Expression of the neural stem cell markers NG2 and L1 in human angiomyolipoma: are angiomyolipomas neoplasms of stem cells?

Angiomyolipomas are benign tumors of the kidney which express phenotypes of smooth muscle, fat, and melanocytes. These tumors appear with increased frequency in the autosomal dominant disorder tuberous sclerosis and are the leading cause of morbidity in adults with tuberous sclerosis. While benign, these tumors are capable of provoking life threatening hemorrhage and replacement of the kidney parenchyma, resulting in renal failure. The histogenesis of these tumors is currently unclear, although currently, we believe these tumors arise from perivascular epithelioid cells of which no normal counterpart has been convincingly demonstrated. Recently, stem cell precursors have been recognized that can give rise to smooth muscle and melanocytes. These precursors have been shown to express the neural stem cell marker NG2 and L1. In order to determine whether angiomyolipomas, which exhibit smooth muscle and melanocytic phenotypes, express NG2 and L1, we performed immunocytochemistry on a cell line derived from a human angiomyolipoma, and found that these cells are uniformly positive. Immunohistochemistry of human angiomyolipoma specimens revealed uniform staining of tumor cells, while renal cell carcinomas revealed positivity only of angiogenic vessels. These results support a novel histogenesis of angiomyolipoma as a defect in differentiation of stem cell precursors

Triphenylmethane Derivatives Have High In Vitro and In Vivo Activity against the Main Causative Agents of Cutaneous Leishmaniasis

Submitted by Nuzia Santos ([email protected]) on 2018-11-20T18:38:06Z No. of bitstreams: 1 Triphenylmethane Derivatives Have .pdf: 319936 bytes, checksum: 6d631fa6e219dd3fa61ff290785fcf6d (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2018-11-21T13:09:45Z (GMT) No. of bitstreams: 1 Triphenylmethane Derivatives Have .pdf: 319936 bytes, checksum: 6d631fa6e219dd3fa61ff290785fcf6d (MD5)Made available in DSpace on 2018-11-21T13:09:45Z (GMT). No. of bitstreams: 1 Triphenylmethane Derivatives Have .pdf: 319936 bytes, checksum: 6d631fa6e219dd3fa61ff290785fcf6d (MD5) Previous issue date: 2013Universidade Federal de Minas Gerais. Departamento de Análises Clínicas e Toxicológicas.Belo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais. Departamento de Análises Clínicas e Toxicológicas.Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Instituto René Rachou. Laboratório de Pesquisa Clínica. Belo Horizonte, MG, Brasil.Department of Dermatology. Emory University School of Medicine. Atlanta, Georgia, United States of America.Department of Dermatology. Emory University School of Medicine. Atlanta, Georgia, United States of America.Fundação Oswaldo Cruz. Instituto René Rachou. Laboratório de Pesquisa Clínica. Belo Horizonte, MG, Brasil.Department of Dermatology. Emory University School of Medicine. Atlanta, Georgia, United States of America.Universidade Federal de Minas Gerais. Departamento de Análises Clínicas e Toxicológicas.Belo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais. Departamento de Análises Clínicas e Toxicológicas.Belo Horizonte, MG, BrazilThe current standard of care for cutaneous leishmaniasis (CL) is organic antimonial compounds, but the administration of these compounds is complicated by a low therapeutic - toxic index, as well as parenteral administration. Thus, there is an urgent need for the development of new and inexpensive therapies for the treatment of CL. In this study, we evaluate the activity of the triphenylmethane (TPM) class of compounds against three species of Leishmania which are pathogenic in humans. The TPM have a history of safe use in humans, dating back to the use of the original member of this class, gentian violet (GV), from the early 20th century. Initially, the in vitro efficacy against Leishmania (Viannia) braziliensis, L. (Leishmania) amazonensis and L. (L.) major of 9 newly synthesized TPM, in addition to GV, was tested. Inhibitory concentrations (IC) IC50 of 0.025 to 0.84 µM had been found in promastigotes in vitro assays. The four most effective compounds were then tested in amastigote intracellular assays, resulting in IC50 of 0.10 to 1.59 µM. A high degree of selectivity of antiparasitic activity over toxicity to mammalian cells was observed. Afterwards, GV and TPM 6 were tested in a topical formulation in mice infected with L. (L.) amazonensis leading to elimination of parasite burdens at the site of lesion/infection. These results demonstrated that TPM present significant anti-leishmanial activities and provide a rationale for human clinical trials of GV and other TPM. TPM are inexpensive and safe, thus using them for treatment of CL may have a major impact on public health

<i>In vitro</i> anti-leishmanial activity of TPM compounds expressed as IC₅₀ (µM) on promastigotes assay.

<p>IC₅₀ values correspond to mean and 95% CI of results obtained from triplicates; n.d., not determined; data obtained for linear regression on MiniTab® 15.1 software, a,b p<0,05 compared IC₅₀ determined for <i>L.(L.) amazonensis</i>, <i>L.(L.) major</i> and <i>L.(V.) braziliensis</i> .</p

Molecular weight and chemical formula for all TPM compounds tested.

<p>Molecular weight and chemical formula for all TPM compounds tested.</p

Cytotoxicity, anti-leishmanial i<i>n vitro</i> activity and selectivity index (SI) of TPM 1, TPM 2, TPM 6, TPM 9 and GV against <i>L. (L.) amazonensis</i> and <i>L. (V.) braziliensis</i> on intracellular amastigotes assay.

<p>IC₅₀ values correspond to mean and 95% CI of results obtained from triplicates; n.d., not determined; data obtained from linear regression on MiniTab® 15.1 software; mean value of parasite growth inhibition observed for control drug (0.2 µg/ml AmB) was 98% for <i>L. (V.) braziliensis</i> and 99.5% for <i>L. (L.) amazonensis</i>.</p

Dose-effect analysis of TPM 6 against <i>L (L.) amazonensis</i>.

<p>Promastigotes of <i>L</i>. (<i>L</i>.) <i>amazonensis</i> were plated in 24 well plates at a plating density of 1×10⁶ parasites/mL in Schneider's medium supplemented with 20% FCS, pH 7.2. TPM 6 was diluted in the same medium and added to parasites suspension at 0.001; 0.005; 0.01 and 0.05 µM, in triplicate. After 48 h, the parasites were counted and compared to the controls containing parasites in absence of drugs. Three independent experiments were done and the results were analyzed with MiniTab® Program. Data are the mean ± SD.</p

<i>In vivo</i> efficacy of GV and TPM6 topical treatment in <i>L (L.) amazonensis</i>-infected BALB/c mice.

<p>Female BALB/c mice were infected with <i>L (L.) amazonensis</i> at the base of the tail; 6 weeks after inoculation. <b>A</b>) Lesions were covered with 50 µl of a gel formulation containing either 1% GV or 1% TPM 6, twice a day, for 20 days. Animals from control group were treated with the gel formulation without GV or TPM 6 (placebo). The treatment efficacy was evaluated through of the parasite quantification at the site of infection. <b>B</b>) Dose-effect study of GV. The GV gel formulation was applied topically at 0.1, 0.5 or 1.0% twice a day, for 20 days. Animals from control group were treated with the gel formulation without GV (placebo). In both experiments, parasite numbers recovered from lesions were evaluated by a limiting dilution assay (* p<0.05 when compared to control group) (n = 5), three days after interruption of treatment. Two independent experiments were done and the results were analyzed with SigmaStat® Program.</p

TPM structures.

<p>TPM structures.</p