Anti‐tumor effect of SLPI on mammary but not colon tumor growth

Secretory leukocyte protease inhibitor (SLPI) is a serine protease inhibitor that was related to cancer development and metastasis dissemination on several types of tumors. However, it is not known the effect of SLPI on mammary and colon tumors. The aim of this study was to examine the effect of SLPI on mammary and colon tumor growth. The effect of SLPI was tested on in vitro cell apoptosis and in vivo tumor growth experiments. SLPI over‐expressing human and murine mammary and colon tumor cells were generated by gene transfection. The administration of murine mammary tumor cells over‐expressing high levels of SLPI did not develop tumors in mice. On the contrary, the administration of murine colon tumor cells over‐expressing SLPI, developed faster tumors than control cells. Intratumoral, but not intraperitoneal administration of SLPI, delayed the growth of tumors and increased the survival of mammary but not colon tumor bearing mice. In vitro culture of mammary tumor cell lines treated with SLPI, and SLPI producer clones were more prone to apoptosis than control cells, mainly under serum deprivation culture conditions. Herein we demonstrated that SLPI induces the apoptosis of mammary tumor cells in vitro and decreases the mammary but not colon tumor growth in vivo. Therefore, SLPI may be a new potential therapeutic tool for certain tumors, such as mammary tumors. J. Cell. Physiol. 228: 469–475, 2013. © 2012 Wiley Periodicals, Inc.     

IL17A augments autophagy in Mycobacterium tuberculosis-infected monocytes from patients with active tuberculosis in association with the severity of the disease

During mycobacterial infection, macroautophagy/autophagy, a process modulated by cytokines, is essential for mounting successful host responses. Autophagy collaborates with human immune responses against Mycobacterium tuberculosis (Mt) in association with specific IFNG secreted against the pathogen. However, IFNG alone is not sufficient to the complete bacterial eradication, and other cytokines might be required. Actually, induction of Th1 and Th17 immune responses are required for protection against Mt. Accordingly, we showed that IL17A and IFNG expression in lymphocytes from tuberculosis patients correlates with disease severity. Here we investigate the role of IFNG and IL17A during autophagy in monocytes infected with Mt H37Rv or the mutant MtΔRD1. Patients with active disease were classified as high responder (HR) or low responder (LR) according to their T cell responses against Mt. IL17A augmented autophagy in infected monocytes from HR patients through a mechanism that activated MAPK1/ERK2-MAPK3/ERK1 but, during infection of monocytes from LR patients, IL17A had no effect on the autophagic response. In contrast, addition of IFNG to infected monocytes, increased autophagy by activating MAPK14/p38 α both in HR and LR patients. Interestingly, proteins codified in the RD1 region did not interfere with IFNG and IL17A autophagy induction. Therefore, in severe tuberculosis patients' monocytes, IL17A was unable to augment autophagy because of a defect in the MAPK1/3 signaling pathway. In contrast, both IFNG and IL17A increased autophagy levels in patients with strong immunity to Mt, promoting mycobacterial killing. Our findings might contribute to recognize new targets for the development of novel therapeutic tools to fight the pathogen.     

Adverse effects of tempol on hidrosaline balance in rats with acute sodium overload

We studied the effects of tempol, an oxygen radical scavenger, on hydrosaline balance in rats with acute sodium overload. Male rats with free access to water were injected with isotonic (control group) or hypertonic saline solution (0.80 mol/l NaCl) either alone (Na group) or with tempol (Na-T group). Hydrosaline balance was determined during a 90 min experimental period. Protein expressions of aquaporin 1 (AQP1), aquaporin 2 (AQP2), angiotensin II (Ang II) and endothelial nitric oxide synthase (eNOS) were measured in renal tissue. Water intake, creatinine clearance, diuresis and natriuresis increased in the Na group. Under conditions of sodium overload, tempol increased plasma sodium and protein levels and increased diuresis, natriuresis and sodium excretion. Tempol also decreased water intake without affecting creatinine clearance. AQP1 and eNOS were increased and Ang II decreased in the renal cortex of the Na group, whereas AQP2 was increased in the renal medulla. Nonglycosylated AQP1 and eNOS were increased further in the renal cortex of the Na-T group, whereas AQP2 was decreased in the renal medulla and was localized mainly in the cell membrane. Moreover, p47-phox immunostaining was increased in the hypothalamus of Na group, and this increase was prevented by tempol. Our findings suggest that tempol causes hypernatremia after acute sodium overload by inhibiting the thirst mechanism and facilitating diuresis, despite increasing renal eNOS expression and natriuresis.     

Inflammatory mediators in exhaled breath condensate of healthy donors and exacerbated COPD patients

Samples of exhaled breath condensate (EBC) provide a convenient and non-invasive method to study inflammation in lung diseases. The aim of the present study was to evaluate and compare the inflammatory protein mediator levels in EBC from healthy donors (HD) and from patients with exacerbation of chronic obstructive pulmonary disease (COPD) using an EBC collection device with and without a coating of albumin as a carrier. We studied 13 HD and 26 patients with exacerbation of COPD. The concentrations of myeloperoxidase (MPO), IFNγ and secretory leukocyte protease inhibitor (SLPI) in EBC were measured by immunoassays. The EBC samples from HD and COPD patients showed higher concentrations of MPO when samples were recovered with an albumin-coated device. Furthermore, levels of MPO in COPD patients were significantly higher than in HD. An inverse correlation was observed between MPO and spirometric parameters (FVC and FEV1). Almost all samples collected with the albumin-coated device showed higher amounts of IFNγ and SLPI than those collected with the uncoated device. The levels of SLPI in COPD patients were significantly higher than in HD. A direct correlation was observed between FVC% predicted and SLPI. We concluded that coating the collection device with albumin increased the sensitivity of the technique, at least for measurements of MPO, SLPI and IFNγ. Furthermore, the higher levels of MPO and SLPI and lower levels of IFNγ in EBC from COPD patients could reflect the immunological status and the response of lung parenchyma to treatment during the exacerbation of the illness.     

Bacterial species and evolution: Theoretical and practical perspectives

A discussion of the species problem in modern evolutionary biology serves as the point of departure for an exploration of how the basic science aspects of this problem relate to efforts to map bacterial diversity for practical pursuits—for prospecting among the bacteria for useful genes and gene-products. Out of a confusing array of species concepts, the Cohesion Species Concept seems the most appropriate and useful for analyzing bacterial diversity. Techniques of allozyme analysis and DNA fingerprinting can be used to put this concept into practice to map bacterial genetic diversity, though the concept requires minor modification to encompass cases of complete asexuality. Examples from studies of phenetically definedBacillus species provide very partial maps of genetic population structure. A major conclusion is that such maps frequently reveal deep genetic subdivision within the phenetically defined specles; divisions that in some cases are clearly distinct genetic species. Knowledge of such subdivisions is bound to make prospecting within bacterial diversity more effective. Under the general concept of genetic cohesion a hypothetical framework for thinking about the full range of species conditions that might exist among bacteria is developed and the consequences of each such model for species delineation, and species identification are discussed. Modes of bacterial evolution, and a theory of bacterial speciation with and without genetic recombination, are examined. The essay concludes with thoughts about prospects for very extensive mapping of bacterial diversity in the service of future efforts to find useful products. In this context, evolutionary biology becomes the handmaiden of important industrial activities. A few examples of past success in commercializing bacterial gene-products from species ofBacillus and a few other bacteria are reviewed.     

Immunotherapy with SLPI over-expressing mammary tumor cells decreases tumor growth

We have demonstrated previously that the inoculation of murine mammary tumor cells genetically modified to express high levels of secretory leukocyte protease inhibitor (2C1) do not develop tumors in immunocompetent mice and these cells are more prone to apoptosis than control cells. The aim of the present study was to evaluate the role of the adaptive immune response in the lack of tumor growth of 2C1 cells and the possibility of using these cells for immunotherapy. The s.c. administration of mock transfected F3II cells induces tumor in BALB/c and Nude mice. However, the inoculation of 2C1 cells develops tumor in Nude but not in BALB/c mice. The inoculation of mock transfected F3II cells to 2C1 immunized BALB/c mice by repeated administration of 2C1 cells (once a week for 3 weeks) developed significantly smaller tumors than those observed in non-immunized mice. Remarkably, survival of tumor-bearing immunized mice was higher than non-immunized animals. Herein, we demonstrate that an immunotherapy with SLPI over-expressing non-irradiated tumor cells which do not develop tumor in immunocompetent mice, partially restrain the tumor growth induced by F3II cells and increase the survival of the mice.