Ionic complexation improves wound healing in deep second-degree burns and reduces in-vitro ciprofloxacin cytotoxicity in fibroblasts

The development of new treatments capable of controlling infections and pain related to burns continues to be a challenge. Antimicrobials are necessary tools, but these can be cytotoxic for regenerating cells. In this study, antibiotic-anesthetic (AA) smart systems obtained by ionic complexation of polyelectrolytes with ciprofloxacin and lidocaine were obtained as films and hydrogels. Ionic complexation with sodium alginate and hyaluronate decreased cytotoxicity of ciprofloxacin above 70% in a primary culture of isolated fibroblasts (p < 0.05). In addition, the relative levels of the proteins involved in cell migration, integrin β1 and p-FAK, increased above 1.5 times (p < 0.05) with no significant differences in cell mobility. Evaluation of the systems in a deep second-degree burn model revealed that reepithelization rate was AA-films = AA-hydrogels > control films > no treated > reference cream (silver sulfadiazine cream). In addition, appendage conservation and complete dermis organization were achieved in AA-films and AA-hydrogels. Encouragingly, both the films and the hydrogels showed a significantly superior performance compared to the reference treatment. This work highlights the great potential of this smart system as an attractive dressing for burns, which surpasses currently available treatments.

Extracellular vesicles from thyroid cancer harbor a functional machinery involved in extracellular matrix remodeling

Extracellular vesicles (EVs) participate in cell-stroma crosstalk within the tumor microenvironment and fibroblasts (Fb) contribute to tumor promotion in thyroid cancer. However, the role of tumor-stroma derived EVs still needs to be deciphered. We hypothesized that the interaction of thyroid tumor cells with Fb would liberate EVs with a specific proteomic profile, which would have an impact on EV-functionality in thyroid tumor progression-related events. Tumor (TPC-1, 8505c) and non-tumor (NThyOri) thyroid cells were co-cultured with human Fb. EVs, obtained by ultracentrifugation of conditioned media, were characterized by nanoparticle tracking analysis and western blotting. EV-proteomic analysis was performed by mass-spectrometry, and metalloproteinases (MMPs) were studied by zymography. EV-exchange was evaluated using immunofluorescence, confocal microscopy and FACS. EVs expressed classical exosome markers, with EVs from thyroid tumor cell-Fb co-cultures showing a proteomic profile related to extracellular matrix (ECM) remodeling. Bidirectional crosstalk between Fb and TPC-1 cells produced significantly more EVs than their isolated cells, and potentiated EV-functionality. In line with this, Fb-TPC-1 derived EVs induced MMP2 activation in NThyOri supernatants, and MMP2 activity could be evidenced in Fb and TPC-1 contact-independent co-cultures. Besides, MMP2 interactors allowed us to discriminate between EVs from thyroid tumoral and non-tumoral milieus. Interestingly, Fb internalized more EVs from TPC-1 than from NThyOri producing cells. Fb and thyroid tumor cell crosstalk produces specialized EVs with an ECM remodeling proteomic profile, enabling activation of MMP2 and possibly facilitating ECM-degradation, which is potentially linked with thyroid tumor progression.

Thyroid tumor cells-fibroblasts crosstalk: role of extracellular vesicles

Tumor-stroma crosstalk leads to a tumor-promoting microenvironment. In this milieu, extracellular vesicles (EVs) are protagonists in cell-cell communication. Despite thyroid cancer being the most common endocrine malignancy, the contribution of the tumor microenvironment to thyroid cancer progression is still largely underexplored. We focused on the role of thyroid tumor cell-fibroblast interaction and EVs as mediators of tumor-stroma interplay, in the promotion of thyroid tumor aggressiveness. Thyroid tumor (TPC-1, 8505c) or non-tumor thyroid cells (NThyOri) were co-cultured with human fibroblasts (Fb). Thyroid cell migration was investigated by the wound-healing assay and actin-network staining. Cell-CD147 expression was characterized by flow cytometry. EVs, obtained by ultracentrifugation of conditioned media (CMs), were characterized by transmission electron-microscopy and CD81 and CD147 expression. Metalloproteinases (MMPs) were evaluated by zymography in CMs. A migratory phenotype was triggered in thyroid tumor cells treated with CMs from Fb or from Fb-thyroid tumor cell co-cultures. Fb-thyroid cell co-cultures induced the secretion of proMMP9 and proMMP2 and led to a significant MMP2 activation in CMs. Fb, thyroid cells and Fb-thyroid cell co-cultures released EVs, and remarkably, EVs released by Fb-thyroid tumor cell co-cultures induced the secretion of proMMP2 and the expression of MMP2 from normal Fb. A significant CD147 expression was demonstrated in Fb-thyroid tumor cell-derived EVs. These findings reveal the role of Fb and thyroid tumor cell-Fb interaction in the promotion of a microenvironment suitable for thyroid tumor progression. Moreover, they highlight, for the first time, the role of thyroid tumor cell-Fb interaction in the production of specialized EVs.

Author Correction: Interplay of fibroblasts with anaplastic tumor cells promotes follicular thyroid cancer progression

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Renal dysfunction and intragraft proMMP9 activity in renal transplant recipients with interstitial fibrosis and tubular atrophy

Chronic renal allograft injury is reflected by interstitial fibrosis and tubular atrophy (IF/TA) and by the accumulation of extracellular matrix (ECM). Metalloproteinases (MMPs) are renal physiologic regulators of ECM degradation. Changes in MMPs expression or activity may disturb ECM turnover leading to glomerular scarring and worsening renal function. Our goal was to investigate intragraft MMP2 and MMP9 activities and their correlation with renal dysfunction. Plasma MMP2 and MMP9 activities were analyzed as noninvasive markers of renal allograft deterioration. Transplanted patients were biopsied and histopathologically characterized as IF/TA+ or IF/TA-. Renal function was evaluated by serum creatinine, glomerular filtration rate (GFR) estimated by Modification of Diet in Renal Disease equation and urinary protein/creatinine ratio. Kidney and plasma MMP2 and MMP9 activities were analyzed by zymography. A significant renal dysfunction was observed in IF/TA+ patients. Intragraft proMMP9 showed a significant higher activity in IF/TA+ than in IF/TA- samples and was inversely correlated with the GFR. Intragraft proMMP2 activity tended to increase in IF/TA+ samples, although no statistic significance was reached. Circulating proMMP2 and proMMP9 activities did not show significant differences between groups. Our data provide evidence that correlates intragraft proMMP9 activity with the fibrotic changes and renal dysfunction observed in IF/TA.

Quercetin 3,7,3',4'-tetrasulphated isolated from Flaveria bidentis inhibits tissue factor expression in human monocyte

Sulphated esters of the flavonoids sulphated quercetin 3,7,3',4'-tetrasulphated (QTS) and quercetin 3-acetyl-7,3,4'-trisulphate (ATS), isolated from Flaveria bidentis, have demonstrated anticoagulant and antiplatelet properties. In this study, we examined if both compounds affected the expression of the procoagulant tissue factor (TF) induced by lipopolysaccharide (LPS) on human monocyte. Monocytes were pretreated with different concentrations of each flavonoid (0.1-500 μM), followed by a 4h incubation with LPS in order to induce TF expression. Results of the TF expression showed different behaviors for the two flavonoids studied. A slight inhibitory effect on the TF expression was detected at a QTS concentration of 0.1 μM, but from 1 μM onwards a significant inhibitory effect that remained up to 500 μM could be observed. In contrast, ATS induced a poor inhibitory effect on TF expression at all concentrations tested. These results suggest that QTS has another antithrombotic property, to be added to its already renowned ability as an anticoagulant and antiplatelet compound.

Polymorphonuclear cells stimulate the migration and metastatic potential of rat sarcoma cells

The tumour microenvironment, which is largely composed of inflammatory cells, is a crucial participant in the neoplastic process through the promotion of cell proliferation, survival and migration. Neutrophil polymorphonuclear cells (PMNs) induce inflammatory reactions that can be either cytotoxic for tumour cells or can promote tumour growth and metastasis. Previously, we have reported a spontaneous metastasis tumour model that has tumour PMNs infiltration, and metastasis, to liver and spleen. The aim of this study was to evaluate the PMNs influences on the tumour cell invasion and metastatic properties. We analysed intercellular adhesion molecule-1 (ICAM-1), urokinase-type plasminogen activator receptor (uPAR), MT1-MMP (membrane type 1-matrix metalloproteinase) and MMP2 protein expression in TuE-t cells cultured with PMNs or PMNs-conditioned medium isolated from tumour bearing and normal rats. The interaction between tumour cells and PMNs induced a decrease in ICAM-1 expression in tumour cells as well as an increase in MMP2 and tumour cell motility. Besides, conserved expression of uPAR and MT1-MMP in tumour cells was also demonstrated. The up-regulation in MMP2 associated with uPAR and MT1-MMP conserved expression may be related to an increased extracellular matrix proteolysis. These results showed that the interaction of tumour cells with PMNs could favour tumour cell spreading through the promotion of a tumour invasive phenotype.

Evaluation of stromal metalloproteinases and vascular endothelial growth factors in a spontaneous metastasis model

This study aims to investigate MMP2 and MT1-MMP protein as well as VEGF-C and VEGF-D mRNA expression in tumor cells and distant organs considered to be targets for metastasis in a tumor spontaneous metastasis model previously described. Cultured tumor cells, able to express pro-MMP2, MMP2, pro-MMP9, and MT1-MMP, develop tumor growth and metastasis, mainly in the liver and spleen, when they are injected in the mammary pad gland of Wistar rats. Immunohistochemical studies of tumor masses showed small groups of tumor cells staining for MT1-MMP but not for MMP2. In the liver, tumor metastatic foci and a stromal positive staining for both MMP2 and MT1-MMP were shown. The spleen and lymph nodes, with only scattered metastatic cells, did not show MMPs immunostaining. Using RT-PCR, a significantly higher VEGF-C and VEGF-D gene expression was shown in the liver of tumor-bearing rats respect to normal rats, whereas spleen and lymph nodes did not show significant differences in mRNA VEGF-C/D levels. Taken together, our results suggest that the stroma microenvironment of target organs for metastasis has the ability to produce MMPs and VEGFs that facilitate the anchorage of tumor cells and promote tumor cell growth and angiogenesis.

Inhibition of glutaminase expression increases Sp1 phosphorylation and Sp1/Sp3 transcriptional activity in Ehrlich tumor cells

Tumor cells expressing antisense glutaminase RNA show a drastic inhibition of glutaminase activity and they acquire a more differentiated phenotype. We have studied the expression of Sp1 and Sp3 transcription factors in both Ehrlich tumor cells and their derivative 0.28AS-2 antisense glutaminase expressing cells. The expression of phosphorylated Sp1 in 0.28AS-2 cells was 3-fold the expression in EATC. Full length Sp3 was also incremented in 0.28AS-2 cells. Sp1 and Sp3 binding to a consensus Sp1 probe was higher in 0.28AS-2 nuclear extracts, as determined by supershift assays. Sp1-DNA binding was inhibited by phosphatase treatment, demonstrating that phosphorylation of Sp1 is critical for its DNA binding capacity. The Sp1 and Sp3 DNA binding found in 0.28AS-2 cells was also correlated with an increased Sp1 activity, as shown in transient transfections assays carried out with a luciferase reporter plasmid. Incubation of Ehrlich tumor cells with the differentiation agent PMA could not totally reproduce the Sp1/Sp3 changes observed in 0.28AS-2 cells. However, it was demonstrated that the intracellular concentration of glutamine, but not glutamate or aspartate, is increased in 0.28AS-2 cells. In conclusion, the antisense inhibition of glutaminase leads to an increased expression of phosphorylated Sp1 and that correlates with an increase in Sp1 activity.

Immune control of tumors by antigen presentation improvement

Tumor cells cannot activate T lymphocytes, since they do not usually express major histocompatibility complex (MHC) class II molecules. Thus, tumor antigens can only be presented indirectly to T cells through professional antigen-presenting cells (APC). In our laboratory, we have treated a tumor cell line (Tu1-A) - derived from an induced rat mammary sarcoma - in order to increase the expression of MHC class I and class II molecules. In our tumor model, the transference of these induced cells into normal rats generated a tumor mass that exhibited a lower tumor growth rate and an earlier regression as compared to those observed in rats inoculated with wild-type Tu1-A cells. This earlier tumor regression was associated with the development of an antigen-specific immune response. 85-87% of the rats in both groups rejected the tumor and were alive at day 60 after tumor cell inoculation. However, in rats treated with wild-type cells the rejection was delayed and took place after tumor ulceration. Rats that had rejected tumors were rechallenged with wild-type cells in order to assay the presence of a long-lived antitumor immunity. All the animals were resistant to the second tumor challenge. We conclude that the development of a specific immune response could be achieved by the superexpression of MHC molecules on tumor cells or when tumor ulceration promotes APC to take up necrotic cells and tumor antigens are presented to T lymphocytes.

Time-course study of cellular immune response and testosterone metabolism in an autoimmune model for chronic prostatic inflammation

PURPOSE

Little is known of the etiology and pathogenesis of chronic inflammatory prostate diseases of noninfectious origin. In our experimental autoimmune rat model for chronic prostatic inflammation (CPI) we evaluated, in a time-course study, the specific cellular immune response to male accessory glands (MAG) and metabolic activity in the prostate gland. Results obtained in CPI rats were compared with data from rats immunized with kidney homogenate as well as from non-treated rats.

MATERIALS AND METHODS

Specific cellular immune response against MAG antigen(s) was studied by delayed type hypersensitivity (DTH) and lymphocyte proliferation tests. The prostate 5alpha-reductase activity was studied in prostate homogenates by thin layer chromatography (TLC).

RESULTS

DTH values were positive in MAG treated rats sacrificed at days 7 and 28 after first immunization (FI) (p < or = 0.05) in relation to kidney treated and non-treated rats. When we analyzed the proliferative responses to MAG antigen(s), an antigen specific proliferation, as shown by the mean [3H]thymidine uptake (cpm), was observed in rats sacrificed on days 14 and 28 (p < or = 0.05) after FI. The metabolic studies indicated that the 5alpha-reductase activity decreased slightly in MAG treated groups at day 14 after FI and diminished significantly at the end of CPI development.

CONCLUSION

These data reveal that the prostatic endocrine cell destruction during CPI could be a consequence of immune/inflammatory cell mediated processes.

Thymoma associated with syndrome of inappropriate antidiuretic hormone secretion and myasthenia gravis

We describe the association of malignant thymoma with the syndrome of inappropriate antidiuretic hormone secretion and myasthenia gravis. Hyponatremia has not been reported associated with those tumors and our case should alert physicians about the potential for a life-threatening complication.

Inflammatory cells and MHC class II antigens expression in prostate during time-course experimental autoimmune prostatitis development

The degree of lymphocytic infiltration alongside the phenotype of the infiltrating cells and MHC class II expression were studied in rats during a time-course experimental autoimmune prostatitis (EAP) development. Inflammatory foci per square millimeter were scarce at day 7 after first immunization (FI) and were composed of few mononuclear cells. The number of inflammatory foci per square millimeter increased at day 14 and remained with slight variations at days 21 and 28 after FI. The number of mononuclear cells per square millimeter increased on day 14, diminished slightly on day 21 and reached the highest level on day 28. All these infiltrates were constituted by CD4 and CD8 T cells whereas only few macrophages were present. Mast cells were also present reaching maximum levels on day 7 after FI and then decreased. MHC class II antigens were found in epithelial cells during EAP development. IA showed a similar pattern in all periods analyzed whereas IE showed a modulating behavior, reaching the highest expression on day 21 after FI. In this experimental model, the differential expression of MHC class II antigens could modulate the immune response during EAP development.

Time course of reactive oxygen intermediates release and histopathological findings during experimental autoimmune prostatitis development

Spontaneous and stimulated reactive oxygen intermediates (ROI) release by peritoneal exudate cells (PEC) and histopathological findings in the prostate gland were assessed during experimental autoimmune prostatitis (EAP) development. Results in EAP rats were compared with data from rats immunized with kidney homogenate, BSA, and CFA, as well as nontreated rats. At 28 days of first immunization (FI), EAP rats spontaneously released significantly more ROI than occurred in the cells from control rats. A similar response was found when ROI release was analyzed after in vitro stimulus. In time course studies, an increased spontaneous O2- production was observed at day 7 after FI, and remained the same during all period studied, (14, 21, and 28 days after FI). The stimulated O2- production showed elevated levels at 7 days after FI and fell afterward to levels similar to those of nontreated rats and increased again at 28 days. Spontaneous or stimulated H2O2 release showed a progressive increase during the study periods. ROI release was correlated with infiltrate formation in the prostate gland. This differential responsiveness could indicate that, during the autoimmune process, the autoantigen(s) amplify the inflammatory response triggered by them.

Determination of type I transglutaminase in differentiating normal and neoplastic human keratinocytes by an in situ radioimmunoassay

The presence of type I transglutaminase was determined in the neoplastic human keratinocyte line SqCC/Y1 and in normal human epidermal keratinocytes (NHEK) by an in situ radioimmunoassay which corresponded directly with the measurement of type I transglutaminase enzymatic activity. Dexamethasone induced differentiation of SqCC/Y1 cells caused a marked increase in transglutaminase immunoreactivity and enzymatic activity over non-steroid treated cells in a concentration-related and a time-related fashion. Retinoic acid suppressed the dexamethasone induced increase in type I transglutaminase immunoreactivity in differentiating SqCC/Y1 cells. The type I transglutaminase radioimmunoassay should be useful in studies focusing on the regulation of transglutaminase activity in normal and neoplastic keratinocytes, and for rapidly screening agents for their effects on squamous cell differentiation.