TMPYP4 exerted antitumor effects in human cervical cancer cells through activation of p38 mitogen-activated protein kinase

BACKGROUND: The aim of the present study was to investigate the potential effects of the 5,10,15,20-tetrakis (1-methylpyridinium-4-yl) porphyrin (TMPyP4) on the proliferation and apoptosis of human cervical cancer cells and the underlying mechanisms by which TMPyP4 exerted its actions. RESULTS: After human cervical cancer cells were treated with different doses of TMPyP4, cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) method, the apoptosis was observed by flow cytometry (FCM), and the expression of p38 mitogen-activated protein kinase (MAPK), phosphated p38 MAPK (p-p38 MAPK), capase-3, MAPKAPK2 (MK-2) and poly ADP-ribose polymerase (PARP) was measured by Western blot analysis. The analysis revealed that TMPyP4 potently suppressed cell viability and induced the apoptosis of human cervical cancer cells in a dose-dependent manner. In addition, the up-regulation of p-p38 MAPK expression levels was detected in TMPyP4-treated human cervical cancer cells. However, followed by the block of p38 MAPK signaling pathway using the inhibitor SB203580, the effects of TMPyP4 on proliferation and apoptosis of human cervical cancer cells were significantly changed. CONCLUSIONS: It was indicated that TMPyP4-inhibited proliferation and -induced apoptosis in human cervical cancer cells was accompanied by activating the p38 MAPK signaling pathway. Taken together, our study demonstrates that TMPyP4 may represent a potential therapeutic method for the treatment of cervical carcinoma.

Retinal nitric oxide and malonyldialdehyde levels following photodynamic therapy.

Background: To determine the retinal nitric oxide (NO) and malonyldialdehyde (MDA) levels following photodynamic therapy (PDT). Materials and Methods: Seven Dutch-belted rabbits received dextrose, while seven others received 2 mg/kg verteporfin infusion over a period of 15 minutes in a dim-lit room. Irradiation to a 1.5 mm diameter intact chorioretinal area in the right eye of verteporfin-infused rabbits, was started 5 minutes after the end of infusion. Three groups were control (dextrose infusion), infusion with verteporfin (left eyes were not irradiated), and irradiation after verteporfin injection (right eyes were irradiated). On the fifth day of the experiment, the eyes were enucleated. The retinas were subsequently frozen and homogenized. Nitrite, a stable end-product of NO and MDA, was measured using the spectrophotometer. Protein concentrations were measured by the Lowry method. Tissue NO and MDA levels were expressed as μmol/gprt and nmol/mgprt, respectively. Results: The mean retinal NO and MDA levels of the control, infusion, and irradiation groups were 24.67 ± 6.66, 0.11 ± 0.02; 45.90 ± 15.52, 0.21 ± 0.09; and 84.43 ± 14.96 μmol/gprt, 0.58 ± 0.14 nmol/mgprt, respectively. The mean retinal NO levels were significantly elevated in the infusion and irradiation groups compared with the control group (P:0.004; P:0.001). The mean retinal MDA levels were significantly elevated in the infusion and irradiation groups compared to the control one (P:0.026; P:0.001). Also the mean retinal NO and MDA levels in the irradiation group were found to be significantly higher than the infusion group (P:0.018; P:0.018). Conclusion: Not only PDT, but also verteporfin infusion alone resulted in NO and MDA level increments in the retina, which might be toxic.

Determination of macromolecular exchange and PO2 in the microcirculation: a simple system for in vivo fluorescence and phosphorescence videomicroscopy

We have developed a system with two epi-illumination sources, a DC-regulated lamp for transillumination and mechanical switches for rapid shift of illumination and detection of defined areas (250-750 æm²) by fluorescence and phosphorescence videomicroscopy. The system permits investigation of standard microvascular parameters, vascular permeability as well as intra- and extravascular PO2 by phosphorescence quenching of Pd-meso-tetra (4-carboxyphenyl) porphine (PORPH). A Pechan prism was used to position a defined region over the photomultiplier and TV camera. In order to validate the system for in vivo use, in vitro tests were performed with probes at concentrations that can be found in microvascular studies. Extensive in vitro evaluations were performed by filling glass capillaries with solutions of various concentrations of FITC-dextran (diluted in blood and in saline) mixed with different amounts of PORPH. Fluorescence intensity and phosphorescence decay were determined for each mixture. FITC-dextran solutions without PORPH and PORPH solutions without FITC-dextran were used as references. Phosphorescence decay curves were relatively unaffected by the presence of FITC-dextran at all concentrations tested (0.1 æg/ml to 5 mg/ml). Likewise, fluorescence determinations were performed in the presence of PORPH (0.05 to 0.5 mg/ml). The system was successfully used to study macromolecular extravasation and PO2 in the rat mesentery circulation under controlled conditions and during ischemia-reperfusion

The photodynamic and non-photodynamic actions of porphyrins

Porphyrias are a family of inherited diseases, each associated with a partial defect in one of the enzymes of the heme biosynthetic pathway. In six of the eight porphyrias described, the main clinical manifestation is skin photosensitivity brought about by the action of light on porphyrins, which are deposited in the upper epidermal layer of the skin. Porphyrins absorb light energy intensively in the UV region, and to a lesser extent in the long visible bands, resulting in transitions to excited electronic states. The excited porphyrin may react directly with biological structures (type I reactions) or with molecular oxygen, generating excited singlet oxygen (type II reactions). Besides this well-known photodynamic action of porphyrins, a novel light-independent effect of porphyrins has been described. Irradiation of enzymes in the presence of porphyrins mainly induces type I reactions, although type II reactions could also occur, further increasing the direct non-photodynamic effect of porphyrins on proteins and macromolecules. Conformational changes of protein structure are induced by porphyrins in the dark or under UV light, resulting in reduced enzyme activity and increased proteolytic susceptibility. The effect of porphyrins depends not only on their physico-chemical properties but also on the specific site on the protein on which they act. Porphyrin action alters the functionality of the enzymes of the heme biosynthetic pathway exacerbating the metabolic deficiencies in porphyrias. Light energy absorption by porphyrins results in the generation of oxygen reactive species, overcoming the protective cellular mechanisms and leading to molecular, cell and tissue damage, thus amplifying the porphyric picture

Acción fotodinámica y no-fotodinámica de las porfirinas sobre la aminolevulico dehidrasa en sangre normal y de pacientes con porfiria cutanea tardia (AU) / Photodinamic action and non-photodinamic action of the porphyrins in aminolevuleico dehydrase in normal blood, and patients with porphyria cutanea tarda

Se ha investigado la acción de concentraciones variables de uroporfirina I, uroporfirinógeno I y mezclas de porfirina aisladas de plasma y orina de pacientes porfíricos sobre la actividad de la alfa-aminolevúlico dehidrasa (ALA-D) de sangre de individuos normales y pacientes con PCT, en diferentes condiciones de iluminación, a 37-C y luego de 2 horas de exposición a la porfirina. La Uro I y el Urogen I inactivan la enzima en la oscuridad, efecto dependiente de la concentración que llega al 30-60% a valore de 10 µM del tetrapirrol. El Urogen I es un inhibidor más efectivo que la Uro I. La presencia de cantidades variables de mezclas de porfirinas aisladas del plasma y orina de pacientes con PCT, en la enzima de sangre normal y porfírica, produce también una inactivación independiente y una dependiente de la luz que aumenta a concentraciones crecientes de la mezcla, a partir de un valor umbral del orden de 1 - 1,5 µM por debajo del cual, los pigmentos no ejercen ningún tipo de inhibición

Hemolysin production by Leptospira interrogans serovar canicola in a protein-free medium with hemin.

Leptospira interrogans serovar canicola strain moulton was grown to a high cell density in a protein-free medium. When hemin was added to this medium, hemolysin was produced. Hemolysin was not detected when other porphyrins or cytochrome C were substituted for hemin in the medium.