of the three cell lines. Treatment with K252α inhibited the viability of the cell lines, while BDNF increased the viability of OVCAR-3 cells. The results supported the hypothesis that GRPR and BDNF/TrkB signaling regulates cancer cell viability. Most importantly, these findings are the first to demonstrate that GRPR blockade can stimulate, rather than inhibits the viability of breast and gynecologic cancer cell lines

International scientific collaboration in HIV and HPV: a network analysis.

Research endeavours require the collaborative effort of an increasing number of individuals. International scientific collaborations are particularly important for HIV and HPV co-infection studies, since the burden of disease is rising in developing countries, but most experts and research funds are found in developed countries, where the prevalence of HIV is low. The objective of our study was to investigate patterns of international scientific collaboration in HIV and HPV research using social network analysis. Through a systematic review of the literature, we obtained epidemiological data, as well as data on countries and authors involved in co-infection studies. The collaboration network was analysed in respect to the following: centrality, density, modularity, connected components, distance, clustering and spectral clustering. We observed that for many low- and middle-income countries there were no epidemiological estimates of HPV infection of the cervix among HIV-infected individuals. Most studies found only involved researchers from the same country (64%). Studies derived from international collaborations including high-income countries and either low- or middle-income countries had on average three times larger sample sizes than those including only high-income countries or low-income countries. The high global clustering coefficient (0.9) coupled with a short average distance between researchers (4.34) suggests a "small-world phenomenon." Researchers from high-income countries seem to have higher degree centrality and tend to cluster together in densely connected communities. We found a large well-connected community, which encompasses 70% of researchers, and 49 other small isolated communities. Our findings suggest that in the field of HIV and HPV, there seems to be both room and incentives for researchers to engage in collaborations between countries of different income-level. Through international collaboration resources available to researchers in high-income countries can be efficiently used to enroll more participants in low- and middle-income countries