Autophagy Modulation for Organelle-Targeting Therapy

Autophagy is a crucial metabolic pathway that sustains cellular homeostasis in health and that can also play either a protective or a destructive role in disease. During the last decade, progress made in understanding of the molecular basis of autophagy has uncovered an exciting opportunity to target it for the treatment of several human illnesses. In fact, there is emerging interest in autophagy-modulating and autophagy-targeted therapy with a variety of pharmacologic agents. However, to develop effective autophagy-targeted therapy, it is essential to identify the pharmacologic key targets in the autophagy pathway. In this chapter, we reviewed the cases of success and pitfalls of activating or inhibiting autophagy attempting therapeutic intervention of diseases, including cancer, neurologic disorders, and infectious diseases. In all these histopathologic states, autophagy is considered as the principal cellular mechanisms of defense and immunochemical homeostasis. In the last section of this chapter, we discuss main directions that may be of particular use in the future investigations, including a promissory avenue for autophagy modulation for organelle-targeting therapy through a promotion of parallel damage in lysosomal and mitochondrial membranes

Search for cytotoxic agents in multiple Laurencia complex seaweed species (Ceramiales, Rhodophyta) harvested from the Atlantic Ocean with emphasis on the Brazilian State of Espírito Santo

The development of new anti-cancer drugs of algal origin represents one of the least explored frontiers in medicinal chemistry. In this regard, the diversity of micro- and macroalgae found in Brazilian coastal waters can be viewed as a largely untapped natural resource. In this report, we describe a comparative study on the cytotoxic properties of extracts obtained from the Laurencia complex: Laurencia aldingensis, L. catarinensis, L. dendroidea, L. intricata, L. translucida, L. sp, and Palisada flagellifera. All of these species were collected in the coastal waters of the State of Espírito Santo, Brazil. Four out of the twelve samples initially investigated were found to show significant levels of toxicity towards a model tumor cell line (human uterine sarcoma, MES-SA). The highest levels of cytotoxicity were typically associated with non-polar (hexane) algal extracts, while the lowest levels of cytotoxicity were found with the corresponding polar (methanol) extracts. In this report, we also describe a biological model currently in development that will not only facilitate the search for new anti-cancer drug candidates of algal origin, but also permit the identification of compounds capable of inducing the destruction of multi-drug resistant tumors with greater efficiency than the pharmaceuticals currently in clinical use.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Ministério da SaúdeMinistério de Ciência e TecnologiaCNPq - INCT-Redoxom

Is surgical debridement necessary in the diabetic foot treated with photodynamic therapy?

Background: Diabetic patients are susceptible to developing foot ulcerswith serious complications such as osteomyelitis and amputations. Treatment approaches are still empirical and the benefit of usual procedures such as surgical debridement has not been properly evaluated. Photodynamic Therapy (PDT) is a non-invasive and highly efficient method for the treatment of the diabetic foot, being able to eradicate the infection and to stimulate healing, decreasing considerably the amputation risk. In the day-to-day practice of our service, we have been faced with the question whether debridement is necessary before PDT. In here, we designed a study to answer that question. Methods: Patients were divided in two groups: In one of the groups (n = 17), debridement was performed before PDT and in the other (n = 40) only PDT treatment was performed. PDT sessions were performed once a week in all patients until healing was achieved, as indicated by visual inspection as well as by radiographic and laboratory exams. At the start of the study, the two groups had no statistical differences concerning their clinical features: average age, gender, insulin use, diabetes mellitus onset time and previous amputations. Results: PDT was effective in the treatment of 100% of the patients showing no relapses after one year of follow up. The group submitted to PDT without previous debridement had a statistically significant (p = 0.036, Mann-Whitney) shorter cure time (29 days, similar to 27%). Conclusion: Our data indicates that debridement is not necessary in the treatment of diabetic foot in patients that have enough peripheral arterial perfusion. In addition, we reproduced previous studies confirming that PDT is an efficient, safe, simple and affordable treatment method for the diabetic foot.Fundacao de Amparo a Pesquisa do Estado de Sao PauloCNPqHosp Anchieta, Fac Med ABC, Sao Bernardo Do Campo, BrazilFac Med ABC, Dept Bioquim, Santo Andre, BrazilUniv Sao Paulo, Dept Bioquim, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Med, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Med, Sao Paulo, BrazilFAPESP: 12/50680-5FAPESP: 13/07937-8Web of Scienc

Autophagy regulation and photodynamic therapy: insights to improve outcomes of cancer treatment

Cancer is considered an age-related disease that, over the next 10 years, will become the most prevalent health problem worldwide. Although cancer therapy has remarkably improved in the last few decades, novel treatment concepts are needed to defeat this disease. Photodynamic Therapy (PDT) signalize a pathway to treat and manage several types of cancer. Over the past three decades, new light sources and photosensitizers (PS) have been developed to be applied in PDT. Nevertheless, there is a lack of knowledge to explain the main biochemical routes needed to trigger regulated cell death mechanisms, affecting, considerably, the scope of the PDT. Although autophagy modulation is being raised as an interesting strategy to be used in cancer therapy, the main aspects referring to the autophagy role over cell succumbing PDT-photoinduced damage remain elusive. Several reports emphasize cytoprotective autophagy, as an ultimate attempt of cells to cope with the photo-induced stress and to survive. Moreover, other underlying molecular mechanisms that evoke PDT-resistance of tumor cells were considered. We reviewed the paradigm about the PDT-regulated cell death mechanisms that involve autophagic impairment or boosted activation. To comprise the autophagy-targeted PDT-protocols to treat cancer, it was underlined those that alleviate or intensify PDT-resistance of tumor cells. Thereby, this review provides insights into the mechanisms by which PDT can be used to modulate autophagy and emphasizes how this field represents a promising therapeutic strategy for cancer treatment.Fil: Martins, Waleska K.. Universidade de Sao Paulo; BrasilFil: Belotto, Renata. Perola Byington Hospital; BrasilFil: Silva, Maryana N.. Universidade de Sao Paulo; BrasilFil: Grasso, Daniel Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Suriani, Maynne D.. Universidade Federal de Uberlandia; BrasilFil: Lavor, Tayná S.. Universidade Federal de Uberlandia; BrasilFil: Itri, Rosangela. Universidade de Sao Paulo; BrasilFil: Baptista, Mauricio S.. Universidade de Sao Paulo; BrasilFil: Tsubone, Tayana M.. Universidade Federal de Uberlandia; Brasi

Metallochlorophylls of magnesium, copper and zinc: evaluation of the influence of the first coordination sphere on their solvatochromism and aggregation properties

In this study the role of different metal centers (magnesium, zinc and copper) on the enhancement of the hydrophilic character of metallochlorophylls, was evaluated. The solvatochromism as well as the aggregation process for these compounds in water/ethanol mixtures at different volume ratios were evaluated using Fluorescence, and Resonant Light Scattering (RLS) measurements, aiming to characterize the behavior of these compounds. Independently on the studied metallochlorophyll, the presence of at least 60% of water results in a considerable increase in the fluorescence emission, probably a direct consequence of a lower aggregation of these compounds, which is confirmed by the results from RLS measurements. Additionally, the results suggest that magnesium and zinc chlorophyll should be promising phototherapeutic agents for Photodynamic Therapy.No presente estudo, o papel de diferentes centros metálicos (magnésio, zinco e cobre) sobre o caráter hidrofílico de metaloclorofilas foi avaliado. O solvatocromismo, assim como o processo de agregação para esses compostos, em misturas água/etanol foram avaliados usando medidas de fluorescência e de espalhamento de luz ressonante (ELR), visando caracterizar o comportamento desses compostos. Independente da metaloclorofila estudada, a presença de ao menos 60% de água resulta em incremento considerável na emissão de fluorescência apresentada por esses compostos. Isso, provavelmente, é uma conseqüência direta de uma menor agregação, o que é confirmado pelos resultados de ELR. Adicionalmente, os resultados sugerem que as clorofilas de magnésio e de zinco devem ser promissores agentes fototerapêuticos para emprego em Terapia Fotodinâmica.FAPESPFundação AraucáriaFAPEMIGCNPqNanobra

The Methylene Blue Self-aggregation in Water/Organic Solvent Mixtures: Relationship Between Solvatochromic Properties and Singlet Oxygen Production

In this work is presented a spectrophotometric investigation focused on the solvatochromic effects upon Methylene Blue (MB). Measurements were carried out in four different water/organic solvent mixtures: low polarity protic solvent (ethanol), polar non-protic solvent (acetonitrile), highly polar protic solvent (glycerol), and non-polar solvent (dioxane). The results showed that the photophysical behavior of MB is highly affected by self-aggregates formation at 80% of water/organic solvent blends. Besides polarity, the protic character and the coordinating properties of the solvent molecules are the key parameters for its photophysical behavior, since the sulfur atom of the cationic structure can act as a coordination center due to its Lewis acid character. In fact, water and acetonitrile coordinating properties have proved to be important to determine MB interactions intensity and its spectroscopic properties as singlet oxygen emission. It was observed that an increase of the amount of the organic solvent resulted in an enhancement of the singlet oxygen emission intensity. The presence of the water increases the dielectric constant of the medium and favors the self-aggregation process. Besides, the water molecules can act as a quencher and it decreases the quantum yield of the fluorescence of MB.FAPESPCNPqFarma Service BioExtract LtdaUniv Fed Sao Joao del Rei, Dept Zootecnia DEZOO, Campus Dom Bosco, BR-36301160 Sao Joao Del Rei, MG, BrazilUniv Vale Paraiba, Ave Shishima Hifumi 2911, BR-12244000 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Quim, Rua Prof Arthur Riedel 275, BR-09972270 Sao Paulo, BrazilUniv Sao Paulo, Dept Bioquim, Inst Quim, Ave Prof Lineu Prestes 748, BR-05508900 Sao Paulo, SP, BrazilUniv Tecnol Fed Parana, Campus Apucarana,Rua Marcilio Dias 635, BR-86812460 Apucarana, Parana, BrazilUniv Fed Santa Catarina, BR-88040900 Florianopolis, SC, BrazilUniv Estadual Maringa, Dept Quim, Av Colombo 5790,Zona 07, BR-87020900 Maringa, Parana, BrazilUniv Fed Rio de Janeiro, Campus Macae,Rua Aloisio da Silva Gomes 50, BR-27930560 Rio De Janeiro, BrazilUniv Estadual Campinas, Inst Quim, BR-13083970 Sao Paulo, BrazilUniv Fed Rio Grande, Escola Quim & Alimentos, Campus Carreiros Pavilhao Quim, BR-96201900 Rio Grande, RS, BrazilUniv Fed ABC, Ctr Engn Modelagem & Ciencias Sociais Aplicadas, Ave Estados 5001, BR-09210580 Sao Paulo, BrazilUniv Fed ABC, Ctr Ciencias Nat & Humanas, Ave Estados 5001, BR-09210580 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Quim, Rua Prof Arthur Riedel 275, BR-09972270 Sao Paulo, BrazilFAPESP: JP 04/02193-1FAPESP: 02/00272-6FAPESP: 06/56701-3FAPESP: 2005/51597-8CNPq: 474019/2012-8]CNPqFarma Service BioExtract LtdaWeb of Scienc

Synthesis, spectroscopic characterization, photochemical and photophysical properties and biological activities of ruthenium complexes with mono- and bi-dentate histamine ligand

The monodentate cis-[Ru(phen)(2)(hist)(2)](2+) 1R and the bidentate cis-[Ru(phen)(2)(hist)](2+) 2A complexes were prepared and characterized using spectroscopic (H-1, (H-1-H-1) COSY and (H-1-C-13) HSQC NMR, UV-vis, luminescence) techniques. The complexes presented absorption and emission in the visible region, as well as a tri-exponential emission decay. The complexes are soluble in aqueous and non-aqueous solution with solubility in a buffer solution of pH 7.4 of 1.14 x 10(-3) mol L-1 for (1R + 2A) and 6.43 x 10(-4) mol L-1 for 2A and lipophilicity measured in an aqueous-octanol solution of -1.14 and -0.96, respectively. Photolysis in the visible region in CH3CN converted the starting complexes into cis-[Ru(phen)(2)(CH3CN)(2)](2+). Histamine photorelease was also observed in pure water and in the presence of BSA (1.0 x 10(-6) mol L-1). The bidentate coordination of the histamine to the ruthenium center in relation to the monodentate coordination increased the photosubstitution quantum yield by a factor of 3. Pharmacological studies showed that the complexes present a moderate inhibition of AChE with an IC50 of 21 mu mol L-1 (referred to risvagtini, IC50 181 mu mol L-1 and galantamine IC50 0.006 mu mol L-1) with no appreciable cytotoxicity toward to the HeLa cells (50% cell viability at 925 mu mol L-1). Cell uptake of the complexes into HeLa cells was detected by fluorescence confocal microscopy. Overall, the observation of a luminescent complex that penetrates the cell wall and has low cytotoxicity, but is reactive photochemically, releasing histamine when irradiated with visible light, are interesting features for application of these complexes as phototherapeutic agents.FAPESP [Proc 2009/08218-0]FAPESPCNPq [Universal 470890/2010-0]CNPqCAPESCAPE