Effect of obesity on biodistribution of nanoparticles

[EN] Nanoparticles have specific features (lipophilicity, surface charge, composition and size). Studies regarding the biological behavior of nanoparticles in diseases such diabetics and obesity are scarce. Here, we evaluated two nanoparticles: magnetic core mesoporous silica (MSN) (58 nm) and polycaprolactone (PCL) nanoparticle (280 nm) in obese mice. Changes in the biodistribution were observed, especially considering the mononuclear phagocyte system (MPS), and the visceral fat tissue. Nonetheless, our data corroborates the influence of size in the biodistribution in obese animals, supporting that smaller nanoparticles, may show a higher tissue deposition at spleen, due the associated splenomegaly and the complications arising from this state. Finally, our study demonstrated that, in obesity, probably due the low-grade inflammatory state associated with metabolic syndrome a difference in accumulation of nanoparticles was found, with profound impact in the tissue deposition of nanoparticles.The authors would like to thank the National Scientific and Technological Research Council (CNPQ) - no. 400018/2016-0 and the Rio de Janeiro State Research Foundation (FAPERJ) - E-26/102.940/2012 for funding. Authors also gratefully acknowledge the financial support from the Ministerio de Economía y Competitividad (Project MAT2012-38429-C04-01) and the Generalitat Valenciana (project PROMETEO/2009/016) for support.Felismino, CDJ.; Helal-Neto, E.; Portilho, F.; Rocha Pinto, S.; Sancenón Galarza, F.; Martínez-Máñez, R.; Ferreira, ADA.... (2018). Effect of obesity on biodistribution of nanoparticles. Journal of Controlled Release. 281:11-18. https://doi.org/10.1016/j.jconrel.2018.05.003S111828

Increased Leptin Response and Inhibition of Apoptosis in Thymocytes of Young Rats Offspring from Protein Deprived Dams during Lactation

Made available in DSpace on 2015-09-21T17:25:49Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) wilson_savino_etal_IOC_2013.pdf: 2058739 bytes, checksum: b0cf992a8dc3f89a54e1abbebefe7dbc (MD5) Previous issue date: 2013Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Departamento de Biologia Celular. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Departamento de Biologia Celular. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Departamento de Biologia Celular. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Departamento de Biologia Celular. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Nutrição. Departamento de Nutrição Básica e Experimental. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Pesquisas sobre o Timo. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Departamento de Biologia Celular. Rio de Janeiro, RJ, Brasil.We investigated the consequences of mild maternal malnutrition in rat dams, in terms of thymocyte responses and the putative role of leptin. The young progeny of dams submitted to protein deprivation (PD) during lactation showed at 30 days of age lower body and thymus weights, significant alterations in CD4/CD8-defined T cell subsets without modifications in total thymocyte number as well as in proliferative response. Despite, the rats from PD group did not present alterations in leptin circulating levels, the expression of leptin receptor ObRb was enhanced in their thymocytes. This change was accompanied by an increase in leptin signaling response of thymocytes from PD rats, with an increase in JAK2 and STAT3 phosphorylation after leptin stimulation. Thymocytes from PD rats also presented a decreased rate of spontaneous apoptosis when compared to controls. Accordingly, higher expression of anti-apoptotic protein Bcl-2, and lower of pro-apoptotic protein Bax, with no change of pro-apoptotic Bad, and higher pro-caspase 3 content were detected in PD thymocytes. Moreover, thymocytes from PD group exhibited a constitutive higher nuclear content of p65 NF-kB associated to a lower IkB content in the cytoplasm. Finally, although there was no change in ob gene expression in PD thymocytes, a higher mRNA expression for the Ob gene was observed in the thymic microenvironment from PD animals. Taken together, the results show that mild maternal protein deprivation during lactation affects thymic homeostasis, enhancing leptin activity, which in turn protects thymocytes from apoptosis in the young progeny, with possible consequences upon the immune response of these animals in adult life

Detrimental role of endogenous nitric oxide in host defence against Sporothrix schenckii

We earlier demonstrated that nitric oxide (NO) is a fungicidal molecule against Sporothrix schenckii in vitro. In the present study we used mice deficient in inducible nitric oxide synthase (iNOS–/–) and C57BL/6 wild-type (WT) mice treated with Nω-nitro-arginine (Nitro-Arg-treated mice), an NOS inhibitor, both defective in the production of reactive nitrogen intermediates, to investigate the role of endogenous NO during systemic sporotrichosis. When inoculated with yeast cells of S. schenckii, WT mice presented T-cell suppression and high tissue fungal dissemination, succumbing to infection. Furthermore, susceptibility of mice seems to be related to apoptosis and high interleukin-10 and tumour necrosis factor-α production by spleen cells. In addition, fungicidal activity and NO production by interferon-γ (IFN-γ) and lipopolysaccharide-activated macrophages from WT mice were abolished after fungal infection. Strikingly, iNOS–/– and Nitro-Arg-treated mice presented fungal resistance, controlling fungal load in tissues and restoring T-cell activity, as well as producing high amounts of IFN-γ Interestingly, macrophages from these groups of mice presented fungicidal activity after in vitro stimulation with higher doses of IFN-γ. Herein, these results suggest that although NO was an essential mediator to the in vitro killing of S. schenckii by macrophages, the activation of NO system in vivo contributes to the immunosuppression and cytokine balance during early phases of infection with S. schenckii

Extracellular Matrix Derived from High Metastatic Human Breast Cancer Triggers Epithelial-Mesenchymal Transition in Epithelial Breast Cancer Cells through αvβ3 Integrin

Alterations in the composition and architecture of the extracellular matrix (ECM) can influence cancer growth and dissemination. During epithelial-mesenchymal transition (EMT), epithelial cells assume a mesenchymal cell phenotype, changing their adhesion profiles from cell-cell contacts to cell-matrix interactions, contributing to metastasis. Breast cancer cells present at different stages of differentiation, producing distinct ECMs in the same tumor mass. However, the contribution of ECM derived from metastatic tumor cells to EMT is unclear. Here, we showed the mechanisms involved in the interaction of MCF-7, a low-metastatic, epithelial breast cancer cell line, with the ECM produced by a high metastatic breast tumor cell, MDA-MB-231 (MDA-ECM). MDA-ECM induced morphological changes in MCF-7 cells, decreased the levels of E-cadherin, up-regulated mesenchymal markers, and augmented cell migration. These changes were accompanied by the activation of integrin-associated signaling, with increased phosphorylation of FAK, ERK, and AKT and activation canonical TGF-β receptor signaling, enhancing phosphorylation of SMAD2 and SMAD4 nuclear translocation in MCF-7 cells. Treatment with Kistrin (Kr), a specific ligand of integrin αvβ3 EMT induced by MDA-ECM, inhibited TGF-β receptor signaling in treated MCF-7 cells. Our results revealed that after interaction with the ECM produced by a high metastatic breast cancer cell, MCF-7 cells lost their characteristic epithelial phenotype undergoing EMT, an effect modulated by integrin signaling in crosstalk with TGF-β receptor signaling pathway. The data evidenced novel potential targets for antimetastatic breast cancer therapies

Thymocytes from PD rats present a higher ObR protein expression in basal conditions, and increase JAK-2 and STAT-3 activation after leptin stimulation.

<p>Panel A shows that ObRb gene expression levels are similar in all CD4/CD8-defined thymocyte subsets from both control and PD rats. Total RNA was harvested and analyzed by qRT-PCR for ObRb mRNA. The result was normalized by GAPDH, and data were expressed as gene expression levels related to control. Panel B depicts immunoblottings showing that the ObR protein contents in thymocytes from PD animals were significantly higher than the control counterparts (*p<0.05). Quantitation of bands was expressed in arbitrary units related to actin expression, applied as internal control of the experiment. Values are means ± S.E of 6–10 animals/group. No differences in the pJAK-2/total JAK-2 ratios were seen in control or PD thymocytes, in basal conditions (panel C). Incubation with leptin significantly enhanced pJAK-2/total JAK-2 ratios in both groups, with the increase being significantly more prominent in the PD group (Panel D). Similar data were recorded for the expression of pSTAT-3 versus total STAT-3 in basal and leptin conditions, as seen in panels <b>e</b> and <b>f</b>. Thymocyteswere incubated in the presence or absence of leptin (10 nM) for 1 hour and pJAK-2 and pSTAT3 protein expression were assessed in total extracts by immunoblotting. Quantification of bands is expressed in arbitrary units. Values are means ± S.E of 6–10 animals/group. *P<0.05 compared to control group; ^ap<0.05 compared to PD group and; ^bP<0.05 compared to control+Leptin group.</p

Maternal protein deprivation does not alter the expression of membrane surface markers of spleen cells in young rats.

<p>Results are expressed as means ± SEM; n = 3–5.</p

Maternal protein deprivation during lactation does not affect serum leptin concentration from 25 and 30-day old offspring.

<p>Blood samples were collected from control and PD animals at 21, 25 and 30 days of age, and leptin serum levels were determined by ELISA. Results are expressed as means ± S.E of 8–12 animals/group. *P<0.05, compared to the control group.</p

Composition of control and protein-restricted (8%) diet.

a<p>Standard diet for rats (Nuvilab – NUVITAL Nutrientes LTDA, Paraná, Brazil).</p>b<p>The protein restricted diet was prepared in our laboratory using the control diet and replacing part of its protein with cornstarch. The amount of the latter was calculated so as to make up for the decrease in energy content due to protein restriction.</p>c<p>Vitamin and mineral mix were formulated according to the American Institute of Nutrition 93-G recommendation for rodents diets <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064220#pone.0064220-Reeves1" target="_blank">[31]</a>.</p

Thymic microenvironment isolated from PD rats presents higher Ob gene expression levels.

<p>Total RNA was harvested and analyzed by qRT-PCR for Ob and ObRb genes mRNA. The results were normalized by GAPDH. The results were expressed as expression related to control. Values are means ± SE of 6 animals/group. *P<0.05 compared to control group.</p

Thymocytes from PD rats present alterations in the pro- and anti-apoptotic protein levels and NF-kB nuclear translocation in basal condition.

<p>Thymocytes isolated from control and PD rats were incubated in the presence or absence of leptin (10 nM) for 24 hours, and BcL-2, Bad, Bax, procaspase 3, NF-kB, IkB, actin and histone protein expression were assessed in total (BcL-2, Bad, Bax, procaspase3, IkB and actin) or nuclear (NF-kB and histone) extracts by western blotting analysis. Quantification of bands is expressed in arbitrary units. Values are means ± S.E of 6 animals/group. *P<0.05 compared to control group.</p