As exogenous ALA (5-aminolevulinic acid) esters can induce the production and accumulation of endogenous photosensitizer PpIX (protoporphyrin IX) in tumor tissues more effectively, they have been the most active photosensitizer prodrug in PDT(photodynamic therapy) field. In this article, along with the procedure of ALA esters based PDT, some primary mechanism and experimental results were considered, which include: first, cellular uptake of ALA esters and its conversion into ALA; second, the production and accumulation of endogenous photosensitizer PpIX induced by eNdogenous ALA esters; last, the photosensitization of PpIX.
Aminolevulinic Acid ; pharmacology ; Esters ; pharmacology ; Photochemotherapy ; Photosensitizing Agents ; pharmacology ; Prodrugs ; Protoporphyrins ; pharmacology

The aim of the present study was to investigate the effect of endogenous carbon monoxide (CO) on respiratory rhythm. The experiments were carried out on the medullary slices of newborn Sprague-Dawley rats. The rhythmic discharge frequency (DF) of hypoglossal rootlets was taken as an index of rhythmic respiratory activity. The slices of medulla oblongata were superfused with ZnPP-9 (inhibitor of heme oxygenase), CO and hemin (substrate of heme oxygenase), respectively, to observe their effects on respiratory rhythm. The preparations were divided into 5 groups: control group of artificial cerebrospinal fluid (ACSF), group of ZnPP-9, group of exogenous CO, group of hemin and group of ZnPP-9 + hemin. The results obtained were as follows. In ZnPP-9 group, the rhythmic DF of the hypoglossal rootlets was increased (P<0.05); while in exogenous CO group, it was decreased (P<0.05). In the groups of hemin and ZnPP-9 + hemin, the rhythmic DF of the hypoglossal rootlets was increased (P<0.05). It is suggested that endogenous CO may play an important role in the regulation of respiratory rhythm.
Animals ; Animals, Newborn ; Carbon Monoxide ; physiology ; Female ; Hemin ; pharmacology ; Hypoglossal Nerve ; drug effects ; physiology ; Male ; Protoporphyrins ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Respiration

The killing effect on S180 cells was studied using the combination of protoporphyrin IX and focused ultrasound at the frequency of 2.2 MHz and different intensities. Cell viability was determined by trypan blue exclusion test, morphology changes were evaluated by means of scanning electron microscopy and transmission electron microscopy after ultrasonic exposure. The results indicated that protoporphyrin IX(PPIX) alone showed no significant effect on S180 cells when compared with that of control group. Ultrasound alone and ultrasound combined with PPIX groups showed some anti-tumor effect, which became more noticeable as the ultrasound intensity and PPIX concentration increased, and when the concentration of PPIX increased to 120 microM, the ultrasound combined with PPIX exerted a more significant anti-tumor effect than did the ultrasound alone in the same experiment.
Animals ; Apoptosis ; drug effects ; radiation effects ; Mice ; Mice, Inbred ICR ; Photochemotherapy ; methods ; Photosensitizing Agents ; pharmacology ; Protoporphyrins ; pharmacology ; Sarcoma 180 ; pathology ; therapy ; Sonication ; Tumor Cells, Cultured ; Ultrasonics

This study was aimed to investigate the effect of AMN107 (nilotinib) combined with heme oxygenase-1 (HO-1) inhibitor zinc protoporphyrin IX (ZnPPIX) on chronic myeloid leukemia (CML) cells and its mechanism. Proliferative rate of cells treated with AMN107 (10 µmol/L) and ZnPPIX (10 µmol/L) alone or both for different time was observed by MTT and trypan blue methods; the expression of HO-1 in the control group, ZnPPIX (10 µmol/L) group, AMN107 (10 µmol/L) group, AMN107 (10 µmol/L) combined with ZnPPIX (10 µmol/L) group was evaluated by semi-quantitative RT-PCR and Western blot at 48 h. Cell apoptosis was detected by flow cytometry with Annexin V/PI double staining at 48 h. The results showed that the strongest inhibition of cell proliferation was detected in combined group, and in a time-dependent manner; the expression level of HO-1 was lowest in combined group; the cell apoptosis rates were (11.38 ± 0.02)%, (17.44 ± 0.08)%, (39.81 ± 0.07)% and (56.46 ± 0.19)% in the control group, ZnPPIX group, AMN107 group, AMN107 combined with ZnPPIX group at 48 h respectively. It is concluded that the second-generation tyrosine kinase inhibitor AMN107 can induce the apoptosis in CML cells. Inhibition of HO-1 expression can enhance the killing effect of AMN107 on CML cells, which provides experimental evidence to further improve the clinical efficacy of CML treatment.
Apoptosis ; drug effects ; Heme Oxygenase-1 ; antagonists & inhibitors ; Humans ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; pathology ; Protoporphyrins ; pharmacology ; Pyrimidines ; pharmacology

OBJECTIVETo investigate the role of heme oxygenase-1 (HO-1) and its catalyst carbon monoxide (CO) in the development of myocardial damage and the effects of zinc protoporphyrin IX (ZnPPIX), an inhibitor of HO-1 on myocardium of mice with acute viral myocarditis.

METHODSA total of 112 inbred male Balb/C mice 4 - 6 weeks of age were divided randomly into 3 groups: the control group (C group, n = 32), the viral myocarditis group (V group, n = 40) and ZnPPIX group (Z group, n = 40). The Z and V groups were inoculated intraperitoneally (i.p.) with 0.1 ml of 10(-4.36) tissue culture infectious dose 50% (TCID(50))/ml Coxsackie virus B3 (CVB(3)) to produce viral myocarditis model on day 0, C group was injected i.p. with virus-free 1640 culture culture medium 0.1 ml at the same time, then operation was done as follows: the mice of group C and group V were injected i.p. with 0.1 ml NS each day. The mice of group Z were injected i.p. with 40 micromol per kilogram of body weight ZnPPIX (HO-1 inhibitor) qod. Eight mice of each group were sacrificed on days 4, 8, 15 and 21, respectively. The blood specimens were collected by taking out the eyeballs to test for the content of carboxyhemoglobin (COHb) using spectrophotometry and cardiac troponin I (cTnI) using chemiluminescent immunoassay. The hearts tissue slides were also stained by immunohistochemistry (IHC) for HO-1 and in situ hybridization (ISH) for HO-1 mRNA. The histological and ultrastructural changes were observed under light and electron microscopes.

RESULTS(1) The histopathological changes of myocardial cells: in the V and Z groups myocardial inflammatory cells infiltration reached the peak on day 8, the Z group histopathological scores were significantly lower than those in V group on day 8 (2.40 +/- 0.31 vs. 1.73 +/- 0.24, P < 0.01) and on day 15 (1.78 +/- 0.29 vs. 1.43 +/- 0.23, P < 0.05). No inflammation was present in group C. (2) The changes of serum cTnI level in both V and Z groups were significantly higher than those in C group on day 4, 8 and 15 (P < 0.01). The level in Z group was significantly lower than that in V group on day 4 [(6.074 +/- 1.475) ng/ml vs (7.911 +/- 1.225) ng/ml, P < 0.05] and day 8 [(0.821 +/- 0.294) ng/ml vs (1.480 +/- 0.454) ng/ml, P < 0.05]. (3) The changes of blood COHb level: compared with V group, in Z group the COHb level was lower on day 4 (P < 0.05) and day 15 (P < 0.01) after CVB(3) inoculation. Surprisingly, in Z group COHb level elevated suddenly on day 8 and showed conspicuously higher than that of V group (P < 0.01). (4) The result of HO-1 IHC staining: in both V and Z group myocardial cells had positive expression, while C group did not. (5) The results of HO-1 ISH were similar to those of HO-1 IHC, the A values of group Z was significantly lower than that of group V on day 4, 15 and 21(P < 0.01), but on day 8 it was higher than that of group C (P < 0.05).

CONCLUSIONHO-1 inhibitor, ZnPP not only could inhibit HO-1 overexpression but also could induce HO-1 expression temporarily and protect against myocardial injury at the early stage of acute viral myocarditis.

Animals ; Heme Oxygenase-1 ; antagonists & inhibitors ; Male ; Mice ; Mice, Inbred BALB C ; Myocarditis ; enzymology ; metabolism ; pathology ; virology ; Myocardium ; pathology ; ultrastructure ; Protoporphyrins ; pharmacology ; Virus Diseases ; metabolism ; pathology

OBJECTIVETo investigate the involvement of heme oxygenase (HO-1) in PM2.5 induced toxic responses in human umbilical vein endothelial cells (HUVECs).

METHODSThe experiment groups are as follows: (1) control group; (2) PM2.5 groups: the cells were cultured with various concentrations of PM2.5 (200, 400, 800 µg/ml) for 24 h and 400 µg/ml was chosen for the main study; (3) PM2.5+Trion group: the cells were pre-treated by 10 µmol/L Trion [a scavenger of reactive oxygen species(ROS)] for 1 h before PM2.5 (400 µg/ml) treatment for 24 h; (4) PM2.5+ZnPP group: the cells were pretreated by HO-1 inhibitor ZnPP (10 µmol/L) for 1 h before treatment with PM2.5 (400 µg/ml) for 24 h. MTT assay was used to detect cell viability. Reverse transcription polymerase chain reaction (RT-PCR) and indirect immunofluorescence assay were used to determine the mRNA and protein expressions of HO-1. Fluorescence labeling probe method was used to measure intracellular ROS level and flow cytometry was used for cell apoptosis. Colorimetric assay was used to detect intracellular caspase-3 activity.

RESULTSCompared with control, PM2.5 significantly decreased cell viability, increased intracellular ROS, cell apoptosis and caspase-3 activity (all P < 0.05), these effects were significantly attenuated in PM2.5+Tiron group while enhanced in PM2.5+ZnPP group (all P < 0.05 vs. PM2.5 group). PM2.5 upregulated HO-1 mRNA and protein expressions in HUVECs which was downregulated in both PM2.5+Tiron group and PM2.5+ZnPP group.

CONCLUSIONPM2.5 could induce oxidative injury through increasing ROS production via modulating HO-1 mRNA and protein expressions, the injury could be aggravated with inhibition of the activity of HO-1 suggesting a potential protective role of HO-1 against PM2.5 induced oxidative stress in HUVECs.

Cells, Cultured ; Heme Oxygenase-1 ; metabolism ; Human Umbilical Vein Endothelial Cells ; enzymology ; Humans ; Oxidative Stress ; Particle Size ; Particulate Matter ; adverse effects ; Protoporphyrins ; pharmacology

This study was aimed to investigate the effects of cobalt protoporphyrin (CoPP) on hyperexpression of heme oxygenase-1 (HO-1) and secretion of IL-10 in bone marrow-derived mesenchymal stem cells (BMMSC). The BMMSC were isolated from rats and cultured, then were randomly divided into 4 groups, and were induced in culture medium with CoPP of 0, 25, 50, and 75 µmol/L respectively. The expressions of CD34, CD45, CD44 and CD71 in BMMSC were detected by flow cytometry; the osteoblast and adipocyte induction of BMMSC was determined by alizarin red and oil red staining respectively; the proliferation status of BMMSC was assayed by MTT method; the HO-1 expression in test groups was detected by RT-PCR; the optimal concentration of CoPP for induction of HO-1 expression was screened. The ELISA kit was used to detect the HO-1 levels in each groups. The results showed that the expressions of CD34, CD45 in BMMSC were negative while the expressions of CD44 and CD71 in BMMSC were positive. After induced by osteoblast and adipocyte inductor, BMMSC were positive for alizarin red staining and oil red staining. Various concentrations of CoPP had no significant impact on cell proliferation. When the CoPP concentration of 50 µmol/L could induce strong expression of HO-1, expression level in test groups was significantly higher than that in control group, meanwhile the IL-10 secretion was significantly higher than that in control group. It is concluded that CoPP has no ability to promote cell proliferation, 50 µmol/L is the optimum concentration for up-regulation of CoPP-induced BMMSC HO-1 expression, the up-regulation of HO-1 expression can increased IL-10 secretion significantly.
Animals ; Bone Marrow Cells ; metabolism ; Cells, Cultured ; Heme Oxygenase (Decyclizing) ; metabolism ; Interleukin-10 ; secretion ; Mesenchymal Stromal Cells ; metabolism ; Protoporphyrins ; pharmacology ; Rats ; Rats, Wistar ; Up-Regulation

OBJECTIVEFebrile seizures (FS) are the most common seizure disorders in children. Approximately one third of children with a febrile seizure have recurrent events. Although most FS may not represent a serious health problem, those that are more prolonged and recurrent may cause hippocampal damage which is the most important pathological basis of temporal lobe epilepsy. The present study aimed to explore the effect of endogenous heme oxygenase (HO)-carbon monoxide (CO) system on brain damage induced by recurrent FS.

METHODTwenty-four Sprague-Dawley rats aged 21 days were randomly divided into three groups: Control group (immersed in 37.0 degrees C water, n = 8), FS group (immersed in 45.2 degrees C water, n = 8), FS + zinc protoporphyrin (ZnPPIX) group (immersed in 45.2 degrees C water, n = 8). FS in rats were induced ten times in a bath of warm water, once every 2 days. The indirect production of CO in plasma was detected by a dual wavelengh spectrophotometer. The intensity, latency, duration and rectal temperature of the seizure in rats were recorded. Morphologic changes of hippocampal neurons were observed with HE staining. The ultrastructural changes of the hippocampal neurons were observed under electron microscope. Semiquantitative analysis of hippocampal neurons was carried out by using Nissl stain.

RESULTAfter recurrent FS, the content of CO in plasma in FS group was increased as compared with that in control group (P < 0.01). The content of CO in plasma in FS + ZnPPIX group was decreased as compared with that in FS group (P < 0.01), while no significant difference in CO content was found as compared with that in control group (P > 0.05). In FS group, with the increase of seizure number, there was a trend of gradual prolongation of the seizure duration. In FS + ZnPPIX group, the seizure latency was gradually shortened and the seizure duration was further prolonged. There were no significant differences in seizure intensity and rectal temperature between the two groups. After recurrent FS, by using light microscope we could see that the arrangement of hippocampal neurons was disordered, polarity was not clear and vacuolization appeared in some neurons. At the same time the ultrastructure of hippocampal neurons under electron microscope changed, which manifested as mitochondrial swelling, dissolved and ruptured ridge and vacuole formation, and dilated rough endoplasmic reticulum (RER). ZnPPIX aggravated neuronal injury. No obvious loss of hippocampal neurons was observed in FS group, while the number of hippocampal neurons in CA(1) and CA(3) subfields in FS + ZnPPIX group decreased respectively as compared with that in FS group and in control group (P < 0.01 for all).

CONCLUSIONThe study by using ZnPPIX which is an inhibitor of HO showed that endogenous HO/CO might act as a protective factor in FS-induced brain damage.

Animals ; Carbon Monoxide ; physiology ; Heme Oxygenase (Decyclizing) ; physiology ; Hippocampus ; pathology ; ultrastructure ; Neurons ; pathology ; ultrastructure ; Protoporphyrins ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Recurrence ; Seizures, Febrile ; complications ; pathology

BACKGROUNDWe assessed whether the CaNa2 EDTA could improve the accumulation of protoporphyrin IX (PpIX) and photosensitisation in HEp-2 cells as well as the depth of treatment of skin cancers on the topical 5-Aminolaevulinic acid (5-ALA) PDT.

METHODSHEp-2 cells were incubated with 5-ALA (0-1 mmol/L) and CaNa2EDTA (0-1 mmol/L) for 4 hours, intracellular protoporphyrin IX content was quantified by extraction, and cell viability was assessed by use of the methyl-tetrazolium (MTT) assay four hours after exposure to light. In comparison with the pictures before and after treatment, depth of treatment could be determined using a Acuson Sequioa 512 phase-array system in paired experiments.

RESULTSPpIX accumulation increased with increasing extracellular concentrations of ALA (0-1 mmol/L). Adding 1 mmol/L of CaNa2EDTA increased 30% PpIX accumulation over the same period of incubation in the concentration of 1 mmol/L ALA. Significant difference was observed between the 5-ALA alone group and 5-ALA combined CaNa2 EDTA group in the PpIX accumulation (P < 0.01). Cell viability after exposure to light decreased with adding CaNa2 EDTA, a statistical difference in a same fluence above 1.2 J/cm2 between two groups was demonstrated (P < 0.05, P < 0.01 respectively). Depth of treatment of skin cancers were increased in CaNa2 EDTA-treated group.

CONCLUSIONCaNa2 EDTA could improve the PpIX accumulation and photosensitisation in HEp-2 cells. Clinically, CaNa2 EDTA could increase the depth of treatment in the cutaneous cancers.

Aminolevulinic Acid ; therapeutic use ; Cell Line, Tumor ; Cell Survival ; Edetic Acid ; pharmacology ; Female ; Humans ; Male ; Middle Aged ; Photochemotherapy ; Protoporphyrins ; analysis ; Skin Neoplasms ; drug therapy

OBJECTIVETo examine the effect of angiotensin-converting enzyme inhibitor (ACEI) on hydrogen peroxide (H(2)O(2))-induced decrease in contraction of isolated rataortic rings, and to investigate its mechanisms.

METHODSThe thoracic aortic rings with endothelium of male Sprague-Dawley rats were mounted on a bath system. Isometric contractions of aortic rings were measured.

RESULT(1) After incubation with captopril (an ACEI with sulfhydryl groups) or perindoprilate (an ACEI without sulfhydryl groups), the decrease in contraction response to PE was prevented in arteries which were pretreated with 300 micromol/L H(2)O(2). (2) Captopril enhanced the HO-1 activity of thoracic aorta. After inhibition of HO-1 activity by ZnPP IX, the protection effect of captopril was abrogated. Hemin (an inducer of HO-1) and bilirubin (a product of HO-1) could mimic the antioxidative effect of captopril. (3) Both L-NAME (an inhibitor of NOS) and methylene blue (an inhibitor of GC) could abolish the protective effect of captopril. (4) SNAP could protect aortic rings against H(2)O(2) attack, and ZnPP IX could cancel the effect of SNAP.

CONCLUSIONBoth ACEI with or without sulfhydryl groups could prevent the H(2)O(2) induced decrease in contraction responses to PE in intact aortic rings. The increase of NO and activation of HO-1 might be involved in the mechanism.

Angiotensin-Converting Enzyme Inhibitors ; pharmacology ; Animals ; Antioxidants ; pharmacology ; Aorta, Thoracic ; drug effects ; metabolism ; physiology ; Bilirubin ; pharmacology ; Captopril ; pharmacology ; Heme Oxygenase-1 ; metabolism ; Hemin ; pharmacology ; Hydrogen Peroxide ; pharmacology ; In Vitro Techniques ; Male ; Methylene Blue ; pharmacology ; NG-Nitroarginine Methyl Ester ; pharmacology ; Nitric Oxide ; metabolism ; Penicillamine ; analogs & derivatives ; pharmacology ; Protoporphyrins ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Vasoconstriction ; drug effects